- djm@cvs.openbsd.org 2009/02/12 03:00:56
[canohost.c canohost.h channels.c channels.h clientloop.c readconf.c]
[readconf.h serverloop.c ssh.c]
support remote port forwarding with a zero listen port (-R0:...) to
dyamically allocate a listen port at runtime (this is actually
specified in rfc4254); bz#1003 ok markus@
diff --git a/channels.c b/channels.c
index 0b1c34c..dea60ba 100644
--- a/channels.c
+++ b/channels.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.c,v 1.294 2009/01/22 09:49:57 djm Exp $ */
+/* $OpenBSD: channels.c,v 1.295 2009/02/12 03:00:56 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2460,7 +2460,8 @@
}
static int
-channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
+channel_setup_fwd_listener(int type, const char *listen_addr,
+ u_short listen_port, int *allocated_listen_port,
const char *host_to_connect, u_short port_to_connect, int gateway_ports)
{
Channel *c;
@@ -2468,6 +2469,7 @@
struct addrinfo hints, *ai, *aitop;
const char *host, *addr;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ in_port_t *lport_p;
host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
listen_addr : host_to_connect;
@@ -2536,10 +2538,29 @@
}
return 0;
}
-
+ if (allocated_listen_port != NULL)
+ *allocated_listen_port = 0;
for (ai = aitop; ai; ai = ai->ai_next) {
- if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
+ switch (ai->ai_family) {
+ case AF_INET:
+ lport_p = &((struct sockaddr_in *)ai->ai_addr)->
+ sin_port;
+ break;
+ case AF_INET6:
+ lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
+ sin6_port;
+ break;
+ default:
continue;
+ }
+ /*
+ * If allocating a port for -R forwards, then use the
+ * same port for all address families.
+ */
+ if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
+ allocated_listen_port != NULL && *allocated_listen_port > 0)
+ *lport_p = htons(*allocated_listen_port);
+
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
error("channel_setup_fwd_listener: getnameinfo failed");
@@ -2555,7 +2576,8 @@
channel_set_reuseaddr(sock);
- debug("Local forwarding listening on %s port %s.", ntop, strport);
+ debug("Local forwarding listening on %s port %s.",
+ ntop, strport);
/* Bind the socket to the address. */
if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
@@ -2574,6 +2596,19 @@
close(sock);
continue;
}
+
+ /*
+ * listen_port == 0 requests a dynamically allocated port -
+ * record what we got.
+ */
+ if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
+ allocated_listen_port != NULL &&
+ *allocated_listen_port == 0) {
+ *allocated_listen_port = get_sock_port(sock, 1);
+ debug("Allocated listen port %d",
+ *allocated_listen_port);
+ }
+
/* Allocate a channel number for the socket. */
c = channel_new("port listener", type, sock, sock, -1,
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
@@ -2616,17 +2651,18 @@
const char *host_to_connect, u_short port_to_connect, int gateway_ports)
{
return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
- listen_host, listen_port, host_to_connect, port_to_connect,
+ listen_host, listen_port, NULL, host_to_connect, port_to_connect,
gateway_ports);
}
/* protocol v2 remote port fwd, used by sshd */
int
channel_setup_remote_fwd_listener(const char *listen_address,
- u_short listen_port, int gateway_ports)
+ u_short listen_port, int *allocated_listen_port, int gateway_ports)
{
return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
- listen_address, listen_port, NULL, 0, gateway_ports);
+ listen_address, listen_port, allocated_listen_port,
+ NULL, 0, gateway_ports);
}
/*