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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
96518518 | 2 | /* |
ef1f7df9 | 3 | * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net> |
18140969 | 4 | * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> |
96518518 | 5 | * |
96518518 PM |
6 | * Development of this code funded by Astaro AG (http://www.astaro.com/) |
7 | */ | |
8 | ||
9 | #include <linux/kernel.h> | |
8cfd23e6 | 10 | #include <linux/if_vlan.h> |
96518518 PM |
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> | |
c9626a2c | 18 | #include <net/netfilter/nf_tables_offload.h> |
18140969 PNA |
19 | /* For layer 4 checksum field offset. */ |
20 | #include <linux/tcp.h> | |
21 | #include <linux/udp.h> | |
22 | #include <linux/icmpv6.h> | |
c9626a2c PNA |
23 | #include <linux/ip.h> |
24 | #include <linux/ipv6.h> | |
96518518 | 25 | |
8dfd8b09 PNA |
26 | static bool nft_payload_rebuild_vlan_hdr(const struct sk_buff *skb, int mac_off, |
27 | struct vlan_ethhdr *veth) | |
28 | { | |
29 | if (skb_copy_bits(skb, mac_off, veth, ETH_HLEN)) | |
30 | return false; | |
31 | ||
32 | veth->h_vlan_proto = skb->vlan_proto; | |
33 | veth->h_vlan_TCI = htons(skb_vlan_tag_get(skb)); | |
34 | veth->h_vlan_encapsulated_proto = skb->protocol; | |
35 | ||
36 | return true; | |
37 | } | |
38 | ||
8cfd23e6 FW |
39 | /* add vlan header into the user buffer for if tag was removed by offloads */ |
40 | static bool | |
41 | nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len) | |
42 | { | |
43 | int mac_off = skb_mac_header(skb) - skb->data; | |
f41f72d0 | 44 | u8 *vlanh, *dst_u8 = (u8 *) d; |
8cfd23e6 | 45 | struct vlan_ethhdr veth; |
f6ae9f12 PNA |
46 | u8 vlan_hlen = 0; |
47 | ||
48 | if ((skb->protocol == htons(ETH_P_8021AD) || | |
49 | skb->protocol == htons(ETH_P_8021Q)) && | |
50 | offset >= VLAN_ETH_HLEN && offset < VLAN_ETH_HLEN + VLAN_HLEN) | |
51 | vlan_hlen += VLAN_HLEN; | |
8cfd23e6 FW |
52 | |
53 | vlanh = (u8 *) &veth; | |
f6ae9f12 | 54 | if (offset < VLAN_ETH_HLEN + vlan_hlen) { |
f41f72d0 | 55 | u8 ethlen = len; |
8cfd23e6 | 56 | |
f6ae9f12 PNA |
57 | if (vlan_hlen && |
58 | skb_copy_bits(skb, mac_off, &veth, VLAN_ETH_HLEN) < 0) | |
59 | return false; | |
60 | else if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth)) | |
8cfd23e6 FW |
61 | return false; |
62 | ||
f6ae9f12 PNA |
63 | if (offset + len > VLAN_ETH_HLEN + vlan_hlen) |
64 | ethlen -= offset + len - VLAN_ETH_HLEN + vlan_hlen; | |
8cfd23e6 | 65 | |
f6ae9f12 | 66 | memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen); |
8cfd23e6 FW |
67 | |
68 | len -= ethlen; | |
69 | if (len == 0) | |
70 | return true; | |
71 | ||
72 | dst_u8 += ethlen; | |
f6ae9f12 | 73 | offset = ETH_HLEN + vlan_hlen; |
f41f72d0 | 74 | } else { |
f6ae9f12 | 75 | offset -= VLAN_HLEN + vlan_hlen; |
8cfd23e6 FW |
76 | } |
77 | ||
8cfd23e6 FW |
78 | return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0; |
79 | } | |
80 | ||
10870dd8 FW |
81 | void nft_payload_eval(const struct nft_expr *expr, |
82 | struct nft_regs *regs, | |
83 | const struct nft_pktinfo *pkt) | |
96518518 PM |
84 | { |
85 | const struct nft_payload *priv = nft_expr_priv(expr); | |
86 | const struct sk_buff *skb = pkt->skb; | |
49499c3e | 87 | u32 *dest = ®s->data[priv->dreg]; |
96518518 PM |
88 | int offset; |
89 | ||
8cfd23e6 | 90 | dest[priv->len / NFT_REG32_SIZE] = 0; |
96518518 PM |
91 | switch (priv->base) { |
92 | case NFT_PAYLOAD_LL_HEADER: | |
93 | if (!skb_mac_header_was_set(skb)) | |
94 | goto err; | |
8cfd23e6 FW |
95 | |
96 | if (skb_vlan_tag_present(skb)) { | |
97 | if (!nft_payload_copy_vlan(dest, skb, | |
98 | priv->offset, priv->len)) | |
99 | goto err; | |
100 | return; | |
101 | } | |
96518518 PM |
102 | offset = skb_mac_header(skb) - skb->data; |
103 | break; | |
104 | case NFT_PAYLOAD_NETWORK_HEADER: | |
105 | offset = skb_network_offset(skb); | |
106 | break; | |
107 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
a20877b5 LZ |
108 | if (!pkt->tprot_set) |
109 | goto err; | |
c54032e0 | 110 | offset = pkt->xt.thoff; |
96518518 PM |
111 | break; |
112 | default: | |
113 | BUG(); | |
114 | } | |
115 | offset += priv->offset; | |
116 | ||
fad136ea | 117 | if (skb_copy_bits(skb, offset, dest, priv->len) < 0) |
96518518 PM |
118 | goto err; |
119 | return; | |
120 | err: | |
a55e22e9 | 121 | regs->verdict.code = NFT_BREAK; |
96518518 PM |
122 | } |
123 | ||
124 | static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = { | |
7ec3f7b4 PM |
125 | [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 }, |
126 | [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 }, | |
127 | [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 }, | |
128 | [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 }, | |
129 | [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 }, | |
130 | [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 }, | |
131 | [NFTA_PAYLOAD_CSUM_OFFSET] = { .type = NLA_U32 }, | |
9d6effb2 | 132 | [NFTA_PAYLOAD_CSUM_FLAGS] = { .type = NLA_U32 }, |
96518518 PM |
133 | }; |
134 | ||
135 | static int nft_payload_init(const struct nft_ctx *ctx, | |
136 | const struct nft_expr *expr, | |
137 | const struct nlattr * const tb[]) | |
138 | { | |
139 | struct nft_payload *priv = nft_expr_priv(expr); | |
96518518 | 140 | |
c29b72e0 | 141 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
96518518 PM |
142 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
143 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); | |
b1c96ed3 | 144 | priv->dreg = nft_parse_register(tb[NFTA_PAYLOAD_DREG]); |
96518518 | 145 | |
1ec10212 PM |
146 | return nft_validate_register_store(ctx, priv->dreg, NULL, |
147 | NFT_DATA_VALUE, priv->len); | |
96518518 PM |
148 | } |
149 | ||
150 | static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
151 | { | |
152 | const struct nft_payload *priv = nft_expr_priv(expr); | |
153 | ||
b1c96ed3 | 154 | if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) || |
96518518 PM |
155 | nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || |
156 | nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || | |
157 | nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len))) | |
158 | goto nla_put_failure; | |
159 | return 0; | |
160 | ||
161 | nla_put_failure: | |
162 | return -1; | |
163 | } | |
164 | ||
c9626a2c PNA |
165 | static int nft_payload_offload_ll(struct nft_offload_ctx *ctx, |
166 | struct nft_flow_rule *flow, | |
167 | const struct nft_payload *priv) | |
168 | { | |
169 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; | |
170 | ||
171 | switch (priv->offset) { | |
172 | case offsetof(struct ethhdr, h_source): | |
a69a85da | 173 | if (priv->len != ETH_ALEN) |
174 | return -EOPNOTSUPP; | |
175 | ||
c9626a2c PNA |
176 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs, |
177 | src, ETH_ALEN, reg); | |
178 | break; | |
179 | case offsetof(struct ethhdr, h_dest): | |
a69a85da | 180 | if (priv->len != ETH_ALEN) |
181 | return -EOPNOTSUPP; | |
182 | ||
c9626a2c PNA |
183 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs, |
184 | dst, ETH_ALEN, reg); | |
185 | break; | |
a82055af PNA |
186 | case offsetof(struct ethhdr, h_proto): |
187 | if (priv->len != sizeof(__be16)) | |
188 | return -EOPNOTSUPP; | |
189 | ||
190 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, | |
191 | n_proto, sizeof(__be16), reg); | |
192 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); | |
193 | break; | |
194 | case offsetof(struct vlan_ethhdr, h_vlan_TCI): | |
195 | if (priv->len != sizeof(__be16)) | |
196 | return -EOPNOTSUPP; | |
197 | ||
198 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan, | |
199 | vlan_tci, sizeof(__be16), reg); | |
200 | break; | |
201 | case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto): | |
202 | if (priv->len != sizeof(__be16)) | |
203 | return -EOPNOTSUPP; | |
204 | ||
205 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan, | |
206 | vlan_tpid, sizeof(__be16), reg); | |
89d8fd44 PNA |
207 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); |
208 | break; | |
209 | case offsetof(struct vlan_ethhdr, h_vlan_TCI) + sizeof(struct vlan_hdr): | |
210 | if (priv->len != sizeof(__be16)) | |
211 | return -EOPNOTSUPP; | |
212 | ||
213 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, vlan, | |
214 | vlan_tci, sizeof(__be16), reg); | |
215 | break; | |
216 | case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto) + | |
217 | sizeof(struct vlan_hdr): | |
218 | if (priv->len != sizeof(__be16)) | |
219 | return -EOPNOTSUPP; | |
220 | ||
221 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, vlan, | |
222 | vlan_tpid, sizeof(__be16), reg); | |
a82055af | 223 | break; |
a69a85da | 224 | default: |
225 | return -EOPNOTSUPP; | |
c9626a2c PNA |
226 | } |
227 | ||
228 | return 0; | |
229 | } | |
230 | ||
231 | static int nft_payload_offload_ip(struct nft_offload_ctx *ctx, | |
232 | struct nft_flow_rule *flow, | |
233 | const struct nft_payload *priv) | |
234 | { | |
235 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; | |
236 | ||
237 | switch (priv->offset) { | |
238 | case offsetof(struct iphdr, saddr): | |
a69a85da | 239 | if (priv->len != sizeof(struct in_addr)) |
240 | return -EOPNOTSUPP; | |
241 | ||
c9626a2c PNA |
242 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src, |
243 | sizeof(struct in_addr), reg); | |
244 | break; | |
245 | case offsetof(struct iphdr, daddr): | |
a69a85da | 246 | if (priv->len != sizeof(struct in_addr)) |
247 | return -EOPNOTSUPP; | |
248 | ||
c9626a2c PNA |
249 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst, |
250 | sizeof(struct in_addr), reg); | |
251 | break; | |
252 | case offsetof(struct iphdr, protocol): | |
a69a85da | 253 | if (priv->len != sizeof(__u8)) |
254 | return -EOPNOTSUPP; | |
255 | ||
c9626a2c PNA |
256 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto, |
257 | sizeof(__u8), reg); | |
258 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT); | |
259 | break; | |
260 | default: | |
261 | return -EOPNOTSUPP; | |
262 | } | |
263 | ||
264 | return 0; | |
265 | } | |
266 | ||
267 | static int nft_payload_offload_ip6(struct nft_offload_ctx *ctx, | |
268 | struct nft_flow_rule *flow, | |
269 | const struct nft_payload *priv) | |
270 | { | |
271 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; | |
272 | ||
273 | switch (priv->offset) { | |
274 | case offsetof(struct ipv6hdr, saddr): | |
a69a85da | 275 | if (priv->len != sizeof(struct in6_addr)) |
276 | return -EOPNOTSUPP; | |
277 | ||
c9626a2c PNA |
278 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src, |
279 | sizeof(struct in6_addr), reg); | |
280 | break; | |
281 | case offsetof(struct ipv6hdr, daddr): | |
a69a85da | 282 | if (priv->len != sizeof(struct in6_addr)) |
283 | return -EOPNOTSUPP; | |
284 | ||
c9626a2c PNA |
285 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst, |
286 | sizeof(struct in6_addr), reg); | |
287 | break; | |
288 | case offsetof(struct ipv6hdr, nexthdr): | |
a69a85da | 289 | if (priv->len != sizeof(__u8)) |
290 | return -EOPNOTSUPP; | |
291 | ||
c9626a2c PNA |
292 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto, |
293 | sizeof(__u8), reg); | |
294 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT); | |
295 | break; | |
296 | default: | |
297 | return -EOPNOTSUPP; | |
298 | } | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | static int nft_payload_offload_nh(struct nft_offload_ctx *ctx, | |
304 | struct nft_flow_rule *flow, | |
305 | const struct nft_payload *priv) | |
306 | { | |
307 | int err; | |
308 | ||
309 | switch (ctx->dep.l3num) { | |
310 | case htons(ETH_P_IP): | |
311 | err = nft_payload_offload_ip(ctx, flow, priv); | |
312 | break; | |
313 | case htons(ETH_P_IPV6): | |
314 | err = nft_payload_offload_ip6(ctx, flow, priv); | |
315 | break; | |
316 | default: | |
317 | return -EOPNOTSUPP; | |
318 | } | |
319 | ||
320 | return err; | |
321 | } | |
322 | ||
323 | static int nft_payload_offload_tcp(struct nft_offload_ctx *ctx, | |
324 | struct nft_flow_rule *flow, | |
325 | const struct nft_payload *priv) | |
326 | { | |
327 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; | |
328 | ||
329 | switch (priv->offset) { | |
330 | case offsetof(struct tcphdr, source): | |
a69a85da | 331 | if (priv->len != sizeof(__be16)) |
332 | return -EOPNOTSUPP; | |
333 | ||
c9626a2c PNA |
334 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src, |
335 | sizeof(__be16), reg); | |
336 | break; | |
337 | case offsetof(struct tcphdr, dest): | |
a69a85da | 338 | if (priv->len != sizeof(__be16)) |
339 | return -EOPNOTSUPP; | |
340 | ||
c9626a2c PNA |
341 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst, |
342 | sizeof(__be16), reg); | |
343 | break; | |
344 | default: | |
345 | return -EOPNOTSUPP; | |
346 | } | |
347 | ||
348 | return 0; | |
349 | } | |
350 | ||
351 | static int nft_payload_offload_udp(struct nft_offload_ctx *ctx, | |
352 | struct nft_flow_rule *flow, | |
353 | const struct nft_payload *priv) | |
354 | { | |
355 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; | |
356 | ||
357 | switch (priv->offset) { | |
358 | case offsetof(struct udphdr, source): | |
a69a85da | 359 | if (priv->len != sizeof(__be16)) |
360 | return -EOPNOTSUPP; | |
361 | ||
c9626a2c PNA |
362 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src, |
363 | sizeof(__be16), reg); | |
364 | break; | |
365 | case offsetof(struct udphdr, dest): | |
a69a85da | 366 | if (priv->len != sizeof(__be16)) |
367 | return -EOPNOTSUPP; | |
368 | ||
c9626a2c PNA |
369 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst, |
370 | sizeof(__be16), reg); | |
371 | break; | |
372 | default: | |
373 | return -EOPNOTSUPP; | |
374 | } | |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | static int nft_payload_offload_th(struct nft_offload_ctx *ctx, | |
380 | struct nft_flow_rule *flow, | |
381 | const struct nft_payload *priv) | |
382 | { | |
383 | int err; | |
384 | ||
385 | switch (ctx->dep.protonum) { | |
386 | case IPPROTO_TCP: | |
387 | err = nft_payload_offload_tcp(ctx, flow, priv); | |
388 | break; | |
389 | case IPPROTO_UDP: | |
390 | err = nft_payload_offload_udp(ctx, flow, priv); | |
391 | break; | |
392 | default: | |
393 | return -EOPNOTSUPP; | |
394 | } | |
395 | ||
396 | return err; | |
397 | } | |
398 | ||
399 | static int nft_payload_offload(struct nft_offload_ctx *ctx, | |
400 | struct nft_flow_rule *flow, | |
401 | const struct nft_expr *expr) | |
402 | { | |
403 | const struct nft_payload *priv = nft_expr_priv(expr); | |
404 | int err; | |
405 | ||
406 | switch (priv->base) { | |
407 | case NFT_PAYLOAD_LL_HEADER: | |
408 | err = nft_payload_offload_ll(ctx, flow, priv); | |
409 | break; | |
410 | case NFT_PAYLOAD_NETWORK_HEADER: | |
411 | err = nft_payload_offload_nh(ctx, flow, priv); | |
412 | break; | |
413 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
414 | err = nft_payload_offload_th(ctx, flow, priv); | |
415 | break; | |
416 | default: | |
417 | err = -EOPNOTSUPP; | |
418 | break; | |
419 | } | |
420 | return err; | |
421 | } | |
422 | ||
ef1f7df9 PM |
423 | static const struct nft_expr_ops nft_payload_ops = { |
424 | .type = &nft_payload_type, | |
96518518 | 425 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), |
96518518 PM |
426 | .eval = nft_payload_eval, |
427 | .init = nft_payload_init, | |
428 | .dump = nft_payload_dump, | |
c9626a2c | 429 | .offload = nft_payload_offload, |
ef1f7df9 PM |
430 | }; |
431 | ||
c29b72e0 PM |
432 | const struct nft_expr_ops nft_payload_fast_ops = { |
433 | .type = &nft_payload_type, | |
434 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), | |
435 | .eval = nft_payload_eval, | |
436 | .init = nft_payload_init, | |
437 | .dump = nft_payload_dump, | |
c9626a2c | 438 | .offload = nft_payload_offload, |
c29b72e0 PM |
439 | }; |
440 | ||
18140969 PNA |
441 | static inline void nft_csum_replace(__sum16 *sum, __wsum fsum, __wsum tsum) |
442 | { | |
443 | *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), fsum), tsum)); | |
444 | if (*sum == 0) | |
445 | *sum = CSUM_MANGLED_0; | |
446 | } | |
447 | ||
448 | static bool nft_payload_udp_checksum(struct sk_buff *skb, unsigned int thoff) | |
449 | { | |
450 | struct udphdr *uh, _uh; | |
451 | ||
452 | uh = skb_header_pointer(skb, thoff, sizeof(_uh), &_uh); | |
453 | if (!uh) | |
454 | return false; | |
455 | ||
5fd02ebe | 456 | return (__force bool)uh->check; |
18140969 PNA |
457 | } |
458 | ||
459 | static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt, | |
460 | struct sk_buff *skb, | |
461 | unsigned int *l4csum_offset) | |
462 | { | |
463 | switch (pkt->tprot) { | |
464 | case IPPROTO_TCP: | |
465 | *l4csum_offset = offsetof(struct tcphdr, check); | |
466 | break; | |
467 | case IPPROTO_UDP: | |
468 | if (!nft_payload_udp_checksum(skb, pkt->xt.thoff)) | |
469 | return -1; | |
954d8297 | 470 | fallthrough; |
18140969 PNA |
471 | case IPPROTO_UDPLITE: |
472 | *l4csum_offset = offsetof(struct udphdr, check); | |
473 | break; | |
474 | case IPPROTO_ICMPV6: | |
475 | *l4csum_offset = offsetof(struct icmp6hdr, icmp6_cksum); | |
476 | break; | |
477 | default: | |
478 | return -1; | |
479 | } | |
480 | ||
481 | *l4csum_offset += pkt->xt.thoff; | |
482 | return 0; | |
483 | } | |
484 | ||
485 | static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt, | |
486 | struct sk_buff *skb, | |
487 | __wsum fsum, __wsum tsum) | |
488 | { | |
489 | int l4csum_offset; | |
490 | __sum16 sum; | |
491 | ||
492 | /* If we cannot determine layer 4 checksum offset or this packet doesn't | |
493 | * require layer 4 checksum recalculation, skip this packet. | |
494 | */ | |
495 | if (nft_payload_l4csum_offset(pkt, skb, &l4csum_offset) < 0) | |
496 | return 0; | |
497 | ||
498 | if (skb_copy_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0) | |
499 | return -1; | |
500 | ||
501 | /* Checksum mangling for an arbitrary amount of bytes, based on | |
502 | * inet_proto_csum_replace*() functions. | |
503 | */ | |
504 | if (skb->ip_summed != CHECKSUM_PARTIAL) { | |
505 | nft_csum_replace(&sum, fsum, tsum); | |
506 | if (skb->ip_summed == CHECKSUM_COMPLETE) { | |
507 | skb->csum = ~csum_add(csum_sub(~(skb->csum), fsum), | |
508 | tsum); | |
509 | } | |
510 | } else { | |
511 | sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum), fsum), | |
512 | tsum)); | |
513 | } | |
514 | ||
7418ee4c | 515 | if (skb_ensure_writable(skb, l4csum_offset + sizeof(sum)) || |
18140969 PNA |
516 | skb_store_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0) |
517 | return -1; | |
518 | ||
519 | return 0; | |
520 | } | |
521 | ||
053d20f5 PNA |
522 | static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src, |
523 | __wsum fsum, __wsum tsum, int csum_offset) | |
524 | { | |
525 | __sum16 sum; | |
526 | ||
527 | if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) | |
528 | return -1; | |
529 | ||
530 | nft_csum_replace(&sum, fsum, tsum); | |
7418ee4c | 531 | if (skb_ensure_writable(skb, csum_offset + sizeof(sum)) || |
053d20f5 PNA |
532 | skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) |
533 | return -1; | |
534 | ||
535 | return 0; | |
536 | } | |
537 | ||
7ec3f7b4 PM |
538 | static void nft_payload_set_eval(const struct nft_expr *expr, |
539 | struct nft_regs *regs, | |
540 | const struct nft_pktinfo *pkt) | |
541 | { | |
542 | const struct nft_payload_set *priv = nft_expr_priv(expr); | |
543 | struct sk_buff *skb = pkt->skb; | |
544 | const u32 *src = ®s->data[priv->sreg]; | |
545 | int offset, csum_offset; | |
546 | __wsum fsum, tsum; | |
7ec3f7b4 PM |
547 | |
548 | switch (priv->base) { | |
549 | case NFT_PAYLOAD_LL_HEADER: | |
550 | if (!skb_mac_header_was_set(skb)) | |
551 | goto err; | |
552 | offset = skb_mac_header(skb) - skb->data; | |
553 | break; | |
554 | case NFT_PAYLOAD_NETWORK_HEADER: | |
555 | offset = skb_network_offset(skb); | |
556 | break; | |
557 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
a20877b5 LZ |
558 | if (!pkt->tprot_set) |
559 | goto err; | |
7ec3f7b4 PM |
560 | offset = pkt->xt.thoff; |
561 | break; | |
562 | default: | |
563 | BUG(); | |
564 | } | |
565 | ||
566 | csum_offset = offset + priv->csum_offset; | |
567 | offset += priv->offset; | |
568 | ||
053d20f5 | 569 | if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) && |
7ec3f7b4 PM |
570 | (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER || |
571 | skb->ip_summed != CHECKSUM_PARTIAL)) { | |
7ec3f7b4 PM |
572 | fsum = skb_checksum(skb, offset, priv->len, 0); |
573 | tsum = csum_partial(src, priv->len, 0); | |
7ec3f7b4 | 574 | |
053d20f5 PNA |
575 | if (priv->csum_type == NFT_PAYLOAD_CSUM_INET && |
576 | nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset)) | |
7ec3f7b4 | 577 | goto err; |
18140969 PNA |
578 | |
579 | if (priv->csum_flags && | |
580 | nft_payload_l4csum_update(pkt, skb, fsum, tsum) < 0) | |
581 | goto err; | |
7ec3f7b4 PM |
582 | } |
583 | ||
7418ee4c | 584 | if (skb_ensure_writable(skb, max(offset + priv->len, 0)) || |
7ec3f7b4 PM |
585 | skb_store_bits(skb, offset, src, priv->len) < 0) |
586 | goto err; | |
587 | ||
588 | return; | |
589 | err: | |
590 | regs->verdict.code = NFT_BREAK; | |
591 | } | |
592 | ||
593 | static int nft_payload_set_init(const struct nft_ctx *ctx, | |
594 | const struct nft_expr *expr, | |
595 | const struct nlattr * const tb[]) | |
596 | { | |
597 | struct nft_payload_set *priv = nft_expr_priv(expr); | |
598 | ||
599 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); | |
600 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); | |
601 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); | |
602 | priv->sreg = nft_parse_register(tb[NFTA_PAYLOAD_SREG]); | |
603 | ||
604 | if (tb[NFTA_PAYLOAD_CSUM_TYPE]) | |
605 | priv->csum_type = | |
606 | ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE])); | |
607 | if (tb[NFTA_PAYLOAD_CSUM_OFFSET]) | |
608 | priv->csum_offset = | |
609 | ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET])); | |
18140969 PNA |
610 | if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) { |
611 | u32 flags; | |
612 | ||
613 | flags = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_FLAGS])); | |
614 | if (flags & ~NFT_PAYLOAD_L4CSUM_PSEUDOHDR) | |
615 | return -EINVAL; | |
616 | ||
617 | priv->csum_flags = flags; | |
618 | } | |
7ec3f7b4 PM |
619 | |
620 | switch (priv->csum_type) { | |
621 | case NFT_PAYLOAD_CSUM_NONE: | |
622 | case NFT_PAYLOAD_CSUM_INET: | |
623 | break; | |
624 | default: | |
625 | return -EOPNOTSUPP; | |
626 | } | |
627 | ||
628 | return nft_validate_register_load(priv->sreg, priv->len); | |
629 | } | |
630 | ||
631 | static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr) | |
632 | { | |
633 | const struct nft_payload_set *priv = nft_expr_priv(expr); | |
634 | ||
635 | if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) || | |
636 | nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || | |
637 | nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || | |
638 | nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) || | |
639 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) || | |
640 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET, | |
18140969 PNA |
641 | htonl(priv->csum_offset)) || |
642 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_FLAGS, htonl(priv->csum_flags))) | |
7ec3f7b4 PM |
643 | goto nla_put_failure; |
644 | return 0; | |
645 | ||
646 | nla_put_failure: | |
647 | return -1; | |
648 | } | |
649 | ||
650 | static const struct nft_expr_ops nft_payload_set_ops = { | |
651 | .type = &nft_payload_type, | |
652 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)), | |
653 | .eval = nft_payload_set_eval, | |
654 | .init = nft_payload_set_init, | |
655 | .dump = nft_payload_set_dump, | |
656 | }; | |
657 | ||
0ca743a5 PNA |
658 | static const struct nft_expr_ops * |
659 | nft_payload_select_ops(const struct nft_ctx *ctx, | |
660 | const struct nlattr * const tb[]) | |
c29b72e0 PM |
661 | { |
662 | enum nft_payload_bases base; | |
663 | unsigned int offset, len; | |
664 | ||
7ec3f7b4 | 665 | if (tb[NFTA_PAYLOAD_BASE] == NULL || |
c29b72e0 PM |
666 | tb[NFTA_PAYLOAD_OFFSET] == NULL || |
667 | tb[NFTA_PAYLOAD_LEN] == NULL) | |
668 | return ERR_PTR(-EINVAL); | |
669 | ||
670 | base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); | |
671 | switch (base) { | |
672 | case NFT_PAYLOAD_LL_HEADER: | |
673 | case NFT_PAYLOAD_NETWORK_HEADER: | |
674 | case NFT_PAYLOAD_TRANSPORT_HEADER: | |
675 | break; | |
676 | default: | |
677 | return ERR_PTR(-EOPNOTSUPP); | |
678 | } | |
679 | ||
7ec3f7b4 PM |
680 | if (tb[NFTA_PAYLOAD_SREG] != NULL) { |
681 | if (tb[NFTA_PAYLOAD_DREG] != NULL) | |
682 | return ERR_PTR(-EINVAL); | |
683 | return &nft_payload_set_ops; | |
684 | } | |
685 | ||
686 | if (tb[NFTA_PAYLOAD_DREG] == NULL) | |
687 | return ERR_PTR(-EINVAL); | |
688 | ||
c29b72e0 | 689 | offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
45d9bcda | 690 | len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
c29b72e0 | 691 | |
f627ed91 NA |
692 | if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) && |
693 | base != NFT_PAYLOAD_LL_HEADER) | |
c29b72e0 PM |
694 | return &nft_payload_fast_ops; |
695 | else | |
696 | return &nft_payload_ops; | |
697 | } | |
698 | ||
4e24877e | 699 | struct nft_expr_type nft_payload_type __read_mostly = { |
ef1f7df9 | 700 | .name = "payload", |
c29b72e0 | 701 | .select_ops = nft_payload_select_ops, |
96518518 PM |
702 | .policy = nft_payload_policy, |
703 | .maxattr = NFTA_PAYLOAD_MAX, | |
ef1f7df9 | 704 | .owner = THIS_MODULE, |
96518518 | 705 | }; |