projects / linux-block.git / blame
| 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; |
| 6d8b49c3 DA |
48 | if (!fl4.flowi4_oif) |
| 49 | fl4.flowi4_oif = l3mdev_master_ifindex(dev); | |
| ed6e4ef8 | 50 | fl4.flowi4_mark = skb->mark; |
| 797fd391 | 51 | fl4.flowi4_flags = flags; |
| 812fa71f | 52 | fib4_rules_early_flow_dissect(net, skb, &fl4, &flkeys); |
| ed6e4ef8 JA |
53 | rt = ip_route_output_key(net, &fl4); |
| 54 | if (IS_ERR(rt)) | |
| c9e1673a | 55 | return PTR_ERR(rt); |
| 020b4c12 | 56 | |
| ed6e4ef8 JA |
57 | /* Drop old route. */ |
| 58 | skb_dst_drop(skb); | |
| 59 | skb_dst_set(skb, &rt->dst); | |
| e905a9ed | 60 | |
| adf30907 | 61 | if (skb_dst(skb)->error) |
| c9e1673a | 62 | return skb_dst(skb)->error; |
| 020b4c12 | 63 | |
| 3e3850e9 | 64 | #ifdef CONFIG_XFRM |
| 3db05fea | 65 | if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && |
| 9d6ec938 | 66 | xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) { |
| adf30907 ED |
67 | struct dst_entry *dst = skb_dst(skb); |
| 68 | skb_dst_set(skb, NULL); | |
| 29e09229 | 69 | dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0); |
| 452edd59 | 70 | if (IS_ERR(dst)) |
| 3d0a0620 | 71 | return PTR_ERR(dst); |
| adf30907 ED |
72 | skb_dst_set(skb, dst); |
| 73 | } | |
| 3e3850e9 PM |
74 | #endif |
| 75 | ||
| 020b4c12 | 76 | /* Change in oif may mean change in hh_len. */ |
| adf30907 | 77 | hh_len = skb_dst(skb)->dev->hard_header_len; |
| 3db05fea | 78 | if (skb_headroom(skb) < hh_len && |
| 5e2afba4 PG |
79 | pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)), |
| 80 | 0, GFP_ATOMIC)) | |
| c9e1673a | 81 | return -ENOMEM; |
| 020b4c12 HW |
82 | |
| 83 | return 0; | |
| 84 | } | |
| 85 | EXPORT_SYMBOL(ip_route_me_harder); | |
| 2cc7d573 | 86 | |
| 3f87c08c PNA |
87 | int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl, |
| 88 | bool strict __always_unused) | |
| 1841a4c7 | 89 | { |
| 31ad3dd6 | 90 | struct rtable *rt = ip_route_output_key(net, &fl->u.ip4); |
| b23dd4fe DM |
91 | if (IS_ERR(rt)) |
| 92 | return PTR_ERR(rt); | |
| 93 | *dst = &rt->dst; | |
| 94 | return 0; | |
| 1841a4c7 | 95 | } |
| 3f87c08c | 96 | EXPORT_SYMBOL_GPL(nf_ip_route); |