From a4cc82665c26e8db94017aacf79d31b83e101c0c Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@FreeBSD.org>
Date: Wed, 23 May 2001 22:47:16 +0000
Subject: [PATCH] A feature to allow one to telnet to a unix domain socket.

Obtained from:   Lyndon Nerenberg <lyndon@orthanc.ab.ca>
---
 usr.bin/telnet/commands.c | 30 +++++++++++++++++++++++++++++-
 usr.bin/telnet/main.c     |  5 ++++-
 usr.bin/telnet/telnet.1   | 13 +++++++++++--
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/usr.bin/telnet/commands.c b/usr.bin/telnet/commands.c
index 5079dc19b845..d8160ccd46d6 100644
--- a/usr.bin/telnet/commands.c
+++ b/usr.bin/telnet/commands.c
@@ -39,6 +39,7 @@ static char sccsid[] = "@(#)commands.c	8.2 (Berkeley) 12/15/93";
 
 #if	defined(unix)
 #include <sys/param.h>
+#include <sys/un.h>
 #if	defined(CRAY) || defined(sysV88)
 #include <sys/types.h>
 #endif
@@ -2109,6 +2110,9 @@ sockaddr_ntop(sa)
     case AF_INET:
 	addr = &((struct sockaddr_in *)sa)->sin_addr;
 	break;
+    case AF_UNIX:
+	addr = &((struct sockaddr_un *)sa)->sun_path;
+	break;
 #ifdef INET6
     case AF_INET6:
 	addr = &((struct sockaddr_in6 *)sa)->sin6_addr;
@@ -2267,7 +2271,30 @@ tn(argc, argv)
 	}
 	src_res0 = src_res;
     }
-    if (hostp[0] == '@' || hostp[0] == '!') {
+    if (hostp[0] == '/') {
+	struct sockaddr_un su;
+	
+	if (strlen(hostp) >= sizeof(su.sun_path)) {
+	    fprintf(stderr, "hostname too long for unix domain socket: %s",
+		    hostp);
+		goto fail;
+	}
+	memset(&su, 0, sizeof su);
+	su.sun_family = AF_UNIX;
+	strncpy(su.sun_path, hostp, sizeof su.sun_path);
+	printf("Trying %s...\n", &su.sun_path);
+	net = socket(PF_UNIX, SOCK_STREAM, 0);
+	if ( net < 0) {
+	    perror("socket");
+	    goto fail;
+	}
+	if (connect(net, (struct sockaddr *)&su, sizeof su) == -1) {
+	    perror(su.sun_path);
+	    (void) NetClose(net);
+	    goto fail;
+	}
+	goto af_unix;
+    } else if (hostp[0] == '@' || hostp[0] == '!') {
 	if (
 #ifdef INET6
 	    family == AF_INET6 ||
@@ -2450,6 +2477,7 @@ tn(argc, argv)
     if (src_res0 != NULL)
         freeaddrinfo(src_res0);
     cmdrc(hostp, hostname);
+ af_unix:    
     if (autologin && user == NULL) {
 	struct passwd *pw;
 
diff --git a/usr.bin/telnet/main.c b/usr.bin/telnet/main.c
index 657f560e64a4..4b4a13a1b410 100644
--- a/usr.bin/telnet/main.c
+++ b/usr.bin/telnet/main.c
@@ -157,11 +157,14 @@ main(argc, argv)
 #define IPSECOPT
 #endif
 	while ((ch = getopt(argc, argv,
-			    "468EKLNS:X:acde:fFk:l:n:rs:t:x" IPSECOPT)) != -1)
+			    "468EKLNS:X:acde:fFk:l:n:rs:t:ux" IPSECOPT)) != -1)
 #undef IPSECOPT
 	{
 
 		switch(ch) {
+		case 'u':
+			family = AF_UNIX;
+			break;
 		case '4':
 			family = AF_INET;
 			break;
diff --git a/usr.bin/telnet/telnet.1 b/usr.bin/telnet/telnet.1
index 56bf05693b35..4c857d9b280a 100644
--- a/usr.bin/telnet/telnet.1
+++ b/usr.bin/telnet/telnet.1
@@ -42,7 +42,7 @@
 protocol
 .Sh SYNOPSIS
 .Nm
-.Op Fl 468EFKLNacdfrx
+.Op Fl u468EFKLNacdfrx
 .Op Fl S Ar tos
 .Op Fl X Ar authtype
 .Op Fl e Ar escapechar
@@ -75,6 +75,11 @@ command with those arguments.
 .Pp
 Options:
 .Bl -tag -width indent
+.It Fl u
+Forces
+.Nm
+to use
+AF_UNIX addresses only (e.g. unix domain sockets, accessed with a file path)
 .It Fl 4
 Forces
 .Nm
@@ -205,7 +210,11 @@ option is not available outside of the United States and
 Canada.
 .It Ar host
 Indicates the official name, an alias, or the Internet address
-of a remote host.
+of a remote host. If
+.Ar host
+starts with a /,
+.Nm
+establishes a connection to the corresponding named socket.
 .It Ar port
 Indicates a port number (address of an application).  If a number is
 not specified, the default