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/ip.h> 8 #include <net/ipv6.h> 9 #include <net/gre.h> 10 #include <net/pptp.h> 11 #include <linux/igmp.h> 12 #include <linux/icmp.h> 13 #include <linux/sctp.h> 14 #include <linux/dccp.h> 15 #include <linux/if_tunnel.h> 16 #include <linux/if_pppox.h> 17 #include <linux/ppp_defs.h> 18 #include <linux/stddef.h> 19 #include <linux/if_ether.h> 20 #include <linux/mpls.h> 21 #include <net/flow_dissector.h> 22 #include <scsi/fc/fc_fcoe.h> 23 24 static void dissector_set_key(struct flow_dissector *flow_dissector, 25 enum flow_dissector_key_id key_id) 26 { 27 flow_dissector->used_keys |= (1 << key_id); 28 } 29 30 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 31 const struct flow_dissector_key *key, 32 unsigned int key_count) 33 { 34 unsigned int i; 35 36 memset(flow_dissector, 0, sizeof(*flow_dissector)); 37 38 for (i = 0; i < key_count; i++, key++) { 39 /* User should make sure that every key target offset is withing 40 * boundaries of unsigned short. 41 */ 42 BUG_ON(key->offset > USHRT_MAX); 43 BUG_ON(dissector_uses_key(flow_dissector, 44 key->key_id)); 45 46 dissector_set_key(flow_dissector, key->key_id); 47 flow_dissector->offset[key->key_id] = key->offset; 48 } 49 50 /* Ensure that the dissector always includes control and basic key. 51 * That way we are able to avoid handling lack of these in fast path. 52 */ 53 BUG_ON(!dissector_uses_key(flow_dissector, 54 FLOW_DISSECTOR_KEY_CONTROL)); 55 BUG_ON(!dissector_uses_key(flow_dissector, 56 FLOW_DISSECTOR_KEY_BASIC)); 57 } 58 EXPORT_SYMBOL(skb_flow_dissector_init); 59 60 /** 61 * skb_flow_get_be16 - extract be16 entity 62 * @skb: sk_buff to extract from 63 * @poff: offset to extract at 64 * @data: raw buffer pointer to the packet 65 * @hlen: packet header length 66 * 67 * The function will try to retrieve a be32 entity at 68 * offset poff 69 */ 70 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff, 71 void *data, int hlen) 72 { 73 __be16 *u, _u; 74 75 u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u); 76 if (u) 77 return *u; 78 79 return 0; 80 } 81 82 /** 83 * __skb_flow_get_ports - extract the upper layer ports and return them 84 * @skb: sk_buff to extract the ports from 85 * @thoff: transport header offset 86 * @ip_proto: protocol for which to get port offset 87 * @data: raw buffer pointer to the packet, if NULL use skb->data 88 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 89 * 90 * The function will try to retrieve the ports at offset thoff + poff where poff 91 * is the protocol port offset returned from proto_ports_offset 92 */ 93 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 94 void *data, int hlen) 95 { 96 int poff = proto_ports_offset(ip_proto); 97 98 if (!data) { 99 data = skb->data; 100 hlen = skb_headlen(skb); 101 } 102 103 if (poff >= 0) { 104 __be32 *ports, _ports; 105 106 ports = __skb_header_pointer(skb, thoff + poff, 107 sizeof(_ports), data, hlen, &_ports); 108 if (ports) 109 return *ports; 110 } 111 112 return 0; 113 } 114 EXPORT_SYMBOL(__skb_flow_get_ports); 115 116 /** 117 * __skb_flow_dissect - extract the flow_keys struct and return it 118 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 119 * @flow_dissector: list of keys to dissect 120 * @target_container: target structure to put dissected values into 121 * @data: raw buffer pointer to the packet, if NULL use skb->data 122 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 123 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 124 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 125 * 126 * The function will try to retrieve individual keys into target specified 127 * by flow_dissector from either the skbuff or a raw buffer specified by the 128 * rest parameters. 129 * 130 * Caller must take care of zeroing target container memory. 131 */ 132 bool __skb_flow_dissect(const struct sk_buff *skb, 133 struct flow_dissector *flow_dissector, 134 void *target_container, 135 void *data, __be16 proto, int nhoff, int hlen, 136 unsigned int flags) 137 { 138 struct flow_dissector_key_control *key_control; 139 struct flow_dissector_key_basic *key_basic; 140 struct flow_dissector_key_addrs *key_addrs; 141 struct flow_dissector_key_ports *key_ports; 142 struct flow_dissector_key_icmp *key_icmp; 143 struct flow_dissector_key_tags *key_tags; 144 struct flow_dissector_key_vlan *key_vlan; 145 struct flow_dissector_key_keyid *key_keyid; 146 bool skip_vlan = false; 147 u8 ip_proto = 0; 148 bool ret; 149 150 if (!data) { 151 data = skb->data; 152 proto = skb_vlan_tag_present(skb) ? 153 skb->vlan_proto : skb->protocol; 154 nhoff = skb_network_offset(skb); 155 hlen = skb_headlen(skb); 156 } 157 158 /* It is ensured by skb_flow_dissector_init() that control key will 159 * be always present. 160 */ 161 key_control = skb_flow_dissector_target(flow_dissector, 162 FLOW_DISSECTOR_KEY_CONTROL, 163 target_container); 164 165 /* It is ensured by skb_flow_dissector_init() that basic key will 166 * be always present. 167 */ 168 key_basic = skb_flow_dissector_target(flow_dissector, 169 FLOW_DISSECTOR_KEY_BASIC, 170 target_container); 171 172 if (dissector_uses_key(flow_dissector, 173 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 174 struct ethhdr *eth = eth_hdr(skb); 175 struct flow_dissector_key_eth_addrs *key_eth_addrs; 176 177 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 178 FLOW_DISSECTOR_KEY_ETH_ADDRS, 179 target_container); 180 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs)); 181 } 182 183 again: 184 switch (proto) { 185 case htons(ETH_P_IP): { 186 const struct iphdr *iph; 187 struct iphdr _iph; 188 ip: 189 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 190 if (!iph || iph->ihl < 5) 191 goto out_bad; 192 nhoff += iph->ihl * 4; 193 194 ip_proto = iph->protocol; 195 196 if (dissector_uses_key(flow_dissector, 197 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 198 key_addrs = skb_flow_dissector_target(flow_dissector, 199 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 200 target_container); 201 202 memcpy(&key_addrs->v4addrs, &iph->saddr, 203 sizeof(key_addrs->v4addrs)); 204 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 205 } 206 207 if (ip_is_fragment(iph)) { 208 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 209 210 if (iph->frag_off & htons(IP_OFFSET)) { 211 goto out_good; 212 } else { 213 key_control->flags |= FLOW_DIS_FIRST_FRAG; 214 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) 215 goto out_good; 216 } 217 } 218 219 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) 220 goto out_good; 221 222 break; 223 } 224 case htons(ETH_P_IPV6): { 225 const struct ipv6hdr *iph; 226 struct ipv6hdr _iph; 227 228 ipv6: 229 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 230 if (!iph) 231 goto out_bad; 232 233 ip_proto = iph->nexthdr; 234 nhoff += sizeof(struct ipv6hdr); 235 236 if (dissector_uses_key(flow_dissector, 237 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 238 key_addrs = skb_flow_dissector_target(flow_dissector, 239 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 240 target_container); 241 242 memcpy(&key_addrs->v6addrs, &iph->saddr, 243 sizeof(key_addrs->v6addrs)); 244 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 245 } 246 247 if ((dissector_uses_key(flow_dissector, 248 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 249 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 250 ip6_flowlabel(iph)) { 251 __be32 flow_label = ip6_flowlabel(iph); 252 253 if (dissector_uses_key(flow_dissector, 254 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 255 key_tags = skb_flow_dissector_target(flow_dissector, 256 FLOW_DISSECTOR_KEY_FLOW_LABEL, 257 target_container); 258 key_tags->flow_label = ntohl(flow_label); 259 } 260 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) 261 goto out_good; 262 } 263 264 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) 265 goto out_good; 266 267 break; 268 } 269 case htons(ETH_P_8021AD): 270 case htons(ETH_P_8021Q): { 271 const struct vlan_hdr *vlan; 272 struct vlan_hdr _vlan; 273 bool vlan_tag_present = skb && skb_vlan_tag_present(skb); 274 275 if (vlan_tag_present) 276 proto = skb->protocol; 277 278 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) { 279 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), 280 data, hlen, &_vlan); 281 if (!vlan) 282 goto out_bad; 283 proto = vlan->h_vlan_encapsulated_proto; 284 nhoff += sizeof(*vlan); 285 if (skip_vlan) 286 goto again; 287 } 288 289 skip_vlan = true; 290 if (dissector_uses_key(flow_dissector, 291 FLOW_DISSECTOR_KEY_VLAN)) { 292 key_vlan = skb_flow_dissector_target(flow_dissector, 293 FLOW_DISSECTOR_KEY_VLAN, 294 target_container); 295 296 if (vlan_tag_present) { 297 key_vlan->vlan_id = skb_vlan_tag_get_id(skb); 298 key_vlan->vlan_priority = 299 (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT); 300 } else { 301 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & 302 VLAN_VID_MASK; 303 key_vlan->vlan_priority = 304 (ntohs(vlan->h_vlan_TCI) & 305 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 306 } 307 } 308 309 goto again; 310 } 311 case htons(ETH_P_PPP_SES): { 312 struct { 313 struct pppoe_hdr hdr; 314 __be16 proto; 315 } *hdr, _hdr; 316 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 317 if (!hdr) 318 goto out_bad; 319 proto = hdr->proto; 320 nhoff += PPPOE_SES_HLEN; 321 switch (proto) { 322 case htons(PPP_IP): 323 goto ip; 324 case htons(PPP_IPV6): 325 goto ipv6; 326 default: 327 goto out_bad; 328 } 329 } 330 case htons(ETH_P_TIPC): { 331 struct { 332 __be32 pre[3]; 333 __be32 srcnode; 334 } *hdr, _hdr; 335 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 336 if (!hdr) 337 goto out_bad; 338 339 if (dissector_uses_key(flow_dissector, 340 FLOW_DISSECTOR_KEY_TIPC_ADDRS)) { 341 key_addrs = skb_flow_dissector_target(flow_dissector, 342 FLOW_DISSECTOR_KEY_TIPC_ADDRS, 343 target_container); 344 key_addrs->tipcaddrs.srcnode = hdr->srcnode; 345 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS; 346 } 347 goto out_good; 348 } 349 350 case htons(ETH_P_MPLS_UC): 351 case htons(ETH_P_MPLS_MC): { 352 struct mpls_label *hdr, _hdr[2]; 353 mpls: 354 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 355 hlen, &_hdr); 356 if (!hdr) 357 goto out_bad; 358 359 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >> 360 MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) { 361 if (dissector_uses_key(flow_dissector, 362 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { 363 key_keyid = skb_flow_dissector_target(flow_dissector, 364 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 365 target_container); 366 key_keyid->keyid = hdr[1].entry & 367 htonl(MPLS_LS_LABEL_MASK); 368 } 369 370 goto out_good; 371 } 372 373 goto out_good; 374 } 375 376 case htons(ETH_P_FCOE): 377 if ((hlen - nhoff) < FCOE_HEADER_LEN) 378 goto out_bad; 379 380 nhoff += FCOE_HEADER_LEN; 381 goto out_good; 382 default: 383 goto out_bad; 384 } 385 386 ip_proto_again: 387 switch (ip_proto) { 388 case IPPROTO_GRE: { 389 struct gre_base_hdr *hdr, _hdr; 390 u16 gre_ver; 391 int offset = 0; 392 393 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 394 if (!hdr) 395 goto out_bad; 396 397 /* Only look inside GRE without routing */ 398 if (hdr->flags & GRE_ROUTING) 399 break; 400 401 /* Only look inside GRE for version 0 and 1 */ 402 gre_ver = ntohs(hdr->flags & GRE_VERSION); 403 if (gre_ver > 1) 404 break; 405 406 proto = hdr->protocol; 407 if (gre_ver) { 408 /* Version1 must be PPTP, and check the flags */ 409 if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) 410 break; 411 } 412 413 offset += sizeof(struct gre_base_hdr); 414 415 if (hdr->flags & GRE_CSUM) 416 offset += sizeof(((struct gre_full_hdr *)0)->csum) + 417 sizeof(((struct gre_full_hdr *)0)->reserved1); 418 419 if (hdr->flags & GRE_KEY) { 420 const __be32 *keyid; 421 __be32 _keyid; 422 423 keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid), 424 data, hlen, &_keyid); 425 if (!keyid) 426 goto out_bad; 427 428 if (dissector_uses_key(flow_dissector, 429 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 430 key_keyid = skb_flow_dissector_target(flow_dissector, 431 FLOW_DISSECTOR_KEY_GRE_KEYID, 432 target_container); 433 if (gre_ver == 0) 434 key_keyid->keyid = *keyid; 435 else 436 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; 437 } 438 offset += sizeof(((struct gre_full_hdr *)0)->key); 439 } 440 441 if (hdr->flags & GRE_SEQ) 442 offset += sizeof(((struct pptp_gre_header *)0)->seq); 443 444 if (gre_ver == 0) { 445 if (proto == htons(ETH_P_TEB)) { 446 const struct ethhdr *eth; 447 struct ethhdr _eth; 448 449 eth = __skb_header_pointer(skb, nhoff + offset, 450 sizeof(_eth), 451 data, hlen, &_eth); 452 if (!eth) 453 goto out_bad; 454 proto = eth->h_proto; 455 offset += sizeof(*eth); 456 457 /* Cap headers that we access via pointers at the 458 * end of the Ethernet header as our maximum alignment 459 * at that point is only 2 bytes. 460 */ 461 if (NET_IP_ALIGN) 462 hlen = (nhoff + offset); 463 } 464 } else { /* version 1, must be PPTP */ 465 u8 _ppp_hdr[PPP_HDRLEN]; 466 u8 *ppp_hdr; 467 468 if (hdr->flags & GRE_ACK) 469 offset += sizeof(((struct pptp_gre_header *)0)->ack); 470 471 ppp_hdr = __skb_header_pointer(skb, nhoff + offset, 472 sizeof(_ppp_hdr), 473 data, hlen, _ppp_hdr); 474 if (!ppp_hdr) 475 goto out_bad; 476 477 switch (PPP_PROTOCOL(ppp_hdr)) { 478 case PPP_IP: 479 proto = htons(ETH_P_IP); 480 break; 481 case PPP_IPV6: 482 proto = htons(ETH_P_IPV6); 483 break; 484 default: 485 /* Could probably catch some more like MPLS */ 486 break; 487 } 488 489 offset += PPP_HDRLEN; 490 } 491 492 nhoff += offset; 493 key_control->flags |= FLOW_DIS_ENCAPSULATION; 494 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 495 goto out_good; 496 497 goto again; 498 } 499 case NEXTHDR_HOP: 500 case NEXTHDR_ROUTING: 501 case NEXTHDR_DEST: { 502 u8 _opthdr[2], *opthdr; 503 504 if (proto != htons(ETH_P_IPV6)) 505 break; 506 507 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 508 data, hlen, &_opthdr); 509 if (!opthdr) 510 goto out_bad; 511 512 ip_proto = opthdr[0]; 513 nhoff += (opthdr[1] + 1) << 3; 514 515 goto ip_proto_again; 516 } 517 case NEXTHDR_FRAGMENT: { 518 struct frag_hdr _fh, *fh; 519 520 if (proto != htons(ETH_P_IPV6)) 521 break; 522 523 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 524 data, hlen, &_fh); 525 526 if (!fh) 527 goto out_bad; 528 529 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 530 531 nhoff += sizeof(_fh); 532 ip_proto = fh->nexthdr; 533 534 if (!(fh->frag_off & htons(IP6_OFFSET))) { 535 key_control->flags |= FLOW_DIS_FIRST_FRAG; 536 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) 537 goto ip_proto_again; 538 } 539 goto out_good; 540 } 541 case IPPROTO_IPIP: 542 proto = htons(ETH_P_IP); 543 544 key_control->flags |= FLOW_DIS_ENCAPSULATION; 545 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 546 goto out_good; 547 548 goto ip; 549 case IPPROTO_IPV6: 550 proto = htons(ETH_P_IPV6); 551 552 key_control->flags |= FLOW_DIS_ENCAPSULATION; 553 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 554 goto out_good; 555 556 goto ipv6; 557 case IPPROTO_MPLS: 558 proto = htons(ETH_P_MPLS_UC); 559 goto mpls; 560 default: 561 break; 562 } 563 564 if (dissector_uses_key(flow_dissector, 565 FLOW_DISSECTOR_KEY_PORTS)) { 566 key_ports = skb_flow_dissector_target(flow_dissector, 567 FLOW_DISSECTOR_KEY_PORTS, 568 target_container); 569 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 570 data, hlen); 571 } 572 573 if (dissector_uses_key(flow_dissector, 574 FLOW_DISSECTOR_KEY_ICMP)) { 575 key_icmp = skb_flow_dissector_target(flow_dissector, 576 FLOW_DISSECTOR_KEY_ICMP, 577 target_container); 578 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen); 579 } 580 581 out_good: 582 ret = true; 583 584 key_control->thoff = (u16)nhoff; 585 out: 586 key_basic->n_proto = proto; 587 key_basic->ip_proto = ip_proto; 588 589 return ret; 590 591 out_bad: 592 ret = false; 593 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); 594 goto out; 595 } 596 EXPORT_SYMBOL(__skb_flow_dissect); 597 598 static u32 hashrnd __read_mostly; 599 static __always_inline void __flow_hash_secret_init(void) 600 { 601 net_get_random_once(&hashrnd, sizeof(hashrnd)); 602 } 603 604 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length, 605 u32 keyval) 606 { 607 return jhash2(words, length, keyval); 608 } 609 610 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow) 611 { 612 const void *p = flow; 613 614 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32)); 615 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET); 616 } 617 618 static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 619 { 620 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 621 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 622 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) != 623 sizeof(*flow) - sizeof(flow->addrs)); 624 625 switch (flow->control.addr_type) { 626 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 627 diff -= sizeof(flow->addrs.v4addrs); 628 break; 629 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 630 diff -= sizeof(flow->addrs.v6addrs); 631 break; 632 case FLOW_DISSECTOR_KEY_TIPC_ADDRS: 633 diff -= sizeof(flow->addrs.tipcaddrs); 634 break; 635 } 636 return (sizeof(*flow) - diff) / sizeof(u32); 637 } 638 639 __be32 flow_get_u32_src(const struct flow_keys *flow) 640 { 641 switch (flow->control.addr_type) { 642 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 643 return flow->addrs.v4addrs.src; 644 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 645 return (__force __be32)ipv6_addr_hash( 646 &flow->addrs.v6addrs.src); 647 case FLOW_DISSECTOR_KEY_TIPC_ADDRS: 648 return flow->addrs.tipcaddrs.srcnode; 649 default: 650 return 0; 651 } 652 } 653 EXPORT_SYMBOL(flow_get_u32_src); 654 655 __be32 flow_get_u32_dst(const struct flow_keys *flow) 656 { 657 switch (flow->control.addr_type) { 658 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 659 return flow->addrs.v4addrs.dst; 660 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 661 return (__force __be32)ipv6_addr_hash( 662 &flow->addrs.v6addrs.dst); 663 default: 664 return 0; 665 } 666 } 667 EXPORT_SYMBOL(flow_get_u32_dst); 668 669 static inline void __flow_hash_consistentify(struct flow_keys *keys) 670 { 671 int addr_diff, i; 672 673 switch (keys->control.addr_type) { 674 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 675 addr_diff = (__force u32)keys->addrs.v4addrs.dst - 676 (__force u32)keys->addrs.v4addrs.src; 677 if ((addr_diff < 0) || 678 (addr_diff == 0 && 679 ((__force u16)keys->ports.dst < 680 (__force u16)keys->ports.src))) { 681 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 682 swap(keys->ports.src, keys->ports.dst); 683 } 684 break; 685 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 686 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 687 &keys->addrs.v6addrs.src, 688 sizeof(keys->addrs.v6addrs.dst)); 689 if ((addr_diff < 0) || 690 (addr_diff == 0 && 691 ((__force u16)keys->ports.dst < 692 (__force u16)keys->ports.src))) { 693 for (i = 0; i < 4; i++) 694 swap(keys->addrs.v6addrs.src.s6_addr32[i], 695 keys->addrs.v6addrs.dst.s6_addr32[i]); 696 swap(keys->ports.src, keys->ports.dst); 697 } 698 break; 699 } 700 } 701 702 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval) 703 { 704 u32 hash; 705 706 __flow_hash_consistentify(keys); 707 708 hash = __flow_hash_words(flow_keys_hash_start(keys), 709 flow_keys_hash_length(keys), keyval); 710 if (!hash) 711 hash = 1; 712 713 return hash; 714 } 715 716 u32 flow_hash_from_keys(struct flow_keys *keys) 717 { 718 __flow_hash_secret_init(); 719 return __flow_hash_from_keys(keys, hashrnd); 720 } 721 EXPORT_SYMBOL(flow_hash_from_keys); 722 723 static inline u32 ___skb_get_hash(const struct sk_buff *skb, 724 struct flow_keys *keys, u32 keyval) 725 { 726 skb_flow_dissect_flow_keys(skb, keys, 727 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 728 729 return __flow_hash_from_keys(keys, keyval); 730 } 731 732 struct _flow_keys_digest_data { 733 __be16 n_proto; 734 u8 ip_proto; 735 u8 padding; 736 __be32 ports; 737 __be32 src; 738 __be32 dst; 739 }; 740 741 void make_flow_keys_digest(struct flow_keys_digest *digest, 742 const struct flow_keys *flow) 743 { 744 struct _flow_keys_digest_data *data = 745 (struct _flow_keys_digest_data *)digest; 746 747 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 748 749 memset(digest, 0, sizeof(*digest)); 750 751 data->n_proto = flow->basic.n_proto; 752 data->ip_proto = flow->basic.ip_proto; 753 data->ports = flow->ports.ports; 754 data->src = flow->addrs.v4addrs.src; 755 data->dst = flow->addrs.v4addrs.dst; 756 } 757 EXPORT_SYMBOL(make_flow_keys_digest); 758 759 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; 760 761 u32 __skb_get_hash_symmetric(const struct sk_buff *skb) 762 { 763 struct flow_keys keys; 764 765 __flow_hash_secret_init(); 766 767 memset(&keys, 0, sizeof(keys)); 768 __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys, 769 NULL, 0, 0, 0, 770 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 771 772 return __flow_hash_from_keys(&keys, hashrnd); 773 } 774 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); 775 776 /** 777 * __skb_get_hash: calculate a flow hash 778 * @skb: sk_buff to calculate flow hash from 779 * 780 * This function calculates a flow hash based on src/dst addresses 781 * and src/dst port numbers. Sets hash in skb to non-zero hash value 782 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 783 * if hash is a canonical 4-tuple hash over transport ports. 784 */ 785 void __skb_get_hash(struct sk_buff *skb) 786 { 787 struct flow_keys keys; 788 u32 hash; 789 790 __flow_hash_secret_init(); 791 792 hash = ___skb_get_hash(skb, &keys, hashrnd); 793 794 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 795 } 796 EXPORT_SYMBOL(__skb_get_hash); 797 798 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb) 799 { 800 struct flow_keys keys; 801 802 return ___skb_get_hash(skb, &keys, perturb); 803 } 804 EXPORT_SYMBOL(skb_get_hash_perturb); 805 806 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 807 { 808 struct flow_keys keys; 809 810 memset(&keys, 0, sizeof(keys)); 811 812 memcpy(&keys.addrs.v6addrs.src, &fl6->saddr, 813 sizeof(keys.addrs.v6addrs.src)); 814 memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr, 815 sizeof(keys.addrs.v6addrs.dst)); 816 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 817 keys.ports.src = fl6->fl6_sport; 818 keys.ports.dst = fl6->fl6_dport; 819 keys.keyid.keyid = fl6->fl6_gre_key; 820 keys.tags.flow_label = (__force u32)fl6->flowlabel; 821 keys.basic.ip_proto = fl6->flowi6_proto; 822 823 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), 824 flow_keys_have_l4(&keys)); 825 826 return skb->hash; 827 } 828 EXPORT_SYMBOL(__skb_get_hash_flowi6); 829 830 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4) 831 { 832 struct flow_keys keys; 833 834 memset(&keys, 0, sizeof(keys)); 835 836 keys.addrs.v4addrs.src = fl4->saddr; 837 keys.addrs.v4addrs.dst = fl4->daddr; 838 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 839 keys.ports.src = fl4->fl4_sport; 840 keys.ports.dst = fl4->fl4_dport; 841 keys.keyid.keyid = fl4->fl4_gre_key; 842 keys.basic.ip_proto = fl4->flowi4_proto; 843 844 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), 845 flow_keys_have_l4(&keys)); 846 847 return skb->hash; 848 } 849 EXPORT_SYMBOL(__skb_get_hash_flowi4); 850 851 u32 __skb_get_poff(const struct sk_buff *skb, void *data, 852 const struct flow_keys *keys, int hlen) 853 { 854 u32 poff = keys->control.thoff; 855 856 /* skip L4 headers for fragments after the first */ 857 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && 858 !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) 859 return poff; 860 861 switch (keys->basic.ip_proto) { 862 case IPPROTO_TCP: { 863 /* access doff as u8 to avoid unaligned access */ 864 const u8 *doff; 865 u8 _doff; 866 867 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 868 data, hlen, &_doff); 869 if (!doff) 870 return poff; 871 872 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 873 break; 874 } 875 case IPPROTO_UDP: 876 case IPPROTO_UDPLITE: 877 poff += sizeof(struct udphdr); 878 break; 879 /* For the rest, we do not really care about header 880 * extensions at this point for now. 881 */ 882 case IPPROTO_ICMP: 883 poff += sizeof(struct icmphdr); 884 break; 885 case IPPROTO_ICMPV6: 886 poff += sizeof(struct icmp6hdr); 887 break; 888 case IPPROTO_IGMP: 889 poff += sizeof(struct igmphdr); 890 break; 891 case IPPROTO_DCCP: 892 poff += sizeof(struct dccp_hdr); 893 break; 894 case IPPROTO_SCTP: 895 poff += sizeof(struct sctphdr); 896 break; 897 } 898 899 return poff; 900 } 901 902 /** 903 * skb_get_poff - get the offset to the payload 904 * @skb: sk_buff to get the payload offset from 905 * 906 * The function will get the offset to the payload as far as it could 907 * be dissected. The main user is currently BPF, so that we can dynamically 908 * truncate packets without needing to push actual payload to the user 909 * space and can analyze headers only, instead. 910 */ 911 u32 skb_get_poff(const struct sk_buff *skb) 912 { 913 struct flow_keys keys; 914 915 if (!skb_flow_dissect_flow_keys(skb, &keys, 0)) 916 return 0; 917 918 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 919 } 920 921 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 922 { 923 memset(keys, 0, sizeof(*keys)); 924 925 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 926 sizeof(keys->addrs.v6addrs.src)); 927 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 928 sizeof(keys->addrs.v6addrs.dst)); 929 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 930 keys->ports.src = fl6->fl6_sport; 931 keys->ports.dst = fl6->fl6_dport; 932 keys->keyid.keyid = fl6->fl6_gre_key; 933 keys->tags.flow_label = (__force u32)fl6->flowlabel; 934 keys->basic.ip_proto = fl6->flowi6_proto; 935 936 return flow_hash_from_keys(keys); 937 } 938 EXPORT_SYMBOL(__get_hash_from_flowi6); 939 940 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys) 941 { 942 memset(keys, 0, sizeof(*keys)); 943 944 keys->addrs.v4addrs.src = fl4->saddr; 945 keys->addrs.v4addrs.dst = fl4->daddr; 946 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 947 keys->ports.src = fl4->fl4_sport; 948 keys->ports.dst = fl4->fl4_dport; 949 keys->keyid.keyid = fl4->fl4_gre_key; 950 keys->basic.ip_proto = fl4->flowi4_proto; 951 952 return flow_hash_from_keys(keys); 953 } 954 EXPORT_SYMBOL(__get_hash_from_flowi4); 955 956 static const struct flow_dissector_key flow_keys_dissector_keys[] = { 957 { 958 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 959 .offset = offsetof(struct flow_keys, control), 960 }, 961 { 962 .key_id = FLOW_DISSECTOR_KEY_BASIC, 963 .offset = offsetof(struct flow_keys, basic), 964 }, 965 { 966 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 967 .offset = offsetof(struct flow_keys, addrs.v4addrs), 968 }, 969 { 970 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 971 .offset = offsetof(struct flow_keys, addrs.v6addrs), 972 }, 973 { 974 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS, 975 .offset = offsetof(struct flow_keys, addrs.tipcaddrs), 976 }, 977 { 978 .key_id = FLOW_DISSECTOR_KEY_PORTS, 979 .offset = offsetof(struct flow_keys, ports), 980 }, 981 { 982 .key_id = FLOW_DISSECTOR_KEY_VLAN, 983 .offset = offsetof(struct flow_keys, vlan), 984 }, 985 { 986 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 987 .offset = offsetof(struct flow_keys, tags), 988 }, 989 { 990 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 991 .offset = offsetof(struct flow_keys, keyid), 992 }, 993 }; 994 995 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { 996 { 997 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 998 .offset = offsetof(struct flow_keys, control), 999 }, 1000 { 1001 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1002 .offset = offsetof(struct flow_keys, basic), 1003 }, 1004 { 1005 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1006 .offset = offsetof(struct flow_keys, addrs.v4addrs), 1007 }, 1008 { 1009 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1010 .offset = offsetof(struct flow_keys, addrs.v6addrs), 1011 }, 1012 { 1013 .key_id = FLOW_DISSECTOR_KEY_PORTS, 1014 .offset = offsetof(struct flow_keys, ports), 1015 }, 1016 }; 1017 1018 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = { 1019 { 1020 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 1021 .offset = offsetof(struct flow_keys, control), 1022 }, 1023 { 1024 .key_id = FLOW_DISSECTOR_KEY_BASIC, 1025 .offset = offsetof(struct flow_keys, basic), 1026 }, 1027 }; 1028 1029 struct flow_dissector flow_keys_dissector __read_mostly; 1030 EXPORT_SYMBOL(flow_keys_dissector); 1031 1032 struct flow_dissector flow_keys_buf_dissector __read_mostly; 1033 1034 static int __init init_default_flow_dissectors(void) 1035 { 1036 skb_flow_dissector_init(&flow_keys_dissector, 1037 flow_keys_dissector_keys, 1038 ARRAY_SIZE(flow_keys_dissector_keys)); 1039 skb_flow_dissector_init(&flow_keys_dissector_symmetric, 1040 flow_keys_dissector_symmetric_keys, 1041 ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); 1042 skb_flow_dissector_init(&flow_keys_buf_dissector, 1043 flow_keys_buf_dissector_keys, 1044 ARRAY_SIZE(flow_keys_buf_dissector_keys)); 1045 return 0; 1046 } 1047 1048 core_initcall(init_default_flow_dissectors); 1049