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0ca743a5 PNA |
1 | /* |
2 | * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> | |
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 | * This software has been sponsored by Sophos Astaro <http://www.sophos.com> | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/netlink.h> | |
15 | #include <linux/netfilter.h> | |
16 | #include <linux/netfilter/nfnetlink.h> | |
17 | #include <linux/netfilter/nf_tables.h> | |
18 | #include <linux/netfilter/nf_tables_compat.h> | |
19 | #include <linux/netfilter/x_tables.h> | |
20 | #include <linux/netfilter_ipv4/ip_tables.h> | |
21 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
22 | #include <asm/uaccess.h> /* for set_fs */ | |
23 | #include <net/netfilter/nf_tables.h> | |
24 | ||
25 | union nft_entry { | |
26 | struct ipt_entry e4; | |
27 | struct ip6t_entry e6; | |
28 | }; | |
29 | ||
30 | static inline void | |
31 | nft_compat_set_par(struct xt_action_param *par, void *xt, const void *xt_info) | |
32 | { | |
33 | par->target = xt; | |
34 | par->targinfo = xt_info; | |
35 | par->hotdrop = false; | |
36 | } | |
37 | ||
38 | static void nft_target_eval(const struct nft_expr *expr, | |
39 | struct nft_data data[NFT_REG_MAX + 1], | |
40 | const struct nft_pktinfo *pkt) | |
41 | { | |
42 | void *info = nft_expr_priv(expr); | |
43 | struct xt_target *target = expr->ops->data; | |
44 | struct sk_buff *skb = pkt->skb; | |
45 | int ret; | |
46 | ||
47 | nft_compat_set_par((struct xt_action_param *)&pkt->xt, target, info); | |
48 | ||
49 | ret = target->target(skb, &pkt->xt); | |
50 | ||
51 | if (pkt->xt.hotdrop) | |
52 | ret = NF_DROP; | |
53 | ||
54 | switch(ret) { | |
55 | case XT_CONTINUE: | |
56 | data[NFT_REG_VERDICT].verdict = NFT_CONTINUE; | |
57 | break; | |
58 | default: | |
59 | data[NFT_REG_VERDICT].verdict = ret; | |
60 | break; | |
61 | } | |
62 | return; | |
63 | } | |
64 | ||
65 | static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = { | |
66 | [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING }, | |
67 | [NFTA_TARGET_REV] = { .type = NLA_U32 }, | |
68 | [NFTA_TARGET_INFO] = { .type = NLA_BINARY }, | |
69 | }; | |
70 | ||
71 | static void | |
72 | nft_target_set_tgchk_param(struct xt_tgchk_param *par, | |
73 | const struct nft_ctx *ctx, | |
74 | struct xt_target *target, void *info, | |
75 | union nft_entry *entry, u8 proto, bool inv) | |
76 | { | |
77 | par->net = &init_net; | |
78 | par->table = ctx->table->name; | |
79 | switch (ctx->afi->family) { | |
80 | case AF_INET: | |
81 | entry->e4.ip.proto = proto; | |
82 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; | |
83 | break; | |
84 | case AF_INET6: | |
85 | entry->e6.ipv6.proto = proto; | |
86 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; | |
87 | break; | |
88 | } | |
89 | par->entryinfo = entry; | |
90 | par->target = target; | |
91 | par->targinfo = info; | |
92 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
93 | const struct nft_base_chain *basechain = | |
94 | nft_base_chain(ctx->chain); | |
95 | const struct nf_hook_ops *ops = &basechain->ops; | |
96 | ||
97 | par->hook_mask = 1 << ops->hooknum; | |
98 | } | |
99 | par->family = ctx->afi->family; | |
100 | } | |
101 | ||
102 | static void target_compat_from_user(struct xt_target *t, void *in, void *out) | |
103 | { | |
104 | #ifdef CONFIG_COMPAT | |
105 | if (t->compat_from_user) { | |
106 | int pad; | |
107 | ||
108 | t->compat_from_user(out, in); | |
109 | pad = XT_ALIGN(t->targetsize) - t->targetsize; | |
110 | if (pad > 0) | |
111 | memset(out + t->targetsize, 0, pad); | |
112 | } else | |
113 | #endif | |
114 | memcpy(out, in, XT_ALIGN(t->targetsize)); | |
115 | } | |
116 | ||
117 | static inline int nft_compat_target_offset(struct xt_target *target) | |
118 | { | |
119 | #ifdef CONFIG_COMPAT | |
120 | return xt_compat_target_offset(target); | |
121 | #else | |
122 | return 0; | |
123 | #endif | |
124 | } | |
125 | ||
126 | static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = { | |
127 | [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 }, | |
128 | [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, | |
129 | }; | |
130 | ||
131 | static u8 nft_parse_compat(const struct nlattr *attr, bool *inv) | |
132 | { | |
133 | struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; | |
134 | u32 flags; | |
135 | int err; | |
136 | ||
137 | err = nla_parse_nested(tb, NFTA_RULE_COMPAT_MAX, attr, | |
138 | nft_rule_compat_policy); | |
139 | if (err < 0) | |
140 | return err; | |
141 | ||
142 | if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS]) | |
143 | return -EINVAL; | |
144 | ||
145 | flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS])); | |
146 | if (flags & ~NFT_RULE_COMPAT_F_MASK) | |
147 | return -EINVAL; | |
148 | if (flags & NFT_RULE_COMPAT_F_INV) | |
149 | *inv = true; | |
150 | ||
151 | return ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); | |
152 | } | |
153 | ||
154 | static int | |
155 | nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
156 | const struct nlattr * const tb[]) | |
157 | { | |
158 | void *info = nft_expr_priv(expr); | |
159 | struct xt_target *target = expr->ops->data; | |
160 | struct xt_tgchk_param par; | |
161 | size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO])); | |
162 | u8 proto = 0; | |
163 | bool inv = false; | |
164 | union nft_entry e = {}; | |
165 | int ret; | |
166 | ||
167 | target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info); | |
168 | ||
169 | if (ctx->nla[NFTA_RULE_COMPAT]) | |
170 | proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv); | |
171 | ||
172 | nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv); | |
173 | ||
174 | ret = xt_check_target(&par, size, proto, inv); | |
175 | if (ret < 0) | |
176 | goto err; | |
177 | ||
178 | /* The standard target cannot be used */ | |
179 | if (target->target == NULL) { | |
180 | ret = -EINVAL; | |
181 | goto err; | |
182 | } | |
183 | ||
184 | return 0; | |
185 | err: | |
186 | module_put(target->me); | |
187 | return ret; | |
188 | } | |
189 | ||
190 | static void | |
191 | nft_target_destroy(const struct nft_expr *expr) | |
192 | { | |
193 | struct xt_target *target = expr->ops->data; | |
194 | ||
195 | module_put(target->me); | |
196 | } | |
197 | ||
198 | static int | |
199 | target_dump_info(struct sk_buff *skb, const struct xt_target *t, const void *in) | |
200 | { | |
201 | int ret; | |
202 | ||
203 | #ifdef CONFIG_COMPAT | |
204 | if (t->compat_to_user) { | |
205 | mm_segment_t old_fs; | |
206 | void *out; | |
207 | ||
208 | out = kmalloc(XT_ALIGN(t->targetsize), GFP_ATOMIC); | |
209 | if (out == NULL) | |
210 | return -ENOMEM; | |
211 | ||
212 | /* We want to reuse existing compat_to_user */ | |
213 | old_fs = get_fs(); | |
214 | set_fs(KERNEL_DS); | |
215 | t->compat_to_user(out, in); | |
216 | set_fs(old_fs); | |
217 | ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), out); | |
218 | kfree(out); | |
219 | } else | |
220 | #endif | |
221 | ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), in); | |
222 | ||
223 | return ret; | |
224 | } | |
225 | ||
226 | static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
227 | { | |
228 | const struct xt_target *target = expr->ops->data; | |
229 | void *info = nft_expr_priv(expr); | |
230 | ||
231 | if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) || | |
232 | nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) || | |
233 | target_dump_info(skb, target, info)) | |
234 | goto nla_put_failure; | |
235 | ||
236 | return 0; | |
237 | ||
238 | nla_put_failure: | |
239 | return -1; | |
240 | } | |
241 | ||
242 | static int nft_target_validate(const struct nft_ctx *ctx, | |
243 | const struct nft_expr *expr, | |
244 | const struct nft_data **data) | |
245 | { | |
246 | struct xt_target *target = expr->ops->data; | |
247 | unsigned int hook_mask = 0; | |
248 | ||
249 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
250 | const struct nft_base_chain *basechain = | |
251 | nft_base_chain(ctx->chain); | |
252 | const struct nf_hook_ops *ops = &basechain->ops; | |
253 | ||
254 | hook_mask = 1 << ops->hooknum; | |
255 | if (hook_mask & target->hooks) | |
256 | return 0; | |
257 | ||
258 | /* This target is being called from an invalid chain */ | |
259 | return -EINVAL; | |
260 | } | |
261 | return 0; | |
262 | } | |
263 | ||
264 | static void nft_match_eval(const struct nft_expr *expr, | |
265 | struct nft_data data[NFT_REG_MAX + 1], | |
266 | const struct nft_pktinfo *pkt) | |
267 | { | |
268 | void *info = nft_expr_priv(expr); | |
269 | struct xt_match *match = expr->ops->data; | |
270 | struct sk_buff *skb = pkt->skb; | |
271 | bool ret; | |
272 | ||
273 | nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info); | |
274 | ||
275 | ret = match->match(skb, (struct xt_action_param *)&pkt->xt); | |
276 | ||
277 | if (pkt->xt.hotdrop) { | |
278 | data[NFT_REG_VERDICT].verdict = NF_DROP; | |
279 | return; | |
280 | } | |
281 | ||
282 | switch(ret) { | |
283 | case true: | |
284 | data[NFT_REG_VERDICT].verdict = NFT_CONTINUE; | |
285 | break; | |
286 | case false: | |
287 | data[NFT_REG_VERDICT].verdict = NFT_BREAK; | |
288 | break; | |
289 | } | |
290 | } | |
291 | ||
292 | static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = { | |
293 | [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING }, | |
294 | [NFTA_MATCH_REV] = { .type = NLA_U32 }, | |
295 | [NFTA_MATCH_INFO] = { .type = NLA_BINARY }, | |
296 | }; | |
297 | ||
298 | /* struct xt_mtchk_param and xt_tgchk_param look very similar */ | |
299 | static void | |
300 | nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx, | |
301 | struct xt_match *match, void *info, | |
302 | union nft_entry *entry, u8 proto, bool inv) | |
303 | { | |
304 | par->net = &init_net; | |
305 | par->table = ctx->table->name; | |
306 | switch (ctx->afi->family) { | |
307 | case AF_INET: | |
308 | entry->e4.ip.proto = proto; | |
309 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; | |
310 | break; | |
311 | case AF_INET6: | |
312 | entry->e6.ipv6.proto = proto; | |
313 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; | |
314 | break; | |
315 | } | |
316 | par->entryinfo = entry; | |
317 | par->match = match; | |
318 | par->matchinfo = info; | |
319 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
320 | const struct nft_base_chain *basechain = | |
321 | nft_base_chain(ctx->chain); | |
322 | const struct nf_hook_ops *ops = &basechain->ops; | |
323 | ||
324 | par->hook_mask = 1 << ops->hooknum; | |
325 | } | |
326 | par->family = ctx->afi->family; | |
327 | } | |
328 | ||
329 | static void match_compat_from_user(struct xt_match *m, void *in, void *out) | |
330 | { | |
331 | #ifdef CONFIG_COMPAT | |
332 | if (m->compat_from_user) { | |
333 | int pad; | |
334 | ||
335 | m->compat_from_user(out, in); | |
336 | pad = XT_ALIGN(m->matchsize) - m->matchsize; | |
337 | if (pad > 0) | |
338 | memset(out + m->matchsize, 0, pad); | |
339 | } else | |
340 | #endif | |
341 | memcpy(out, in, XT_ALIGN(m->matchsize)); | |
342 | } | |
343 | ||
344 | static int | |
345 | nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, | |
346 | const struct nlattr * const tb[]) | |
347 | { | |
348 | void *info = nft_expr_priv(expr); | |
349 | struct xt_match *match = expr->ops->data; | |
350 | struct xt_mtchk_param par; | |
351 | size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO])); | |
352 | u8 proto = 0; | |
353 | bool inv = false; | |
354 | union nft_entry e = {}; | |
355 | int ret; | |
356 | ||
357 | match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info); | |
358 | ||
359 | if (ctx->nla[NFTA_RULE_COMPAT]) | |
360 | proto = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &inv); | |
361 | ||
362 | nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv); | |
363 | ||
364 | ret = xt_check_match(&par, size, proto, inv); | |
365 | if (ret < 0) | |
366 | goto err; | |
367 | ||
368 | return 0; | |
369 | err: | |
370 | module_put(match->me); | |
371 | return ret; | |
372 | } | |
373 | ||
374 | static void | |
375 | nft_match_destroy(const struct nft_expr *expr) | |
376 | { | |
377 | struct xt_match *match = expr->ops->data; | |
378 | ||
379 | module_put(match->me); | |
380 | } | |
381 | ||
382 | static int | |
383 | match_dump_info(struct sk_buff *skb, const struct xt_match *m, const void *in) | |
384 | { | |
385 | int ret; | |
386 | ||
387 | #ifdef CONFIG_COMPAT | |
388 | if (m->compat_to_user) { | |
389 | mm_segment_t old_fs; | |
390 | void *out; | |
391 | ||
392 | out = kmalloc(XT_ALIGN(m->matchsize), GFP_ATOMIC); | |
393 | if (out == NULL) | |
394 | return -ENOMEM; | |
395 | ||
396 | /* We want to reuse existing compat_to_user */ | |
397 | old_fs = get_fs(); | |
398 | set_fs(KERNEL_DS); | |
399 | m->compat_to_user(out, in); | |
400 | set_fs(old_fs); | |
401 | ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), out); | |
402 | kfree(out); | |
403 | } else | |
404 | #endif | |
405 | ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), in); | |
406 | ||
407 | return ret; | |
408 | } | |
409 | ||
410 | static inline int nft_compat_match_offset(struct xt_match *match) | |
411 | { | |
412 | #ifdef CONFIG_COMPAT | |
413 | return xt_compat_match_offset(match); | |
414 | #else | |
415 | return 0; | |
416 | #endif | |
417 | } | |
418 | ||
419 | static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
420 | { | |
421 | void *info = nft_expr_priv(expr); | |
422 | struct xt_match *match = expr->ops->data; | |
423 | ||
424 | if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) || | |
425 | nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) || | |
426 | match_dump_info(skb, match, info)) | |
427 | goto nla_put_failure; | |
428 | ||
429 | return 0; | |
430 | ||
431 | nla_put_failure: | |
432 | return -1; | |
433 | } | |
434 | ||
435 | static int nft_match_validate(const struct nft_ctx *ctx, | |
436 | const struct nft_expr *expr, | |
437 | const struct nft_data **data) | |
438 | { | |
439 | struct xt_match *match = expr->ops->data; | |
440 | unsigned int hook_mask = 0; | |
441 | ||
442 | if (ctx->chain->flags & NFT_BASE_CHAIN) { | |
443 | const struct nft_base_chain *basechain = | |
444 | nft_base_chain(ctx->chain); | |
445 | const struct nf_hook_ops *ops = &basechain->ops; | |
446 | ||
447 | hook_mask = 1 << ops->hooknum; | |
448 | if (hook_mask & match->hooks) | |
449 | return 0; | |
450 | ||
451 | /* This match is being called from an invalid chain */ | |
452 | return -EINVAL; | |
453 | } | |
454 | return 0; | |
455 | } | |
456 | ||
457 | static int | |
458 | nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, | |
459 | int event, u16 family, const char *name, | |
460 | int rev, int target) | |
461 | { | |
462 | struct nlmsghdr *nlh; | |
463 | struct nfgenmsg *nfmsg; | |
464 | unsigned int flags = portid ? NLM_F_MULTI : 0; | |
465 | ||
466 | event |= NFNL_SUBSYS_NFT_COMPAT << 8; | |
467 | nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags); | |
468 | if (nlh == NULL) | |
469 | goto nlmsg_failure; | |
470 | ||
471 | nfmsg = nlmsg_data(nlh); | |
472 | nfmsg->nfgen_family = family; | |
473 | nfmsg->version = NFNETLINK_V0; | |
474 | nfmsg->res_id = 0; | |
475 | ||
476 | if (nla_put_string(skb, NFTA_COMPAT_NAME, name) || | |
477 | nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) || | |
478 | nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target))) | |
479 | goto nla_put_failure; | |
480 | ||
481 | nlmsg_end(skb, nlh); | |
482 | return skb->len; | |
483 | ||
484 | nlmsg_failure: | |
485 | nla_put_failure: | |
486 | nlmsg_cancel(skb, nlh); | |
487 | return -1; | |
488 | } | |
489 | ||
490 | static int | |
491 | nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb, | |
492 | const struct nlmsghdr *nlh, const struct nlattr * const tb[]) | |
493 | { | |
494 | int ret = 0, target; | |
495 | struct nfgenmsg *nfmsg; | |
496 | const char *fmt; | |
497 | const char *name; | |
498 | u32 rev; | |
499 | struct sk_buff *skb2; | |
500 | ||
501 | if (tb[NFTA_COMPAT_NAME] == NULL || | |
502 | tb[NFTA_COMPAT_REV] == NULL || | |
503 | tb[NFTA_COMPAT_TYPE] == NULL) | |
504 | return -EINVAL; | |
505 | ||
506 | name = nla_data(tb[NFTA_COMPAT_NAME]); | |
507 | rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV])); | |
508 | target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE])); | |
509 | ||
510 | nfmsg = nlmsg_data(nlh); | |
511 | ||
512 | switch(nfmsg->nfgen_family) { | |
513 | case AF_INET: | |
514 | fmt = "ipt_%s"; | |
515 | break; | |
516 | case AF_INET6: | |
517 | fmt = "ip6t_%s"; | |
518 | break; | |
519 | default: | |
520 | pr_err("nft_compat: unsupported protocol %d\n", | |
521 | nfmsg->nfgen_family); | |
522 | return -EINVAL; | |
523 | } | |
524 | ||
525 | try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name, | |
526 | rev, target, &ret), | |
527 | fmt, name); | |
528 | ||
529 | if (ret < 0) | |
530 | return ret; | |
531 | ||
532 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); | |
533 | if (skb2 == NULL) | |
534 | return -ENOMEM; | |
535 | ||
536 | /* include the best revision for this extension in the message */ | |
537 | if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid, | |
538 | nlh->nlmsg_seq, | |
539 | NFNL_MSG_TYPE(nlh->nlmsg_type), | |
540 | NFNL_MSG_COMPAT_GET, | |
541 | nfmsg->nfgen_family, | |
542 | name, ret, target) <= 0) { | |
543 | kfree_skb(skb2); | |
544 | return -ENOSPC; | |
545 | } | |
546 | ||
547 | ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid, | |
548 | MSG_DONTWAIT); | |
549 | if (ret > 0) | |
550 | ret = 0; | |
551 | ||
552 | return ret == -EAGAIN ? -ENOBUFS : ret; | |
553 | } | |
554 | ||
555 | static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { | |
556 | [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING, | |
557 | .len = NFT_COMPAT_NAME_MAX-1 }, | |
558 | [NFTA_COMPAT_REV] = { .type = NLA_U32 }, | |
559 | [NFTA_COMPAT_TYPE] = { .type = NLA_U32 }, | |
560 | }; | |
561 | ||
562 | static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = { | |
563 | [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get, | |
564 | .attr_count = NFTA_COMPAT_MAX, | |
565 | .policy = nfnl_compat_policy_get }, | |
566 | }; | |
567 | ||
568 | static const struct nfnetlink_subsystem nfnl_compat_subsys = { | |
569 | .name = "nft-compat", | |
570 | .subsys_id = NFNL_SUBSYS_NFT_COMPAT, | |
571 | .cb_count = NFNL_MSG_COMPAT_MAX, | |
572 | .cb = nfnl_nft_compat_cb, | |
573 | }; | |
574 | ||
575 | static LIST_HEAD(nft_match_list); | |
576 | ||
577 | struct nft_xt { | |
578 | struct list_head head; | |
579 | struct nft_expr_ops ops; | |
580 | }; | |
581 | ||
582 | static struct nft_expr_type nft_match_type; | |
583 | ||
584 | static const struct nft_expr_ops * | |
585 | nft_match_select_ops(const struct nft_ctx *ctx, | |
586 | const struct nlattr * const tb[]) | |
587 | { | |
588 | struct nft_xt *nft_match; | |
589 | struct xt_match *match; | |
590 | char *mt_name; | |
591 | __u32 rev, family; | |
592 | ||
593 | if (tb[NFTA_MATCH_NAME] == NULL || | |
594 | tb[NFTA_MATCH_REV] == NULL || | |
595 | tb[NFTA_MATCH_INFO] == NULL) | |
596 | return ERR_PTR(-EINVAL); | |
597 | ||
598 | mt_name = nla_data(tb[NFTA_MATCH_NAME]); | |
599 | rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV])); | |
600 | family = ctx->afi->family; | |
601 | ||
602 | /* Re-use the existing match if it's already loaded. */ | |
603 | list_for_each_entry(nft_match, &nft_match_list, head) { | |
604 | struct xt_match *match = nft_match->ops.data; | |
605 | ||
606 | if (strcmp(match->name, mt_name) == 0 && | |
607 | match->revision == rev && match->family == family) | |
608 | return &nft_match->ops; | |
609 | } | |
610 | ||
611 | match = xt_request_find_match(family, mt_name, rev); | |
612 | if (IS_ERR(match)) | |
613 | return ERR_PTR(-ENOENT); | |
614 | ||
615 | /* This is the first time we use this match, allocate operations */ | |
616 | nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL); | |
617 | if (nft_match == NULL) | |
618 | return ERR_PTR(-ENOMEM); | |
619 | ||
620 | nft_match->ops.type = &nft_match_type; | |
621 | nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize) + | |
622 | nft_compat_match_offset(match)); | |
623 | nft_match->ops.eval = nft_match_eval; | |
624 | nft_match->ops.init = nft_match_init; | |
625 | nft_match->ops.destroy = nft_match_destroy; | |
626 | nft_match->ops.dump = nft_match_dump; | |
627 | nft_match->ops.validate = nft_match_validate; | |
628 | nft_match->ops.data = match; | |
629 | ||
630 | list_add(&nft_match->head, &nft_match_list); | |
631 | ||
632 | return &nft_match->ops; | |
633 | } | |
634 | ||
635 | static void nft_match_release(void) | |
636 | { | |
637 | struct nft_xt *nft_match; | |
638 | ||
639 | list_for_each_entry(nft_match, &nft_match_list, head) | |
640 | kfree(nft_match); | |
641 | } | |
642 | ||
643 | static struct nft_expr_type nft_match_type __read_mostly = { | |
644 | .name = "match", | |
645 | .select_ops = nft_match_select_ops, | |
646 | .policy = nft_match_policy, | |
647 | .maxattr = NFTA_MATCH_MAX, | |
648 | .owner = THIS_MODULE, | |
649 | }; | |
650 | ||
651 | static LIST_HEAD(nft_target_list); | |
652 | ||
653 | static struct nft_expr_type nft_target_type; | |
654 | ||
655 | static const struct nft_expr_ops * | |
656 | nft_target_select_ops(const struct nft_ctx *ctx, | |
657 | const struct nlattr * const tb[]) | |
658 | { | |
659 | struct nft_xt *nft_target; | |
660 | struct xt_target *target; | |
661 | char *tg_name; | |
662 | __u32 rev, family; | |
663 | ||
664 | if (tb[NFTA_TARGET_NAME] == NULL || | |
665 | tb[NFTA_TARGET_REV] == NULL || | |
666 | tb[NFTA_TARGET_INFO] == NULL) | |
667 | return ERR_PTR(-EINVAL); | |
668 | ||
669 | tg_name = nla_data(tb[NFTA_TARGET_NAME]); | |
670 | rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); | |
671 | family = ctx->afi->family; | |
672 | ||
673 | /* Re-use the existing target if it's already loaded. */ | |
674 | list_for_each_entry(nft_target, &nft_match_list, head) { | |
675 | struct xt_target *target = nft_target->ops.data; | |
676 | ||
677 | if (strcmp(target->name, tg_name) == 0 && | |
678 | target->revision == rev && target->family == family) | |
679 | return &nft_target->ops; | |
680 | } | |
681 | ||
682 | target = xt_request_find_target(family, tg_name, rev); | |
683 | if (IS_ERR(target)) | |
684 | return ERR_PTR(-ENOENT); | |
685 | ||
686 | /* This is the first time we use this target, allocate operations */ | |
687 | nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL); | |
688 | if (nft_target == NULL) | |
689 | return ERR_PTR(-ENOMEM); | |
690 | ||
691 | nft_target->ops.type = &nft_target_type; | |
692 | nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize) + | |
693 | nft_compat_target_offset(target)); | |
694 | nft_target->ops.eval = nft_target_eval; | |
695 | nft_target->ops.init = nft_target_init; | |
696 | nft_target->ops.destroy = nft_target_destroy; | |
697 | nft_target->ops.dump = nft_target_dump; | |
698 | nft_target->ops.validate = nft_target_validate; | |
699 | nft_target->ops.data = target; | |
700 | ||
701 | list_add(&nft_target->head, &nft_target_list); | |
702 | ||
703 | return &nft_target->ops; | |
704 | } | |
705 | ||
706 | static void nft_target_release(void) | |
707 | { | |
708 | struct nft_xt *nft_target; | |
709 | ||
710 | list_for_each_entry(nft_target, &nft_target_list, head) | |
711 | kfree(nft_target); | |
712 | } | |
713 | ||
714 | static struct nft_expr_type nft_target_type __read_mostly = { | |
715 | .name = "target", | |
716 | .select_ops = nft_target_select_ops, | |
717 | .policy = nft_target_policy, | |
718 | .maxattr = NFTA_TARGET_MAX, | |
719 | .owner = THIS_MODULE, | |
720 | }; | |
721 | ||
722 | static int __init nft_compat_module_init(void) | |
723 | { | |
724 | int ret; | |
725 | ||
726 | ret = nft_register_expr(&nft_match_type); | |
727 | if (ret < 0) | |
728 | return ret; | |
729 | ||
730 | ret = nft_register_expr(&nft_target_type); | |
731 | if (ret < 0) | |
732 | goto err_match; | |
733 | ||
734 | ret = nfnetlink_subsys_register(&nfnl_compat_subsys); | |
735 | if (ret < 0) { | |
736 | pr_err("nft_compat: cannot register with nfnetlink.\n"); | |
737 | goto err_target; | |
738 | } | |
739 | ||
740 | pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n"); | |
741 | ||
742 | return ret; | |
743 | ||
744 | err_target: | |
745 | nft_unregister_expr(&nft_target_type); | |
746 | err_match: | |
747 | nft_unregister_expr(&nft_match_type); | |
748 | return ret; | |
749 | } | |
750 | ||
751 | static void __exit nft_compat_module_exit(void) | |
752 | { | |
753 | nfnetlink_subsys_unregister(&nfnl_compat_subsys); | |
754 | nft_unregister_expr(&nft_target_type); | |
755 | nft_unregister_expr(&nft_match_type); | |
756 | nft_match_release(); | |
757 | nft_target_release(); | |
758 | } | |
759 | ||
760 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT); | |
761 | ||
762 | module_init(nft_compat_module_init); | |
763 | module_exit(nft_compat_module_exit); | |
764 | ||
765 | MODULE_LICENSE("GPL"); | |
766 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); | |
767 | MODULE_ALIAS_NFT_EXPR("match"); | |
768 | MODULE_ALIAS_NFT_EXPR("target"); |