1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/kernel.h> 3 #include <linux/skbuff.h> 4 #include <linux/export.h> 5 #include <linux/ip.h> 6 #include <linux/ipv6.h> 7 #include <linux/if_vlan.h> 8 #include <linux/filter.h> 9 #include <net/dsa.h> 10 #include <net/dst_metadata.h> 11 #include <net/ip.h> 12 #include <net/ipv6.h> 13 #include <net/gre.h> 14 #include <net/pptp.h> 15 #include <net/tipc.h> 16 #include <linux/igmp.h> 17 #include <linux/icmp.h> 18 #include <linux/sctp.h> 19 #include <linux/dccp.h> 20 #include <linux/if_tunnel.h> 21 #include <linux/if_pppox.h> 22 #include <linux/ppp_defs.h> 23 #include <linux/stddef.h> 24 #include <linux/if_ether.h> 25 #include <linux/if_hsr.h> 26 #include <linux/mpls.h> 27 #include <linux/tcp.h> 28 #include <linux/ptp_classify.h> 29 #include <net/flow_dissector.h> 30 #include <net/pkt_cls.h> 31 #include <scsi/fc/fc_fcoe.h> 32 #include <uapi/linux/batadv_packet.h> 33 #include <linux/bpf.h> 34 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 35 #include <net/netfilter/nf_conntrack_core.h> 36 #include <net/netfilter/nf_conntrack_labels.h> 37 #endif 38 #include <linux/bpf-netns.h> 39 40 static void dissector_set_key(struct flow_dissector *flow_dissector, 41 enum flow_dissector_key_id key_id) 42 { 43 flow_dissector->used_keys |= (1ULL << key_id); 44 } 45 46 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 47 const struct flow_dissector_key *key, 48 unsigned int key_count) 49 { 50 unsigned int i; 51 52 memset(flow_dissector, 0, sizeof(*flow_dissector)); 53 54 for (i = 0; i < key_count; i++, key++) { 55 /* User should make sure that every key target offset is within 56 * boundaries of unsigned short. 57 */ 58 BUG_ON(key->offset > USHRT_MAX); 59 BUG_ON(dissector_uses_key(flow_dissector, 60 key->key_id)); 61 62 dissector_set_key(flow_dissector, key->key_id); 63 flow_dissector->offset[key->key_id] = key->offset; 64 } 65 66 /* Ensure that the dissector always includes control and basic key. 67 * That way we are able to avoid handling lack of these in fast path. 68 */ 69 BUG_ON(!dissector_uses_key(flow_dissector, 70 FLOW_DISSECTOR_KEY_CONTROL)); 71 BUG_ON(!dissector_uses_key(flow_dissector, 72 FLOW_DISSECTOR_KEY_BASIC)); 73 } 74 EXPORT_SYMBOL(skb_flow_dissector_init); 75 76 #ifdef CONFIG_BPF_SYSCALL 77 int flow_dissector_bpf_prog_attach_check(struct net *net, 78 struct bpf_prog *prog) 79 { 80 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; 81 82 if (net == &init_net) { 83 /* BPF flow dissector in the root namespace overrides 84 * any per-net-namespace one. When attaching to root, 85 * make sure we don't have any BPF program attached 86 * to the non-root namespaces. 87 */ 88 struct net *ns; 89 90 for_each_net(ns) { 91 if (ns == &init_net) 92 continue; 93 if (rcu_access_pointer(ns->bpf.run_array[type])) 94 return -EEXIST; 95 } 96 } else { 97 /* Make sure root flow dissector is not attached 98 * when attaching to the non-root namespace. 99 */ 100 if (rcu_access_pointer(init_net.bpf.run_array[type])) 101 return -EEXIST; 102 } 103 104 return 0; 105 } 106 #endif /* CONFIG_BPF_SYSCALL */ 107 108 /** 109 * __skb_flow_get_ports - extract the upper layer ports and return them 110 * @skb: sk_buff to extract the ports from 111 * @thoff: transport header offset 112 * @ip_proto: protocol for which to get port offset 113 * @data: raw buffer pointer to the packet, if NULL use skb->data 114 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 115 * 116 * The function will try to retrieve the ports at offset thoff + poff where poff 117 * is the protocol port offset returned from proto_ports_offset 118 */ 119 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 120 const void *data, int hlen) 121 { 122 int poff = proto_ports_offset(ip_proto); 123 124 if (!data) { 125 data = skb->data; 126 hlen = skb_headlen(skb); 127 } 128 129 if (poff >= 0) { 130 __be32 *ports, _ports; 131 132 ports = __skb_header_pointer(skb, thoff + poff, 133 sizeof(_ports), data, hlen, &_ports); 134 if (ports) 135 return *ports; 136 } 137 138 return 0; 139 } 140 EXPORT_SYMBOL(__skb_flow_get_ports); 141 142 static bool icmp_has_id(u8 type) 143 { 144 switch (type) { 145 case ICMP_ECHO: 146 case ICMP_ECHOREPLY: 147 case ICMP_TIMESTAMP: 148 case ICMP_TIMESTAMPREPLY: 149 case ICMPV6_ECHO_REQUEST: 150 case ICMPV6_ECHO_REPLY: 151 return true; 152 } 153 154 return false; 155 } 156 157 /** 158 * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields 159 * @skb: sk_buff to extract from 160 * @key_icmp: struct flow_dissector_key_icmp to fill 161 * @data: raw buffer pointer to the packet 162 * @thoff: offset to extract at 163 * @hlen: packet header length 164 */ 165 void skb_flow_get_icmp_tci(const struct sk_buff *skb, 166 struct flow_dissector_key_icmp *key_icmp, 167 const void *data, int thoff, int hlen) 168 { 169 struct icmphdr *ih, _ih; 170 171 ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih); 172 if (!ih) 173 return; 174 175 key_icmp->type = ih->type; 176 key_icmp->code = ih->code; 177 178 /* As we use 0 to signal that the Id field is not present, 179 * avoid confusion with packets without such field 180 */ 181 if (icmp_has_id(ih->type)) 182 key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1; 183 else 184 key_icmp->id = 0; 185 } 186 EXPORT_SYMBOL(skb_flow_get_icmp_tci); 187 188 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet 189 * using skb_flow_get_icmp_tci(). 190 */ 191 static void __skb_flow_dissect_icmp(const struct sk_buff *skb, 192 struct flow_dissector *flow_dissector, 193 void *target_container, const void *data, 194 int thoff, int hlen) 195 { 196 struct flow_dissector_key_icmp *key_icmp; 197 198 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP)) 199 return; 200 201 key_icmp = skb_flow_dissector_target(flow_dissector, 202 FLOW_DISSECTOR_KEY_ICMP, 203 target_container); 204 205 skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen); 206 } 207 208 static void __skb_flow_dissect_ah(const struct sk_buff *skb, 209 struct flow_dissector *flow_dissector, 210 void *target_container, const void *data, 211 int nhoff, int hlen) 212 { 213 struct flow_dissector_key_ipsec *key_ah; 214 struct ip_auth_hdr _hdr, *hdr; 215 216 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC)) 217 return; 218 219 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 220 if (!hdr) 221 return; 222 223 key_ah = skb_flow_dissector_target(flow_dissector, 224 FLOW_DISSECTOR_KEY_IPSEC, 225 target_container); 226 227 key_ah->spi = hdr->spi; 228 } 229 230 static void __skb_flow_dissect_esp(const struct sk_buff *skb, 231 struct flow_dissector *flow_dissector, 232 void *target_container, const void *data, 233 int nhoff, int hlen) 234 { 235 struct flow_dissector_key_ipsec *key_esp; 236 struct ip_esp_hdr _hdr, *hdr; 237 238 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC)) 239 return; 240 241 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 242 if (!hdr) 243 return; 244 245 key_esp = skb_flow_dissector_target(flow_dissector, 246 FLOW_DISSECTOR_KEY_IPSEC, 247 target_container); 248 249 key_esp->spi = hdr->spi; 250 } 251 252 static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb, 253 struct flow_dissector *flow_dissector, 254 void *target_container, const void *data, 255 int nhoff, int hlen) 256 { 257 struct flow_dissector_key_l2tpv3 *key_l2tpv3; 258 struct { 259 __be32 session_id; 260 } *hdr, _hdr; 261 262 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3)) 263 return; 264 265 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 266 if (!hdr) 267 return; 268 269 key_l2tpv3 = skb_flow_dissector_target(flow_dissector, 270 FLOW_DISSECTOR_KEY_L2TPV3, 271 target_container); 272 273 key_l2tpv3->session_id = hdr->session_id; 274 } 275 276 void skb_flow_dissect_meta(const struct sk_buff *skb, 277 struct flow_dissector *flow_dissector, 278 void *target_container) 279 { 280 struct flow_dissector_key_meta *meta; 281 282 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META)) 283 return; 284 285 meta = skb_flow_dissector_target(flow_dissector, 286 FLOW_DISSECTOR_KEY_META, 287 target_container); 288 meta->ingress_ifindex = skb->skb_iif; 289 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 290 if (tc_skb_ext_tc_enabled()) { 291 struct tc_skb_ext *ext; 292 293 ext = skb_ext_find(skb, TC_SKB_EXT); 294 if (ext) 295 meta->l2_miss = ext->l2_miss; 296 } 297 #endif 298 } 299 EXPORT_SYMBOL(skb_flow_dissect_meta); 300 301 static void 302 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type, 303 struct flow_dissector *flow_dissector, 304 void *target_container) 305 { 306 struct flow_dissector_key_control *ctrl; 307 308 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL)) 309 return; 310 311 ctrl = skb_flow_dissector_target(flow_dissector, 312 FLOW_DISSECTOR_KEY_ENC_CONTROL, 313 target_container); 314 ctrl->addr_type = type; 315 } 316 317 void 318 skb_flow_dissect_ct(const struct sk_buff *skb, 319 struct flow_dissector *flow_dissector, 320 void *target_container, u16 *ctinfo_map, 321 size_t mapsize, bool post_ct, u16 zone) 322 { 323 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 324 struct flow_dissector_key_ct *key; 325 enum ip_conntrack_info ctinfo; 326 struct nf_conn_labels *cl; 327 struct nf_conn *ct; 328 329 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT)) 330 return; 331 332 ct = nf_ct_get(skb, &ctinfo); 333 if (!ct && !post_ct) 334 return; 335 336 key = skb_flow_dissector_target(flow_dissector, 337 FLOW_DISSECTOR_KEY_CT, 338 target_container); 339 340 if (!ct) { 341 key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED | 342 TCA_FLOWER_KEY_CT_FLAGS_INVALID; 343 key->ct_zone = zone; 344 return; 345 } 346 347 if (ctinfo < mapsize) 348 key->ct_state = ctinfo_map[ctinfo]; 349 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) 350 key->ct_zone = ct->zone.id; 351 #endif 352 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) 353 key->ct_mark = READ_ONCE(ct->mark); 354 #endif 355 356 cl = nf_ct_labels_find(ct); 357 if (cl) 358 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels)); 359 #endif /* CONFIG_NF_CONNTRACK */ 360 } 361 EXPORT_SYMBOL(skb_flow_dissect_ct); 362 363 void 364 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 365 struct flow_dissector *flow_dissector, 366 void *target_container) 367 { 368 struct ip_tunnel_info *info; 369 struct ip_tunnel_key *key; 370 371 /* A quick check to see if there might be something to do. */ 372 if (!dissector_uses_key(flow_dissector, 373 FLOW_DISSECTOR_KEY_ENC_KEYID) && 374 !dissector_uses_key(flow_dissector, 375 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) && 376 !dissector_uses_key(flow_dissector, 377 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) && 378 !dissector_uses_key(flow_dissector, 379 FLOW_DISSECTOR_KEY_ENC_CONTROL) && 380 !dissector_uses_key(flow_dissector, 381 FLOW_DISSECTOR_KEY_ENC_PORTS) && 382 !dissector_uses_key(flow_dissector, 383 FLOW_DISSECTOR_KEY_ENC_IP) && 384 !dissector_uses_key(flow_dissector, 385 FLOW_DISSECTOR_KEY_ENC_OPTS)) 386 return; 387 388 info = skb_tunnel_info(skb); 389 if (!info) 390 return; 391 392 key = &info->key; 393 394 switch (ip_tunnel_info_af(info)) { 395 case AF_INET: 396 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS, 397 flow_dissector, 398 target_container); 399 if (dissector_uses_key(flow_dissector, 400 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) { 401 struct flow_dissector_key_ipv4_addrs *ipv4; 402 403 ipv4 = skb_flow_dissector_target(flow_dissector, 404 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, 405 target_container); 406 ipv4->src = key->u.ipv4.src; 407 ipv4->dst = key->u.ipv4.dst; 408 } 409 break; 410 case AF_INET6: 411 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS, 412 flow_dissector, 413 target_container); 414 if (dissector_uses_key(flow_dissector, 415 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) { 416 struct flow_dissector_key_ipv6_addrs *ipv6; 417 418 ipv6 = skb_flow_dissector_target(flow_dissector, 419 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, 420 target_container); 421 ipv6->src = key->u.ipv6.src; 422 ipv6->dst = key->u.ipv6.dst; 423 } 424 break; 425 } 426 427 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) { 428 struct flow_dissector_key_keyid *keyid; 429 430 keyid = skb_flow_dissector_target(flow_dissector, 431 FLOW_DISSECTOR_KEY_ENC_KEYID, 432 target_container); 433 keyid->keyid = tunnel_id_to_key32(key->tun_id); 434 } 435 436 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) { 437 struct flow_dissector_key_ports *tp; 438 439 tp = skb_flow_dissector_target(flow_dissector, 440 FLOW_DISSECTOR_KEY_ENC_PORTS, 441 target_container); 442 tp->src = key->tp_src; 443 tp->dst = key->tp_dst; 444 } 445 446 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) { 447 struct flow_dissector_key_ip *ip; 448 449 ip = skb_flow_dissector_target(flow_dissector, 450 FLOW_DISSECTOR_KEY_ENC_IP, 451 target_container); 452 ip->tos = key->tos; 453 ip->ttl = key->ttl; 454 } 455 456 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) { 457 struct flow_dissector_key_enc_opts *enc_opt; 458 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 459 u32 val; 460 461 enc_opt = skb_flow_dissector_target(flow_dissector, 462 FLOW_DISSECTOR_KEY_ENC_OPTS, 463 target_container); 464 465 if (!info->options_len) 466 return; 467 468 enc_opt->len = info->options_len; 469 ip_tunnel_info_opts_get(enc_opt->data, info); 470 471 ip_tunnel_set_options_present(flags); 472 ip_tunnel_flags_and(flags, info->key.tun_flags, flags); 473 474 val = find_next_bit(flags, __IP_TUNNEL_FLAG_NUM, 475 IP_TUNNEL_GENEVE_OPT_BIT); 476 enc_opt->dst_opt_type = val < __IP_TUNNEL_FLAG_NUM ? val : 0; 477 } 478 } 479 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); 480 481 void skb_flow_dissect_hash(const struct sk_buff *skb, 482 struct flow_dissector *flow_dissector, 483 void *target_container) 484 { 485 struct flow_dissector_key_hash *key; 486 487 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH)) 488 return; 489 490 key = skb_flow_dissector_target(flow_dissector, 491 FLOW_DISSECTOR_KEY_HASH, 492 target_container); 493 494 key->hash = skb_get_hash_raw(skb); 495 } 496 EXPORT_SYMBOL(skb_flow_dissect_hash); 497 498 static enum flow_dissect_ret 499 __skb_flow_dissect_mpls(const struct sk_buff *skb, 500 struct flow_dissector *flow_dissector, 501 void *target_container, const void *data, int nhoff, 502 int hlen, int lse_index, bool *entropy_label) 503 { 504 struct mpls_label *hdr, _hdr; 505 u32 entry, label, bos; 506 507 if (!dissector_uses_key(flow_dissector, 508 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && 509 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) 510 return FLOW_DISSECT_RET_OUT_GOOD; 511 512 if (lse_index >= FLOW_DIS_MPLS_MAX) 513 return FLOW_DISSECT_RET_OUT_GOOD; 514 515 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 516 hlen, &_hdr); 517 if (!hdr) 518 return FLOW_DISSECT_RET_OUT_BAD; 519 520 entry = ntohl(hdr->entry); 521 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; 522 bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT; 523 524 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) { 525 struct flow_dissector_key_mpls *key_mpls; 526 struct flow_dissector_mpls_lse *lse; 527 528 key_mpls = skb_flow_dissector_target(flow_dissector, 529 FLOW_DISSECTOR_KEY_MPLS, 530 target_container); 531 lse = &key_mpls->ls[lse_index]; 532 533 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; 534 lse->mpls_bos = bos; 535 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT; 536 lse->mpls_label = label; 537 dissector_set_mpls_lse(key_mpls, lse_index); 538 } 539 540 if (*entropy_label && 541 dissector_uses_key(flow_dissector, 542 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { 543 struct flow_dissector_key_keyid *key_keyid; 544 545 key_keyid = skb_flow_dissector_target(flow_dissector, 546 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 547 target_container); 548 key_keyid->keyid = cpu_to_be32(label); 549 } 550 551 *entropy_label = label == MPLS_LABEL_ENTROPY; 552 553 return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN; 554 } 555 556 static enum flow_dissect_ret 557 __skb_flow_dissect_arp(const struct sk_buff *skb, 558 struct flow_dissector *flow_dissector, 559 void *target_container, const void *data, 560 int nhoff, int hlen) 561 { 562 struct flow_dissector_key_arp *key_arp; 563 struct { 564 unsigned char ar_sha[ETH_ALEN]; 565 unsigned char ar_sip[4]; 566 unsigned char ar_tha[ETH_ALEN]; 567 unsigned char ar_tip[4]; 568 } *arp_eth, _arp_eth; 569 const struct arphdr *arp; 570 struct arphdr _arp; 571 572 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP)) 573 return FLOW_DISSECT_RET_OUT_GOOD; 574 575 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, 576 hlen, &_arp); 577 if (!arp) 578 return FLOW_DISSECT_RET_OUT_BAD; 579 580 if (arp->ar_hrd != htons(ARPHRD_ETHER) || 581 arp->ar_pro != htons(ETH_P_IP) || 582 arp->ar_hln != ETH_ALEN || 583 arp->ar_pln != 4 || 584 (arp->ar_op != htons(ARPOP_REPLY) && 585 arp->ar_op != htons(ARPOP_REQUEST))) 586 return FLOW_DISSECT_RET_OUT_BAD; 587 588 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), 589 sizeof(_arp_eth), data, 590 hlen, &_arp_eth); 591 if (!arp_eth) 592 return FLOW_DISSECT_RET_OUT_BAD; 593 594 key_arp = skb_flow_dissector_target(flow_dissector, 595 FLOW_DISSECTOR_KEY_ARP, 596 target_container); 597 598 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); 599 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); 600 601 /* Only store the lower byte of the opcode; 602 * this covers ARPOP_REPLY and ARPOP_REQUEST. 603 */ 604 key_arp->op = ntohs(arp->ar_op) & 0xff; 605 606 ether_addr_copy(key_arp->sha, arp_eth->ar_sha); 607 ether_addr_copy(key_arp->tha, arp_eth->ar_tha); 608 609 return FLOW_DISSECT_RET_OUT_GOOD; 610 } 611 612 static enum flow_dissect_ret 613 __skb_flow_dissect_cfm(const struct sk_buff *skb, 614 struct flow_dissector *flow_dissector, 615 void *target_container, const void *data, 616 int nhoff, int hlen) 617 { 618 struct flow_dissector_key_cfm *key, *hdr, _hdr; 619 620 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM)) 621 return FLOW_DISSECT_RET_OUT_GOOD; 622 623 hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr); 624 if (!hdr) 625 return FLOW_DISSECT_RET_OUT_BAD; 626 627 key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM, 628 target_container); 629 630 key->mdl_ver = hdr->mdl_ver; 631 key->opcode = hdr->opcode; 632 633 return FLOW_DISSECT_RET_OUT_GOOD; 634 } 635 636 static enum flow_dissect_ret 637 __skb_flow_dissect_gre(const struct sk_buff *skb, 638 struct flow_dissector_key_control *key_control, 639 struct flow_dissector *flow_dissector, 640 void *target_container, const void *data, 641 __be16 *p_proto, int *p_nhoff, int *p_hlen, 642 unsigned int flags) 643 { 644 struct flow_dissector_key_keyid *key_keyid; 645 struct gre_base_hdr *hdr, _hdr; 646 int offset = 0; 647 u16 gre_ver; 648 649 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), 650 data, *p_hlen, &_hdr); 651 if (!hdr) 652 return FLOW_DISSECT_RET_OUT_BAD; 653 654 /* Only look inside GRE without routing */ 655 if (hdr->flags & GRE_ROUTING) 656 return FLOW_DISSECT_RET_OUT_GOOD; 657 658 /* Only look inside GRE for version 0 and 1 */ 659 gre_ver = ntohs(hdr->flags & GRE_VERSION); 660 if (gre_ver > 1) 661 return FLOW_DISSECT_RET_OUT_GOOD; 662 663 *p_proto = hdr->protocol; 664 if (gre_ver) { 665 /* Version1 must be PPTP, and check the flags */ 666 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) 667 return FLOW_DISSECT_RET_OUT_GOOD; 668 } 669 670 offset += sizeof(struct gre_base_hdr); 671 672 if (hdr->flags & GRE_CSUM) 673 offset += sizeof_field(struct gre_full_hdr, csum) + 674 sizeof_field(struct gre_full_hdr, reserved1); 675 676 if (hdr->flags & GRE_KEY) { 677 const __be32 *keyid; 678 __be32 _keyid; 679 680 keyid = __skb_header_pointer(skb, *p_nhoff + offset, 681 sizeof(_keyid), 682 data, *p_hlen, &_keyid); 683 if (!keyid) 684 return FLOW_DISSECT_RET_OUT_BAD; 685 686 if (dissector_uses_key(flow_dissector, 687 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 688 key_keyid = skb_flow_dissector_target(flow_dissector, 689 FLOW_DISSECTOR_KEY_GRE_KEYID, 690 target_container); 691 if (gre_ver == 0) 692 key_keyid->keyid = *keyid; 693 else 694 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; 695 } 696 offset += sizeof_field(struct gre_full_hdr, key); 697 } 698 699 if (hdr->flags & GRE_SEQ) 700 offset += sizeof_field(struct pptp_gre_header, seq); 701 702 if (gre_ver == 0) { 703 if (*p_proto == htons(ETH_P_TEB)) { 704 const struct ethhdr *eth; 705 struct ethhdr _eth; 706 707 eth = __skb_header_pointer(skb, *p_nhoff + offset, 708 sizeof(_eth), 709 data, *p_hlen, &_eth); 710 if (!eth) 711 return FLOW_DISSECT_RET_OUT_BAD; 712 *p_proto = eth->h_proto; 713 offset += sizeof(*eth); 714 715 /* Cap headers that we access via pointers at the 716 * end of the Ethernet header as our maximum alignment 717 * at that point is only 2 bytes. 718 */ 719 if (NET_IP_ALIGN) 720 *p_hlen = *p_nhoff + offset; 721 } 722 } else { /* version 1, must be PPTP */ 723 u8 _ppp_hdr[PPP_HDRLEN]; 724 u8 *ppp_hdr; 725 726 if (hdr->flags & GRE_ACK) 727 offset += sizeof_field(struct pptp_gre_header, ack); 728 729 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset, 730 sizeof(_ppp_hdr), 731 data, *p_hlen, _ppp_hdr); 732 if (!ppp_hdr) 733 return FLOW_DISSECT_RET_OUT_BAD; 734 735 switch (PPP_PROTOCOL(ppp_hdr)) { 736 case PPP_IP: 737 *p_proto = htons(ETH_P_IP); 738 break; 739 case PPP_IPV6: 740 *p_proto = htons(ETH_P_IPV6); 741 break; 742 default: 743 /* Could probably catch some more like MPLS */ 744 break; 745 } 746 747 offset += PPP_HDRLEN; 748 } 749 750 *p_nhoff += offset; 751 key_control->flags |= FLOW_DIS_ENCAPSULATION; 752 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 753 return FLOW_DISSECT_RET_OUT_GOOD; 754 755 return FLOW_DISSECT_RET_PROTO_AGAIN; 756 } 757 758 /** 759 * __skb_flow_dissect_batadv() - dissect batman-adv header 760 * @skb: sk_buff to with the batman-adv header 761 * @key_control: flow dissectors control key 762 * @data: raw buffer pointer to the packet, if NULL use skb->data 763 * @p_proto: pointer used to update the protocol to process next 764 * @p_nhoff: pointer used to update inner network header offset 765 * @hlen: packet header length 766 * @flags: any combination of FLOW_DISSECTOR_F_* 767 * 768 * ETH_P_BATMAN packets are tried to be dissected. Only 769 * &struct batadv_unicast packets are actually processed because they contain an 770 * inner ethernet header and are usually followed by actual network header. This 771 * allows the flow dissector to continue processing the packet. 772 * 773 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, 774 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, 775 * otherwise FLOW_DISSECT_RET_OUT_BAD 776 */ 777 static enum flow_dissect_ret 778 __skb_flow_dissect_batadv(const struct sk_buff *skb, 779 struct flow_dissector_key_control *key_control, 780 const void *data, __be16 *p_proto, int *p_nhoff, 781 int hlen, unsigned int flags) 782 { 783 struct { 784 struct batadv_unicast_packet batadv_unicast; 785 struct ethhdr eth; 786 } *hdr, _hdr; 787 788 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen, 789 &_hdr); 790 if (!hdr) 791 return FLOW_DISSECT_RET_OUT_BAD; 792 793 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) 794 return FLOW_DISSECT_RET_OUT_BAD; 795 796 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) 797 return FLOW_DISSECT_RET_OUT_BAD; 798 799 *p_proto = hdr->eth.h_proto; 800 *p_nhoff += sizeof(*hdr); 801 802 key_control->flags |= FLOW_DIS_ENCAPSULATION; 803 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 804 return FLOW_DISSECT_RET_OUT_GOOD; 805 806 return FLOW_DISSECT_RET_PROTO_AGAIN; 807 } 808 809 static void 810 __skb_flow_dissect_tcp(const struct sk_buff *skb, 811 struct flow_dissector *flow_dissector, 812 void *target_container, const void *data, 813 int thoff, int hlen) 814 { 815 struct flow_dissector_key_tcp *key_tcp; 816 struct tcphdr *th, _th; 817 818 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP)) 819 return; 820 821 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th); 822 if (!th) 823 return; 824 825 if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) 826 return; 827 828 key_tcp = skb_flow_dissector_target(flow_dissector, 829 FLOW_DISSECTOR_KEY_TCP, 830 target_container); 831 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); 832 } 833 834 static void 835 __skb_flow_dissect_ports(const struct sk_buff *skb, 836 struct flow_dissector *flow_dissector, 837 void *target_container, const void *data, 838 int nhoff, u8 ip_proto, int hlen) 839 { 840 enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX; 841 struct flow_dissector_key_ports *key_ports; 842 843 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 844 dissector_ports = FLOW_DISSECTOR_KEY_PORTS; 845 else if (dissector_uses_key(flow_dissector, 846 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 847 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE; 848 849 if (dissector_ports == FLOW_DISSECTOR_KEY_MAX) 850 return; 851 852 key_ports = skb_flow_dissector_target(flow_dissector, 853 dissector_ports, 854 target_container); 855 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 856 data, hlen); 857 } 858 859 static void 860 __skb_flow_dissect_ipv4(const struct sk_buff *skb, 861 struct flow_dissector *flow_dissector, 862 void *target_container, const void *data, 863 const struct iphdr *iph) 864 { 865 struct flow_dissector_key_ip *key_ip; 866 867 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 868 return; 869 870 key_ip = skb_flow_dissector_target(flow_dissector, 871 FLOW_DISSECTOR_KEY_IP, 872 target_container); 873 key_ip->tos = iph->tos; 874 key_ip->ttl = iph->ttl; 875 } 876 877 static void 878 __skb_flow_dissect_ipv6(const struct sk_buff *skb, 879 struct flow_dissector *flow_dissector, 880 void *target_container, const void *data, 881 const struct ipv6hdr *iph) 882 { 883 struct flow_dissector_key_ip *key_ip; 884 885 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 886 return; 887 888 key_ip = skb_flow_dissector_target(flow_dissector, 889 FLOW_DISSECTOR_KEY_IP, 890 target_container); 891 key_ip->tos = ipv6_get_dsfield(iph); 892 key_ip->ttl = iph->hop_limit; 893 } 894 895 /* Maximum number of protocol headers that can be parsed in 896 * __skb_flow_dissect 897 */ 898 #define MAX_FLOW_DISSECT_HDRS 15 899 900 static bool skb_flow_dissect_allowed(int *num_hdrs) 901 { 902 ++*num_hdrs; 903 904 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); 905 } 906 907 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, 908 struct flow_dissector *flow_dissector, 909 void *target_container) 910 { 911 struct flow_dissector_key_ports *key_ports = NULL; 912 struct flow_dissector_key_control *key_control; 913 struct flow_dissector_key_basic *key_basic; 914 struct flow_dissector_key_addrs *key_addrs; 915 struct flow_dissector_key_tags *key_tags; 916 917 key_control = skb_flow_dissector_target(flow_dissector, 918 FLOW_DISSECTOR_KEY_CONTROL, 919 target_container); 920 key_control->thoff = flow_keys->thoff; 921 if (flow_keys->is_frag) 922 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 923 if (flow_keys->is_first_frag) 924 key_control->flags |= FLOW_DIS_FIRST_FRAG; 925 if (flow_keys->is_encap) 926 key_control->flags |= FLOW_DIS_ENCAPSULATION; 927 928 key_basic = skb_flow_dissector_target(flow_dissector, 929 FLOW_DISSECTOR_KEY_BASIC, 930 target_container); 931 key_basic->n_proto = flow_keys->n_proto; 932 key_basic->ip_proto = flow_keys->ip_proto; 933 934 if (flow_keys->addr_proto == ETH_P_IP && 935 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 936 key_addrs = skb_flow_dissector_target(flow_dissector, 937 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 938 target_container); 939 key_addrs->v4addrs.src = flow_keys->ipv4_src; 940 key_addrs->v4addrs.dst = flow_keys->ipv4_dst; 941 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 942 } else if (flow_keys->addr_proto == ETH_P_IPV6 && 943 dissector_uses_key(flow_dissector, 944 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 945 key_addrs = skb_flow_dissector_target(flow_dissector, 946 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 947 target_container); 948 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, 949 sizeof(key_addrs->v6addrs.src)); 950 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, 951 sizeof(key_addrs->v6addrs.dst)); 952 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 953 } 954 955 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 956 key_ports = skb_flow_dissector_target(flow_dissector, 957 FLOW_DISSECTOR_KEY_PORTS, 958 target_container); 959 else if (dissector_uses_key(flow_dissector, 960 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 961 key_ports = skb_flow_dissector_target(flow_dissector, 962 FLOW_DISSECTOR_KEY_PORTS_RANGE, 963 target_container); 964 965 if (key_ports) { 966 key_ports->src = flow_keys->sport; 967 key_ports->dst = flow_keys->dport; 968 } 969 970 if (dissector_uses_key(flow_dissector, 971 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 972 key_tags = skb_flow_dissector_target(flow_dissector, 973 FLOW_DISSECTOR_KEY_FLOW_LABEL, 974 target_container); 975 key_tags->flow_label = ntohl(flow_keys->flow_label); 976 } 977 } 978 979 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 980 __be16 proto, int nhoff, int hlen, unsigned int flags) 981 { 982 struct bpf_flow_keys *flow_keys = ctx->flow_keys; 983 u32 result; 984 985 /* Pass parameters to the BPF program */ 986 memset(flow_keys, 0, sizeof(*flow_keys)); 987 flow_keys->n_proto = proto; 988 flow_keys->nhoff = nhoff; 989 flow_keys->thoff = flow_keys->nhoff; 990 991 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG != 992 (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG); 993 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL != 994 (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 995 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP != 996 (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); 997 flow_keys->flags = flags; 998 999 result = bpf_prog_run_pin_on_cpu(prog, ctx); 1000 1001 flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen); 1002 flow_keys->thoff = clamp_t(u16, flow_keys->thoff, 1003 flow_keys->nhoff, hlen); 1004 1005 return result; 1006 } 1007 1008 static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr) 1009 { 1010 return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0; 1011 } 1012 1013 /** 1014 * __skb_flow_dissect - extract the flow_keys struct and return it 1015 * @net: associated network namespace, derived from @skb if NULL 1016 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 1017 * @flow_dissector: list of keys to dissect 1018 * @target_container: target structure to put dissected values into 1019 * @data: raw buffer pointer to the packet, if NULL use skb->data 1020 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 1021 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 1022 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 1023 * @flags: flags that control the dissection process, e.g. 1024 * FLOW_DISSECTOR_F_STOP_AT_ENCAP. 1025 * 1026 * The function will try to retrieve individual keys into target specified 1027 * by flow_dissector from either the skbuff or a raw buffer specified by the 1028 * rest parameters. 1029 * 1030 * Caller must take care of zeroing target container memory. 1031 */ 1032 bool __skb_flow_dissect(const struct net *net, 1033 const struct sk_buff *skb, 1034 struct flow_dissector *flow_dissector, 1035 void *target_container, const void *data, 1036 __be16 proto, int nhoff, int hlen, unsigned int flags) 1037 { 1038 struct flow_dissector_key_control *key_control; 1039 struct flow_dissector_key_basic *key_basic; 1040 struct flow_dissector_key_addrs *key_addrs; 1041 struct flow_dissector_key_tags *key_tags; 1042 struct flow_dissector_key_vlan *key_vlan; 1043 enum flow_dissect_ret fdret; 1044 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; 1045 bool mpls_el = false; 1046 int mpls_lse = 0; 1047 int num_hdrs = 0; 1048 u8 ip_proto = 0; 1049 bool ret; 1050 1051 if (!data) { 1052 data = skb->data; 1053 proto = skb_vlan_tag_present(skb) ? 1054 skb->vlan_proto : skb->protocol; 1055 nhoff = skb_network_offset(skb); 1056 hlen = skb_headlen(skb); 1057 #if IS_ENABLED(CONFIG_NET_DSA) 1058 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) && 1059 proto == htons(ETH_P_XDSA))) { 1060 struct metadata_dst *md_dst = skb_metadata_dst(skb); 1061 const struct dsa_device_ops *ops; 1062 int offset = 0; 1063 1064 ops = skb->dev->dsa_ptr->tag_ops; 1065 /* Only DSA header taggers break flow dissection */ 1066 if (ops->needed_headroom && 1067 (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) { 1068 if (ops->flow_dissect) 1069 ops->flow_dissect(skb, &proto, &offset); 1070 else 1071 dsa_tag_generic_flow_dissect(skb, 1072 &proto, 1073 &offset); 1074 hlen -= offset; 1075 nhoff += offset; 1076 } 1077 } 1078 #endif 1079 } 1080 1081 /* It is ensured by skb_flow_dissector_init() that control key will 1082 * be always present. 1083 */ 1084 key_control = skb_flow_dissector_target(flow_dissector, 1085 FLOW_DISSECTOR_KEY_CONTROL, 1086 target_container); 1087 1088 /* It is ensured by skb_flow_dissector_init() that basic key will 1089 * be always present. 1090 */ 1091 key_basic = skb_flow_dissector_target(flow_dissector, 1092 FLOW_DISSECTOR_KEY_BASIC, 1093 target_container); 1094 1095 if (skb) { 1096 if (!net) { 1097 if (skb->dev) 1098 net = dev_net(skb->dev); 1099 else if (skb->sk) 1100 net = sock_net(skb->sk); 1101 } 1102 } 1103 1104 WARN_ON_ONCE(!net); 1105 if (net) { 1106 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; 1107 struct bpf_prog_array *run_array; 1108 1109 rcu_read_lock(); 1110 run_array = rcu_dereference(init_net.bpf.run_array[type]); 1111 if (!run_array) 1112 run_array = rcu_dereference(net->bpf.run_array[type]); 1113 1114 if (run_array) { 1115 struct bpf_flow_keys flow_keys; 1116 struct bpf_flow_dissector ctx = { 1117 .flow_keys = &flow_keys, 1118 .data = data, 1119 .data_end = data + hlen, 1120 }; 1121 __be16 n_proto = proto; 1122 struct bpf_prog *prog; 1123 u32 result; 1124 1125 if (skb) { 1126 ctx.skb = skb; 1127 /* we can't use 'proto' in the skb case 1128 * because it might be set to skb->vlan_proto 1129 * which has been pulled from the data 1130 */ 1131 n_proto = skb->protocol; 1132 } 1133 1134 prog = READ_ONCE(run_array->items[0].prog); 1135 result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff, 1136 hlen, flags); 1137 if (result == BPF_FLOW_DISSECTOR_CONTINUE) 1138 goto dissect_continue; 1139 __skb_flow_bpf_to_target(&flow_keys, flow_dissector, 1140 target_container); 1141 rcu_read_unlock(); 1142 return result == BPF_OK; 1143 } 1144 dissect_continue: 1145 rcu_read_unlock(); 1146 } 1147 1148 if (dissector_uses_key(flow_dissector, 1149 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 1150 struct ethhdr *eth = eth_hdr(skb); 1151 struct flow_dissector_key_eth_addrs *key_eth_addrs; 1152 1153 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 1154 FLOW_DISSECTOR_KEY_ETH_ADDRS, 1155 target_container); 1156 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs)); 1157 } 1158 1159 if (dissector_uses_key(flow_dissector, 1160 FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) { 1161 struct flow_dissector_key_num_of_vlans *key_num_of_vlans; 1162 1163 key_num_of_vlans = skb_flow_dissector_target(flow_dissector, 1164 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1165 target_container); 1166 key_num_of_vlans->num_of_vlans = 0; 1167 } 1168 1169 proto_again: 1170 fdret = FLOW_DISSECT_RET_CONTINUE; 1171 1172 switch (proto) { 1173 case htons(ETH_P_IP): { 1174 const struct iphdr *iph; 1175 struct iphdr _iph; 1176 1177 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1178 if (!iph || iph->ihl < 5) { 1179 fdret = FLOW_DISSECT_RET_OUT_BAD; 1180 break; 1181 } 1182 1183 nhoff += iph->ihl * 4; 1184 1185 ip_proto = iph->protocol; 1186 1187 if (dissector_uses_key(flow_dissector, 1188 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 1189 key_addrs = skb_flow_dissector_target(flow_dissector, 1190 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1191 target_container); 1192 1193 memcpy(&key_addrs->v4addrs.src, &iph->saddr, 1194 sizeof(key_addrs->v4addrs.src)); 1195 memcpy(&key_addrs->v4addrs.dst, &iph->daddr, 1196 sizeof(key_addrs->v4addrs.dst)); 1197 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1198 } 1199 1200 __skb_flow_dissect_ipv4(skb, flow_dissector, 1201 target_container, data, iph); 1202 1203 if (ip_is_fragment(iph)) { 1204 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1205 1206 if (iph->frag_off & htons(IP_OFFSET)) { 1207 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1208 break; 1209 } else { 1210 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1211 if (!(flags & 1212 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { 1213 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1214 break; 1215 } 1216 } 1217 } 1218 1219 break; 1220 } 1221 case htons(ETH_P_IPV6): { 1222 const struct ipv6hdr *iph; 1223 struct ipv6hdr _iph; 1224 1225 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1226 if (!iph) { 1227 fdret = FLOW_DISSECT_RET_OUT_BAD; 1228 break; 1229 } 1230 1231 ip_proto = iph->nexthdr; 1232 nhoff += sizeof(struct ipv6hdr); 1233 1234 if (dissector_uses_key(flow_dissector, 1235 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 1236 key_addrs = skb_flow_dissector_target(flow_dissector, 1237 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1238 target_container); 1239 1240 memcpy(&key_addrs->v6addrs.src, &iph->saddr, 1241 sizeof(key_addrs->v6addrs.src)); 1242 memcpy(&key_addrs->v6addrs.dst, &iph->daddr, 1243 sizeof(key_addrs->v6addrs.dst)); 1244 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1245 } 1246 1247 if ((dissector_uses_key(flow_dissector, 1248 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 1249 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 1250 ip6_flowlabel(iph)) { 1251 __be32 flow_label = ip6_flowlabel(iph); 1252 1253 if (dissector_uses_key(flow_dissector, 1254 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 1255 key_tags = skb_flow_dissector_target(flow_dissector, 1256 FLOW_DISSECTOR_KEY_FLOW_LABEL, 1257 target_container); 1258 key_tags->flow_label = ntohl(flow_label); 1259 } 1260 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { 1261 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1262 break; 1263 } 1264 } 1265 1266 __skb_flow_dissect_ipv6(skb, flow_dissector, 1267 target_container, data, iph); 1268 1269 break; 1270 } 1271 case htons(ETH_P_8021AD): 1272 case htons(ETH_P_8021Q): { 1273 const struct vlan_hdr *vlan = NULL; 1274 struct vlan_hdr _vlan; 1275 __be16 saved_vlan_tpid = proto; 1276 1277 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && 1278 skb && skb_vlan_tag_present(skb)) { 1279 proto = skb->protocol; 1280 } else { 1281 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), 1282 data, hlen, &_vlan); 1283 if (!vlan) { 1284 fdret = FLOW_DISSECT_RET_OUT_BAD; 1285 break; 1286 } 1287 1288 proto = vlan->h_vlan_encapsulated_proto; 1289 nhoff += sizeof(*vlan); 1290 } 1291 1292 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) && 1293 !(key_control->flags & FLOW_DIS_ENCAPSULATION)) { 1294 struct flow_dissector_key_num_of_vlans *key_nvs; 1295 1296 key_nvs = skb_flow_dissector_target(flow_dissector, 1297 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1298 target_container); 1299 key_nvs->num_of_vlans++; 1300 } 1301 1302 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { 1303 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; 1304 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { 1305 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; 1306 } else { 1307 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1308 break; 1309 } 1310 1311 if (dissector_uses_key(flow_dissector, dissector_vlan)) { 1312 key_vlan = skb_flow_dissector_target(flow_dissector, 1313 dissector_vlan, 1314 target_container); 1315 1316 if (!vlan) { 1317 key_vlan->vlan_id = skb_vlan_tag_get_id(skb); 1318 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb); 1319 } else { 1320 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & 1321 VLAN_VID_MASK; 1322 key_vlan->vlan_priority = 1323 (ntohs(vlan->h_vlan_TCI) & 1324 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 1325 } 1326 key_vlan->vlan_tpid = saved_vlan_tpid; 1327 key_vlan->vlan_eth_type = proto; 1328 } 1329 1330 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1331 break; 1332 } 1333 case htons(ETH_P_PPP_SES): { 1334 struct { 1335 struct pppoe_hdr hdr; 1336 __be16 proto; 1337 } *hdr, _hdr; 1338 u16 ppp_proto; 1339 1340 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 1341 if (!hdr) { 1342 fdret = FLOW_DISSECT_RET_OUT_BAD; 1343 break; 1344 } 1345 1346 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) { 1347 fdret = FLOW_DISSECT_RET_OUT_BAD; 1348 break; 1349 } 1350 1351 /* least significant bit of the most significant octet 1352 * indicates if protocol field was compressed 1353 */ 1354 ppp_proto = ntohs(hdr->proto); 1355 if (ppp_proto & 0x0100) { 1356 ppp_proto = ppp_proto >> 8; 1357 nhoff += PPPOE_SES_HLEN - 1; 1358 } else { 1359 nhoff += PPPOE_SES_HLEN; 1360 } 1361 1362 if (ppp_proto == PPP_IP) { 1363 proto = htons(ETH_P_IP); 1364 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1365 } else if (ppp_proto == PPP_IPV6) { 1366 proto = htons(ETH_P_IPV6); 1367 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1368 } else if (ppp_proto == PPP_MPLS_UC) { 1369 proto = htons(ETH_P_MPLS_UC); 1370 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1371 } else if (ppp_proto == PPP_MPLS_MC) { 1372 proto = htons(ETH_P_MPLS_MC); 1373 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1374 } else if (ppp_proto_is_valid(ppp_proto)) { 1375 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1376 } else { 1377 fdret = FLOW_DISSECT_RET_OUT_BAD; 1378 break; 1379 } 1380 1381 if (dissector_uses_key(flow_dissector, 1382 FLOW_DISSECTOR_KEY_PPPOE)) { 1383 struct flow_dissector_key_pppoe *key_pppoe; 1384 1385 key_pppoe = skb_flow_dissector_target(flow_dissector, 1386 FLOW_DISSECTOR_KEY_PPPOE, 1387 target_container); 1388 key_pppoe->session_id = hdr->hdr.sid; 1389 key_pppoe->ppp_proto = htons(ppp_proto); 1390 key_pppoe->type = htons(ETH_P_PPP_SES); 1391 } 1392 break; 1393 } 1394 case htons(ETH_P_TIPC): { 1395 struct tipc_basic_hdr *hdr, _hdr; 1396 1397 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), 1398 data, hlen, &_hdr); 1399 if (!hdr) { 1400 fdret = FLOW_DISSECT_RET_OUT_BAD; 1401 break; 1402 } 1403 1404 if (dissector_uses_key(flow_dissector, 1405 FLOW_DISSECTOR_KEY_TIPC)) { 1406 key_addrs = skb_flow_dissector_target(flow_dissector, 1407 FLOW_DISSECTOR_KEY_TIPC, 1408 target_container); 1409 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); 1410 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; 1411 } 1412 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1413 break; 1414 } 1415 1416 case htons(ETH_P_MPLS_UC): 1417 case htons(ETH_P_MPLS_MC): 1418 fdret = __skb_flow_dissect_mpls(skb, flow_dissector, 1419 target_container, data, 1420 nhoff, hlen, mpls_lse, 1421 &mpls_el); 1422 nhoff += sizeof(struct mpls_label); 1423 mpls_lse++; 1424 break; 1425 case htons(ETH_P_FCOE): 1426 if ((hlen - nhoff) < FCOE_HEADER_LEN) { 1427 fdret = FLOW_DISSECT_RET_OUT_BAD; 1428 break; 1429 } 1430 1431 nhoff += FCOE_HEADER_LEN; 1432 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1433 break; 1434 1435 case htons(ETH_P_ARP): 1436 case htons(ETH_P_RARP): 1437 fdret = __skb_flow_dissect_arp(skb, flow_dissector, 1438 target_container, data, 1439 nhoff, hlen); 1440 break; 1441 1442 case htons(ETH_P_BATMAN): 1443 fdret = __skb_flow_dissect_batadv(skb, key_control, data, 1444 &proto, &nhoff, hlen, flags); 1445 break; 1446 1447 case htons(ETH_P_1588): { 1448 struct ptp_header *hdr, _hdr; 1449 1450 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 1451 hlen, &_hdr); 1452 if (!hdr) { 1453 fdret = FLOW_DISSECT_RET_OUT_BAD; 1454 break; 1455 } 1456 1457 nhoff += sizeof(struct ptp_header); 1458 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1459 break; 1460 } 1461 1462 case htons(ETH_P_PRP): 1463 case htons(ETH_P_HSR): { 1464 struct hsr_tag *hdr, _hdr; 1465 1466 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, 1467 &_hdr); 1468 if (!hdr) { 1469 fdret = FLOW_DISSECT_RET_OUT_BAD; 1470 break; 1471 } 1472 1473 proto = hdr->encap_proto; 1474 nhoff += HSR_HLEN; 1475 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1476 break; 1477 } 1478 1479 case htons(ETH_P_CFM): 1480 fdret = __skb_flow_dissect_cfm(skb, flow_dissector, 1481 target_container, data, 1482 nhoff, hlen); 1483 break; 1484 1485 default: 1486 fdret = FLOW_DISSECT_RET_OUT_BAD; 1487 break; 1488 } 1489 1490 /* Process result of proto processing */ 1491 switch (fdret) { 1492 case FLOW_DISSECT_RET_OUT_GOOD: 1493 goto out_good; 1494 case FLOW_DISSECT_RET_PROTO_AGAIN: 1495 if (skb_flow_dissect_allowed(&num_hdrs)) 1496 goto proto_again; 1497 goto out_good; 1498 case FLOW_DISSECT_RET_CONTINUE: 1499 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1500 break; 1501 case FLOW_DISSECT_RET_OUT_BAD: 1502 default: 1503 goto out_bad; 1504 } 1505 1506 ip_proto_again: 1507 fdret = FLOW_DISSECT_RET_CONTINUE; 1508 1509 switch (ip_proto) { 1510 case IPPROTO_GRE: 1511 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1512 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1513 break; 1514 } 1515 1516 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, 1517 target_container, data, 1518 &proto, &nhoff, &hlen, flags); 1519 break; 1520 1521 case NEXTHDR_HOP: 1522 case NEXTHDR_ROUTING: 1523 case NEXTHDR_DEST: { 1524 u8 _opthdr[2], *opthdr; 1525 1526 if (proto != htons(ETH_P_IPV6)) 1527 break; 1528 1529 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 1530 data, hlen, &_opthdr); 1531 if (!opthdr) { 1532 fdret = FLOW_DISSECT_RET_OUT_BAD; 1533 break; 1534 } 1535 1536 ip_proto = opthdr[0]; 1537 nhoff += (opthdr[1] + 1) << 3; 1538 1539 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1540 break; 1541 } 1542 case NEXTHDR_FRAGMENT: { 1543 struct frag_hdr _fh, *fh; 1544 1545 if (proto != htons(ETH_P_IPV6)) 1546 break; 1547 1548 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 1549 data, hlen, &_fh); 1550 1551 if (!fh) { 1552 fdret = FLOW_DISSECT_RET_OUT_BAD; 1553 break; 1554 } 1555 1556 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1557 1558 nhoff += sizeof(_fh); 1559 ip_proto = fh->nexthdr; 1560 1561 if (!(fh->frag_off & htons(IP6_OFFSET))) { 1562 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1563 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { 1564 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1565 break; 1566 } 1567 } 1568 1569 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1570 break; 1571 } 1572 case IPPROTO_IPIP: 1573 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1574 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1575 break; 1576 } 1577 1578 proto = htons(ETH_P_IP); 1579 1580 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1581 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1582 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1583 break; 1584 } 1585 1586 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1587 break; 1588 1589 case IPPROTO_IPV6: 1590 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1591 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1592 break; 1593 } 1594 1595 proto = htons(ETH_P_IPV6); 1596 1597 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1598 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1599 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1600 break; 1601 } 1602 1603 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1604 break; 1605 1606 1607 case IPPROTO_MPLS: 1608 proto = htons(ETH_P_MPLS_UC); 1609 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1610 break; 1611 1612 case IPPROTO_TCP: 1613 __skb_flow_dissect_tcp(skb, flow_dissector, target_container, 1614 data, nhoff, hlen); 1615 break; 1616 1617 case IPPROTO_ICMP: 1618 case IPPROTO_ICMPV6: 1619 __skb_flow_dissect_icmp(skb, flow_dissector, target_container, 1620 data, nhoff, hlen); 1621 break; 1622 case IPPROTO_L2TP: 1623 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container, 1624 data, nhoff, hlen); 1625 break; 1626 case IPPROTO_ESP: 1627 __skb_flow_dissect_esp(skb, flow_dissector, target_container, 1628 data, nhoff, hlen); 1629 break; 1630 case IPPROTO_AH: 1631 __skb_flow_dissect_ah(skb, flow_dissector, target_container, 1632 data, nhoff, hlen); 1633 break; 1634 default: 1635 break; 1636 } 1637 1638 if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT)) 1639 __skb_flow_dissect_ports(skb, flow_dissector, target_container, 1640 data, nhoff, ip_proto, hlen); 1641 1642 /* Process result of IP proto processing */ 1643 switch (fdret) { 1644 case FLOW_DISSECT_RET_PROTO_AGAIN: 1645 if (skb_flow_dissect_allowed(&num_hdrs)) 1646 goto proto_again; 1647 break; 1648 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1649 if (skb_flow_dissect_allowed(&num_hdrs)) 1650 goto ip_proto_again; 1651 break; 1652 case FLOW_DISSECT_RET_OUT_GOOD: 1653 case FLOW_DISSECT_RET_CONTINUE: 1654 break; 1655 case FLOW_DISSECT_RET_OUT_BAD: 1656 default: 1657 goto out_bad; 1658 } 1659 1660 out_good: 1661 ret = true; 1662 1663 out: 1664 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); 1665 key_basic->n_proto = proto; 1666 key_basic->ip_proto = ip_proto; 1667 1668 return ret; 1669 1670 out_bad: 1671 ret = false; 1672 goto out; 1673 } 1674 EXPORT_SYMBOL(__skb_flow_dissect); 1675 1676 static siphash_aligned_key_t hashrnd; 1677 static __always_inline void __flow_hash_secret_init(void) 1678 { 1679 net_get_random_once(&hashrnd, sizeof(hashrnd)); 1680 } 1681 1682 static const void *flow_keys_hash_start(const struct flow_keys *flow) 1683 { 1684 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT); 1685 return &flow->FLOW_KEYS_HASH_START_FIELD; 1686 } 1687 1688 static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 1689 { 1690 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 1691 1692 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 1693 1694 switch (flow->control.addr_type) { 1695 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1696 diff -= sizeof(flow->addrs.v4addrs); 1697 break; 1698 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1699 diff -= sizeof(flow->addrs.v6addrs); 1700 break; 1701 case FLOW_DISSECTOR_KEY_TIPC: 1702 diff -= sizeof(flow->addrs.tipckey); 1703 break; 1704 } 1705 return sizeof(*flow) - diff; 1706 } 1707 1708 __be32 flow_get_u32_src(const struct flow_keys *flow) 1709 { 1710 switch (flow->control.addr_type) { 1711 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1712 return flow->addrs.v4addrs.src; 1713 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1714 return (__force __be32)ipv6_addr_hash( 1715 &flow->addrs.v6addrs.src); 1716 case FLOW_DISSECTOR_KEY_TIPC: 1717 return flow->addrs.tipckey.key; 1718 default: 1719 return 0; 1720 } 1721 } 1722 EXPORT_SYMBOL(flow_get_u32_src); 1723 1724 __be32 flow_get_u32_dst(const struct flow_keys *flow) 1725 { 1726 switch (flow->control.addr_type) { 1727 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1728 return flow->addrs.v4addrs.dst; 1729 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1730 return (__force __be32)ipv6_addr_hash( 1731 &flow->addrs.v6addrs.dst); 1732 default: 1733 return 0; 1734 } 1735 } 1736 EXPORT_SYMBOL(flow_get_u32_dst); 1737 1738 /* Sort the source and destination IP and the ports, 1739 * to have consistent hash within the two directions 1740 */ 1741 static inline void __flow_hash_consistentify(struct flow_keys *keys) 1742 { 1743 int addr_diff, i; 1744 1745 switch (keys->control.addr_type) { 1746 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1747 if ((__force u32)keys->addrs.v4addrs.dst < 1748 (__force u32)keys->addrs.v4addrs.src) 1749 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 1750 1751 if ((__force u16)keys->ports.dst < 1752 (__force u16)keys->ports.src) { 1753 swap(keys->ports.src, keys->ports.dst); 1754 } 1755 break; 1756 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1757 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 1758 &keys->addrs.v6addrs.src, 1759 sizeof(keys->addrs.v6addrs.dst)); 1760 if (addr_diff < 0) { 1761 for (i = 0; i < 4; i++) 1762 swap(keys->addrs.v6addrs.src.s6_addr32[i], 1763 keys->addrs.v6addrs.dst.s6_addr32[i]); 1764 } 1765 if ((__force u16)keys->ports.dst < 1766 (__force u16)keys->ports.src) { 1767 swap(keys->ports.src, keys->ports.dst); 1768 } 1769 break; 1770 } 1771 } 1772 1773 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, 1774 const siphash_key_t *keyval) 1775 { 1776 u32 hash; 1777 1778 __flow_hash_consistentify(keys); 1779 1780 hash = siphash(flow_keys_hash_start(keys), 1781 flow_keys_hash_length(keys), keyval); 1782 if (!hash) 1783 hash = 1; 1784 1785 return hash; 1786 } 1787 1788 u32 flow_hash_from_keys(struct flow_keys *keys) 1789 { 1790 __flow_hash_secret_init(); 1791 return __flow_hash_from_keys(keys, &hashrnd); 1792 } 1793 EXPORT_SYMBOL(flow_hash_from_keys); 1794 1795 static inline u32 ___skb_get_hash(const struct sk_buff *skb, 1796 struct flow_keys *keys, 1797 const siphash_key_t *keyval) 1798 { 1799 skb_flow_dissect_flow_keys(skb, keys, 1800 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1801 1802 return __flow_hash_from_keys(keys, keyval); 1803 } 1804 1805 struct _flow_keys_digest_data { 1806 __be16 n_proto; 1807 u8 ip_proto; 1808 u8 padding; 1809 __be32 ports; 1810 __be32 src; 1811 __be32 dst; 1812 }; 1813 1814 void make_flow_keys_digest(struct flow_keys_digest *digest, 1815 const struct flow_keys *flow) 1816 { 1817 struct _flow_keys_digest_data *data = 1818 (struct _flow_keys_digest_data *)digest; 1819 1820 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 1821 1822 memset(digest, 0, sizeof(*digest)); 1823 1824 data->n_proto = flow->basic.n_proto; 1825 data->ip_proto = flow->basic.ip_proto; 1826 data->ports = flow->ports.ports; 1827 data->src = flow->addrs.v4addrs.src; 1828 data->dst = flow->addrs.v4addrs.dst; 1829 } 1830 EXPORT_SYMBOL(make_flow_keys_digest); 1831 1832 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; 1833 1834 u32 __skb_get_hash_symmetric(const struct sk_buff *skb) 1835 { 1836 struct flow_keys keys; 1837 1838 __flow_hash_secret_init(); 1839 1840 memset(&keys, 0, sizeof(keys)); 1841 __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric, 1842 &keys, NULL, 0, 0, 0, 0); 1843 1844 return __flow_hash_from_keys(&keys, &hashrnd); 1845 } 1846 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); 1847 1848 /** 1849 * __skb_get_hash: calculate a flow hash 1850 * @skb: sk_buff to calculate flow hash from 1851 * 1852 * This function calculates a flow hash based on src/dst addresses 1853 * and src/dst port numbers. Sets hash in skb to non-zero hash value 1854 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 1855 * if hash is a canonical 4-tuple hash over transport ports. 1856 */ 1857 void __skb_get_hash(struct sk_buff *skb) 1858 { 1859 struct flow_keys keys; 1860 u32 hash; 1861 1862 __flow_hash_secret_init(); 1863 1864 hash = ___skb_get_hash(skb, &keys, &hashrnd); 1865 1866 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1867 } 1868 EXPORT_SYMBOL(__skb_get_hash); 1869 1870 __u32 skb_get_hash_perturb(const struct sk_buff *skb, 1871 const siphash_key_t *perturb) 1872 { 1873 struct flow_keys keys; 1874 1875 return ___skb_get_hash(skb, &keys, perturb); 1876 } 1877 EXPORT_SYMBOL(skb_get_hash_perturb); 1878 1879 u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1880 const struct flow_keys_basic *keys, int hlen) 1881 { 1882 u32 poff = keys->control.thoff; 1883 1884 /* skip L4 headers for fragments after the first */ 1885 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && 1886 !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) 1887 return poff; 1888 1889 switch (keys->basic.ip_proto) { 1890 case IPPROTO_TCP: { 1891 /* access doff as u8 to avoid unaligned access */ 1892 const u8 *doff; 1893 u8 _doff; 1894 1895 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 1896 data, hlen, &_doff); 1897 if (!doff) 1898 return poff; 1899 1900 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 1901 break; 1902 } 1903 case IPPROTO_UDP: 1904 case IPPROTO_UDPLITE: 1905 poff += sizeof(struct udphdr); 1906 break; 1907 /* For the rest, we do not really care about header 1908 * extensions at this point for now. 1909 */ 1910 case IPPROTO_ICMP: 1911 poff += sizeof(struct icmphdr); 1912 break; 1913 case IPPROTO_ICMPV6: 1914 poff += sizeof(struct icmp6hdr); 1915 break; 1916 case IPPROTO_IGMP: 1917 poff += sizeof(struct igmphdr); 1918 break; 1919 case IPPROTO_DCCP: 1920 poff += sizeof(struct dccp_hdr); 1921 break; 1922 case IPPROTO_SCTP: 1923 poff += sizeof(struct sctphdr); 1924 break; 1925 } 1926 1927 return poff; 1928 } 1929 1930 /** 1931 * skb_get_poff - get the offset to the payload 1932 * @skb: sk_buff to get the payload offset from 1933 * 1934 * The function will get the offset to the payload as far as it could 1935 * be dissected. The main user is currently BPF, so that we can dynamically 1936 * truncate packets without needing to push actual payload to the user 1937 * space and can analyze headers only, instead. 1938 */ 1939 u32 skb_get_poff(const struct sk_buff *skb) 1940 { 1941 struct flow_keys_basic keys; 1942 1943 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 1944 NULL, 0, 0, 0, 0)) 1945 return 0; 1946 1947 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 1948 } 1949 1950 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 1951 { 1952 memset(keys, 0, sizeof(*keys)); 1953 1954 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 1955 sizeof(keys->addrs.v6addrs.src)); 1956 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 1957 sizeof(keys->addrs.v6addrs.dst)); 1958 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1959 keys->ports.src = fl6->fl6_sport; 1960 keys->ports.dst = fl6->fl6_dport; 1961 keys->keyid.keyid = fl6->fl6_gre_key; 1962 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 1963 keys->basic.ip_proto = fl6->flowi6_proto; 1964 1965 return flow_hash_from_keys(keys); 1966 } 1967 EXPORT_SYMBOL(__get_hash_from_flowi6); 1968 1969 static const struct flow_dissector_key flow_keys_dissector_keys[] = { 1970 { 1971 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1972 .offset = offsetof(struct flow_keys, control), 1973 }, 1974 { 1975 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1976 .offset = offsetof(struct flow_keys, basic), 1977 }, 1978 { 1979 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1980 .offset = offsetof(struct flow_keys, addrs.v4addrs), 1981 }, 1982 { 1983 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1984 .offset = offsetof(struct flow_keys, addrs.v6addrs), 1985 }, 1986 { 1987 .key_id = FLOW_DISSECTOR_KEY_TIPC, 1988 .offset = offsetof(struct flow_keys, addrs.tipckey), 1989 }, 1990 { 1991 .key_id = FLOW_DISSECTOR_KEY_PORTS, 1992 .offset = offsetof(struct flow_keys, ports), 1993 }, 1994 { 1995 .key_id = FLOW_DISSECTOR_KEY_VLAN, 1996 .offset = offsetof(struct flow_keys, vlan), 1997 }, 1998 { 1999 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 2000 .offset = offsetof(struct flow_keys, tags), 2001 }, 2002 { 2003 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 2004 .offset = offsetof(struct flow_keys, keyid), 2005 }, 2006 }; 2007 2008 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { 2009 { 2010 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2011 .offset = offsetof(struct flow_keys, control), 2012 }, 2013 { 2014 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2015 .offset = offsetof(struct flow_keys, basic), 2016 }, 2017 { 2018 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 2019 .offset = offsetof(struct flow_keys, addrs.v4addrs), 2020 }, 2021 { 2022 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 2023 .offset = offsetof(struct flow_keys, addrs.v6addrs), 2024 }, 2025 { 2026 .key_id = FLOW_DISSECTOR_KEY_PORTS, 2027 .offset = offsetof(struct flow_keys, ports), 2028 }, 2029 }; 2030 2031 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { 2032 { 2033 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2034 .offset = offsetof(struct flow_keys, control), 2035 }, 2036 { 2037 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2038 .offset = offsetof(struct flow_keys, basic), 2039 }, 2040 }; 2041 2042 struct flow_dissector flow_keys_dissector __read_mostly; 2043 EXPORT_SYMBOL(flow_keys_dissector); 2044 2045 struct flow_dissector flow_keys_basic_dissector __read_mostly; 2046 EXPORT_SYMBOL(flow_keys_basic_dissector); 2047 2048 static int __init init_default_flow_dissectors(void) 2049 { 2050 skb_flow_dissector_init(&flow_keys_dissector, 2051 flow_keys_dissector_keys, 2052 ARRAY_SIZE(flow_keys_dissector_keys)); 2053 skb_flow_dissector_init(&flow_keys_dissector_symmetric, 2054 flow_keys_dissector_symmetric_keys, 2055 ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); 2056 skb_flow_dissector_init(&flow_keys_basic_dissector, 2057 flow_keys_basic_dissector_keys, 2058 ARRAY_SIZE(flow_keys_basic_dissector_keys)); 2059 return 0; 2060 } 2061 core_initcall(init_default_flow_dissectors); 2062