net/openvswitch/flow.c

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