net/openvswitch/actions.c

   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 push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 123                      const struct ovs_action_push_mpls *mpls)
 124 {
 125         __be32 *new_mpls_lse;
 126         struct ethhdr *hdr;
 127
 128         /* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
 129         if (skb->encapsulation)
 130                 return -ENOTSUPP;
 131
 132         if (skb_cow_head(skb, MPLS_HLEN) < 0)
 133                 return -ENOMEM;
 134
 135         skb_push(skb, MPLS_HLEN);
 136         memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
 137                 skb->mac_len);
 138         skb_reset_mac_header(skb);
 139
 140         new_mpls_lse = (__be32 *)skb_mpls_header(skb);
 141         *new_mpls_lse = mpls->mpls_lse;
 142
 143         if (skb->ip_summed == CHECKSUM_COMPLETE)
 144                 skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse,
 145                                                              MPLS_HLEN, 0));
 146
 147         hdr = eth_hdr(skb);
 148         hdr->h_proto = mpls->mpls_ethertype;
 149
 150         if (!skb->inner_protocol)
 151                 skb_set_inner_protocol(skb, skb->protocol);
 152         skb->protocol = mpls->mpls_ethertype;
 153
 154         invalidate_flow_key(key);
 155         return 0;
 156 }
 157
 158 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 159                     const __be16 ethertype)
 160 {
 161         struct ethhdr *hdr;
 162         int err;
 163
 164         err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 165         if (unlikely(err))
 166                 return err;
 167
 168         skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);
 169
 170         memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
 171                 skb->mac_len);
 172
 173         __skb_pull(skb, MPLS_HLEN);
 174         skb_reset_mac_header(skb);
 175
 176         /* skb_mpls_header() is used to locate the ethertype
 177          * field correctly in the presence of VLAN tags.
 178          */
 179         hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN);
 180         hdr->h_proto = ethertype;
 181         if (eth_p_mpls(skb->protocol))
 182                 skb->protocol = ethertype;
 183
 184         invalidate_flow_key(key);
 185         return 0;
 186 }
 187
 188 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 189                     const __be32 *mpls_lse)
 190 {
 191         __be32 *stack;
 192         int err;
 193
 194         err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 195         if (unlikely(err))
 196                 return err;
 197
 198         stack = (__be32 *)skb_mpls_header(skb);
 199         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 200                 __be32 diff[] = { ~(*stack), *mpls_lse };
 201                 skb->csum = ~csum_partial((char *)diff, sizeof(diff),
 202                                           ~skb->csum);
 203         }
 204
 205         *stack = *mpls_lse;
 206         key->mpls.top_lse = *mpls_lse;
 207         return 0;
 208 }
 209
 210 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 211 {
 212         int err;
 213
 214         err = skb_vlan_pop(skb);
 215         if (vlan_tx_tag_present(skb))
 216                 invalidate_flow_key(key);
 217         else
 218                 key->eth.tci = 0;
 219         return err;
 220 }
 221
 222 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 223                      const struct ovs_action_push_vlan *vlan)
 224 {
 225         if (vlan_tx_tag_present(skb))
 226                 invalidate_flow_key(key);
 227         else
 228                 key->eth.tci = vlan->vlan_tci;
 229         return skb_vlan_push(skb, vlan->vlan_tpid,
 230                              ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 231 }
 232
 233 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
 234                         const struct ovs_key_ethernet *eth_key)
 235 {
 236         int err;
 237         err = skb_ensure_writable(skb, ETH_HLEN);
 238         if (unlikely(err))
 239                 return err;
 240
 241         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 242
 243         ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
 244         ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);
 245
 246         ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 247
 248         ether_addr_copy(key->eth.src, eth_key->eth_src);
 249         ether_addr_copy(key->eth.dst, eth_key->eth_dst);
 250         return 0;
 251 }
 252
 253 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 254                         __be32 *addr, __be32 new_addr)
 255 {
 256         int transport_len = skb->len - skb_transport_offset(skb);
 257
 258         if (nh->protocol == IPPROTO_TCP) {
 259                 if (likely(transport_len >= sizeof(struct tcphdr)))
 260                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 261                                                  *addr, new_addr, 1);
 262         } else if (nh->protocol == IPPROTO_UDP) {
 263                 if (likely(transport_len >= sizeof(struct udphdr))) {
 264                         struct udphdr *uh = udp_hdr(skb);
 265
 266                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 267                                 inet_proto_csum_replace4(&uh->check, skb,
 268                                                          *addr, new_addr, 1);
 269                                 if (!uh->check)
 270                                         uh->check = CSUM_MANGLED_0;
 271                         }
 272                 }
 273         }
 274
 275         csum_replace4(&nh->check, *addr, new_addr);
 276         skb_clear_hash(skb);
 277         *addr = new_addr;
 278 }
 279
 280 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 281                                  __be32 addr[4], const __be32 new_addr[4])
 282 {
 283         int transport_len = skb->len - skb_transport_offset(skb);
 284
 285         if (l4_proto == NEXTHDR_TCP) {
 286                 if (likely(transport_len >= sizeof(struct tcphdr)))
 287                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 288                                                   addr, new_addr, 1);
 289         } else if (l4_proto == NEXTHDR_UDP) {
 290                 if (likely(transport_len >= sizeof(struct udphdr))) {
 291                         struct udphdr *uh = udp_hdr(skb);
 292
 293                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 294                                 inet_proto_csum_replace16(&uh->check, skb,
 295                                                           addr, new_addr, 1);
 296                                 if (!uh->check)
 297                                         uh->check = CSUM_MANGLED_0;
 298                         }
 299                 }
 300         } else if (l4_proto == NEXTHDR_ICMP) {
 301                 if (likely(transport_len >= sizeof(struct icmp6hdr)))
 302                         inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 303                                                   skb, addr, new_addr, 1);
 304         }
 305 }
 306
 307 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 308                           __be32 addr[4], const __be32 new_addr[4],
 309                           bool recalculate_csum)
 310 {
 311         if (recalculate_csum)
 312                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 313
 314         skb_clear_hash(skb);
 315         memcpy(addr, new_addr, sizeof(__be32[4]));
 316 }
 317
 318 static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
 319 {
 320         nh->priority = tc >> 4;
 321         nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
 322 }
 323
 324 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
 325 {
 326         nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
 327         nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
 328         nh->flow_lbl[2] = fl & 0x000000FF;
 329 }
 330
 331 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
 332 {
 333         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 334         nh->ttl = new_ttl;
 335 }
 336
 337 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key,
 338                     const struct ovs_key_ipv4 *ipv4_key)
 339 {
 340         struct iphdr *nh;
 341         int err;
 342
 343         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 344                                   sizeof(struct iphdr));
 345         if (unlikely(err))
 346                 return err;
 347
 348         nh = ip_hdr(skb);
 349
 350         if (ipv4_key->ipv4_src != nh->saddr) {
 351                 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
 352                 key->ipv4.addr.src = ipv4_key->ipv4_src;
 353         }
 354
 355         if (ipv4_key->ipv4_dst != nh->daddr) {
 356                 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
 357                 key->ipv4.addr.dst = ipv4_key->ipv4_dst;
 358         }
 359
 360         if (ipv4_key->ipv4_tos != nh->tos) {
 361                 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
 362                 key->ip.tos = nh->tos;
 363         }
 364
 365         if (ipv4_key->ipv4_ttl != nh->ttl) {
 366                 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
 367                 key->ip.ttl = ipv4_key->ipv4_ttl;
 368         }
 369
 370         return 0;
 371 }
 372
 373 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
 374                     const struct ovs_key_ipv6 *ipv6_key)
 375 {
 376         struct ipv6hdr *nh;
 377         int err;
 378         __be32 *saddr;
 379         __be32 *daddr;
 380
 381         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 382                                   sizeof(struct ipv6hdr));
 383         if (unlikely(err))
 384                 return err;
 385
 386         nh = ipv6_hdr(skb);
 387         saddr = (__be32 *)&nh->saddr;
 388         daddr = (__be32 *)&nh->daddr;
 389
 390         if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
 391                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
 392                               ipv6_key->ipv6_src, true);
 393                 memcpy(&key->ipv6.addr.src, ipv6_key->ipv6_src,
 394                        sizeof(ipv6_key->ipv6_src));
 395         }
 396
 397         if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
 398                 unsigned int offset = 0;
 399                 int flags = IP6_FH_F_SKIP_RH;
 400                 bool recalc_csum = true;
 401
 402                 if (ipv6_ext_hdr(nh->nexthdr))
 403                         recalc_csum = ipv6_find_hdr(skb, &offset,
 404                                                     NEXTHDR_ROUTING, NULL,
 405                                                     &flags) != NEXTHDR_ROUTING;
 406
 407                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
 408                               ipv6_key->ipv6_dst, recalc_csum);
 409                 memcpy(&key->ipv6.addr.dst, ipv6_key->ipv6_dst,
 410                        sizeof(ipv6_key->ipv6_dst));
 411         }
 412
 413         set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
 414         key->ip.tos = ipv6_get_dsfield(nh);
 415
 416         set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
 417         key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 418
 419         nh->hop_limit = ipv6_key->ipv6_hlimit;
 420         key->ip.ttl = ipv6_key->ipv6_hlimit;
 421         return 0;
 422 }
 423
 424 /* Must follow skb_ensure_writable() since that can move the skb data. */
 425 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 426                          __be16 new_port, __sum16 *check)
 427 {
 428         inet_proto_csum_replace2(check, skb, *port, new_port, 0);
 429         *port = new_port;
 430         skb_clear_hash(skb);
 431 }
 432
 433 static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
 434 {
 435         struct udphdr *uh = udp_hdr(skb);
 436
 437         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 438                 set_tp_port(skb, port, new_port, &uh->check);
 439
 440                 if (!uh->check)
 441                         uh->check = CSUM_MANGLED_0;
 442         } else {
 443                 *port = new_port;
 444                 skb_clear_hash(skb);
 445         }
 446 }
 447
 448 static int set_udp(struct sk_buff *skb, struct sw_flow_key *key,
 449                    const struct ovs_key_udp *udp_port_key)
 450 {
 451         struct udphdr *uh;
 452         int err;
 453
 454         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 455                                   sizeof(struct udphdr));
 456         if (unlikely(err))
 457                 return err;
 458
 459         uh = udp_hdr(skb);
 460         if (udp_port_key->udp_src != uh->source) {
 461                 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
 462                 key->tp.src = udp_port_key->udp_src;
 463         }
 464
 465         if (udp_port_key->udp_dst != uh->dest) {
 466                 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
 467                 key->tp.dst = udp_port_key->udp_dst;
 468         }
 469
 470         return 0;
 471 }
 472
 473 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key,
 474                    const struct ovs_key_tcp *tcp_port_key)
 475 {
 476         struct tcphdr *th;
 477         int err;
 478
 479         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 480                                   sizeof(struct tcphdr));
 481         if (unlikely(err))
 482                 return err;
 483
 484         th = tcp_hdr(skb);
 485         if (tcp_port_key->tcp_src != th->source) {
 486                 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
 487                 key->tp.src = tcp_port_key->tcp_src;
 488         }
 489
 490         if (tcp_port_key->tcp_dst != th->dest) {
 491                 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
 492                 key->tp.dst = tcp_port_key->tcp_dst;
 493         }
 494
 495         return 0;
 496 }
 497
 498 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key,
 499                     const struct ovs_key_sctp *sctp_port_key)
 500 {
 501         struct sctphdr *sh;
 502         int err;
 503         unsigned int sctphoff = skb_transport_offset(skb);
 504
 505         err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 506         if (unlikely(err))
 507                 return err;
 508
 509         sh = sctp_hdr(skb);
 510         if (sctp_port_key->sctp_src != sh->source ||
 511             sctp_port_key->sctp_dst != sh->dest) {
 512                 __le32 old_correct_csum, new_csum, old_csum;
 513
 514                 old_csum = sh->checksum;
 515                 old_correct_csum = sctp_compute_cksum(skb, sctphoff);
 516
 517                 sh->source = sctp_port_key->sctp_src;
 518                 sh->dest = sctp_port_key->sctp_dst;
 519
 520                 new_csum = sctp_compute_cksum(skb, sctphoff);
 521
 522                 /* Carry any checksum errors through. */
 523                 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 524
 525                 skb_clear_hash(skb);
 526                 key->tp.src = sctp_port_key->sctp_src;
 527                 key->tp.dst = sctp_port_key->sctp_dst;
 528         }
 529
 530         return 0;
 531 }
 532
 533 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
 534 {
 535         struct vport *vport = ovs_vport_rcu(dp, out_port);
 536
 537         if (likely(vport))
 538                 ovs_vport_send(vport, skb);
 539         else
 540                 kfree_skb(skb);
 541 }
 542
 543 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 544                             struct sw_flow_key *key, const struct nlattr *attr)
 545 {
 546         struct ovs_tunnel_info info;
 547         struct dp_upcall_info upcall;
 548         const struct nlattr *a;
 549         int rem;
 550
 551         upcall.cmd = OVS_PACKET_CMD_ACTION;
 552         upcall.userdata = NULL;
 553         upcall.portid = 0;
 554         upcall.egress_tun_info = NULL;
 555
 556         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 557                  a = nla_next(a, &rem)) {
 558                 switch (nla_type(a)) {
 559                 case OVS_USERSPACE_ATTR_USERDATA:
 560                         upcall.userdata = a;
 561                         break;
 562
 563                 case OVS_USERSPACE_ATTR_PID:
 564                         upcall.portid = nla_get_u32(a);
 565                         break;
 566
 567                 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 568                         /* Get out tunnel info. */
 569                         struct vport *vport;
 570
 571                         vport = ovs_vport_rcu(dp, nla_get_u32(a));
 572                         if (vport) {
 573                                 int err;
 574
 575                                 err = ovs_vport_get_egress_tun_info(vport, skb,
 576                                                                     &info);
 577                                 if (!err)
 578                                         upcall.egress_tun_info = &info;
 579                         }
 580                         break;
 581                 }
 582
 583                 } /* End of switch. */
 584         }
 585
 586         return ovs_dp_upcall(dp, skb, key, &upcall);
 587 }
 588
 589 static int sample(struct datapath *dp, struct sk_buff *skb,
 590                   struct sw_flow_key *key, const struct nlattr *attr)
 591 {
 592         const struct nlattr *acts_list = NULL;
 593         const struct nlattr *a;
 594         int rem;
 595
 596         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 597                  a = nla_next(a, &rem)) {
 598                 switch (nla_type(a)) {
 599                 case OVS_SAMPLE_ATTR_PROBABILITY:
 600                         if (prandom_u32() >= nla_get_u32(a))
 601                                 return 0;
 602                         break;
 603
 604                 case OVS_SAMPLE_ATTR_ACTIONS:
 605                         acts_list = a;
 606                         break;
 607                 }
 608         }
 609
 610         rem = nla_len(acts_list);
 611         a = nla_data(acts_list);
 612
 613         /* Actions list is empty, do nothing */
 614         if (unlikely(!rem))
 615                 return 0;
 616
 617         /* The only known usage of sample action is having a single user-space
 618          * action. Treat this usage as a special case.
 619          * The output_userspace() should clone the skb to be sent to the
 620          * user space. This skb will be consumed by its caller.
 621          */
 622         if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
 623                    nla_is_last(a, rem)))
 624                 return output_userspace(dp, skb, key, a);
 625
 626         skb = skb_clone(skb, GFP_ATOMIC);
 627         if (!skb)
 628                 /* Skip the sample action when out of memory. */
 629                 return 0;
 630
 631         if (!add_deferred_actions(skb, key, a)) {
 632                 if (net_ratelimit())
 633                         pr_warn("%s: deferred actions limit reached, dropping sample action\n",
 634                                 ovs_dp_name(dp));
 635
 636                 kfree_skb(skb);
 637         }
 638         return 0;
 639 }
 640
 641 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
 642                          const struct nlattr *attr)
 643 {
 644         struct ovs_action_hash *hash_act = nla_data(attr);
 645         u32 hash = 0;
 646
 647         /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
 648         hash = skb_get_hash(skb);
 649         hash = jhash_1word(hash, hash_act->hash_basis);
 650         if (!hash)
 651                 hash = 0x1;
 652
 653         key->ovs_flow_hash = hash;
 654 }
 655
 656 static int execute_set_action(struct sk_buff *skb, struct sw_flow_key *key,
 657                               const struct nlattr *nested_attr)
 658 {
 659         int err = 0;
 660
 661         switch (nla_type(nested_attr)) {
 662         case OVS_KEY_ATTR_PRIORITY:
 663                 skb->priority = nla_get_u32(nested_attr);
 664                 key->phy.priority = skb->priority;
 665                 break;
 666
 667         case OVS_KEY_ATTR_SKB_MARK:
 668                 skb->mark = nla_get_u32(nested_attr);
 669                 key->phy.skb_mark = skb->mark;
 670                 break;
 671
 672         case OVS_KEY_ATTR_TUNNEL_INFO:
 673                 OVS_CB(skb)->egress_tun_info = nla_data(nested_attr);
 674                 break;
 675
 676         case OVS_KEY_ATTR_ETHERNET:
 677                 err = set_eth_addr(skb, key, nla_data(nested_attr));
 678                 break;
 679
 680         case OVS_KEY_ATTR_IPV4:
 681                 err = set_ipv4(skb, key, nla_data(nested_attr));
 682                 break;
 683
 684         case OVS_KEY_ATTR_IPV6:
 685                 err = set_ipv6(skb, key, nla_data(nested_attr));
 686                 break;
 687
 688         case OVS_KEY_ATTR_TCP:
 689                 err = set_tcp(skb, key, nla_data(nested_attr));
 690                 break;
 691
 692         case OVS_KEY_ATTR_UDP:
 693                 err = set_udp(skb, key, nla_data(nested_attr));
 694                 break;
 695
 696         case OVS_KEY_ATTR_SCTP:
 697                 err = set_sctp(skb, key, nla_data(nested_attr));
 698                 break;
 699
 700         case OVS_KEY_ATTR_MPLS:
 701                 err = set_mpls(skb, key, nla_data(nested_attr));
 702                 break;
 703         }
 704
 705         return err;
 706 }
 707
 708 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
 709                           struct sw_flow_key *key,
 710                           const struct nlattr *a, int rem)
 711 {
 712         struct deferred_action *da;
 713
 714         if (!is_flow_key_valid(key)) {
 715                 int err;
 716
 717                 err = ovs_flow_key_update(skb, key);
 718                 if (err)
 719                         return err;
 720         }
 721         BUG_ON(!is_flow_key_valid(key));
 722
 723         if (!nla_is_last(a, rem)) {
 724                 /* Recirc action is the not the last action
 725                  * of the action list, need to clone the skb.
 726                  */
 727                 skb = skb_clone(skb, GFP_ATOMIC);
 728
 729                 /* Skip the recirc action when out of memory, but
 730                  * continue on with the rest of the action list.
 731                  */
 732                 if (!skb)
 733                         return 0;
 734         }
 735
 736         da = add_deferred_actions(skb, key, NULL);
 737         if (da) {
 738                 da->pkt_key.recirc_id = nla_get_u32(a);
 739         } else {
 740                 kfree_skb(skb);
 741
 742                 if (net_ratelimit())
 743                         pr_warn("%s: deferred action limit reached, drop recirc action\n",
 744                                 ovs_dp_name(dp));
 745         }
 746
 747         return 0;
 748 }
 749
 750 /* Execute a list of actions against 'skb'. */
 751 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 752                               struct sw_flow_key *key,
 753                               const struct nlattr *attr, int len)
 754 {
 755         /* Every output action needs a separate clone of 'skb', but the common
 756          * case is just a single output action, so that doing a clone and
 757          * then freeing the original skbuff is wasteful.  So the following code
 758          * is slightly obscure just to avoid that.
 759          */
 760         int prev_port = -1;
 761         const struct nlattr *a;
 762         int rem;
 763
 764         for (a = attr, rem = len; rem > 0;
 765              a = nla_next(a, &rem)) {
 766                 int err = 0;
 767
 768                 if (unlikely(prev_port != -1)) {
 769                         struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
 770
 771                         if (out_skb)
 772                                 do_output(dp, out_skb, prev_port);
 773
 774                         prev_port = -1;
 775                 }
 776
 777                 switch (nla_type(a)) {
 778                 case OVS_ACTION_ATTR_OUTPUT:
 779                         prev_port = nla_get_u32(a);
 780                         break;
 781
 782                 case OVS_ACTION_ATTR_USERSPACE:
 783                         output_userspace(dp, skb, key, a);
 784                         break;
 785
 786                 case OVS_ACTION_ATTR_HASH:
 787                         execute_hash(skb, key, a);
 788                         break;
 789
 790                 case OVS_ACTION_ATTR_PUSH_MPLS:
 791                         err = push_mpls(skb, key, nla_data(a));
 792                         break;
 793
 794                 case OVS_ACTION_ATTR_POP_MPLS:
 795                         err = pop_mpls(skb, key, nla_get_be16(a));
 796                         break;
 797
 798                 case OVS_ACTION_ATTR_PUSH_VLAN:
 799                         err = push_vlan(skb, key, nla_data(a));
 800                         break;
 801
 802                 case OVS_ACTION_ATTR_POP_VLAN:
 803                         err = pop_vlan(skb, key);
 804                         break;
 805
 806                 case OVS_ACTION_ATTR_RECIRC:
 807                         err = execute_recirc(dp, skb, key, a, rem);
 808                         if (nla_is_last(a, rem)) {
 809                                 /* If this is the last action, the skb has
 810                                  * been consumed or freed.
 811                                  * Return immediately.
 812                                  */
 813                                 return err;
 814                         }
 815                         break;
 816
 817                 case OVS_ACTION_ATTR_SET:
 818                         err = execute_set_action(skb, key, nla_data(a));
 819                         break;
 820
 821                 case OVS_ACTION_ATTR_SAMPLE:
 822                         err = sample(dp, skb, key, a);
 823                         break;
 824                 }
 825
 826                 if (unlikely(err)) {
 827                         kfree_skb(skb);
 828                         return err;
 829                 }
 830         }
 831
 832         if (prev_port != -1)
 833                 do_output(dp, skb, prev_port);
 834         else
 835                 consume_skb(skb);
 836
 837         return 0;
 838 }
 839
 840 static void process_deferred_actions(struct datapath *dp)
 841 {
 842         struct action_fifo *fifo = this_cpu_ptr(action_fifos);
 843
 844         /* Do not touch the FIFO in case there is no deferred actions. */
 845         if (action_fifo_is_empty(fifo))
 846                 return;
 847
 848         /* Finishing executing all deferred actions. */
 849         do {
 850                 struct deferred_action *da = action_fifo_get(fifo);
 851                 struct sk_buff *skb = da->skb;
 852                 struct sw_flow_key *key = &da->pkt_key;
 853                 const struct nlattr *actions = da->actions;
 854
 855                 if (actions)
 856                         do_execute_actions(dp, skb, key, actions,
 857                                            nla_len(actions));
 858                 else
 859                         ovs_dp_process_packet(skb, key);
 860         } while (!action_fifo_is_empty(fifo));
 861
 862         /* Reset FIFO for the next packet.  */
 863         action_fifo_init(fifo);
 864 }
 865
 866 /* Execute a list of actions against 'skb'. */
 867 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 868                         const struct sw_flow_actions *acts,
 869                         struct sw_flow_key *key)
 870 {
 871         int level = this_cpu_read(exec_actions_level);
 872         int err;
 873
 874         this_cpu_inc(exec_actions_level);
 875         OVS_CB(skb)->egress_tun_info = NULL;
 876         err = do_execute_actions(dp, skb, key,
 877                                  acts->actions, acts->actions_len);
 878
 879         if (!level)
 880                 process_deferred_actions(dp);
 881
 882         this_cpu_dec(exec_actions_level);
 883         return err;
 884 }
 885
 886 int action_fifos_init(void)
 887 {
 888         action_fifos = alloc_percpu(struct action_fifo);
 889         if (!action_fifos)
 890                 return -ENOMEM;
 891
 892         return 0;
 893 }
 894
 895 void action_fifos_exit(void)
 896 {
 897         free_percpu(action_fifos);
 898 }