Attachment 2455 Details for Bug 2255 – delay reply to multiplexied stdio forwards until confirmation has been received

[patch] delay reply to multiplexied stdio forwards until confirmation has been received

mux-stdio-report.diff (text/plain), 3.87 KB, created by Damien Miller on 2014-07-16 15:18:50 AEST

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Creator: Damien Miller

Created: 2014-07-16 15:18:50 AEST

Size: 3.87 KB

patch

obsolete

>diff --git mux.c mux.c
>index 7df32df..b8d9790 100644
>--- mux.c
>+++ mux.c
>@@ -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 *);
>@@ -870,6 +876,7 @@ 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 ||
>@@ -949,15 +956,60 @@ 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)
> {
>@@ -1902,7 +1954,7 @@ 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 ssh.c ssh.c
>index 950d623..8439fb3 100644
>--- ssh.c
>+++ ssh.c
>@@ -1300,6 +1300,13 @@ client_cleanup_stdio_fwd(int id, void *arg)
> }
> 
> static void
>+ssh_stdio_confirm(int id, int success, void *arg)
>+{
>+	if (!success)
>+		fatal("stdio forwarding failed");
>+}
>+
>+static void
> ssh_init_stdio_forwarding(void)
> {
> 	Channel *c;
>@@ -1319,6 +1326,7 @@ 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

Flags:

dtucker: ok+

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Attachments on bug 2255: 2455