net/openvswitch/flow.c

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This source file includes following definitions.
ovs_flow_used_time
ovs_flow_stats_update
ovs_flow_stats_get
ovs_flow_stats_clear
check_header
arphdr_ok
check_iphdr
tcphdr_ok
udphdr_ok
sctphdr_ok
icmphdr_ok
parse_ipv6hdr
icmp6hdr_ok
parse_vlan_tag
clear_vlan
parse_vlan
parse_ethertype
parse_icmpv6
parse_nsh
key_extract_l3l4
key_extract
ovs_flow_key_update_l3l4
ovs_flow_key_update
key_extract_mac_proto
ovs_flow_key_extract
ovs_flow_key_extract_userspace
   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  * Returns ERROR on memory error.
 298  * Returns 0 if it encounters a non-vlan or incomplete packet.
 299  * Returns 1 after successfully parsing vlan tag.
 300  */
 301 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
 302                           bool untag_vlan)
 303 {
 304         struct vlan_head *vh = (struct vlan_head *)skb->data;
 305 
 306         if (likely(!eth_type_vlan(vh->tpid)))
 307                 return 0;
 308 
 309         if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
 310                 return 0;
 311 
 312         if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
 313                                  sizeof(__be16))))
 314                 return -ENOMEM;
 315 
 316         vh = (struct vlan_head *)skb->data;
 317         key_vh->tci = vh->tci | htons(VLAN_CFI_MASK);
 318         key_vh->tpid = vh->tpid;
 319 
 320         if (unlikely(untag_vlan)) {
 321                 int offset = skb->data - skb_mac_header(skb);
 322                 u16 tci;
 323                 int err;
 324 
 325                 __skb_push(skb, offset);
 326                 err = __skb_vlan_pop(skb, &tci);
 327                 __skb_pull(skb, offset);
 328                 if (err)
 329                         return err;
 330                 __vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
 331         } else {
 332                 __skb_pull(skb, sizeof(struct vlan_head));
 333         }
 334         return 1;
 335 }
 336 
 337 static void clear_vlan(struct sw_flow_key *key)
 338 {
 339         key->eth.vlan.tci = 0;
 340         key->eth.vlan.tpid = 0;
 341         key->eth.cvlan.tci = 0;
 342         key->eth.cvlan.tpid = 0;
 343 }
 344 
 345 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 346 {
 347         int res;
 348 
 349         if (skb_vlan_tag_present(skb)) {
 350                 key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK);
 351                 key->eth.vlan.tpid = skb->vlan_proto;
 352         } else {
 353                 /* Parse outer vlan tag in the non-accelerated case. */
 354                 res = parse_vlan_tag(skb, &key->eth.vlan, true);
 355                 if (res <= 0)
 356                         return res;
 357         }
 358 
 359         /* Parse inner vlan tag. */
 360         res = parse_vlan_tag(skb, &key->eth.cvlan, false);
 361         if (res <= 0)
 362                 return res;
 363 
 364         return 0;
 365 }
 366 
 367 static __be16 parse_ethertype(struct sk_buff *skb)
 368 {
 369         struct llc_snap_hdr {
 370                 u8  dsap;  /* Always 0xAA */
 371                 u8  ssap;  /* Always 0xAA */
 372                 u8  ctrl;
 373                 u8  oui[3];
 374                 __be16 ethertype;
 375         };
 376         struct llc_snap_hdr *llc;
 377         __be16 proto;
 378 
 379         proto = *(__be16 *) skb->data;
 380         __skb_pull(skb, sizeof(__be16));
 381 
 382         if (eth_proto_is_802_3(proto))
 383                 return proto;
 384 
 385         if (skb->len < sizeof(struct llc_snap_hdr))
 386                 return htons(ETH_P_802_2);
 387 
 388         if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
 389                 return htons(0);
 390 
 391         llc = (struct llc_snap_hdr *) skb->data;
 392         if (llc->dsap != LLC_SAP_SNAP ||
 393             llc->ssap != LLC_SAP_SNAP ||
 394             (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
 395                 return htons(ETH_P_802_2);
 396 
 397         __skb_pull(skb, sizeof(struct llc_snap_hdr));
 398 
 399         if (eth_proto_is_802_3(llc->ethertype))
 400                 return llc->ethertype;
 401 
 402         return htons(ETH_P_802_2);
 403 }
 404 
 405 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
 406                         int nh_len)
 407 {
 408         struct icmp6hdr *icmp = icmp6_hdr(skb);
 409 
 410         /* The ICMPv6 type and code fields use the 16-bit transport port
 411          * fields, so we need to store them in 16-bit network byte order.
 412          */
 413         key->tp.src = htons(icmp->icmp6_type);
 414         key->tp.dst = htons(icmp->icmp6_code);
 415         memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));
 416 
 417         if (icmp->icmp6_code == 0 &&
 418             (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
 419              icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
 420                 int icmp_len = skb->len - skb_transport_offset(skb);
 421                 struct nd_msg *nd;
 422                 int offset;
 423 
 424                 /* In order to process neighbor discovery options, we need the
 425                  * entire packet.
 426                  */
 427                 if (unlikely(icmp_len < sizeof(*nd)))
 428                         return 0;
 429 
 430                 if (unlikely(skb_linearize(skb)))
 431                         return -ENOMEM;
 432 
 433                 nd = (struct nd_msg *)skb_transport_header(skb);
 434                 key->ipv6.nd.target = nd->target;
 435 
 436                 icmp_len -= sizeof(*nd);
 437                 offset = 0;
 438                 while (icmp_len >= 8) {
 439                         struct nd_opt_hdr *nd_opt =
 440                                  (struct nd_opt_hdr *)(nd->opt + offset);
 441                         int opt_len = nd_opt->nd_opt_len * 8;
 442 
 443                         if (unlikely(!opt_len || opt_len > icmp_len))
 444                                 return 0;
 445 
 446                         /* Store the link layer address if the appropriate
 447                          * option is provided.  It is considered an error if
 448                          * the same link layer option is specified twice.
 449                          */
 450                         if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
 451                             && opt_len == 8) {
 452                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
 453                                         goto invalid;
 454                                 ether_addr_copy(key->ipv6.nd.sll,
 455                                                 &nd->opt[offset+sizeof(*nd_opt)]);
 456                         } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
 457                                    && opt_len == 8) {
 458                                 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
 459                                         goto invalid;
 460                                 ether_addr_copy(key->ipv6.nd.tll,
 461                                                 &nd->opt[offset+sizeof(*nd_opt)]);
 462                         }
 463 
 464                         icmp_len -= opt_len;
 465                         offset += opt_len;
 466                 }
 467         }
 468 
 469         return 0;
 470 
 471 invalid:
 472         memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
 473         memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
 474         memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
 475 
 476         return 0;
 477 }
 478 
 479 static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
 480 {
 481         struct nshhdr *nh;
 482         unsigned int nh_ofs = skb_network_offset(skb);
 483         u8 version, length;
 484         int err;
 485 
 486         err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
 487         if (unlikely(err))
 488                 return err;
 489 
 490         nh = nsh_hdr(skb);
 491         version = nsh_get_ver(nh);
 492         length = nsh_hdr_len(nh);
 493 
 494         if (version != 0)
 495                 return -EINVAL;
 496 
 497         err = check_header(skb, nh_ofs + length);
 498         if (unlikely(err))
 499                 return err;
 500 
 501         nh = nsh_hdr(skb);
 502         key->nsh.base.flags = nsh_get_flags(nh);
 503         key->nsh.base.ttl = nsh_get_ttl(nh);
 504         key->nsh.base.mdtype = nh->mdtype;
 505         key->nsh.base.np = nh->np;
 506         key->nsh.base.path_hdr = nh->path_hdr;
 507         switch (key->nsh.base.mdtype) {
 508         case NSH_M_TYPE1:
 509                 if (length != NSH_M_TYPE1_LEN)
 510                         return -EINVAL;
 511                 memcpy(key->nsh.context, nh->md1.context,
 512                        sizeof(nh->md1));
 513                 break;
 514         case NSH_M_TYPE2:
 515                 memset(key->nsh.context, 0,
 516                        sizeof(nh->md1));
 517                 break;
 518         default:
 519                 return -EINVAL;
 520         }
 521 
 522         return 0;
 523 }
 524 
 525 /**
 526  * key_extract_l3l4 - extracts L3/L4 header information.
 527  * @skb: sk_buff that contains the frame, with skb->data pointing to the
 528  *       L3 header
 529  * @key: output flow key
 530  *
 531  */
 532 static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
 533 {
 534         int error;
 535 
 536         /* Network layer. */
 537         if (key->eth.type == htons(ETH_P_IP)) {
 538                 struct iphdr *nh;
 539                 __be16 offset;
 540 
 541                 error = check_iphdr(skb);
 542                 if (unlikely(error)) {
 543                         memset(&key->ip, 0, sizeof(key->ip));
 544                         memset(&key->ipv4, 0, sizeof(key->ipv4));
 545                         if (error == -EINVAL) {
 546                                 skb->transport_header = skb->network_header;
 547                                 error = 0;
 548                         }
 549                         return error;
 550                 }
 551 
 552                 nh = ip_hdr(skb);
 553                 key->ipv4.addr.src = nh->saddr;
 554                 key->ipv4.addr.dst = nh->daddr;
 555 
 556                 key->ip.proto = nh->protocol;
 557                 key->ip.tos = nh->tos;
 558                 key->ip.ttl = nh->ttl;
 559 
 560                 offset = nh->frag_off & htons(IP_OFFSET);
 561                 if (offset) {
 562                         key->ip.frag = OVS_FRAG_TYPE_LATER;
 563                         memset(&key->tp, 0, sizeof(key->tp));
 564                         return 0;
 565                 }
 566                 if (nh->frag_off & htons(IP_MF) ||
 567                         skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 568                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 569                 else
 570                         key->ip.frag = OVS_FRAG_TYPE_NONE;
 571 
 572                 /* Transport layer. */
 573                 if (key->ip.proto == IPPROTO_TCP) {
 574                         if (tcphdr_ok(skb)) {
 575                                 struct tcphdr *tcp = tcp_hdr(skb);
 576                                 key->tp.src = tcp->source;
 577                                 key->tp.dst = tcp->dest;
 578                                 key->tp.flags = TCP_FLAGS_BE16(tcp);
 579                         } else {
 580                                 memset(&key->tp, 0, sizeof(key->tp));
 581                         }
 582 
 583                 } else if (key->ip.proto == IPPROTO_UDP) {
 584                         if (udphdr_ok(skb)) {
 585                                 struct udphdr *udp = udp_hdr(skb);
 586                                 key->tp.src = udp->source;
 587                                 key->tp.dst = udp->dest;
 588                         } else {
 589                                 memset(&key->tp, 0, sizeof(key->tp));
 590                         }
 591                 } else if (key->ip.proto == IPPROTO_SCTP) {
 592                         if (sctphdr_ok(skb)) {
 593                                 struct sctphdr *sctp = sctp_hdr(skb);
 594                                 key->tp.src = sctp->source;
 595                                 key->tp.dst = sctp->dest;
 596                         } else {
 597                                 memset(&key->tp, 0, sizeof(key->tp));
 598                         }
 599                 } else if (key->ip.proto == IPPROTO_ICMP) {
 600                         if (icmphdr_ok(skb)) {
 601                                 struct icmphdr *icmp = icmp_hdr(skb);
 602                                 /* The ICMP type and code fields use the 16-bit
 603                                  * transport port fields, so we need to store
 604                                  * them in 16-bit network byte order. */
 605                                 key->tp.src = htons(icmp->type);
 606                                 key->tp.dst = htons(icmp->code);
 607                         } else {
 608                                 memset(&key->tp, 0, sizeof(key->tp));
 609                         }
 610                 }
 611 
 612         } else if (key->eth.type == htons(ETH_P_ARP) ||
 613                    key->eth.type == htons(ETH_P_RARP)) {
 614                 struct arp_eth_header *arp;
 615                 bool arp_available = arphdr_ok(skb);
 616 
 617                 arp = (struct arp_eth_header *)skb_network_header(skb);
 618 
 619                 if (arp_available &&
 620                     arp->ar_hrd == htons(ARPHRD_ETHER) &&
 621                     arp->ar_pro == htons(ETH_P_IP) &&
 622                     arp->ar_hln == ETH_ALEN &&
 623                     arp->ar_pln == 4) {
 624 
 625                         /* We only match on the lower 8 bits of the opcode. */
 626                         if (ntohs(arp->ar_op) <= 0xff)
 627                                 key->ip.proto = ntohs(arp->ar_op);
 628                         else
 629                                 key->ip.proto = 0;
 630 
 631                         memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
 632                         memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
 633                         ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
 634                         ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
 635                 } else {
 636                         memset(&key->ip, 0, sizeof(key->ip));
 637                         memset(&key->ipv4, 0, sizeof(key->ipv4));
 638                 }
 639         } else if (eth_p_mpls(key->eth.type)) {
 640                 size_t stack_len = MPLS_HLEN;
 641 
 642                 skb_set_inner_network_header(skb, skb->mac_len);
 643                 while (1) {
 644                         __be32 lse;
 645 
 646                         error = check_header(skb, skb->mac_len + stack_len);
 647                         if (unlikely(error))
 648                                 return 0;
 649 
 650                         memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
 651 
 652                         if (stack_len == MPLS_HLEN)
 653                                 memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);
 654 
 655                         skb_set_inner_network_header(skb, skb->mac_len + stack_len);
 656                         if (lse & htonl(MPLS_LS_S_MASK))
 657                                 break;
 658 
 659                         stack_len += MPLS_HLEN;
 660                 }
 661         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 662                 int nh_len;             /* IPv6 Header + Extensions */
 663 
 664                 nh_len = parse_ipv6hdr(skb, key);
 665                 if (unlikely(nh_len < 0)) {
 666                         switch (nh_len) {
 667                         case -EINVAL:
 668                                 memset(&key->ip, 0, sizeof(key->ip));
 669                                 memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
 670                                 /* fall-through */
 671                         case -EPROTO:
 672                                 skb->transport_header = skb->network_header;
 673                                 error = 0;
 674                                 break;
 675                         default:
 676                                 error = nh_len;
 677                         }
 678                         return error;
 679                 }
 680 
 681                 if (key->ip.frag == OVS_FRAG_TYPE_LATER) {
 682                         memset(&key->tp, 0, sizeof(key->tp));
 683                         return 0;
 684                 }
 685                 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
 686                         key->ip.frag = OVS_FRAG_TYPE_FIRST;
 687 
 688                 /* Transport layer. */
 689                 if (key->ip.proto == NEXTHDR_TCP) {
 690                         if (tcphdr_ok(skb)) {
 691                                 struct tcphdr *tcp = tcp_hdr(skb);
 692                                 key->tp.src = tcp->source;
 693                                 key->tp.dst = tcp->dest;
 694                                 key->tp.flags = TCP_FLAGS_BE16(tcp);
 695                         } else {
 696                                 memset(&key->tp, 0, sizeof(key->tp));
 697                         }
 698                 } else if (key->ip.proto == NEXTHDR_UDP) {
 699                         if (udphdr_ok(skb)) {
 700                                 struct udphdr *udp = udp_hdr(skb);
 701                                 key->tp.src = udp->source;
 702                                 key->tp.dst = udp->dest;
 703                         } else {
 704                                 memset(&key->tp, 0, sizeof(key->tp));
 705                         }
 706                 } else if (key->ip.proto == NEXTHDR_SCTP) {
 707                         if (sctphdr_ok(skb)) {
 708                                 struct sctphdr *sctp = sctp_hdr(skb);
 709                                 key->tp.src = sctp->source;
 710                                 key->tp.dst = sctp->dest;
 711                         } else {
 712                                 memset(&key->tp, 0, sizeof(key->tp));
 713                         }
 714                 } else if (key->ip.proto == NEXTHDR_ICMP) {
 715                         if (icmp6hdr_ok(skb)) {
 716                                 error = parse_icmpv6(skb, key, nh_len);
 717                                 if (error)
 718                                         return error;
 719                         } else {
 720                                 memset(&key->tp, 0, sizeof(key->tp));
 721                         }
 722                 }
 723         } else if (key->eth.type == htons(ETH_P_NSH)) {
 724                 error = parse_nsh(skb, key);
 725                 if (error)
 726                         return error;
 727         }
 728         return 0;
 729 }
 730 
 731 /**
 732  * key_extract - extracts a flow key from an Ethernet frame.
 733  * @skb: sk_buff that contains the frame, with skb->data pointing to the
 734  * Ethernet header
 735  * @key: output flow key
 736  *
 737  * The caller must ensure that skb->len >= ETH_HLEN.
 738  *
 739  * Returns 0 if successful, otherwise a negative errno value.
 740  *
 741  * Initializes @skb header fields as follows:
 742  *
 743  *    - skb->mac_header: the L2 header.
 744  *
 745  *    - skb->network_header: just past the L2 header, or just past the
 746  *      VLAN header, to the first byte of the L2 payload.
 747  *
 748  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
 749  *      on output, then just past the IP header, if one is present and
 750  *      of a correct length, otherwise the same as skb->network_header.
 751  *      For other key->eth.type values it is left untouched.
 752  *
 753  *    - skb->protocol: the type of the data starting at skb->network_header.
 754  *      Equals to key->eth.type.
 755  */
 756 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
 757 {
 758         struct ethhdr *eth;
 759 
 760         /* Flags are always used as part of stats */
 761         key->tp.flags = 0;
 762 
 763         skb_reset_mac_header(skb);
 764 
 765         /* Link layer. */
 766         clear_vlan(key);
 767         if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
 768                 if (unlikely(eth_type_vlan(skb->protocol)))
 769                         return -EINVAL;
 770 
 771                 skb_reset_network_header(skb);
 772                 key->eth.type = skb->protocol;
 773         } else {
 774                 eth = eth_hdr(skb);
 775                 ether_addr_copy(key->eth.src, eth->h_source);
 776                 ether_addr_copy(key->eth.dst, eth->h_dest);
 777 
 778                 __skb_pull(skb, 2 * ETH_ALEN);
 779                 /* We are going to push all headers that we pull, so no need to
 780                  * update skb->csum here.
 781                  */
 782 
 783                 if (unlikely(parse_vlan(skb, key)))
 784                         return -ENOMEM;
 785 
 786                 key->eth.type = parse_ethertype(skb);
 787                 if (unlikely(key->eth.type == htons(0)))
 788                         return -ENOMEM;
 789 
 790                 /* Multiple tagged packets need to retain TPID to satisfy
 791                  * skb_vlan_pop(), which will later shift the ethertype into
 792                  * skb->protocol.
 793                  */
 794                 if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK))
 795                         skb->protocol = key->eth.cvlan.tpid;
 796                 else
 797                         skb->protocol = key->eth.type;
 798 
 799                 skb_reset_network_header(skb);
 800                 __skb_push(skb, skb->data - skb_mac_header(skb));
 801         }
 802 
 803         skb_reset_mac_len(skb);
 804 
 805         /* Fill out L3/L4 key info, if any */
 806         return key_extract_l3l4(skb, key);
 807 }
 808 
 809 /* In the case of conntrack fragment handling it expects L3 headers,
 810  * add a helper.
 811  */
 812 int ovs_flow_key_update_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
 813 {
 814         return key_extract_l3l4(skb, key);
 815 }
 816 
 817 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
 818 {
 819         int res;
 820 
 821         res = key_extract(skb, key);
 822         if (!res)
 823                 key->mac_proto &= ~SW_FLOW_KEY_INVALID;
 824 
 825         return res;
 826 }
 827 
 828 static int key_extract_mac_proto(struct sk_buff *skb)
 829 {
 830         switch (skb->dev->type) {
 831         case ARPHRD_ETHER:
 832                 return MAC_PROTO_ETHERNET;
 833         case ARPHRD_NONE:
 834                 if (skb->protocol == htons(ETH_P_TEB))
 835                         return MAC_PROTO_ETHERNET;
 836                 return MAC_PROTO_NONE;
 837         }
 838         WARN_ON_ONCE(1);
 839         return -EINVAL;
 840 }
 841 
 842 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
 843                          struct sk_buff *skb, struct sw_flow_key *key)
 844 {
 845 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 846         struct tc_skb_ext *tc_ext;
 847 #endif
 848         int res, err;
 849 
 850         /* Extract metadata from packet. */
 851         if (tun_info) {
 852                 key->tun_proto = ip_tunnel_info_af(tun_info);
 853                 memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
 854 
 855                 if (tun_info->options_len) {
 856                         BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
 857                                                    8)) - 1
 858                                         > sizeof(key->tun_opts));
 859 
 860                         ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
 861                                                 tun_info);
 862                         key->tun_opts_len = tun_info->options_len;
 863                 } else {
 864                         key->tun_opts_len = 0;
 865                 }
 866         } else  {
 867                 key->tun_proto = 0;
 868                 key->tun_opts_len = 0;
 869                 memset(&key->tun_key, 0, sizeof(key->tun_key));
 870         }
 871 
 872         key->phy.priority = skb->priority;
 873         key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
 874         key->phy.skb_mark = skb->mark;
 875         key->ovs_flow_hash = 0;
 876         res = key_extract_mac_proto(skb);
 877         if (res < 0)
 878                 return res;
 879         key->mac_proto = res;
 880 
 881 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 882         if (static_branch_unlikely(&tc_recirc_sharing_support)) {
 883                 tc_ext = skb_ext_find(skb, TC_SKB_EXT);
 884                 key->recirc_id = tc_ext ? tc_ext->chain : 0;
 885         } else {
 886                 key->recirc_id = 0;
 887         }
 888 #else
 889         key->recirc_id = 0;
 890 #endif
 891 
 892         err = key_extract(skb, key);
 893         if (!err)
 894                 ovs_ct_fill_key(skb, key);   /* Must be after key_extract(). */
 895         return err;
 896 }
 897 
 898 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
 899                                    struct sk_buff *skb,
 900                                    struct sw_flow_key *key, bool log)
 901 {
 902         const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
 903         u64 attrs = 0;
 904         int err;
 905 
 906         err = parse_flow_nlattrs(attr, a, &attrs, log);
 907         if (err)
 908                 return -EINVAL;
 909 
 910         /* Extract metadata from netlink attributes. */
 911         err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
 912         if (err)
 913                 return err;
 914 
 915         /* key_extract assumes that skb->protocol is set-up for
 916          * layer 3 packets which is the case for other callers,
 917          * in particular packets received from the network stack.
 918          * Here the correct value can be set from the metadata
 919          * extracted above.
 920          * For L2 packet key eth type would be zero. skb protocol
 921          * would be set to correct value later during key-extact.
 922          */
 923 
 924         skb->protocol = key->eth.type;
 925         err = key_extract(skb, key);
 926         if (err)
 927                 return err;
 928 
 929         /* Check that we have conntrack original direction tuple metadata only
 930          * for packets for which it makes sense.  Otherwise the key may be
 931          * corrupted due to overlapping key fields.
 932          */
 933         if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
 934             key->eth.type != htons(ETH_P_IP))
 935                 return -EINVAL;
 936         if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
 937             (key->eth.type != htons(ETH_P_IPV6) ||
 938              sw_flow_key_is_nd(key)))
 939                 return -EINVAL;
 940 
 941         return 0;
 942 }
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root/net/openvswitch/flow.c

DEFINITIONS
