feat: DB operations can fail

src/db/common.rs

@@ -2,6 +2,7 @@ use tokio::sync::RwLock;
 
 use std::sync::Arc;
 
+use crate::db::error::BoxableError;
 use crate::db::{DatabaseInterface, UserRef};
 
 #[derive(Clone, Debug)]
@@ -26,13 +27,17 @@ impl<D: DatabaseInterface> Database<D> {
     /// TODO: we may want to make sure the method runs in constant time
     ///       to avoid leaking information about existing users...
     ///       or maybe we do not care.
-    pub async fn check_password(&self, user: &UserRef, password: &str) -> bool {
-        let Some(user) = self.get_user(user).await else {
+    pub async fn check_password(
+        &self,
+        user: &UserRef,
+        password: &str,
+    ) -> Result<bool, Box<dyn BoxableError>> {
+        let Some(user) = self.get_user(user).await? else {
             tracing::debug!("check_password: User not found {user}");
-            return false;
+            return Ok(false);
         };
 
         tracing::debug!("Comparing {} and {}", user.password, password);
-        user.password == password
+        Ok(user.password == password)
     }
 }

src/db/error.rs

@@ -1,6 +1,21 @@
+use ldap3_proto::LdapResultCode;
+
 use std::fmt;
 
 use crate::db::UserRef;
+use crate::ldap::LdapReturnError;
+
+pub trait BoxableError: std::error::Error + tracing::Value + Sync + Send + 'static {}
+
+impl<T: ?Sized + BoxableError> LdapReturnError for T {
+    fn code(&self) -> LdapResultCode {
+        LdapResultCode::Unavailable
+    }
+
+    fn message(&self) -> String {
+        self.to_string()
+    }
+}
 
 #[derive(Debug)]
 pub struct UserAlreadyExists(pub UserRef);

src/db/interface.rs

@@ -1,17 +1,23 @@
-use crate::db::error::UserAlreadyExists;
+use crate::db::error::{BoxableError, UserAlreadyExists};
 use crate::db::{Database, User, UserRef};
 
 impl<D: DatabaseInterface> DatabaseInterface for Database<D> {
-    async fn get_user(&self, user: &UserRef) -> Option<User> {
+    async fn get_user(&self, user: &UserRef) -> Result<Option<User>, Box<dyn BoxableError>> {
         self.inner.read().await.get_user(user).await
     }
 
-    async fn create_user(&mut self, user: User) -> Result<(), UserAlreadyExists> {
+    async fn create_user(
+        &mut self,
+        user: User,
+    ) -> Result<Result<(), UserAlreadyExists>, Box<dyn BoxableError>> {
         self.inner.write().await.create_user(user).await
     }
 }
 
 pub trait DatabaseInterface {
-    async fn get_user(&self, user: &UserRef) -> Option<User>;
-    async fn create_user(&mut self, user: User) -> Result<(), UserAlreadyExists>;
+    async fn get_user(&self, user: &UserRef) -> Result<Option<User>, Box<dyn BoxableError>>;
+    async fn create_user(
+        &mut self,
+        user: User,
+    ) -> Result<Result<(), UserAlreadyExists>, Box<dyn BoxableError>>;
 }

src/db/memory.rs

@@ -1,6 +1,6 @@
 use std::future::{Future, ready};
 
-use crate::db::error::UserAlreadyExists;
+use crate::db::error::{BoxableError, UserAlreadyExists};
 use crate::db::{Database, DatabaseInterface, Group, User, UserRef};
 
 #[derive(Clone, Debug, Default)]
@@ -16,23 +16,29 @@ impl MemoryDatabase {
 }
 
 impl DatabaseInterface for MemoryDatabase {
-    fn get_user(&self, req_user: &UserRef) -> impl Future<Output = Option<User>> {
+    fn get_user(
+        &self,
+        req_user: &UserRef,
+    ) -> impl Future<Output = Result<Option<User>, Box<dyn BoxableError>>> {
         for user in &self.users {
             if user.username == req_user.username && user.domain == req_user.domain {
-                return ready(Some(user.clone()));
+                return ready(Ok(Some(user.clone())));
             }
         }
 
-        ready(None)
+        ready(Ok(None))
     }
 
-    async fn create_user(&mut self, user: User) -> Result<(), UserAlreadyExists> {
+    async fn create_user(
+        &mut self,
+        user: User,
+    ) -> Result<Result<(), UserAlreadyExists>, Box<dyn BoxableError>> {
         let user_ref = user.user_ref();
-        if self.get_user(&user_ref).await.is_some() {
-            return Err(UserAlreadyExists(user_ref));
+        if self.get_user(&user_ref).await?.is_some() {
+            return Ok(Err(UserAlreadyExists(user_ref)));
         }
 
         self.users.push(user);
-        Ok(())
+        Ok(Ok(()))
     }
 }

src/ldap/op/bind.rs

@@ -1,13 +1,15 @@
 use ldap3_proto::proto::{LdapBindCred, LdapBindRequest, LdapBindResponse, LdapOp, LdapResult};
 use ldap3_proto::{LdapMsg, LdapResultCode};
 
+use crate::db::error::BoxableError;
 use crate::db::{Database, DatabaseInterface};
 use crate::ldap::{
     Dn, InvalidDnError, LdapReturnError, LdapStream, LdapStreamError, NotUserDnError,
 };
 
+#[derive(Debug)]
 pub enum BindError {
-    // TODO: DB Error
+    Db(Box<dyn BoxableError>),
     InvalidCredentials,
     InvalidDn(InvalidDnError),
     NotUserDn(NotUserDnError),
@@ -20,6 +22,7 @@ impl BindError {
         stream: &mut LdapStream,
         msgid: i32,
     ) -> Result<(), LdapStreamError> {
+        tracing::debug!(error=?self, "Bind failed");
         let resp_msg = LdapMsg {
             msgid,
             op: LdapOp::BindResponse(LdapBindResponse {
@@ -48,6 +51,7 @@ impl From<InvalidDnError> for BindError {
 impl LdapReturnError for BindError {
     fn code(&self) -> LdapResultCode {
         match self {
+            Self::Db(e) => e.code(),
             Self::InvalidCredentials => LdapResultCode::InvalidCredentials,
             Self::InvalidDn(e) => e.code(),
             Self::NotUserDn(e) => e.code(),
@@ -57,6 +61,7 @@ impl LdapReturnError for BindError {
 
     fn message(&self) -> String {
         match self {
+            Self::Db(e) => e.message(),
             Self::InvalidCredentials => "Wrong username or password".to_string(),
             Self::InvalidDn(e) => e.message(),
             Self::NotUserDn(e) => e.message(),
@@ -117,7 +122,16 @@ pub async fn op_bind<D: DatabaseInterface>(
         }
     };
 
-    if db.check_password(&user_ref, &password).await {
+    let success = match db.check_password(&user_ref, &password).await {
+        Ok(success) => success,
+        Err(e) => {
+            tracing::error!(error = e, "Database failure");
+            BindError::Db(e).error_message(stream, msgid).await?;
+            return Ok(None);
+        }
+    };
+
+    if success {
         bind_success(stream, msgid).await?;
         Ok(Some(dn))
     } else {

src/main.rs

@@ -22,6 +22,7 @@ async fn create_dummy_users<D: DatabaseInterface>(db: &mut Database<D>) {
             mail: format!("{domain}@{domain}.localhost"),
         })
         .await
+        .unwrap()
         .unwrap();
     }
 }