[Openvpn-devel] [PATCH] Add parameter "dev " to add_route and delete_route for IPv4, as it is done for IPv6.

[Xavier Franquet]

When openvpn tries to add (or delete) an IPv4 route, doesn't use the parameter 
"dev <device>" in the command.
If there's a local subnet that matches the VPN Server network, the route would 
use a wrong interface.
Ex:
   local subnet 10.100.0.0/24 on iface eth2
   openvpn pool 10.100.0.0/16 on iface tap2 (ifconfig_pool_remote_ip is 
10.100.0.1)
      push "route 10.10.0.1 255.255.255.255"

   Without the patch, the route will be added with eth2, instead of tap2

Signed-off-by: Xavier Franquet <xav...@saimanet.net>
---
 route.c |   23 +++++++++++++++--------
 1 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/route.c b/route.c
index cb685c3..b9b478f 100644
--- a/route.c
+++ b/route.c
@@ -1090,6 +1090,7 @@ add_route (struct route *r, const struct tuntap *tt, 
unsigned int flags, const s
   const char *netmask;
   const char *gateway;
   bool status = false;
+  const char *device = tt->actual_name;

   if (!r->defined)
     return;
@@ -1113,23 +1114,26 @@ add_route (struct route *r, const struct tuntap *tt, 
unsigned int flags, const s

 #if defined(TARGET_LINUX)
 #ifdef CONFIG_FEATURE_IPROUTE
-  argv_printf (&argv, "%s route add %s/%d via %s",
+  argv_printf (&argv, "%s route add %s/%d via %s dev %s",
              iproute_path,
              network,
              count_netmask_bits(netmask),
-             gateway);
+             gateway,
+             device);
   if (r->metric_defined)
     argv_printf_cat (&argv, "metric %d", r->metric);

 #else
-  argv_printf (&argv, "%s add -net %s netmask %s gw %s",
+  argv_printf (&argv, "%s add -net %s netmask %s gw %s dev %s",
                ROUTE_PATH,
              network,
              netmask,
-             gateway);
+             gateway,
+             device);
   if (r->metric_defined)
     argv_printf_cat (&argv, "metric %d", r->metric);
 #endif  /*CONFIG_FEATURE_IPROUTE*/
+
   argv_msg (D_ROUTE, &argv);
   status = openvpn_execve_check (&argv, es, 0, "ERROR: Linux route add command 
failed");

@@ -1452,6 +1456,7 @@ delete_route (const struct route *r, const struct tuntap 
*tt, unsigned int flags
   const char *network;
   const char *netmask;
   const char *gateway;
+  const char *device = tt->actual_name;

   if (!r->defined)
     return;
@@ -1465,16 +1470,18 @@ delete_route (const struct route *r, const struct 
tuntap *tt, unsigned int flags

 #if defined(TARGET_LINUX)
 #ifdef CONFIG_FEATURE_IPROUTE
-  argv_printf (&argv, "%s route del %s/%d",
+  argv_printf (&argv, "%s route del %s/%d dev %s",
              iproute_path,
              network,
-             count_netmask_bits(netmask));
+             count_netmask_bits(netmask),
+             device);
 #else

-  argv_printf (&argv, "%s del -net %s netmask %s",
+  argv_printf (&argv, "%s del -net %s netmask %s dev %s",
                ROUTE_PATH,
              network,
-             netmask);
+             netmask,
+             device);
 #endif /*CONFIG_FEATURE_IPROUTE*/
   if (r->metric_defined)
     argv_printf_cat (&argv, "metric %d", r->metric);
-- 
1.7.1