summaryrefslogtreecommitdiffstats
path: root/iptables/nft-cache.c
blob: 6db261fbba4b38b0a9be72053647ddd9e84b8c8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
/*
 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
 */

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <xtables.h>

#include <linux/netfilter/nf_tables.h>

#include <libmnl/libmnl.h>
#include <libnftnl/gen.h>
#include <libnftnl/set.h>
#include <libnftnl/table.h>

#include "nft.h"
#include "nft-cache.h"

void nft_cache_level_set(struct nft_handle *h, int level)
{
	if (level <= h->cache_level)
		return;

	h->cache_level = level;
}

static int genid_cb(const struct nlmsghdr *nlh, void *data)
{
	uint32_t *genid = data;
	struct nftnl_gen *gen;

	gen = nftnl_gen_alloc();
	if (!gen)
		return MNL_CB_ERROR;

	if (nftnl_gen_nlmsg_parse(nlh, gen) < 0)
		goto out;

	*genid = nftnl_gen_get_u32(gen, NFTNL_GEN_ID);

	nftnl_gen_free(gen);
	return MNL_CB_STOP;
out:
	nftnl_gen_free(gen);
	return MNL_CB_ERROR;
}

static void mnl_genid_get(struct nft_handle *h, uint32_t *genid)
{
	char buf[MNL_SOCKET_BUFFER_SIZE];
	struct nlmsghdr *nlh;
	int ret;

	nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETGEN, 0, 0, h->seq);
	ret = mnl_talk(h, nlh, genid_cb, genid);
	if (ret == 0)
		return;

	xtables_error(RESOURCE_PROBLEM,
		      "Could not fetch rule set generation id: %s\n", nft_strerror(errno));
}

static int nftnl_table_list_cb(const struct nlmsghdr *nlh, void *data)
{
	struct nftnl_table *t;
	struct nftnl_table_list *list = data;

	t = nftnl_table_alloc();
	if (t == NULL)
		goto err;

	if (nftnl_table_nlmsg_parse(nlh, t) < 0)
		goto out;

	nftnl_table_list_add_tail(t, list);

	return MNL_CB_OK;
out:
	nftnl_table_free(t);
err:
	return MNL_CB_OK;
}

static int fetch_table_cache(struct nft_handle *h)
{
	char buf[16536];
	struct nlmsghdr *nlh;
	struct nftnl_table_list *list;
	int i, ret;

	if (h->cache->tables)
		return 0;

	list = nftnl_table_list_alloc();
	if (list == NULL)
		return 0;

	nlh = nftnl_rule_nlmsg_build_hdr(buf, NFT_MSG_GETTABLE, h->family,
					NLM_F_DUMP, h->seq);

	ret = mnl_talk(h, nlh, nftnl_table_list_cb, list);
	if (ret < 0 && errno == EINTR)
		assert(nft_restart(h) >= 0);

	h->cache->tables = list;

	for (i = 0; i < NFT_TABLE_MAX; i++) {
		enum nft_table_type type = h->tables[i].type;

		if (!h->tables[i].name)
			continue;

		h->cache->table[type].chains = nftnl_chain_list_alloc();
		if (!h->cache->table[type].chains)
			return 0;

		h->cache->table[type].sets = nftnl_set_list_alloc();
		if (!h->cache->table[type].sets)
			return 0;
	}

	return 1;
}

struct nftnl_chain_list_cb_data {
	struct nft_handle *h;
	const struct builtin_table *t;
};

static int nftnl_chain_list_cb(const struct nlmsghdr *nlh, void *data)
{
	struct nftnl_chain_list_cb_data *d = data;
	const struct builtin_table *t = d->t;
	struct nftnl_chain_list *list;
	struct nft_handle *h = d->h;
	const char *tname, *cname;
	struct nftnl_chain *c;

	c = nftnl_chain_alloc();
	if (c == NULL)
		goto err;

	if (nftnl_chain_nlmsg_parse(nlh, c) < 0)
		goto out;

	tname = nftnl_chain_get_str(c, NFTNL_CHAIN_TABLE);

	if (!t) {
		t = nft_table_builtin_find(h, tname);
		if (!t)
			goto out;
	} else if (strcmp(t->name, tname)) {
		goto out;
	}

	list = h->cache->table[t->type].chains;
	cname = nftnl_chain_get_str(c, NFTNL_CHAIN_NAME);

	if (nftnl_chain_list_lookup_byname(list, cname))
		goto out;

	nftnl_chain_list_add_tail(c, list);

	return MNL_CB_OK;
out:
	nftnl_chain_free(c);
err:
	return MNL_CB_OK;
}

struct nftnl_set_list_cb_data {
	struct nft_handle *h;
	const struct builtin_table *t;
};

static int nftnl_set_list_cb(const struct nlmsghdr *nlh, void *data)
{
	struct nftnl_set_list_cb_data *d = data;
	const struct builtin_table *t = d->t;
	struct nftnl_set_list *list;
	struct nft_handle *h = d->h;
	const char *tname, *sname;
	struct nftnl_set *s;

	s = nftnl_set_alloc();
	if (s == NULL)
		return MNL_CB_OK;

	if (nftnl_set_nlmsg_parse(nlh, s) < 0)
		goto out_free;

	tname = nftnl_set_get_str(s, NFTNL_SET_TABLE);

	if (!t)
		t = nft_table_builtin_find(h, tname);
	else if (strcmp(t->name, tname))
		goto out_free;

	if (!t)
		goto out_free;

	list = h->cache->table[t->type].sets;
	sname = nftnl_set_get_str(s, NFTNL_SET_NAME);

	if (nftnl_set_list_lookup_byname(list, sname))
		goto out_free;

	nftnl_set_list_add_tail(s, list);

	return MNL_CB_OK;
out_free:
	nftnl_set_free(s);
	return MNL_CB_OK;
}

static int set_elem_cb(const struct nlmsghdr *nlh, void *data)
{
	return nftnl_set_elems_nlmsg_parse(nlh, data) ? -1 : MNL_CB_OK;
}

static bool set_has_elements(struct nftnl_set *s)
{
	struct nftnl_set_elems_iter *iter;
	bool ret = false;

	iter = nftnl_set_elems_iter_create(s);
	if (iter) {
		ret = !!nftnl_set_elems_iter_cur(iter);
		nftnl_set_elems_iter_destroy(iter);
	}
	return ret;
}

static int set_fetch_elem_cb(struct nftnl_set *s, void *data)
{
	char buf[MNL_SOCKET_BUFFER_SIZE];
	struct nft_handle *h = data;
	struct nlmsghdr *nlh;

	if (set_has_elements(s))
		return 0;

	nlh = nftnl_nlmsg_build_hdr(buf, NFT_MSG_GETSETELEM, h->family,
				    NLM_F_DUMP, h->seq);
	nftnl_set_elems_nlmsg_build_payload(nlh, s);

	return mnl_talk(h, nlh, set_elem_cb, s);
}

static int fetch_set_cache(struct nft_handle *h,
			   const struct builtin_table *t, const char *set)
{
	struct nftnl_set_list_cb_data d = {
		.h = h,
		.t = t,
	};
	uint16_t flags = NLM_F_DUMP;
	struct nftnl_set *s = NULL;
	struct nlmsghdr *nlh;
	char buf[16536];
	int i, ret;

	if (t) {
		s = nftnl_set_alloc();
		if (!s)
			return -1;

		nftnl_set_set_str(s, NFTNL_SET_TABLE, t->name);

		if (set) {
			nftnl_set_set_str(s, NFTNL_SET_NAME, set);
			flags = NLM_F_ACK;
		}
	}

	nlh = nftnl_set_nlmsg_build_hdr(buf, NFT_MSG_GETSET,
					h->family, flags, h->seq);

	if (s) {
		nftnl_set_nlmsg_build_payload(nlh, s);
		nftnl_set_free(s);
	}

	ret = mnl_talk(h, nlh, nftnl_set_list_cb, &d);
	if (ret < 0 && errno == EINTR) {
		assert(nft_restart(h) >= 0);
		return ret;
	}

	if (t && set) {
		s = nftnl_set_list_lookup_byname(h->cache->table[t->type].sets,
						 set);
		set_fetch_elem_cb(s, h);
	} else if (t) {
		nftnl_set_list_foreach(h->cache->table[t->type].sets,
				       set_fetch_elem_cb, h);
	} else {
		for (i = 0; i < NFT_TABLE_MAX; i++) {
			enum nft_table_type type = h->tables[i].type;

			if (!h->tables[i].name)
				continue;

			nftnl_set_list_foreach(h->cache->table[type].sets,
					       set_fetch_elem_cb, h);
		}
	}
	return ret;
}

static int fetch_chain_cache(struct nft_handle *h,
			     const struct builtin_table *t,
			     const char *chain)
{
	struct nftnl_chain_list_cb_data d = {
		.h = h,
		.t = t,
	};
	char buf[16536];
	struct nlmsghdr *nlh;
	int ret;

	if (t && chain) {
		struct nftnl_chain *c = nftnl_chain_alloc();

		if (!c)
			return -1;

		nlh = nftnl_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN,
						  h->family, NLM_F_ACK,
						  h->seq);
		nftnl_chain_set_str(c, NFTNL_CHAIN_TABLE, t->name);
		nftnl_chain_set_str(c, NFTNL_CHAIN_NAME, chain);
		nftnl_chain_nlmsg_build_payload(nlh, c);
		nftnl_chain_free(c);
	} else {
		nlh = nftnl_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN,
						  h->family, NLM_F_DUMP,
						  h->seq);
	}

	ret = mnl_talk(h, nlh, nftnl_chain_list_cb, &d);
	if (ret < 0 && errno == EINTR)
		assert(nft_restart(h) >= 0);

	return ret;
}

static int nftnl_rule_list_cb(const struct nlmsghdr *nlh, void *data)
{
	struct nftnl_chain *c = data;
	struct nftnl_rule *r;

	r = nftnl_rule_alloc();
	if (r == NULL)
		return MNL_CB_OK;

	if (nftnl_rule_nlmsg_parse(nlh, r) < 0) {
		nftnl_rule_free(r);
		return MNL_CB_OK;
	}

	nftnl_chain_rule_add_tail(r, c);
	return MNL_CB_OK;
}

static int nft_rule_list_update(struct nftnl_chain *c, void *data)
{
	struct nft_handle *h = data;
	char buf[16536];
	struct nlmsghdr *nlh;
	struct nftnl_rule *rule;
	int ret;

	if (nftnl_rule_lookup_byindex(c, 0))
		return 0;

	rule = nftnl_rule_alloc();
	if (!rule)
		return -1;

	nftnl_rule_set_str(rule, NFTNL_RULE_TABLE,
			   nftnl_chain_get_str(c, NFTNL_CHAIN_TABLE));
	nftnl_rule_set_str(rule, NFTNL_RULE_CHAIN,
			   nftnl_chain_get_str(c, NFTNL_CHAIN_NAME));

	nlh = nftnl_rule_nlmsg_build_hdr(buf, NFT_MSG_GETRULE, h->family,
					NLM_F_DUMP, h->seq);
	nftnl_rule_nlmsg_build_payload(nlh, rule);

	ret = mnl_talk(h, nlh, nftnl_rule_list_cb, c);
	if (ret < 0 && errno == EINTR)
		assert(nft_restart(h) >= 0);

	nftnl_rule_free(rule);

	if (h->family == NFPROTO_BRIDGE)
		nft_bridge_chain_postprocess(h, c);

	return 0;
}

static int fetch_rule_cache(struct nft_handle *h,
			    const struct builtin_table *t, const char *chain)
{
	int i;

	if (t) {
		struct nftnl_chain_list *list;
		struct nftnl_chain *c;

		list = h->cache->table[t->type].chains;

		if (chain) {
			c = nftnl_chain_list_lookup_byname(list, chain);
			return nft_rule_list_update(c, h);
		}
		return nftnl_chain_list_foreach(list, nft_rule_list_update, h);
	}

	for (i = 0; i < NFT_TABLE_MAX; i++) {
		enum nft_table_type type = h->tables[i].type;

		if (!h->tables[i].name)
			continue;

		if (nftnl_chain_list_foreach(h->cache->table[type].chains,
					     nft_rule_list_update, h))
			return -1;
	}
	return 0;
}

static void
__nft_build_cache(struct nft_handle *h, enum nft_cache_level level,
		  const struct builtin_table *t, const char *set,
		  const char *chain)
{
	if (h->cache_init)
		return;

	h->cache_init = true;
	mnl_genid_get(h, &h->nft_genid);

	if (h->cache_level >= NFT_CL_TABLES)
		fetch_table_cache(h);
	if (h->cache_level >= NFT_CL_CHAINS)
		fetch_chain_cache(h, t, chain);
	if (h->cache_level >= NFT_CL_SETS)
		fetch_set_cache(h, t, set);
	if (h->cache_level >= NFT_CL_RULES)
		fetch_rule_cache(h, t, chain);
}

void nft_fake_cache(struct nft_handle *h)
{
	fetch_table_cache(h);

	h->cache_level = NFT_CL_FAKE;
	h->cache_init = true;
	mnl_genid_get(h, &h->nft_genid);
}

static void __nft_flush_cache(struct nft_handle *h)
{
	if (!h->cache_index) {
		h->cache_index++;
		h->cache = &h->__cache[h->cache_index];
	} else {
		flush_chain_cache(h, NULL);
	}
}

static int ____flush_rule_cache(struct nftnl_rule *r, void *data)
{
	nftnl_rule_list_del(r);
	nftnl_rule_free(r);

	return 0;
}

static int __flush_rule_cache(struct nftnl_chain *c, void *data)
{
	return nftnl_rule_foreach(c, ____flush_rule_cache, NULL);
}

int flush_rule_cache(struct nft_handle *h, const char *table,
		     struct nftnl_chain *c)
{
	const struct builtin_table *t;

	if (c)
		return __flush_rule_cache(c, NULL);

	t = nft_table_builtin_find(h, table);
	if (!t || !h->cache->table[t->type].chains)
		return 0;

	return nftnl_chain_list_foreach(h->cache->table[t->type].chains,
					__flush_rule_cache, NULL);
}

static int __flush_chain_cache(struct nftnl_chain *c, void *data)
{
	nftnl_chain_list_del(c);
	nftnl_chain_free(c);

	return 0;
}

static int __flush_set_cache(struct nftnl_set *s, void *data)
{
	nftnl_set_list_del(s);
	nftnl_set_free(s);

	return 0;
}

static int flush_cache(struct nft_handle *h, struct nft_cache *c,
		       const char *tablename)
{
	const struct builtin_table *table;
	int i;

	if (tablename) {
		table = nft_table_builtin_find(h, tablename);
		if (!table)
			return 0;
		if (c->table[table->type].chains)
			nftnl_chain_list_foreach(c->table[table->type].chains,
						 __flush_chain_cache, NULL);
		if (c->table[table->type].sets)
			nftnl_set_list_foreach(c->table[table->type].sets,
					       __flush_set_cache, NULL);
		return 0;
	}

	for (i = 0; i < NFT_TABLE_MAX; i++) {
		if (h->tables[i].name == NULL)
			continue;

		if (c->table[i].chains) {
			nftnl_chain_list_free(c->table[i].chains);
			c->table[i].chains = NULL;
		}
		if (c->table[i].sets) {
			nftnl_set_list_free(c->table[i].sets);
			c->table[i].sets = NULL;
		}
	}
	if (c->tables) {
		nftnl_table_list_free(c->tables);
		c->tables = NULL;
	}

	return 1;
}

void flush_chain_cache(struct nft_handle *h, const char *tablename)
{
	if (!h->cache_init)
		return;

	if (flush_cache(h, h->cache, tablename))
		h->cache_init = false;
}

void nft_rebuild_cache(struct nft_handle *h)
{
	if (h->cache_init) {
		__nft_flush_cache(h);
		h->cache_init = false;
	}

	if (h->cache_level == NFT_CL_FAKE)
		nft_fake_cache(h);
	else
		__nft_build_cache(h, h->cache_level, NULL, NULL, NULL);
}

void nft_cache_build(struct nft_handle *h)
{
	__nft_build_cache(h, h->cache_level, NULL, NULL, NULL);
}

void nft_release_cache(struct nft_handle *h)
{
	if (!h->cache_index)
		return;

	flush_cache(h, &h->__cache[0], NULL);
	memcpy(&h->__cache[0], &h->__cache[1], sizeof(h->__cache[0]));
	memset(&h->__cache[1], 0, sizeof(h->__cache[1]));
	h->cache_index = 0;
	h->cache = &h->__cache[0];
}

struct nftnl_table_list *nftnl_table_list_get(struct nft_handle *h)
{
	return h->cache->tables;
}

struct nftnl_set_list *
nft_set_list_get(struct nft_handle *h, const char *table, const char *set)
{
	const struct builtin_table *t;

	t = nft_table_builtin_find(h, table);
	if (!t)
		return NULL;

	return h->cache->table[t->type].sets;
}

struct nftnl_chain_list *
nft_chain_list_get(struct nft_handle *h, const char *table, const char *chain)
{
	const struct builtin_table *t;

	t = nft_table_builtin_find(h, table);
	if (!t)
		return NULL;

	return h->cache->table[t->type].chains;
}