upstream: SIGINFO handler for ssh(1) to dump active

channels/sessions ok deraadt@

OpenBSD-Commit-ID: 12f88a5044bca40ef5f41ff61b1755d0e25df901

diff --git a/clientloop.c b/clientloop.c
index 5f6577f6563282565bf4ef27d75bea5d2f9978bb..b9c050409861480713f3168318257a0ad21f9576 100644 (file)
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.412 2025/06/17 01:20:17 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.413 2025/08/18 03:28:36 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -147,7 +147,8 @@ extern char *forward_agent_sock_path;
  * because this is updated in a signal handler.
  */
 static volatile sig_atomic_t received_window_change_signal = 0;
-static volatile sig_atomic_t received_signal = 0;
+static volatile sig_atomic_t siginfo_received = 0;
+static volatile sig_atomic_t received_signal = 0; /* exit signals */
 
 /* Time when backgrounded control master using ControlPersist should exit */
 static time_t control_persist_exit_time = 0;
@@ -224,6 +225,13 @@ window_change_handler(int sig)
        received_window_change_signal = 1;
 }
 
+/* Signal handler for SIGINFO */
+static void
+siginfo_handler(int sig)
+{
+       siginfo_received = 1;
+}
+
 /*
  * Signal handler for signals that cause the program to terminate.  These
  * signals must be trapped to restore terminal modes.
@@ -1514,6 +1522,7 @@ client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
        if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN)
                ssh_signal(SIGTERM, signal_handler);
        ssh_signal(SIGWINCH, window_change_handler);
+       ssh_signal(SIGINFO, siginfo_handler);
 
        if (have_pty)
                enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
@@ -1536,7 +1545,8 @@ client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
            sigaddset(&bsigset, SIGHUP) == -1 ||
            sigaddset(&bsigset, SIGINT) == -1 ||
            sigaddset(&bsigset, SIGQUIT) == -1 ||
-           sigaddset(&bsigset, SIGTERM) == -1)
+           sigaddset(&bsigset, SIGTERM) == -1 ||
+           sigaddset(&bsigset, SIGINFO) == -1)
                error_f("bsigset setup: %s", strerror(errno));
 
        /* Main loop of the client for the interactive session mode. */
@@ -1577,6 +1587,10 @@ client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
                 */
                if (sigprocmask(SIG_BLOCK, &bsigset, &osigset) == -1)
                        error_f("bsigset sigprocmask: %s", strerror(errno));
+               if (siginfo_received) {
+                       siginfo_received = 0;
+                       channel_report_open(ssh, SYSLOG_LEVEL_INFO);
+               }
                if (quit_pending)
                        break;
                client_wait_until_can_do_something(ssh, &pfd, &npfd_alloc,