1 /* 2 * Copyright (c) 2007-2014 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/skbuff.h> 22 #include <linux/in.h> 23 #include <linux/ip.h> 24 #include <linux/openvswitch.h> 25 #include <linux/sctp.h> 26 #include <linux/tcp.h> 27 #include <linux/udp.h> 28 #include <linux/in6.h> 29 #include <linux/if_arp.h> 30 #include <linux/if_vlan.h> 31 32 #include <net/ip.h> 33 #include <net/ipv6.h> 34 #include <net/checksum.h> 35 #include <net/dsfield.h> 36 #include <net/mpls.h> 37 #include <net/sctp/checksum.h> 38 39 #include "datapath.h" 40 #include "flow.h" 41 #include "vport.h" 42 43 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, 44 struct sw_flow_key *key, 45 const struct nlattr *attr, int len); 46 47 struct deferred_action { 48 struct sk_buff *skb; 49 const struct nlattr *actions; 50 51 /* Store pkt_key clone when creating deferred action. */ 52 struct sw_flow_key pkt_key; 53 }; 54 55 #define DEFERRED_ACTION_FIFO_SIZE 10 56 struct action_fifo { 57 int head; 58 int tail; 59 /* Deferred action fifo queue storage. */ 60 struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE]; 61 }; 62 63 static struct action_fifo __percpu *action_fifos; 64 static DEFINE_PER_CPU(int, exec_actions_level); 65 66 static void action_fifo_init(struct action_fifo *fifo) 67 { 68 fifo->head = 0; 69 fifo->tail = 0; 70 } 71 72 static bool action_fifo_is_empty(const struct action_fifo *fifo) 73 { 74 return (fifo->head == fifo->tail); 75 } 76 77 static struct deferred_action *action_fifo_get(struct action_fifo *fifo) 78 { 79 if (action_fifo_is_empty(fifo)) 80 return NULL; 81 82 return &fifo->fifo[fifo->tail++]; 83 } 84 85 static struct deferred_action *action_fifo_put(struct action_fifo *fifo) 86 { 87 if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1) 88 return NULL; 89 90 return &fifo->fifo[fifo->head++]; 91 } 92 93 /* Return true if fifo is not full */ 94 static struct deferred_action *add_deferred_actions(struct sk_buff *skb, 95 const struct sw_flow_key *key, 96 const struct nlattr *attr) 97 { 98 struct action_fifo *fifo; 99 struct deferred_action *da; 100 101 fifo = this_cpu_ptr(action_fifos); 102 da = action_fifo_put(fifo); 103 if (da) { 104 da->skb = skb; 105 da->actions = attr; 106 da->pkt_key = *key; 107 } 108 109 return da; 110 } 111 112 static void invalidate_flow_key(struct sw_flow_key *key) 113 { 114 key->eth.type = htons(0); 115 } 116 117 static bool is_flow_key_valid(const struct sw_flow_key *key) 118 { 119 return !!key->eth.type; 120 } 121 122 static int make_writable(struct sk_buff *skb, int write_len) 123 { 124 if (!pskb_may_pull(skb, write_len)) 125 return -ENOMEM; 126 127 if (!skb_cloned(skb) || skb_clone_writable(skb, write_len)) 128 return 0; 129 130 return pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 131 } 132 133 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key, 134 const struct ovs_action_push_mpls *mpls) 135 { 136 __be32 *new_mpls_lse; 137 struct ethhdr *hdr; 138 139 /* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */ 140 if (skb->encapsulation) 141 return -ENOTSUPP; 142 143 if (skb_cow_head(skb, MPLS_HLEN) < 0) 144 return -ENOMEM; 145 146 skb_push(skb, MPLS_HLEN); 147 memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb), 148 skb->mac_len); 149 skb_reset_mac_header(skb); 150 151 new_mpls_lse = (__be32 *)skb_mpls_header(skb); 152 *new_mpls_lse = mpls->mpls_lse; 153 154 if (skb->ip_summed == CHECKSUM_COMPLETE) 155 skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse, 156 MPLS_HLEN, 0)); 157 158 hdr = eth_hdr(skb); 159 hdr->h_proto = mpls->mpls_ethertype; 160 161 skb_set_inner_protocol(skb, skb->protocol); 162 skb->protocol = mpls->mpls_ethertype; 163 164 invalidate_flow_key(key); 165 return 0; 166 } 167 168 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key, 169 const __be16 ethertype) 170 { 171 struct ethhdr *hdr; 172 int err; 173 174 err = make_writable(skb, skb->mac_len + MPLS_HLEN); 175 if (unlikely(err)) 176 return err; 177 178 if (skb->ip_summed == CHECKSUM_COMPLETE) 179 skb->csum = csum_sub(skb->csum, 180 csum_partial(skb_mpls_header(skb), 181 MPLS_HLEN, 0)); 182 183 memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), 184 skb->mac_len); 185 186 __skb_pull(skb, MPLS_HLEN); 187 skb_reset_mac_header(skb); 188 189 /* skb_mpls_header() is used to locate the ethertype 190 * field correctly in the presence of VLAN tags. 191 */ 192 hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN); 193 hdr->h_proto = ethertype; 194 if (eth_p_mpls(skb->protocol)) 195 skb->protocol = ethertype; 196 197 invalidate_flow_key(key); 198 return 0; 199 } 200 201 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key, 202 const __be32 *mpls_lse) 203 { 204 __be32 *stack; 205 int err; 206 207 err = make_writable(skb, skb->mac_len + MPLS_HLEN); 208 if (unlikely(err)) 209 return err; 210 211 stack = (__be32 *)skb_mpls_header(skb); 212 if (skb->ip_summed == CHECKSUM_COMPLETE) { 213 __be32 diff[] = { ~(*stack), *mpls_lse }; 214 skb->csum = ~csum_partial((char *)diff, sizeof(diff), 215 ~skb->csum); 216 } 217 218 *stack = *mpls_lse; 219 key->mpls.top_lse = *mpls_lse; 220 return 0; 221 } 222 223 /* remove VLAN header from packet and update csum accordingly. */ 224 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci) 225 { 226 struct vlan_hdr *vhdr; 227 int err; 228 229 err = make_writable(skb, VLAN_ETH_HLEN); 230 if (unlikely(err)) 231 return err; 232 233 if (skb->ip_summed == CHECKSUM_COMPLETE) 234 skb->csum = csum_sub(skb->csum, csum_partial(skb->data 235 + (2 * ETH_ALEN), VLAN_HLEN, 0)); 236 237 vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); 238 *current_tci = vhdr->h_vlan_TCI; 239 240 memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); 241 __skb_pull(skb, VLAN_HLEN); 242 243 vlan_set_encap_proto(skb, vhdr); 244 skb->mac_header += VLAN_HLEN; 245 246 if (skb_network_offset(skb) < ETH_HLEN) 247 skb_set_network_header(skb, ETH_HLEN); 248 249 /* Update mac_len for subsequent MPLS actions */ 250 skb_reset_mac_len(skb); 251 return 0; 252 } 253 254 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key) 255 { 256 __be16 tci; 257 int err; 258 259 if (likely(vlan_tx_tag_present(skb))) { 260 skb->vlan_tci = 0; 261 } else { 262 if (unlikely(skb->protocol != htons(ETH_P_8021Q) || 263 skb->len < VLAN_ETH_HLEN)) 264 return 0; 265 266 err = __pop_vlan_tci(skb, &tci); 267 if (err) 268 return err; 269 } 270 /* move next vlan tag to hw accel tag */ 271 if (likely(skb->protocol != htons(ETH_P_8021Q) || 272 skb->len < VLAN_ETH_HLEN)) { 273 key->eth.tci = 0; 274 return 0; 275 } 276 277 invalidate_flow_key(key); 278 err = __pop_vlan_tci(skb, &tci); 279 if (unlikely(err)) 280 return err; 281 282 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci)); 283 return 0; 284 } 285 286 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key, 287 const struct ovs_action_push_vlan *vlan) 288 { 289 if (unlikely(vlan_tx_tag_present(skb))) { 290 u16 current_tag; 291 292 /* push down current VLAN tag */ 293 current_tag = vlan_tx_tag_get(skb); 294 295 if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag)) 296 return -ENOMEM; 297 /* Update mac_len for subsequent MPLS actions */ 298 skb->mac_len += VLAN_HLEN; 299 300 if (skb->ip_summed == CHECKSUM_COMPLETE) 301 skb->csum = csum_add(skb->csum, csum_partial(skb->data 302 + (2 * ETH_ALEN), VLAN_HLEN, 0)); 303 304 invalidate_flow_key(key); 305 } else { 306 key->eth.tci = vlan->vlan_tci; 307 } 308 __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT); 309 return 0; 310 } 311 312 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key, 313 const struct ovs_key_ethernet *eth_key) 314 { 315 int err; 316 err = make_writable(skb, ETH_HLEN); 317 if (unlikely(err)) 318 return err; 319 320 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2); 321 322 ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src); 323 ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst); 324 325 ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2); 326 327 ether_addr_copy(key->eth.src, eth_key->eth_src); 328 ether_addr_copy(key->eth.dst, eth_key->eth_dst); 329 return 0; 330 } 331 332 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh, 333 __be32 *addr, __be32 new_addr) 334 { 335 int transport_len = skb->len - skb_transport_offset(skb); 336 337 if (nh->protocol == IPPROTO_TCP) { 338 if (likely(transport_len >= sizeof(struct tcphdr))) 339 inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb, 340 *addr, new_addr, 1); 341 } else if (nh->protocol == IPPROTO_UDP) { 342 if (likely(transport_len >= sizeof(struct udphdr))) { 343 struct udphdr *uh = udp_hdr(skb); 344 345 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) { 346 inet_proto_csum_replace4(&uh->check, skb, 347 *addr, new_addr, 1); 348 if (!uh->check) 349 uh->check = CSUM_MANGLED_0; 350 } 351 } 352 } 353 354 csum_replace4(&nh->check, *addr, new_addr); 355 skb_clear_hash(skb); 356 *addr = new_addr; 357 } 358 359 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto, 360 __be32 addr[4], const __be32 new_addr[4]) 361 { 362 int transport_len = skb->len - skb_transport_offset(skb); 363 364 if (l4_proto == IPPROTO_TCP) { 365 if (likely(transport_len >= sizeof(struct tcphdr))) 366 inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb, 367 addr, new_addr, 1); 368 } else if (l4_proto == IPPROTO_UDP) { 369 if (likely(transport_len >= sizeof(struct udphdr))) { 370 struct udphdr *uh = udp_hdr(skb); 371 372 if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) { 373 inet_proto_csum_replace16(&uh->check, skb, 374 addr, new_addr, 1); 375 if (!uh->check) 376 uh->check = CSUM_MANGLED_0; 377 } 378 } 379 } 380 } 381 382 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto, 383 __be32 addr[4], const __be32 new_addr[4], 384 bool recalculate_csum) 385 { 386 if (recalculate_csum) 387 update_ipv6_checksum(skb, l4_proto, addr, new_addr); 388 389 skb_clear_hash(skb); 390 memcpy(addr, new_addr, sizeof(__be32[4])); 391 } 392 393 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc) 394 { 395 nh->priority = tc >> 4; 396 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4); 397 } 398 399 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl) 400 { 401 nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16; 402 nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8; 403 nh->flow_lbl[2] = fl & 0x000000FF; 404 } 405 406 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl) 407 { 408 csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8)); 409 nh->ttl = new_ttl; 410 } 411 412 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key, 413 const struct ovs_key_ipv4 *ipv4_key) 414 { 415 struct iphdr *nh; 416 int err; 417 418 err = make_writable(skb, skb_network_offset(skb) + 419 sizeof(struct iphdr)); 420 if (unlikely(err)) 421 return err; 422 423 nh = ip_hdr(skb); 424 425 if (ipv4_key->ipv4_src != nh->saddr) { 426 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src); 427 key->ipv4.addr.src = ipv4_key->ipv4_src; 428 } 429 430 if (ipv4_key->ipv4_dst != nh->daddr) { 431 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst); 432 key->ipv4.addr.dst = ipv4_key->ipv4_dst; 433 } 434 435 if (ipv4_key->ipv4_tos != nh->tos) { 436 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos); 437 key->ip.tos = nh->tos; 438 } 439 440 if (ipv4_key->ipv4_ttl != nh->ttl) { 441 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl); 442 key->ip.ttl = ipv4_key->ipv4_ttl; 443 } 444 445 return 0; 446 } 447 448 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key, 449 const struct ovs_key_ipv6 *ipv6_key) 450 { 451 struct ipv6hdr *nh; 452 int err; 453 __be32 *saddr; 454 __be32 *daddr; 455 456 err = make_writable(skb, skb_network_offset(skb) + 457 sizeof(struct ipv6hdr)); 458 if (unlikely(err)) 459 return err; 460 461 nh = ipv6_hdr(skb); 462 saddr = (__be32 *)&nh->saddr; 463 daddr = (__be32 *)&nh->daddr; 464 465 if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) { 466 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr, 467 ipv6_key->ipv6_src, true); 468 memcpy(&key->ipv6.addr.src, ipv6_key->ipv6_src, 469 sizeof(ipv6_key->ipv6_src)); 470 } 471 472 if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) { 473 unsigned int offset = 0; 474 int flags = IP6_FH_F_SKIP_RH; 475 bool recalc_csum = true; 476 477 if (ipv6_ext_hdr(nh->nexthdr)) 478 recalc_csum = ipv6_find_hdr(skb, &offset, 479 NEXTHDR_ROUTING, NULL, 480 &flags) != NEXTHDR_ROUTING; 481 482 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr, 483 ipv6_key->ipv6_dst, recalc_csum); 484 memcpy(&key->ipv6.addr.dst, ipv6_key->ipv6_dst, 485 sizeof(ipv6_key->ipv6_dst)); 486 } 487 488 set_ipv6_tc(nh, ipv6_key->ipv6_tclass); 489 key->ip.tos = ipv6_get_dsfield(nh); 490 491 set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label)); 492 key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); 493 494 nh->hop_limit = ipv6_key->ipv6_hlimit; 495 key->ip.ttl = ipv6_key->ipv6_hlimit; 496 return 0; 497 } 498 499 /* Must follow make_writable() since that can move the skb data. */ 500 static void set_tp_port(struct sk_buff *skb, __be16 *port, 501 __be16 new_port, __sum16 *check) 502 { 503 inet_proto_csum_replace2(check, skb, *port, new_port, 0); 504 *port = new_port; 505 skb_clear_hash(skb); 506 } 507 508 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port) 509 { 510 struct udphdr *uh = udp_hdr(skb); 511 512 if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) { 513 set_tp_port(skb, port, new_port, &uh->check); 514 515 if (!uh->check) 516 uh->check = CSUM_MANGLED_0; 517 } else { 518 *port = new_port; 519 skb_clear_hash(skb); 520 } 521 } 522 523 static int set_udp(struct sk_buff *skb, struct sw_flow_key *key, 524 const struct ovs_key_udp *udp_port_key) 525 { 526 struct udphdr *uh; 527 int err; 528 529 err = make_writable(skb, skb_transport_offset(skb) + 530 sizeof(struct udphdr)); 531 if (unlikely(err)) 532 return err; 533 534 uh = udp_hdr(skb); 535 if (udp_port_key->udp_src != uh->source) { 536 set_udp_port(skb, &uh->source, udp_port_key->udp_src); 537 key->tp.src = udp_port_key->udp_src; 538 } 539 540 if (udp_port_key->udp_dst != uh->dest) { 541 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst); 542 key->tp.dst = udp_port_key->udp_dst; 543 } 544 545 return 0; 546 } 547 548 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key, 549 const struct ovs_key_tcp *tcp_port_key) 550 { 551 struct tcphdr *th; 552 int err; 553 554 err = make_writable(skb, skb_transport_offset(skb) + 555 sizeof(struct tcphdr)); 556 if (unlikely(err)) 557 return err; 558 559 th = tcp_hdr(skb); 560 if (tcp_port_key->tcp_src != th->source) { 561 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check); 562 key->tp.src = tcp_port_key->tcp_src; 563 } 564 565 if (tcp_port_key->tcp_dst != th->dest) { 566 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check); 567 key->tp.dst = tcp_port_key->tcp_dst; 568 } 569 570 return 0; 571 } 572 573 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key, 574 const struct ovs_key_sctp *sctp_port_key) 575 { 576 struct sctphdr *sh; 577 int err; 578 unsigned int sctphoff = skb_transport_offset(skb); 579 580 err = make_writable(skb, sctphoff + sizeof(struct sctphdr)); 581 if (unlikely(err)) 582 return err; 583 584 sh = sctp_hdr(skb); 585 if (sctp_port_key->sctp_src != sh->source || 586 sctp_port_key->sctp_dst != sh->dest) { 587 __le32 old_correct_csum, new_csum, old_csum; 588 589 old_csum = sh->checksum; 590 old_correct_csum = sctp_compute_cksum(skb, sctphoff); 591 592 sh->source = sctp_port_key->sctp_src; 593 sh->dest = sctp_port_key->sctp_dst; 594 595 new_csum = sctp_compute_cksum(skb, sctphoff); 596 597 /* Carry any checksum errors through. */ 598 sh->checksum = old_csum ^ old_correct_csum ^ new_csum; 599 600 skb_clear_hash(skb); 601 key->tp.src = sctp_port_key->sctp_src; 602 key->tp.dst = sctp_port_key->sctp_dst; 603 } 604 605 return 0; 606 } 607 608 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port) 609 { 610 struct vport *vport = ovs_vport_rcu(dp, out_port); 611 612 if (likely(vport)) 613 ovs_vport_send(vport, skb); 614 else 615 kfree_skb(skb); 616 } 617 618 static int output_userspace(struct datapath *dp, struct sk_buff *skb, 619 struct sw_flow_key *key, const struct nlattr *attr) 620 { 621 struct ovs_tunnel_info info; 622 struct dp_upcall_info upcall; 623 const struct nlattr *a; 624 int rem; 625 626 upcall.cmd = OVS_PACKET_CMD_ACTION; 627 upcall.userdata = NULL; 628 upcall.portid = 0; 629 upcall.egress_tun_info = NULL; 630 631 for (a = nla_data(attr), rem = nla_len(attr); rem > 0; 632 a = nla_next(a, &rem)) { 633 switch (nla_type(a)) { 634 case OVS_USERSPACE_ATTR_USERDATA: 635 upcall.userdata = a; 636 break; 637 638 case OVS_USERSPACE_ATTR_PID: 639 upcall.portid = nla_get_u32(a); 640 break; 641 642 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: { 643 /* Get out tunnel info. */ 644 struct vport *vport; 645 646 vport = ovs_vport_rcu(dp, nla_get_u32(a)); 647 if (vport) { 648 int err; 649 650 err = ovs_vport_get_egress_tun_info(vport, skb, 651 &info); 652 if (!err) 653 upcall.egress_tun_info = &info; 654 } 655 break; 656 } 657 658 } /* End of switch. */ 659 } 660 661 return ovs_dp_upcall(dp, skb, key, &upcall); 662 } 663 664 static int sample(struct datapath *dp, struct sk_buff *skb, 665 struct sw_flow_key *key, const struct nlattr *attr) 666 { 667 const struct nlattr *acts_list = NULL; 668 const struct nlattr *a; 669 int rem; 670 671 for (a = nla_data(attr), rem = nla_len(attr); rem > 0; 672 a = nla_next(a, &rem)) { 673 switch (nla_type(a)) { 674 case OVS_SAMPLE_ATTR_PROBABILITY: 675 if (prandom_u32() >= nla_get_u32(a)) 676 return 0; 677 break; 678 679 case OVS_SAMPLE_ATTR_ACTIONS: 680 acts_list = a; 681 break; 682 } 683 } 684 685 rem = nla_len(acts_list); 686 a = nla_data(acts_list); 687 688 /* Actions list is empty, do nothing */ 689 if (unlikely(!rem)) 690 return 0; 691 692 /* The only known usage of sample action is having a single user-space 693 * action. Treat this usage as a special case. 694 * The output_userspace() should clone the skb to be sent to the 695 * user space. This skb will be consumed by its caller. 696 */ 697 if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE && 698 nla_is_last(a, rem))) 699 return output_userspace(dp, skb, key, a); 700 701 skb = skb_clone(skb, GFP_ATOMIC); 702 if (!skb) 703 /* Skip the sample action when out of memory. */ 704 return 0; 705 706 if (!add_deferred_actions(skb, key, a)) { 707 if (net_ratelimit()) 708 pr_warn("%s: deferred actions limit reached, dropping sample action\n", 709 ovs_dp_name(dp)); 710 711 kfree_skb(skb); 712 } 713 return 0; 714 } 715 716 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key, 717 const struct nlattr *attr) 718 { 719 struct ovs_action_hash *hash_act = nla_data(attr); 720 u32 hash = 0; 721 722 /* OVS_HASH_ALG_L4 is the only possible hash algorithm. */ 723 hash = skb_get_hash(skb); 724 hash = jhash_1word(hash, hash_act->hash_basis); 725 if (!hash) 726 hash = 0x1; 727 728 key->ovs_flow_hash = hash; 729 } 730 731 static int execute_set_action(struct sk_buff *skb, struct sw_flow_key *key, 732 const struct nlattr *nested_attr) 733 { 734 int err = 0; 735 736 switch (nla_type(nested_attr)) { 737 case OVS_KEY_ATTR_PRIORITY: 738 skb->priority = nla_get_u32(nested_attr); 739 key->phy.priority = skb->priority; 740 break; 741 742 case OVS_KEY_ATTR_SKB_MARK: 743 skb->mark = nla_get_u32(nested_attr); 744 key->phy.skb_mark = skb->mark; 745 break; 746 747 case OVS_KEY_ATTR_TUNNEL_INFO: 748 OVS_CB(skb)->egress_tun_info = nla_data(nested_attr); 749 break; 750 751 case OVS_KEY_ATTR_ETHERNET: 752 err = set_eth_addr(skb, key, nla_data(nested_attr)); 753 break; 754 755 case OVS_KEY_ATTR_IPV4: 756 err = set_ipv4(skb, key, nla_data(nested_attr)); 757 break; 758 759 case OVS_KEY_ATTR_IPV6: 760 err = set_ipv6(skb, key, nla_data(nested_attr)); 761 break; 762 763 case OVS_KEY_ATTR_TCP: 764 err = set_tcp(skb, key, nla_data(nested_attr)); 765 break; 766 767 case OVS_KEY_ATTR_UDP: 768 err = set_udp(skb, key, nla_data(nested_attr)); 769 break; 770 771 case OVS_KEY_ATTR_SCTP: 772 err = set_sctp(skb, key, nla_data(nested_attr)); 773 break; 774 775 case OVS_KEY_ATTR_MPLS: 776 err = set_mpls(skb, key, nla_data(nested_attr)); 777 break; 778 } 779 780 return err; 781 } 782 783 static int execute_recirc(struct datapath *dp, struct sk_buff *skb, 784 struct sw_flow_key *key, 785 const struct nlattr *a, int rem) 786 { 787 struct deferred_action *da; 788 789 if (!is_flow_key_valid(key)) { 790 int err; 791 792 err = ovs_flow_key_update(skb, key); 793 if (err) 794 return err; 795 } 796 BUG_ON(!is_flow_key_valid(key)); 797 798 if (!nla_is_last(a, rem)) { 799 /* Recirc action is the not the last action 800 * of the action list, need to clone the skb. 801 */ 802 skb = skb_clone(skb, GFP_ATOMIC); 803 804 /* Skip the recirc action when out of memory, but 805 * continue on with the rest of the action list. 806 */ 807 if (!skb) 808 return 0; 809 } 810 811 da = add_deferred_actions(skb, key, NULL); 812 if (da) { 813 da->pkt_key.recirc_id = nla_get_u32(a); 814 } else { 815 kfree_skb(skb); 816 817 if (net_ratelimit()) 818 pr_warn("%s: deferred action limit reached, drop recirc action\n", 819 ovs_dp_name(dp)); 820 } 821 822 return 0; 823 } 824 825 /* Execute a list of actions against 'skb'. */ 826 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, 827 struct sw_flow_key *key, 828 const struct nlattr *attr, int len) 829 { 830 /* Every output action needs a separate clone of 'skb', but the common 831 * case is just a single output action, so that doing a clone and 832 * then freeing the original skbuff is wasteful. So the following code 833 * is slightly obscure just to avoid that. 834 */ 835 int prev_port = -1; 836 const struct nlattr *a; 837 int rem; 838 839 for (a = attr, rem = len; rem > 0; 840 a = nla_next(a, &rem)) { 841 int err = 0; 842 843 if (unlikely(prev_port != -1)) { 844 struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC); 845 846 if (out_skb) 847 do_output(dp, out_skb, prev_port); 848 849 prev_port = -1; 850 } 851 852 switch (nla_type(a)) { 853 case OVS_ACTION_ATTR_OUTPUT: 854 prev_port = nla_get_u32(a); 855 break; 856 857 case OVS_ACTION_ATTR_USERSPACE: 858 output_userspace(dp, skb, key, a); 859 break; 860 861 case OVS_ACTION_ATTR_HASH: 862 execute_hash(skb, key, a); 863 break; 864 865 case OVS_ACTION_ATTR_PUSH_MPLS: 866 err = push_mpls(skb, key, nla_data(a)); 867 break; 868 869 case OVS_ACTION_ATTR_POP_MPLS: 870 err = pop_mpls(skb, key, nla_get_be16(a)); 871 break; 872 873 case OVS_ACTION_ATTR_PUSH_VLAN: 874 err = push_vlan(skb, key, nla_data(a)); 875 if (unlikely(err)) /* skb already freed. */ 876 return err; 877 break; 878 879 case OVS_ACTION_ATTR_POP_VLAN: 880 err = pop_vlan(skb, key); 881 break; 882 883 case OVS_ACTION_ATTR_RECIRC: 884 err = execute_recirc(dp, skb, key, a, rem); 885 if (nla_is_last(a, rem)) { 886 /* If this is the last action, the skb has 887 * been consumed or freed. 888 * Return immediately. 889 */ 890 return err; 891 } 892 break; 893 894 case OVS_ACTION_ATTR_SET: 895 err = execute_set_action(skb, key, nla_data(a)); 896 break; 897 898 case OVS_ACTION_ATTR_SAMPLE: 899 err = sample(dp, skb, key, a); 900 if (unlikely(err)) /* skb already freed. */ 901 return err; 902 break; 903 } 904 905 if (unlikely(err)) { 906 kfree_skb(skb); 907 return err; 908 } 909 } 910 911 if (prev_port != -1) 912 do_output(dp, skb, prev_port); 913 else 914 consume_skb(skb); 915 916 return 0; 917 } 918 919 static void process_deferred_actions(struct datapath *dp) 920 { 921 struct action_fifo *fifo = this_cpu_ptr(action_fifos); 922 923 /* Do not touch the FIFO in case there is no deferred actions. */ 924 if (action_fifo_is_empty(fifo)) 925 return; 926 927 /* Finishing executing all deferred actions. */ 928 do { 929 struct deferred_action *da = action_fifo_get(fifo); 930 struct sk_buff *skb = da->skb; 931 struct sw_flow_key *key = &da->pkt_key; 932 const struct nlattr *actions = da->actions; 933 934 if (actions) 935 do_execute_actions(dp, skb, key, actions, 936 nla_len(actions)); 937 else 938 ovs_dp_process_packet(skb, key); 939 } while (!action_fifo_is_empty(fifo)); 940 941 /* Reset FIFO for the next packet. */ 942 action_fifo_init(fifo); 943 } 944 945 /* Execute a list of actions against 'skb'. */ 946 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb, 947 const struct sw_flow_actions *acts, 948 struct sw_flow_key *key) 949 { 950 int level = this_cpu_read(exec_actions_level); 951 int err; 952 953 this_cpu_inc(exec_actions_level); 954 OVS_CB(skb)->egress_tun_info = NULL; 955 err = do_execute_actions(dp, skb, key, 956 acts->actions, acts->actions_len); 957 958 if (!level) 959 process_deferred_actions(dp); 960 961 this_cpu_dec(exec_actions_level); 962 return err; 963 } 964 965 int action_fifos_init(void) 966 { 967 action_fifos = alloc_percpu(struct action_fifo); 968 if (!action_fifos) 969 return -ENOMEM; 970 971 return 0; 972 } 973 974 void action_fifos_exit(void) 975 { 976 free_percpu(action_fifos); 977 } 978