reflect stdio-forward ("ssh -W host:port ...") failures in exit status.

previously we were always returning 0. bz#2255 reported by Brendan
Germain; ok dtucker

diff --git a/usr.bin/ssh/mux.c b/usr.bin/ssh/mux.c
index e9d01d6..0e0728b 100644 (file)
--- a/usr.bin/ssh/mux.c
+++ b/usr.bin/ssh/mux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mux.c,v 1.47 2014/07/17 00:10:18 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.48 2014/07/17 07:22:19 djm Exp $ */
 /*
  * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
  *
@@ -92,6 +92,11 @@ struct mux_session_confirm_ctx {
        u_int rid;
 };
 
+/* Context for stdio fwd open confirmation callback */
+struct mux_stdio_confirm_ctx {
+       u_int rid;
+};
+
 /* Context for global channel callback */
 struct mux_channel_confirm_ctx {
        u_int cid;      /* channel id */
@@ -144,6 +149,7 @@ struct mux_master_state {
 #define MUX_FWD_DYNAMIC 3
 
 static void mux_session_confirm(int, int, void *);
+static void mux_stdio_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 *);
@@ -910,6 +916,7 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
        char *reserved, *chost;
        u_int cport, i, j;
        int new_fd[2];
+       struct mux_stdio_confirm_ctx *cctx;
 
        chost = reserved = NULL;
        if ((reserved = buffer_get_string_ret(m, NULL)) == NULL ||
@@ -989,15 +996,60 @@ process_mux_stdio_fwd(u_int rid, Channel *c, Buffer *m, Buffer *r)
 
        channel_register_cleanup(nc->self, mux_master_session_cleanup_cb, 1);
 
-       /* prepare reply */
-       /* XXX defer until channel confirmed */
-       buffer_put_int(r, MUX_S_SESSION_OPENED);
-       buffer_put_int(r, rid);
-       buffer_put_int(r, nc->self);
+       cctx = xcalloc(1, sizeof(*cctx));
+       cctx->rid = rid;
+       channel_register_open_confirm(nc->self, mux_stdio_confirm, cctx);
+       c->mux_pause = 1; /* stop handling messages until open_confirm done */
 
+       /* reply is deferred, sent by mux_session_confirm */
        return 0;
 }
 
+/* Callback on open confirmation in mux master for a mux stdio fwd session. */
+static void
+mux_stdio_confirm(int id, int success, void *arg)
+{
+       struct mux_stdio_confirm_ctx *cctx = arg;
+       Channel *c, *cc;
+       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;
+       }
+
+       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;
+       free(cctx);
+}
+
 static int
 process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
 {
@@ -1936,7 +1988,7 @@ mux_client_request_stdio_fwd(int fd)
        case MUX_S_FAILURE:
                e = buffer_get_string(&m, NULL);
                buffer_free(&m);
-               fatal("%s: stdio forwarding request failed: %s", __func__, e);
+               fatal("Stdio forwarding request failed: %s", e);
        default:
                buffer_free(&m);
                error("%s: unexpected response from master 0x%08x",

diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index 7d71665..d83b023 100644 (file)
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.406 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: ssh.c,v 1.407 2014/07/17 07:22:19 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1310,6 +1310,13 @@ client_cleanup_stdio_fwd(int id, void *arg)
        cleanup_exit(0);
 }
 
+static void
+ssh_stdio_confirm(int id, int success, void *arg)
+{
+       if (!success)
+               fatal("stdio forwarding failed");
+}
+
 static void
 ssh_init_stdio_forwarding(void)
 {
@@ -1330,6 +1337,7 @@ ssh_init_stdio_forwarding(void)
            stdio_forward_port, in, out)) == NULL)
                fatal("%s: channel_connect_stdio_fwd failed", __func__);
        channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
+       channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL);
 }
 
 static void