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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> | |
27 | ||
933a41e7 | 28 | static unsigned long nf_ct_icmpv6_timeout __read_mostly = 30*HZ; |
9fb9cbb1 | 29 | |
9fb9cbb1 YK |
30 | static int icmpv6_pkt_to_tuple(const struct sk_buff *skb, |
31 | unsigned int dataoff, | |
32 | struct nf_conntrack_tuple *tuple) | |
33 | { | |
34 | struct icmp6hdr _hdr, *hp; | |
35 | ||
36 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); | |
37 | if (hp == NULL) | |
38 | return 0; | |
39 | tuple->dst.u.icmp.type = hp->icmp6_type; | |
40 | tuple->src.u.icmp.id = hp->icmp6_identifier; | |
41 | tuple->dst.u.icmp.code = hp->icmp6_code; | |
42 | ||
43 | return 1; | |
44 | } | |
45 | ||
c1d10adb PNA |
46 | /* Add 1; spaces filled with 0. */ |
47 | static u_int8_t invmap[] = { | |
48 | [ICMPV6_ECHO_REQUEST - 128] = ICMPV6_ECHO_REPLY + 1, | |
49 | [ICMPV6_ECHO_REPLY - 128] = ICMPV6_ECHO_REQUEST + 1, | |
50 | [ICMPV6_NI_QUERY - 128] = ICMPV6_NI_QUERY + 1, | |
51 | [ICMPV6_NI_REPLY - 128] = ICMPV6_NI_REPLY +1 | |
52 | }; | |
53 | ||
9fb9cbb1 YK |
54 | static int icmpv6_invert_tuple(struct nf_conntrack_tuple *tuple, |
55 | const struct nf_conntrack_tuple *orig) | |
56 | { | |
f16c9107 YK |
57 | int type = orig->dst.u.icmp.type - 128; |
58 | if (type < 0 || type >= sizeof(invmap) || !invmap[type]) | |
9fb9cbb1 YK |
59 | return 0; |
60 | ||
61 | tuple->src.u.icmp.id = orig->src.u.icmp.id; | |
62 | tuple->dst.u.icmp.type = invmap[type] - 1; | |
63 | tuple->dst.u.icmp.code = orig->dst.u.icmp.code; | |
64 | return 1; | |
65 | } | |
66 | ||
67 | /* Print out the per-protocol part of the tuple. */ | |
68 | static int icmpv6_print_tuple(struct seq_file *s, | |
69 | const struct nf_conntrack_tuple *tuple) | |
70 | { | |
71 | return seq_printf(s, "type=%u code=%u id=%u ", | |
72 | tuple->dst.u.icmp.type, | |
73 | tuple->dst.u.icmp.code, | |
74 | ntohs(tuple->src.u.icmp.id)); | |
75 | } | |
76 | ||
77 | /* Print out the private part of the conntrack. */ | |
78 | static int icmpv6_print_conntrack(struct seq_file *s, | |
79 | const struct nf_conn *conntrack) | |
80 | { | |
81 | return 0; | |
82 | } | |
83 | ||
84 | /* Returns verdict for packet, or -1 for invalid. */ | |
85 | static int icmpv6_packet(struct nf_conn *ct, | |
86 | const struct sk_buff *skb, | |
87 | unsigned int dataoff, | |
88 | enum ip_conntrack_info ctinfo, | |
89 | int pf, | |
90 | unsigned int hooknum) | |
91 | { | |
92 | /* Try to delete connection immediately after all replies: | |
1ab1457c YH |
93 | won't actually vanish as we still have skb, and del_timer |
94 | means this will only run once even if count hits zero twice | |
95 | (theoretically possible with SMP) */ | |
9fb9cbb1 YK |
96 | if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY) { |
97 | if (atomic_dec_and_test(&ct->proto.icmp.count) | |
98 | && del_timer(&ct->timeout)) | |
99 | ct->timeout.function((unsigned long)ct); | |
100 | } else { | |
101 | atomic_inc(&ct->proto.icmp.count); | |
102 | nf_conntrack_event_cache(IPCT_PROTOINFO_VOLATILE, skb); | |
103 | nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmpv6_timeout); | |
104 | } | |
105 | ||
106 | return NF_ACCEPT; | |
107 | } | |
108 | ||
109 | /* Called when a new connection for this protocol found. */ | |
110 | static int icmpv6_new(struct nf_conn *conntrack, | |
111 | const struct sk_buff *skb, | |
112 | unsigned int dataoff) | |
113 | { | |
114 | static u_int8_t valid_new[] = { | |
115 | [ICMPV6_ECHO_REQUEST - 128] = 1, | |
116 | [ICMPV6_NI_QUERY - 128] = 1 | |
117 | }; | |
f16c9107 | 118 | int type = conntrack->tuplehash[0].tuple.dst.u.icmp.type - 128; |
9fb9cbb1 | 119 | |
f16c9107 | 120 | if (type < 0 || type >= sizeof(valid_new) || !valid_new[type]) { |
9fb9cbb1 | 121 | /* Can't create a new ICMPv6 `conn' with this. */ |
0d53778e PM |
122 | pr_debug("icmpv6: can't create new conn with type %u\n", |
123 | type + 128); | |
9fb9cbb1 YK |
124 | NF_CT_DUMP_TUPLE(&conntrack->tuplehash[0].tuple); |
125 | return 0; | |
126 | } | |
127 | atomic_set(&conntrack->proto.icmp.count, 0); | |
128 | return 1; | |
129 | } | |
130 | ||
9fb9cbb1 YK |
131 | static int |
132 | icmpv6_error_message(struct sk_buff *skb, | |
133 | unsigned int icmp6off, | |
134 | enum ip_conntrack_info *ctinfo, | |
135 | unsigned int hooknum) | |
136 | { | |
137 | struct nf_conntrack_tuple intuple, origtuple; | |
138 | struct nf_conntrack_tuple_hash *h; | |
605dcad6 | 139 | struct nf_conntrack_l4proto *inproto; |
9fb9cbb1 YK |
140 | |
141 | NF_CT_ASSERT(skb->nfct == NULL); | |
142 | ||
9fb9cbb1 | 143 | /* Are they talking about one of our connections? */ |
e2a3123f YK |
144 | if (!nf_ct_get_tuplepr(skb, |
145 | skb_network_offset(skb) | |
146 | + sizeof(struct ipv6hdr) | |
147 | + sizeof(struct icmp6hdr), | |
148 | PF_INET6, &origtuple)) { | |
0d53778e | 149 | pr_debug("icmpv6_error: Can't get tuple\n"); |
9fb9cbb1 YK |
150 | return -NF_ACCEPT; |
151 | } | |
152 | ||
e2a3123f YK |
153 | /* rcu_read_lock()ed by nf_hook_slow */ |
154 | inproto = __nf_ct_l4proto_find(PF_INET6, origtuple.dst.protonum); | |
155 | ||
9fb9cbb1 YK |
156 | /* Ordinarily, we'd expect the inverted tupleproto, but it's |
157 | been preserved inside the ICMP. */ | |
158 | if (!nf_ct_invert_tuple(&intuple, &origtuple, | |
159 | &nf_conntrack_l3proto_ipv6, inproto)) { | |
0d53778e | 160 | pr_debug("icmpv6_error: Can't invert tuple\n"); |
9fb9cbb1 YK |
161 | return -NF_ACCEPT; |
162 | } | |
163 | ||
164 | *ctinfo = IP_CT_RELATED; | |
165 | ||
330f7db5 | 166 | h = nf_conntrack_find_get(&intuple); |
9fb9cbb1 | 167 | if (!h) { |
0d53778e | 168 | pr_debug("icmpv6_error: no match\n"); |
9fb9cbb1 YK |
169 | return -NF_ACCEPT; |
170 | } else { | |
171 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) | |
172 | *ctinfo += IP_CT_IS_REPLY; | |
173 | } | |
174 | ||
175 | /* Update skb to refer to this connection */ | |
176 | skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general; | |
177 | skb->nfctinfo = *ctinfo; | |
178 | return -NF_ACCEPT; | |
179 | } | |
180 | ||
181 | static int | |
182 | icmpv6_error(struct sk_buff *skb, unsigned int dataoff, | |
183 | enum ip_conntrack_info *ctinfo, int pf, unsigned int hooknum) | |
184 | { | |
185 | struct icmp6hdr _ih, *icmp6h; | |
186 | ||
187 | icmp6h = skb_header_pointer(skb, dataoff, sizeof(_ih), &_ih); | |
188 | if (icmp6h == NULL) { | |
189 | if (LOG_INVALID(IPPROTO_ICMPV6)) | |
190 | nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL, | |
191 | "nf_ct_icmpv6: short packet "); | |
192 | return -NF_ACCEPT; | |
193 | } | |
194 | ||
39a27a35 | 195 | if (nf_conntrack_checksum && hooknum == NF_IP6_PRE_ROUTING && |
96f6bf82 | 196 | nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) { |
9fb9cbb1 YK |
197 | nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL, |
198 | "nf_ct_icmpv6: ICMPv6 checksum failed\n"); | |
199 | return -NF_ACCEPT; | |
200 | } | |
201 | ||
9fb9cbb1 YK |
202 | /* is not error message ? */ |
203 | if (icmp6h->icmp6_type >= 128) | |
204 | return NF_ACCEPT; | |
205 | ||
206 | return icmpv6_error_message(skb, dataoff, ctinfo, hooknum); | |
207 | } | |
208 | ||
e281db5c | 209 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
210 | |
211 | #include <linux/netfilter/nfnetlink.h> | |
212 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
213 | static int icmpv6_tuple_to_nfattr(struct sk_buff *skb, | |
214 | const struct nf_conntrack_tuple *t) | |
215 | { | |
df6fb868 | 216 | NLA_PUT(skb, CTA_PROTO_ICMPV6_ID, sizeof(u_int16_t), |
c1d10adb | 217 | &t->src.u.icmp.id); |
df6fb868 | 218 | NLA_PUT(skb, CTA_PROTO_ICMPV6_TYPE, sizeof(u_int8_t), |
c1d10adb | 219 | &t->dst.u.icmp.type); |
df6fb868 | 220 | NLA_PUT(skb, CTA_PROTO_ICMPV6_CODE, sizeof(u_int8_t), |
c1d10adb PNA |
221 | &t->dst.u.icmp.code); |
222 | ||
223 | return 0; | |
224 | ||
df6fb868 | 225 | nla_put_failure: |
c1d10adb PNA |
226 | return -1; |
227 | } | |
228 | ||
df6fb868 PM |
229 | static const size_t cta_min_proto[CTA_PROTO_MAX+1] = { |
230 | [CTA_PROTO_ICMPV6_TYPE] = sizeof(u_int8_t), | |
231 | [CTA_PROTO_ICMPV6_CODE] = sizeof(u_int8_t), | |
232 | [CTA_PROTO_ICMPV6_ID] = sizeof(u_int16_t) | |
c1d10adb PNA |
233 | }; |
234 | ||
df6fb868 | 235 | static int icmpv6_nfattr_to_tuple(struct nlattr *tb[], |
c1d10adb PNA |
236 | struct nf_conntrack_tuple *tuple) |
237 | { | |
df6fb868 PM |
238 | if (!tb[CTA_PROTO_ICMPV6_TYPE] |
239 | || !tb[CTA_PROTO_ICMPV6_CODE] | |
240 | || !tb[CTA_PROTO_ICMPV6_ID]) | |
c1d10adb PNA |
241 | return -EINVAL; |
242 | ||
243 | if (nfattr_bad_size(tb, CTA_PROTO_MAX, cta_min_proto)) | |
244 | return -EINVAL; | |
245 | ||
246 | tuple->dst.u.icmp.type = | |
df6fb868 | 247 | *(u_int8_t *)nla_data(tb[CTA_PROTO_ICMPV6_TYPE]); |
c1d10adb | 248 | tuple->dst.u.icmp.code = |
df6fb868 | 249 | *(u_int8_t *)nla_data(tb[CTA_PROTO_ICMPV6_CODE]); |
c1d10adb | 250 | tuple->src.u.icmp.id = |
df6fb868 | 251 | *(__be16 *)nla_data(tb[CTA_PROTO_ICMPV6_ID]); |
c1d10adb PNA |
252 | |
253 | if (tuple->dst.u.icmp.type < 128 | |
254 | || tuple->dst.u.icmp.type - 128 >= sizeof(invmap) | |
255 | || !invmap[tuple->dst.u.icmp.type - 128]) | |
256 | return -EINVAL; | |
257 | ||
258 | return 0; | |
259 | } | |
260 | #endif | |
261 | ||
933a41e7 PM |
262 | #ifdef CONFIG_SYSCTL |
263 | static struct ctl_table_header *icmpv6_sysctl_header; | |
264 | static struct ctl_table icmpv6_sysctl_table[] = { | |
265 | { | |
266 | .ctl_name = NET_NF_CONNTRACK_ICMPV6_TIMEOUT, | |
267 | .procname = "nf_conntrack_icmpv6_timeout", | |
268 | .data = &nf_ct_icmpv6_timeout, | |
269 | .maxlen = sizeof(unsigned int), | |
270 | .mode = 0644, | |
271 | .proc_handler = &proc_dointvec_jiffies, | |
272 | }, | |
273 | { | |
274 | .ctl_name = 0 | |
275 | } | |
276 | }; | |
277 | #endif /* CONFIG_SYSCTL */ | |
278 | ||
61075af5 | 279 | struct nf_conntrack_l4proto nf_conntrack_l4proto_icmpv6 __read_mostly = |
9fb9cbb1 YK |
280 | { |
281 | .l3proto = PF_INET6, | |
605dcad6 | 282 | .l4proto = IPPROTO_ICMPV6, |
9fb9cbb1 YK |
283 | .name = "icmpv6", |
284 | .pkt_to_tuple = icmpv6_pkt_to_tuple, | |
285 | .invert_tuple = icmpv6_invert_tuple, | |
286 | .print_tuple = icmpv6_print_tuple, | |
287 | .print_conntrack = icmpv6_print_conntrack, | |
288 | .packet = icmpv6_packet, | |
289 | .new = icmpv6_new, | |
290 | .error = icmpv6_error, | |
e281db5c | 291 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
c1d10adb PNA |
292 | .tuple_to_nfattr = icmpv6_tuple_to_nfattr, |
293 | .nfattr_to_tuple = icmpv6_nfattr_to_tuple, | |
294 | #endif | |
933a41e7 PM |
295 | #ifdef CONFIG_SYSCTL |
296 | .ctl_table_header = &icmpv6_sysctl_header, | |
297 | .ctl_table = icmpv6_sysctl_table, | |
298 | #endif | |
9fb9cbb1 | 299 | }; |