From: Asain Kujovic <asainnp@gmail.com>
Date: Tue, 24 Dec 2024 01:13:36 +0000 (+0100)
Subject: - LXC attach should exit on SIGCHLD
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f02158439677d0c1d4b2ed2ed1ba9bc43923a05d;p=thirdparty%2Flxc.git

- LXC attach should exit on SIGCHLD

Signed-off-by: Asain Kujovic <asainnp@gmail.com>
---

diff --git a/src/lxc/attach.c b/src/lxc/attach.c
index 8f2f7a37c..27acd401e 100644
--- a/src/lxc/attach.c
+++ b/src/lxc/attach.c
@@ -1430,6 +1430,15 @@ static inline void lxc_attach_terminal_close_log(struct lxc_terminal *terminal)
 	close_prot_errno_disarm(terminal->log_fd);
 }
 
+void lxc_attach_sig_handler(int signum) {
+	// exit on SIGCHLD, but not if sender-pid is 0 (main process)
+	if (signum == SIGCHLD) {
+		int sender_pid = waitpid(-1, NULL, WNOHANG);
+		if (sender_pid > 0)
+			exit(EXIT_SUCCESS);
+	}
+}
+
 int lxc_attach(struct lxc_container *container, lxc_attach_exec_t exec_function,
 	       void *exec_payload, lxc_attach_options_t *options,
 	       pid_t *attached_process)
@@ -1734,6 +1743,7 @@ int lxc_attach(struct lxc_container *container, lxc_attach_exec_t exec_function,
 		signal(SIGINT, SIG_IGN);
 		signal(SIGQUIT, SIG_IGN);
 	}
+	signal(SIGCHLD, lxc_attach_sig_handler);
 
 	/* Reap transient process. */
 	ret = wait_for_pid(pid);