| 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 | |
| 27 | static 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 */ |
| 41 | static bool |
| 42 | nft_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 | |
| 82 | static int __nft_payload_inner_offset(struct nft_pktinfo *pkt) |
| 83 | { |
| 84 | unsigned int thoff = nft_thoff(pkt); |
| 85 | |
| 86 | if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) |
| 87 | return -1; |
| 88 | |
| 89 | switch (pkt->tprot) { |
| 90 | case IPPROTO_UDP: |
| 91 | pkt->inneroff = thoff + sizeof(struct udphdr); |
| 92 | break; |
| 93 | case IPPROTO_TCP: { |
| 94 | struct tcphdr *th, _tcph; |
| 95 | |
| 96 | th = skb_header_pointer(pkt->skb, thoff, sizeof(_tcph), &_tcph); |
| 97 | if (!th) |
| 98 | return -1; |
| 99 | |
| 100 | pkt->inneroff = thoff + __tcp_hdrlen(th); |
| 101 | } |
| 102 | break; |
| 103 | default: |
| 104 | return -1; |
| 105 | } |
| 106 | |
| 107 | pkt->flags |= NFT_PKTINFO_INNER; |
| 108 | |
| 109 | return 0; |
| 110 | } |
| 111 | |
| 112 | static int nft_payload_inner_offset(const struct nft_pktinfo *pkt) |
| 113 | { |
| 114 | if (!(pkt->flags & NFT_PKTINFO_INNER) && |
| 115 | __nft_payload_inner_offset((struct nft_pktinfo *)pkt) < 0) |
| 116 | return -1; |
| 117 | |
| 118 | return pkt->inneroff; |
| 119 | } |
| 120 | |
| 121 | void nft_payload_eval(const struct nft_expr *expr, |
| 122 | struct nft_regs *regs, |
| 123 | const struct nft_pktinfo *pkt) |
| 124 | { |
| 125 | const struct nft_payload *priv = nft_expr_priv(expr); |
| 126 | const struct sk_buff *skb = pkt->skb; |
| 127 | u32 *dest = ®s->data[priv->dreg]; |
| 128 | int offset; |
| 129 | |
| 130 | if (priv->len % NFT_REG32_SIZE) |
| 131 | dest[priv->len / NFT_REG32_SIZE] = 0; |
| 132 | |
| 133 | switch (priv->base) { |
| 134 | case NFT_PAYLOAD_LL_HEADER: |
| 135 | if (!skb_mac_header_was_set(skb)) |
| 136 | goto err; |
| 137 | |
| 138 | if (skb_vlan_tag_present(skb)) { |
| 139 | if (!nft_payload_copy_vlan(dest, skb, |
| 140 | priv->offset, priv->len)) |
| 141 | goto err; |
| 142 | return; |
| 143 | } |
| 144 | offset = skb_mac_header(skb) - skb->data; |
| 145 | break; |
| 146 | case NFT_PAYLOAD_NETWORK_HEADER: |
| 147 | offset = skb_network_offset(skb); |
| 148 | break; |
| 149 | case NFT_PAYLOAD_TRANSPORT_HEADER: |
| 150 | if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) |
| 151 | goto err; |
| 152 | offset = nft_thoff(pkt); |
| 153 | break; |
| 154 | case NFT_PAYLOAD_INNER_HEADER: |
| 155 | offset = nft_payload_inner_offset(pkt); |
| 156 | if (offset < 0) |
| 157 | goto err; |
| 158 | break; |
| 159 | default: |
| 160 | WARN_ON_ONCE(1); |
| 161 | goto err; |
| 162 | } |
| 163 | offset += priv->offset; |
| 164 | |
| 165 | if (skb_copy_bits(skb, offset, dest, priv->len) < 0) |
| 166 | goto err; |
| 167 | return; |
| 168 | err: |
| 169 | regs->verdict.code = NFT_BREAK; |
| 170 | } |
| 171 | |
| 172 | static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = { |
| 173 | [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 }, |
| 174 | [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 }, |
| 175 | [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 }, |
| 176 | [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 }, |
| 177 | [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 }, |
| 178 | [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 }, |
| 179 | [NFTA_PAYLOAD_CSUM_OFFSET] = { .type = NLA_U32 }, |
| 180 | [NFTA_PAYLOAD_CSUM_FLAGS] = { .type = NLA_U32 }, |
| 181 | }; |
| 182 | |
| 183 | static int nft_payload_init(const struct nft_ctx *ctx, |
| 184 | const struct nft_expr *expr, |
| 185 | const struct nlattr * const tb[]) |
| 186 | { |
| 187 | struct nft_payload *priv = nft_expr_priv(expr); |
| 188 | |
| 189 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
| 190 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
| 191 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
| 192 | |
| 193 | return nft_parse_register_store(ctx, tb[NFTA_PAYLOAD_DREG], |
| 194 | &priv->dreg, NULL, NFT_DATA_VALUE, |
| 195 | priv->len); |
| 196 | } |
| 197 | |
| 198 | static int nft_payload_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 199 | { |
| 200 | const struct nft_payload *priv = nft_expr_priv(expr); |
| 201 | |
| 202 | if (nft_dump_register(skb, NFTA_PAYLOAD_DREG, priv->dreg) || |
| 203 | nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || |
| 204 | nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || |
| 205 | nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len))) |
| 206 | goto nla_put_failure; |
| 207 | return 0; |
| 208 | |
| 209 | nla_put_failure: |
| 210 | return -1; |
| 211 | } |
| 212 | |
| 213 | static bool nft_payload_reduce(struct nft_regs_track *track, |
| 214 | const struct nft_expr *expr) |
| 215 | { |
| 216 | const struct nft_payload *priv = nft_expr_priv(expr); |
| 217 | const struct nft_payload *payload; |
| 218 | |
| 219 | if (!nft_reg_track_cmp(track, expr, priv->dreg)) { |
| 220 | nft_reg_track_update(track, expr, priv->dreg, priv->len); |
| 221 | return false; |
| 222 | } |
| 223 | |
| 224 | payload = nft_expr_priv(track->regs[priv->dreg].selector); |
| 225 | if (priv->base != payload->base || |
| 226 | priv->offset != payload->offset || |
| 227 | priv->len != payload->len) { |
| 228 | nft_reg_track_update(track, expr, priv->dreg, priv->len); |
| 229 | return false; |
| 230 | } |
| 231 | |
| 232 | if (!track->regs[priv->dreg].bitwise) |
| 233 | return true; |
| 234 | |
| 235 | return nft_expr_reduce_bitwise(track, expr); |
| 236 | } |
| 237 | |
| 238 | static bool nft_payload_offload_mask(struct nft_offload_reg *reg, |
| 239 | u32 priv_len, u32 field_len) |
| 240 | { |
| 241 | unsigned int remainder, delta, k; |
| 242 | struct nft_data mask = {}; |
| 243 | __be32 remainder_mask; |
| 244 | |
| 245 | if (priv_len == field_len) { |
| 246 | memset(®->mask, 0xff, priv_len); |
| 247 | return true; |
| 248 | } else if (priv_len > field_len) { |
| 249 | return false; |
| 250 | } |
| 251 | |
| 252 | memset(&mask, 0xff, field_len); |
| 253 | remainder = priv_len % sizeof(u32); |
| 254 | if (remainder) { |
| 255 | k = priv_len / sizeof(u32); |
| 256 | delta = field_len - priv_len; |
| 257 | remainder_mask = htonl(~((1 << (delta * BITS_PER_BYTE)) - 1)); |
| 258 | mask.data[k] = (__force u32)remainder_mask; |
| 259 | } |
| 260 | |
| 261 | memcpy(®->mask, &mask, field_len); |
| 262 | |
| 263 | return true; |
| 264 | } |
| 265 | |
| 266 | static int nft_payload_offload_ll(struct nft_offload_ctx *ctx, |
| 267 | struct nft_flow_rule *flow, |
| 268 | const struct nft_payload *priv) |
| 269 | { |
| 270 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; |
| 271 | |
| 272 | switch (priv->offset) { |
| 273 | case offsetof(struct ethhdr, h_source): |
| 274 | if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN)) |
| 275 | return -EOPNOTSUPP; |
| 276 | |
| 277 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs, |
| 278 | src, ETH_ALEN, reg); |
| 279 | break; |
| 280 | case offsetof(struct ethhdr, h_dest): |
| 281 | if (!nft_payload_offload_mask(reg, priv->len, ETH_ALEN)) |
| 282 | return -EOPNOTSUPP; |
| 283 | |
| 284 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_ETH_ADDRS, eth_addrs, |
| 285 | dst, ETH_ALEN, reg); |
| 286 | break; |
| 287 | case offsetof(struct ethhdr, h_proto): |
| 288 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 289 | return -EOPNOTSUPP; |
| 290 | |
| 291 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, |
| 292 | n_proto, sizeof(__be16), reg); |
| 293 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); |
| 294 | break; |
| 295 | case offsetof(struct vlan_ethhdr, h_vlan_TCI): |
| 296 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 297 | return -EOPNOTSUPP; |
| 298 | |
| 299 | NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_VLAN, vlan, |
| 300 | vlan_tci, sizeof(__be16), reg, |
| 301 | NFT_OFFLOAD_F_NETWORK2HOST); |
| 302 | break; |
| 303 | case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto): |
| 304 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 305 | return -EOPNOTSUPP; |
| 306 | |
| 307 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_VLAN, vlan, |
| 308 | vlan_tpid, sizeof(__be16), reg); |
| 309 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); |
| 310 | break; |
| 311 | case offsetof(struct vlan_ethhdr, h_vlan_TCI) + sizeof(struct vlan_hdr): |
| 312 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 313 | return -EOPNOTSUPP; |
| 314 | |
| 315 | NFT_OFFLOAD_MATCH_FLAGS(FLOW_DISSECTOR_KEY_CVLAN, cvlan, |
| 316 | vlan_tci, sizeof(__be16), reg, |
| 317 | NFT_OFFLOAD_F_NETWORK2HOST); |
| 318 | break; |
| 319 | case offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto) + |
| 320 | sizeof(struct vlan_hdr): |
| 321 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 322 | return -EOPNOTSUPP; |
| 323 | |
| 324 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_CVLAN, cvlan, |
| 325 | vlan_tpid, sizeof(__be16), reg); |
| 326 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_NETWORK); |
| 327 | break; |
| 328 | default: |
| 329 | return -EOPNOTSUPP; |
| 330 | } |
| 331 | |
| 332 | return 0; |
| 333 | } |
| 334 | |
| 335 | static int nft_payload_offload_ip(struct nft_offload_ctx *ctx, |
| 336 | struct nft_flow_rule *flow, |
| 337 | const struct nft_payload *priv) |
| 338 | { |
| 339 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; |
| 340 | |
| 341 | switch (priv->offset) { |
| 342 | case offsetof(struct iphdr, saddr): |
| 343 | if (!nft_payload_offload_mask(reg, priv->len, |
| 344 | sizeof(struct in_addr))) |
| 345 | return -EOPNOTSUPP; |
| 346 | |
| 347 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, src, |
| 348 | sizeof(struct in_addr), reg); |
| 349 | nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS); |
| 350 | break; |
| 351 | case offsetof(struct iphdr, daddr): |
| 352 | if (!nft_payload_offload_mask(reg, priv->len, |
| 353 | sizeof(struct in_addr))) |
| 354 | return -EOPNOTSUPP; |
| 355 | |
| 356 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4, dst, |
| 357 | sizeof(struct in_addr), reg); |
| 358 | nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV4_ADDRS); |
| 359 | break; |
| 360 | case offsetof(struct iphdr, protocol): |
| 361 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__u8))) |
| 362 | return -EOPNOTSUPP; |
| 363 | |
| 364 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_BASIC, basic, ip_proto, |
| 365 | sizeof(__u8), reg); |
| 366 | nft_offload_set_dependency(ctx, NFT_OFFLOAD_DEP_TRANSPORT); |
| 367 | break; |
| 368 | default: |
| 369 | return -EOPNOTSUPP; |
| 370 | } |
| 371 | |
| 372 | return 0; |
| 373 | } |
| 374 | |
| 375 | static int nft_payload_offload_ip6(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 ipv6hdr, saddr): |
| 383 | if (!nft_payload_offload_mask(reg, priv->len, |
| 384 | sizeof(struct in6_addr))) |
| 385 | return -EOPNOTSUPP; |
| 386 | |
| 387 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, src, |
| 388 | sizeof(struct in6_addr), reg); |
| 389 | nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS); |
| 390 | break; |
| 391 | case offsetof(struct ipv6hdr, daddr): |
| 392 | if (!nft_payload_offload_mask(reg, priv->len, |
| 393 | sizeof(struct in6_addr))) |
| 394 | return -EOPNOTSUPP; |
| 395 | |
| 396 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6, dst, |
| 397 | sizeof(struct in6_addr), reg); |
| 398 | nft_flow_rule_set_addr_type(flow, FLOW_DISSECTOR_KEY_IPV6_ADDRS); |
| 399 | break; |
| 400 | case offsetof(struct ipv6hdr, nexthdr): |
| 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 | |
| 415 | static int nft_payload_offload_nh(struct nft_offload_ctx *ctx, |
| 416 | struct nft_flow_rule *flow, |
| 417 | const struct nft_payload *priv) |
| 418 | { |
| 419 | int err; |
| 420 | |
| 421 | switch (ctx->dep.l3num) { |
| 422 | case htons(ETH_P_IP): |
| 423 | err = nft_payload_offload_ip(ctx, flow, priv); |
| 424 | break; |
| 425 | case htons(ETH_P_IPV6): |
| 426 | err = nft_payload_offload_ip6(ctx, flow, priv); |
| 427 | break; |
| 428 | default: |
| 429 | return -EOPNOTSUPP; |
| 430 | } |
| 431 | |
| 432 | return err; |
| 433 | } |
| 434 | |
| 435 | static int nft_payload_offload_tcp(struct nft_offload_ctx *ctx, |
| 436 | struct nft_flow_rule *flow, |
| 437 | const struct nft_payload *priv) |
| 438 | { |
| 439 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; |
| 440 | |
| 441 | switch (priv->offset) { |
| 442 | case offsetof(struct tcphdr, source): |
| 443 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 444 | return -EOPNOTSUPP; |
| 445 | |
| 446 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src, |
| 447 | sizeof(__be16), reg); |
| 448 | break; |
| 449 | case offsetof(struct tcphdr, dest): |
| 450 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 451 | return -EOPNOTSUPP; |
| 452 | |
| 453 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst, |
| 454 | sizeof(__be16), reg); |
| 455 | break; |
| 456 | default: |
| 457 | return -EOPNOTSUPP; |
| 458 | } |
| 459 | |
| 460 | return 0; |
| 461 | } |
| 462 | |
| 463 | static int nft_payload_offload_udp(struct nft_offload_ctx *ctx, |
| 464 | struct nft_flow_rule *flow, |
| 465 | const struct nft_payload *priv) |
| 466 | { |
| 467 | struct nft_offload_reg *reg = &ctx->regs[priv->dreg]; |
| 468 | |
| 469 | switch (priv->offset) { |
| 470 | case offsetof(struct udphdr, source): |
| 471 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 472 | return -EOPNOTSUPP; |
| 473 | |
| 474 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, src, |
| 475 | sizeof(__be16), reg); |
| 476 | break; |
| 477 | case offsetof(struct udphdr, dest): |
| 478 | if (!nft_payload_offload_mask(reg, priv->len, sizeof(__be16))) |
| 479 | return -EOPNOTSUPP; |
| 480 | |
| 481 | NFT_OFFLOAD_MATCH(FLOW_DISSECTOR_KEY_PORTS, tp, dst, |
| 482 | sizeof(__be16), reg); |
| 483 | break; |
| 484 | default: |
| 485 | return -EOPNOTSUPP; |
| 486 | } |
| 487 | |
| 488 | return 0; |
| 489 | } |
| 490 | |
| 491 | static int nft_payload_offload_th(struct nft_offload_ctx *ctx, |
| 492 | struct nft_flow_rule *flow, |
| 493 | const struct nft_payload *priv) |
| 494 | { |
| 495 | int err; |
| 496 | |
| 497 | switch (ctx->dep.protonum) { |
| 498 | case IPPROTO_TCP: |
| 499 | err = nft_payload_offload_tcp(ctx, flow, priv); |
| 500 | break; |
| 501 | case IPPROTO_UDP: |
| 502 | err = nft_payload_offload_udp(ctx, flow, priv); |
| 503 | break; |
| 504 | default: |
| 505 | return -EOPNOTSUPP; |
| 506 | } |
| 507 | |
| 508 | return err; |
| 509 | } |
| 510 | |
| 511 | static int nft_payload_offload(struct nft_offload_ctx *ctx, |
| 512 | struct nft_flow_rule *flow, |
| 513 | const struct nft_expr *expr) |
| 514 | { |
| 515 | const struct nft_payload *priv = nft_expr_priv(expr); |
| 516 | int err; |
| 517 | |
| 518 | switch (priv->base) { |
| 519 | case NFT_PAYLOAD_LL_HEADER: |
| 520 | err = nft_payload_offload_ll(ctx, flow, priv); |
| 521 | break; |
| 522 | case NFT_PAYLOAD_NETWORK_HEADER: |
| 523 | err = nft_payload_offload_nh(ctx, flow, priv); |
| 524 | break; |
| 525 | case NFT_PAYLOAD_TRANSPORT_HEADER: |
| 526 | err = nft_payload_offload_th(ctx, flow, priv); |
| 527 | break; |
| 528 | default: |
| 529 | err = -EOPNOTSUPP; |
| 530 | break; |
| 531 | } |
| 532 | return err; |
| 533 | } |
| 534 | |
| 535 | static const struct nft_expr_ops nft_payload_ops = { |
| 536 | .type = &nft_payload_type, |
| 537 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), |
| 538 | .eval = nft_payload_eval, |
| 539 | .init = nft_payload_init, |
| 540 | .dump = nft_payload_dump, |
| 541 | .reduce = nft_payload_reduce, |
| 542 | .offload = nft_payload_offload, |
| 543 | }; |
| 544 | |
| 545 | const struct nft_expr_ops nft_payload_fast_ops = { |
| 546 | .type = &nft_payload_type, |
| 547 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload)), |
| 548 | .eval = nft_payload_eval, |
| 549 | .init = nft_payload_init, |
| 550 | .dump = nft_payload_dump, |
| 551 | .reduce = nft_payload_reduce, |
| 552 | .offload = nft_payload_offload, |
| 553 | }; |
| 554 | |
| 555 | static inline void nft_csum_replace(__sum16 *sum, __wsum fsum, __wsum tsum) |
| 556 | { |
| 557 | *sum = csum_fold(csum_add(csum_sub(~csum_unfold(*sum), fsum), tsum)); |
| 558 | if (*sum == 0) |
| 559 | *sum = CSUM_MANGLED_0; |
| 560 | } |
| 561 | |
| 562 | static bool nft_payload_udp_checksum(struct sk_buff *skb, unsigned int thoff) |
| 563 | { |
| 564 | struct udphdr *uh, _uh; |
| 565 | |
| 566 | uh = skb_header_pointer(skb, thoff, sizeof(_uh), &_uh); |
| 567 | if (!uh) |
| 568 | return false; |
| 569 | |
| 570 | return (__force bool)uh->check; |
| 571 | } |
| 572 | |
| 573 | static int nft_payload_l4csum_offset(const struct nft_pktinfo *pkt, |
| 574 | struct sk_buff *skb, |
| 575 | unsigned int *l4csum_offset) |
| 576 | { |
| 577 | if (pkt->fragoff) |
| 578 | return -1; |
| 579 | |
| 580 | switch (pkt->tprot) { |
| 581 | case IPPROTO_TCP: |
| 582 | *l4csum_offset = offsetof(struct tcphdr, check); |
| 583 | break; |
| 584 | case IPPROTO_UDP: |
| 585 | if (!nft_payload_udp_checksum(skb, nft_thoff(pkt))) |
| 586 | return -1; |
| 587 | fallthrough; |
| 588 | case IPPROTO_UDPLITE: |
| 589 | *l4csum_offset = offsetof(struct udphdr, check); |
| 590 | break; |
| 591 | case IPPROTO_ICMPV6: |
| 592 | *l4csum_offset = offsetof(struct icmp6hdr, icmp6_cksum); |
| 593 | break; |
| 594 | default: |
| 595 | return -1; |
| 596 | } |
| 597 | |
| 598 | *l4csum_offset += nft_thoff(pkt); |
| 599 | return 0; |
| 600 | } |
| 601 | |
| 602 | static int nft_payload_csum_sctp(struct sk_buff *skb, int offset) |
| 603 | { |
| 604 | struct sctphdr *sh; |
| 605 | |
| 606 | if (skb_ensure_writable(skb, offset + sizeof(*sh))) |
| 607 | return -1; |
| 608 | |
| 609 | sh = (struct sctphdr *)(skb->data + offset); |
| 610 | sh->checksum = sctp_compute_cksum(skb, offset); |
| 611 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 612 | return 0; |
| 613 | } |
| 614 | |
| 615 | static int nft_payload_l4csum_update(const struct nft_pktinfo *pkt, |
| 616 | struct sk_buff *skb, |
| 617 | __wsum fsum, __wsum tsum) |
| 618 | { |
| 619 | int l4csum_offset; |
| 620 | __sum16 sum; |
| 621 | |
| 622 | /* If we cannot determine layer 4 checksum offset or this packet doesn't |
| 623 | * require layer 4 checksum recalculation, skip this packet. |
| 624 | */ |
| 625 | if (nft_payload_l4csum_offset(pkt, skb, &l4csum_offset) < 0) |
| 626 | return 0; |
| 627 | |
| 628 | if (skb_copy_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0) |
| 629 | return -1; |
| 630 | |
| 631 | /* Checksum mangling for an arbitrary amount of bytes, based on |
| 632 | * inet_proto_csum_replace*() functions. |
| 633 | */ |
| 634 | if (skb->ip_summed != CHECKSUM_PARTIAL) { |
| 635 | nft_csum_replace(&sum, fsum, tsum); |
| 636 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
| 637 | skb->csum = ~csum_add(csum_sub(~(skb->csum), fsum), |
| 638 | tsum); |
| 639 | } |
| 640 | } else { |
| 641 | sum = ~csum_fold(csum_add(csum_sub(csum_unfold(sum), fsum), |
| 642 | tsum)); |
| 643 | } |
| 644 | |
| 645 | if (skb_ensure_writable(skb, l4csum_offset + sizeof(sum)) || |
| 646 | skb_store_bits(skb, l4csum_offset, &sum, sizeof(sum)) < 0) |
| 647 | return -1; |
| 648 | |
| 649 | return 0; |
| 650 | } |
| 651 | |
| 652 | static int nft_payload_csum_inet(struct sk_buff *skb, const u32 *src, |
| 653 | __wsum fsum, __wsum tsum, int csum_offset) |
| 654 | { |
| 655 | __sum16 sum; |
| 656 | |
| 657 | if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) |
| 658 | return -1; |
| 659 | |
| 660 | nft_csum_replace(&sum, fsum, tsum); |
| 661 | if (skb_ensure_writable(skb, csum_offset + sizeof(sum)) || |
| 662 | skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) |
| 663 | return -1; |
| 664 | |
| 665 | return 0; |
| 666 | } |
| 667 | |
| 668 | static void nft_payload_set_eval(const struct nft_expr *expr, |
| 669 | struct nft_regs *regs, |
| 670 | const struct nft_pktinfo *pkt) |
| 671 | { |
| 672 | const struct nft_payload_set *priv = nft_expr_priv(expr); |
| 673 | struct sk_buff *skb = pkt->skb; |
| 674 | const u32 *src = ®s->data[priv->sreg]; |
| 675 | int offset, csum_offset; |
| 676 | __wsum fsum, tsum; |
| 677 | |
| 678 | switch (priv->base) { |
| 679 | case NFT_PAYLOAD_LL_HEADER: |
| 680 | if (!skb_mac_header_was_set(skb)) |
| 681 | goto err; |
| 682 | offset = skb_mac_header(skb) - skb->data; |
| 683 | break; |
| 684 | case NFT_PAYLOAD_NETWORK_HEADER: |
| 685 | offset = skb_network_offset(skb); |
| 686 | break; |
| 687 | case NFT_PAYLOAD_TRANSPORT_HEADER: |
| 688 | if (!(pkt->flags & NFT_PKTINFO_L4PROTO) || pkt->fragoff) |
| 689 | goto err; |
| 690 | offset = nft_thoff(pkt); |
| 691 | break; |
| 692 | case NFT_PAYLOAD_INNER_HEADER: |
| 693 | offset = nft_payload_inner_offset(pkt); |
| 694 | if (offset < 0) |
| 695 | goto err; |
| 696 | break; |
| 697 | default: |
| 698 | WARN_ON_ONCE(1); |
| 699 | goto err; |
| 700 | } |
| 701 | |
| 702 | csum_offset = offset + priv->csum_offset; |
| 703 | offset += priv->offset; |
| 704 | |
| 705 | if ((priv->csum_type == NFT_PAYLOAD_CSUM_INET || priv->csum_flags) && |
| 706 | ((priv->base != NFT_PAYLOAD_TRANSPORT_HEADER && |
| 707 | priv->base != NFT_PAYLOAD_INNER_HEADER) || |
| 708 | skb->ip_summed != CHECKSUM_PARTIAL)) { |
| 709 | fsum = skb_checksum(skb, offset, priv->len, 0); |
| 710 | tsum = csum_partial(src, priv->len, 0); |
| 711 | |
| 712 | if (priv->csum_type == NFT_PAYLOAD_CSUM_INET && |
| 713 | nft_payload_csum_inet(skb, src, fsum, tsum, csum_offset)) |
| 714 | goto err; |
| 715 | |
| 716 | if (priv->csum_flags && |
| 717 | nft_payload_l4csum_update(pkt, skb, fsum, tsum) < 0) |
| 718 | goto err; |
| 719 | } |
| 720 | |
| 721 | if (skb_ensure_writable(skb, max(offset + priv->len, 0)) || |
| 722 | skb_store_bits(skb, offset, src, priv->len) < 0) |
| 723 | goto err; |
| 724 | |
| 725 | if (priv->csum_type == NFT_PAYLOAD_CSUM_SCTP && |
| 726 | pkt->tprot == IPPROTO_SCTP && |
| 727 | skb->ip_summed != CHECKSUM_PARTIAL) { |
| 728 | if (pkt->fragoff == 0 && |
| 729 | nft_payload_csum_sctp(skb, nft_thoff(pkt))) |
| 730 | goto err; |
| 731 | } |
| 732 | |
| 733 | return; |
| 734 | err: |
| 735 | regs->verdict.code = NFT_BREAK; |
| 736 | } |
| 737 | |
| 738 | static int nft_payload_set_init(const struct nft_ctx *ctx, |
| 739 | const struct nft_expr *expr, |
| 740 | const struct nlattr * const tb[]) |
| 741 | { |
| 742 | struct nft_payload_set *priv = nft_expr_priv(expr); |
| 743 | |
| 744 | priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
| 745 | priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
| 746 | priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
| 747 | |
| 748 | if (tb[NFTA_PAYLOAD_CSUM_TYPE]) |
| 749 | priv->csum_type = |
| 750 | ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE])); |
| 751 | if (tb[NFTA_PAYLOAD_CSUM_OFFSET]) |
| 752 | priv->csum_offset = |
| 753 | ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET])); |
| 754 | if (tb[NFTA_PAYLOAD_CSUM_FLAGS]) { |
| 755 | u32 flags; |
| 756 | |
| 757 | flags = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_FLAGS])); |
| 758 | if (flags & ~NFT_PAYLOAD_L4CSUM_PSEUDOHDR) |
| 759 | return -EINVAL; |
| 760 | |
| 761 | priv->csum_flags = flags; |
| 762 | } |
| 763 | |
| 764 | switch (priv->csum_type) { |
| 765 | case NFT_PAYLOAD_CSUM_NONE: |
| 766 | case NFT_PAYLOAD_CSUM_INET: |
| 767 | break; |
| 768 | case NFT_PAYLOAD_CSUM_SCTP: |
| 769 | if (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER) |
| 770 | return -EINVAL; |
| 771 | |
| 772 | if (priv->csum_offset != offsetof(struct sctphdr, checksum)) |
| 773 | return -EINVAL; |
| 774 | break; |
| 775 | default: |
| 776 | return -EOPNOTSUPP; |
| 777 | } |
| 778 | |
| 779 | return nft_parse_register_load(tb[NFTA_PAYLOAD_SREG], &priv->sreg, |
| 780 | priv->len); |
| 781 | } |
| 782 | |
| 783 | static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr) |
| 784 | { |
| 785 | const struct nft_payload_set *priv = nft_expr_priv(expr); |
| 786 | |
| 787 | if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) || |
| 788 | nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || |
| 789 | nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || |
| 790 | nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) || |
| 791 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) || |
| 792 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET, |
| 793 | htonl(priv->csum_offset)) || |
| 794 | nla_put_be32(skb, NFTA_PAYLOAD_CSUM_FLAGS, htonl(priv->csum_flags))) |
| 795 | goto nla_put_failure; |
| 796 | return 0; |
| 797 | |
| 798 | nla_put_failure: |
| 799 | return -1; |
| 800 | } |
| 801 | |
| 802 | static bool nft_payload_set_reduce(struct nft_regs_track *track, |
| 803 | const struct nft_expr *expr) |
| 804 | { |
| 805 | int i; |
| 806 | |
| 807 | for (i = 0; i < NFT_REG32_NUM; i++) { |
| 808 | if (!track->regs[i].selector) |
| 809 | continue; |
| 810 | |
| 811 | if (track->regs[i].selector->ops != &nft_payload_ops && |
| 812 | track->regs[i].selector->ops != &nft_payload_fast_ops) |
| 813 | continue; |
| 814 | |
| 815 | __nft_reg_track_cancel(track, i); |
| 816 | } |
| 817 | |
| 818 | return false; |
| 819 | } |
| 820 | |
| 821 | static const struct nft_expr_ops nft_payload_set_ops = { |
| 822 | .type = &nft_payload_type, |
| 823 | .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)), |
| 824 | .eval = nft_payload_set_eval, |
| 825 | .init = nft_payload_set_init, |
| 826 | .dump = nft_payload_set_dump, |
| 827 | .reduce = nft_payload_set_reduce, |
| 828 | }; |
| 829 | |
| 830 | static const struct nft_expr_ops * |
| 831 | nft_payload_select_ops(const struct nft_ctx *ctx, |
| 832 | const struct nlattr * const tb[]) |
| 833 | { |
| 834 | enum nft_payload_bases base; |
| 835 | unsigned int offset, len; |
| 836 | |
| 837 | if (tb[NFTA_PAYLOAD_BASE] == NULL || |
| 838 | tb[NFTA_PAYLOAD_OFFSET] == NULL || |
| 839 | tb[NFTA_PAYLOAD_LEN] == NULL) |
| 840 | return ERR_PTR(-EINVAL); |
| 841 | |
| 842 | base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); |
| 843 | switch (base) { |
| 844 | case NFT_PAYLOAD_LL_HEADER: |
| 845 | case NFT_PAYLOAD_NETWORK_HEADER: |
| 846 | case NFT_PAYLOAD_TRANSPORT_HEADER: |
| 847 | case NFT_PAYLOAD_INNER_HEADER: |
| 848 | break; |
| 849 | default: |
| 850 | return ERR_PTR(-EOPNOTSUPP); |
| 851 | } |
| 852 | |
| 853 | if (tb[NFTA_PAYLOAD_SREG] != NULL) { |
| 854 | if (tb[NFTA_PAYLOAD_DREG] != NULL) |
| 855 | return ERR_PTR(-EINVAL); |
| 856 | return &nft_payload_set_ops; |
| 857 | } |
| 858 | |
| 859 | if (tb[NFTA_PAYLOAD_DREG] == NULL) |
| 860 | return ERR_PTR(-EINVAL); |
| 861 | |
| 862 | offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); |
| 863 | len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |
| 864 | |
| 865 | if (len <= 4 && is_power_of_2(len) && IS_ALIGNED(offset, len) && |
| 866 | base != NFT_PAYLOAD_LL_HEADER && base != NFT_PAYLOAD_INNER_HEADER) |
| 867 | return &nft_payload_fast_ops; |
| 868 | else |
| 869 | return &nft_payload_ops; |
| 870 | } |
| 871 | |
| 872 | struct nft_expr_type nft_payload_type __read_mostly = { |
| 873 | .name = "payload", |
| 874 | .select_ops = nft_payload_select_ops, |
| 875 | .policy = nft_payload_policy, |
| 876 | .maxattr = NFTA_PAYLOAD_MAX, |
| 877 | .owner = THIS_MODULE, |
| 878 | }; |