2 * Copyright (C)2003,2004 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 * - ICMPv6 tracking support. Derived from the original ip_conntrack code
13 * net/ipv4/netfilter/ip_conntrack_proto_icmp.c which had the following
14 * copyright information:
15 * (C) 1999-2001 Paul `Rusty' Russell
16 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
19 #include <linux/types.h>
20 #include <linux/sched.h>
21 #include <linux/timer.h>
22 #include <linux/module.h>
23 #include <linux/netfilter.h>
24 #include <linux/in6.h>
25 #include <linux/icmpv6.h>
26 #include <linux/ipv6.h>
28 #include <net/ip6_checksum.h>
29 #include <linux/seq_file.h>
30 #include <linux/netfilter_ipv6.h>
31 #include <net/netfilter/nf_conntrack_tuple.h>
32 #include <net/netfilter/nf_conntrack_protocol.h>
33 #include <net/netfilter/nf_conntrack_core.h>
34 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
36 unsigned long nf_ct_icmpv6_timeout = 30*HZ;
41 #define DEBUGP(format, args...)
44 static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
46 struct nf_conntrack_tuple *tuple)
48 struct icmp6hdr _hdr, *hp;
50 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
53 tuple->dst.u.icmp.type = hp->icmp6_type;
54 tuple->src.u.icmp.id = hp->icmp6_identifier;
55 tuple->dst.u.icmp.code = hp->icmp6_code;
60 /* Add 1; spaces filled with 0. */
61 static u_int8_t invmap[] = {
62 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
63 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
64 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1,
65 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1
68 static int icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
69 const struct nf_conntrack_tuple *orig)
71 int type = orig->dst.u.icmp.type - 128;
72 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
75 tuple->src.u.icmp.id = orig->src.u.icmp.id;
76 tuple->dst.u.icmp.type = invmap[type] - 1;
77 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
81 /* Print out the per-protocol part of the tuple. */
82 static int icmpv6_print_tuple(struct seq_file *s,
83 const struct nf_conntrack_tuple *tuple)
85 return seq_printf(s, "type=%u code=%u id=%u ",
86 tuple->dst.u.icmp.type,
87 tuple->dst.u.icmp.code,
88 ntohs(tuple->src.u.icmp.id));
91 /* Print out the private part of the conntrack. */
92 static int icmpv6_print_conntrack(struct seq_file *s,
93 const struct nf_conn *conntrack)
98 /* Returns verdict for packet, or -1 for invalid. */
99 static int icmpv6_packet(struct nf_conn *ct,
100 const struct sk_buff *skb,
101 unsigned int dataoff,
102 enum ip_conntrack_info ctinfo,
104 unsigned int hooknum)
106 /* Try to delete connection immediately after all replies:
107 won't actually vanish as we still have skb, and del_timer
108 means this will only run once even if count hits zero twice
109 (theoretically possible with SMP) */
110 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
111 if (atomic_dec_and_test(&ct->proto.icmp.count)
112 && del_timer(&ct->timeout))
113 ct->timeout.function((unsigned long)ct);
115 atomic_inc(&ct->proto.icmp.count);
116 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
117 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
123 /* Called when a new connection for this protocol found. */
124 static int icmpv6_new(struct nf_conn *conntrack,
125 const struct sk_buff *skb,
126 unsigned int dataoff)
128 static u_int8_t valid_new[] = {
129 [ICMPV6_ECHO_REQUEST - 128] = 1,
130 [ICMPV6_NI_QUERY - 128] = 1
132 int type = conntrack->tuplehash[0].tuple.dst.u.icmp.type - 128;
134 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
135 /* Can't create a new ICMPv6 `conn' with this. */
136 DEBUGP("icmpv6: can't create new conn with type %u\n",
138 NF_CT_DUMP_TUPLE(&conntrack->tuplehash[0].tuple);
141 atomic_set(&conntrack->proto.icmp.count, 0);
146 nf_ct_ipv6_skip_exthdr(struct sk_buff *skb, int start, u8 *nexthdrp, int len);
147 extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6;
149 icmpv6_error_message(struct sk_buff *skb,
150 unsigned int icmp6off,
151 enum ip_conntrack_info *ctinfo,
152 unsigned int hooknum)
154 struct nf_conntrack_tuple intuple, origtuple;
155 struct nf_conntrack_tuple_hash *h;
156 struct icmp6hdr _hdr, *hp;
157 unsigned int inip6off;
158 struct nf_conntrack_protocol *inproto;
160 unsigned int inprotoff;
162 NF_CT_ASSERT(skb->nfct == NULL);
164 hp = skb_header_pointer(skb, icmp6off, sizeof(_hdr), &_hdr);
166 DEBUGP("icmpv6_error: Can't get ICMPv6 hdr.\n");
170 inip6off = icmp6off + sizeof(_hdr);
171 if (skb_copy_bits(skb, inip6off+offsetof(struct ipv6hdr, nexthdr),
172 &inprotonum, sizeof(inprotonum)) != 0) {
173 DEBUGP("icmpv6_error: Can't get nexthdr in inner IPv6 header.\n");
176 inprotoff = nf_ct_ipv6_skip_exthdr(skb,
177 inip6off + sizeof(struct ipv6hdr),
180 - sizeof(struct ipv6hdr));
182 if ((inprotoff < 0) || (inprotoff > skb->len) ||
183 (inprotonum == NEXTHDR_FRAGMENT)) {
184 DEBUGP("icmpv6_error: Can't get protocol header in ICMPv6 payload.\n");
188 inproto = __nf_ct_proto_find(PF_INET6, inprotonum);
190 /* Are they talking about one of our connections? */
191 if (!nf_ct_get_tuple(skb, inip6off, inprotoff, PF_INET6, inprotonum,
192 &origtuple, &nf_conntrack_l3proto_ipv6, inproto)) {
193 DEBUGP("icmpv6_error: Can't get tuple\n");
197 /* Ordinarily, we'd expect the inverted tupleproto, but it's
198 been preserved inside the ICMP. */
199 if (!nf_ct_invert_tuple(&intuple, &origtuple,
200 &nf_conntrack_l3proto_ipv6, inproto)) {
201 DEBUGP("icmpv6_error: Can't invert tuple\n");
205 *ctinfo = IP_CT_RELATED;
207 h = nf_conntrack_find_get(&intuple, NULL);
209 DEBUGP("icmpv6_error: no match\n");
212 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
213 *ctinfo += IP_CT_IS_REPLY;
216 /* Update skb to refer to this connection */
217 skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
218 skb->nfctinfo = *ctinfo;
223 icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
224 enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
226 struct icmp6hdr _ih, *icmp6h;
228 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
229 if (icmp6h == NULL) {
230 if (LOG_INVALID(IPPROTO_ICMPV6))
231 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
232 "nf_ct_icmpv6: short packet ");
236 if (hooknum != NF_IP6_PRE_ROUTING)
239 /* Ignore it if the checksum's bogus. */
240 if (csum_ipv6_magic(&skb->nh.ipv6h->saddr, &skb->nh.ipv6h->daddr,
241 skb->len - dataoff, IPPROTO_ICMPV6,
242 skb_checksum(skb, dataoff,
243 skb->len - dataoff, 0))) {
244 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
245 "nf_ct_icmpv6: ICMPv6 checksum failed\n");
251 /* is not error message ? */
252 if (icmp6h->icmp6_type >= 128)
255 return icmpv6_error_message(skb, dataoff, ctinfo, hooknum);
258 #if defined(CONFIG_NF_CT_NETLINK) || \
259 defined(CONFIG_NF_CT_NETLINK_MODULE)
261 #include <linux/netfilter/nfnetlink.h>
262 #include <linux/netfilter/nfnetlink_conntrack.h>
263 static int icmpv6_tuple_to_nfattr(struct sk_buff *skb,
264 const struct nf_conntrack_tuple *t)
266 NFA_PUT(skb, CTA_PROTO_ICMPV6_ID, sizeof(u_int16_t),
268 NFA_PUT(skb, CTA_PROTO_ICMPV6_TYPE, sizeof(u_int8_t),
269 &t->dst.u.icmp.type);
270 NFA_PUT(skb, CTA_PROTO_ICMPV6_CODE, sizeof(u_int8_t),
271 &t->dst.u.icmp.code);
279 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
280 [CTA_PROTO_ICMPV6_TYPE-1] = sizeof(u_int8_t),
281 [CTA_PROTO_ICMPV6_CODE-1] = sizeof(u_int8_t),
282 [CTA_PROTO_ICMPV6_ID-1] = sizeof(u_int16_t)
285 static int icmpv6_nfattr_to_tuple(struct nfattr *tb[],
286 struct nf_conntrack_tuple *tuple)
288 if (!tb[CTA_PROTO_ICMPV6_TYPE-1]
289 || !tb[CTA_PROTO_ICMPV6_CODE-1]
290 || !tb[CTA_PROTO_ICMPV6_ID-1])
293 if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
296 tuple->dst.u.icmp.type =
297 *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_ICMPV6_TYPE-1]);
298 tuple->dst.u.icmp.code =
299 *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_ICMPV6_CODE-1]);
300 tuple->src.u.icmp.id =
301 *(u_int16_t *)NFA_DATA(tb[CTA_PROTO_ICMPV6_ID-1]);
303 if (tuple->dst.u.icmp.type < 128
304 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
305 || !invmap[tuple->dst.u.icmp.type - 128])
312 struct nf_conntrack_protocol nf_conntrack_protocol_icmpv6 =
315 .proto = IPPROTO_ICMPV6,
317 .pkt_to_tuple = icmpv6_pkt_to_tuple,
318 .invert_tuple = icmpv6_invert_tuple,
319 .print_tuple = icmpv6_print_tuple,
320 .print_conntrack = icmpv6_print_conntrack,
321 .packet = icmpv6_packet,
323 .error = icmpv6_error,
324 #if defined(CONFIG_NF_CT_NETLINK) || \
325 defined(CONFIG_NF_CT_NETLINK_MODULE)
326 .tuple_to_nfattr = icmpv6_tuple_to_nfattr,
327 .nfattr_to_tuple = icmpv6_nfattr_to_tuple,
331 EXPORT_SYMBOL(nf_conntrack_protocol_icmpv6);