Check the socket path before the daemon writes

The daemon checks the length of the socket path first, before it reads
the config, takes the token lock, or opens the agent. With a data
directory whose path is too long, it gives the error and leaves the
directory empty, so a failed start leaves no agent or lock file behind.

Issue: 5daf23e

diff --git a/daemon.go b/daemon.go
index 034cac7fdd43af811b70e84ed1aa203d6ab43c44..58bf502b5bba1b31d226f9439ac9038310a253ad 100644 (file)
--- a/daemon.go
+++ b/daemon.go
@@ -56,6 +56,14 @@ func daemon(ctx context.Context, out io.Writer) (err error) {
                return err
        }
 
+       // Check the socket path before the daemon writes a file, so that a data
+       // directory with a long path stays empty.
+       socket := filepath.Join(dir, socketFileName)
+       err = checkSocketPath(socket)
+       if err != nil {
+               return err
+       }
+
        config, err := loadConfig(dir)
        if err != nil {
                return err
@@ -90,7 +98,7 @@ func daemon(ctx context.Context, out io.Writer) (err error) {
                err = errors.Join(err, memory.Close())
        }()
 
-       listener, err := listenSocket(filepath.Join(dir, socketFileName))
+       listener, err := listenSocket(socket)
        if err != nil {
                return err
        }

diff --git a/daemon_test.go b/daemon_test.go
index 91d6ecc8658095f12c6be089e2b229ab7db83889..fe409293d85f50638eeb7cc017942e0e19488e01 100644 (file)
--- a/daemon_test.go
+++ b/daemon_test.go
@@ -116,6 +116,18 @@ func TestListenSocketRefusesALongPath(t *testing.T) {
        require.ErrorContains(t, err, "set ONECHAT_DIR to a shorter path")
 }
 
+func TestDaemonWritesNoFileForALongSocketPath(t *testing.T) {
+       dir := filepath.Join(t.TempDir(), strings.Repeat("d", 100))
+       t.Setenv("ONECHAT_DIR", dir)
+
+       err := daemon(t.Context(), io.Discard)
+       require.ErrorContains(t, err, "set ONECHAT_DIR to a shorter path")
+
+       entries, err := os.ReadDir(dir)
+       require.NoError(t, err)
+       require.Empty(t, entries)
+}
+
 func TestOneProcessHoldsTheTokens(t *testing.T) {
        dir := t.TempDir()
        lock, err := lockTokens(dir)