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