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 net_device *dev = skb_dst(skb)->dev;
28 struct flow_keys flkeys;
30 struct dst_entry *dst;
31 int strict = (ipv6_addr_type(&iph->daddr) &
32 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
34 .flowi6_l3mdev = l3mdev_master_ifindex(dev),
35 .flowi6_mark = skb->mark,
36 .flowi6_uid = sock_net_uid(net, sk),
39 .flowlabel = ip6_flowinfo(iph),
43 if (sk && sk->sk_bound_dev_if)
44 fl6.flowi6_oif = sk->sk_bound_dev_if;
46 fl6.flowi6_oif = dev->ifindex;
48 fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys);
49 dst = ip6_route_output(net, sk, &fl6);
52 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
53 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
61 skb_dst_set(skb, dst);
64 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
65 xfrm_decode_session(net, skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
66 skb_dst_set(skb, NULL);
67 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
70 skb_dst_set(skb, dst);
74 /* Change in oif may mean change in hh_len. */
75 hh_len = skb_dst(skb)->dev->hard_header_len;
76 if (skb_headroom(skb) < hh_len &&
77 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
83 EXPORT_SYMBOL(ip6_route_me_harder);
85 static int nf_ip6_reroute(struct sk_buff *skb,
86 const struct nf_queue_entry *entry)
88 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
90 if (entry->state.hook == NF_INET_LOCAL_OUT) {
91 const struct ipv6hdr *iph = ipv6_hdr(skb);
92 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
93 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
94 skb->mark != rt_info->mark)
95 return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
100 int __nf_ip6_route(struct net *net, struct dst_entry **dst,
101 struct flowi *fl, bool strict)
103 static const struct ipv6_pinfo fake_pinfo;
104 static const struct inet_sock fake_sk = {
105 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
106 .sk.sk_bound_dev_if = 1,
107 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
109 const void *sk = strict ? &fake_sk : NULL;
110 struct dst_entry *result;
113 result = ip6_route_output(net, sk, &fl->u.ip6);
121 EXPORT_SYMBOL_GPL(__nf_ip6_route);
123 int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
124 struct nf_bridge_frag_data *data,
125 int (*output)(struct net *, struct sock *sk,
126 const struct nf_bridge_frag_data *data,
129 int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
130 u8 tstamp_type = skb->tstamp_type;
131 ktime_t tstamp = skb->tstamp;
132 struct ip6_frag_state state;
133 u8 *prevhdr, nexthdr = 0;
134 unsigned int mtu, hlen;
138 err = ip6_find_1stfragopt(skb, &prevhdr);
145 if (frag_max_size > mtu ||
146 frag_max_size < IPV6_MIN_MTU)
150 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
152 mtu -= hlen + sizeof(struct frag_hdr);
154 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
155 &ipv6_hdr(skb)->saddr);
157 if (skb->ip_summed == CHECKSUM_PARTIAL &&
158 (err = skb_checksum_help(skb)))
161 hroom = LL_RESERVED_SPACE(skb->dev);
162 if (skb_has_frag_list(skb)) {
163 unsigned int first_len = skb_pagelen(skb);
164 struct ip6_fraglist_iter iter;
165 struct sk_buff *frag2;
167 if (first_len - hlen > mtu ||
168 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
174 skb_walk_frags(skb, frag2) {
175 if (frag2->len > mtu ||
176 skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
179 /* Partially cloned skb? */
180 if (skb_shared(frag2))
184 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
190 /* Prepare header of the next frame,
191 * before previous one went down.
194 ip6_fraglist_prepare(skb, &iter);
196 skb_set_delivery_time(skb, tstamp, tstamp_type);
197 err = output(net, sk, data, skb);
198 if (err || !iter.frag)
201 skb = ip6_fraglist_next(&iter);
208 kfree_skb_list(iter.frag);
212 /* This is a linearized skbuff, the original geometry is lost for us.
213 * This may also be a clone skbuff, we could preserve the geometry for
214 * the copies but probably not worth the effort.
216 ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
217 LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
220 while (state.left > 0) {
221 struct sk_buff *skb2;
223 skb2 = ip6_frag_next(skb, &state);
229 skb_set_delivery_time(skb2, tstamp, tstamp_type);
230 err = output(net, sk, data, skb2);
241 EXPORT_SYMBOL_GPL(br_ip6_fragment);
243 static const struct nf_ipv6_ops ipv6ops = {
244 #if IS_MODULE(CONFIG_IPV6)
245 .chk_addr = ipv6_chk_addr,
246 .route_me_harder = ip6_route_me_harder,
247 .dev_get_saddr = ipv6_dev_get_saddr,
248 .route = __nf_ip6_route,
249 #if IS_ENABLED(CONFIG_SYN_COOKIES)
250 .cookie_init_sequence = __cookie_v6_init_sequence,
251 .cookie_v6_check = __cookie_v6_check,
254 .route_input = ip6_route_input,
255 .fragment = ip6_fragment,
256 .reroute = nf_ip6_reroute,
257 #if IS_MODULE(CONFIG_IPV6)
258 .br_fragment = br_ip6_fragment,
262 int __init ipv6_netfilter_init(void)
264 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
268 /* This can be called from inet6_init() on errors, so it cannot
269 * be marked __exit. -DaveM
271 void ipv6_netfilter_fini(void)
273 RCU_INIT_POINTER(nf_ipv6_ops, NULL);