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9fb9cbb1 YK |
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> | |
9fb9cbb1 YK |
10 | */ |
11 | ||
12 | #include <linux/types.h> | |
9fb9cbb1 YK |
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> |
9fb9cbb1 YK |
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 | 29 | static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ; |
9fb9cbb1 | 30 | |
09f263cd JE |
31 | static bool icmpv6_pkt_to_tuple(const struct sk_buff *skb, |
32 | unsigned int dataoff, | |
33 | struct nf_conntrack_tuple *tuple) | |
9fb9cbb1 | 34 | { |
7cc3864d JE |
35 | const struct icmp6hdr *hp; |
36 | struct icmp6hdr _hdr; | |
9fb9cbb1 YK |
37 | |
38 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
39 | if (hp == NULL) | |
09f263cd | 40 | return false; |
9fb9cbb1 YK |
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; |
9fb9cbb1 YK |
46 | } |
47 | ||
c1d10adb | 48 | /* Add 1; spaces filled with 0. */ |
7cc3864d | 49 | static const u_int8_t invmap[] = { |
c1d10adb PNA |
50 | [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1, |
51 | [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1, | |
52 | [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1, | |
53 | [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1 | |
54 | }; | |
55 | ||
09f263cd JE |
56 | static bool icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple, |
57 | const struct nf_conntrack_tuple *orig) | |
9fb9cbb1 | 58 | { |
f16c9107 YK |
59 | int type = orig->dst.u.icmp.type - 128; |
60 | if (type < 0 || type >= sizeof(invmap) || !invmap[type]) | |
09f263cd | 61 | return false; |
9fb9cbb1 YK |
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; |
9fb9cbb1 YK |
67 | } |
68 | ||
69 | /* Print out the per-protocol part of the tuple. */ | |
70 | static 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 | ||
9fb9cbb1 YK |
79 | /* Returns verdict for packet, or -1 for invalid. */ |
80 | static 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, |
9fb9cbb1 YK |
85 | unsigned int hooknum) |
86 | { | |
87 | /* Try to delete connection immediately after all replies: | |
1ab1457c YH |
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); |
9fb9cbb1 YK |
94 | } else { |
95 | atomic_inc(&ct->proto.icmp.count); | |
a71996fc | 96 | nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, ct); |
9fb9cbb1 YK |
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 |
104 | static 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[] = { |
9fb9cbb1 YK |
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. */ |
0d53778e PM |
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; |
9fb9cbb1 YK |
122 | } |
123 | ||
9fb9cbb1 | 124 | static int |
74c51a14 AD |
125 | icmpv6_error_message(struct net *net, |
126 | struct sk_buff *skb, | |
9fb9cbb1 YK |
127 | unsigned int icmp6off, |
128 | enum ip_conntrack_info *ctinfo, | |
129 | unsigned int hooknum) | |
130 | { | |
131 | struct nf_conntrack_tuple intuple, origtuple; | |
7cc3864d JE |
132 | const struct nf_conntrack_tuple_hash *h; |
133 | const struct nf_conntrack_l4proto *inproto; | |
9fb9cbb1 YK |
134 | |
135 | NF_CT_ASSERT(skb->nfct == NULL); | |
136 | ||
9fb9cbb1 | 137 | /* Are they talking about one of our connections? */ |
e2a3123f YK |
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"); |
9fb9cbb1 YK |
144 | return -NF_ACCEPT; |
145 | } | |
146 | ||
e2a3123f YK |
147 | /* rcu_read_lock()ed by nf_hook_slow */ |
148 | inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum); | |
149 | ||
9fb9cbb1 YK |
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"); |
9fb9cbb1 YK |
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"); |
9fb9cbb1 YK |
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 | ||
175 | static int | |
74c51a14 | 176 | icmpv6_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 | { |
7cc3864d JE |
179 | const struct icmp6hdr *icmp6h; |
180 | struct icmp6hdr _ih; | |
9fb9cbb1 YK |
181 | |
182 | icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih); | |
183 | if (icmp6h == NULL) { | |
c2a2c7e0 | 184 | if (LOG_INVALID(net, IPPROTO_ICMPV6)) |
9fb9cbb1 YK |
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)) { |
9fb9cbb1 YK |
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 | ||
9fb9cbb1 YK |
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); |
9fb9cbb1 YK |
202 | } |
203 | ||
e281db5c | 204 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
205 | |
206 | #include <linux/netfilter/nfnetlink.h> | |
207 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
fdf70832 | 208 | static int icmpv6_tuple_to_nlattr(struct sk_buff *skb, |
c1d10adb PNA |
209 | const struct nf_conntrack_tuple *t) |
210 | { | |
77236b6e PM |
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); | |
c1d10adb PNA |
214 | |
215 | return 0; | |
216 | ||
df6fb868 | 217 | nla_put_failure: |
c1d10adb PNA |
218 | return -1; |
219 | } | |
220 | ||
f73e924c PM |
221 | static 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 }, | |
c1d10adb PNA |
225 | }; |
226 | ||
fdf70832 | 227 | static int icmpv6_nlattr_to_tuple(struct nlattr *tb[], |
c1d10adb PNA |
228 | struct nf_conntrack_tuple *tuple) |
229 | { | |
df6fb868 PM |
230 | if (!tb[CTA_PROTO_ICMPV6_TYPE] |
231 | || !tb[CTA_PROTO_ICMPV6_CODE] | |
232 | || !tb[CTA_PROTO_ICMPV6_ID]) | |
c1d10adb PNA |
233 | return -EINVAL; |
234 | ||
77236b6e PM |
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]); | |
c1d10adb PNA |
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 | ||
933a41e7 PM |
248 | #ifdef CONFIG_SYSCTL |
249 | static struct ctl_table_header *icmpv6_sysctl_header; | |
250 | static struct ctl_table icmpv6_sysctl_table[] = { | |
251 | { | |
933a41e7 PM |
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, |
933a41e7 PM |
257 | }, |
258 | { | |
259 | .ctl_name = 0 | |
260 | } | |
261 | }; | |
262 | #endif /* CONFIG_SYSCTL */ | |
263 | ||
61075af5 | 264 | struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly = |
9fb9cbb1 YK |
265 | { |
266 | .l3proto = PF_INET6, | |
605dcad6 | 267 | .l4proto = IPPROTO_ICMPV6, |
9fb9cbb1 YK |
268 | .name = "icmpv6", |
269 | .pkt_to_tuple = icmpv6_pkt_to_tuple, | |
270 | .invert_tuple = icmpv6_invert_tuple, | |
271 | .print_tuple = icmpv6_print_tuple, | |
9fb9cbb1 YK |
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) |
fdf70832 PM |
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 |
933a41e7 PM |
280 | #ifdef CONFIG_SYSCTL |
281 | .ctl_table_header = &icmpv6_sysctl_header, | |
282 | .ctl_table = icmpv6_sysctl_table, | |
283 | #endif | |
9fb9cbb1 | 284 | }; |