Attachment 1498 Details for Bug 343 – try subsequent addresses

[patch] try subsequent addresses

fwd-try-next-addr.diff (text/plain), 11.79 KB, created by Damien Miller on 2008-05-09 01:01:36 AEST

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Creator: Damien Miller

Created: 2008-05-09 01:01:36 AEST

Size: 11.79 KB

patch

obsolete

>Index: channels.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/channels.c,v
>retrieving revision 1.275
>diff -u -p -r1.275 channels.c
>--- channels.c	8 May 2008 12:02:23 -0000	1.275
>+++ channels.c	8 May 2008 14:59:21 -0000
>@@ -161,6 +161,8 @@ static int IPv4or6 = AF_UNSPEC;
> /* helper */
> static void port_open_helper(Channel *c, char *rtype);
> 
>+static int connect_next(struct addrinfo **, const char *, int);
>+
> /* -- channel core */
> 
> Channel *
>@@ -1420,7 +1422,7 @@ channel_post_auth_listener(Channel *c, f
> static void
> channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
> {
>-	int err = 0;
>+	int err = 0, sock;
> 	socklen_t sz = sizeof(err);
> 
> 	if (FD_ISSET(c->sock, writeset)) {
>@@ -1429,7 +1431,12 @@ channel_post_connecting(Channel *c, fd_s
> 			error("getsockopt SO_ERROR failed");
> 		}
> 		if (err == 0) {
>-			debug("channel %d: connected", c->self);
>+			debug("channel %d: connected to %s port %d",
>+			    c->self, c->connect_ctx.host, c->connect_ctx.port);
>+			xfree(c->connect_ctx.host);
>+			c->connect_ctx.host = NULL;
>+			freeaddrinfo(c->connect_ctx.aitop);
>+			c->connect_ctx.ai = c->connect_ctx.aitop = NULL;
> 			c->type = SSH_CHANNEL_OPEN;
> 			if (compat20) {
> 				packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
>@@ -1443,8 +1450,23 @@ channel_post_connecting(Channel *c, fd_s
> 				packet_put_int(c->self);
> 			}
> 		} else {
>-			debug("channel %d: not connected: %s",
>+			debug("channel %d: connection failed: %s",
> 			    c->self, strerror(err));
>+			/* Try next address, if any */
>+			if ((sock = connect_next(&c->connect_ctx.ai,
>+			    c->connect_ctx.host, c->connect_ctx.port)) > 0) {
>+				close(c->sock);
>+				c->sock = c->rfd = c->wfd = sock;
>+				channel_max_fd = channel_find_maxfd();
>+				return;
>+			}
>+			/* Exhausted all addresses */
>+			error("connect_to %.100s port %d: failed.",
>+			    c->connect_ctx.host, c->connect_ctx.port);
>+			xfree(c->connect_ctx.host);
>+			c->connect_ctx.host = NULL;
>+			freeaddrinfo(c->connect_ctx.aitop);
>+			c->connect_ctx.ai = c->connect_ctx.aitop = NULL;
> 			if (compat20) {
> 				packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
> 				packet_put_int(c->remote_id);
>@@ -2311,6 +2333,7 @@ channel_input_port_open(int type, u_int3
> 	u_short host_port;
> 	char *host, *originator_string;
> 	int remote_id, sock = -1;
>+	struct addrinfo *ai, *aitop;
> 
> 	remote_id = packet_get_int();
> 	host = packet_get_string(NULL);
>@@ -2322,12 +2345,16 @@ channel_input_port_open(int type, u_int3
> 		originator_string = xstrdup("unknown (remote did not supply name)");
> 	}
> 	packet_check_eom();
>-	sock = channel_connect_to(host, host_port);
>+	sock = channel_connect_to(host, host_port, &ai, &aitop);
> 	if (sock != -1) {
> 		c = channel_new("connected socket",
> 		    SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
> 		    originator_string, 1);
> 		c->remote_id = remote_id;
>+		c->connect_ctx.host = xstrdup(host);
>+		c->connect_ctx.port = host_port;
>+		c->connect_ctx.ai = ai;
>+		c->connect_ctx.aitop = aitop;
> 	}
> 	xfree(originator_string);
> 	if (c == NULL) {
>@@ -2747,30 +2774,26 @@ channel_clear_adm_permitted_opens(void)
> 	num_adm_permitted_opens = 0;
> }
> 
>-/* return socket to remote host, port */
>+/*
>+ * Attempt non-blocking connect to next host on addrinfo list at *aip.
>+ * Returns in-progress socket and updates *aip to next host in list,
>+ * allowing continuation in cases where the connection ends up failing.
>+ */
> static int
>-connect_to(const char *host, u_short port)
>+connect_next(struct addrinfo **aip, const char *host, int port)
> {
>-	struct addrinfo hints, *ai, *aitop;
>+	struct addrinfo *ai = *aip;
>+	int sock, saved_errno;
> 	char ntop[NI_MAXHOST], strport[NI_MAXSERV];
>-	int gaierr;
>-	int sock = -1;
> 
>-	memset(&hints, 0, sizeof(hints));
>-	hints.ai_family = IPv4or6;
>-	hints.ai_socktype = SOCK_STREAM;
>-	snprintf(strport, sizeof strport, "%d", port);
>-	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
>-		error("connect_to %.100s: unknown host (%s)", host,
>-		    ssh_gai_strerror(gaierr));
>-		return -1;
>-	}
>-	for (ai = aitop; ai; ai = ai->ai_next) {
>+	for (; ai; ai = ai->ai_next) {
> 		if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
> 			continue;
>-		if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
>-		    strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
>-			error("connect_to: getnameinfo failed");
>+		if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
>+		    ntop, sizeof(ntop),
>+		    strport, sizeof(strport),
>+		    NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
>+			error("connect_next: getnameinfo failed");
> 			continue;
> 		}
> 		sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
>@@ -2785,35 +2808,79 @@ connect_to(const char *host, u_short por
> 			fatal("%s: set_nonblock(%d)", __func__, sock);
> 		if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
> 		    errno != EINPROGRESS) {
>-			error("connect_to %.100s port %s: %.100s", ntop, strport,
>-			    strerror(errno));
>+			debug("connect_next: host %.100s ([%.100s]:%s): "
>+			    "%.100s", host, ntop, strport, strerror(errno));
>+			saved_errno = errno;
> 			close(sock);
>+			errno = saved_errno;
> 			continue;	/* fail -- try next */
> 		}
>-		break; /* success */
>+		debug("connect_next: host %.100s ([%.100s]:%s) "
>+		    "in progress, fd=%d", host, ntop, strport, sock);
>+		*aip = ai->ai_next;
>+		set_nodelay(sock);
>+		return sock;
>+	}
>+	*aip = NULL;
>+	return -1;
>+}
>+	
>+/* return socket to remote host, port */
>+static int
>+connect_to(const char *host, u_short port, struct addrinfo **aip,
>+    struct addrinfo **aitopp)
>+{
>+	struct addrinfo hints, *ai, *aitop;
>+	int gaierr;
>+	int sock = -1;
>+	char strport[NI_MAXSERV];
> 
>+	memset(&hints, 0, sizeof(hints));
>+	hints.ai_family = IPv4or6;
>+	hints.ai_socktype = SOCK_STREAM;
>+	snprintf(strport, sizeof strport, "%d", port);
>+	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
>+		error("connect_to %.100s: unknown host (%s)", host,
>+		    ssh_gai_strerror(gaierr));
>+		return -1;
> 	}
>-	freeaddrinfo(aitop);
>-	if (!ai) {
>-		error("connect_to %.100s port %d: failed.", host, port);
>+
>+	ai = aitop;
>+	if ((sock = connect_next(&ai, host, port)) == -1) {
>+		error("connect to %.100s port %d failed: %s",
>+		    host, port, strerror(errno));
>+		freeaddrinfo(aitop);
>+		*aip = NULL;
>+		*aitopp = NULL;
> 		return -1;
> 	}
>+
> 	/* success */
>-	set_nodelay(sock);
>+	*aip = ai;
>+	*aitopp = aitop;
> 	return sock;
> }
> 
> int
>-channel_connect_by_listen_address(u_short listen_port)
>+channel_connect_by_listen_address(u_short listen_port,
>+     char **dhost, int *dport, struct addrinfo **aip, struct addrinfo **aitopp)
> {
>-	int i;
>+	int i, r;
> 
>-	for (i = 0; i < num_permitted_opens; i++)
>+	for (i = 0; i < num_permitted_opens; i++) {
> 		if (permitted_opens[i].host_to_connect != NULL &&
>-		    permitted_opens[i].listen_port == listen_port)
>-			return connect_to(
>+		    permitted_opens[i].listen_port == listen_port) {
>+			if ((r = connect_to(
> 			    permitted_opens[i].host_to_connect,
>-			    permitted_opens[i].port_to_connect);
>+			    permitted_opens[i].port_to_connect,
>+			    aip, aitopp)) != -1) {
>+				*dhost = xstrdup(
>+				    permitted_opens[i].host_to_connect);
>+				*dport = permitted_opens[i].port_to_connect;
>+			}
>+			return r;
>+		}
>+	}
> 	error("WARNING: Server requests forwarding for unknown listen_port %d",
> 	    listen_port);
> 	return -1;
>@@ -2821,7 +2888,8 @@ channel_connect_by_listen_address(u_shor
> 
> /* Check if connecting to that port is permitted and connect. */
> int
>-channel_connect_to(const char *host, u_short port)
>+channel_connect_to(const char *host, u_short port, struct addrinfo **aip,
>+    struct addrinfo **aitopp)
> {
> 	int i, permit, permit_adm = 1;
> 
>@@ -2849,7 +2917,7 @@ channel_connect_to(const char *host, u_s
> 		    "but the request was denied.", host, port);
> 		return -1;
> 	}
>-	return connect_to(host, port);
>+	return connect_to(host, port, aip, aitopp);
> }
> 
> void
>Index: channels.h
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/channels.h,v
>retrieving revision 1.90
>diff -u -p -r1.90 channels.h
>--- channels.h	8 May 2008 12:02:23 -0000	1.90
>+++ channels.h	8 May 2008 14:59:21 -0000
>@@ -125,6 +125,13 @@ struct Channel {
> 	channel_outfilter_fn	*output_filter;
> 
> 	int     datagram;	/* keep boundaries */
>+
>+	/* non-blocking connect */
>+	struct {
>+		char *host;
>+		int port;
>+		struct addrinfo *ai, *aitop;
>+	}	connect_ctx;
> };
> 
> #define CHAN_EXTENDED_IGNORE		0
>@@ -224,8 +231,10 @@ int	 channel_add_adm_permitted_opens(cha
> void	 channel_clear_permitted_opens(void);
> void	 channel_clear_adm_permitted_opens(void);
> int      channel_input_port_forward_request(int, int);
>-int	 channel_connect_to(const char *, u_short);
>-int	 channel_connect_by_listen_address(u_short);
>+int	 channel_connect_to(const char *, u_short, struct addrinfo **,
>+    struct addrinfo **);
>+int	 channel_connect_by_listen_address(u_short, char **, int *,
>+    struct addrinfo **, struct addrinfo **);
> int	 channel_request_remote_forwarding(const char *, u_short,
> 	     const char *, u_short);
> int	 channel_setup_local_fwd_listener(const char *, u_short,
>Index: clientloop.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/clientloop.c,v
>retrieving revision 1.190
>diff -u -p -r1.190 clientloop.c
>--- clientloop.c	8 May 2008 13:06:10 -0000	1.190
>+++ clientloop.c	8 May 2008 14:59:22 -0000
>@@ -1753,8 +1753,10 @@ client_request_forwarded_tcpip(const cha
> {
> 	Channel *c = NULL;
> 	char *listen_address, *originator_address;
>-	int listen_port, originator_port;
>+	int listen_port, originator_port, dport;
> 	int sock;
>+	char *dhost;
>+	struct addrinfo *ai, *aitop;
> 
> 	/* Get rest of the packet */
> 	listen_address = packet_get_string(NULL);
>@@ -1766,7 +1768,8 @@ client_request_forwarded_tcpip(const cha
> 	debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
> 	    listen_address, listen_port, originator_address, originator_port);
> 
>-	sock = channel_connect_by_listen_address(listen_port);
>+	sock = channel_connect_by_listen_address(listen_port,
>+	    &dhost, &dport, &ai, &aitop);
> 	if (sock < 0) {
> 		xfree(originator_address);
> 		xfree(listen_address);
>@@ -1776,6 +1779,10 @@ client_request_forwarded_tcpip(const cha
> 	    SSH_CHANNEL_CONNECTING, sock, sock, -1,
> 	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
> 	    originator_address, 1);
>+	c->connect_ctx.host = dhost;
>+	c->connect_ctx.port = dport;
>+	c->connect_ctx.ai = ai;
>+	c->connect_ctx.aitop = aitop;
> 	xfree(originator_address);
> 	xfree(listen_address);
> 	return c;
>Index: serverloop.c
>===================================================================
>RCS file: /cvs/src/usr.bin/ssh/serverloop.c,v
>retrieving revision 1.149
>diff -u -p -r1.149 serverloop.c
>--- serverloop.c	8 May 2008 12:02:23 -0000	1.149
>+++ serverloop.c	8 May 2008 14:59:22 -0000
>@@ -911,6 +911,7 @@ server_request_direct_tcpip(void)
> 	int sock;
> 	char *target, *originator;
> 	int target_port, originator_port;
>+	struct addrinfo *ai, *aitop;
> 
> 	target = packet_get_string(NULL);
> 	target_port = packet_get_int();
>@@ -918,18 +919,24 @@ server_request_direct_tcpip(void)
> 	originator_port = packet_get_int();
> 	packet_check_eom();
> 
>-	debug("server_request_direct_tcpip: originator %s port %d, target %s port %d",
>-	    originator, originator_port, target, target_port);
>+	debug("server_request_direct_tcpip: originator %s port %d, target %s "
>+	    "port %d", originator, originator_port, target, target_port);
> 
> 	/* XXX check permission */
>-	sock = channel_connect_to(target, target_port);
>-	xfree(target);
>+	sock = channel_connect_to(target, target_port, &ai, &aitop);
> 	xfree(originator);
>-	if (sock < 0)
>+	if (sock < 0) {
>+		xfree(target);
> 		return NULL;
>+	}
> 	c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING,
> 	    sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT,
> 	    CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1);
>+	c->connect_ctx.host = target;
>+	c->connect_ctx.port = target_port;
>+	c->connect_ctx.ai = ai;
>+	c->connect_ctx.aitop = aitop;
>+
> 	return c;
> }
>

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Attachments on bug 343: 1498