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
nft_compat_chain_validate_dependency(const struct nft_ctx * ctx,const char * tablename)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
nft_compat_set_par(struct xt_action_param * par,const struct nft_pktinfo * pkt,const void * xt,const void * xt_info)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
nft_target_eval_xt(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)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(&xt, pkt, target, 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
nft_target_eval_bridge(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)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(&xt, pkt, target, 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
nft_target_set_tgchk_param(struct xt_tgchk_param * par,const struct nft_ctx * ctx,struct xt_target * target,void * info,union nft_entry * entry,u16 proto,bool inv)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(ctx->chain)) {
173 const struct nft_base_chain *basechain =
174 nft_base_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
target_compat_from_user(struct xt_target * t,void * in,void * out)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
nft_parse_compat(const struct nlattr * attr,u16 * proto,bool * inv)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, attr,
208 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
nft_compat_wait_for_destructors(void)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
nft_target_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])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(target, nla_data(tb[NFTA_TARGET_INFO]), info);
256
257 if (ctx->nla[NFTA_RULE_COMPAT]) {
258 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
259 if (ret < 0)
260 return ret;
261 }
262
263 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
264
265 nft_compat_wait_for_destructors();
266
267 ret = xt_check_target(&par, size, 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(ctx->net, "%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
__nft_mt_tg_destroy(struct module * me,const struct nft_expr * expr)292 static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr)
293 {
294 module_put(me);
295 kfree(expr->ops);
296 }
297
298 static void
nft_target_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)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
nft_extension_dump_info(struct sk_buff * skb,int attr,const void * info,unsigned int size,unsigned int user_size)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, attr, 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
nft_target_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)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, NFTA_TARGET_NAME, target->name) ||
341 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
342 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info,
343 target->targetsize, target->usersize))
344 goto nla_put_failure;
345
346 return 0;
347
348 nla_put_failure:
349 return -1;
350 }
351
nft_target_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)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(ctx->chain,
368 (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(ctx->chain)) {
377 const struct nft_base_chain *basechain =
378 nft_base_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, target->table);
386 if (ret < 0)
387 return ret;
388 }
389 return 0;
390 }
391
__nft_match_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt,void * info)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(&xt, pkt, match, 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
nft_match_large_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)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, priv->info);
428 }
429
nft_match_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)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, 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
nft_match_set_mtchk_param(struct xt_mtchk_param * par,const struct nft_ctx * ctx,struct xt_match * match,void * info,union nft_entry * entry,u16 proto,bool inv)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(ctx->chain)) {
474 const struct nft_base_chain *basechain =
475 nft_base_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
match_compat_from_user(struct xt_match * m,void * in,void * out)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
__nft_match_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[],void * info)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(match, nla_data(tb[NFTA_MATCH_INFO]), info);
510
511 if (ctx->nla[NFTA_RULE_COMPAT]) {
512 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
513 if (ret < 0)
514 return ret;
515 }
516
517 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
518
519 nft_compat_wait_for_destructors();
520
521 return xt_check_match(&par, size, proto, inv);
522 }
523
524 static int
nft_match_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])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, nft_expr_priv(expr));
529 }
530
531 static int
nft_match_large_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])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, priv->info);
544 if (ret)
545 kfree(priv->info);
546 return ret;
547 }
548
549 static void
__nft_match_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr,void * info)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
nft_match_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)568 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
569 {
570 __nft_match_destroy(ctx, expr, nft_expr_priv(expr));
571 }
572
573 static void
nft_match_large_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)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, priv->info);
579 kfree(priv->info);
580 }
581
__nft_match_dump(struct sk_buff * skb,const struct nft_expr * expr,void * info)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, NFTA_MATCH_NAME, match->name) ||
588 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
589 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info,
590 match->matchsize, match->usersize))
591 goto nla_put_failure;
592
593 return 0;
594
595 nla_put_failure:
596 return -1;
597 }
598
nft_match_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)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, nft_expr_priv(expr));
603 }
604
nft_match_large_dump(struct sk_buff * skb,const struct nft_expr * e,bool reset)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(e);
609
610 return __nft_match_dump(skb, e, priv->info);
611 }
612
nft_match_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** data)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(ctx->chain,
629 (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(ctx->chain)) {
638 const struct nft_base_chain *basechain =
639 nft_base_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, match->table);
647 if (ret < 0)
648 return ret;
649 }
650 return 0;
651 }
652
653 static int
nfnl_compat_fill_info(struct sk_buff * skb,u32 portid,u32 seq,u32 type,int event,u16 family,const char * name,int rev,int target)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, event);
662 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family,
663 NFNETLINK_V0, 0);
664 if (!nlh)
665 goto nlmsg_failure;
666
667 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
668 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
669 nla_put_be32(skb, 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
nfnl_compat_get_rcu(struct sk_buff * skb,const struct nfnl_info * info,const struct nlattr * const tb[])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(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(skb2, NETLINK_CB(skb).portid,
735 info->nlh->nlmsg_seq,
736 NFNL_MSG_TYPE(info->nlh->nlmsg_type),
737 NFNL_MSG_COMPAT_GET,
738 family, name, ret, target) <= 0) {
739 kfree_skb(skb2);
740 goto out_put;
741 }
742
743 ret = nfnetlink_unicast(skb2, 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
nft_match_reduce(struct nft_regs_track * track,const struct nft_expr * expr)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 *
nft_match_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])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(-EINVAL);
799
800 mt_name = nla_data(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(family, mt_name, rev);
805 if (IS_ERR(match))
806 return ERR_PTR(-ENOENT);
807
808 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) {
809 err = -EINVAL;
810 goto err;
811 }
812
813 ops = kzalloc(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(match->me);
843 return ERR_PTR(err);
844 }
845
nft_match_release_ops(const struct nft_expr_ops * ops)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(match->me);
851 kfree(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 *
nft_target_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])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(-EINVAL);
879
880 tg_name = nla_data(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(-EINVAL);
888
889 target = xt_request_find_target(family, tg_name, rev);
890 if (IS_ERR(target))
891 return ERR_PTR(-ENOENT);
892
893 if (!target->target) {
894 err = -EINVAL;
895 goto err;
896 }
897
898 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) {
899 err = -EINVAL;
900 goto err;
901 }
902
903 ops = kzalloc(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(target->me);
926 return ERR_PTR(err);
927 }
928
nft_target_release_ops(const struct nft_expr_ops * ops)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(target->me);
934 kfree(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
nft_compat_module_init(void)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(&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
nft_compat_module_exit(void)972 static void __exit nft_compat_module_exit(void)
973 {
974 nfnetlink_subsys_unregister(&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