From patchwork Sun Aug 19 20:07:03 2018
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Subject: [Openvpn-devel] Fix combination of --dev tap and --topology subnet
 across multiple platforms.
X-Patchwork-Submitter: Gert Doering <gert@greenie.muc.de>
X-Patchwork-Id: 452
Message-Id: <20180819200703.20362-1-gert@greenie.muc.de>
To: openvpn-devel@lists.sourceforge.net
Date: Sun, 19 Aug 2018 22:07:03 +0200
From: Gert Doering <gert@greenie.muc.de>
List-Id: <openvpn-devel.lists.sourceforge.net>

--topology should have no effect in tap mode (tap is always "subnet"),
but due to the way options are checked, setting "topology subnet" caught
an improper branch on all non-linux and non-win32 platforms.

Easily tested by adding "--topology subnet" to a "--dev tap" t_client
test.

Tested, verified, and fixed on FreeBSD 10.4, NetBSD 7.0.1, OpenBSD 6.0,
and OpenSolaris 10.  Compile-tested on MacOS X.

Trac: #1085

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
---
 src/openvpn/tun.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index db7c25ff..8fa07afa 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -1091,7 +1091,7 @@ do_ifconfig(struct tuntap *tt,
                         actual
                         );
         }
-        else if (tt->topology == TOP_SUBNET)
+        else if (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             argv_printf(&argv,
                         "%s %s %s %s netmask %s mtu %d up",
@@ -1173,7 +1173,7 @@ do_ifconfig(struct tuntap *tt,
             }
         }
 
-        if (!tun && tt->topology == TOP_SUBNET)
+        if (!tun && tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             /* Add a network route for the local tun interface */
             struct route_ipv4 r;
@@ -1210,7 +1210,7 @@ do_ifconfig(struct tuntap *tt,
                         tun_mtu
                         );
         }
-        else if (tt->topology == TOP_SUBNET)
+        else if (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             remote_end = create_arbitrary_remote( tt );
             argv_printf(&argv,
@@ -1239,7 +1239,7 @@ do_ifconfig(struct tuntap *tt,
         openvpn_execve_check(&argv, es, S_FATAL, "OpenBSD ifconfig failed");
 
         /* Add a network route for the local tun interface */
-        if (!tun && tt->topology == TOP_SUBNET)
+        if (!tun && tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             struct route_ipv4 r;
             CLEAR(r);
@@ -1282,7 +1282,7 @@ do_ifconfig(struct tuntap *tt,
                         tun_mtu
                         );
         }
-        else if (tt->topology == TOP_SUBNET)
+        else if (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             remote_end = create_arbitrary_remote( tt );
             argv_printf(&argv,
@@ -1316,7 +1316,7 @@ do_ifconfig(struct tuntap *tt,
         openvpn_execve_check(&argv, es, S_FATAL, "NetBSD ifconfig failed");
 
         /* Add a network route for the local tun interface */
-        if (!tun && tt->topology == TOP_SUBNET)
+        if (!tun && tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             struct route_ipv4 r;
             CLEAR(r);
@@ -1372,7 +1372,7 @@ do_ifconfig(struct tuntap *tt,
         }
         else
         {
-            if (tt->topology == TOP_SUBNET)
+            if (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
             {
                 argv_printf(&argv,
                             "%s %s %s %s netmask %s mtu %d up",
@@ -1402,7 +1402,7 @@ do_ifconfig(struct tuntap *tt,
         tt->did_ifconfig = true;
 
         /* Add a network route for the local tun interface */
-        if (!tun && tt->topology == TOP_SUBNET)
+        if (!tun && tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             struct route_ipv4 r;
             CLEAR(r);
@@ -1445,7 +1445,7 @@ do_ifconfig(struct tuntap *tt,
                         tun_mtu
                         );
         }
-        else if (tt->topology == TOP_SUBNET)
+        else if (tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             remote_end = create_arbitrary_remote( tt );
             argv_printf(&argv,
@@ -1475,7 +1475,7 @@ do_ifconfig(struct tuntap *tt,
         tt->did_ifconfig = true;
 
         /* Add a network route for the local tun interface */
-        if (!tun && tt->topology == TOP_SUBNET)
+        if (!tun && tt->type == DEV_TYPE_TUN && tt->topology == TOP_SUBNET)
         {
             struct route_ipv4 r;
             CLEAR(r);