2 * IPv6 specific functions of netfilter core
4 * Rusty Russell (C) 2000 -- This code is GPL.
5 * Patrick McHardy (C) 2006-2012
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9 #include <linux/ipv6.h>
10 #include <linux/netfilter.h>
11 #include <linux/netfilter_ipv6.h>
12 #include <linux/export.h>
13 #include <net/addrconf.h>
16 #include <net/ip6_route.h>
18 #include <net/netfilter/nf_queue.h>
19 #include <net/netfilter/nf_conntrack_bridge.h>
20 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
21 #include "../bridge/br_private.h"
23 int ip6_route_me_harder(struct net *net, struct sk_buff *skb)
25 const struct ipv6hdr *iph = ipv6_hdr(skb);
26 struct sock *sk = sk_to_full_sk(skb->sk);
28 struct dst_entry *dst;
29 int strict = (ipv6_addr_type(&iph->daddr) &
30 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
32 .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
33 strict ? skb_dst(skb)->dev->ifindex : 0,
34 .flowi6_mark = skb->mark,
35 .flowi6_uid = sock_net_uid(net, sk),
41 dst = ip6_route_output(net, sk, &fl6);
44 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
45 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
53 skb_dst_set(skb, dst);
56 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
57 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
58 skb_dst_set(skb, NULL);
59 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
62 skb_dst_set(skb, dst);
66 /* Change in oif may mean change in hh_len. */
67 hh_len = skb_dst(skb)->dev->hard_header_len;
68 if (skb_headroom(skb) < hh_len &&
69 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
75 EXPORT_SYMBOL(ip6_route_me_harder);
77 static int nf_ip6_reroute(struct sk_buff *skb,
78 const struct nf_queue_entry *entry)
80 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
82 if (entry->state.hook == NF_INET_LOCAL_OUT) {
83 const struct ipv6hdr *iph = ipv6_hdr(skb);
84 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
85 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
86 skb->mark != rt_info->mark)
87 return ip6_route_me_harder(entry->state.net, skb);
92 int __nf_ip6_route(struct net *net, struct dst_entry **dst,
93 struct flowi *fl, bool strict)
95 static const struct ipv6_pinfo fake_pinfo;
96 static const struct inet_sock fake_sk = {
97 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
98 .sk.sk_bound_dev_if = 1,
99 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
101 const void *sk = strict ? &fake_sk : NULL;
102 struct dst_entry *result;
105 result = ip6_route_output(net, sk, &fl->u.ip6);
113 EXPORT_SYMBOL_GPL(__nf_ip6_route);
115 int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
116 struct nf_bridge_frag_data *data,
117 int (*output)(struct net *, struct sock *sk,
118 const struct nf_bridge_frag_data *data,
121 int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
122 struct ip6_frag_state state;
123 u8 *prevhdr, nexthdr = 0;
124 unsigned int mtu, hlen;
128 err = ip6_find_1stfragopt(skb, &prevhdr);
135 if (frag_max_size > mtu ||
136 frag_max_size < IPV6_MIN_MTU)
140 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
142 mtu -= hlen + sizeof(struct frag_hdr);
144 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
145 &ipv6_hdr(skb)->saddr);
147 if (skb->ip_summed == CHECKSUM_PARTIAL &&
148 (err = skb_checksum_help(skb)))
151 hroom = LL_RESERVED_SPACE(skb->dev);
152 if (skb_has_frag_list(skb)) {
153 unsigned int first_len = skb_pagelen(skb);
154 struct ip6_fraglist_iter iter;
155 struct sk_buff *frag2;
157 if (first_len - hlen > mtu ||
158 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
164 skb_walk_frags(skb, frag2) {
165 if (frag2->len > mtu ||
166 skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
169 /* Partially cloned skb? */
170 if (skb_shared(frag2))
174 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
180 /* Prepare header of the next frame,
181 * before previous one went down.
184 ip6_fraglist_prepare(skb, &iter);
186 err = output(net, sk, data, skb);
187 if (err || !iter.frag)
190 skb = ip6_fraglist_next(&iter);
197 kfree_skb_list(iter.frag);
201 /* This is a linearized skbuff, the original geometry is lost for us.
202 * This may also be a clone skbuff, we could preserve the geometry for
203 * the copies but probably not worth the effort.
205 ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
206 LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
209 while (state.left > 0) {
210 struct sk_buff *skb2;
212 skb2 = ip6_frag_next(skb, &state);
218 err = output(net, sk, data, skb2);
229 EXPORT_SYMBOL_GPL(br_ip6_fragment);
231 static const struct nf_ipv6_ops ipv6ops = {
232 #if IS_MODULE(CONFIG_IPV6)
233 .chk_addr = ipv6_chk_addr,
234 .route_me_harder = ip6_route_me_harder,
235 .dev_get_saddr = ipv6_dev_get_saddr,
236 .route = __nf_ip6_route,
237 #if IS_ENABLED(CONFIG_SYN_COOKIES)
238 .cookie_init_sequence = __cookie_v6_init_sequence,
239 .cookie_v6_check = __cookie_v6_check,
242 .route_input = ip6_route_input,
243 .fragment = ip6_fragment,
244 .reroute = nf_ip6_reroute,
245 #if IS_MODULE(CONFIG_IPV6) && IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
246 .br_defrag = nf_ct_frag6_gather,
248 #if IS_MODULE(CONFIG_IPV6)
249 .br_fragment = br_ip6_fragment,
253 int __init ipv6_netfilter_init(void)
255 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
259 /* This can be called from inet6_init() on errors, so it cannot
260 * be marked __exit. -DaveM
262 void ipv6_netfilter_fini(void)
264 RCU_INIT_POINTER(nf_ipv6_ops, NULL);