1 files changed, 152 insertions, 29 deletions

diff --git a/mux.c b/mux.c
index 825fb7a9a..5c3857ee8 100644
--- a/mux.c
+++ b/mux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mux.c,v 1.14 2010/01/30 02:54:53 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.21 2010/06/25 23:15:36 djm Exp $ */
 /*
  * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
  *
@@ -71,6 +71,7 @@
 #include "xmalloc.h"
 #include "log.h"
 #include "ssh.h"
+#include "ssh2.h"
 #include "pathnames.h"
 #include "misc.h"
 #include "match.h"
@@ -106,6 +107,14 @@ struct mux_session_confirm_ctx {
         char *term;
         struct termios tio;
         char **env;
+        u_int rid;
+};
+
+/* Context for global channel callback */
+struct mux_channel_confirm_ctx {
+        u_int cid;      /* channel id */
+        u_int rid;      /* request id */
+        int fid;        /* forward id */
 };
 
 /* fd to control socket */
@@ -143,13 +152,14 @@ struct mux_master_state {
 #define MUX_S_EXIT_MESSAGE      0x80000004
 #define MUX_S_ALIVE             0x80000005
 #define MUX_S_SESSION_OPENED    0x80000006
+#define MUX_S_REMOTE_PORT       0x80000007
 
 /* type codes for MUX_C_OPEN_FWD and MUX_C_CLOSE_FWD */
 #define MUX_FWD_LOCAL   1
 #define MUX_FWD_REMOTE  2
 #define MUX_FWD_DYNAMIC 3
 
-static void mux_session_confirm(int, void *);
+static void mux_session_confirm(int, int, void *);
 
 static int process_mux_master_hello(u_int, Channel *, Buffer *, Buffer *);
 static int process_mux_new_session(u_int, Channel *, Buffer *, Buffer *);
@@ -206,7 +216,7 @@ mux_master_control_cleanup_cb(int cid, void *unused)
                 fatal("%s: channel_by_id(%i) == NULL", __func__, cid);
         if (c->remote_id != -1) {
                 if ((sc = channel_by_id(c->remote_id)) == NULL)
-                        debug2("%s: channel %d n session channel %d",
+                        fatal("%s: channel %d missing session channel %d",
                             __func__, c->self, c->remote_id);
                 c->remote_id = -1;
                 sc->ctl_chan = -1;
@@ -301,6 +311,7 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
         /* Reply for SSHMUX_COMMAND_OPEN */
         cctx = xcalloc(1, sizeof(*cctx));
         cctx->term = NULL;
+        cctx->rid = rid;
         cmd = reserved = NULL;
         if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
             buffer_get_int_ret(&cctx->want_tty, m) != 0 ||
@@ -454,14 +465,10 @@ process_mux_new_session(u_int rid, Channel *c, Buffer *m, Buffer *r)
 
         channel_send_open(nc->self);
         channel_register_open_confirm(nc->self, mux_session_confirm, cctx);
-        channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 0);
-
-        /* prepare reply */
-        /* XXX defer until mux_session_confirm() fires */
-        buffer_put_int(r, MUX_S_SESSION_OPENED);
-        buffer_put_int(r, rid);
-        buffer_put_int(r, nc->self);
+        c->mux_pause = 1; /* stop handling messages until open_confirm done */
+        channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
 
+        /* reply is deferred, sent by mux_session_confirm */
         return 0;
 }
 
@@ -559,6 +566,61 @@ compare_forward(Forward *a, Forward *b)
         return 1;
 }
 
+static void
+mux_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
+{
+        struct mux_channel_confirm_ctx *fctx = ctxt;
+        char *failmsg = NULL;
+        Forward *rfwd;
+        Channel *c;
+        Buffer out;
+
+        if ((c = channel_by_id(fctx->cid)) == NULL) {
+                /* no channel for reply */
+                error("%s: unknown channel", __func__);
+                return;
+        }
+        buffer_init(&out);
+        if (fctx->fid >= options.num_remote_forwards) {
+                xasprintf(&failmsg, "unknown forwarding id %d", fctx->fid);
+                goto fail;
+        }
+        rfwd = &options.remote_forwards[fctx->fid];
+        debug("%s: %s for: listen %d, connect %s:%d", __func__,
+            type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
+            rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
+        if (type == SSH2_MSG_REQUEST_SUCCESS) {
+                if (rfwd->listen_port == 0) {
+                        rfwd->allocated_port = packet_get_int();
+                        logit("Allocated port %u for mux remote forward"
+                            " to %s:%d", rfwd->allocated_port,
+                            rfwd->connect_host, rfwd->connect_port);
+                        buffer_put_int(&out, MUX_S_REMOTE_PORT);
+                        buffer_put_int(&out, fctx->rid);
+                        buffer_put_int(&out, rfwd->allocated_port);
+                } else {
+                        buffer_put_int(&out, MUX_S_OK);
+                        buffer_put_int(&out, fctx->rid);
+                }
+                goto out;
+        } else {
+                xasprintf(&failmsg, "remote port forwarding failed for "
+                    "listen port %d", rfwd->listen_port);
+        }
+ fail:
+        error("%s: %s", __func__, failmsg);
+        buffer_put_int(&out, MUX_S_FAILURE);
+        buffer_put_int(&out, fctx->rid);
+        buffer_put_cstring(&out, failmsg);
+        xfree(failmsg);
+ out:
+        buffer_put_string(&c->output, buffer_ptr(&out), buffer_len(&out));
+        buffer_free(&out);
+        if (c->mux_pause <= 0)
+                fatal("%s: mux_pause %d", __func__, c->mux_pause);
+        c->mux_pause = 0; /* start processing messages again */
+}
+
 static int
 process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
 {
@@ -594,15 +656,16 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
             ftype != MUX_FWD_DYNAMIC) {
                 logit("%s: invalid forwarding type %u", __func__, ftype);
  invalid:
-                xfree(fwd.listen_host);
-                xfree(fwd.connect_host);
+                if (fwd.listen_host)
+                        xfree(fwd.listen_host);
+                if (fwd.connect_host)
+                        xfree(fwd.connect_host);
                 buffer_put_int(r, MUX_S_FAILURE);
                 buffer_put_int(r, rid);
                 buffer_put_cstring(r, "Invalid forwarding request");
                 return 0;
         }
-        /* XXX support rport0 forwarding with reply of port assigned */
-        if (fwd.listen_port == 0 || fwd.listen_port >= 65536) {
+        if (fwd.listen_port >= 65536) {
                 logit("%s: invalid listen port %u", __func__,
                     fwd.listen_port);
                 goto invalid;
@@ -637,8 +700,17 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
         case MUX_FWD_REMOTE:
                 for (i = 0; i < options.num_remote_forwards; i++) {
                         if (compare_forward(&fwd,
-                            options.remote_forwards + i))
-                                goto exists;
+                            options.remote_forwards + i)) {
+                                if (fwd.listen_port != 0)
+                                        goto exists;
+                                debug2("%s: found allocated port",
+                                    __func__);
+                                buffer_put_int(r, MUX_S_REMOTE_PORT);
+                                buffer_put_int(r, rid);
+                                buffer_put_int(r,
+                                    options.remote_forwards[i].allocated_port);
+                                goto out;
+                        }
                 }
                 break;
         }
@@ -655,9 +727,7 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
         }
 
         if (ftype == MUX_FWD_LOCAL || ftype == MUX_FWD_DYNAMIC) {
-                if (options.num_local_forwards + 1 >=
-                    SSH_MAX_FORWARDS_PER_DIRECTION ||
-                    channel_setup_local_fwd_listener(fwd.listen_host,
+                if (channel_setup_local_fwd_listener(fwd.listen_host,
                     fwd.listen_port, fwd.connect_host, fwd.connect_port,
                     options.gateway_ports) < 0) {
  fail:
@@ -670,14 +740,22 @@ process_mux_open_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
                 add_local_forward(&options, &fwd);
                 freefwd = 0;
         } else {
-                /* XXX wait for remote to confirm */
-                if (options.num_remote_forwards + 1 >=
-                    SSH_MAX_FORWARDS_PER_DIRECTION ||
-                    channel_request_remote_forwarding(fwd.listen_host,
+                struct mux_channel_confirm_ctx *fctx;
+
+                if (channel_request_remote_forwarding(fwd.listen_host,
                     fwd.listen_port, fwd.connect_host, fwd.connect_port) < 0)
                         goto fail;
                 add_remote_forward(&options, &fwd);
+                fctx = xcalloc(1, sizeof(*fctx));
+                fctx->cid = c->self;
+                fctx->rid = rid;
+                fctx->fid = options.num_remote_forwards - 1;
+                client_register_global_confirm(mux_confirm_remote_forward,
+                    fctx);
                 freefwd = 0;
+                c->mux_pause = 1; /* wait for mux_confirm_remote_forward */
+                /* delayed reply in mux_confirm_remote_forward */
+                goto out;
         }
         buffer_put_int(r, MUX_S_OK);
         buffer_put_int(r, rid);
@@ -826,7 +904,7 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
         debug2("%s: channel_new: %d linked to control channel %d",
             __func__, nc->self, nc->ctl_chan);
 
-        channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 0);
+        channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
 
         /* prepare reply */
         /* XXX defer until channel confirmed */
@@ -849,7 +927,7 @@ mux_master_read_cb(Channel *c)
 
         /* Setup ctx and  */
         if (c->mux_ctx == NULL) {
-                state = xcalloc(1, sizeof(state));
+                state = xcalloc(1, sizeof(*state));
                 c->mux_ctx = state;
                 channel_register_cleanup(c->self,
                     mux_master_control_cleanup_cb, 0);
@@ -1000,26 +1078,43 @@ muxserver_listen(void)
 
 /* Callback on open confirmation in mux master for a mux client session. */
 static void
-mux_session_confirm(int id, void *arg)
+mux_session_confirm(int id, int success, void *arg)
 {
         struct mux_session_confirm_ctx *cctx = arg;
         const char *display;
-        Channel *c;
+        Channel *c, *cc;
         int i;
+        Buffer reply;
 
         if (cctx == NULL)
                 fatal("%s: cctx == NULL", __func__);
         if ((c = channel_by_id(id)) == NULL)
                 fatal("%s: no channel for id %d", __func__, id);
+        if ((cc = channel_by_id(c->ctl_chan)) == NULL)
+                fatal("%s: channel %d lacks control channel %d", __func__,
+                    id, c->ctl_chan);
+
+        if (!success) {
+                debug3("%s: sending failure reply", __func__);
+                /* prepare reply */
+                buffer_init(&reply);
+                buffer_put_int(&reply, MUX_S_FAILURE);
+                buffer_put_int(&reply, cctx->rid);
+                buffer_put_cstring(&reply, "Session open refused by peer");
+                goto done;
+        }
 
         display = getenv("DISPLAY");
         if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
                 char *proto, *data;
+
                 /* Get reasonable local authentication information. */
                 client_x11_get_proto(display, options.xauth_location,
-                    options.forward_x11_trusted, &proto, &data);
+                    options.forward_x11_trusted, options.forward_x11_timeout,
+                    &proto, &data);
                 /* Request forwarding with authentication spoofing. */
-                debug("Requesting X11 forwarding with authentication spoofing.");
+                debug("Requesting X11 forwarding with authentication "
+                    "spoofing.");
                 x11_request_forwarding_with_spoofing(id, display, proto, data);
                 /* XXX wait for reply */
         }
@@ -1033,6 +1128,21 @@ mux_session_confirm(int id, void *arg)
         client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
             cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env);
 
+        debug3("%s: sending success reply", __func__);
+        /* prepare reply */
+        buffer_init(&reply);
+        buffer_put_int(&reply, MUX_S_SESSION_OPENED);
+        buffer_put_int(&reply, cctx->rid);
+        buffer_put_int(&reply, c->self);
+
+ done:
+        /* Send reply */
+        buffer_put_string(&cc->output, buffer_ptr(&reply), buffer_len(&reply));
+        buffer_free(&reply);
+
+        if (cc->mux_pause <= 0)
+                fatal("%s: mux_pause %d", __func__, cc->mux_pause);
+        cc->mux_pause = 0; /* start processing messages again */
         c->open_confirm_ctx = NULL;
         buffer_free(&cctx->cmd);
         xfree(cctx->term);
@@ -1365,6 +1475,15 @@ mux_client_request_forward(int fd, u_int ftype, Forward *fwd)
         switch (type) {
         case MUX_S_OK:
                 break;
+        case MUX_S_REMOTE_PORT:
+                fwd->allocated_port = buffer_get_int(&m);
+                logit("Allocated port %u for remote forward to %s:%d",
+                    fwd->allocated_port,
+                    fwd->connect_host ? fwd->connect_host : "",
+                    fwd->connect_port);
+                if (muxclient_command == SSHMUX_COMMAND_FORWARD)
+                        fprintf(stdout, "%u\n", fwd->allocated_port);
+                break;
         case MUX_S_PERMISSION_DENIED:
                 e = buffer_get_string(&m, NULL);
                 buffer_free(&m);
@@ -1731,6 +1850,10 @@ muxclient(const char *path)
                 mux_client_request_terminate(sock);
                 fprintf(stderr, "Exit request sent.\r\n");
                 exit(0);
+        case SSHMUX_COMMAND_FORWARD:
+                if (mux_client_request_forwards(sock) != 0)
+                        fatal("%s: master forward request failed", __func__);
+                exit(0);
         case SSHMUX_COMMAND_OPEN:
                 if (mux_client_request_forwards(sock) != 0) {
                         error("%s: master forward request failed", __func__);