path: root/net/ipv4/ip_tunnel_core.c
diff options
authorJiri Benc <jbenc@redhat.com>2015-09-22 18:12:11 +0200
committerDavid S. Miller <davem@davemloft.net>2015-09-24 14:31:36 -0700
commit63d008a4e9ee86614ca5671b7f3ba447df007190 (patch)
tree3122aaf73744bc976113cffb2367b4e770b901f8 /net/ipv4/ip_tunnel_core.c
parentnet: gianfar: remove misuse of IRQF_NO_SUSPEND flag (diff)
ipv4: send arp replies to the correct tunnel
When using ip lwtunnels, the additional data for xmit (basically, the actual tunnel to use) are carried in ip_tunnel_info either in dst->lwtstate or in metadata dst. When replying to ARP requests, we need to send the reply to the same tunnel the request came from. This means we need to construct proper metadata dst for ARP replies. We could perform another route lookup to get a dst entry with the correct lwtstate. However, this won't always ensure that the outgoing tunnel is the same as the incoming one, and it won't work anyway for IPv4 duplicate address detection. The only thing to do is to "reverse" the ip_tunnel_info. Signed-off-by: Jiri Benc <jbenc@redhat.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_tunnel_core.c')
1 files changed, 28 insertions, 0 deletions
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 9b97204b8c81..ce3a1e728606 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -46,6 +46,7 @@
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
+#include <net/dst_metadata.h>
int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
__be32 src, __be32 dst, __u8 proto,
@@ -119,6 +120,33 @@ int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto)
+struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
+ gfp_t flags)
+ struct metadata_dst *res;
+ struct ip_tunnel_info *dst, *src;
+ if (!md || md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
+ return NULL;
+ res = metadata_dst_alloc(0, flags);
+ if (!res)
+ return NULL;
+ dst = &res->u.tun_info;
+ src = &md->u.tun_info;
+ dst->key.tun_id = src->key.tun_id;
+ if (src->mode & IP_TUNNEL_INFO_IPV6)
+ memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
+ sizeof(struct in6_addr));
+ else
+ dst->key.u.ipv4.dst = src->key.u.ipv4.src;
+ dst->mode = src->mode | IP_TUNNEL_INFO_TX;
+ return res;
struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb,
bool csum_help,
int gso_type_mask)