upstream commit

Handle the split of tun(4) "link0" into tap(4) in ssh
 tun-forwarding. Adapted from portable (using separate devices for this is the
 normal case in most OS). ok djm@

Upstream-ID: 90facf4c59ce73d6741db1bc926e578ef465cd39

1 files changed, 11 insertions, 21 deletions

diff --git a/misc.c b/misc.c
index b6503abbb..b358a035e 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.98 2015/10/07 00:54:06 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.99 2015/10/24 08:34:09 sthen Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -653,14 +653,19 @@ tun_open(int tun, int mode)
         struct ifreq ifr;
         char name[100];
         int fd = -1, sock;
+        const char *tunbase = "tun";
+
+        if (mode == SSH_TUNMODE_ETHERNET)
+                tunbase = "tap";
 
         /* Open the tunnel device */
         if (tun <= SSH_TUNID_MAX) {
-                snprintf(name, sizeof(name), "/dev/tun%d", tun);
+                snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
                 fd = open(name, O_RDWR);
         } else if (tun == SSH_TUNID_ANY) {
                 for (tun = 100; tun >= 0; tun--) {
-                        snprintf(name, sizeof(name), "/dev/tun%d", tun);
+                        snprintf(name, sizeof(name), "/dev/%s%d",
+                            tunbase, tun);
                         if ((fd = open(name, O_RDWR)) >= 0)
                                 break;
                 }
@@ -676,12 +681,10 @@ tun_open(int tun, int mode)
 
         debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
 
-        /* Set the tunnel device operation mode */
-        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
-        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) {
-                error("%s: socket: %s", __func__, strerror(errno));
+        /* Bring interface up if it is not already */
+        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
+        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
                 goto failed;
-        }
 
         if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
                 debug("%s: get interface %s flags: %s", __func__,
@@ -689,19 +692,6 @@ tun_open(int tun, int mode)
                 goto failed;
         }
 
-        /* Set interface mode if not already in correct mode */
-        if ((mode == SSH_TUNMODE_ETHERNET && !(ifr.ifr_flags & IFF_LINK0)) ||
-            (mode != SSH_TUNMODE_ETHERNET && (ifr.ifr_flags & IFF_LINK0))) {
-                ifr.ifr_flags &= ~IFF_UP;
-                ifr.ifr_flags ^= IFF_LINK0;
-                if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
-                        debug("%s: reset interface %s flags: %s", __func__,
-                            ifr.ifr_name, strerror(errno));
-                        goto failed;
-                }
-        }
-
-        /* Bring interface up if it is not already */
         if (!(ifr.ifr_flags & IFF_UP)) {
                 ifr.ifr_flags |= IFF_UP;
                 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {