summaryrefslogtreecommitdiffstats
path: root/src/ct.c
blob: 1dda799d117e2edbb67e26be5da49cd51a106257 (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
/*
 * Conntrack expression related definitions and types.
 *
 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

#include <nft.h>

#include <stddef.h>
#include <stdio.h>
#include <inttypes.h>

#include <netinet/ip.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/nf_conntrack_tuple_common.h>

#include <errno.h>
#include <erec.h>
#include <expression.h>
#include <datatype.h>
#include <ct.h>
#include <gmputil.h>
#include <utils.h>
#include <statement.h>

#define CONNLABEL_CONF	DEFAULT_INCLUDE_PATH "/connlabel.conf"

static const struct symbol_table ct_state_tbl = {
	.base		= BASE_HEXADECIMAL,
	.symbols	= {
		SYMBOL("invalid",	NF_CT_STATE_INVALID_BIT),
		SYMBOL("new",		NF_CT_STATE_BIT(IP_CT_NEW)),
		SYMBOL("established",	NF_CT_STATE_BIT(IP_CT_ESTABLISHED)),
		SYMBOL("related",	NF_CT_STATE_BIT(IP_CT_RELATED)),
		SYMBOL("untracked",	NF_CT_STATE_UNTRACKED_BIT),
		SYMBOL_LIST_END
	}
};

const struct datatype ct_state_type = {
	.type		= TYPE_CT_STATE,
	.name		= "ct_state",
	.desc		= "conntrack state",
	.byteorder	= BYTEORDER_HOST_ENDIAN,
	.size		= 4 * BITS_PER_BYTE,
	.basetype	= &bitmask_type,
	.sym_tbl	= &ct_state_tbl,
};

static const struct symbol_table ct_dir_tbl = {
	.base		= BASE_DECIMAL,
	.symbols	= {
		SYMBOL("original",	IP_CT_DIR_ORIGINAL),
		SYMBOL("reply",		IP_CT_DIR_REPLY),
		SYMBOL_LIST_END
	}
};

const char *ct_dir2str(int dir)
{
	const struct symbolic_constant *s;

	for (s = ct_dir_tbl.symbols; s->identifier != NULL; s++) {
		if (dir == (int)s->value)
			return s->identifier;
	}

	return NULL;
}

const struct datatype ct_dir_type = {
	.type		= TYPE_CT_DIR,
	.name		= "ct_dir",
	.desc		= "conntrack direction",
	.byteorder	= BYTEORDER_INVALID,
	.size		= BITS_PER_BYTE,
	.basetype	= &integer_type,
	.sym_tbl	= &ct_dir_tbl,
};

static const struct symbol_table ct_status_tbl = {
	/*
	 * There are more, but most of them don't make sense for filtering.
	 */
	.base		= BASE_HEXADECIMAL,
	.symbols	= {
		SYMBOL("expected",	IPS_EXPECTED),
		SYMBOL("seen-reply",	IPS_SEEN_REPLY),
		SYMBOL("assured",	IPS_ASSURED),
		SYMBOL("confirmed",	IPS_CONFIRMED),
		SYMBOL("snat",		IPS_SRC_NAT),
		SYMBOL("dnat",		IPS_DST_NAT),
		SYMBOL("dying",		IPS_DYING),
		SYMBOL_LIST_END
	},
};

const struct datatype ct_status_type = {
	.type		= TYPE_CT_STATUS,
	.name		= "ct_status",
	.desc		= "conntrack status",
	.byteorder	= BYTEORDER_HOST_ENDIAN,
	.size		= 4 * BITS_PER_BYTE,
	.basetype	= &bitmask_type,
	.sym_tbl	= &ct_status_tbl,
};

static const struct symbol_table ct_events_tbl = {
	.base		= BASE_HEXADECIMAL,
	.symbols	= {
		SYMBOL("new",		1 << IPCT_NEW),
		SYMBOL("related",	1 << IPCT_RELATED),
		SYMBOL("destroy",	1 << IPCT_DESTROY),
		SYMBOL("reply",		1 << IPCT_REPLY),
		SYMBOL("assured",	1 << IPCT_ASSURED),
		SYMBOL("protoinfo",	1 << IPCT_PROTOINFO),
		SYMBOL("helper",	1 << IPCT_HELPER),
		SYMBOL("mark",		1 << IPCT_MARK),
		SYMBOL("seqadj",	1 << IPCT_SEQADJ),
		SYMBOL("secmark",	1 << IPCT_SECMARK),
		SYMBOL("label",		1 << IPCT_LABEL),
		SYMBOL_LIST_END
	},
};

const struct datatype ct_event_type = {
	.type		= TYPE_CT_EVENTBIT,
	.name		= "ct_event",
	.desc		= "conntrack event bits",
	.byteorder	= BYTEORDER_HOST_ENDIAN,
	.size		= 4 * BITS_PER_BYTE,
	.basetype	= &bitmask_type,
	.sym_tbl	= &ct_events_tbl,
};

#define CT_LABEL_BIT_SIZE 128

const char *ct_label2str(const struct symbol_table *ct_label_tbl,
			 unsigned long value)
{
	const struct symbolic_constant *s;

	for (s = ct_label_tbl->symbols; s->identifier; s++) {
		if (value == s->value)
			return s->identifier;
	}

	return NULL;
}

static void ct_label_type_print(const struct expr *expr,
				 struct output_ctx *octx)
{
	unsigned long bit = mpz_scan1(expr->value, 0);
	const char *labelstr = ct_label2str(octx->tbl.ct_label, bit);

	if (labelstr) {
		nft_print(octx, "\"%s\"", labelstr);
		return;
	}
	/* can happen when connlabel.conf is altered after rules were added */
	nft_print(octx, "%lu", bit);
}

static struct error_record *ct_label_type_parse(struct parse_ctx *ctx,
						const struct expr *sym,
						struct expr **res)
{
	const struct symbolic_constant *s;
	const struct datatype *dtype;
	uint8_t data[CT_LABEL_BIT_SIZE / BITS_PER_BYTE];
	uint64_t bit;
	mpz_t value;

	for (s = ctx->tbl->ct_label->symbols; s->identifier != NULL; s++) {
		if (!strcmp(sym->identifier, s->identifier))
			break;
	}

	dtype = sym->dtype;
	if (s->identifier == NULL) {
		char *ptr;

		errno = 0;
		bit = strtoull(sym->identifier, &ptr, 0);
		if (*ptr)
			return error(&sym->location, "%s: could not parse %s \"%s\"",
				     CONNLABEL_CONF, dtype->desc, sym->identifier);
		if (errno)
			return error(&sym->location, "%s: could not parse %s \"%s\": %s",
				     CONNLABEL_CONF, dtype->desc, sym->identifier, strerror(errno));

	} else {
		bit = s->value;
	}

	if (bit >= CT_LABEL_BIT_SIZE)
		return error(&sym->location, "%s: bit %" PRIu64 " out of range (%u max)",
			     sym->identifier, bit, CT_LABEL_BIT_SIZE);

	mpz_init2(value, dtype->size);
	mpz_setbit(value, bit);
	mpz_export_data(data, value, BYTEORDER_HOST_ENDIAN, sizeof(data));

	*res = constant_expr_alloc(&sym->location, dtype,
				   dtype->byteorder, CT_LABEL_BIT_SIZE, data);
	mpz_clear(value);
	return NULL;
}

const struct datatype ct_label_type = {
	.type		= TYPE_CT_LABEL,
	.name		= "ct_label",
	.desc		= "conntrack label",
	.byteorder	= BYTEORDER_HOST_ENDIAN,
	.size		= CT_LABEL_BIT_SIZE,
	.basetype	= &bitmask_type,
	.print		= ct_label_type_print,
	.json		= ct_label_type_json,
	.parse		= ct_label_type_parse,
};

void ct_label_table_init(struct nft_ctx *ctx)
{
	ctx->output.tbl.ct_label = rt_symbol_table_init(CONNLABEL_CONF);
}

void ct_label_table_exit(struct nft_ctx *ctx)
{
	rt_symbol_table_free(ctx->output.tbl.ct_label);
}

#ifndef NF_CT_HELPER_NAME_LEN
#define NF_CT_HELPER_NAME_LEN	16
#endif

const struct ct_template ct_templates[__NFT_CT_MAX] = {
	[NFT_CT_STATE]		= CT_TEMPLATE("state",	    &ct_state_type,
					      BYTEORDER_HOST_ENDIAN,
					      4 * BITS_PER_BYTE),
	[NFT_CT_DIRECTION]	= CT_TEMPLATE("direction",  &ct_dir_type,
					      BYTEORDER_HOST_ENDIAN,
					      BITS_PER_BYTE),
	[NFT_CT_STATUS]		= CT_TEMPLATE("status",	    &ct_status_type,
					      BYTEORDER_HOST_ENDIAN,
					      4 * BITS_PER_BYTE),
	[NFT_CT_MARK]		= CT_TEMPLATE("mark",	    &mark_type,
					      BYTEORDER_HOST_ENDIAN,
					      4 * BITS_PER_BYTE),
	[NFT_CT_EXPIRATION]	= CT_TEMPLATE("expiration", &time_type,
					      BYTEORDER_HOST_ENDIAN,
					      4 * BITS_PER_BYTE),
	[NFT_CT_HELPER]		= CT_TEMPLATE("helper",	    &string_type,
					      BYTEORDER_HOST_ENDIAN,
					      NF_CT_HELPER_NAME_LEN * BITS_PER_BYTE),
	[NFT_CT_L3PROTOCOL]	= CT_TEMPLATE("l3proto",    &nfproto_type,
					      BYTEORDER_HOST_ENDIAN,
					      BITS_PER_BYTE),
	[NFT_CT_SRC]		= CT_TEMPLATE("saddr",	    &invalid_type,
					      BYTEORDER_BIG_ENDIAN, 0),
	[NFT_CT_DST]		= CT_TEMPLATE("daddr",	    &invalid_type,
					      BYTEORDER_BIG_ENDIAN, 0),
	[NFT_CT_PROTOCOL]	= CT_TEMPLATE("protocol",   &inet_protocol_type,
					      BYTEORDER_BIG_ENDIAN,
					      BITS_PER_BYTE),
	[NFT_CT_PROTO_SRC]	= CT_TEMPLATE("proto-src",  &inet_service_type,
					      BYTEORDER_BIG_ENDIAN,
					      2 * BITS_PER_BYTE),
	[NFT_CT_PROTO_DST]	= CT_TEMPLATE("proto-dst",  &inet_service_type,
					      BYTEORDER_BIG_ENDIAN,
					      2 * BITS_PER_BYTE),
	[NFT_CT_LABELS]		= CT_TEMPLATE("label", &ct_label_type,
					      BYTEORDER_HOST_ENDIAN,
					      CT_LABEL_BIT_SIZE),
	[NFT_CT_BYTES]		= CT_TEMPLATE("bytes", &integer_type,
					      BYTEORDER_HOST_ENDIAN, 64),
	[NFT_CT_PKTS]		= CT_TEMPLATE("packets", &integer_type,
					      BYTEORDER_HOST_ENDIAN, 64),
	[NFT_CT_AVGPKT]		= CT_TEMPLATE("avgpkt", &integer_type,
					      BYTEORDER_HOST_ENDIAN, 64),
	[NFT_CT_ZONE]		= CT_TEMPLATE("zone", &integer_type,
					      BYTEORDER_HOST_ENDIAN, 16),
	[NFT_CT_EVENTMASK]	= CT_TEMPLATE("event", &ct_event_type,
					      BYTEORDER_HOST_ENDIAN, 32),
	[NFT_CT_SRC_IP]		= CT_TEMPLATE("ip saddr", &ipaddr_type,
					      BYTEORDER_BIG_ENDIAN, 32),
	[NFT_CT_DST_IP]		= CT_TEMPLATE("ip daddr", &ipaddr_type,
					      BYTEORDER_BIG_ENDIAN, 32),
	[NFT_CT_SRC_IP6]	= CT_TEMPLATE("ip6 saddr", &ip6addr_type,
					      BYTEORDER_BIG_ENDIAN, 128),
	[NFT_CT_DST_IP6]	= CT_TEMPLATE("ip6 daddr", &ip6addr_type,
					      BYTEORDER_BIG_ENDIAN, 128),
	[NFT_CT_SECMARK]	= CT_TEMPLATE("secmark", &integer_type,
					      BYTEORDER_HOST_ENDIAN, 32),
	[NFT_CT_ID]		= CT_TEMPLATE("id", &integer_type,
					      BYTEORDER_BIG_ENDIAN, 32),
};

static void ct_print(enum nft_ct_keys key, int8_t dir, uint8_t nfproto,
		     struct output_ctx *octx)
{
	const char *dirstr = ct_dir2str(dir);
	const struct proto_desc *desc;

	nft_print(octx, "ct ");
	if (dir < 0)
		goto done;

	if (dirstr)
		nft_print(octx, "%s ", dirstr);

	switch (key) {
	case NFT_CT_SRC:
	case NFT_CT_DST:
		desc = proto_find_upper(&proto_inet, nfproto);
		if (desc)
			nft_print(octx, "%s ", desc->name);
		break;
	default:
		break;
	}

 done:
	nft_print(octx, "%s", ct_templates[key].token);
}

static void ct_expr_print(const struct expr *expr, struct output_ctx *octx)
{
	ct_print(expr->ct.key, expr->ct.direction, expr->ct.nfproto, octx);
}

static bool ct_expr_cmp(const struct expr *e1, const struct expr *e2)
{
	if (e1->ct.key != e2->ct.key)
		return false;

	return e1->ct.direction == e2->ct.direction;
}

static void ct_expr_clone(struct expr *new, const struct expr *expr)
{
	new->ct = expr->ct;
}

static void ct_expr_pctx_update(struct proto_ctx *ctx,
				const struct location *loc,
				const struct expr *left,
				const struct expr *right)
{
	const struct proto_desc *base = NULL, *desc;
	uint32_t nhproto;

	nhproto = mpz_get_uint32(right->value);

	base = ctx->protocol[left->ct.base].desc;
	if (!base)
		return;
	desc = proto_find_upper(base, nhproto);
	if (!desc)
		return;

	proto_ctx_update(ctx, left->ct.base + 1, loc, desc);
}

#define NFTNL_UDATA_CT_KEY 0
#define NFTNL_UDATA_CT_DIR 1
#define NFTNL_UDATA_CT_MAX 2

static int ct_expr_build_udata(struct nftnl_udata_buf *udbuf,
			       const struct expr *expr)
{
	nftnl_udata_put_u32(udbuf, NFTNL_UDATA_CT_KEY, expr->ct.key);
	nftnl_udata_put_u32(udbuf, NFTNL_UDATA_CT_DIR, expr->ct.direction);

	return 0;
}

static int ct_parse_udata(const struct nftnl_udata *attr, void *data)
{
	const struct nftnl_udata **ud = data;
	uint8_t type = nftnl_udata_type(attr);
	uint8_t len = nftnl_udata_len(attr);

	switch (type) {
	case NFTNL_UDATA_CT_KEY:
	case NFTNL_UDATA_CT_DIR:
		if (len != sizeof(uint32_t))
			return -1;
		break;
	default:
		return 0;
	}

	ud[type] = attr;
	return 0;
}

static struct expr *ct_expr_parse_udata(const struct nftnl_udata *attr)
{
	const struct nftnl_udata *ud[NFTNL_UDATA_CT_MAX + 1] = {};
	uint32_t key, dir;
	int err;

	err = nftnl_udata_parse(nftnl_udata_get(attr), nftnl_udata_len(attr),
				ct_parse_udata, ud);
	if (err < 0)
		return NULL;

	if (!ud[NFTNL_UDATA_CT_KEY] ||
	    !ud[NFTNL_UDATA_CT_DIR])
		return NULL;

	key = nftnl_udata_get_u32(ud[NFTNL_UDATA_CT_KEY]);
	dir = nftnl_udata_get_u32(ud[NFTNL_UDATA_CT_DIR]);

	return ct_expr_alloc(&internal_location, key, dir);
}

const struct expr_ops ct_expr_ops = {
	.type		= EXPR_CT,
	.name		= "ct",
	.print		= ct_expr_print,
	.json		= ct_expr_json,
	.cmp		= ct_expr_cmp,
	.clone		= ct_expr_clone,
	.pctx_update	= ct_expr_pctx_update,
	.parse_udata	= ct_expr_parse_udata,
	.build_udata	= ct_expr_build_udata,
};

struct expr *ct_expr_alloc(const struct location *loc, enum nft_ct_keys key,
			   int8_t direction)
{
	const struct ct_template *tmpl = &ct_templates[key];
	struct expr *expr;

	expr = expr_alloc(loc, EXPR_CT, tmpl->dtype,
			  tmpl->byteorder, tmpl->len);
	expr->ct.key = key;
	expr->ct.direction = direction;

	switch (key) {
	case NFT_CT_SRC:
	case NFT_CT_DST:
		expr->ct.base = PROTO_BASE_NETWORK_HDR;
		break;
	case NFT_CT_PROTO_SRC:
	case NFT_CT_PROTO_DST:
		expr->ct.base = PROTO_BASE_TRANSPORT_HDR;
		break;
	case NFT_CT_PROTOCOL:
		expr->flags = EXPR_F_PROTOCOL;
		expr->ct.base = PROTO_BASE_NETWORK_HDR;
		break;
	case NFT_CT_L3PROTOCOL:
		expr->flags = EXPR_F_PROTOCOL;
		expr->ct.base = PROTO_BASE_LL_HDR;
		break;
	default:
		break;
	}

	return expr;
}

void ct_expr_update_type(struct proto_ctx *ctx, struct expr *expr)
{
	const struct proto_desc *desc;

	desc = ctx->protocol[expr->ct.base].desc;

	switch (expr->ct.key) {
	case NFT_CT_SRC:
	case NFT_CT_DST:
		if (desc == &proto_ip) {
			datatype_set(expr, &ipaddr_type);
			expr->ct.nfproto = NFPROTO_IPV4;
		} else if (desc == &proto_ip6) {
			datatype_set(expr, &ip6addr_type);
			expr->ct.nfproto = NFPROTO_IPV6;
		}

		expr->len = expr->dtype->size;
		break;
	case NFT_CT_PROTO_SRC:
	case NFT_CT_PROTO_DST:
		if (desc == NULL)
			break;
		datatype_set(expr, &inet_service_type);
		break;
	case NFT_CT_SRC_IP:
	case NFT_CT_DST_IP:
		expr->dtype = &ipaddr_type;
		expr->len = expr->dtype->size;
		break;
	case NFT_CT_SRC_IP6:
	case NFT_CT_DST_IP6:
		expr->dtype = &ip6addr_type;
		expr->len = expr->dtype->size;
		break;
	default:
		break;
	}
}

static void ct_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
{
	ct_print(stmt->ct.key, stmt->ct.direction, 0, octx);
	nft_print(octx, " set ");
	expr_print(stmt->ct.expr, octx);
}

static void ct_stmt_destroy(struct stmt *stmt)
{
	expr_free(stmt->ct.expr);
}

static const struct stmt_ops ct_stmt_ops = {
	.type		= STMT_CT,
	.name		= "ct",
	.print		= ct_stmt_print,
	.json		= ct_stmt_json,
	.destroy	= ct_stmt_destroy,
};

struct stmt *ct_stmt_alloc(const struct location *loc, enum nft_ct_keys key,
			   int8_t direction, struct expr *expr)
{
	struct stmt *stmt;

	stmt = stmt_alloc(loc, &ct_stmt_ops);
	stmt->ct.key	= key;
	stmt->ct.tmpl	= &ct_templates[key];
	stmt->ct.expr	= expr;
	stmt->ct.direction = direction;

	return stmt;
}

static void notrack_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
{
	nft_print(octx, "notrack");
}

static const struct stmt_ops notrack_stmt_ops = {
	.type		= STMT_NOTRACK,
	.name		= "notrack",
	.print		= notrack_stmt_print,
	.json		= notrack_stmt_json,
};

struct stmt *notrack_stmt_alloc(const struct location *loc)
{
	return stmt_alloc(loc, &notrack_stmt_ops);
}

static void flow_offload_stmt_print(const struct stmt *stmt,
				    struct output_ctx *octx)
{
	nft_print(octx, "flow add @%s", stmt->flow.table_name);
}

static void flow_offload_stmt_destroy(struct stmt *stmt)
{
	xfree(stmt->flow.table_name);
}

static const struct stmt_ops flow_offload_stmt_ops = {
	.type		= STMT_FLOW_OFFLOAD,
	.name		= "flow_offload",
	.print		= flow_offload_stmt_print,
	.destroy	= flow_offload_stmt_destroy,
	.json		= flow_offload_stmt_json,
};

struct stmt *flow_offload_stmt_alloc(const struct location *loc,
				     const char *table_name)
{
	struct stmt *stmt;

	stmt = stmt_alloc(loc, &flow_offload_stmt_ops);
	stmt->flow.table_name	= table_name;

	return stmt;
}