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