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1#include <linux/kernel.h>
2#include <linux/init.h>
3#include <linux/ipv6.h>
4#include <linux/netfilter.h>
5#include <linux/netfilter_ipv6.h>
6#include <net/dst.h>
7#include <net/ipv6.h>
8#include <net/ip6_route.h>
9#include <net/xfrm.h>
10#include <net/ip6_checksum.h>
11#include <net/netfilter/nf_queue.h>
12
13int ip6_route_me_harder(struct sk_buff *skb)
14{
15 struct net *net = dev_net(skb_dst(skb)->dev);
16 const struct ipv6hdr *iph = ipv6_hdr(skb);
17 struct dst_entry *dst;
18 struct flowi6 fl6 = {
19 .flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
20 .flowi6_mark = skb->mark,
21 .daddr = iph->daddr,
22 .saddr = iph->saddr,
23 };
24
25 dst = ip6_route_output(net, skb->sk, &fl6);
26 if (dst->error) {
27 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
28 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
29 dst_release(dst);
30 return -EINVAL;
31 }
32
33 /* Drop old route. */
34 skb_dst_drop(skb);
35
36 skb_dst_set(skb, dst);
37
38#ifdef CONFIG_XFRM
39 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
40 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
41 skb_dst_set(skb, NULL);
42 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
43 if (IS_ERR(dst))
44 return -1;
45 skb_dst_set(skb, dst);
46 }
47#endif
48
49 return 0;
50}
51EXPORT_SYMBOL(ip6_route_me_harder);
52
53/*
54 * Extra routing may needed on local out, as the QUEUE target never
55 * returns control to the table.
56 */
57
58struct ip6_rt_info {
59 struct in6_addr daddr;
60 struct in6_addr saddr;
61 u_int32_t mark;
62};
63
64static void nf_ip6_saveroute(const struct sk_buff *skb,
65 struct nf_queue_entry *entry)
66{
67 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
68
69 if (entry->hook == NF_INET_LOCAL_OUT) {
70 const struct ipv6hdr *iph = ipv6_hdr(skb);
71
72 rt_info->daddr = iph->daddr;
73 rt_info->saddr = iph->saddr;
74 rt_info->mark = skb->mark;
75 }
76}
77
78static int nf_ip6_reroute(struct sk_buff *skb,
79 const struct nf_queue_entry *entry)
80{
81 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
82
83 if (entry->hook == NF_INET_LOCAL_OUT) {
84 const struct ipv6hdr *iph = ipv6_hdr(skb);
85 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
86 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
87 skb->mark != rt_info->mark)
88 return ip6_route_me_harder(skb);
89 }
90 return 0;
91}
92
93static int nf_ip6_route(struct net *net, struct dst_entry **dst,
94 struct flowi *fl, bool strict)
95{
96 static const struct ipv6_pinfo fake_pinfo;
97 static const struct inet_sock fake_sk = {
98 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
99 .sk.sk_bound_dev_if = 1,
100 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
101 };
102 const void *sk = strict ? &fake_sk : NULL;
103
104 *dst = ip6_route_output(net, sk, &fl->u.ip6);
105 return (*dst)->error;
106}
107
108__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
109 unsigned int dataoff, u_int8_t protocol)
110{
111 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
112 __sum16 csum = 0;
113
114 switch (skb->ip_summed) {
115 case CHECKSUM_COMPLETE:
116 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
117 break;
118 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
119 skb->len - dataoff, protocol,
120 csum_sub(skb->csum,
121 skb_checksum(skb, 0,
122 dataoff, 0)))) {
123 skb->ip_summed = CHECKSUM_UNNECESSARY;
124 break;
125 }
126 /* fall through */
127 case CHECKSUM_NONE:
128 skb->csum = ~csum_unfold(
129 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
130 skb->len - dataoff,
131 protocol,
132 csum_sub(0,
133 skb_checksum(skb, 0,
134 dataoff, 0))));
135 csum = __skb_checksum_complete(skb);
136 }
137 return csum;
138}
139EXPORT_SYMBOL(nf_ip6_checksum);
140
141static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
142 unsigned int dataoff, unsigned int len,
143 u_int8_t protocol)
144{
145 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
146 __wsum hsum;
147 __sum16 csum = 0;
148
149 switch (skb->ip_summed) {
150 case CHECKSUM_COMPLETE:
151 if (len == skb->len - dataoff)
152 return nf_ip6_checksum(skb, hook, dataoff, protocol);
153 /* fall through */
154 case CHECKSUM_NONE:
155 hsum = skb_checksum(skb, 0, dataoff, 0);
156 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
157 &ip6h->daddr,
158 skb->len - dataoff,
159 protocol,
160 csum_sub(0, hsum)));
161 skb->ip_summed = CHECKSUM_NONE;
162 return __skb_checksum_complete_head(skb, dataoff + len);
163 }
164 return csum;
165};
166
167static const struct nf_afinfo nf_ip6_afinfo = {
168 .family = AF_INET6,
169 .checksum = nf_ip6_checksum,
170 .checksum_partial = nf_ip6_checksum_partial,
171 .route = nf_ip6_route,
172 .saveroute = nf_ip6_saveroute,
173 .reroute = nf_ip6_reroute,
174 .route_key_size = sizeof(struct ip6_rt_info),
175};
176
177int __init ipv6_netfilter_init(void)
178{
179 return nf_register_afinfo(&nf_ip6_afinfo);
180}
181
182/* This can be called from inet6_init() on errors, so it cannot
183 * be marked __exit. -DaveM
184 */
185void ipv6_netfilter_fini(void)
186{
187 nf_unregister_afinfo(&nf_ip6_afinfo);
188}
1/*
2 * IPv6 specific functions of netfilter core
3 *
4 * Rusty Russell (C) 2000 -- This code is GPL.
5 * Patrick McHardy (C) 2006-2012
6 */
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>
14#include <net/dst.h>
15#include <net/ipv6.h>
16#include <net/ip6_route.h>
17#include <net/xfrm.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"
22
23int ip6_route_me_harder(struct net *net, struct sock *sk_partial, struct sk_buff *skb)
24{
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;
29 unsigned int hh_len;
30 struct dst_entry *dst;
31 int strict = (ipv6_addr_type(&iph->daddr) &
32 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
33 struct flowi6 fl6 = {
34 .flowi6_l3mdev = l3mdev_master_ifindex(dev),
35 .flowi6_mark = skb->mark,
36 .flowi6_uid = sock_net_uid(net, sk),
37 .daddr = iph->daddr,
38 .saddr = iph->saddr,
39 };
40 int err;
41
42 if (sk && sk->sk_bound_dev_if)
43 fl6.flowi6_oif = sk->sk_bound_dev_if;
44 else if (strict)
45 fl6.flowi6_oif = dev->ifindex;
46
47 fib6_rules_early_flow_dissect(net, skb, &fl6, &flkeys);
48 dst = ip6_route_output(net, sk, &fl6);
49 err = dst->error;
50 if (err) {
51 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
52 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
53 dst_release(dst);
54 return err;
55 }
56
57 /* Drop old route. */
58 skb_dst_drop(skb);
59
60 skb_dst_set(skb, dst);
61
62#ifdef CONFIG_XFRM
63 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
64 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
65 skb_dst_set(skb, NULL);
66 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
67 if (IS_ERR(dst))
68 return PTR_ERR(dst);
69 skb_dst_set(skb, dst);
70 }
71#endif
72
73 /* Change in oif may mean change in hh_len. */
74 hh_len = skb_dst(skb)->dev->hard_header_len;
75 if (skb_headroom(skb) < hh_len &&
76 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
77 0, GFP_ATOMIC))
78 return -ENOMEM;
79
80 return 0;
81}
82EXPORT_SYMBOL(ip6_route_me_harder);
83
84static int nf_ip6_reroute(struct sk_buff *skb,
85 const struct nf_queue_entry *entry)
86{
87 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
88
89 if (entry->state.hook == NF_INET_LOCAL_OUT) {
90 const struct ipv6hdr *iph = ipv6_hdr(skb);
91 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
92 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
93 skb->mark != rt_info->mark)
94 return ip6_route_me_harder(entry->state.net, entry->state.sk, skb);
95 }
96 return 0;
97}
98
99int __nf_ip6_route(struct net *net, struct dst_entry **dst,
100 struct flowi *fl, bool strict)
101{
102 static const struct ipv6_pinfo fake_pinfo;
103 static const struct inet_sock fake_sk = {
104 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
105 .sk.sk_bound_dev_if = 1,
106 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
107 };
108 const void *sk = strict ? &fake_sk : NULL;
109 struct dst_entry *result;
110 int err;
111
112 result = ip6_route_output(net, sk, &fl->u.ip6);
113 err = result->error;
114 if (err)
115 dst_release(result);
116 else
117 *dst = result;
118 return err;
119}
120EXPORT_SYMBOL_GPL(__nf_ip6_route);
121
122int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
123 struct nf_bridge_frag_data *data,
124 int (*output)(struct net *, struct sock *sk,
125 const struct nf_bridge_frag_data *data,
126 struct sk_buff *))
127{
128 int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
129 bool mono_delivery_time = skb->mono_delivery_time;
130 ktime_t tstamp = skb->tstamp;
131 struct ip6_frag_state state;
132 u8 *prevhdr, nexthdr = 0;
133 unsigned int mtu, hlen;
134 int hroom, err = 0;
135 __be32 frag_id;
136
137 err = ip6_find_1stfragopt(skb, &prevhdr);
138 if (err < 0)
139 goto blackhole;
140 hlen = err;
141 nexthdr = *prevhdr;
142
143 mtu = skb->dev->mtu;
144 if (frag_max_size > mtu ||
145 frag_max_size < IPV6_MIN_MTU)
146 goto blackhole;
147
148 mtu = frag_max_size;
149 if (mtu < hlen + sizeof(struct frag_hdr) + 8)
150 goto blackhole;
151 mtu -= hlen + sizeof(struct frag_hdr);
152
153 frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
154 &ipv6_hdr(skb)->saddr);
155
156 if (skb->ip_summed == CHECKSUM_PARTIAL &&
157 (err = skb_checksum_help(skb)))
158 goto blackhole;
159
160 hroom = LL_RESERVED_SPACE(skb->dev);
161 if (skb_has_frag_list(skb)) {
162 unsigned int first_len = skb_pagelen(skb);
163 struct ip6_fraglist_iter iter;
164 struct sk_buff *frag2;
165
166 if (first_len - hlen > mtu ||
167 skb_headroom(skb) < (hroom + sizeof(struct frag_hdr)))
168 goto blackhole;
169
170 if (skb_cloned(skb))
171 goto slow_path;
172
173 skb_walk_frags(skb, frag2) {
174 if (frag2->len > mtu ||
175 skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr)))
176 goto blackhole;
177
178 /* Partially cloned skb? */
179 if (skb_shared(frag2))
180 goto slow_path;
181 }
182
183 err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id,
184 &iter);
185 if (err < 0)
186 goto blackhole;
187
188 for (;;) {
189 /* Prepare header of the next frame,
190 * before previous one went down.
191 */
192 if (iter.frag)
193 ip6_fraglist_prepare(skb, &iter);
194
195 skb_set_delivery_time(skb, tstamp, mono_delivery_time);
196 err = output(net, sk, data, skb);
197 if (err || !iter.frag)
198 break;
199
200 skb = ip6_fraglist_next(&iter);
201 }
202
203 kfree(iter.tmp_hdr);
204 if (!err)
205 return 0;
206
207 kfree_skb_list(iter.frag);
208 return err;
209 }
210slow_path:
211 /* This is a linearized skbuff, the original geometry is lost for us.
212 * This may also be a clone skbuff, we could preserve the geometry for
213 * the copies but probably not worth the effort.
214 */
215 ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom,
216 LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id,
217 &state);
218
219 while (state.left > 0) {
220 struct sk_buff *skb2;
221
222 skb2 = ip6_frag_next(skb, &state);
223 if (IS_ERR(skb2)) {
224 err = PTR_ERR(skb2);
225 goto blackhole;
226 }
227
228 skb_set_delivery_time(skb2, tstamp, mono_delivery_time);
229 err = output(net, sk, data, skb2);
230 if (err)
231 goto blackhole;
232 }
233 consume_skb(skb);
234 return err;
235
236blackhole:
237 kfree_skb(skb);
238 return 0;
239}
240EXPORT_SYMBOL_GPL(br_ip6_fragment);
241
242static const struct nf_ipv6_ops ipv6ops = {
243#if IS_MODULE(CONFIG_IPV6)
244 .chk_addr = ipv6_chk_addr,
245 .route_me_harder = ip6_route_me_harder,
246 .dev_get_saddr = ipv6_dev_get_saddr,
247 .route = __nf_ip6_route,
248#if IS_ENABLED(CONFIG_SYN_COOKIES)
249 .cookie_init_sequence = __cookie_v6_init_sequence,
250 .cookie_v6_check = __cookie_v6_check,
251#endif
252#endif
253 .route_input = ip6_route_input,
254 .fragment = ip6_fragment,
255 .reroute = nf_ip6_reroute,
256#if IS_MODULE(CONFIG_IPV6)
257 .br_fragment = br_ip6_fragment,
258#endif
259};
260
261int __init ipv6_netfilter_init(void)
262{
263 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
264 return 0;
265}
266
267/* This can be called from inet6_init() on errors, so it cannot
268 * be marked __exit. -DaveM
269 */
270void ipv6_netfilter_fini(void)
271{
272 RCU_INIT_POINTER(nf_ipv6_ops, NULL);
273}