diff options
Diffstat (limited to 'net/ipv4/route.c')
| -rw-r--r-- | net/ipv4/route.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index dcc4fa10138d..f88c93c38f11 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2019,10 +2019,52 @@ static int ip_mkroute_input(struct sk_buff *skb, return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); } +/* Implements all the saddr-related checks as ip_route_input_slow(), + * assuming daddr is valid and the destination is not a local broadcast one. + * Uses the provided hint instead of performing a route lookup. + */ +int ip_route_use_hint(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev, + const struct sk_buff *hint) +{ + struct in_device *in_dev = __in_dev_get_rcu(dev); + struct rtable *rt = (struct rtable *)hint; + struct net *net = dev_net(dev); + int err = -EINVAL; + u32 tag = 0; + + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) + goto martian_source; + + if (ipv4_is_zeronet(saddr)) + goto martian_source; + + if (ipv4_is_loopback(saddr) && !IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) + goto martian_source; + + if (rt->rt_type != RTN_LOCAL) + goto skip_validate_source; + + tos &= IPTOS_RT_MASK; + err = fib_validate_source(skb, saddr, daddr, tos, 0, dev, in_dev, &tag); + if (err < 0) + goto martian_source; + +skip_validate_source: + skb_dst_copy(skb, hint); + return 0; + +martian_source: + ip_handle_martian_source(dev, in_dev, skb, daddr, saddr); + return err; +} + /* * NOTE. We drop all the packets that has local source * addresses, because every properly looped back packet * must have correct destination already attached by output routine. + * Changes in the enforced policies must be applied also to + * ip_route_use_hint(). * * Such approach solves two big problems: * 1. Not simplex devices are handled properly. |