diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_input.c | 35 | ||||
| -rw-r--r-- | net/ipv4/route.c | 42 |
2 files changed, 73 insertions, 4 deletions
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index 24a95126e698..aa438c6758a7 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -302,16 +302,31 @@ drop: return true; } +static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph, + const struct sk_buff *hint) +{ + return hint && !skb_dst(skb) && ip_hdr(hint)->daddr == iph->daddr && + ip_hdr(hint)->tos == iph->tos; +} + INDIRECT_CALLABLE_DECLARE(int udp_v4_early_demux(struct sk_buff *)); INDIRECT_CALLABLE_DECLARE(int tcp_v4_early_demux(struct sk_buff *)); static int ip_rcv_finish_core(struct net *net, struct sock *sk, - struct sk_buff *skb, struct net_device *dev) + struct sk_buff *skb, struct net_device *dev, + const struct sk_buff *hint) { const struct iphdr *iph = ip_hdr(skb); int (*edemux)(struct sk_buff *skb); struct rtable *rt; int err; + if (ip_can_use_hint(skb, iph, hint)) { + err = ip_route_use_hint(skb, iph->daddr, iph->saddr, iph->tos, + dev, hint); + if (unlikely(err)) + goto drop_error; + } + if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && !skb->sk && @@ -408,7 +423,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb) if (!skb) return NET_RX_SUCCESS; - ret = ip_rcv_finish_core(net, sk, skb, dev); + ret = ip_rcv_finish_core(net, sk, skb, dev, NULL); if (ret != NET_RX_DROP) ret = dst_input(skb); return ret; @@ -535,11 +550,20 @@ static void ip_sublist_rcv_finish(struct list_head *head) } } +static struct sk_buff *ip_extract_route_hint(const struct net *net, + struct sk_buff *skb, int rt_type) +{ + if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST) + return NULL; + + return skb; +} + static void ip_list_rcv_finish(struct net *net, struct sock *sk, struct list_head *head) { + struct sk_buff *skb, *next, *hint = NULL; struct dst_entry *curr_dst = NULL; - struct sk_buff *skb, *next; struct list_head sublist; INIT_LIST_HEAD(&sublist); @@ -554,11 +578,14 @@ static void ip_list_rcv_finish(struct net *net, struct sock *sk, skb = l3mdev_ip_rcv(skb); if (!skb) continue; - if (ip_rcv_finish_core(net, sk, skb, dev) == NET_RX_DROP) + if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP) continue; dst = skb_dst(skb); if (curr_dst != dst) { + hint = ip_extract_route_hint(net, skb, + ((struct rtable *)dst)->rt_type); + /* dispatch old sublist */ if (!list_empty(&sublist)) ip_sublist_rcv_finish(&sublist); 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. |