]> bbs.cooldavid.org Git - net-next-2.6.git/blame - net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
netfilter: fix tuple inversion for Node information request
[net-next-2.6.git] / net / ipv6 / netfilter / nf_conntrack_proto_icmpv6.c
CommitLineData
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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>
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10 */
11
12#include <linux/types.h>
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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>
605dcad6 24#include <net/netfilter/nf_conntrack_l4proto.h>
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25#include <net/netfilter/nf_conntrack_core.h>
26#include <net/netfilter/ipv6/nf_conntrack_icmpv6.h>
f01ffbd6 27#include <net/netfilter/nf_log.h>
9fb9cbb1 28
71320afc 29static unsigned int nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
9fb9cbb1 30
09f263cd
JE
31static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
32 unsigned int dataoff,
33 struct nf_conntrack_tuple *tuple)
9fb9cbb1 34{
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35 const struct icmp6hdr *hp;
36 struct icmp6hdr _hdr;
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37
38 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
39 if (hp == NULL)
09f263cd 40 return false;
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41 tuple->dst.u.icmp.type = hp->icmp6_type;
42 tuple->src.u.icmp.id = hp->icmp6_identifier;
43 tuple->dst.u.icmp.code = hp->icmp6_code;
44
09f263cd 45 return true;
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46}
47
c1d10adb 48/* Add 1; spaces filled with 0. */
7cc3864d 49static const u_int8_t invmap[] = {
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50 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
51 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
a51f42f3
EL
52 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_REPLY + 1,
53 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_QUERY +1
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54};
55
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56static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
57 const struct nf_conntrack_tuple *orig)
9fb9cbb1 58{
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59 int type = orig->dst.u.icmp.type - 128;
60 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
09f263cd 61 return false;
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62
63 tuple->src.u.icmp.id = orig->src.u.icmp.id;
64 tuple->dst.u.icmp.type = invmap[type] - 1;
65 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
09f263cd 66 return true;
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67}
68
69/* Print out the per-protocol part of the tuple. */
70static int icmpv6_print_tuple(struct seq_file *s,
71 const struct nf_conntrack_tuple *tuple)
72{
73 return seq_printf(s, "type=%u code=%u id=%u ",
74 tuple->dst.u.icmp.type,
75 tuple->dst.u.icmp.code,
76 ntohs(tuple->src.u.icmp.id));
77}
78
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79/* Returns verdict for packet, or -1 for invalid. */
80static int icmpv6_packet(struct nf_conn *ct,
81 const struct sk_buff *skb,
82 unsigned int dataoff,
83 enum ip_conntrack_info ctinfo,
76108cea 84 u_int8_t pf,
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85 unsigned int hooknum)
86{
87 /* Try to delete connection immediately after all replies:
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88 won't actually vanish as we still have skb, and del_timer
89 means this will only run once even if count hits zero twice
90 (theoretically possible with SMP) */
9fb9cbb1 91 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
51091764 92 if (atomic_dec_and_test(&ct->proto.icmp.count))
718d4ad9 93 nf_ct_kill_acct(ct, ctinfo, skb);
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94 } else {
95 atomic_inc(&ct->proto.icmp.count);
a71996fc 96 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct);
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97 nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout);
98 }
99
100 return NF_ACCEPT;
101}
102
103/* Called when a new connection for this protocol found. */
09f263cd
JE
104static bool icmpv6_new(struct nf_conn *ct, const struct sk_buff *skb,
105 unsigned int dataoff)
9fb9cbb1 106{
7cc3864d 107 static const u_int8_t valid_new[] = {
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108 [ICMPV6_ECHO_REQUEST - 128] = 1,
109 [ICMPV6_NI_QUERY - 128] = 1
110 };
c88130bc 111 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
9fb9cbb1 112
f16c9107 113 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
9fb9cbb1 114 /* Can't create a new ICMPv6 `conn' with this. */
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115 pr_debug("icmpv6: can't create new conn with type %u\n",
116 type + 128);
3c9fba65 117 nf_ct_dump_tuple_ipv6(&ct->tuplehash[0].tuple);
09f263cd 118 return false;
9fb9cbb1 119 }
c88130bc 120 atomic_set(&ct->proto.icmp.count, 0);
09f263cd 121 return true;
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122}
123
9fb9cbb1 124static int
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125icmpv6_error_message(struct net *net,
126 struct sk_buff *skb,
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127 unsigned int icmp6off,
128 enum ip_conntrack_info *ctinfo,
129 unsigned int hooknum)
130{
131 struct nf_conntrack_tuple intuple, origtuple;
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132 const struct nf_conntrack_tuple_hash *h;
133 const struct nf_conntrack_l4proto *inproto;
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134
135 NF_CT_ASSERT(skb->nfct == NULL);
136
9fb9cbb1 137 /* Are they talking about one of our connections? */
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138 if (!nf_ct_get_tuplepr(skb,
139 skb_network_offset(skb)
140 + sizeof(struct ipv6hdr)
141 + sizeof(struct icmp6hdr),
142 PF_INET6, &origtuple)) {
0d53778e 143 pr_debug("icmpv6_error: Can't get tuple\n");
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144 return -NF_ACCEPT;
145 }
146
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147 /* rcu_read_lock()ed by nf_hook_slow */
148 inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum);
149
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150 /* Ordinarily, we'd expect the inverted tupleproto, but it's
151 been preserved inside the ICMP. */
152 if (!nf_ct_invert_tuple(&intuple, &origtuple,
153 &nf_conntrack_l3proto_ipv6, inproto)) {
0d53778e 154 pr_debug("icmpv6_error: Can't invert tuple\n");
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155 return -NF_ACCEPT;
156 }
157
158 *ctinfo = IP_CT_RELATED;
159
74c51a14 160 h = nf_conntrack_find_get(net, &intuple);
9fb9cbb1 161 if (!h) {
0d53778e 162 pr_debug("icmpv6_error: no match\n");
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163 return -NF_ACCEPT;
164 } else {
165 if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
166 *ctinfo += IP_CT_IS_REPLY;
167 }
168
169 /* Update skb to refer to this connection */
170 skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
171 skb->nfctinfo = *ctinfo;
172 return -NF_ACCEPT;
173}
174
175static int
74c51a14 176icmpv6_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
76108cea 177 enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
9fb9cbb1 178{
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179 const struct icmp6hdr *icmp6h;
180 struct icmp6hdr _ih;
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181
182 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
183 if (icmp6h == NULL) {
c2a2c7e0 184 if (LOG_INVALID(net, IPPROTO_ICMPV6))
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185 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
186 "nf_ct_icmpv6: short packet ");
187 return -NF_ACCEPT;
188 }
189
c04d0552 190 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
96f6bf82 191 nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
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192 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
193 "nf_ct_icmpv6: ICMPv6 checksum failed\n");
194 return -NF_ACCEPT;
195 }
196
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197 /* is not error message ? */
198 if (icmp6h->icmp6_type >= 128)
199 return NF_ACCEPT;
200
74c51a14 201 return icmpv6_error_message(net, skb, dataoff, ctinfo, hooknum);
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202}
203
e281db5c 204#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
c1d10adb
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205
206#include <linux/netfilter/nfnetlink.h>
207#include <linux/netfilter/nfnetlink_conntrack.h>
fdf70832 208static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
c1d10adb
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209 const struct nf_conntrack_tuple *t)
210{
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211 NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
212 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
213 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
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214
215 return 0;
216
df6fb868 217nla_put_failure:
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218 return -1;
219}
220
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221static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
222 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
223 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
224 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
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225};
226
fdf70832 227static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
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228 struct nf_conntrack_tuple *tuple)
229{
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230 if (!tb[CTA_PROTO_ICMPV6_TYPE]
231 || !tb[CTA_PROTO_ICMPV6_CODE]
232 || !tb[CTA_PROTO_ICMPV6_ID])
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233 return -EINVAL;
234
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235 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
236 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
237 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
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238
239 if (tuple->dst.u.icmp.type < 128
240 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
241 || !invmap[tuple->dst.u.icmp.type - 128])
242 return -EINVAL;
243
244 return 0;
245}
246#endif
247
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248#ifdef CONFIG_SYSCTL
249static struct ctl_table_header *icmpv6_sysctl_header;
250static struct ctl_table icmpv6_sysctl_table[] = {
251 {
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252 .procname = "nf_conntrack_icmpv6_timeout",
253 .data = &nf_ct_icmpv6_timeout,
254 .maxlen = sizeof(unsigned int),
255 .mode = 0644,
6d9f239a 256 .proc_handler = proc_dointvec_jiffies,
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257 },
258 {
259 .ctl_name = 0
260 }
261};
262#endif /* CONFIG_SYSCTL */
263
61075af5 264struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
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265{
266 .l3proto = PF_INET6,
605dcad6 267 .l4proto = IPPROTO_ICMPV6,
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268 .name = "icmpv6",
269 .pkt_to_tuple = icmpv6_pkt_to_tuple,
270 .invert_tuple = icmpv6_invert_tuple,
271 .print_tuple = icmpv6_print_tuple,
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272 .packet = icmpv6_packet,
273 .new = icmpv6_new,
274 .error = icmpv6_error,
e281db5c 275#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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276 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
277 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
f73e924c 278 .nla_policy = icmpv6_nla_policy,
c1d10adb 279#endif
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280#ifdef CONFIG_SYSCTL
281 .ctl_table_header = &icmpv6_sysctl_header,
282 .ctl_table = icmpv6_sysctl_table,
283#endif
9fb9cbb1 284};