- djm@cvs.openbsd.org 2011/04/17 22:42:42
[PROTOCOL.mux clientloop.c clientloop.h mux.c ssh.1 ssh.c]
allow graceful shutdown of multiplexing: request that a mux server
removes its listener socket and refuse future multiplexing requests;
ok markus@
diff --git a/mux.c b/mux.c
index e370462..0946835 100644
--- a/mux.c
+++ b/mux.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: mux.c,v 1.24 2011/01/13 21:54:53 djm Exp $ */
+/* $OpenBSD: mux.c,v 1.25 2011/04/17 22:42:41 djm Exp $ */
/*
* Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
*
@@ -146,6 +146,7 @@
#define MUX_C_OPEN_FWD 0x10000006
#define MUX_C_CLOSE_FWD 0x10000007
#define MUX_C_NEW_STDIO_FWD 0x10000008
+#define MUX_C_STOP_LISTENING 0x10000009
#define MUX_S_OK 0x80000001
#define MUX_S_PERMISSION_DENIED 0x80000002
#define MUX_S_FAILURE 0x80000003
@@ -168,6 +169,7 @@
static int process_mux_open_fwd(u_int, Channel *, Buffer *, Buffer *);
static int process_mux_close_fwd(u_int, Channel *, Buffer *, Buffer *);
static int process_mux_stdio_fwd(u_int, Channel *, Buffer *, Buffer *);
+static int process_mux_stop_listening(u_int, Channel *, Buffer *, Buffer *);
static const struct {
u_int type;
@@ -180,6 +182,7 @@
{ MUX_C_OPEN_FWD, process_mux_open_fwd },
{ MUX_C_CLOSE_FWD, process_mux_close_fwd },
{ MUX_C_NEW_STDIO_FWD, process_mux_stdio_fwd },
+ { MUX_C_STOP_LISTENING, process_mux_stop_listening },
{ 0, NULL }
};
@@ -915,6 +918,39 @@
return 0;
}
+static int
+process_mux_stop_listening(u_int rid, Channel *c, Buffer *m, Buffer *r)
+{
+ debug("%s: channel %d: stop listening", __func__, c->self);
+
+ if (options.control_master == SSHCTL_MASTER_ASK ||
+ options.control_master == SSHCTL_MASTER_AUTO_ASK) {
+ if (!ask_permission("Disable further multiplexing on shared "
+ "connection to %s? ", host)) {
+ debug2("%s: stop listen refused by user", __func__);
+ buffer_put_int(r, MUX_S_PERMISSION_DENIED);
+ buffer_put_int(r, rid);
+ buffer_put_cstring(r, "Permission denied");
+ return 0;
+ }
+ }
+
+ if (mux_listener_channel != NULL) {
+ channel_free(mux_listener_channel);
+ client_stop_mux();
+ xfree(options.control_path);
+ options.control_path = NULL;
+ mux_listener_channel = NULL;
+ muxserver_sock = -1;
+ }
+
+ /* prepare reply */
+ buffer_put_int(r, MUX_S_OK);
+ buffer_put_int(r, rid);
+
+ return 0;
+}
+
/* Channel callbacks fired on read/write from mux slave fd */
static int
mux_master_read_cb(Channel *c)
@@ -1813,6 +1849,50 @@
fatal("%s: master returned unexpected message %u", __func__, type);
}
+static void
+mux_client_request_stop_listening(int fd)
+{
+ Buffer m;
+ char *e;
+ u_int type, rid;
+
+ debug3("%s: entering", __func__);
+
+ buffer_init(&m);
+ buffer_put_int(&m, MUX_C_STOP_LISTENING);
+ buffer_put_int(&m, muxclient_request_id);
+
+ if (mux_client_write_packet(fd, &m) != 0)
+ fatal("%s: write packet: %s", __func__, strerror(errno));
+
+ buffer_clear(&m);
+
+ /* Read their reply */
+ if (mux_client_read_packet(fd, &m) != 0)
+ fatal("%s: read from master failed: %s",
+ __func__, strerror(errno));
+
+ type = buffer_get_int(&m);
+ if ((rid = buffer_get_int(&m)) != muxclient_request_id)
+ fatal("%s: out of sequence reply: my id %u theirs %u",
+ __func__, muxclient_request_id, rid);
+ switch (type) {
+ case MUX_S_OK:
+ break;
+ case MUX_S_PERMISSION_DENIED:
+ e = buffer_get_string(&m, NULL);
+ fatal("Master refused stop listening request: %s", e);
+ case MUX_S_FAILURE:
+ e = buffer_get_string(&m, NULL);
+ fatal("%s: stop listening request failed: %s", __func__, e);
+ default:
+ fatal("%s: unexpected response from master 0x%08x",
+ __func__, type);
+ }
+ buffer_free(&m);
+ muxclient_request_id++;
+}
+
/* Multiplex client main loop. */
void
muxclient(const char *path)
@@ -1906,6 +1986,10 @@
case SSHMUX_COMMAND_STDIO_FWD:
mux_client_request_stdio_fwd(sock);
exit(0);
+ case SSHMUX_COMMAND_STOP:
+ mux_client_request_stop_listening(sock);
+ fprintf(stderr, "Stop listening request sent.\r\n");
+ exit(0);
default:
fatal("unrecognised muxclient_command %d", muxclient_command);
}