Commit | Line | Data |
---|---|---|
9fb9cbb1 YK |
1 | /* |
2 | * Copyright (C)2004 USAGI/WIDE Project | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * Author: | |
9 | * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
9fb9cbb1 YK |
10 | */ |
11 | ||
9fb9cbb1 YK |
12 | #include <linux/types.h> |
13 | #include <linux/ipv6.h> | |
14 | #include <linux/in6.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/skbuff.h> | |
18 | #include <linux/icmp.h> | |
19 | #include <linux/sysctl.h> | |
20 | #include <net/ipv6.h> | |
04128f23 | 21 | #include <net/inet_frag.h> |
9fb9cbb1 YK |
22 | |
23 | #include <linux/netfilter_ipv6.h> | |
24 | #include <net/netfilter/nf_conntrack.h> | |
25 | #include <net/netfilter/nf_conntrack_helper.h> | |
605dcad6 | 26 | #include <net/netfilter/nf_conntrack_l4proto.h> |
9fb9cbb1 YK |
27 | #include <net/netfilter/nf_conntrack_l3proto.h> |
28 | #include <net/netfilter/nf_conntrack_core.h> | |
9d2493f8 | 29 | #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> |
9fb9cbb1 | 30 | |
8ce8439a JE |
31 | static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff, |
32 | struct nf_conntrack_tuple *tuple) | |
9fb9cbb1 | 33 | { |
32948588 JE |
34 | const u_int32_t *ap; |
35 | u_int32_t _addrs[8]; | |
9fb9cbb1 YK |
36 | |
37 | ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr), | |
38 | sizeof(_addrs), _addrs); | |
39 | if (ap == NULL) | |
8ce8439a | 40 | return false; |
9fb9cbb1 YK |
41 | |
42 | memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6)); | |
43 | memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6)); | |
44 | ||
8ce8439a | 45 | return true; |
9fb9cbb1 YK |
46 | } |
47 | ||
8ce8439a JE |
48 | static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple, |
49 | const struct nf_conntrack_tuple *orig) | |
9fb9cbb1 YK |
50 | { |
51 | memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6)); | |
52 | memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6)); | |
53 | ||
8ce8439a | 54 | return true; |
9fb9cbb1 YK |
55 | } |
56 | ||
57 | static int ipv6_print_tuple(struct seq_file *s, | |
58 | const struct nf_conntrack_tuple *tuple) | |
59 | { | |
5b095d98 | 60 | return seq_printf(s, "src=%pI6 dst=%pI6 ", |
0c6ce78a | 61 | tuple->src.u3.ip6, tuple->dst.u3.ip6); |
9fb9cbb1 YK |
62 | } |
63 | ||
9fb9cbb1 YK |
64 | /* |
65 | * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c | |
66 | * | |
67 | * This function parses (probably truncated) exthdr set "hdr" | |
68 | * of length "len". "nexthdrp" initially points to some place, | |
69 | * where type of the first header can be found. | |
70 | * | |
71 | * It skips all well-known exthdrs, and returns pointer to the start | |
72 | * of unparsable area i.e. the first header with unknown type. | |
73 | * if success, *nexthdr is updated by type/protocol of this header. | |
74 | * | |
75 | * NOTES: - it may return pointer pointing beyond end of packet, | |
76 | * if the last recognized header is truncated in the middle. | |
77 | * - if packet is truncated, so that all parsed headers are skipped, | |
78 | * it returns -1. | |
79 | * - if packet is fragmented, return pointer of the fragment header. | |
80 | * - ESP is unparsable for now and considered like | |
81 | * normal payload protocol. | |
82 | * - Note also special handling of AUTH header. Thanks to IPsec wizards. | |
83 | */ | |
84 | ||
1a3a206f AB |
85 | static int nf_ct_ipv6_skip_exthdr(const struct sk_buff *skb, int start, |
86 | u8 *nexthdrp, int len) | |
9fb9cbb1 YK |
87 | { |
88 | u8 nexthdr = *nexthdrp; | |
89 | ||
90 | while (ipv6_ext_hdr(nexthdr)) { | |
91 | struct ipv6_opt_hdr hdr; | |
92 | int hdrlen; | |
93 | ||
94 | if (len < (int)sizeof(struct ipv6_opt_hdr)) | |
95 | return -1; | |
96 | if (nexthdr == NEXTHDR_NONE) | |
97 | break; | |
98 | if (nexthdr == NEXTHDR_FRAGMENT) | |
99 | break; | |
100 | if (skb_copy_bits(skb, start, &hdr, sizeof(hdr))) | |
101 | BUG(); | |
102 | if (nexthdr == NEXTHDR_AUTH) | |
103 | hdrlen = (hdr.hdrlen+2)<<2; | |
104 | else | |
105 | hdrlen = ipv6_optlen(&hdr); | |
106 | ||
107 | nexthdr = hdr.nexthdr; | |
108 | len -= hdrlen; | |
109 | start += hdrlen; | |
110 | } | |
111 | ||
112 | *nexthdrp = nexthdr; | |
113 | return start; | |
114 | } | |
115 | ||
ffc30690 YK |
116 | static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff, |
117 | unsigned int *dataoff, u_int8_t *protonum) | |
9fb9cbb1 | 118 | { |
ffc30690 YK |
119 | unsigned int extoff = nhoff + sizeof(struct ipv6hdr); |
120 | unsigned char pnum; | |
121 | int protoff; | |
122 | ||
123 | if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr), | |
124 | &pnum, sizeof(pnum)) != 0) { | |
125 | pr_debug("ip6_conntrack_core: can't get nexthdr\n"); | |
126 | return -NF_ACCEPT; | |
127 | } | |
128 | protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, skb->len - extoff); | |
9fb9cbb1 | 129 | /* |
ffc30690 | 130 | * (protoff == skb->len) mean that the packet doesn't have no data |
9fb9cbb1 YK |
131 | * except of IPv6 & ext headers. but it's tracked anyway. - YK |
132 | */ | |
ffc30690 | 133 | if ((protoff < 0) || (protoff > skb->len)) { |
0d53778e | 134 | pr_debug("ip6_conntrack_core: can't find proto in pkt\n"); |
9fb9cbb1 YK |
135 | return -NF_ACCEPT; |
136 | } | |
137 | ||
138 | *dataoff = protoff; | |
139 | *protonum = pnum; | |
140 | return NF_ACCEPT; | |
141 | } | |
142 | ||
9fb9cbb1 | 143 | static unsigned int ipv6_confirm(unsigned int hooknum, |
3db05fea | 144 | struct sk_buff *skb, |
9fb9cbb1 YK |
145 | const struct net_device *in, |
146 | const struct net_device *out, | |
147 | int (*okfn)(struct sk_buff *)) | |
148 | { | |
149 | struct nf_conn *ct; | |
32948588 JE |
150 | const struct nf_conn_help *help; |
151 | const struct nf_conntrack_helper *helper; | |
9fb9cbb1 | 152 | enum ip_conntrack_info ctinfo; |
dc808fe2 | 153 | unsigned int ret, protoff; |
3db05fea HX |
154 | unsigned int extoff = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
155 | unsigned char pnum = ipv6_hdr(skb)->nexthdr; | |
dc808fe2 | 156 | |
9fb9cbb1 YK |
157 | |
158 | /* This is where we call the helper: as the packet goes out. */ | |
3db05fea | 159 | ct = nf_ct_get(skb, &ctinfo); |
6442f1cf | 160 | if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY) |
dc808fe2 HW |
161 | goto out; |
162 | ||
163 | help = nfct_help(ct); | |
3c158f7f PM |
164 | if (!help) |
165 | goto out; | |
166 | /* rcu_read_lock()ed by nf_hook_slow */ | |
167 | helper = rcu_dereference(help->helper); | |
168 | if (!helper) | |
dc808fe2 HW |
169 | goto out; |
170 | ||
3db05fea HX |
171 | protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, |
172 | skb->len - extoff); | |
173 | if (protoff > skb->len || pnum == NEXTHDR_FRAGMENT) { | |
0d53778e | 174 | pr_debug("proto header not found\n"); |
dc808fe2 | 175 | return NF_ACCEPT; |
9fb9cbb1 YK |
176 | } |
177 | ||
3db05fea | 178 | ret = helper->help(skb, protoff, ct, ctinfo); |
dc808fe2 HW |
179 | if (ret != NF_ACCEPT) |
180 | return ret; | |
181 | out: | |
9fb9cbb1 | 182 | /* We've seen it coming out the other side: confirm it */ |
3db05fea | 183 | return nf_conntrack_confirm(skb); |
9fb9cbb1 YK |
184 | } |
185 | ||
9fb9cbb1 | 186 | static unsigned int ipv6_defrag(unsigned int hooknum, |
3db05fea | 187 | struct sk_buff *skb, |
9fb9cbb1 YK |
188 | const struct net_device *in, |
189 | const struct net_device *out, | |
190 | int (*okfn)(struct sk_buff *)) | |
191 | { | |
192 | struct sk_buff *reasm; | |
193 | ||
194 | /* Previously seen (loopback)? */ | |
3db05fea | 195 | if (skb->nfct) |
9fb9cbb1 YK |
196 | return NF_ACCEPT; |
197 | ||
3db05fea | 198 | reasm = nf_ct_frag6_gather(skb); |
9fb9cbb1 YK |
199 | |
200 | /* queued */ | |
201 | if (reasm == NULL) | |
202 | return NF_STOLEN; | |
203 | ||
204 | /* error occured or not fragmented */ | |
3db05fea | 205 | if (reasm == skb) |
9fb9cbb1 YK |
206 | return NF_ACCEPT; |
207 | ||
208 | nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in, | |
209 | (struct net_device *)out, okfn); | |
210 | ||
211 | return NF_STOLEN; | |
212 | } | |
213 | ||
a702a65f AD |
214 | static unsigned int __ipv6_conntrack_in(struct net *net, |
215 | unsigned int hooknum, | |
216 | struct sk_buff *skb, | |
217 | int (*okfn)(struct sk_buff *)) | |
9fb9cbb1 | 218 | { |
3db05fea | 219 | struct sk_buff *reasm = skb->nfct_reasm; |
9fb9cbb1 YK |
220 | |
221 | /* This packet is fragmented and has reassembled packet. */ | |
222 | if (reasm) { | |
223 | /* Reassembled packet isn't parsed yet ? */ | |
224 | if (!reasm->nfct) { | |
225 | unsigned int ret; | |
226 | ||
a702a65f | 227 | ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm); |
9fb9cbb1 YK |
228 | if (ret != NF_ACCEPT) |
229 | return ret; | |
230 | } | |
231 | nf_conntrack_get(reasm->nfct); | |
3db05fea HX |
232 | skb->nfct = reasm->nfct; |
233 | skb->nfctinfo = reasm->nfctinfo; | |
9fb9cbb1 YK |
234 | return NF_ACCEPT; |
235 | } | |
236 | ||
a702a65f AD |
237 | return nf_conntrack_in(net, PF_INET6, hooknum, skb); |
238 | } | |
239 | ||
240 | static unsigned int ipv6_conntrack_in(unsigned int hooknum, | |
241 | struct sk_buff *skb, | |
242 | const struct net_device *in, | |
243 | const struct net_device *out, | |
244 | int (*okfn)(struct sk_buff *)) | |
245 | { | |
246 | return __ipv6_conntrack_in(dev_net(in), hooknum, skb, okfn); | |
9fb9cbb1 YK |
247 | } |
248 | ||
249 | static unsigned int ipv6_conntrack_local(unsigned int hooknum, | |
3db05fea | 250 | struct sk_buff *skb, |
9fb9cbb1 YK |
251 | const struct net_device *in, |
252 | const struct net_device *out, | |
253 | int (*okfn)(struct sk_buff *)) | |
254 | { | |
255 | /* root is playing with raw sockets. */ | |
3db05fea | 256 | if (skb->len < sizeof(struct ipv6hdr)) { |
9fb9cbb1 YK |
257 | if (net_ratelimit()) |
258 | printk("ipv6_conntrack_local: packet too short\n"); | |
259 | return NF_ACCEPT; | |
260 | } | |
a702a65f | 261 | return __ipv6_conntrack_in(dev_net(out), hooknum, skb, okfn); |
9fb9cbb1 YK |
262 | } |
263 | ||
1999414a | 264 | static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = { |
964ddaa1 PM |
265 | { |
266 | .hook = ipv6_defrag, | |
267 | .owner = THIS_MODULE, | |
268 | .pf = PF_INET6, | |
6e23ae2a | 269 | .hooknum = NF_INET_PRE_ROUTING, |
964ddaa1 PM |
270 | .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, |
271 | }, | |
272 | { | |
273 | .hook = ipv6_conntrack_in, | |
274 | .owner = THIS_MODULE, | |
275 | .pf = PF_INET6, | |
6e23ae2a | 276 | .hooknum = NF_INET_PRE_ROUTING, |
964ddaa1 PM |
277 | .priority = NF_IP6_PRI_CONNTRACK, |
278 | }, | |
279 | { | |
280 | .hook = ipv6_conntrack_local, | |
281 | .owner = THIS_MODULE, | |
282 | .pf = PF_INET6, | |
6e23ae2a | 283 | .hooknum = NF_INET_LOCAL_OUT, |
964ddaa1 PM |
284 | .priority = NF_IP6_PRI_CONNTRACK, |
285 | }, | |
286 | { | |
287 | .hook = ipv6_defrag, | |
288 | .owner = THIS_MODULE, | |
289 | .pf = PF_INET6, | |
6e23ae2a | 290 | .hooknum = NF_INET_LOCAL_OUT, |
964ddaa1 PM |
291 | .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, |
292 | }, | |
293 | { | |
294 | .hook = ipv6_confirm, | |
295 | .owner = THIS_MODULE, | |
296 | .pf = PF_INET6, | |
6e23ae2a | 297 | .hooknum = NF_INET_POST_ROUTING, |
964ddaa1 PM |
298 | .priority = NF_IP6_PRI_LAST, |
299 | }, | |
300 | { | |
301 | .hook = ipv6_confirm, | |
302 | .owner = THIS_MODULE, | |
303 | .pf = PF_INET6, | |
6e23ae2a | 304 | .hooknum = NF_INET_LOCAL_IN, |
964ddaa1 PM |
305 | .priority = NF_IP6_PRI_LAST-1, |
306 | }, | |
9fb9cbb1 YK |
307 | }; |
308 | ||
e281db5c | 309 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
310 | |
311 | #include <linux/netfilter/nfnetlink.h> | |
312 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
313 | ||
fdf70832 | 314 | static int ipv6_tuple_to_nlattr(struct sk_buff *skb, |
c1d10adb PNA |
315 | const struct nf_conntrack_tuple *tuple) |
316 | { | |
df6fb868 | 317 | NLA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4, |
c1d10adb | 318 | &tuple->src.u3.ip6); |
df6fb868 | 319 | NLA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4, |
c1d10adb PNA |
320 | &tuple->dst.u3.ip6); |
321 | return 0; | |
322 | ||
df6fb868 | 323 | nla_put_failure: |
c1d10adb PNA |
324 | return -1; |
325 | } | |
326 | ||
f73e924c PM |
327 | static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = { |
328 | [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 }, | |
329 | [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 }, | |
c1d10adb PNA |
330 | }; |
331 | ||
fdf70832 | 332 | static int ipv6_nlattr_to_tuple(struct nlattr *tb[], |
c1d10adb PNA |
333 | struct nf_conntrack_tuple *t) |
334 | { | |
df6fb868 | 335 | if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST]) |
c1d10adb PNA |
336 | return -EINVAL; |
337 | ||
df6fb868 | 338 | memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]), |
c1d10adb | 339 | sizeof(u_int32_t) * 4); |
df6fb868 | 340 | memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]), |
c1d10adb PNA |
341 | sizeof(u_int32_t) * 4); |
342 | ||
343 | return 0; | |
344 | } | |
345 | #endif | |
346 | ||
61075af5 | 347 | struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = { |
9fb9cbb1 YK |
348 | .l3proto = PF_INET6, |
349 | .name = "ipv6", | |
350 | .pkt_to_tuple = ipv6_pkt_to_tuple, | |
351 | .invert_tuple = ipv6_invert_tuple, | |
352 | .print_tuple = ipv6_print_tuple, | |
ffc30690 | 353 | .get_l4proto = ipv6_get_l4proto, |
e281db5c | 354 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
fdf70832 PM |
355 | .tuple_to_nlattr = ipv6_tuple_to_nlattr, |
356 | .nlattr_to_tuple = ipv6_nlattr_to_tuple, | |
f73e924c | 357 | .nla_policy = ipv6_nla_policy, |
933a41e7 PM |
358 | #endif |
359 | #ifdef CONFIG_SYSCTL | |
360 | .ctl_table_path = nf_net_netfilter_sysctl_path, | |
361 | .ctl_table = nf_ct_ipv6_sysctl_table, | |
c1d10adb | 362 | #endif |
9fb9cbb1 YK |
363 | .me = THIS_MODULE, |
364 | }; | |
365 | ||
32292a7f PM |
366 | MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6)); |
367 | MODULE_LICENSE("GPL"); | |
368 | MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>"); | |
369 | ||
370 | static int __init nf_conntrack_l3proto_ipv6_init(void) | |
9fb9cbb1 YK |
371 | { |
372 | int ret = 0; | |
373 | ||
32292a7f | 374 | need_conntrack(); |
9fb9cbb1 YK |
375 | |
376 | ret = nf_ct_frag6_init(); | |
377 | if (ret < 0) { | |
378 | printk("nf_conntrack_ipv6: can't initialize frag6.\n"); | |
32292a7f | 379 | return ret; |
9fb9cbb1 | 380 | } |
605dcad6 | 381 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6); |
9fb9cbb1 YK |
382 | if (ret < 0) { |
383 | printk("nf_conntrack_ipv6: can't register tcp.\n"); | |
384 | goto cleanup_frag6; | |
385 | } | |
386 | ||
605dcad6 | 387 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6); |
9fb9cbb1 YK |
388 | if (ret < 0) { |
389 | printk("nf_conntrack_ipv6: can't register udp.\n"); | |
390 | goto cleanup_tcp; | |
391 | } | |
392 | ||
605dcad6 | 393 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6); |
9fb9cbb1 YK |
394 | if (ret < 0) { |
395 | printk("nf_conntrack_ipv6: can't register icmpv6.\n"); | |
396 | goto cleanup_udp; | |
397 | } | |
398 | ||
399 | ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6); | |
400 | if (ret < 0) { | |
401 | printk("nf_conntrack_ipv6: can't register ipv6\n"); | |
402 | goto cleanup_icmpv6; | |
403 | } | |
404 | ||
964ddaa1 PM |
405 | ret = nf_register_hooks(ipv6_conntrack_ops, |
406 | ARRAY_SIZE(ipv6_conntrack_ops)); | |
9fb9cbb1 YK |
407 | if (ret < 0) { |
408 | printk("nf_conntrack_ipv6: can't register pre-routing defrag " | |
409 | "hook.\n"); | |
410 | goto cleanup_ipv6; | |
411 | } | |
9fb9cbb1 YK |
412 | return ret; |
413 | ||
9fb9cbb1 YK |
414 | cleanup_ipv6: |
415 | nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6); | |
416 | cleanup_icmpv6: | |
605dcad6 | 417 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6); |
9fb9cbb1 | 418 | cleanup_udp: |
605dcad6 | 419 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6); |
9fb9cbb1 | 420 | cleanup_tcp: |
605dcad6 | 421 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6); |
9fb9cbb1 YK |
422 | cleanup_frag6: |
423 | nf_ct_frag6_cleanup(); | |
9fb9cbb1 YK |
424 | return ret; |
425 | } | |
426 | ||
65b4b4e8 | 427 | static void __exit nf_conntrack_l3proto_ipv6_fini(void) |
9fb9cbb1 | 428 | { |
32292a7f | 429 | synchronize_net(); |
32292a7f PM |
430 | nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops)); |
431 | nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6); | |
605dcad6 MJ |
432 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6); |
433 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6); | |
434 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6); | |
32292a7f | 435 | nf_ct_frag6_cleanup(); |
9fb9cbb1 YK |
436 | } |
437 | ||
65b4b4e8 AM |
438 | module_init(nf_conntrack_l3proto_ipv6_init); |
439 | module_exit(nf_conntrack_l3proto_ipv6_fini); |