- djm@cvs.openbsd.org 2005/06/08 11:25:09

     [clientloop.c readconf.c readconf.h ssh.c ssh_config.5]
     add ControlMaster=auto/autoask options to support opportunistic
     multiplexing; tested avsm@ and jakob@, ok markus@

diff --git a/ChangeLog b/ChangeLog
index c7664fadb7d055907a961a16feb87130de2d83c6..f776eed7c2764adcda6d8636271c1002aa72e6c6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,10 @@
      [ssh-keygen.1 ssh-keygen.c sshd.8]
      increase default rsa/dsa key length from 1024 to 2048 bits;
      ok markus@ deraadt@
+   - djm@cvs.openbsd.org 2005/06/08 11:25:09
+     [clientloop.c readconf.c readconf.h ssh.c ssh_config.5]
+     add ControlMaster=auto/autoask options to support opportunistic
+     multiplexing; tested avsm@ and jakob@, ok markus@
 
 20050609
  - (dtucker) [cipher.c openbsd-compat/Makefile.in

diff --git a/clientloop.c b/clientloop.c
index 1591215bdabfcf889e98d9ba701338d63c42aa02..ae4dce820a92a7e7b188db81d3d3415f71c90f22 100644 (file)
--- a/clientloop.c
+++ b/clientloop.c
@@ -59,7 +59,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.136 2005/03/10 22:01:05 deraadt Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.137 2005/06/08 11:25:09 djm Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -616,13 +616,15 @@ client_process_control(fd_set * readset)
 
        switch (command) {
        case SSHMUX_COMMAND_OPEN:
-               if (options.control_master == 2)
+               if (options.control_master == SSHCTL_MASTER_ASK ||
+                   options.control_master == SSHCTL_MASTER_AUTO_ASK)
                        allowed = ask_permission("Allow shared connection "
                            "to %s? ", host);
                /* continue below */
                break;
        case SSHMUX_COMMAND_TERMINATE:
-               if (options.control_master == 2)
+               if (options.control_master == SSHCTL_MASTER_ASK ||
+                   options.control_master == SSHCTL_MASTER_AUTO_ASK)
                        allowed = ask_permission("Terminate shared connection "
                            "to %s? ", host);
                if (allowed)

diff --git a/readconf.c b/readconf.c
index d41220807ad0df0d9d38b969a2d477cb9b36af59..5ec89e2f03d9af46b1732dfab97e68ae9afcf1e0 100644 (file)
--- a/readconf.c
+++ b/readconf.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: readconf.c,v 1.140 2005/05/16 15:30:51 markus Exp $");
+RCSID("$OpenBSD: readconf.c,v 1.141 2005/06/08 11:25:09 djm Exp $");
 
 #include "ssh.h"
 #include "xmalloc.h"
@@ -796,7 +796,27 @@ parse_int:
 
        case oControlMaster:
                intptr = &options->control_master;
-               goto parse_yesnoask;
+               arg = strdelim(&s);
+               if (!arg || *arg == '\0')
+                       fatal("%.200s line %d: Missing ControlMaster argument.",
+                           filename, linenum);
+               value = 0;      /* To avoid compiler warning... */
+               if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
+                       value = SSHCTL_MASTER_YES;
+               else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
+                       value = SSHCTL_MASTER_NO;
+               else if (strcmp(arg, "auto") == 0)
+                       value = SSHCTL_MASTER_AUTO;
+               else if (strcmp(arg, "ask") == 0)
+                       value = SSHCTL_MASTER_ASK;
+               else if (strcmp(arg, "autoask") == 0)
+                       value = SSHCTL_MASTER_AUTO_ASK;
+               else
+                       fatal("%.200s line %d: Bad ControlMaster argument.",
+                           filename, linenum);
+               if (*activep && *intptr == -1)
+                       *intptr = value;
+               break;
 
        case oHashKnownHosts:
                intptr = &options->hash_known_hosts;

diff --git a/readconf.h b/readconf.h
index de4b4cb2787cfdaea148bd2a973459d9da68a858..2b9deb9db393cd9c427c74a88913b86a15aacdb7 100644 (file)
--- a/readconf.h
+++ b/readconf.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: readconf.h,v 1.66 2005/03/01 10:40:27 djm Exp $       */
+/*     $OpenBSD: readconf.h,v 1.67 2005/06/08 11:25:09 djm Exp $       */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -116,6 +116,11 @@ typedef struct {
        int     hash_known_hosts;
 }       Options;
 
+#define SSHCTL_MASTER_NO       0
+#define SSHCTL_MASTER_YES      1
+#define SSHCTL_MASTER_AUTO     2
+#define SSHCTL_MASTER_ASK      3
+#define SSHCTL_MASTER_AUTO_ASK 4
 
 void     initialize_options(Options *);
 void     fill_default_options(Options *);

diff --git a/ssh.c b/ssh.c
index 0871d06de1609dfe63a1ae7cf5e894843ea44a2a..a27c457254ce49bdb77e556968e8c387f9108ff0 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -40,7 +40,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh.c,v 1.241 2005/06/06 11:20:36 djm Exp $");
+RCSID("$OpenBSD: ssh.c,v 1.242 2005/06/08 11:25:09 djm Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -386,8 +386,10 @@ again:
                        }
                        break;
                case 'M':
-                       options.control_master =
-                           (options.control_master >= 1) ? 2 : 1;
+                       if (options.control_master == SSHCTL_MASTER_YES)
+                               options.control_master = SSHCTL_MASTER_ASK;
+                       else
+                               options.control_master = SSHCTL_MASTER_YES;
                        break;
                case 'p':
                        options.port = a2port(optarg);
@@ -618,11 +620,8 @@ again:
        }
        if (mux_command != 0 && options.control_path == NULL)
                fatal("No ControlPath specified for \"-O\" command");
-       if (options.control_path != NULL && options.control_master == 0) {
-               if (mux_command == 0)
-                       mux_command = SSHMUX_COMMAND_OPEN;
+       if (options.control_path != NULL)
                control_client(options.control_path);
-       }
 
        /* Open a connection to the remote host. */
        if (ssh_connect(host, &hostaddr, options.port,
@@ -1086,9 +1085,12 @@ ssh_control_listener(void)
        mode_t old_umask;
        int addr_len;
 
-       if (options.control_path == NULL || options.control_master <= 0)
+       if (options.control_path == NULL ||
+           options.control_master == SSHCTL_MASTER_NO)
                return;
 
+       debug("setting up multiplex master socket");
+
        memset(&addr, '\0', sizeof(addr));
        addr.sun_family = AF_UNIX;
        addr_len = offsetof(struct sockaddr_un, sun_path) +
@@ -1299,6 +1301,20 @@ control_client(const char *path)
        extern char **environ;
        u_int  flags;
 
+       if (mux_command == 0)
+               mux_command = SSHMUX_COMMAND_OPEN;
+
+       switch (options.control_master) {
+       case SSHCTL_MASTER_AUTO:
+       case SSHCTL_MASTER_AUTO_ASK:
+               debug("auto-mux: Trying existing master");
+               /* FALLTHROUGH */
+       case SSHCTL_MASTER_NO:
+               break;
+       default:
+               return;
+       }
+
        memset(&addr, '\0', sizeof(addr));
        addr.sun_family = AF_UNIX;
        addr_len = offsetof(struct sockaddr_un, sun_path) +

diff --git a/ssh_config.5 b/ssh_config.5
index 2afc3c093916b7c9d18b0953f7ac8c0da824b7a3..a04ffc288f0f90f71fb5febcc97f734434abc4fd 100644 (file)
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -34,7 +34,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh_config.5,v 1.55 2005/06/06 11:20:36 djm Exp $
+.\" $OpenBSD: ssh_config.5,v 1.56 2005/06/08 11:25:09 djm Exp $
 .Dd September 25, 1999
 .Dt SSH_CONFIG 5
 .Os
@@ -278,6 +278,17 @@ If the
 can not be opened,
 .Nm ssh
 will continue without connecting to a master instance.
+.Pp
+Two additional options allow for opportunistic multiplexing: try to use a
+master connection but fall back to creating a new one if one does not already
+exist.
+These options are:
+.Dq auto
+and
+.Dq autoask .
+The latter requires confirmation like the
+.Dq ask
+option.
 .It Cm ControlPath
 Specify the path to the control socket used for connection sharing as described
 in the
@@ -290,6 +301,11 @@ will be substituted by the target host name,
 the port and
 .Ql %r
 by the remote login username.
+It is recommended that any
+.Cm ControlPath
+used for opportunistic connection sharing include
+all three of these escape sequences.
+This ensures that shared connections are uniquely identified.
 .It Cm DynamicForward
 Specifies that a TCP/IP port on the local machine be forwarded
 over the secure channel, and the application