1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (c) 2007-2014 Nicira, Inc. 4 */ 5 6#include <linux/uaccess.h> 7#include <linux/netdevice.h> 8#include <linux/etherdevice.h> 9#include <linux/if_ether.h> 10#include <linux/if_vlan.h> 11#include <net/llc_pdu.h> 12#include <linux/kernel.h> 13#include <linux/jhash.h> 14#include <linux/jiffies.h> 15#include <linux/llc.h> 16#include <linux/module.h> 17#include <linux/in.h> 18#include <linux/rcupdate.h> 19#include <linux/cpumask.h> 20#include <linux/if_arp.h> 21#include <linux/ip.h> 22#include <linux/ipv6.h> 23#include <linux/mpls.h> 24#include <linux/sctp.h> 25#include <linux/smp.h> 26#include <linux/tcp.h> 27#include <linux/udp.h> 28#include <linux/icmp.h> 29#include <linux/icmpv6.h> 30#include <linux/rculist.h> 31#include <net/ip.h> 32#include <net/ip_tunnels.h> 33#include <net/ipv6.h> 34#include <net/mpls.h> 35#include <net/ndisc.h> 36#include <net/nsh.h> 37#include <net/pkt_cls.h> 38#include <net/netfilter/nf_conntrack_zones.h> 39 40#include "conntrack.h" 41#include "datapath.h" 42#include "flow.h" 43#include "flow_netlink.h" 44#include "vport.h" 45 46u64 ovs_flow_used_time(unsigned long flow_jiffies) 47{ 48 struct timespec64 cur_ts; 49 u64 cur_ms, idle_ms; 50 51 ktime_get_ts64(&cur_ts); 52 idle_ms = jiffies_to_msecs(jiffies - flow_jiffies); 53 cur_ms = (u64)(u32)cur_ts.tv_sec * MSEC_PER_SEC + 54 cur_ts.tv_nsec / NSEC_PER_MSEC; 55 56 return cur_ms - idle_ms; 57} 58 59#define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF)) 60 61void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags, 62 const struct sk_buff *skb) 63{ 64 struct sw_flow_stats *stats; 65 unsigned int cpu = smp_processor_id(); 66 int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0); 67 68 stats = rcu_dereference(flow->stats[cpu]); 69 70 /* Check if already have CPU-specific stats. */ 71 if (likely(stats)) { 72 spin_lock(&stats->lock); 73 /* Mark if we write on the pre-allocated stats. */ 74 if (cpu == 0 && unlikely(flow->stats_last_writer != cpu)) 75 flow->stats_last_writer = cpu; 76 } else { 77 stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */ 78 spin_lock(&stats->lock); 79 80 /* If the current CPU is the only writer on the 81 * pre-allocated stats keep using them. 82 */ 83 if (unlikely(flow->stats_last_writer != cpu)) { 84 /* A previous locker may have already allocated the 85 * stats, so we need to check again. If CPU-specific 86 * stats were already allocated, we update the pre- 87 * allocated stats as we have already locked them. 88 */ 89 if (likely(flow->stats_last_writer != -1) && 90 likely(!rcu_access_pointer(flow->stats[cpu]))) { 91 /* Try to allocate CPU-specific stats. */ 92 struct sw_flow_stats *new_stats; 93 94 new_stats = 95 kmem_cache_alloc_node(flow_stats_cache, 96 GFP_NOWAIT | 97 __GFP_THISNODE | 98 __GFP_NOWARN | 99 __GFP_NOMEMALLOC, 100 numa_node_id()); 101 if (likely(new_stats)) { 102 new_stats->used = jiffies; 103 new_stats->packet_count = 1; 104 new_stats->byte_count = len; 105 new_stats->tcp_flags = tcp_flags; 106 spin_lock_init(&new_stats->lock); 107 108 rcu_assign_pointer(flow->stats[cpu], 109 new_stats); 110 cpumask_set_cpu(cpu, 111 flow->cpu_used_mask); 112 goto unlock; 113 } 114 } 115 flow->stats_last_writer = cpu; 116 } 117 } 118 119 stats->used = jiffies; 120 stats->packet_count++; 121 stats->byte_count += len; 122 stats->tcp_flags |= tcp_flags; 123unlock: 124 spin_unlock(&stats->lock); 125} 126 127/* Must be called with rcu_read_lock or ovs_mutex. */ 128void ovs_flow_stats_get(const struct sw_flow *flow, 129 struct ovs_flow_stats *ovs_stats, 130 unsigned long *used, __be16 *tcp_flags) 131{ 132 int cpu; 133 134 *used = 0; 135 *tcp_flags = 0; 136 memset(ovs_stats, 0, sizeof(*ovs_stats)); 137 138 /* We open code this to make sure cpu 0 is always considered */ 139 for (cpu = 0; cpu < nr_cpu_ids; 140 cpu = cpumask_next(cpu, flow->cpu_used_mask)) { 141 struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]); 142 143 if (stats) { 144 /* Local CPU may write on non-local stats, so we must 145 * block bottom-halves here. 146 */ 147 spin_lock_bh(&stats->lock); 148 if (!*used || time_after(stats->used, *used)) 149 *used = stats->used; 150 *tcp_flags |= stats->tcp_flags; 151 ovs_stats->n_packets += stats->packet_count; 152 ovs_stats->n_bytes += stats->byte_count; 153 spin_unlock_bh(&stats->lock); 154 } 155 } 156} 157 158/* Called with ovs_mutex. */ 159void ovs_flow_stats_clear(struct sw_flow *flow) 160{ 161 int cpu; 162 163 /* We open code this to make sure cpu 0 is always considered */ 164 for (cpu = 0; cpu < nr_cpu_ids; 165 cpu = cpumask_next(cpu, flow->cpu_used_mask)) { 166 struct sw_flow_stats *stats = ovsl_dereference(flow->stats[cpu]); 167 168 if (stats) { 169 spin_lock_bh(&stats->lock); 170 stats->used = 0; 171 stats->packet_count = 0; 172 stats->byte_count = 0; 173 stats->tcp_flags = 0; 174 spin_unlock_bh(&stats->lock); 175 } 176 } 177} 178 179static int check_header(struct sk_buff *skb, int len) 180{ 181 if (unlikely(skb->len < len)) 182 return -EINVAL; 183 if (unlikely(!pskb_may_pull(skb, len))) 184 return -ENOMEM; 185 return 0; 186} 187 188static bool arphdr_ok(struct sk_buff *skb) 189{ 190 return pskb_may_pull(skb, skb_network_offset(skb) + 191 sizeof(struct arp_eth_header)); 192} 193 194static int check_iphdr(struct sk_buff *skb) 195{ 196 unsigned int nh_ofs = skb_network_offset(skb); 197 unsigned int ip_len; 198 int err; 199 200 err = check_header(skb, nh_ofs + sizeof(struct iphdr)); 201 if (unlikely(err)) 202 return err; 203 204 ip_len = ip_hdrlen(skb); 205 if (unlikely(ip_len < sizeof(struct iphdr) || 206 skb->len < nh_ofs + ip_len)) 207 return -EINVAL; 208 209 skb_set_transport_header(skb, nh_ofs + ip_len); 210 return 0; 211} 212 213static bool tcphdr_ok(struct sk_buff *skb) 214{ 215 int th_ofs = skb_transport_offset(skb); 216 int tcp_len; 217 218 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr)))) 219 return false; 220 221 tcp_len = tcp_hdrlen(skb); 222 if (unlikely(tcp_len < sizeof(struct tcphdr) || 223 skb->len < th_ofs + tcp_len)) 224 return false; 225 226 return true; 227} 228 229static bool udphdr_ok(struct sk_buff *skb) 230{ 231 return pskb_may_pull(skb, skb_transport_offset(skb) + 232 sizeof(struct udphdr)); 233} 234 235static bool sctphdr_ok(struct sk_buff *skb) 236{ 237 return pskb_may_pull(skb, skb_transport_offset(skb) + 238 sizeof(struct sctphdr)); 239} 240 241static bool icmphdr_ok(struct sk_buff *skb) 242{ 243 return pskb_may_pull(skb, skb_transport_offset(skb) + 244 sizeof(struct icmphdr)); 245} 246 247/** 248 * get_ipv6_ext_hdrs() - Parses packet and sets IPv6 extension header flags. 249 * 250 * @skb: buffer where extension header data starts in packet 251 * @nh: ipv6 header 252 * @ext_hdrs: flags are stored here 253 * 254 * OFPIEH12_UNREP is set if more than one of a given IPv6 extension header 255 * is unexpectedly encountered. (Two destination options headers may be 256 * expected and would not cause this bit to be set.) 257 * 258 * OFPIEH12_UNSEQ is set if IPv6 extension headers were not in the order 259 * preferred (but not required) by RFC 2460: 260 * 261 * When more than one extension header is used in the same packet, it is 262 * recommended that those headers appear in the following order: 263 * IPv6 header 264 * Hop-by-Hop Options header 265 * Destination Options header 266 * Routing header 267 * Fragment header 268 * Authentication header 269 * Encapsulating Security Payload header 270 * Destination Options header 271 * upper-layer header 272 */ 273static void get_ipv6_ext_hdrs(struct sk_buff *skb, struct ipv6hdr *nh, 274 u16 *ext_hdrs) 275{ 276 u8 next_type = nh->nexthdr; 277 unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr); 278 int dest_options_header_count = 0; 279 280 *ext_hdrs = 0; 281 282 while (ipv6_ext_hdr(next_type)) { 283 struct ipv6_opt_hdr _hdr, *hp; 284 285 switch (next_type) { 286 case IPPROTO_NONE: 287 *ext_hdrs |= OFPIEH12_NONEXT; 288 /* stop parsing */ 289 return; 290 291 case IPPROTO_ESP: 292 if (*ext_hdrs & OFPIEH12_ESP) 293 *ext_hdrs |= OFPIEH12_UNREP; 294 if ((*ext_hdrs & ~(OFPIEH12_HOP | OFPIEH12_DEST | 295 OFPIEH12_ROUTER | IPPROTO_FRAGMENT | 296 OFPIEH12_AUTH | OFPIEH12_UNREP)) || 297 dest_options_header_count >= 2) { 298 *ext_hdrs |= OFPIEH12_UNSEQ; 299 } 300 *ext_hdrs |= OFPIEH12_ESP; 301 break; 302 303 case IPPROTO_AH: 304 if (*ext_hdrs & OFPIEH12_AUTH) 305 *ext_hdrs |= OFPIEH12_UNREP; 306 if ((*ext_hdrs & 307 ~(OFPIEH12_HOP | OFPIEH12_DEST | OFPIEH12_ROUTER | 308 IPPROTO_FRAGMENT | OFPIEH12_UNREP)) || 309 dest_options_header_count >= 2) { 310 *ext_hdrs |= OFPIEH12_UNSEQ; 311 } 312 *ext_hdrs |= OFPIEH12_AUTH; 313 break; 314 315 case IPPROTO_DSTOPTS: 316 if (dest_options_header_count == 0) { 317 if (*ext_hdrs & 318 ~(OFPIEH12_HOP | OFPIEH12_UNREP)) 319 *ext_hdrs |= OFPIEH12_UNSEQ; 320 *ext_hdrs |= OFPIEH12_DEST; 321 } else if (dest_options_header_count == 1) { 322 if (*ext_hdrs & 323 ~(OFPIEH12_HOP | OFPIEH12_DEST | 324 OFPIEH12_ROUTER | OFPIEH12_FRAG | 325 OFPIEH12_AUTH | OFPIEH12_ESP | 326 OFPIEH12_UNREP)) { 327 *ext_hdrs |= OFPIEH12_UNSEQ; 328 } 329 } else { 330 *ext_hdrs |= OFPIEH12_UNREP; 331 } 332 dest_options_header_count++; 333 break; 334 335 case IPPROTO_FRAGMENT: 336 if (*ext_hdrs & OFPIEH12_FRAG) 337 *ext_hdrs |= OFPIEH12_UNREP; 338 if ((*ext_hdrs & ~(OFPIEH12_HOP | 339 OFPIEH12_DEST | 340 OFPIEH12_ROUTER | 341 OFPIEH12_UNREP)) || 342 dest_options_header_count >= 2) { 343 *ext_hdrs |= OFPIEH12_UNSEQ; 344 } 345 *ext_hdrs |= OFPIEH12_FRAG; 346 break; 347 348 case IPPROTO_ROUTING: 349 if (*ext_hdrs & OFPIEH12_ROUTER) 350 *ext_hdrs |= OFPIEH12_UNREP; 351 if ((*ext_hdrs & ~(OFPIEH12_HOP | 352 OFPIEH12_DEST | 353 OFPIEH12_UNREP)) || 354 dest_options_header_count >= 2) { 355 *ext_hdrs |= OFPIEH12_UNSEQ; 356 } 357 *ext_hdrs |= OFPIEH12_ROUTER; 358 break; 359 360 case IPPROTO_HOPOPTS: 361 if (*ext_hdrs & OFPIEH12_HOP) 362 *ext_hdrs |= OFPIEH12_UNREP; 363 /* OFPIEH12_HOP is set to 1 if a hop-by-hop IPv6 364 * extension header is present as the first 365 * extension header in the packet. 366 */ 367 if (*ext_hdrs == 0) 368 *ext_hdrs |= OFPIEH12_HOP; 369 else 370 *ext_hdrs |= OFPIEH12_UNSEQ; 371 break; 372 373 default: 374 return; 375 } 376 377 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); 378 if (!hp) 379 break; 380 next_type = hp->nexthdr; 381 start += ipv6_optlen(hp); 382 } 383} 384 385static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) 386{ 387 unsigned short frag_off; 388 unsigned int payload_ofs = 0; 389 unsigned int nh_ofs = skb_network_offset(skb); 390 unsigned int nh_len; 391 struct ipv6hdr *nh; 392 int err, nexthdr, flags = 0; 393 394 err = check_header(skb, nh_ofs + sizeof(*nh)); 395 if (unlikely(err)) 396 return err; 397 398 nh = ipv6_hdr(skb); 399 400 get_ipv6_ext_hdrs(skb, nh, &key->ipv6.exthdrs); 401 402 key->ip.proto = NEXTHDR_NONE; 403 key->ip.tos = ipv6_get_dsfield(nh); 404 key->ip.ttl = nh->hop_limit; 405 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); 406 key->ipv6.addr.src = nh->saddr; 407 key->ipv6.addr.dst = nh->daddr; 408 409 nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags); 410 if (flags & IP6_FH_F_FRAG) { 411 if (frag_off) { 412 key->ip.frag = OVS_FRAG_TYPE_LATER; 413 key->ip.proto = NEXTHDR_FRAGMENT; 414 return 0; 415 } 416 key->ip.frag = OVS_FRAG_TYPE_FIRST; 417 } else { 418 key->ip.frag = OVS_FRAG_TYPE_NONE; 419 } 420 421 /* Delayed handling of error in ipv6_find_hdr() as it 422 * always sets flags and frag_off to a valid value which may be 423 * used to set key->ip.frag above. 424 */ 425 if (unlikely(nexthdr < 0)) 426 return -EPROTO; 427 428 nh_len = payload_ofs - nh_ofs; 429 skb_set_transport_header(skb, nh_ofs + nh_len); 430 key->ip.proto = nexthdr; 431 return nh_len; 432} 433 434static bool icmp6hdr_ok(struct sk_buff *skb) 435{ 436 return pskb_may_pull(skb, skb_transport_offset(skb) + 437 sizeof(struct icmp6hdr)); 438} 439 440/** 441 * parse_vlan_tag - Parse vlan tag from vlan header. 442 * @skb: skb containing frame to parse 443 * @key_vh: pointer to parsed vlan tag 444 * @untag_vlan: should the vlan header be removed from the frame 445 * 446 * Return: ERROR on memory error. 447 * %0 if it encounters a non-vlan or incomplete packet. 448 * %1 after successfully parsing vlan tag. 449 */ 450static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh, 451 bool untag_vlan) 452{ 453 struct vlan_head *vh = (struct vlan_head *)skb->data; 454 455 if (likely(!eth_type_vlan(vh->tpid))) 456 return 0; 457 458 if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16))) 459 return 0; 460 461 if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) + 462 sizeof(__be16)))) 463 return -ENOMEM; 464 465 vh = (struct vlan_head *)skb->data; 466 key_vh->tci = vh->tci | htons(VLAN_CFI_MASK); 467 key_vh->tpid = vh->tpid; 468 469 if (unlikely(untag_vlan)) { 470 int offset = skb->data - skb_mac_header(skb); 471 u16 tci; 472 int err; 473 474 __skb_push(skb, offset); 475 err = __skb_vlan_pop(skb, &tci); 476 __skb_pull(skb, offset); 477 if (err) 478 return err; 479 __vlan_hwaccel_put_tag(skb, key_vh->tpid, tci); 480 } else { 481 __skb_pull(skb, sizeof(struct vlan_head)); 482 } 483 return 1; 484} 485 486static void clear_vlan(struct sw_flow_key *key) 487{ 488 key->eth.vlan.tci = 0; 489 key->eth.vlan.tpid = 0; 490 key->eth.cvlan.tci = 0; 491 key->eth.cvlan.tpid = 0; 492} 493 494static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) 495{ 496 int res; 497 498 if (skb_vlan_tag_present(skb)) { 499 key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK); 500 key->eth.vlan.tpid = skb->vlan_proto; 501 } else { 502 /* Parse outer vlan tag in the non-accelerated case. */ 503 res = parse_vlan_tag(skb, &key->eth.vlan, true); 504 if (res <= 0) 505 return res; 506 } 507 508 /* Parse inner vlan tag. */ 509 res = parse_vlan_tag(skb, &key->eth.cvlan, false); 510 if (res <= 0) 511 return res; 512 513 return 0; 514} 515 516static __be16 parse_ethertype(struct sk_buff *skb) 517{ 518 struct llc_snap_hdr { 519 u8 dsap; /* Always 0xAA */ 520 u8 ssap; /* Always 0xAA */ 521 u8 ctrl; 522 u8 oui[3]; 523 __be16 ethertype; 524 }; 525 struct llc_snap_hdr *llc; 526 __be16 proto; 527 528 proto = *(__be16 *) skb->data; 529 __skb_pull(skb, sizeof(__be16)); 530 531 if (eth_proto_is_802_3(proto)) 532 return proto; 533 534 if (skb->len < sizeof(struct llc_snap_hdr)) 535 return htons(ETH_P_802_2); 536 537 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr)))) 538 return htons(0); 539 540 llc = (struct llc_snap_hdr *) skb->data; 541 if (llc->dsap != LLC_SAP_SNAP || 542 llc->ssap != LLC_SAP_SNAP || 543 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0) 544 return htons(ETH_P_802_2); 545 546 __skb_pull(skb, sizeof(struct llc_snap_hdr)); 547 548 if (eth_proto_is_802_3(llc->ethertype)) 549 return llc->ethertype; 550 551 return htons(ETH_P_802_2); 552} 553 554static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, 555 int nh_len) 556{ 557 struct icmp6hdr *icmp = icmp6_hdr(skb); 558 559 /* The ICMPv6 type and code fields use the 16-bit transport port 560 * fields, so we need to store them in 16-bit network byte order. 561 */ 562 key->tp.src = htons(icmp->icmp6_type); 563 key->tp.dst = htons(icmp->icmp6_code); 564 memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd)); 565 566 if (icmp->icmp6_code == 0 && 567 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || 568 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) { 569 int icmp_len = skb->len - skb_transport_offset(skb); 570 struct nd_msg *nd; 571 int offset; 572 573 /* In order to process neighbor discovery options, we need the 574 * entire packet. 575 */ 576 if (unlikely(icmp_len < sizeof(*nd))) 577 return 0; 578 579 if (unlikely(skb_linearize(skb))) 580 return -ENOMEM; 581 582 nd = (struct nd_msg *)skb_transport_header(skb); 583 key->ipv6.nd.target = nd->target; 584 585 icmp_len -= sizeof(*nd); 586 offset = 0; 587 while (icmp_len >= 8) { 588 struct nd_opt_hdr *nd_opt = 589 (struct nd_opt_hdr *)(nd->opt + offset); 590 int opt_len = nd_opt->nd_opt_len * 8; 591 592 if (unlikely(!opt_len || opt_len > icmp_len)) 593 return 0; 594 595 /* Store the link layer address if the appropriate 596 * option is provided. It is considered an error if 597 * the same link layer option is specified twice. 598 */ 599 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR 600 && opt_len == 8) { 601 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll))) 602 goto invalid; 603 ether_addr_copy(key->ipv6.nd.sll, 604 &nd->opt[offset+sizeof(*nd_opt)]); 605 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR 606 && opt_len == 8) { 607 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll))) 608 goto invalid; 609 ether_addr_copy(key->ipv6.nd.tll, 610 &nd->opt[offset+sizeof(*nd_opt)]); 611 } 612 613 icmp_len -= opt_len; 614 offset += opt_len; 615 } 616 } 617 618 return 0; 619 620invalid: 621 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target)); 622 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll)); 623 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll)); 624 625 return 0; 626} 627 628static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key) 629{ 630 struct nshhdr *nh; 631 unsigned int nh_ofs = skb_network_offset(skb); 632 u8 version, length; 633 int err; 634 635 err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN); 636 if (unlikely(err)) 637 return err; 638 639 nh = nsh_hdr(skb); 640 version = nsh_get_ver(nh); 641 length = nsh_hdr_len(nh); 642 643 if (version != 0) 644 return -EINVAL; 645 646 err = check_header(skb, nh_ofs + length); 647 if (unlikely(err)) 648 return err; 649 650 nh = nsh_hdr(skb); 651 key->nsh.base.flags = nsh_get_flags(nh); 652 key->nsh.base.ttl = nsh_get_ttl(nh); 653 key->nsh.base.mdtype = nh->mdtype; 654 key->nsh.base.np = nh->np; 655 key->nsh.base.path_hdr = nh->path_hdr; 656 switch (key->nsh.base.mdtype) { 657 case NSH_M_TYPE1: 658 if (length != NSH_M_TYPE1_LEN) 659 return -EINVAL; 660 memcpy(key->nsh.context, nh->md1.context, 661 sizeof(nh->md1)); 662 break; 663 case NSH_M_TYPE2: 664 memset(key->nsh.context, 0, 665 sizeof(nh->md1)); 666 break; 667 default: 668 return -EINVAL; 669 } 670 671 return 0; 672} 673 674/** 675 * key_extract_l3l4 - extracts L3/L4 header information. 676 * @skb: sk_buff that contains the frame, with skb->data pointing to the 677 * L3 header 678 * @key: output flow key 679 * 680 * Return: %0 if successful, otherwise a negative errno value. 681 */ 682static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key) 683{ 684 int error; 685 686 /* Network layer. */ 687 if (key->eth.type == htons(ETH_P_IP)) { 688 struct iphdr *nh; 689 __be16 offset; 690 691 error = check_iphdr(skb); 692 if (unlikely(error)) { 693 memset(&key->ip, 0, sizeof(key->ip)); 694 memset(&key->ipv4, 0, sizeof(key->ipv4)); 695 if (error == -EINVAL) { 696 skb->transport_header = skb->network_header; 697 error = 0; 698 } 699 return error; 700 } 701 702 nh = ip_hdr(skb); 703 key->ipv4.addr.src = nh->saddr; 704 key->ipv4.addr.dst = nh->daddr; 705 706 key->ip.proto = nh->protocol; 707 key->ip.tos = nh->tos; 708 key->ip.ttl = nh->ttl; 709 710 offset = nh->frag_off & htons(IP_OFFSET); 711 if (offset) { 712 key->ip.frag = OVS_FRAG_TYPE_LATER; 713 memset(&key->tp, 0, sizeof(key->tp)); 714 return 0; 715 } 716 if (nh->frag_off & htons(IP_MF) || 717 skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 718 key->ip.frag = OVS_FRAG_TYPE_FIRST; 719 else 720 key->ip.frag = OVS_FRAG_TYPE_NONE; 721 722 /* Transport layer. */ 723 if (key->ip.proto == IPPROTO_TCP) { 724 if (tcphdr_ok(skb)) { 725 struct tcphdr *tcp = tcp_hdr(skb); 726 key->tp.src = tcp->source; 727 key->tp.dst = tcp->dest; 728 key->tp.flags = TCP_FLAGS_BE16(tcp); 729 } else { 730 memset(&key->tp, 0, sizeof(key->tp)); 731 } 732 733 } else if (key->ip.proto == IPPROTO_UDP) { 734 if (udphdr_ok(skb)) { 735 struct udphdr *udp = udp_hdr(skb); 736 key->tp.src = udp->source; 737 key->tp.dst = udp->dest; 738 } else { 739 memset(&key->tp, 0, sizeof(key->tp)); 740 } 741 } else if (key->ip.proto == IPPROTO_SCTP) { 742 if (sctphdr_ok(skb)) { 743 struct sctphdr *sctp = sctp_hdr(skb); 744 key->tp.src = sctp->source; 745 key->tp.dst = sctp->dest; 746 } else { 747 memset(&key->tp, 0, sizeof(key->tp)); 748 } 749 } else if (key->ip.proto == IPPROTO_ICMP) { 750 if (icmphdr_ok(skb)) { 751 struct icmphdr *icmp = icmp_hdr(skb); 752 /* The ICMP type and code fields use the 16-bit 753 * transport port fields, so we need to store 754 * them in 16-bit network byte order. */ 755 key->tp.src = htons(icmp->type); 756 key->tp.dst = htons(icmp->code); 757 } else { 758 memset(&key->tp, 0, sizeof(key->tp)); 759 } 760 } 761 762 } else if (key->eth.type == htons(ETH_P_ARP) || 763 key->eth.type == htons(ETH_P_RARP)) { 764 struct arp_eth_header *arp; 765 bool arp_available = arphdr_ok(skb); 766 767 arp = (struct arp_eth_header *)skb_network_header(skb); 768 769 if (arp_available && 770 arp->ar_hrd == htons(ARPHRD_ETHER) && 771 arp->ar_pro == htons(ETH_P_IP) && 772 arp->ar_hln == ETH_ALEN && 773 arp->ar_pln == 4) { 774 775 /* We only match on the lower 8 bits of the opcode. */ 776 if (ntohs(arp->ar_op) <= 0xff) 777 key->ip.proto = ntohs(arp->ar_op); 778 else 779 key->ip.proto = 0; 780 781 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); 782 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); 783 ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha); 784 ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha); 785 } else { 786 memset(&key->ip, 0, sizeof(key->ip)); 787 memset(&key->ipv4, 0, sizeof(key->ipv4)); 788 } 789 } else if (eth_p_mpls(key->eth.type)) { 790 u8 label_count = 1; 791 792 memset(&key->mpls, 0, sizeof(key->mpls)); 793 skb_set_inner_network_header(skb, skb->mac_len); 794 while (1) { 795 __be32 lse; 796 797 error = check_header(skb, skb->mac_len + 798 label_count * MPLS_HLEN); 799 if (unlikely(error)) 800 return 0; 801 802 memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN); 803 804 if (label_count <= MPLS_LABEL_DEPTH) 805 memcpy(&key->mpls.lse[label_count - 1], &lse, 806 MPLS_HLEN); 807 808 skb_set_inner_network_header(skb, skb->mac_len + 809 label_count * MPLS_HLEN); 810 if (lse & htonl(MPLS_LS_S_MASK)) 811 break; 812 813 label_count++; 814 } 815 if (label_count > MPLS_LABEL_DEPTH) 816 label_count = MPLS_LABEL_DEPTH; 817 818 key->mpls.num_labels_mask = GENMASK(label_count - 1, 0); 819 } else if (key->eth.type == htons(ETH_P_IPV6)) { 820 int nh_len; /* IPv6 Header + Extensions */ 821 822 nh_len = parse_ipv6hdr(skb, key); 823 if (unlikely(nh_len < 0)) { 824 switch (nh_len) { 825 case -EINVAL: 826 memset(&key->ip, 0, sizeof(key->ip)); 827 memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr)); 828 fallthrough; 829 case -EPROTO: 830 skb->transport_header = skb->network_header; 831 error = 0; 832 break; 833 default: 834 error = nh_len; 835 } 836 return error; 837 } 838 839 if (key->ip.frag == OVS_FRAG_TYPE_LATER) { 840 memset(&key->tp, 0, sizeof(key->tp)); 841 return 0; 842 } 843 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 844 key->ip.frag = OVS_FRAG_TYPE_FIRST; 845 846 /* Transport layer. */ 847 if (key->ip.proto == NEXTHDR_TCP) { 848 if (tcphdr_ok(skb)) { 849 struct tcphdr *tcp = tcp_hdr(skb); 850 key->tp.src = tcp->source; 851 key->tp.dst = tcp->dest; 852 key->tp.flags = TCP_FLAGS_BE16(tcp); 853 } else { 854 memset(&key->tp, 0, sizeof(key->tp)); 855 } 856 } else if (key->ip.proto == NEXTHDR_UDP) { 857 if (udphdr_ok(skb)) { 858 struct udphdr *udp = udp_hdr(skb); 859 key->tp.src = udp->source; 860 key->tp.dst = udp->dest; 861 } else { 862 memset(&key->tp, 0, sizeof(key->tp)); 863 } 864 } else if (key->ip.proto == NEXTHDR_SCTP) { 865 if (sctphdr_ok(skb)) { 866 struct sctphdr *sctp = sctp_hdr(skb); 867 key->tp.src = sctp->source; 868 key->tp.dst = sctp->dest; 869 } else { 870 memset(&key->tp, 0, sizeof(key->tp)); 871 } 872 } else if (key->ip.proto == NEXTHDR_ICMP) { 873 if (icmp6hdr_ok(skb)) { 874 error = parse_icmpv6(skb, key, nh_len); 875 if (error) 876 return error; 877 } else { 878 memset(&key->tp, 0, sizeof(key->tp)); 879 } 880 } 881 } else if (key->eth.type == htons(ETH_P_NSH)) { 882 error = parse_nsh(skb, key); 883 if (error) 884 return error; 885 } 886 return 0; 887} 888 889/** 890 * key_extract - extracts a flow key from an Ethernet frame. 891 * @skb: sk_buff that contains the frame, with skb->data pointing to the 892 * Ethernet header 893 * @key: output flow key 894 * 895 * The caller must ensure that skb->len >= ETH_HLEN. 896 * 897 * Initializes @skb header fields as follows: 898 * 899 * - skb->mac_header: the L2 header. 900 * 901 * - skb->network_header: just past the L2 header, or just past the 902 * VLAN header, to the first byte of the L2 payload. 903 * 904 * - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6 905 * on output, then just past the IP header, if one is present and 906 * of a correct length, otherwise the same as skb->network_header. 907 * For other key->eth.type values it is left untouched. 908 * 909 * - skb->protocol: the type of the data starting at skb->network_header. 910 * Equals to key->eth.type. 911 * 912 * Return: %0 if successful, otherwise a negative errno value. 913 */ 914static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) 915{ 916 struct ethhdr *eth; 917 918 /* Flags are always used as part of stats */ 919 key->tp.flags = 0; 920 921 skb_reset_mac_header(skb); 922 923 /* Link layer. */ 924 clear_vlan(key); 925 if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) { 926 if (unlikely(eth_type_vlan(skb->protocol))) 927 return -EINVAL; 928 929 skb_reset_network_header(skb); 930 key->eth.type = skb->protocol; 931 } else { 932 eth = eth_hdr(skb); 933 ether_addr_copy(key->eth.src, eth->h_source); 934 ether_addr_copy(key->eth.dst, eth->h_dest); 935 936 __skb_pull(skb, 2 * ETH_ALEN); 937 /* We are going to push all headers that we pull, so no need to 938 * update skb->csum here. 939 */ 940 941 if (unlikely(parse_vlan(skb, key))) 942 return -ENOMEM; 943 944 key->eth.type = parse_ethertype(skb); 945 if (unlikely(key->eth.type == htons(0))) 946 return -ENOMEM; 947 948 /* Multiple tagged packets need to retain TPID to satisfy 949 * skb_vlan_pop(), which will later shift the ethertype into 950 * skb->protocol. 951 */ 952 if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK)) 953 skb->protocol = key->eth.cvlan.tpid; 954 else 955 skb->protocol = key->eth.type; 956 957 skb_reset_network_header(skb); 958 __skb_push(skb, skb->data - skb_mac_header(skb)); 959 } 960 961 skb_reset_mac_len(skb); 962 963 /* Fill out L3/L4 key info, if any */ 964 return key_extract_l3l4(skb, key); 965} 966 967/* In the case of conntrack fragment handling it expects L3 headers, 968 * add a helper. 969 */ 970int ovs_flow_key_update_l3l4(struct sk_buff *skb, struct sw_flow_key *key) 971{ 972 return key_extract_l3l4(skb, key); 973} 974 975int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key) 976{ 977 int res; 978 979 res = key_extract(skb, key); 980 if (!res) 981 key->mac_proto &= ~SW_FLOW_KEY_INVALID; 982 983 return res; 984} 985 986static int key_extract_mac_proto(struct sk_buff *skb) 987{ 988 switch (skb->dev->type) { 989 case ARPHRD_ETHER: 990 return MAC_PROTO_ETHERNET; 991 case ARPHRD_NONE: 992 if (skb->protocol == htons(ETH_P_TEB)) 993 return MAC_PROTO_ETHERNET; 994 return MAC_PROTO_NONE; 995 } 996 WARN_ON_ONCE(1); 997 return -EINVAL; 998} 999 1000int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info, 1001 struct sk_buff *skb, struct sw_flow_key *key) 1002{ 1003#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 1004 struct tc_skb_ext *tc_ext; 1005#endif 1006 bool post_ct = false, post_ct_snat = false, post_ct_dnat = false; 1007 int res, err; 1008 u16 zone = 0; 1009 1010 /* Extract metadata from packet. */ 1011 if (tun_info) { 1012 key->tun_proto = ip_tunnel_info_af(tun_info); 1013 memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key)); 1014 1015 if (tun_info->options_len) { 1016 BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) * 1017 8)) - 1 1018 > sizeof(key->tun_opts)); 1019 1020 ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len), 1021 tun_info); 1022 key->tun_opts_len = tun_info->options_len; 1023 } else { 1024 key->tun_opts_len = 0; 1025 } 1026 } else { 1027 key->tun_proto = 0; 1028 key->tun_opts_len = 0; 1029 memset(&key->tun_key, 0, sizeof(key->tun_key)); 1030 } 1031 1032 key->phy.priority = skb->priority; 1033 key->phy.in_port = OVS_CB(skb)->input_vport->port_no; 1034 key->phy.skb_mark = skb->mark; 1035 key->ovs_flow_hash = 0; 1036 res = key_extract_mac_proto(skb); 1037 if (res < 0) 1038 return res; 1039 key->mac_proto = res; 1040 1041#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) 1042 if (tc_skb_ext_tc_enabled()) { 1043 tc_ext = skb_ext_find(skb, TC_SKB_EXT); 1044 key->recirc_id = tc_ext && !tc_ext->act_miss ? 1045 tc_ext->chain : 0; 1046 OVS_CB(skb)->mru = tc_ext ? tc_ext->mru : 0; 1047 post_ct = tc_ext ? tc_ext->post_ct : false; 1048 post_ct_snat = post_ct ? tc_ext->post_ct_snat : false; 1049 post_ct_dnat = post_ct ? tc_ext->post_ct_dnat : false; 1050 zone = post_ct ? tc_ext->zone : 0; 1051 } else { 1052 key->recirc_id = 0; 1053 } 1054#else 1055 key->recirc_id = 0; 1056#endif 1057 1058 err = key_extract(skb, key); 1059 if (!err) { 1060 ovs_ct_fill_key(skb, key, post_ct); /* Must be after key_extract(). */ 1061 if (post_ct) { 1062 if (!skb_get_nfct(skb)) { 1063 key->ct_zone = zone; 1064 } else { 1065 if (!post_ct_dnat) 1066 key->ct_state &= ~OVS_CS_F_DST_NAT; 1067 if (!post_ct_snat) 1068 key->ct_state &= ~OVS_CS_F_SRC_NAT; 1069 } 1070 } 1071 } 1072 return err; 1073} 1074 1075int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr, 1076 struct sk_buff *skb, 1077 struct sw_flow_key *key, bool log) 1078{ 1079 const struct nlattr *a[OVS_KEY_ATTR_MAX + 1]; 1080 u64 attrs = 0; 1081 int err; 1082 1083 err = parse_flow_nlattrs(attr, a, &attrs, log); 1084 if (err) 1085 return -EINVAL; 1086 1087 /* Extract metadata from netlink attributes. */ 1088 err = ovs_nla_get_flow_metadata(net, a, attrs, key, log); 1089 if (err) 1090 return err; 1091 1092 /* key_extract assumes that skb->protocol is set-up for 1093 * layer 3 packets which is the case for other callers, 1094 * in particular packets received from the network stack. 1095 * Here the correct value can be set from the metadata 1096 * extracted above. 1097 * For L2 packet key eth type would be zero. skb protocol 1098 * would be set to correct value later during key-extact. 1099 */ 1100 1101 skb->protocol = key->eth.type; 1102 err = key_extract(skb, key); 1103 if (err) 1104 return err; 1105 1106 /* Check that we have conntrack original direction tuple metadata only 1107 * for packets for which it makes sense. Otherwise the key may be 1108 * corrupted due to overlapping key fields. 1109 */ 1110 if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) && 1111 key->eth.type != htons(ETH_P_IP)) 1112 return -EINVAL; 1113 if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) && 1114 (key->eth.type != htons(ETH_P_IPV6) || 1115 sw_flow_key_is_nd(key))) 1116 return -EINVAL; 1117 1118 return 0; 1119} 1120