implement 'ssh -b bind_address' like 'telnet -b'

5 files changed, 64 insertions, 18 deletions

diff --git a/usr.bin/ssh/readconf.c b/usr.bin/ssh/readconf.c
index cbb93b7b061..7c7a4ebab4c 100644
--- a/usr.bin/ssh/readconf.c
+++ b/usr.bin/ssh/readconf.c
@@ -12,7 +12,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: readconf.c,v 1.76 2001/04/17 10:53:25 markus Exp $");
+RCSID("$OpenBSD: readconf.c,v 1.77 2001/04/30 11:18:51 markus Exp $");
 
 #include "ssh.h"
 #include "xmalloc.h"
@@ -111,7 +111,7 @@ typedef enum {
 	oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication,
 	oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
 	oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
-	oHostKeyAlgorithms
+	oHostKeyAlgorithms, oBindAddress
 } OpCodes;
 
 /* Textual representations of the tokens. */
@@ -177,6 +177,7 @@ static struct {
 	{ "dynamicforward", oDynamicForward },
 	{ "preferredauthentications", oPreferredAuthentications },
 	{ "hostkeyalgorithms", oHostKeyAlgorithms },
+	{ "bindaddress", oBindAddress },
 	{ NULL, 0 }
 };
 
@@ -457,6 +458,10 @@ parse_string:
 		charptr = &options->preferred_authentications;
 		goto parse_string;
 
+	case oBindAddress:
+		charptr = &options->bind_address;
+		goto parse_string;
+
 	case oProxyCommand:
 		charptr = &options->proxy_command;
 		string = xstrdup("");
@@ -759,6 +764,7 @@ initialize_options(Options * options)
 	options->num_remote_forwards = 0;
 	options->log_level = (LogLevel) - 1;
 	options->preferred_authentications = NULL;
+	options->bind_address = NULL;
 }
 
 /*
diff --git a/usr.bin/ssh/readconf.h b/usr.bin/ssh/readconf.h
index 9e943f905c5..4b20c93bf5d 100644
--- a/usr.bin/ssh/readconf.h
+++ b/usr.bin/ssh/readconf.h
@@ -11,7 +11,7 @@
  * called by a name other than "ssh" or "Secure Shell".
  */
 
-/* RCSID("$OpenBSD: readconf.h,v 1.30 2001/04/17 10:53:25 markus Exp $"); */
+/* RCSID("$OpenBSD: readconf.h,v 1.31 2001/04/30 11:18:52 markus Exp $"); */
 
 #ifndef READCONF_H
 #define READCONF_H
@@ -85,6 +85,7 @@ typedef struct {
 	char   *system_hostfile2;
 	char   *user_hostfile2;
 	char   *preferred_authentications;
+	char   *bind_address;	/* local socket address for connection to sshd */
 
 	int     num_identity_files;	/* Number of files for RSA/DSA identities. */
 	char   *identity_files[SSH_MAX_IDENTITY_FILES];
diff --git a/usr.bin/ssh/ssh.1 b/usr.bin/ssh/ssh.1
index 0d26197b693..6f4110e4189 100644
--- a/usr.bin/ssh/ssh.1
+++ b/usr.bin/ssh/ssh.1
@@ -34,7 +34,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh.1,v 1.107 2001/04/22 23:58:36 markus Exp $
+.\" $OpenBSD: ssh.1,v 1.108 2001/04/30 11:18:52 markus Exp $
 .Dd September 25, 1999
 .Dt SSH 1
 .Os
@@ -49,6 +49,7 @@
 .Pp
 .Nm ssh
 .Op Fl afgknqstvxACNPTX1246
+.Op Fl b Ar bind_address
 .Op Fl c Ar cipher_spec
 .Op Fl e Ar escape_char
 .Op Fl i Ar identity_file
@@ -383,6 +384,9 @@ Disables forwarding of the authentication agent connection.
 .It Fl A
 Enables forwarding of the authentication agent connection.
 This can also be specified on a per-host basis in a configuration file.
+.It Fl b Ar bind_address
+Specify the interface to transmit from on machines with multiple
+interfaces or aliased addresses.
 .It Fl c Ar blowfish|3des
 Selects the cipher to use for encrypting the session.
 .Ar 3des
@@ -667,6 +671,13 @@ or
 .Dq no .
 The default is
 .Dq no .
+.It Cm BindAddress
+Specify the interface to transmit from on machines with multiple
+interfaces or aliased addresses.
+Note that this option does not work if
+.Cm UsePrivilegedPort
+is set to
+.Dq yes .
 .It Cm CheckHostIP
 If this flag is set to
 .Dq yes ,
diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index b9a56c938bc..32092b888b6 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -39,7 +39,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: ssh.c,v 1.116 2001/04/17 12:55:04 markus Exp $");
+RCSID("$OpenBSD: ssh.c,v 1.117 2001/04/30 11:18:52 markus Exp $");
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
@@ -183,6 +183,7 @@ usage(void)
 	fprintf(stderr, "  -6          Use IPv6 only.\n");
 	fprintf(stderr, "  -o 'option' Process the option as if it was read from a configuration file.\n");
 	fprintf(stderr, "  -s          Invoke command (mandatory) as SSH2 subsystem.\n");
+	fprintf(stderr, "  -b          Local IP address.\n");
 	exit(1);
 }
 
@@ -305,7 +306,7 @@ main(int ac, char **av)
 		opt = av[optind][1];
 		if (!opt)
 			usage();
-		if (strchr("eilcmpLRDo", opt)) {   /* options with arguments */
+		if (strchr("eilcmpbLRDo", opt)) {   /* options with arguments */
 			optarg = av[optind] + 2;
 			if (strcmp(optarg, "") == 0) {
 				if (optind >= ac - 1)
@@ -504,6 +505,9 @@ main(int ac, char **av)
 		case 's':
 			subsystem_flag = 1;
 			break;
+		case 'b':
+			options.bind_address = optarg;
+			break;
 		default:
 			usage();
 		}
diff --git a/usr.bin/ssh/sshconnect.c b/usr.bin/ssh/sshconnect.c
index 31d06964bb0..39a661a6602 100644
--- a/usr.bin/ssh/sshconnect.c
+++ b/usr.bin/ssh/sshconnect.c
@@ -13,7 +13,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: sshconnect.c,v 1.104 2001/04/12 19:15:25 markus Exp $");
+RCSID("$OpenBSD: sshconnect.c,v 1.105 2001/04/30 11:18:52 markus Exp $");
 
 #include <openssl/bn.h>
 
@@ -147,7 +147,8 @@ ssh_proxy_connect(const char *host, u_short port, struct passwd *pw,
 int
 ssh_create_socket(struct passwd *pw, int privileged, int family)
 {
-	int sock;
+	int sock, gaierr;
+	struct addrinfo hints, *res;
 
 	/*
 	 * If we are running as root and want to connect to a privileged
@@ -160,17 +161,40 @@ ssh_create_socket(struct passwd *pw, int privileged, int family)
 			error("rresvport: af=%d %.100s", family, strerror(errno));
 		else
 			debug("Allocated local port %d.", p);
-	} else {
-		/*
-		 * Just create an ordinary socket on arbitrary port.  We use
-		 * the user's uid to create the socket.
-		 */
-		temporarily_use_uid(pw);
-		sock = socket(family, SOCK_STREAM, 0);
-		if (sock < 0)
-			error("socket: %.100s", strerror(errno));
-		restore_uid();
+		return sock;
+	}
+	/*
+	 * Just create an ordinary socket on arbitrary port.  We use
+	 * the user's uid to create the socket.
+	 */
+	temporarily_use_uid(pw);
+	sock = socket(family, SOCK_STREAM, 0);
+	if (sock < 0)
+		error("socket: %.100s", strerror(errno));
+	restore_uid();
+
+	/* Bind the socket to an alternative local IP address */
+	if (options.bind_address == NULL)
+		return sock;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = IPv4or6;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+	gaierr = getaddrinfo(options.bind_address, "0", &hints, &res);
+	if (gaierr) {
+		error("getaddrinfo: %s: %s", options.bind_address,
+		    gai_strerror(gaierr));
+		close(sock);
+		return -1;
+	}
+	if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
+		error("bind: %s: %s", options.bind_address, strerror(errno));
+		close(sock);
+		freeaddrinfo(res);
+		return -1;
 	}
+	freeaddrinfo(res);
 	return sock;
 }