1 #include <linux/kernel.h> 2 #include <linux/skbuff.h> 3 #include <linux/export.h> 4 #include <linux/ip.h> 5 #include <linux/ipv6.h> 6 #include <linux/if_vlan.h> 7 #include <net/dsa.h> 8 #include <net/dst_metadata.h> 9 #include <net/ip.h> 10 #include <net/ipv6.h> 11 #include <net/gre.h> 12 #include <net/pptp.h> 13 #include <net/tipc.h> 14 #include <linux/igmp.h> 15 #include <linux/icmp.h> 16 #include <linux/sctp.h> 17 #include <linux/dccp.h> 18 #include <linux/if_tunnel.h> 19 #include <linux/if_pppox.h> 20 #include <linux/ppp_defs.h> 21 #include <linux/stddef.h> 22 #include <linux/if_ether.h> 23 #include <linux/mpls.h> 24 #include <linux/tcp.h> 25 #include <net/flow_dissector.h> 26 #include <scsi/fc/fc_fcoe.h> 27 #include <uapi/linux/batadv_packet.h> 28 29 static void dissector_set_key(struct flow_dissector *flow_dissector, 30 enum flow_dissector_key_id key_id) 31 { 32 flow_dissector->used_keys |= (1 << key_id); 33 } 34 35 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 36 const struct flow_dissector_key *key, 37 unsigned int key_count) 38 { 39 unsigned int i; 40 41 memset(flow_dissector, 0, sizeof(*flow_dissector)); 42 43 for (i = 0; i < key_count; i++, key++) { 44 /* User should make sure that every key target offset is withing 45 * boundaries of unsigned short. 46 */ 47 BUG_ON(key->offset > USHRT_MAX); 48 BUG_ON(dissector_uses_key(flow_dissector, 49 key->key_id)); 50 51 dissector_set_key(flow_dissector, key->key_id); 52 flow_dissector->offset[key->key_id] = key->offset; 53 } 54 55 /* Ensure that the dissector always includes control and basic key. 56 * That way we are able to avoid handling lack of these in fast path. 57 */ 58 BUG_ON(!dissector_uses_key(flow_dissector, 59 FLOW_DISSECTOR_KEY_CONTROL)); 60 BUG_ON(!dissector_uses_key(flow_dissector, 61 FLOW_DISSECTOR_KEY_BASIC)); 62 } 63 EXPORT_SYMBOL(skb_flow_dissector_init); 64 65 /** 66 * skb_flow_get_be16 - extract be16 entity 67 * @skb: sk_buff to extract from 68 * @poff: offset to extract at 69 * @data: raw buffer pointer to the packet 70 * @hlen: packet header length 71 * 72 * The function will try to retrieve a be32 entity at 73 * offset poff 74 */ 75 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff, 76 void *data, int hlen) 77 { 78 __be16 *u, _u; 79 80 u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u); 81 if (u) 82 return *u; 83 84 return 0; 85 } 86 87 /** 88 * __skb_flow_get_ports - extract the upper layer ports and return them 89 * @skb: sk_buff to extract the ports from 90 * @thoff: transport header offset 91 * @ip_proto: protocol for which to get port offset 92 * @data: raw buffer pointer to the packet, if NULL use skb->data 93 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 94 * 95 * The function will try to retrieve the ports at offset thoff + poff where poff 96 * is the protocol port offset returned from proto_ports_offset 97 */ 98 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 99 void *data, int hlen) 100 { 101 int poff = proto_ports_offset(ip_proto); 102 103 if (!data) { 104 data = skb->data; 105 hlen = skb_headlen(skb); 106 } 107 108 if (poff >= 0) { 109 __be32 *ports, _ports; 110 111 ports = __skb_header_pointer(skb, thoff + poff, 112 sizeof(_ports), data, hlen, &_ports); 113 if (ports) 114 return *ports; 115 } 116 117 return 0; 118 } 119 EXPORT_SYMBOL(__skb_flow_get_ports); 120 121 static void 122 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type, 123 struct flow_dissector *flow_dissector, 124 void *target_container) 125 { 126 struct flow_dissector_key_control *ctrl; 127 128 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL)) 129 return; 130 131 ctrl = skb_flow_dissector_target(flow_dissector, 132 FLOW_DISSECTOR_KEY_ENC_CONTROL, 133 target_container); 134 ctrl->addr_type = type; 135 } 136 137 void 138 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 139 struct flow_dissector *flow_dissector, 140 void *target_container) 141 { 142 struct ip_tunnel_info *info; 143 struct ip_tunnel_key *key; 144 145 /* A quick check to see if there might be something to do. */ 146 if (!dissector_uses_key(flow_dissector, 147 FLOW_DISSECTOR_KEY_ENC_KEYID) && 148 !dissector_uses_key(flow_dissector, 149 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) && 150 !dissector_uses_key(flow_dissector, 151 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) && 152 !dissector_uses_key(flow_dissector, 153 FLOW_DISSECTOR_KEY_ENC_CONTROL) && 154 !dissector_uses_key(flow_dissector, 155 FLOW_DISSECTOR_KEY_ENC_PORTS) && 156 !dissector_uses_key(flow_dissector, 157 FLOW_DISSECTOR_KEY_ENC_IP) && 158 !dissector_uses_key(flow_dissector, 159 FLOW_DISSECTOR_KEY_ENC_OPTS)) 160 return; 161 162 info = skb_tunnel_info(skb); 163 if (!info) 164 return; 165 166 key = &info->key; 167 168 switch (ip_tunnel_info_af(info)) { 169 case AF_INET: 170 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS, 171 flow_dissector, 172 target_container); 173 if (dissector_uses_key(flow_dissector, 174 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) { 175 struct flow_dissector_key_ipv4_addrs *ipv4; 176 177 ipv4 = skb_flow_dissector_target(flow_dissector, 178 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, 179 target_container); 180 ipv4->src = key->u.ipv4.src; 181 ipv4->dst = key->u.ipv4.dst; 182 } 183 break; 184 case AF_INET6: 185 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS, 186 flow_dissector, 187 target_container); 188 if (dissector_uses_key(flow_dissector, 189 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) { 190 struct flow_dissector_key_ipv6_addrs *ipv6; 191 192 ipv6 = skb_flow_dissector_target(flow_dissector, 193 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, 194 target_container); 195 ipv6->src = key->u.ipv6.src; 196 ipv6->dst = key->u.ipv6.dst; 197 } 198 break; 199 } 200 201 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) { 202 struct flow_dissector_key_keyid *keyid; 203 204 keyid = skb_flow_dissector_target(flow_dissector, 205 FLOW_DISSECTOR_KEY_ENC_KEYID, 206 target_container); 207 keyid->keyid = tunnel_id_to_key32(key->tun_id); 208 } 209 210 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) { 211 struct flow_dissector_key_ports *tp; 212 213 tp = skb_flow_dissector_target(flow_dissector, 214 FLOW_DISSECTOR_KEY_ENC_PORTS, 215 target_container); 216 tp->src = key->tp_src; 217 tp->dst = key->tp_dst; 218 } 219 220 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) { 221 struct flow_dissector_key_ip *ip; 222 223 ip = skb_flow_dissector_target(flow_dissector, 224 FLOW_DISSECTOR_KEY_ENC_IP, 225 target_container); 226 ip->tos = key->tos; 227 ip->ttl = key->ttl; 228 } 229 230 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) { 231 struct flow_dissector_key_enc_opts *enc_opt; 232 233 enc_opt = skb_flow_dissector_target(flow_dissector, 234 FLOW_DISSECTOR_KEY_ENC_OPTS, 235 target_container); 236 237 if (info->options_len) { 238 enc_opt->len = info->options_len; 239 ip_tunnel_info_opts_get(enc_opt->data, info); 240 enc_opt->dst_opt_type = info->key.tun_flags & 241 TUNNEL_OPTIONS_PRESENT; 242 } 243 } 244 } 245 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); 246 247 static enum flow_dissect_ret 248 __skb_flow_dissect_mpls(const struct sk_buff *skb, 249 struct flow_dissector *flow_dissector, 250 void *target_container, void *data, int nhoff, int hlen) 251 { 252 struct flow_dissector_key_keyid *key_keyid; 253 struct mpls_label *hdr, _hdr[2]; 254 u32 entry, label; 255 256 if (!dissector_uses_key(flow_dissector, 257 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && 258 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) 259 return FLOW_DISSECT_RET_OUT_GOOD; 260 261 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 262 hlen, &_hdr); 263 if (!hdr) 264 return FLOW_DISSECT_RET_OUT_BAD; 265 266 entry = ntohl(hdr[0].entry); 267 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; 268 269 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) { 270 struct flow_dissector_key_mpls *key_mpls; 271 272 key_mpls = skb_flow_dissector_target(flow_dissector, 273 FLOW_DISSECTOR_KEY_MPLS, 274 target_container); 275 key_mpls->mpls_label = label; 276 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK) 277 >> MPLS_LS_TTL_SHIFT; 278 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK) 279 >> MPLS_LS_TC_SHIFT; 280 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK) 281 >> MPLS_LS_S_SHIFT; 282 } 283 284 if (label == MPLS_LABEL_ENTROPY) { 285 key_keyid = skb_flow_dissector_target(flow_dissector, 286 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 287 target_container); 288 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK); 289 } 290 return FLOW_DISSECT_RET_OUT_GOOD; 291 } 292 293 static enum flow_dissect_ret 294 __skb_flow_dissect_arp(const struct sk_buff *skb, 295 struct flow_dissector *flow_dissector, 296 void *target_container, void *data, int nhoff, int hlen) 297 { 298 struct flow_dissector_key_arp *key_arp; 299 struct { 300 unsigned char ar_sha[ETH_ALEN]; 301 unsigned char ar_sip[4]; 302 unsigned char ar_tha[ETH_ALEN]; 303 unsigned char ar_tip[4]; 304 } *arp_eth, _arp_eth; 305 const struct arphdr *arp; 306 struct arphdr _arp; 307 308 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP)) 309 return FLOW_DISSECT_RET_OUT_GOOD; 310 311 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, 312 hlen, &_arp); 313 if (!arp) 314 return FLOW_DISSECT_RET_OUT_BAD; 315 316 if (arp->ar_hrd != htons(ARPHRD_ETHER) || 317 arp->ar_pro != htons(ETH_P_IP) || 318 arp->ar_hln != ETH_ALEN || 319 arp->ar_pln != 4 || 320 (arp->ar_op != htons(ARPOP_REPLY) && 321 arp->ar_op != htons(ARPOP_REQUEST))) 322 return FLOW_DISSECT_RET_OUT_BAD; 323 324 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), 325 sizeof(_arp_eth), data, 326 hlen, &_arp_eth); 327 if (!arp_eth) 328 return FLOW_DISSECT_RET_OUT_BAD; 329 330 key_arp = skb_flow_dissector_target(flow_dissector, 331 FLOW_DISSECTOR_KEY_ARP, 332 target_container); 333 334 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); 335 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); 336 337 /* Only store the lower byte of the opcode; 338 * this covers ARPOP_REPLY and ARPOP_REQUEST. 339 */ 340 key_arp->op = ntohs(arp->ar_op) & 0xff; 341 342 ether_addr_copy(key_arp->sha, arp_eth->ar_sha); 343 ether_addr_copy(key_arp->tha, arp_eth->ar_tha); 344 345 return FLOW_DISSECT_RET_OUT_GOOD; 346 } 347 348 static enum flow_dissect_ret 349 __skb_flow_dissect_gre(const struct sk_buff *skb, 350 struct flow_dissector_key_control *key_control, 351 struct flow_dissector *flow_dissector, 352 void *target_container, void *data, 353 __be16 *p_proto, int *p_nhoff, int *p_hlen, 354 unsigned int flags) 355 { 356 struct flow_dissector_key_keyid *key_keyid; 357 struct gre_base_hdr *hdr, _hdr; 358 int offset = 0; 359 u16 gre_ver; 360 361 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), 362 data, *p_hlen, &_hdr); 363 if (!hdr) 364 return FLOW_DISSECT_RET_OUT_BAD; 365 366 /* Only look inside GRE without routing */ 367 if (hdr->flags & GRE_ROUTING) 368 return FLOW_DISSECT_RET_OUT_GOOD; 369 370 /* Only look inside GRE for version 0 and 1 */ 371 gre_ver = ntohs(hdr->flags & GRE_VERSION); 372 if (gre_ver > 1) 373 return FLOW_DISSECT_RET_OUT_GOOD; 374 375 *p_proto = hdr->protocol; 376 if (gre_ver) { 377 /* Version1 must be PPTP, and check the flags */ 378 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) 379 return FLOW_DISSECT_RET_OUT_GOOD; 380 } 381 382 offset += sizeof(struct gre_base_hdr); 383 384 if (hdr->flags & GRE_CSUM) 385 offset += sizeof(((struct gre_full_hdr *) 0)->csum) + 386 sizeof(((struct gre_full_hdr *) 0)->reserved1); 387 388 if (hdr->flags & GRE_KEY) { 389 const __be32 *keyid; 390 __be32 _keyid; 391 392 keyid = __skb_header_pointer(skb, *p_nhoff + offset, 393 sizeof(_keyid), 394 data, *p_hlen, &_keyid); 395 if (!keyid) 396 return FLOW_DISSECT_RET_OUT_BAD; 397 398 if (dissector_uses_key(flow_dissector, 399 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 400 key_keyid = skb_flow_dissector_target(flow_dissector, 401 FLOW_DISSECTOR_KEY_GRE_KEYID, 402 target_container); 403 if (gre_ver == 0) 404 key_keyid->keyid = *keyid; 405 else 406 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; 407 } 408 offset += sizeof(((struct gre_full_hdr *) 0)->key); 409 } 410 411 if (hdr->flags & GRE_SEQ) 412 offset += sizeof(((struct pptp_gre_header *) 0)->seq); 413 414 if (gre_ver == 0) { 415 if (*p_proto == htons(ETH_P_TEB)) { 416 const struct ethhdr *eth; 417 struct ethhdr _eth; 418 419 eth = __skb_header_pointer(skb, *p_nhoff + offset, 420 sizeof(_eth), 421 data, *p_hlen, &_eth); 422 if (!eth) 423 return FLOW_DISSECT_RET_OUT_BAD; 424 *p_proto = eth->h_proto; 425 offset += sizeof(*eth); 426 427 /* Cap headers that we access via pointers at the 428 * end of the Ethernet header as our maximum alignment 429 * at that point is only 2 bytes. 430 */ 431 if (NET_IP_ALIGN) 432 *p_hlen = *p_nhoff + offset; 433 } 434 } else { /* version 1, must be PPTP */ 435 u8 _ppp_hdr[PPP_HDRLEN]; 436 u8 *ppp_hdr; 437 438 if (hdr->flags & GRE_ACK) 439 offset += sizeof(((struct pptp_gre_header *) 0)->ack); 440 441 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset, 442 sizeof(_ppp_hdr), 443 data, *p_hlen, _ppp_hdr); 444 if (!ppp_hdr) 445 return FLOW_DISSECT_RET_OUT_BAD; 446 447 switch (PPP_PROTOCOL(ppp_hdr)) { 448 case PPP_IP: 449 *p_proto = htons(ETH_P_IP); 450 break; 451 case PPP_IPV6: 452 *p_proto = htons(ETH_P_IPV6); 453 break; 454 default: 455 /* Could probably catch some more like MPLS */ 456 break; 457 } 458 459 offset += PPP_HDRLEN; 460 } 461 462 *p_nhoff += offset; 463 key_control->flags |= FLOW_DIS_ENCAPSULATION; 464 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 465 return FLOW_DISSECT_RET_OUT_GOOD; 466 467 return FLOW_DISSECT_RET_PROTO_AGAIN; 468 } 469 470 /** 471 * __skb_flow_dissect_batadv() - dissect batman-adv header 472 * @skb: sk_buff to with the batman-adv header 473 * @key_control: flow dissectors control key 474 * @data: raw buffer pointer to the packet, if NULL use skb->data 475 * @p_proto: pointer used to update the protocol to process next 476 * @p_nhoff: pointer used to update inner network header offset 477 * @hlen: packet header length 478 * @flags: any combination of FLOW_DISSECTOR_F_* 479 * 480 * ETH_P_BATMAN packets are tried to be dissected. Only 481 * &struct batadv_unicast packets are actually processed because they contain an 482 * inner ethernet header and are usually followed by actual network header. This 483 * allows the flow dissector to continue processing the packet. 484 * 485 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, 486 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, 487 * otherwise FLOW_DISSECT_RET_OUT_BAD 488 */ 489 static enum flow_dissect_ret 490 __skb_flow_dissect_batadv(const struct sk_buff *skb, 491 struct flow_dissector_key_control *key_control, 492 void *data, __be16 *p_proto, int *p_nhoff, int hlen, 493 unsigned int flags) 494 { 495 struct { 496 struct batadv_unicast_packet batadv_unicast; 497 struct ethhdr eth; 498 } *hdr, _hdr; 499 500 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen, 501 &_hdr); 502 if (!hdr) 503 return FLOW_DISSECT_RET_OUT_BAD; 504 505 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) 506 return FLOW_DISSECT_RET_OUT_BAD; 507 508 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) 509 return FLOW_DISSECT_RET_OUT_BAD; 510 511 *p_proto = hdr->eth.h_proto; 512 *p_nhoff += sizeof(*hdr); 513 514 key_control->flags |= FLOW_DIS_ENCAPSULATION; 515 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 516 return FLOW_DISSECT_RET_OUT_GOOD; 517 518 return FLOW_DISSECT_RET_PROTO_AGAIN; 519 } 520 521 static void 522 __skb_flow_dissect_tcp(const struct sk_buff *skb, 523 struct flow_dissector *flow_dissector, 524 void *target_container, void *data, int thoff, int hlen) 525 { 526 struct flow_dissector_key_tcp *key_tcp; 527 struct tcphdr *th, _th; 528 529 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP)) 530 return; 531 532 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th); 533 if (!th) 534 return; 535 536 if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) 537 return; 538 539 key_tcp = skb_flow_dissector_target(flow_dissector, 540 FLOW_DISSECTOR_KEY_TCP, 541 target_container); 542 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); 543 } 544 545 static void 546 __skb_flow_dissect_ipv4(const struct sk_buff *skb, 547 struct flow_dissector *flow_dissector, 548 void *target_container, void *data, const struct iphdr *iph) 549 { 550 struct flow_dissector_key_ip *key_ip; 551 552 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 553 return; 554 555 key_ip = skb_flow_dissector_target(flow_dissector, 556 FLOW_DISSECTOR_KEY_IP, 557 target_container); 558 key_ip->tos = iph->tos; 559 key_ip->ttl = iph->ttl; 560 } 561 562 static void 563 __skb_flow_dissect_ipv6(const struct sk_buff *skb, 564 struct flow_dissector *flow_dissector, 565 void *target_container, void *data, const struct ipv6hdr *iph) 566 { 567 struct flow_dissector_key_ip *key_ip; 568 569 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 570 return; 571 572 key_ip = skb_flow_dissector_target(flow_dissector, 573 FLOW_DISSECTOR_KEY_IP, 574 target_container); 575 key_ip->tos = ipv6_get_dsfield(iph); 576 key_ip->ttl = iph->hop_limit; 577 } 578 579 /* Maximum number of protocol headers that can be parsed in 580 * __skb_flow_dissect 581 */ 582 #define MAX_FLOW_DISSECT_HDRS 15 583 584 static bool skb_flow_dissect_allowed(int *num_hdrs) 585 { 586 ++*num_hdrs; 587 588 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); 589 } 590 591 /** 592 * __skb_flow_dissect - extract the flow_keys struct and return it 593 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 594 * @flow_dissector: list of keys to dissect 595 * @target_container: target structure to put dissected values into 596 * @data: raw buffer pointer to the packet, if NULL use skb->data 597 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 598 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 599 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 600 * 601 * The function will try to retrieve individual keys into target specified 602 * by flow_dissector from either the skbuff or a raw buffer specified by the 603 * rest parameters. 604 * 605 * Caller must take care of zeroing target container memory. 606 */ 607 bool __skb_flow_dissect(const struct sk_buff *skb, 608 struct flow_dissector *flow_dissector, 609 void *target_container, 610 void *data, __be16 proto, int nhoff, int hlen, 611 unsigned int flags) 612 { 613 struct flow_dissector_key_control *key_control; 614 struct flow_dissector_key_basic *key_basic; 615 struct flow_dissector_key_addrs *key_addrs; 616 struct flow_dissector_key_ports *key_ports; 617 struct flow_dissector_key_icmp *key_icmp; 618 struct flow_dissector_key_tags *key_tags; 619 struct flow_dissector_key_vlan *key_vlan; 620 enum flow_dissect_ret fdret; 621 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; 622 int num_hdrs = 0; 623 u8 ip_proto = 0; 624 bool ret; 625 626 if (!data) { 627 data = skb->data; 628 proto = skb_vlan_tag_present(skb) ? 629 skb->vlan_proto : skb->protocol; 630 nhoff = skb_network_offset(skb); 631 hlen = skb_headlen(skb); 632 #if IS_ENABLED(CONFIG_NET_DSA) 633 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) { 634 const struct dsa_device_ops *ops; 635 int offset; 636 637 ops = skb->dev->dsa_ptr->tag_ops; 638 if (ops->flow_dissect && 639 !ops->flow_dissect(skb, &proto, &offset)) { 640 hlen -= offset; 641 nhoff += offset; 642 } 643 } 644 #endif 645 } 646 647 /* It is ensured by skb_flow_dissector_init() that control key will 648 * be always present. 649 */ 650 key_control = skb_flow_dissector_target(flow_dissector, 651 FLOW_DISSECTOR_KEY_CONTROL, 652 target_container); 653 654 /* It is ensured by skb_flow_dissector_init() that basic key will 655 * be always present. 656 */ 657 key_basic = skb_flow_dissector_target(flow_dissector, 658 FLOW_DISSECTOR_KEY_BASIC, 659 target_container); 660 661 if (dissector_uses_key(flow_dissector, 662 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 663 struct ethhdr *eth = eth_hdr(skb); 664 struct flow_dissector_key_eth_addrs *key_eth_addrs; 665 666 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 667 FLOW_DISSECTOR_KEY_ETH_ADDRS, 668 target_container); 669 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs)); 670 } 671 672 proto_again: 673 fdret = FLOW_DISSECT_RET_CONTINUE; 674 675 switch (proto) { 676 case htons(ETH_P_IP): { 677 const struct iphdr *iph; 678 struct iphdr _iph; 679 680 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 681 if (!iph || iph->ihl < 5) { 682 fdret = FLOW_DISSECT_RET_OUT_BAD; 683 break; 684 } 685 686 nhoff += iph->ihl * 4; 687 688 ip_proto = iph->protocol; 689 690 if (dissector_uses_key(flow_dissector, 691 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 692 key_addrs = skb_flow_dissector_target(flow_dissector, 693 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 694 target_container); 695 696 memcpy(&key_addrs->v4addrs, &iph->saddr, 697 sizeof(key_addrs->v4addrs)); 698 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 699 } 700 701 if (ip_is_fragment(iph)) { 702 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 703 704 if (iph->frag_off & htons(IP_OFFSET)) { 705 fdret = FLOW_DISSECT_RET_OUT_GOOD; 706 break; 707 } else { 708 key_control->flags |= FLOW_DIS_FIRST_FRAG; 709 if (!(flags & 710 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { 711 fdret = FLOW_DISSECT_RET_OUT_GOOD; 712 break; 713 } 714 } 715 } 716 717 __skb_flow_dissect_ipv4(skb, flow_dissector, 718 target_container, data, iph); 719 720 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) { 721 fdret = FLOW_DISSECT_RET_OUT_GOOD; 722 break; 723 } 724 725 break; 726 } 727 case htons(ETH_P_IPV6): { 728 const struct ipv6hdr *iph; 729 struct ipv6hdr _iph; 730 731 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 732 if (!iph) { 733 fdret = FLOW_DISSECT_RET_OUT_BAD; 734 break; 735 } 736 737 ip_proto = iph->nexthdr; 738 nhoff += sizeof(struct ipv6hdr); 739 740 if (dissector_uses_key(flow_dissector, 741 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 742 key_addrs = skb_flow_dissector_target(flow_dissector, 743 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 744 target_container); 745 746 memcpy(&key_addrs->v6addrs, &iph->saddr, 747 sizeof(key_addrs->v6addrs)); 748 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 749 } 750 751 if ((dissector_uses_key(flow_dissector, 752 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 753 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 754 ip6_flowlabel(iph)) { 755 __be32 flow_label = ip6_flowlabel(iph); 756 757 if (dissector_uses_key(flow_dissector, 758 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 759 key_tags = skb_flow_dissector_target(flow_dissector, 760 FLOW_DISSECTOR_KEY_FLOW_LABEL, 761 target_container); 762 key_tags->flow_label = ntohl(flow_label); 763 } 764 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { 765 fdret = FLOW_DISSECT_RET_OUT_GOOD; 766 break; 767 } 768 } 769 770 __skb_flow_dissect_ipv6(skb, flow_dissector, 771 target_container, data, iph); 772 773 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) 774 fdret = FLOW_DISSECT_RET_OUT_GOOD; 775 776 break; 777 } 778 case htons(ETH_P_8021AD): 779 case htons(ETH_P_8021Q): { 780 const struct vlan_hdr *vlan = NULL; 781 struct vlan_hdr _vlan; 782 __be16 saved_vlan_tpid = proto; 783 784 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && 785 skb && skb_vlan_tag_present(skb)) { 786 proto = skb->protocol; 787 } else { 788 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), 789 data, hlen, &_vlan); 790 if (!vlan) { 791 fdret = FLOW_DISSECT_RET_OUT_BAD; 792 break; 793 } 794 795 proto = vlan->h_vlan_encapsulated_proto; 796 nhoff += sizeof(*vlan); 797 } 798 799 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { 800 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; 801 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { 802 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; 803 } else { 804 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 805 break; 806 } 807 808 if (dissector_uses_key(flow_dissector, dissector_vlan)) { 809 key_vlan = skb_flow_dissector_target(flow_dissector, 810 dissector_vlan, 811 target_container); 812 813 if (!vlan) { 814 key_vlan->vlan_id = skb_vlan_tag_get_id(skb); 815 key_vlan->vlan_priority = 816 (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT); 817 } else { 818 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & 819 VLAN_VID_MASK; 820 key_vlan->vlan_priority = 821 (ntohs(vlan->h_vlan_TCI) & 822 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 823 } 824 key_vlan->vlan_tpid = saved_vlan_tpid; 825 } 826 827 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 828 break; 829 } 830 case htons(ETH_P_PPP_SES): { 831 struct { 832 struct pppoe_hdr hdr; 833 __be16 proto; 834 } *hdr, _hdr; 835 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 836 if (!hdr) { 837 fdret = FLOW_DISSECT_RET_OUT_BAD; 838 break; 839 } 840 841 proto = hdr->proto; 842 nhoff += PPPOE_SES_HLEN; 843 switch (proto) { 844 case htons(PPP_IP): 845 proto = htons(ETH_P_IP); 846 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 847 break; 848 case htons(PPP_IPV6): 849 proto = htons(ETH_P_IPV6); 850 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 851 break; 852 default: 853 fdret = FLOW_DISSECT_RET_OUT_BAD; 854 break; 855 } 856 break; 857 } 858 case htons(ETH_P_TIPC): { 859 struct tipc_basic_hdr *hdr, _hdr; 860 861 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), 862 data, hlen, &_hdr); 863 if (!hdr) { 864 fdret = FLOW_DISSECT_RET_OUT_BAD; 865 break; 866 } 867 868 if (dissector_uses_key(flow_dissector, 869 FLOW_DISSECTOR_KEY_TIPC)) { 870 key_addrs = skb_flow_dissector_target(flow_dissector, 871 FLOW_DISSECTOR_KEY_TIPC, 872 target_container); 873 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); 874 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; 875 } 876 fdret = FLOW_DISSECT_RET_OUT_GOOD; 877 break; 878 } 879 880 case htons(ETH_P_MPLS_UC): 881 case htons(ETH_P_MPLS_MC): 882 fdret = __skb_flow_dissect_mpls(skb, flow_dissector, 883 target_container, data, 884 nhoff, hlen); 885 break; 886 case htons(ETH_P_FCOE): 887 if ((hlen - nhoff) < FCOE_HEADER_LEN) { 888 fdret = FLOW_DISSECT_RET_OUT_BAD; 889 break; 890 } 891 892 nhoff += FCOE_HEADER_LEN; 893 fdret = FLOW_DISSECT_RET_OUT_GOOD; 894 break; 895 896 case htons(ETH_P_ARP): 897 case htons(ETH_P_RARP): 898 fdret = __skb_flow_dissect_arp(skb, flow_dissector, 899 target_container, data, 900 nhoff, hlen); 901 break; 902 903 case htons(ETH_P_BATMAN): 904 fdret = __skb_flow_dissect_batadv(skb, key_control, data, 905 &proto, &nhoff, hlen, flags); 906 break; 907 908 default: 909 fdret = FLOW_DISSECT_RET_OUT_BAD; 910 break; 911 } 912 913 /* Process result of proto processing */ 914 switch (fdret) { 915 case FLOW_DISSECT_RET_OUT_GOOD: 916 goto out_good; 917 case FLOW_DISSECT_RET_PROTO_AGAIN: 918 if (skb_flow_dissect_allowed(&num_hdrs)) 919 goto proto_again; 920 goto out_good; 921 case FLOW_DISSECT_RET_CONTINUE: 922 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 923 break; 924 case FLOW_DISSECT_RET_OUT_BAD: 925 default: 926 goto out_bad; 927 } 928 929 ip_proto_again: 930 fdret = FLOW_DISSECT_RET_CONTINUE; 931 932 switch (ip_proto) { 933 case IPPROTO_GRE: 934 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, 935 target_container, data, 936 &proto, &nhoff, &hlen, flags); 937 break; 938 939 case NEXTHDR_HOP: 940 case NEXTHDR_ROUTING: 941 case NEXTHDR_DEST: { 942 u8 _opthdr[2], *opthdr; 943 944 if (proto != htons(ETH_P_IPV6)) 945 break; 946 947 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 948 data, hlen, &_opthdr); 949 if (!opthdr) { 950 fdret = FLOW_DISSECT_RET_OUT_BAD; 951 break; 952 } 953 954 ip_proto = opthdr[0]; 955 nhoff += (opthdr[1] + 1) << 3; 956 957 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 958 break; 959 } 960 case NEXTHDR_FRAGMENT: { 961 struct frag_hdr _fh, *fh; 962 963 if (proto != htons(ETH_P_IPV6)) 964 break; 965 966 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 967 data, hlen, &_fh); 968 969 if (!fh) { 970 fdret = FLOW_DISSECT_RET_OUT_BAD; 971 break; 972 } 973 974 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 975 976 nhoff += sizeof(_fh); 977 ip_proto = fh->nexthdr; 978 979 if (!(fh->frag_off & htons(IP6_OFFSET))) { 980 key_control->flags |= FLOW_DIS_FIRST_FRAG; 981 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { 982 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 983 break; 984 } 985 } 986 987 fdret = FLOW_DISSECT_RET_OUT_GOOD; 988 break; 989 } 990 case IPPROTO_IPIP: 991 proto = htons(ETH_P_IP); 992 993 key_control->flags |= FLOW_DIS_ENCAPSULATION; 994 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 995 fdret = FLOW_DISSECT_RET_OUT_GOOD; 996 break; 997 } 998 999 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1000 break; 1001 1002 case IPPROTO_IPV6: 1003 proto = htons(ETH_P_IPV6); 1004 1005 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1006 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1007 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1008 break; 1009 } 1010 1011 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1012 break; 1013 1014 1015 case IPPROTO_MPLS: 1016 proto = htons(ETH_P_MPLS_UC); 1017 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1018 break; 1019 1020 case IPPROTO_TCP: 1021 __skb_flow_dissect_tcp(skb, flow_dissector, target_container, 1022 data, nhoff, hlen); 1023 break; 1024 1025 default: 1026 break; 1027 } 1028 1029 if (dissector_uses_key(flow_dissector, 1030 FLOW_DISSECTOR_KEY_PORTS)) { 1031 key_ports = skb_flow_dissector_target(flow_dissector, 1032 FLOW_DISSECTOR_KEY_PORTS, 1033 target_container); 1034 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 1035 data, hlen); 1036 } 1037 1038 if (dissector_uses_key(flow_dissector, 1039 FLOW_DISSECTOR_KEY_ICMP)) { 1040 key_icmp = skb_flow_dissector_target(flow_dissector, 1041 FLOW_DISSECTOR_KEY_ICMP, 1042 target_container); 1043 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen); 1044 } 1045 1046 /* Process result of IP proto processing */ 1047 switch (fdret) { 1048 case FLOW_DISSECT_RET_PROTO_AGAIN: 1049 if (skb_flow_dissect_allowed(&num_hdrs)) 1050 goto proto_again; 1051 break; 1052 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1053 if (skb_flow_dissect_allowed(&num_hdrs)) 1054 goto ip_proto_again; 1055 break; 1056 case FLOW_DISSECT_RET_OUT_GOOD: 1057 case FLOW_DISSECT_RET_CONTINUE: 1058 break; 1059 case FLOW_DISSECT_RET_OUT_BAD: 1060 default: 1061 goto out_bad; 1062 } 1063 1064 out_good: 1065 ret = true; 1066 1067 out: 1068 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); 1069 key_basic->n_proto = proto; 1070 key_basic->ip_proto = ip_proto; 1071 1072 return ret; 1073 1074 out_bad: 1075 ret = false; 1076 goto out; 1077 } 1078 EXPORT_SYMBOL(__skb_flow_dissect); 1079 1080 static u32 hashrnd __read_mostly; 1081 static __always_inline void __flow_hash_secret_init(void) 1082 { 1083 net_get_random_once(&hashrnd, sizeof(hashrnd)); 1084 } 1085 1086 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length, 1087 u32 keyval) 1088 { 1089 return jhash2(words, length, keyval); 1090 } 1091 1092 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow) 1093 { 1094 const void *p = flow; 1095 1096 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32)); 1097 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET); 1098 } 1099 1100 static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 1101 { 1102 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 1103 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 1104 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) != 1105 sizeof(*flow) - sizeof(flow->addrs)); 1106 1107 switch (flow->control.addr_type) { 1108 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1109 diff -= sizeof(flow->addrs.v4addrs); 1110 break; 1111 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1112 diff -= sizeof(flow->addrs.v6addrs); 1113 break; 1114 case FLOW_DISSECTOR_KEY_TIPC: 1115 diff -= sizeof(flow->addrs.tipckey); 1116 break; 1117 } 1118 return (sizeof(*flow) - diff) / sizeof(u32); 1119 } 1120 1121 __be32 flow_get_u32_src(const struct flow_keys *flow) 1122 { 1123 switch (flow->control.addr_type) { 1124 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1125 return flow->addrs.v4addrs.src; 1126 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1127 return (__force __be32)ipv6_addr_hash( 1128 &flow->addrs.v6addrs.src); 1129 case FLOW_DISSECTOR_KEY_TIPC: 1130 return flow->addrs.tipckey.key; 1131 default: 1132 return 0; 1133 } 1134 } 1135 EXPORT_SYMBOL(flow_get_u32_src); 1136 1137 __be32 flow_get_u32_dst(const struct flow_keys *flow) 1138 { 1139 switch (flow->control.addr_type) { 1140 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1141 return flow->addrs.v4addrs.dst; 1142 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1143 return (__force __be32)ipv6_addr_hash( 1144 &flow->addrs.v6addrs.dst); 1145 default: 1146 return 0; 1147 } 1148 } 1149 EXPORT_SYMBOL(flow_get_u32_dst); 1150 1151 static inline void __flow_hash_consistentify(struct flow_keys *keys) 1152 { 1153 int addr_diff, i; 1154 1155 switch (keys->control.addr_type) { 1156 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1157 addr_diff = (__force u32)keys->addrs.v4addrs.dst - 1158 (__force u32)keys->addrs.v4addrs.src; 1159 if ((addr_diff < 0) || 1160 (addr_diff == 0 && 1161 ((__force u16)keys->ports.dst < 1162 (__force u16)keys->ports.src))) { 1163 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 1164 swap(keys->ports.src, keys->ports.dst); 1165 } 1166 break; 1167 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1168 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 1169 &keys->addrs.v6addrs.src, 1170 sizeof(keys->addrs.v6addrs.dst)); 1171 if ((addr_diff < 0) || 1172 (addr_diff == 0 && 1173 ((__force u16)keys->ports.dst < 1174 (__force u16)keys->ports.src))) { 1175 for (i = 0; i < 4; i++) 1176 swap(keys->addrs.v6addrs.src.s6_addr32[i], 1177 keys->addrs.v6addrs.dst.s6_addr32[i]); 1178 swap(keys->ports.src, keys->ports.dst); 1179 } 1180 break; 1181 } 1182 } 1183 1184 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval) 1185 { 1186 u32 hash; 1187 1188 __flow_hash_consistentify(keys); 1189 1190 hash = __flow_hash_words(flow_keys_hash_start(keys), 1191 flow_keys_hash_length(keys), keyval); 1192 if (!hash) 1193 hash = 1; 1194 1195 return hash; 1196 } 1197 1198 u32 flow_hash_from_keys(struct flow_keys *keys) 1199 { 1200 __flow_hash_secret_init(); 1201 return __flow_hash_from_keys(keys, hashrnd); 1202 } 1203 EXPORT_SYMBOL(flow_hash_from_keys); 1204 1205 static inline u32 ___skb_get_hash(const struct sk_buff *skb, 1206 struct flow_keys *keys, u32 keyval) 1207 { 1208 skb_flow_dissect_flow_keys(skb, keys, 1209 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1210 1211 return __flow_hash_from_keys(keys, keyval); 1212 } 1213 1214 struct _flow_keys_digest_data { 1215 __be16 n_proto; 1216 u8 ip_proto; 1217 u8 padding; 1218 __be32 ports; 1219 __be32 src; 1220 __be32 dst; 1221 }; 1222 1223 void make_flow_keys_digest(struct flow_keys_digest *digest, 1224 const struct flow_keys *flow) 1225 { 1226 struct _flow_keys_digest_data *data = 1227 (struct _flow_keys_digest_data *)digest; 1228 1229 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 1230 1231 memset(digest, 0, sizeof(*digest)); 1232 1233 data->n_proto = flow->basic.n_proto; 1234 data->ip_proto = flow->basic.ip_proto; 1235 data->ports = flow->ports.ports; 1236 data->src = flow->addrs.v4addrs.src; 1237 data->dst = flow->addrs.v4addrs.dst; 1238 } 1239 EXPORT_SYMBOL(make_flow_keys_digest); 1240 1241 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; 1242 1243 u32 __skb_get_hash_symmetric(const struct sk_buff *skb) 1244 { 1245 struct flow_keys keys; 1246 1247 __flow_hash_secret_init(); 1248 1249 memset(&keys, 0, sizeof(keys)); 1250 __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys, 1251 NULL, 0, 0, 0, 1252 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1253 1254 return __flow_hash_from_keys(&keys, hashrnd); 1255 } 1256 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); 1257 1258 /** 1259 * __skb_get_hash: calculate a flow hash 1260 * @skb: sk_buff to calculate flow hash from 1261 * 1262 * This function calculates a flow hash based on src/dst addresses 1263 * and src/dst port numbers. Sets hash in skb to non-zero hash value 1264 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 1265 * if hash is a canonical 4-tuple hash over transport ports. 1266 */ 1267 void __skb_get_hash(struct sk_buff *skb) 1268 { 1269 struct flow_keys keys; 1270 u32 hash; 1271 1272 __flow_hash_secret_init(); 1273 1274 hash = ___skb_get_hash(skb, &keys, hashrnd); 1275 1276 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1277 } 1278 EXPORT_SYMBOL(__skb_get_hash); 1279 1280 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb) 1281 { 1282 struct flow_keys keys; 1283 1284 return ___skb_get_hash(skb, &keys, perturb); 1285 } 1286 EXPORT_SYMBOL(skb_get_hash_perturb); 1287 1288 u32 __skb_get_poff(const struct sk_buff *skb, void *data, 1289 const struct flow_keys_basic *keys, int hlen) 1290 { 1291 u32 poff = keys->control.thoff; 1292 1293 /* skip L4 headers for fragments after the first */ 1294 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && 1295 !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) 1296 return poff; 1297 1298 switch (keys->basic.ip_proto) { 1299 case IPPROTO_TCP: { 1300 /* access doff as u8 to avoid unaligned access */ 1301 const u8 *doff; 1302 u8 _doff; 1303 1304 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 1305 data, hlen, &_doff); 1306 if (!doff) 1307 return poff; 1308 1309 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 1310 break; 1311 } 1312 case IPPROTO_UDP: 1313 case IPPROTO_UDPLITE: 1314 poff += sizeof(struct udphdr); 1315 break; 1316 /* For the rest, we do not really care about header 1317 * extensions at this point for now. 1318 */ 1319 case IPPROTO_ICMP: 1320 poff += sizeof(struct icmphdr); 1321 break; 1322 case IPPROTO_ICMPV6: 1323 poff += sizeof(struct icmp6hdr); 1324 break; 1325 case IPPROTO_IGMP: 1326 poff += sizeof(struct igmphdr); 1327 break; 1328 case IPPROTO_DCCP: 1329 poff += sizeof(struct dccp_hdr); 1330 break; 1331 case IPPROTO_SCTP: 1332 poff += sizeof(struct sctphdr); 1333 break; 1334 } 1335 1336 return poff; 1337 } 1338 1339 /** 1340 * skb_get_poff - get the offset to the payload 1341 * @skb: sk_buff to get the payload offset from 1342 * 1343 * The function will get the offset to the payload as far as it could 1344 * be dissected. The main user is currently BPF, so that we can dynamically 1345 * truncate packets without needing to push actual payload to the user 1346 * space and can analyze headers only, instead. 1347 */ 1348 u32 skb_get_poff(const struct sk_buff *skb) 1349 { 1350 struct flow_keys_basic keys; 1351 1352 if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0)) 1353 return 0; 1354 1355 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 1356 } 1357 1358 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 1359 { 1360 memset(keys, 0, sizeof(*keys)); 1361 1362 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 1363 sizeof(keys->addrs.v6addrs.src)); 1364 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 1365 sizeof(keys->addrs.v6addrs.dst)); 1366 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1367 keys->ports.src = fl6->fl6_sport; 1368 keys->ports.dst = fl6->fl6_dport; 1369 keys->keyid.keyid = fl6->fl6_gre_key; 1370 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 1371 keys->basic.ip_proto = fl6->flowi6_proto; 1372 1373 return flow_hash_from_keys(keys); 1374 } 1375 EXPORT_SYMBOL(__get_hash_from_flowi6); 1376 1377 static const struct flow_dissector_key flow_keys_dissector_keys[] = { 1378 { 1379 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1380 .offset = offsetof(struct flow_keys, control), 1381 }, 1382 { 1383 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1384 .offset = offsetof(struct flow_keys, basic), 1385 }, 1386 { 1387 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1388 .offset = offsetof(struct flow_keys, addrs.v4addrs), 1389 }, 1390 { 1391 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1392 .offset = offsetof(struct flow_keys, addrs.v6addrs), 1393 }, 1394 { 1395 .key_id = FLOW_DISSECTOR_KEY_TIPC, 1396 .offset = offsetof(struct flow_keys, addrs.tipckey), 1397 }, 1398 { 1399 .key_id = FLOW_DISSECTOR_KEY_PORTS, 1400 .offset = offsetof(struct flow_keys, ports), 1401 }, 1402 { 1403 .key_id = FLOW_DISSECTOR_KEY_VLAN, 1404 .offset = offsetof(struct flow_keys, vlan), 1405 }, 1406 { 1407 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 1408 .offset = offsetof(struct flow_keys, tags), 1409 }, 1410 { 1411 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 1412 .offset = offsetof(struct flow_keys, keyid), 1413 }, 1414 }; 1415 1416 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { 1417 { 1418 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1419 .offset = offsetof(struct flow_keys, control), 1420 }, 1421 { 1422 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1423 .offset = offsetof(struct flow_keys, basic), 1424 }, 1425 { 1426 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1427 .offset = offsetof(struct flow_keys, addrs.v4addrs), 1428 }, 1429 { 1430 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1431 .offset = offsetof(struct flow_keys, addrs.v6addrs), 1432 }, 1433 { 1434 .key_id = FLOW_DISSECTOR_KEY_PORTS, 1435 .offset = offsetof(struct flow_keys, ports), 1436 }, 1437 }; 1438 1439 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { 1440 { 1441 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1442 .offset = offsetof(struct flow_keys, control), 1443 }, 1444 { 1445 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1446 .offset = offsetof(struct flow_keys, basic), 1447 }, 1448 }; 1449 1450 struct flow_dissector flow_keys_dissector __read_mostly; 1451 EXPORT_SYMBOL(flow_keys_dissector); 1452 1453 struct flow_dissector flow_keys_basic_dissector __read_mostly; 1454 EXPORT_SYMBOL(flow_keys_basic_dissector); 1455 1456 static int __init init_default_flow_dissectors(void) 1457 { 1458 skb_flow_dissector_init(&flow_keys_dissector, 1459 flow_keys_dissector_keys, 1460 ARRAY_SIZE(flow_keys_dissector_keys)); 1461 skb_flow_dissector_init(&flow_keys_dissector_symmetric, 1462 flow_keys_dissector_symmetric_keys, 1463 ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); 1464 skb_flow_dissector_init(&flow_keys_basic_dissector, 1465 flow_keys_basic_dissector_keys, 1466 ARRAY_SIZE(flow_keys_basic_dissector_keys)); 1467 return 0; 1468 } 1469 1470 core_initcall(init_default_flow_dissectors); 1471