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[NETFILTER]: nf_{conntrack,nat}_proto_gre: annotate with const
[thirdparty/kernel/stable.git] / net / ipv6 / netfilter / nf_conntrack_proto_icmpv6.c
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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
933a41e7 29static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ;
9fb9cbb1 30
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31static int icmpv6_pkt_to_tuple(const struct sk_buff *skb,
32 unsigned int dataoff,
33 struct nf_conntrack_tuple *tuple)
34{
35 struct icmp6hdr _hdr, *hp;
36
37 hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
38 if (hp == NULL)
39 return 0;
40 tuple->dst.u.icmp.type = hp->icmp6_type;
41 tuple->src.u.icmp.id = hp->icmp6_identifier;
42 tuple->dst.u.icmp.code = hp->icmp6_code;
43
44 return 1;
45}
46
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47/* Add 1; spaces filled with 0. */
48static u_int8_t invmap[] = {
49 [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1,
50 [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1,
51 [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1,
52 [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1
53};
54
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55static int icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple,
56 const struct nf_conntrack_tuple *orig)
57{
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58 int type = orig->dst.u.icmp.type - 128;
59 if (type < 0 || type >= sizeof(invmap) || !invmap[type])
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60 return 0;
61
62 tuple->src.u.icmp.id = orig->src.u.icmp.id;
63 tuple->dst.u.icmp.type = invmap[type] - 1;
64 tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
65 return 1;
66}
67
68/* Print out the per-protocol part of the tuple. */
69static int icmpv6_print_tuple(struct seq_file *s,
70 const struct nf_conntrack_tuple *tuple)
71{
72 return seq_printf(s, "type=%u code=%u id=%u ",
73 tuple->dst.u.icmp.type,
74 tuple->dst.u.icmp.code,
75 ntohs(tuple->src.u.icmp.id));
76}
77
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78/* Returns verdict for packet, or -1 for invalid. */
79static int icmpv6_packet(struct nf_conn *ct,
80 const struct sk_buff *skb,
81 unsigned int dataoff,
82 enum ip_conntrack_info ctinfo,
83 int pf,
84 unsigned int hooknum)
85{
86 /* Try to delete connection immediately after all replies:
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87 won't actually vanish as we still have skb, and del_timer
88 means this will only run once even if count hits zero twice
89 (theoretically possible with SMP) */
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90 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) {
91 if (atomic_dec_and_test(&ct->proto.icmp.count)
92 && del_timer(&ct->timeout))
93 ct->timeout.function((unsigned long)ct);
94 } else {
95 atomic_inc(&ct->proto.icmp.count);
96 nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb);
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. */
c88130bc 104static int icmpv6_new(struct nf_conn *ct,
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105 const struct sk_buff *skb,
106 unsigned int dataoff)
107{
108 static u_int8_t valid_new[] = {
109 [ICMPV6_ECHO_REQUEST - 128] = 1,
110 [ICMPV6_NI_QUERY - 128] = 1
111 };
c88130bc 112 int type = ct->tuplehash[0].tuple.dst.u.icmp.type - 128;
9fb9cbb1 113
f16c9107 114 if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) {
9fb9cbb1 115 /* Can't create a new ICMPv6 `conn' with this. */
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116 pr_debug("icmpv6: can't create new conn with type %u\n",
117 type + 128);
c88130bc 118 NF_CT_DUMP_TUPLE(&ct->tuplehash[0].tuple);
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119 return 0;
120 }
c88130bc 121 atomic_set(&ct->proto.icmp.count, 0);
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122 return 1;
123}
124
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125static int
126icmpv6_error_message(struct sk_buff *skb,
127 unsigned int icmp6off,
128 enum ip_conntrack_info *ctinfo,
129 unsigned int hooknum)
130{
131 struct nf_conntrack_tuple intuple, origtuple;
132 struct nf_conntrack_tuple_hash *h;
605dcad6 133 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
330f7db5 160 h = nf_conntrack_find_get(&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
176icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
177 enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum)
178{
179 struct icmp6hdr _ih, *icmp6h;
180
181 icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih);
182 if (icmp6h == NULL) {
183 if (LOG_INVALID(IPPROTO_ICMPV6))
184 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
185 "nf_ct_icmpv6: short packet ");
186 return -NF_ACCEPT;
187 }
188
6e23ae2a 189 if (nf_conntrack_checksum && hooknum == NF_INET_PRE_ROUTING &&
96f6bf82 190 nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
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191 nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
192 "nf_ct_icmpv6: ICMPv6 checksum failed\n");
193 return -NF_ACCEPT;
194 }
195
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196 /* is not error message ? */
197 if (icmp6h->icmp6_type >= 128)
198 return NF_ACCEPT;
199
200 return icmpv6_error_message(skb, dataoff, ctinfo, hooknum);
201}
202
e281db5c 203#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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204
205#include <linux/netfilter/nfnetlink.h>
206#include <linux/netfilter/nfnetlink_conntrack.h>
fdf70832 207static int icmpv6_tuple_to_nlattr(struct sk_buff *skb,
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208 const struct nf_conntrack_tuple *t)
209{
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210 NLA_PUT_BE16(skb, CTA_PROTO_ICMPV6_ID, t->src.u.icmp.id);
211 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_TYPE, t->dst.u.icmp.type);
212 NLA_PUT_U8(skb, CTA_PROTO_ICMPV6_CODE, t->dst.u.icmp.code);
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213
214 return 0;
215
df6fb868 216nla_put_failure:
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217 return -1;
218}
219
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220static const struct nla_policy icmpv6_nla_policy[CTA_PROTO_MAX+1] = {
221 [CTA_PROTO_ICMPV6_TYPE] = { .type = NLA_U8 },
222 [CTA_PROTO_ICMPV6_CODE] = { .type = NLA_U8 },
223 [CTA_PROTO_ICMPV6_ID] = { .type = NLA_U16 },
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224};
225
fdf70832 226static int icmpv6_nlattr_to_tuple(struct nlattr *tb[],
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227 struct nf_conntrack_tuple *tuple)
228{
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229 if (!tb[CTA_PROTO_ICMPV6_TYPE]
230 || !tb[CTA_PROTO_ICMPV6_CODE]
231 || !tb[CTA_PROTO_ICMPV6_ID])
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232 return -EINVAL;
233
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234 tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMPV6_TYPE]);
235 tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMPV6_CODE]);
236 tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMPV6_ID]);
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237
238 if (tuple->dst.u.icmp.type < 128
239 || tuple->dst.u.icmp.type - 128 >= sizeof(invmap)
240 || !invmap[tuple->dst.u.icmp.type - 128])
241 return -EINVAL;
242
243 return 0;
244}
245#endif
246
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247#ifdef CONFIG_SYSCTL
248static struct ctl_table_header *icmpv6_sysctl_header;
249static struct ctl_table icmpv6_sysctl_table[] = {
250 {
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251 .procname = "nf_conntrack_icmpv6_timeout",
252 .data = &nf_ct_icmpv6_timeout,
253 .maxlen = sizeof(unsigned int),
254 .mode = 0644,
255 .proc_handler = &proc_dointvec_jiffies,
256 },
257 {
258 .ctl_name = 0
259 }
260};
261#endif /* CONFIG_SYSCTL */
262
61075af5 263struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly =
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264{
265 .l3proto = PF_INET6,
605dcad6 266 .l4proto = IPPROTO_ICMPV6,
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267 .name = "icmpv6",
268 .pkt_to_tuple = icmpv6_pkt_to_tuple,
269 .invert_tuple = icmpv6_invert_tuple,
270 .print_tuple = icmpv6_print_tuple,
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271 .packet = icmpv6_packet,
272 .new = icmpv6_new,
273 .error = icmpv6_error,
e281db5c 274#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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275 .tuple_to_nlattr = icmpv6_tuple_to_nlattr,
276 .nlattr_to_tuple = icmpv6_nlattr_to_tuple,
f73e924c 277 .nla_policy = icmpv6_nla_policy,
c1d10adb 278#endif
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279#ifdef CONFIG_SYSCTL
280 .ctl_table_header = &icmpv6_sysctl_header,
281 .ctl_table = icmpv6_sysctl_table,
282#endif
9fb9cbb1 283};