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/tcp.h> 39 #include <linux/udp.h> 40 #include <linux/icmp.h> 41 #include <linux/icmpv6.h> 42 #include <linux/rculist.h> 43 #include <net/ip.h> 44 #include <net/ip_tunnels.h> 45 #include <net/ipv6.h> 46 #include <net/ndisc.h> 47 48 u64 ovs_flow_used_time(unsigned long flow_jiffies) 49 { 50 struct timespec cur_ts; 51 u64 cur_ms, idle_ms; 52 53 ktime_get_ts(&cur_ts); 54 idle_ms = jiffies_to_msecs(jiffies - flow_jiffies); 55 cur_ms = (u64)cur_ts.tv_sec * MSEC_PER_SEC + 56 cur_ts.tv_nsec / NSEC_PER_MSEC; 57 58 return cur_ms - idle_ms; 59 } 60 61 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF)) 62 63 void ovs_flow_used(struct sw_flow *flow, struct sk_buff *skb) 64 { 65 __be16 tcp_flags = 0; 66 67 if ((flow->key.eth.type == htons(ETH_P_IP) || 68 flow->key.eth.type == htons(ETH_P_IPV6)) && 69 flow->key.ip.proto == IPPROTO_TCP && 70 likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) { 71 tcp_flags = TCP_FLAGS_BE16(tcp_hdr(skb)); 72 } 73 74 spin_lock(&flow->lock); 75 flow->used = jiffies; 76 flow->packet_count++; 77 flow->byte_count += skb->len; 78 flow->tcp_flags |= tcp_flags; 79 spin_unlock(&flow->lock); 80 } 81 82 static int check_header(struct sk_buff *skb, int len) 83 { 84 if (unlikely(skb->len < len)) 85 return -EINVAL; 86 if (unlikely(!pskb_may_pull(skb, len))) 87 return -ENOMEM; 88 return 0; 89 } 90 91 static bool arphdr_ok(struct sk_buff *skb) 92 { 93 return pskb_may_pull(skb, skb_network_offset(skb) + 94 sizeof(struct arp_eth_header)); 95 } 96 97 static int check_iphdr(struct sk_buff *skb) 98 { 99 unsigned int nh_ofs = skb_network_offset(skb); 100 unsigned int ip_len; 101 int err; 102 103 err = check_header(skb, nh_ofs + sizeof(struct iphdr)); 104 if (unlikely(err)) 105 return err; 106 107 ip_len = ip_hdrlen(skb); 108 if (unlikely(ip_len < sizeof(struct iphdr) || 109 skb->len < nh_ofs + ip_len)) 110 return -EINVAL; 111 112 skb_set_transport_header(skb, nh_ofs + ip_len); 113 return 0; 114 } 115 116 static bool tcphdr_ok(struct sk_buff *skb) 117 { 118 int th_ofs = skb_transport_offset(skb); 119 int tcp_len; 120 121 if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr)))) 122 return false; 123 124 tcp_len = tcp_hdrlen(skb); 125 if (unlikely(tcp_len < sizeof(struct tcphdr) || 126 skb->len < th_ofs + tcp_len)) 127 return false; 128 129 return true; 130 } 131 132 static bool udphdr_ok(struct sk_buff *skb) 133 { 134 return pskb_may_pull(skb, skb_transport_offset(skb) + 135 sizeof(struct udphdr)); 136 } 137 138 static bool sctphdr_ok(struct sk_buff *skb) 139 { 140 return pskb_may_pull(skb, skb_transport_offset(skb) + 141 sizeof(struct sctphdr)); 142 } 143 144 static bool icmphdr_ok(struct sk_buff *skb) 145 { 146 return pskb_may_pull(skb, skb_transport_offset(skb) + 147 sizeof(struct icmphdr)); 148 } 149 150 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) 151 { 152 unsigned int nh_ofs = skb_network_offset(skb); 153 unsigned int nh_len; 154 int payload_ofs; 155 struct ipv6hdr *nh; 156 uint8_t nexthdr; 157 __be16 frag_off; 158 int err; 159 160 err = check_header(skb, nh_ofs + sizeof(*nh)); 161 if (unlikely(err)) 162 return err; 163 164 nh = ipv6_hdr(skb); 165 nexthdr = nh->nexthdr; 166 payload_ofs = (u8 *)(nh + 1) - skb->data; 167 168 key->ip.proto = NEXTHDR_NONE; 169 key->ip.tos = ipv6_get_dsfield(nh); 170 key->ip.ttl = nh->hop_limit; 171 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); 172 key->ipv6.addr.src = nh->saddr; 173 key->ipv6.addr.dst = nh->daddr; 174 175 payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off); 176 if (unlikely(payload_ofs < 0)) 177 return -EINVAL; 178 179 if (frag_off) { 180 if (frag_off & htons(~0x7)) 181 key->ip.frag = OVS_FRAG_TYPE_LATER; 182 else 183 key->ip.frag = OVS_FRAG_TYPE_FIRST; 184 } 185 186 nh_len = payload_ofs - nh_ofs; 187 skb_set_transport_header(skb, nh_ofs + nh_len); 188 key->ip.proto = nexthdr; 189 return nh_len; 190 } 191 192 static bool icmp6hdr_ok(struct sk_buff *skb) 193 { 194 return pskb_may_pull(skb, skb_transport_offset(skb) + 195 sizeof(struct icmp6hdr)); 196 } 197 198 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) 199 { 200 struct qtag_prefix { 201 __be16 eth_type; /* ETH_P_8021Q */ 202 __be16 tci; 203 }; 204 struct qtag_prefix *qp; 205 206 if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16))) 207 return 0; 208 209 if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) + 210 sizeof(__be16)))) 211 return -ENOMEM; 212 213 qp = (struct qtag_prefix *) skb->data; 214 key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT); 215 __skb_pull(skb, sizeof(struct qtag_prefix)); 216 217 return 0; 218 } 219 220 static __be16 parse_ethertype(struct sk_buff *skb) 221 { 222 struct llc_snap_hdr { 223 u8 dsap; /* Always 0xAA */ 224 u8 ssap; /* Always 0xAA */ 225 u8 ctrl; 226 u8 oui[3]; 227 __be16 ethertype; 228 }; 229 struct llc_snap_hdr *llc; 230 __be16 proto; 231 232 proto = *(__be16 *) skb->data; 233 __skb_pull(skb, sizeof(__be16)); 234 235 if (ntohs(proto) >= ETH_P_802_3_MIN) 236 return proto; 237 238 if (skb->len < sizeof(struct llc_snap_hdr)) 239 return htons(ETH_P_802_2); 240 241 if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr)))) 242 return htons(0); 243 244 llc = (struct llc_snap_hdr *) skb->data; 245 if (llc->dsap != LLC_SAP_SNAP || 246 llc->ssap != LLC_SAP_SNAP || 247 (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0) 248 return htons(ETH_P_802_2); 249 250 __skb_pull(skb, sizeof(struct llc_snap_hdr)); 251 252 if (ntohs(llc->ethertype) >= ETH_P_802_3_MIN) 253 return llc->ethertype; 254 255 return htons(ETH_P_802_2); 256 } 257 258 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key, 259 int nh_len) 260 { 261 struct icmp6hdr *icmp = icmp6_hdr(skb); 262 263 /* The ICMPv6 type and code fields use the 16-bit transport port 264 * fields, so we need to store them in 16-bit network byte order. 265 */ 266 key->ipv6.tp.src = htons(icmp->icmp6_type); 267 key->ipv6.tp.dst = htons(icmp->icmp6_code); 268 269 if (icmp->icmp6_code == 0 && 270 (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION || 271 icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) { 272 int icmp_len = skb->len - skb_transport_offset(skb); 273 struct nd_msg *nd; 274 int offset; 275 276 /* In order to process neighbor discovery options, we need the 277 * entire packet. 278 */ 279 if (unlikely(icmp_len < sizeof(*nd))) 280 return 0; 281 282 if (unlikely(skb_linearize(skb))) 283 return -ENOMEM; 284 285 nd = (struct nd_msg *)skb_transport_header(skb); 286 key->ipv6.nd.target = nd->target; 287 288 icmp_len -= sizeof(*nd); 289 offset = 0; 290 while (icmp_len >= 8) { 291 struct nd_opt_hdr *nd_opt = 292 (struct nd_opt_hdr *)(nd->opt + offset); 293 int opt_len = nd_opt->nd_opt_len * 8; 294 295 if (unlikely(!opt_len || opt_len > icmp_len)) 296 return 0; 297 298 /* Store the link layer address if the appropriate 299 * option is provided. It is considered an error if 300 * the same link layer option is specified twice. 301 */ 302 if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR 303 && opt_len == 8) { 304 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll))) 305 goto invalid; 306 memcpy(key->ipv6.nd.sll, 307 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN); 308 } else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR 309 && opt_len == 8) { 310 if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll))) 311 goto invalid; 312 memcpy(key->ipv6.nd.tll, 313 &nd->opt[offset+sizeof(*nd_opt)], ETH_ALEN); 314 } 315 316 icmp_len -= opt_len; 317 offset += opt_len; 318 } 319 } 320 321 return 0; 322 323 invalid: 324 memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target)); 325 memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll)); 326 memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll)); 327 328 return 0; 329 } 330 331 /** 332 * ovs_flow_extract - extracts a flow key from an Ethernet frame. 333 * @skb: sk_buff that contains the frame, with skb->data pointing to the 334 * Ethernet header 335 * @in_port: port number on which @skb was received. 336 * @key: output flow key 337 * 338 * The caller must ensure that skb->len >= ETH_HLEN. 339 * 340 * Returns 0 if successful, otherwise a negative errno value. 341 * 342 * Initializes @skb header pointers as follows: 343 * 344 * - skb->mac_header: the Ethernet header. 345 * 346 * - skb->network_header: just past the Ethernet header, or just past the 347 * VLAN header, to the first byte of the Ethernet payload. 348 * 349 * - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6 350 * on output, then just past the IP header, if one is present and 351 * of a correct length, otherwise the same as skb->network_header. 352 * For other key->eth.type values it is left untouched. 353 */ 354 int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key) 355 { 356 int error; 357 struct ethhdr *eth; 358 359 memset(key, 0, sizeof(*key)); 360 361 key->phy.priority = skb->priority; 362 if (OVS_CB(skb)->tun_key) 363 memcpy(&key->tun_key, OVS_CB(skb)->tun_key, sizeof(key->tun_key)); 364 key->phy.in_port = in_port; 365 key->phy.skb_mark = skb->mark; 366 367 skb_reset_mac_header(skb); 368 369 /* Link layer. We are guaranteed to have at least the 14 byte Ethernet 370 * header in the linear data area. 371 */ 372 eth = eth_hdr(skb); 373 memcpy(key->eth.src, eth->h_source, ETH_ALEN); 374 memcpy(key->eth.dst, eth->h_dest, ETH_ALEN); 375 376 __skb_pull(skb, 2 * ETH_ALEN); 377 /* We are going to push all headers that we pull, so no need to 378 * update skb->csum here. 379 */ 380 381 if (vlan_tx_tag_present(skb)) 382 key->eth.tci = htons(skb->vlan_tci); 383 else if (eth->h_proto == htons(ETH_P_8021Q)) 384 if (unlikely(parse_vlan(skb, key))) 385 return -ENOMEM; 386 387 key->eth.type = parse_ethertype(skb); 388 if (unlikely(key->eth.type == htons(0))) 389 return -ENOMEM; 390 391 skb_reset_network_header(skb); 392 __skb_push(skb, skb->data - skb_mac_header(skb)); 393 394 /* Network layer. */ 395 if (key->eth.type == htons(ETH_P_IP)) { 396 struct iphdr *nh; 397 __be16 offset; 398 399 error = check_iphdr(skb); 400 if (unlikely(error)) { 401 if (error == -EINVAL) { 402 skb->transport_header = skb->network_header; 403 error = 0; 404 } 405 return error; 406 } 407 408 nh = ip_hdr(skb); 409 key->ipv4.addr.src = nh->saddr; 410 key->ipv4.addr.dst = nh->daddr; 411 412 key->ip.proto = nh->protocol; 413 key->ip.tos = nh->tos; 414 key->ip.ttl = nh->ttl; 415 416 offset = nh->frag_off & htons(IP_OFFSET); 417 if (offset) { 418 key->ip.frag = OVS_FRAG_TYPE_LATER; 419 return 0; 420 } 421 if (nh->frag_off & htons(IP_MF) || 422 skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 423 key->ip.frag = OVS_FRAG_TYPE_FIRST; 424 425 /* Transport layer. */ 426 if (key->ip.proto == IPPROTO_TCP) { 427 if (tcphdr_ok(skb)) { 428 struct tcphdr *tcp = tcp_hdr(skb); 429 key->ipv4.tp.src = tcp->source; 430 key->ipv4.tp.dst = tcp->dest; 431 key->ipv4.tp.flags = TCP_FLAGS_BE16(tcp); 432 } 433 } else if (key->ip.proto == IPPROTO_UDP) { 434 if (udphdr_ok(skb)) { 435 struct udphdr *udp = udp_hdr(skb); 436 key->ipv4.tp.src = udp->source; 437 key->ipv4.tp.dst = udp->dest; 438 } 439 } else if (key->ip.proto == IPPROTO_SCTP) { 440 if (sctphdr_ok(skb)) { 441 struct sctphdr *sctp = sctp_hdr(skb); 442 key->ipv4.tp.src = sctp->source; 443 key->ipv4.tp.dst = sctp->dest; 444 } 445 } else if (key->ip.proto == IPPROTO_ICMP) { 446 if (icmphdr_ok(skb)) { 447 struct icmphdr *icmp = icmp_hdr(skb); 448 /* The ICMP type and code fields use the 16-bit 449 * transport port fields, so we need to store 450 * them in 16-bit network byte order. */ 451 key->ipv4.tp.src = htons(icmp->type); 452 key->ipv4.tp.dst = htons(icmp->code); 453 } 454 } 455 456 } else if ((key->eth.type == htons(ETH_P_ARP) || 457 key->eth.type == htons(ETH_P_RARP)) && arphdr_ok(skb)) { 458 struct arp_eth_header *arp; 459 460 arp = (struct arp_eth_header *)skb_network_header(skb); 461 462 if (arp->ar_hrd == htons(ARPHRD_ETHER) 463 && arp->ar_pro == htons(ETH_P_IP) 464 && arp->ar_hln == ETH_ALEN 465 && arp->ar_pln == 4) { 466 467 /* We only match on the lower 8 bits of the opcode. */ 468 if (ntohs(arp->ar_op) <= 0xff) 469 key->ip.proto = ntohs(arp->ar_op); 470 memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src)); 471 memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst)); 472 memcpy(key->ipv4.arp.sha, arp->ar_sha, ETH_ALEN); 473 memcpy(key->ipv4.arp.tha, arp->ar_tha, ETH_ALEN); 474 } 475 } else if (key->eth.type == htons(ETH_P_IPV6)) { 476 int nh_len; /* IPv6 Header + Extensions */ 477 478 nh_len = parse_ipv6hdr(skb, key); 479 if (unlikely(nh_len < 0)) { 480 if (nh_len == -EINVAL) { 481 skb->transport_header = skb->network_header; 482 error = 0; 483 } else { 484 error = nh_len; 485 } 486 return error; 487 } 488 489 if (key->ip.frag == OVS_FRAG_TYPE_LATER) 490 return 0; 491 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP) 492 key->ip.frag = OVS_FRAG_TYPE_FIRST; 493 494 /* Transport layer. */ 495 if (key->ip.proto == NEXTHDR_TCP) { 496 if (tcphdr_ok(skb)) { 497 struct tcphdr *tcp = tcp_hdr(skb); 498 key->ipv6.tp.src = tcp->source; 499 key->ipv6.tp.dst = tcp->dest; 500 key->ipv6.tp.flags = TCP_FLAGS_BE16(tcp); 501 } 502 } else if (key->ip.proto == NEXTHDR_UDP) { 503 if (udphdr_ok(skb)) { 504 struct udphdr *udp = udp_hdr(skb); 505 key->ipv6.tp.src = udp->source; 506 key->ipv6.tp.dst = udp->dest; 507 } 508 } else if (key->ip.proto == NEXTHDR_SCTP) { 509 if (sctphdr_ok(skb)) { 510 struct sctphdr *sctp = sctp_hdr(skb); 511 key->ipv6.tp.src = sctp->source; 512 key->ipv6.tp.dst = sctp->dest; 513 } 514 } else if (key->ip.proto == NEXTHDR_ICMP) { 515 if (icmp6hdr_ok(skb)) { 516 error = parse_icmpv6(skb, key, nh_len); 517 if (error) 518 return error; 519 } 520 } 521 } 522 523 return 0; 524 } 525