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 sock *sk_partial, struct sk_buff *skb)
25 const struct ipv6hdr *iph = ipv6_hdr(skb);
26 struct sock *sk = sk_to_full_sk(sk_partial);
27 struct flow_keys flkeys;
29 struct dst_entry *dst;
30 int strict = (ipv6_addr_type(&iph->daddr) &
31 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
33 .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
34 strict ? skb_dst(skb)->dev->ifindex : 0,
35 .flowi6_mark = skb->mark,
36 .flowi6_uid = sock_net_uid(net, sk),
42 fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys);
43 dst = ip6_route_output(net, sk, &fl6);
46 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
47 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
55 skb_dst_set(skb, dst);
58 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
59 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
60 skb_dst_set(skb, NULL);
61 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
64 skb_dst_set(skb, dst);
68 /* Change in oif may mean change in hh_len. */
69 hh_len = skb_dst(skb)->dev->hard_header_len;
70 if (skb_headroom(skb) < hh_len &&
71 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
77 EXPORT_SYMBOL(ip6_route_me_harder);
79 static int nf_ip6_reroute(struct sk_buff *skb,
80 const struct nf_queue_entry *entry)
82 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
84 if (entry->state.hook == NF_INET_LOCAL_OUT) {
85 const struct ipv6hdr *iph = ipv6_hdr(skb);
86 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
87 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
88 skb->mark != rt_info->mark)
89 return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
94 int __nf_ip6_route(struct net *net, struct dst_entry **dst,
95 struct flowi *fl, bool strict)
97 static const struct ipv6_pinfo fake_pinfo;
98 static const struct inet_sock fake_sk = {
99 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
100 .sk.sk_bound_dev_if = 1,
101 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
103 const void *sk = strict ? &fake_sk : NULL;
104 struct dst_entry *result;
107 result = ip6_route_output(net, sk, &fl->u.ip6);
115 EXPORT_SYMBOL_GPL(__nf_ip6_route);
117 int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
118 struct nf_bridge_frag_data *data,
119 int (*output)(struct net *, struct sock *sk,
120 const struct nf_bridge_frag_data *data,
123 int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
124 ktime_t tstamp = skb->tstamp;
125 struct ip6_frag_state state;
126 u8 *prevhdr, nexthdr = 0;
127 unsigned int mtu, hlen;
131 err = ip6_find_1stfragopt(skb, &prevhdr);
138 if (frag_max_size > mtu ||
139 frag_max_size < IPV6_MIN_MTU)
143 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
145 mtu -= hlen + sizeof(struct frag_hdr);
147 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
148 &ipv6_hdr(skb)->saddr);
150 if (skb->ip_summed == CHECKSUM_PARTIAL &&
151 (err = skb_checksum_help(skb)))
154 hroom = LL_RESERVED_SPACE(skb->dev);
155 if (skb_has_frag_list(skb)) {
156 unsigned int first_len = skb_pagelen(skb);
157 struct ip6_fraglist_iter iter;
158 struct sk_buff *frag2;
160 if (first_len - hlen > mtu ||
161 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
167 skb_walk_frags(skb, frag2) {
168 if (frag2->len > mtu ||
169 skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
172 /* Partially cloned skb? */
173 if (skb_shared(frag2))
177 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
183 /* Prepare header of the next frame,
184 * before previous one went down.
187 ip6_fraglist_prepare(skb, &iter);
189 skb->tstamp = tstamp;
190 err = output(net, sk, data, skb);
191 if (err || !iter.frag)
194 skb = ip6_fraglist_next(&iter);
201 kfree_skb_list(iter.frag);
205 /* This is a linearized skbuff, the original geometry is lost for us.
206 * This may also be a clone skbuff, we could preserve the geometry for
207 * the copies but probably not worth the effort.
209 ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
210 LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
213 while (state.left > 0) {
214 struct sk_buff *skb2;
216 skb2 = ip6_frag_next(skb, &state);
222 skb2->tstamp = tstamp;
223 err = output(net, sk, data, skb2);
234 EXPORT_SYMBOL_GPL(br_ip6_fragment);
236 static const struct nf_ipv6_ops ipv6ops = {
237 #if IS_MODULE(CONFIG_IPV6)
238 .chk_addr = ipv6_chk_addr,
239 .route_me_harder = ip6_route_me_harder,
240 .dev_get_saddr = ipv6_dev_get_saddr,
241 .route = __nf_ip6_route,
242 #if IS_ENABLED(CONFIG_SYN_COOKIES)
243 .cookie_init_sequence = __cookie_v6_init_sequence,
244 .cookie_v6_check = __cookie_v6_check,
247 .route_input = ip6_route_input,
248 .fragment = ip6_fragment,
249 .reroute = nf_ip6_reroute,
250 #if IS_MODULE(CONFIG_IPV6)
251 .br_fragment = br_ip6_fragment,
255 int __init ipv6_netfilter_init(void)
257 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
261 /* This can be called from inet6_init() on errors, so it cannot
262 * be marked __exit. -DaveM
264 void ipv6_netfilter_fini(void)
266 RCU_INIT_POINTER(nf_ipv6_ops, NULL);