Attachment 1338 Details for Bug 1330 – patch for three way ControlPersist=yes/no/timeout option.

[patch] patch for three way ControlPersist=yes/no/timeout option.

ssh-controlpersist-patch (text/plain), 10.73 KB, created by Alan Barrett on 2007-08-11 07:26:36 AEST

(hide)

Description:

Filename:

MIME Type:

Creator: Alan Barrett

Created: 2007-08-11 07:26:36 AEST

Size: 10.73 KB

patch

obsolete

>Add a "ControlPersist" option to ssh.  From the ssh_config(5)
>man page:
>
>     ControlPersist
>             When used in conjunction with ControlMaster, specifies that the
>             master connection should remain open in the background (waiting
>             for future client connections) after the initial client connec-
>             tion has been closed.  If set to ``no'', then the master connec-
>             tion will not be placed into the background, and will close as
>             soon as the initial client connection is closed.  If set to
>             ``yes'', then the master connection will remain in the background
>             indefinitely (until killed or closed via a mechanism such as the
>             ssh(1) ``-O exit'' option).  If set to a time in seconds, or a
>             time in any of the formats documented in sshd_config(5), then the
>             backgrounded master connection will automatically terminate after
>             it has remained idle (with no client connections) for the speci-
>             fied time.
>
>This patch is relative to the current version of portable openssh
>as checked out from CVS on 2007-08-10.
>
>Index: clientloop.c
>===================================================================
>diff -d -u -r1.166 clientloop.c
>--- clientloop.c	8 Aug 2007 04:32:41 -0000	1.166
>+++ clientloop.c	10 Aug 2007 21:02:45 -0000
>@@ -141,6 +141,9 @@
> /* Flag indicating whether the user's terminal is in non-blocking mode. */
> static int in_non_blocking_mode = 0;
> 
>+/* Time when backgrounded control master using ControlPersist should exit */
>+static time_t control_persist_exit_time = 0;
>+
> /* Common data for the client loop code. */
> static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
> static int escape_char;		/* Escape character. */
>@@ -235,6 +238,32 @@
> 	return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
> }
> 
>+/*
>+ * Sets control_persist_exit_time to the absolute time when the
>+ * backgrounded control master should exit due to expiry of the
>+ * ControlPersist timeout.  Sets it to 0 if we are not a backgrounded
>+ * control master process, or if there is no ControlPersist timeout.
>+ */
>+static void
>+set_control_persist_exit_time(void)
>+{
>+	if (control_fd == -1 || !options.control_persist
>+	    || options.control_persist_timeout == 0)
>+		/* not using a ControlPersist timeout */
>+		control_persist_exit_time = 0;
>+	else if (channel_still_open())
>+		/* some client connections are still open */
>+		control_persist_exit_time = 0;
>+	else if (control_persist_exit_time <= 0) {
>+		/* a client connection has recently closed */
>+		time_t now = time(NULL);
>+
>+		control_persist_exit_time = now +
>+			(time_t)options.control_persist_timeout;
>+	}
>+	/* else we are already counting down to the timeout */
>+}
>+
> #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
> void
> client_x11_get_proto(const char *display, const char *xauth_path,
>@@ -483,6 +512,8 @@
>     int *maxfdp, u_int *nallocp, int rekeying)
> {
> 	struct timeval tv, *tvp;
>+	time_t now;
>+	int timeout_secs;
> 	int ret;
> 
> 	/* Add any selections by the channel mechanism. */
>@@ -529,13 +560,25 @@
> 	/*
> 	 * Wait for something to happen.  This will suspend the process until
> 	 * some selected descriptor can be read, written, or has some other
>-	 * event pending.
>+	 * event pending, or a timeout expires.
> 	 */
> 
>-	if (options.server_alive_interval == 0 || !compat20)
>+	now = time(NULL);
>+	timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
>+	if (options.server_alive_interval > 0 && compat20)
>+		timeout_secs = MIN(timeout_secs,
>+			options.server_alive_interval);
>+	set_control_persist_exit_time();
>+	if (control_persist_exit_time > 0) {
>+		timeout_secs = MIN(timeout_secs,
>+			control_persist_exit_time - now);
>+		if (timeout_secs < 0)
>+			timeout_secs = 0;
>+	}
>+	if (timeout_secs == INT_MAX)
> 		tvp = NULL;
> 	else {
>-		tv.tv_sec = options.server_alive_interval;
>+		tv.tv_sec = timeout_secs;
> 		tv.tv_usec = 0;
> 		tvp = &tv;
> 	}
>@@ -1514,6 +1557,23 @@
> 		/* Send as much buffered packet data as possible to the sender. */
> 		if (FD_ISSET(connection_out, writeset))
> 			packet_write_poll();
>+
>+		/*
>+		 * If we are a backgrounded control master, and the
>+		 * timeout has expired without any active client
>+		 * connections, then quit.
>+		 */
>+		if (control_fd != -1 && options.control_persist
>+		    && options.control_persist_timeout > 0
>+		    && control_persist_exit_time > 0)
>+		{
>+			time_t now = time(NULL);
>+
>+			if (now >= control_persist_exit_time) {
>+				debug("ControlPersist timeout expired");
>+				break;
>+			}
>+		}
> 	}
> 	if (readset)
> 		xfree(readset);
>Index: readconf.c
>===================================================================
>diff -d -u -r1.139 readconf.c
>--- readconf.c	21 Mar 2007 09:46:03 -0000	1.139
>+++ readconf.c	10 Aug 2007 21:02:47 -0000
>@@ -128,7 +128,8 @@
> 	oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
> 	oAddressFamily, oGssAuthentication, oGssDelegateCreds,
> 	oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
>-	oSendEnv, oControlPath, oControlMaster, oHashKnownHosts,
>+	oSendEnv, oControlPath, oControlMaster, oControlPersist,
>+	oHashKnownHosts,
> 	oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand,
> 	oDeprecated, oUnsupported
> } OpCodes;
>@@ -221,6 +222,7 @@
> 	{ "sendenv", oSendEnv },
> 	{ "controlpath", oControlPath },
> 	{ "controlmaster", oControlMaster },
>+	{ "controlpersist", oControlPersist },
> 	{ "hashknownhosts", oHashKnownHosts },
> 	{ "tunnel", oTunnel },
> 	{ "tunneldevice", oTunnelDevice },
>@@ -868,6 +870,30 @@
> 			*intptr = value;
> 		break;
> 
>+	case oControlPersist:
>+		/* no/false/yes/true, or a time spec */
>+		intptr = &options->control_persist;
>+		arg = strdelim(&s);
>+		if (!arg || *arg == '\0')
>+			fatal("%.200s line %d: Missing ControlPersist"
>+			    " argument.", filename, linenum);
>+		value = 0;	/* To avoid compiler warning... */
>+		value2 = 0;	/* timeout */
>+		if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
>+			value = 0;
>+		else if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
>+			value = 1;
>+		else if ((value2 = convtime(arg)) > 0)
>+			value = 1;
>+		else
>+			fatal("%.200s line %d: Bad ControlPersist argument.",
>+			    filename, linenum);
>+		if (*activep && *intptr == -1) {
>+			*intptr = value;
>+			options->control_persist_timeout = value2;
>+		}
>+		break;
>+
> 	case oHashKnownHosts:
> 		intptr = &options->hash_known_hosts;
> 		goto parse_flag;
>@@ -1059,6 +1085,8 @@
> 	options->num_send_env = 0;
> 	options->control_path = NULL;
> 	options->control_master = -1;
>+	options->control_persist = -1;
>+	options->control_persist_timeout = 0;
> 	options->hash_known_hosts = -1;
> 	options->tun_open = -1;
> 	options->tun_local = -1;
>@@ -1189,6 +1217,10 @@
> 		options->server_alive_count_max = 3;
> 	if (options->control_master == -1)
> 		options->control_master = 0;
>+	if (options->control_persist == -1) {
>+		options->control_persist = 0;
>+		options->control_persist_timeout = 0;
>+	}
> 	if (options->hash_known_hosts == -1)
> 		options->hash_known_hosts = 0;
> 	if (options->tun_open == -1)
>Index: readconf.h
>===================================================================
>diff -d -u -r1.63 readconf.h
>--- readconf.h	5 Aug 2006 02:39:40 -0000	1.63
>+++ readconf.h	10 Aug 2007 21:02:47 -0000
>@@ -111,6 +111,8 @@
> 
> 	char	*control_path;
> 	int	control_master;
>+	int     control_persist; /* ControlPersist flag */
>+	int     control_persist_timeout; /* ControlPersist timeout (seconds) */
> 
> 	int	hash_known_hosts;
> 
>Index: ssh.c
>===================================================================
>diff -d -u -r1.292 ssh.c
>--- ssh.c	8 Aug 2007 04:32:41 -0000	1.292
>+++ ssh.c	10 Aug 2007 21:02:48 -0000
>@@ -680,6 +680,8 @@
> 		fatal("No ControlPath specified for \"-O\" command");
> 	if (options.control_path != NULL)
> 		control_client(options.control_path);
>+		/* If control_client() can connect to a master socket,
>+		 * then it doesn't return. */
> 
> 	/* Open a connection to the remote host. */
> 	if (ssh_connect(host, &hostaddr, options.port,
>@@ -1190,6 +1192,46 @@
> 	/* XXX should be pre-session */
> 	ssh_init_forwarding();
> 
>+	/* Start listening for multiplex clients */
>+	ssh_control_listener();
>+
>+ 	/*
>+ 	 * If we are the control master, and if control_persist is set,
>+ 	 * then move the master into the background, and make the
>+ 	 * foreground process a client of the backgrounded master.
>+ 	 */
>+ 	if (options.control_persist && control_fd != -1) {
>+ 		pid_t childpid;
>+ 
>+ 		childpid = fork();
>+		if (childpid < 0) {
>+ 			fatal("fork() failed");
>+ 		} else if (childpid == 0) {
>+ 			/*
>+ 			 * This is the child.  Set some variables to let
>+ 			 * it continue continue operating as the control
>+ 			 * master in the background.
>+ 			 */
>+ 			debug("backgrounding control master");
>+ 			fork_after_authentication_flag = 1;
>+ 			stdin_null_flag = 1;
>+ 			no_shell_flag = 1;
>+ 			no_tty_flag = 1;
>+ 			tty_flag = 0;
>+ 		} else {
>+ 			/*
>+ 			 * This is the foreground process.  Make it a
>+ 			 * client of the newly-backgrounded control
>+ 			 * master.  control_client() doesn't return
>+ 			 * unless it fails.
>+ 			 */
>+ 			close(control_fd);
>+ 			control_fd = -1;
>+ 			control_client(options.control_path);
>+ 			fatal("Failed to connect to new control master");
>+ 		}
>+ 	}
>+
> 	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
> 		id = ssh_session2_open();
> 
>@@ -1197,9 +1239,6 @@
> 	if (options.local_command != NULL &&
> 	    options.permit_local_command)
> 		ssh_local_cmd(options.local_command);
>-
>-	/* Start listening for multiplex clients */
>-	ssh_control_listener();
> 
> 	/* If requested, let ssh continue in the background. */
> 	if (fork_after_authentication_flag)
>Index: ssh_config.5
>===================================================================
>diff -d -u -r1.101 ssh_config.5
>--- ssh_config.5	11 Jun 2007 04:06:32 -0000	1.101
>+++ ssh_config.5	10 Aug 2007 21:02:49 -0000
>@@ -318,6 +318,28 @@
> used for opportunistic connection sharing include
> at least %h, %p, and %r.
> This ensures that shared connections are uniquely identified.
>+.It Cm ControlPersist
>+When used in conjunction with
>+.Cm ControlMaster ,
>+specifies that the master connection should remain open
>+in the background (waiting for future client connections)
>+after the initial client connection has been closed.
>+If set to
>+.Dq no ,
>+then the master connection will not be placed into the background,
>+and will close as soon as the initial client connection is closed.
>+If set to
>+.Dq yes ,
>+then the master connection will remain in the background indefinitely
>+(until killed or closed via a mechanism such as the
>+.Xr ssh 1
>+.Dq Fl O No exit
>+option).
>+If set to a time in seconds, or a time in any of the formats documented in
>+.Xr sshd_config 5 ,
>+then the backgrounded master connection will automatically terminate
>+after it has remained idle (with no client connections) for the
>+specified time.
> .It Cm DynamicForward
> Specifies that a TCP port on the local machine be forwarded
> over the secure channel, and the application

Actions: View | Diff

Attachments on bug 1330: 1319 | 1322 | 1331 | 1338 | 1605 | 1858 | 1897