Integrate better with systemd + better logs and protocol usage

This commits adds the following:

- Better systemd integration and usage:
  - More hardening
  - A watchdog thread
  - Journald native logging

as well as

- Better logs
- Some protocol usage fixes

Cargo.lock

@@ -253,6 +253,16 @@ dependencies = [
  "clap_derive",
 ]
 
+[[package]]
+name = "clap-verbosity-flag"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63d19864d6b68464c59f7162c9914a0b569ddc2926b4a2d71afe62a9738eff53"
+dependencies = [
+ "clap",
+ "log",
+]
+
 [[package]]
 name = "clap_builder"
 version = "4.5.15"
@@ -993,6 +1003,9 @@ name = "log"
 version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+dependencies = [
+ "value-bag",
+]
 
 [[package]]
 name = "lru"
@@ -1064,6 +1077,7 @@ dependencies = [
  "async-bincode",
  "bincode",
  "clap",
+ "clap-verbosity-flag",
  "clap_complete",
  "derive_more",
  "dialoguer",
@@ -1082,6 +1096,7 @@ dependencies = [
  "serde",
  "serde_json",
  "sqlx",
+ "systemd-journal-logger",
  "tokio",
  "tokio-serde",
  "tokio-stream",
@@ -1996,6 +2011,16 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "systemd-journal-logger"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5f3848dd723f2a54ac1d96da793b32923b52de8dfcced8722516dac312a5b2a"
+dependencies = [
+ "log",
+ "rustix",
+]
+
 [[package]]
 name = "tempfile"
 version = "3.12.0"
@@ -2287,6 +2312,12 @@ dependencies = [
  "getrandom",
 ]
 
+[[package]]
+name = "value-bag"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a84c137d37ab0142f0f2ddfe332651fdbf252e7b7dbb4e67b6c1f1b2e925101"
+
 [[package]]
 name = "vcpkg"
 version = "0.2.15"

Cargo.toml

@@ -8,6 +8,7 @@ anyhow = "1.0.86"
 async-bincode = "0.7.2"
 bincode = "1.3.3"
 clap = { version = "4.5.16", features = ["derive"] }
+clap-verbosity-flag = "2.2.1"
 clap_complete = "4.5.18"
 derive_more = { version = "1.0.0", features = ["display", "error"] }
 dialoguer = "0.11.0"
@@ -25,6 +26,7 @@ sd-notify = "0.4.2"
 serde = "1.0.208"
 serde_json = { version = "1.0.125", features = ["preserve_order"] }
 sqlx = { version = "0.8.0", features = ["runtime-tokio", "mysql", "tls-rustls"] }
+systemd-journal-logger = "2.1.1"
 tokio = { version = "1.39.3", features = ["rt", "macros"] }
 tokio-serde = { version = "0.9.0", features = ["bincode"] }
 tokio-stream = "0.1.15"

nix/module.nix

@@ -15,6 +15,20 @@ in
       description = "Create a local database user for mysqladm-rs";
     };
 
+    logLevel = lib.mkOption {
+      type = lib.types.enum [ "quiet" "error" "warn" "info" "debug" "trace" ];
+      default = "debug";
+      description = "Log level for mysqladm-rs";
+      apply = level: {
+        "quiet" = "-q";
+        "error" = "";
+        "warn" = "-v";
+        "info" = "-vv";
+        "debug" = "-vvv";
+        "trace" = "-vvvv";
+      }.${level};
+    };
+
     settings = lib.mkOption {
       default = { };
       type = lib.types.submodule {
@@ -76,7 +90,7 @@ in
         name = cfg.settings.mysql.username;
         ensurePermissions = {
           "mysql.*" = "SELECT, INSERT, UPDATE, DELETE";
-          "*.*" = "CREATE USER, GRANT OPTION";
+          "*.*" = "GRANT OPTION, CREATE, DROP";
         };
       }
     ];
@@ -86,7 +100,9 @@ in
       environment.RUST_LOG = "debug";
       serviceConfig = {
         Type = "notify";
-        ExecStart = "${lib.getExe cfg.package} server socket-activate --config ${configFile}";
+        ExecStart = "${lib.getExe cfg.package} ${cfg.logLevel} server --systemd socket-activate --config ${configFile}";
+
+        WatchdogSec = 15;
 
         User = "mysqladm";
         Group = "mysqladm";
@@ -95,7 +111,18 @@ in
         # This is required to read unix user/group details.
         PrivateUsers = false;
 
-        CapabilityBoundingSet = "";
+        # Needed to communicate with MySQL.
+        PrivateNetwork = false;
+
+        IPAddressDeny =
+          lib.optionals (lib.elem cfg.settings.mysql.host [ null "localhost" "127.0.0.1" ]) [ "any" ];
+
+        RestrictAddressFamilies = [ "AF_UNIX" ]
+          ++ (lib.optionals (cfg.settings.mysql.host != null) [ "AF_INET" "AF_INET6" ]);
+
+        AmbientCapabilities = [ "" ];
+        CapabilityBoundingSet = [ "" ];
+        DeviceAllow = [ "" ];
         LockPersonality = true;
         MemoryDenyWriteExecute = true;
         NoNewPrivileges = true;
@@ -113,12 +140,12 @@ in
         ProtectProc = "invisible";
         ProtectSystem = "strict";
         RemoveIPC = true;
-        UMask = "0000";
+        UMask = "0777";
-        RestrictAddressFamilies = [ "AF_UNIX" "AF_INET" "AF_INET6" ];
         RestrictNamespaces = true;
         RestrictRealtime = true;
         RestrictSUIDSGID = true;
         SystemCallArchitectures = "native";
+        SocketBindDeny = [ "any" ];
         SystemCallFilter = [
           "@system-service"
           "~@privileged"

src/cli/database_command.rs

@@ -393,6 +393,7 @@ pub async fn edit_database_privileges(
 
     if diffs.is_empty() {
         println!("No changes to make.");
+        server_connection.send(Request::Exit).await?;
         return Ok(());
     }
 

src/main.rs

@@ -3,6 +3,7 @@ extern crate prettytable;
 
 use clap::{CommandFactory, Parser, ValueEnum};
 use clap_complete::{generate, Shell};
+use clap_verbosity_flag::Verbosity;
 
 use std::path::PathBuf;
 
@@ -62,6 +63,10 @@ struct Args {
     )]
     config: Option<PathBuf>,
 
+    #[command(flatten)]
+    verbose: Verbosity,
+
+    /// Run in TUI mode.
     #[cfg(feature = "tui")]
     #[arg(short, long, alias = "tui", global = true)]
     interactive: bool,
@@ -103,11 +108,6 @@ enum ToplevelCommands {
 //       comments emphasizing the need for caution.
 
 fn main() -> anyhow::Result<()> {
-    // TODO: find out if there are any security risks of running
-    //       env_logger and clap with elevated privileges.
-
-    env_logger::init();
-
     #[cfg(feature = "mysql-admutils-compatibility")]
     if handle_mysql_admutils_command()?.is_some() {
         return Ok(());
@@ -126,6 +126,10 @@ fn main() -> anyhow::Result<()> {
     let server_connection =
         bootstrap_server_connection_and_drop_privileges(args.server_socket_path, args.config)?;
 
+    env_logger::Builder::new()
+        .filter_level(args.verbose.log_level_filter())
+        .init();
+
     tokio_run_command(args.command, server_connection)?;
 
     Ok(())
@@ -151,6 +155,7 @@ fn handle_server_command(args: &Args) -> anyhow::Result<Option<()>> {
             tokio_start_server(
                 args.server_socket_path.clone(),
                 args.config.clone(),
+                args.verbose.clone(),
                 command.clone(),
             )?;
             Ok(Some(()))
@@ -188,6 +193,7 @@ fn handle_generate_completions_command(args: &Args) -> anyhow::Result<Option<()>
 fn tokio_start_server(
     server_socket_path: Option<PathBuf>,
     config_path: Option<PathBuf>,
+    verbosity: Verbosity,
     args: ServerArgs,
 ) -> anyhow::Result<()> {
     tokio::runtime::Builder::new_current_thread()
@@ -195,7 +201,7 @@ fn tokio_start_server(
         .build()
         .unwrap()
         .block_on(async {
-            server::command::handle_command(server_socket_path, config_path, args).await
+            server::command::handle_command(server_socket_path, config_path, verbosity, args).await
         })
 }
 

src/server/command.rs

@@ -3,11 +3,16 @@ use std::path::PathBuf;
 
 use anyhow::Context;
 use clap::Parser;
+use clap_verbosity_flag::Verbosity;
+use futures::SinkExt;
+use indoc::concatdoc;
+use systemd_journal_logger::JournalLog;
 
 use std::os::unix::net::UnixStream as StdUnixStream;
 use tokio::net::UnixStream as TokioUnixStream;
 
 use crate::core::common::UnixUser;
+use crate::core::protocol::{create_server_to_client_message_stream, Response};
 use crate::server::config::read_config_from_path_with_arg_overrides;
 use crate::server::server_loop::listen_for_incoming_connections;
 use crate::server::{
@@ -22,6 +27,9 @@ pub struct ServerArgs {
 
     #[command(flatten)]
     config_overrides: ServerConfigArgs,
+
+    #[arg(long)]
+    systemd: bool,
 }
 
 #[derive(Parser, Debug, Clone)]
@@ -33,27 +41,148 @@ pub enum ServerCommand {
     SocketActivate,
 }
 
+const LOG_LEVEL_WARNING: &str = r#"
+===================================================
+== WARNING: LOG LEVEL IS SET TO 'TRACE'!         ==
+== THIS WILL CAUSE THE SERVER TO LOG SQL QUERIES ==
+== THAT MAY CONTAIN SENSITIVE INFORMATION LIKE   ==
+== PASSWORDS AND AUTHENTICATION TOKENS.          ==
+== THIS IS INTENDED FOR DEBUGGING PURPOSES ONLY  ==
+== AND SHOULD *NEVER* BE USED IN PRODUCTION.     ==
+===================================================
+"#;
+
 pub async fn handle_command(
     socket_path: Option<PathBuf>,
     config_path: Option<PathBuf>,
+    verbosity: Verbosity,
     args: ServerArgs,
 ) -> anyhow::Result<()> {
+    let mut auto_detected_systemd_mode = false;
+    let systemd_mode = args.systemd || {
+        if let Ok(true) = sd_notify::booted() {
+            auto_detected_systemd_mode = true;
+            true
+        } else {
+            false
+        }
+    };
+    if systemd_mode {
+        JournalLog::new()
+            .context("Failed to initialize journald logging")?
+            .install()
+            .context("Failed to install journald logger")?;
+
+        log::set_max_level(verbosity.log_level_filter());
+
+        if verbosity.log_level_filter() >= log::LevelFilter::Trace {
+            log::warn!("{}", LOG_LEVEL_WARNING.trim());
+        }
+
+        if auto_detected_systemd_mode {
+            log::info!("Running in systemd mode, auto-detected");
+        } else {
+            log::info!("Running in systemd mode");
+        }
+
+        start_watchdog_thread_if_enabled();
+    } else {
+        env_logger::Builder::new()
+            .filter_level(verbosity.log_level_filter())
+            .init();
+
+        log::info!("Running in standalone mode");
+    }
+
     let config = read_config_from_path_with_arg_overrides(config_path, args.config_overrides)?;
 
     match args.subcmd {
         ServerCommand::Listen => listen_for_incoming_connections(socket_path, config).await,
-        ServerCommand::SocketActivate => socket_activate(config).await,
+        ServerCommand::SocketActivate => {
+            if !args.systemd {
+                anyhow::bail!(concat!(
+                    "The `--systemd` flag must be used with the `socket-activate` command.\n",
+                    "This command currently only supports socket activation under systemd."
+                ));
+            }
+
+            socket_activate(config).await
+        }
+    }
+}
+
+fn start_watchdog_thread_if_enabled() {
+    let mut micro_seconds: u64 = 0;
+    let watchdog_enabled = sd_notify::watchdog_enabled(true, &mut micro_seconds);
+
+    if watchdog_enabled {
+        micro_seconds = micro_seconds.max(2_000_000).div_ceil(2);
+
+        tokio::spawn(async move {
+            log::debug!(
+                "Starting systemd watchdog thread with {} millisecond interval",
+                micro_seconds.div_ceil(1000)
+            );
+            loop {
+                tokio::time::sleep(tokio::time::Duration::from_micros(micro_seconds)).await;
+                if let Err(err) = sd_notify::notify(false, &[sd_notify::NotifyState::Watchdog]) {
+                    log::warn!("Failed to notify systemd watchdog: {}", err);
+                } else {
+                    log::trace!("Ping sent to systemd watchdog");
+                }
+            }
+        });
+    } else {
+        log::debug!("Systemd watchdog not enabled, skipping watchdog thread");
     }
 }
 
 async fn socket_activate(config: ServerConfig) -> anyhow::Result<()> {
     let conn = get_socket_from_systemd().await?;
-    let uid = conn.peer_cred()?.uid();
+
-    let unix_user = UnixUser::from_uid(uid)?;
+    let uid = match conn.peer_cred() {
+        Ok(cred) => cred.uid(),
+        Err(e) => {
+            log::error!("Failed to get peer credentials from socket: {}", e);
+            let mut message_stream = create_server_to_client_message_stream(conn);
+            message_stream
+                .send(Response::Error(
+                    (concatdoc! {
+                        "Server failed to get peer credentials from socket\n",
+                        "Please check the server logs or contact the system administrators"
+                    })
+                    .to_string(),
+                ))
+                .await
+                .ok();
+            anyhow::bail!("Failed to get peer credentials from socket");
+        }
+    };
+
+    log::debug!("Accepted connection from uid {}", uid);
+
+    let unix_user = match UnixUser::from_uid(uid) {
+        Ok(user) => user,
+        Err(e) => {
+            log::error!("Failed to get username from uid: {}", e);
+            let mut message_stream = create_server_to_client_message_stream(conn);
+            message_stream
+                .send(Response::Error(
+                    (concatdoc! {
+                        "Server failed to get user data from the system\n",
+                        "Please check the server logs or contact the system administrators"
+                    })
+                    .to_string(),
+                ))
+                .await
+                .ok();
+            anyhow::bail!("Failed to get username from uid");
+        }
+    };
 
     log::info!("Accepted connection from {}", unix_user.username);
 
-    sd_notify::notify(true, &[sd_notify::NotifyState::Ready]).ok();
+    sd_notify::notify(false, &[sd_notify::NotifyState::Ready]).ok();
 
     handle_requests_for_single_session(conn, &unix_user, &config).await?;
 
@@ -66,7 +195,12 @@ async fn get_socket_from_systemd() -> anyhow::Result<TokioUnixStream> {
         .next()
         .context("No file descriptors received from systemd")?;
 
-    log::debug!("Received file descriptor from systemd: {}", fd);
+    debug_assert!(fd == 3, "Unexpected file descriptor from systemd: {}", fd);
+
+    log::debug!(
+        "Received file descriptor from systemd with id: '{}', assuming socket",
+        fd
+    );
 
     let std_unix_stream = unsafe { StdUnixStream::from_raw_fd(fd) };
     let socket = TokioUnixStream::from_std(std_unix_stream)?;

src/server/config.rs

@@ -109,18 +109,12 @@ pub fn read_config_from_path_with_arg_overrides(
 pub fn read_config_from_path(config_path: Option<PathBuf>) -> anyhow::Result<ServerConfig> {
     let config_path = config_path.unwrap_or_else(|| PathBuf::from(DEFAULT_CONFIG_PATH));
 
-    log::debug!("Reading config from {:?}", &config_path);
+    log::debug!("Reading config file at {:?}", &config_path);
 
     fs::read_to_string(&config_path)
-        .context(format!(
+        .context(format!("Failed to read config file at {:?}", &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!(
+        .context(format!("Failed to parse config file at {:?}", &config_path))
-            "Failed to parse config file from {:?}",
-            &config_path
-        ))
 }
 
 fn log_config(config: &MysqlConfig) {
@@ -141,7 +135,9 @@ pub async fn create_mysql_connection_from_config(
 ) -> anyhow::Result<MySqlConnection> {
     log_config(config);
 
-    let mut mysql_options = MySqlConnectOptions::new().database("mysql");
+    let mut mysql_options = MySqlConnectOptions::new()
+        .database("mysql")
+        .log_statements(log::LevelFilter::Trace);
 
     if let Some(username) = &config.username {
         mysql_options = mysql_options.username(username);

src/server/server_loop.rs

@@ -7,6 +7,7 @@ use tokio::net::{UnixListener, UnixStream};
 use sqlx::prelude::*;
 use sqlx::MySqlConnection;
 
+use crate::core::protocol::SetPasswordError;
 use crate::server::sql::database_operations::list_databases;
 use crate::{
     core::{
@@ -56,7 +57,7 @@ pub async fn listen_for_incoming_connections(
 
     let listener = UnixListener::bind(socket_path)?;
 
-    sd_notify::notify(true, &[sd_notify::NotifyState::Ready]).ok();
+    sd_notify::notify(false, &[sd_notify::NotifyState::Ready]).ok();
 
     while let Ok((conn, _addr)) = listener.accept().await {
         let uid = match conn.peer_cred() {
@@ -78,7 +79,7 @@ pub async fn listen_for_incoming_connections(
             }
         };
 
-        log::trace!("Accepted connection from uid {}", uid);
+        log::debug!("Accepted connection from uid {}", uid);
 
         let unix_user = match UnixUser::from_uid(uid) {
             Ok(user) => user,
@@ -173,47 +174,47 @@ pub async fn handle_requests_for_single_session_with_db_connection(
             }
         };
 
-        log::trace!("Received request: {:?}", request);
+        // TODO: don't clone the request
+        let request_to_display = match &request {
+            Request::PasswdUser(db_user, _) => {
+                Request::PasswdUser(db_user.to_owned(), "<REDACTED>".to_string())
+            }
+            request => request.to_owned(),
+        };
+        log::info!("Received request: {:#?}", request_to_display);
 
-        match request {
+        let response = match request {
             Request::CreateDatabases(databases_names) => {
                 let result = create_databases(databases_names, unix_user, db_connection).await;
-                stream.send(Response::CreateDatabases(result)).await?;
+                Response::CreateDatabases(result)
             }
             Request::DropDatabases(databases_names) => {
                 let result = drop_databases(databases_names, unix_user, db_connection).await;
-                stream.send(Response::DropDatabases(result)).await?;
+                Response::DropDatabases(result)
-            }
-            Request::ListDatabases(database_names) => {
-                let response = match database_names {
-                    Some(database_names) => {
-                        let result = list_databases(database_names, unix_user, db_connection).await;
-                        Response::ListDatabases(result)
-                    }
-                    None => {
-                        let result = list_all_databases_for_user(unix_user, db_connection).await;
-                        Response::ListAllDatabases(result)
-                    }
-                };
-                stream.send(response).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?;
             }
+            Request::ListDatabases(database_names) => match database_names {
+                Some(database_names) => {
+                    let result = list_databases(database_names, unix_user, db_connection).await;
+                    Response::ListDatabases(result)
+                }
+                None => {
+                    let result = list_all_databases_for_user(unix_user, db_connection).await;
+                    Response::ListAllDatabases(result)
+                }
+            },
+            Request::ListPrivileges(database_names) => 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)
+                }
+            },
             Request::ModifyPrivileges(database_privilege_diffs) => {
                 let result = apply_privilege_diffs(
                     BTreeSet::from_iter(database_privilege_diffs),
@@ -221,50 +222,58 @@ pub async fn handle_requests_for_single_session_with_db_connection(
                     db_connection,
                 )
                 .await;
-                stream.send(Response::ModifyPrivileges(result)).await?;
+                Response::ModifyPrivileges(result)
             }
             Request::CreateUsers(db_users) => {
                 let result = create_database_users(db_users, unix_user, db_connection).await;
-                stream.send(Response::CreateUsers(result)).await?;
+                Response::CreateUsers(result)
             }
             Request::DropUsers(db_users) => {
                 let result = drop_database_users(db_users, unix_user, db_connection).await;
-                stream.send(Response::DropUsers(result)).await?;
+                Response::DropUsers(result)
             }
             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?;
+                Response::PasswdUser(result)
-            }
-            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?;
             }
+            Request::ListUsers(db_users) => 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)
+                }
+            },
             Request::LockUsers(db_users) => {
                 let result = lock_database_users(db_users, unix_user, db_connection).await;
-                stream.send(Response::LockUsers(result)).await?;
+                Response::LockUsers(result)
             }
             Request::UnlockUsers(db_users) => {
                 let result = unlock_database_users(db_users, unix_user, db_connection).await;
-                stream.send(Response::UnlockUsers(result)).await?;
+                Response::UnlockUsers(result)
             }
             Request::Exit => {
                 break;
             }
-        }
+        };
 
+        // TODO: don't clone the response
+        let response_to_display = match &response {
+            Response::PasswdUser(Err(SetPasswordError::MySqlError(_))) => {
+                Response::PasswdUser(Err(SetPasswordError::MySqlError("<REDACTED>".to_string())))
+            }
+            response => response.to_owned(),
+        };
+        log::info!("Response: {:#?}", response_to_display);
+
+        stream.send(response).await?;
         stream.flush().await?;
+        log::debug!("Successfully processed request");
     }
 
     Ok(())

src/server/sql/user_operations.rs

@@ -167,7 +167,7 @@ pub async fn set_password_for_database_user(
         format!(
             "ALTER USER {}@'%' IDENTIFIED BY {}",
             quote_literal(db_user),
-            quote_literal(password).as_str()
+            quote_literal(password).as_str(),
         )
         .as_str(),
     )
@@ -176,11 +176,10 @@ pub async fn set_password_for_database_user(
     .map(|_| ())
     .map_err(|err| SetPasswordError::MySqlError(err.to_string()));
 
-    if let Err(err) = &result {
+    if result.is_err() {
         log::error!(
-            "Failed to set password for database user '{}': {:?}",
+            "Failed to set password for database user '{}': <REDACTED>",
             &db_user,
-            err
         );
     }