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 = 0; 68 int node = numa_node_id(); 69 70 stats = rcu_dereference(flow->stats[node]); 71 72 if ((flow->key.eth.type == htons(ETH_P_IP) || 73 flow->key.eth.type == htons(ETH_P_IPV6)) && 74 flow->key.ip.frag != OVS_FRAG_TYPE_LATER && 75 flow->key.ip.proto == IPPROTO_TCP && 76 likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) { 77 tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb)); 78 } 79 80 /* Check if already have node-specific stats. */ 81 if (likely(stats)) { 82 spin_lock(&stats->lock); 83 /* Mark if we write on the pre-allocated stats. */ 84 if (node == 0 && unlikely(flow->stats_last_writer != node)) 85 flow->stats_last_writer = node; 86 } else { 87 stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */ 88 spin_lock(&stats->lock); 89 90 /* If the current NUMA-node is the only writer on the 91 * pre-allocated stats keep using them. 92 */ 93 if (unlikely(flow->stats_last_writer != node)) { 94 /* A previous locker may have already allocated the 95 * stats, so we need to check again. If node-specific 96 * stats were already allocated, we update the pre- 97 * allocated stats as we have already locked them. 98 */ 99 if (likely(flow->stats_last_writer != NUMA_NO_NODE) 100 && likely(!rcu_dereference(flow->stats[node]))) { 101 /* Try to allocate node-specific stats. */ 102 struct flow_stats *new_stats; 103 104 new_stats = 105 kmem_cache_alloc_node(flow_stats_cache, 106 GFP_THISNODE | 107 __GFP_NOMEMALLOC, 108 node); 109 if (likely(new_stats)) { 110 new_stats->used = jiffies; 111 new_stats->packet_count = 1; 112 new_stats->byte_count = skb->len; 113 new_stats->tcp_flags = tcp_flags; 114 spin_lock_init(&new_stats->lock); 115 116 rcu_assign_pointer(flow->stats[node], 117 new_stats); 118 goto unlock; 119 } 120 } 121 flow->stats_last_writer = node; 122 } 123 } 124 125 stats->used = jiffies; 126 stats->packet_count++; 127 stats->byte_count += skb->len; 128 stats->tcp_flags |= tcp_flags; 129 unlock: 130 spin_unlock(&stats->lock); 131 } 132 133 void ovs_flow_stats_get(struct sw_flow *flow, struct ovs_flow_stats *ovs_stats, 134 unsigned long *used, __be16 *tcp_flags) 135 { 136 int node; 137 138 *used = 0; 139 *tcp_flags = 0; 140 memset(ovs_stats, 0, sizeof(*ovs_stats)); 141 142 for_each_node(node) { 143 struct flow_stats *stats = rcu_dereference(flow->stats[node]); 144 145 if (stats) { 146 /* Local CPU may write on non-local stats, so we must 147 * block bottom-halves here. 148 */ 149 spin_lock_bh(&stats->lock); 150 if (!*used || time_after(stats->used, *used)) 151 *used = stats->used; 152 *tcp_flags |= stats->tcp_flags; 153 ovs_stats->n_packets += stats->packet_count; 154 ovs_stats->n_bytes += stats->byte_count; 155 spin_unlock_bh(&stats->lock); 156 } 157 } 158 } 159 160 void ovs_flow_stats_clear(struct sw_flow *flow) 161 { 162 int node; 163 164 for_each_node(node) { 165 struct flow_stats *stats = rcu_dereference(flow->stats[node]); 166 167 if (stats) { 168 spin_lock_bh(&stats->lock); 169 stats->used = 0; 170 stats->packet_count = 0; 171 stats->byte_count = 0; 172 stats->tcp_flags = 0; 173 spin_unlock_bh(&stats->lock); 174 } 175 } 176 } 177 178 static int check_header(struct sk_buff *skb, int len) 179 { 180 if (unlikely(skb->len < len)) 181 return -EINVAL; 182 if (unlikely(!pskb_may_pull(skb, len))) 183 return -ENOMEM; 184 return 0; 185 } 186 187 static bool arphdr_ok(struct sk_buff *skb) 188 { 189 return pskb_may_pull(skb, skb_network_offset(skb) + 190 sizeof(struct arp_eth_header)); 191 } 192 193 static int check_iphdr(struct sk_buff *skb) 194 { 195 unsigned int nh_ofs = skb_network_offset(skb); 196 unsigned int ip_len; 197 int err; 198 199 err = check_header(skb, nh_ofs + sizeof(struct iphdr)); 200 if (unlikely(err)) 201 return err; 202 203 ip_len = ip_hdrlen(skb); 204 if (unlikely(ip_len < sizeof(struct iphdr) || 205 skb->len < nh_ofs + ip_len)) 206 return -EINVAL; 207 208 skb_set_transport_header(skb, nh_ofs + ip_len); 209 return 0; 210 } 211 212 static bool tcphdr_ok(struct sk_buff *skb) 213 { 214 int th_ofs = skb_transport_offset(skb); 215 int tcp_len; 216 217 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr)))) 218 return false; 219 220 tcp_len = tcp_hdrlen(skb); 221 if (unlikely(tcp_len < sizeof(struct tcphdr) || 222 skb->len < th_ofs + tcp_len)) 223 return false; 224 225 return true; 226 } 227 228 static bool udphdr_ok(struct sk_buff *skb) 229 { 230 return pskb_may_pull(skb, skb_transport_offset(skb) + 231 sizeof(struct udphdr)); 232 } 233 234 static bool sctphdr_ok(struct sk_buff *skb) 235 { 236 return pskb_may_pull(skb, skb_transport_offset(skb) + 237 sizeof(struct sctphdr)); 238 } 239 240 static bool icmphdr_ok(struct sk_buff *skb) 241 { 242 return pskb_may_pull(skb, skb_transport_offset(skb) + 243 sizeof(struct icmphdr)); 244 } 245 246 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) 247 { 248 unsigned int nh_ofs = skb_network_offset(skb); 249 unsigned int nh_len; 250 int payload_ofs; 251 struct ipv6hdr *nh; 252 uint8_t nexthdr; 253 __be16 frag_off; 254 int err; 255 256 err = check_header(skb, nh_ofs + sizeof(*nh)); 257 if (unlikely(err)) 258 return err; 259 260 nh = ipv6_hdr(skb); 261 nexthdr = nh->nexthdr; 262 payload_ofs = (u8 *)(nh + 1) - skb->data; 263 264 key->ip.proto = NEXTHDR_NONE; 265 key->ip.tos = ipv6_get_dsfield(nh); 266 key->ip.ttl = nh->hop_limit; 267 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); 268 key->ipv6.addr.src = nh->saddr; 269 key->ipv6.addr.dst = nh->daddr; 270 271 payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off); 272 if (unlikely(payload_ofs < 0)) 273 return -EINVAL; 274 275 if (frag_off) { 276 if (frag_off & htons(~0x7)) 277 key->ip.frag = OVS_FRAG_TYPE_LATER; 278 else 279 key->ip.frag = OVS_FRAG_TYPE_FIRST; 280 } 281 282 nh_len = payload_ofs - nh_ofs; 283 skb_set_transport_header(skb, nh_ofs + nh_len); 284 key->ip.proto = nexthdr; 285 return nh_len; 286 } 287 288 static bool icmp6hdr_ok(struct sk_buff *skb) 289 { 290 return pskb_may_pull(skb, skb_transport_offset(skb) + 291 sizeof(struct icmp6hdr)); 292 } 293 294 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) 295 { 296 struct qtag_prefix { 297 __be16 eth_type; /* ETH_P_8021Q */ 298 __be16 tci; 299 }; 300 struct qtag_prefix *qp; 301 302 if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))) 303 return 0; 304 305 if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) + 306 sizeof(__be16)))) 307 return -ENOMEM; 308 309 qp = (struct qtag_prefix *) skb->data; 310 key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT); 311 __skb_pull(skb, sizeof(struct qtag_prefix)); 312 313 return 0; 314 } 315 316 static __be16 parse_ethertype(struct sk_buff *skb) 317 { 318 struct llc_snap_hdr { 319 u8 dsap; /* Always 0xAA */ 320 u8 ssap; /* Always 0xAA */ 321 u8 ctrl; 322 u8 oui[3]; 323 __be16 ethertype; 324 }; 325 struct llc_snap_hdr *llc; 326 __be16 proto; 327 328 proto = *(__be16 *) skb->data; 329 __skb_pull(skb, sizeof(__be16)); 330 331 if (ntohs(proto) >= ETH_P_802_3_MIN) 332 return proto; 333 334 if (skb->len < sizeof(struct llc_snap_hdr)) 335 return htons(ETH_P_802_2); 336 337 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr)))) 338 return htons(0); 339 340 llc = (struct llc_snap_hdr *) skb->data; 341 if (llc->dsap != LLC_SAP_SNAP || 342 llc->ssap != LLC_SAP_SNAP || 343 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0) 344 return htons(ETH_P_802_2); 345 346 __skb_pull(skb, sizeof(struct llc_snap_hdr)); 347 348 if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN) 349 return llc->ethertype; 350 351 return htons(ETH_P_802_2); 352 } 353 354 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, 355 int nh_len) 356 { 357 struct icmp6hdr *icmp = icmp6_hdr(skb); 358 359 /* The ICMPv6 type and code fields use the 16-bit transport port 360 * fields, so we need to store them in 16-bit network byte order. 361 */ 362 key->ipv6.tp.src = htons(icmp->icmp6_type); 363 key->ipv6.tp.dst = htons(icmp->icmp6_code); 364 365 if (icmp->icmp6_code == 0 && 366 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || 367 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) { 368 int icmp_len = skb->len - skb_transport_offset(skb); 369 struct nd_msg *nd; 370 int offset; 371 372 /* In order to process neighbor discovery options, we need the 373 * entire packet. 374 */ 375 if (unlikely(icmp_len < sizeof(*nd))) 376 return 0; 377 378 if (unlikely(skb_linearize(skb))) 379 return -ENOMEM; 380 381 nd = (struct nd_msg *)skb_transport_header(skb); 382 key->ipv6.nd.target = nd->target; 383 384 icmp_len -= sizeof(*nd); 385 offset = 0; 386 while (icmp_len >= 8) { 387 struct nd_opt_hdr *nd_opt = 388 (struct nd_opt_hdr *)(nd->opt + offset); 389 int opt_len = nd_opt->nd_opt_len * 8; 390 391 if (unlikely(!opt_len || opt_len > icmp_len)) 392 return 0; 393 394 /* Store the link layer address if the appropriate 395 * option is provided. It is considered an error if 396 * the same link layer option is specified twice. 397 */ 398 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR 399 && opt_len == 8) { 400 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll))) 401 goto invalid; 402 ether_addr_copy(key->ipv6.nd.sll, 403 &nd->opt[offset+sizeof(*nd_opt)]); 404 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR 405 && opt_len == 8) { 406 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll))) 407 goto invalid; 408 ether_addr_copy(key->ipv6.nd.tll, 409 &nd->opt[offset+sizeof(*nd_opt)]); 410 } 411 412 icmp_len -= opt_len; 413 offset += opt_len; 414 } 415 } 416 417 return 0; 418 419 invalid: 420 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target)); 421 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll)); 422 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll)); 423 424 return 0; 425 } 426 427 /** 428 * ovs_flow_extract - extracts a flow key from an Ethernet frame. 429 * @skb: sk_buff that contains the frame, with skb->data pointing to the 430 * Ethernet header 431 * @in_port: port number on which @skb was received. 432 * @key: output flow key 433 * 434 * The caller must ensure that skb->len >= ETH_HLEN. 435 * 436 * Returns 0 if successful, otherwise a negative errno value. 437 * 438 * Initializes @skb header pointers as follows: 439 * 440 * - skb->mac_header: the Ethernet header. 441 * 442 * - skb->network_header: just past the Ethernet header, or just past the 443 * VLAN header, to the first byte of the Ethernet payload. 444 * 445 * - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6 446 * on output, then just past the IP header, if one is present and 447 * of a correct length, otherwise the same as skb->network_header. 448 * For other key->eth.type values it is left untouched. 449 */ 450 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key) 451 { 452 int error; 453 struct ethhdr *eth; 454 455 memset(key, 0, sizeof(*key)); 456 457 key->phy.priority = skb->priority; 458 if (OVS_CB(skb)->tun_key) 459 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key)); 460 key->phy.in_port = in_port; 461 key->phy.skb_mark = skb->mark; 462 463 skb_reset_mac_header(skb); 464 465 /* Link layer. We are guaranteed to have at least the 14 byte Ethernet 466 * header in the linear data area. 467 */ 468 eth = eth_hdr(skb); 469 ether_addr_copy(key->eth.src, eth->h_source); 470 ether_addr_copy(key->eth.dst, eth->h_dest); 471 472 __skb_pull(skb, 2 * ETH_ALEN); 473 /* We are going to push all headers that we pull, so no need to 474 * update skb->csum here. 475 */ 476 477 if (vlan_tx_tag_present(skb)) 478 key->eth.tci = htons(skb->vlan_tci); 479 else if (eth->h_proto == htons(ETH_P_8021Q)) 480 if (unlikely(parse_vlan(skb, key))) 481 return -ENOMEM; 482 483 key->eth.type = parse_ethertype(skb); 484 if (unlikely(key->eth.type == htons(0))) 485 return -ENOMEM; 486 487 skb_reset_network_header(skb); 488 __skb_push(skb, skb->data - skb_mac_header(skb)); 489 490 /* Network layer. */ 491 if (key->eth.type == htons(ETH_P_IP)) { 492 struct iphdr *nh; 493 __be16 offset; 494 495 error = check_iphdr(skb); 496 if (unlikely(error)) { 497 if (error == -EINVAL) { 498 skb->transport_header = skb->network_header; 499 error = 0; 500 } 501 return error; 502 } 503 504 nh = ip_hdr(skb); 505 key->ipv4.addr.src = nh->saddr; 506 key->ipv4.addr.dst = nh->daddr; 507 508 key->ip.proto = nh->protocol; 509 key->ip.tos = nh->tos; 510 key->ip.ttl = nh->ttl; 511 512 offset = nh->frag_off & htons(IP_OFFSET); 513 if (offset) { 514 key->ip.frag = OVS_FRAG_TYPE_LATER; 515 return 0; 516 } 517 if (nh->frag_off & htons(IP_MF) || 518 skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 519 key->ip.frag = OVS_FRAG_TYPE_FIRST; 520 521 /* Transport layer. */ 522 if (key->ip.proto == IPPROTO_TCP) { 523 if (tcphdr_ok(skb)) { 524 struct tcphdr *tcp = tcp_hdr(skb); 525 key->ipv4.tp.src = tcp->source; 526 key->ipv4.tp.dst = tcp->dest; 527 key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp); 528 } 529 } else if (key->ip.proto == IPPROTO_UDP) { 530 if (udphdr_ok(skb)) { 531 struct udphdr *udp = udp_hdr(skb); 532 key->ipv4.tp.src = udp->source; 533 key->ipv4.tp.dst = udp->dest; 534 } 535 } else if (key->ip.proto == IPPROTO_SCTP) { 536 if (sctphdr_ok(skb)) { 537 struct sctphdr *sctp = sctp_hdr(skb); 538 key->ipv4.tp.src = sctp->source; 539 key->ipv4.tp.dst = sctp->dest; 540 } 541 } else if (key->ip.proto == IPPROTO_ICMP) { 542 if (icmphdr_ok(skb)) { 543 struct icmphdr *icmp = icmp_hdr(skb); 544 /* The ICMP type and code fields use the 16-bit 545 * transport port fields, so we need to store 546 * them in 16-bit network byte order. */ 547 key->ipv4.tp.src = htons(icmp->type); 548 key->ipv4.tp.dst = htons(icmp->code); 549 } 550 } 551 552 } else if ((key->eth.type == htons(ETH_P_ARP) || 553 key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) { 554 struct arp_eth_header *arp; 555 556 arp = (struct arp_eth_header *)skb_network_header(skb); 557 558 if (arp->ar_hrd == htons(ARPHRD_ETHER) 559 && arp->ar_pro == htons(ETH_P_IP) 560 && arp->ar_hln == ETH_ALEN 561 && arp->ar_pln == 4) { 562 563 /* We only match on the lower 8 bits of the opcode. */ 564 if (ntohs(arp->ar_op) <= 0xff) 565 key->ip.proto = ntohs(arp->ar_op); 566 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); 567 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); 568 ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha); 569 ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha); 570 } 571 } else if (key->eth.type == htons(ETH_P_IPV6)) { 572 int nh_len; /* IPv6 Header + Extensions */ 573 574 nh_len = parse_ipv6hdr(skb, key); 575 if (unlikely(nh_len < 0)) { 576 if (nh_len == -EINVAL) { 577 skb->transport_header = skb->network_header; 578 error = 0; 579 } else { 580 error = nh_len; 581 } 582 return error; 583 } 584 585 if (key->ip.frag == OVS_FRAG_TYPE_LATER) 586 return 0; 587 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 588 key->ip.frag = OVS_FRAG_TYPE_FIRST; 589 590 /* Transport layer. */ 591 if (key->ip.proto == NEXTHDR_TCP) { 592 if (tcphdr_ok(skb)) { 593 struct tcphdr *tcp = tcp_hdr(skb); 594 key->ipv6.tp.src = tcp->source; 595 key->ipv6.tp.dst = tcp->dest; 596 key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp); 597 } 598 } else if (key->ip.proto == NEXTHDR_UDP) { 599 if (udphdr_ok(skb)) { 600 struct udphdr *udp = udp_hdr(skb); 601 key->ipv6.tp.src = udp->source; 602 key->ipv6.tp.dst = udp->dest; 603 } 604 } else if (key->ip.proto == NEXTHDR_SCTP) { 605 if (sctphdr_ok(skb)) { 606 struct sctphdr *sctp = sctp_hdr(skb); 607 key->ipv6.tp.src = sctp->source; 608 key->ipv6.tp.dst = sctp->dest; 609 } 610 } else if (key->ip.proto == NEXTHDR_ICMP) { 611 if (icmp6hdr_ok(skb)) { 612 error = parse_icmpv6(skb, key, nh_len); 613 if (error) 614 return error; 615 } 616 } 617 } 618 619 return 0; 620 } 621