]>
Commit | Line | Data |
---|---|---|
9fb9cbb1 YK |
1 | /* (C) 1999-2001 Paul `Rusty' Russell |
2 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
f229f6ce | 3 | * (C) 2006-2010 Patrick McHardy <kaber@trash.net> |
9fb9cbb1 YK |
4 | * |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
9fb9cbb1 YK |
8 | */ |
9 | ||
10 | #include <linux/types.h> | |
9fb9cbb1 YK |
11 | #include <linux/timer.h> |
12 | #include <linux/netfilter.h> | |
13 | #include <linux/in.h> | |
14 | #include <linux/icmp.h> | |
15 | #include <linux/seq_file.h> | |
16 | #include <net/ip.h> | |
17 | #include <net/checksum.h> | |
18 | #include <linux/netfilter_ipv4.h> | |
19 | #include <net/netfilter/nf_conntrack_tuple.h> | |
605dcad6 | 20 | #include <net/netfilter/nf_conntrack_l4proto.h> |
9fb9cbb1 | 21 | #include <net/netfilter/nf_conntrack_core.h> |
5d0aa2cc | 22 | #include <net/netfilter/nf_conntrack_zones.h> |
f01ffbd6 | 23 | #include <net/netfilter/nf_log.h> |
9fb9cbb1 | 24 | |
71320afc | 25 | static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ; |
9fb9cbb1 | 26 | |
4b626b9c G |
27 | static inline struct nf_icmp_net *icmp_pernet(struct net *net) |
28 | { | |
29 | return &net->ct.nf_ct_proto.icmp; | |
30 | } | |
31 | ||
09f263cd | 32 | static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff, |
a31f1adc | 33 | struct net *net, struct nf_conntrack_tuple *tuple) |
9fb9cbb1 | 34 | { |
7cc3864d JE |
35 | const struct icmphdr *hp; |
36 | struct icmphdr _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 | |
42 | tuple->dst.u.icmp.type = hp->type; | |
43 | tuple->src.u.icmp.id = hp->un.echo.id; | |
44 | tuple->dst.u.icmp.code = hp->code; | |
45 | ||
09f263cd | 46 | return true; |
9fb9cbb1 YK |
47 | } |
48 | ||
c1d10adb PNA |
49 | /* Add 1; spaces filled with 0. */ |
50 | static const u_int8_t invmap[] = { | |
51 | [ICMP_ECHO] = ICMP_ECHOREPLY + 1, | |
52 | [ICMP_ECHOREPLY] = ICMP_ECHO + 1, | |
53 | [ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1, | |
54 | [ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1, | |
55 | [ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1, | |
56 | [ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1, | |
57 | [ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1, | |
58 | [ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1 | |
59 | }; | |
60 | ||
09f263cd JE |
61 | static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple, |
62 | const struct nf_conntrack_tuple *orig) | |
9fb9cbb1 | 63 | { |
3666ed1c JP |
64 | if (orig->dst.u.icmp.type >= sizeof(invmap) || |
65 | !invmap[orig->dst.u.icmp.type]) | |
09f263cd | 66 | return false; |
9fb9cbb1 YK |
67 | |
68 | tuple->src.u.icmp.id = orig->src.u.icmp.id; | |
69 | tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1; | |
70 | tuple->dst.u.icmp.code = orig->dst.u.icmp.code; | |
09f263cd | 71 | return true; |
9fb9cbb1 YK |
72 | } |
73 | ||
74 | /* Print out the per-protocol part of the tuple. */ | |
824f1fbe | 75 | static void icmp_print_tuple(struct seq_file *s, |
9fb9cbb1 YK |
76 | const struct nf_conntrack_tuple *tuple) |
77 | { | |
824f1fbe JP |
78 | seq_printf(s, "type=%u code=%u id=%u ", |
79 | tuple->dst.u.icmp.type, | |
80 | tuple->dst.u.icmp.code, | |
81 | ntohs(tuple->src.u.icmp.id)); | |
9fb9cbb1 YK |
82 | } |
83 | ||
2c8503f5 PNA |
84 | static unsigned int *icmp_get_timeouts(struct net *net) |
85 | { | |
4b626b9c | 86 | return &icmp_pernet(net)->timeout; |
2c8503f5 PNA |
87 | } |
88 | ||
9fb9cbb1 YK |
89 | /* Returns verdict for packet, or -1 for invalid. */ |
90 | static int icmp_packet(struct nf_conn *ct, | |
91 | const struct sk_buff *skb, | |
92 | unsigned int dataoff, | |
93 | enum ip_conntrack_info ctinfo, | |
76108cea | 94 | u_int8_t pf, |
2c8503f5 PNA |
95 | unsigned int hooknum, |
96 | unsigned int *timeout) | |
9fb9cbb1 | 97 | { |
f87fb666 JK |
98 | /* Do not immediately delete the connection after the first |
99 | successful reply to avoid excessive conntrackd traffic | |
100 | and also to handle correctly ICMP echo reply duplicates. */ | |
2c8503f5 | 101 | nf_ct_refresh_acct(ct, ctinfo, skb, *timeout); |
9fb9cbb1 YK |
102 | |
103 | return NF_ACCEPT; | |
104 | } | |
105 | ||
106 | /* Called when a new connection for this protocol found. */ | |
09f263cd | 107 | static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb, |
2c8503f5 | 108 | unsigned int dataoff, unsigned int *timeouts) |
9fb9cbb1 | 109 | { |
c1d10adb PNA |
110 | static const u_int8_t valid_new[] = { |
111 | [ICMP_ECHO] = 1, | |
112 | [ICMP_TIMESTAMP] = 1, | |
113 | [ICMP_INFO_REQUEST] = 1, | |
114 | [ICMP_ADDRESS] = 1 | |
115 | }; | |
9fb9cbb1 | 116 | |
3666ed1c JP |
117 | if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new) || |
118 | !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) { | |
9fb9cbb1 | 119 | /* Can't create a new ICMP `conn' with this. */ |
0d53778e | 120 | pr_debug("icmp: can't create new conn with type %u\n", |
c88130bc | 121 | ct->tuplehash[0].tuple.dst.u.icmp.type); |
3c9fba65 | 122 | nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple); |
09f263cd | 123 | return false; |
9fb9cbb1 | 124 | } |
09f263cd | 125 | return true; |
9fb9cbb1 YK |
126 | } |
127 | ||
9fb9cbb1 YK |
128 | /* Returns conntrack if it dealt with ICMP, and filled in skb fields */ |
129 | static int | |
5d0aa2cc | 130 | icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb, |
e905a9ed | 131 | unsigned int hooknum) |
9fb9cbb1 YK |
132 | { |
133 | struct nf_conntrack_tuple innertuple, origtuple; | |
7cc3864d JE |
134 | const struct nf_conntrack_l4proto *innerproto; |
135 | const struct nf_conntrack_tuple_hash *h; | |
308ac914 | 136 | const struct nf_conntrack_zone *zone; |
11df4b76 | 137 | enum ip_conntrack_info ctinfo; |
5e8018fc | 138 | struct nf_conntrack_zone tmp; |
9fb9cbb1 | 139 | |
cb9c6836 | 140 | NF_CT_ASSERT(!skb_nfct(skb)); |
5e8018fc | 141 | zone = nf_ct_zone_tmpl(tmpl, skb, &tmp); |
9fb9cbb1 | 142 | |
e2a3123f YK |
143 | /* Are they talking about one of our connections? */ |
144 | if (!nf_ct_get_tuplepr(skb, | |
145 | skb_network_offset(skb) + ip_hdrlen(skb) | |
146 | + sizeof(struct icmphdr), | |
a31f1adc | 147 | PF_INET, net, &origtuple)) { |
e2a3123f | 148 | pr_debug("icmp_error_message: failed to get tuple\n"); |
9fb9cbb1 YK |
149 | return -NF_ACCEPT; |
150 | } | |
151 | ||
e2361cb9 | 152 | /* rcu_read_lock()ed by nf_hook_thresh */ |
e2a3123f | 153 | innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum); |
9fb9cbb1 | 154 | |
e905a9ed YH |
155 | /* Ordinarily, we'd expect the inverted tupleproto, but it's |
156 | been preserved inside the ICMP. */ | |
157 | if (!nf_ct_invert_tuple(&innertuple, &origtuple, | |
9fb9cbb1 | 158 | &nf_conntrack_l3proto_ipv4, innerproto)) { |
0d53778e | 159 | pr_debug("icmp_error_message: no match\n"); |
9fb9cbb1 YK |
160 | return -NF_ACCEPT; |
161 | } | |
162 | ||
11df4b76 | 163 | ctinfo = IP_CT_RELATED; |
9fb9cbb1 | 164 | |
5d0aa2cc | 165 | h = nf_conntrack_find_get(net, zone, &innertuple); |
9fb9cbb1 | 166 | if (!h) { |
130e7a83 YK |
167 | pr_debug("icmp_error_message: no match\n"); |
168 | return -NF_ACCEPT; | |
9fb9cbb1 YK |
169 | } |
170 | ||
130e7a83 | 171 | if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY) |
11df4b76 | 172 | ctinfo += IP_CT_IS_REPLY; |
130e7a83 | 173 | |
e905a9ed YH |
174 | /* Update skb to refer to this connection */ |
175 | skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general; | |
11df4b76 | 176 | skb->nfctinfo = ctinfo; |
88ed01d1 | 177 | return NF_ACCEPT; |
9fb9cbb1 YK |
178 | } |
179 | ||
180 | /* Small and modified version of icmp_rcv */ | |
181 | static int | |
8fea97ec PM |
182 | icmp_error(struct net *net, struct nf_conn *tmpl, |
183 | struct sk_buff *skb, unsigned int dataoff, | |
11df4b76 | 184 | u8 pf, unsigned int hooknum) |
9fb9cbb1 | 185 | { |
7cc3864d JE |
186 | const struct icmphdr *icmph; |
187 | struct icmphdr _ih; | |
9fb9cbb1 YK |
188 | |
189 | /* Not enough header? */ | |
c9bdd4b5 | 190 | icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih); |
9fb9cbb1 | 191 | if (icmph == NULL) { |
c2a2c7e0 | 192 | if (LOG_INVALID(net, IPPROTO_ICMP)) |
30e0c6a6 G |
193 | nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, |
194 | NULL, "nf_ct_icmp: short packet "); | |
9fb9cbb1 YK |
195 | return -NF_ACCEPT; |
196 | } | |
197 | ||
198 | /* See ip_conntrack_proto_tcp.c */ | |
c04d0552 | 199 | if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && |
96f6bf82 | 200 | nf_ip_checksum(skb, hooknum, dataoff, 0)) { |
c2a2c7e0 | 201 | if (LOG_INVALID(net, IPPROTO_ICMP)) |
30e0c6a6 | 202 | nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL, |
9fb9cbb1 YK |
203 | "nf_ct_icmp: bad HW ICMP checksum "); |
204 | return -NF_ACCEPT; | |
9fb9cbb1 YK |
205 | } |
206 | ||
9fb9cbb1 YK |
207 | /* |
208 | * 18 is the highest 'known' ICMP type. Anything else is a mystery | |
209 | * | |
210 | * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently | |
211 | * discarded. | |
212 | */ | |
213 | if (icmph->type > NR_ICMP_TYPES) { | |
c2a2c7e0 | 214 | if (LOG_INVALID(net, IPPROTO_ICMP)) |
30e0c6a6 | 215 | nf_log_packet(net, PF_INET, 0, skb, NULL, NULL, NULL, |
9fb9cbb1 YK |
216 | "nf_ct_icmp: invalid ICMP type "); |
217 | return -NF_ACCEPT; | |
218 | } | |
219 | ||
220 | /* Need to track icmp error message? */ | |
3666ed1c JP |
221 | if (icmph->type != ICMP_DEST_UNREACH && |
222 | icmph->type != ICMP_SOURCE_QUENCH && | |
223 | icmph->type != ICMP_TIME_EXCEEDED && | |
224 | icmph->type != ICMP_PARAMETERPROB && | |
225 | icmph->type != ICMP_REDIRECT) | |
9fb9cbb1 YK |
226 | return NF_ACCEPT; |
227 | ||
11df4b76 | 228 | return icmp_error_message(net, tmpl, skb, hooknum); |
9fb9cbb1 YK |
229 | } |
230 | ||
24de3d37 | 231 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
c1d10adb PNA |
232 | |
233 | #include <linux/netfilter/nfnetlink.h> | |
234 | #include <linux/netfilter/nfnetlink_conntrack.h> | |
235 | ||
fdf70832 | 236 | static int icmp_tuple_to_nlattr(struct sk_buff *skb, |
c1d10adb PNA |
237 | const struct nf_conntrack_tuple *t) |
238 | { | |
d317e4f6 DM |
239 | if (nla_put_be16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id) || |
240 | nla_put_u8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type) || | |
241 | nla_put_u8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code)) | |
242 | goto nla_put_failure; | |
c1d10adb PNA |
243 | return 0; |
244 | ||
df6fb868 | 245 | nla_put_failure: |
c1d10adb PNA |
246 | return -1; |
247 | } | |
248 | ||
f73e924c PM |
249 | static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = { |
250 | [CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 }, | |
251 | [CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 }, | |
252 | [CTA_PROTO_ICMP_ID] = { .type = NLA_U16 }, | |
c1d10adb PNA |
253 | }; |
254 | ||
fdf70832 | 255 | static int icmp_nlattr_to_tuple(struct nlattr *tb[], |
c1d10adb PNA |
256 | struct nf_conntrack_tuple *tuple) |
257 | { | |
3666ed1c JP |
258 | if (!tb[CTA_PROTO_ICMP_TYPE] || |
259 | !tb[CTA_PROTO_ICMP_CODE] || | |
260 | !tb[CTA_PROTO_ICMP_ID]) | |
c1d10adb PNA |
261 | return -EINVAL; |
262 | ||
77236b6e PM |
263 | tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]); |
264 | tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]); | |
265 | tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]); | |
c1d10adb | 266 | |
3666ed1c JP |
267 | if (tuple->dst.u.icmp.type >= sizeof(invmap) || |
268 | !invmap[tuple->dst.u.icmp.type]) | |
c1d10adb PNA |
269 | return -EINVAL; |
270 | ||
271 | return 0; | |
272 | } | |
a400c30e HE |
273 | |
274 | static int icmp_nlattr_tuple_size(void) | |
275 | { | |
276 | return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1); | |
277 | } | |
c1d10adb PNA |
278 | #endif |
279 | ||
50978462 PNA |
280 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) |
281 | ||
282 | #include <linux/netfilter/nfnetlink.h> | |
283 | #include <linux/netfilter/nfnetlink_cttimeout.h> | |
284 | ||
8264deb8 G |
285 | static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[], |
286 | struct net *net, void *data) | |
50978462 PNA |
287 | { |
288 | unsigned int *timeout = data; | |
8264deb8 | 289 | struct nf_icmp_net *in = icmp_pernet(net); |
50978462 PNA |
290 | |
291 | if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) { | |
292 | *timeout = | |
293 | ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ; | |
294 | } else { | |
295 | /* Set default ICMP timeout. */ | |
8264deb8 | 296 | *timeout = in->timeout; |
50978462 PNA |
297 | } |
298 | return 0; | |
299 | } | |
300 | ||
301 | static int | |
302 | icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) | |
303 | { | |
304 | const unsigned int *timeout = data; | |
305 | ||
d317e4f6 DM |
306 | if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ))) |
307 | goto nla_put_failure; | |
50978462 PNA |
308 | return 0; |
309 | ||
310 | nla_put_failure: | |
311 | return -ENOSPC; | |
312 | } | |
313 | ||
314 | static const struct nla_policy | |
315 | icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = { | |
316 | [CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 }, | |
317 | }; | |
318 | #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ | |
319 | ||
933a41e7 | 320 | #ifdef CONFIG_SYSCTL |
933a41e7 PM |
321 | static struct ctl_table icmp_sysctl_table[] = { |
322 | { | |
933a41e7 | 323 | .procname = "nf_conntrack_icmp_timeout", |
933a41e7 PM |
324 | .maxlen = sizeof(unsigned int), |
325 | .mode = 0644, | |
6d9f239a | 326 | .proc_handler = proc_dointvec_jiffies, |
933a41e7 | 327 | }, |
f8572d8f | 328 | { } |
933a41e7 PM |
329 | }; |
330 | #endif /* CONFIG_SYSCTL */ | |
331 | ||
a9082b45 G |
332 | static int icmp_kmemdup_sysctl_table(struct nf_proto_net *pn, |
333 | struct nf_icmp_net *in) | |
4b626b9c | 334 | { |
4b626b9c G |
335 | #ifdef CONFIG_SYSCTL |
336 | pn->ctl_table = kmemdup(icmp_sysctl_table, | |
337 | sizeof(icmp_sysctl_table), | |
338 | GFP_KERNEL); | |
339 | if (!pn->ctl_table) | |
340 | return -ENOMEM; | |
a9082b45 | 341 | |
4b626b9c | 342 | pn->ctl_table[0].data = &in->timeout; |
a9082b45 G |
343 | #endif |
344 | return 0; | |
345 | } | |
346 | ||
a9082b45 G |
347 | static int icmp_init_net(struct net *net, u_int16_t proto) |
348 | { | |
a9082b45 G |
349 | struct nf_icmp_net *in = icmp_pernet(net); |
350 | struct nf_proto_net *pn = &in->pn; | |
351 | ||
352 | in->timeout = nf_ct_icmp_timeout; | |
353 | ||
adf05168 | 354 | return icmp_kmemdup_sysctl_table(pn, in); |
a9082b45 G |
355 | } |
356 | ||
08911475 PNA |
357 | static struct nf_proto_net *icmp_get_net_proto(struct net *net) |
358 | { | |
359 | return &net->ct.nf_ct_proto.icmp.pn; | |
360 | } | |
361 | ||
61075af5 | 362 | struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly = |
9fb9cbb1 | 363 | { |
9fb9cbb1 | 364 | .l3proto = PF_INET, |
605dcad6 | 365 | .l4proto = IPPROTO_ICMP, |
9fb9cbb1 YK |
366 | .name = "icmp", |
367 | .pkt_to_tuple = icmp_pkt_to_tuple, | |
368 | .invert_tuple = icmp_invert_tuple, | |
369 | .print_tuple = icmp_print_tuple, | |
9fb9cbb1 | 370 | .packet = icmp_packet, |
2c8503f5 | 371 | .get_timeouts = icmp_get_timeouts, |
9fb9cbb1 YK |
372 | .new = icmp_new, |
373 | .error = icmp_error, | |
374 | .destroy = NULL, | |
c1d10adb | 375 | .me = NULL, |
24de3d37 | 376 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK) |
fdf70832 | 377 | .tuple_to_nlattr = icmp_tuple_to_nlattr, |
a400c30e | 378 | .nlattr_tuple_size = icmp_nlattr_tuple_size, |
fdf70832 | 379 | .nlattr_to_tuple = icmp_nlattr_to_tuple, |
f73e924c | 380 | .nla_policy = icmp_nla_policy, |
c1d10adb | 381 | #endif |
50978462 PNA |
382 | #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) |
383 | .ctnl_timeout = { | |
384 | .nlattr_to_obj = icmp_timeout_nlattr_to_obj, | |
385 | .obj_to_nlattr = icmp_timeout_obj_to_nlattr, | |
386 | .nlattr_max = CTA_TIMEOUT_ICMP_MAX, | |
387 | .obj_size = sizeof(unsigned int), | |
388 | .nla_policy = icmp_timeout_nla_policy, | |
389 | }, | |
390 | #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ | |
4b626b9c | 391 | .init_net = icmp_init_net, |
08911475 | 392 | .get_net_proto = icmp_get_net_proto, |
9fb9cbb1 | 393 | }; |