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| author | David S. Miller <davem@davemloft.net> | 2012-06-28 14:59:11 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-28 14:59:11 +0400 |
| commit | 35ebf65e851c6d9731abc6362b189858eb59f4d3 (patch) | |
| tree | 2e78c2c81bc72aeeb172484996cdff268f0111a2 /net/ipv4/ip_options.c | |
| parent | 70e7341673a47fb1525cfc7d6651cc98b5348928 (diff) | |
| download | linux-35ebf65e851c6d9731abc6362b189858eb59f4d3.tar.xz | |
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 'net/ipv4/ip_options.c')
| -rw-r--r-- | net/ipv4/ip_options.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c index 708b99494e23..766dfe56885a 100644 --- a/net/ipv4/ip_options.c +++ b/net/ipv4/ip_options.c @@ -27,6 +27,7 @@ #include <net/icmp.h> #include <net/route.h> #include <net/cipso_ipv4.h> +#include <net/ip_fib.h> /* * Write options to IP header, record destination address to @@ -104,7 +105,7 @@ int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb) sptr = skb_network_header(skb); dptr = dopt->__data; - daddr = skb_rtable(skb)->rt_spec_dst; + daddr = fib_compute_spec_dst(skb); if (sopt->rr) { optlen = sptr[sopt->rr+1]; @@ -250,15 +251,14 @@ void ip_options_fragment(struct sk_buff *skb) int ip_options_compile(struct net *net, struct ip_options *opt, struct sk_buff *skb) { - int l; - unsigned char *iph; - unsigned char *optptr; - int optlen; + __be32 spec_dst = (__force __be32) 0; unsigned char *pp_ptr = NULL; - struct rtable *rt = NULL; + unsigned char *optptr; + unsigned char *iph; + int optlen, l; if (skb != NULL) { - rt = skb_rtable(skb); + spec_dst = fib_compute_spec_dst(skb); optptr = (unsigned char *)&(ip_hdr(skb)[1]); } else optptr = opt->__data; @@ -330,8 +330,8 @@ int ip_options_compile(struct net *net, pp_ptr = optptr + 2; goto error; } - if (rt) { - memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); + if (skb) { + memcpy(&optptr[optptr[2]-1], &spec_dst, 4); opt->is_changed = 1; } optptr[2] += 4; @@ -372,8 +372,8 @@ int ip_options_compile(struct net *net, goto error; } opt->ts = optptr - iph; - if (rt) { - memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4); + if (skb) { + memcpy(&optptr[optptr[2]-1], &spec_dst, 4); timeptr = &optptr[optptr[2]+3]; } opt->ts_needaddr = 1; |