1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <linux/kernel.h> 3 #include <linux/skbuff.h> 4 #include <linux/export.h> 5 #include <linux/ip.h> 6 #include <linux/ipv6.h> 7 #include <linux/if_vlan.h> 8 #include <linux/filter.h> 9 #include <net/dsa.h> 10 #include <net/dst_metadata.h> 11 #include <net/ip.h> 12 #include <net/ipv6.h> 13 #include <net/gre.h> 14 #include <net/pptp.h> 15 #include <net/tipc.h> 16 #include <linux/igmp.h> 17 #include <linux/icmp.h> 18 #include <linux/sctp.h> 19 #include <linux/dccp.h> 20 #include <linux/if_tunnel.h> 21 #include <linux/if_pppox.h> 22 #include <linux/ppp_defs.h> 23 #include <linux/stddef.h> 24 #include <linux/if_ether.h> 25 #include <linux/if_hsr.h> 26 #include <linux/mpls.h> 27 #include <linux/tcp.h> 28 #include <linux/ptp_classify.h> 29 #include <net/flow_dissector.h> 30 #include <net/pkt_cls.h> 31 #include <scsi/fc/fc_fcoe.h> 32 #include <uapi/linux/batadv_packet.h> 33 #include <linux/bpf.h> 34 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 35 #include <net/netfilter/nf_conntrack_core.h> 36 #include <net/netfilter/nf_conntrack_labels.h> 37 #endif 38 #include <linux/bpf-netns.h> 39 dissector_set_key(struct flow_dissector * flow_dissector,enum flow_dissector_key_id key_id)40 static void dissector_set_key(struct flow_dissector *flow_dissector, 41 enum flow_dissector_key_id key_id) 42 { 43 flow_dissector->used_keys |= (1ULL << key_id); 44 } 45 skb_flow_dissector_init(struct flow_dissector * flow_dissector,const struct flow_dissector_key * key,unsigned int key_count)46 void skb_flow_dissector_init(struct flow_dissector *flow_dissector, 47 const struct flow_dissector_key *key, 48 unsigned int key_count) 49 { 50 unsigned int i; 51 52 memset(flow_dissector, 0, sizeof(*flow_dissector)); 53 54 for (i = 0; i < key_count; i++, key++) { 55 /* User should make sure that every key target offset is within 56 * boundaries of unsigned short. 57 */ 58 BUG_ON(key->offset > USHRT_MAX); 59 BUG_ON(dissector_uses_key(flow_dissector, 60 key->key_id)); 61 62 dissector_set_key(flow_dissector, key->key_id); 63 flow_dissector->offset[key->key_id] = key->offset; 64 } 65 66 /* Ensure that the dissector always includes control and basic key. 67 * That way we are able to avoid handling lack of these in fast path. 68 */ 69 BUG_ON(!dissector_uses_key(flow_dissector, 70 FLOW_DISSECTOR_KEY_CONTROL)); 71 BUG_ON(!dissector_uses_key(flow_dissector, 72 FLOW_DISSECTOR_KEY_BASIC)); 73 } 74 EXPORT_SYMBOL(skb_flow_dissector_init); 75 76 #ifdef CONFIG_BPF_SYSCALL flow_dissector_bpf_prog_attach_check(struct net * net,struct bpf_prog * prog)77 int flow_dissector_bpf_prog_attach_check(struct net *net, 78 struct bpf_prog *prog) 79 { 80 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; 81 82 if (net == &init_net) { 83 /* BPF flow dissector in the root namespace overrides 84 * any per-net-namespace one. When attaching to root, 85 * make sure we don't have any BPF program attached 86 * to the non-root namespaces. 87 */ 88 struct net *ns; 89 90 for_each_net(ns) { 91 if (ns == &init_net) 92 continue; 93 if (rcu_access_pointer(ns->bpf.run_array[type])) 94 return -EEXIST; 95 } 96 } else { 97 /* Make sure root flow dissector is not attached 98 * when attaching to the non-root namespace. 99 */ 100 if (rcu_access_pointer(init_net.bpf.run_array[type])) 101 return -EEXIST; 102 } 103 104 return 0; 105 } 106 #endif /* CONFIG_BPF_SYSCALL */ 107 108 /** 109 * __skb_flow_get_ports - extract the upper layer ports and return them 110 * @skb: sk_buff to extract the ports from 111 * @thoff: transport header offset 112 * @ip_proto: protocol for which to get port offset 113 * @data: raw buffer pointer to the packet, if NULL use skb->data 114 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 115 * 116 * The function will try to retrieve the ports at offset thoff + poff where poff 117 * is the protocol port offset returned from proto_ports_offset 118 */ __skb_flow_get_ports(const struct sk_buff * skb,int thoff,u8 ip_proto,const void * data,int hlen)119 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, 120 const void *data, int hlen) 121 { 122 int poff = proto_ports_offset(ip_proto); 123 124 if (!data) { 125 data = skb->data; 126 hlen = skb_headlen(skb); 127 } 128 129 if (poff >= 0) { 130 __be32 *ports, _ports; 131 132 ports = __skb_header_pointer(skb, thoff + poff, 133 sizeof(_ports), data, hlen, &_ports); 134 if (ports) 135 return *ports; 136 } 137 138 return 0; 139 } 140 EXPORT_SYMBOL(__skb_flow_get_ports); 141 icmp_has_id(u8 type)142 static bool icmp_has_id(u8 type) 143 { 144 switch (type) { 145 case ICMP_ECHO: 146 case ICMP_ECHOREPLY: 147 case ICMP_TIMESTAMP: 148 case ICMP_TIMESTAMPREPLY: 149 case ICMPV6_ECHO_REQUEST: 150 case ICMPV6_ECHO_REPLY: 151 return true; 152 } 153 154 return false; 155 } 156 157 /** 158 * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields 159 * @skb: sk_buff to extract from 160 * @key_icmp: struct flow_dissector_key_icmp to fill 161 * @data: raw buffer pointer to the packet 162 * @thoff: offset to extract at 163 * @hlen: packet header length 164 */ skb_flow_get_icmp_tci(const struct sk_buff * skb,struct flow_dissector_key_icmp * key_icmp,const void * data,int thoff,int hlen)165 void skb_flow_get_icmp_tci(const struct sk_buff *skb, 166 struct flow_dissector_key_icmp *key_icmp, 167 const void *data, int thoff, int hlen) 168 { 169 struct icmphdr *ih, _ih; 170 171 ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih); 172 if (!ih) 173 return; 174 175 key_icmp->type = ih->type; 176 key_icmp->code = ih->code; 177 178 /* As we use 0 to signal that the Id field is not present, 179 * avoid confusion with packets without such field 180 */ 181 if (icmp_has_id(ih->type)) 182 key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1; 183 else 184 key_icmp->id = 0; 185 } 186 EXPORT_SYMBOL(skb_flow_get_icmp_tci); 187 188 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet 189 * using skb_flow_get_icmp_tci(). 190 */ __skb_flow_dissect_icmp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int thoff,int hlen)191 static void __skb_flow_dissect_icmp(const struct sk_buff *skb, 192 struct flow_dissector *flow_dissector, 193 void *target_container, const void *data, 194 int thoff, int hlen) 195 { 196 struct flow_dissector_key_icmp *key_icmp; 197 198 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP)) 199 return; 200 201 key_icmp = skb_flow_dissector_target(flow_dissector, 202 FLOW_DISSECTOR_KEY_ICMP, 203 target_container); 204 205 skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen); 206 } 207 __skb_flow_dissect_ah(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen)208 static void __skb_flow_dissect_ah(const struct sk_buff *skb, 209 struct flow_dissector *flow_dissector, 210 void *target_container, const void *data, 211 int nhoff, int hlen) 212 { 213 struct flow_dissector_key_ipsec *key_ah; 214 struct ip_auth_hdr _hdr, *hdr; 215 216 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC)) 217 return; 218 219 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 220 if (!hdr) 221 return; 222 223 key_ah = skb_flow_dissector_target(flow_dissector, 224 FLOW_DISSECTOR_KEY_IPSEC, 225 target_container); 226 227 key_ah->spi = hdr->spi; 228 } 229 __skb_flow_dissect_esp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen)230 static void __skb_flow_dissect_esp(const struct sk_buff *skb, 231 struct flow_dissector *flow_dissector, 232 void *target_container, const void *data, 233 int nhoff, int hlen) 234 { 235 struct flow_dissector_key_ipsec *key_esp; 236 struct ip_esp_hdr _hdr, *hdr; 237 238 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC)) 239 return; 240 241 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 242 if (!hdr) 243 return; 244 245 key_esp = skb_flow_dissector_target(flow_dissector, 246 FLOW_DISSECTOR_KEY_IPSEC, 247 target_container); 248 249 key_esp->spi = hdr->spi; 250 } 251 __skb_flow_dissect_l2tpv3(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen)252 static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb, 253 struct flow_dissector *flow_dissector, 254 void *target_container, const void *data, 255 int nhoff, int hlen) 256 { 257 struct flow_dissector_key_l2tpv3 *key_l2tpv3; 258 struct { 259 __be32 session_id; 260 } *hdr, _hdr; 261 262 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3)) 263 return; 264 265 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 266 if (!hdr) 267 return; 268 269 key_l2tpv3 = skb_flow_dissector_target(flow_dissector, 270 FLOW_DISSECTOR_KEY_L2TPV3, 271 target_container); 272 273 key_l2tpv3->session_id = hdr->session_id; 274 } 275 skb_flow_dissect_meta(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container)276 void skb_flow_dissect_meta(const struct sk_buff *skb, 277 struct flow_dissector *flow_dissector, 278 void *target_container) 279 { 280 struct flow_dissector_key_meta *meta; 281 282 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META)) 283 return; 284 285 meta = skb_flow_dissector_target(flow_dissector, 286 FLOW_DISSECTOR_KEY_META, 287 target_container); 288 meta->ingress_ifindex = skb->skb_iif; 289 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 290 if (tc_skb_ext_tc_enabled()) { 291 struct tc_skb_ext *ext; 292 293 ext = skb_ext_find(skb, TC_SKB_EXT); 294 if (ext) 295 meta->l2_miss = ext->l2_miss; 296 } 297 #endif 298 } 299 EXPORT_SYMBOL(skb_flow_dissect_meta); 300 301 static void skb_flow_dissect_set_enc_control(enum flow_dissector_key_id type,u32 ctrl_flags,struct flow_dissector * flow_dissector,void * target_container)302 skb_flow_dissect_set_enc_control(enum flow_dissector_key_id type, 303 u32 ctrl_flags, 304 struct flow_dissector *flow_dissector, 305 void *target_container) 306 { 307 struct flow_dissector_key_control *ctrl; 308 309 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL)) 310 return; 311 312 ctrl = skb_flow_dissector_target(flow_dissector, 313 FLOW_DISSECTOR_KEY_ENC_CONTROL, 314 target_container); 315 ctrl->addr_type = type; 316 ctrl->flags = ctrl_flags; 317 } 318 319 void skb_flow_dissect_ct(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,u16 * ctinfo_map,size_t mapsize,bool post_ct,u16 zone)320 skb_flow_dissect_ct(const struct sk_buff *skb, 321 struct flow_dissector *flow_dissector, 322 void *target_container, u16 *ctinfo_map, 323 size_t mapsize, bool post_ct, u16 zone) 324 { 325 #if IS_ENABLED(CONFIG_NF_CONNTRACK) 326 struct flow_dissector_key_ct *key; 327 enum ip_conntrack_info ctinfo; 328 struct nf_conn_labels *cl; 329 struct nf_conn *ct; 330 331 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT)) 332 return; 333 334 ct = nf_ct_get(skb, &ctinfo); 335 if (!ct && !post_ct) 336 return; 337 338 key = skb_flow_dissector_target(flow_dissector, 339 FLOW_DISSECTOR_KEY_CT, 340 target_container); 341 342 if (!ct) { 343 key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED | 344 TCA_FLOWER_KEY_CT_FLAGS_INVALID; 345 key->ct_zone = zone; 346 return; 347 } 348 349 if (ctinfo < mapsize) 350 key->ct_state = ctinfo_map[ctinfo]; 351 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) 352 key->ct_zone = ct->zone.id; 353 #endif 354 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) 355 key->ct_mark = READ_ONCE(ct->mark); 356 #endif 357 358 cl = nf_ct_labels_find(ct); 359 if (cl) 360 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels)); 361 #endif /* CONFIG_NF_CONNTRACK */ 362 } 363 EXPORT_SYMBOL(skb_flow_dissect_ct); 364 365 void skb_flow_dissect_tunnel_info(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container)366 skb_flow_dissect_tunnel_info(const struct sk_buff *skb, 367 struct flow_dissector *flow_dissector, 368 void *target_container) 369 { 370 struct ip_tunnel_info *info; 371 struct ip_tunnel_key *key; 372 u32 ctrl_flags = 0; 373 374 /* A quick check to see if there might be something to do. */ 375 if (!dissector_uses_key(flow_dissector, 376 FLOW_DISSECTOR_KEY_ENC_KEYID) && 377 !dissector_uses_key(flow_dissector, 378 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) && 379 !dissector_uses_key(flow_dissector, 380 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) && 381 !dissector_uses_key(flow_dissector, 382 FLOW_DISSECTOR_KEY_ENC_CONTROL) && 383 !dissector_uses_key(flow_dissector, 384 FLOW_DISSECTOR_KEY_ENC_PORTS) && 385 !dissector_uses_key(flow_dissector, 386 FLOW_DISSECTOR_KEY_ENC_IP) && 387 !dissector_uses_key(flow_dissector, 388 FLOW_DISSECTOR_KEY_ENC_OPTS)) 389 return; 390 391 info = skb_tunnel_info(skb); 392 if (!info) 393 return; 394 395 key = &info->key; 396 397 if (test_bit(IP_TUNNEL_CSUM_BIT, key->tun_flags)) 398 ctrl_flags |= FLOW_DIS_F_TUNNEL_CSUM; 399 if (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags)) 400 ctrl_flags |= FLOW_DIS_F_TUNNEL_DONT_FRAGMENT; 401 if (test_bit(IP_TUNNEL_OAM_BIT, key->tun_flags)) 402 ctrl_flags |= FLOW_DIS_F_TUNNEL_OAM; 403 if (test_bit(IP_TUNNEL_CRIT_OPT_BIT, key->tun_flags)) 404 ctrl_flags |= FLOW_DIS_F_TUNNEL_CRIT_OPT; 405 406 switch (ip_tunnel_info_af(info)) { 407 case AF_INET: 408 skb_flow_dissect_set_enc_control(FLOW_DISSECTOR_KEY_IPV4_ADDRS, 409 ctrl_flags, flow_dissector, 410 target_container); 411 if (dissector_uses_key(flow_dissector, 412 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) { 413 struct flow_dissector_key_ipv4_addrs *ipv4; 414 415 ipv4 = skb_flow_dissector_target(flow_dissector, 416 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, 417 target_container); 418 ipv4->src = key->u.ipv4.src; 419 ipv4->dst = key->u.ipv4.dst; 420 } 421 break; 422 case AF_INET6: 423 skb_flow_dissect_set_enc_control(FLOW_DISSECTOR_KEY_IPV6_ADDRS, 424 ctrl_flags, flow_dissector, 425 target_container); 426 if (dissector_uses_key(flow_dissector, 427 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) { 428 struct flow_dissector_key_ipv6_addrs *ipv6; 429 430 ipv6 = skb_flow_dissector_target(flow_dissector, 431 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, 432 target_container); 433 ipv6->src = key->u.ipv6.src; 434 ipv6->dst = key->u.ipv6.dst; 435 } 436 break; 437 default: 438 skb_flow_dissect_set_enc_control(0, ctrl_flags, flow_dissector, 439 target_container); 440 break; 441 } 442 443 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) { 444 struct flow_dissector_key_keyid *keyid; 445 446 keyid = skb_flow_dissector_target(flow_dissector, 447 FLOW_DISSECTOR_KEY_ENC_KEYID, 448 target_container); 449 keyid->keyid = tunnel_id_to_key32(key->tun_id); 450 } 451 452 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) { 453 struct flow_dissector_key_ports *tp; 454 455 tp = skb_flow_dissector_target(flow_dissector, 456 FLOW_DISSECTOR_KEY_ENC_PORTS, 457 target_container); 458 tp->src = key->tp_src; 459 tp->dst = key->tp_dst; 460 } 461 462 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) { 463 struct flow_dissector_key_ip *ip; 464 465 ip = skb_flow_dissector_target(flow_dissector, 466 FLOW_DISSECTOR_KEY_ENC_IP, 467 target_container); 468 ip->tos = key->tos; 469 ip->ttl = key->ttl; 470 } 471 472 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) { 473 struct flow_dissector_key_enc_opts *enc_opt; 474 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 475 u32 val; 476 477 enc_opt = skb_flow_dissector_target(flow_dissector, 478 FLOW_DISSECTOR_KEY_ENC_OPTS, 479 target_container); 480 481 if (!info->options_len) 482 return; 483 484 enc_opt->len = info->options_len; 485 ip_tunnel_info_opts_get(enc_opt->data, info); 486 487 ip_tunnel_set_options_present(flags); 488 ip_tunnel_flags_and(flags, info->key.tun_flags, flags); 489 490 val = find_next_bit(flags, __IP_TUNNEL_FLAG_NUM, 491 IP_TUNNEL_GENEVE_OPT_BIT); 492 enc_opt->dst_opt_type = val < __IP_TUNNEL_FLAG_NUM ? val : 0; 493 } 494 } 495 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); 496 skb_flow_dissect_hash(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container)497 void skb_flow_dissect_hash(const struct sk_buff *skb, 498 struct flow_dissector *flow_dissector, 499 void *target_container) 500 { 501 struct flow_dissector_key_hash *key; 502 503 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH)) 504 return; 505 506 key = skb_flow_dissector_target(flow_dissector, 507 FLOW_DISSECTOR_KEY_HASH, 508 target_container); 509 510 key->hash = skb_get_hash_raw(skb); 511 } 512 EXPORT_SYMBOL(skb_flow_dissect_hash); 513 514 static enum flow_dissect_ret __skb_flow_dissect_mpls(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen,int lse_index,bool * entropy_label)515 __skb_flow_dissect_mpls(const struct sk_buff *skb, 516 struct flow_dissector *flow_dissector, 517 void *target_container, const void *data, int nhoff, 518 int hlen, int lse_index, bool *entropy_label) 519 { 520 struct mpls_label *hdr, _hdr; 521 u32 entry, label, bos; 522 523 if (!dissector_uses_key(flow_dissector, 524 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && 525 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) 526 return FLOW_DISSECT_RET_OUT_GOOD; 527 528 if (lse_index >= FLOW_DIS_MPLS_MAX) 529 return FLOW_DISSECT_RET_OUT_GOOD; 530 531 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 532 hlen, &_hdr); 533 if (!hdr) 534 return FLOW_DISSECT_RET_OUT_BAD; 535 536 entry = ntohl(hdr->entry); 537 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; 538 bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT; 539 540 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) { 541 struct flow_dissector_key_mpls *key_mpls; 542 struct flow_dissector_mpls_lse *lse; 543 544 key_mpls = skb_flow_dissector_target(flow_dissector, 545 FLOW_DISSECTOR_KEY_MPLS, 546 target_container); 547 lse = &key_mpls->ls[lse_index]; 548 549 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; 550 lse->mpls_bos = bos; 551 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT; 552 lse->mpls_label = label; 553 dissector_set_mpls_lse(key_mpls, lse_index); 554 } 555 556 if (*entropy_label && 557 dissector_uses_key(flow_dissector, 558 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { 559 struct flow_dissector_key_keyid *key_keyid; 560 561 key_keyid = skb_flow_dissector_target(flow_dissector, 562 FLOW_DISSECTOR_KEY_MPLS_ENTROPY, 563 target_container); 564 key_keyid->keyid = cpu_to_be32(label); 565 } 566 567 *entropy_label = label == MPLS_LABEL_ENTROPY; 568 569 return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN; 570 } 571 572 static enum flow_dissect_ret __skb_flow_dissect_arp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen)573 __skb_flow_dissect_arp(const struct sk_buff *skb, 574 struct flow_dissector *flow_dissector, 575 void *target_container, const void *data, 576 int nhoff, int hlen) 577 { 578 struct flow_dissector_key_arp *key_arp; 579 struct { 580 unsigned char ar_sha[ETH_ALEN]; 581 unsigned char ar_sip[4]; 582 unsigned char ar_tha[ETH_ALEN]; 583 unsigned char ar_tip[4]; 584 } *arp_eth, _arp_eth; 585 const struct arphdr *arp; 586 struct arphdr _arp; 587 588 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP)) 589 return FLOW_DISSECT_RET_OUT_GOOD; 590 591 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data, 592 hlen, &_arp); 593 if (!arp) 594 return FLOW_DISSECT_RET_OUT_BAD; 595 596 if (arp->ar_hrd != htons(ARPHRD_ETHER) || 597 arp->ar_pro != htons(ETH_P_IP) || 598 arp->ar_hln != ETH_ALEN || 599 arp->ar_pln != 4 || 600 (arp->ar_op != htons(ARPOP_REPLY) && 601 arp->ar_op != htons(ARPOP_REQUEST))) 602 return FLOW_DISSECT_RET_OUT_BAD; 603 604 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp), 605 sizeof(_arp_eth), data, 606 hlen, &_arp_eth); 607 if (!arp_eth) 608 return FLOW_DISSECT_RET_OUT_BAD; 609 610 key_arp = skb_flow_dissector_target(flow_dissector, 611 FLOW_DISSECTOR_KEY_ARP, 612 target_container); 613 614 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); 615 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); 616 617 /* Only store the lower byte of the opcode; 618 * this covers ARPOP_REPLY and ARPOP_REQUEST. 619 */ 620 key_arp->op = ntohs(arp->ar_op) & 0xff; 621 622 ether_addr_copy(key_arp->sha, arp_eth->ar_sha); 623 ether_addr_copy(key_arp->tha, arp_eth->ar_tha); 624 625 return FLOW_DISSECT_RET_OUT_GOOD; 626 } 627 628 static enum flow_dissect_ret __skb_flow_dissect_cfm(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,int hlen)629 __skb_flow_dissect_cfm(const struct sk_buff *skb, 630 struct flow_dissector *flow_dissector, 631 void *target_container, const void *data, 632 int nhoff, int hlen) 633 { 634 struct flow_dissector_key_cfm *key, *hdr, _hdr; 635 636 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM)) 637 return FLOW_DISSECT_RET_OUT_GOOD; 638 639 hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr); 640 if (!hdr) 641 return FLOW_DISSECT_RET_OUT_BAD; 642 643 key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM, 644 target_container); 645 646 key->mdl_ver = hdr->mdl_ver; 647 key->opcode = hdr->opcode; 648 649 return FLOW_DISSECT_RET_OUT_GOOD; 650 } 651 652 static enum flow_dissect_ret __skb_flow_dissect_gre(const struct sk_buff * skb,struct flow_dissector_key_control * key_control,struct flow_dissector * flow_dissector,void * target_container,const void * data,__be16 * p_proto,int * p_nhoff,int * p_hlen,unsigned int flags)653 __skb_flow_dissect_gre(const struct sk_buff *skb, 654 struct flow_dissector_key_control *key_control, 655 struct flow_dissector *flow_dissector, 656 void *target_container, const void *data, 657 __be16 *p_proto, int *p_nhoff, int *p_hlen, 658 unsigned int flags) 659 { 660 struct flow_dissector_key_keyid *key_keyid; 661 struct gre_base_hdr *hdr, _hdr; 662 int offset = 0; 663 u16 gre_ver; 664 665 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), 666 data, *p_hlen, &_hdr); 667 if (!hdr) 668 return FLOW_DISSECT_RET_OUT_BAD; 669 670 /* Only look inside GRE without routing */ 671 if (hdr->flags & GRE_ROUTING) 672 return FLOW_DISSECT_RET_OUT_GOOD; 673 674 /* Only look inside GRE for version 0 and 1 */ 675 gre_ver = ntohs(hdr->flags & GRE_VERSION); 676 if (gre_ver > 1) 677 return FLOW_DISSECT_RET_OUT_GOOD; 678 679 *p_proto = hdr->protocol; 680 if (gre_ver) { 681 /* Version1 must be PPTP, and check the flags */ 682 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) 683 return FLOW_DISSECT_RET_OUT_GOOD; 684 } 685 686 offset += sizeof(struct gre_base_hdr); 687 688 if (hdr->flags & GRE_CSUM) 689 offset += sizeof_field(struct gre_full_hdr, csum) + 690 sizeof_field(struct gre_full_hdr, reserved1); 691 692 if (hdr->flags & GRE_KEY) { 693 const __be32 *keyid; 694 __be32 _keyid; 695 696 keyid = __skb_header_pointer(skb, *p_nhoff + offset, 697 sizeof(_keyid), 698 data, *p_hlen, &_keyid); 699 if (!keyid) 700 return FLOW_DISSECT_RET_OUT_BAD; 701 702 if (dissector_uses_key(flow_dissector, 703 FLOW_DISSECTOR_KEY_GRE_KEYID)) { 704 key_keyid = skb_flow_dissector_target(flow_dissector, 705 FLOW_DISSECTOR_KEY_GRE_KEYID, 706 target_container); 707 if (gre_ver == 0) 708 key_keyid->keyid = *keyid; 709 else 710 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; 711 } 712 offset += sizeof_field(struct gre_full_hdr, key); 713 } 714 715 if (hdr->flags & GRE_SEQ) 716 offset += sizeof_field(struct pptp_gre_header, seq); 717 718 if (gre_ver == 0) { 719 if (*p_proto == htons(ETH_P_TEB)) { 720 const struct ethhdr *eth; 721 struct ethhdr _eth; 722 723 eth = __skb_header_pointer(skb, *p_nhoff + offset, 724 sizeof(_eth), 725 data, *p_hlen, &_eth); 726 if (!eth) 727 return FLOW_DISSECT_RET_OUT_BAD; 728 *p_proto = eth->h_proto; 729 offset += sizeof(*eth); 730 731 /* Cap headers that we access via pointers at the 732 * end of the Ethernet header as our maximum alignment 733 * at that point is only 2 bytes. 734 */ 735 if (NET_IP_ALIGN) 736 *p_hlen = *p_nhoff + offset; 737 } 738 } else { /* version 1, must be PPTP */ 739 u8 _ppp_hdr[PPP_HDRLEN]; 740 u8 *ppp_hdr; 741 742 if (hdr->flags & GRE_ACK) 743 offset += sizeof_field(struct pptp_gre_header, ack); 744 745 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset, 746 sizeof(_ppp_hdr), 747 data, *p_hlen, _ppp_hdr); 748 if (!ppp_hdr) 749 return FLOW_DISSECT_RET_OUT_BAD; 750 751 switch (PPP_PROTOCOL(ppp_hdr)) { 752 case PPP_IP: 753 *p_proto = htons(ETH_P_IP); 754 break; 755 case PPP_IPV6: 756 *p_proto = htons(ETH_P_IPV6); 757 break; 758 default: 759 /* Could probably catch some more like MPLS */ 760 break; 761 } 762 763 offset += PPP_HDRLEN; 764 } 765 766 *p_nhoff += offset; 767 key_control->flags |= FLOW_DIS_ENCAPSULATION; 768 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 769 return FLOW_DISSECT_RET_OUT_GOOD; 770 771 return FLOW_DISSECT_RET_PROTO_AGAIN; 772 } 773 774 /** 775 * __skb_flow_dissect_batadv() - dissect batman-adv header 776 * @skb: sk_buff to with the batman-adv header 777 * @key_control: flow dissectors control key 778 * @data: raw buffer pointer to the packet, if NULL use skb->data 779 * @p_proto: pointer used to update the protocol to process next 780 * @p_nhoff: pointer used to update inner network header offset 781 * @hlen: packet header length 782 * @flags: any combination of FLOW_DISSECTOR_F_* 783 * 784 * ETH_P_BATMAN packets are tried to be dissected. Only 785 * &struct batadv_unicast packets are actually processed because they contain an 786 * inner ethernet header and are usually followed by actual network header. This 787 * allows the flow dissector to continue processing the packet. 788 * 789 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, 790 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, 791 * otherwise FLOW_DISSECT_RET_OUT_BAD 792 */ 793 static enum flow_dissect_ret __skb_flow_dissect_batadv(const struct sk_buff * skb,struct flow_dissector_key_control * key_control,const void * data,__be16 * p_proto,int * p_nhoff,int hlen,unsigned int flags)794 __skb_flow_dissect_batadv(const struct sk_buff *skb, 795 struct flow_dissector_key_control *key_control, 796 const void *data, __be16 *p_proto, int *p_nhoff, 797 int hlen, unsigned int flags) 798 { 799 struct { 800 struct batadv_unicast_packet batadv_unicast; 801 struct ethhdr eth; 802 } *hdr, _hdr; 803 804 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen, 805 &_hdr); 806 if (!hdr) 807 return FLOW_DISSECT_RET_OUT_BAD; 808 809 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) 810 return FLOW_DISSECT_RET_OUT_BAD; 811 812 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) 813 return FLOW_DISSECT_RET_OUT_BAD; 814 815 *p_proto = hdr->eth.h_proto; 816 *p_nhoff += sizeof(*hdr); 817 818 key_control->flags |= FLOW_DIS_ENCAPSULATION; 819 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) 820 return FLOW_DISSECT_RET_OUT_GOOD; 821 822 return FLOW_DISSECT_RET_PROTO_AGAIN; 823 } 824 825 static void __skb_flow_dissect_tcp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int thoff,int hlen)826 __skb_flow_dissect_tcp(const struct sk_buff *skb, 827 struct flow_dissector *flow_dissector, 828 void *target_container, const void *data, 829 int thoff, int hlen) 830 { 831 struct flow_dissector_key_tcp *key_tcp; 832 struct tcphdr *th, _th; 833 834 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP)) 835 return; 836 837 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th); 838 if (!th) 839 return; 840 841 if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) 842 return; 843 844 key_tcp = skb_flow_dissector_target(flow_dissector, 845 FLOW_DISSECTOR_KEY_TCP, 846 target_container); 847 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); 848 } 849 850 static void __skb_flow_dissect_ports(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,int nhoff,u8 ip_proto,int hlen)851 __skb_flow_dissect_ports(const struct sk_buff *skb, 852 struct flow_dissector *flow_dissector, 853 void *target_container, const void *data, 854 int nhoff, u8 ip_proto, int hlen) 855 { 856 enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX; 857 struct flow_dissector_key_ports *key_ports; 858 859 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 860 dissector_ports = FLOW_DISSECTOR_KEY_PORTS; 861 else if (dissector_uses_key(flow_dissector, 862 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 863 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE; 864 865 if (dissector_ports == FLOW_DISSECTOR_KEY_MAX) 866 return; 867 868 key_ports = skb_flow_dissector_target(flow_dissector, 869 dissector_ports, 870 target_container); 871 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, 872 data, hlen); 873 } 874 875 static void __skb_flow_dissect_ipv4(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,const struct iphdr * iph)876 __skb_flow_dissect_ipv4(const struct sk_buff *skb, 877 struct flow_dissector *flow_dissector, 878 void *target_container, const void *data, 879 const struct iphdr *iph) 880 { 881 struct flow_dissector_key_ip *key_ip; 882 883 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 884 return; 885 886 key_ip = skb_flow_dissector_target(flow_dissector, 887 FLOW_DISSECTOR_KEY_IP, 888 target_container); 889 key_ip->tos = iph->tos; 890 key_ip->ttl = iph->ttl; 891 } 892 893 static void __skb_flow_dissect_ipv6(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,const struct ipv6hdr * iph)894 __skb_flow_dissect_ipv6(const struct sk_buff *skb, 895 struct flow_dissector *flow_dissector, 896 void *target_container, const void *data, 897 const struct ipv6hdr *iph) 898 { 899 struct flow_dissector_key_ip *key_ip; 900 901 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP)) 902 return; 903 904 key_ip = skb_flow_dissector_target(flow_dissector, 905 FLOW_DISSECTOR_KEY_IP, 906 target_container); 907 key_ip->tos = ipv6_get_dsfield(iph); 908 key_ip->ttl = iph->hop_limit; 909 } 910 911 /* Maximum number of protocol headers that can be parsed in 912 * __skb_flow_dissect 913 */ 914 #define MAX_FLOW_DISSECT_HDRS 15 915 skb_flow_dissect_allowed(int * num_hdrs)916 static bool skb_flow_dissect_allowed(int *num_hdrs) 917 { 918 ++*num_hdrs; 919 920 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); 921 } 922 __skb_flow_bpf_to_target(const struct bpf_flow_keys * flow_keys,struct flow_dissector * flow_dissector,void * target_container)923 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, 924 struct flow_dissector *flow_dissector, 925 void *target_container) 926 { 927 struct flow_dissector_key_ports *key_ports = NULL; 928 struct flow_dissector_key_control *key_control; 929 struct flow_dissector_key_basic *key_basic; 930 struct flow_dissector_key_addrs *key_addrs; 931 struct flow_dissector_key_tags *key_tags; 932 933 key_control = skb_flow_dissector_target(flow_dissector, 934 FLOW_DISSECTOR_KEY_CONTROL, 935 target_container); 936 key_control->thoff = flow_keys->thoff; 937 if (flow_keys->is_frag) 938 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 939 if (flow_keys->is_first_frag) 940 key_control->flags |= FLOW_DIS_FIRST_FRAG; 941 if (flow_keys->is_encap) 942 key_control->flags |= FLOW_DIS_ENCAPSULATION; 943 944 key_basic = skb_flow_dissector_target(flow_dissector, 945 FLOW_DISSECTOR_KEY_BASIC, 946 target_container); 947 key_basic->n_proto = flow_keys->n_proto; 948 key_basic->ip_proto = flow_keys->ip_proto; 949 950 if (flow_keys->addr_proto == ETH_P_IP && 951 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 952 key_addrs = skb_flow_dissector_target(flow_dissector, 953 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 954 target_container); 955 key_addrs->v4addrs.src = flow_keys->ipv4_src; 956 key_addrs->v4addrs.dst = flow_keys->ipv4_dst; 957 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 958 } else if (flow_keys->addr_proto == ETH_P_IPV6 && 959 dissector_uses_key(flow_dissector, 960 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 961 key_addrs = skb_flow_dissector_target(flow_dissector, 962 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 963 target_container); 964 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, 965 sizeof(key_addrs->v6addrs.src)); 966 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, 967 sizeof(key_addrs->v6addrs.dst)); 968 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 969 } 970 971 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) 972 key_ports = skb_flow_dissector_target(flow_dissector, 973 FLOW_DISSECTOR_KEY_PORTS, 974 target_container); 975 else if (dissector_uses_key(flow_dissector, 976 FLOW_DISSECTOR_KEY_PORTS_RANGE)) 977 key_ports = skb_flow_dissector_target(flow_dissector, 978 FLOW_DISSECTOR_KEY_PORTS_RANGE, 979 target_container); 980 981 if (key_ports) { 982 key_ports->src = flow_keys->sport; 983 key_ports->dst = flow_keys->dport; 984 } 985 986 if (dissector_uses_key(flow_dissector, 987 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 988 key_tags = skb_flow_dissector_target(flow_dissector, 989 FLOW_DISSECTOR_KEY_FLOW_LABEL, 990 target_container); 991 key_tags->flow_label = ntohl(flow_keys->flow_label); 992 } 993 } 994 bpf_flow_dissect(struct bpf_prog * prog,struct bpf_flow_dissector * ctx,__be16 proto,int nhoff,int hlen,unsigned int flags)995 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, 996 __be16 proto, int nhoff, int hlen, unsigned int flags) 997 { 998 struct bpf_flow_keys *flow_keys = ctx->flow_keys; 999 u32 result; 1000 1001 /* Pass parameters to the BPF program */ 1002 memset(flow_keys, 0, sizeof(*flow_keys)); 1003 flow_keys->n_proto = proto; 1004 flow_keys->nhoff = nhoff; 1005 flow_keys->thoff = flow_keys->nhoff; 1006 1007 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG != 1008 (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG); 1009 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL != 1010 (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1011 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP != 1012 (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); 1013 flow_keys->flags = flags; 1014 1015 result = bpf_prog_run_pin_on_cpu(prog, ctx); 1016 1017 flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen); 1018 flow_keys->thoff = clamp_t(u16, flow_keys->thoff, 1019 flow_keys->nhoff, hlen); 1020 1021 return result; 1022 } 1023 is_pppoe_ses_hdr_valid(const struct pppoe_hdr * hdr)1024 static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr) 1025 { 1026 return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0; 1027 } 1028 1029 /** 1030 * __skb_flow_dissect - extract the flow_keys struct and return it 1031 * @net: associated network namespace, derived from @skb if NULL 1032 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified 1033 * @flow_dissector: list of keys to dissect 1034 * @target_container: target structure to put dissected values into 1035 * @data: raw buffer pointer to the packet, if NULL use skb->data 1036 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol 1037 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) 1038 * @hlen: packet header length, if @data is NULL use skb_headlen(skb) 1039 * @flags: flags that control the dissection process, e.g. 1040 * FLOW_DISSECTOR_F_STOP_AT_ENCAP. 1041 * 1042 * The function will try to retrieve individual keys into target specified 1043 * by flow_dissector from either the skbuff or a raw buffer specified by the 1044 * rest parameters. 1045 * 1046 * Caller must take care of zeroing target container memory. 1047 */ __skb_flow_dissect(const struct net * net,const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,const void * data,__be16 proto,int nhoff,int hlen,unsigned int flags)1048 bool __skb_flow_dissect(const struct net *net, 1049 const struct sk_buff *skb, 1050 struct flow_dissector *flow_dissector, 1051 void *target_container, const void *data, 1052 __be16 proto, int nhoff, int hlen, unsigned int flags) 1053 { 1054 struct flow_dissector_key_control *key_control; 1055 struct flow_dissector_key_basic *key_basic; 1056 struct flow_dissector_key_addrs *key_addrs; 1057 struct flow_dissector_key_tags *key_tags; 1058 struct flow_dissector_key_vlan *key_vlan; 1059 enum flow_dissect_ret fdret; 1060 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; 1061 bool mpls_el = false; 1062 int mpls_lse = 0; 1063 int num_hdrs = 0; 1064 u8 ip_proto = 0; 1065 bool ret; 1066 1067 if (!data) { 1068 data = skb->data; 1069 proto = skb_vlan_tag_present(skb) ? 1070 skb->vlan_proto : skb->protocol; 1071 nhoff = skb_network_offset(skb); 1072 hlen = skb_headlen(skb); 1073 #if IS_ENABLED(CONFIG_NET_DSA) 1074 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) && 1075 proto == htons(ETH_P_XDSA))) { 1076 struct metadata_dst *md_dst = skb_metadata_dst(skb); 1077 const struct dsa_device_ops *ops; 1078 int offset = 0; 1079 1080 ops = skb->dev->dsa_ptr->tag_ops; 1081 /* Only DSA header taggers break flow dissection */ 1082 if (ops->needed_headroom && 1083 (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) { 1084 if (ops->flow_dissect) 1085 ops->flow_dissect(skb, &proto, &offset); 1086 else 1087 dsa_tag_generic_flow_dissect(skb, 1088 &proto, 1089 &offset); 1090 hlen -= offset; 1091 nhoff += offset; 1092 } 1093 } 1094 #endif 1095 } 1096 1097 /* It is ensured by skb_flow_dissector_init() that control key will 1098 * be always present. 1099 */ 1100 key_control = skb_flow_dissector_target(flow_dissector, 1101 FLOW_DISSECTOR_KEY_CONTROL, 1102 target_container); 1103 1104 /* It is ensured by skb_flow_dissector_init() that basic key will 1105 * be always present. 1106 */ 1107 key_basic = skb_flow_dissector_target(flow_dissector, 1108 FLOW_DISSECTOR_KEY_BASIC, 1109 target_container); 1110 1111 if (skb) { 1112 if (!net) { 1113 if (skb->dev) 1114 net = dev_net(skb->dev); 1115 else if (skb->sk) 1116 net = sock_net(skb->sk); 1117 } 1118 } 1119 1120 DEBUG_NET_WARN_ON_ONCE(!net); 1121 if (net) { 1122 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; 1123 struct bpf_prog_array *run_array; 1124 1125 rcu_read_lock(); 1126 run_array = rcu_dereference(init_net.bpf.run_array[type]); 1127 if (!run_array) 1128 run_array = rcu_dereference(net->bpf.run_array[type]); 1129 1130 if (run_array) { 1131 struct bpf_flow_keys flow_keys; 1132 struct bpf_flow_dissector ctx = { 1133 .flow_keys = &flow_keys, 1134 .data = data, 1135 .data_end = data + hlen, 1136 }; 1137 __be16 n_proto = proto; 1138 struct bpf_prog *prog; 1139 u32 result; 1140 1141 if (skb) { 1142 ctx.skb = skb; 1143 /* we can't use 'proto' in the skb case 1144 * because it might be set to skb->vlan_proto 1145 * which has been pulled from the data 1146 */ 1147 n_proto = skb->protocol; 1148 } 1149 1150 prog = READ_ONCE(run_array->items[0].prog); 1151 result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff, 1152 hlen, flags); 1153 if (result == BPF_FLOW_DISSECTOR_CONTINUE) 1154 goto dissect_continue; 1155 __skb_flow_bpf_to_target(&flow_keys, flow_dissector, 1156 target_container); 1157 rcu_read_unlock(); 1158 return result == BPF_OK; 1159 } 1160 dissect_continue: 1161 rcu_read_unlock(); 1162 } 1163 1164 if (dissector_uses_key(flow_dissector, 1165 FLOW_DISSECTOR_KEY_ETH_ADDRS)) { 1166 struct ethhdr *eth = eth_hdr(skb); 1167 struct flow_dissector_key_eth_addrs *key_eth_addrs; 1168 1169 key_eth_addrs = skb_flow_dissector_target(flow_dissector, 1170 FLOW_DISSECTOR_KEY_ETH_ADDRS, 1171 target_container); 1172 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs)); 1173 } 1174 1175 if (dissector_uses_key(flow_dissector, 1176 FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) { 1177 struct flow_dissector_key_num_of_vlans *key_num_of_vlans; 1178 1179 key_num_of_vlans = skb_flow_dissector_target(flow_dissector, 1180 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1181 target_container); 1182 key_num_of_vlans->num_of_vlans = 0; 1183 } 1184 1185 proto_again: 1186 fdret = FLOW_DISSECT_RET_CONTINUE; 1187 1188 switch (proto) { 1189 case htons(ETH_P_IP): { 1190 const struct iphdr *iph; 1191 struct iphdr _iph; 1192 1193 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1194 if (!iph || iph->ihl < 5) { 1195 fdret = FLOW_DISSECT_RET_OUT_BAD; 1196 break; 1197 } 1198 1199 nhoff += iph->ihl * 4; 1200 1201 ip_proto = iph->protocol; 1202 1203 if (dissector_uses_key(flow_dissector, 1204 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { 1205 key_addrs = skb_flow_dissector_target(flow_dissector, 1206 FLOW_DISSECTOR_KEY_IPV4_ADDRS, 1207 target_container); 1208 1209 memcpy(&key_addrs->v4addrs.src, &iph->saddr, 1210 sizeof(key_addrs->v4addrs.src)); 1211 memcpy(&key_addrs->v4addrs.dst, &iph->daddr, 1212 sizeof(key_addrs->v4addrs.dst)); 1213 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 1214 } 1215 1216 __skb_flow_dissect_ipv4(skb, flow_dissector, 1217 target_container, data, iph); 1218 1219 if (ip_is_fragment(iph)) { 1220 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1221 1222 if (iph->frag_off & htons(IP_OFFSET)) { 1223 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1224 break; 1225 } else { 1226 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1227 if (!(flags & 1228 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { 1229 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1230 break; 1231 } 1232 } 1233 } 1234 1235 break; 1236 } 1237 case htons(ETH_P_IPV6): { 1238 const struct ipv6hdr *iph; 1239 struct ipv6hdr _iph; 1240 1241 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph); 1242 if (!iph) { 1243 fdret = FLOW_DISSECT_RET_OUT_BAD; 1244 break; 1245 } 1246 1247 ip_proto = iph->nexthdr; 1248 nhoff += sizeof(struct ipv6hdr); 1249 1250 if (dissector_uses_key(flow_dissector, 1251 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { 1252 key_addrs = skb_flow_dissector_target(flow_dissector, 1253 FLOW_DISSECTOR_KEY_IPV6_ADDRS, 1254 target_container); 1255 1256 memcpy(&key_addrs->v6addrs.src, &iph->saddr, 1257 sizeof(key_addrs->v6addrs.src)); 1258 memcpy(&key_addrs->v6addrs.dst, &iph->daddr, 1259 sizeof(key_addrs->v6addrs.dst)); 1260 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1261 } 1262 1263 if ((dissector_uses_key(flow_dissector, 1264 FLOW_DISSECTOR_KEY_FLOW_LABEL) || 1265 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && 1266 ip6_flowlabel(iph)) { 1267 __be32 flow_label = ip6_flowlabel(iph); 1268 1269 if (dissector_uses_key(flow_dissector, 1270 FLOW_DISSECTOR_KEY_FLOW_LABEL)) { 1271 key_tags = skb_flow_dissector_target(flow_dissector, 1272 FLOW_DISSECTOR_KEY_FLOW_LABEL, 1273 target_container); 1274 key_tags->flow_label = ntohl(flow_label); 1275 } 1276 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { 1277 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1278 break; 1279 } 1280 } 1281 1282 __skb_flow_dissect_ipv6(skb, flow_dissector, 1283 target_container, data, iph); 1284 1285 break; 1286 } 1287 case htons(ETH_P_8021AD): 1288 case htons(ETH_P_8021Q): { 1289 const struct vlan_hdr *vlan = NULL; 1290 struct vlan_hdr _vlan; 1291 __be16 saved_vlan_tpid = proto; 1292 1293 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && 1294 skb && skb_vlan_tag_present(skb)) { 1295 proto = skb->protocol; 1296 } else { 1297 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), 1298 data, hlen, &_vlan); 1299 if (!vlan) { 1300 fdret = FLOW_DISSECT_RET_OUT_BAD; 1301 break; 1302 } 1303 1304 proto = vlan->h_vlan_encapsulated_proto; 1305 nhoff += sizeof(*vlan); 1306 } 1307 1308 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) && 1309 !(key_control->flags & FLOW_DIS_ENCAPSULATION)) { 1310 struct flow_dissector_key_num_of_vlans *key_nvs; 1311 1312 key_nvs = skb_flow_dissector_target(flow_dissector, 1313 FLOW_DISSECTOR_KEY_NUM_OF_VLANS, 1314 target_container); 1315 key_nvs->num_of_vlans++; 1316 } 1317 1318 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { 1319 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; 1320 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { 1321 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; 1322 } else { 1323 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1324 break; 1325 } 1326 1327 if (dissector_uses_key(flow_dissector, dissector_vlan)) { 1328 key_vlan = skb_flow_dissector_target(flow_dissector, 1329 dissector_vlan, 1330 target_container); 1331 1332 if (!vlan) { 1333 key_vlan->vlan_id = skb_vlan_tag_get_id(skb); 1334 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb); 1335 } else { 1336 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & 1337 VLAN_VID_MASK; 1338 key_vlan->vlan_priority = 1339 (ntohs(vlan->h_vlan_TCI) & 1340 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 1341 } 1342 key_vlan->vlan_tpid = saved_vlan_tpid; 1343 key_vlan->vlan_eth_type = proto; 1344 } 1345 1346 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1347 break; 1348 } 1349 case htons(ETH_P_PPP_SES): { 1350 struct { 1351 struct pppoe_hdr hdr; 1352 __be16 proto; 1353 } *hdr, _hdr; 1354 u16 ppp_proto; 1355 1356 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr); 1357 if (!hdr) { 1358 fdret = FLOW_DISSECT_RET_OUT_BAD; 1359 break; 1360 } 1361 1362 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) { 1363 fdret = FLOW_DISSECT_RET_OUT_BAD; 1364 break; 1365 } 1366 1367 /* least significant bit of the most significant octet 1368 * indicates if protocol field was compressed 1369 */ 1370 ppp_proto = ntohs(hdr->proto); 1371 if (ppp_proto & 0x0100) { 1372 ppp_proto = ppp_proto >> 8; 1373 nhoff += PPPOE_SES_HLEN - 1; 1374 } else { 1375 nhoff += PPPOE_SES_HLEN; 1376 } 1377 1378 if (ppp_proto == PPP_IP) { 1379 proto = htons(ETH_P_IP); 1380 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1381 } else if (ppp_proto == PPP_IPV6) { 1382 proto = htons(ETH_P_IPV6); 1383 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1384 } else if (ppp_proto == PPP_MPLS_UC) { 1385 proto = htons(ETH_P_MPLS_UC); 1386 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1387 } else if (ppp_proto == PPP_MPLS_MC) { 1388 proto = htons(ETH_P_MPLS_MC); 1389 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1390 } else if (ppp_proto_is_valid(ppp_proto)) { 1391 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1392 } else { 1393 fdret = FLOW_DISSECT_RET_OUT_BAD; 1394 break; 1395 } 1396 1397 if (dissector_uses_key(flow_dissector, 1398 FLOW_DISSECTOR_KEY_PPPOE)) { 1399 struct flow_dissector_key_pppoe *key_pppoe; 1400 1401 key_pppoe = skb_flow_dissector_target(flow_dissector, 1402 FLOW_DISSECTOR_KEY_PPPOE, 1403 target_container); 1404 key_pppoe->session_id = hdr->hdr.sid; 1405 key_pppoe->ppp_proto = htons(ppp_proto); 1406 key_pppoe->type = htons(ETH_P_PPP_SES); 1407 } 1408 break; 1409 } 1410 case htons(ETH_P_TIPC): { 1411 struct tipc_basic_hdr *hdr, _hdr; 1412 1413 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), 1414 data, hlen, &_hdr); 1415 if (!hdr) { 1416 fdret = FLOW_DISSECT_RET_OUT_BAD; 1417 break; 1418 } 1419 1420 if (dissector_uses_key(flow_dissector, 1421 FLOW_DISSECTOR_KEY_TIPC)) { 1422 key_addrs = skb_flow_dissector_target(flow_dissector, 1423 FLOW_DISSECTOR_KEY_TIPC, 1424 target_container); 1425 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); 1426 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; 1427 } 1428 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1429 break; 1430 } 1431 1432 case htons(ETH_P_MPLS_UC): 1433 case htons(ETH_P_MPLS_MC): 1434 fdret = __skb_flow_dissect_mpls(skb, flow_dissector, 1435 target_container, data, 1436 nhoff, hlen, mpls_lse, 1437 &mpls_el); 1438 nhoff += sizeof(struct mpls_label); 1439 mpls_lse++; 1440 break; 1441 case htons(ETH_P_FCOE): 1442 if ((hlen - nhoff) < FCOE_HEADER_LEN) { 1443 fdret = FLOW_DISSECT_RET_OUT_BAD; 1444 break; 1445 } 1446 1447 nhoff += FCOE_HEADER_LEN; 1448 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1449 break; 1450 1451 case htons(ETH_P_ARP): 1452 case htons(ETH_P_RARP): 1453 fdret = __skb_flow_dissect_arp(skb, flow_dissector, 1454 target_container, data, 1455 nhoff, hlen); 1456 break; 1457 1458 case htons(ETH_P_BATMAN): 1459 fdret = __skb_flow_dissect_batadv(skb, key_control, data, 1460 &proto, &nhoff, hlen, flags); 1461 break; 1462 1463 case htons(ETH_P_1588): { 1464 struct ptp_header *hdr, _hdr; 1465 1466 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, 1467 hlen, &_hdr); 1468 if (!hdr) { 1469 fdret = FLOW_DISSECT_RET_OUT_BAD; 1470 break; 1471 } 1472 1473 nhoff += sizeof(struct ptp_header); 1474 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1475 break; 1476 } 1477 1478 case htons(ETH_P_PRP): 1479 case htons(ETH_P_HSR): { 1480 struct hsr_tag *hdr, _hdr; 1481 1482 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, 1483 &_hdr); 1484 if (!hdr) { 1485 fdret = FLOW_DISSECT_RET_OUT_BAD; 1486 break; 1487 } 1488 1489 proto = hdr->encap_proto; 1490 nhoff += HSR_HLEN; 1491 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1492 break; 1493 } 1494 1495 case htons(ETH_P_CFM): 1496 fdret = __skb_flow_dissect_cfm(skb, flow_dissector, 1497 target_container, data, 1498 nhoff, hlen); 1499 break; 1500 1501 default: 1502 fdret = FLOW_DISSECT_RET_OUT_BAD; 1503 break; 1504 } 1505 1506 /* Process result of proto processing */ 1507 switch (fdret) { 1508 case FLOW_DISSECT_RET_OUT_GOOD: 1509 goto out_good; 1510 case FLOW_DISSECT_RET_PROTO_AGAIN: 1511 if (skb_flow_dissect_allowed(&num_hdrs)) 1512 goto proto_again; 1513 goto out_good; 1514 case FLOW_DISSECT_RET_CONTINUE: 1515 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1516 break; 1517 case FLOW_DISSECT_RET_OUT_BAD: 1518 default: 1519 goto out_bad; 1520 } 1521 1522 ip_proto_again: 1523 fdret = FLOW_DISSECT_RET_CONTINUE; 1524 1525 switch (ip_proto) { 1526 case IPPROTO_GRE: 1527 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1528 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1529 break; 1530 } 1531 1532 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, 1533 target_container, data, 1534 &proto, &nhoff, &hlen, flags); 1535 break; 1536 1537 case NEXTHDR_HOP: 1538 case NEXTHDR_ROUTING: 1539 case NEXTHDR_DEST: { 1540 u8 _opthdr[2], *opthdr; 1541 1542 if (proto != htons(ETH_P_IPV6)) 1543 break; 1544 1545 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr), 1546 data, hlen, &_opthdr); 1547 if (!opthdr) { 1548 fdret = FLOW_DISSECT_RET_OUT_BAD; 1549 break; 1550 } 1551 1552 ip_proto = opthdr[0]; 1553 nhoff += (opthdr[1] + 1) << 3; 1554 1555 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1556 break; 1557 } 1558 case NEXTHDR_FRAGMENT: { 1559 struct frag_hdr _fh, *fh; 1560 1561 if (proto != htons(ETH_P_IPV6)) 1562 break; 1563 1564 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh), 1565 data, hlen, &_fh); 1566 1567 if (!fh) { 1568 fdret = FLOW_DISSECT_RET_OUT_BAD; 1569 break; 1570 } 1571 1572 key_control->flags |= FLOW_DIS_IS_FRAGMENT; 1573 1574 nhoff += sizeof(_fh); 1575 ip_proto = fh->nexthdr; 1576 1577 if (!(fh->frag_off & htons(IP6_OFFSET))) { 1578 key_control->flags |= FLOW_DIS_FIRST_FRAG; 1579 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { 1580 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; 1581 break; 1582 } 1583 } 1584 1585 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1586 break; 1587 } 1588 case IPPROTO_IPIP: 1589 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1590 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1591 break; 1592 } 1593 1594 proto = htons(ETH_P_IP); 1595 1596 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1597 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1598 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1599 break; 1600 } 1601 1602 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1603 break; 1604 1605 case IPPROTO_IPV6: 1606 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { 1607 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1608 break; 1609 } 1610 1611 proto = htons(ETH_P_IPV6); 1612 1613 key_control->flags |= FLOW_DIS_ENCAPSULATION; 1614 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { 1615 fdret = FLOW_DISSECT_RET_OUT_GOOD; 1616 break; 1617 } 1618 1619 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1620 break; 1621 1622 1623 case IPPROTO_MPLS: 1624 proto = htons(ETH_P_MPLS_UC); 1625 fdret = FLOW_DISSECT_RET_PROTO_AGAIN; 1626 break; 1627 1628 case IPPROTO_TCP: 1629 __skb_flow_dissect_tcp(skb, flow_dissector, target_container, 1630 data, nhoff, hlen); 1631 break; 1632 1633 case IPPROTO_ICMP: 1634 case IPPROTO_ICMPV6: 1635 __skb_flow_dissect_icmp(skb, flow_dissector, target_container, 1636 data, nhoff, hlen); 1637 break; 1638 case IPPROTO_L2TP: 1639 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container, 1640 data, nhoff, hlen); 1641 break; 1642 case IPPROTO_ESP: 1643 __skb_flow_dissect_esp(skb, flow_dissector, target_container, 1644 data, nhoff, hlen); 1645 break; 1646 case IPPROTO_AH: 1647 __skb_flow_dissect_ah(skb, flow_dissector, target_container, 1648 data, nhoff, hlen); 1649 break; 1650 default: 1651 break; 1652 } 1653 1654 if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT)) 1655 __skb_flow_dissect_ports(skb, flow_dissector, target_container, 1656 data, nhoff, ip_proto, hlen); 1657 1658 /* Process result of IP proto processing */ 1659 switch (fdret) { 1660 case FLOW_DISSECT_RET_PROTO_AGAIN: 1661 if (skb_flow_dissect_allowed(&num_hdrs)) 1662 goto proto_again; 1663 break; 1664 case FLOW_DISSECT_RET_IPPROTO_AGAIN: 1665 if (skb_flow_dissect_allowed(&num_hdrs)) 1666 goto ip_proto_again; 1667 break; 1668 case FLOW_DISSECT_RET_OUT_GOOD: 1669 case FLOW_DISSECT_RET_CONTINUE: 1670 break; 1671 case FLOW_DISSECT_RET_OUT_BAD: 1672 default: 1673 goto out_bad; 1674 } 1675 1676 out_good: 1677 ret = true; 1678 1679 out: 1680 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); 1681 key_basic->n_proto = proto; 1682 key_basic->ip_proto = ip_proto; 1683 1684 return ret; 1685 1686 out_bad: 1687 ret = false; 1688 goto out; 1689 } 1690 EXPORT_SYMBOL(__skb_flow_dissect); 1691 1692 static siphash_aligned_key_t hashrnd; __flow_hash_secret_init(void)1693 static __always_inline void __flow_hash_secret_init(void) 1694 { 1695 net_get_random_once(&hashrnd, sizeof(hashrnd)); 1696 } 1697 flow_keys_hash_start(const struct flow_keys * flow)1698 static const void *flow_keys_hash_start(const struct flow_keys *flow) 1699 { 1700 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT); 1701 return &flow->FLOW_KEYS_HASH_START_FIELD; 1702 } 1703 flow_keys_hash_length(const struct flow_keys * flow)1704 static inline size_t flow_keys_hash_length(const struct flow_keys *flow) 1705 { 1706 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); 1707 1708 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); 1709 1710 switch (flow->control.addr_type) { 1711 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1712 diff -= sizeof(flow->addrs.v4addrs); 1713 break; 1714 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1715 diff -= sizeof(flow->addrs.v6addrs); 1716 break; 1717 case FLOW_DISSECTOR_KEY_TIPC: 1718 diff -= sizeof(flow->addrs.tipckey); 1719 break; 1720 } 1721 return sizeof(*flow) - diff; 1722 } 1723 flow_get_u32_src(const struct flow_keys * flow)1724 __be32 flow_get_u32_src(const struct flow_keys *flow) 1725 { 1726 switch (flow->control.addr_type) { 1727 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1728 return flow->addrs.v4addrs.src; 1729 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1730 return (__force __be32)ipv6_addr_hash( 1731 &flow->addrs.v6addrs.src); 1732 case FLOW_DISSECTOR_KEY_TIPC: 1733 return flow->addrs.tipckey.key; 1734 default: 1735 return 0; 1736 } 1737 } 1738 EXPORT_SYMBOL(flow_get_u32_src); 1739 flow_get_u32_dst(const struct flow_keys * flow)1740 __be32 flow_get_u32_dst(const struct flow_keys *flow) 1741 { 1742 switch (flow->control.addr_type) { 1743 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1744 return flow->addrs.v4addrs.dst; 1745 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1746 return (__force __be32)ipv6_addr_hash( 1747 &flow->addrs.v6addrs.dst); 1748 default: 1749 return 0; 1750 } 1751 } 1752 EXPORT_SYMBOL(flow_get_u32_dst); 1753 1754 /* Sort the source and destination IP and the ports, 1755 * to have consistent hash within the two directions 1756 */ __flow_hash_consistentify(struct flow_keys * keys)1757 static inline void __flow_hash_consistentify(struct flow_keys *keys) 1758 { 1759 int addr_diff, i; 1760 1761 switch (keys->control.addr_type) { 1762 case FLOW_DISSECTOR_KEY_IPV4_ADDRS: 1763 if ((__force u32)keys->addrs.v4addrs.dst < 1764 (__force u32)keys->addrs.v4addrs.src) 1765 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); 1766 1767 if ((__force u16)keys->ports.dst < 1768 (__force u16)keys->ports.src) { 1769 swap(keys->ports.src, keys->ports.dst); 1770 } 1771 break; 1772 case FLOW_DISSECTOR_KEY_IPV6_ADDRS: 1773 addr_diff = memcmp(&keys->addrs.v6addrs.dst, 1774 &keys->addrs.v6addrs.src, 1775 sizeof(keys->addrs.v6addrs.dst)); 1776 if (addr_diff < 0) { 1777 for (i = 0; i < 4; i++) 1778 swap(keys->addrs.v6addrs.src.s6_addr32[i], 1779 keys->addrs.v6addrs.dst.s6_addr32[i]); 1780 } 1781 if ((__force u16)keys->ports.dst < 1782 (__force u16)keys->ports.src) { 1783 swap(keys->ports.src, keys->ports.dst); 1784 } 1785 break; 1786 } 1787 } 1788 __flow_hash_from_keys(struct flow_keys * keys,const siphash_key_t * keyval)1789 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, 1790 const siphash_key_t *keyval) 1791 { 1792 u32 hash; 1793 1794 __flow_hash_consistentify(keys); 1795 1796 hash = siphash(flow_keys_hash_start(keys), 1797 flow_keys_hash_length(keys), keyval); 1798 if (!hash) 1799 hash = 1; 1800 1801 return hash; 1802 } 1803 flow_hash_from_keys(struct flow_keys * keys)1804 u32 flow_hash_from_keys(struct flow_keys *keys) 1805 { 1806 __flow_hash_secret_init(); 1807 return __flow_hash_from_keys(keys, &hashrnd); 1808 } 1809 EXPORT_SYMBOL(flow_hash_from_keys); 1810 flow_hash_from_keys_seed(struct flow_keys * keys,const siphash_key_t * keyval)1811 u32 flow_hash_from_keys_seed(struct flow_keys *keys, 1812 const siphash_key_t *keyval) 1813 { 1814 return __flow_hash_from_keys(keys, keyval); 1815 } 1816 EXPORT_SYMBOL(flow_hash_from_keys_seed); 1817 ___skb_get_hash(const struct sk_buff * skb,struct flow_keys * keys,const siphash_key_t * keyval)1818 static inline u32 ___skb_get_hash(const struct sk_buff *skb, 1819 struct flow_keys *keys, 1820 const siphash_key_t *keyval) 1821 { 1822 skb_flow_dissect_flow_keys(skb, keys, 1823 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1824 1825 return __flow_hash_from_keys(keys, keyval); 1826 } 1827 1828 struct _flow_keys_digest_data { 1829 __be16 n_proto; 1830 u8 ip_proto; 1831 u8 padding; 1832 __be32 ports; 1833 __be32 src; 1834 __be32 dst; 1835 }; 1836 make_flow_keys_digest(struct flow_keys_digest * digest,const struct flow_keys * flow)1837 void make_flow_keys_digest(struct flow_keys_digest *digest, 1838 const struct flow_keys *flow) 1839 { 1840 struct _flow_keys_digest_data *data = 1841 (struct _flow_keys_digest_data *)digest; 1842 1843 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); 1844 1845 memset(digest, 0, sizeof(*digest)); 1846 1847 data->n_proto = flow->basic.n_proto; 1848 data->ip_proto = flow->basic.ip_proto; 1849 data->ports = flow->ports.ports; 1850 data->src = flow->addrs.v4addrs.src; 1851 data->dst = flow->addrs.v4addrs.dst; 1852 } 1853 EXPORT_SYMBOL(make_flow_keys_digest); 1854 1855 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; 1856 __skb_get_hash_symmetric_net(const struct net * net,const struct sk_buff * skb)1857 u32 __skb_get_hash_symmetric_net(const struct net *net, const struct sk_buff *skb) 1858 { 1859 struct flow_keys keys; 1860 1861 __flow_hash_secret_init(); 1862 1863 memset(&keys, 0, sizeof(keys)); 1864 __skb_flow_dissect(net, skb, &flow_keys_dissector_symmetric, 1865 &keys, NULL, 0, 0, 0, 0); 1866 1867 return __flow_hash_from_keys(&keys, &hashrnd); 1868 } 1869 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric_net); 1870 1871 /** 1872 * __skb_get_hash_net: calculate a flow hash 1873 * @net: associated network namespace, derived from @skb if NULL 1874 * @skb: sk_buff to calculate flow hash from 1875 * 1876 * This function calculates a flow hash based on src/dst addresses 1877 * and src/dst port numbers. Sets hash in skb to non-zero hash value 1878 * on success, zero indicates no valid hash. Also, sets l4_hash in skb 1879 * if hash is a canonical 4-tuple hash over transport ports. 1880 */ __skb_get_hash_net(const struct net * net,struct sk_buff * skb)1881 void __skb_get_hash_net(const struct net *net, struct sk_buff *skb) 1882 { 1883 struct flow_keys keys; 1884 u32 hash; 1885 1886 memset(&keys, 0, sizeof(keys)); 1887 1888 __skb_flow_dissect(net, skb, &flow_keys_dissector, 1889 &keys, NULL, 0, 0, 0, 1890 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); 1891 1892 __flow_hash_secret_init(); 1893 1894 hash = __flow_hash_from_keys(&keys, &hashrnd); 1895 1896 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys)); 1897 } 1898 EXPORT_SYMBOL(__skb_get_hash_net); 1899 skb_get_hash_perturb(const struct sk_buff * skb,const siphash_key_t * perturb)1900 __u32 skb_get_hash_perturb(const struct sk_buff *skb, 1901 const siphash_key_t *perturb) 1902 { 1903 struct flow_keys keys; 1904 1905 return ___skb_get_hash(skb, &keys, perturb); 1906 } 1907 EXPORT_SYMBOL(skb_get_hash_perturb); 1908 __skb_get_poff(const struct sk_buff * skb,const void * data,const struct flow_keys_basic * keys,int hlen)1909 u32 __skb_get_poff(const struct sk_buff *skb, const void *data, 1910 const struct flow_keys_basic *keys, int hlen) 1911 { 1912 u32 poff = keys->control.thoff; 1913 1914 /* skip L4 headers for fragments after the first */ 1915 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && 1916 !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) 1917 return poff; 1918 1919 switch (keys->basic.ip_proto) { 1920 case IPPROTO_TCP: { 1921 /* access doff as u8 to avoid unaligned access */ 1922 const u8 *doff; 1923 u8 _doff; 1924 1925 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff), 1926 data, hlen, &_doff); 1927 if (!doff) 1928 return poff; 1929 1930 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); 1931 break; 1932 } 1933 case IPPROTO_UDP: 1934 case IPPROTO_UDPLITE: 1935 poff += sizeof(struct udphdr); 1936 break; 1937 /* For the rest, we do not really care about header 1938 * extensions at this point for now. 1939 */ 1940 case IPPROTO_ICMP: 1941 poff += sizeof(struct icmphdr); 1942 break; 1943 case IPPROTO_ICMPV6: 1944 poff += sizeof(struct icmp6hdr); 1945 break; 1946 case IPPROTO_IGMP: 1947 poff += sizeof(struct igmphdr); 1948 break; 1949 case IPPROTO_DCCP: 1950 poff += sizeof(struct dccp_hdr); 1951 break; 1952 case IPPROTO_SCTP: 1953 poff += sizeof(struct sctphdr); 1954 break; 1955 } 1956 1957 return poff; 1958 } 1959 1960 /** 1961 * skb_get_poff - get the offset to the payload 1962 * @skb: sk_buff to get the payload offset from 1963 * 1964 * The function will get the offset to the payload as far as it could 1965 * be dissected. The main user is currently BPF, so that we can dynamically 1966 * truncate packets without needing to push actual payload to the user 1967 * space and can analyze headers only, instead. 1968 */ skb_get_poff(const struct sk_buff * skb)1969 u32 skb_get_poff(const struct sk_buff *skb) 1970 { 1971 struct flow_keys_basic keys; 1972 1973 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, 1974 NULL, 0, 0, 0, 0)) 1975 return 0; 1976 1977 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); 1978 } 1979 __get_hash_from_flowi6(const struct flowi6 * fl6,struct flow_keys * keys)1980 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) 1981 { 1982 memset(keys, 0, sizeof(*keys)); 1983 1984 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, 1985 sizeof(keys->addrs.v6addrs.src)); 1986 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, 1987 sizeof(keys->addrs.v6addrs.dst)); 1988 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 1989 keys->ports.src = fl6->fl6_sport; 1990 keys->ports.dst = fl6->fl6_dport; 1991 keys->keyid.keyid = fl6->fl6_gre_key; 1992 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 1993 keys->basic.ip_proto = fl6->flowi6_proto; 1994 1995 return flow_hash_from_keys(keys); 1996 } 1997 EXPORT_SYMBOL(__get_hash_from_flowi6); 1998 1999 static const struct flow_dissector_key flow_keys_dissector_keys[] = { 2000 { 2001 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2002 .offset = offsetof(struct flow_keys, control), 2003 }, 2004 { 2005 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2006 .offset = offsetof(struct flow_keys, basic), 2007 }, 2008 { 2009 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 2010 .offset = offsetof(struct flow_keys, addrs.v4addrs), 2011 }, 2012 { 2013 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 2014 .offset = offsetof(struct flow_keys, addrs.v6addrs), 2015 }, 2016 { 2017 .key_id = FLOW_DISSECTOR_KEY_TIPC, 2018 .offset = offsetof(struct flow_keys, addrs.tipckey), 2019 }, 2020 { 2021 .key_id = FLOW_DISSECTOR_KEY_PORTS, 2022 .offset = offsetof(struct flow_keys, ports), 2023 }, 2024 { 2025 .key_id = FLOW_DISSECTOR_KEY_VLAN, 2026 .offset = offsetof(struct flow_keys, vlan), 2027 }, 2028 { 2029 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, 2030 .offset = offsetof(struct flow_keys, tags), 2031 }, 2032 { 2033 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, 2034 .offset = offsetof(struct flow_keys, keyid), 2035 }, 2036 }; 2037 2038 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { 2039 { 2040 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2041 .offset = offsetof(struct flow_keys, control), 2042 }, 2043 { 2044 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2045 .offset = offsetof(struct flow_keys, basic), 2046 }, 2047 { 2048 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, 2049 .offset = offsetof(struct flow_keys, addrs.v4addrs), 2050 }, 2051 { 2052 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, 2053 .offset = offsetof(struct flow_keys, addrs.v6addrs), 2054 }, 2055 { 2056 .key_id = FLOW_DISSECTOR_KEY_PORTS, 2057 .offset = offsetof(struct flow_keys, ports), 2058 }, 2059 }; 2060 2061 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { 2062 { 2063 .key_id = FLOW_DISSECTOR_KEY_CONTROL, 2064 .offset = offsetof(struct flow_keys, control), 2065 }, 2066 { 2067 .key_id = FLOW_DISSECTOR_KEY_BASIC, 2068 .offset = offsetof(struct flow_keys, basic), 2069 }, 2070 }; 2071 2072 struct flow_dissector flow_keys_dissector __read_mostly; 2073 EXPORT_SYMBOL(flow_keys_dissector); 2074 2075 struct flow_dissector flow_keys_basic_dissector __read_mostly; 2076 EXPORT_SYMBOL(flow_keys_basic_dissector); 2077 init_default_flow_dissectors(void)2078 static int __init init_default_flow_dissectors(void) 2079 { 2080 skb_flow_dissector_init(&flow_keys_dissector, 2081 flow_keys_dissector_keys, 2082 ARRAY_SIZE(flow_keys_dissector_keys)); 2083 skb_flow_dissector_init(&flow_keys_dissector_symmetric, 2084 flow_keys_dissector_symmetric_keys, 2085 ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); 2086 skb_flow_dissector_init(&flow_keys_basic_dissector, 2087 flow_keys_basic_dissector_keys, 2088 ARRAY_SIZE(flow_keys_basic_dissector_keys)); 2089 return 0; 2090 } 2091 core_initcall(init_default_flow_dissectors); 2092