Attachment 1335 Details for Bug 1349 – Fix race in ControlMaster=auto

[patch] Fix race in ControlMaster=auto

master-race.patch (text/plain), 2.28 KB, created by Tony Finch on 2007-08-05 04:18:14 AEST

(hide)

Description:

Filename:

MIME Type:

Creator: Tony Finch

Created: 2007-08-05 04:18:14 AEST

Size: 2.28 KB

patch

obsolete

>--- ssh.c~	Fri Jan  5 05:30:17 2007
>+++ ssh.c	Fri Aug  3 19:21:18 2007
>@@ -1045,18 +1045,19 @@
> 	}
> }
> 
>-static void
>-ssh_control_listener(void)
>+static int
>+ssh_control_listener(int test)
> {
> 	struct sockaddr_un addr;
> 	mode_t old_umask;
> 	int addr_len;
> 
> 	if (options.control_path == NULL ||
>-	    options.control_master == SSHCTL_MASTER_NO)
>-		return;
>+	    options.control_master == SSHCTL_MASTER_NO ||
>+	    control_fd != -1)
>+		return 1;
> 
>-	debug("setting up multiplex master socket");
>+	debug("trying to set up multiplex master socket");
> 
> 	memset(&addr, '\0', sizeof(addr));
> 	addr.sun_family = AF_UNIX;
>@@ -1073,11 +1074,9 @@
> 	old_umask = umask(0177);
> 	if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) {
> 		control_fd = -1;
>-		if (errno == EINVAL || errno == EADDRINUSE)
>-			fatal("ControlSocket %s already exists",
>-			    options.control_path);
>-		else
>+		if (errno != EINVAL && errno != EADDRINUSE)
> 			fatal("%s bind(): %s", __func__, strerror(errno));
>+		return 0;
> 	}
> 	umask(old_umask);
> 
>@@ -1085,6 +1084,9 @@
> 		fatal("%s listen(): %s", __func__, strerror(errno));
> 
> 	set_nonblock(control_fd);
>+
>+	debug("control master listening on %s", options.control_path);
>+	return 1;
> }
> 
> /* request pty/x11/agent/tcpfwd/shell for channel */
>@@ -1201,7 +1203,9 @@
> 
> 	/* XXX should be pre-session */
> 	ssh_init_forwarding();
>-	ssh_control_listener();
>+	if (!ssh_control_listener(0))
>+		fatal("control master socket %s already exists",
>+		    options.control_path);
> 
> 	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
> 		id = ssh_session2_open();
>@@ -1319,7 +1323,13 @@
> 	switch (options.control_master) {
> 	case SSHCTL_MASTER_AUTO:
> 	case SSHCTL_MASTER_AUTO_ASK:
>-		debug("auto-mux: Trying existing master");
>+		/* see if we can create a control master socket
>+		   to avoid a race between two auto clients */
>+		if (mux_command == SSHMUX_COMMAND_OPEN &&
>+		    ssh_control_listener(1))
>+			return;
>+		debug("trying to connect to control master socket %s",
>+		    options.control_path);
> 		/* FALLTHROUGH */
> 	case SSHCTL_MASTER_NO:
> 		break;
>@@ -1452,6 +1462,8 @@
> 	signal(SIGINT, control_client_sighandler);
> 	signal(SIGTERM, control_client_sighandler);
> 	signal(SIGWINCH, control_client_sigrelay);
>+
>+	debug("connected to control master; waiting for exit");
> 
> 	if (tty_flag)
> 		enter_raw_mode();

Actions: View | Diff

Attachments on bug 1349: 1335 | 1461 | 1462