reject overlapping media and database paths

src/config.rs

@@ -538,5 +538,27 @@ where
         return Err(Error::RegistrationTokenEmpty);
     }
 
+    match &config.media.backend {
+        MediaBackendConfig::Filesystem(x) => {
+            let media_path = x
+                .path
+                .canonicalize()
+                .map_err(|e| Error::Canonicalize(e, x.path.clone()))?;
+
+            let database_path =
+                config.database.path.canonicalize().map_err(|e| {
+                    Error::Canonicalize(e, config.database.path.clone())
+                })?;
+
+            let overlap = media_path == database_path
+                || media_path.starts_with(&database_path)
+                || database_path.starts_with(&media_path);
+
+            if overlap {
+                return Err(Error::DatabaseMediaOverlap);
+            }
+        }
+    }
+
     Ok(config)
 }

src/error.rs

@@ -134,8 +134,14 @@ pub(crate) enum Config {
     #[error("failed to parse configuration file {1:?}")]
     Parse(#[source] toml::de::Error, PathBuf),
 
+    #[error("failed to canonicalize path {}", .1.display())]
+    Canonicalize(#[source] std::io::Error, PathBuf),
+
     #[error("registration token must not be empty")]
     RegistrationTokenEmpty,
+
+    #[error("database and media paths overlap")]
+    DatabaseMediaOverlap,
 }
 
 /// Errors that can occur while searching for a config file

tests/integrations/check_config.rs

@@ -93,3 +93,21 @@ make_snapshot_test!(
     "A config with invalid values fails",
     "invalid-values.toml",
 );
+
+make_snapshot_test!(
+    overlapping_paths_equal,
+    "A config with equal paths fails",
+    "equal-paths.toml",
+);
+
+make_snapshot_test!(
+    overlapping_paths_media,
+    "A config with the media path inside the database path fails",
+    "media-in-database.toml",
+);
+
+make_snapshot_test!(
+    overlapping_paths_database,
+    "A config with the database path inside the media path fails",
+    "database-in-media.toml",
+);

tests/integrations/fixtures/check_config/database-in-media.toml

@@ -0,0 +1,12 @@
+server_name = "example.com"
+
+[server_discovery]
+client.base_url = "https://matrix.example.com"
+
+[database]
+backend = "rocksdb"
+path = "tests/integrations/fixtures/check_config/dirs/c/a"
+
+[media.backend]
+type = "filesystem"
+path = "tests/integrations/fixtures/check_config/dirs/c"

tests/integrations/fixtures/check_config/dirs/a/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

tests/integrations/fixtures/check_config/dirs/b/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

tests/integrations/fixtures/check_config/dirs/c/a/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

tests/integrations/fixtures/check_config/equal-paths.toml

@@ -0,0 +1,12 @@
+server_name = "example.com"
+
+[server_discovery]
+client.base_url = "https://matrix.example.com"
+
+[database]
+backend = "rocksdb"
+path = "tests/integrations/fixtures/check_config/dirs/a"
+
+[media.backend]
+type = "filesystem"
+path = "tests/integrations/fixtures/check_config/dirs/a"

tests/integrations/fixtures/check_config/media-in-database.toml

@@ -0,0 +1,12 @@
+server_name = "example.com"
+
+[server_discovery]
+client.base_url = "https://matrix.example.com"
+
+[database]
+backend = "rocksdb"
+path = "tests/integrations/fixtures/check_config/dirs/c"
+
+[media.backend]
+type = "filesystem"
+path = "tests/integrations/fixtures/check_config/dirs/c/a"

tests/integrations/fixtures/check_config/minimal-valid.toml

@@ -5,8 +5,8 @@ client.base_url = "https://matrix.example.com"
 
 [database]
 backend = "rocksdb"
-path = "/var/lib/grapevine/database"
+path = "tests/integrations/fixtures/check_config/dirs/a"
 
 [media.backend]
 type = "filesystem"
-path = "/var/lib/grapevine/media"
+path = "tests/integrations/fixtures/check_config/dirs/b"

tests/integrations/fixtures/check_config/valid.toml

@@ -10,11 +10,11 @@ client.base_url = "https://matrix.example.com"
 
 [database]
 backend = "rocksdb"
-path = "/var/lib/grapevine/database"
+path = "tests/integrations/fixtures/check_config/dirs/a"
 
 [media.backend]
 type = "filesystem"
-path = "/var/lib/grapevine/media"
+path = "tests/integrations/fixtures/check_config/dirs/b"
 
 [federation]
 enable = true

tests/integrations/snapshots/integrations__check_config__overlapping_paths_database@status_code.snap

@@ -0,0 +1,7 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the database path inside the media path fails
+---
+Some(
+    1,
+)

tests/integrations/snapshots/integrations__check_config__overlapping_paths_database@stderr.snap

@@ -0,0 +1,6 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the database path inside the media path fails
+---
+Error: failed to validate configuration
+    Caused by: database and media paths overlap

tests/integrations/snapshots/integrations__check_config__overlapping_paths_database@stdout.snap

@@ -0,0 +1,5 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the database path inside the media path fails
+---
+

tests/integrations/snapshots/integrations__check_config__overlapping_paths_equal@status_code.snap

@@ -0,0 +1,7 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with equal paths fails
+---
+Some(
+    1,
+)

tests/integrations/snapshots/integrations__check_config__overlapping_paths_equal@stderr.snap

@@ -0,0 +1,6 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with equal paths fails
+---
+Error: failed to validate configuration
+    Caused by: database and media paths overlap

tests/integrations/snapshots/integrations__check_config__overlapping_paths_equal@stdout.snap

@@ -0,0 +1,5 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with equal paths fails
+---
+

tests/integrations/snapshots/integrations__check_config__overlapping_paths_media@status_code.snap

@@ -0,0 +1,7 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the media path inside the database path fails
+---
+Some(
+    1,
+)

tests/integrations/snapshots/integrations__check_config__overlapping_paths_media@stderr.snap

@@ -0,0 +1,6 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the media path inside the database path fails
+---
+Error: failed to validate configuration
+    Caused by: database and media paths overlap

tests/integrations/snapshots/integrations__check_config__overlapping_paths_media@stdout.snap

@@ -0,0 +1,5 @@
+---
+source: tests/integrations/check_config.rs
+description: A config with the media path inside the database path fails
+---
+