icmp: Fix regression in nexthop resolution during replies.

icmp_route_lookup() uses the wrong flow parameters if the reverse
session route lookup isn't used.

So do not commit to the re-decoded flow until we actually make a
final decision to use a real route saved in 'rt2'.

Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2011-07-22 06:22:10 -07:00
parent ace62dd1a8
commit 415b3334a2

View File

@ -380,6 +380,7 @@ static struct rtable *icmp_route_lookup(struct net *net,
struct icmp_bxm *param)
{
struct rtable *rt, *rt2;
struct flowi4 fl4_dec;
int err;
memset(fl4, 0, sizeof(*fl4));
@ -408,19 +409,19 @@ static struct rtable *icmp_route_lookup(struct net *net,
} else
return rt;
err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(fl4), AF_INET);
err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
if (err)
goto relookup_failed;
if (inet_addr_type(net, fl4->saddr) == RTN_LOCAL) {
rt2 = __ip_route_output_key(net, fl4);
if (inet_addr_type(net, fl4_dec.saddr) == RTN_LOCAL) {
rt2 = __ip_route_output_key(net, &fl4_dec);
if (IS_ERR(rt2))
err = PTR_ERR(rt2);
} else {
struct flowi4 fl4_2 = {};
unsigned long orefdst;
fl4_2.daddr = fl4->saddr;
fl4_2.daddr = fl4_dec.saddr;
rt2 = ip_route_output_key(net, &fl4_2);
if (IS_ERR(rt2)) {
err = PTR_ERR(rt2);
@ -428,7 +429,7 @@ static struct rtable *icmp_route_lookup(struct net *net,
}
/* Ugh! */
orefdst = skb_in->_skb_refdst; /* save old refdst */
err = ip_route_input(skb_in, fl4->daddr, fl4->saddr,
err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr,
RT_TOS(tos), rt2->dst.dev);
dst_release(&rt2->dst);
@ -440,10 +441,11 @@ static struct rtable *icmp_route_lookup(struct net *net,
goto relookup_failed;
rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
flowi4_to_flowi(fl4), NULL,
flowi4_to_flowi(&fl4_dec), NULL,
XFRM_LOOKUP_ICMP);
if (!IS_ERR(rt2)) {
dst_release(&rt->dst);
memcpy(fl4, &fl4_dec, sizeof(*fl4));
rt = rt2;
} else if (PTR_ERR(rt2) == -EPERM) {
if (rt)