ip_vti: Fix 'ip tunnel add' with 'key' parameters

ip tunnel add remote 10.2.2.1 local 10.2.2.2 mode vti ikey 1 okey 2
translates to p->iflags = VTI_ISVTI|GRE_KEY and p->i_key = 1, but GRE_KEY !=
TUNNEL_KEY, so ip_tunnel_ioctl would set i_key to 0 (same story with o_key)
making us unable to create vti tunnels with [io]key via ip tunnel.

We cannot simply translate GRE_KEY to TUNNEL_KEY (as GRE module does) because
vti_tunnels with same local/remote addresses but different ikeys will be treated
as different then. So, imo the best option here is to move p->i_flags & *_KEY
check for vti tunnels from ip_tunnel.c to ip_vti.c and to think about [io]_mark
field for ip_tunnel_parm in the future.

Signed-off-by: Dmitry Popov <ixaphire@qrator.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 13 insertions, 5 deletions

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 3f6135bc54ef..3dbb550abb30 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -748,10 +748,12 @@ int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
                         goto done;
                 if (p->iph.ttl)
                         p->iph.frag_off |= htons(IP_DF);
-                if (!(p->i_flags&TUNNEL_KEY))
-                        p->i_key = 0;
-                if (!(p->o_flags&TUNNEL_KEY))
-                        p->o_key = 0;
+                if (!(p->i_flags & VTI_ISVTI)) {
+                        if (!(p->i_flags & TUNNEL_KEY))
+                                p->i_key = 0;
+                        if (!(p->o_flags & TUNNEL_KEY))
+                                p->o_key = 0;
+                }
 
                 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type);
 
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 13ef00f1e17b..b8960f3527f3 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -313,7 +313,13 @@ vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
                         return -EINVAL;
         }
 
-        p.i_flags |= VTI_ISVTI;
+        if (!(p.i_flags & GRE_KEY))
+                p.i_key = 0;
+        if (!(p.o_flags & GRE_KEY))
+                p.o_key = 0;
+
+        p.i_flags = VTI_ISVTI;
+
         err = ip_tunnel_ioctl(dev, &p, cmd);
         if (err)
                 return err;