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> | |
29 | ||
9fb9cbb1 YK |
30 | static int ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff, |
31 | struct nf_conntrack_tuple *tuple) | |
32 | { | |
32948588 JE |
33 | const u_int32_t *ap; |
34 | u_int32_t _addrs[8]; | |
9fb9cbb1 YK |
35 | |
36 | ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr), | |
37 | sizeof(_addrs), _addrs); | |
38 | if (ap == NULL) | |
39 | return 0; | |
40 | ||
41 | memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6)); | |
42 | memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6)); | |
43 | ||
44 | return 1; | |
45 | } | |
46 | ||
47 | static int ipv6_invert_tuple(struct nf_conntrack_tuple *tuple, | |
48 | const struct nf_conntrack_tuple *orig) | |
49 | { | |
50 | memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6)); | |
51 | memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6)); | |
52 | ||
53 | return 1; | |
54 | } | |
55 | ||
56 | static int ipv6_print_tuple(struct seq_file *s, | |
57 | const struct nf_conntrack_tuple *tuple) | |
58 | { | |
46b86a2d | 59 | return seq_printf(s, "src=" NIP6_FMT " dst=" NIP6_FMT " ", |
9fb9cbb1 YK |
60 | NIP6(*((struct in6_addr *)tuple->src.u3.ip6)), |
61 | NIP6(*((struct in6_addr *)tuple->dst.u3.ip6))); | |
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 | ||
214 | static unsigned int ipv6_conntrack_in(unsigned int hooknum, | |
3db05fea | 215 | struct sk_buff *skb, |
9fb9cbb1 YK |
216 | const struct net_device *in, |
217 | const struct net_device *out, | |
218 | int (*okfn)(struct sk_buff *)) | |
219 | { | |
3db05fea | 220 | struct sk_buff *reasm = skb->nfct_reasm; |
9fb9cbb1 YK |
221 | |
222 | /* This packet is fragmented and has reassembled packet. */ | |
223 | if (reasm) { | |
224 | /* Reassembled packet isn't parsed yet ? */ | |
225 | if (!reasm->nfct) { | |
226 | unsigned int ret; | |
227 | ||
3db05fea | 228 | ret = nf_conntrack_in(PF_INET6, hooknum, reasm); |
9fb9cbb1 YK |
229 | if (ret != NF_ACCEPT) |
230 | return ret; | |
231 | } | |
232 | nf_conntrack_get(reasm->nfct); | |
3db05fea HX |
233 | skb->nfct = reasm->nfct; |
234 | skb->nfctinfo = reasm->nfctinfo; | |
9fb9cbb1 YK |
235 | return NF_ACCEPT; |
236 | } | |
237 | ||
3db05fea | 238 | return nf_conntrack_in(PF_INET6, hooknum, skb); |
9fb9cbb1 YK |
239 | } |
240 | ||
241 | static unsigned int ipv6_conntrack_local(unsigned int hooknum, | |
3db05fea | 242 | struct sk_buff *skb, |
9fb9cbb1 YK |
243 | const struct net_device *in, |
244 | const struct net_device *out, | |
245 | int (*okfn)(struct sk_buff *)) | |
246 | { | |
247 | /* root is playing with raw sockets. */ | |
3db05fea | 248 | if (skb->len < sizeof(struct ipv6hdr)) { |
9fb9cbb1 YK |
249 | if (net_ratelimit()) |
250 | printk("ipv6_conntrack_local: packet too short\n"); | |
251 | return NF_ACCEPT; | |
252 | } | |
3db05fea | 253 | return ipv6_conntrack_in(hooknum, skb, in, out, okfn); |
9fb9cbb1 YK |
254 | } |
255 | ||
1999414a | 256 | static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = { |
964ddaa1 PM |
257 | { |
258 | .hook = ipv6_defrag, | |
259 | .owner = THIS_MODULE, | |
260 | .pf = PF_INET6, | |
6e23ae2a | 261 | .hooknum = NF_INET_PRE_ROUTING, |
964ddaa1 PM |
262 | .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, |
263 | }, | |
264 | { | |
265 | .hook = ipv6_conntrack_in, | |
266 | .owner = THIS_MODULE, | |
267 | .pf = PF_INET6, | |
6e23ae2a | 268 | .hooknum = NF_INET_PRE_ROUTING, |
964ddaa1 PM |
269 | .priority = NF_IP6_PRI_CONNTRACK, |
270 | }, | |
271 | { | |
272 | .hook = ipv6_conntrack_local, | |
273 | .owner = THIS_MODULE, | |
274 | .pf = PF_INET6, | |
6e23ae2a | 275 | .hooknum = NF_INET_LOCAL_OUT, |
964ddaa1 PM |
276 | .priority = NF_IP6_PRI_CONNTRACK, |
277 | }, | |
278 | { | |
279 | .hook = ipv6_defrag, | |
280 | .owner = THIS_MODULE, | |
281 | .pf = PF_INET6, | |
6e23ae2a | 282 | .hooknum = NF_INET_LOCAL_OUT, |
964ddaa1 PM |
283 | .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, |
284 | }, | |
285 | { | |
286 | .hook = ipv6_confirm, | |
287 | .owner = THIS_MODULE, | |
288 | .pf = PF_INET6, | |
6e23ae2a | 289 | .hooknum = NF_INET_POST_ROUTING, |
964ddaa1 PM |
290 | .priority = NF_IP6_PRI_LAST, |
291 | }, | |
292 | { | |
293 | .hook = ipv6_confirm, | |
294 | .owner = THIS_MODULE, | |
295 | .pf = PF_INET6, | |
6e23ae2a | 296 | .hooknum = NF_INET_LOCAL_IN, |
964ddaa1 PM |
297 | .priority = NF_IP6_PRI_LAST-1, |
298 | }, | |
9fb9cbb1 YK |
299 | }; |
300 | ||
e281db5c | 301 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
302 | |
303 | #include <linux/netfilter/nfnetlink.h> | |
304 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
305 | ||
fdf70832 | 306 | static int ipv6_tuple_to_nlattr(struct sk_buff *skb, |
c1d10adb PNA |
307 | const struct nf_conntrack_tuple *tuple) |
308 | { | |
df6fb868 | 309 | NLA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4, |
c1d10adb | 310 | &tuple->src.u3.ip6); |
df6fb868 | 311 | NLA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4, |
c1d10adb PNA |
312 | &tuple->dst.u3.ip6); |
313 | return 0; | |
314 | ||
df6fb868 | 315 | nla_put_failure: |
c1d10adb PNA |
316 | return -1; |
317 | } | |
318 | ||
f73e924c PM |
319 | static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = { |
320 | [CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 }, | |
321 | [CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 }, | |
c1d10adb PNA |
322 | }; |
323 | ||
fdf70832 | 324 | static int ipv6_nlattr_to_tuple(struct nlattr *tb[], |
c1d10adb PNA |
325 | struct nf_conntrack_tuple *t) |
326 | { | |
df6fb868 | 327 | if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST]) |
c1d10adb PNA |
328 | return -EINVAL; |
329 | ||
df6fb868 | 330 | memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]), |
c1d10adb | 331 | sizeof(u_int32_t) * 4); |
df6fb868 | 332 | memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]), |
c1d10adb PNA |
333 | sizeof(u_int32_t) * 4); |
334 | ||
335 | return 0; | |
336 | } | |
337 | #endif | |
338 | ||
61075af5 | 339 | struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = { |
9fb9cbb1 YK |
340 | .l3proto = PF_INET6, |
341 | .name = "ipv6", | |
342 | .pkt_to_tuple = ipv6_pkt_to_tuple, | |
343 | .invert_tuple = ipv6_invert_tuple, | |
344 | .print_tuple = ipv6_print_tuple, | |
ffc30690 | 345 | .get_l4proto = ipv6_get_l4proto, |
e281db5c | 346 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
fdf70832 PM |
347 | .tuple_to_nlattr = ipv6_tuple_to_nlattr, |
348 | .nlattr_to_tuple = ipv6_nlattr_to_tuple, | |
f73e924c | 349 | .nla_policy = ipv6_nla_policy, |
933a41e7 PM |
350 | #endif |
351 | #ifdef CONFIG_SYSCTL | |
352 | .ctl_table_path = nf_net_netfilter_sysctl_path, | |
353 | .ctl_table = nf_ct_ipv6_sysctl_table, | |
c1d10adb | 354 | #endif |
9fb9cbb1 YK |
355 | .me = THIS_MODULE, |
356 | }; | |
357 | ||
32292a7f PM |
358 | MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6)); |
359 | MODULE_LICENSE("GPL"); | |
360 | MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>"); | |
361 | ||
362 | static int __init nf_conntrack_l3proto_ipv6_init(void) | |
9fb9cbb1 YK |
363 | { |
364 | int ret = 0; | |
365 | ||
32292a7f | 366 | need_conntrack(); |
9fb9cbb1 YK |
367 | |
368 | ret = nf_ct_frag6_init(); | |
369 | if (ret < 0) { | |
370 | printk("nf_conntrack_ipv6: can't initialize frag6.\n"); | |
32292a7f | 371 | return ret; |
9fb9cbb1 | 372 | } |
605dcad6 | 373 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6); |
9fb9cbb1 YK |
374 | if (ret < 0) { |
375 | printk("nf_conntrack_ipv6: can't register tcp.\n"); | |
376 | goto cleanup_frag6; | |
377 | } | |
378 | ||
605dcad6 | 379 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6); |
9fb9cbb1 YK |
380 | if (ret < 0) { |
381 | printk("nf_conntrack_ipv6: can't register udp.\n"); | |
382 | goto cleanup_tcp; | |
383 | } | |
384 | ||
605dcad6 | 385 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6); |
9fb9cbb1 YK |
386 | if (ret < 0) { |
387 | printk("nf_conntrack_ipv6: can't register icmpv6.\n"); | |
388 | goto cleanup_udp; | |
389 | } | |
390 | ||
391 | ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6); | |
392 | if (ret < 0) { | |
393 | printk("nf_conntrack_ipv6: can't register ipv6\n"); | |
394 | goto cleanup_icmpv6; | |
395 | } | |
396 | ||
964ddaa1 PM |
397 | ret = nf_register_hooks(ipv6_conntrack_ops, |
398 | ARRAY_SIZE(ipv6_conntrack_ops)); | |
9fb9cbb1 YK |
399 | if (ret < 0) { |
400 | printk("nf_conntrack_ipv6: can't register pre-routing defrag " | |
401 | "hook.\n"); | |
402 | goto cleanup_ipv6; | |
403 | } | |
9fb9cbb1 YK |
404 | return ret; |
405 | ||
9fb9cbb1 YK |
406 | cleanup_ipv6: |
407 | nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6); | |
408 | cleanup_icmpv6: | |
605dcad6 | 409 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6); |
9fb9cbb1 | 410 | cleanup_udp: |
605dcad6 | 411 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6); |
9fb9cbb1 | 412 | cleanup_tcp: |
605dcad6 | 413 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6); |
9fb9cbb1 YK |
414 | cleanup_frag6: |
415 | nf_ct_frag6_cleanup(); | |
9fb9cbb1 YK |
416 | return ret; |
417 | } | |
418 | ||
65b4b4e8 | 419 | static void __exit nf_conntrack_l3proto_ipv6_fini(void) |
9fb9cbb1 | 420 | { |
32292a7f | 421 | synchronize_net(); |
32292a7f PM |
422 | nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops)); |
423 | nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6); | |
605dcad6 MJ |
424 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6); |
425 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6); | |
426 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6); | |
32292a7f | 427 | nf_ct_frag6_cleanup(); |
9fb9cbb1 YK |
428 | } |
429 | ||
65b4b4e8 AM |
430 | module_init(nf_conntrack_l3proto_ipv6_init); |
431 | module_exit(nf_conntrack_l3proto_ipv6_fini); |