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@

diff --git a/usr.bin/ssh/misc.c b/usr.bin/ssh/misc.c
index a7c8047..429c451 100644 (file)
--- a/usr.bin/ssh/misc.c
+++ b/usr.bin/ssh/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.
@@ -633,14 +633,19 @@ 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;
                }
@@ -656,12 +661,10 @@ 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__,
@@ -669,19 +672,6 @@ 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) {