1 /* 2 * Copyright (c) 2007-2013 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 16 * 02110-1301, USA 17 */ 18 19 #include "flow.h" 20 #include "datapath.h" 21 #include <linux/uaccess.h> 22 #include <linux/netdevice.h> 23 #include <linux/etherdevice.h> 24 #include <linux/if_ether.h> 25 #include <linux/if_vlan.h> 26 #include <net/llc_pdu.h> 27 #include <linux/kernel.h> 28 #include <linux/jhash.h> 29 #include <linux/jiffies.h> 30 #include <linux/llc.h> 31 #include <linux/module.h> 32 #include <linux/in.h> 33 #include <linux/rcupdate.h> 34 #include <linux/if_arp.h> 35 #include <linux/ip.h> 36 #include <linux/ipv6.h> 37 #include <linux/sctp.h> 38 #include <linux/smp.h> 39 #include <linux/tcp.h> 40 #include <linux/udp.h> 41 #include <linux/icmp.h> 42 #include <linux/icmpv6.h> 43 #include <linux/rculist.h> 44 #include <net/ip.h> 45 #include <net/ip_tunnels.h> 46 #include <net/ipv6.h> 47 #include <net/ndisc.h> 48 49 u64 ovs_flow_used_time(unsigned long flow_jiffies) 50 { 51 struct timespec cur_ts; 52 u64 cur_ms, idle_ms; 53 54 ktime_get_ts(&cur_ts); 55 idle_ms = jiffies_to_msecs(jiffies - flow_jiffies); 56 cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC + 57 cur_ts.tv_nsec / NSEC_PER_MSEC; 58 59 return cur_ms - idle_ms; 60 } 61 62 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF)) 63 64 void ovs_flow_stats_update(struct sw_flow *flow, struct sk_buff *skb) 65 { 66 struct flow_stats *stats; 67 __be16 tcp_flags = flow->key.tp.flags; 68 int node = numa_node_id(); 69 70 stats = rcu_dereference(flow->stats[node]); 71 72 /* Check if already have node-specific stats. */ 73 if (likely(stats)) { 74 spin_lock(&stats->lock); 75 /* Mark if we write on the pre-allocated stats. */ 76 if (node == 0 && unlikely(flow->stats_last_writer != node)) 77 flow->stats_last_writer = node; 78 } else { 79 stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */ 80 spin_lock(&stats->lock); 81 82 /* If the current NUMA-node is the only writer on the 83 * pre-allocated stats keep using them. 84 */ 85 if (unlikely(flow->stats_last_writer != node)) { 86 /* A previous locker may have already allocated the 87 * stats, so we need to check again. If node-specific 88 * stats were already allocated, we update the pre- 89 * allocated stats as we have already locked them. 90 */ 91 if (likely(flow->stats_last_writer != NUMA_NO_NODE) 92 && likely(!rcu_dereference(flow->stats[node]))) { 93 /* Try to allocate node-specific stats. */ 94 struct flow_stats *new_stats; 95 96 new_stats = 97 kmem_cache_alloc_node(flow_stats_cache, 98 GFP_THISNODE | 99 __GFP_NOMEMALLOC, 100 node); 101 if (likely(new_stats)) { 102 new_stats->used = jiffies; 103 new_stats->packet_count = 1; 104 new_stats->byte_count = skb->len; 105 new_stats->tcp_flags = tcp_flags; 106 spin_lock_init(&new_stats->lock); 107 108 rcu_assign_pointer(flow->stats[node], 109 new_stats); 110 goto unlock; 111 } 112 } 113 flow->stats_last_writer = node; 114 } 115 } 116 117 stats->used = jiffies; 118 stats->packet_count++; 119 stats->byte_count += skb->len; 120 stats->tcp_flags |= tcp_flags; 121 unlock: 122 spin_unlock(&stats->lock); 123 } 124 125 /* Must be called with rcu_read_lock or ovs_mutex. */ 126 void ovs_flow_stats_get(const struct sw_flow *flow, 127 struct ovs_flow_stats *ovs_stats, 128 unsigned long *used, __be16 *tcp_flags) 129 { 130 int node; 131 132 *used = 0; 133 *tcp_flags = 0; 134 memset(ovs_stats, 0, sizeof(*ovs_stats)); 135 136 for_each_node(node) { 137 struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[node]); 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 node; 158 159 for_each_node(node) { 160 struct flow_stats *stats = ovsl_dereference(flow->stats[node]); 161 162 if (stats) { 163 spin_lock_bh(&stats->lock); 164 stats->used = 0; 165 stats->packet_count = 0; 166 stats->byte_count = 0; 167 stats->tcp_flags = 0; 168 spin_unlock_bh(&stats->lock); 169 } 170 } 171 } 172 173 static int check_header(struct sk_buff *skb, int len) 174 { 175 if (unlikely(skb->len < len)) 176 return -EINVAL; 177 if (unlikely(!pskb_may_pull(skb, len))) 178 return -ENOMEM; 179 return 0; 180 } 181 182 static bool arphdr_ok(struct sk_buff *skb) 183 { 184 return pskb_may_pull(skb, skb_network_offset(skb) + 185 sizeof(struct arp_eth_header)); 186 } 187 188 static int check_iphdr(struct sk_buff *skb) 189 { 190 unsigned int nh_ofs = skb_network_offset(skb); 191 unsigned int ip_len; 192 int err; 193 194 err = check_header(skb, nh_ofs + sizeof(struct iphdr)); 195 if (unlikely(err)) 196 return err; 197 198 ip_len = ip_hdrlen(skb); 199 if (unlikely(ip_len < sizeof(struct iphdr) || 200 skb->len < nh_ofs + ip_len)) 201 return -EINVAL; 202 203 skb_set_transport_header(skb, nh_ofs + ip_len); 204 return 0; 205 } 206 207 static bool tcphdr_ok(struct sk_buff *skb) 208 { 209 int th_ofs = skb_transport_offset(skb); 210 int tcp_len; 211 212 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr)))) 213 return false; 214 215 tcp_len = tcp_hdrlen(skb); 216 if (unlikely(tcp_len < sizeof(struct tcphdr) || 217 skb->len < th_ofs + tcp_len)) 218 return false; 219 220 return true; 221 } 222 223 static bool udphdr_ok(struct sk_buff *skb) 224 { 225 return pskb_may_pull(skb, skb_transport_offset(skb) + 226 sizeof(struct udphdr)); 227 } 228 229 static bool sctphdr_ok(struct sk_buff *skb) 230 { 231 return pskb_may_pull(skb, skb_transport_offset(skb) + 232 sizeof(struct sctphdr)); 233 } 234 235 static bool icmphdr_ok(struct sk_buff *skb) 236 { 237 return pskb_may_pull(skb, skb_transport_offset(skb) + 238 sizeof(struct icmphdr)); 239 } 240 241 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) 242 { 243 unsigned int nh_ofs = skb_network_offset(skb); 244 unsigned int nh_len; 245 int payload_ofs; 246 struct ipv6hdr *nh; 247 uint8_t nexthdr; 248 __be16 frag_off; 249 int err; 250 251 err = check_header(skb, nh_ofs + sizeof(*nh)); 252 if (unlikely(err)) 253 return err; 254 255 nh = ipv6_hdr(skb); 256 nexthdr = nh->nexthdr; 257 payload_ofs = (u8 *)(nh + 1) - skb->data; 258 259 key->ip.proto = NEXTHDR_NONE; 260 key->ip.tos = ipv6_get_dsfield(nh); 261 key->ip.ttl = nh->hop_limit; 262 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); 263 key->ipv6.addr.src = nh->saddr; 264 key->ipv6.addr.dst = nh->daddr; 265 266 payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off); 267 if (unlikely(payload_ofs < 0)) 268 return -EINVAL; 269 270 if (frag_off) { 271 if (frag_off & htons(~0x7)) 272 key->ip.frag = OVS_FRAG_TYPE_LATER; 273 else 274 key->ip.frag = OVS_FRAG_TYPE_FIRST; 275 } 276 277 nh_len = payload_ofs - nh_ofs; 278 skb_set_transport_header(skb, nh_ofs + nh_len); 279 key->ip.proto = nexthdr; 280 return nh_len; 281 } 282 283 static bool icmp6hdr_ok(struct sk_buff *skb) 284 { 285 return pskb_may_pull(skb, skb_transport_offset(skb) + 286 sizeof(struct icmp6hdr)); 287 } 288 289 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) 290 { 291 struct qtag_prefix { 292 __be16 eth_type; /* ETH_P_8021Q */ 293 __be16 tci; 294 }; 295 struct qtag_prefix *qp; 296 297 if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))) 298 return 0; 299 300 if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) + 301 sizeof(__be16)))) 302 return -ENOMEM; 303 304 qp = (struct qtag_prefix *) skb->data; 305 key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT); 306 __skb_pull(skb, sizeof(struct qtag_prefix)); 307 308 return 0; 309 } 310 311 static __be16 parse_ethertype(struct sk_buff *skb) 312 { 313 struct llc_snap_hdr { 314 u8 dsap; /* Always 0xAA */ 315 u8 ssap; /* Always 0xAA */ 316 u8 ctrl; 317 u8 oui[3]; 318 __be16 ethertype; 319 }; 320 struct llc_snap_hdr *llc; 321 __be16 proto; 322 323 proto = *(__be16 *) skb->data; 324 __skb_pull(skb, sizeof(__be16)); 325 326 if (ntohs(proto) >= ETH_P_802_3_MIN) 327 return proto; 328 329 if (skb->len < sizeof(struct llc_snap_hdr)) 330 return htons(ETH_P_802_2); 331 332 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr)))) 333 return htons(0); 334 335 llc = (struct llc_snap_hdr *) skb->data; 336 if (llc->dsap != LLC_SAP_SNAP || 337 llc->ssap != LLC_SAP_SNAP || 338 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0) 339 return htons(ETH_P_802_2); 340 341 __skb_pull(skb, sizeof(struct llc_snap_hdr)); 342 343 if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN) 344 return llc->ethertype; 345 346 return htons(ETH_P_802_2); 347 } 348 349 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, 350 int nh_len) 351 { 352 struct icmp6hdr *icmp = icmp6_hdr(skb); 353 354 /* The ICMPv6 type and code fields use the 16-bit transport port 355 * fields, so we need to store them in 16-bit network byte order. 356 */ 357 key->tp.src = htons(icmp->icmp6_type); 358 key->tp.dst = htons(icmp->icmp6_code); 359 360 if (icmp->icmp6_code == 0 && 361 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || 362 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) { 363 int icmp_len = skb->len - skb_transport_offset(skb); 364 struct nd_msg *nd; 365 int offset; 366 367 /* In order to process neighbor discovery options, we need the 368 * entire packet. 369 */ 370 if (unlikely(icmp_len < sizeof(*nd))) 371 return 0; 372 373 if (unlikely(skb_linearize(skb))) 374 return -ENOMEM; 375 376 nd = (struct nd_msg *)skb_transport_header(skb); 377 key->ipv6.nd.target = nd->target; 378 379 icmp_len -= sizeof(*nd); 380 offset = 0; 381 while (icmp_len >= 8) { 382 struct nd_opt_hdr *nd_opt = 383 (struct nd_opt_hdr *)(nd->opt + offset); 384 int opt_len = nd_opt->nd_opt_len * 8; 385 386 if (unlikely(!opt_len || opt_len > icmp_len)) 387 return 0; 388 389 /* Store the link layer address if the appropriate 390 * option is provided. It is considered an error if 391 * the same link layer option is specified twice. 392 */ 393 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR 394 && opt_len == 8) { 395 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll))) 396 goto invalid; 397 ether_addr_copy(key->ipv6.nd.sll, 398 &nd->opt[offset+sizeof(*nd_opt)]); 399 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR 400 && opt_len == 8) { 401 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll))) 402 goto invalid; 403 ether_addr_copy(key->ipv6.nd.tll, 404 &nd->opt[offset+sizeof(*nd_opt)]); 405 } 406 407 icmp_len -= opt_len; 408 offset += opt_len; 409 } 410 } 411 412 return 0; 413 414 invalid: 415 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target)); 416 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll)); 417 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll)); 418 419 return 0; 420 } 421 422 /** 423 * ovs_flow_extract - extracts a flow key from an Ethernet frame. 424 * @skb: sk_buff that contains the frame, with skb->data pointing to the 425 * Ethernet header 426 * @in_port: port number on which @skb was received. 427 * @key: output flow key 428 * 429 * The caller must ensure that skb->len >= ETH_HLEN. 430 * 431 * Returns 0 if successful, otherwise a negative errno value. 432 * 433 * Initializes @skb header pointers as follows: 434 * 435 * - skb->mac_header: the Ethernet header. 436 * 437 * - skb->network_header: just past the Ethernet header, or just past the 438 * VLAN header, to the first byte of the Ethernet payload. 439 * 440 * - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6 441 * on output, then just past the IP header, if one is present and 442 * of a correct length, otherwise the same as skb->network_header. 443 * For other key->eth.type values it is left untouched. 444 */ 445 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key) 446 { 447 int error; 448 struct ethhdr *eth; 449 450 memset(key, 0, sizeof(*key)); 451 452 key->phy.priority = skb->priority; 453 if (OVS_CB(skb)->tun_key) 454 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key)); 455 key->phy.in_port = in_port; 456 key->phy.skb_mark = skb->mark; 457 458 skb_reset_mac_header(skb); 459 460 /* Link layer. We are guaranteed to have at least the 14 byte Ethernet 461 * header in the linear data area. 462 */ 463 eth = eth_hdr(skb); 464 ether_addr_copy(key->eth.src, eth->h_source); 465 ether_addr_copy(key->eth.dst, eth->h_dest); 466 467 __skb_pull(skb, 2 * ETH_ALEN); 468 /* We are going to push all headers that we pull, so no need to 469 * update skb->csum here. 470 */ 471 472 if (vlan_tx_tag_present(skb)) 473 key->eth.tci = htons(skb->vlan_tci); 474 else if (eth->h_proto == htons(ETH_P_8021Q)) 475 if (unlikely(parse_vlan(skb, key))) 476 return -ENOMEM; 477 478 key->eth.type = parse_ethertype(skb); 479 if (unlikely(key->eth.type == htons(0))) 480 return -ENOMEM; 481 482 skb_reset_network_header(skb); 483 __skb_push(skb, skb->data - skb_mac_header(skb)); 484 485 /* Network layer. */ 486 if (key->eth.type == htons(ETH_P_IP)) { 487 struct iphdr *nh; 488 __be16 offset; 489 490 error = check_iphdr(skb); 491 if (unlikely(error)) { 492 if (error == -EINVAL) { 493 skb->transport_header = skb->network_header; 494 error = 0; 495 } 496 return error; 497 } 498 499 nh = ip_hdr(skb); 500 key->ipv4.addr.src = nh->saddr; 501 key->ipv4.addr.dst = nh->daddr; 502 503 key->ip.proto = nh->protocol; 504 key->ip.tos = nh->tos; 505 key->ip.ttl = nh->ttl; 506 507 offset = nh->frag_off & htons(IP_OFFSET); 508 if (offset) { 509 key->ip.frag = OVS_FRAG_TYPE_LATER; 510 return 0; 511 } 512 if (nh->frag_off & htons(IP_MF) || 513 skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 514 key->ip.frag = OVS_FRAG_TYPE_FIRST; 515 516 /* Transport layer. */ 517 if (key->ip.proto == IPPROTO_TCP) { 518 if (tcphdr_ok(skb)) { 519 struct tcphdr *tcp = tcp_hdr(skb); 520 key->tp.src = tcp->source; 521 key->tp.dst = tcp->dest; 522 key->tp.flags = TCP_FLAGS_BE16(tcp); 523 } 524 } else if (key->ip.proto == IPPROTO_UDP) { 525 if (udphdr_ok(skb)) { 526 struct udphdr *udp = udp_hdr(skb); 527 key->tp.src = udp->source; 528 key->tp.dst = udp->dest; 529 } 530 } else if (key->ip.proto == IPPROTO_SCTP) { 531 if (sctphdr_ok(skb)) { 532 struct sctphdr *sctp = sctp_hdr(skb); 533 key->tp.src = sctp->source; 534 key->tp.dst = sctp->dest; 535 } 536 } else if (key->ip.proto == IPPROTO_ICMP) { 537 if (icmphdr_ok(skb)) { 538 struct icmphdr *icmp = icmp_hdr(skb); 539 /* The ICMP type and code fields use the 16-bit 540 * transport port fields, so we need to store 541 * them in 16-bit network byte order. */ 542 key->tp.src = htons(icmp->type); 543 key->tp.dst = htons(icmp->code); 544 } 545 } 546 547 } else if ((key->eth.type == htons(ETH_P_ARP) || 548 key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) { 549 struct arp_eth_header *arp; 550 551 arp = (struct arp_eth_header *)skb_network_header(skb); 552 553 if (arp->ar_hrd == htons(ARPHRD_ETHER) 554 && arp->ar_pro == htons(ETH_P_IP) 555 && arp->ar_hln == ETH_ALEN 556 && arp->ar_pln == 4) { 557 558 /* We only match on the lower 8 bits of the opcode. */ 559 if (ntohs(arp->ar_op) <= 0xff) 560 key->ip.proto = ntohs(arp->ar_op); 561 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); 562 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); 563 ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha); 564 ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha); 565 } 566 } else if (key->eth.type == htons(ETH_P_IPV6)) { 567 int nh_len; /* IPv6 Header + Extensions */ 568 569 nh_len = parse_ipv6hdr(skb, key); 570 if (unlikely(nh_len < 0)) { 571 if (nh_len == -EINVAL) { 572 skb->transport_header = skb->network_header; 573 error = 0; 574 } else { 575 error = nh_len; 576 } 577 return error; 578 } 579 580 if (key->ip.frag == OVS_FRAG_TYPE_LATER) 581 return 0; 582 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 583 key->ip.frag = OVS_FRAG_TYPE_FIRST; 584 585 /* Transport layer. */ 586 if (key->ip.proto == NEXTHDR_TCP) { 587 if (tcphdr_ok(skb)) { 588 struct tcphdr *tcp = tcp_hdr(skb); 589 key->tp.src = tcp->source; 590 key->tp.dst = tcp->dest; 591 key->tp.flags = TCP_FLAGS_BE16(tcp); 592 } 593 } else if (key->ip.proto == NEXTHDR_UDP) { 594 if (udphdr_ok(skb)) { 595 struct udphdr *udp = udp_hdr(skb); 596 key->tp.src = udp->source; 597 key->tp.dst = udp->dest; 598 } 599 } else if (key->ip.proto == NEXTHDR_SCTP) { 600 if (sctphdr_ok(skb)) { 601 struct sctphdr *sctp = sctp_hdr(skb); 602 key->tp.src = sctp->source; 603 key->tp.dst = sctp->dest; 604 } 605 } else if (key->ip.proto == NEXTHDR_ICMP) { 606 if (icmp6hdr_ok(skb)) { 607 error = parse_icmpv6(skb, key, nh_len); 608 if (error) 609 return error; 610 } 611 } 612 } 613 614 return 0; 615 } 616