Commit | Line | Data |
---|---|---|
f229f6ce PM |
1 | /* |
2 | * IPv4 specific functions of netfilter core | |
3 | * | |
4 | * Rusty Russell (C) 2000 -- This code is GPL. | |
5 | * Patrick McHardy (C) 2006-2012 | |
6 | */ | |
020b4c12 HW |
7 | #include <linux/kernel.h> |
8 | #include <linux/netfilter.h> | |
2cc7d573 | 9 | #include <linux/netfilter_ipv4.h> |
3e3850e9 | 10 | #include <linux/ip.h> |
2ca7b0ac | 11 | #include <linux/skbuff.h> |
5a0e3ad6 | 12 | #include <linux/gfp.h> |
bc3b2d7f | 13 | #include <linux/export.h> |
020b4c12 | 14 | #include <net/route.h> |
3e3850e9 PM |
15 | #include <net/xfrm.h> |
16 | #include <net/ip.h> | |
c01cd429 | 17 | #include <net/netfilter/nf_queue.h> |
020b4c12 HW |
18 | |
19 | /* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */ | |
46d6c5ae | 20 | int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, unsigned int addr_type) |
020b4c12 | 21 | { |
3db05fea | 22 | const struct iphdr *iph = ip_hdr(skb); |
020b4c12 | 23 | struct rtable *rt; |
9d6ec938 | 24 | struct flowi4 fl4 = {}; |
ed6e4ef8 | 25 | __be32 saddr = iph->saddr; |
46d6c5ae | 26 | __u8 flags; |
6d8b49c3 | 27 | struct net_device *dev = skb_dst(skb)->dev; |
812fa71f | 28 | struct flow_keys flkeys; |
020b4c12 HW |
29 | unsigned int hh_len; |
30 | ||
46d6c5ae JD |
31 | sk = sk_to_full_sk(sk); |
32 | flags = sk ? inet_sk_flowi_flags(sk) : 0; | |
33 | ||
797fd391 | 34 | if (addr_type == RTN_UNSPEC) |
6d8b49c3 | 35 | addr_type = inet_addr_type_dev_table(net, dev, saddr); |
797fd391 JA |
36 | if (addr_type == RTN_LOCAL || addr_type == RTN_UNICAST) |
37 | flags |= FLOWI_FLAG_ANYSRC; | |
38 | else | |
39 | saddr = 0; | |
b4c4ed17 | 40 | |
020b4c12 | 41 | /* some non-standard hacks like ipt_REJECT.c:send_reset() can cause |
6e23ae2a | 42 | * packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook. |
020b4c12 | 43 | */ |
ed6e4ef8 JA |
44 | fl4.daddr = iph->daddr; |
45 | fl4.saddr = saddr; | |
46 | fl4.flowi4_tos = RT_TOS(iph->tos); | |
29e09229 | 47 | fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0; |
2c50fc04 | 48 | fl4.flowi4_l3mdev = l3mdev_master_ifindex(dev); |
ed6e4ef8 | 49 | fl4.flowi4_mark = skb->mark; |
797fd391 | 50 | fl4.flowi4_flags = flags; |
812fa71f | 51 | fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys); |
ed6e4ef8 JA |
52 | rt = ip_route_output_key(net, &fl4); |
53 | if (IS_ERR(rt)) | |
c9e1673a | 54 | return PTR_ERR(rt); |
020b4c12 | 55 | |
ed6e4ef8 JA |
56 | /* Drop old route. */ |
57 | skb_dst_drop(skb); | |
58 | skb_dst_set(skb, &rt->dst); | |
e905a9ed | 59 | |
adf30907 | 60 | if (skb_dst(skb)->error) |
c9e1673a | 61 | return skb_dst(skb)->error; |
020b4c12 | 62 | |
3e3850e9 | 63 | #ifdef CONFIG_XFRM |
3db05fea | 64 | if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && |
9d6ec938 | 65 | xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { |
adf30907 ED |
66 | struct dst_entry *dst = skb_dst(skb); |
67 | skb_dst_set(skb, NULL); | |
29e09229 | 68 | dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); |
452edd59 | 69 | if (IS_ERR(dst)) |
3d0a0620 | 70 | return PTR_ERR(dst); |
adf30907 ED |
71 | skb_dst_set(skb, dst); |
72 | } | |
3e3850e9 PM |
73 | #endif |
74 | ||
020b4c12 | 75 | /* Change in oif may mean change in hh_len. */ |
adf30907 | 76 | hh_len = skb_dst(skb)->dev->hard_header_len; |
3db05fea | 77 | if (skb_headroom(skb) < hh_len && |
5e2afba4 PG |
78 | pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)), |
79 | 0, GFP_ATOMIC)) | |
c9e1673a | 80 | return -ENOMEM; |
020b4c12 HW |
81 | |
82 | return 0; | |
83 | } | |
84 | EXPORT_SYMBOL(ip_route_me_harder); | |
2cc7d573 | 85 | |
3f87c08c PNA |
86 | int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl, |
87 | bool strict __always_unused) | |
1841a4c7 | 88 | { |
31ad3dd6 | 89 | struct rtable *rt = ip_route_output_key(net, &fl->u.ip4); |
b23dd4fe DM |
90 | if (IS_ERR(rt)) |
91 | return PTR_ERR(rt); | |
92 | *dst = &rt->dst; | |
93 | return 0; | |
1841a4c7 | 94 | } |
3f87c08c | 95 | EXPORT_SYMBOL_GPL(nf_ip_route); |