- djm@cvs.openbsd.org 2008/06/12 03:40:52

[openssh.git] / mux.c

diff --git a/mux.c b/mux.c
index 8b9105b0402e50988e186aed6a2f33bba975f363..efc3840cbbf5b509729b124b9335f51d6f2f47d2 100644 (file)
--- a/mux.c
+++ b/mux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mux.c,v 1.1 2008/05/09 14:18:44 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.2 2008/06/12 03:40:52 djm Exp $ */
 /*
  * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
  *
@@ -19,6 +19,20 @@
 
 #include "includes.h"
 
+/*
+ * TODO:
+ *   1. partial reads in muxserver_accept_control (maybe make channels
+ *      from accepted connections)
+ *   2. Better signalling from master to slave, especially passing of
+ *      error messages
+ *   3. Better fall-back from mux slave error to new connection.
+ *   3. Add/delete forwardings via slave
+ *   4. ExitOnForwardingFailure (after #3 obviously)
+ *   5. Maybe extension mechanisms for multi-X11/multi-agent forwarding
+ *   6. Document the mux mini-protocol somewhere.
+ *   6. Support ~^Z in mux slaves.
+ */
+
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/stat.h>
@@ -71,6 +85,18 @@ extern char *host;
 int subsystem_flag;
 extern Buffer command;
 
+/* Context for session open confirmation callback */
+struct mux_session_confirm_ctx {
+       int want_tty;
+       int want_subsys;
+       int want_x_fwd;
+       int want_agent_fwd;
+       Buffer cmd;
+       char *term;
+       struct termios tio;
+       char **env;
+};
+
 /* fd to control socket */
 int muxserver_sock = -1;
 
@@ -131,7 +157,7 @@ muxserver_listen(void)
 
 /* Callback on open confirmation in mux master for a mux client session. */
 static void
-client_extra_session2_setup(int id, void *arg)
+mux_session_confirm(int id, void *arg)
 {
        struct mux_session_confirm_ctx *cctx = arg;
        const char *display;
@@ -190,7 +216,7 @@ muxserver_accept_control(void)
        struct sockaddr_storage addr;
        struct mux_session_confirm_ctx *cctx;
        char *cmd;
-       u_int i, j, len, env_len, mux_command, flags;
+       u_int i, j, len, env_len, mux_command, flags, escape_char;
        uid_t euid;
        gid_t egid;
        int start_close = 0;
@@ -317,6 +343,7 @@ muxserver_accept_control(void)
        cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
        cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
        cctx->term = buffer_get_string(&m, &len);
+       escape_char = buffer_get_int(&m);
 
        cmd = buffer_get_string(&m, &len);
        buffer_init(&cctx->cmd);
@@ -402,14 +429,17 @@ muxserver_accept_control(void)
            new_fd[0], new_fd[1], new_fd[2], window, packetmax,
            CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
 
-       /* XXX */
        c->ctl_fd = client_fd;
+       if (cctx->want_tty && escape_char != 0xffffffff) {
+               channel_register_filter(c->self,
+                   client_simple_escape_filter, NULL,
+                   client_new_escape_filter_ctx((int)escape_char));
+       }
 
        debug3("%s: channel_new: %d", __func__, c->self);
 
        channel_send_open(c->self);
-       channel_register_open_confirm(c->self,
-           client_extra_session2_setup, cctx);
+       channel_register_open_confirm(c->self, mux_session_confirm, cctx);
        return 0;
 }
 
@@ -561,33 +591,34 @@ muxclient(const char *path)
                fprintf(stderr, "Exit request sent.\r\n");
                exit(0);
        case SSHMUX_COMMAND_OPEN:
-               /* continue below */
+               buffer_put_cstring(&m, term ? term : "");
+               if (options.escape_char == SSH_ESCAPECHAR_NONE)
+                       buffer_put_int(&m, 0xffffffff);
+               else
+                       buffer_put_int(&m, options.escape_char);
+               buffer_append(&command, "\0", 1);
+               buffer_put_cstring(&m, buffer_ptr(&command));
+
+               if (options.num_send_env == 0 || environ == NULL) {
+                       buffer_put_int(&m, 0);
+               } else {
+                       /* Pass environment */
+                       num_env = 0;
+                       for (i = 0; environ[i] != NULL; i++) {
+                               if (env_permitted(environ[i]))
+                                       num_env++; /* Count */
+                       }
+                       buffer_put_int(&m, num_env);
+               for (i = 0; environ[i] != NULL && num_env >= 0; i++) {
+                               if (env_permitted(environ[i])) {
+                                       num_env--;
+                                       buffer_put_cstring(&m, environ[i]);
+                               }
+                       }
+               }
                break;
        default:
-               fatal("silly muxclient_command %d", muxclient_command);
-       }
-
-       /* SSHMUX_COMMAND_OPEN */
-       buffer_put_cstring(&m, term ? term : "");
-       buffer_append(&command, "\0", 1);
-       buffer_put_cstring(&m, buffer_ptr(&command));
-
-       if (options.num_send_env == 0 || environ == NULL) {
-               buffer_put_int(&m, 0);
-       } else {
-               /* Pass environment */
-               num_env = 0;
-               for (i = 0; environ[i] != NULL; i++)
-                       if (env_permitted(environ[i]))
-                               num_env++; /* Count */
-
-               buffer_put_int(&m, num_env);
-
-               for (i = 0; environ[i] != NULL && num_env >= 0; i++)
-                       if (env_permitted(environ[i])) {
-                               num_env--;
-                               buffer_put_cstring(&m, environ[i]);
-                       }
+               fatal("unrecognised muxclient_command %d", muxclient_command);
        }
 
        if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)