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 <net/gre.h>
23 #include <linux/icmpv6.h>
24 #include <linux/ip.h>
25 #include <linux/ipv6.h>
26 #include <net/sctp/checksum.h>
27
nft_payload_rebuild_vlan_hdr(const struct sk_buff * skb,int mac_off,struct vlan_ethhdr * veth)28 static bool nft_payload_rebuild_vlan_hdr(const struct sk_buff *skb, int mac_off,
29 struct vlan_ethhdr *veth)
30 {
31 if (skb_copy_bits(skb, mac_off, veth, ETH_HLEN))
32 return false;
33
34 veth->h_vlan_proto = skb->vlan_proto;
35 veth->h_vlan_TCI = htons(skb_vlan_tag_get(skb));
36 veth->h_vlan_encapsulated_proto = skb->protocol;
37
38 return true;
39 }
40
41 /* add vlan header into the user buffer for if tag was removed by offloads */
42 static bool
nft_payload_copy_vlan(u32 * d,const struct sk_buff * skb,u8 offset,u8 len)43 nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
44 {
45 int mac_off = skb_mac_header(skb) - skb->data;
46 u8 *vlanh, *dst_u8 = (u8 *) d;
47 struct vlan_ethhdr veth;
48
49 vlanh = (u8 *) &veth;
50 if (offset < VLAN_ETH_HLEN) {
51 u8 ethlen = len;
52
53 if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
54 return false;
55
56 if (offset + len > VLAN_ETH_HLEN)
57 ethlen -= offset + len - VLAN_ETH_HLEN;
58
59 memcpy(dst_u8, vlanh + offset, ethlen);
60
61 len -= ethlen;
62 if (len == 0)
63 return true;
64
65 dst_u8 += ethlen;
66 offset = ETH_HLEN;
67 } else {
68 offset -= VLAN_HLEN;
69 }
70
71 return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;
72 }
73
__nft_payload_inner_offset(struct nft_pktinfo * pkt)74 static int __nft_payload_inner_offset(struct nft_pktinfo *pkt)
75 {
76 unsigned int thoff = nft_thoff(pkt);
77
78 if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff)
79 return -1;
80
81 switch (pkt->tprot) {
82 case IPPROTO_UDP:
83 pkt->inneroff = thoff + sizeof(struct udphdr);
84 break;
85 case IPPROTO_TCP: {
86 struct tcphdr *th, _tcph;
87
88 th = skb_header_pointer(pkt->skb, thoff, sizeof(_tcph), &_tcph);
89 if (!th)
90 return -1;
91
92 pkt->inneroff = thoff + __tcp_hdrlen(th);
93 }
94 break;
95 case IPPROTO_GRE: {
96 u32 offset = sizeof(struct gre_base_hdr);
97 struct gre_base_hdr *gre, _gre;
98 __be16 version;
99
100 gre = skb_header_pointer(pkt->skb, thoff, sizeof(_gre), &_gre);
101 if (!gre)
102 return -1;
103
104 version = gre->flags & GRE_VERSION;
105 switch (version) {
106 case GRE_VERSION_0:
107 if (gre->flags & GRE_ROUTING)
108 return -1;
109
110 if (gre->flags & GRE_CSUM) {
111 offset += sizeof_field(struct gre_full_hdr, csum) +
112 sizeof_field(struct gre_full_hdr, reserved1);
113 }
114 if (gre->flags & GRE_KEY)
115 offset += sizeof_field(struct gre_full_hdr, key);
116
117 if (gre->flags & GRE_SEQ)
118 offset += sizeof_field(struct gre_full_hdr, seq);
119 break;
120 default:
121 return -1;
122 }
123
124 pkt->inneroff = thoff + offset;
125 }
126 break;
127 case IPPROTO_IPIP:
128 pkt->inneroff = thoff;
129 break;
130 default:
131 return -1;
132 }
133
134 pkt->flags |= NFT_PKTINFO_INNER;
135
136 return 0;
137 }
138
nft_payload_inner_offset(const struct nft_pktinfo * pkt)139 int nft_payload_inner_offset(const struct nft_pktinfo *pkt)
140 {
141 if (!(pkt->flags & NFT_PKTINFO_INNER) &&
142 __nft_payload_inner_offset((struct nft_pktinfo *)pkt) < 0)
143 return -1;
144
145 return pkt->inneroff;
146 }
147
nft_payload_need_vlan_adjust(u32 offset,u32 len)148 static bool nft_payload_need_vlan_adjust(u32 offset, u32 len)
149 {
150 unsigned int boundary = offset + len;
151
152 /* data past ether src/dst requested, copy needed */
153 if (boundary > offsetof(struct ethhdr, h_proto))
154 return true;
155
156 return false;
157 }
158
nft_payload_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)159 void nft_payload_eval(const struct nft_expr *expr,
160 struct nft_regs *regs,
161 const struct nft_pktinfo *pkt)
162 {
163 const struct nft_payload *priv = nft_expr_priv(expr);
164 const struct sk_buff *skb = pkt->skb;
165 u32 *dest = ®s->data[priv->dreg];
166 int offset;
167
168 if (priv->len % NFT_REG32_SIZE)
169 dest[priv->len / NFT_REG32_SIZE] = 0;
170
171 switch (priv->base) {
172 case NFT_PAYLOAD_LL_HEADER:
173 if (!skb_mac_header_was_set(skb) || skb_mac_header_len(skb) == 0)
174 goto err;
175
176 if (skb_vlan_tag_present(skb) &&
177 nft_payload_need_vlan_adjust(priv->offset, priv->len)) {
178 if (!nft_payload_copy_vlan(dest, skb,
179 priv->offset, priv->len))
180 goto err;
181 return;
182 }
183 offset = skb_mac_header(skb) - skb->data;
184 break;
185 case NFT_PAYLOAD_NETWORK_HEADER:
186 offset = skb_network_offset(skb);
187 break;
188 case NFT_PAYLOAD_TRANSPORT_HEADER:
189 if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff)
190 goto err;
191 offset = nft_thoff(pkt);
192 break;
193 case NFT_PAYLOAD_INNER_HEADER:
194 offset = nft_payload_inner_offset(pkt);
195 if (offset < 0)
196 goto err;
197 break;
198 default:
199 WARN_ON_ONCE(1);
200 goto err;
201 }
202 offset += priv->offset;
203
204 if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
205 goto err;
206 return;
207 err:
208 regs->verdict.code = NFT_BREAK;
209 }
210
211 static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = {
212 [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 },
213 [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 },
214 [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 },
215 [NFTA_PAYLOAD_OFFSET] = NLA_POLICY_MAX(NLA_BE32, 255),
216 [NFTA_PAYLOAD_LEN] = NLA_POLICY_MAX(NLA_BE32, 255),
217 [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 },
218 [NFTA_PAYLOAD_CSUM_OFFSET] = NLA_POLICY_MAX(NLA_BE32, 255),
219 [NFTA_PAYLOAD_CSUM_FLAGS] = { .type = NLA_U32 },
220 };
221
nft_payload_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])222 static int nft_payload_init(const struct nft_ctx *ctx,
223 const struct nft_expr *expr,
224 const struct nlattr * const tb[])
225 {
226 struct nft_payload *priv = nft_expr_priv(expr);
227
228 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
229 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
230 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
231
232 return nft_parse_register_store(ctx, tb[NFTA_PAYLOAD_DREG],
233 &priv->dreg, NULL, NFT_DATA_VALUE,
234 priv->len);
235 }
236
nft_payload_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)237 static int nft_payload_dump(struct sk_buff *skb,
238 const struct nft_expr *expr, bool reset)
239 {
240 const struct nft_payload *priv = nft_expr_priv(expr);
241
242 if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) ||
243 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
244 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
245 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)))
246 goto nla_put_failure;
247 return 0;
248
249 nla_put_failure:
250 return -1;
251 }
252
nft_payload_reduce(struct nft_regs_track * track,const struct nft_expr * expr)253 static bool nft_payload_reduce(struct nft_regs_track *track,
254 const struct nft_expr *expr)
255 {
256 const struct nft_payload *priv = nft_expr_priv(expr);
257 const struct nft_payload *payload;
258
259 if (!nft_reg_track_cmp(track, expr, priv->dreg)) {
260 nft_reg_track_update(track, expr, priv->dreg, priv->len);
261 return false;
262 }
263
264 payload = nft_expr_priv(track->regs[priv->dreg].selector);
265 if (priv->base != payload->base ||
266 priv->offset != payload->offset ||
267 priv->len != payload->len) {
268 nft_reg_track_update(track, expr, priv->dreg, priv->len);
269 return false;
270 }
271
272 if (!track->regs[priv->dreg].bitwise)
273 return true;
274
275 return nft_expr_reduce_bitwise(track, expr);
276 }
277
nft_payload_offload_mask(struct nft_offload_reg * reg,u32 priv_len,u32 field_len)278 static bool nft_payload_offload_mask(struct nft_offload_reg *reg,
279 u32 priv_len, u32 field_len)
280 {
281 unsigned int remainder, delta, k;
282 struct nft_data mask = {};
283 __be32 remainder_mask;
284
285 if (priv_len == field_len) {
286 memset(®->mask, 0xff, priv_len);
287 return true;
288 } else if (priv_len > field_len) {
289 return false;
290 }
291
292 memset(&mask, 0xff, field_len);
293 remainder = priv_len % sizeof(u32);
294 if (remainder) {
295 k = priv_len / sizeof(u32);
296 delta = field_len - priv_len;
297 remainder_mask = htonl(~((1 << (delta * BITS_PER_BYTE)) - 1));
298 mask.data[k] = (__force u32)remainder_mask;
299 }
300
301 memcpy(®->mask, &mask, field_len);
302
303 return true;
304 }
305
nft_payload_offload_ll(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)306 static int nft_payload_offload_ll(struct nft_offload_ctx *ctx,
307 struct nft_flow_rule *flow,
308 const struct nft_payload *priv)
309 {
310 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
311
312 switch (priv->offset) {
313 case offsetof(struct ethhdr, h_source):
314 if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN))
315 return -EOPNOTSUPP;
316
317 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
318 src, ETH_ALEN, reg);
319 break;
320 case offsetof(struct ethhdr, h_dest):
321 if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN))
322 return -EOPNOTSUPP;
323
324 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs,
325 dst, ETH_ALEN, reg);
326 break;
327 case offsetof(struct ethhdr, h_proto):
328 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
329 return -EOPNOTSUPP;
330
331 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic,
332 n_proto, sizeof(__be16), reg);
333 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
334 break;
335 case offsetof(struct vlan_ethhdr, h_vlan_TCI):
336 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
337 return -EOPNOTSUPP;
338
339 NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_VLAN, vlan,
340 vlan_tci, sizeof(__be16), reg,
341 NFT_OFFLOAD_F_NETWORK2HOST);
342 break;
343 case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto):
344 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
345 return -EOPNOTSUPP;
346
347 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan,
348 vlan_tpid, sizeof(__be16), reg);
349 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
350 break;
351 case offsetof(struct vlan_ethhdr, h_vlan_TCI) + sizeof(struct vlan_hdr):
352 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
353 return -EOPNOTSUPP;
354
355 NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_CVLAN, cvlan,
356 vlan_tci, sizeof(__be16), reg,
357 NFT_OFFLOAD_F_NETWORK2HOST);
358 break;
359 case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto) +
360 sizeof(struct vlan_hdr):
361 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
362 return -EOPNOTSUPP;
363
364 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, cvlan,
365 vlan_tpid, sizeof(__be16), reg);
366 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK);
367 break;
368 default:
369 return -EOPNOTSUPP;
370 }
371
372 return 0;
373 }
374
nft_payload_offload_ip(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)375 static int nft_payload_offload_ip(struct nft_offload_ctx *ctx,
376 struct nft_flow_rule *flow,
377 const struct nft_payload *priv)
378 {
379 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
380
381 switch (priv->offset) {
382 case offsetof(struct iphdr, saddr):
383 if (!nft_payload_offload_mask(reg, priv->len,
384 sizeof(struct in_addr)))
385 return -EOPNOTSUPP;
386
387 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src,
388 sizeof(struct in_addr), reg);
389 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
390 break;
391 case offsetof(struct iphdr, daddr):
392 if (!nft_payload_offload_mask(reg, priv->len,
393 sizeof(struct in_addr)))
394 return -EOPNOTSUPP;
395
396 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst,
397 sizeof(struct in_addr), reg);
398 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS);
399 break;
400 case offsetof(struct iphdr, protocol):
401 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__u8)))
402 return -EOPNOTSUPP;
403
404 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
405 sizeof(__u8), reg);
406 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
407 break;
408 default:
409 return -EOPNOTSUPP;
410 }
411
412 return 0;
413 }
414
nft_payload_offload_ip6(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)415 static int nft_payload_offload_ip6(struct nft_offload_ctx *ctx,
416 struct nft_flow_rule *flow,
417 const struct nft_payload *priv)
418 {
419 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
420
421 switch (priv->offset) {
422 case offsetof(struct ipv6hdr, saddr):
423 if (!nft_payload_offload_mask(reg, priv->len,
424 sizeof(struct in6_addr)))
425 return -EOPNOTSUPP;
426
427 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src,
428 sizeof(struct in6_addr), reg);
429 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
430 break;
431 case offsetof(struct ipv6hdr, daddr):
432 if (!nft_payload_offload_mask(reg, priv->len,
433 sizeof(struct in6_addr)))
434 return -EOPNOTSUPP;
435
436 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst,
437 sizeof(struct in6_addr), reg);
438 nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS);
439 break;
440 case offsetof(struct ipv6hdr, nexthdr):
441 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__u8)))
442 return -EOPNOTSUPP;
443
444 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto,
445 sizeof(__u8), reg);
446 nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT);
447 break;
448 default:
449 return -EOPNOTSUPP;
450 }
451
452 return 0;
453 }
454
nft_payload_offload_nh(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)455 static int nft_payload_offload_nh(struct nft_offload_ctx *ctx,
456 struct nft_flow_rule *flow,
457 const struct nft_payload *priv)
458 {
459 int err;
460
461 switch (ctx->dep.l3num) {
462 case htons(ETH_P_IP):
463 err = nft_payload_offload_ip(ctx, flow, priv);
464 break;
465 case htons(ETH_P_IPV6):
466 err = nft_payload_offload_ip6(ctx, flow, priv);
467 break;
468 default:
469 return -EOPNOTSUPP;
470 }
471
472 return err;
473 }
474
nft_payload_offload_tcp(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)475 static int nft_payload_offload_tcp(struct nft_offload_ctx *ctx,
476 struct nft_flow_rule *flow,
477 const struct nft_payload *priv)
478 {
479 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
480
481 switch (priv->offset) {
482 case offsetof(struct tcphdr, source):
483 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
484 return -EOPNOTSUPP;
485
486 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
487 sizeof(__be16), reg);
488 break;
489 case offsetof(struct tcphdr, dest):
490 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
491 return -EOPNOTSUPP;
492
493 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
494 sizeof(__be16), reg);
495 break;
496 default:
497 return -EOPNOTSUPP;
498 }
499
500 return 0;
501 }
502
nft_payload_offload_udp(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)503 static int nft_payload_offload_udp(struct nft_offload_ctx *ctx,
504 struct nft_flow_rule *flow,
505 const struct nft_payload *priv)
506 {
507 struct nft_offload_reg *reg = &ctx->regs[priv->dreg];
508
509 switch (priv->offset) {
510 case offsetof(struct udphdr, source):
511 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
512 return -EOPNOTSUPP;
513
514 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src,
515 sizeof(__be16), reg);
516 break;
517 case offsetof(struct udphdr, dest):
518 if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16)))
519 return -EOPNOTSUPP;
520
521 NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst,
522 sizeof(__be16), reg);
523 break;
524 default:
525 return -EOPNOTSUPP;
526 }
527
528 return 0;
529 }
530
nft_payload_offload_th(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_payload * priv)531 static int nft_payload_offload_th(struct nft_offload_ctx *ctx,
532 struct nft_flow_rule *flow,
533 const struct nft_payload *priv)
534 {
535 int err;
536
537 switch (ctx->dep.protonum) {
538 case IPPROTO_TCP:
539 err = nft_payload_offload_tcp(ctx, flow, priv);
540 break;
541 case IPPROTO_UDP:
542 err = nft_payload_offload_udp(ctx, flow, priv);
543 break;
544 default:
545 return -EOPNOTSUPP;
546 }
547
548 return err;
549 }
550
nft_payload_offload(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_expr * expr)551 static int nft_payload_offload(struct nft_offload_ctx *ctx,
552 struct nft_flow_rule *flow,
553 const struct nft_expr *expr)
554 {
555 const struct nft_payload *priv = nft_expr_priv(expr);
556 int err;
557
558 switch (priv->base) {
559 case NFT_PAYLOAD_LL_HEADER:
560 err = nft_payload_offload_ll(ctx, flow, priv);
561 break;
562 case NFT_PAYLOAD_NETWORK_HEADER:
563 err = nft_payload_offload_nh(ctx, flow, priv);
564 break;
565 case NFT_PAYLOAD_TRANSPORT_HEADER:
566 err = nft_payload_offload_th(ctx, flow, priv);
567 break;
568 default:
569 err = -EOPNOTSUPP;
570 break;
571 }
572 return err;
573 }
574
575 static const struct nft_expr_ops nft_payload_ops = {
576 .type = &nft_payload_type,
577 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
578 .eval = nft_payload_eval,
579 .init = nft_payload_init,
580 .dump = nft_payload_dump,
581 .reduce = nft_payload_reduce,
582 .offload = nft_payload_offload,
583 };
584
585 const struct nft_expr_ops nft_payload_fast_ops = {
586 .type = &nft_payload_type,
587 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
588 .eval = nft_payload_eval,
589 .init = nft_payload_init,
590 .dump = nft_payload_dump,
591 .reduce = nft_payload_reduce,
592 .offload = nft_payload_offload,
593 };
594
nft_payload_inner_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt,struct nft_inner_tun_ctx * tun_ctx)595 void nft_payload_inner_eval(const struct nft_expr *expr, struct nft_regs *regs,
596 const struct nft_pktinfo *pkt,
597 struct nft_inner_tun_ctx *tun_ctx)
598 {
599 const struct nft_payload *priv = nft_expr_priv(expr);
600 const struct sk_buff *skb = pkt->skb;
601 u32 *dest = ®s->data[priv->dreg];
602 int offset;
603
604 if (priv->len % NFT_REG32_SIZE)
605 dest[priv->len / NFT_REG32_SIZE] = 0;
606
607 switch (priv->base) {
608 case NFT_PAYLOAD_TUN_HEADER:
609 if (!(tun_ctx->flags & NFT_PAYLOAD_CTX_INNER_TUN))
610 goto err;
611
612 offset = tun_ctx->inner_tunoff;
613 break;
614 case NFT_PAYLOAD_LL_HEADER:
615 if (!(tun_ctx->flags & NFT_PAYLOAD_CTX_INNER_LL))
616 goto err;
617
618 offset = tun_ctx->inner_lloff;
619 break;
620 case NFT_PAYLOAD_NETWORK_HEADER:
621 if (!(tun_ctx->flags & NFT_PAYLOAD_CTX_INNER_NH))
622 goto err;
623
624 offset = tun_ctx->inner_nhoff;
625 break;
626 case NFT_PAYLOAD_TRANSPORT_HEADER:
627 if (!(tun_ctx->flags & NFT_PAYLOAD_CTX_INNER_TH))
628 goto err;
629
630 offset = tun_ctx->inner_thoff;
631 break;
632 default:
633 WARN_ON_ONCE(1);
634 goto err;
635 }
636 offset += priv->offset;
637
638 if (skb_copy_bits(skb, offset, dest, priv->len) < 0)
639 goto err;
640
641 return;
642 err:
643 regs->verdict.code = NFT_BREAK;
644 }
645
nft_payload_inner_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])646 static int nft_payload_inner_init(const struct nft_ctx *ctx,
647 const struct nft_expr *expr,
648 const struct nlattr * const tb[])
649 {
650 struct nft_payload *priv = nft_expr_priv(expr);
651 u32 base;
652
653 if (!tb[NFTA_PAYLOAD_BASE] || !tb[NFTA_PAYLOAD_OFFSET] ||
654 !tb[NFTA_PAYLOAD_LEN] || !tb[NFTA_PAYLOAD_DREG])
655 return -EINVAL;
656
657 base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
658 switch (base) {
659 case NFT_PAYLOAD_TUN_HEADER:
660 case NFT_PAYLOAD_LL_HEADER:
661 case NFT_PAYLOAD_NETWORK_HEADER:
662 case NFT_PAYLOAD_TRANSPORT_HEADER:
663 break;
664 default:
665 return -EOPNOTSUPP;
666 }
667
668 priv->base = base;
669 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
670 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
671
672 return nft_parse_register_store(ctx, tb[NFTA_PAYLOAD_DREG],
673 &priv->dreg, NULL, NFT_DATA_VALUE,
674 priv->len);
675 }
676
677 static const struct nft_expr_ops nft_payload_inner_ops = {
678 .type = &nft_payload_type,
679 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)),
680 .init = nft_payload_inner_init,
681 .dump = nft_payload_dump,
682 /* direct call to nft_payload_inner_eval(). */
683 };
684
nft_csum_replace(__sum16 * sum,__wsum fsum,__wsum tsum)685 static inline void nft_csum_replace(__sum16 *sum, __wsum fsum, __wsum tsum)
686 {
687 *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), fsum), tsum));
688 if (*sum == 0)
689 *sum = CSUM_MANGLED_0;
690 }
691
nft_payload_udp_checksum(struct sk_buff * skb,unsigned int thoff)692 static bool nft_payload_udp_checksum(struct sk_buff *skb, unsigned int thoff)
693 {
694 struct udphdr *uh, _uh;
695
696 uh = skb_header_pointer(skb, thoff, sizeof(_uh), &_uh);
697 if (!uh)
698 return false;
699
700 return (__force bool)uh->check;
701 }
702
nft_payload_l4csum_offset(const struct nft_pktinfo * pkt,struct sk_buff * skb,unsigned int * l4csum_offset)703 static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt,
704 struct sk_buff *skb,
705 unsigned int *l4csum_offset)
706 {
707 if (pkt->fragoff)
708 return -1;
709
710 switch (pkt->tprot) {
711 case IPPROTO_TCP:
712 *l4csum_offset = offsetof(struct tcphdr, check);
713 break;
714 case IPPROTO_UDP:
715 if (!nft_payload_udp_checksum(skb, nft_thoff(pkt)))
716 return -1;
717 fallthrough;
718 case IPPROTO_UDPLITE:
719 *l4csum_offset = offsetof(struct udphdr, check);
720 break;
721 case IPPROTO_ICMPV6:
722 *l4csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
723 break;
724 default:
725 return -1;
726 }
727
728 *l4csum_offset += nft_thoff(pkt);
729 return 0;
730 }
731
nft_payload_csum_sctp(struct sk_buff * skb,int offset)732 static int nft_payload_csum_sctp(struct sk_buff *skb, int offset)
733 {
734 struct sctphdr *sh;
735
736 if (skb_ensure_writable(skb, offset + sizeof(*sh)))
737 return -1;
738
739 sh = (struct sctphdr *)(skb->data + offset);
740 sh->checksum = sctp_compute_cksum(skb, offset);
741 skb->ip_summed = CHECKSUM_UNNECESSARY;
742 return 0;
743 }
744
nft_payload_l4csum_update(const struct nft_pktinfo * pkt,struct sk_buff * skb,__wsum fsum,__wsum tsum)745 static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt,
746 struct sk_buff *skb,
747 __wsum fsum, __wsum tsum)
748 {
749 int l4csum_offset;
750 __sum16 sum;
751
752 /* If we cannot determine layer 4 checksum offset or this packet doesn't
753 * require layer 4 checksum recalculation, skip this packet.
754 */
755 if (nft_payload_l4csum_offset(pkt, skb, &l4csum_offset) < 0)
756 return 0;
757
758 if (skb_copy_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
759 return -1;
760
761 /* Checksum mangling for an arbitrary amount of bytes, based on
762 * inet_proto_csum_replace*() functions.
763 */
764 if (skb->ip_summed != CHECKSUM_PARTIAL) {
765 nft_csum_replace(&sum, fsum, tsum);
766 if (skb->ip_summed == CHECKSUM_COMPLETE) {
767 skb->csum = ~csum_add(csum_sub(~(skb->csum), fsum),
768 tsum);
769 }
770 } else {
771 sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum), fsum),
772 tsum));
773 }
774
775 if (skb_ensure_writable(skb, l4csum_offset + sizeof(sum)) ||
776 skb_store_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0)
777 return -1;
778
779 return 0;
780 }
781
nft_payload_csum_inet(struct sk_buff * skb,const u32 * src,__wsum fsum,__wsum tsum,int csum_offset)782 static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src,
783 __wsum fsum, __wsum tsum, int csum_offset)
784 {
785 __sum16 sum;
786
787 if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
788 return -1;
789
790 nft_csum_replace(&sum, fsum, tsum);
791 if (skb_ensure_writable(skb, csum_offset + sizeof(sum)) ||
792 skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0)
793 return -1;
794
795 return 0;
796 }
797
798 struct nft_payload_set {
799 enum nft_payload_bases base:8;
800 u8 offset;
801 u8 len;
802 u8 sreg;
803 u8 csum_type;
804 u8 csum_offset;
805 u8 csum_flags;
806 };
807
808 /* This is not struct vlan_hdr. */
809 struct nft_payload_vlan_hdr {
810 __be16 h_vlan_proto;
811 __be16 h_vlan_TCI;
812 };
813
814 static bool
nft_payload_set_vlan(const u32 * src,struct sk_buff * skb,u8 offset,u8 len,int * vlan_hlen)815 nft_payload_set_vlan(const u32 *src, struct sk_buff *skb, u8 offset, u8 len,
816 int *vlan_hlen)
817 {
818 struct nft_payload_vlan_hdr *vlanh;
819 __be16 vlan_proto;
820 u16 vlan_tci;
821
822 if (offset >= offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto)) {
823 *vlan_hlen = VLAN_HLEN;
824 return true;
825 }
826
827 switch (offset) {
828 case offsetof(struct vlan_ethhdr, h_vlan_proto):
829 if (len == 2) {
830 vlan_proto = nft_reg_load_be16(src);
831 skb->vlan_proto = vlan_proto;
832 } else if (len == 4) {
833 vlanh = (struct nft_payload_vlan_hdr *)src;
834 __vlan_hwaccel_put_tag(skb, vlanh->h_vlan_proto,
835 ntohs(vlanh->h_vlan_TCI));
836 } else {
837 return false;
838 }
839 break;
840 case offsetof(struct vlan_ethhdr, h_vlan_TCI):
841 if (len != 2)
842 return false;
843
844 vlan_tci = ntohs(nft_reg_load_be16(src));
845 skb->vlan_tci = vlan_tci;
846 break;
847 default:
848 return false;
849 }
850
851 return true;
852 }
853
nft_payload_set_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)854 static void nft_payload_set_eval(const struct nft_expr *expr,
855 struct nft_regs *regs,
856 const struct nft_pktinfo *pkt)
857 {
858 const struct nft_payload_set *priv = nft_expr_priv(expr);
859 const u32 *src = ®s->data[priv->sreg];
860 int offset, csum_offset, vlan_hlen = 0;
861 struct sk_buff *skb = pkt->skb;
862 __wsum fsum, tsum;
863
864 switch (priv->base) {
865 case NFT_PAYLOAD_LL_HEADER:
866 if (!skb_mac_header_was_set(skb))
867 goto err;
868
869 if (skb_vlan_tag_present(skb) &&
870 nft_payload_need_vlan_adjust(priv->offset, priv->len)) {
871 if (!nft_payload_set_vlan(src, skb,
872 priv->offset, priv->len,
873 &vlan_hlen))
874 goto err;
875
876 if (!vlan_hlen)
877 return;
878 }
879
880 offset = skb_mac_header(skb) - skb->data - vlan_hlen;
881 break;
882 case NFT_PAYLOAD_NETWORK_HEADER:
883 offset = skb_network_offset(skb);
884 break;
885 case NFT_PAYLOAD_TRANSPORT_HEADER:
886 if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff)
887 goto err;
888 offset = nft_thoff(pkt);
889 break;
890 case NFT_PAYLOAD_INNER_HEADER:
891 offset = nft_payload_inner_offset(pkt);
892 if (offset < 0)
893 goto err;
894 break;
895 default:
896 WARN_ON_ONCE(1);
897 goto err;
898 }
899
900 csum_offset = offset + priv->csum_offset;
901 offset += priv->offset;
902
903 if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) &&
904 ((priv->base != NFT_PAYLOAD_TRANSPORT_HEADER &&
905 priv->base != NFT_PAYLOAD_INNER_HEADER) ||
906 skb->ip_summed != CHECKSUM_PARTIAL)) {
907 fsum = skb_checksum(skb, offset, priv->len, 0);
908 tsum = csum_partial(src, priv->len, 0);
909
910 if (priv->csum_type == NFT_PAYLOAD_CSUM_INET &&
911 nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset))
912 goto err;
913
914 if (priv->csum_flags &&
915 nft_payload_l4csum_update(pkt, skb, fsum, tsum) < 0)
916 goto err;
917 }
918
919 if (skb_ensure_writable(skb, max(offset + priv->len, 0)) ||
920 skb_store_bits(skb, offset, src, priv->len) < 0)
921 goto err;
922
923 if (priv->csum_type == NFT_PAYLOAD_CSUM_SCTP &&
924 pkt->tprot == IPPROTO_SCTP &&
925 skb->ip_summed != CHECKSUM_PARTIAL) {
926 if (pkt->fragoff == 0 &&
927 nft_payload_csum_sctp(skb, nft_thoff(pkt)))
928 goto err;
929 }
930
931 return;
932 err:
933 regs->verdict.code = NFT_BREAK;
934 }
935
nft_payload_set_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])936 static int nft_payload_set_init(const struct nft_ctx *ctx,
937 const struct nft_expr *expr,
938 const struct nlattr * const tb[])
939 {
940 struct nft_payload_set *priv = nft_expr_priv(expr);
941 u32 csum_offset, csum_type = NFT_PAYLOAD_CSUM_NONE;
942 int err;
943
944 priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
945 priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET]));
946 priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN]));
947
948 if (tb[NFTA_PAYLOAD_CSUM_TYPE])
949 csum_type = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE]));
950 if (tb[NFTA_PAYLOAD_CSUM_OFFSET]) {
951 err = nft_parse_u32_check(tb[NFTA_PAYLOAD_CSUM_OFFSET], U8_MAX,
952 &csum_offset);
953 if (err < 0)
954 return err;
955
956 priv->csum_offset = csum_offset;
957 }
958 if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) {
959 u32 flags;
960
961 flags = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_FLAGS]));
962 if (flags & ~NFT_PAYLOAD_L4CSUM_PSEUDOHDR)
963 return -EINVAL;
964
965 priv->csum_flags = flags;
966 }
967
968 switch (csum_type) {
969 case NFT_PAYLOAD_CSUM_NONE:
970 case NFT_PAYLOAD_CSUM_INET:
971 break;
972 case NFT_PAYLOAD_CSUM_SCTP:
973 if (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER)
974 return -EINVAL;
975
976 if (priv->csum_offset != offsetof(struct sctphdr, checksum))
977 return -EINVAL;
978 break;
979 default:
980 return -EOPNOTSUPP;
981 }
982 priv->csum_type = csum_type;
983
984 return nft_parse_register_load(tb[NFTA_PAYLOAD_SREG], &priv->sreg,
985 priv->len);
986 }
987
nft_payload_set_dump(struct sk_buff * skb,const struct nft_expr * expr,bool reset)988 static int nft_payload_set_dump(struct sk_buff *skb,
989 const struct nft_expr *expr, bool reset)
990 {
991 const struct nft_payload_set *priv = nft_expr_priv(expr);
992
993 if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) ||
994 nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) ||
995 nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) ||
996 nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) ||
997 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) ||
998 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET,
999 htonl(priv->csum_offset)) ||
1000 nla_put_be32(skb, NFTA_PAYLOAD_CSUM_FLAGS, htonl(priv->csum_flags)))
1001 goto nla_put_failure;
1002 return 0;
1003
1004 nla_put_failure:
1005 return -1;
1006 }
1007
nft_payload_set_reduce(struct nft_regs_track * track,const struct nft_expr * expr)1008 static bool nft_payload_set_reduce(struct nft_regs_track *track,
1009 const struct nft_expr *expr)
1010 {
1011 int i;
1012
1013 for (i = 0; i < NFT_REG32_NUM; i++) {
1014 if (!track->regs[i].selector)
1015 continue;
1016
1017 if (track->regs[i].selector->ops != &nft_payload_ops &&
1018 track->regs[i].selector->ops != &nft_payload_fast_ops)
1019 continue;
1020
1021 __nft_reg_track_cancel(track, i);
1022 }
1023
1024 return false;
1025 }
1026
1027 static const struct nft_expr_ops nft_payload_set_ops = {
1028 .type = &nft_payload_type,
1029 .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)),
1030 .eval = nft_payload_set_eval,
1031 .init = nft_payload_set_init,
1032 .dump = nft_payload_set_dump,
1033 .reduce = nft_payload_set_reduce,
1034 };
1035
1036 static const struct nft_expr_ops *
nft_payload_select_ops(const struct nft_ctx * ctx,const struct nlattr * const tb[])1037 nft_payload_select_ops(const struct nft_ctx *ctx,
1038 const struct nlattr * const tb[])
1039 {
1040 enum nft_payload_bases base;
1041 unsigned int offset, len;
1042 int err;
1043
1044 if (tb[NFTA_PAYLOAD_BASE] == NULL ||
1045 tb[NFTA_PAYLOAD_OFFSET] == NULL ||
1046 tb[NFTA_PAYLOAD_LEN] == NULL)
1047 return ERR_PTR(-EINVAL);
1048
1049 base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE]));
1050 switch (base) {
1051 case NFT_PAYLOAD_LL_HEADER:
1052 case NFT_PAYLOAD_NETWORK_HEADER:
1053 case NFT_PAYLOAD_TRANSPORT_HEADER:
1054 case NFT_PAYLOAD_INNER_HEADER:
1055 break;
1056 default:
1057 return ERR_PTR(-EOPNOTSUPP);
1058 }
1059
1060 if (tb[NFTA_PAYLOAD_SREG] != NULL) {
1061 if (tb[NFTA_PAYLOAD_DREG] != NULL)
1062 return ERR_PTR(-EINVAL);
1063 return &nft_payload_set_ops;
1064 }
1065
1066 if (tb[NFTA_PAYLOAD_DREG] == NULL)
1067 return ERR_PTR(-EINVAL);
1068
1069 err = nft_parse_u32_check(tb[NFTA_PAYLOAD_OFFSET], U8_MAX, &offset);
1070 if (err < 0)
1071 return ERR_PTR(err);
1072
1073 err = nft_parse_u32_check(tb[NFTA_PAYLOAD_LEN], U8_MAX, &len);
1074 if (err < 0)
1075 return ERR_PTR(err);
1076
1077 if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) &&
1078 base != NFT_PAYLOAD_LL_HEADER && base != NFT_PAYLOAD_INNER_HEADER)
1079 return &nft_payload_fast_ops;
1080 else
1081 return &nft_payload_ops;
1082 }
1083
1084 struct nft_expr_type nft_payload_type __read_mostly = {
1085 .name = "payload",
1086 .select_ops = nft_payload_select_ops,
1087 .inner_ops = &nft_payload_inner_ops,
1088 .policy = nft_payload_policy,
1089 .maxattr = NFTA_PAYLOAD_MAX,
1090 .owner = THIS_MODULE,
1091 };
1092