1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> |
4 | * |
5 | * This software has been sponsored by Sophos Astaro <http://www.sophos.com> |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/init.h> |
10 | #include <linux/module.h> |
11 | #include <linux/netlink.h> |
12 | #include <linux/netfilter.h> |
13 | #include <linux/netfilter/nfnetlink.h> |
14 | #include <linux/netfilter/nf_tables.h> |
15 | #include <linux/netfilter/nf_tables_compat.h> |
16 | #include <linux/netfilter/x_tables.h> |
17 | #include <linux/netfilter_ipv4/ip_tables.h> |
18 | #include <linux/netfilter_ipv6/ip6_tables.h> |
19 | #include <linux/netfilter_bridge/ebtables.h> |
20 | #include <linux/netfilter_arp/arp_tables.h> |
21 | #include <net/netfilter/nf_tables.h> |
22 | #include <net/netfilter/nf_log.h> |
23 | |
24 | /* Used for matches where *info is larger than X byte */ |
25 | #define NFT_MATCH_LARGE_THRESH 192 |
26 | |
27 | struct nft_xt_match_priv { |
28 | void *info; |
29 | }; |
30 | |
31 | static int nft_compat_chain_validate_dependency(const struct nft_ctx *ctx, |
32 | const char *tablename) |
33 | { |
34 | enum nft_chain_types type = NFT_CHAIN_T_DEFAULT; |
35 | const struct nft_chain *chain = ctx->chain; |
36 | const struct nft_base_chain *basechain; |
37 | |
38 | if (!tablename || |
39 | !nft_is_base_chain(chain)) |
40 | return 0; |
41 | |
42 | basechain = nft_base_chain(chain); |
43 | if (strcmp(tablename, "nat" ) == 0) { |
44 | if (ctx->family != NFPROTO_BRIDGE) |
45 | type = NFT_CHAIN_T_NAT; |
46 | if (basechain->type->type != type) |
47 | return -EINVAL; |
48 | } |
49 | |
50 | return 0; |
51 | } |
52 | |
53 | union nft_entry { |
54 | struct ipt_entry e4; |
55 | struct ip6t_entry e6; |
56 | struct ebt_entry ebt; |
57 | struct arpt_entry arp; |
58 | }; |
59 | |
60 | static inline void |
61 | nft_compat_set_par(struct xt_action_param *par, |
62 | const struct nft_pktinfo *pkt, |
63 | const void *xt, const void *xt_info) |
64 | { |
65 | par->state = pkt->state; |
66 | par->thoff = nft_thoff(pkt); |
67 | par->fragoff = pkt->fragoff; |
68 | par->target = xt; |
69 | par->targinfo = xt_info; |
70 | par->hotdrop = false; |
71 | } |
72 | |
73 | static void nft_target_eval_xt(const struct nft_expr *expr, |
74 | struct nft_regs *regs, |
75 | const struct nft_pktinfo *pkt) |
76 | { |
77 | void *info = nft_expr_priv(expr); |
78 | struct xt_target *target = expr->ops->data; |
79 | struct sk_buff *skb = pkt->skb; |
80 | struct xt_action_param xt; |
81 | int ret; |
82 | |
83 | nft_compat_set_par(par: &xt, pkt, xt: target, xt_info: info); |
84 | |
85 | ret = target->target(skb, &xt); |
86 | |
87 | if (xt.hotdrop) |
88 | ret = NF_DROP; |
89 | |
90 | switch (ret) { |
91 | case XT_CONTINUE: |
92 | regs->verdict.code = NFT_CONTINUE; |
93 | break; |
94 | default: |
95 | regs->verdict.code = ret; |
96 | break; |
97 | } |
98 | } |
99 | |
100 | static void nft_target_eval_bridge(const struct nft_expr *expr, |
101 | struct nft_regs *regs, |
102 | const struct nft_pktinfo *pkt) |
103 | { |
104 | void *info = nft_expr_priv(expr); |
105 | struct xt_target *target = expr->ops->data; |
106 | struct sk_buff *skb = pkt->skb; |
107 | struct xt_action_param xt; |
108 | int ret; |
109 | |
110 | nft_compat_set_par(par: &xt, pkt, xt: target, xt_info: info); |
111 | |
112 | ret = target->target(skb, &xt); |
113 | |
114 | if (xt.hotdrop) |
115 | ret = NF_DROP; |
116 | |
117 | switch (ret) { |
118 | case EBT_ACCEPT: |
119 | regs->verdict.code = NF_ACCEPT; |
120 | break; |
121 | case EBT_DROP: |
122 | regs->verdict.code = NF_DROP; |
123 | break; |
124 | case EBT_CONTINUE: |
125 | regs->verdict.code = NFT_CONTINUE; |
126 | break; |
127 | case EBT_RETURN: |
128 | regs->verdict.code = NFT_RETURN; |
129 | break; |
130 | default: |
131 | regs->verdict.code = ret; |
132 | break; |
133 | } |
134 | } |
135 | |
136 | static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = { |
137 | [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING }, |
138 | [NFTA_TARGET_REV] = NLA_POLICY_MAX(NLA_BE32, 255), |
139 | [NFTA_TARGET_INFO] = { .type = NLA_BINARY }, |
140 | }; |
141 | |
142 | static void |
143 | nft_target_set_tgchk_param(struct xt_tgchk_param *par, |
144 | const struct nft_ctx *ctx, |
145 | struct xt_target *target, void *info, |
146 | union nft_entry *entry, u16 proto, bool inv) |
147 | { |
148 | par->net = ctx->net; |
149 | par->table = ctx->table->name; |
150 | switch (ctx->family) { |
151 | case AF_INET: |
152 | entry->e4.ip.proto = proto; |
153 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; |
154 | break; |
155 | case AF_INET6: |
156 | if (proto) |
157 | entry->e6.ipv6.flags |= IP6T_F_PROTO; |
158 | |
159 | entry->e6.ipv6.proto = proto; |
160 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; |
161 | break; |
162 | case NFPROTO_BRIDGE: |
163 | entry->ebt.ethproto = (__force __be16)proto; |
164 | entry->ebt.invflags = inv ? EBT_IPROTO : 0; |
165 | break; |
166 | case NFPROTO_ARP: |
167 | break; |
168 | } |
169 | par->entryinfo = entry; |
170 | par->target = target; |
171 | par->targinfo = info; |
172 | if (nft_is_base_chain(chain: ctx->chain)) { |
173 | const struct nft_base_chain *basechain = |
174 | nft_base_chain(chain: ctx->chain); |
175 | const struct nf_hook_ops *ops = &basechain->ops; |
176 | |
177 | par->hook_mask = 1 << ops->hooknum; |
178 | } else { |
179 | par->hook_mask = 0; |
180 | } |
181 | par->family = ctx->family; |
182 | par->nft_compat = true; |
183 | } |
184 | |
185 | static void target_compat_from_user(struct xt_target *t, void *in, void *out) |
186 | { |
187 | int pad; |
188 | |
189 | memcpy(out, in, t->targetsize); |
190 | pad = XT_ALIGN(t->targetsize) - t->targetsize; |
191 | if (pad > 0) |
192 | memset(out + t->targetsize, 0, pad); |
193 | } |
194 | |
195 | static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = { |
196 | [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 }, |
197 | [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, |
198 | }; |
199 | |
200 | static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) |
201 | { |
202 | struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; |
203 | u32 l4proto; |
204 | u32 flags; |
205 | int err; |
206 | |
207 | err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_MAX, nla: attr, |
208 | policy: nft_rule_compat_policy, NULL); |
209 | if (err < 0) |
210 | return err; |
211 | |
212 | if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS]) |
213 | return -EINVAL; |
214 | |
215 | flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS])); |
216 | if (flags & NFT_RULE_COMPAT_F_UNUSED || |
217 | flags & ~NFT_RULE_COMPAT_F_MASK) |
218 | return -EINVAL; |
219 | if (flags & NFT_RULE_COMPAT_F_INV) |
220 | *inv = true; |
221 | |
222 | l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); |
223 | if (l4proto > U16_MAX) |
224 | return -EINVAL; |
225 | |
226 | *proto = l4proto; |
227 | |
228 | return 0; |
229 | } |
230 | |
231 | static void nft_compat_wait_for_destructors(void) |
232 | { |
233 | /* xtables matches or targets can have side effects, e.g. |
234 | * creation/destruction of /proc files. |
235 | * The xt ->destroy functions are run asynchronously from |
236 | * work queue. If we have pending invocations we thus |
237 | * need to wait for those to finish. |
238 | */ |
239 | nf_tables_trans_destroy_flush_work(); |
240 | } |
241 | |
242 | static int |
243 | nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
244 | const struct nlattr * const tb[]) |
245 | { |
246 | void *info = nft_expr_priv(expr); |
247 | struct xt_target *target = expr->ops->data; |
248 | struct xt_tgchk_param par; |
249 | size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO])); |
250 | u16 proto = 0; |
251 | bool inv = false; |
252 | union nft_entry e = {}; |
253 | int ret; |
254 | |
255 | target_compat_from_user(t: target, in: nla_data(nla: tb[NFTA_TARGET_INFO]), out: info); |
256 | |
257 | if (ctx->nla[NFTA_RULE_COMPAT]) { |
258 | ret = nft_parse_compat(attr: ctx->nla[NFTA_RULE_COMPAT], proto: &proto, inv: &inv); |
259 | if (ret < 0) |
260 | return ret; |
261 | } |
262 | |
263 | nft_target_set_tgchk_param(par: &par, ctx, target, info, entry: &e, proto, inv); |
264 | |
265 | nft_compat_wait_for_destructors(); |
266 | |
267 | ret = xt_check_target(&par, size, proto, inv_proto: inv); |
268 | if (ret < 0) { |
269 | if (ret == -ENOENT) { |
270 | const char *modname = NULL; |
271 | |
272 | if (strcmp(target->name, "LOG" ) == 0) |
273 | modname = "nf_log_syslog" ; |
274 | else if (strcmp(target->name, "NFLOG" ) == 0) |
275 | modname = "nfnetlink_log" ; |
276 | |
277 | if (modname && |
278 | nft_request_module(net: ctx->net, fmt: "%s" , modname) == -EAGAIN) |
279 | return -EAGAIN; |
280 | } |
281 | |
282 | return ret; |
283 | } |
284 | |
285 | /* The standard target cannot be used */ |
286 | if (!target->target) |
287 | return -EINVAL; |
288 | |
289 | return 0; |
290 | } |
291 | |
292 | static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr) |
293 | { |
294 | module_put(module: me); |
295 | kfree(objp: expr->ops); |
296 | } |
297 | |
298 | static void |
299 | nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) |
300 | { |
301 | struct xt_target *target = expr->ops->data; |
302 | void *info = nft_expr_priv(expr); |
303 | struct module *me = target->me; |
304 | struct xt_tgdtor_param par; |
305 | |
306 | par.net = ctx->net; |
307 | par.target = target; |
308 | par.targinfo = info; |
309 | par.family = ctx->family; |
310 | if (par.target->destroy != NULL) |
311 | par.target->destroy(&par); |
312 | |
313 | __nft_mt_tg_destroy(me, expr); |
314 | } |
315 | |
316 | static int nft_extension_dump_info(struct sk_buff *skb, int attr, |
317 | const void *info, |
318 | unsigned int size, unsigned int user_size) |
319 | { |
320 | unsigned int info_size, aligned_size = XT_ALIGN(size); |
321 | struct nlattr *nla; |
322 | |
323 | nla = nla_reserve(skb, attrtype: attr, attrlen: aligned_size); |
324 | if (!nla) |
325 | return -1; |
326 | |
327 | info_size = user_size ? : size; |
328 | memcpy(nla_data(nla), info, info_size); |
329 | memset(nla_data(nla) + info_size, 0, aligned_size - info_size); |
330 | |
331 | return 0; |
332 | } |
333 | |
334 | static int nft_target_dump(struct sk_buff *skb, |
335 | const struct nft_expr *expr, bool reset) |
336 | { |
337 | const struct xt_target *target = expr->ops->data; |
338 | void *info = nft_expr_priv(expr); |
339 | |
340 | if (nla_put_string(skb, attrtype: NFTA_TARGET_NAME, str: target->name) || |
341 | nla_put_be32(skb, attrtype: NFTA_TARGET_REV, htonl(target->revision)) || |
342 | nft_extension_dump_info(skb, attr: NFTA_TARGET_INFO, info, |
343 | size: target->targetsize, user_size: target->usersize)) |
344 | goto nla_put_failure; |
345 | |
346 | return 0; |
347 | |
348 | nla_put_failure: |
349 | return -1; |
350 | } |
351 | |
352 | static int nft_target_validate(const struct nft_ctx *ctx, |
353 | const struct nft_expr *expr, |
354 | const struct nft_data **data) |
355 | { |
356 | struct xt_target *target = expr->ops->data; |
357 | unsigned int hook_mask = 0; |
358 | int ret; |
359 | |
360 | if (ctx->family != NFPROTO_IPV4 && |
361 | ctx->family != NFPROTO_IPV6 && |
362 | ctx->family != NFPROTO_INET && |
363 | ctx->family != NFPROTO_BRIDGE && |
364 | ctx->family != NFPROTO_ARP) |
365 | return -EOPNOTSUPP; |
366 | |
367 | ret = nft_chain_validate_hooks(chain: ctx->chain, |
368 | hook_flags: (1 << NF_INET_PRE_ROUTING) | |
369 | (1 << NF_INET_LOCAL_IN) | |
370 | (1 << NF_INET_FORWARD) | |
371 | (1 << NF_INET_LOCAL_OUT) | |
372 | (1 << NF_INET_POST_ROUTING)); |
373 | if (ret) |
374 | return ret; |
375 | |
376 | if (nft_is_base_chain(chain: ctx->chain)) { |
377 | const struct nft_base_chain *basechain = |
378 | nft_base_chain(chain: ctx->chain); |
379 | const struct nf_hook_ops *ops = &basechain->ops; |
380 | |
381 | hook_mask = 1 << ops->hooknum; |
382 | if (target->hooks && !(hook_mask & target->hooks)) |
383 | return -EINVAL; |
384 | |
385 | ret = nft_compat_chain_validate_dependency(ctx, tablename: target->table); |
386 | if (ret < 0) |
387 | return ret; |
388 | } |
389 | return 0; |
390 | } |
391 | |
392 | static void __nft_match_eval(const struct nft_expr *expr, |
393 | struct nft_regs *regs, |
394 | const struct nft_pktinfo *pkt, |
395 | void *info) |
396 | { |
397 | struct xt_match *match = expr->ops->data; |
398 | struct sk_buff *skb = pkt->skb; |
399 | struct xt_action_param xt; |
400 | bool ret; |
401 | |
402 | nft_compat_set_par(par: &xt, pkt, xt: match, xt_info: info); |
403 | |
404 | ret = match->match(skb, &xt); |
405 | |
406 | if (xt.hotdrop) { |
407 | regs->verdict.code = NF_DROP; |
408 | return; |
409 | } |
410 | |
411 | switch (ret ? 1 : 0) { |
412 | case 1: |
413 | regs->verdict.code = NFT_CONTINUE; |
414 | break; |
415 | case 0: |
416 | regs->verdict.code = NFT_BREAK; |
417 | break; |
418 | } |
419 | } |
420 | |
421 | static void nft_match_large_eval(const struct nft_expr *expr, |
422 | struct nft_regs *regs, |
423 | const struct nft_pktinfo *pkt) |
424 | { |
425 | struct nft_xt_match_priv *priv = nft_expr_priv(expr); |
426 | |
427 | __nft_match_eval(expr, regs, pkt, info: priv->info); |
428 | } |
429 | |
430 | static void nft_match_eval(const struct nft_expr *expr, |
431 | struct nft_regs *regs, |
432 | const struct nft_pktinfo *pkt) |
433 | { |
434 | __nft_match_eval(expr, regs, pkt, info: nft_expr_priv(expr)); |
435 | } |
436 | |
437 | static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = { |
438 | [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING }, |
439 | [NFTA_MATCH_REV] = NLA_POLICY_MAX(NLA_BE32, 255), |
440 | [NFTA_MATCH_INFO] = { .type = NLA_BINARY }, |
441 | }; |
442 | |
443 | /* struct xt_mtchk_param and xt_tgchk_param look very similar */ |
444 | static void |
445 | nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx, |
446 | struct xt_match *match, void *info, |
447 | union nft_entry *entry, u16 proto, bool inv) |
448 | { |
449 | par->net = ctx->net; |
450 | par->table = ctx->table->name; |
451 | switch (ctx->family) { |
452 | case AF_INET: |
453 | entry->e4.ip.proto = proto; |
454 | entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; |
455 | break; |
456 | case AF_INET6: |
457 | if (proto) |
458 | entry->e6.ipv6.flags |= IP6T_F_PROTO; |
459 | |
460 | entry->e6.ipv6.proto = proto; |
461 | entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; |
462 | break; |
463 | case NFPROTO_BRIDGE: |
464 | entry->ebt.ethproto = (__force __be16)proto; |
465 | entry->ebt.invflags = inv ? EBT_IPROTO : 0; |
466 | break; |
467 | case NFPROTO_ARP: |
468 | break; |
469 | } |
470 | par->entryinfo = entry; |
471 | par->match = match; |
472 | par->matchinfo = info; |
473 | if (nft_is_base_chain(chain: ctx->chain)) { |
474 | const struct nft_base_chain *basechain = |
475 | nft_base_chain(chain: ctx->chain); |
476 | const struct nf_hook_ops *ops = &basechain->ops; |
477 | |
478 | par->hook_mask = 1 << ops->hooknum; |
479 | } else { |
480 | par->hook_mask = 0; |
481 | } |
482 | par->family = ctx->family; |
483 | par->nft_compat = true; |
484 | } |
485 | |
486 | static void match_compat_from_user(struct xt_match *m, void *in, void *out) |
487 | { |
488 | int pad; |
489 | |
490 | memcpy(out, in, m->matchsize); |
491 | pad = XT_ALIGN(m->matchsize) - m->matchsize; |
492 | if (pad > 0) |
493 | memset(out + m->matchsize, 0, pad); |
494 | } |
495 | |
496 | static int |
497 | __nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
498 | const struct nlattr * const tb[], |
499 | void *info) |
500 | { |
501 | struct xt_match *match = expr->ops->data; |
502 | struct xt_mtchk_param par; |
503 | size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO])); |
504 | u16 proto = 0; |
505 | bool inv = false; |
506 | union nft_entry e = {}; |
507 | int ret; |
508 | |
509 | match_compat_from_user(m: match, in: nla_data(nla: tb[NFTA_MATCH_INFO]), out: info); |
510 | |
511 | if (ctx->nla[NFTA_RULE_COMPAT]) { |
512 | ret = nft_parse_compat(attr: ctx->nla[NFTA_RULE_COMPAT], proto: &proto, inv: &inv); |
513 | if (ret < 0) |
514 | return ret; |
515 | } |
516 | |
517 | nft_match_set_mtchk_param(par: &par, ctx, match, info, entry: &e, proto, inv); |
518 | |
519 | nft_compat_wait_for_destructors(); |
520 | |
521 | return xt_check_match(&par, size, proto, inv_proto: inv); |
522 | } |
523 | |
524 | static int |
525 | nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
526 | const struct nlattr * const tb[]) |
527 | { |
528 | return __nft_match_init(ctx, expr, tb, info: nft_expr_priv(expr)); |
529 | } |
530 | |
531 | static int |
532 | nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr, |
533 | const struct nlattr * const tb[]) |
534 | { |
535 | struct nft_xt_match_priv *priv = nft_expr_priv(expr); |
536 | struct xt_match *m = expr->ops->data; |
537 | int ret; |
538 | |
539 | priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL); |
540 | if (!priv->info) |
541 | return -ENOMEM; |
542 | |
543 | ret = __nft_match_init(ctx, expr, tb, info: priv->info); |
544 | if (ret) |
545 | kfree(objp: priv->info); |
546 | return ret; |
547 | } |
548 | |
549 | static void |
550 | __nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr, |
551 | void *info) |
552 | { |
553 | struct xt_match *match = expr->ops->data; |
554 | struct module *me = match->me; |
555 | struct xt_mtdtor_param par; |
556 | |
557 | par.net = ctx->net; |
558 | par.match = match; |
559 | par.matchinfo = info; |
560 | par.family = ctx->family; |
561 | if (par.match->destroy != NULL) |
562 | par.match->destroy(&par); |
563 | |
564 | __nft_mt_tg_destroy(me, expr); |
565 | } |
566 | |
567 | static void |
568 | nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) |
569 | { |
570 | __nft_match_destroy(ctx, expr, info: nft_expr_priv(expr)); |
571 | } |
572 | |
573 | static void |
574 | nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) |
575 | { |
576 | struct nft_xt_match_priv *priv = nft_expr_priv(expr); |
577 | |
578 | __nft_match_destroy(ctx, expr, info: priv->info); |
579 | kfree(objp: priv->info); |
580 | } |
581 | |
582 | static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr, |
583 | void *info) |
584 | { |
585 | struct xt_match *match = expr->ops->data; |
586 | |
587 | if (nla_put_string(skb, attrtype: NFTA_MATCH_NAME, str: match->name) || |
588 | nla_put_be32(skb, attrtype: NFTA_MATCH_REV, htonl(match->revision)) || |
589 | nft_extension_dump_info(skb, attr: NFTA_MATCH_INFO, info, |
590 | size: match->matchsize, user_size: match->usersize)) |
591 | goto nla_put_failure; |
592 | |
593 | return 0; |
594 | |
595 | nla_put_failure: |
596 | return -1; |
597 | } |
598 | |
599 | static int nft_match_dump(struct sk_buff *skb, |
600 | const struct nft_expr *expr, bool reset) |
601 | { |
602 | return __nft_match_dump(skb, expr, info: nft_expr_priv(expr)); |
603 | } |
604 | |
605 | static int nft_match_large_dump(struct sk_buff *skb, |
606 | const struct nft_expr *e, bool reset) |
607 | { |
608 | struct nft_xt_match_priv *priv = nft_expr_priv(expr: e); |
609 | |
610 | return __nft_match_dump(skb, expr: e, info: priv->info); |
611 | } |
612 | |
613 | static int nft_match_validate(const struct nft_ctx *ctx, |
614 | const struct nft_expr *expr, |
615 | const struct nft_data **data) |
616 | { |
617 | struct xt_match *match = expr->ops->data; |
618 | unsigned int hook_mask = 0; |
619 | int ret; |
620 | |
621 | if (ctx->family != NFPROTO_IPV4 && |
622 | ctx->family != NFPROTO_IPV6 && |
623 | ctx->family != NFPROTO_INET && |
624 | ctx->family != NFPROTO_BRIDGE && |
625 | ctx->family != NFPROTO_ARP) |
626 | return -EOPNOTSUPP; |
627 | |
628 | ret = nft_chain_validate_hooks(chain: ctx->chain, |
629 | hook_flags: (1 << NF_INET_PRE_ROUTING) | |
630 | (1 << NF_INET_LOCAL_IN) | |
631 | (1 << NF_INET_FORWARD) | |
632 | (1 << NF_INET_LOCAL_OUT) | |
633 | (1 << NF_INET_POST_ROUTING)); |
634 | if (ret) |
635 | return ret; |
636 | |
637 | if (nft_is_base_chain(chain: ctx->chain)) { |
638 | const struct nft_base_chain *basechain = |
639 | nft_base_chain(chain: ctx->chain); |
640 | const struct nf_hook_ops *ops = &basechain->ops; |
641 | |
642 | hook_mask = 1 << ops->hooknum; |
643 | if (match->hooks && !(hook_mask & match->hooks)) |
644 | return -EINVAL; |
645 | |
646 | ret = nft_compat_chain_validate_dependency(ctx, tablename: match->table); |
647 | if (ret < 0) |
648 | return ret; |
649 | } |
650 | return 0; |
651 | } |
652 | |
653 | static int |
654 | nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, |
655 | int event, u16 family, const char *name, |
656 | int rev, int target) |
657 | { |
658 | struct nlmsghdr *nlh; |
659 | unsigned int flags = portid ? NLM_F_MULTI : 0; |
660 | |
661 | event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, msg_type: event); |
662 | nlh = nfnl_msg_put(skb, portid, seq, type: event, flags, family, |
663 | NFNETLINK_V0, res_id: 0); |
664 | if (!nlh) |
665 | goto nlmsg_failure; |
666 | |
667 | if (nla_put_string(skb, attrtype: NFTA_COMPAT_NAME, str: name) || |
668 | nla_put_be32(skb, attrtype: NFTA_COMPAT_REV, htonl(rev)) || |
669 | nla_put_be32(skb, attrtype: NFTA_COMPAT_TYPE, htonl(target))) |
670 | goto nla_put_failure; |
671 | |
672 | nlmsg_end(skb, nlh); |
673 | return skb->len; |
674 | |
675 | nlmsg_failure: |
676 | nla_put_failure: |
677 | nlmsg_cancel(skb, nlh); |
678 | return -1; |
679 | } |
680 | |
681 | static int nfnl_compat_get_rcu(struct sk_buff *skb, |
682 | const struct nfnl_info *info, |
683 | const struct nlattr * const tb[]) |
684 | { |
685 | u8 family = info->nfmsg->nfgen_family; |
686 | const char *name, *fmt; |
687 | struct sk_buff *skb2; |
688 | int ret = 0, target; |
689 | u32 rev; |
690 | |
691 | if (tb[NFTA_COMPAT_NAME] == NULL || |
692 | tb[NFTA_COMPAT_REV] == NULL || |
693 | tb[NFTA_COMPAT_TYPE] == NULL) |
694 | return -EINVAL; |
695 | |
696 | name = nla_data(nla: tb[NFTA_COMPAT_NAME]); |
697 | rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV])); |
698 | target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE])); |
699 | |
700 | switch(family) { |
701 | case AF_INET: |
702 | fmt = "ipt_%s" ; |
703 | break; |
704 | case AF_INET6: |
705 | fmt = "ip6t_%s" ; |
706 | break; |
707 | case NFPROTO_BRIDGE: |
708 | fmt = "ebt_%s" ; |
709 | break; |
710 | case NFPROTO_ARP: |
711 | fmt = "arpt_%s" ; |
712 | break; |
713 | default: |
714 | pr_err("nft_compat: unsupported protocol %d\n" , family); |
715 | return -EINVAL; |
716 | } |
717 | |
718 | if (!try_module_get(THIS_MODULE)) |
719 | return -EINVAL; |
720 | |
721 | rcu_read_unlock(); |
722 | try_then_request_module(xt_find_revision(family, name, rev, target, &ret), |
723 | fmt, name); |
724 | if (ret < 0) |
725 | goto out_put; |
726 | |
727 | skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
728 | if (skb2 == NULL) { |
729 | ret = -ENOMEM; |
730 | goto out_put; |
731 | } |
732 | |
733 | /* include the best revision for this extension in the message */ |
734 | if (nfnl_compat_fill_info(skb: skb2, NETLINK_CB(skb).portid, |
735 | seq: info->nlh->nlmsg_seq, |
736 | NFNL_MSG_TYPE(info->nlh->nlmsg_type), |
737 | event: NFNL_MSG_COMPAT_GET, |
738 | family, name, rev: ret, target) <= 0) { |
739 | kfree_skb(skb: skb2); |
740 | goto out_put; |
741 | } |
742 | |
743 | ret = nfnetlink_unicast(skb: skb2, net: info->net, NETLINK_CB(skb).portid); |
744 | out_put: |
745 | rcu_read_lock(); |
746 | module_put(THIS_MODULE); |
747 | |
748 | return ret; |
749 | } |
750 | |
751 | static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { |
752 | [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING, |
753 | .len = NFT_COMPAT_NAME_MAX-1 }, |
754 | [NFTA_COMPAT_REV] = NLA_POLICY_MAX(NLA_BE32, 255), |
755 | [NFTA_COMPAT_TYPE] = { .type = NLA_U32 }, |
756 | }; |
757 | |
758 | static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = { |
759 | [NFNL_MSG_COMPAT_GET] = { |
760 | .call = nfnl_compat_get_rcu, |
761 | .type = NFNL_CB_RCU, |
762 | .attr_count = NFTA_COMPAT_MAX, |
763 | .policy = nfnl_compat_policy_get |
764 | }, |
765 | }; |
766 | |
767 | static const struct nfnetlink_subsystem nfnl_compat_subsys = { |
768 | .name = "nft-compat" , |
769 | .subsys_id = NFNL_SUBSYS_NFT_COMPAT, |
770 | .cb_count = NFNL_MSG_COMPAT_MAX, |
771 | .cb = nfnl_nft_compat_cb, |
772 | }; |
773 | |
774 | static struct nft_expr_type nft_match_type; |
775 | |
776 | static bool nft_match_reduce(struct nft_regs_track *track, |
777 | const struct nft_expr *expr) |
778 | { |
779 | const struct xt_match *match = expr->ops->data; |
780 | |
781 | return strcmp(match->name, "comment" ) == 0; |
782 | } |
783 | |
784 | static const struct nft_expr_ops * |
785 | nft_match_select_ops(const struct nft_ctx *ctx, |
786 | const struct nlattr * const tb[]) |
787 | { |
788 | struct nft_expr_ops *ops; |
789 | struct xt_match *match; |
790 | unsigned int matchsize; |
791 | char *mt_name; |
792 | u32 rev, family; |
793 | int err; |
794 | |
795 | if (tb[NFTA_MATCH_NAME] == NULL || |
796 | tb[NFTA_MATCH_REV] == NULL || |
797 | tb[NFTA_MATCH_INFO] == NULL) |
798 | return ERR_PTR(error: -EINVAL); |
799 | |
800 | mt_name = nla_data(nla: tb[NFTA_MATCH_NAME]); |
801 | rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV])); |
802 | family = ctx->family; |
803 | |
804 | match = xt_request_find_match(af: family, name: mt_name, revision: rev); |
805 | if (IS_ERR(ptr: match)) |
806 | return ERR_PTR(error: -ENOENT); |
807 | |
808 | if (match->matchsize > nla_len(nla: tb[NFTA_MATCH_INFO])) { |
809 | err = -EINVAL; |
810 | goto err; |
811 | } |
812 | |
813 | ops = kzalloc(size: sizeof(struct nft_expr_ops), GFP_KERNEL); |
814 | if (!ops) { |
815 | err = -ENOMEM; |
816 | goto err; |
817 | } |
818 | |
819 | ops->type = &nft_match_type; |
820 | ops->eval = nft_match_eval; |
821 | ops->init = nft_match_init; |
822 | ops->destroy = nft_match_destroy; |
823 | ops->dump = nft_match_dump; |
824 | ops->validate = nft_match_validate; |
825 | ops->data = match; |
826 | ops->reduce = nft_match_reduce; |
827 | |
828 | matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize)); |
829 | if (matchsize > NFT_MATCH_LARGE_THRESH) { |
830 | matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv)); |
831 | |
832 | ops->eval = nft_match_large_eval; |
833 | ops->init = nft_match_large_init; |
834 | ops->destroy = nft_match_large_destroy; |
835 | ops->dump = nft_match_large_dump; |
836 | } |
837 | |
838 | ops->size = matchsize; |
839 | |
840 | return ops; |
841 | err: |
842 | module_put(module: match->me); |
843 | return ERR_PTR(error: err); |
844 | } |
845 | |
846 | static void nft_match_release_ops(const struct nft_expr_ops *ops) |
847 | { |
848 | struct xt_match *match = ops->data; |
849 | |
850 | module_put(module: match->me); |
851 | kfree(objp: ops); |
852 | } |
853 | |
854 | static struct nft_expr_type nft_match_type __read_mostly = { |
855 | .name = "match" , |
856 | .select_ops = nft_match_select_ops, |
857 | .release_ops = nft_match_release_ops, |
858 | .policy = nft_match_policy, |
859 | .maxattr = NFTA_MATCH_MAX, |
860 | .owner = THIS_MODULE, |
861 | }; |
862 | |
863 | static struct nft_expr_type nft_target_type; |
864 | |
865 | static const struct nft_expr_ops * |
866 | nft_target_select_ops(const struct nft_ctx *ctx, |
867 | const struct nlattr * const tb[]) |
868 | { |
869 | struct nft_expr_ops *ops; |
870 | struct xt_target *target; |
871 | char *tg_name; |
872 | u32 rev, family; |
873 | int err; |
874 | |
875 | if (tb[NFTA_TARGET_NAME] == NULL || |
876 | tb[NFTA_TARGET_REV] == NULL || |
877 | tb[NFTA_TARGET_INFO] == NULL) |
878 | return ERR_PTR(error: -EINVAL); |
879 | |
880 | tg_name = nla_data(nla: tb[NFTA_TARGET_NAME]); |
881 | rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); |
882 | family = ctx->family; |
883 | |
884 | if (strcmp(tg_name, XT_ERROR_TARGET) == 0 || |
885 | strcmp(tg_name, XT_STANDARD_TARGET) == 0 || |
886 | strcmp(tg_name, "standard" ) == 0) |
887 | return ERR_PTR(error: -EINVAL); |
888 | |
889 | target = xt_request_find_target(af: family, name: tg_name, revision: rev); |
890 | if (IS_ERR(ptr: target)) |
891 | return ERR_PTR(error: -ENOENT); |
892 | |
893 | if (!target->target) { |
894 | err = -EINVAL; |
895 | goto err; |
896 | } |
897 | |
898 | if (target->targetsize > nla_len(nla: tb[NFTA_TARGET_INFO])) { |
899 | err = -EINVAL; |
900 | goto err; |
901 | } |
902 | |
903 | ops = kzalloc(size: sizeof(struct nft_expr_ops), GFP_KERNEL); |
904 | if (!ops) { |
905 | err = -ENOMEM; |
906 | goto err; |
907 | } |
908 | |
909 | ops->type = &nft_target_type; |
910 | ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize)); |
911 | ops->init = nft_target_init; |
912 | ops->destroy = nft_target_destroy; |
913 | ops->dump = nft_target_dump; |
914 | ops->validate = nft_target_validate; |
915 | ops->data = target; |
916 | ops->reduce = NFT_REDUCE_READONLY; |
917 | |
918 | if (family == NFPROTO_BRIDGE) |
919 | ops->eval = nft_target_eval_bridge; |
920 | else |
921 | ops->eval = nft_target_eval_xt; |
922 | |
923 | return ops; |
924 | err: |
925 | module_put(module: target->me); |
926 | return ERR_PTR(error: err); |
927 | } |
928 | |
929 | static void nft_target_release_ops(const struct nft_expr_ops *ops) |
930 | { |
931 | struct xt_target *target = ops->data; |
932 | |
933 | module_put(module: target->me); |
934 | kfree(objp: ops); |
935 | } |
936 | |
937 | static struct nft_expr_type nft_target_type __read_mostly = { |
938 | .name = "target" , |
939 | .select_ops = nft_target_select_ops, |
940 | .release_ops = nft_target_release_ops, |
941 | .policy = nft_target_policy, |
942 | .maxattr = NFTA_TARGET_MAX, |
943 | .owner = THIS_MODULE, |
944 | }; |
945 | |
946 | static int __init nft_compat_module_init(void) |
947 | { |
948 | int ret; |
949 | |
950 | ret = nft_register_expr(&nft_match_type); |
951 | if (ret < 0) |
952 | return ret; |
953 | |
954 | ret = nft_register_expr(&nft_target_type); |
955 | if (ret < 0) |
956 | goto err_match; |
957 | |
958 | ret = nfnetlink_subsys_register(n: &nfnl_compat_subsys); |
959 | if (ret < 0) { |
960 | pr_err("nft_compat: cannot register with nfnetlink.\n" ); |
961 | goto err_target; |
962 | } |
963 | |
964 | return ret; |
965 | err_target: |
966 | nft_unregister_expr(&nft_target_type); |
967 | err_match: |
968 | nft_unregister_expr(&nft_match_type); |
969 | return ret; |
970 | } |
971 | |
972 | static void __exit nft_compat_module_exit(void) |
973 | { |
974 | nfnetlink_subsys_unregister(n: &nfnl_compat_subsys); |
975 | nft_unregister_expr(&nft_target_type); |
976 | nft_unregister_expr(&nft_match_type); |
977 | } |
978 | |
979 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT); |
980 | |
981 | module_init(nft_compat_module_init); |
982 | module_exit(nft_compat_module_exit); |
983 | |
984 | MODULE_LICENSE("GPL" ); |
985 | MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>" ); |
986 | MODULE_ALIAS_NFT_EXPR("match" ); |
987 | MODULE_ALIAS_NFT_EXPR("target" ); |
988 | MODULE_DESCRIPTION("x_tables over nftables support" ); |
989 | |