Commit | Line | Data |
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5b1158e9 JK |
1 | /* NAT for netfilter; shared with compatibility layer. */ |
2 | ||
3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
4 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include <linux/types.h> | |
13 | #include <linux/timer.h> | |
14 | #include <linux/skbuff.h> | |
5b1158e9 JK |
15 | #include <net/checksum.h> |
16 | #include <net/icmp.h> | |
17 | #include <net/ip.h> | |
18 | #include <net/tcp.h> /* For tcp_prot in getorigdst */ | |
19 | #include <linux/icmp.h> | |
20 | #include <linux/udp.h> | |
21 | #include <linux/jhash.h> | |
22 | ||
23 | #include <linux/netfilter_ipv4.h> | |
24 | #include <net/netfilter/nf_conntrack.h> | |
25 | #include <net/netfilter/nf_conntrack_core.h> | |
26 | #include <net/netfilter/nf_nat.h> | |
27 | #include <net/netfilter/nf_nat_protocol.h> | |
28 | #include <net/netfilter/nf_nat_core.h> | |
29 | #include <net/netfilter/nf_nat_helper.h> | |
30 | #include <net/netfilter/nf_conntrack_helper.h> | |
31 | #include <net/netfilter/nf_conntrack_l3proto.h> | |
32 | #include <net/netfilter/nf_conntrack_l4proto.h> | |
33 | ||
5b1158e9 JK |
34 | static DEFINE_RWLOCK(nf_nat_lock); |
35 | ||
36 | static struct nf_conntrack_l3proto *l3proto = NULL; | |
37 | ||
38 | /* Calculated at init based on memory size */ | |
39 | static unsigned int nf_nat_htable_size; | |
53aba597 | 40 | static int nf_nat_vmalloced; |
5b1158e9 | 41 | |
53aba597 | 42 | static struct hlist_head *bysource; |
5b1158e9 JK |
43 | |
44 | #define MAX_IP_NAT_PROTO 256 | |
45 | static struct nf_nat_protocol *nf_nat_protos[MAX_IP_NAT_PROTO]; | |
46 | ||
47 | static inline struct nf_nat_protocol * | |
48 | __nf_nat_proto_find(u_int8_t protonum) | |
49 | { | |
e22a0548 | 50 | return rcu_dereference(nf_nat_protos[protonum]); |
5b1158e9 JK |
51 | } |
52 | ||
53 | struct nf_nat_protocol * | |
54 | nf_nat_proto_find_get(u_int8_t protonum) | |
55 | { | |
56 | struct nf_nat_protocol *p; | |
57 | ||
e22a0548 | 58 | rcu_read_lock(); |
5b1158e9 JK |
59 | p = __nf_nat_proto_find(protonum); |
60 | if (!try_module_get(p->me)) | |
61 | p = &nf_nat_unknown_protocol; | |
e22a0548 | 62 | rcu_read_unlock(); |
5b1158e9 JK |
63 | |
64 | return p; | |
65 | } | |
66 | EXPORT_SYMBOL_GPL(nf_nat_proto_find_get); | |
67 | ||
68 | void | |
69 | nf_nat_proto_put(struct nf_nat_protocol *p) | |
70 | { | |
71 | module_put(p->me); | |
72 | } | |
73 | EXPORT_SYMBOL_GPL(nf_nat_proto_put); | |
74 | ||
75 | /* We keep an extra hash for each conntrack, for fast searching. */ | |
76 | static inline unsigned int | |
77 | hash_by_src(const struct nf_conntrack_tuple *tuple) | |
78 | { | |
79 | /* Original src, to ensure we map it consistently if poss. */ | |
80 | return jhash_3words((__force u32)tuple->src.u3.ip, tuple->src.u.all, | |
81 | tuple->dst.protonum, 0) % nf_nat_htable_size; | |
82 | } | |
83 | ||
5b1158e9 JK |
84 | /* Is this tuple already taken? (not by us) */ |
85 | int | |
86 | nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple, | |
87 | const struct nf_conn *ignored_conntrack) | |
88 | { | |
89 | /* Conntrack tracking doesn't keep track of outgoing tuples; only | |
90 | incoming ones. NAT means they don't have a fixed mapping, | |
91 | so we invert the tuple and look for the incoming reply. | |
92 | ||
93 | We could keep a separate hash if this proves too slow. */ | |
94 | struct nf_conntrack_tuple reply; | |
95 | ||
96 | nf_ct_invert_tuplepr(&reply, tuple); | |
97 | return nf_conntrack_tuple_taken(&reply, ignored_conntrack); | |
98 | } | |
99 | EXPORT_SYMBOL(nf_nat_used_tuple); | |
100 | ||
101 | /* If we source map this tuple so reply looks like reply_tuple, will | |
102 | * that meet the constraints of range. */ | |
103 | static int | |
104 | in_range(const struct nf_conntrack_tuple *tuple, | |
105 | const struct nf_nat_range *range) | |
106 | { | |
107 | struct nf_nat_protocol *proto; | |
e22a0548 | 108 | int ret = 0; |
5b1158e9 | 109 | |
5b1158e9 JK |
110 | /* If we are supposed to map IPs, then we must be in the |
111 | range specified, otherwise let this drag us onto a new src IP. */ | |
112 | if (range->flags & IP_NAT_RANGE_MAP_IPS) { | |
113 | if (ntohl(tuple->src.u3.ip) < ntohl(range->min_ip) || | |
114 | ntohl(tuple->src.u3.ip) > ntohl(range->max_ip)) | |
115 | return 0; | |
116 | } | |
117 | ||
e22a0548 PM |
118 | rcu_read_lock(); |
119 | proto = __nf_nat_proto_find(tuple->dst.protonum); | |
5b1158e9 JK |
120 | if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) || |
121 | proto->in_range(tuple, IP_NAT_MANIP_SRC, | |
122 | &range->min, &range->max)) | |
e22a0548 PM |
123 | ret = 1; |
124 | rcu_read_unlock(); | |
5b1158e9 | 125 | |
e22a0548 | 126 | return ret; |
5b1158e9 JK |
127 | } |
128 | ||
129 | static inline int | |
130 | same_src(const struct nf_conn *ct, | |
131 | const struct nf_conntrack_tuple *tuple) | |
132 | { | |
133 | const struct nf_conntrack_tuple *t; | |
134 | ||
135 | t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; | |
136 | return (t->dst.protonum == tuple->dst.protonum && | |
137 | t->src.u3.ip == tuple->src.u3.ip && | |
138 | t->src.u.all == tuple->src.u.all); | |
139 | } | |
140 | ||
141 | /* Only called for SRC manip */ | |
142 | static int | |
143 | find_appropriate_src(const struct nf_conntrack_tuple *tuple, | |
144 | struct nf_conntrack_tuple *result, | |
145 | const struct nf_nat_range *range) | |
146 | { | |
147 | unsigned int h = hash_by_src(tuple); | |
148 | struct nf_conn_nat *nat; | |
149 | struct nf_conn *ct; | |
53aba597 | 150 | struct hlist_node *n; |
5b1158e9 JK |
151 | |
152 | read_lock_bh(&nf_nat_lock); | |
53aba597 | 153 | hlist_for_each_entry(nat, n, &bysource[h], bysource) { |
b6b84d4a | 154 | ct = nat->ct; |
5b1158e9 JK |
155 | if (same_src(ct, tuple)) { |
156 | /* Copy source part from reply tuple. */ | |
157 | nf_ct_invert_tuplepr(result, | |
158 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
159 | result->dst = tuple->dst; | |
160 | ||
161 | if (in_range(result, range)) { | |
162 | read_unlock_bh(&nf_nat_lock); | |
163 | return 1; | |
164 | } | |
165 | } | |
166 | } | |
167 | read_unlock_bh(&nf_nat_lock); | |
168 | return 0; | |
169 | } | |
170 | ||
171 | /* For [FUTURE] fragmentation handling, we want the least-used | |
172 | src-ip/dst-ip/proto triple. Fairness doesn't come into it. Thus | |
173 | if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports | |
174 | 1-65535, we don't do pro-rata allocation based on ports; we choose | |
175 | the ip with the lowest src-ip/dst-ip/proto usage. | |
176 | */ | |
177 | static void | |
178 | find_best_ips_proto(struct nf_conntrack_tuple *tuple, | |
179 | const struct nf_nat_range *range, | |
180 | const struct nf_conn *ct, | |
181 | enum nf_nat_manip_type maniptype) | |
182 | { | |
183 | __be32 *var_ipp; | |
184 | /* Host order */ | |
185 | u_int32_t minip, maxip, j; | |
186 | ||
187 | /* No IP mapping? Do nothing. */ | |
188 | if (!(range->flags & IP_NAT_RANGE_MAP_IPS)) | |
189 | return; | |
190 | ||
191 | if (maniptype == IP_NAT_MANIP_SRC) | |
192 | var_ipp = &tuple->src.u3.ip; | |
193 | else | |
194 | var_ipp = &tuple->dst.u3.ip; | |
195 | ||
196 | /* Fast path: only one choice. */ | |
197 | if (range->min_ip == range->max_ip) { | |
198 | *var_ipp = range->min_ip; | |
199 | return; | |
200 | } | |
201 | ||
202 | /* Hashing source and destination IPs gives a fairly even | |
203 | * spread in practice (if there are a small number of IPs | |
204 | * involved, there usually aren't that many connections | |
205 | * anyway). The consistency means that servers see the same | |
206 | * client coming from the same IP (some Internet Banking sites | |
207 | * like this), even across reboots. */ | |
208 | minip = ntohl(range->min_ip); | |
209 | maxip = ntohl(range->max_ip); | |
210 | j = jhash_2words((__force u32)tuple->src.u3.ip, | |
211 | (__force u32)tuple->dst.u3.ip, 0); | |
212 | *var_ipp = htonl(minip + j % (maxip - minip + 1)); | |
213 | } | |
214 | ||
215 | /* Manipulate the tuple into the range given. For NF_IP_POST_ROUTING, | |
216 | * we change the source to map into the range. For NF_IP_PRE_ROUTING | |
217 | * and NF_IP_LOCAL_OUT, we change the destination to map into the | |
218 | * range. It might not be possible to get a unique tuple, but we try. | |
219 | * At worst (or if we race), we will end up with a final duplicate in | |
220 | * __ip_conntrack_confirm and drop the packet. */ | |
221 | static void | |
222 | get_unique_tuple(struct nf_conntrack_tuple *tuple, | |
223 | const struct nf_conntrack_tuple *orig_tuple, | |
224 | const struct nf_nat_range *range, | |
225 | struct nf_conn *ct, | |
226 | enum nf_nat_manip_type maniptype) | |
227 | { | |
228 | struct nf_nat_protocol *proto; | |
229 | ||
230 | /* 1) If this srcip/proto/src-proto-part is currently mapped, | |
231 | and that same mapping gives a unique tuple within the given | |
232 | range, use that. | |
233 | ||
234 | This is only required for source (ie. NAT/masq) mappings. | |
235 | So far, we don't do local source mappings, so multiple | |
236 | manips not an issue. */ | |
237 | if (maniptype == IP_NAT_MANIP_SRC) { | |
238 | if (find_appropriate_src(orig_tuple, tuple, range)) { | |
0d53778e | 239 | pr_debug("get_unique_tuple: Found current src map\n"); |
41f4689a EL |
240 | if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) |
241 | if (!nf_nat_used_tuple(tuple, ct)) | |
242 | return; | |
5b1158e9 JK |
243 | } |
244 | } | |
245 | ||
246 | /* 2) Select the least-used IP/proto combination in the given | |
247 | range. */ | |
248 | *tuple = *orig_tuple; | |
249 | find_best_ips_proto(tuple, range, ct, maniptype); | |
250 | ||
251 | /* 3) The per-protocol part of the manip is made to map into | |
252 | the range to make a unique tuple. */ | |
253 | ||
e22a0548 PM |
254 | rcu_read_lock(); |
255 | proto = __nf_nat_proto_find(orig_tuple->dst.protonum); | |
5b1158e9 | 256 | |
41f4689a EL |
257 | /* Change protocol info to have some randomization */ |
258 | if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) { | |
259 | proto->unique_tuple(tuple, range, maniptype, ct); | |
e22a0548 | 260 | goto out; |
41f4689a EL |
261 | } |
262 | ||
5b1158e9 JK |
263 | /* Only bother mapping if it's not already in range and unique */ |
264 | if ((!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED) || | |
265 | proto->in_range(tuple, maniptype, &range->min, &range->max)) && | |
e22a0548 PM |
266 | !nf_nat_used_tuple(tuple, ct)) |
267 | goto out; | |
5b1158e9 JK |
268 | |
269 | /* Last change: get protocol to try to obtain unique tuple. */ | |
270 | proto->unique_tuple(tuple, range, maniptype, ct); | |
e22a0548 PM |
271 | out: |
272 | rcu_read_unlock(); | |
5b1158e9 JK |
273 | } |
274 | ||
275 | unsigned int | |
276 | nf_nat_setup_info(struct nf_conn *ct, | |
277 | const struct nf_nat_range *range, | |
278 | unsigned int hooknum) | |
279 | { | |
280 | struct nf_conntrack_tuple curr_tuple, new_tuple; | |
2d59e5ca | 281 | struct nf_conn_nat *nat; |
5b1158e9 JK |
282 | int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK); |
283 | enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum); | |
284 | ||
2d59e5ca YK |
285 | /* nat helper or nfctnetlink also setup binding */ |
286 | nat = nfct_nat(ct); | |
287 | if (!nat) { | |
288 | nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC); | |
289 | if (nat == NULL) { | |
0d53778e | 290 | pr_debug("failed to add NAT extension\n"); |
2d59e5ca YK |
291 | return NF_ACCEPT; |
292 | } | |
293 | } | |
294 | ||
5b1158e9 JK |
295 | NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING || |
296 | hooknum == NF_IP_POST_ROUTING || | |
297 | hooknum == NF_IP_LOCAL_IN || | |
298 | hooknum == NF_IP_LOCAL_OUT); | |
299 | BUG_ON(nf_nat_initialized(ct, maniptype)); | |
300 | ||
301 | /* What we've got will look like inverse of reply. Normally | |
302 | this is what is in the conntrack, except for prior | |
303 | manipulations (future optimization: if num_manips == 0, | |
304 | orig_tp = | |
305 | conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple) */ | |
306 | nf_ct_invert_tuplepr(&curr_tuple, | |
307 | &ct->tuplehash[IP_CT_DIR_REPLY].tuple); | |
308 | ||
309 | get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype); | |
310 | ||
311 | if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) { | |
312 | struct nf_conntrack_tuple reply; | |
313 | ||
314 | /* Alter conntrack table so will recognize replies. */ | |
315 | nf_ct_invert_tuplepr(&reply, &new_tuple); | |
316 | nf_conntrack_alter_reply(ct, &reply); | |
317 | ||
318 | /* Non-atomic: we own this at the moment. */ | |
319 | if (maniptype == IP_NAT_MANIP_SRC) | |
320 | ct->status |= IPS_SRC_NAT; | |
321 | else | |
322 | ct->status |= IPS_DST_NAT; | |
323 | } | |
324 | ||
325 | /* Place in source hash if this is the first time. */ | |
326 | if (have_to_hash) { | |
327 | unsigned int srchash; | |
328 | ||
329 | srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
330 | write_lock_bh(&nf_nat_lock); | |
2d59e5ca | 331 | /* nf_conntrack_alter_reply might re-allocate exntension aera */ |
b6b84d4a YK |
332 | nat = nfct_nat(ct); |
333 | nat->ct = ct; | |
53aba597 | 334 | hlist_add_head(&nat->bysource, &bysource[srchash]); |
5b1158e9 JK |
335 | write_unlock_bh(&nf_nat_lock); |
336 | } | |
337 | ||
338 | /* It's done. */ | |
339 | if (maniptype == IP_NAT_MANIP_DST) | |
340 | set_bit(IPS_DST_NAT_DONE_BIT, &ct->status); | |
341 | else | |
342 | set_bit(IPS_SRC_NAT_DONE_BIT, &ct->status); | |
343 | ||
344 | return NF_ACCEPT; | |
345 | } | |
346 | EXPORT_SYMBOL(nf_nat_setup_info); | |
347 | ||
348 | /* Returns true if succeeded. */ | |
349 | static int | |
350 | manip_pkt(u_int16_t proto, | |
351 | struct sk_buff **pskb, | |
352 | unsigned int iphdroff, | |
353 | const struct nf_conntrack_tuple *target, | |
354 | enum nf_nat_manip_type maniptype) | |
355 | { | |
356 | struct iphdr *iph; | |
357 | struct nf_nat_protocol *p; | |
358 | ||
359 | if (!skb_make_writable(pskb, iphdroff + sizeof(*iph))) | |
360 | return 0; | |
361 | ||
362 | iph = (void *)(*pskb)->data + iphdroff; | |
363 | ||
364 | /* Manipulate protcol part. */ | |
e22a0548 PM |
365 | |
366 | /* rcu_read_lock()ed by nf_hook_slow */ | |
367 | p = __nf_nat_proto_find(proto); | |
368 | if (!p->manip_pkt(pskb, iphdroff, target, maniptype)) | |
5b1158e9 | 369 | return 0; |
5b1158e9 JK |
370 | |
371 | iph = (void *)(*pskb)->data + iphdroff; | |
372 | ||
373 | if (maniptype == IP_NAT_MANIP_SRC) { | |
374 | nf_csum_replace4(&iph->check, iph->saddr, target->src.u3.ip); | |
375 | iph->saddr = target->src.u3.ip; | |
376 | } else { | |
377 | nf_csum_replace4(&iph->check, iph->daddr, target->dst.u3.ip); | |
378 | iph->daddr = target->dst.u3.ip; | |
379 | } | |
380 | return 1; | |
381 | } | |
382 | ||
383 | /* Do packet manipulations according to nf_nat_setup_info. */ | |
384 | unsigned int nf_nat_packet(struct nf_conn *ct, | |
385 | enum ip_conntrack_info ctinfo, | |
386 | unsigned int hooknum, | |
387 | struct sk_buff **pskb) | |
388 | { | |
389 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); | |
390 | unsigned long statusbit; | |
391 | enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum); | |
392 | ||
393 | if (mtype == IP_NAT_MANIP_SRC) | |
394 | statusbit = IPS_SRC_NAT; | |
395 | else | |
396 | statusbit = IPS_DST_NAT; | |
397 | ||
398 | /* Invert if this is reply dir. */ | |
399 | if (dir == IP_CT_DIR_REPLY) | |
400 | statusbit ^= IPS_NAT_MASK; | |
401 | ||
402 | /* Non-atomic: these bits don't change. */ | |
403 | if (ct->status & statusbit) { | |
404 | struct nf_conntrack_tuple target; | |
405 | ||
406 | /* We are aiming to look like inverse of other direction. */ | |
407 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); | |
408 | ||
409 | if (!manip_pkt(target.dst.protonum, pskb, 0, &target, mtype)) | |
410 | return NF_DROP; | |
411 | } | |
412 | return NF_ACCEPT; | |
413 | } | |
414 | EXPORT_SYMBOL_GPL(nf_nat_packet); | |
415 | ||
416 | /* Dir is direction ICMP is coming from (opposite to packet it contains) */ | |
417 | int nf_nat_icmp_reply_translation(struct nf_conn *ct, | |
418 | enum ip_conntrack_info ctinfo, | |
419 | unsigned int hooknum, | |
420 | struct sk_buff **pskb) | |
421 | { | |
422 | struct { | |
423 | struct icmphdr icmp; | |
424 | struct iphdr ip; | |
425 | } *inside; | |
923f4902 | 426 | struct nf_conntrack_l4proto *l4proto; |
5b1158e9 | 427 | struct nf_conntrack_tuple inner, target; |
c9bdd4b5 | 428 | int hdrlen = ip_hdrlen(*pskb); |
5b1158e9 JK |
429 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
430 | unsigned long statusbit; | |
431 | enum nf_nat_manip_type manip = HOOK2MANIP(hooknum); | |
432 | ||
433 | if (!skb_make_writable(pskb, hdrlen + sizeof(*inside))) | |
434 | return 0; | |
435 | ||
c9bdd4b5 | 436 | inside = (void *)(*pskb)->data + ip_hdrlen(*pskb); |
5b1158e9 JK |
437 | |
438 | /* We're actually going to mangle it beyond trivial checksum | |
439 | adjustment, so make sure the current checksum is correct. */ | |
440 | if (nf_ip_checksum(*pskb, hooknum, hdrlen, 0)) | |
441 | return 0; | |
442 | ||
443 | /* Must be RELATED */ | |
444 | NF_CT_ASSERT((*pskb)->nfctinfo == IP_CT_RELATED || | |
445 | (*pskb)->nfctinfo == IP_CT_RELATED+IP_CT_IS_REPLY); | |
446 | ||
447 | /* Redirects on non-null nats must be dropped, else they'll | |
e905a9ed YH |
448 | start talking to each other without our translation, and be |
449 | confused... --RR */ | |
5b1158e9 JK |
450 | if (inside->icmp.type == ICMP_REDIRECT) { |
451 | /* If NAT isn't finished, assume it and drop. */ | |
452 | if ((ct->status & IPS_NAT_DONE_MASK) != IPS_NAT_DONE_MASK) | |
453 | return 0; | |
454 | ||
455 | if (ct->status & IPS_NAT_MASK) | |
456 | return 0; | |
457 | } | |
458 | ||
0d53778e PM |
459 | pr_debug("icmp_reply_translation: translating error %p manip %u " |
460 | "dir %s\n", *pskb, manip, | |
461 | dir == IP_CT_DIR_ORIGINAL ? "ORIG" : "REPLY"); | |
5b1158e9 | 462 | |
923f4902 PM |
463 | /* rcu_read_lock()ed by nf_hook_slow */ |
464 | l4proto = __nf_ct_l4proto_find(PF_INET, inside->ip.protocol); | |
465 | ||
5b1158e9 | 466 | if (!nf_ct_get_tuple(*pskb, |
c9bdd4b5 ACM |
467 | ip_hdrlen(*pskb) + sizeof(struct icmphdr), |
468 | (ip_hdrlen(*pskb) + | |
469 | sizeof(struct icmphdr) + inside->ip.ihl * 4), | |
e905a9ed YH |
470 | (u_int16_t)AF_INET, |
471 | inside->ip.protocol, | |
923f4902 | 472 | &inner, l3proto, l4proto)) |
5b1158e9 JK |
473 | return 0; |
474 | ||
475 | /* Change inner back to look like incoming packet. We do the | |
476 | opposite manip on this hook to normal, because it might not | |
477 | pass all hooks (locally-generated ICMP). Consider incoming | |
478 | packet: PREROUTING (DST manip), routing produces ICMP, goes | |
479 | through POSTROUTING (which must correct the DST manip). */ | |
480 | if (!manip_pkt(inside->ip.protocol, pskb, | |
c9bdd4b5 | 481 | ip_hdrlen(*pskb) + sizeof(inside->icmp), |
5b1158e9 JK |
482 | &ct->tuplehash[!dir].tuple, |
483 | !manip)) | |
484 | return 0; | |
485 | ||
486 | if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) { | |
487 | /* Reloading "inside" here since manip_pkt inner. */ | |
c9bdd4b5 | 488 | inside = (void *)(*pskb)->data + ip_hdrlen(*pskb); |
5b1158e9 JK |
489 | inside->icmp.checksum = 0; |
490 | inside->icmp.checksum = | |
491 | csum_fold(skb_checksum(*pskb, hdrlen, | |
492 | (*pskb)->len - hdrlen, 0)); | |
493 | } | |
494 | ||
495 | /* Change outer to look the reply to an incoming packet | |
496 | * (proto 0 means don't invert per-proto part). */ | |
497 | if (manip == IP_NAT_MANIP_SRC) | |
498 | statusbit = IPS_SRC_NAT; | |
499 | else | |
500 | statusbit = IPS_DST_NAT; | |
501 | ||
502 | /* Invert if this is reply dir. */ | |
503 | if (dir == IP_CT_DIR_REPLY) | |
504 | statusbit ^= IPS_NAT_MASK; | |
505 | ||
506 | if (ct->status & statusbit) { | |
507 | nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple); | |
508 | if (!manip_pkt(0, pskb, 0, &target, manip)) | |
509 | return 0; | |
510 | } | |
511 | ||
512 | return 1; | |
513 | } | |
514 | EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); | |
515 | ||
516 | /* Protocol registration. */ | |
517 | int nf_nat_protocol_register(struct nf_nat_protocol *proto) | |
518 | { | |
519 | int ret = 0; | |
520 | ||
521 | write_lock_bh(&nf_nat_lock); | |
522 | if (nf_nat_protos[proto->protonum] != &nf_nat_unknown_protocol) { | |
523 | ret = -EBUSY; | |
524 | goto out; | |
525 | } | |
e22a0548 | 526 | rcu_assign_pointer(nf_nat_protos[proto->protonum], proto); |
5b1158e9 JK |
527 | out: |
528 | write_unlock_bh(&nf_nat_lock); | |
529 | return ret; | |
530 | } | |
531 | EXPORT_SYMBOL(nf_nat_protocol_register); | |
532 | ||
533 | /* Noone stores the protocol anywhere; simply delete it. */ | |
534 | void nf_nat_protocol_unregister(struct nf_nat_protocol *proto) | |
535 | { | |
536 | write_lock_bh(&nf_nat_lock); | |
e22a0548 PM |
537 | rcu_assign_pointer(nf_nat_protos[proto->protonum], |
538 | &nf_nat_unknown_protocol); | |
5b1158e9 | 539 | write_unlock_bh(&nf_nat_lock); |
e22a0548 | 540 | synchronize_rcu(); |
5b1158e9 JK |
541 | } |
542 | EXPORT_SYMBOL(nf_nat_protocol_unregister); | |
543 | ||
e281db5c | 544 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
5b1158e9 JK |
545 | int |
546 | nf_nat_port_range_to_nfattr(struct sk_buff *skb, | |
547 | const struct nf_nat_range *range) | |
548 | { | |
549 | NFA_PUT(skb, CTA_PROTONAT_PORT_MIN, sizeof(__be16), | |
550 | &range->min.tcp.port); | |
551 | NFA_PUT(skb, CTA_PROTONAT_PORT_MAX, sizeof(__be16), | |
552 | &range->max.tcp.port); | |
553 | ||
554 | return 0; | |
555 | ||
556 | nfattr_failure: | |
557 | return -1; | |
558 | } | |
559 | EXPORT_SYMBOL_GPL(nf_nat_port_nfattr_to_range); | |
560 | ||
561 | int | |
562 | nf_nat_port_nfattr_to_range(struct nfattr *tb[], struct nf_nat_range *range) | |
563 | { | |
564 | int ret = 0; | |
565 | ||
566 | /* we have to return whether we actually parsed something or not */ | |
567 | ||
568 | if (tb[CTA_PROTONAT_PORT_MIN-1]) { | |
569 | ret = 1; | |
570 | range->min.tcp.port = | |
571 | *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MIN-1]); | |
572 | } | |
573 | ||
574 | if (!tb[CTA_PROTONAT_PORT_MAX-1]) { | |
575 | if (ret) | |
576 | range->max.tcp.port = range->min.tcp.port; | |
577 | } else { | |
578 | ret = 1; | |
579 | range->max.tcp.port = | |
580 | *(__be16 *)NFA_DATA(tb[CTA_PROTONAT_PORT_MAX-1]); | |
581 | } | |
582 | ||
583 | return ret; | |
584 | } | |
585 | EXPORT_SYMBOL_GPL(nf_nat_port_range_to_nfattr); | |
586 | #endif | |
587 | ||
d8a0509a YK |
588 | /* Noone using conntrack by the time this called. */ |
589 | static void nf_nat_cleanup_conntrack(struct nf_conn *ct) | |
590 | { | |
591 | struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT); | |
592 | ||
b6b84d4a | 593 | if (nat == NULL || nat->ct == NULL) |
d8a0509a YK |
594 | return; |
595 | ||
b6b84d4a | 596 | NF_CT_ASSERT(nat->ct->status & IPS_NAT_DONE_MASK); |
d8a0509a YK |
597 | |
598 | write_lock_bh(&nf_nat_lock); | |
53aba597 | 599 | hlist_del(&nat->bysource); |
b6b84d4a | 600 | nat->ct = NULL; |
d8a0509a YK |
601 | write_unlock_bh(&nf_nat_lock); |
602 | } | |
603 | ||
2d59e5ca YK |
604 | static void nf_nat_move_storage(struct nf_conn *conntrack, void *old) |
605 | { | |
606 | struct nf_conn_nat *new_nat = nf_ct_ext_find(conntrack, NF_CT_EXT_NAT); | |
607 | struct nf_conn_nat *old_nat = (struct nf_conn_nat *)old; | |
b6b84d4a | 608 | struct nf_conn *ct = old_nat->ct; |
2d59e5ca YK |
609 | unsigned int srchash; |
610 | ||
611 | if (!(ct->status & IPS_NAT_DONE_MASK)) | |
612 | return; | |
613 | ||
614 | srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); | |
615 | ||
616 | write_lock_bh(&nf_nat_lock); | |
53aba597 | 617 | hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource); |
b6b84d4a | 618 | new_nat->ct = ct; |
2d59e5ca YK |
619 | write_unlock_bh(&nf_nat_lock); |
620 | } | |
621 | ||
61eb3107 | 622 | static struct nf_ct_ext_type nat_extend __read_mostly = { |
d8a0509a YK |
623 | .len = sizeof(struct nf_conn_nat), |
624 | .align = __alignof__(struct nf_conn_nat), | |
625 | .destroy = nf_nat_cleanup_conntrack, | |
626 | .move = nf_nat_move_storage, | |
627 | .id = NF_CT_EXT_NAT, | |
628 | .flags = NF_CT_EXT_F_PREALLOC, | |
2d59e5ca YK |
629 | }; |
630 | ||
5b1158e9 JK |
631 | static int __init nf_nat_init(void) |
632 | { | |
633 | size_t i; | |
2d59e5ca YK |
634 | int ret; |
635 | ||
636 | ret = nf_ct_extend_register(&nat_extend); | |
637 | if (ret < 0) { | |
638 | printk(KERN_ERR "nf_nat_core: Unable to register extension\n"); | |
639 | return ret; | |
640 | } | |
5b1158e9 JK |
641 | |
642 | /* Leave them the same for the moment. */ | |
643 | nf_nat_htable_size = nf_conntrack_htable_size; | |
644 | ||
53aba597 PM |
645 | bysource = nf_ct_alloc_hashtable(&nf_nat_htable_size, |
646 | &nf_nat_vmalloced); | |
2d59e5ca YK |
647 | if (!bysource) { |
648 | ret = -ENOMEM; | |
649 | goto cleanup_extend; | |
650 | } | |
5b1158e9 JK |
651 | |
652 | /* Sew in builtin protocols. */ | |
653 | write_lock_bh(&nf_nat_lock); | |
654 | for (i = 0; i < MAX_IP_NAT_PROTO; i++) | |
e22a0548 PM |
655 | rcu_assign_pointer(nf_nat_protos[i], &nf_nat_unknown_protocol); |
656 | rcu_assign_pointer(nf_nat_protos[IPPROTO_TCP], &nf_nat_protocol_tcp); | |
657 | rcu_assign_pointer(nf_nat_protos[IPPROTO_UDP], &nf_nat_protocol_udp); | |
658 | rcu_assign_pointer(nf_nat_protos[IPPROTO_ICMP], &nf_nat_protocol_icmp); | |
5b1158e9 JK |
659 | write_unlock_bh(&nf_nat_lock); |
660 | ||
661 | for (i = 0; i < nf_nat_htable_size; i++) { | |
53aba597 | 662 | INIT_HLIST_HEAD(&bysource[i]); |
5b1158e9 JK |
663 | } |
664 | ||
5b1158e9 JK |
665 | /* Initialize fake conntrack so that NAT will skip it */ |
666 | nf_conntrack_untracked.status |= IPS_NAT_DONE_MASK; | |
667 | ||
668 | l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET); | |
669 | return 0; | |
2d59e5ca YK |
670 | |
671 | cleanup_extend: | |
672 | nf_ct_extend_unregister(&nat_extend); | |
673 | return ret; | |
5b1158e9 JK |
674 | } |
675 | ||
676 | /* Clear NAT section of all conntracks, in case we're loaded again. */ | |
677 | static int clean_nat(struct nf_conn *i, void *data) | |
678 | { | |
679 | struct nf_conn_nat *nat = nfct_nat(i); | |
680 | ||
681 | if (!nat) | |
682 | return 0; | |
683 | memset(nat, 0, sizeof(nat)); | |
684 | i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK | IPS_SEQ_ADJUST); | |
685 | return 0; | |
686 | } | |
687 | ||
688 | static void __exit nf_nat_cleanup(void) | |
689 | { | |
690 | nf_ct_iterate_cleanup(&clean_nat, NULL); | |
982d9a9c | 691 | synchronize_rcu(); |
53aba597 | 692 | nf_ct_free_hashtable(bysource, nf_nat_vmalloced, nf_nat_htable_size); |
5b1158e9 | 693 | nf_ct_l3proto_put(l3proto); |
2d59e5ca | 694 | nf_ct_extend_unregister(&nat_extend); |
5b1158e9 JK |
695 | } |
696 | ||
697 | MODULE_LICENSE("GPL"); | |
698 | ||
699 | module_init(nf_nat_init); | |
700 | module_exit(nf_nat_cleanup); |