Add "-s src_addr" option to allow setting of the source IP address.

usr.bin/telnet/commands.c

@@ -2100,7 +2100,7 @@ tn(argc, argv)
     char *argv[];
 {
     register struct hostent *host = 0;
-    struct sockaddr_in sin;
+    struct sockaddr_in sin, src_sin;
     struct servent *sp = 0;
     unsigned long temp;
 #if	defined(IP_OPTIONS) && defined(IPPROTO_IP)
@@ -2108,6 +2108,7 @@ tn(argc, argv)
     unsigned long sourceroute(), srlen;
 #endif
     char *cmd, *hostp = 0, *portp = 0, *user = 0;
+    char *src_addr = NULL;
 
     /* clear the socket address prior to use */
     bzero((char *)&sin, sizeof(sin));
@@ -2143,6 +2144,14 @@ tn(argc, argv)
 	    autologin = 1;
 	    continue;
 	}
+	if (strcmp(*argv, "-s") == 0) {
+	    --argc; ++argv;
+	    if (argc == 0)
+		goto usage;
+	    src_addr = *argv++;
+	    --argc;
+	    continue;
+	}
 	if (hostp == 0) {
 	    hostp = *argv++;
 	    --argc;
@@ -2154,13 +2163,31 @@ tn(argc, argv)
 	    continue;
 	}
     usage:
-	printf("usage: telnet [-l user] [-a] host-name [port]\n");
+	printf("usage: telnet [-l user] [-a] [-s src_addr] host-name [port]\n");
 	setuid(getuid());
 	return 0;
     }
     if (hostp == 0)
 	goto usage;
 
+    if (src_addr != NULL) {
+	bzero((char *)&src_sin, sizeof(src_sin));
+	src_sin.sin_family = AF_INET;
+	if (!inet_aton(src_addr, &src_sin.sin_addr)) {
+	    host = gethostbyname2(src_addr, AF_INET);
+	    if (host == NULL) {
+		herror(src_addr);
+		return 0;
+	    }
+	    if (host->h_length != sizeof(src_sin.sin_addr)) {
+		fprintf(stderr, "telnet: gethostbyname2: invalid address\n");
+		return 0;
+	    }
+	    memcpy((void *)&src_sin.sin_addr, (void *)host->h_addr_list[0],
+			sizeof(src_sin.sin_addr));
+	}
+    }
+
 #if	defined(IP_OPTIONS) && defined(IPPROTO_IP)
     if (hostp[0] == '@' || hostp[0] == '!') {
 	if ((hostname = strrchr(hostp, ':')) == NULL)
@@ -2285,6 +2312,13 @@ tn(argc, argv)
 		perror("setsockopt (SO_DEBUG)");
 	}
 
+	if (src_addr != NULL) {
+	    if (bind(net, (struct sockaddr *)&src_sin, sizeof(src_sin)) == -1) {
+		perror("bind");
+		return 0;
+	    }
+	}
+
 	if (connect(net, (struct sockaddr *)&sin, sizeof (sin)) < 0) {
 #if	defined(h_addr)		/* In 4.3, this is a #define */
 	    if (host && host->h_addr_list[1]) {

usr.bin/telnet/main.c

@@ -85,16 +85,18 @@ usage()
 	    "\n\t[-k realm] [-l user] [-f/-F] [-n tracefile] ",
 #else
 	    "[-8] [-E] [-L] [-S tos] [-a] [-c] [-d] [-e char] [-l user]",
-	    "\n\t[-n tracefile]",
+	    "\n\t[-n tracefile] ",
 #endif
 #if defined(TN3270) && defined(unix)
 # ifdef AUTHENTICATION
-	    "[-noasynch] [-noasynctty]\n\t[-noasyncnet] [-r] [-t transcom] ",
+	    "[-noasynch] [-noasynctty]\n\t"
+	    "[-noasyncnet] [-r] [-s src_addr] [-t transcom] ",
 # else
-	    "[-noasynch] [-noasynctty] [-noasyncnet] [-r]\n\t[-t transcom]",
+	    "[-noasynch] [-noasynctty] [-noasyncnet] [-r]\n\t"
+	    "[-s src_addr] [-t transcom]",
 # endif
 #else
-	    "[-r] ",
+	    "[-r] [-s src_addr] ",
 #endif
 	    "[host-name [port]]"
 	);
@@ -114,6 +116,7 @@ main(argc, argv)
 	extern int optind;
 	int ch;
 	char *user, *strrchr();
+	char *src_addr = NULL;
 #ifdef	FORWARD
 	extern int forward_flags;
 #endif	/* FORWARD */
@@ -135,7 +138,7 @@ main(argc, argv)
 	rlogin = (strncmp(prompt, "rlog", 4) == 0) ? '~' : _POSIX_VDISABLE;
 	autologin = -1;
 
-	while ((ch = getopt(argc, argv, "8EKLNS:X:acde:fFk:l:n:rt:x")) != -1) {
+	while ((ch = getopt(argc, argv, "8EKLNS:X:acde:fFk:l:n:rs:t:x")) != -1) {
 		switch(ch) {
 		case '8':
 			eight = 3;	/* binary output and input */
@@ -255,6 +258,9 @@ main(argc, argv)
 		case 'r':
 			rlogin = '~';
 			break;
+		case 's':
+			src_addr = optarg;
+			break;
 		case 't':
 #if defined(TN3270) && defined(unix)
 			transcom = tline;
@@ -283,7 +289,7 @@ main(argc, argv)
 	argv += optind;
 
 	if (argc) {
-		char *args[7], **argp = args;
+		char *args[9], **argp = args;
 
 		if (argc > 2)
 			usage();
@@ -292,6 +298,10 @@ main(argc, argv)
 			*argp++ = "-l";
 			*argp++ = user;
 		}
+		if (src_addr) {
+			*argp++ = "-s";
+			*argp++ = src_addr;
+		}
 		*argp++ = argv[0];		/* host */
 		if (argc > 1)
 			*argp++ = argv[1];	/* port */

usr.bin/telnet/telnet.1

@@ -30,7 +30,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"	@(#)telnet.1	8.5 (Berkeley) 3/1/94
-.\"	$Id: telnet.1,v 1.9 1997/12/27 18:58:27 steve Exp $
+.\"	$Id: telnet.1,v 1.10 1998/12/14 22:40:38 billf Exp $
 .\"
 .Dd March 1, 1994
 .Dt TELNET 1
@@ -49,6 +49,7 @@ protocol
 .Op Fl k Ar realm
 .Op Fl l Ar user
 .Op Fl n Ar tracefile
+.Op Fl s Ar src_addr
 .Oo
 .Ar host
 .Op Ar port
@@ -184,6 +185,12 @@ mode, the escape character is set to the tilde (~) character,
 unless modified by the
 .Fl e
 option.
+.It Fl s Ar src_addr
+Set the source IP address for the
+.Nm
+connection to
+.Ar src_addr ,
+which can be an IP address or a host name.
 .It Fl x
 Turns on encryption of the data stream if possible.  This
 option is not available outside of the United States and