2 * Copyright (C)2004 USAGI/WIDE Project
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.
9 * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
11 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
12 * - support Layer 3 protocol independent connection tracking.
13 * Based on the original ip_conntrack code which had the following
14 * copyright information:
15 * (C) 1999-2001 Paul `Rusty' Russell
16 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
18 * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
19 * - add get_features() to support various size of conntrack
23 #include <linux/types.h>
24 #include <linux/ipv6.h>
25 #include <linux/in6.h>
26 #include <linux/netfilter.h>
27 #include <linux/module.h>
28 #include <linux/skbuff.h>
29 #include <linux/icmp.h>
30 #include <linux/sysctl.h>
33 #include <linux/netfilter_ipv6.h>
34 #include <net/netfilter/nf_conntrack.h>
35 #include <net/netfilter/nf_conntrack_helper.h>
36 #include <net/netfilter/nf_conntrack_l4proto.h>
37 #include <net/netfilter/nf_conntrack_l3proto.h>
38 #include <net/netfilter/nf_conntrack_core.h>
43 #define DEBUGP(format, args...)
46 static int ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
47 struct nf_conntrack_tuple *tuple)
49 u_int32_t _addrs[8], *ap;
51 ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
52 sizeof(_addrs), _addrs);
56 memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
57 memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
62 static int ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
63 const struct nf_conntrack_tuple *orig)
65 memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
66 memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
71 static int ipv6_print_tuple(struct seq_file *s,
72 const struct nf_conntrack_tuple *tuple)
74 return seq_printf(s, "src=" NIP6_FMT " dst=" NIP6_FMT " ",
75 NIP6(*((struct in6_addr *)tuple->src.u3.ip6)),
76 NIP6(*((struct in6_addr *)tuple->dst.u3.ip6)));
79 static int ipv6_print_conntrack(struct seq_file *s,
80 const struct nf_conn *conntrack)
86 * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
88 * This function parses (probably truncated) exthdr set "hdr"
89 * of length "len". "nexthdrp" initially points to some place,
90 * where type of the first header can be found.
92 * It skips all well-known exthdrs, and returns pointer to the start
93 * of unparsable area i.e. the first header with unknown type.
94 * if success, *nexthdr is updated by type/protocol of this header.
96 * NOTES: - it may return pointer pointing beyond end of packet,
97 * if the last recognized header is truncated in the middle.
98 * - if packet is truncated, so that all parsed headers are skipped,
100 * - if packet is fragmented, return pointer of the fragment header.
101 * - ESP is unparsable for now and considered like
102 * normal payload protocol.
103 * - Note also special handling of AUTH header. Thanks to IPsec wizards.
106 int nf_ct_ipv6_skip_exthdr(struct sk_buff *skb, int start, u8 *nexthdrp,
109 u8 nexthdr = *nexthdrp;
111 while (ipv6_ext_hdr(nexthdr)) {
112 struct ipv6_opt_hdr hdr;
115 if (len < (int)sizeof(struct ipv6_opt_hdr))
117 if (nexthdr == NEXTHDR_NONE)
119 if (nexthdr == NEXTHDR_FRAGMENT)
121 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
123 if (nexthdr == NEXTHDR_AUTH)
124 hdrlen = (hdr.hdrlen+2)<<2;
126 hdrlen = ipv6_optlen(&hdr);
128 nexthdr = hdr.nexthdr;
138 ipv6_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
145 extoff = (u8*)((*pskb)->nh.ipv6h + 1) - (*pskb)->data;
146 pnum = (*pskb)->nh.ipv6h->nexthdr;
148 protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
149 (*pskb)->len - extoff);
152 * (protoff == (*pskb)->len) mean that the packet doesn't have no data
153 * except of IPv6 & ext headers. but it's tracked anyway. - YK
155 if ((protoff < 0) || (protoff > (*pskb)->len)) {
156 DEBUGP("ip6_conntrack_core: can't find proto in pkt\n");
157 NF_CT_STAT_INC_ATOMIC(error);
158 NF_CT_STAT_INC_ATOMIC(invalid);
167 static u_int32_t ipv6_get_features(const struct nf_conntrack_tuple *tuple)
169 return NF_CT_F_BASIC;
172 static unsigned int ipv6_confirm(unsigned int hooknum,
173 struct sk_buff **pskb,
174 const struct net_device *in,
175 const struct net_device *out,
176 int (*okfn)(struct sk_buff *))
179 struct nf_conn_help *help;
180 enum ip_conntrack_info ctinfo;
181 unsigned int ret, protoff;
182 unsigned int extoff = (u8*)((*pskb)->nh.ipv6h + 1)
184 unsigned char pnum = (*pskb)->nh.ipv6h->nexthdr;
187 /* This is where we call the helper: as the packet goes out. */
188 ct = nf_ct_get(*pskb, &ctinfo);
189 if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
192 help = nfct_help(ct);
193 if (!help || !help->helper)
196 protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum,
197 (*pskb)->len - extoff);
198 if (protoff < 0 || protoff > (*pskb)->len ||
199 pnum == NEXTHDR_FRAGMENT) {
200 DEBUGP("proto header not found\n");
204 ret = help->helper->help(pskb, protoff, ct, ctinfo);
205 if (ret != NF_ACCEPT)
208 /* We've seen it coming out the other side: confirm it */
209 return nf_conntrack_confirm(pskb);
212 static unsigned int ipv6_defrag(unsigned int hooknum,
213 struct sk_buff **pskb,
214 const struct net_device *in,
215 const struct net_device *out,
216 int (*okfn)(struct sk_buff *))
218 struct sk_buff *reasm;
220 /* Previously seen (loopback)? */
224 reasm = nf_ct_frag6_gather(*pskb);
230 /* error occured or not fragmented */
234 nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
235 (struct net_device *)out, okfn);
240 static unsigned int ipv6_conntrack_in(unsigned int hooknum,
241 struct sk_buff **pskb,
242 const struct net_device *in,
243 const struct net_device *out,
244 int (*okfn)(struct sk_buff *))
246 struct sk_buff *reasm = (*pskb)->nfct_reasm;
248 /* This packet is fragmented and has reassembled packet. */
250 /* Reassembled packet isn't parsed yet ? */
254 ret = nf_conntrack_in(PF_INET6, hooknum, &reasm);
255 if (ret != NF_ACCEPT)
258 nf_conntrack_get(reasm->nfct);
259 (*pskb)->nfct = reasm->nfct;
263 return nf_conntrack_in(PF_INET6, hooknum, pskb);
266 static unsigned int ipv6_conntrack_local(unsigned int hooknum,
267 struct sk_buff **pskb,
268 const struct net_device *in,
269 const struct net_device *out,
270 int (*okfn)(struct sk_buff *))
272 /* root is playing with raw sockets. */
273 if ((*pskb)->len < sizeof(struct ipv6hdr)) {
275 printk("ipv6_conntrack_local: packet too short\n");
278 return ipv6_conntrack_in(hooknum, pskb, in, out, okfn);
281 static struct nf_hook_ops ipv6_conntrack_ops[] = {
284 .owner = THIS_MODULE,
286 .hooknum = NF_IP6_PRE_ROUTING,
287 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
290 .hook = ipv6_conntrack_in,
291 .owner = THIS_MODULE,
293 .hooknum = NF_IP6_PRE_ROUTING,
294 .priority = NF_IP6_PRI_CONNTRACK,
297 .hook = ipv6_conntrack_local,
298 .owner = THIS_MODULE,
300 .hooknum = NF_IP6_LOCAL_OUT,
301 .priority = NF_IP6_PRI_CONNTRACK,
305 .owner = THIS_MODULE,
307 .hooknum = NF_IP6_LOCAL_OUT,
308 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
311 .hook = ipv6_confirm,
312 .owner = THIS_MODULE,
314 .hooknum = NF_IP6_POST_ROUTING,
315 .priority = NF_IP6_PRI_LAST,
318 .hook = ipv6_confirm,
319 .owner = THIS_MODULE,
321 .hooknum = NF_IP6_LOCAL_IN,
322 .priority = NF_IP6_PRI_LAST-1,
327 static ctl_table nf_ct_ipv6_sysctl_table[] = {
329 .ctl_name = NET_NF_CONNTRACK_FRAG6_TIMEOUT,
330 .procname = "nf_conntrack_frag6_timeout",
331 .data = &nf_ct_frag6_timeout,
332 .maxlen = sizeof(unsigned int),
334 .proc_handler = &proc_dointvec_jiffies,
337 .ctl_name = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
338 .procname = "nf_conntrack_frag6_low_thresh",
339 .data = &nf_ct_frag6_low_thresh,
340 .maxlen = sizeof(unsigned int),
342 .proc_handler = &proc_dointvec,
345 .ctl_name = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
346 .procname = "nf_conntrack_frag6_high_thresh",
347 .data = &nf_ct_frag6_high_thresh,
348 .maxlen = sizeof(unsigned int),
350 .proc_handler = &proc_dointvec,
356 #if defined(CONFIG_NF_CT_NETLINK) || \
357 defined(CONFIG_NF_CT_NETLINK_MODULE)
359 #include <linux/netfilter/nfnetlink.h>
360 #include <linux/netfilter/nfnetlink_conntrack.h>
362 static int ipv6_tuple_to_nfattr(struct sk_buff *skb,
363 const struct nf_conntrack_tuple *tuple)
365 NFA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
367 NFA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
375 static const size_t cta_min_ip[CTA_IP_MAX] = {
376 [CTA_IP_V6_SRC-1] = sizeof(u_int32_t)*4,
377 [CTA_IP_V6_DST-1] = sizeof(u_int32_t)*4,
380 static int ipv6_nfattr_to_tuple(struct nfattr *tb[],
381 struct nf_conntrack_tuple *t)
383 if (!tb[CTA_IP_V6_SRC-1] || !tb[CTA_IP_V6_DST-1])
386 if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
389 memcpy(&t->src.u3.ip6, NFA_DATA(tb[CTA_IP_V6_SRC-1]),
390 sizeof(u_int32_t) * 4);
391 memcpy(&t->dst.u3.ip6, NFA_DATA(tb[CTA_IP_V6_DST-1]),
392 sizeof(u_int32_t) * 4);
398 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = {
401 .pkt_to_tuple = ipv6_pkt_to_tuple,
402 .invert_tuple = ipv6_invert_tuple,
403 .print_tuple = ipv6_print_tuple,
404 .print_conntrack = ipv6_print_conntrack,
405 .prepare = ipv6_prepare,
406 #if defined(CONFIG_NF_CT_NETLINK) || \
407 defined(CONFIG_NF_CT_NETLINK_MODULE)
408 .tuple_to_nfattr = ipv6_tuple_to_nfattr,
409 .nfattr_to_tuple = ipv6_nfattr_to_tuple,
412 .ctl_table_path = nf_net_netfilter_sysctl_path,
413 .ctl_table = nf_ct_ipv6_sysctl_table,
415 .get_features = ipv6_get_features,
419 MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
420 MODULE_LICENSE("GPL");
421 MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
423 static int __init nf_conntrack_l3proto_ipv6_init(void)
429 ret = nf_ct_frag6_init();
431 printk("nf_conntrack_ipv6: can't initialize frag6.\n");
434 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6);
436 printk("nf_conntrack_ipv6: can't register tcp.\n");
440 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6);
442 printk("nf_conntrack_ipv6: can't register udp.\n");
446 ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6);
448 printk("nf_conntrack_ipv6: can't register icmpv6.\n");
452 ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6);
454 printk("nf_conntrack_ipv6: can't register ipv6\n");
458 ret = nf_register_hooks(ipv6_conntrack_ops,
459 ARRAY_SIZE(ipv6_conntrack_ops));
461 printk("nf_conntrack_ipv6: can't register pre-routing defrag "
468 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
470 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
472 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
474 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
476 nf_ct_frag6_cleanup();
480 static void __exit nf_conntrack_l3proto_ipv6_fini(void)
483 nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
484 nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
485 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
486 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
487 nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
488 nf_ct_frag6_cleanup();
491 module_init(nf_conntrack_l3proto_ipv6_init);
492 module_exit(nf_conntrack_l3proto_ipv6_fini);