From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 18 Mar 2025 17:05:55 +0000 (+0000)
Subject: pty: Automatically drain when the event loop finishes
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5cf2d4d5b0f7fb283301b7d18ddf2049e179c531;p=pakfire.git

pty: Automatically drain when the event loop finishes

There was the problem that some content could have remained stuck in the
buffers on occasion.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/pakfire/jail.c b/src/pakfire/jail.c
index 065b2cf4..cf138530 100644
--- a/src/pakfire/jail.c
+++ b/src/pakfire/jail.c
@@ -982,9 +982,6 @@ static int pakfire_jail_exited(sd_event_source* source, const siginfo_t* si, voi
 			break;
 	}
 
-	// Drain the PTY
-	pakfire_pty_drain(ctx->pty);
-
 	// Terminate the event loop
 	return sd_event_exit(ctx->loop, 0);
 }
diff --git a/src/pakfire/pty.c b/src/pakfire/pty.c
index a343255c..88c00ca5 100644
--- a/src/pakfire/pty.c
+++ b/src/pakfire/pty.c
@@ -97,6 +97,9 @@ struct pakfire_pty {
 	// SIGWINCH Event
 	sd_event_source* sigwinch_event;
 
+	// Exit Event
+	sd_event_source* exit_event;
+
 	// State
 	enum {
 		PAKFIRE_PTY_STATE_INIT = 0,
@@ -257,6 +260,8 @@ static int pakfire_pty_disconnect(struct pakfire_pty* pty) {
 		pty->stdout.event = sd_event_source_unref(pty->stdout.event);
 	if (pty->sigwinch_event)
 		pty->sigwinch_event = sd_event_source_unref(pty->sigwinch_event);
+	if (pty->exit_event)
+		pty->exit_event = sd_event_source_unref(pty->exit_event);
 
 	// Close the PTY
 	if (pty->master.fd >= 0) {
@@ -796,6 +801,42 @@ static int pakfire_pty_SIGWINCH(sd_event_source* source, const struct signalfd_s
 	return 0;
 }
 
+static int pakfire_pty_drain(struct pakfire_pty* pty) {
+	// Log action
+	DEBUG(pty->ctx, "Draining requested\n");
+
+	// Update state
+	pty->state = PAKFIRE_PTY_STATE_DRAINING;
+
+	return pakfire_pty_drained(pty);
+}
+
+static int pakfire_pty_exit(sd_event_source* source, void* data) {
+	struct pakfire_pty* self = data;
+	int r;
+
+	DEBUG(self->ctx, "Exiting the PTY...\n");
+
+	// Unless we are already drained, try to drain all buffers
+	if (!pakfire_pty_drain(self)) {
+		if (!(self->master.io & PAKFIRE_PTY_HANGUP))
+			self->master.io |= PAKFIRE_PTY_READY_TO_READ | PAKFIRE_PTY_READY_TO_WRITE;
+
+		if (!(self->stdin.io & PAKFIRE_PTY_HANGUP))
+			self->stdin.io |= PAKFIRE_PTY_READY_TO_READ;
+
+		if (!(self->stdout.io & PAKFIRE_PTY_HANGUP))
+			self->stdout.io |= PAKFIRE_PTY_READY_TO_WRITE;
+
+		// Keep forwarding...
+		r = pakfire_pty_forward(self);
+		if (r < 0)
+			return r;
+	}
+
+	return pakfire_pty_done(self, 0);
+}
+
 static int pakfire_pty_activity(struct pakfire_pty* pty, struct pakfire_pty_stdio* stdio, uint32_t events) {
 	// Do we have data to read?
 	if (events & (EPOLLIN|EPOLLHUP))
@@ -1231,6 +1272,13 @@ static int pakfire_pty_setup(sd_event_source* source, int fd, uint32_t events, v
 		return -errno;
 	}
 
+	// Drain all buffers on exit
+	r = sd_event_add_exit(pty->loop, &pty->exit_event, pakfire_pty_exit, pty);
+	if (r < 0) {
+		ERROR(pty->ctx, "Could not register exit callback: %s\n", strerror(-r));
+		return r;
+	}
+
 	// Setup forwarding
 	r = pakfire_pty_setup_forwarding(pty);
 	if (r < 0)
@@ -1495,12 +1543,6 @@ int pakfire_pty_open(struct pakfire_pty* pty) {
 	return 0;
 }
 
-int pakfire_pty_drain(struct pakfire_pty* pty) {
-	pty->state = PAKFIRE_PTY_STATE_DRAINING;
-
-	return pakfire_pty_drained(pty);
-}
-
 /*
 	Creates an independent copy of the output buffer
 */
diff --git a/src/pakfire/pty.h b/src/pakfire/pty.h
index a8374def..d6fc0d1c 100644
--- a/src/pakfire/pty.h
+++ b/src/pakfire/pty.h
@@ -48,8 +48,6 @@ struct pakfire_pty* pakfire_pty_unref(struct pakfire_pty* pty);
 
 int pakfire_pty_open(struct pakfire_pty* pty);
 
-int pakfire_pty_drain(struct pakfire_pty* pty);
-
 char* pakfire_pty_output(struct pakfire_pty* pty, size_t* length);
 
 typedef ssize_t (*pakfire_pty_stdin_callback)(