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Linux 3.17-rc2
[linux/fpc-iii.git] / net / netfilter / nft_compat.c
blob1840989092ed8eb84f465bf6302131773cb01d87
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[0];
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 int nft_parse_compat(const struct nlattr *attr, u8 *proto, 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 *proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO]));
152 return 0;
153 }
154
155 static int
156 nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
157 const struct nlattr * const tb[])
158 {
159 void *info = nft_expr_priv(expr);
160 struct xt_target *target = expr->ops->data;
161 struct xt_tgchk_param par;
162 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO]));
163 u8 proto = 0;
164 bool inv = false;
165 union nft_entry e = {};
166 int ret;
167
168 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info);
169
170 if (ctx->nla[NFTA_RULE_COMPAT]) {
171 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
172 if (ret < 0)
173 goto err;
174 }
175
176 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv);
177
178 ret = xt_check_target(&par, size, proto, inv);
179 if (ret < 0)
180 goto err;
181
182 /* The standard target cannot be used */
183 if (target->target == NULL) {
184 ret = -EINVAL;
185 goto err;
186 }
187
188 return 0;
189 err:
190 module_put(target->me);
191 return ret;
192 }
193
194 static void
195 nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
196 {
197 struct xt_target *target = expr->ops->data;
198 void *info = nft_expr_priv(expr);
199 struct xt_tgdtor_param par;
200
201 par.net = ctx->net;
202 par.target = target;
203 par.targinfo = info;
204 par.family = ctx->afi->family;
205 if (par.target->destroy != NULL)
206 par.target->destroy(&par);
207
208 module_put(target->me);
209 }
210
211 static int
212 target_dump_info(struct sk_buff *skb, const struct xt_target *t, const void *in)
213 {
214 int ret;
215
216 #ifdef CONFIG_COMPAT
217 if (t->compat_to_user) {
218 mm_segment_t old_fs;
219 void *out;
220
221 out = kmalloc(XT_ALIGN(t->targetsize), GFP_ATOMIC);
222 if (out == NULL)
223 return -ENOMEM;
224
225 /* We want to reuse existing compat_to_user */
226 old_fs = get_fs();
227 set_fs(KERNEL_DS);
228 t->compat_to_user(out, in);
229 set_fs(old_fs);
230 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), out);
231 kfree(out);
232 } else
233 #endif
234 ret = nla_put(skb, NFTA_TARGET_INFO, XT_ALIGN(t->targetsize), in);
235
236 return ret;
237 }
238
239 static int nft_target_dump(struct sk_buff *skb, const struct nft_expr *expr)
240 {
241 const struct xt_target *target = expr->ops->data;
242 void *info = nft_expr_priv(expr);
243
244 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) ||
245 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) ||
246 target_dump_info(skb, target, info))
247 goto nla_put_failure;
248
249 return 0;
250
251 nla_put_failure:
252 return -1;
253 }
254
255 static int nft_target_validate(const struct nft_ctx *ctx,
256 const struct nft_expr *expr,
257 const struct nft_data **data)
258 {
259 struct xt_target *target = expr->ops->data;
260 unsigned int hook_mask = 0;
261
262 if (ctx->chain->flags & NFT_BASE_CHAIN) {
263 const struct nft_base_chain *basechain =
264 nft_base_chain(ctx->chain);
265 const struct nf_hook_ops *ops = &basechain->ops[0];
266
267 hook_mask = 1 << ops->hooknum;
268 if (hook_mask & target->hooks)
269 return 0;
270
271 /* This target is being called from an invalid chain */
272 return -EINVAL;
273 }
274 return 0;
275 }
276
277 static void nft_match_eval(const struct nft_expr *expr,
278 struct nft_data data[NFT_REG_MAX + 1],
279 const struct nft_pktinfo *pkt)
280 {
281 void *info = nft_expr_priv(expr);
282 struct xt_match *match = expr->ops->data;
283 struct sk_buff *skb = pkt->skb;
284 bool ret;
285
286 nft_compat_set_par((struct xt_action_param *)&pkt->xt, match, info);
287
288 ret = match->match(skb, (struct xt_action_param *)&pkt->xt);
289
290 if (pkt->xt.hotdrop) {
291 data[NFT_REG_VERDICT].verdict = NF_DROP;
292 return;
293 }
294
295 switch(ret) {
296 case true:
297 data[NFT_REG_VERDICT].verdict = NFT_CONTINUE;
298 break;
299 case false:
300 data[NFT_REG_VERDICT].verdict = NFT_BREAK;
301 break;
302 }
303 }
304
305 static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = {
306 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING },
307 [NFTA_MATCH_REV] = { .type = NLA_U32 },
308 [NFTA_MATCH_INFO] = { .type = NLA_BINARY },
309 };
310
311 /* struct xt_mtchk_param and xt_tgchk_param look very similar */
312 static void
313 nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx,
314 struct xt_match *match, void *info,
315 union nft_entry *entry, u8 proto, bool inv)
316 {
317 par->net = &init_net;
318 par->table = ctx->table->name;
319 switch (ctx->afi->family) {
320 case AF_INET:
321 entry->e4.ip.proto = proto;
322 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0;
323 break;
324 case AF_INET6:
325 entry->e6.ipv6.proto = proto;
326 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0;
327 break;
328 }
329 par->entryinfo = entry;
330 par->match = match;
331 par->matchinfo = info;
332 if (ctx->chain->flags & NFT_BASE_CHAIN) {
333 const struct nft_base_chain *basechain =
334 nft_base_chain(ctx->chain);
335 const struct nf_hook_ops *ops = &basechain->ops[0];
336
337 par->hook_mask = 1 << ops->hooknum;
338 }
339 par->family = ctx->afi->family;
340 }
341
342 static void match_compat_from_user(struct xt_match *m, void *in, void *out)
343 {
344 #ifdef CONFIG_COMPAT
345 if (m->compat_from_user) {
346 int pad;
347
348 m->compat_from_user(out, in);
349 pad = XT_ALIGN(m->matchsize) - m->matchsize;
350 if (pad > 0)
351 memset(out + m->matchsize, 0, pad);
352 } else
353 #endif
354 memcpy(out, in, XT_ALIGN(m->matchsize));
355 }
356
357 static int
358 nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
359 const struct nlattr * const tb[])
360 {
361 void *info = nft_expr_priv(expr);
362 struct xt_match *match = expr->ops->data;
363 struct xt_mtchk_param par;
364 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO]));
365 u8 proto = 0;
366 bool inv = false;
367 union nft_entry e = {};
368 int ret;
369
370 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info);
371
372 if (ctx->nla[NFTA_RULE_COMPAT]) {
373 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv);
374 if (ret < 0)
375 goto err;
376 }
377
378 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv);
379
380 ret = xt_check_match(&par, size, proto, inv);
381 if (ret < 0)
382 goto err;
383
384 return 0;
385 err:
386 module_put(match->me);
387 return ret;
388 }
389
390 static void
391 nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
392 {
393 struct xt_match *match = expr->ops->data;
394 void *info = nft_expr_priv(expr);
395 struct xt_mtdtor_param par;
396
397 par.net = ctx->net;
398 par.match = match;
399 par.matchinfo = info;
400 par.family = ctx->afi->family;
401 if (par.match->destroy != NULL)
402 par.match->destroy(&par);
403
404 module_put(match->me);
405 }
406
407 static int
408 match_dump_info(struct sk_buff *skb, const struct xt_match *m, const void *in)
409 {
410 int ret;
411
412 #ifdef CONFIG_COMPAT
413 if (m->compat_to_user) {
414 mm_segment_t old_fs;
415 void *out;
416
417 out = kmalloc(XT_ALIGN(m->matchsize), GFP_ATOMIC);
418 if (out == NULL)
419 return -ENOMEM;
420
421 /* We want to reuse existing compat_to_user */
422 old_fs = get_fs();
423 set_fs(KERNEL_DS);
424 m->compat_to_user(out, in);
425 set_fs(old_fs);
426 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), out);
427 kfree(out);
428 } else
429 #endif
430 ret = nla_put(skb, NFTA_MATCH_INFO, XT_ALIGN(m->matchsize), in);
431
432 return ret;
433 }
434
435 static inline int nft_compat_match_offset(struct xt_match *match)
436 {
437 #ifdef CONFIG_COMPAT
438 return xt_compat_match_offset(match);
439 #else
440 return 0;
441 #endif
442 }
443
444 static int nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr)
445 {
446 void *info = nft_expr_priv(expr);
447 struct xt_match *match = expr->ops->data;
448
449 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) ||
450 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) ||
451 match_dump_info(skb, match, info))
452 goto nla_put_failure;
453
454 return 0;
455
456 nla_put_failure:
457 return -1;
458 }
459
460 static int nft_match_validate(const struct nft_ctx *ctx,
461 const struct nft_expr *expr,
462 const struct nft_data **data)
463 {
464 struct xt_match *match = expr->ops->data;
465 unsigned int hook_mask = 0;
466
467 if (ctx->chain->flags & NFT_BASE_CHAIN) {
468 const struct nft_base_chain *basechain =
469 nft_base_chain(ctx->chain);
470 const struct nf_hook_ops *ops = &basechain->ops[0];
471
472 hook_mask = 1 << ops->hooknum;
473 if (hook_mask & match->hooks)
474 return 0;
475
476 /* This match is being called from an invalid chain */
477 return -EINVAL;
478 }
479 return 0;
480 }
481
482 static int
483 nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
484 int event, u16 family, const char *name,
485 int rev, int target)
486 {
487 struct nlmsghdr *nlh;
488 struct nfgenmsg *nfmsg;
489 unsigned int flags = portid ? NLM_F_MULTI : 0;
490
491 event |= NFNL_SUBSYS_NFT_COMPAT << 8;
492 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
493 if (nlh == NULL)
494 goto nlmsg_failure;
495
496 nfmsg = nlmsg_data(nlh);
497 nfmsg->nfgen_family = family;
498 nfmsg->version = NFNETLINK_V0;
499 nfmsg->res_id = 0;
500
501 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
502 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
503 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
504 goto nla_put_failure;
505
506 nlmsg_end(skb, nlh);
507 return skb->len;
508
509 nlmsg_failure:
510 nla_put_failure:
511 nlmsg_cancel(skb, nlh);
512 return -1;
513 }
514
515 static int
516 nfnl_compat_get(struct sock *nfnl, struct sk_buff *skb,
517 const struct nlmsghdr *nlh, const struct nlattr * const tb[])
518 {
519 int ret = 0, target;
520 struct nfgenmsg *nfmsg;
521 const char *fmt;
522 const char *name;
523 u32 rev;
524 struct sk_buff *skb2;
525
526 if (tb[NFTA_COMPAT_NAME] == NULL ||
527 tb[NFTA_COMPAT_REV] == NULL ||
528 tb[NFTA_COMPAT_TYPE] == NULL)
529 return -EINVAL;
530
531 name = nla_data(tb[NFTA_COMPAT_NAME]);
532 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV]));
533 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE]));
534
535 nfmsg = nlmsg_data(nlh);
536
537 switch(nfmsg->nfgen_family) {
538 case AF_INET:
539 fmt = "ipt_%s";
540 break;
541 case AF_INET6:
542 fmt = "ip6t_%s";
543 break;
544 default:
545 pr_err("nft_compat: unsupported protocol %d\n",
546 nfmsg->nfgen_family);
547 return -EINVAL;
548 }
549
550 try_then_request_module(xt_find_revision(nfmsg->nfgen_family, name,
551 rev, target, &ret),
552 fmt, name);
553
554 if (ret < 0)
555 return ret;
556
557 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
558 if (skb2 == NULL)
559 return -ENOMEM;
560
561 /* include the best revision for this extension in the message */
562 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid,
563 nlh->nlmsg_seq,
564 NFNL_MSG_TYPE(nlh->nlmsg_type),
565 NFNL_MSG_COMPAT_GET,
566 nfmsg->nfgen_family,
567 name, ret, target) <= 0) {
568 kfree_skb(skb2);
569 return -ENOSPC;
570 }
571
572 ret = netlink_unicast(nfnl, skb2, NETLINK_CB(skb).portid,
573 MSG_DONTWAIT);
574 if (ret > 0)
575 ret = 0;
576
577 return ret == -EAGAIN ? -ENOBUFS : ret;
578 }
579
580 static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = {
581 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING,
582 .len = NFT_COMPAT_NAME_MAX-1 },
583 [NFTA_COMPAT_REV] = { .type = NLA_U32 },
584 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 },
585 };
586
587 static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = {
588 [NFNL_MSG_COMPAT_GET] = { .call = nfnl_compat_get,
589 .attr_count = NFTA_COMPAT_MAX,
590 .policy = nfnl_compat_policy_get },
591 };
592
593 static const struct nfnetlink_subsystem nfnl_compat_subsys = {
594 .name = "nft-compat",
595 .subsys_id = NFNL_SUBSYS_NFT_COMPAT,
596 .cb_count = NFNL_MSG_COMPAT_MAX,
597 .cb = nfnl_nft_compat_cb,
598 };
599
600 static LIST_HEAD(nft_match_list);
601
602 struct nft_xt {
603 struct list_head head;
604 struct nft_expr_ops ops;
605 };
606
607 static struct nft_expr_type nft_match_type;
608
609 static const struct nft_expr_ops *
610 nft_match_select_ops(const struct nft_ctx *ctx,
611 const struct nlattr * const tb[])
612 {
613 struct nft_xt *nft_match;
614 struct xt_match *match;
615 char *mt_name;
616 __u32 rev, family;
617
618 if (tb[NFTA_MATCH_NAME] == NULL ||
619 tb[NFTA_MATCH_REV] == NULL ||
620 tb[NFTA_MATCH_INFO] == NULL)
621 return ERR_PTR(-EINVAL);
622
623 mt_name = nla_data(tb[NFTA_MATCH_NAME]);
624 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV]));
625 family = ctx->afi->family;
626
627 /* Re-use the existing match if it's already loaded. */
628 list_for_each_entry(nft_match, &nft_match_list, head) {
629 struct xt_match *match = nft_match->ops.data;
630
631 if (strcmp(match->name, mt_name) == 0 &&
632 match->revision == rev && match->family == family)
633 return &nft_match->ops;
634 }
635
636 match = xt_request_find_match(family, mt_name, rev);
637 if (IS_ERR(match))
638 return ERR_PTR(-ENOENT);
639
640 /* This is the first time we use this match, allocate operations */
641 nft_match = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
642 if (nft_match == NULL)
643 return ERR_PTR(-ENOMEM);
644
645 nft_match->ops.type = &nft_match_type;
646 nft_match->ops.size = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize) +
647 nft_compat_match_offset(match));
648 nft_match->ops.eval = nft_match_eval;
649 nft_match->ops.init = nft_match_init;
650 nft_match->ops.destroy = nft_match_destroy;
651 nft_match->ops.dump = nft_match_dump;
652 nft_match->ops.validate = nft_match_validate;
653 nft_match->ops.data = match;
654
655 list_add(&nft_match->head, &nft_match_list);
656
657 return &nft_match->ops;
658 }
659
660 static void nft_match_release(void)
661 {
662 struct nft_xt *nft_match, *tmp;
663
664 list_for_each_entry_safe(nft_match, tmp, &nft_match_list, head)
665 kfree(nft_match);
666 }
667
668 static struct nft_expr_type nft_match_type __read_mostly = {
669 .name = "match",
670 .select_ops = nft_match_select_ops,
671 .policy = nft_match_policy,
672 .maxattr = NFTA_MATCH_MAX,
673 .owner = THIS_MODULE,
674 };
675
676 static LIST_HEAD(nft_target_list);
677
678 static struct nft_expr_type nft_target_type;
679
680 static const struct nft_expr_ops *
681 nft_target_select_ops(const struct nft_ctx *ctx,
682 const struct nlattr * const tb[])
683 {
684 struct nft_xt *nft_target;
685 struct xt_target *target;
686 char *tg_name;
687 __u32 rev, family;
688
689 if (tb[NFTA_TARGET_NAME] == NULL ||
690 tb[NFTA_TARGET_REV] == NULL ||
691 tb[NFTA_TARGET_INFO] == NULL)
692 return ERR_PTR(-EINVAL);
693
694 tg_name = nla_data(tb[NFTA_TARGET_NAME]);
695 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV]));
696 family = ctx->afi->family;
697
698 /* Re-use the existing target if it's already loaded. */
699 list_for_each_entry(nft_target, &nft_match_list, head) {
700 struct xt_target *target = nft_target->ops.data;
701
702 if (strcmp(target->name, tg_name) == 0 &&
703 target->revision == rev && target->family == family)
704 return &nft_target->ops;
705 }
706
707 target = xt_request_find_target(family, tg_name, rev);
708 if (IS_ERR(target))
709 return ERR_PTR(-ENOENT);
710
711 /* This is the first time we use this target, allocate operations */
712 nft_target = kzalloc(sizeof(struct nft_xt), GFP_KERNEL);
713 if (nft_target == NULL)
714 return ERR_PTR(-ENOMEM);
715
716 nft_target->ops.type = &nft_target_type;
717 nft_target->ops.size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize) +
718 nft_compat_target_offset(target));
719 nft_target->ops.eval = nft_target_eval;
720 nft_target->ops.init = nft_target_init;
721 nft_target->ops.destroy = nft_target_destroy;
722 nft_target->ops.dump = nft_target_dump;
723 nft_target->ops.validate = nft_target_validate;
724 nft_target->ops.data = target;
725
726 list_add(&nft_target->head, &nft_target_list);
727
728 return &nft_target->ops;
729 }
730
731 static void nft_target_release(void)
732 {
733 struct nft_xt *nft_target, *tmp;
734
735 list_for_each_entry_safe(nft_target, tmp, &nft_target_list, head)
736 kfree(nft_target);
737 }
738
739 static struct nft_expr_type nft_target_type __read_mostly = {
740 .name = "target",
741 .select_ops = nft_target_select_ops,
742 .policy = nft_target_policy,
743 .maxattr = NFTA_TARGET_MAX,
744 .owner = THIS_MODULE,
745 };
746
747 static int __init nft_compat_module_init(void)
748 {
749 int ret;
750
751 ret = nft_register_expr(&nft_match_type);
752 if (ret < 0)
753 return ret;
754
755 ret = nft_register_expr(&nft_target_type);
756 if (ret < 0)
757 goto err_match;
758
759 ret = nfnetlink_subsys_register(&nfnl_compat_subsys);
760 if (ret < 0) {
761 pr_err("nft_compat: cannot register with nfnetlink.\n");
762 goto err_target;
763 }
764
765 pr_info("nf_tables_compat: (c) 2012 Pablo Neira Ayuso <pablo@netfilter.org>\n");
766
767 return ret;
768
769 err_target:
770 nft_unregister_expr(&nft_target_type);
771 err_match:
772 nft_unregister_expr(&nft_match_type);
773 return ret;
774 }
775
776 static void __exit nft_compat_module_exit(void)
777 {
778 nfnetlink_subsys_unregister(&nfnl_compat_subsys);
779 nft_unregister_expr(&nft_target_type);
780 nft_unregister_expr(&nft_match_type);
781 nft_match_release();
782 nft_target_release();
783 }
784
785 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT);
786
787 module_init(nft_compat_module_init);
788 module_exit(nft_compat_module_exit);
789
790 MODULE_LICENSE("GPL");
791 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
792 MODULE_ALIAS_NFT_EXPR("match");
793 MODULE_ALIAS_NFT_EXPR("target");
Linux with added FPC-III support