diff options
| author | David S. Miller <davem@davemloft.net> | 2012-06-28 03:59:11 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-28 03:59:11 -0700 |
| commit | 35ebf65e851c6d9731abc6362b189858eb59f4d3 (patch) | |
| tree | 2e78c2c81bc72aeeb172484996cdff268f0111a2 /include/net/ip_fib.h | |
| parent | 70e7341673a47fb1525cfc7d6651cc98b5348928 (diff) | |
ipv4: Create and use fib_compute_spec_dst() helper.
The specific destination is the host we direct unicast replies to.
Usually this is the original packet source address, but if we are
responding to a multicast or broadcast packet we have to use something
different.
Specifically we must use the source address we would use if we were to
send a packet to the unicast source of the original packet.
The routing cache precomputes this value, but we want to remove that
precomputation because it creates a hard dependency on the expensive
rpfilter source address validation which we'd like to make cheaper.
There are only three places where this matters:
1) ICMP replies.
2) pktinfo CMSG
3) IP options
Now there will be no real users of rt->rt_spec_dst and we can simply
remove it altogether.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/ip_fib.h')
| -rw-r--r-- | include/net/ip_fib.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 4b347c0ca094..1687b3de54ff 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -230,6 +230,7 @@ extern struct fib_table *fib_get_table(struct net *net, u32 id); /* Exported by fib_frontend.c */ extern const struct nla_policy rtm_ipv4_policy[]; extern void ip_fib_init(void); +extern __be32 fib_compute_spec_dst(struct sk_buff *skb); extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos, int oif, struct net_device *dev, __be32 *spec_dst, u32 *itag); |