[NETFILTER]: nf_conntrack: remove 'ignore_conntrack' argument from nf_conntrack_find_get
[linux-2.6.git] / net / ipv6 / netfilter / nf_conntrack_proto_icmpv6.c
1 /*
2  * Copyright (C)2003,2004 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>
10  */
11
12 #include <linux/types.h>
13 #include <linux/timer.h>
14 #include <linux/module.h>
15 #include <linux/netfilter.h>
16 #include <linux/in6.h>
17 #include <linux/icmpv6.h>
18 #include <linux/ipv6.h>
19 #include <net/ipv6.h>
20 #include <net/ip6_checksum.h>
21 #include <linux/seq_file.h>
22 #include <linux/netfilter_ipv6.h>
23 #include <net/netfilter/nf_conntrack_tuple.h>
24 #include <net/netfilter/nf_conntrack_l4proto.h>
25 #include <net/netfilter/nf_conntrack_core.h>
26 #include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
27
28 static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
29
30 #if 0
31 #define DEBUGP printk
32 #else
33 #define DEBUGP(format, args...)
34 #endif
35
36 static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
37                                unsigned int dataoff,
38                                struct nf_conntrack_tuple *tuple)
39 {
40         struct icmp6hdr _hdr, *hp;
41
42         hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
43         if (hp == NULL)
44                 return 0;
45         tuple->dst.u.icmp.type = hp->icmp6_type;
46         tuple->src.u.icmp.id = hp->icmp6_identifier;
47         tuple->dst.u.icmp.code = hp->icmp6_code;
48
49         return 1;
50 }
51
52 /* Add 1; spaces filled with 0. */
53 static u_int8_t invmap[] = {
54         [ICMPV6_ECHO_REQUEST - 128]     = ICMPV6_ECHO_REPLY + 1,
55         [ICMPV6_ECHO_REPLY - 128]       = ICMPV6_ECHO_REQUEST + 1,
56         [ICMPV6_NI_QUERY - 128]         = ICMPV6_NI_QUERY + 1,
57         [ICMPV6_NI_REPLY - 128]         = ICMPV6_NI_REPLY +1
58 };
59
60 static int icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
61                                const struct nf_conntrack_tuple *orig)
62 {
63         int type = orig->dst.u.icmp.type - 128;
64         if (type < 0 || type >= sizeof(invmap) || !invmap[type])
65                 return 0;
66
67         tuple->src.u.icmp.id   = orig->src.u.icmp.id;
68         tuple->dst.u.icmp.type = invmap[type] - 1;
69         tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
70         return 1;
71 }
72
73 /* Print out the per-protocol part of the tuple. */
74 static int icmpv6_print_tuple(struct seq_file *s,
75                               const struct nf_conntrack_tuple *tuple)
76 {
77         return seq_printf(s, "type=%u code=%u id=%u ",
78                           tuple->dst.u.icmp.type,
79                           tuple->dst.u.icmp.code,
80                           ntohs(tuple->src.u.icmp.id));
81 }
82
83 /* Print out the private part of the conntrack. */
84 static int icmpv6_print_conntrack(struct seq_file *s,
85                                   const struct nf_conn *conntrack)
86 {
87         return 0;
88 }
89
90 /* Returns verdict for packet, or -1 for invalid. */
91 static int icmpv6_packet(struct nf_conn *ct,
92                        const struct sk_buff *skb,
93                        unsigned int dataoff,
94                        enum ip_conntrack_info ctinfo,
95                        int pf,
96                        unsigned int hooknum)
97 {
98         /* Try to delete connection immediately after all replies:
99            won't actually vanish as we still have skb, and del_timer
100            means this will only run once even if count hits zero twice
101            (theoretically possible with SMP) */
102         if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
103                 if (atomic_dec_and_test(&ct->proto.icmp.count)
104                     && del_timer(&ct->timeout))
105                         ct->timeout.function((unsigned long)ct);
106         } else {
107                 atomic_inc(&ct->proto.icmp.count);
108                 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
109                 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
110         }
111
112         return NF_ACCEPT;
113 }
114
115 /* Called when a new connection for this protocol found. */
116 static int icmpv6_new(struct nf_conn *conntrack,
117                       const struct sk_buff *skb,
118                       unsigned int dataoff)
119 {
120         static u_int8_t valid_new[] = {
121                 [ICMPV6_ECHO_REQUEST - 128] = 1,
122                 [ICMPV6_NI_QUERY - 128] = 1
123         };
124         int type = conntrack->tuplehash[0].tuple.dst.u.icmp.type - 128;
125
126         if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
127                 /* Can't create a new ICMPv6 `conn' with this. */
128                 DEBUGP("icmpv6: can't create new conn with type %u\n",
129                        type + 128);
130                 NF_CT_DUMP_TUPLE(&conntrack->tuplehash[0].tuple);
131                 return 0;
132         }
133         atomic_set(&conntrack->proto.icmp.count, 0);
134         return 1;
135 }
136
137 static int
138 icmpv6_error_message(struct sk_buff *skb,
139                      unsigned int icmp6off,
140                      enum ip_conntrack_info *ctinfo,
141                      unsigned int hooknum)
142 {
143         struct nf_conntrack_tuple intuple, origtuple;
144         struct nf_conntrack_tuple_hash *h;
145         struct icmp6hdr _hdr, *hp;
146         unsigned int inip6off;
147         struct nf_conntrack_l4proto *inproto;
148         u_int8_t inprotonum;
149         unsigned int inprotoff;
150
151         NF_CT_ASSERT(skb->nfct == NULL);
152
153         hp = skb_header_pointer(skb, icmp6off, sizeof(_hdr), &_hdr);
154         if (hp == NULL) {
155                 DEBUGP("icmpv6_error: Can't get ICMPv6 hdr.\n");
156                 return -NF_ACCEPT;
157         }
158
159         inip6off = icmp6off + sizeof(_hdr);
160         if (skb_copy_bits(skb, inip6off+offsetof(struct ipv6hdr, nexthdr),
161                           &inprotonum, sizeof(inprotonum)) != 0) {
162                 DEBUGP("icmpv6_error: Can't get nexthdr in inner IPv6 header.\n");
163                 return -NF_ACCEPT;
164         }
165         inprotoff = nf_ct_ipv6_skip_exthdr(skb,
166                                            inip6off + sizeof(struct ipv6hdr),
167                                            &inprotonum,
168                                            skb->len - inip6off
169                                                     - sizeof(struct ipv6hdr));
170
171         if ((inprotoff > skb->len) || (inprotonum == NEXTHDR_FRAGMENT)) {
172                 DEBUGP("icmpv6_error: Can't get protocol header in ICMPv6 payload.\n");
173                 return -NF_ACCEPT;
174         }
175
176         /* rcu_read_lock()ed by nf_hook_slow */
177         inproto = __nf_ct_l4proto_find(PF_INET6, inprotonum);
178
179         /* Are they talking about one of our connections? */
180         if (!nf_ct_get_tuple(skb, inip6off, inprotoff, PF_INET6, inprotonum,
181                              &origtuple, &nf_conntrack_l3proto_ipv6, inproto)) {
182                 DEBUGP("icmpv6_error: Can't get tuple\n");
183                 return -NF_ACCEPT;
184         }
185
186         /* Ordinarily, we'd expect the inverted tupleproto, but it's
187            been preserved inside the ICMP. */
188         if (!nf_ct_invert_tuple(&intuple, &origtuple,
189                                 &nf_conntrack_l3proto_ipv6, inproto)) {
190                 DEBUGP("icmpv6_error: Can't invert tuple\n");
191                 return -NF_ACCEPT;
192         }
193
194         *ctinfo = IP_CT_RELATED;
195
196         h = nf_conntrack_find_get(&intuple);
197         if (!h) {
198                 DEBUGP("icmpv6_error: no match\n");
199                 return -NF_ACCEPT;
200         } else {
201                 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
202                         *ctinfo += IP_CT_IS_REPLY;
203         }
204
205         /* Update skb to refer to this connection */
206         skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
207         skb->nfctinfo = *ctinfo;
208         return -NF_ACCEPT;
209 }
210
211 static int
212 icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
213              enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
214 {
215         struct icmp6hdr _ih, *icmp6h;
216
217         icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
218         if (icmp6h == NULL) {
219                 if (LOG_INVALID(IPPROTO_ICMPV6))
220                 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
221                               "nf_ct_icmpv6: short packet ");
222                 return -NF_ACCEPT;
223         }
224
225         if (nf_conntrack_checksum && hooknum == NF_IP6_PRE_ROUTING &&
226             nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
227                 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
228                               "nf_ct_icmpv6: ICMPv6 checksum failed\n");
229                 return -NF_ACCEPT;
230         }
231
232         /* is not error message ? */
233         if (icmp6h->icmp6_type >= 128)
234                 return NF_ACCEPT;
235
236         return icmpv6_error_message(skb, dataoff, ctinfo, hooknum);
237 }
238
239 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
240
241 #include <linux/netfilter/nfnetlink.h>
242 #include <linux/netfilter/nfnetlink_conntrack.h>
243 static int icmpv6_tuple_to_nfattr(struct sk_buff *skb,
244                                   const struct nf_conntrack_tuple *t)
245 {
246         NFA_PUT(skb, CTA_PROTO_ICMPV6_ID, sizeof(u_int16_t),
247                 &t->src.u.icmp.id);
248         NFA_PUT(skb, CTA_PROTO_ICMPV6_TYPE, sizeof(u_int8_t),
249                 &t->dst.u.icmp.type);
250         NFA_PUT(skb, CTA_PROTO_ICMPV6_CODE, sizeof(u_int8_t),
251                 &t->dst.u.icmp.code);
252
253         return 0;
254
255 nfattr_failure:
256         return -1;
257 }
258
259 static const size_t cta_min_proto[CTA_PROTO_MAX] = {
260         [CTA_PROTO_ICMPV6_TYPE-1] = sizeof(u_int8_t),
261         [CTA_PROTO_ICMPV6_CODE-1] = sizeof(u_int8_t),
262         [CTA_PROTO_ICMPV6_ID-1]   = sizeof(u_int16_t)
263 };
264
265 static int icmpv6_nfattr_to_tuple(struct nfattr *tb[],
266                                 struct nf_conntrack_tuple *tuple)
267 {
268         if (!tb[CTA_PROTO_ICMPV6_TYPE-1]
269             || !tb[CTA_PROTO_ICMPV6_CODE-1]
270             || !tb[CTA_PROTO_ICMPV6_ID-1])
271                 return -EINVAL;
272
273         if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto))
274                 return -EINVAL;
275
276         tuple->dst.u.icmp.type =
277                         *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_ICMPV6_TYPE-1]);
278         tuple->dst.u.icmp.code =
279                         *(u_int8_t *)NFA_DATA(tb[CTA_PROTO_ICMPV6_CODE-1]);
280         tuple->src.u.icmp.id =
281                         *(__be16 *)NFA_DATA(tb[CTA_PROTO_ICMPV6_ID-1]);
282
283         if (tuple->dst.u.icmp.type < 128
284             || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
285             || !invmap[tuple->dst.u.icmp.type - 128])
286                 return -EINVAL;
287
288         return 0;
289 }
290 #endif
291
292 #ifdef CONFIG_SYSCTL
293 static struct ctl_table_header *icmpv6_sysctl_header;
294 static struct ctl_table icmpv6_sysctl_table[] = {
295         {
296                 .ctl_name       = NET_NF_CONNTRACK_ICMPV6_TIMEOUT,
297                 .procname       = "nf_conntrack_icmpv6_timeout",
298                 .data           = &nf_ct_icmpv6_timeout,
299                 .maxlen         = sizeof(unsigned int),
300                 .mode           = 0644,
301                 .proc_handler   = &proc_dointvec_jiffies,
302         },
303         {
304                 .ctl_name       = 0
305         }
306 };
307 #endif /* CONFIG_SYSCTL */
308
309 struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 =
310 {
311         .l3proto                = PF_INET6,
312         .l4proto                = IPPROTO_ICMPV6,
313         .name                   = "icmpv6",
314         .pkt_to_tuple           = icmpv6_pkt_to_tuple,
315         .invert_tuple           = icmpv6_invert_tuple,
316         .print_tuple            = icmpv6_print_tuple,
317         .print_conntrack        = icmpv6_print_conntrack,
318         .packet                 = icmpv6_packet,
319         .new                    = icmpv6_new,
320         .error                  = icmpv6_error,
321 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
322         .tuple_to_nfattr        = icmpv6_tuple_to_nfattr,
323         .nfattr_to_tuple        = icmpv6_nfattr_to_tuple,
324 #endif
325 #ifdef CONFIG_SYSCTL
326         .ctl_table_header       = &icmpv6_sysctl_header,
327         .ctl_table              = icmpv6_sysctl_table,
328 #endif
329 };
330
331 EXPORT_SYMBOL(nf_conntrack_l4proto_icmpv6);