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 bool dissector_uses_key(const struct flow_dissector *flow_dissector, 23 enum flow_dissector_key_id key_id) 24 { 25 return flow_dissector->used_keys & (1 << key_id); 26 } 27 28 static void dissector_set_key(struct flow_dissector *flow_dissector, 29 enum flow_dissector_key_id key_id) 30 { 31 flow_dissector->used_keys |= (1 << key_id); 32 } 33 34 static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector, 35 enum flow_dissector_key_id key_id, 36 void *target_container) 37 { 38 return ((char *) target_container) + flow_dissector->offset[key_id]; 39 } 40 41 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 42 const struct flow_dissector_key *key, 43 unsigned int key_count) 44 { 45 unsigned int i; 46 47 memset(flow_dissector, 0, sizeof(*flow_dissector)); 48 49 for (i = 0; i < key_count; i++, key++) { 50 /* User should make sure that every key target offset is withing 51 * boundaries of unsigned short. 52 */ 53 BUG_ON(key->offset > USHRT_MAX); 54 BUG_ON(dissector_uses_key(flow_dissector, 55 key->key_id)); 56 57 dissector_set_key(flow_dissector, key->key_id); 58 flow_dissector->offset[key->key_id] = key->offset; 59 } 60 61 /* Ensure that the dissector always includes control and basic key. 62 * That way we are able to avoid handling lack of these in fast path. 63 */ 64 BUG_ON(!dissector_uses_key(flow_dissector, 65 FLOW_DISSECTOR_KEY_CONTROL)); 66 BUG_ON(!dissector_uses_key(flow_dissector, 67 FLOW_DISSECTOR_KEY_BASIC)); 68 } 69 EXPORT_SYMBOL(skb_flow_dissector_init); 70 71 /** 72 * __skb_flow_get_ports - extract the upper layer ports and return them 73 * @skb: sk_buff to extract the ports from 74 * @thoff: transport header offset 75 * @ip_proto: protocol for which to get port offset 76 * @data: raw buffer pointer to the packet, if NULL use skb->data 77 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 78 * 79 * The function will try to retrieve the ports at offset thoff + poff where poff 80 * is the protocol port offset returned from proto_ports_offset 81 */ 82 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 83 void *data, int hlen) 84 { 85 int poff = proto_ports_offset(ip_proto); 86 87 if (!data) { 88 data = skb->data; 89 hlen = skb_headlen(skb); 90 } 91 92 if (poff >= 0) { 93 __be32 *ports, _ports; 94 95 ports = __skb_header_pointer(skb, thoff + poff, 96 sizeof(_ports), data, hlen, &_ports); 97 if (ports) 98 return *ports; 99 } 100 101 return 0; 102 } 103 EXPORT_SYMBOL(__skb_flow_get_ports); 104 105 /** 106 * __skb_flow_dissect - extract the flow_keys struct and return it 107 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 108 * @flow_dissector: list of keys to dissect 109 * @target_container: target structure to put dissected values into 110 * @data: raw buffer pointer to the packet, if NULL use skb->data 111 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 112 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 113 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 114 * 115 * The function will try to retrieve individual keys into target specified 116 * by flow_dissector from either the skbuff or a raw buffer specified by the 117 * rest parameters. 118 * 119 * Caller must take care of zeroing target container memory. 120 */ 121 bool __skb_flow_dissect(const struct sk_buff *skb, 122 struct flow_dissector *flow_dissector, 123 void *target_container, 124 void *data, __be16 proto, int nhoff, int hlen, 125 unsigned int flags) 126 { 127 struct flow_dissector_key_control *key_control; 128 struct flow_dissector_key_basic *key_basic; 129 struct flow_dissector_key_addrs *key_addrs; 130 struct flow_dissector_key_ports *key_ports; 131 struct flow_dissector_key_tags *key_tags; 132 struct flow_dissector_key_keyid *key_keyid; 133 u8 ip_proto = 0; 134 bool ret = false; 135 136 if (!data) { 137 data = skb->data; 138 proto = skb->protocol; 139 nhoff = skb_network_offset(skb); 140 hlen = skb_headlen(skb); 141 } 142 143 /* It is ensured by skb_flow_dissector_init() that control key will 144 * be always present. 145 */ 146 key_control = skb_flow_dissector_target(flow_dissector, 147 FLOW_DISSECTOR_KEY_CONTROL, 148 target_container); 149 150 /* It is ensured by skb_flow_dissector_init() that basic key will 151 * be always present. 152 */ 153 key_basic = skb_flow_dissector_target(flow_dissector, 154 FLOW_DISSECTOR_KEY_BASIC, 155 target_container); 156 157 if (dissector_uses_key(flow_dissector, 158 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 159 struct ethhdr *eth = eth_hdr(skb); 160 struct flow_dissector_key_eth_addrs *key_eth_addrs; 161 162 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 163 FLOW_DISSECTOR_KEY_ETH_ADDRS, 164 target_container); 165 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs)); 166 } 167 168 again: 169 switch (proto) { 170 case htons(ETH_P_IP): { 171 const struct iphdr *iph; 172 struct iphdr _iph; 173 ip: 174 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 175 if (!iph || iph->ihl < 5) 176 goto out_bad; 177 nhoff += iph->ihl * 4; 178 179 ip_proto = iph->protocol; 180 181 if (!dissector_uses_key(flow_dissector, 182 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) 183 break; 184 185 key_addrs = skb_flow_dissector_target(flow_dissector, 186 FLOW_DISSECTOR_KEY_IPV4_ADDRS, target_container); 187 memcpy(&key_addrs->v4addrs, &iph->saddr, 188 sizeof(key_addrs->v4addrs)); 189 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 190 191 if (ip_is_fragment(iph)) { 192 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 193 194 if (iph->frag_off & htons(IP_OFFSET)) { 195 goto out_good; 196 } else { 197 key_control->flags |= FLOW_DIS_FIRST_FRAG; 198 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) 199 goto out_good; 200 } 201 } 202 203 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) 204 goto out_good; 205 206 break; 207 } 208 case htons(ETH_P_IPV6): { 209 const struct ipv6hdr *iph; 210 struct ipv6hdr _iph; 211 212 ipv6: 213 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 214 if (!iph) 215 goto out_bad; 216 217 ip_proto = iph->nexthdr; 218 nhoff += sizeof(struct ipv6hdr); 219 220 if (dissector_uses_key(flow_dissector, 221 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 222 struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs; 223 224 key_ipv6_addrs = skb_flow_dissector_target(flow_dissector, 225 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 226 target_container); 227 228 memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs)); 229 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 230 } 231 232 if ((dissector_uses_key(flow_dissector, 233 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 234 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 235 ip6_flowlabel(iph)) { 236 __be32 flow_label = ip6_flowlabel(iph); 237 238 if (dissector_uses_key(flow_dissector, 239 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 240 key_tags = skb_flow_dissector_target(flow_dissector, 241 FLOW_DISSECTOR_KEY_FLOW_LABEL, 242 target_container); 243 key_tags->flow_label = ntohl(flow_label); 244 } 245 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) 246 goto out_good; 247 } 248 249 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) 250 goto out_good; 251 252 break; 253 } 254 case htons(ETH_P_8021AD): 255 case htons(ETH_P_8021Q): { 256 const struct vlan_hdr *vlan; 257 struct vlan_hdr _vlan; 258 259 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan); 260 if (!vlan) 261 goto out_bad; 262 263 if (dissector_uses_key(flow_dissector, 264 FLOW_DISSECTOR_KEY_VLANID)) { 265 key_tags = skb_flow_dissector_target(flow_dissector, 266 FLOW_DISSECTOR_KEY_VLANID, 267 target_container); 268 269 key_tags->vlan_id = skb_vlan_tag_get_id(skb); 270 } 271 272 proto = vlan->h_vlan_encapsulated_proto; 273 nhoff += sizeof(*vlan); 274 goto again; 275 } 276 case htons(ETH_P_PPP_SES): { 277 struct { 278 struct pppoe_hdr hdr; 279 __be16 proto; 280 } *hdr, _hdr; 281 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 282 if (!hdr) 283 goto out_bad; 284 proto = hdr->proto; 285 nhoff += PPPOE_SES_HLEN; 286 switch (proto) { 287 case htons(PPP_IP): 288 goto ip; 289 case htons(PPP_IPV6): 290 goto ipv6; 291 default: 292 goto out_bad; 293 } 294 } 295 case htons(ETH_P_TIPC): { 296 struct { 297 __be32 pre[3]; 298 __be32 srcnode; 299 } *hdr, _hdr; 300 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 301 if (!hdr) 302 goto out_bad; 303 304 if (dissector_uses_key(flow_dissector, 305 FLOW_DISSECTOR_KEY_TIPC_ADDRS)) { 306 key_addrs = skb_flow_dissector_target(flow_dissector, 307 FLOW_DISSECTOR_KEY_TIPC_ADDRS, 308 target_container); 309 key_addrs->tipcaddrs.srcnode = hdr->srcnode; 310 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS; 311 } 312 goto out_good; 313 } 314 315 case htons(ETH_P_MPLS_UC): 316 case htons(ETH_P_MPLS_MC): { 317 struct mpls_label *hdr, _hdr[2]; 318 mpls: 319 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 320 hlen, &_hdr); 321 if (!hdr) 322 goto out_bad; 323 324 if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >> 325 MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) { 326 if (dissector_uses_key(flow_dissector, 327 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { 328 key_keyid = skb_flow_dissector_target(flow_dissector, 329 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 330 target_container); 331 key_keyid->keyid = hdr[1].entry & 332 htonl(MPLS_LS_LABEL_MASK); 333 } 334 335 goto out_good; 336 } 337 338 goto out_good; 339 } 340 341 case htons(ETH_P_FCOE): 342 key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN); 343 /* fall through */ 344 default: 345 goto out_bad; 346 } 347 348 ip_proto_again: 349 switch (ip_proto) { 350 case IPPROTO_GRE: { 351 struct gre_hdr { 352 __be16 flags; 353 __be16 proto; 354 } *hdr, _hdr; 355 356 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 357 if (!hdr) 358 goto out_bad; 359 /* 360 * Only look inside GRE if version zero and no 361 * routing 362 */ 363 if (hdr->flags & (GRE_VERSION | GRE_ROUTING)) 364 break; 365 366 proto = hdr->proto; 367 nhoff += 4; 368 if (hdr->flags & GRE_CSUM) 369 nhoff += 4; 370 if (hdr->flags & GRE_KEY) { 371 const __be32 *keyid; 372 __be32 _keyid; 373 374 keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid), 375 data, hlen, &_keyid); 376 377 if (!keyid) 378 goto out_bad; 379 380 if (dissector_uses_key(flow_dissector, 381 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 382 key_keyid = skb_flow_dissector_target(flow_dissector, 383 FLOW_DISSECTOR_KEY_GRE_KEYID, 384 target_container); 385 key_keyid->keyid = *keyid; 386 } 387 nhoff += 4; 388 } 389 if (hdr->flags & GRE_SEQ) 390 nhoff += 4; 391 if (proto == htons(ETH_P_TEB)) { 392 const struct ethhdr *eth; 393 struct ethhdr _eth; 394 395 eth = __skb_header_pointer(skb, nhoff, 396 sizeof(_eth), 397 data, hlen, &_eth); 398 if (!eth) 399 goto out_bad; 400 proto = eth->h_proto; 401 nhoff += sizeof(*eth); 402 } 403 404 key_control->flags |= FLOW_DIS_ENCAPSULATION; 405 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 406 goto out_good; 407 408 goto again; 409 } 410 case NEXTHDR_HOP: 411 case NEXTHDR_ROUTING: 412 case NEXTHDR_DEST: { 413 u8 _opthdr[2], *opthdr; 414 415 if (proto != htons(ETH_P_IPV6)) 416 break; 417 418 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 419 data, hlen, &_opthdr); 420 if (!opthdr) 421 goto out_bad; 422 423 ip_proto = opthdr[0]; 424 nhoff += (opthdr[1] + 1) << 3; 425 426 goto ip_proto_again; 427 } 428 case NEXTHDR_FRAGMENT: { 429 struct frag_hdr _fh, *fh; 430 431 if (proto != htons(ETH_P_IPV6)) 432 break; 433 434 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 435 data, hlen, &_fh); 436 437 if (!fh) 438 goto out_bad; 439 440 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 441 442 nhoff += sizeof(_fh); 443 444 if (!(fh->frag_off & htons(IP6_OFFSET))) { 445 key_control->flags |= FLOW_DIS_FIRST_FRAG; 446 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { 447 ip_proto = fh->nexthdr; 448 goto ip_proto_again; 449 } 450 } 451 goto out_good; 452 } 453 case IPPROTO_IPIP: 454 proto = htons(ETH_P_IP); 455 456 key_control->flags |= FLOW_DIS_ENCAPSULATION; 457 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 458 goto out_good; 459 460 goto ip; 461 case IPPROTO_IPV6: 462 proto = htons(ETH_P_IPV6); 463 464 key_control->flags |= FLOW_DIS_ENCAPSULATION; 465 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 466 goto out_good; 467 468 goto ipv6; 469 case IPPROTO_MPLS: 470 proto = htons(ETH_P_MPLS_UC); 471 goto mpls; 472 default: 473 break; 474 } 475 476 if (dissector_uses_key(flow_dissector, 477 FLOW_DISSECTOR_KEY_PORTS)) { 478 key_ports = skb_flow_dissector_target(flow_dissector, 479 FLOW_DISSECTOR_KEY_PORTS, 480 target_container); 481 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 482 data, hlen); 483 } 484 485 out_good: 486 ret = true; 487 488 out_bad: 489 key_basic->n_proto = proto; 490 key_basic->ip_proto = ip_proto; 491 key_control->thoff = (u16)nhoff; 492 493 return ret; 494 } 495 EXPORT_SYMBOL(__skb_flow_dissect); 496 497 static u32 hashrnd __read_mostly; 498 static __always_inline void __flow_hash_secret_init(void) 499 { 500 net_get_random_once(&hashrnd, sizeof(hashrnd)); 501 } 502 503 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length, 504 u32 keyval) 505 { 506 return jhash2(words, length, keyval); 507 } 508 509 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow) 510 { 511 const void *p = flow; 512 513 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32)); 514 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET); 515 } 516 517 static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 518 { 519 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 520 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 521 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) != 522 sizeof(*flow) - sizeof(flow->addrs)); 523 524 switch (flow->control.addr_type) { 525 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 526 diff -= sizeof(flow->addrs.v4addrs); 527 break; 528 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 529 diff -= sizeof(flow->addrs.v6addrs); 530 break; 531 case FLOW_DISSECTOR_KEY_TIPC_ADDRS: 532 diff -= sizeof(flow->addrs.tipcaddrs); 533 break; 534 } 535 return (sizeof(*flow) - diff) / sizeof(u32); 536 } 537 538 __be32 flow_get_u32_src(const struct flow_keys *flow) 539 { 540 switch (flow->control.addr_type) { 541 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 542 return flow->addrs.v4addrs.src; 543 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 544 return (__force __be32)ipv6_addr_hash( 545 &flow->addrs.v6addrs.src); 546 case FLOW_DISSECTOR_KEY_TIPC_ADDRS: 547 return flow->addrs.tipcaddrs.srcnode; 548 default: 549 return 0; 550 } 551 } 552 EXPORT_SYMBOL(flow_get_u32_src); 553 554 __be32 flow_get_u32_dst(const struct flow_keys *flow) 555 { 556 switch (flow->control.addr_type) { 557 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 558 return flow->addrs.v4addrs.dst; 559 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 560 return (__force __be32)ipv6_addr_hash( 561 &flow->addrs.v6addrs.dst); 562 default: 563 return 0; 564 } 565 } 566 EXPORT_SYMBOL(flow_get_u32_dst); 567 568 static inline void __flow_hash_consistentify(struct flow_keys *keys) 569 { 570 int addr_diff, i; 571 572 switch (keys->control.addr_type) { 573 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 574 addr_diff = (__force u32)keys->addrs.v4addrs.dst - 575 (__force u32)keys->addrs.v4addrs.src; 576 if ((addr_diff < 0) || 577 (addr_diff == 0 && 578 ((__force u16)keys->ports.dst < 579 (__force u16)keys->ports.src))) { 580 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 581 swap(keys->ports.src, keys->ports.dst); 582 } 583 break; 584 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 585 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 586 &keys->addrs.v6addrs.src, 587 sizeof(keys->addrs.v6addrs.dst)); 588 if ((addr_diff < 0) || 589 (addr_diff == 0 && 590 ((__force u16)keys->ports.dst < 591 (__force u16)keys->ports.src))) { 592 for (i = 0; i < 4; i++) 593 swap(keys->addrs.v6addrs.src.s6_addr32[i], 594 keys->addrs.v6addrs.dst.s6_addr32[i]); 595 swap(keys->ports.src, keys->ports.dst); 596 } 597 break; 598 } 599 } 600 601 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval) 602 { 603 u32 hash; 604 605 __flow_hash_consistentify(keys); 606 607 hash = __flow_hash_words(flow_keys_hash_start(keys), 608 flow_keys_hash_length(keys), keyval); 609 if (!hash) 610 hash = 1; 611 612 return hash; 613 } 614 615 u32 flow_hash_from_keys(struct flow_keys *keys) 616 { 617 __flow_hash_secret_init(); 618 return __flow_hash_from_keys(keys, hashrnd); 619 } 620 EXPORT_SYMBOL(flow_hash_from_keys); 621 622 static inline u32 ___skb_get_hash(const struct sk_buff *skb, 623 struct flow_keys *keys, u32 keyval) 624 { 625 skb_flow_dissect_flow_keys(skb, keys, 626 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 627 628 return __flow_hash_from_keys(keys, keyval); 629 } 630 631 struct _flow_keys_digest_data { 632 __be16 n_proto; 633 u8 ip_proto; 634 u8 padding; 635 __be32 ports; 636 __be32 src; 637 __be32 dst; 638 }; 639 640 void make_flow_keys_digest(struct flow_keys_digest *digest, 641 const struct flow_keys *flow) 642 { 643 struct _flow_keys_digest_data *data = 644 (struct _flow_keys_digest_data *)digest; 645 646 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 647 648 memset(digest, 0, sizeof(*digest)); 649 650 data->n_proto = flow->basic.n_proto; 651 data->ip_proto = flow->basic.ip_proto; 652 data->ports = flow->ports.ports; 653 data->src = flow->addrs.v4addrs.src; 654 data->dst = flow->addrs.v4addrs.dst; 655 } 656 EXPORT_SYMBOL(make_flow_keys_digest); 657 658 /** 659 * __skb_get_hash: calculate a flow hash 660 * @skb: sk_buff to calculate flow hash from 661 * 662 * This function calculates a flow hash based on src/dst addresses 663 * and src/dst port numbers. Sets hash in skb to non-zero hash value 664 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 665 * if hash is a canonical 4-tuple hash over transport ports. 666 */ 667 void __skb_get_hash(struct sk_buff *skb) 668 { 669 struct flow_keys keys; 670 671 __flow_hash_secret_init(); 672 673 __skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd), 674 flow_keys_have_l4(&keys)); 675 } 676 EXPORT_SYMBOL(__skb_get_hash); 677 678 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb) 679 { 680 struct flow_keys keys; 681 682 return ___skb_get_hash(skb, &keys, perturb); 683 } 684 EXPORT_SYMBOL(skb_get_hash_perturb); 685 686 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6) 687 { 688 struct flow_keys keys; 689 690 memset(&keys, 0, sizeof(keys)); 691 692 memcpy(&keys.addrs.v6addrs.src, &fl6->saddr, 693 sizeof(keys.addrs.v6addrs.src)); 694 memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr, 695 sizeof(keys.addrs.v6addrs.dst)); 696 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 697 keys.ports.src = fl6->fl6_sport; 698 keys.ports.dst = fl6->fl6_dport; 699 keys.keyid.keyid = fl6->fl6_gre_key; 700 keys.tags.flow_label = (__force u32)fl6->flowlabel; 701 keys.basic.ip_proto = fl6->flowi6_proto; 702 703 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), 704 flow_keys_have_l4(&keys)); 705 706 return skb->hash; 707 } 708 EXPORT_SYMBOL(__skb_get_hash_flowi6); 709 710 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4) 711 { 712 struct flow_keys keys; 713 714 memset(&keys, 0, sizeof(keys)); 715 716 keys.addrs.v4addrs.src = fl4->saddr; 717 keys.addrs.v4addrs.dst = fl4->daddr; 718 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 719 keys.ports.src = fl4->fl4_sport; 720 keys.ports.dst = fl4->fl4_dport; 721 keys.keyid.keyid = fl4->fl4_gre_key; 722 keys.basic.ip_proto = fl4->flowi4_proto; 723 724 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys), 725 flow_keys_have_l4(&keys)); 726 727 return skb->hash; 728 } 729 EXPORT_SYMBOL(__skb_get_hash_flowi4); 730 731 u32 __skb_get_poff(const struct sk_buff *skb, void *data, 732 const struct flow_keys *keys, int hlen) 733 { 734 u32 poff = keys->control.thoff; 735 736 switch (keys->basic.ip_proto) { 737 case IPPROTO_TCP: { 738 /* access doff as u8 to avoid unaligned access */ 739 const u8 *doff; 740 u8 _doff; 741 742 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 743 data, hlen, &_doff); 744 if (!doff) 745 return poff; 746 747 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 748 break; 749 } 750 case IPPROTO_UDP: 751 case IPPROTO_UDPLITE: 752 poff += sizeof(struct udphdr); 753 break; 754 /* For the rest, we do not really care about header 755 * extensions at this point for now. 756 */ 757 case IPPROTO_ICMP: 758 poff += sizeof(struct icmphdr); 759 break; 760 case IPPROTO_ICMPV6: 761 poff += sizeof(struct icmp6hdr); 762 break; 763 case IPPROTO_IGMP: 764 poff += sizeof(struct igmphdr); 765 break; 766 case IPPROTO_DCCP: 767 poff += sizeof(struct dccp_hdr); 768 break; 769 case IPPROTO_SCTP: 770 poff += sizeof(struct sctphdr); 771 break; 772 } 773 774 return poff; 775 } 776 777 /** 778 * skb_get_poff - get the offset to the payload 779 * @skb: sk_buff to get the payload offset from 780 * 781 * The function will get the offset to the payload as far as it could 782 * be dissected. The main user is currently BPF, so that we can dynamically 783 * truncate packets without needing to push actual payload to the user 784 * space and can analyze headers only, instead. 785 */ 786 u32 skb_get_poff(const struct sk_buff *skb) 787 { 788 struct flow_keys keys; 789 790 if (!skb_flow_dissect_flow_keys(skb, &keys, 0)) 791 return 0; 792 793 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 794 } 795 796 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 797 { 798 memset(keys, 0, sizeof(*keys)); 799 800 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 801 sizeof(keys->addrs.v6addrs.src)); 802 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 803 sizeof(keys->addrs.v6addrs.dst)); 804 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 805 keys->ports.src = fl6->fl6_sport; 806 keys->ports.dst = fl6->fl6_dport; 807 keys->keyid.keyid = fl6->fl6_gre_key; 808 keys->tags.flow_label = (__force u32)fl6->flowlabel; 809 keys->basic.ip_proto = fl6->flowi6_proto; 810 811 return flow_hash_from_keys(keys); 812 } 813 EXPORT_SYMBOL(__get_hash_from_flowi6); 814 815 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys) 816 { 817 memset(keys, 0, sizeof(*keys)); 818 819 keys->addrs.v4addrs.src = fl4->saddr; 820 keys->addrs.v4addrs.dst = fl4->daddr; 821 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 822 keys->ports.src = fl4->fl4_sport; 823 keys->ports.dst = fl4->fl4_dport; 824 keys->keyid.keyid = fl4->fl4_gre_key; 825 keys->basic.ip_proto = fl4->flowi4_proto; 826 827 return flow_hash_from_keys(keys); 828 } 829 EXPORT_SYMBOL(__get_hash_from_flowi4); 830 831 static const struct flow_dissector_key flow_keys_dissector_keys[] = { 832 { 833 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 834 .offset = offsetof(struct flow_keys, control), 835 }, 836 { 837 .key_id = FLOW_DISSECTOR_KEY_BASIC, 838 .offset = offsetof(struct flow_keys, basic), 839 }, 840 { 841 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 842 .offset = offsetof(struct flow_keys, addrs.v4addrs), 843 }, 844 { 845 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 846 .offset = offsetof(struct flow_keys, addrs.v6addrs), 847 }, 848 { 849 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS, 850 .offset = offsetof(struct flow_keys, addrs.tipcaddrs), 851 }, 852 { 853 .key_id = FLOW_DISSECTOR_KEY_PORTS, 854 .offset = offsetof(struct flow_keys, ports), 855 }, 856 { 857 .key_id = FLOW_DISSECTOR_KEY_VLANID, 858 .offset = offsetof(struct flow_keys, tags), 859 }, 860 { 861 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 862 .offset = offsetof(struct flow_keys, tags), 863 }, 864 { 865 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 866 .offset = offsetof(struct flow_keys, keyid), 867 }, 868 }; 869 870 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = { 871 { 872 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 873 .offset = offsetof(struct flow_keys, control), 874 }, 875 { 876 .key_id = FLOW_DISSECTOR_KEY_BASIC, 877 .offset = offsetof(struct flow_keys, basic), 878 }, 879 }; 880 881 struct flow_dissector flow_keys_dissector __read_mostly; 882 EXPORT_SYMBOL(flow_keys_dissector); 883 884 struct flow_dissector flow_keys_buf_dissector __read_mostly; 885 886 static int __init init_default_flow_dissectors(void) 887 { 888 skb_flow_dissector_init(&flow_keys_dissector, 889 flow_keys_dissector_keys, 890 ARRAY_SIZE(flow_keys_dissector_keys)); 891 skb_flow_dissector_init(&flow_keys_buf_dissector, 892 flow_keys_buf_dissector_keys, 893 ARRAY_SIZE(flow_keys_buf_dissector_keys)); 894 return 0; 895 } 896 897 late_initcall_sync(init_default_flow_dissectors); 898