Add command check-auth

src/client/commands.rs

@@ -1,3 +1,4 @@
+mod check_auth;
 mod create_db;
 mod create_user;
 mod drop_db;
@@ -10,6 +11,7 @@ mod show_privs;
 mod show_user;
 mod unlock_user;
 
+pub use check_auth::*;
 pub use create_db::*;
 pub use create_user::*;
 pub use drop_db::*;
@@ -28,6 +30,10 @@ use crate::core::protocol::{ClientToServerMessageStream, Response};
 
 #[derive(Parser, Debug, Clone)]
 pub enum ClientCommand {
+    /// Check whether you are authorized to manage the specified databases or users.
+    #[command()]
+    CheckAuth(CheckAuthArgs),
+
     /// Create one or more databases
     #[command()]
     CreateDb(CreateDbArgs),
@@ -141,6 +147,7 @@ pub async fn handle_command(
     server_connection: ClientToServerMessageStream,
 ) -> anyhow::Result<()> {
     match command {
+        ClientCommand::CheckAuth(args) => check_authorization(args, server_connection).await,
         ClientCommand::CreateDb(args) => create_databases(args, server_connection).await,
         ClientCommand::DropDb(args) => drop_databases(args, server_connection).await,
         ClientCommand::ShowDb(args) => show_databases(args, server_connection).await,

src/client/commands/check_auth.rs

@@ -0,0 +1,67 @@
+use crate::{
+    client::commands::erroneous_server_response,
+    core::{
+        protocol::{
+            ClientToServerMessageStream, Request, Response,
+            print_check_authorization_output_status, print_check_authorization_output_status_json,
+        },
+        types::DbOrUser,
+    },
+};
+use clap::Parser;
+use futures_util::SinkExt;
+use tokio_stream::StreamExt;
+
+#[derive(Parser, Debug, Clone)]
+pub struct CheckAuthArgs {
+    /// The name of the database(s) or user(s) to check authorization for
+    #[arg(num_args = 1..)]
+    name: Vec<String>,
+
+    /// Assume the names are users, not databases
+    #[arg(short, long)]
+    users: bool,
+
+    /// Print the information as JSON
+    #[arg(short, long)]
+    json: bool,
+}
+
+pub async fn check_authorization(
+    args: CheckAuthArgs,
+    mut server_connection: ClientToServerMessageStream,
+) -> anyhow::Result<()> {
+    if args.name.is_empty() {
+        anyhow::bail!("No database/user names provided");
+    }
+
+    let payload = args
+        .name
+        .into_iter()
+        .map(|name| {
+            if args.users {
+                DbOrUser::User(name.into())
+            } else {
+                DbOrUser::Database(name.into())
+            }
+        })
+        .collect::<Vec<_>>();
+
+    let message = Request::CheckAuthorization(payload);
+    server_connection.send(message).await?;
+
+    let result = match server_connection.next().await {
+        Some(Ok(Response::CheckAuthorization(response))) => response,
+        response => return erroneous_server_response(response),
+    };
+
+    server_connection.send(Request::Exit).await?;
+
+    if args.json {
+        print_check_authorization_output_status_json(&result);
+    } else {
+        print_check_authorization_output_status(&result);
+    }
+
+    Ok(())
+}

src/core/protocol/commands.rs

@@ -1,3 +1,4 @@
+mod check_authorization;
 mod create_databases;
 mod create_users;
 mod drop_databases;
@@ -13,6 +14,7 @@ mod modify_privileges;
 mod passwd_user;
 mod unlock_users;
 
+pub use check_authorization::*;
 pub use create_databases::*;
 pub use create_users::*;
 pub use drop_databases::*;
@@ -60,6 +62,8 @@ pub fn create_client_to_server_message_stream(socket: UnixStream) -> ClientToSer
 #[non_exhaustive]
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub enum Request {
+    CheckAuthorization(CheckAuthorizationRequest),
+
     CreateDatabases(CreateDatabasesRequest),
     DropDatabases(DropDatabasesRequest),
     ListDatabases(ListDatabasesRequest),
@@ -82,6 +86,8 @@ pub enum Request {
 #[non_exhaustive]
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
 pub enum Response {
+    CheckAuthorization(CheckAuthorizationResponse),
+
     // Specific data for specific commands
     CreateDatabases(CreateDatabasesResponse),
     DropDatabases(DropDatabasesResponse),

src/core/protocol/commands/check_authorization.rs

@@ -0,0 +1,80 @@
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+use serde_json::json;
+
+use crate::core::{
+    protocol::request_validation::{NameValidationError, OwnerValidationError},
+    types::DbOrUser,
+};
+
+pub type CheckAuthorizationRequest = Vec<DbOrUser>;
+
+pub type CheckAuthorizationResponse = BTreeMap<DbOrUser, Result<(), CheckAuthorizationError>>;
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum CheckAuthorizationError {
+    SanitizationError(NameValidationError),
+    OwnershipError(OwnerValidationError),
+    // AuthorizationHandlerError(String),
+}
+
+pub fn print_check_authorization_output_status(output: &CheckAuthorizationResponse) {
+    for (db_or_user, result) in output {
+        match result {
+            Ok(()) => {
+                println!("'{}': OK", db_or_user.name());
+            }
+            Err(err) => {
+                println!(
+                    "'{}': {}",
+                    db_or_user.name(),
+                    err.to_error_message(db_or_user)
+                );
+            }
+        }
+    }
+}
+
+pub fn print_check_authorization_output_status_json(output: &CheckAuthorizationResponse) {
+    let value = output
+        .iter()
+        .map(|(db_or_user, result)| match result {
+            Ok(()) => (
+                db_or_user.name().to_string(),
+                json!({ "status": "success" }),
+            ),
+            Err(err) => (
+                db_or_user.name().to_string(),
+                json!({
+                  "status": "error",
+                  "error": err.to_error_message(db_or_user),
+                }),
+            ),
+        })
+        .collect::<serde_json::Map<_, _>>();
+    println!(
+        "{}",
+        serde_json::to_string_pretty(&value)
+            .unwrap_or("Failed to serialize result to JSON".to_string())
+    );
+}
+
+impl CheckAuthorizationError {
+    pub fn to_error_message(&self, db_or_user: &DbOrUser) -> String {
+        match self {
+            CheckAuthorizationError::SanitizationError(err) => {
+                err.to_error_message(db_or_user.clone())
+            }
+            CheckAuthorizationError::OwnershipError(err) => {
+                err.to_error_message(db_or_user.clone())
+            } // CheckAuthorizationError::AuthorizationHandlerError(msg) => {
+              //     format!(
+              //         "Authorization handler error for '{}': {}",
+              //         db_or_user.name(),
+              //         msg
+              //     )
+              // }
+        }
+    }
+}

src/core/types.rs

@@ -92,8 +92,7 @@ impl From<String> for MySQLDatabase {
     }
 }
 
-/// This enum is used to differentiate between database and user operations.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
 pub enum DbOrUser {
     Database(MySQLDatabase),
     User(MySQLUser),

src/server.rs

@@ -1,3 +1,4 @@
+mod authorization;
 pub mod command;
 mod common;
 pub mod config;

src/server/authorization.rs

@@ -0,0 +1,33 @@
+use crate::{
+    core::{common::UnixUser, protocol::CheckAuthorizationError, types::DbOrUser},
+    server::input_sanitization::{validate_name, validate_ownership_by_unix_user},
+};
+
+pub async fn check_authorization(
+    dbs_or_users: Vec<DbOrUser>,
+    unix_user: &UnixUser,
+) -> std::collections::BTreeMap<DbOrUser, Result<(), CheckAuthorizationError>> {
+    let mut results = std::collections::BTreeMap::new();
+
+    for db_or_user in dbs_or_users {
+        if let Err(err) = validate_name(db_or_user.name()) {
+            results.insert(
+                db_or_user.clone(),
+                Err(CheckAuthorizationError::SanitizationError(err)),
+            );
+            continue;
+        }
+
+        if let Err(err) = validate_ownership_by_unix_user(db_or_user.name(), unix_user) {
+            results.insert(
+                db_or_user.clone(),
+                Err(CheckAuthorizationError::OwnershipError(err)),
+            );
+            continue;
+        }
+
+        results.insert(db_or_user.clone(), Ok(()));
+    }
+
+    results
+}

src/server/session_handler.rs

@@ -13,7 +13,9 @@ use crate::{
             create_server_to_client_message_stream,
         },
     },
-    server::sql::{
+    server::{
+        authorization::check_authorization,
+        sql::{
             database_operations::{
                 create_databases, drop_databases, list_all_databases_for_user, list_databases,
             },
@@ -26,6 +28,7 @@ use crate::{
                 unlock_database_users,
             },
         },
+    },
 };
 
 // TODO: don't use database connection unless necessary.
@@ -119,6 +122,8 @@ async fn session_handler_with_db_connection(
     stream.send(Response::Ready).await?;
     loop {
         // TODO: better error handling
+        // TODO: timeout for receiving requests
+        // TODO: cancel on request by supervisor
         let request = match stream.next().await {
             Some(Ok(request)) => request,
             Some(Err(e)) => return Err(e.into()),
@@ -138,6 +143,10 @@ async fn session_handler_with_db_connection(
         log::info!("Received request: {:#?}", request_to_display);
 
         let response = match request {
+            Request::CheckAuthorization(dbs_or_users) => {
+                let result = check_authorization(dbs_or_users, unix_user).await;
+                Response::CheckAuthorization(result)
+            }
             Request::CreateDatabases(databases_names) => {
                 let result = create_databases(databases_names, unix_user, db_connection).await;
                 Response::CreateDatabases(result)