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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
5 *
6 * Development of this code funded by Astaro AG (http://www.astaro.com/)
7 */
8
9#include <linux/kernel.h>
10#include <linux/if_vlan.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/netlink.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables_core.h>
17#include <net/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables_offload.h>
19/* For layer 4 checksum field offset. */
20#include <linux/tcp.h>
21#include <linux/udp.h>
22#include <linux/icmpv6.h>
23#include <linux/ip.h>
24#include <linux/ipv6.h>
25#include <net/sctp/checksum.h>
26
27static bool nft_payload_rebuild_vlan_hdr(const struct sk_buff *skb, int mac_off,
28 struct vlan_ethhdr *veth)
29{
30 if (skb_copy_bits(skb, mac_off, veth, ETH_HLEN))
31 return false;
32
33 veth->h_vlan_proto = skb->vlan_proto;
34 veth->h_vlan_TCI = htons(skb_vlan_tag_get(skb));
35 veth->h_vlan_encapsulated_proto = skb->protocol;
36
37 return true;
38}
39
40/* add vlan header into the user buffer for if tag was removed by offloads */
41static bool
42nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
43{
44 int mac_off = skb_mac_header(skb) - skb->data;
45 u8 *vlanh, *dst_u8 = (u8 *) d;
46 struct vlan_ethhdr veth;
47 u8 vlan_hlen = 0;
48
49 if ((skb->protocol == htons(ETH_P_8021AD) ||
50 skb->protocol == htons(ETH_P_8021Q)) &&
51 offset >= VLAN_ETH_HLEN && offset < VLAN_ETH_HLEN + VLAN_HLEN)
52 vlan_hlen += VLAN_HLEN;
53
54 vlanh = (u8 *) &veth;
55 if (offset < VLAN_ETH_HLEN + vlan_hlen) {
56 u8 ethlen = len;
57
58 if (vlan_hlen &&
59 skb_copy_bits(skb, mac_off, &veth, VLAN_ETH_HLEN) < 0)
60 return false;
61 else if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
62 return false;
63
64 if (offset + len > VLAN_ETH_HLEN + vlan_hlen)
65 ethlen -= offset + len - VLAN_ETH_HLEN + vlan_hlen;
66
67 memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen);
68
69 len -= ethlen;
70 if (len == 0)
71 return true;
72
73 dst_u8 += ethlen;
74 offset = ETH_HLEN + vlan_hlen;
75 } else {
76 offset -= VLAN_HLEN + vlan_hlen;
77 }
78
79 return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
80}
81
82void nft_payload_eval(const struct nft_expr *expr,
83 struct nft_regs *regs,
84 const struct nft_pktinfo *pkt)
85{
86 const struct nft_payload *priv = nft_expr_priv(expr);
87 const struct sk_buff *skb = pkt->skb;
88 u32 *dest = ®s->data[priv->dreg];
89 int offset;
90
91 if (priv->len % NFT_REG32_SIZE)
92 dest[priv->len / NFT_REG32_SIZE] = 0;
93
94 switch (priv->base) {
95 case NFT_PAYLOAD_LL_HEADER:
96 if (!skb_mac_header_was_set(skb))
97 goto err;
98
99 if (skb_vlan_tag_present(skb)) {
100 if (!nft_payload_copy_vlan(dest, skb,
101 priv->offset, priv->len))
102 goto err;
103 return;
104 }
105 offset = skb_mac_header(skb) - skb->data;
106 break;
107 case NFT_PAYLOAD_NETWORK_HEADER:
108 offset = skb_network_offset(skb);
109 break;
110 case NFT_PAYLOAD_TRANSPORT_HEADER:
111 if (!pkt->tprot_set)
112 goto err;
113 offset = nft_thoff(pkt);
114 break;
115 default:
116 BUG();
117 }
118 offset += priv->offset;
119
120 if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
121 goto err;
122 return;
123err:
124 regs->verdict.code = NFT_BREAK;
125}
126
127static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
128 [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 },
129 [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
130 [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
131 [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 },
132 [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 },
133 [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 },
134 [NFTA_PAYLOAD_CSUM_OFFSET] = { .type = NLA_U32 },
135 [NFTA_PAYLOAD_CSUM_FLAGS] = { .type = NLA_U32 },
136};
137
138static int nft_payload_init(const struct nft_ctx *ctx,
139 const struct nft_expr *expr,
140 const struct nlattr * const tb[])
141{
142 struct nft_payload *priv = nft_expr_priv(expr);
143
144 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
145 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
146 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
147
148 return nft_parse_register_store(ctx, tb[NFTA_PAYLOAD_DREG],
149 &priv->dreg, NULL, NFT_DATA_VALUE,
150 priv->len);
151}
152
153static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr)
154{
155 const struct nft_payload *priv = nft_expr_priv(expr);
156
157 if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) ||
158 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
159 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
160 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
161 goto nla_put_failure;
162 return 0;
163
164nla_put_failure:
165 return -1;
166}
167
168static bool nft_payload_offload_mask(struct nft_offload_reg *reg,
169 u32 priv_len, u32 field_len)
170{
171 unsigned int remainder, delta, k;
172 struct nft_data mask = {};
173 __be32 remainder_mask;
174
175 if (priv_len == field_len) {
176 memset(®->mask, 0xff, priv_len);
177 return true;
178 } else if (priv_len > field_len) {
179 return false;
180 }
181
182 memset(&mask, 0xff, field_len);
183 remainder = priv_len % sizeof(u32);
184 if (remainder) {
185 k = priv_len / sizeof(u32);
186 delta = field_len - priv_len;
187 remainder_mask = htonl(~((1 << (delta * BITS_PER_BYTE)) - 1));
188 mask.data[k] = (__force u32)remainder_mask;
189 }
190
191 memcpy(®->mask, &mask, field_len);
192
193 return true;
194}
195
196static int nft_payload_offload_ll(struct nft_offload_ctx *ctx,
197 struct nft_flow_rule *flow,
198 const struct nft_payload *priv)
199{
200 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
201
202 switch (priv->offset) {
203 case offsetof(struct ethhdr, h_source):
204 if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN))
205 return -EOPNOTSUPP;
206
207 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
208 src, ETH_ALEN, reg);
209 break;
210 case offsetof(struct ethhdr, h_dest):
211 if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN))
212 return -EOPNOTSUPP;
213
214 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
215 dst, ETH_ALEN, reg);
216 break;
217 case offsetof(struct ethhdr, h_proto):
218 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
219 return -EOPNOTSUPP;
220
221 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic,
222 n_proto, sizeof(__be16), reg);
223 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
224 break;
225 case offsetof(struct vlan_ethhdr, h_vlan_TCI):
226 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
227 return -EOPNOTSUPP;
228
229 NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_VLAN, vlan,
230 vlan_tci, sizeof(__be16), reg,
231 NFT_OFFLOAD_F_NETWORK2HOST);
232 break;
233 case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto):
234 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
235 return -EOPNOTSUPP;
236
237 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan,
238 vlan_tpid, sizeof(__be16), reg);
239 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
240 break;
241 case offsetof(struct vlan_ethhdr, h_vlan_TCI) + sizeof(struct vlan_hdr):
242 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
243 return -EOPNOTSUPP;
244
245 NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_CVLAN, cvlan,
246 vlan_tci, sizeof(__be16), reg,
247 NFT_OFFLOAD_F_NETWORK2HOST);
248 break;
249 case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto) +
250 sizeof(struct vlan_hdr):
251 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
252 return -EOPNOTSUPP;
253
254 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, cvlan,
255 vlan_tpid, sizeof(__be16), reg);
256 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
257 break;
258 default:
259 return -EOPNOTSUPP;
260 }
261
262 return 0;
263}
264
265static int nft_payload_offload_ip(struct nft_offload_ctx *ctx,
266 struct nft_flow_rule *flow,
267 const struct nft_payload *priv)
268{
269 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
270
271 switch (priv->offset) {
272 case offsetof(struct iphdr, saddr):
273 if (!nft_payload_offload_mask(reg, priv->len,
274 sizeof(struct in_addr)))
275 return -EOPNOTSUPP;
276
277 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src,
278 sizeof(struct in_addr), reg);
279 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
280 break;
281 case offsetof(struct iphdr, daddr):
282 if (!nft_payload_offload_mask(reg, priv->len,
283 sizeof(struct in_addr)))
284 return -EOPNOTSUPP;
285
286 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst,
287 sizeof(struct in_addr), reg);
288 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
289 break;
290 case offsetof(struct iphdr, protocol):
291 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__u8)))
292 return -EOPNOTSUPP;
293
294 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
295 sizeof(__u8), reg);
296 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
297 break;
298 default:
299 return -EOPNOTSUPP;
300 }
301
302 return 0;
303}
304
305static int nft_payload_offload_ip6(struct nft_offload_ctx *ctx,
306 struct nft_flow_rule *flow,
307 const struct nft_payload *priv)
308{
309 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
310
311 switch (priv->offset) {
312 case offsetof(struct ipv6hdr, saddr):
313 if (!nft_payload_offload_mask(reg, priv->len,
314 sizeof(struct in6_addr)))
315 return -EOPNOTSUPP;
316
317 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src,
318 sizeof(struct in6_addr), reg);
319 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
320 break;
321 case offsetof(struct ipv6hdr, daddr):
322 if (!nft_payload_offload_mask(reg, priv->len,
323 sizeof(struct in6_addr)))
324 return -EOPNOTSUPP;
325
326 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst,
327 sizeof(struct in6_addr), reg);
328 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
329 break;
330 case offsetof(struct ipv6hdr, nexthdr):
331 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__u8)))
332 return -EOPNOTSUPP;
333
334 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
335 sizeof(__u8), reg);
336 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
337 break;
338 default:
339 return -EOPNOTSUPP;
340 }
341
342 return 0;
343}
344
345static int nft_payload_offload_nh(struct nft_offload_ctx *ctx,
346 struct nft_flow_rule *flow,
347 const struct nft_payload *priv)
348{
349 int err;
350
351 switch (ctx->dep.l3num) {
352 case htons(ETH_P_IP):
353 err = nft_payload_offload_ip(ctx, flow, priv);
354 break;
355 case htons(ETH_P_IPV6):
356 err = nft_payload_offload_ip6(ctx, flow, priv);
357 break;
358 default:
359 return -EOPNOTSUPP;
360 }
361
362 return err;
363}
364
365static int nft_payload_offload_tcp(struct nft_offload_ctx *ctx,
366 struct nft_flow_rule *flow,
367 const struct nft_payload *priv)
368{
369 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
370
371 switch (priv->offset) {
372 case offsetof(struct tcphdr, source):
373 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
374 return -EOPNOTSUPP;
375
376 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
377 sizeof(__be16), reg);
378 break;
379 case offsetof(struct tcphdr, dest):
380 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
381 return -EOPNOTSUPP;
382
383 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
384 sizeof(__be16), reg);
385 break;
386 default:
387 return -EOPNOTSUPP;
388 }
389
390 return 0;
391}
392
393static int nft_payload_offload_udp(struct nft_offload_ctx *ctx,
394 struct nft_flow_rule *flow,
395 const struct nft_payload *priv)
396{
397 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
398
399 switch (priv->offset) {
400 case offsetof(struct udphdr, source):
401 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
402 return -EOPNOTSUPP;
403
404 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
405 sizeof(__be16), reg);
406 break;
407 case offsetof(struct udphdr, dest):
408 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
409 return -EOPNOTSUPP;
410
411 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
412 sizeof(__be16), reg);
413 break;
414 default:
415 return -EOPNOTSUPP;
416 }
417
418 return 0;
419}
420
421static int nft_payload_offload_th(struct nft_offload_ctx *ctx,
422 struct nft_flow_rule *flow,
423 const struct nft_payload *priv)
424{
425 int err;
426
427 switch (ctx->dep.protonum) {
428 case IPPROTO_TCP:
429 err = nft_payload_offload_tcp(ctx, flow, priv);
430 break;
431 case IPPROTO_UDP:
432 err = nft_payload_offload_udp(ctx, flow, priv);
433 break;
434 default:
435 return -EOPNOTSUPP;
436 }
437
438 return err;
439}
440
441static int nft_payload_offload(struct nft_offload_ctx *ctx,
442 struct nft_flow_rule *flow,
443 const struct nft_expr *expr)
444{
445 const struct nft_payload *priv = nft_expr_priv(expr);
446 int err;
447
448 switch (priv->base) {
449 case NFT_PAYLOAD_LL_HEADER:
450 err = nft_payload_offload_ll(ctx, flow, priv);
451 break;
452 case NFT_PAYLOAD_NETWORK_HEADER:
453 err = nft_payload_offload_nh(ctx, flow, priv);
454 break;
455 case NFT_PAYLOAD_TRANSPORT_HEADER:
456 err = nft_payload_offload_th(ctx, flow, priv);
457 break;
458 default:
459 err = -EOPNOTSUPP;
460 break;
461 }
462 return err;
463}
464
465static const struct nft_expr_ops nft_payload_ops = {
466 .type = &nft_payload_type,
467 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
468 .eval = nft_payload_eval,
469 .init = nft_payload_init,
470 .dump = nft_payload_dump,
471 .offload = nft_payload_offload,
472};
473
474const struct nft_expr_ops nft_payload_fast_ops = {
475 .type = &nft_payload_type,
476 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
477 .eval = nft_payload_eval,
478 .init = nft_payload_init,
479 .dump = nft_payload_dump,
480 .offload = nft_payload_offload,
481};
482
483static inline void nft_csum_replace(__sum16 *sum, __wsum fsum, __wsum tsum)
484{
485 *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), fsum), tsum));
486 if (*sum == 0)
487 *sum = CSUM_MANGLED_0;
488}
489
490static bool nft_payload_udp_checksum(struct sk_buff *skb, unsigned int thoff)
491{
492 struct udphdr *uh, _uh;
493
494 uh = skb_header_pointer(skb, thoff, sizeof(_uh), &_uh);
495 if (!uh)
496 return false;
497
498 return (__force bool)uh->check;
499}
500
501static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt,
502 struct sk_buff *skb,
503 unsigned int *l4csum_offset)
504{
505 switch (pkt->tprot) {
506 case IPPROTO_TCP:
507 *l4csum_offset = offsetof(struct tcphdr, check);
508 break;
509 case IPPROTO_UDP:
510 if (!nft_payload_udp_checksum(skb, nft_thoff(pkt)))
511 return -1;
512 fallthrough;
513 case IPPROTO_UDPLITE:
514 *l4csum_offset = offsetof(struct udphdr, check);
515 break;
516 case IPPROTO_ICMPV6:
517 *l4csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
518 break;
519 default:
520 return -1;
521 }
522
523 *l4csum_offset += nft_thoff(pkt);
524 return 0;
525}
526
527static int nft_payload_csum_sctp(struct sk_buff *skb, int offset)
528{
529 struct sctphdr *sh;
530
531 if (skb_ensure_writable(skb, offset + sizeof(*sh)))
532 return -1;
533
534 sh = (struct sctphdr *)(skb->data + offset);
535 sh->checksum = sctp_compute_cksum(skb, offset);
536 skb->ip_summed = CHECKSUM_UNNECESSARY;
537 return 0;
538}
539
540static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt,
541 struct sk_buff *skb,
542 __wsum fsum, __wsum tsum)
543{
544 int l4csum_offset;
545 __sum16 sum;
546
547 /* If we cannot determine layer 4 checksum offset or this packet doesn't
548 * require layer 4 checksum recalculation, skip this packet.
549 */
550 if (nft_payload_l4csum_offset(pkt, skb, &l4csum_offset) < 0)
551 return 0;
552
553 if (skb_copy_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
554 return -1;
555
556 /* Checksum mangling for an arbitrary amount of bytes, based on
557 * inet_proto_csum_replace*() functions.
558 */
559 if (skb->ip_summed != CHECKSUM_PARTIAL) {
560 nft_csum_replace(&sum, fsum, tsum);
561 if (skb->ip_summed == CHECKSUM_COMPLETE) {
562 skb->csum = ~csum_add(csum_sub(~(skb->csum), fsum),
563 tsum);
564 }
565 } else {
566 sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum), fsum),
567 tsum));
568 }
569
570 if (skb_ensure_writable(skb, l4csum_offset + sizeof(sum)) ||
571 skb_store_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
572 return -1;
573
574 return 0;
575}
576
577static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src,
578 __wsum fsum, __wsum tsum, int csum_offset)
579{
580 __sum16 sum;
581
582 if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
583 return -1;
584
585 nft_csum_replace(&sum, fsum, tsum);
586 if (skb_ensure_writable(skb, csum_offset + sizeof(sum)) ||
587 skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
588 return -1;
589
590 return 0;
591}
592
593static void nft_payload_set_eval(const struct nft_expr *expr,
594 struct nft_regs *regs,
595 const struct nft_pktinfo *pkt)
596{
597 const struct nft_payload_set *priv = nft_expr_priv(expr);
598 struct sk_buff *skb = pkt->skb;
599 const u32 *src = ®s->data[priv->sreg];
600 int offset, csum_offset;
601 __wsum fsum, tsum;
602
603 switch (priv->base) {
604 case NFT_PAYLOAD_LL_HEADER:
605 if (!skb_mac_header_was_set(skb))
606 goto err;
607 offset = skb_mac_header(skb) - skb->data;
608 break;
609 case NFT_PAYLOAD_NETWORK_HEADER:
610 offset = skb_network_offset(skb);
611 break;
612 case NFT_PAYLOAD_TRANSPORT_HEADER:
613 if (!pkt->tprot_set)
614 goto err;
615 offset = nft_thoff(pkt);
616 break;
617 default:
618 BUG();
619 }
620
621 csum_offset = offset + priv->csum_offset;
622 offset += priv->offset;
623
624 if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) &&
625 (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER ||
626 skb->ip_summed != CHECKSUM_PARTIAL)) {
627 fsum = skb_checksum(skb, offset, priv->len, 0);
628 tsum = csum_partial(src, priv->len, 0);
629
630 if (priv->csum_type == NFT_PAYLOAD_CSUM_INET &&
631 nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset))
632 goto err;
633
634 if (priv->csum_flags &&
635 nft_payload_l4csum_update(pkt, skb, fsum, tsum) < 0)
636 goto err;
637 }
638
639 if (skb_ensure_writable(skb, max(offset + priv->len, 0)) ||
640 skb_store_bits(skb, offset, src, priv->len) < 0)
641 goto err;
642
643 if (priv->csum_type == NFT_PAYLOAD_CSUM_SCTP &&
644 pkt->tprot == IPPROTO_SCTP &&
645 skb->ip_summed != CHECKSUM_PARTIAL) {
646 if (nft_payload_csum_sctp(skb, nft_thoff(pkt)))
647 goto err;
648 }
649
650 return;
651err:
652 regs->verdict.code = NFT_BREAK;
653}
654
655static int nft_payload_set_init(const struct nft_ctx *ctx,
656 const struct nft_expr *expr,
657 const struct nlattr * const tb[])
658{
659 struct nft_payload_set *priv = nft_expr_priv(expr);
660
661 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
662 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
663 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
664
665 if (tb[NFTA_PAYLOAD_CSUM_TYPE])
666 priv->csum_type =
667 ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE]));
668 if (tb[NFTA_PAYLOAD_CSUM_OFFSET])
669 priv->csum_offset =
670 ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET]));
671 if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) {
672 u32 flags;
673
674 flags = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_FLAGS]));
675 if (flags & ~NFT_PAYLOAD_L4CSUM_PSEUDOHDR)
676 return -EINVAL;
677
678 priv->csum_flags = flags;
679 }
680
681 switch (priv->csum_type) {
682 case NFT_PAYLOAD_CSUM_NONE:
683 case NFT_PAYLOAD_CSUM_INET:
684 break;
685 case NFT_PAYLOAD_CSUM_SCTP:
686 if (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER)
687 return -EINVAL;
688
689 if (priv->csum_offset != offsetof(struct sctphdr, checksum))
690 return -EINVAL;
691 break;
692 default:
693 return -EOPNOTSUPP;
694 }
695
696 return nft_parse_register_load(tb[NFTA_PAYLOAD_SREG], &priv->sreg,
697 priv->len);
698}
699
700static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
701{
702 const struct nft_payload_set *priv = nft_expr_priv(expr);
703
704 if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) ||
705 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
706 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
707 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) ||
708 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) ||
709 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET,
710 htonl(priv->csum_offset)) ||
711 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_FLAGS, htonl(priv->csum_flags)))
712 goto nla_put_failure;
713 return 0;
714
715nla_put_failure:
716 return -1;
717}
718
719static const struct nft_expr_ops nft_payload_set_ops = {
720 .type = &nft_payload_type,
721 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)),
722 .eval = nft_payload_set_eval,
723 .init = nft_payload_set_init,
724 .dump = nft_payload_set_dump,
725};
726
727static const struct nft_expr_ops *
728nft_payload_select_ops(const struct nft_ctx *ctx,
729 const struct nlattr * const tb[])
730{
731 enum nft_payload_bases base;
732 unsigned int offset, len;
733
734 if (tb[NFTA_PAYLOAD_BASE] == NULL ||
735 tb[NFTA_PAYLOAD_OFFSET] == NULL ||
736 tb[NFTA_PAYLOAD_LEN] == NULL)
737 return ERR_PTR(-EINVAL);
738
739 base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
740 switch (base) {
741 case NFT_PAYLOAD_LL_HEADER:
742 case NFT_PAYLOAD_NETWORK_HEADER:
743 case NFT_PAYLOAD_TRANSPORT_HEADER:
744 break;
745 default:
746 return ERR_PTR(-EOPNOTSUPP);
747 }
748
749 if (tb[NFTA_PAYLOAD_SREG] != NULL) {
750 if (tb[NFTA_PAYLOAD_DREG] != NULL)
751 return ERR_PTR(-EINVAL);
752 return &nft_payload_set_ops;
753 }
754
755 if (tb[NFTA_PAYLOAD_DREG] == NULL)
756 return ERR_PTR(-EINVAL);
757
758 offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
759 len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
760
761 if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
762 base != NFT_PAYLOAD_LL_HEADER)
763 return &nft_payload_fast_ops;
764 else
765 return &nft_payload_ops;
766}
767
768struct nft_expr_type nft_payload_type __read_mostly = {
769 .name = "payload",
770 .select_ops = nft_payload_select_ops,
771 .policy = nft_payload_policy,
772 .maxattr = NFTA_PAYLOAD_MAX,
773 .owner = THIS_MODULE,
774};
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
4 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
5 *
6 * Development of this code funded by Astaro AG (http://www.astaro.com/)
7 */
8
9#include <linux/kernel.h>
10#include <linux/if_vlan.h>
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/netlink.h>
14#include <linux/netfilter.h>
15#include <linux/netfilter/nf_tables.h>
16#include <net/netfilter/nf_tables_core.h>
17#include <net/netfilter/nf_tables.h>
18#include <net/netfilter/nf_tables_offload.h>
19/* For layer 4 checksum field offset. */
20#include <linux/tcp.h>
21#include <linux/udp.h>
22#include <linux/icmpv6.h>
23#include <linux/ip.h>
24#include <linux/ipv6.h>
25
26/* add vlan header into the user buffer for if tag was removed by offloads */
27static bool
28nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
29{
30 int mac_off = skb_mac_header(skb) - skb->data;
31 u8 vlan_len, *vlanh, *dst_u8 = (u8 *) d;
32 struct vlan_ethhdr veth;
33
34 vlanh = (u8 *) &veth;
35 if (offset < ETH_HLEN) {
36 u8 ethlen = min_t(u8, len, ETH_HLEN - offset);
37
38 if (skb_copy_bits(skb, mac_off, &veth, ETH_HLEN))
39 return false;
40
41 veth.h_vlan_proto = skb->vlan_proto;
42
43 memcpy(dst_u8, vlanh + offset, ethlen);
44
45 len -= ethlen;
46 if (len == 0)
47 return true;
48
49 dst_u8 += ethlen;
50 offset = ETH_HLEN;
51 } else if (offset >= VLAN_ETH_HLEN) {
52 offset -= VLAN_HLEN;
53 goto skip;
54 }
55
56 veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
57 veth.h_vlan_encapsulated_proto = skb->protocol;
58
59 vlanh += offset;
60
61 vlan_len = min_t(u8, len, VLAN_ETH_HLEN - offset);
62 memcpy(dst_u8, vlanh, vlan_len);
63
64 len -= vlan_len;
65 if (!len)
66 return true;
67
68 dst_u8 += vlan_len;
69 skip:
70 return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
71}
72
73void nft_payload_eval(const struct nft_expr *expr,
74 struct nft_regs *regs,
75 const struct nft_pktinfo *pkt)
76{
77 const struct nft_payload *priv = nft_expr_priv(expr);
78 const struct sk_buff *skb = pkt->skb;
79 u32 *dest = ®s->data[priv->dreg];
80 int offset;
81
82 dest[priv->len / NFT_REG32_SIZE] = 0;
83 switch (priv->base) {
84 case NFT_PAYLOAD_LL_HEADER:
85 if (!skb_mac_header_was_set(skb))
86 goto err;
87
88 if (skb_vlan_tag_present(skb)) {
89 if (!nft_payload_copy_vlan(dest, skb,
90 priv->offset, priv->len))
91 goto err;
92 return;
93 }
94 offset = skb_mac_header(skb) - skb->data;
95 break;
96 case NFT_PAYLOAD_NETWORK_HEADER:
97 offset = skb_network_offset(skb);
98 break;
99 case NFT_PAYLOAD_TRANSPORT_HEADER:
100 if (!pkt->tprot_set)
101 goto err;
102 offset = pkt->xt.thoff;
103 break;
104 default:
105 BUG();
106 }
107 offset += priv->offset;
108
109 if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
110 goto err;
111 return;
112err:
113 regs->verdict.code = NFT_BREAK;
114}
115
116static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
117 [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 },
118 [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
119 [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
120 [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 },
121 [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 },
122 [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 },
123 [NFTA_PAYLOAD_CSUM_OFFSET] = { .type = NLA_U32 },
124};
125
126static int nft_payload_init(const struct nft_ctx *ctx,
127 const struct nft_expr *expr,
128 const struct nlattr * const tb[])
129{
130 struct nft_payload *priv = nft_expr_priv(expr);
131
132 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
133 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
134 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
135 priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]);
136
137 return nft_validate_register_store(ctx, priv->dreg, NULL,
138 NFT_DATA_VALUE, priv->len);
139}
140
141static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr)
142{
143 const struct nft_payload *priv = nft_expr_priv(expr);
144
145 if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) ||
146 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
147 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
148 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
149 goto nla_put_failure;
150 return 0;
151
152nla_put_failure:
153 return -1;
154}
155
156static int nft_payload_offload_ll(struct nft_offload_ctx *ctx,
157 struct nft_flow_rule *flow,
158 const struct nft_payload *priv)
159{
160 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
161
162 switch (priv->offset) {
163 case offsetof(struct ethhdr, h_source):
164 if (priv->len != ETH_ALEN)
165 return -EOPNOTSUPP;
166
167 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
168 src, ETH_ALEN, reg);
169 break;
170 case offsetof(struct ethhdr, h_dest):
171 if (priv->len != ETH_ALEN)
172 return -EOPNOTSUPP;
173
174 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
175 dst, ETH_ALEN, reg);
176 break;
177 default:
178 return -EOPNOTSUPP;
179 }
180
181 return 0;
182}
183
184static int nft_payload_offload_ip(struct nft_offload_ctx *ctx,
185 struct nft_flow_rule *flow,
186 const struct nft_payload *priv)
187{
188 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
189
190 switch (priv->offset) {
191 case offsetof(struct iphdr, saddr):
192 if (priv->len != sizeof(struct in_addr))
193 return -EOPNOTSUPP;
194
195 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src,
196 sizeof(struct in_addr), reg);
197 break;
198 case offsetof(struct iphdr, daddr):
199 if (priv->len != sizeof(struct in_addr))
200 return -EOPNOTSUPP;
201
202 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst,
203 sizeof(struct in_addr), reg);
204 break;
205 case offsetof(struct iphdr, protocol):
206 if (priv->len != sizeof(__u8))
207 return -EOPNOTSUPP;
208
209 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
210 sizeof(__u8), reg);
211 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
212 break;
213 default:
214 return -EOPNOTSUPP;
215 }
216
217 return 0;
218}
219
220static int nft_payload_offload_ip6(struct nft_offload_ctx *ctx,
221 struct nft_flow_rule *flow,
222 const struct nft_payload *priv)
223{
224 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
225
226 switch (priv->offset) {
227 case offsetof(struct ipv6hdr, saddr):
228 if (priv->len != sizeof(struct in6_addr))
229 return -EOPNOTSUPP;
230
231 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src,
232 sizeof(struct in6_addr), reg);
233 break;
234 case offsetof(struct ipv6hdr, daddr):
235 if (priv->len != sizeof(struct in6_addr))
236 return -EOPNOTSUPP;
237
238 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst,
239 sizeof(struct in6_addr), reg);
240 break;
241 case offsetof(struct ipv6hdr, nexthdr):
242 if (priv->len != sizeof(__u8))
243 return -EOPNOTSUPP;
244
245 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
246 sizeof(__u8), reg);
247 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
248 break;
249 default:
250 return -EOPNOTSUPP;
251 }
252
253 return 0;
254}
255
256static int nft_payload_offload_nh(struct nft_offload_ctx *ctx,
257 struct nft_flow_rule *flow,
258 const struct nft_payload *priv)
259{
260 int err;
261
262 switch (ctx->dep.l3num) {
263 case htons(ETH_P_IP):
264 err = nft_payload_offload_ip(ctx, flow, priv);
265 break;
266 case htons(ETH_P_IPV6):
267 err = nft_payload_offload_ip6(ctx, flow, priv);
268 break;
269 default:
270 return -EOPNOTSUPP;
271 }
272
273 return err;
274}
275
276static int nft_payload_offload_tcp(struct nft_offload_ctx *ctx,
277 struct nft_flow_rule *flow,
278 const struct nft_payload *priv)
279{
280 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
281
282 switch (priv->offset) {
283 case offsetof(struct tcphdr, source):
284 if (priv->len != sizeof(__be16))
285 return -EOPNOTSUPP;
286
287 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
288 sizeof(__be16), reg);
289 break;
290 case offsetof(struct tcphdr, dest):
291 if (priv->len != sizeof(__be16))
292 return -EOPNOTSUPP;
293
294 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
295 sizeof(__be16), reg);
296 break;
297 default:
298 return -EOPNOTSUPP;
299 }
300
301 return 0;
302}
303
304static int nft_payload_offload_udp(struct nft_offload_ctx *ctx,
305 struct nft_flow_rule *flow,
306 const struct nft_payload *priv)
307{
308 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
309
310 switch (priv->offset) {
311 case offsetof(struct udphdr, source):
312 if (priv->len != sizeof(__be16))
313 return -EOPNOTSUPP;
314
315 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
316 sizeof(__be16), reg);
317 break;
318 case offsetof(struct udphdr, dest):
319 if (priv->len != sizeof(__be16))
320 return -EOPNOTSUPP;
321
322 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
323 sizeof(__be16), reg);
324 break;
325 default:
326 return -EOPNOTSUPP;
327 }
328
329 return 0;
330}
331
332static int nft_payload_offload_th(struct nft_offload_ctx *ctx,
333 struct nft_flow_rule *flow,
334 const struct nft_payload *priv)
335{
336 int err;
337
338 switch (ctx->dep.protonum) {
339 case IPPROTO_TCP:
340 err = nft_payload_offload_tcp(ctx, flow, priv);
341 break;
342 case IPPROTO_UDP:
343 err = nft_payload_offload_udp(ctx, flow, priv);
344 break;
345 default:
346 return -EOPNOTSUPP;
347 }
348
349 return err;
350}
351
352static int nft_payload_offload(struct nft_offload_ctx *ctx,
353 struct nft_flow_rule *flow,
354 const struct nft_expr *expr)
355{
356 const struct nft_payload *priv = nft_expr_priv(expr);
357 int err;
358
359 switch (priv->base) {
360 case NFT_PAYLOAD_LL_HEADER:
361 err = nft_payload_offload_ll(ctx, flow, priv);
362 break;
363 case NFT_PAYLOAD_NETWORK_HEADER:
364 err = nft_payload_offload_nh(ctx, flow, priv);
365 break;
366 case NFT_PAYLOAD_TRANSPORT_HEADER:
367 err = nft_payload_offload_th(ctx, flow, priv);
368 break;
369 default:
370 err = -EOPNOTSUPP;
371 break;
372 }
373 return err;
374}
375
376static const struct nft_expr_ops nft_payload_ops = {
377 .type = &nft_payload_type,
378 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
379 .eval = nft_payload_eval,
380 .init = nft_payload_init,
381 .dump = nft_payload_dump,
382 .offload = nft_payload_offload,
383};
384
385const struct nft_expr_ops nft_payload_fast_ops = {
386 .type = &nft_payload_type,
387 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
388 .eval = nft_payload_eval,
389 .init = nft_payload_init,
390 .dump = nft_payload_dump,
391 .offload = nft_payload_offload,
392};
393
394static inline void nft_csum_replace(__sum16 *sum, __wsum fsum, __wsum tsum)
395{
396 *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), fsum), tsum));
397 if (*sum == 0)
398 *sum = CSUM_MANGLED_0;
399}
400
401static bool nft_payload_udp_checksum(struct sk_buff *skb, unsigned int thoff)
402{
403 struct udphdr *uh, _uh;
404
405 uh = skb_header_pointer(skb, thoff, sizeof(_uh), &_uh);
406 if (!uh)
407 return false;
408
409 return (__force bool)uh->check;
410}
411
412static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt,
413 struct sk_buff *skb,
414 unsigned int *l4csum_offset)
415{
416 switch (pkt->tprot) {
417 case IPPROTO_TCP:
418 *l4csum_offset = offsetof(struct tcphdr, check);
419 break;
420 case IPPROTO_UDP:
421 if (!nft_payload_udp_checksum(skb, pkt->xt.thoff))
422 return -1;
423 /* Fall through. */
424 case IPPROTO_UDPLITE:
425 *l4csum_offset = offsetof(struct udphdr, check);
426 break;
427 case IPPROTO_ICMPV6:
428 *l4csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
429 break;
430 default:
431 return -1;
432 }
433
434 *l4csum_offset += pkt->xt.thoff;
435 return 0;
436}
437
438static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt,
439 struct sk_buff *skb,
440 __wsum fsum, __wsum tsum)
441{
442 int l4csum_offset;
443 __sum16 sum;
444
445 /* If we cannot determine layer 4 checksum offset or this packet doesn't
446 * require layer 4 checksum recalculation, skip this packet.
447 */
448 if (nft_payload_l4csum_offset(pkt, skb, &l4csum_offset) < 0)
449 return 0;
450
451 if (skb_copy_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
452 return -1;
453
454 /* Checksum mangling for an arbitrary amount of bytes, based on
455 * inet_proto_csum_replace*() functions.
456 */
457 if (skb->ip_summed != CHECKSUM_PARTIAL) {
458 nft_csum_replace(&sum, fsum, tsum);
459 if (skb->ip_summed == CHECKSUM_COMPLETE) {
460 skb->csum = ~csum_add(csum_sub(~(skb->csum), fsum),
461 tsum);
462 }
463 } else {
464 sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum), fsum),
465 tsum));
466 }
467
468 if (skb_ensure_writable(skb, l4csum_offset + sizeof(sum)) ||
469 skb_store_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
470 return -1;
471
472 return 0;
473}
474
475static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src,
476 __wsum fsum, __wsum tsum, int csum_offset)
477{
478 __sum16 sum;
479
480 if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
481 return -1;
482
483 nft_csum_replace(&sum, fsum, tsum);
484 if (skb_ensure_writable(skb, csum_offset + sizeof(sum)) ||
485 skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
486 return -1;
487
488 return 0;
489}
490
491static void nft_payload_set_eval(const struct nft_expr *expr,
492 struct nft_regs *regs,
493 const struct nft_pktinfo *pkt)
494{
495 const struct nft_payload_set *priv = nft_expr_priv(expr);
496 struct sk_buff *skb = pkt->skb;
497 const u32 *src = ®s->data[priv->sreg];
498 int offset, csum_offset;
499 __wsum fsum, tsum;
500
501 switch (priv->base) {
502 case NFT_PAYLOAD_LL_HEADER:
503 if (!skb_mac_header_was_set(skb))
504 goto err;
505 offset = skb_mac_header(skb) - skb->data;
506 break;
507 case NFT_PAYLOAD_NETWORK_HEADER:
508 offset = skb_network_offset(skb);
509 break;
510 case NFT_PAYLOAD_TRANSPORT_HEADER:
511 if (!pkt->tprot_set)
512 goto err;
513 offset = pkt->xt.thoff;
514 break;
515 default:
516 BUG();
517 }
518
519 csum_offset = offset + priv->csum_offset;
520 offset += priv->offset;
521
522 if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) &&
523 (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER ||
524 skb->ip_summed != CHECKSUM_PARTIAL)) {
525 fsum = skb_checksum(skb, offset, priv->len, 0);
526 tsum = csum_partial(src, priv->len, 0);
527
528 if (priv->csum_type == NFT_PAYLOAD_CSUM_INET &&
529 nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset))
530 goto err;
531
532 if (priv->csum_flags &&
533 nft_payload_l4csum_update(pkt, skb, fsum, tsum) < 0)
534 goto err;
535 }
536
537 if (skb_ensure_writable(skb, max(offset + priv->len, 0)) ||
538 skb_store_bits(skb, offset, src, priv->len) < 0)
539 goto err;
540
541 return;
542err:
543 regs->verdict.code = NFT_BREAK;
544}
545
546static int nft_payload_set_init(const struct nft_ctx *ctx,
547 const struct nft_expr *expr,
548 const struct nlattr * const tb[])
549{
550 struct nft_payload_set *priv = nft_expr_priv(expr);
551
552 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
553 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
554 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
555 priv->sreg = nft_parse_register(tb[NFTA_PAYLOAD_SREG]);
556
557 if (tb[NFTA_PAYLOAD_CSUM_TYPE])
558 priv->csum_type =
559 ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE]));
560 if (tb[NFTA_PAYLOAD_CSUM_OFFSET])
561 priv->csum_offset =
562 ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET]));
563 if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) {
564 u32 flags;
565
566 flags = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_FLAGS]));
567 if (flags & ~NFT_PAYLOAD_L4CSUM_PSEUDOHDR)
568 return -EINVAL;
569
570 priv->csum_flags = flags;
571 }
572
573 switch (priv->csum_type) {
574 case NFT_PAYLOAD_CSUM_NONE:
575 case NFT_PAYLOAD_CSUM_INET:
576 break;
577 default:
578 return -EOPNOTSUPP;
579 }
580
581 return nft_validate_register_load(priv->sreg, priv->len);
582}
583
584static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
585{
586 const struct nft_payload_set *priv = nft_expr_priv(expr);
587
588 if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) ||
589 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
590 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
591 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) ||
592 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) ||
593 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET,
594 htonl(priv->csum_offset)) ||
595 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_FLAGS, htonl(priv->csum_flags)))
596 goto nla_put_failure;
597 return 0;
598
599nla_put_failure:
600 return -1;
601}
602
603static const struct nft_expr_ops nft_payload_set_ops = {
604 .type = &nft_payload_type,
605 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)),
606 .eval = nft_payload_set_eval,
607 .init = nft_payload_set_init,
608 .dump = nft_payload_set_dump,
609};
610
611static const struct nft_expr_ops *
612nft_payload_select_ops(const struct nft_ctx *ctx,
613 const struct nlattr * const tb[])
614{
615 enum nft_payload_bases base;
616 unsigned int offset, len;
617
618 if (tb[NFTA_PAYLOAD_BASE] == NULL ||
619 tb[NFTA_PAYLOAD_OFFSET] == NULL ||
620 tb[NFTA_PAYLOAD_LEN] == NULL)
621 return ERR_PTR(-EINVAL);
622
623 base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
624 switch (base) {
625 case NFT_PAYLOAD_LL_HEADER:
626 case NFT_PAYLOAD_NETWORK_HEADER:
627 case NFT_PAYLOAD_TRANSPORT_HEADER:
628 break;
629 default:
630 return ERR_PTR(-EOPNOTSUPP);
631 }
632
633 if (tb[NFTA_PAYLOAD_SREG] != NULL) {
634 if (tb[NFTA_PAYLOAD_DREG] != NULL)
635 return ERR_PTR(-EINVAL);
636 return &nft_payload_set_ops;
637 }
638
639 if (tb[NFTA_PAYLOAD_DREG] == NULL)
640 return ERR_PTR(-EINVAL);
641
642 offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
643 len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
644
645 if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
646 base != NFT_PAYLOAD_LL_HEADER)
647 return &nft_payload_fast_ops;
648 else
649 return &nft_payload_ops;
650}
651
652struct nft_expr_type nft_payload_type __read_mostly = {
653 .name = "payload",
654 .select_ops = nft_payload_select_ops,
655 .policy = nft_payload_policy,
656 .maxattr = NFTA_PAYLOAD_MAX,
657 .owner = THIS_MODULE,
658};