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1/*
2 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
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 * Development of this code funded by Astaro AG (http://www.astaro.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/nf_tables.h>
17#include <net/netfilter/nf_tables.h>
18// FIXME:
19#include <net/ipv6.h>
20
21struct nft_exthdr {
22 u8 type;
23 u8 offset;
24 u8 len;
25 enum nft_registers dreg:8;
26};
27
28static void nft_exthdr_eval(const struct nft_expr *expr,
29 struct nft_regs *regs,
30 const struct nft_pktinfo *pkt)
31{
32 struct nft_exthdr *priv = nft_expr_priv(expr);
33 u32 *dest = ®s->data[priv->dreg];
34 unsigned int offset = 0;
35 int err;
36
37 err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
38 if (err < 0)
39 goto err;
40 offset += priv->offset;
41
42 dest[priv->len / NFT_REG32_SIZE] = 0;
43 if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
44 goto err;
45 return;
46err:
47 regs->verdict.code = NFT_BREAK;
48}
49
50static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
51 [NFTA_EXTHDR_DREG] = { .type = NLA_U32 },
52 [NFTA_EXTHDR_TYPE] = { .type = NLA_U8 },
53 [NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 },
54 [NFTA_EXTHDR_LEN] = { .type = NLA_U32 },
55};
56
57static int nft_exthdr_init(const struct nft_ctx *ctx,
58 const struct nft_expr *expr,
59 const struct nlattr * const tb[])
60{
61 struct nft_exthdr *priv = nft_expr_priv(expr);
62 u32 offset, len;
63 int err;
64
65 if (tb[NFTA_EXTHDR_DREG] == NULL ||
66 tb[NFTA_EXTHDR_TYPE] == NULL ||
67 tb[NFTA_EXTHDR_OFFSET] == NULL ||
68 tb[NFTA_EXTHDR_LEN] == NULL)
69 return -EINVAL;
70
71 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
72 if (err < 0)
73 return err;
74
75 err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
76 if (err < 0)
77 return err;
78
79 priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
80 priv->offset = offset;
81 priv->len = len;
82 priv->dreg = nft_parse_register(tb[NFTA_EXTHDR_DREG]);
83
84 return nft_validate_register_store(ctx, priv->dreg, NULL,
85 NFT_DATA_VALUE, priv->len);
86}
87
88static int nft_exthdr_dump(struct sk_buff *skb, const struct nft_expr *expr)
89{
90 const struct nft_exthdr *priv = nft_expr_priv(expr);
91
92 if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
93 goto nla_put_failure;
94 if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
95 goto nla_put_failure;
96 if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
97 goto nla_put_failure;
98 if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
99 goto nla_put_failure;
100 return 0;
101
102nla_put_failure:
103 return -1;
104}
105
106static struct nft_expr_type nft_exthdr_type;
107static const struct nft_expr_ops nft_exthdr_ops = {
108 .type = &nft_exthdr_type,
109 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
110 .eval = nft_exthdr_eval,
111 .init = nft_exthdr_init,
112 .dump = nft_exthdr_dump,
113};
114
115static struct nft_expr_type nft_exthdr_type __read_mostly = {
116 .name = "exthdr",
117 .ops = &nft_exthdr_ops,
118 .policy = nft_exthdr_policy,
119 .maxattr = NFTA_EXTHDR_MAX,
120 .owner = THIS_MODULE,
121};
122
123static int __init nft_exthdr_module_init(void)
124{
125 return nft_register_expr(&nft_exthdr_type);
126}
127
128static void __exit nft_exthdr_module_exit(void)
129{
130 nft_unregister_expr(&nft_exthdr_type);
131}
132
133module_init(nft_exthdr_module_init);
134module_exit(nft_exthdr_module_exit);
135
136MODULE_LICENSE("GPL");
137MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
138MODULE_ALIAS_NFT_EXPR("exthdr");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
4 *
5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
6 */
7
8#include <asm/unaligned.h>
9#include <linux/kernel.h>
10#include <linux/netlink.h>
11#include <linux/netfilter.h>
12#include <linux/netfilter/nf_tables.h>
13#include <linux/sctp.h>
14#include <net/netfilter/nf_tables_core.h>
15#include <net/netfilter/nf_tables.h>
16#include <net/tcp.h>
17
18struct nft_exthdr {
19 u8 type;
20 u8 offset;
21 u8 len;
22 u8 op;
23 u8 dreg;
24 u8 sreg;
25 u8 flags;
26};
27
28static unsigned int optlen(const u8 *opt, unsigned int offset)
29{
30 /* Beware zero-length options: make finite progress */
31 if (opt[offset] <= TCPOPT_NOP || opt[offset + 1] == 0)
32 return 1;
33 else
34 return opt[offset + 1];
35}
36
37static void nft_exthdr_ipv6_eval(const struct nft_expr *expr,
38 struct nft_regs *regs,
39 const struct nft_pktinfo *pkt)
40{
41 struct nft_exthdr *priv = nft_expr_priv(expr);
42 u32 *dest = ®s->data[priv->dreg];
43 unsigned int offset = 0;
44 int err;
45
46 if (pkt->skb->protocol != htons(ETH_P_IPV6))
47 goto err;
48
49 err = ipv6_find_hdr(pkt->skb, &offset, priv->type, NULL, NULL);
50 if (priv->flags & NFT_EXTHDR_F_PRESENT) {
51 nft_reg_store8(dest, err >= 0);
52 return;
53 } else if (err < 0) {
54 goto err;
55 }
56 offset += priv->offset;
57
58 dest[priv->len / NFT_REG32_SIZE] = 0;
59 if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
60 goto err;
61 return;
62err:
63 regs->verdict.code = NFT_BREAK;
64}
65
66/* find the offset to specified option.
67 *
68 * If target header is found, its offset is set in *offset and return option
69 * number. Otherwise, return negative error.
70 *
71 * If the first fragment doesn't contain the End of Options it is considered
72 * invalid.
73 */
74static int ipv4_find_option(struct net *net, struct sk_buff *skb,
75 unsigned int *offset, int target)
76{
77 unsigned char optbuf[sizeof(struct ip_options) + 40];
78 struct ip_options *opt = (struct ip_options *)optbuf;
79 struct iphdr *iph, _iph;
80 unsigned int start;
81 bool found = false;
82 __be32 info;
83 int optlen;
84
85 iph = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
86 if (!iph)
87 return -EBADMSG;
88 start = sizeof(struct iphdr);
89
90 optlen = iph->ihl * 4 - (int)sizeof(struct iphdr);
91 if (optlen <= 0)
92 return -ENOENT;
93
94 memset(opt, 0, sizeof(struct ip_options));
95 /* Copy the options since __ip_options_compile() modifies
96 * the options.
97 */
98 if (skb_copy_bits(skb, start, opt->__data, optlen))
99 return -EBADMSG;
100 opt->optlen = optlen;
101
102 if (__ip_options_compile(net, opt, NULL, &info))
103 return -EBADMSG;
104
105 switch (target) {
106 case IPOPT_SSRR:
107 case IPOPT_LSRR:
108 if (!opt->srr)
109 break;
110 found = target == IPOPT_SSRR ? opt->is_strictroute :
111 !opt->is_strictroute;
112 if (found)
113 *offset = opt->srr + start;
114 break;
115 case IPOPT_RR:
116 if (!opt->rr)
117 break;
118 *offset = opt->rr + start;
119 found = true;
120 break;
121 case IPOPT_RA:
122 if (!opt->router_alert)
123 break;
124 *offset = opt->router_alert + start;
125 found = true;
126 break;
127 default:
128 return -EOPNOTSUPP;
129 }
130 return found ? target : -ENOENT;
131}
132
133static void nft_exthdr_ipv4_eval(const struct nft_expr *expr,
134 struct nft_regs *regs,
135 const struct nft_pktinfo *pkt)
136{
137 struct nft_exthdr *priv = nft_expr_priv(expr);
138 u32 *dest = ®s->data[priv->dreg];
139 struct sk_buff *skb = pkt->skb;
140 unsigned int offset;
141 int err;
142
143 if (skb->protocol != htons(ETH_P_IP))
144 goto err;
145
146 err = ipv4_find_option(nft_net(pkt), skb, &offset, priv->type);
147 if (priv->flags & NFT_EXTHDR_F_PRESENT) {
148 nft_reg_store8(dest, err >= 0);
149 return;
150 } else if (err < 0) {
151 goto err;
152 }
153 offset += priv->offset;
154
155 dest[priv->len / NFT_REG32_SIZE] = 0;
156 if (skb_copy_bits(pkt->skb, offset, dest, priv->len) < 0)
157 goto err;
158 return;
159err:
160 regs->verdict.code = NFT_BREAK;
161}
162
163static void *
164nft_tcp_header_pointer(const struct nft_pktinfo *pkt,
165 unsigned int len, void *buffer, unsigned int *tcphdr_len)
166{
167 struct tcphdr *tcph;
168
169 if (pkt->tprot != IPPROTO_TCP || pkt->fragoff)
170 return NULL;
171
172 tcph = skb_header_pointer(pkt->skb, nft_thoff(pkt), sizeof(*tcph), buffer);
173 if (!tcph)
174 return NULL;
175
176 *tcphdr_len = __tcp_hdrlen(tcph);
177 if (*tcphdr_len < sizeof(*tcph) || *tcphdr_len > len)
178 return NULL;
179
180 return skb_header_pointer(pkt->skb, nft_thoff(pkt), *tcphdr_len, buffer);
181}
182
183static void nft_exthdr_tcp_eval(const struct nft_expr *expr,
184 struct nft_regs *regs,
185 const struct nft_pktinfo *pkt)
186{
187 u8 buff[sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE];
188 struct nft_exthdr *priv = nft_expr_priv(expr);
189 unsigned int i, optl, tcphdr_len, offset;
190 u32 *dest = ®s->data[priv->dreg];
191 struct tcphdr *tcph;
192 u8 *opt;
193
194 tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
195 if (!tcph)
196 goto err;
197
198 opt = (u8 *)tcph;
199 for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
200 optl = optlen(opt, i);
201
202 if (priv->type != opt[i])
203 continue;
204
205 if (i + optl > tcphdr_len || priv->len + priv->offset > optl)
206 goto err;
207
208 offset = i + priv->offset;
209 if (priv->flags & NFT_EXTHDR_F_PRESENT) {
210 *dest = 1;
211 } else {
212 dest[priv->len / NFT_REG32_SIZE] = 0;
213 memcpy(dest, opt + offset, priv->len);
214 }
215
216 return;
217 }
218
219err:
220 if (priv->flags & NFT_EXTHDR_F_PRESENT)
221 *dest = 0;
222 else
223 regs->verdict.code = NFT_BREAK;
224}
225
226static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr,
227 struct nft_regs *regs,
228 const struct nft_pktinfo *pkt)
229{
230 u8 buff[sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE];
231 struct nft_exthdr *priv = nft_expr_priv(expr);
232 unsigned int i, optl, tcphdr_len, offset;
233 struct tcphdr *tcph;
234 u8 *opt;
235
236 tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
237 if (!tcph)
238 goto err;
239
240 opt = (u8 *)tcph;
241 for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
242 union {
243 __be16 v16;
244 __be32 v32;
245 } old, new;
246
247 optl = optlen(opt, i);
248
249 if (priv->type != opt[i])
250 continue;
251
252 if (i + optl > tcphdr_len || priv->len + priv->offset > optl)
253 goto err;
254
255 if (skb_ensure_writable(pkt->skb,
256 nft_thoff(pkt) + i + priv->len))
257 goto err;
258
259 tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff,
260 &tcphdr_len);
261 if (!tcph)
262 goto err;
263
264 offset = i + priv->offset;
265
266 switch (priv->len) {
267 case 2:
268 old.v16 = (__force __be16)get_unaligned((u16 *)(opt + offset));
269 new.v16 = (__force __be16)nft_reg_load16(
270 ®s->data[priv->sreg]);
271
272 switch (priv->type) {
273 case TCPOPT_MSS:
274 /* increase can cause connection to stall */
275 if (ntohs(old.v16) <= ntohs(new.v16))
276 return;
277 break;
278 }
279
280 if (old.v16 == new.v16)
281 return;
282
283 put_unaligned(new.v16, (__be16*)(opt + offset));
284 inet_proto_csum_replace2(&tcph->check, pkt->skb,
285 old.v16, new.v16, false);
286 break;
287 case 4:
288 new.v32 = nft_reg_load_be32(®s->data[priv->sreg]);
289 old.v32 = (__force __be32)get_unaligned((u32 *)(opt + offset));
290
291 if (old.v32 == new.v32)
292 return;
293
294 put_unaligned(new.v32, (__be32*)(opt + offset));
295 inet_proto_csum_replace4(&tcph->check, pkt->skb,
296 old.v32, new.v32, false);
297 break;
298 default:
299 WARN_ON_ONCE(1);
300 break;
301 }
302
303 return;
304 }
305 return;
306err:
307 regs->verdict.code = NFT_BREAK;
308}
309
310static void nft_exthdr_tcp_strip_eval(const struct nft_expr *expr,
311 struct nft_regs *regs,
312 const struct nft_pktinfo *pkt)
313{
314 u8 buff[sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE];
315 struct nft_exthdr *priv = nft_expr_priv(expr);
316 unsigned int i, tcphdr_len, optl;
317 struct tcphdr *tcph;
318 u8 *opt;
319
320 tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
321 if (!tcph)
322 goto err;
323
324 if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len))
325 goto drop;
326
327 opt = (u8 *)nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len);
328 if (!opt)
329 goto err;
330 for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) {
331 unsigned int j;
332
333 optl = optlen(opt, i);
334 if (priv->type != opt[i])
335 continue;
336
337 if (i + optl > tcphdr_len)
338 goto drop;
339
340 for (j = 0; j < optl; ++j) {
341 u16 n = TCPOPT_NOP;
342 u16 o = opt[i+j];
343
344 if ((i + j) % 2 == 0) {
345 o <<= 8;
346 n <<= 8;
347 }
348 inet_proto_csum_replace2(&tcph->check, pkt->skb, htons(o),
349 htons(n), false);
350 }
351 memset(opt + i, TCPOPT_NOP, optl);
352 return;
353 }
354
355 /* option not found, continue. This allows to do multiple
356 * option removals per rule.
357 */
358 return;
359err:
360 regs->verdict.code = NFT_BREAK;
361 return;
362drop:
363 /* can't remove, no choice but to drop */
364 regs->verdict.code = NF_DROP;
365}
366
367static void nft_exthdr_sctp_eval(const struct nft_expr *expr,
368 struct nft_regs *regs,
369 const struct nft_pktinfo *pkt)
370{
371 unsigned int offset = nft_thoff(pkt) + sizeof(struct sctphdr);
372 struct nft_exthdr *priv = nft_expr_priv(expr);
373 u32 *dest = ®s->data[priv->dreg];
374 const struct sctp_chunkhdr *sch;
375 struct sctp_chunkhdr _sch;
376
377 if (pkt->tprot != IPPROTO_SCTP)
378 goto err;
379
380 do {
381 sch = skb_header_pointer(pkt->skb, offset, sizeof(_sch), &_sch);
382 if (!sch || !sch->length)
383 break;
384
385 if (sch->type == priv->type) {
386 if (priv->flags & NFT_EXTHDR_F_PRESENT) {
387 nft_reg_store8(dest, true);
388 return;
389 }
390 if (priv->offset + priv->len > ntohs(sch->length) ||
391 offset + ntohs(sch->length) > pkt->skb->len)
392 break;
393
394 dest[priv->len / NFT_REG32_SIZE] = 0;
395 if (skb_copy_bits(pkt->skb, offset + priv->offset,
396 dest, priv->len) < 0)
397 break;
398 return;
399 }
400 offset += SCTP_PAD4(ntohs(sch->length));
401 } while (offset < pkt->skb->len);
402err:
403 if (priv->flags & NFT_EXTHDR_F_PRESENT)
404 nft_reg_store8(dest, false);
405 else
406 regs->verdict.code = NFT_BREAK;
407}
408
409static const struct nla_policy nft_exthdr_policy[NFTA_EXTHDR_MAX + 1] = {
410 [NFTA_EXTHDR_DREG] = { .type = NLA_U32 },
411 [NFTA_EXTHDR_TYPE] = { .type = NLA_U8 },
412 [NFTA_EXTHDR_OFFSET] = { .type = NLA_U32 },
413 [NFTA_EXTHDR_LEN] = { .type = NLA_U32 },
414 [NFTA_EXTHDR_FLAGS] = { .type = NLA_U32 },
415 [NFTA_EXTHDR_OP] = { .type = NLA_U32 },
416 [NFTA_EXTHDR_SREG] = { .type = NLA_U32 },
417};
418
419static int nft_exthdr_init(const struct nft_ctx *ctx,
420 const struct nft_expr *expr,
421 const struct nlattr * const tb[])
422{
423 struct nft_exthdr *priv = nft_expr_priv(expr);
424 u32 offset, len, flags = 0, op = NFT_EXTHDR_OP_IPV6;
425 int err;
426
427 if (!tb[NFTA_EXTHDR_DREG] ||
428 !tb[NFTA_EXTHDR_TYPE] ||
429 !tb[NFTA_EXTHDR_OFFSET] ||
430 !tb[NFTA_EXTHDR_LEN])
431 return -EINVAL;
432
433 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
434 if (err < 0)
435 return err;
436
437 err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
438 if (err < 0)
439 return err;
440
441 if (tb[NFTA_EXTHDR_FLAGS]) {
442 err = nft_parse_u32_check(tb[NFTA_EXTHDR_FLAGS], U8_MAX, &flags);
443 if (err < 0)
444 return err;
445
446 if (flags & ~NFT_EXTHDR_F_PRESENT)
447 return -EINVAL;
448 }
449
450 if (tb[NFTA_EXTHDR_OP]) {
451 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OP], U8_MAX, &op);
452 if (err < 0)
453 return err;
454 }
455
456 priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
457 priv->offset = offset;
458 priv->len = len;
459 priv->flags = flags;
460 priv->op = op;
461
462 return nft_parse_register_store(ctx, tb[NFTA_EXTHDR_DREG],
463 &priv->dreg, NULL, NFT_DATA_VALUE,
464 priv->len);
465}
466
467static int nft_exthdr_tcp_set_init(const struct nft_ctx *ctx,
468 const struct nft_expr *expr,
469 const struct nlattr * const tb[])
470{
471 struct nft_exthdr *priv = nft_expr_priv(expr);
472 u32 offset, len, flags = 0, op = NFT_EXTHDR_OP_IPV6;
473 int err;
474
475 if (!tb[NFTA_EXTHDR_SREG] ||
476 !tb[NFTA_EXTHDR_TYPE] ||
477 !tb[NFTA_EXTHDR_OFFSET] ||
478 !tb[NFTA_EXTHDR_LEN])
479 return -EINVAL;
480
481 if (tb[NFTA_EXTHDR_DREG] || tb[NFTA_EXTHDR_FLAGS])
482 return -EINVAL;
483
484 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OFFSET], U8_MAX, &offset);
485 if (err < 0)
486 return err;
487
488 err = nft_parse_u32_check(tb[NFTA_EXTHDR_LEN], U8_MAX, &len);
489 if (err < 0)
490 return err;
491
492 if (offset < 2)
493 return -EOPNOTSUPP;
494
495 switch (len) {
496 case 2: break;
497 case 4: break;
498 default:
499 return -EOPNOTSUPP;
500 }
501
502 err = nft_parse_u32_check(tb[NFTA_EXTHDR_OP], U8_MAX, &op);
503 if (err < 0)
504 return err;
505
506 priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
507 priv->offset = offset;
508 priv->len = len;
509 priv->flags = flags;
510 priv->op = op;
511
512 return nft_parse_register_load(tb[NFTA_EXTHDR_SREG], &priv->sreg,
513 priv->len);
514}
515
516static int nft_exthdr_tcp_strip_init(const struct nft_ctx *ctx,
517 const struct nft_expr *expr,
518 const struct nlattr * const tb[])
519{
520 struct nft_exthdr *priv = nft_expr_priv(expr);
521
522 if (tb[NFTA_EXTHDR_SREG] ||
523 tb[NFTA_EXTHDR_DREG] ||
524 tb[NFTA_EXTHDR_FLAGS] ||
525 tb[NFTA_EXTHDR_OFFSET] ||
526 tb[NFTA_EXTHDR_LEN])
527 return -EINVAL;
528
529 if (!tb[NFTA_EXTHDR_TYPE])
530 return -EINVAL;
531
532 priv->type = nla_get_u8(tb[NFTA_EXTHDR_TYPE]);
533 priv->op = NFT_EXTHDR_OP_TCPOPT;
534
535 return 0;
536}
537
538static int nft_exthdr_ipv4_init(const struct nft_ctx *ctx,
539 const struct nft_expr *expr,
540 const struct nlattr * const tb[])
541{
542 struct nft_exthdr *priv = nft_expr_priv(expr);
543 int err = nft_exthdr_init(ctx, expr, tb);
544
545 if (err < 0)
546 return err;
547
548 switch (priv->type) {
549 case IPOPT_SSRR:
550 case IPOPT_LSRR:
551 case IPOPT_RR:
552 case IPOPT_RA:
553 break;
554 default:
555 return -EOPNOTSUPP;
556 }
557 return 0;
558}
559
560static int nft_exthdr_dump_common(struct sk_buff *skb, const struct nft_exthdr *priv)
561{
562 if (nla_put_u8(skb, NFTA_EXTHDR_TYPE, priv->type))
563 goto nla_put_failure;
564 if (nla_put_be32(skb, NFTA_EXTHDR_OFFSET, htonl(priv->offset)))
565 goto nla_put_failure;
566 if (nla_put_be32(skb, NFTA_EXTHDR_LEN, htonl(priv->len)))
567 goto nla_put_failure;
568 if (nla_put_be32(skb, NFTA_EXTHDR_FLAGS, htonl(priv->flags)))
569 goto nla_put_failure;
570 if (nla_put_be32(skb, NFTA_EXTHDR_OP, htonl(priv->op)))
571 goto nla_put_failure;
572 return 0;
573
574nla_put_failure:
575 return -1;
576}
577
578static int nft_exthdr_dump(struct sk_buff *skb,
579 const struct nft_expr *expr, bool reset)
580{
581 const struct nft_exthdr *priv = nft_expr_priv(expr);
582
583 if (nft_dump_register(skb, NFTA_EXTHDR_DREG, priv->dreg))
584 return -1;
585
586 return nft_exthdr_dump_common(skb, priv);
587}
588
589static int nft_exthdr_dump_set(struct sk_buff *skb,
590 const struct nft_expr *expr, bool reset)
591{
592 const struct nft_exthdr *priv = nft_expr_priv(expr);
593
594 if (nft_dump_register(skb, NFTA_EXTHDR_SREG, priv->sreg))
595 return -1;
596
597 return nft_exthdr_dump_common(skb, priv);
598}
599
600static int nft_exthdr_dump_strip(struct sk_buff *skb,
601 const struct nft_expr *expr, bool reset)
602{
603 const struct nft_exthdr *priv = nft_expr_priv(expr);
604
605 return nft_exthdr_dump_common(skb, priv);
606}
607
608static bool nft_exthdr_reduce(struct nft_regs_track *track,
609 const struct nft_expr *expr)
610{
611 const struct nft_exthdr *priv = nft_expr_priv(expr);
612 const struct nft_exthdr *exthdr;
613
614 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
615 nft_reg_track_update(track, expr, priv->dreg, priv->len);
616 return false;
617 }
618
619 exthdr = nft_expr_priv(track->regs[priv->dreg].selector);
620 if (priv->type != exthdr->type ||
621 priv->op != exthdr->op ||
622 priv->flags != exthdr->flags ||
623 priv->offset != exthdr->offset ||
624 priv->len != exthdr->len) {
625 nft_reg_track_update(track, expr, priv->dreg, priv->len);
626 return false;
627 }
628
629 if (!track->regs[priv->dreg].bitwise)
630 return true;
631
632 return nft_expr_reduce_bitwise(track, expr);
633}
634
635static const struct nft_expr_ops nft_exthdr_ipv6_ops = {
636 .type = &nft_exthdr_type,
637 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
638 .eval = nft_exthdr_ipv6_eval,
639 .init = nft_exthdr_init,
640 .dump = nft_exthdr_dump,
641 .reduce = nft_exthdr_reduce,
642};
643
644static const struct nft_expr_ops nft_exthdr_ipv4_ops = {
645 .type = &nft_exthdr_type,
646 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
647 .eval = nft_exthdr_ipv4_eval,
648 .init = nft_exthdr_ipv4_init,
649 .dump = nft_exthdr_dump,
650 .reduce = nft_exthdr_reduce,
651};
652
653static const struct nft_expr_ops nft_exthdr_tcp_ops = {
654 .type = &nft_exthdr_type,
655 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
656 .eval = nft_exthdr_tcp_eval,
657 .init = nft_exthdr_init,
658 .dump = nft_exthdr_dump,
659 .reduce = nft_exthdr_reduce,
660};
661
662static const struct nft_expr_ops nft_exthdr_tcp_set_ops = {
663 .type = &nft_exthdr_type,
664 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
665 .eval = nft_exthdr_tcp_set_eval,
666 .init = nft_exthdr_tcp_set_init,
667 .dump = nft_exthdr_dump_set,
668 .reduce = NFT_REDUCE_READONLY,
669};
670
671static const struct nft_expr_ops nft_exthdr_tcp_strip_ops = {
672 .type = &nft_exthdr_type,
673 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
674 .eval = nft_exthdr_tcp_strip_eval,
675 .init = nft_exthdr_tcp_strip_init,
676 .dump = nft_exthdr_dump_strip,
677 .reduce = NFT_REDUCE_READONLY,
678};
679
680static const struct nft_expr_ops nft_exthdr_sctp_ops = {
681 .type = &nft_exthdr_type,
682 .size = NFT_EXPR_SIZE(sizeof(struct nft_exthdr)),
683 .eval = nft_exthdr_sctp_eval,
684 .init = nft_exthdr_init,
685 .dump = nft_exthdr_dump,
686 .reduce = nft_exthdr_reduce,
687};
688
689static const struct nft_expr_ops *
690nft_exthdr_select_ops(const struct nft_ctx *ctx,
691 const struct nlattr * const tb[])
692{
693 u32 op;
694
695 if (!tb[NFTA_EXTHDR_OP])
696 return &nft_exthdr_ipv6_ops;
697
698 if (tb[NFTA_EXTHDR_SREG] && tb[NFTA_EXTHDR_DREG])
699 return ERR_PTR(-EOPNOTSUPP);
700
701 op = ntohl(nla_get_be32(tb[NFTA_EXTHDR_OP]));
702 switch (op) {
703 case NFT_EXTHDR_OP_TCPOPT:
704 if (tb[NFTA_EXTHDR_SREG])
705 return &nft_exthdr_tcp_set_ops;
706 if (tb[NFTA_EXTHDR_DREG])
707 return &nft_exthdr_tcp_ops;
708 return &nft_exthdr_tcp_strip_ops;
709 case NFT_EXTHDR_OP_IPV6:
710 if (tb[NFTA_EXTHDR_DREG])
711 return &nft_exthdr_ipv6_ops;
712 break;
713 case NFT_EXTHDR_OP_IPV4:
714 if (ctx->family != NFPROTO_IPV6) {
715 if (tb[NFTA_EXTHDR_DREG])
716 return &nft_exthdr_ipv4_ops;
717 }
718 break;
719 case NFT_EXTHDR_OP_SCTP:
720 if (tb[NFTA_EXTHDR_DREG])
721 return &nft_exthdr_sctp_ops;
722 break;
723 }
724
725 return ERR_PTR(-EOPNOTSUPP);
726}
727
728struct nft_expr_type nft_exthdr_type __read_mostly = {
729 .name = "exthdr",
730 .select_ops = nft_exthdr_select_ops,
731 .policy = nft_exthdr_policy,
732 .maxattr = NFTA_EXTHDR_MAX,
733 .owner = THIS_MODULE,
734};