From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 24 Mar 2025 18:13:39 +0000 (+0000)
Subject: jail: Only make the parent ends of the pipes non-blocking
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fb87a15ce1c4e9f9a9c8cfb424e19bfd530345d6;p=pakfire.git

jail: Only make the parent ends of the pipes non-blocking

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

diff --git a/src/pakfire/jail.c b/src/pakfire/jail.c
index 65ea4125..2e66363d 100644
--- a/src/pakfire/jail.c
+++ b/src/pakfire/jail.c
@@ -1239,6 +1239,11 @@ static int pakfire_jail_parent(struct pakfire_jail* jail, struct pakfire_jail_ex
 	// Prepare standard input for writing
 	fd = pakfire_jail_get_pipe_to_write(jail, &ctx->pipes.stdin);
 	if (fd >= 0) {
+		r = pakfire_fd_set_non_blocking(jail->ctx, fd);
+		if (r < 0)
+			return r;
+
+		// Add the file descriptor to the event loop
 		r = sd_event_add_io(ctx->loop, NULL, fd, EPOLLOUT|EPOLLHUP|EPOLLET, pakfire_jail_stdin, ctx);
 		if (r < 0) {
 			ERROR(jail->ctx, "Failed to register standard input for writing: %s\n", strerror(-r));
@@ -1249,6 +1254,11 @@ static int pakfire_jail_parent(struct pakfire_jail* jail, struct pakfire_jail_ex
 	// Prepare standard output for reading
 	fd = pakfire_jail_get_pipe_to_read(jail, &ctx->pipes.stdout);
 	if (fd >= 0) {
+		r = pakfire_fd_set_non_blocking(jail->ctx, fd);
+		if (r < 0)
+			return r;
+
+		// Add the file descriptor to the event loop
 		r = sd_event_add_io(ctx->loop, NULL, fd, EPOLLIN|EPOLLHUP|EPOLLET, pakfire_jail_stdout, ctx);
 		if (r < 0) {
 			ERROR(jail->ctx, "Failed to register standard output for reading: %s\n", strerror(-r));
@@ -1259,6 +1269,11 @@ static int pakfire_jail_parent(struct pakfire_jail* jail, struct pakfire_jail_ex
 	// Prepare standard error for reading
 	fd = pakfire_jail_get_pipe_to_read(jail, &ctx->pipes.stderr);
 	if (fd >= 0) {
+		r = pakfire_fd_set_non_blocking(jail->ctx, fd);
+		if (r < 0)
+			return r;
+
+		// Add the file descriptor to the event loop
 		r = sd_event_add_io(ctx->loop, NULL, fd, EPOLLIN|EPOLLHUP|EPOLLET, pakfire_jail_stderr, ctx);
 		if (r < 0) {
 			ERROR(jail->ctx, "Failed to register standard error for reading: %s\n", strerror(-r));
@@ -1701,19 +1716,19 @@ static int __pakfire_jail_exec(struct pakfire_jail* jail,
 	// Otherwise we are running a non-interactive session
 	} else {
 		// Create a pipe for the standard input only when a callback is set
-		if (stdin_callback) {
-			r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stdin, O_NONBLOCK);
+		if (input_callback) {
+			r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stdin, 0);
 			if (r < 0)
 				goto ERROR;
 		}
 
 		// Create a pipe for standard output
-		r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stdout, O_NONBLOCK);
+		r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stdout, 0);
 		if (r < 0)
 			goto ERROR;
 
 		// Create a pipe for standard error
-		r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stderr, O_NONBLOCK);
+		r = pakfire_jail_setup_pipe(jail, &ctx.pipes.stderr, 0);
 		if (r < 0)
 			goto ERROR;
 
diff --git a/src/pakfire/util.c b/src/pakfire/util.c
index 3debaf2c..bf2e856b 100644
--- a/src/pakfire/util.c
+++ b/src/pakfire/util.c
@@ -477,3 +477,24 @@ int pakfire_copy(struct pakfire_ctx* ctx, FILE* src, FILE* dst) {
 
 	return 0;
 }
+
+int pakfire_fd_set_non_blocking(struct pakfire_ctx* ctx, int fd) {
+	int flags;
+	int r;
+
+	// Fetch the flags
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags < 0) {
+		ERROR(ctx, "Could not set flags for file descriptor %d: %m\n", fd);
+		return -errno;
+	}
+
+	// Turn on non-blocking mode
+	r = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+	if (r < 0) {
+		ERROR(ctx, "Could not set flags for file descriptor %d: %m\n", fd);
+		return -errno;
+	}
+
+	return 0;
+}
diff --git a/src/pakfire/util.h b/src/pakfire/util.h
index 5adb68ca..e72ffea7 100644
--- a/src/pakfire/util.h
+++ b/src/pakfire/util.h
@@ -91,6 +91,9 @@ int pakfire_compile_regex(struct pakfire_ctx* ctx, pcre2_code** regex, const cha
 // Copy
 int pakfire_copy(struct pakfire_ctx* ctx, FILE* src, FILE* dst);
 
+// File Descriptors
+int pakfire_fd_set_non_blocking(struct pakfire_ctx* ctx, int fd);
+
 // Time
 
 // seconds to microseconds