WIP

Cargo.lock

@@ -418,6 +418,27 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "derive_more"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a9b99b9cbbe49445b21764dc0625032a89b145a2642e67603e1c936f5458d05"
+dependencies = [
+ "derive_more-impl",
+]
+
+[[package]]
+name = "derive_more-impl"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb7330aeadfbe296029522e6c40f315320aba36fc43a5b3632f3795348f3bd22"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.60",
+ "unicode-xid",
+]
+
 [[package]]
 name = "dialoguer"
 version = "0.11.0"
@@ -993,6 +1014,7 @@ dependencies = [
  "async-bincode",
  "bincode",
  "clap",
+ "derive_more",
  "dialoguer",
  "env_logger",
  "futures",
@@ -1007,7 +1029,6 @@ dependencies = [
  "serde",
  "serde_json",
  "sqlx",
- "thiserror",
  "tokio",
  "tokio-serde",
  "tokio-stream",
@@ -2130,6 +2151,12 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e51733f11c9c4f72aa0c160008246859e340b00807569a0da0e7a1079b27ba85"
 
+[[package]]
+name = "unicode-xid"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f962df74c8c05a667b5ee8bcf162993134c104e96440b663c8daa176dc772d8c"
+
 [[package]]
 name = "unicode_categories"
 version = "0.1.1"

Cargo.toml

@@ -8,6 +8,7 @@ anyhow = "1.0.82"
 async-bincode = "0.7.2"
 bincode = "1.3.3"
 clap = { version = "4.5.4", features = ["derive"] }
+derive_more = { version = "1.0.0", features = ["display", "error"] }
 dialoguer = "0.11.0"
 env_logger = "0.11.3"
 futures = "0.3.30"
@@ -15,14 +16,13 @@ futures-util = "0.3.30"
 indoc = "2.0.5"
 itertools = "0.12.1"
 log = "0.4.21"
-nix = { version = "0.28.0", features = ["fs", "user"] }
+nix = { version = "0.28.0", features = ["fs", "process", "user"] }
 prettytable = "0.10.0"
 rand = "0.8.5"
 ratatui = { version = "0.26.2", optional = true }
 serde = "1.0.198"
 serde_json = { version = "1.0.116", features = ["preserve_order"] }
 sqlx = { version = "0.7.4", features = ["runtime-tokio", "mysql", "tls-rustls"] }
-thiserror = "1.0.63"
 tokio = { version = "1.37.0", features = ["rt", "macros"] }
 tokio-serde = { version = "0.9.0", features = ["bincode"] }
 tokio-stream = "0.1.15"

src/cli.rs

@@ -1,3 +1,4 @@
 pub mod database_command;
-pub mod mysql_admutils_compatibility;
+// pub mod mysql_admutils_compatibility;
+mod common;
 pub mod user_command;

src/cli/common.rs

@@ -0,0 +1,44 @@
+use crate::core::protocol::Response;
+
+/// This enum is used to differentiate between database and user operations.
+/// Their output are very similar, but there are slight differences in the words used.
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum DbOrUser {
+    Database,
+    User,
+}
+
+impl DbOrUser {
+    pub fn lowercased(&self) -> String {
+        match self {
+            DbOrUser::Database => "database".to_string(),
+            DbOrUser::User => "user".to_string(),
+        }
+    }
+
+    pub fn capitalized(&self) -> String {
+        match self {
+            DbOrUser::Database => "Database".to_string(),
+            DbOrUser::User => "User".to_string(),
+        }
+    }
+}
+
+pub fn erroneous_server_response(
+    response: Option<Result<Response, std::io::Error>>,
+) -> anyhow::Result<()> {
+    match response {
+        Some(Ok(Response::Error(e))) => {
+            anyhow::bail!("Error from server: {}", e);
+        }
+        Some(Err(e)) => {
+            anyhow::bail!(e);
+        }
+        Some(response) => {
+            anyhow::bail!("Unexpected response from server: {:?}", response);
+        }
+        None => {
+            anyhow::bail!("No response from server");
+        }
+    }
+}

src/cli/database_command.rs

@@ -1,17 +1,25 @@
 use anyhow::Context;
 use clap::Parser;
-use dialoguer::{Confirm, Editor};
+use dialoguer::Editor;
+use futures_util::{SinkExt, StreamExt};
+use nix::unistd::{getuid, User};
 use prettytable::{Cell, Row, Table};
-use sqlx::{Connection, MySqlConnection};
 
-use crate::core::{
+use crate::{
-    common::{close_database_connection, get_current_unix_user, yn, CommandStatus},
+    cli::common::erroneous_server_response,
-    database_operations::*,
+    core::{
-    database_privilege_operations::*,
+        common::yn,
-    user_operations::user_exists,
+        database_privileges::{
+            db_priv_field_human_readable_name, diff_privileges,
+            generate_editor_content_from_privilege_data, parse_privilege_data_from_editor_content,
+            parse_privilege_table_cli_arg,
+        },
+        protocol::{ClientToServerMessageStream, Request, Response},
+    },
+    server::sql::database_privilege_operations::{DatabasePrivilegeRow, DATABASE_PRIVILEGE_FIELDS},
 };
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 // #[command(next_help_heading = Some(DATABASE_COMMAND_HEADER))]
 pub enum DatabaseCommand {
     /// Create one or more databases
@@ -86,28 +94,28 @@ pub enum DatabaseCommand {
     EditDbPrivs(DatabaseEditPrivsArgs),
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct DatabaseCreateArgs {
     /// The name of the database(s) to create.
     #[arg(num_args = 1..)]
     name: Vec<String>,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct DatabaseDropArgs {
     /// The name of the database(s) to drop.
     #[arg(num_args = 1..)]
     name: Vec<String>,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct DatabaseListArgs {
     /// Whether to output the information in JSON format.
     #[arg(short, long)]
     json: bool,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct DatabaseShowPrivsArgs {
     /// The name of the database(s) to show.
     #[arg(num_args = 0..)]
@@ -118,7 +126,7 @@ pub struct DatabaseShowPrivsArgs {
     json: bool,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct DatabaseEditPrivsArgs {
     /// The name of the database to edit privileges for.
     pub name: Option<String>,
@@ -141,125 +149,158 @@ pub struct DatabaseEditPrivsArgs {
 
 pub async fn handle_command(
     command: DatabaseCommand,
-    mut connection: MySqlConnection,
+    server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let result = connection
-        .transaction(|txn| {
-            Box::pin(async move {
     match command {
-                    DatabaseCommand::CreateDb(args) => create_databases(args, txn).await,
+        DatabaseCommand::CreateDb(args) => create_databases(args, server_connection).await,
-                    DatabaseCommand::DropDb(args) => drop_databases(args, txn).await,
+        DatabaseCommand::DropDb(args) => drop_databases(args, server_connection).await,
-                    DatabaseCommand::ListDb(args) => list_databases(args, txn).await,
+        DatabaseCommand::ListDb(args) => list_databases(args, server_connection).await,
-                    DatabaseCommand::ShowDbPrivs(args) => show_database_privileges(args, txn).await,
+        DatabaseCommand::ShowDbPrivs(args) => {
-                    DatabaseCommand::EditDbPrivs(args) => edit_privileges(args, txn).await,
+            show_database_privileges(args, server_connection).await
+        }
+        DatabaseCommand::EditDbPrivs(args) => {
+            edit_database_privileges(args, server_connection).await
+        }
     }
-            })
-        })
-        .await;
-
-    close_database_connection(connection).await;
-
-    result
 }
 
 async fn create_databases(
     args: DatabaseCreateArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.name.is_empty() {
         anyhow::bail!("No database names provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::CreateDatabases(args.name.clone());
+    server_connection.send(message).await?;
 
-    for name in args.name {
+    let result = match server_connection.next().await {
-        // TODO: This can be optimized by fetching all the database privileges in one query.
+        Some(Ok(Response::CreateDatabases(result))) => result,
-        if let Err(e) = create_database(&name, connection).await {
+        response => return erroneous_server_response(response),
-            eprintln!("Failed to create database '{}': {}", name, e);
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    for (database_name, result) in result.iter() {
+        match result {
+            Ok(_) => println!("Database '{}' created.", database_name),
+            Err(err) => {
+                eprintln!("{:?}", err);
                 eprintln!("Skipping...");
-            result = CommandStatus::PartiallySuccessfullyModified;
+            }
-        } else {
-            println!("Database '{}' created.", name);
         }
     }
 
-    Ok(result)
+    Ok(())
 }
 
 async fn drop_databases(
     args: DatabaseDropArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.name.is_empty() {
         anyhow::bail!("No database names provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::DropDatabases(args.name.clone());
+    server_connection.send(message).await?;
 
-    for name in args.name {
+    let result = match server_connection.next().await {
-        // TODO: This can be optimized by fetching all the database privileges in one query.
+        Some(Ok(Response::DropDatabases(result))) => result,
-        if let Err(e) = drop_database(&name, connection).await {
+        response => return erroneous_server_response(response),
-            eprintln!("Failed to drop database '{}': {}", name, e);
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    for (database_name, result) in result.iter() {
+        match result {
+            Ok(_) => println!("Database '{}' dropped.", database_name),
+            Err(err) => {
+                eprintln!("{:?}", err);
                 eprintln!("Skipping...");
-            result = CommandStatus::PartiallySuccessfullyModified;
+            }
-        } else {
-            println!("Database '{}' dropped.", name);
         }
     }
 
-    Ok(result)
+    Ok(())
 }
 
 async fn list_databases(
     args: DatabaseListArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let databases = get_database_list(connection).await?;
+    let message = Request::ListDatabases;
+    server_connection.send(message).await?;
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::ListAllDatabases(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    let database_list = match result {
+        Ok(list) => list,
+        Err(err) => {
+            eprintln!("{:?}", err);
+            return Ok(());
+        }
+    };
 
     if args.json {
-        println!("{}", serde_json::to_string_pretty(&databases)?);
+        println!("{}", serde_json::to_string_pretty(&database_list)?);
-        return Ok(CommandStatus::NoModificationsIntended);
+    } else if database_list.is_empty() {
-    }
-
-    if databases.is_empty() {
         println!("No databases to show.");
     } else {
-        for db in databases {
+        for db in database_list {
             println!("{}", db);
         }
     }
 
-    Ok(CommandStatus::NoModificationsIntended)
+    Ok(())
 }
 
 async fn show_database_privileges(
     args: DatabaseShowPrivsArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let database_users_to_show = if args.name.is_empty() {
+    let message = if args.name.is_empty() {
-        get_all_database_privileges(connection).await?
+        Request::ListPrivileges(None)
     } else {
-        // TODO: This can be optimized by fetching all the database privileges in one query.
+        Request::ListPrivileges(Some(args.name.clone()))
-        let mut result = Vec::with_capacity(args.name.len());
+    };
-        for name in args.name {
+    server_connection.send(message).await?;
-            match get_database_privileges(&name, connection).await {
+
-                Ok(db) => result.extend(db),
+    let result = match server_connection.next().await {
-                Err(e) => {
+        Some(Ok(Response::ListPrivileges(databases))) => databases
-                    eprintln!("Failed to show database '{}': {}", name, e);
+            .into_iter()
+            .filter_map(|(_db, result)| match result {
+                Ok(privileges) => Some(privileges),
+                Err(err) => {
+                    eprintln!("{:?}", err);
                     eprintln!("Skipping...");
+                    None
                 }
+            })
+            .flatten()
+            .collect::<Vec<_>>(),
+        Some(Ok(Response::ListAllPrivileges(privilege_rows))) => match privilege_rows {
+            Ok(list) => list,
+            Err(err) => {
+                eprintln!("{:?}", err);
+                return Ok(());
             }
-        }
+        },
-        result
+        response => return erroneous_server_response(response),
     };
 
-    if args.json {
+    server_connection.send(Request::Exit).await?;
-        println!("{}", serde_json::to_string_pretty(&database_users_to_show)?);
-        return Ok(CommandStatus::NoModificationsIntended);
-    }
 
-    if database_users_to_show.is_empty() {
+    if args.json {
-        println!("No database users to show.");
+        println!("{}", serde_json::to_string_pretty(&result)?);
+    } else if result.is_empty() {
+        println!("No database privileges to show.");
     } else {
         let mut table = Table::new();
         table.add_row(Row::new(
@@ -270,7 +311,7 @@ async fn show_database_privileges(
                 .collect(),
         ));
 
-        for row in database_users_to_show {
+        for row in result {
             table.add_row(row![
                 row.db,
                 row.user,
@@ -290,17 +331,35 @@ async fn show_database_privileges(
         table.printstd();
     }
 
-    Ok(CommandStatus::NoModificationsIntended)
+    Ok(())
 }
 
-pub async fn edit_privileges(
+async fn edit_database_privileges(
     args: DatabaseEditPrivsArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let privilege_data = if let Some(name) = &args.name {
+    let message = Request::ListPrivileges(args.name.clone().map(|name| vec![name]));
-        get_database_privileges(name, connection).await?
+
-    } else {
+    server_connection.send(message).await?;
-        get_all_database_privileges(connection).await?
+
+    let privilege_data = match server_connection.next().await {
+        Some(Ok(Response::ListPrivileges(databases))) => {
+            match databases.get(args.name.as_ref().unwrap()).unwrap() {
+                Ok(privileges) => privileges.clone(),
+                Err(err) => {
+                    eprintln!("{:?}", err);
+                    return Ok(());
+                }
+            }
+        }
+        Some(Ok(Response::ListAllPrivileges(privilege_rows))) => match privilege_rows {
+            Ok(list) => list,
+            Err(err) => {
+                eprintln!("{:?}", err);
+                return Ok(());
+            }
+        },
+        response => return erroneous_server_response(response),
     };
 
     // TODO: The data from args should not be absolute.
@@ -316,37 +375,74 @@ pub async fn edit_privileges(
         edit_privileges_with_editor(&privilege_data)?
     };
 
-    for row in privileges_to_change.iter() {
+    // for row in privileges_to_change.iter() {
-        if !user_exists(&row.user, connection).await? {
+    //     if !user_exists(&row.user, connection).await? {
-            // TODO: allow user to return and correct their mistake
+    //         // TODO: allow user to return and correct their mistake
-            anyhow::bail!("User {} does not exist", row.user);
+    //         anyhow::bail!("User {} does not exist", row.user);
-        }
+    //     }
-    }
+    // }
 
     let diffs = diff_privileges(&privilege_data, &privileges_to_change);
 
-    if diffs.is_empty() {
+    todo!();
-        println!("No changes to make.");
-        return Ok(CommandStatus::NoModificationsNeeded);
-    }
 
-    println!("The following changes will be made:\n");
+    Ok(())
-    println!("{}", display_privilege_diffs(&diffs));
-    if !args.yes
-        && !Confirm::new()
-            .with_prompt("Do you want to apply these changes?")
-            .default(false)
-            .show_default(true)
-            .interact()?
-    {
-        return Ok(CommandStatus::Cancelled);
-    }
-
-    apply_privilege_diffs(diffs, connection).await?;
-
-    Ok(CommandStatus::SuccessfullyModified)
 }
 
+// pub async fn edit_privileges(
+//     args: DatabaseEditPrivsArgs,
+//     connection: &mut MySqlConnection,
+// ) -> anyhow::Result<CommandStatus> {
+//     let privilege_data = if let Some(name) = &args.name {
+//         get_database_privileges(name, connection).await?
+//     } else {
+//         get_all_database_privileges(connection).await?
+//     };
+
+//     // TODO: The data from args should not be absolute.
+//     //       In the current implementation, the user would need to
+//     //       provide all privileges for all users on all databases.
+//     //       The intended effect is to modify the privileges which have
+//     //       matching users and databases, as well as add any
+//     //       new db-user pairs. This makes it impossible to remove
+//     //       privileges, but that is an issue for another day.
+//     let privileges_to_change = if !args.privs.is_empty() {
+//         parse_privilege_tables_from_args(&args)?
+//     } else {
+//         edit_privileges_with_editor(&privilege_data)?
+//     };
+
+//     for row in privileges_to_change.iter() {
+//         if !user_exists(&row.user, connection).await? {
+//             // TODO: allow user to return and correct their mistake
+//             anyhow::bail!("User {} does not exist", row.user);
+//         }
+//     }
+
+//     let diffs = diff_privileges(&privilege_data, &privileges_to_change);
+
+//     if diffs.is_empty() {
+//         println!("No changes to make.");
+//         return Ok(CommandStatus::NoModificationsNeeded);
+//     }
+
+//     println!("The following changes will be made:\n");
+//     println!("{}", display_privilege_diffs(&diffs));
+//     if !args.yes
+//         && !Confirm::new()
+//             .with_prompt("Do you want to apply these changes?")
+//             .default(false)
+//             .show_default(true)
+//             .interact()?
+//     {
+//         return Ok(CommandStatus::Cancelled);
+//     }
+
+//     apply_privilege_diffs(diffs, connection).await?;
+
+//     Ok(CommandStatus::SuccessfullyModified)
+// }
+
 pub fn parse_privilege_tables_from_args(
     args: &DatabaseEditPrivsArgs,
 ) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
@@ -374,7 +470,9 @@ pub fn parse_privilege_tables_from_args(
 pub fn edit_privileges_with_editor(
     privilege_data: &[DatabasePrivilegeRow],
 ) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    let unix_user = get_current_unix_user()?;
+    let unix_user = User::from_uid(getuid())
+        .context("Failed to look up your UNIX username")
+        .and_then(|u| u.ok_or(anyhow::anyhow!("Failed to look up your UNIX username")))?;
 
     let editor_content =
         generate_editor_content_from_privilege_data(privilege_data, &unix_user.name);

src/cli/user_command.rs

@@ -1,27 +1,20 @@
-use std::collections::BTreeMap;
-use std::vec;
-
 use anyhow::Context;
 use clap::Parser;
 use dialoguer::{Confirm, Password};
-use prettytable::Table;
+use futures_util::{SinkExt, StreamExt};
-use serde_json::json;
-use sqlx::{Connection, MySqlConnection};
 
-use crate::core::{
+use crate::core::protocol::{ClientToServerMessageStream, Request, Response};
-    common::{close_database_connection, get_current_unix_user, CommandStatus},
-    database_operations::*,
-    user_operations::*,
-};
 
-#[derive(Parser)]
+use super::common::erroneous_server_response;
+
+#[derive(Parser, Debug, Clone)]
 pub struct UserArgs {
     #[clap(subcommand)]
     subcmd: UserCommand,
 }
 
 #[allow(clippy::enum_variant_names)]
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub enum UserCommand {
     /// Create one or more users
     #[command()]
@@ -50,7 +43,7 @@ pub enum UserCommand {
     UnlockUser(UserUnlockArgs),
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserCreateArgs {
     #[arg(num_args = 1..)]
     username: Vec<String>,
@@ -60,13 +53,13 @@ pub struct UserCreateArgs {
     no_password: bool,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserDeleteArgs {
     #[arg(num_args = 1..)]
     username: Vec<String>,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserPasswdArgs {
     username: String,
 
@@ -74,7 +67,7 @@ pub struct UserPasswdArgs {
     password_file: Option<String>,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserShowArgs {
     #[arg(num_args = 0..)]
     username: Vec<String>,
@@ -83,13 +76,13 @@ pub struct UserShowArgs {
     json: bool,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserLockArgs {
     #[arg(num_args = 1..)]
     username: Vec<String>,
 }
 
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 pub struct UserUnlockArgs {
     #[arg(num_args = 1..)]
     username: Vec<String>,
@@ -97,48 +90,47 @@ pub struct UserUnlockArgs {
 
 pub async fn handle_command(
     command: UserCommand,
-    mut connection: MySqlConnection,
+    server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let result = connection
-        .transaction(|txn| {
-            Box::pin(async move {
     match command {
-                    UserCommand::CreateUser(args) => create_users(args, txn).await,
+        UserCommand::CreateUser(args) => create_users(args, server_connection).await,
-                    UserCommand::DropUser(args) => drop_users(args, txn).await,
+        UserCommand::DropUser(args) => drop_users(args, server_connection).await,
-                    UserCommand::PasswdUser(args) => change_password_for_user(args, txn).await,
+        UserCommand::PasswdUser(args) => passwd_user(args, server_connection).await,
-                    UserCommand::ShowUser(args) => show_users(args, txn).await,
+        UserCommand::ShowUser(args) => show_users(args, server_connection).await,
-                    UserCommand::LockUser(args) => lock_users(args, txn).await,
+        UserCommand::LockUser(args) => lock_users(args, server_connection).await,
-                    UserCommand::UnlockUser(args) => unlock_users(args, txn).await,
+        UserCommand::UnlockUser(args) => unlock_users(args, server_connection).await,
     }
-            })
-        })
-        .await;
-
-    close_database_connection(connection).await;
-
-    result
 }
 
 async fn create_users(
     args: UserCreateArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.username.is_empty() {
         anyhow::bail!("No usernames provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::CreateUsers(args.username.clone());
-
+    // TODO: better error handling
-    for username in args.username {
+    if let Err(err) = server_connection.send(message).await {
-        if let Err(e) = create_database_user(&username, connection).await {
+        server_connection.close().await.ok();
-            eprintln!("{}", e);
+        anyhow::bail!(err);
-            eprintln!("Skipping...\n");
-            result = CommandStatus::PartiallySuccessfullyModified;
-            continue;
-        } else {
-            println!("User '{}' created.", username);
     }
 
+    let result = match server_connection.next().await {
+        Some(Ok(Response::CreateUsers(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    let successfully_created_users = result
+        .iter()
+        .filter_map(|(username, result)| match result {
+            Ok(_) => Some(username),
+            Err(_) => None,
+        })
+        .collect::<Vec<_>>();
+
+    for username in successfully_created_users {
         if !args.no_password
             && Confirm::new()
                 .with_prompt(format!(
@@ -147,41 +139,65 @@ async fn create_users(
                 ))
                 .interact()?
         {
-            change_password_for_user(
+            let password = read_password_from_stdin_with_double_check(username)?;
-                UserPasswdArgs {
+            let message = Request::PasswdUser(username.clone(), password);
-                    username,
+
-                    password_file: None,
+            if let Err(err) = server_connection.send(message).await {
+                server_connection.close().await.ok();
+                anyhow::bail!(err);
+            }
+
+            match server_connection.next().await {
+                Some(Ok(Response::PasswdUser(result))) => match result {
+                    Ok(_) => println!("Password set for user '{}'", username),
+                    Err(e) => {
+                        eprintln!("{:?}", e);
+                        eprintln!("Skipping...\n");
+                    }
                 },
-                connection,
+                response => return erroneous_server_response(response),
-            )
-            .await?;
             }
-        println!();
         }
-    Ok(result)
+    }
+
+    server_connection.send(Request::Exit).await?;
+
+    Ok(())
 }
 
 async fn drop_users(
     args: UserDeleteArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.username.is_empty() {
         anyhow::bail!("No usernames provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::DropUsers(args.username.clone());
 
-    for username in args.username {
+    if let Err(err) = server_connection.send(message).await {
-        if let Err(e) = delete_database_user(&username, connection).await {
+        server_connection.close().await.ok();
-            eprintln!("{}", e);
+        anyhow::bail!(err);
+    }
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::DropUsers(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    for (username, result) in result.iter() {
+        match result {
+            Ok(_) => println!("User '{}' dropped.", username),
+            Err(err) => {
+                eprintln!("{:?}", err);
                 eprintln!("Skipping...");
-            result = CommandStatus::PartiallySuccessfullyModified;
+            }
-        } else {
-            println!("User '{}' dropped.", username);
         }
     }
 
-    Ok(result)
+    Ok(())
 }
 
 pub fn read_password_from_stdin_with_double_check(username: &str) -> anyhow::Result<String> {
@@ -195,15 +211,10 @@ pub fn read_password_from_stdin_with_double_check(username: &str) -> anyhow::Res
         .map_err(Into::into)
 }
 
-async fn change_password_for_user(
+async fn passwd_user(
     args: UserPasswdArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    // NOTE: although this also is checked in `set_password_for_database_user`, we check it here
-    //       to provide a more natural order of error messages.
-    let unix_user = get_current_unix_user()?;
-    validate_user_name(&args.username, &unix_user)?;
-
     let password = if let Some(password_file) = args.password_file {
         std::fs::read_to_string(password_file)
             .context("Failed to read password file")?
@@ -213,129 +224,170 @@ async fn change_password_for_user(
         read_password_from_stdin_with_double_check(&args.username)?
     };
 
-    set_password_for_database_user(&args.username, &password, connection).await?;
+    let message = Request::PasswdUser(args.username.clone(), password);
 
-    Ok(CommandStatus::SuccessfullyModified)
+    if let Err(err) = server_connection.send(message).await {
+        server_connection.close().await.ok();
+        anyhow::bail!(err);
+    }
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::PasswdUser(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    match result {
+        Ok(_) => println!("Password set for user '{}'", args.username),
+        Err(e) => {
+            eprintln!("{:?}", e);
+            eprintln!("Skipping...\n");
+        }
+    };
+
+    Ok(())
 }
 
 async fn show_users(
     args: UserShowArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
-    let unix_user = get_current_unix_user()?;
+    let message = if args.username.is_empty() {
-
+        Request::ListUsers(None)
-    let users = if args.username.is_empty() {
-        get_all_database_users_for_unix_user(&unix_user, connection).await?
     } else {
-        let mut result = vec![];
+        Request::ListUsers(Some(args.username.clone()))
-        for username in args.username {
-            if let Err(e) = validate_user_name(&username, &unix_user) {
-                eprintln!("{}", e);
-                eprintln!("Skipping...");
-                continue;
-            }
-
-            let user = get_database_user_for_user(&username, connection).await?;
-            if let Some(user) = user {
-                result.push(user);
-            } else {
-                eprintln!("User not found: {}", username);
-            }
-        }
-        result
     };
 
-    let mut user_databases: BTreeMap<String, Vec<String>> = BTreeMap::new();
+    if let Err(err) = server_connection.send(message).await {
-    for user in users.iter() {
+        server_connection.close().await.ok();
-        user_databases.insert(
+        anyhow::bail!(err);
-            user.user.clone(),
-            get_databases_where_user_has_privileges(&user.user, connection).await?,
-        );
     }
 
-    if args.json {
+    let users = match server_connection.next().await {
-        let users_json = users
+        Some(Ok(Response::ListUsers(users))) => users
             .into_iter()
-            .map(|user| {
+            .filter_map(|(_username, result)| match result {
-                json!({
+                Ok(user) => Some(user),
-                    "user": user.user,
+                Err(err) => {
-                    "has_password": user.has_password,
+                    eprintln!("{:?}", err);
-                    "is_locked": user.is_locked,
+                    eprintln!("Skipping...");
-                    "databases": user_databases.get(&user.user).unwrap_or(&vec![]),
+                    None
+                }
             })
-            })
+            .collect::<Vec<_>>(),
-            .collect::<serde_json::Value>();
+        Some(Ok(Response::ListAllUsers(users))) => match users {
+            Ok(users) => users,
+            Err(err) => {
+                eprintln!("{:?}", err);
+                // TODO: close connection
+                return Ok(());
+            }
+        },
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    // TODO: print erroneous users
+    // for user in users.iter()
+
+    // TODO: print databases where user has privileges
+    if args.json {
         println!(
             "{}",
-            serde_json::to_string_pretty(&users_json)
+            serde_json::to_string_pretty(&users).context("Failed to serialize users to JSON")?
-                .context("Failed to serialize users to JSON")?
         );
     } else if users.is_empty() {
-        println!("No users found.");
+        println!("No users to show.");
     } else {
-        let mut table = Table::new();
+        let mut table = prettytable::Table::new();
         table.add_row(row![
             "User",
             "Password is set",
             "Locked",
-            "Databases where user has privileges"
+            // "Databases where user has privileges"
         ]);
         for user in users {
             table.add_row(row![
                 user.user,
                 user.has_password,
                 user.is_locked,
-                user_databases.get(&user.user).unwrap_or(&vec![]).join("\n")
+                // user.databases.join("\n")
             ]);
         }
         table.printstd();
     }
 
-    Ok(CommandStatus::NoModificationsIntended)
+    Ok(())
 }
 
 async fn lock_users(
     args: UserLockArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.username.is_empty() {
         anyhow::bail!("No usernames provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::LockUsers(args.username.clone());
 
-    for username in args.username {
+    if let Err(err) = server_connection.send(message).await {
-        if let Err(e) = lock_database_user(&username, connection).await {
+        server_connection.close().await.ok();
-            eprintln!("{}", e);
+        anyhow::bail!(err);
+    }
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::LockUsers(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    for (username, result) in result.iter() {
+        match result {
+            Ok(_) => println!("User '{}' locked.", username),
+            Err(err) => {
+                eprintln!("{:?}", err);
                 eprintln!("Skipping...");
-            result = CommandStatus::PartiallySuccessfullyModified;
+            }
-        } else {
-            println!("User '{}' locked.", username);
         }
     }
 
-    Ok(result)
+    Ok(())
 }
 
 async fn unlock_users(
     args: UserUnlockArgs,
-    connection: &mut MySqlConnection,
+    mut server_connection: ClientToServerMessageStream,
-) -> anyhow::Result<CommandStatus> {
+) -> anyhow::Result<()> {
     if args.username.is_empty() {
         anyhow::bail!("No usernames provided");
     }
 
-    let mut result = CommandStatus::SuccessfullyModified;
+    let message = Request::UnlockUsers(args.username.clone());
 
-    for username in args.username {
+    if let Err(err) = server_connection.send(message).await {
-        if let Err(e) = unlock_database_user(&username, connection).await {
+        server_connection.close().await.ok();
-            eprintln!("{}", e);
+        anyhow::bail!(err);
+    }
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::UnlockUsers(result))) => result,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    for (username, result) in result.iter() {
+        match result {
+            Ok(_) => println!("User '{}' unlocked.", username),
+            Err(err) => {
+                eprintln!("{:?}", err);
                 eprintln!("Skipping...");
-            result = CommandStatus::PartiallySuccessfullyModified;
+            }
-        } else {
-            println!("User '{}' unlocked.", username);
         }
     }
 
-    Ok(result)
+    Ok(())
 }

src/core.rs

@@ -1,5 +1,4 @@
+pub mod bootstrap;
 pub mod common;
-pub mod config;
+pub mod database_privileges;
-pub mod database_operations;
+pub mod protocol;
-pub mod database_privilege_operations;
-pub mod user_operations;

src/core/bootstrap.rs

@@ -0,0 +1,143 @@
+use std::{fs, path::PathBuf};
+
+use nix::libc::{exit, EXIT_SUCCESS};
+use std::os::unix::net::UnixStream as StdUnixStream;
+use tokio::net::UnixStream as TokioUnixStream;
+
+use crate::core::bootstrap::authenticated_unix_socket::client_authenticate;
+use crate::core::common::{DEFAULT_CONFIG_PATH, DEFAULT_SOCKET_PATH};
+use crate::server::config::read_config_form_path;
+use crate::server::server_loop::handle_requests_for_single_session;
+
+use super::common::UnixUser;
+
+pub mod authenticated_unix_socket;
+
+pub fn drop_privs() -> anyhow::Result<()> {
+    log::debug!("Dropping privileges");
+    let real_uid = nix::unistd::getuid();
+    let real_gid = nix::unistd::getgid();
+
+    nix::unistd::setuid(real_uid)
+        .map_err(|e| anyhow::anyhow!("Failed to drop privileges: {}", e))?;
+    nix::unistd::setgid(real_gid)
+        .map_err(|e| anyhow::anyhow!("Failed to drop privileges: {}", e))?;
+
+    log::debug!("Privileges dropped successfully");
+    Ok(())
+}
+
+pub fn bootstrap_server_connection_and_drop_privileges(
+    server_socket_path: Option<PathBuf>,
+    config_path: Option<PathBuf>,
+) -> anyhow::Result<StdUnixStream> {
+    if server_socket_path.is_some() && config_path.is_some() {
+        anyhow::bail!("Cannot provide both a socket path and a config path");
+    }
+
+    log::debug!("Starting the server connection bootstrap process");
+
+    let socket = bootstrap_server_connection(server_socket_path, config_path)?;
+
+    drop_privs()?;
+
+    let result: anyhow::Result<StdUnixStream> = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()
+        .unwrap()
+        .block_on(async {
+            let mut socket = TokioUnixStream::from_std(socket)?;
+            client_authenticate(&mut socket, None).await?;
+            Ok(socket.into_std()?)
+        });
+    result
+}
+
+fn bootstrap_server_connection(
+    socket_path: Option<PathBuf>,
+    config_path: Option<PathBuf>,
+) -> anyhow::Result<StdUnixStream> {
+    dbg!(&socket_path, &config_path);
+
+    // TODO: ensure this is both readable and writable
+    if let Some(socket_path) = socket_path {
+        log::debug!("Connecting to socket at {:?}", socket_path);
+        return match StdUnixStream::connect(socket_path) {
+            Ok(socket) => Ok(socket),
+            Err(e) => match e.kind() {
+                std::io::ErrorKind::NotFound => Err(anyhow::anyhow!("Socket not found")),
+                std::io::ErrorKind::PermissionDenied => Err(anyhow::anyhow!("Permission denied")),
+                _ => Err(anyhow::anyhow!("Failed to connect to socket: {}", e)),
+            },
+        };
+    }
+    if let Some(config_path) = config_path {
+        // ensure config exists and is readable
+        if fs::metadata(&config_path).is_err() {
+            return Err(anyhow::anyhow!("Config file not found or not readable"));
+        }
+
+        log::debug!("Starting server with config at {:?}", config_path);
+        return invoke_server_with_config(config_path);
+    }
+
+    if fs::metadata(DEFAULT_SOCKET_PATH).is_ok() {
+        return match StdUnixStream::connect(DEFAULT_SOCKET_PATH) {
+            Ok(socket) => Ok(socket),
+            Err(e) => match e.kind() {
+                std::io::ErrorKind::NotFound => Err(anyhow::anyhow!("Socket not found")),
+                std::io::ErrorKind::PermissionDenied => Err(anyhow::anyhow!("Permission denied")),
+                _ => Err(anyhow::anyhow!("Failed to connect to socket: {}", e)),
+            },
+        };
+    }
+
+    let config_path = PathBuf::from(DEFAULT_CONFIG_PATH);
+    if fs::metadata(&config_path).is_ok() {
+        return invoke_server_with_config(config_path);
+    }
+
+    anyhow::bail!("No socket path or config path provided, and no default socket or config found");
+}
+
+// TODO: we should somehow ensure that the forked process is killed on completion,
+//       just in case the client does not behave properly.
+fn invoke_server_with_config(config_path: PathBuf) -> anyhow::Result<StdUnixStream> {
+    let (server_socket, client_socket) = StdUnixStream::pair()?;
+    let unix_user = UnixUser::from_uid(nix::unistd::getuid().as_raw())?;
+
+    match unsafe { nix::unistd::fork() } {
+        Ok(nix::unistd::ForkResult::Parent { child }) => {
+            log::debug!("Forked child process with PID {}", child);
+            Ok(client_socket)
+        }
+        Ok(nix::unistd::ForkResult::Child) => {
+            log::debug!("Running server in child process");
+
+            let config = read_config_form_path(Some(config_path))?;
+
+            let result: anyhow::Result<()> = tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async {
+                    let mut socket = TokioUnixStream::from_std(server_socket)?;
+
+                    // TODO: this is not necessary when forking
+                    let _ = authenticated_unix_socket::server_authenticate(&mut socket).await?;
+
+                    handle_requests_for_single_session(socket, &unix_user, &config).await?;
+                    Ok(())
+                });
+
+            result?;
+
+            unsafe {
+                exit(EXIT_SUCCESS);
+            }
+        }
+        Err(e) => {
+            Err(anyhow::anyhow!("Failed to fork: {}", e))
+        }
+    }
+}

src/core/bootstrap/authenticated_unix_socket.rs

@@ -30,10 +30,13 @@
 //! Also note that it is essential that the client does not send any sensitive information
 //! over it's authentication socket, since it is readable by any user on the system.
 
+// TODO: rewrite this so that it can be used with a normal std::os::unix::net::UnixStream
+
 use std::os::unix::io::AsRawFd;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use async_bincode::{tokio::AsyncBincodeStream, AsyncDestination};
+use derive_more::derive::{Display, Error};
 use futures::{SinkExt, StreamExt};
 use nix::{sys::stat, unistd::Uid};
 use rand::distributions::Alphanumeric;
@@ -52,7 +55,7 @@ pub enum ClientRequest {
     Cancel,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, Display, Error)]
 pub enum ServerResponse {
     Authenticated,
     ChallengeDidNotMatch,
@@ -61,7 +64,7 @@ pub enum ServerResponse {
 
 // TODO: wrap more data into the errors
 
-#[derive(Debug, PartialEq, Serialize, Deserialize, Clone)]
+#[derive(Debug, Display, PartialEq, Serialize, Deserialize, Clone, Error)]
 pub enum ServerError {
     InvalidRequest,
     UnableToReadPermissionsFromAuthSocket,
@@ -72,7 +75,7 @@ pub enum ServerError {
     InvalidChallenge,
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Display, Error)]
 pub enum ClientError {
     UnableToConnectToServer,
     UnableToOpenAuthSocket,
@@ -86,7 +89,7 @@ pub enum ClientError {
     ServerError(ServerError),
 }
 
-async fn create_auth_socket(socket_addr: &str) -> Result<UnixListener, ClientError> {
+async fn create_auth_socket(socket_addr: &PathBuf) -> Result<UnixListener, ClientError> {
     let auth_socket =
         UnixListener::bind(socket_addr).map_err(|_err| ClientError::UnableToOpenAuthSocket)?;
 
@@ -109,11 +112,13 @@ type AuthStream<'a> = AsyncBincodeStream<&'a mut UnixStream, u64, u64, AsyncDest
 
 // TODO: add timeout
 
+// TODO: respect $XDG_RUNTIME_DIR and $TMPDIR
+
 const AUTH_SOCKET_NAME: &str = "mysqladm-rs-cli-auth.sock";
+
 pub async fn client_authenticate(
     normal_socket: &mut UnixStream,
-    #[cfg(not(test))] auth_socket_dir: Option<PathBuf>,
+    auth_socket_dir: Option<PathBuf>,
-    #[cfg(test)] auth_socket_file: Option<PathBuf>,
 ) -> Result<(), ClientError> {
     let random_prefix: String = rand::thread_rng()
         .sample_iter(&Alphanumeric)
@@ -123,32 +128,16 @@ pub async fn client_authenticate(
 
     let socket_name = format!("{}-{}", random_prefix, AUTH_SOCKET_NAME);
 
-    #[cfg(not(test))]
+    let auth_socket_address = auth_socket_dir
-    let auth_socket_address = match auth_socket_dir {
+        .unwrap_or(std::env::temp_dir())
-        Some(dir) => dir.join(socket_name).to_str().unwrap().to_string(),
+        .join(socket_name);
-        None => std::env::temp_dir()
-            .join(socket_name)
-            .to_str()
-            .unwrap()
-            .to_string(),
-    };
-
-    #[cfg(test)]
-    let auth_socket_address = match auth_socket_file {
-        Some(file) => file.to_str().unwrap().to_string(),
-        None => std::env::temp_dir()
-            .join(socket_name)
-            .to_str()
-            .unwrap()
-            .to_string(),
-    };
 
     client_authenticate_with_auth_socket_address(normal_socket, &auth_socket_address).await
 }
 
 async fn client_authenticate_with_auth_socket_address(
     normal_socket: &mut UnixStream,
-    auth_socket_address: &str,
+    auth_socket_address: &PathBuf,
 ) -> Result<(), ClientError> {
     let auth_socket = create_auth_socket(auth_socket_address).await?;
 
@@ -164,7 +153,7 @@ async fn client_authenticate_with_auth_socket_address(
 async fn client_authenticate_with_auth_socket(
     normal_socket: &mut UnixStream,
     auth_socket: UnixListener,
-    auth_socket_address: &str,
+    auth_socket_address: &Path,
 ) -> Result<(), ClientError> {
     let challenge = rand::random::<u64>();
     let uid = nix::unistd::getuid();
@@ -199,7 +188,7 @@ async fn client_authenticate_with_auth_socket(
     let client_hello = ClientRequest::Initialize {
         uid: uid.into(),
         challenge,
-        auth_socket: auth_socket_address.to_string(),
+        auth_socket: auth_socket_address.to_str().unwrap().to_owned(),
     };
 
     normal_socket
@@ -239,9 +228,13 @@ macro_rules! report_server_error_and_return {
     }};
 }
 
-async fn server_authenticate(
+pub async fn server_authenticate(normal_socket: &mut UnixStream) -> Result<Uid, ServerError> {
+    _server_authenticate(normal_socket, None).await
+}
+
+pub async fn _server_authenticate(
     normal_socket: &mut UnixStream,
-    #[cfg(test)] unix_user_uid: Option<u32>,
+    unix_user_uid: Option<u32>,
 ) -> Result<Uid, ServerError> {
     let mut normal_socket: ServerToClientStream =
         AsyncBincodeStream::from(normal_socket).for_async();
@@ -256,22 +249,15 @@ async fn server_authenticate(
         _ => report_server_error_and_return!(normal_socket, ServerError::InvalidRequest),
     };
 
-    #[cfg(test)]
     let auth_socket_uid = match unix_user_uid {
         Some(uid) => uid,
-        None => report_server_error_and_return!(
+        None => match stat::stat(auth_socket.as_str()) {
-            normal_socket,
-            ServerError::UnableToReadPermissionsFromAuthSocket
-        ),
-    };
-
-    #[cfg(not(test))]
-    let auth_socket_uid = match stat::stat(auth_socket.as_str()) {
             Ok(stat) => stat.st_uid,
             Err(_err) => report_server_error_and_return!(
                 normal_socket,
                 ServerError::UnableToReadPermissionsFromAuthSocket
             ),
+        },
     };
 
     if uid != auth_socket_uid {
@@ -324,10 +310,7 @@ mod test {
         let client_handle =
             tokio::spawn(async move { client_authenticate(&mut client, None).await });
 
-        let server_handle = tokio::spawn(async move {
+        let server_handle = tokio::spawn(async move { server_authenticate(&mut server).await });
-            let uid = nix::unistd::getuid().into();
-            server_authenticate(&mut server, Some(uid)).await
-        });
 
         client_handle.await.unwrap().unwrap();
         server_handle.await.unwrap().unwrap();
@@ -340,15 +323,12 @@ mod test {
         let client_handle = tokio::spawn(async move {
             client_authenticate_with_auth_socket_address(
                 &mut client,
-                "/tmp/test_auth_socket_does_not_exist.sock",
+                &PathBuf::from("/tmp/test_auth_socket_does_not_exist.sock"),
             )
             .await
         });
 
-        let server_handle = tokio::spawn(async move {
+        let server_handle = tokio::spawn(async move { server_authenticate(&mut server).await });
-            let uid = nix::unistd::getuid().into();
-            server_authenticate(&mut server, Some(uid)).await
-        });
 
         client_handle.await.unwrap().unwrap();
         server_handle.await.unwrap().unwrap();
@@ -365,7 +345,7 @@ mod test {
 
         let server_handle = tokio::spawn(async move {
             let uid: u32 = nix::unistd::getuid().into();
-            let err = server_authenticate(&mut server, Some(uid + 1)).await;
+            let err = _server_authenticate(&mut server, Some(uid + 1)).await;
             assert_eq!(err, Err(ServerError::UidMismatch));
         });
 
@@ -379,13 +359,19 @@ mod test {
 
         let socket_path = std::env::temp_dir().join("socket_to_snoop.sock");
         let socket_path_clone = socket_path.clone();
-        let client_handle =
+        let client_handle = tokio::spawn(async move {
-            tokio::spawn(
+            client_authenticate_with_auth_socket_address(&mut client, &socket_path_clone).await
-                async move { client_authenticate(&mut client, Some(socket_path_clone)).await },
+        });
-            );
 
-        while !socket_path.exists() {
+        for i in 0..100 {
-            sleep(std::time::Duration::from_millis(10)).await;
+            if socket_path.exists() {
+                break;
+            }
+            sleep(Duration::from_millis(10)).await;
+
+            if i == 99 {
+                panic!("Socket not created after 1 second, assuming test failure");
+            }
         }
 
         let mut snooper = UnixStream::connect(socket_path.clone()).await.unwrap();
@@ -409,10 +395,7 @@ mod test {
 
         sleep(Duration::from_millis(10)).await;
 
-        let server_handle = tokio::spawn(async move {
+        let server_handle = tokio::spawn(async move { server_authenticate(&mut server).await });
-            let uid: u32 = nix::unistd::getuid().into();
-            server_authenticate(&mut server, Some(uid)).await
-        });
 
         client_handle.await.unwrap().unwrap();
         server_handle.await.unwrap().unwrap();

src/core/common.rs

@@ -1,56 +1,32 @@
 use anyhow::Context;
-use indoc::indoc;
+use nix::unistd::{Group as LibcGroup, User as LibcUser};
-use itertools::Itertools;
-use nix::unistd::{getuid, Group, User};
-use sqlx::{Connection, MySqlConnection};
 
 #[cfg(not(target_os = "macos"))]
 use std::ffi::CString;
 
-/// Report the result status of a command.
+pub const DEFAULT_CONFIG_PATH: &str = "/etc/mysqladm/config.toml";
-/// This is used to display a status message to the user.
+pub const DEFAULT_SOCKET_PATH: &str = "/run/mysqladm/mysqladm.sock";
-pub enum CommandStatus {
-    /// The command was successful,
-    /// and made modification to the database.
-    SuccessfullyModified,
 
-    /// The command was mostly successful,
+pub struct UnixUser {
-    /// and modifications have been made to the database.
+    pub username: String,
-    /// However, some of the requested modifications failed.
+    pub uid: u32,
-    PartiallySuccessfullyModified,
+    pub gid: u32,
-
+    pub groups: Vec<String>,
-    /// The command was successful,
-    /// but no modifications were needed.
-    NoModificationsNeeded,
-
-    /// The command was successful,
-    /// and made no modification to the database.
-    NoModificationsIntended,
-
-    /// The command was cancelled, either through a dialog or a signal.
-    /// No modifications have been made to the database.
-    Cancelled,
-}
-
-pub fn get_current_unix_user() -> anyhow::Result<User> {
-    User::from_uid(getuid())
-        .context("Failed to look up your UNIX username")
-        .and_then(|u| u.ok_or(anyhow::anyhow!("Failed to look up your UNIX username")))
 }
 
 #[cfg(target_os = "macos")]
-pub fn get_unix_groups(_user: &User) -> anyhow::Result<Vec<Group>> {
+fn get_unix_groups(_user: &User) -> anyhow::Result<Vec<Group>> {
     // Return an empty list on macOS since there is no `getgrouplist` function
     Ok(vec![])
 }
 
 #[cfg(not(target_os = "macos"))]
-pub fn get_unix_groups(user: &User) -> anyhow::Result<Vec<Group>> {
+fn get_unix_groups(user: &LibcUser) -> anyhow::Result<Vec<LibcGroup>> {
     let user_cstr =
         CString::new(user.name.as_bytes()).context("Failed to convert username to CStr")?;
     let groups = nix::unistd::getgrouplist(&user_cstr, user.gid)?
         .iter()
-        .filter_map(|gid| match Group::from_gid(*gid) {
+        .filter_map(|gid| match LibcGroup::from_gid(*gid) {
             Ok(Some(group)) => Some(group),
             Ok(None) => None,
             Err(e) => {
@@ -62,211 +38,29 @@ pub fn get_unix_groups(user: &User) -> anyhow::Result<Vec<Group>> {
                 None
             }
         })
-        .collect::<Vec<Group>>();
+        .collect::<Vec<LibcGroup>>();
 
     Ok(groups)
 }
 
-/// This function creates a regex that matches items (users, databases)
+impl UnixUser {
-/// that belong to the user or any of the user's groups.
+    pub fn from_uid(uid: u32) -> anyhow::Result<Self> {
-pub fn create_user_group_matching_regex(user: &User) -> String {
+        let libc_uid = nix::unistd::Uid::from_raw(uid);
-    let groups = get_unix_groups(user).unwrap_or_default();
+        let libc_user = LibcUser::from_uid(libc_uid)
+            .context("Failed to look up your UNIX username")?
+            .ok_or(anyhow::anyhow!("Failed to look up your UNIX username"))?;
 
-    if groups.is_empty() {
+        let groups = get_unix_groups(&libc_user)?;
-        format!("{}(_.+)?", user.name)
+
-    } else {
+        Ok(UnixUser {
-        format!(
+            username: libc_user.name,
-            "({}|{})(_.+)?",
+            uid,
-            user.name,
+            gid: libc_user.gid.into(),
-            groups
+            groups: groups.iter().map(|g| g.name.clone()).collect(),
-                .iter()
+        })
-                .map(|g| g.name.as_str())
-                .collect::<Vec<_>>()
-                .join("|")
-        )
     }
 }
 
-/// This enum is used to differentiate between database and user operations.
-/// Their output are very similar, but there are slight differences in the words used.
-#[derive(Debug, PartialEq, Eq, Clone, Copy)]
-pub enum DbOrUser {
-    Database,
-    User,
-}
-
-impl DbOrUser {
-    pub fn lowercased(&self) -> String {
-        match self {
-            DbOrUser::Database => "database".to_string(),
-            DbOrUser::User => "user".to_string(),
-        }
-    }
-
-    pub fn capitalized(&self) -> String {
-        match self {
-            DbOrUser::Database => "Database".to_string(),
-            DbOrUser::User => "User".to_string(),
-        }
-    }
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub enum NameValidationResult {
-    Valid,
-    EmptyString,
-    InvalidCharacters,
-    TooLong,
-}
-
-pub fn validate_name(name: &str) -> NameValidationResult {
-    if name.is_empty() {
-        NameValidationResult::EmptyString
-    } else if name.len() > 64 {
-        NameValidationResult::TooLong
-    } else if !name
-        .chars()
-        .all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '-')
-    {
-        NameValidationResult::InvalidCharacters
-    } else {
-        NameValidationResult::Valid
-    }
-}
-
-pub fn validate_name_or_error(name: &str, db_or_user: DbOrUser) -> anyhow::Result<()> {
-    match validate_name(name) {
-        NameValidationResult::Valid => Ok(()),
-        NameValidationResult::EmptyString => {
-            anyhow::bail!("{} name cannot be empty.", db_or_user.capitalized())
-        }
-        NameValidationResult::TooLong => anyhow::bail!(
-            "{} is too long. Maximum length is 64 characters.",
-            db_or_user.capitalized()
-        ),
-        NameValidationResult::InvalidCharacters => anyhow::bail!(
-            indoc! {r#"
-              Invalid characters in {} name: '{}'
-
-              Only A-Z, a-z, 0-9, _ (underscore) and - (dash) are permitted.
-            "#},
-            db_or_user.lowercased(),
-            name
-        ),
-    }
-}
-
-#[derive(Debug, PartialEq, Eq)]
-pub enum OwnerValidationResult {
-    // The name is valid and matches one of the given prefixes
-    Match,
-
-    // The name is valid, but none of the given prefixes matched the name
-    NoMatch,
-
-    // The name is empty, which is invalid
-    StringEmpty,
-
-    // The name is in the format "_<postfix>", which is invalid
-    MissingPrefix,
-
-    // The name is in the format "<prefix>_", which is invalid
-    MissingPostfix,
-}
-
-/// Core logic for validating the ownership of a database name.
-/// This function checks if the given name matches any of the given prefixes.
-/// These prefixes will in most cases be the user's unix username and any
-/// unix groups the user is a member of.
-pub fn validate_ownership_by_prefixes(name: &str, prefixes: &[String]) -> OwnerValidationResult {
-    if name.is_empty() {
-        return OwnerValidationResult::StringEmpty;
-    }
-
-    if name.starts_with('_') {
-        return OwnerValidationResult::MissingPrefix;
-    }
-
-    let (prefix, _) = match name.split_once('_') {
-        Some(pair) => pair,
-        None => return OwnerValidationResult::MissingPostfix,
-    };
-
-    if prefixes.iter().any(|g| g == prefix) {
-        OwnerValidationResult::Match
-    } else {
-        OwnerValidationResult::NoMatch
-    }
-}
-
-/// Validate the ownership of a database name or database user name.
-/// This function takes the name of a database or user and a unix user,
-/// for which it fetches the user's groups. It then checks if the name
-/// is prefixed with the user's username or any of the user's groups.
-pub fn validate_ownership_or_error<'a>(
-    name: &'a str,
-    user: &User,
-    db_or_user: DbOrUser,
-) -> anyhow::Result<&'a str> {
-    let user_groups = get_unix_groups(user)?;
-    let prefixes = std::iter::once(user.name.clone())
-        .chain(user_groups.iter().map(|g| g.name.clone()))
-        .collect::<Vec<String>>();
-
-    match validate_ownership_by_prefixes(name, &prefixes) {
-        OwnerValidationResult::Match => Ok(name),
-        OwnerValidationResult::NoMatch => {
-            anyhow::bail!(
-                indoc! {r#"
-                  Invalid {} name prefix: '{}' does not match your username or any of your groups.
-                  Are you sure you are allowed to create {} names with this prefix?
-
-                  Allowed prefixes:
-                    - {}
-                  {}
-                "#},
-                db_or_user.lowercased(),
-                name,
-                db_or_user.lowercased(),
-                user.name,
-                user_groups
-                    .iter()
-                    .filter(|g| g.name != user.name)
-                    .map(|g| format!("  - {}", g.name))
-                    .sorted()
-                    .join("\n"),
-            );
-        }
-        _ => anyhow::bail!(
-            "'{}' is not a valid {} name.",
-            name,
-            db_or_user.lowercased()
-        ),
-    }
-}
-
-/// Gracefully close a MySQL connection.
-pub async fn close_database_connection(connection: MySqlConnection) {
-    if let Err(e) = connection
-        .close()
-        .await
-        .context("Failed to close connection properly")
-    {
-        eprintln!("{}", e);
-        eprintln!("Ignoring...");
-    }
-}
-
-#[inline]
-pub fn quote_literal(s: &str) -> String {
-    format!("'{}'", s.replace('\'', r"\'"))
-}
-
-#[inline]
-pub fn quote_identifier(s: &str) -> String {
-    format!("`{}`", s.replace('`', r"\`"))
-}
-
 #[inline]
 pub(crate) fn yn(b: bool) -> &'static str {
     if b {
@@ -303,94 +97,4 @@ mod test {
         assert_eq!(rev_yn("n"), Some(false));
         assert_eq!(rev_yn("X"), None);
     }
-
-    #[test]
-    fn test_quote_literal() {
-        let payload = "' OR 1=1 --";
-        assert_eq!(quote_literal(payload), r#"'\' OR 1=1 --'"#);
-    }
-
-    #[test]
-    fn test_quote_identifier() {
-        let payload = "` OR 1=1 --";
-        assert_eq!(quote_identifier(payload), r#"`\` OR 1=1 --`"#);
-    }
-
-    #[test]
-    fn test_validate_name() {
-        assert_eq!(validate_name(""), NameValidationResult::EmptyString);
-        assert_eq!(
-            validate_name("abcdefghijklmnopqrstuvwxyz"),
-            NameValidationResult::Valid
-        );
-        assert_eq!(
-            validate_name("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
-            NameValidationResult::Valid
-        );
-        assert_eq!(validate_name("0123456789_-"), NameValidationResult::Valid);
-
-        for c in "\n\t\r !@#$%^&*()+=[]{}|;:,.<>?/".chars() {
-            assert_eq!(
-                validate_name(&c.to_string()),
-                NameValidationResult::InvalidCharacters
-            );
-        }
-
-        assert_eq!(validate_name(&"a".repeat(64)), NameValidationResult::Valid);
-
-        assert_eq!(
-            validate_name(&"a".repeat(65)),
-            NameValidationResult::TooLong
-        );
-    }
-
-    #[test]
-    fn test_validate_owner_by_prefixes() {
-        let prefixes = vec!["user".to_string(), "group".to_string()];
-
-        assert_eq!(
-            validate_ownership_by_prefixes("", &prefixes),
-            OwnerValidationResult::StringEmpty
-        );
-
-        assert_eq!(
-            validate_ownership_by_prefixes("user", &prefixes),
-            OwnerValidationResult::MissingPostfix
-        );
-        assert_eq!(
-            validate_ownership_by_prefixes("something", &prefixes),
-            OwnerValidationResult::MissingPostfix
-        );
-        assert_eq!(
-            validate_ownership_by_prefixes("user-testdb", &prefixes),
-            OwnerValidationResult::MissingPostfix
-        );
-
-        assert_eq!(
-            validate_ownership_by_prefixes("_testdb", &prefixes),
-            OwnerValidationResult::MissingPrefix
-        );
-
-        assert_eq!(
-            validate_ownership_by_prefixes("user_testdb", &prefixes),
-            OwnerValidationResult::Match
-        );
-        assert_eq!(
-            validate_ownership_by_prefixes("group_testdb", &prefixes),
-            OwnerValidationResult::Match
-        );
-        assert_eq!(
-            validate_ownership_by_prefixes("group_test_db", &prefixes),
-            OwnerValidationResult::Match
-        );
-        assert_eq!(
-            validate_ownership_by_prefixes("group_test-db", &prefixes),
-            OwnerValidationResult::Match
-        );
-
-        assert_eq!(
-            validate_ownership_by_prefixes("nonexistent_testdb", &prefixes),
-            OwnerValidationResult::NoMatch
-        );
-    }
 }

src/core/database_operations.rs

@@ -1,120 +0,0 @@
-use anyhow::Context;
-use indoc::formatdoc;
-use itertools::Itertools;
-use nix::unistd::User;
-use sqlx::{prelude::*, MySqlConnection};
-
-use crate::core::{
-    common::{
-        create_user_group_matching_regex, get_current_unix_user, quote_identifier,
-        validate_name_or_error, validate_ownership_or_error, DbOrUser,
-    },
-    database_privilege_operations::DATABASE_PRIVILEGE_FIELDS,
-};
-
-pub async fn create_database(name: &str, connection: &mut MySqlConnection) -> anyhow::Result<()> {
-    let user = get_current_unix_user()?;
-    validate_database_name(name, &user)?;
-
-    // NOTE: see the note about SQL injections in `validate_owner_of_database_name`
-    sqlx::query(&format!("CREATE DATABASE {}", quote_identifier(name)))
-        .execute(connection)
-        .await
-        .map_err(|e| {
-            if e.to_string().contains("database exists") {
-                anyhow::anyhow!("Database '{}' already exists", name)
-            } else {
-                e.into()
-            }
-        })?;
-
-    Ok(())
-}
-
-pub async fn drop_database(name: &str, connection: &mut MySqlConnection) -> anyhow::Result<()> {
-    let user = get_current_unix_user()?;
-    validate_database_name(name, &user)?;
-
-    // NOTE: see the note about SQL injections in `validate_owner_of_database_name`
-    sqlx::query(&format!("DROP DATABASE {}", quote_identifier(name)))
-        .execute(connection)
-        .await
-        .map_err(|e| {
-            if e.to_string().contains("doesn't exist") {
-                anyhow::anyhow!("Database '{}' does not exist", name)
-            } else {
-                e.into()
-            }
-        })?;
-
-    Ok(())
-}
-
-pub async fn get_database_list(connection: &mut MySqlConnection) -> anyhow::Result<Vec<String>> {
-    let unix_user = get_current_unix_user()?;
-
-    let databases: Vec<String> = sqlx::query(
-        r#"
-          SELECT `SCHEMA_NAME` AS `database`
-          FROM `information_schema`.`SCHEMATA`
-          WHERE `SCHEMA_NAME` NOT IN ('information_schema', 'performance_schema', 'mysql', 'sys')
-            AND `SCHEMA_NAME` REGEXP ?
-        "#,
-    )
-    .bind(create_user_group_matching_regex(&unix_user))
-    .fetch_all(connection)
-    .await
-    .and_then(|row| {
-        row.into_iter()
-            .map(|row| row.try_get::<String, _>("database"))
-            .collect::<Result<_, _>>()
-    })
-    .context(format!(
-        "Failed to get databases for user '{}'",
-        unix_user.name
-    ))?;
-
-    Ok(databases)
-}
-
-pub async fn get_databases_where_user_has_privileges(
-    username: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<String>> {
-    let result = sqlx::query(
-        formatdoc!(
-            r#"
-            SELECT `db` AS `database`
-            FROM `db`
-            WHERE `user` = ?
-              AND ({})
-        "#,
-            DATABASE_PRIVILEGE_FIELDS
-                .iter()
-                .map(|field| format!("`{}` = 'Y'", field))
-                .join(" OR "),
-        )
-        .as_str(),
-    )
-    .bind(username)
-    .fetch_all(connection)
-    .await?
-    .into_iter()
-    .map(|databases| databases.try_get::<String, _>("database").unwrap())
-    .collect();
-
-    Ok(result)
-}
-
-/// NOTE: It is very critical that this function validates the database name
-///       properly. MySQL does not seem to allow for prepared statements, binding
-///       the database name as a parameter to the query. This means that we have
-///       to validate the database name ourselves to prevent SQL injection.
-pub fn validate_database_name(name: &str, user: &User) -> anyhow::Result<()> {
-    validate_name_or_error(name, DbOrUser::Database)
-        .context(format!("Invalid database name: '{}'", name))?;
-    validate_ownership_or_error(name, user, DbOrUser::Database)
-        .context(format!("Invalid database name: '{}'", name))?;
-
-    Ok(())
-}

src/core/database_privileges.rs

@@ -1,53 +1,14 @@
-//! Database privilege operations
-//!
-//! This module contains functions for querying, modifying,
-//! displaying and comparing database privileges.
-//!
-//! A lot of the complexity comes from two core components:
-//!
-//! - The privilege editor that needs to be able to print
-//!   an editable table of privileges and reparse the content
-//!   after the user has made manual changes.
-//!
-//! - The comparison functionality that tells the user what
-//!   changes will be made when applying a set of changes
-//!   to the list of database privileges.
-
-use std::collections::{BTreeSet, HashMap};
-
 use anyhow::{anyhow, Context};
-use indoc::indoc;
 use itertools::Itertools;
 use prettytable::Table;
 use serde::{Deserialize, Serialize};
-use sqlx::{mysql::MySqlRow, prelude::*, MySqlConnection};
+use std::collections::{BTreeSet, HashMap};
 
-use crate::core::{
+use super::common::{rev_yn, yn};
-    common::{
+use crate::server::sql::database_privilege_operations::{
-        create_user_group_matching_regex, get_current_unix_user, quote_identifier, rev_yn, yn,
+    DatabasePrivilegeRow, DATABASE_PRIVILEGE_FIELDS,
-    },
-    database_operations::validate_database_name,
 };
 
-/// This is the list of fields that are used to fetch the db + user + privileges
-/// from the `db` table in the database. If you need to add or remove privilege
-/// fields, this is a good place to start.
-pub const DATABASE_PRIVILEGE_FIELDS: [&str; 13] = [
-    "db",
-    "user",
-    "select_priv",
-    "insert_priv",
-    "update_priv",
-    "delete_priv",
-    "create_priv",
-    "drop_priv",
-    "alter_priv",
-    "index_priv",
-    "create_tmp_table_priv",
-    "lock_tables_priv",
-    "references_priv",
-];
-
 pub fn db_priv_field_human_readable_name(name: &str) -> String {
     match name {
         "db" => "Database".to_owned(),
@@ -67,162 +28,24 @@ pub fn db_priv_field_human_readable_name(name: &str) -> String {
     }
 }
 
-/// This struct represents the set of privileges for a single user on a single database.
+pub fn diff(row1: &DatabasePrivilegeRow, row2: &DatabasePrivilegeRow) -> DatabasePrivilegeRowDiff {
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
+    debug_assert!(row1.db == row2.db && row1.user == row2.user);
-pub struct DatabasePrivilegeRow {
-    pub db: String,
-    pub user: String,
-    pub select_priv: bool,
-    pub insert_priv: bool,
-    pub update_priv: bool,
-    pub delete_priv: bool,
-    pub create_priv: bool,
-    pub drop_priv: bool,
-    pub alter_priv: bool,
-    pub index_priv: bool,
-    pub create_tmp_table_priv: bool,
-    pub lock_tables_priv: bool,
-    pub references_priv: bool,
-}
-
-impl DatabasePrivilegeRow {
-    pub fn empty(db: &str, user: &str) -> Self {
-        Self {
-            db: db.to_owned(),
-            user: user.to_owned(),
-            select_priv: false,
-            insert_priv: false,
-            update_priv: false,
-            delete_priv: false,
-            create_priv: false,
-            drop_priv: false,
-            alter_priv: false,
-            index_priv: false,
-            create_tmp_table_priv: false,
-            lock_tables_priv: false,
-            references_priv: false,
-        }
-    }
-
-    pub fn get_privilege_by_name(&self, name: &str) -> bool {
-        match name {
-            "select_priv" => self.select_priv,
-            "insert_priv" => self.insert_priv,
-            "update_priv" => self.update_priv,
-            "delete_priv" => self.delete_priv,
-            "create_priv" => self.create_priv,
-            "drop_priv" => self.drop_priv,
-            "alter_priv" => self.alter_priv,
-            "index_priv" => self.index_priv,
-            "create_tmp_table_priv" => self.create_tmp_table_priv,
-            "lock_tables_priv" => self.lock_tables_priv,
-            "references_priv" => self.references_priv,
-            _ => false,
-        }
-    }
-
-    pub fn diff(&self, other: &DatabasePrivilegeRow) -> DatabasePrivilegeRowDiff {
-        debug_assert!(self.db == other.db && self.user == other.user);
 
     DatabasePrivilegeRowDiff {
-            db: self.db.clone(),
+        db: row1.db.clone(),
-            user: self.user.clone(),
+        user: row1.user.clone(),
         diff: DATABASE_PRIVILEGE_FIELDS
             .into_iter()
             .skip(2)
             .filter_map(|field| {
                 DatabasePrivilegeChange::new(
-                        self.get_privilege_by_name(field),
+                    row1.get_privilege_by_name(field),
-                        other.get_privilege_by_name(field),
+                    row2.get_privilege_by_name(field),
                     field,
                 )
             })
             .collect(),
     }
-    }
-}
-
-#[inline]
-fn get_mysql_row_priv_field(row: &MySqlRow, position: usize) -> Result<bool, sqlx::Error> {
-    let field = DATABASE_PRIVILEGE_FIELDS[position];
-    let value = row.try_get(position)?;
-    match rev_yn(value) {
-        Some(val) => Ok(val),
-        _ => {
-            log::warn!(r#"Invalid value for privilege "{}": '{}'"#, field, value);
-            Ok(false)
-        }
-    }
-}
-
-impl FromRow<'_, MySqlRow> for DatabasePrivilegeRow {
-    fn from_row(row: &MySqlRow) -> Result<Self, sqlx::Error> {
-        Ok(Self {
-            db: row.try_get("db")?,
-            user: row.try_get("user")?,
-            select_priv: get_mysql_row_priv_field(row, 2)?,
-            insert_priv: get_mysql_row_priv_field(row, 3)?,
-            update_priv: get_mysql_row_priv_field(row, 4)?,
-            delete_priv: get_mysql_row_priv_field(row, 5)?,
-            create_priv: get_mysql_row_priv_field(row, 6)?,
-            drop_priv: get_mysql_row_priv_field(row, 7)?,
-            alter_priv: get_mysql_row_priv_field(row, 8)?,
-            index_priv: get_mysql_row_priv_field(row, 9)?,
-            create_tmp_table_priv: get_mysql_row_priv_field(row, 10)?,
-            lock_tables_priv: get_mysql_row_priv_field(row, 11)?,
-            references_priv: get_mysql_row_priv_field(row, 12)?,
-        })
-    }
-}
-
-/// Get all users + privileges for a single database.
-pub async fn get_database_privileges(
-    database_name: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    let unix_user = get_current_unix_user()?;
-    validate_database_name(database_name, &unix_user)?;
-
-    let result = sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
-        "SELECT {} FROM `db` WHERE `db` = ?",
-        DATABASE_PRIVILEGE_FIELDS
-            .iter()
-            .map(|field| quote_identifier(field))
-            .join(","),
-    ))
-    .bind(database_name)
-    .fetch_all(connection)
-    .await
-    .context("Failed to show database")?;
-
-    Ok(result)
-}
-
-/// Get all database + user + privileges pairs that are owned by the current user.
-pub async fn get_all_database_privileges(
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    let unix_user = get_current_unix_user()?;
-
-    let result = sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
-        indoc! {r#"
-          SELECT {} FROM `db` WHERE `db` IN
-          (SELECT DISTINCT `SCHEMA_NAME` AS `database`
-            FROM `information_schema`.`SCHEMATA`
-            WHERE `SCHEMA_NAME` NOT IN ('information_schema', 'performance_schema', 'mysql', 'sys')
-              AND `SCHEMA_NAME` REGEXP ?)
-        "#},
-        DATABASE_PRIVILEGE_FIELDS
-            .iter()
-            .map(|field| format!("`{field}`"))
-            .join(","),
-    ))
-    .bind(create_user_group_matching_regex(&unix_user))
-    .fetch_all(connection)
-    .await
-    .context("Failed to show databases")?;
-
-    Ok(result)
 }
 
 /*************************/
@@ -578,7 +401,7 @@ pub fn parse_privilege_data_from_editor_content(
 /// instances of privilege sets for a single user on a single database.
 ///
 /// The `User` and `Database` are the same for both instances.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
 pub struct DatabasePrivilegeRowDiff {
     pub db: String,
     pub user: String,
@@ -586,7 +409,7 @@ pub struct DatabasePrivilegeRowDiff {
 }
 
 /// This enum represents a change for a single privilege.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
 pub enum DatabasePrivilegeChange {
     YesToNo(String),
     NoToYes(String),
@@ -603,13 +426,31 @@ impl DatabasePrivilegeChange {
 }
 
 /// This enum encapsulates whether a [`DatabasePrivilegeRow`] was intrduced, modified or deleted.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
 pub enum DatabasePrivilegesDiff {
     New(DatabasePrivilegeRow),
     Modified(DatabasePrivilegeRowDiff),
     Deleted(DatabasePrivilegeRow),
 }
 
+impl DatabasePrivilegesDiff {
+    pub fn get_database_name(&self) -> &str {
+        match self {
+            DatabasePrivilegesDiff::New(p) => &p.db,
+            DatabasePrivilegesDiff::Modified(p) => &p.db,
+            DatabasePrivilegesDiff::Deleted(p) => &p.db,
+        }
+    }
+
+    pub fn get_user_name(&self) -> &str {
+        match self {
+            DatabasePrivilegesDiff::New(p) => &p.user,
+            DatabasePrivilegesDiff::Modified(p) => &p.user,
+            DatabasePrivilegesDiff::Deleted(p) => &p.user,
+        }
+    }
+}
+
 /// This function calculates the differences between two sets of database privileges.
 /// It returns a set of [`DatabasePrivilegesDiff`] that can be used to display or
 /// apply a set of privilege modifications to the database.
@@ -633,7 +474,7 @@ pub fn diff_privileges(
 
     for p in to {
         if let Some(old_p) = from_lookup_table.get(&(p.db.clone(), p.user.clone())) {
-            let diff = old_p.diff(p);
+            let diff = diff(old_p, p);
             if !diff.diff.is_empty() {
                 result.insert(DatabasePrivilegesDiff::Modified(diff));
             }
@@ -651,72 +492,6 @@ pub fn diff_privileges(
     result
 }
 
-/// Uses the result of [`diff_privileges`] to modify privileges in the database.
-pub async fn apply_privilege_diffs(
-    diffs: BTreeSet<DatabasePrivilegesDiff>,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    for diff in diffs {
-        match diff {
-            DatabasePrivilegesDiff::New(p) => {
-                let tables = DATABASE_PRIVILEGE_FIELDS
-                    .iter()
-                    .map(|field| format!("`{field}`"))
-                    .join(",");
-
-                let question_marks = std::iter::repeat("?")
-                    .take(DATABASE_PRIVILEGE_FIELDS.len())
-                    .join(",");
-
-                sqlx::query(
-                    format!("INSERT INTO `db` ({}) VALUES ({})", tables, question_marks).as_str(),
-                )
-                .bind(p.db)
-                .bind(p.user)
-                .bind(yn(p.select_priv))
-                .bind(yn(p.insert_priv))
-                .bind(yn(p.update_priv))
-                .bind(yn(p.delete_priv))
-                .bind(yn(p.create_priv))
-                .bind(yn(p.drop_priv))
-                .bind(yn(p.alter_priv))
-                .bind(yn(p.index_priv))
-                .bind(yn(p.create_tmp_table_priv))
-                .bind(yn(p.lock_tables_priv))
-                .bind(yn(p.references_priv))
-                .execute(&mut *connection)
-                .await?;
-            }
-            DatabasePrivilegesDiff::Modified(p) => {
-                let tables = p
-                    .diff
-                    .iter()
-                    .map(|diff| match diff {
-                        DatabasePrivilegeChange::YesToNo(name) => format!("`{}` = 'N'", name),
-                        DatabasePrivilegeChange::NoToYes(name) => format!("`{}` = 'Y'", name),
-                    })
-                    .join(",");
-
-                sqlx::query(
-                    format!("UPDATE `db` SET {} WHERE `db` = ? AND `user` = ?", tables).as_str(),
-                )
-                .bind(p.db)
-                .bind(p.user)
-                .execute(&mut *connection)
-                .await?;
-            }
-            DatabasePrivilegesDiff::Deleted(p) => {
-                sqlx::query("DELETE FROM `db` WHERE `db` = ? AND `user` = ?")
-                    .bind(p.db)
-                    .bind(p.user)
-                    .execute(&mut *connection)
-                    .await?;
-            }
-        }
-    }
-    Ok(())
-}
-
 fn display_privilege_cell(diff: &DatabasePrivilegeRowDiff) -> String {
     diff.diff
         .iter()
@@ -742,9 +517,10 @@ pub fn display_privilege_diffs(diffs: &BTreeSet<DatabasePrivilegesDiff>) -> Stri
                     p.db,
                     p.user,
                     "(New user)\n".to_string()
-                        + &display_privilege_cell(
+                        + &display_privilege_cell(&diff(
-                            &DatabasePrivilegeRow::empty(&p.db, &p.user).diff(p)
+                            &DatabasePrivilegeRow::empty(&p.db, &p.user),
-                        )
+                            p
+                        ))
                 ]);
             }
             DatabasePrivilegesDiff::Modified(p) => {
@@ -755,9 +531,10 @@ pub fn display_privilege_diffs(diffs: &BTreeSet<DatabasePrivilegesDiff>) -> Stri
                     p.db,
                     p.user,
                     "(All privileges removed)\n".to_string()
-                        + &display_privilege_cell(
+                        + &display_privilege_cell(&diff(
-                            &p.diff(&DatabasePrivilegeRow::empty(&p.db, &p.user))
+                            p,
-                        )
+                            &DatabasePrivilegeRow::empty(&p.db, &p.user)
+                        ))
                 ]);
             }
         }

src/core/protocol.rs

@@ -0,0 +1,89 @@
+use serde::{Deserialize, Serialize};
+use tokio::net::UnixStream;
+use tokio_serde::{formats::Bincode, Framed as SerdeFramed};
+use tokio_util::codec::{Framed, LengthDelimitedCodec};
+
+use crate::{
+    core::database_privileges::DatabasePrivilegesDiff,
+    server::sql::{
+        database_operations::{CreateDatabasesOutput, DropDatabasesOutput, ListAllDatabasesOutput},
+        database_privilege_operations::{
+            GetAllDatabasesPrivilegeData, GetDatabasesPrivilegeData, ModifyDatabasePrivilegesOutput,
+        },
+        user_operations::{
+            CreateUsersOutput, DropUsersOutput, ListAllUsersOutput, ListUsersOutput,
+            LockUsersOutput, SetPasswordOutput, UnlockUsersOutput,
+        },
+    },
+};
+
+pub type ServerToClientMessageStream = SerdeFramed<
+    Framed<UnixStream, LengthDelimitedCodec>,
+    Request,
+    Response,
+    Bincode<Request, Response>,
+>;
+
+pub type ClientToServerMessageStream = SerdeFramed<
+    Framed<UnixStream, LengthDelimitedCodec>,
+    Response,
+    Request,
+    Bincode<Response, Request>,
+>;
+
+pub fn create_server_to_client_message_stream(socket: UnixStream) -> ServerToClientMessageStream {
+    let length_delimited = Framed::new(socket, LengthDelimitedCodec::new());
+    tokio_serde::Framed::new(length_delimited, Bincode::default())
+}
+
+pub fn create_client_to_server_message_stream(socket: UnixStream) -> ClientToServerMessageStream {
+    let length_delimited = Framed::new(socket, LengthDelimitedCodec::new());
+    tokio_serde::Framed::new(length_delimited, Bincode::default())
+}
+
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum Request {
+    CreateDatabases(Vec<String>),
+    DropDatabases(Vec<String>),
+    ListDatabases,
+    ListPrivileges(Option<Vec<String>>),
+    ModifyPrivileges(Vec<DatabasePrivilegesDiff>),
+
+    CreateUsers(Vec<String>),
+    DropUsers(Vec<String>),
+    PasswdUser(String, String),
+    ListUsers(Option<Vec<String>>),
+    LockUsers(Vec<String>),
+    UnlockUsers(Vec<String>),
+
+    // Commit,
+    Exit,
+}
+
+// TODO: include a generic "message" that will display a message to the user?
+
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum Response {
+    // Specific data for specific commands
+    CreateDatabases(CreateDatabasesOutput),
+    DropDatabases(DropDatabasesOutput),
+    ListAllDatabases(ListAllDatabasesOutput),
+    ListPrivileges(GetDatabasesPrivilegeData),
+    ListAllPrivileges(GetAllDatabasesPrivilegeData),
+    ModifyPrivileges(ModifyDatabasePrivilegesOutput),
+
+    CreateUsers(CreateUsersOutput),
+    DropUsers(DropUsersOutput),
+    PasswdUser(SetPasswordOutput),
+    ListUsers(ListUsersOutput),
+    ListAllUsers(ListAllUsersOutput),
+    LockUsers(LockUsersOutput),
+    UnlockUsers(UnlockUsersOutput),
+
+    // Generic responses
+    OperationAborted,
+    Error(String),
+    Exit,
+}

src/core/user_operations.rs

@@ -1,249 +0,0 @@
-use anyhow::Context;
-use nix::unistd::User;
-use serde::{Deserialize, Serialize};
-use sqlx::{prelude::*, MySqlConnection};
-
-use crate::core::common::{
-    create_user_group_matching_regex, get_current_unix_user, quote_literal, validate_name_or_error,
-    validate_ownership_or_error, DbOrUser,
-};
-
-pub async fn user_exists(db_user: &str, connection: &mut MySqlConnection) -> anyhow::Result<bool> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    let user_exists = sqlx::query(
-        r#"
-          SELECT EXISTS(
-            SELECT 1
-            FROM `mysql`.`user`
-            WHERE `User` = ?
-          )
-        "#,
-    )
-    .bind(db_user)
-    .fetch_one(connection)
-    .await?
-    .get::<bool, _>(0);
-
-    Ok(user_exists)
-}
-
-pub async fn create_database_user(
-    db_user: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    if user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' already exists", db_user);
-    }
-
-    // NOTE: see the note about SQL injections in `validate_ownership_of_user_name`
-    sqlx::query(format!("CREATE USER {}@'%'", quote_literal(db_user),).as_str())
-        .execute(connection)
-        .await?;
-
-    Ok(())
-}
-
-pub async fn delete_database_user(
-    db_user: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    if !user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' does not exist", db_user);
-    }
-
-    // NOTE: see the note about SQL injections in `validate_ownership_of_user_name`
-    sqlx::query(format!("DROP USER {}@'%'", quote_literal(db_user),).as_str())
-        .execute(connection)
-        .await?;
-
-    Ok(())
-}
-
-pub async fn set_password_for_database_user(
-    db_user: &str,
-    password: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let unix_user = crate::core::common::get_current_unix_user()?;
-    validate_user_name(db_user, &unix_user)?;
-
-    if !user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' does not exist", db_user);
-    }
-
-    // NOTE: see the note about SQL injections in `validate_ownership_of_user_name`
-    sqlx::query(
-        format!(
-            "ALTER USER {}@'%' IDENTIFIED BY {}",
-            quote_literal(db_user),
-            quote_literal(password).as_str()
-        )
-        .as_str(),
-    )
-    .execute(connection)
-    .await?;
-
-    Ok(())
-}
-
-async fn user_is_locked(db_user: &str, connection: &mut MySqlConnection) -> anyhow::Result<bool> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    if !user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' does not exist", db_user);
-    }
-
-    let is_locked = sqlx::query(
-        r#"
-          SELECT JSON_EXTRACT(`mysql`.`global_priv`.`priv`, "$.account_locked") = 'true'
-          FROM `mysql`.`global_priv`
-          WHERE `User` = ?
-          AND `Host` = '%'
-        "#,
-    )
-    .bind(db_user)
-    .fetch_one(connection)
-    .await?
-    .get::<bool, _>(0);
-
-    Ok(is_locked)
-}
-
-pub async fn lock_database_user(
-    db_user: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    if !user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' does not exist", db_user);
-    }
-
-    if user_is_locked(db_user, connection).await? {
-        anyhow::bail!("User '{}' is already locked", db_user);
-    }
-
-    // NOTE: see the note about SQL injections in `validate_ownership_of_user_name`
-    sqlx::query(format!("ALTER USER {}@'%' ACCOUNT LOCK", quote_literal(db_user),).as_str())
-        .execute(connection)
-        .await?;
-
-    Ok(())
-}
-
-pub async fn unlock_database_user(
-    db_user: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let unix_user = get_current_unix_user()?;
-
-    validate_user_name(db_user, &unix_user)?;
-
-    if !user_exists(db_user, connection).await? {
-        anyhow::bail!("User '{}' does not exist", db_user);
-    }
-
-    if !user_is_locked(db_user, connection).await? {
-        anyhow::bail!("User '{}' is already unlocked", db_user);
-    }
-
-    // NOTE: see the note about SQL injections in `validate_ownership_of_user_name`
-    sqlx::query(format!("ALTER USER {}@'%' ACCOUNT UNLOCK", quote_literal(db_user),).as_str())
-        .execute(connection)
-        .await?;
-
-    Ok(())
-}
-
-/// This struct contains information about a database user.
-/// This can be extended if we need more information in the future.
-#[derive(Debug, Clone, FromRow, Serialize, Deserialize)]
-pub struct DatabaseUser {
-    #[sqlx(rename = "User")]
-    pub user: String,
-
-    #[allow(dead_code)]
-    #[serde(skip)]
-    #[sqlx(rename = "Host")]
-    pub host: String,
-
-    #[sqlx(rename = "has_password")]
-    pub has_password: bool,
-
-    #[sqlx(rename = "is_locked")]
-    pub is_locked: bool,
-}
-
-const DB_USER_SELECT_STATEMENT: &str = r#"
-SELECT
-  `mysql`.`user`.`User`,
-  `mysql`.`user`.`Host`,
-  `mysql`.`user`.`Password` != '' OR `mysql`.`user`.`authentication_string` != '' AS `has_password`,
-  COALESCE(
-    JSON_EXTRACT(`mysql`.`global_priv`.`priv`, "$.account_locked"),
-    'false'
-  ) != 'false' AS `is_locked`
-FROM `mysql`.`user`
-JOIN `mysql`.`global_priv` ON
-  `mysql`.`user`.`User` = `mysql`.`global_priv`.`User`
-  AND `mysql`.`user`.`Host` = `mysql`.`global_priv`.`Host`
-"#;
-
-/// This function fetches all database users that have a prefix matching the
-/// unix username and group names of the given unix user.
-pub async fn get_all_database_users_for_unix_user(
-    unix_user: &User,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<DatabaseUser>> {
-    let users = sqlx::query_as::<_, DatabaseUser>(
-        &(DB_USER_SELECT_STATEMENT.to_string() + "WHERE `mysql`.`user`.`User` REGEXP ?"),
-    )
-    .bind(create_user_group_matching_regex(unix_user))
-    .fetch_all(connection)
-    .await?;
-
-    Ok(users)
-}
-
-/// This function fetches a database user if it exists.
-pub async fn get_database_user_for_user(
-    username: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Option<DatabaseUser>> {
-    let user = sqlx::query_as::<_, DatabaseUser>(
-        &(DB_USER_SELECT_STATEMENT.to_string() + "WHERE `mysql`.`user`.`User` = ?"),
-    )
-    .bind(username)
-    .fetch_optional(connection)
-    .await?;
-
-    Ok(user)
-}
-
-/// NOTE: It is very critical that this function validates the database name
-///       properly. MySQL does not seem to allow for prepared statements, binding
-///       the database name as a parameter to the query. This means that we have
-///       to validate the database name ourselves to prevent SQL injection.
-pub fn validate_user_name(name: &str, user: &User) -> anyhow::Result<()> {
-    validate_name_or_error(name, DbOrUser::User)
-        .context(format!("Invalid username: '{}'", name))?;
-    validate_ownership_or_error(name, user, DbOrUser::User)
-        .context(format!("Invalid username: '{}'", name))?;
-
-    Ok(())
-}

src/main.rs

@@ -1,42 +1,73 @@
 #[macro_use]
 extern crate prettytable;
 
-use core::common::CommandStatus;
-#[cfg(feature = "mysql-admutils-compatibility")]
-use std::path::PathBuf;
-
-#[cfg(feature = "mysql-admutils-compatibility")]
-use crate::cli::mysql_admutils_compatibility::{mysql_dbadm, mysql_useradm};
-
 use clap::Parser;
 
-mod authenticated_unix_socket;
+use std::path::PathBuf;
+
+use std::os::unix::net::UnixStream as StdUnixStream;
+use tokio::net::UnixStream as TokioUnixStream;
+
+use crate::{
+    core::{
+        bootstrap::{bootstrap_server_connection_and_drop_privileges, drop_privs},
+        protocol::create_client_to_server_message_stream,
+    },
+    server::command::ServerArgs,
+};
+
+// use core::common::CommandStatus;
+// #[cfg(feature = "mysql-admutils-compatibility")]
+// use std::path::PathBuf;
+
+// #[cfg(feature = "mysql-admutils-compatibility")]
+// use crate::cli::mysql_admutils_compatibility::{mysql_dbadm, mysql_useradm};
+
+mod server;
+
 mod cli;
 mod core;
 
 #[cfg(feature = "tui")]
 mod tui;
 
-#[derive(Parser)]
+#[derive(Parser, Debug)]
 struct Args {
     #[command(subcommand)]
     command: Command,
 
-    #[command(flatten)]
+    /// Path to the socket of the server, if it already exists.
-    config_overrides: core::config::GlobalConfigArgs,
+    #[arg(
+        short,
+        long,
+        value_name = "PATH",
+        global = true,
+        // hide_short_help = true,
+    )]
+    server_socket_path: Option<PathBuf>,
+
+    /// Config file to use for the server.
+    #[arg(
+        short,
+        long,
+        value_name = "PATH",
+        global = true,
+        // hide_short_help = true,
+    )]
+    config: Option<PathBuf>,
 
     #[cfg(feature = "tui")]
     #[arg(short, long, alias = "tui", global = true)]
     interactive: bool,
 }
 
-/// Database administration tool for non-admin users to manage their own MySQL databases and users.
+// Database administration tool for non-admin users to manage their own MySQL databases and users.
-///
+//
-/// This tool allows you to manage users and databases in MySQL.
+// This tool allows you to manage users and databases in MySQL.
-///
+//
-/// You are only allowed to manage databases and users that are prefixed with
+// You are only allowed to manage databases and users that are prefixed with
-/// either your username, or a group that you are a member of.
+// either your username, or a group that you are a member of.
-#[derive(Parser)]
+#[derive(Parser, Debug, Clone)]
 #[command(version, about, disable_help_subcommand = true)]
 enum Command {
     #[command(flatten)]
@@ -44,57 +75,79 @@ enum Command {
 
     #[command(flatten)]
     User(cli::user_command::UserCommand),
+
+    #[command(hide = true)]
+    Server(server::command::ServerArgs),
 }
 
-#[tokio::main(flavor = "current_thread")]
+// #[tokio::main(flavor = "current_thread")]
-async fn main() -> anyhow::Result<()> {
+fn main() -> anyhow::Result<()> {
     env_logger::init();
 
-    #[cfg(feature = "mysql-admutils-compatibility")]
+    // #[cfg(feature = "mysql-admutils-compatibility")]
-    {
+    // {
-        let argv0 = std::env::args().next().and_then(|s| {
+    //     let argv0 = std::env::args().next().and_then(|s| {
-            PathBuf::from(s)
+    //         PathBuf::from(s)
-                .file_name()
+    //             .file_name()
-                .map(|s| s.to_string_lossy().to_string())
+    //             .map(|s| s.to_string_lossy().to_string())
-        });
+    //     });
 
-        match argv0.as_deref() {
+    //     match argv0.as_deref() {
-            Some("mysql-dbadm") => return mysql_dbadm::main().await,
+    //         Some("mysql-dbadm") => return mysql_dbadm::main().await,
-            Some("mysql-useradm") => return mysql_useradm::main().await,
+    //         Some("mysql-useradm") => return mysql_useradm::main().await,
-            _ => { /* fall through */ }
+    //         _ => { /* fall through */ }
-        }
+    //     }
-    }
+    // }
 
     let args: Args = Args::parse();
-    let config = core::config::get_config(args.config_overrides)?;
+    dbg!(&args);
-    let connection = core::config::create_mysql_connection_from_config(config.mysql).await?;
+    match args.command {
+        Command::Server(ref command) => {
+            drop_privs()?;
+            tokio_start_server(args.server_socket_path, args.config, command.clone())?;
+            return Ok(());
+        }
+        _ => { /* fall through */ }
+    }
 
-    let result = match args.command {
+    let server_connection =
-        Command::Db(command) => cli::database_command::handle_command(command, connection).await,
+        bootstrap_server_connection_and_drop_privileges(args.server_socket_path, args.config)?;
-        Command::User(user_args) => cli::user_command::handle_command(user_args, connection).await,
+
-    };
+    tokio_run_command(args.command, server_connection)?;
 
-    match result {
-        Ok(CommandStatus::SuccessfullyModified) => {
-            println!("Modifications committed successfully");
     Ok(())
-        }
+}
-        Ok(CommandStatus::PartiallySuccessfullyModified) => {
+
-            println!("Some modifications committed successfully");
+fn tokio_start_server(
-            Ok(())
+    server_socket_path: Option<PathBuf>,
-        }
+    config_path: Option<PathBuf>,
-        Ok(CommandStatus::NoModificationsNeeded) => {
+    args: ServerArgs,
-            println!("No modifications made");
+) -> anyhow::Result<()> {
-            Ok(())
+    tokio::runtime::Builder::new_current_thread()
-        }
+        .enable_all()
-        Ok(CommandStatus::NoModificationsIntended) => {
+        .build()
-            /* Don't report anything */
+        .unwrap()
-            Ok(())
+        .block_on(async {
-        }
+            server::command::handle_command(server_socket_path, config_path, args).await
-        Ok(CommandStatus::Cancelled) => {
+        })
-            println!("Command cancelled successfully");
+}
-            Ok(())
+
-        }
+fn tokio_run_command(command: Command, server_connection: StdUnixStream) -> anyhow::Result<()> {
-        Err(e) => Err(e),
+    tokio::runtime::Builder::new_current_thread()
-    }
+        .enable_all()
+        .build()
+        .unwrap()
+        .block_on(async {
+            let tokio_socket = TokioUnixStream::from_std(server_connection)?;
+            let message_stream = create_client_to_server_message_stream(tokio_socket);
+            match command {
+                Command::User(user_args) => {
+                    cli::user_command::handle_command(user_args, message_stream).await
+                }
+                Command::Db(db_args) => {
+                    cli::database_command::handle_command(db_args, message_stream).await
+                }
+                Command::Server(_) => unreachable!(),
+            }
+        })
 }

src/server.rs

@@ -1,6 +1,6 @@
+pub mod command;
 mod common;
-mod database_operations;
+pub mod config;
-mod entrypoint;
 mod input_sanitization;
-mod protocol;
+pub mod server_loop;
-mod user_operations;
+pub mod sql;

src/server/command.rs

@@ -0,0 +1,77 @@
+use std::os::fd::FromRawFd;
+use std::path::PathBuf;
+
+use anyhow::Context;
+use clap::Parser;
+
+use std::os::unix::net::UnixStream as StdUnixStream;
+use tokio::net::UnixStream as TokioUnixStream;
+
+use crate::core::bootstrap::authenticated_unix_socket;
+use crate::core::common::UnixUser;
+use crate::server::config::read_config_from_path_with_arg_overrides;
+use crate::server::server_loop::listen_for_incoming_connections;
+use crate::server::{
+    config::{ServerConfig, ServerConfigArgs},
+    server_loop::handle_requests_for_single_session,
+};
+
+#[derive(Parser, Debug, Clone)]
+pub struct ServerArgs {
+    #[command(subcommand)]
+    subcmd: ServerCommand,
+
+    #[command(flatten)]
+    config_overrides: ServerConfigArgs,
+}
+
+#[derive(Parser, Debug, Clone)]
+pub enum ServerCommand {
+    #[command()]
+    Listen,
+
+    #[command()]
+    SocketActivate,
+}
+
+pub async fn handle_command(
+    socket_path: Option<PathBuf>,
+    config_path: Option<PathBuf>,
+    args: ServerArgs,
+) -> anyhow::Result<()> {
+    let config = read_config_from_path_with_arg_overrides(config_path, args.config_overrides)?;
+
+    // if let Err(e) = &result {
+    //     eprintln!("{}", e);
+    // }
+
+    match args.subcmd {
+        ServerCommand::Listen => listen_for_incoming_connections(socket_path, config).await,
+        ServerCommand::SocketActivate => socket_activate(config).await,
+    }
+}
+
+async fn socket_activate(config: ServerConfig) -> anyhow::Result<()> {
+    // TODO: allow getting socket path from other socket activation sources
+    let mut conn = get_socket_from_systemd().await?;
+    let uid = authenticated_unix_socket::server_authenticate(&mut conn).await?;
+    let unix_user = UnixUser::from_uid(uid.into())?;
+    handle_requests_for_single_session(conn, &unix_user, &config).await?;
+
+    Ok(())
+}
+
+async fn get_socket_from_systemd() -> anyhow::Result<TokioUnixStream> {
+    let fd = std::env::var("LISTEN_FDS")
+        .context("LISTEN_FDS not set, not running under systemd?")?
+        .parse::<i32>()
+        .context("Failed to parse LISTEN_FDS")?;
+
+    if fd != 1 {
+        return Err(anyhow::anyhow!("Unexpected LISTEN_FDS value: {}", fd));
+    }
+
+    let std_unix_stream = unsafe { StdUnixStream::from_raw_fd(fd) };
+    let socket = TokioUnixStream::from_std(std_unix_stream)?;
+    Ok(socket)
+}

src/server/common.rs

@@ -1,94 +1,4 @@
-use anyhow::Context;
+use crate::core::common::UnixUser;
-use nix::unistd::{Group as LibcGroup, User as LibcUser};
-use sqlx::{Connection, MySqlConnection};
-
-#[cfg(not(target_os = "macos"))]
-use std::ffi::CString;
-
-/// Report the result status of a command.
-/// This is used to display a status message to the user.
-pub enum CommandStatus {
-    /// The command was successful,
-    /// and made modification to the database.
-    SuccessfullyModified,
-
-    /// The command was mostly successful,
-    /// and modifications have been made to the database.
-    /// However, some of the requested modifications failed.
-    PartiallySuccessfullyModified,
-
-    /// The command was successful,
-    /// but no modifications were needed.
-    NoModificationsNeeded,
-
-    /// The command was successful,
-    /// and made no modification to the database.
-    NoModificationsIntended,
-
-    /// The command was cancelled, either through a dialog or a signal.
-    /// No modifications have been made to the database.
-    Cancelled,
-}
-
-// pub fn get_current_unix_user() -> anyhow::Result<User> {
-//     User::from_uid(getuid())
-//         .context("Failed to look up your UNIX username")
-//         .and_then(|u| u.ok_or(anyhow::anyhow!("Failed to look up your UNIX username")))
-// }
-
-pub struct UnixUser {
-    pub username: String,
-    pub uid: u32,
-    pub gid: u32,
-    pub groups: Vec<String>,
-}
-
-#[cfg(target_os = "macos")]
-fn get_unix_groups(_user: &User) -> anyhow::Result<Vec<Group>> {
-    // Return an empty list on macOS since there is no `getgrouplist` function
-    Ok(vec![])
-}
-
-#[cfg(not(target_os = "macos"))]
-fn get_unix_groups(user: &LibcUser) -> anyhow::Result<Vec<LibcGroup>> {
-    let user_cstr =
-        CString::new(user.name.as_bytes()).context("Failed to convert username to CStr")?;
-    let groups = nix::unistd::getgrouplist(&user_cstr, user.gid)?
-        .iter()
-        .filter_map(|gid| match LibcGroup::from_gid(*gid) {
-            Ok(Some(group)) => Some(group),
-            Ok(None) => None,
-            Err(e) => {
-                log::warn!(
-                    "Failed to look up group with GID {}: {}\nIgnoring...",
-                    gid,
-                    e
-                );
-                None
-            }
-        })
-        .collect::<Vec<LibcGroup>>();
-
-    Ok(groups)
-}
-
-impl UnixUser {
-    pub fn from_uid(uid: u32) -> anyhow::Result<Self> {
-        let libc_uid = nix::unistd::Uid::from_raw(uid);
-        let libc_user = LibcUser::from_uid(libc_uid)
-            .context("Failed to look up your UNIX username")?
-            .ok_or(anyhow::anyhow!("Failed to look up your UNIX username"))?;
-
-        let groups = get_unix_groups(&libc_user)?;
-
-        Ok(UnixUser {
-            username: libc_user.name,
-            uid,
-            gid: libc_user.gid.into(),
-            groups: groups.iter().map(|g| g.name.clone()).collect(),
-        })
-    }
-}
 
 /// This function creates a regex that matches items (users, databases)
 /// that belong to the user or any of the user's groups.
@@ -99,15 +9,3 @@ pub fn create_user_group_matching_regex(user: &UnixUser) -> String {
         format!("({}|{})(_.+)?", user.username, user.groups.join("|"))
     }
 }
-
-/// Gracefully close a MySQL connection.
-pub async fn close_database_connection(connection: MySqlConnection) {
-    if let Err(e) = connection
-        .close()
-        .await
-        .context("Failed to close connection properly")
-    {
-        eprintln!("{}", e);
-        eprintln!("Ignoring...");
-    }
-}

src/server/config.rs

@@ -5,11 +5,16 @@ use clap::Parser;
 use serde::{Deserialize, Serialize};
 use sqlx::{mysql::MySqlConnectOptions, ConnectOptions, MySqlConnection};
 
+use crate::core::common::DEFAULT_CONFIG_PATH;
+
+pub const DEFAULT_PORT: u16 = 3306;
+pub const DEFAULT_TIMEOUT: u64 = 2;
+
 // NOTE: this might look empty now, and the extra wrapping for the mysql
 //       config seems unnecessary, but it will be useful later when we
 //       add more configuration options.
 #[derive(Debug, Clone, Deserialize, Serialize)]
-pub struct Config {
+pub struct ServerConfig {
     pub mysql: MysqlConfig,
 }
 
@@ -23,58 +28,36 @@ pub struct MysqlConfig {
     pub timeout: Option<u64>,
 }
 
-const DEFAULT_PORT: u16 = 3306;
+#[derive(Parser, Debug, Clone)]
-const DEFAULT_TIMEOUT: u64 = 2;
+pub struct ServerConfigArgs {
-
-#[derive(Parser)]
-pub struct GlobalConfigArgs {
-    /// Path to the configuration file.
-    #[arg(
-        short,
-        long,
-        value_name = "PATH",
-        global = true,
-        hide_short_help = true,
-        default_value = "/etc/mysqladm/config.toml"
-    )]
-    config_file: String,
-
     /// Hostname of the MySQL server.
-    #[arg(long, value_name = "HOST", global = true, hide_short_help = true)]
+    #[arg(long, value_name = "HOST", global = true)]
     mysql_host: Option<String>,
 
     /// Port of the MySQL server.
-    #[arg(long, value_name = "PORT", global = true, hide_short_help = true)]
+    #[arg(long, value_name = "PORT", global = true)]
     mysql_port: Option<u16>,
 
     /// Username to use for the MySQL connection.
-    #[arg(long, value_name = "USER", global = true, hide_short_help = true)]
+    #[arg(long, value_name = "USER", global = true)]
     mysql_user: Option<String>,
 
     /// Path to a file containing the MySQL password.
-    #[arg(long, value_name = "PATH", global = true, hide_short_help = true)]
+    #[arg(long, value_name = "PATH", global = true)]
     mysql_password_file: Option<String>,
 
     /// Seconds to wait for the MySQL connection to be established.
-    #[arg(long, value_name = "SECONDS", global = true, hide_short_help = true)]
+    #[arg(long, value_name = "SECONDS", global = true)]
     mysql_connect_timeout: Option<u64>,
 }
 
 /// Use the arguments and whichever configuration file which might or might not
 /// be found and default values to determine the configuration for the program.
-pub fn get_config(args: GlobalConfigArgs) -> anyhow::Result<Config> {
+pub fn read_config_from_path_with_arg_overrides(
-    let config_path = PathBuf::from(args.config_file);
+    config_path: Option<PathBuf>,
-
+    args: ServerConfigArgs,
-    let config: Config = fs::read_to_string(&config_path)
+) -> anyhow::Result<ServerConfig> {
-        .context(format!(
+    let config = read_config_form_path(config_path)?;
-            "Failed to read config file from {:?}",
-            &config_path
-        ))
-        .and_then(|c| toml::from_str(&c).context("Failed to parse config file"))
-        .context(format!(
-            "Failed to parse config file from {:?}",
-            &config_path
-        ))?;
 
     let mysql = &config.mysql;
 
@@ -86,22 +69,35 @@ pub fn get_config(args: GlobalConfigArgs) -> anyhow::Result<Config> {
         mysql.password.to_owned()
     };
 
-    let mysql_config = MysqlConfig {
+    Ok(ServerConfig {
+        mysql: MysqlConfig {
             host: args.mysql_host.unwrap_or(mysql.host.to_owned()),
             port: args.mysql_port.or(mysql.port),
             username: args.mysql_user.unwrap_or(mysql.username.to_owned()),
             password,
             timeout: args.mysql_connect_timeout.or(mysql.timeout),
-    };
+        },
-
-    Ok(Config {
-        mysql: mysql_config,
     })
 }
 
+pub fn read_config_form_path(config_path: Option<PathBuf>) -> anyhow::Result<ServerConfig> {
+    let config_path = config_path.unwrap_or_else(|| PathBuf::from(DEFAULT_CONFIG_PATH));
+
+    fs::read_to_string(&config_path)
+        .context(format!(
+            "Failed to read config file from {:?}",
+            &config_path
+        ))
+        .and_then(|c| toml::from_str(&c).context("Failed to parse config file"))
+        .context(format!(
+            "Failed to parse config file from {:?}",
+            &config_path
+        ))
+}
+
 /// Use the provided configuration to establish a connection to a MySQL server.
 pub async fn create_mysql_connection_from_config(
-    config: MysqlConfig,
+    config: &MysqlConfig,
 ) -> anyhow::Result<MySqlConnection> {
     match tokio::time::timeout(
         Duration::from_secs(config.timeout.unwrap_or(DEFAULT_TIMEOUT)),

src/server/database_privilege_operations.rs

@@ -1,888 +0,0 @@
-//! Database privilege operations
-//!
-//! This module contains functions for querying, modifying,
-//! displaying and comparing database privileges.
-//!
-//! A lot of the complexity comes from two core components:
-//!
-//! - The privilege editor that needs to be able to print
-//!   an editable table of privileges and reparse the content
-//!   after the user has made manual changes.
-//!
-//! - The comparison functionality that tells the user what
-//!   changes will be made when applying a set of changes
-//!   to the list of database privileges.
-
-use std::collections::{BTreeSet, HashMap};
-
-use anyhow::{anyhow, Context};
-use indoc::indoc;
-use itertools::Itertools;
-use prettytable::Table;
-use serde::{Deserialize, Serialize};
-use sqlx::{mysql::MySqlRow, prelude::*, MySqlConnection};
-
-use crate::core::{
-    common::{
-        create_user_group_matching_regex, get_current_unix_user, quote_identifier, rev_yn, yn,
-    },
-    database_operations::validate_database_name,
-};
-
-/// This is the list of fields that are used to fetch the db + user + privileges
-/// from the `db` table in the database. If you need to add or remove privilege
-/// fields, this is a good place to start.
-pub const DATABASE_PRIVILEGE_FIELDS: [&str; 13] = [
-    "db",
-    "user",
-    "select_priv",
-    "insert_priv",
-    "update_priv",
-    "delete_priv",
-    "create_priv",
-    "drop_priv",
-    "alter_priv",
-    "index_priv",
-    "create_tmp_table_priv",
-    "lock_tables_priv",
-    "references_priv",
-];
-
-pub fn db_priv_field_human_readable_name(name: &str) -> String {
-    match name {
-        "db" => "Database".to_owned(),
-        "user" => "User".to_owned(),
-        "select_priv" => "Select".to_owned(),
-        "insert_priv" => "Insert".to_owned(),
-        "update_priv" => "Update".to_owned(),
-        "delete_priv" => "Delete".to_owned(),
-        "create_priv" => "Create".to_owned(),
-        "drop_priv" => "Drop".to_owned(),
-        "alter_priv" => "Alter".to_owned(),
-        "index_priv" => "Index".to_owned(),
-        "create_tmp_table_priv" => "Temp".to_owned(),
-        "lock_tables_priv" => "Lock".to_owned(),
-        "references_priv" => "References".to_owned(),
-        _ => format!("Unknown({})", name),
-    }
-}
-
-// NOTE: ord is needed for BTreeSet to accept the type, but it
-//       doesn't have any natural implementation semantics.
-
-/// This struct represents the set of privileges for a single user on a single database.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
-pub struct DatabasePrivilegeRow {
-    pub db: String,
-    pub user: String,
-    pub select_priv: bool,
-    pub insert_priv: bool,
-    pub update_priv: bool,
-    pub delete_priv: bool,
-    pub create_priv: bool,
-    pub drop_priv: bool,
-    pub alter_priv: bool,
-    pub index_priv: bool,
-    pub create_tmp_table_priv: bool,
-    pub lock_tables_priv: bool,
-    pub references_priv: bool,
-}
-
-impl DatabasePrivilegeRow {
-    pub fn empty(db: &str, user: &str) -> Self {
-        Self {
-            db: db.to_owned(),
-            user: user.to_owned(),
-            select_priv: false,
-            insert_priv: false,
-            update_priv: false,
-            delete_priv: false,
-            create_priv: false,
-            drop_priv: false,
-            alter_priv: false,
-            index_priv: false,
-            create_tmp_table_priv: false,
-            lock_tables_priv: false,
-            references_priv: false,
-        }
-    }
-
-    pub fn get_privilege_by_name(&self, name: &str) -> bool {
-        match name {
-            "select_priv" => self.select_priv,
-            "insert_priv" => self.insert_priv,
-            "update_priv" => self.update_priv,
-            "delete_priv" => self.delete_priv,
-            "create_priv" => self.create_priv,
-            "drop_priv" => self.drop_priv,
-            "alter_priv" => self.alter_priv,
-            "index_priv" => self.index_priv,
-            "create_tmp_table_priv" => self.create_tmp_table_priv,
-            "lock_tables_priv" => self.lock_tables_priv,
-            "references_priv" => self.references_priv,
-            _ => false,
-        }
-    }
-
-    pub fn diff(&self, other: &DatabasePrivilegeRow) -> DatabasePrivilegeRowDiff {
-        debug_assert!(self.db == other.db && self.user == other.user);
-
-        DatabasePrivilegeRowDiff {
-            db: self.db.clone(),
-            user: self.user.clone(),
-            diff: DATABASE_PRIVILEGE_FIELDS
-                .into_iter()
-                .skip(2)
-                .filter_map(|field| {
-                    DatabasePrivilegeChange::new(
-                        self.get_privilege_by_name(field),
-                        other.get_privilege_by_name(field),
-                        field,
-                    )
-                })
-                .collect(),
-        }
-    }
-}
-
-#[inline]
-fn get_mysql_row_priv_field(row: &MySqlRow, position: usize) -> Result<bool, sqlx::Error> {
-    let field = DATABASE_PRIVILEGE_FIELDS[position];
-    let value = row.try_get(position)?;
-    match rev_yn(value) {
-        Some(val) => Ok(val),
-        _ => {
-            log::warn!(r#"Invalid value for privilege "{}": '{}'"#, field, value);
-            Ok(false)
-        }
-    }
-}
-
-impl FromRow<'_, MySqlRow> for DatabasePrivilegeRow {
-    fn from_row(row: &MySqlRow) -> Result<Self, sqlx::Error> {
-        Ok(Self {
-            db: row.try_get("db")?,
-            user: row.try_get("user")?,
-            select_priv: get_mysql_row_priv_field(row, 2)?,
-            insert_priv: get_mysql_row_priv_field(row, 3)?,
-            update_priv: get_mysql_row_priv_field(row, 4)?,
-            delete_priv: get_mysql_row_priv_field(row, 5)?,
-            create_priv: get_mysql_row_priv_field(row, 6)?,
-            drop_priv: get_mysql_row_priv_field(row, 7)?,
-            alter_priv: get_mysql_row_priv_field(row, 8)?,
-            index_priv: get_mysql_row_priv_field(row, 9)?,
-            create_tmp_table_priv: get_mysql_row_priv_field(row, 10)?,
-            lock_tables_priv: get_mysql_row_priv_field(row, 11)?,
-            references_priv: get_mysql_row_priv_field(row, 12)?,
-        })
-    }
-}
-
-/// Get all users + privileges for a single database.
-pub async fn get_database_privileges(
-    database_name: &str,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    let unix_user = get_current_unix_user()?;
-    validate_database_name(database_name, &unix_user)?;
-
-    let result = sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
-        "SELECT {} FROM `db` WHERE `db` = ?",
-        DATABASE_PRIVILEGE_FIELDS
-            .iter()
-            .map(|field| quote_identifier(field))
-            .join(","),
-    ))
-    .bind(database_name)
-    .fetch_all(connection)
-    .await
-    .context("Failed to show database")?;
-
-    Ok(result)
-}
-
-/// Get all database + user + privileges pairs that are owned by the current user.
-pub async fn get_all_database_privileges(
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    let unix_user = get_current_unix_user()?;
-
-    let result = sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
-        indoc! {r#"
-          SELECT {} FROM `db` WHERE `db` IN
-          (SELECT DISTINCT `SCHEMA_NAME` AS `database`
-            FROM `information_schema`.`SCHEMATA`
-            WHERE `SCHEMA_NAME` NOT IN ('information_schema', 'performance_schema', 'mysql', 'sys')
-              AND `SCHEMA_NAME` REGEXP ?)
-        "#},
-        DATABASE_PRIVILEGE_FIELDS
-            .iter()
-            .map(|field| format!("`{field}`"))
-            .join(","),
-    ))
-    .bind(create_user_group_matching_regex(&unix_user))
-    .fetch_all(connection)
-    .await
-    .context("Failed to show databases")?;
-
-    Ok(result)
-}
-
-/*************************/
-/* CLI INTERFACE PARSING */
-/*************************/
-
-/// See documentation for [`DatabaseCommand::EditDbPrivs`].
-pub fn parse_privilege_table_cli_arg(arg: &str) -> anyhow::Result<DatabasePrivilegeRow> {
-    let parts: Vec<&str> = arg.split(':').collect();
-    if parts.len() != 3 {
-        anyhow::bail!("Invalid argument format. See `edit-db-privs --help` for more information.");
-    }
-
-    let db = parts[0].to_string();
-    let user = parts[1].to_string();
-    let privs = parts[2].to_string();
-
-    let mut result = DatabasePrivilegeRow {
-        db,
-        user,
-        select_priv: false,
-        insert_priv: false,
-        update_priv: false,
-        delete_priv: false,
-        create_priv: false,
-        drop_priv: false,
-        alter_priv: false,
-        index_priv: false,
-        create_tmp_table_priv: false,
-        lock_tables_priv: false,
-        references_priv: false,
-    };
-
-    for char in privs.chars() {
-        match char {
-            's' => result.select_priv = true,
-            'i' => result.insert_priv = true,
-            'u' => result.update_priv = true,
-            'd' => result.delete_priv = true,
-            'c' => result.create_priv = true,
-            'D' => result.drop_priv = true,
-            'a' => result.alter_priv = true,
-            'I' => result.index_priv = true,
-            't' => result.create_tmp_table_priv = true,
-            'l' => result.lock_tables_priv = true,
-            'r' => result.references_priv = true,
-            'A' => {
-                result.select_priv = true;
-                result.insert_priv = true;
-                result.update_priv = true;
-                result.delete_priv = true;
-                result.create_priv = true;
-                result.drop_priv = true;
-                result.alter_priv = true;
-                result.index_priv = true;
-                result.create_tmp_table_priv = true;
-                result.lock_tables_priv = true;
-                result.references_priv = true;
-            }
-            _ => anyhow::bail!("Invalid privilege character: {}", char),
-        }
-    }
-
-    Ok(result)
-}
-
-/**********************************/
-/* EDITOR CONTENT DISPLAY/DISPLAY */
-/**********************************/
-
-/// Generates a single row of the privileges table for the editor.
-pub fn format_privileges_line_for_editor(
-    privs: &DatabasePrivilegeRow,
-    username_len: usize,
-    database_name_len: usize,
-) -> String {
-    DATABASE_PRIVILEGE_FIELDS
-        .into_iter()
-        .map(|field| match field {
-            "db" => format!("{:width$}", privs.db, width = database_name_len),
-            "user" => format!("{:width$}", privs.user, width = username_len),
-            privilege => format!(
-                "{:width$}",
-                yn(privs.get_privilege_by_name(privilege)),
-                width = db_priv_field_human_readable_name(privilege).len()
-            ),
-        })
-        .join(" ")
-        .trim()
-        .to_string()
-}
-
-const EDITOR_COMMENT: &str = r#"
-# Welcome to the privilege editor.
-# Each line defines what privileges a single user has on a single database.
-# The first two columns respectively represent the database name and the user, and the remaining columns are the privileges.
-# If the user should have a certain privilege, write 'Y', otherwise write 'N'.
-#
-# Lines starting with '#' are comments and will be ignored.
-"#;
-
-/// Generates the content for the privilege editor.
-///
-/// The unix user is used in case there are no privileges to edit,
-/// so that the user can see an example line based on their username.
-pub fn generate_editor_content_from_privilege_data(
-    privilege_data: &[DatabasePrivilegeRow],
-    unix_user: &str,
-) -> String {
-    let example_user = format!("{}_user", unix_user);
-    let example_db = format!("{}_db", unix_user);
-
-    // NOTE: `.max()`` fails when the iterator is empty.
-    //       In this case, we know that the only fields in the
-    //       editor will be the example user and example db name.
-    //       Hence, it's put as the fallback value, despite not really
-    //       being a "fallback" in the normal sense.
-    let longest_username = privilege_data
-        .iter()
-        .map(|p| p.user.len())
-        .max()
-        .unwrap_or(example_user.len());
-
-    let longest_database_name = privilege_data
-        .iter()
-        .map(|p| p.db.len())
-        .max()
-        .unwrap_or(example_db.len());
-
-    let mut header: Vec<_> = DATABASE_PRIVILEGE_FIELDS
-        .into_iter()
-        .map(db_priv_field_human_readable_name)
-        .collect();
-
-    // Pad the first two columns with spaces to align the privileges.
-    header[0] = format!("{:width$}", header[0], width = longest_database_name);
-    header[1] = format!("{:width$}", header[1], width = longest_username);
-
-    let example_line = format_privileges_line_for_editor(
-        &DatabasePrivilegeRow {
-            db: example_db,
-            user: example_user,
-            select_priv: true,
-            insert_priv: true,
-            update_priv: true,
-            delete_priv: true,
-            create_priv: false,
-            drop_priv: false,
-            alter_priv: false,
-            index_priv: false,
-            create_tmp_table_priv: false,
-            lock_tables_priv: false,
-            references_priv: false,
-        },
-        longest_username,
-        longest_database_name,
-    );
-
-    format!(
-        "{}\n{}\n{}",
-        EDITOR_COMMENT,
-        header.join(" "),
-        if privilege_data.is_empty() {
-            format!("# {}", example_line)
-        } else {
-            privilege_data
-                .iter()
-                .map(|privs| {
-                    format_privileges_line_for_editor(
-                        privs,
-                        longest_username,
-                        longest_database_name,
-                    )
-                })
-                .join("\n")
-        }
-    )
-}
-
-#[derive(Debug)]
-enum PrivilegeRowParseResult {
-    PrivilegeRow(DatabasePrivilegeRow),
-    ParserError(anyhow::Error),
-    TooFewFields(usize),
-    TooManyFields(usize),
-    Header,
-    Comment,
-    Empty,
-}
-
-#[inline]
-fn parse_privilege_cell_from_editor(yn: &str, name: &str) -> anyhow::Result<bool> {
-    rev_yn(yn)
-        .ok_or_else(|| anyhow!("Expected Y or N, found {}", yn))
-        .context(format!("Could not parse {} privilege", name))
-}
-
-#[inline]
-fn editor_row_is_header(row: &str) -> bool {
-    row.split_ascii_whitespace()
-        .zip(DATABASE_PRIVILEGE_FIELDS.iter())
-        .map(|(field, priv_name)| (field, db_priv_field_human_readable_name(priv_name)))
-        .all(|(field, header_field)| field == header_field)
-}
-
-/// Parse a single row of the privileges table from the editor.
-fn parse_privilege_row_from_editor(row: &str) -> PrivilegeRowParseResult {
-    if row.starts_with('#') || row.starts_with("//") {
-        return PrivilegeRowParseResult::Comment;
-    }
-
-    if row.trim().is_empty() {
-        return PrivilegeRowParseResult::Empty;
-    }
-
-    let parts: Vec<&str> = row.trim().split_ascii_whitespace().collect();
-
-    match parts.len() {
-        n if (n < DATABASE_PRIVILEGE_FIELDS.len()) => {
-            return PrivilegeRowParseResult::TooFewFields(n)
-        }
-        n if (n > DATABASE_PRIVILEGE_FIELDS.len()) => {
-            return PrivilegeRowParseResult::TooManyFields(n)
-        }
-        _ => {}
-    }
-
-    if editor_row_is_header(row) {
-        return PrivilegeRowParseResult::Header;
-    }
-
-    let row = DatabasePrivilegeRow {
-        db: (*parts.first().unwrap()).to_owned(),
-        user: (*parts.get(1).unwrap()).to_owned(),
-        select_priv: match parse_privilege_cell_from_editor(
-            parts.get(2).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[2],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        insert_priv: match parse_privilege_cell_from_editor(
-            parts.get(3).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[3],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        update_priv: match parse_privilege_cell_from_editor(
-            parts.get(4).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[4],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        delete_priv: match parse_privilege_cell_from_editor(
-            parts.get(5).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[5],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        create_priv: match parse_privilege_cell_from_editor(
-            parts.get(6).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[6],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        drop_priv: match parse_privilege_cell_from_editor(
-            parts.get(7).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[7],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        alter_priv: match parse_privilege_cell_from_editor(
-            parts.get(8).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[8],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        index_priv: match parse_privilege_cell_from_editor(
-            parts.get(9).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[9],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        create_tmp_table_priv: match parse_privilege_cell_from_editor(
-            parts.get(10).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[10],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        lock_tables_priv: match parse_privilege_cell_from_editor(
-            parts.get(11).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[11],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-        references_priv: match parse_privilege_cell_from_editor(
-            parts.get(12).unwrap(),
-            DATABASE_PRIVILEGE_FIELDS[12],
-        ) {
-            Ok(p) => p,
-            Err(e) => return PrivilegeRowParseResult::ParserError(e),
-        },
-    };
-
-    PrivilegeRowParseResult::PrivilegeRow(row)
-}
-
-// TODO: return better errors
-
-pub fn parse_privilege_data_from_editor_content(
-    content: String,
-) -> anyhow::Result<Vec<DatabasePrivilegeRow>> {
-    content
-        .trim()
-        .split('\n')
-        .map(|line| line.trim())
-        .map(parse_privilege_row_from_editor)
-        .map(|result| match result {
-            PrivilegeRowParseResult::PrivilegeRow(row) => Ok(Some(row)),
-            PrivilegeRowParseResult::ParserError(e) => Err(e),
-            PrivilegeRowParseResult::TooFewFields(n) => Err(anyhow!(
-                "Too few fields in line. Expected to find {} fields, found {}",
-                DATABASE_PRIVILEGE_FIELDS.len(),
-                n
-            )),
-            PrivilegeRowParseResult::TooManyFields(n) => Err(anyhow!(
-                "Too many fields in line. Expected to find {} fields, found {}",
-                DATABASE_PRIVILEGE_FIELDS.len(),
-                n
-            )),
-            PrivilegeRowParseResult::Header => Ok(None),
-            PrivilegeRowParseResult::Comment => Ok(None),
-            PrivilegeRowParseResult::Empty => Ok(None),
-        })
-        .filter_map(|result| result.transpose())
-        .collect::<anyhow::Result<Vec<DatabasePrivilegeRow>>>()
-}
-
-/*****************************/
-/* CALCULATE PRIVILEGE DIFFS */
-/*****************************/
-
-/// This struct represents encapsulates the differences between two
-/// instances of privilege sets for a single user on a single database.
-///
-/// The `User` and `Database` are the same for both instances.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
-pub struct DatabasePrivilegeRowDiff {
-    pub db: String,
-    pub user: String,
-    pub diff: BTreeSet<DatabasePrivilegeChange>,
-}
-
-/// This enum represents a change for a single privilege.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
-pub enum DatabasePrivilegeChange {
-    YesToNo(String),
-    NoToYes(String),
-}
-
-impl DatabasePrivilegeChange {
-    pub fn new(p1: bool, p2: bool, name: &str) -> Option<DatabasePrivilegeChange> {
-        match (p1, p2) {
-            (true, false) => Some(DatabasePrivilegeChange::YesToNo(name.to_owned())),
-            (false, true) => Some(DatabasePrivilegeChange::NoToYes(name.to_owned())),
-            _ => None,
-        }
-    }
-}
-
-/// This enum encapsulates whether a [`DatabasePrivilegeRow`] was intrduced, modified or deleted.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, PartialOrd, Ord)]
-pub enum DatabasePrivilegesDiff {
-    New(DatabasePrivilegeRow),
-    Modified(DatabasePrivilegeRowDiff),
-    Deleted(DatabasePrivilegeRow),
-}
-
-/// This function calculates the differences between two sets of database privileges.
-/// It returns a set of [`DatabasePrivilegesDiff`] that can be used to display or
-/// apply a set of privilege modifications to the database.
-pub fn diff_privileges(
-    from: &[DatabasePrivilegeRow],
-    to: &[DatabasePrivilegeRow],
-) -> BTreeSet<DatabasePrivilegesDiff> {
-    let from_lookup_table: HashMap<(String, String), DatabasePrivilegeRow> = HashMap::from_iter(
-        from.iter()
-            .cloned()
-            .map(|p| ((p.db.clone(), p.user.clone()), p)),
-    );
-
-    let to_lookup_table: HashMap<(String, String), DatabasePrivilegeRow> = HashMap::from_iter(
-        to.iter()
-            .cloned()
-            .map(|p| ((p.db.clone(), p.user.clone()), p)),
-    );
-
-    let mut result = BTreeSet::new();
-
-    for p in to {
-        if let Some(old_p) = from_lookup_table.get(&(p.db.clone(), p.user.clone())) {
-            let diff = old_p.diff(p);
-            if !diff.diff.is_empty() {
-                result.insert(DatabasePrivilegesDiff::Modified(diff));
-            }
-        } else {
-            result.insert(DatabasePrivilegesDiff::New(p.clone()));
-        }
-    }
-
-    for p in from {
-        if !to_lookup_table.contains_key(&(p.db.clone(), p.user.clone())) {
-            result.insert(DatabasePrivilegesDiff::Deleted(p.clone()));
-        }
-    }
-
-    result
-}
-
-/// Uses the result of [`diff_privileges`] to modify privileges in the database.
-pub async fn apply_privilege_diffs(
-    diffs: BTreeSet<DatabasePrivilegesDiff>,
-    connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    for diff in diffs {
-        match diff {
-            DatabasePrivilegesDiff::New(p) => {
-                let tables = DATABASE_PRIVILEGE_FIELDS
-                    .iter()
-                    .map(|field| format!("`{field}`"))
-                    .join(",");
-
-                let question_marks = std::iter::repeat("?")
-                    .take(DATABASE_PRIVILEGE_FIELDS.len())
-                    .join(",");
-
-                sqlx::query(
-                    format!("INSERT INTO `db` ({}) VALUES ({})", tables, question_marks).as_str(),
-                )
-                .bind(p.db)
-                .bind(p.user)
-                .bind(yn(p.select_priv))
-                .bind(yn(p.insert_priv))
-                .bind(yn(p.update_priv))
-                .bind(yn(p.delete_priv))
-                .bind(yn(p.create_priv))
-                .bind(yn(p.drop_priv))
-                .bind(yn(p.alter_priv))
-                .bind(yn(p.index_priv))
-                .bind(yn(p.create_tmp_table_priv))
-                .bind(yn(p.lock_tables_priv))
-                .bind(yn(p.references_priv))
-                .execute(&mut *connection)
-                .await?;
-            }
-            DatabasePrivilegesDiff::Modified(p) => {
-                let tables = p
-                    .diff
-                    .iter()
-                    .map(|diff| match diff {
-                        DatabasePrivilegeChange::YesToNo(name) => format!("`{}` = 'N'", name),
-                        DatabasePrivilegeChange::NoToYes(name) => format!("`{}` = 'Y'", name),
-                    })
-                    .join(",");
-
-                sqlx::query(
-                    format!("UPDATE `db` SET {} WHERE `db` = ? AND `user` = ?", tables).as_str(),
-                )
-                .bind(p.db)
-                .bind(p.user)
-                .execute(&mut *connection)
-                .await?;
-            }
-            DatabasePrivilegesDiff::Deleted(p) => {
-                sqlx::query("DELETE FROM `db` WHERE `db` = ? AND `user` = ?")
-                    .bind(p.db)
-                    .bind(p.user)
-                    .execute(&mut *connection)
-                    .await?;
-            }
-        }
-    }
-    Ok(())
-}
-
-fn display_privilege_cell(diff: &DatabasePrivilegeRowDiff) -> String {
-    diff.diff
-        .iter()
-        .map(|change| match change {
-            DatabasePrivilegeChange::YesToNo(name) => {
-                format!("{}: Y -> N", db_priv_field_human_readable_name(name))
-            }
-            DatabasePrivilegeChange::NoToYes(name) => {
-                format!("{}: N -> Y", db_priv_field_human_readable_name(name))
-            }
-        })
-        .join("\n")
-}
-
-/// Displays the difference between two sets of database privileges.
-pub fn display_privilege_diffs(diffs: &BTreeSet<DatabasePrivilegesDiff>) -> String {
-    let mut table = Table::new();
-    table.set_titles(row!["Database", "User", "Privilege diff",]);
-    for row in diffs {
-        match row {
-            DatabasePrivilegesDiff::New(p) => {
-                table.add_row(row![
-                    p.db,
-                    p.user,
-                    "(New user)\n".to_string()
-                        + &display_privilege_cell(
-                            &DatabasePrivilegeRow::empty(&p.db, &p.user).diff(p)
-                        )
-                ]);
-            }
-            DatabasePrivilegesDiff::Modified(p) => {
-                table.add_row(row![p.db, p.user, display_privilege_cell(p),]);
-            }
-            DatabasePrivilegesDiff::Deleted(p) => {
-                table.add_row(row![
-                    p.db,
-                    p.user,
-                    "(All privileges removed)\n".to_string()
-                        + &display_privilege_cell(
-                            &p.diff(&DatabasePrivilegeRow::empty(&p.db, &p.user))
-                        )
-                ]);
-            }
-        }
-    }
-
-    table.to_string()
-}
-
-/*********/
-/* TESTS */
-/*********/
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_database_privilege_change_creation() {
-        assert_eq!(
-            DatabasePrivilegeChange::new(true, false, "test"),
-            Some(DatabasePrivilegeChange::YesToNo("test".to_owned()))
-        );
-        assert_eq!(
-            DatabasePrivilegeChange::new(false, true, "test"),
-            Some(DatabasePrivilegeChange::NoToYes("test".to_owned()))
-        );
-        assert_eq!(DatabasePrivilegeChange::new(true, true, "test"), None);
-        assert_eq!(DatabasePrivilegeChange::new(false, false, "test"), None);
-    }
-
-    #[test]
-    fn test_diff_privileges() {
-        let row_to_be_modified = DatabasePrivilegeRow {
-            db: "db".to_owned(),
-            user: "user".to_owned(),
-            select_priv: true,
-            insert_priv: true,
-            update_priv: true,
-            delete_priv: true,
-            create_priv: true,
-            drop_priv: true,
-            alter_priv: true,
-            index_priv: false,
-            create_tmp_table_priv: true,
-            lock_tables_priv: true,
-            references_priv: false,
-        };
-
-        let mut row_to_be_deleted = row_to_be_modified.clone();
-        "user2".clone_into(&mut row_to_be_deleted.user);
-
-        let from = vec![row_to_be_modified.clone(), row_to_be_deleted.clone()];
-
-        let mut modified_row = row_to_be_modified.clone();
-        modified_row.select_priv = false;
-        modified_row.insert_priv = false;
-        modified_row.index_priv = true;
-
-        let mut new_row = row_to_be_modified.clone();
-        "user3".clone_into(&mut new_row.user);
-
-        let to = vec![modified_row.clone(), new_row.clone()];
-
-        let diffs = diff_privileges(&from, &to);
-
-        assert_eq!(
-            diffs,
-            BTreeSet::from_iter(vec![
-                DatabasePrivilegesDiff::Deleted(row_to_be_deleted),
-                DatabasePrivilegesDiff::Modified(DatabasePrivilegeRowDiff {
-                    db: "db".to_owned(),
-                    user: "user".to_owned(),
-                    diff: BTreeSet::from_iter(vec![
-                        DatabasePrivilegeChange::YesToNo("select_priv".to_owned()),
-                        DatabasePrivilegeChange::YesToNo("insert_priv".to_owned()),
-                        DatabasePrivilegeChange::NoToYes("index_priv".to_owned()),
-                    ]),
-                }),
-                DatabasePrivilegesDiff::New(new_row),
-            ])
-        );
-    }
-
-    #[test]
-    fn ensure_generated_and_parsed_editor_content_is_equal() {
-        let permissions = vec![
-            DatabasePrivilegeRow {
-                db: "db".to_owned(),
-                user: "user".to_owned(),
-                select_priv: true,
-                insert_priv: true,
-                update_priv: true,
-                delete_priv: true,
-                create_priv: true,
-                drop_priv: true,
-                alter_priv: true,
-                index_priv: true,
-                create_tmp_table_priv: true,
-                lock_tables_priv: true,
-                references_priv: true,
-            },
-            DatabasePrivilegeRow {
-                db: "db2".to_owned(),
-                user: "user2".to_owned(),
-                select_priv: false,
-                insert_priv: false,
-                update_priv: false,
-                delete_priv: false,
-                create_priv: false,
-                drop_priv: false,
-                alter_priv: false,
-                index_priv: false,
-                create_tmp_table_priv: false,
-                lock_tables_priv: false,
-                references_priv: false,
-            },
-        ];
-
-        let content = generate_editor_content_from_privilege_data(&permissions, "user");
-
-        let parsed_permissions = parse_privilege_data_from_editor_content(content).unwrap();
-
-        assert_eq!(permissions, parsed_permissions);
-    }
-}

src/server/entrypoint.rs

@@ -1,89 +0,0 @@
-use futures_util::{SinkExt, StreamExt};
-use sqlx::MySqlConnection;
-use tokio::net::UnixStream;
-use tokio_serde::{formats::Bincode, Framed as SerdeFramed};
-use tokio_util::codec::{Framed, LengthDelimitedCodec};
-
-// use crate::server::
-
-use crate::server::protocol::{Request, Response};
-
-use super::{
-    common::UnixUser, database_operations::{create_databases, drop_databases}, user_operations::{create_database_users, drop_database_users, set_password_for_database_user}
-};
-
-pub type ClientToServerMessageStream<'a> = SerdeFramed<
-    Framed<&'a mut UnixStream, LengthDelimitedCodec>,
-    Request,
-    Response,
-    Bincode<Request, Response>,
->;
-
-pub async fn run_server(
-    socket: &mut UnixStream,
-    unix_user: &UnixUser,
-    db_connection: &mut MySqlConnection,
-) -> anyhow::Result<()> {
-    let length_delimited = Framed::new(socket, LengthDelimitedCodec::new());
-    let mut stream: ClientToServerMessageStream =
-        tokio_serde::Framed::new(length_delimited, Bincode::default());
-
-    // TODO: better error handling
-    let request = match stream.next().await {
-        Some(Ok(request)) => request,
-        Some(Err(e)) => return Err(e.into()),
-        None => return Err(anyhow::anyhow!("No request received")),
-    };
-
-    match request {
-        Request::CreateDatabases(databases) => {
-            let result = create_databases(databases, unix_user, db_connection).await;
-            stream.send(Response::CreateDatabases(result)).await?;
-            stream.flush().await?;
-        }
-        Request::DropDatabases(databases) => {
-            let result = drop_databases(databases, unix_user, db_connection).await;
-            stream.send(Response::DropDatabases(result)).await?;
-            stream.flush().await?;
-        }
-        Request::ListDatabases => {
-            println!("Listing databases");
-            // let result = list_databases(unix_user, db_connection).await;
-            // stream.send(Response::ListDatabases(result)).await?;
-            // stream.flush().await?;
-        }
-        Request::ListPrivileges(users) => {
-            println!("Listing privileges for users: {:?}", users);
-        }
-        Request::ModifyPrivileges(()) => {
-            println!("Modifying privileges");
-        }
-        Request::CreateUsers(db_users) => {
-            let result = create_database_users(db_users, unix_user, db_connection).await;
-            stream.send(Response::CreateUsers(result)).await?;
-            stream.flush().await?;
-        }
-        Request::DropUsers(db_users) => {
-            let result = drop_database_users(db_users, unix_user, db_connection).await;
-            stream.send(Response::DropUsers(result)).await?;
-            stream.flush().await?;
-        }
-        Request::PasswdUser(db_user, password) => {
-            let result =
-                set_password_for_database_user(&db_user, &password, unix_user, db_connection).await;
-            stream.send(Response::PasswdUser(result)).await?;
-            stream.flush().await?;
-        }
-        Request::ListUsers(db_users) => {
-            println!("Listing users: {:?}", db_users);
-        }
-        Request::LockUsers(db_users) => {
-            println!("Locking users: {:?}", db_users);
-        }
-        Request::UnlockUsers(db_users) => {
-            println!("Unlocking users: {:?}", db_users);
-        }
-    }
-
-    Ok(())
-}

src/server/input_sanitization.rs

@@ -1,7 +1,7 @@
-use super::common::UnixUser;
-
 use serde::{Deserialize, Serialize};
 
+use crate::core::common::UnixUser;
+
 const MAX_NAME_LENGTH: usize = 64;
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Serialize, Deserialize)]

src/server/protocol.rs

@@ -1,45 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-use super::{database_operations::{CreateDatabasesOutput, DropDatabasesOutput}, user_operations::{
-    CreateUsersOutput, DropUsersOutput, LockUsersOutput, SetPasswordOutput, UnlockUsersOutput,
-}};
-
-#[non_exhaustive]
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub enum Request {
-    CreateDatabases(Vec<String>),
-    DropDatabases(Vec<String>),
-    ListDatabases,
-    ListPrivileges(Vec<String>),
-    ModifyPrivileges(()), // what data should be sent with this command? Who should calculate the diff?
-
-    CreateUsers(Vec<String>),
-    DropUsers(Vec<String>),
-    PasswdUser(String, String),
-    ListUsers(Option<Vec<String>>),
-    LockUsers(Vec<String>),
-    UnlockUsers(Vec<String>),
-}
-
-// TODO: include a generic "message" that will display a message to the user?
-
-#[non_exhaustive]
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub enum Response {
-    // Specific data for specific commands
-    CreateDatabases(CreateDatabasesOutput),
-    DropDatabases(DropDatabasesOutput),
-    // ListDatabases(ListDatabasesOutput),
-    // ListPrivileges(ListPrivilegesOutput),
-    CreateUsers(CreateUsersOutput),
-    DropUsers(DropUsersOutput),
-    PasswdUser(SetPasswordOutput),
-    ListUsers(()), // what data should be sent with this response?
-    LockUsers(LockUsersOutput),
-    UnlockUsers(UnlockUsersOutput),
-
-    // Generic responses
-    OperationAborted,
-    Error(String),
-    Exit,
-}

src/server/server_loop.rs

@@ -0,0 +1,222 @@
+use std::{collections::BTreeSet, fs, path::PathBuf};
+
+use anyhow::Context;
+
+use futures_util::{SinkExt, StreamExt};
+use tokio::io::AsyncWriteExt;
+use tokio::net::{UnixListener, UnixStream};
+
+use sqlx::prelude::*;
+use sqlx::MySqlConnection;
+
+use crate::{
+    core::{
+        bootstrap::authenticated_unix_socket,
+        common::{UnixUser, DEFAULT_SOCKET_PATH},
+        protocol::{
+            create_server_to_client_message_stream, Request, Response, ServerToClientMessageStream,
+        },
+    },
+    server::{
+        config::{create_mysql_connection_from_config, ServerConfig},
+        sql::{
+            database_operations::{create_databases, drop_databases, list_databases_for_user},
+            database_privilege_operations::{
+                apply_privilege_diffs, get_all_database_privileges, get_databases_privilege_data,
+            },
+            user_operations::{
+                create_database_users, drop_database_users, list_all_database_users_for_unix_user,
+                list_database_users, lock_database_users, set_password_for_database_user,
+                unlock_database_users,
+            },
+        },
+    },
+};
+
+pub async fn listen_for_incoming_connections(
+    socket_path: Option<PathBuf>,
+    config: ServerConfig,
+    // db_connection: &mut MySqlConnection,
+) -> anyhow::Result<()> {
+    let socket_path = socket_path.unwrap_or(PathBuf::from(DEFAULT_SOCKET_PATH));
+
+    let parent_directory = socket_path.parent().unwrap();
+    if !parent_directory.exists() {
+        println!("Creating directory {:?}", parent_directory);
+        fs::create_dir_all(parent_directory)?;
+    }
+
+    println!("Listening on {:?}", socket_path);
+    match fs::remove_file(socket_path.as_path()) {
+        Ok(_) => {}
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {}
+        Err(e) => return Err(e.into()),
+    }
+
+    let listener = UnixListener::bind(socket_path)?;
+
+    while let Ok((mut conn, _addr)) = listener.accept().await {
+        let uid = match authenticated_unix_socket::server_authenticate(&mut conn).await {
+            Ok(uid) => uid,
+            Err(e) => {
+                eprintln!("Failed to authenticate client: {}", e);
+                conn.shutdown().await?;
+                continue;
+            }
+        };
+        let unix_user = match UnixUser::from_uid(uid.into()) {
+            Ok(user) => user,
+            Err(e) => {
+                eprintln!("Failed to get UnixUser from uid: {}", e);
+                conn.shutdown().await?;
+                continue;
+            }
+        };
+        match handle_requests_for_single_session(conn, &unix_user, &config).await {
+            Ok(_) => {}
+            Err(e) => {
+                eprintln!("Failed to run server: {}", e);
+            }
+        }
+    }
+
+    Ok(())
+}
+
+pub async fn handle_requests_for_single_session(
+    socket: UnixStream,
+    unix_user: &UnixUser,
+    config: &ServerConfig,
+) -> anyhow::Result<()> {
+    let message_stream = create_server_to_client_message_stream(socket);
+    let mut db_connection = create_mysql_connection_from_config(&config.mysql).await?;
+
+    let result = handle_requests_for_single_session_with_db_connection(
+        message_stream,
+        unix_user,
+        &mut db_connection,
+    )
+    .await;
+
+    if let Err(e) = db_connection
+        .close()
+        .await
+        .context("Failed to close connection properly")
+    {
+        eprintln!("{}", e);
+        eprintln!("Ignoring...");
+    }
+
+    result
+}
+
+pub async fn handle_requests_for_single_session_with_db_connection(
+    mut stream: ServerToClientMessageStream,
+    unix_user: &UnixUser,
+    db_connection: &mut MySqlConnection,
+) -> anyhow::Result<()> {
+    loop {
+        // TODO: better error handling
+        let request = match stream.next().await {
+            Some(Ok(request)) => request,
+            Some(Err(e)) => return Err(e.into()),
+            None => {
+                log::warn!("Client disconnected without sending an exit message");
+                break;
+            }
+        };
+
+        match request {
+            Request::CreateDatabases(databases_names) => {
+                let result = create_databases(databases_names, unix_user, db_connection).await;
+                stream.send(Response::CreateDatabases(result)).await?;
+                stream.flush().await?;
+            }
+            Request::DropDatabases(databases_names) => {
+                let result = drop_databases(databases_names, unix_user, db_connection).await;
+                stream.send(Response::DropDatabases(result)).await?;
+                stream.flush().await?;
+            }
+            Request::ListDatabases => {
+                let result = list_databases_for_user(unix_user, db_connection).await;
+                stream.send(Response::ListAllDatabases(result)).await?;
+                stream.flush().await?;
+            }
+            Request::ListPrivileges(database_names) => {
+                let response = match database_names {
+                    Some(database_names) => {
+                        let privilege_data =
+                            get_databases_privilege_data(database_names, unix_user, db_connection)
+                                .await;
+                        Response::ListPrivileges(privilege_data)
+                    }
+                    None => {
+                        let privilege_data =
+                            get_all_database_privileges(unix_user, db_connection).await;
+                        Response::ListAllPrivileges(privilege_data)
+                    }
+                };
+
+                stream.send(response).await?;
+                stream.flush().await?;
+            }
+            Request::ModifyPrivileges(database_privilege_diffs) => {
+                let result = apply_privilege_diffs(
+                    BTreeSet::from_iter(database_privilege_diffs),
+                    unix_user,
+                    db_connection,
+                )
+                .await;
+                stream.send(Response::ModifyPrivileges(result)).await?;
+                stream.flush().await?;
+            }
+            Request::CreateUsers(db_users) => {
+                let result = create_database_users(db_users, unix_user, db_connection).await;
+                stream.send(Response::CreateUsers(result)).await?;
+                stream.flush().await?;
+            }
+            Request::DropUsers(db_users) => {
+                let result = drop_database_users(db_users, unix_user, db_connection).await;
+                stream.send(Response::DropUsers(result)).await?;
+                stream.flush().await?;
+            }
+            Request::PasswdUser(db_user, password) => {
+                let result =
+                    set_password_for_database_user(&db_user, &password, unix_user, db_connection)
+                        .await;
+                stream.send(Response::PasswdUser(result)).await?;
+                stream.flush().await?;
+            }
+            Request::ListUsers(db_users) => {
+                let response = match db_users {
+                    Some(db_users) => {
+                        let result = list_database_users(db_users, unix_user, db_connection).await;
+                        Response::ListUsers(result)
+                    }
+                    None => {
+                        let result =
+                            list_all_database_users_for_unix_user(unix_user, db_connection).await;
+                        Response::ListAllUsers(result)
+                    }
+                };
+                stream.send(response).await?;
+                stream.flush().await?;
+            }
+            Request::LockUsers(db_users) => {
+                let result = lock_database_users(db_users, unix_user, db_connection).await;
+                stream.send(Response::LockUsers(result)).await?;
+                stream.flush().await?;
+            }
+            Request::UnlockUsers(db_users) => {
+                let result = unlock_database_users(db_users, unix_user, db_connection).await;
+                stream.send(Response::UnlockUsers(result)).await?;
+                stream.flush().await?;
+            }
+            Request::Exit => {
+                break;
+            }
+        }
+    }
+
+    Ok(())
+}

src/server/sql.rs

@@ -0,0 +1,3 @@
+pub mod database_operations;
+pub mod database_privilege_operations;
+pub mod user_operations;

src/server/sql/database_operations.rs

@@ -1,7 +1,13 @@
-use crate::server::common::UnixUser;
+use crate::{
-use crate::server::input_sanitization::quote_identifier;
+    core::common::UnixUser,
-use crate::server::input_sanitization::{validate_name, validate_ownership_by_unix_user};
+    server::{
-use crate::server::input_sanitization::{NameValidationError, OwnerValidationError};
+        common::create_user_group_matching_regex,
+        input_sanitization::{
+            quote_identifier, validate_name, validate_ownership_by_unix_user, NameValidationError,
+            OwnerValidationError,
+        },
+    },
+};
 
 use serde::{Deserialize, Serialize};
 use sqlx::prelude::*;
@@ -9,16 +15,14 @@ use sqlx::prelude::*;
 use sqlx::MySqlConnection;
 use std::collections::BTreeMap;
 
-use super::common::create_user_group_matching_regex;
-
 // NOTE: this function is unsafe because it does no input validation.
-async fn unsafe_database_exists(
+pub(super) async fn unsafe_database_exists(
-    db_name: &str,
+    database_name: &str,
     connection: &mut MySqlConnection,
 ) -> Result<bool, sqlx::Error> {
     let result =
         sqlx::query("SELECT SCHEMA_NAME FROM information_schema.SCHEMATA WHERE SCHEMA_NAME = ?")
-            .bind(db_name)
+            .bind(database_name)
             .fetch_optional(connection)
             .await?;
 
@@ -153,7 +157,7 @@ pub async fn drop_databases(
     results
 }
 
-pub type ListDatabasesOutput = Result<Vec<String>, ListDatabasesError>;
+pub type ListAllDatabasesOutput = Result<Vec<String>, ListDatabasesError>;
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub enum ListDatabasesError {
     MySqlError(String),

src/server/sql/database_privilege_operations.rs

@@ -0,0 +1,405 @@
+// TODO: fix comment
+//! Database privilege operations
+//!
+//! This module contains functions for querying, modifying,
+//! displaying and comparing database privileges.
+//!
+//! A lot of the complexity comes from two core components:
+//!
+//! - The privilege editor that needs to be able to print
+//!   an editable table of privileges and reparse the content
+//!   after the user has made manual changes.
+//!
+//! - The comparison functionality that tells the user what
+//!   changes will be made when applying a set of changes
+//!   to the list of database privileges.
+
+use std::collections::{BTreeMap, BTreeSet};
+
+use indoc::indoc;
+use itertools::Itertools;
+use serde::{Deserialize, Serialize};
+use sqlx::{mysql::MySqlRow, prelude::*, MySqlConnection};
+
+use crate::{
+    core::{
+        common::{rev_yn, yn, UnixUser},
+        database_privileges::{DatabasePrivilegeChange, DatabasePrivilegesDiff},
+    },
+    server::{
+        common::create_user_group_matching_regex,
+        input_sanitization::{
+            quote_identifier, validate_name, validate_ownership_by_unix_user, NameValidationError,
+            OwnerValidationError,
+        },
+        sql::database_operations::unsafe_database_exists,
+    },
+};
+
+/// This is the list of fields that are used to fetch the db + user + privileges
+/// from the `db` table in the database. If you need to add or remove privilege
+/// fields, this is a good place to start.
+pub const DATABASE_PRIVILEGE_FIELDS: [&str; 13] = [
+    "db",
+    "user",
+    "select_priv",
+    "insert_priv",
+    "update_priv",
+    "delete_priv",
+    "create_priv",
+    "drop_priv",
+    "alter_priv",
+    "index_priv",
+    "create_tmp_table_priv",
+    "lock_tables_priv",
+    "references_priv",
+];
+
+// NOTE: ord is needed for BTreeSet to accept the type, but it
+//       doesn't have any natural implementation semantics.
+
+/// This struct represents the set of privileges for a single user on a single database.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, PartialOrd, Ord)]
+pub struct DatabasePrivilegeRow {
+    pub db: String,
+    pub user: String,
+    pub select_priv: bool,
+    pub insert_priv: bool,
+    pub update_priv: bool,
+    pub delete_priv: bool,
+    pub create_priv: bool,
+    pub drop_priv: bool,
+    pub alter_priv: bool,
+    pub index_priv: bool,
+    pub create_tmp_table_priv: bool,
+    pub lock_tables_priv: bool,
+    pub references_priv: bool,
+}
+
+impl DatabasePrivilegeRow {
+    pub fn empty(db: &str, user: &str) -> Self {
+        Self {
+            db: db.to_owned(),
+            user: user.to_owned(),
+            select_priv: false,
+            insert_priv: false,
+            update_priv: false,
+            delete_priv: false,
+            create_priv: false,
+            drop_priv: false,
+            alter_priv: false,
+            index_priv: false,
+            create_tmp_table_priv: false,
+            lock_tables_priv: false,
+            references_priv: false,
+        }
+    }
+
+    pub fn get_privilege_by_name(&self, name: &str) -> bool {
+        match name {
+            "select_priv" => self.select_priv,
+            "insert_priv" => self.insert_priv,
+            "update_priv" => self.update_priv,
+            "delete_priv" => self.delete_priv,
+            "create_priv" => self.create_priv,
+            "drop_priv" => self.drop_priv,
+            "alter_priv" => self.alter_priv,
+            "index_priv" => self.index_priv,
+            "create_tmp_table_priv" => self.create_tmp_table_priv,
+            "lock_tables_priv" => self.lock_tables_priv,
+            "references_priv" => self.references_priv,
+            _ => false,
+        }
+    }
+}
+
+#[inline]
+fn get_mysql_row_priv_field(row: &MySqlRow, position: usize) -> Result<bool, sqlx::Error> {
+    let field = DATABASE_PRIVILEGE_FIELDS[position];
+    let value = row.try_get(position)?;
+    match rev_yn(value) {
+        Some(val) => Ok(val),
+        _ => {
+            log::warn!(r#"Invalid value for privilege "{}": '{}'"#, field, value);
+            Ok(false)
+        }
+    }
+}
+
+impl FromRow<'_, MySqlRow> for DatabasePrivilegeRow {
+    fn from_row(row: &MySqlRow) -> Result<Self, sqlx::Error> {
+        Ok(Self {
+            db: row.try_get("db")?,
+            user: row.try_get("user")?,
+            select_priv: get_mysql_row_priv_field(row, 2)?,
+            insert_priv: get_mysql_row_priv_field(row, 3)?,
+            update_priv: get_mysql_row_priv_field(row, 4)?,
+            delete_priv: get_mysql_row_priv_field(row, 5)?,
+            create_priv: get_mysql_row_priv_field(row, 6)?,
+            drop_priv: get_mysql_row_priv_field(row, 7)?,
+            alter_priv: get_mysql_row_priv_field(row, 8)?,
+            index_priv: get_mysql_row_priv_field(row, 9)?,
+            create_tmp_table_priv: get_mysql_row_priv_field(row, 10)?,
+            lock_tables_priv: get_mysql_row_priv_field(row, 11)?,
+            references_priv: get_mysql_row_priv_field(row, 12)?,
+        })
+    }
+}
+
+// NOTE: this function is unsafe because it does no input validation.
+/// Get all users + privileges for a single database.
+async fn unsafe_get_database_privileges(
+    database_name: &str,
+    connection: &mut MySqlConnection,
+) -> Result<Vec<DatabasePrivilegeRow>, sqlx::Error> {
+    sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
+        "SELECT {} FROM `db` WHERE `db` = ?",
+        DATABASE_PRIVILEGE_FIELDS
+            .iter()
+            .map(|field| quote_identifier(field))
+            .join(","),
+    ))
+    .bind(database_name)
+    .fetch_all(connection)
+    .await
+}
+
+// TODO: merge all rows into a single collection.
+//       they already contain which database they belong to.
+//       no need to index by database name.
+
+pub type GetDatabasesPrivilegeData =
+    BTreeMap<String, Result<Vec<DatabasePrivilegeRow>, GetDatabasesPrivilegeDataError>>;
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum GetDatabasesPrivilegeDataError {
+    SanitizationError(NameValidationError),
+    OwnershipError(OwnerValidationError),
+    DatabaseDoesNotExist,
+    MySqlError(String),
+}
+
+pub async fn get_databases_privilege_data(
+    database_names: Vec<String>,
+    unix_user: &UnixUser,
+    connection: &mut MySqlConnection,
+) -> GetDatabasesPrivilegeData {
+    let mut results = BTreeMap::new();
+
+    for database_name in database_names.iter() {
+        if let Err(err) = validate_name(database_name) {
+            results.insert(
+                database_name.clone(),
+                Err(GetDatabasesPrivilegeDataError::SanitizationError(err)),
+            );
+            continue;
+        }
+
+        if let Err(err) = validate_ownership_by_unix_user(database_name, unix_user) {
+            results.insert(
+                database_name.clone(),
+                Err(GetDatabasesPrivilegeDataError::OwnershipError(err)),
+            );
+            continue;
+        }
+
+        if !unsafe_database_exists(database_name, connection)
+            .await
+            .unwrap()
+        {
+            results.insert(
+                database_name.clone(),
+                Err(GetDatabasesPrivilegeDataError::DatabaseDoesNotExist),
+            );
+            continue;
+        }
+
+        let result = unsafe_get_database_privileges(database_name, connection)
+            .await
+            .map_err(|e| GetDatabasesPrivilegeDataError::MySqlError(e.to_string()));
+
+        results.insert(database_name.clone(), result);
+    }
+
+    debug_assert!(database_names.len() == results.len());
+
+    results
+}
+
+pub type GetAllDatabasesPrivilegeData =
+    Result<Vec<DatabasePrivilegeRow>, GetAllDatabasesPrivilegeDataError>;
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum GetAllDatabasesPrivilegeDataError {
+    MySqlError(String),
+}
+
+/// Get all database + user + privileges pairs that are owned by the current user.
+pub async fn get_all_database_privileges(
+    unix_user: &UnixUser,
+    connection: &mut MySqlConnection,
+) -> GetAllDatabasesPrivilegeData {
+    sqlx::query_as::<_, DatabasePrivilegeRow>(&format!(
+        indoc! {r#"
+          SELECT {} FROM `db` WHERE `db` IN
+          (SELECT DISTINCT `SCHEMA_NAME` AS `database`
+            FROM `information_schema`.`SCHEMATA`
+            WHERE `SCHEMA_NAME` NOT IN ('information_schema', 'performance_schema', 'mysql', 'sys')
+              AND `SCHEMA_NAME` REGEXP ?)
+        "#},
+        DATABASE_PRIVILEGE_FIELDS
+            .iter()
+            .map(|field| quote_identifier(field))
+            .join(","),
+    ))
+    .bind(create_user_group_matching_regex(unix_user))
+    .fetch_all(connection)
+    .await
+    .map_err(|e| GetAllDatabasesPrivilegeDataError::MySqlError(e.to_string()))
+}
+
+async fn unsafe_apply_privilege_diff(
+    database_privilege_diff: &DatabasePrivilegesDiff,
+    connection: &mut MySqlConnection,
+) -> Result<(), sqlx::Error> {
+    match database_privilege_diff {
+        DatabasePrivilegesDiff::New(p) => {
+            let tables = DATABASE_PRIVILEGE_FIELDS
+                .iter()
+                .map(|field| quote_identifier(field))
+                .join(",");
+
+            let question_marks = std::iter::repeat("?")
+                .take(DATABASE_PRIVILEGE_FIELDS.len())
+                .join(",");
+
+            sqlx::query(
+                format!("INSERT INTO `db` ({}) VALUES ({})", tables, question_marks).as_str(),
+            )
+            .bind(p.db.to_string())
+            .bind(p.user.to_string())
+            .bind(yn(p.select_priv))
+            .bind(yn(p.insert_priv))
+            .bind(yn(p.update_priv))
+            .bind(yn(p.delete_priv))
+            .bind(yn(p.create_priv))
+            .bind(yn(p.drop_priv))
+            .bind(yn(p.alter_priv))
+            .bind(yn(p.index_priv))
+            .bind(yn(p.create_tmp_table_priv))
+            .bind(yn(p.lock_tables_priv))
+            .bind(yn(p.references_priv))
+            .execute(connection)
+            .await
+            .map(|_| ())
+        }
+        DatabasePrivilegesDiff::Modified(p) => {
+            let changes = p
+                .diff
+                .iter()
+                .map(|diff| match diff {
+                    DatabasePrivilegeChange::YesToNo(name) => {
+                        format!("{} = 'N'", quote_identifier(name))
+                    }
+                    DatabasePrivilegeChange::NoToYes(name) => {
+                        format!("{} = 'Y'", quote_identifier(name))
+                    }
+                })
+                .join(",");
+
+            sqlx::query(
+                format!("UPDATE `db` SET {} WHERE `db` = ? AND `user` = ?", changes).as_str(),
+            )
+            .bind(p.db.to_string())
+            .bind(p.user.to_string())
+            .execute(connection)
+            .await
+            .map(|_| ())
+        }
+        DatabasePrivilegesDiff::Deleted(p) => {
+            sqlx::query("DELETE FROM `db` WHERE `db` = ? AND `user` = ?")
+                .bind(p.db.to_string())
+                .bind(p.user.to_string())
+                .execute(connection)
+                .await
+                .map(|_| ())
+        }
+    }
+}
+
+pub type ModifyDatabasePrivilegesOutput =
+    BTreeMap<String, Result<(), ModifyDatabasePrivilegesError>>;
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum ModifyDatabasePrivilegesError {
+    DatabaseSanitizationError(NameValidationError),
+    DatabaseOwnershipError(OwnerValidationError),
+    UserSanitizationError(NameValidationError),
+    UserOwnershipError(OwnerValidationError),
+    DatabaseDoesNotExist,
+    DiffDoesNotApply(DatabasePrivilegeChange),
+    MySqlError(String),
+}
+
+/// Uses the result of [`diff_privileges`] to modify privileges in the database.
+pub async fn apply_privilege_diffs(
+    database_privilege_diffs: BTreeSet<DatabasePrivilegesDiff>,
+    unix_user: &UnixUser,
+    connection: &mut MySqlConnection,
+) -> ModifyDatabasePrivilegesOutput {
+    let mut results: BTreeMap<String, _> = BTreeMap::new();
+
+    for diff in database_privilege_diffs {
+        if let Err(err) = validate_name(diff.get_database_name()) {
+            results.insert(
+                diff.get_database_name().to_string(),
+                Err(ModifyDatabasePrivilegesError::DatabaseSanitizationError(
+                    err,
+                )),
+            );
+            continue;
+        }
+
+        if let Err(err) = validate_ownership_by_unix_user(diff.get_database_name(), unix_user) {
+            results.insert(
+                diff.get_database_name().to_string(),
+                Err(ModifyDatabasePrivilegesError::DatabaseOwnershipError(err)),
+            );
+            continue;
+        }
+
+        if let Err(err) = validate_name(diff.get_user_name()) {
+            results.insert(
+                diff.get_database_name().to_string(),
+                Err(ModifyDatabasePrivilegesError::UserSanitizationError(err)),
+            );
+            continue;
+        }
+
+        if let Err(err) = validate_ownership_by_unix_user(diff.get_user_name(), unix_user) {
+            results.insert(
+                diff.get_database_name().to_string(),
+                Err(ModifyDatabasePrivilegesError::UserOwnershipError(err)),
+            );
+            continue;
+        }
+
+        if !unsafe_database_exists(diff.get_database_name(), connection)
+            .await
+            .unwrap()
+        {
+            results.insert(
+                diff.get_database_name().to_string(),
+                Err(ModifyDatabasePrivilegesError::DatabaseDoesNotExist),
+            );
+            continue;
+        }
+
+        // TODO: validate that the diff actually applies to the database
+
+        let result = unsafe_apply_privilege_diff(&diff, connection)
+            .await
+            .map_err(|e| ModifyDatabasePrivilegesError::MySqlError(e.to_string()));
+
+        results.insert(diff.get_database_name().to_string(), result);
+    }
+
+    results
+}

src/server/sql/user_operations.rs

@@ -5,11 +5,15 @@ use serde::{Deserialize, Serialize};
 use sqlx::prelude::*;
 use sqlx::MySqlConnection;
 
-use super::common::create_user_group_matching_regex;
+use crate::{
-use super::common::UnixUser;
+    core::common::UnixUser,
-use super::input_sanitization::{
+    server::{
+        common::create_user_group_matching_regex,
+        input_sanitization::{
             quote_literal, validate_name, validate_ownership_by_unix_user, NameValidationError,
             OwnerValidationError,
+        },
+    },
 };
 
 // NOTE: this function is unsafe because it does no input validation.
@@ -272,7 +276,7 @@ pub enum UnlockUserError {
     MySqlError(String),
 }
 
-pub async fn unlock_database_user(
+pub async fn unlock_database_users(
     db_users: Vec<String>,
     unix_user: &UnixUser,
     connection: &mut MySqlConnection,
@@ -362,34 +366,65 @@ JOIN `mysql`.`global_priv` ON
   AND `mysql`.`user`.`Host` = `mysql`.`global_priv`.`Host`
 "#;
 
-pub async fn get_all_database_users_for_unix_user(
+pub type ListUsersOutput = BTreeMap<String, Result<DatabaseUser, ListUsersError>>;
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum ListUsersError {
+    SanitizationError(NameValidationError),
+    OwnershipError(OwnerValidationError),
+    UserDoesNotExist,
+    MySqlError(String),
+}
+
+pub async fn list_database_users(
+    db_users: Vec<String>,
     unix_user: &UnixUser,
     connection: &mut MySqlConnection,
-) -> Result<Vec<DatabaseUser>, sqlx::Error> {
+) -> ListUsersOutput {
+    let mut results = BTreeMap::new();
+
+    for db_user in db_users {
+        if let Err(err) = validate_name(&db_user) {
+            results.insert(db_user, Err(ListUsersError::SanitizationError(err)));
+            continue;
+        }
+
+        if let Err(err) = validate_ownership_by_unix_user(&db_user, unix_user) {
+            results.insert(db_user, Err(ListUsersError::OwnershipError(err)));
+            continue;
+        }
+
+        let result = sqlx::query_as::<_, DatabaseUser>(
+            &(DB_USER_SELECT_STATEMENT.to_string() + "WHERE `mysql`.`user`.`User` = ?"),
+        )
+        .bind(&db_user)
+        .fetch_optional(&mut *connection)
+        .await;
+
+        match result {
+            Ok(Some(user)) => results.insert(db_user, Ok(user)),
+            Ok(None) => results.insert(db_user, Err(ListUsersError::UserDoesNotExist)),
+            Err(err) => results.insert(db_user, Err(ListUsersError::MySqlError(err.to_string()))),
+        };
+    }
+
+    results
+}
+
+pub type ListAllUsersOutput = Result<Vec<DatabaseUser>, ListAllUsersError>;
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum ListAllUsersError {
+    MySqlError(String),
+}
+
+pub async fn list_all_database_users_for_unix_user(
+    unix_user: &UnixUser,
+    connection: &mut MySqlConnection,
+) -> ListAllUsersOutput {
     sqlx::query_as::<_, DatabaseUser>(
         &(DB_USER_SELECT_STATEMENT.to_string() + "WHERE `mysql`.`user`.`User` REGEXP ?"),
     )
     .bind(create_user_group_matching_regex(unix_user))
     .fetch_all(connection)
     .await
+    .map_err(|err| ListAllUsersError::MySqlError(err.to_string()))
 }
-
-// /// This function fetches a database user if it exists.
-// pub async fn get_database_user_for_user(
-//     username: &str,
-//     connection: &mut MySqlConnection,
-// ) -> anyhow::Result<Option<DatabaseUser>> {
-//     let user = sqlx::query_as::<_, DatabaseUser>(
-//         &(DB_USER_SELECT_STATEMENT.to_string() + "WHERE `mysql`.`user`.`User` = ?"),
-//     )
-//     .bind(username)
-//     .fetch_optional(connection)
-//     .await?;
-
-//     Ok(user)
-// }
-
-// /// NOTE: It is very critical that this function validates the database name
-// ///       properly. MySQL does not seem to allow for prepared statements, binding
-// ///       the database name as a parameter to the query. This means that we have
-// ///       to validate the database name ourselves to prevent SQL injection.