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 40static 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 46void 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} 74EXPORT_SYMBOL(skb_flow_dissector_init); 75 76#ifdef CONFIG_BPF_SYSCALL 77int 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} 140EXPORT_SYMBOL(__skb_flow_get_ports); 141 142static 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 */ 165void 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} 186EXPORT_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 */ 191static 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 208static 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 230static 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 252static 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 276void 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} 299EXPORT_SYMBOL(skb_flow_dissect_meta); 300 301static void 302skb_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 317void 318skb_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} 361EXPORT_SYMBOL(skb_flow_dissect_ct); 362 363void 364skb_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; 458 459 enc_opt = skb_flow_dissector_target(flow_dissector, 460 FLOW_DISSECTOR_KEY_ENC_OPTS, 461 target_container); 462 463 if (info->options_len) { 464 enc_opt->len = info->options_len; 465 ip_tunnel_info_opts_get(enc_opt->data, info); 466 enc_opt->dst_opt_type = info->key.tun_flags & 467 TUNNEL_OPTIONS_PRESENT; 468 } 469 } 470} 471EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); 472 473void skb_flow_dissect_hash(const struct sk_buff *skb, 474 struct flow_dissector *flow_dissector, 475 void *target_container) 476{ 477 struct flow_dissector_key_hash *key; 478 479 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH)) 480 return; 481 482 key = skb_flow_dissector_target(flow_dissector, 483 FLOW_DISSECTOR_KEY_HASH, 484 target_container); 485 486 key->hash = skb_get_hash_raw(skb); 487} 488EXPORT_SYMBOL(skb_flow_dissect_hash); 489 490static enum flow_dissect_ret 491__skb_flow_dissect_mpls(const struct sk_buff *skb, 492 struct flow_dissector *flow_dissector, 493 void *target_container, const void *data, int nhoff, 494 int hlen, int lse_index, bool *entropy_label) 495{ 496 struct mpls_label *hdr, _hdr; 497 u32 entry, label, bos; 498 499 if (!dissector_uses_key(flow_dissector, 500 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && 501 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) 502 return FLOW_DISSECT_RET_OUT_GOOD; 503 504 if (lse_index >= FLOW_DIS_MPLS_MAX) 505 return FLOW_DISSECT_RET_OUT_GOOD; 506 507 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 508 hlen, &_hdr); 509 if (!hdr) 510 return FLOW_DISSECT_RET_OUT_BAD; 511 512 entry = ntohl(hdr->entry); 513 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; 514 bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT; 515 516 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) { 517 struct flow_dissector_key_mpls *key_mpls; 518 struct flow_dissector_mpls_lse *lse; 519 520 key_mpls = skb_flow_dissector_target(flow_dissector, 521 FLOW_DISSECTOR_KEY_MPLS, 522 target_container); 523 lse = &key_mpls->ls[lse_index]; 524 525 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; 526 lse->mpls_bos = bos; 527 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT; 528 lse->mpls_label = label; 529 dissector_set_mpls_lse(key_mpls, lse_index); 530 } 531 532 if (*entropy_label && 533 dissector_uses_key(flow_dissector, 534 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { 535 struct flow_dissector_key_keyid *key_keyid; 536 537 key_keyid = skb_flow_dissector_target(flow_dissector, 538 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 539 target_container); 540 key_keyid->keyid = cpu_to_be32(label); 541 } 542 543 *entropy_label = label == MPLS_LABEL_ENTROPY; 544 545 return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN; 546} 547 548static enum flow_dissect_ret 549__skb_flow_dissect_arp(const struct sk_buff *skb, 550 struct flow_dissector *flow_dissector, 551 void *target_container, const void *data, 552 int nhoff, int hlen) 553{ 554 struct flow_dissector_key_arp *key_arp; 555 struct { 556 unsigned char ar_sha[ETH_ALEN]; 557 unsigned char ar_sip[4]; 558 unsigned char ar_tha[ETH_ALEN]; 559 unsigned char ar_tip[4]; 560 } *arp_eth, _arp_eth; 561 const struct arphdr *arp; 562 struct arphdr _arp; 563 564 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP)) 565 return FLOW_DISSECT_RET_OUT_GOOD; 566 567 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, 568 hlen, &_arp); 569 if (!arp) 570 return FLOW_DISSECT_RET_OUT_BAD; 571 572 if (arp->ar_hrd != htons(ARPHRD_ETHER) || 573 arp->ar_pro != htons(ETH_P_IP) || 574 arp->ar_hln != ETH_ALEN || 575 arp->ar_pln != 4 || 576 (arp->ar_op != htons(ARPOP_REPLY) && 577 arp->ar_op != htons(ARPOP_REQUEST))) 578 return FLOW_DISSECT_RET_OUT_BAD; 579 580 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), 581 sizeof(_arp_eth), data, 582 hlen, &_arp_eth); 583 if (!arp_eth) 584 return FLOW_DISSECT_RET_OUT_BAD; 585 586 key_arp = skb_flow_dissector_target(flow_dissector, 587 FLOW_DISSECTOR_KEY_ARP, 588 target_container); 589 590 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); 591 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); 592 593 /* Only store the lower byte of the opcode; 594 * this covers ARPOP_REPLY and ARPOP_REQUEST. 595 */ 596 key_arp->op = ntohs(arp->ar_op) & 0xff; 597 598 ether_addr_copy(key_arp->sha, arp_eth->ar_sha); 599 ether_addr_copy(key_arp->tha, arp_eth->ar_tha); 600 601 return FLOW_DISSECT_RET_OUT_GOOD; 602} 603 604static enum flow_dissect_ret 605__skb_flow_dissect_cfm(const struct sk_buff *skb, 606 struct flow_dissector *flow_dissector, 607 void *target_container, const void *data, 608 int nhoff, int hlen) 609{ 610 struct flow_dissector_key_cfm *key, *hdr, _hdr; 611 612 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM)) 613 return FLOW_DISSECT_RET_OUT_GOOD; 614 615 hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr); 616 if (!hdr) 617 return FLOW_DISSECT_RET_OUT_BAD; 618 619 key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM, 620 target_container); 621 622 key->mdl_ver = hdr->mdl_ver; 623 key->opcode = hdr->opcode; 624 625 return FLOW_DISSECT_RET_OUT_GOOD; 626} 627 628static enum flow_dissect_ret 629__skb_flow_dissect_gre(const struct sk_buff *skb, 630 struct flow_dissector_key_control *key_control, 631 struct flow_dissector *flow_dissector, 632 void *target_container, const void *data, 633 __be16 *p_proto, int *p_nhoff, int *p_hlen, 634 unsigned int flags) 635{ 636 struct flow_dissector_key_keyid *key_keyid; 637 struct gre_base_hdr *hdr, _hdr; 638 int offset = 0; 639 u16 gre_ver; 640 641 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), 642 data, *p_hlen, &_hdr); 643 if (!hdr) 644 return FLOW_DISSECT_RET_OUT_BAD; 645 646 /* Only look inside GRE without routing */ 647 if (hdr->flags & GRE_ROUTING) 648 return FLOW_DISSECT_RET_OUT_GOOD; 649 650 /* Only look inside GRE for version 0 and 1 */ 651 gre_ver = ntohs(hdr->flags & GRE_VERSION); 652 if (gre_ver > 1) 653 return FLOW_DISSECT_RET_OUT_GOOD; 654 655 *p_proto = hdr->protocol; 656 if (gre_ver) { 657 /* Version1 must be PPTP, and check the flags */ 658 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) 659 return FLOW_DISSECT_RET_OUT_GOOD; 660 } 661 662 offset += sizeof(struct gre_base_hdr); 663 664 if (hdr->flags & GRE_CSUM) 665 offset += sizeof_field(struct gre_full_hdr, csum) + 666 sizeof_field(struct gre_full_hdr, reserved1); 667 668 if (hdr->flags & GRE_KEY) { 669 const __be32 *keyid; 670 __be32 _keyid; 671 672 keyid = __skb_header_pointer(skb, *p_nhoff + offset, 673 sizeof(_keyid), 674 data, *p_hlen, &_keyid); 675 if (!keyid) 676 return FLOW_DISSECT_RET_OUT_BAD; 677 678 if (dissector_uses_key(flow_dissector, 679 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 680 key_keyid = skb_flow_dissector_target(flow_dissector, 681 FLOW_DISSECTOR_KEY_GRE_KEYID, 682 target_container); 683 if (gre_ver == 0) 684 key_keyid->keyid = *keyid; 685 else 686 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; 687 } 688 offset += sizeof_field(struct gre_full_hdr, key); 689 } 690 691 if (hdr->flags & GRE_SEQ) 692 offset += sizeof_field(struct pptp_gre_header, seq); 693 694 if (gre_ver == 0) { 695 if (*p_proto == htons(ETH_P_TEB)) { 696 const struct ethhdr *eth; 697 struct ethhdr _eth; 698 699 eth = __skb_header_pointer(skb, *p_nhoff + offset, 700 sizeof(_eth), 701 data, *p_hlen, &_eth); 702 if (!eth) 703 return FLOW_DISSECT_RET_OUT_BAD; 704 *p_proto = eth->h_proto; 705 offset += sizeof(*eth); 706 707 /* Cap headers that we access via pointers at the 708 * end of the Ethernet header as our maximum alignment 709 * at that point is only 2 bytes. 710 */ 711 if (NET_IP_ALIGN) 712 *p_hlen = *p_nhoff + offset; 713 } 714 } else { /* version 1, must be PPTP */ 715 u8 _ppp_hdr[PPP_HDRLEN]; 716 u8 *ppp_hdr; 717 718 if (hdr->flags & GRE_ACK) 719 offset += sizeof_field(struct pptp_gre_header, ack); 720 721 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset, 722 sizeof(_ppp_hdr), 723 data, *p_hlen, _ppp_hdr); 724 if (!ppp_hdr) 725 return FLOW_DISSECT_RET_OUT_BAD; 726 727 switch (PPP_PROTOCOL(ppp_hdr)) { 728 case PPP_IP: 729 *p_proto = htons(ETH_P_IP); 730 break; 731 case PPP_IPV6: 732 *p_proto = htons(ETH_P_IPV6); 733 break; 734 default: 735 /* Could probably catch some more like MPLS */ 736 break; 737 } 738 739 offset += PPP_HDRLEN; 740 } 741 742 *p_nhoff += offset; 743 key_control->flags |= FLOW_DIS_ENCAPSULATION; 744 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 745 return FLOW_DISSECT_RET_OUT_GOOD; 746 747 return FLOW_DISSECT_RET_PROTO_AGAIN; 748} 749 750/** 751 * __skb_flow_dissect_batadv() - dissect batman-adv header 752 * @skb: sk_buff to with the batman-adv header 753 * @key_control: flow dissectors control key 754 * @data: raw buffer pointer to the packet, if NULL use skb->data 755 * @p_proto: pointer used to update the protocol to process next 756 * @p_nhoff: pointer used to update inner network header offset 757 * @hlen: packet header length 758 * @flags: any combination of FLOW_DISSECTOR_F_* 759 * 760 * ETH_P_BATMAN packets are tried to be dissected. Only 761 * &struct batadv_unicast packets are actually processed because they contain an 762 * inner ethernet header and are usually followed by actual network header. This 763 * allows the flow dissector to continue processing the packet. 764 * 765 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, 766 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, 767 * otherwise FLOW_DISSECT_RET_OUT_BAD 768 */ 769static enum flow_dissect_ret 770__skb_flow_dissect_batadv(const struct sk_buff *skb, 771 struct flow_dissector_key_control *key_control, 772 const void *data, __be16 *p_proto, int *p_nhoff, 773 int hlen, unsigned int flags) 774{ 775 struct { 776 struct batadv_unicast_packet batadv_unicast; 777 struct ethhdr eth; 778 } *hdr, _hdr; 779 780 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen, 781 &_hdr); 782 if (!hdr) 783 return FLOW_DISSECT_RET_OUT_BAD; 784 785 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) 786 return FLOW_DISSECT_RET_OUT_BAD; 787 788 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) 789 return FLOW_DISSECT_RET_OUT_BAD; 790 791 *p_proto = hdr->eth.h_proto; 792 *p_nhoff += sizeof(*hdr); 793 794 key_control->flags |= FLOW_DIS_ENCAPSULATION; 795 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 796 return FLOW_DISSECT_RET_OUT_GOOD; 797 798 return FLOW_DISSECT_RET_PROTO_AGAIN; 799} 800 801static void 802__skb_flow_dissect_tcp(const struct sk_buff *skb, 803 struct flow_dissector *flow_dissector, 804 void *target_container, const void *data, 805 int thoff, int hlen) 806{ 807 struct flow_dissector_key_tcp *key_tcp; 808 struct tcphdr *th, _th; 809 810 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP)) 811 return; 812 813 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th); 814 if (!th) 815 return; 816 817 if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) 818 return; 819 820 key_tcp = skb_flow_dissector_target(flow_dissector, 821 FLOW_DISSECTOR_KEY_TCP, 822 target_container); 823 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); 824} 825 826static void 827__skb_flow_dissect_ports(const struct sk_buff *skb, 828 struct flow_dissector *flow_dissector, 829 void *target_container, const void *data, 830 int nhoff, u8 ip_proto, int hlen) 831{ 832 enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX; 833 struct flow_dissector_key_ports *key_ports; 834 835 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 836 dissector_ports = FLOW_DISSECTOR_KEY_PORTS; 837 else if (dissector_uses_key(flow_dissector, 838 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 839 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE; 840 841 if (dissector_ports == FLOW_DISSECTOR_KEY_MAX) 842 return; 843 844 key_ports = skb_flow_dissector_target(flow_dissector, 845 dissector_ports, 846 target_container); 847 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 848 data, hlen); 849} 850 851static void 852__skb_flow_dissect_ipv4(const struct sk_buff *skb, 853 struct flow_dissector *flow_dissector, 854 void *target_container, const void *data, 855 const struct iphdr *iph) 856{ 857 struct flow_dissector_key_ip *key_ip; 858 859 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 860 return; 861 862 key_ip = skb_flow_dissector_target(flow_dissector, 863 FLOW_DISSECTOR_KEY_IP, 864 target_container); 865 key_ip->tos = iph->tos; 866 key_ip->ttl = iph->ttl; 867} 868 869static void 870__skb_flow_dissect_ipv6(const struct sk_buff *skb, 871 struct flow_dissector *flow_dissector, 872 void *target_container, const void *data, 873 const struct ipv6hdr *iph) 874{ 875 struct flow_dissector_key_ip *key_ip; 876 877 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 878 return; 879 880 key_ip = skb_flow_dissector_target(flow_dissector, 881 FLOW_DISSECTOR_KEY_IP, 882 target_container); 883 key_ip->tos = ipv6_get_dsfield(iph); 884 key_ip->ttl = iph->hop_limit; 885} 886 887/* Maximum number of protocol headers that can be parsed in 888 * __skb_flow_dissect 889 */ 890#define MAX_FLOW_DISSECT_HDRS 15 891 892static bool skb_flow_dissect_allowed(int *num_hdrs) 893{ 894 ++*num_hdrs; 895 896 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); 897} 898 899static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, 900 struct flow_dissector *flow_dissector, 901 void *target_container) 902{ 903 struct flow_dissector_key_ports *key_ports = NULL; 904 struct flow_dissector_key_control *key_control; 905 struct flow_dissector_key_basic *key_basic; 906 struct flow_dissector_key_addrs *key_addrs; 907 struct flow_dissector_key_tags *key_tags; 908 909 key_control = skb_flow_dissector_target(flow_dissector, 910 FLOW_DISSECTOR_KEY_CONTROL, 911 target_container); 912 key_control->thoff = flow_keys->thoff; 913 if (flow_keys->is_frag) 914 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 915 if (flow_keys->is_first_frag) 916 key_control->flags |= FLOW_DIS_FIRST_FRAG; 917 if (flow_keys->is_encap) 918 key_control->flags |= FLOW_DIS_ENCAPSULATION; 919 920 key_basic = skb_flow_dissector_target(flow_dissector, 921 FLOW_DISSECTOR_KEY_BASIC, 922 target_container); 923 key_basic->n_proto = flow_keys->n_proto; 924 key_basic->ip_proto = flow_keys->ip_proto; 925 926 if (flow_keys->addr_proto == ETH_P_IP && 927 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 928 key_addrs = skb_flow_dissector_target(flow_dissector, 929 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 930 target_container); 931 key_addrs->v4addrs.src = flow_keys->ipv4_src; 932 key_addrs->v4addrs.dst = flow_keys->ipv4_dst; 933 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 934 } else if (flow_keys->addr_proto == ETH_P_IPV6 && 935 dissector_uses_key(flow_dissector, 936 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 937 key_addrs = skb_flow_dissector_target(flow_dissector, 938 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 939 target_container); 940 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, 941 sizeof(key_addrs->v6addrs.src)); 942 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, 943 sizeof(key_addrs->v6addrs.dst)); 944 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 945 } 946 947 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 948 key_ports = skb_flow_dissector_target(flow_dissector, 949 FLOW_DISSECTOR_KEY_PORTS, 950 target_container); 951 else if (dissector_uses_key(flow_dissector, 952 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 953 key_ports = skb_flow_dissector_target(flow_dissector, 954 FLOW_DISSECTOR_KEY_PORTS_RANGE, 955 target_container); 956 957 if (key_ports) { 958 key_ports->src = flow_keys->sport; 959 key_ports->dst = flow_keys->dport; 960 } 961 962 if (dissector_uses_key(flow_dissector, 963 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 964 key_tags = skb_flow_dissector_target(flow_dissector, 965 FLOW_DISSECTOR_KEY_FLOW_LABEL, 966 target_container); 967 key_tags->flow_label = ntohl(flow_keys->flow_label); 968 } 969} 970 971u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 972 __be16 proto, int nhoff, int hlen, unsigned int flags) 973{ 974 struct bpf_flow_keys *flow_keys = ctx->flow_keys; 975 u32 result; 976 977 /* Pass parameters to the BPF program */ 978 memset(flow_keys, 0, sizeof(*flow_keys)); 979 flow_keys->n_proto = proto; 980 flow_keys->nhoff = nhoff; 981 flow_keys->thoff = flow_keys->nhoff; 982 983 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG != 984 (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG); 985 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL != 986 (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 987 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP != 988 (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); 989 flow_keys->flags = flags; 990 991 result = bpf_prog_run_pin_on_cpu(prog, ctx); 992 993 flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen); 994 flow_keys->thoff = clamp_t(u16, flow_keys->thoff, 995 flow_keys->nhoff, hlen); 996 997 return result; 998} 999 1000static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr) 1001{ 1002 return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0; 1003} 1004 1005/** 1006 * __skb_flow_dissect - extract the flow_keys struct and return it 1007 * @net: associated network namespace, derived from @skb if NULL 1008 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 1009 * @flow_dissector: list of keys to dissect 1010 * @target_container: target structure to put dissected values into 1011 * @data: raw buffer pointer to the packet, if NULL use skb->data 1012 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 1013 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 1014 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 1015 * @flags: flags that control the dissection process, e.g. 1016 * FLOW_DISSECTOR_F_STOP_AT_ENCAP. 1017 * 1018 * The function will try to retrieve individual keys into target specified 1019 * by flow_dissector from either the skbuff or a raw buffer specified by the 1020 * rest parameters. 1021 * 1022 * Caller must take care of zeroing target container memory. 1023 */ 1024bool __skb_flow_dissect(const struct net *net, 1025 const struct sk_buff *skb, 1026 struct flow_dissector *flow_dissector, 1027 void *target_container, const void *data, 1028 __be16 proto, int nhoff, int hlen, unsigned int flags) 1029{ 1030 struct flow_dissector_key_control *key_control; 1031 struct flow_dissector_key_basic *key_basic; 1032 struct flow_dissector_key_addrs *key_addrs; 1033 struct flow_dissector_key_tags *key_tags; 1034 struct flow_dissector_key_vlan *key_vlan; 1035 enum flow_dissect_ret fdret; 1036 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; 1037 bool mpls_el = false; 1038 int mpls_lse = 0; 1039 int num_hdrs = 0; 1040 u8 ip_proto = 0; 1041 bool ret; 1042 1043 if (!data) { 1044 data = skb->data; 1045 proto = skb_vlan_tag_present(skb) ? 1046 skb->vlan_proto : skb->protocol; 1047 nhoff = skb_network_offset(skb); 1048 hlen = skb_headlen(skb); 1049#if IS_ENABLED(CONFIG_NET_DSA) 1050 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) && 1051 proto == htons(ETH_P_XDSA))) { 1052 struct metadata_dst *md_dst = skb_metadata_dst(skb); 1053 const struct dsa_device_ops *ops; 1054 int offset = 0; 1055 1056 ops = skb->dev->dsa_ptr->tag_ops; 1057 /* Only DSA header taggers break flow dissection */ 1058 if (ops->needed_headroom && 1059 (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) { 1060 if (ops->flow_dissect) 1061 ops->flow_dissect(skb, &proto, &offset); 1062 else 1063 dsa_tag_generic_flow_dissect(skb, 1064 &proto, 1065 &offset); 1066 hlen -= offset; 1067 nhoff += offset; 1068 } 1069 } 1070#endif 1071 } 1072 1073 /* It is ensured by skb_flow_dissector_init() that control key will 1074 * be always present. 1075 */ 1076 key_control = skb_flow_dissector_target(flow_dissector, 1077 FLOW_DISSECTOR_KEY_CONTROL, 1078 target_container); 1079 1080 /* It is ensured by skb_flow_dissector_init() that basic key will 1081 * be always present. 1082 */ 1083 key_basic = skb_flow_dissector_target(flow_dissector, 1084 FLOW_DISSECTOR_KEY_BASIC, 1085 target_container); 1086 1087 if (skb) { 1088 if (!net) { 1089 if (skb->dev) 1090 net = dev_net(skb->dev); 1091 else if (skb->sk) 1092 net = sock_net(skb->sk); 1093 } 1094 } 1095 1096 WARN_ON_ONCE(!net); 1097 if (net) { 1098 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; 1099 struct bpf_prog_array *run_array; 1100 1101 rcu_read_lock(); 1102 run_array = rcu_dereference(init_net.bpf.run_array[type]); 1103 if (!run_array) 1104 run_array = rcu_dereference(net->bpf.run_array[type]); 1105 1106 if (run_array) { 1107 struct bpf_flow_keys flow_keys; 1108 struct bpf_flow_dissector ctx = { 1109 .flow_keys = &flow_keys, 1110 .data = data, 1111 .data_end = data + hlen, 1112 }; 1113 __be16 n_proto = proto; 1114 struct bpf_prog *prog; 1115 u32 result; 1116 1117 if (skb) { 1118 ctx.skb = skb; 1119 /* we can't use 'proto' in the skb case 1120 * because it might be set to skb->vlan_proto 1121 * which has been pulled from the data 1122 */ 1123 n_proto = skb->protocol; 1124 } 1125 1126 prog = READ_ONCE(run_array->items[0].prog); 1127 result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff, 1128 hlen, flags); 1129 if (result == BPF_FLOW_DISSECTOR_CONTINUE) 1130 goto dissect_continue; 1131 __skb_flow_bpf_to_target(&flow_keys, flow_dissector, 1132 target_container); 1133 rcu_read_unlock(); 1134 return result == BPF_OK; 1135 } 1136dissect_continue: 1137 rcu_read_unlock(); 1138 } 1139 1140 if (dissector_uses_key(flow_dissector, 1141 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 1142 struct ethhdr *eth = eth_hdr(skb); 1143 struct flow_dissector_key_eth_addrs *key_eth_addrs; 1144 1145 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 1146 FLOW_DISSECTOR_KEY_ETH_ADDRS, 1147 target_container); 1148 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs)); 1149 } 1150 1151 if (dissector_uses_key(flow_dissector, 1152 FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) { 1153 struct flow_dissector_key_num_of_vlans *key_num_of_vlans; 1154 1155 key_num_of_vlans = skb_flow_dissector_target(flow_dissector, 1156 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1157 target_container); 1158 key_num_of_vlans->num_of_vlans = 0; 1159 } 1160 1161proto_again: 1162 fdret = FLOW_DISSECT_RET_CONTINUE; 1163 1164 switch (proto) { 1165 case htons(ETH_P_IP): { 1166 const struct iphdr *iph; 1167 struct iphdr _iph; 1168 1169 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1170 if (!iph || iph->ihl < 5) { 1171 fdret = FLOW_DISSECT_RET_OUT_BAD; 1172 break; 1173 } 1174 1175 nhoff += iph->ihl * 4; 1176 1177 ip_proto = iph->protocol; 1178 1179 if (dissector_uses_key(flow_dissector, 1180 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 1181 key_addrs = skb_flow_dissector_target(flow_dissector, 1182 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1183 target_container); 1184 1185 memcpy(&key_addrs->v4addrs.src, &iph->saddr, 1186 sizeof(key_addrs->v4addrs.src)); 1187 memcpy(&key_addrs->v4addrs.dst, &iph->daddr, 1188 sizeof(key_addrs->v4addrs.dst)); 1189 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1190 } 1191 1192 __skb_flow_dissect_ipv4(skb, flow_dissector, 1193 target_container, data, iph); 1194 1195 if (ip_is_fragment(iph)) { 1196 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1197 1198 if (iph->frag_off & htons(IP_OFFSET)) { 1199 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1200 break; 1201 } else { 1202 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1203 if (!(flags & 1204 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { 1205 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1206 break; 1207 } 1208 } 1209 } 1210 1211 break; 1212 } 1213 case htons(ETH_P_IPV6): { 1214 const struct ipv6hdr *iph; 1215 struct ipv6hdr _iph; 1216 1217 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1218 if (!iph) { 1219 fdret = FLOW_DISSECT_RET_OUT_BAD; 1220 break; 1221 } 1222 1223 ip_proto = iph->nexthdr; 1224 nhoff += sizeof(struct ipv6hdr); 1225 1226 if (dissector_uses_key(flow_dissector, 1227 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 1228 key_addrs = skb_flow_dissector_target(flow_dissector, 1229 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1230 target_container); 1231 1232 memcpy(&key_addrs->v6addrs.src, &iph->saddr, 1233 sizeof(key_addrs->v6addrs.src)); 1234 memcpy(&key_addrs->v6addrs.dst, &iph->daddr, 1235 sizeof(key_addrs->v6addrs.dst)); 1236 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1237 } 1238 1239 if ((dissector_uses_key(flow_dissector, 1240 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 1241 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 1242 ip6_flowlabel(iph)) { 1243 __be32 flow_label = ip6_flowlabel(iph); 1244 1245 if (dissector_uses_key(flow_dissector, 1246 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 1247 key_tags = skb_flow_dissector_target(flow_dissector, 1248 FLOW_DISSECTOR_KEY_FLOW_LABEL, 1249 target_container); 1250 key_tags->flow_label = ntohl(flow_label); 1251 } 1252 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { 1253 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1254 break; 1255 } 1256 } 1257 1258 __skb_flow_dissect_ipv6(skb, flow_dissector, 1259 target_container, data, iph); 1260 1261 break; 1262 } 1263 case htons(ETH_P_8021AD): 1264 case htons(ETH_P_8021Q): { 1265 const struct vlan_hdr *vlan = NULL; 1266 struct vlan_hdr _vlan; 1267 __be16 saved_vlan_tpid = proto; 1268 1269 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && 1270 skb && skb_vlan_tag_present(skb)) { 1271 proto = skb->protocol; 1272 } else { 1273 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), 1274 data, hlen, &_vlan); 1275 if (!vlan) { 1276 fdret = FLOW_DISSECT_RET_OUT_BAD; 1277 break; 1278 } 1279 1280 proto = vlan->h_vlan_encapsulated_proto; 1281 nhoff += sizeof(*vlan); 1282 } 1283 1284 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) && 1285 !(key_control->flags & FLOW_DIS_ENCAPSULATION)) { 1286 struct flow_dissector_key_num_of_vlans *key_nvs; 1287 1288 key_nvs = skb_flow_dissector_target(flow_dissector, 1289 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1290 target_container); 1291 key_nvs->num_of_vlans++; 1292 } 1293 1294 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { 1295 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; 1296 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { 1297 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; 1298 } else { 1299 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1300 break; 1301 } 1302 1303 if (dissector_uses_key(flow_dissector, dissector_vlan)) { 1304 key_vlan = skb_flow_dissector_target(flow_dissector, 1305 dissector_vlan, 1306 target_container); 1307 1308 if (!vlan) { 1309 key_vlan->vlan_id = skb_vlan_tag_get_id(skb); 1310 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb); 1311 } else { 1312 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & 1313 VLAN_VID_MASK; 1314 key_vlan->vlan_priority = 1315 (ntohs(vlan->h_vlan_TCI) & 1316 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 1317 } 1318 key_vlan->vlan_tpid = saved_vlan_tpid; 1319 key_vlan->vlan_eth_type = proto; 1320 } 1321 1322 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1323 break; 1324 } 1325 case htons(ETH_P_PPP_SES): { 1326 struct { 1327 struct pppoe_hdr hdr; 1328 __be16 proto; 1329 } *hdr, _hdr; 1330 u16 ppp_proto; 1331 1332 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 1333 if (!hdr) { 1334 fdret = FLOW_DISSECT_RET_OUT_BAD; 1335 break; 1336 } 1337 1338 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) { 1339 fdret = FLOW_DISSECT_RET_OUT_BAD; 1340 break; 1341 } 1342 1343 /* least significant bit of the most significant octet 1344 * indicates if protocol field was compressed 1345 */ 1346 ppp_proto = ntohs(hdr->proto); 1347 if (ppp_proto & 0x0100) { 1348 ppp_proto = ppp_proto >> 8; 1349 nhoff += PPPOE_SES_HLEN - 1; 1350 } else { 1351 nhoff += PPPOE_SES_HLEN; 1352 } 1353 1354 if (ppp_proto == PPP_IP) { 1355 proto = htons(ETH_P_IP); 1356 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1357 } else if (ppp_proto == PPP_IPV6) { 1358 proto = htons(ETH_P_IPV6); 1359 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1360 } else if (ppp_proto == PPP_MPLS_UC) { 1361 proto = htons(ETH_P_MPLS_UC); 1362 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1363 } else if (ppp_proto == PPP_MPLS_MC) { 1364 proto = htons(ETH_P_MPLS_MC); 1365 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1366 } else if (ppp_proto_is_valid(ppp_proto)) { 1367 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1368 } else { 1369 fdret = FLOW_DISSECT_RET_OUT_BAD; 1370 break; 1371 } 1372 1373 if (dissector_uses_key(flow_dissector, 1374 FLOW_DISSECTOR_KEY_PPPOE)) { 1375 struct flow_dissector_key_pppoe *key_pppoe; 1376 1377 key_pppoe = skb_flow_dissector_target(flow_dissector, 1378 FLOW_DISSECTOR_KEY_PPPOE, 1379 target_container); 1380 key_pppoe->session_id = hdr->hdr.sid; 1381 key_pppoe->ppp_proto = htons(ppp_proto); 1382 key_pppoe->type = htons(ETH_P_PPP_SES); 1383 } 1384 break; 1385 } 1386 case htons(ETH_P_TIPC): { 1387 struct tipc_basic_hdr *hdr, _hdr; 1388 1389 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), 1390 data, hlen, &_hdr); 1391 if (!hdr) { 1392 fdret = FLOW_DISSECT_RET_OUT_BAD; 1393 break; 1394 } 1395 1396 if (dissector_uses_key(flow_dissector, 1397 FLOW_DISSECTOR_KEY_TIPC)) { 1398 key_addrs = skb_flow_dissector_target(flow_dissector, 1399 FLOW_DISSECTOR_KEY_TIPC, 1400 target_container); 1401 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); 1402 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; 1403 } 1404 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1405 break; 1406 } 1407 1408 case htons(ETH_P_MPLS_UC): 1409 case htons(ETH_P_MPLS_MC): 1410 fdret = __skb_flow_dissect_mpls(skb, flow_dissector, 1411 target_container, data, 1412 nhoff, hlen, mpls_lse, 1413 &mpls_el); 1414 nhoff += sizeof(struct mpls_label); 1415 mpls_lse++; 1416 break; 1417 case htons(ETH_P_FCOE): 1418 if ((hlen - nhoff) < FCOE_HEADER_LEN) { 1419 fdret = FLOW_DISSECT_RET_OUT_BAD; 1420 break; 1421 } 1422 1423 nhoff += FCOE_HEADER_LEN; 1424 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1425 break; 1426 1427 case htons(ETH_P_ARP): 1428 case htons(ETH_P_RARP): 1429 fdret = __skb_flow_dissect_arp(skb, flow_dissector, 1430 target_container, data, 1431 nhoff, hlen); 1432 break; 1433 1434 case htons(ETH_P_BATMAN): 1435 fdret = __skb_flow_dissect_batadv(skb, key_control, data, 1436 &proto, &nhoff, hlen, flags); 1437 break; 1438 1439 case htons(ETH_P_1588): { 1440 struct ptp_header *hdr, _hdr; 1441 1442 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 1443 hlen, &_hdr); 1444 if (!hdr) { 1445 fdret = FLOW_DISSECT_RET_OUT_BAD; 1446 break; 1447 } 1448 1449 nhoff += sizeof(struct ptp_header); 1450 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1451 break; 1452 } 1453 1454 case htons(ETH_P_PRP): 1455 case htons(ETH_P_HSR): { 1456 struct hsr_tag *hdr, _hdr; 1457 1458 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, 1459 &_hdr); 1460 if (!hdr) { 1461 fdret = FLOW_DISSECT_RET_OUT_BAD; 1462 break; 1463 } 1464 1465 proto = hdr->encap_proto; 1466 nhoff += HSR_HLEN; 1467 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1468 break; 1469 } 1470 1471 case htons(ETH_P_CFM): 1472 fdret = __skb_flow_dissect_cfm(skb, flow_dissector, 1473 target_container, data, 1474 nhoff, hlen); 1475 break; 1476 1477 default: 1478 fdret = FLOW_DISSECT_RET_OUT_BAD; 1479 break; 1480 } 1481 1482 /* Process result of proto processing */ 1483 switch (fdret) { 1484 case FLOW_DISSECT_RET_OUT_GOOD: 1485 goto out_good; 1486 case FLOW_DISSECT_RET_PROTO_AGAIN: 1487 if (skb_flow_dissect_allowed(&num_hdrs)) 1488 goto proto_again; 1489 goto out_good; 1490 case FLOW_DISSECT_RET_CONTINUE: 1491 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1492 break; 1493 case FLOW_DISSECT_RET_OUT_BAD: 1494 default: 1495 goto out_bad; 1496 } 1497 1498ip_proto_again: 1499 fdret = FLOW_DISSECT_RET_CONTINUE; 1500 1501 switch (ip_proto) { 1502 case IPPROTO_GRE: 1503 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1504 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1505 break; 1506 } 1507 1508 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, 1509 target_container, data, 1510 &proto, &nhoff, &hlen, flags); 1511 break; 1512 1513 case NEXTHDR_HOP: 1514 case NEXTHDR_ROUTING: 1515 case NEXTHDR_DEST: { 1516 u8 _opthdr[2], *opthdr; 1517 1518 if (proto != htons(ETH_P_IPV6)) 1519 break; 1520 1521 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 1522 data, hlen, &_opthdr); 1523 if (!opthdr) { 1524 fdret = FLOW_DISSECT_RET_OUT_BAD; 1525 break; 1526 } 1527 1528 ip_proto = opthdr[0]; 1529 nhoff += (opthdr[1] + 1) << 3; 1530 1531 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1532 break; 1533 } 1534 case NEXTHDR_FRAGMENT: { 1535 struct frag_hdr _fh, *fh; 1536 1537 if (proto != htons(ETH_P_IPV6)) 1538 break; 1539 1540 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 1541 data, hlen, &_fh); 1542 1543 if (!fh) { 1544 fdret = FLOW_DISSECT_RET_OUT_BAD; 1545 break; 1546 } 1547 1548 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1549 1550 nhoff += sizeof(_fh); 1551 ip_proto = fh->nexthdr; 1552 1553 if (!(fh->frag_off & htons(IP6_OFFSET))) { 1554 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1555 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { 1556 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1557 break; 1558 } 1559 } 1560 1561 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1562 break; 1563 } 1564 case IPPROTO_IPIP: 1565 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1566 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1567 break; 1568 } 1569 1570 proto = htons(ETH_P_IP); 1571 1572 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1573 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1574 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1575 break; 1576 } 1577 1578 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1579 break; 1580 1581 case IPPROTO_IPV6: 1582 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1583 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1584 break; 1585 } 1586 1587 proto = htons(ETH_P_IPV6); 1588 1589 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1590 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1591 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1592 break; 1593 } 1594 1595 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1596 break; 1597 1598 1599 case IPPROTO_MPLS: 1600 proto = htons(ETH_P_MPLS_UC); 1601 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1602 break; 1603 1604 case IPPROTO_TCP: 1605 __skb_flow_dissect_tcp(skb, flow_dissector, target_container, 1606 data, nhoff, hlen); 1607 break; 1608 1609 case IPPROTO_ICMP: 1610 case IPPROTO_ICMPV6: 1611 __skb_flow_dissect_icmp(skb, flow_dissector, target_container, 1612 data, nhoff, hlen); 1613 break; 1614 case IPPROTO_L2TP: 1615 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container, 1616 data, nhoff, hlen); 1617 break; 1618 case IPPROTO_ESP: 1619 __skb_flow_dissect_esp(skb, flow_dissector, target_container, 1620 data, nhoff, hlen); 1621 break; 1622 case IPPROTO_AH: 1623 __skb_flow_dissect_ah(skb, flow_dissector, target_container, 1624 data, nhoff, hlen); 1625 break; 1626 default: 1627 break; 1628 } 1629 1630 if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT)) 1631 __skb_flow_dissect_ports(skb, flow_dissector, target_container, 1632 data, nhoff, ip_proto, hlen); 1633 1634 /* Process result of IP proto processing */ 1635 switch (fdret) { 1636 case FLOW_DISSECT_RET_PROTO_AGAIN: 1637 if (skb_flow_dissect_allowed(&num_hdrs)) 1638 goto proto_again; 1639 break; 1640 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1641 if (skb_flow_dissect_allowed(&num_hdrs)) 1642 goto ip_proto_again; 1643 break; 1644 case FLOW_DISSECT_RET_OUT_GOOD: 1645 case FLOW_DISSECT_RET_CONTINUE: 1646 break; 1647 case FLOW_DISSECT_RET_OUT_BAD: 1648 default: 1649 goto out_bad; 1650 } 1651 1652out_good: 1653 ret = true; 1654 1655out: 1656 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); 1657 key_basic->n_proto = proto; 1658 key_basic->ip_proto = ip_proto; 1659 1660 return ret; 1661 1662out_bad: 1663 ret = false; 1664 goto out; 1665} 1666EXPORT_SYMBOL(__skb_flow_dissect); 1667 1668static siphash_aligned_key_t hashrnd; 1669static __always_inline void __flow_hash_secret_init(void) 1670{ 1671 net_get_random_once(&hashrnd, sizeof(hashrnd)); 1672} 1673 1674static const void *flow_keys_hash_start(const struct flow_keys *flow) 1675{ 1676 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT); 1677 return &flow->FLOW_KEYS_HASH_START_FIELD; 1678} 1679 1680static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 1681{ 1682 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 1683 1684 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 1685 1686 switch (flow->control.addr_type) { 1687 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1688 diff -= sizeof(flow->addrs.v4addrs); 1689 break; 1690 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1691 diff -= sizeof(flow->addrs.v6addrs); 1692 break; 1693 case FLOW_DISSECTOR_KEY_TIPC: 1694 diff -= sizeof(flow->addrs.tipckey); 1695 break; 1696 } 1697 return sizeof(*flow) - diff; 1698} 1699 1700__be32 flow_get_u32_src(const struct flow_keys *flow) 1701{ 1702 switch (flow->control.addr_type) { 1703 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1704 return flow->addrs.v4addrs.src; 1705 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1706 return (__force __be32)ipv6_addr_hash( 1707 &flow->addrs.v6addrs.src); 1708 case FLOW_DISSECTOR_KEY_TIPC: 1709 return flow->addrs.tipckey.key; 1710 default: 1711 return 0; 1712 } 1713} 1714EXPORT_SYMBOL(flow_get_u32_src); 1715 1716__be32 flow_get_u32_dst(const struct flow_keys *flow) 1717{ 1718 switch (flow->control.addr_type) { 1719 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1720 return flow->addrs.v4addrs.dst; 1721 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1722 return (__force __be32)ipv6_addr_hash( 1723 &flow->addrs.v6addrs.dst); 1724 default: 1725 return 0; 1726 } 1727} 1728EXPORT_SYMBOL(flow_get_u32_dst); 1729 1730/* Sort the source and destination IP and the ports, 1731 * to have consistent hash within the two directions 1732 */ 1733static inline void __flow_hash_consistentify(struct flow_keys *keys) 1734{ 1735 int addr_diff, i; 1736 1737 switch (keys->control.addr_type) { 1738 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1739 if ((__force u32)keys->addrs.v4addrs.dst < 1740 (__force u32)keys->addrs.v4addrs.src) 1741 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 1742 1743 if ((__force u16)keys->ports.dst < 1744 (__force u16)keys->ports.src) { 1745 swap(keys->ports.src, keys->ports.dst); 1746 } 1747 break; 1748 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1749 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 1750 &keys->addrs.v6addrs.src, 1751 sizeof(keys->addrs.v6addrs.dst)); 1752 if (addr_diff < 0) { 1753 for (i = 0; i < 4; i++) 1754 swap(keys->addrs.v6addrs.src.s6_addr32[i], 1755 keys->addrs.v6addrs.dst.s6_addr32[i]); 1756 } 1757 if ((__force u16)keys->ports.dst < 1758 (__force u16)keys->ports.src) { 1759 swap(keys->ports.src, keys->ports.dst); 1760 } 1761 break; 1762 } 1763} 1764 1765static inline u32 __flow_hash_from_keys(struct flow_keys *keys, 1766 const siphash_key_t *keyval) 1767{ 1768 u32 hash; 1769 1770 __flow_hash_consistentify(keys); 1771 1772 hash = siphash(flow_keys_hash_start(keys), 1773 flow_keys_hash_length(keys), keyval); 1774 if (!hash) 1775 hash = 1; 1776 1777 return hash; 1778} 1779 1780u32 flow_hash_from_keys(struct flow_keys *keys) 1781{ 1782 __flow_hash_secret_init(); 1783 return __flow_hash_from_keys(keys, &hashrnd); 1784} 1785EXPORT_SYMBOL(flow_hash_from_keys); 1786 1787static inline u32 ___skb_get_hash(const struct sk_buff *skb, 1788 struct flow_keys *keys, 1789 const siphash_key_t *keyval) 1790{ 1791 skb_flow_dissect_flow_keys(skb, keys, 1792 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1793 1794 return __flow_hash_from_keys(keys, keyval); 1795} 1796 1797struct _flow_keys_digest_data { 1798 __be16 n_proto; 1799 u8 ip_proto; 1800 u8 padding; 1801 __be32 ports; 1802 __be32 src; 1803 __be32 dst; 1804}; 1805 1806void make_flow_keys_digest(struct flow_keys_digest *digest, 1807 const struct flow_keys *flow) 1808{ 1809 struct _flow_keys_digest_data *data = 1810 (struct _flow_keys_digest_data *)digest; 1811 1812 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 1813 1814 memset(digest, 0, sizeof(*digest)); 1815 1816 data->n_proto = flow->basic.n_proto; 1817 data->ip_proto = flow->basic.ip_proto; 1818 data->ports = flow->ports.ports; 1819 data->src = flow->addrs.v4addrs.src; 1820 data->dst = flow->addrs.v4addrs.dst; 1821} 1822EXPORT_SYMBOL(make_flow_keys_digest); 1823 1824static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; 1825 1826u32 __skb_get_hash_symmetric(const struct sk_buff *skb) 1827{ 1828 struct flow_keys keys; 1829 1830 __flow_hash_secret_init(); 1831 1832 memset(&keys, 0, sizeof(keys)); 1833 __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric, 1834 &keys, NULL, 0, 0, 0, 0); 1835 1836 return __flow_hash_from_keys(&keys, &hashrnd); 1837} 1838EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); 1839 1840/** 1841 * __skb_get_hash: calculate a flow hash 1842 * @skb: sk_buff to calculate flow hash from 1843 * 1844 * This function calculates a flow hash based on src/dst addresses 1845 * and src/dst port numbers. Sets hash in skb to non-zero hash value 1846 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 1847 * if hash is a canonical 4-tuple hash over transport ports. 1848 */ 1849void __skb_get_hash(struct sk_buff *skb) 1850{ 1851 struct flow_keys keys; 1852 u32 hash; 1853 1854 __flow_hash_secret_init(); 1855 1856 hash = ___skb_get_hash(skb, &keys, &hashrnd); 1857 1858 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1859} 1860EXPORT_SYMBOL(__skb_get_hash); 1861 1862__u32 skb_get_hash_perturb(const struct sk_buff *skb, 1863 const siphash_key_t *perturb) 1864{ 1865 struct flow_keys keys; 1866 1867 return ___skb_get_hash(skb, &keys, perturb); 1868} 1869EXPORT_SYMBOL(skb_get_hash_perturb); 1870 1871u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1872 const struct flow_keys_basic *keys, int hlen) 1873{ 1874 u32 poff = keys->control.thoff; 1875 1876 /* skip L4 headers for fragments after the first */ 1877 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && 1878 !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) 1879 return poff; 1880 1881 switch (keys->basic.ip_proto) { 1882 case IPPROTO_TCP: { 1883 /* access doff as u8 to avoid unaligned access */ 1884 const u8 *doff; 1885 u8 _doff; 1886 1887 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 1888 data, hlen, &_doff); 1889 if (!doff) 1890 return poff; 1891 1892 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 1893 break; 1894 } 1895 case IPPROTO_UDP: 1896 case IPPROTO_UDPLITE: 1897 poff += sizeof(struct udphdr); 1898 break; 1899 /* For the rest, we do not really care about header 1900 * extensions at this point for now. 1901 */ 1902 case IPPROTO_ICMP: 1903 poff += sizeof(struct icmphdr); 1904 break; 1905 case IPPROTO_ICMPV6: 1906 poff += sizeof(struct icmp6hdr); 1907 break; 1908 case IPPROTO_IGMP: 1909 poff += sizeof(struct igmphdr); 1910 break; 1911 case IPPROTO_DCCP: 1912 poff += sizeof(struct dccp_hdr); 1913 break; 1914 case IPPROTO_SCTP: 1915 poff += sizeof(struct sctphdr); 1916 break; 1917 } 1918 1919 return poff; 1920} 1921 1922/** 1923 * skb_get_poff - get the offset to the payload 1924 * @skb: sk_buff to get the payload offset from 1925 * 1926 * The function will get the offset to the payload as far as it could 1927 * be dissected. The main user is currently BPF, so that we can dynamically 1928 * truncate packets without needing to push actual payload to the user 1929 * space and can analyze headers only, instead. 1930 */ 1931u32 skb_get_poff(const struct sk_buff *skb) 1932{ 1933 struct flow_keys_basic keys; 1934 1935 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 1936 NULL, 0, 0, 0, 0)) 1937 return 0; 1938 1939 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 1940} 1941 1942__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 1943{ 1944 memset(keys, 0, sizeof(*keys)); 1945 1946 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 1947 sizeof(keys->addrs.v6addrs.src)); 1948 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 1949 sizeof(keys->addrs.v6addrs.dst)); 1950 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1951 keys->ports.src = fl6->fl6_sport; 1952 keys->ports.dst = fl6->fl6_dport; 1953 keys->keyid.keyid = fl6->fl6_gre_key; 1954 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 1955 keys->basic.ip_proto = fl6->flowi6_proto; 1956 1957 return flow_hash_from_keys(keys); 1958} 1959EXPORT_SYMBOL(__get_hash_from_flowi6); 1960 1961static const struct flow_dissector_key flow_keys_dissector_keys[] = { 1962 { 1963 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1964 .offset = offsetof(struct flow_keys, control), 1965 }, 1966 { 1967 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1968 .offset = offsetof(struct flow_keys, basic), 1969 }, 1970 { 1971 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1972 .offset = offsetof(struct flow_keys, addrs.v4addrs), 1973 }, 1974 { 1975 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1976 .offset = offsetof(struct flow_keys, addrs.v6addrs), 1977 }, 1978 { 1979 .key_id = FLOW_DISSECTOR_KEY_TIPC, 1980 .offset = offsetof(struct flow_keys, addrs.tipckey), 1981 }, 1982 { 1983 .key_id = FLOW_DISSECTOR_KEY_PORTS, 1984 .offset = offsetof(struct flow_keys, ports), 1985 }, 1986 { 1987 .key_id = FLOW_DISSECTOR_KEY_VLAN, 1988 .offset = offsetof(struct flow_keys, vlan), 1989 }, 1990 { 1991 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 1992 .offset = offsetof(struct flow_keys, tags), 1993 }, 1994 { 1995 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 1996 .offset = offsetof(struct flow_keys, keyid), 1997 }, 1998}; 1999 2000static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { 2001 { 2002 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2003 .offset = offsetof(struct flow_keys, control), 2004 }, 2005 { 2006 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2007 .offset = offsetof(struct flow_keys, basic), 2008 }, 2009 { 2010 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 2011 .offset = offsetof(struct flow_keys, addrs.v4addrs), 2012 }, 2013 { 2014 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 2015 .offset = offsetof(struct flow_keys, addrs.v6addrs), 2016 }, 2017 { 2018 .key_id = FLOW_DISSECTOR_KEY_PORTS, 2019 .offset = offsetof(struct flow_keys, ports), 2020 }, 2021}; 2022 2023static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { 2024 { 2025 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2026 .offset = offsetof(struct flow_keys, control), 2027 }, 2028 { 2029 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2030 .offset = offsetof(struct flow_keys, basic), 2031 }, 2032}; 2033 2034struct flow_dissector flow_keys_dissector __read_mostly; 2035EXPORT_SYMBOL(flow_keys_dissector); 2036 2037struct flow_dissector flow_keys_basic_dissector __read_mostly; 2038EXPORT_SYMBOL(flow_keys_basic_dissector); 2039 2040static int __init init_default_flow_dissectors(void) 2041{ 2042 skb_flow_dissector_init(&flow_keys_dissector, 2043 flow_keys_dissector_keys, 2044 ARRAY_SIZE(flow_keys_dissector_keys)); 2045 skb_flow_dissector_init(&flow_keys_dissector_symmetric, 2046 flow_keys_dissector_symmetric_keys, 2047 ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); 2048 skb_flow_dissector_init(&flow_keys_basic_dissector, 2049 flow_keys_basic_dissector_keys, 2050 ARRAY_SIZE(flow_keys_basic_dissector_keys)); 2051 return 0; 2052} 2053core_initcall(init_default_flow_dissectors); 2054