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 /* 'KEY' must not have any bits set outside of the 'MASK' */
 189 #define MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 190 #define SET_MASKED(OLD, KEY, MASK) ((OLD) = MASKED(OLD, KEY, MASK))
 191
 192 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
 193                     const __be32 *mpls_lse, const __be32 *mask)
 194 {
 195         __be32 *stack;
 196         __be32 lse;
 197         int err;
 198
 199         err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 200         if (unlikely(err))
 201                 return err;
 202
 203         stack = (__be32 *)skb_mpls_header(skb);
 204         lse = MASKED(*stack, *mpls_lse, *mask);
 205         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 206                 __be32 diff[] = { ~(*stack), lse };
 207
 208                 skb->csum = ~csum_partial((char *)diff, sizeof(diff),
 209                                           ~skb->csum);
 210         }
 211
 212         *stack = lse;
 213         flow_key->mpls.top_lse = lse;
 214         return 0;
 215 }
 216
 217 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 218 {
 219         int err;
 220
 221         err = skb_vlan_pop(skb);
 222         if (skb_vlan_tag_present(skb))
 223                 invalidate_flow_key(key);
 224         else
 225                 key->eth.tci = 0;
 226         return err;
 227 }
 228
 229 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 230                      const struct ovs_action_push_vlan *vlan)
 231 {
 232         if (skb_vlan_tag_present(skb))
 233                 invalidate_flow_key(key);
 234         else
 235                 key->eth.tci = vlan->vlan_tci;
 236         return skb_vlan_push(skb, vlan->vlan_tpid,
 237                              ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 238 }
 239
 240 /* 'src' is already properly masked. */
 241 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
 242 {
 243         u16 *dst = (u16 *)dst_;
 244         const u16 *src = (const u16 *)src_;
 245         const u16 *mask = (const u16 *)mask_;
 246
 247         SET_MASKED(dst[0], src[0], mask[0]);
 248         SET_MASKED(dst[1], src[1], mask[1]);
 249         SET_MASKED(dst[2], src[2], mask[2]);
 250 }
 251
 252 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
 253                         const struct ovs_key_ethernet *key,
 254                         const struct ovs_key_ethernet *mask)
 255 {
 256         int err;
 257
 258         err = skb_ensure_writable(skb, ETH_HLEN);
 259         if (unlikely(err))
 260                 return err;
 261
 262         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 263
 264         ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
 265                                mask->eth_src);
 266         ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
 267                                mask->eth_dst);
 268
 269         ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 270
 271         ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
 272         ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
 273         return 0;
 274 }
 275
 276 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
 277                                   __be32 addr, __be32 new_addr)
 278 {
 279         int transport_len = skb->len - skb_transport_offset(skb);
 280
 281         if (nh->frag_off & htons(IP_OFFSET))
 282                 return;
 283
 284         if (nh->protocol == IPPROTO_TCP) {
 285                 if (likely(transport_len >= sizeof(struct tcphdr)))
 286                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 287                                                  addr, new_addr, 1);
 288         } else if (nh->protocol == IPPROTO_UDP) {
 289                 if (likely(transport_len >= sizeof(struct udphdr))) {
 290                         struct udphdr *uh = udp_hdr(skb);
 291
 292                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 293                                 inet_proto_csum_replace4(&uh->check, skb,
 294                                                          addr, new_addr, 1);
 295                                 if (!uh->check)
 296                                         uh->check = CSUM_MANGLED_0;
 297                         }
 298                 }
 299         }
 300 }
 301
 302 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 303                         __be32 *addr, __be32 new_addr)
 304 {
 305         update_ip_l4_checksum(skb, nh, *addr, new_addr);
 306         csum_replace4(&nh->check, *addr, new_addr);
 307         skb_clear_hash(skb);
 308         *addr = new_addr;
 309 }
 310
 311 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 312                                  __be32 addr[4], const __be32 new_addr[4])
 313 {
 314         int transport_len = skb->len - skb_transport_offset(skb);
 315
 316         if (l4_proto == NEXTHDR_TCP) {
 317                 if (likely(transport_len >= sizeof(struct tcphdr)))
 318                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 319                                                   addr, new_addr, 1);
 320         } else if (l4_proto == NEXTHDR_UDP) {
 321                 if (likely(transport_len >= sizeof(struct udphdr))) {
 322                         struct udphdr *uh = udp_hdr(skb);
 323
 324                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 325                                 inet_proto_csum_replace16(&uh->check, skb,
 326                                                           addr, new_addr, 1);
 327                                 if (!uh->check)
 328                                         uh->check = CSUM_MANGLED_0;
 329                         }
 330                 }
 331         } else if (l4_proto == NEXTHDR_ICMP) {
 332                 if (likely(transport_len >= sizeof(struct icmp6hdr)))
 333                         inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 334                                                   skb, addr, new_addr, 1);
 335         }
 336 }
 337
 338 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
 339                            const __be32 mask[4], __be32 masked[4])
 340 {
 341         masked[0] = MASKED(old[0], addr[0], mask[0]);
 342         masked[1] = MASKED(old[1], addr[1], mask[1]);
 343         masked[2] = MASKED(old[2], addr[2], mask[2]);
 344         masked[3] = MASKED(old[3], addr[3], mask[3]);
 345 }
 346
 347 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 348                           __be32 addr[4], const __be32 new_addr[4],
 349                           bool recalculate_csum)
 350 {
 351         if (recalculate_csum)
 352                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 353
 354         skb_clear_hash(skb);
 355         memcpy(addr, new_addr, sizeof(__be32[4]));
 356 }
 357
 358 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
 359 {
 360         /* Bits 21-24 are always unmasked, so this retains their values. */
 361         SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
 362         SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
 363         SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
 364 }
 365
 366 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
 367                        u8 mask)
 368 {
 369         new_ttl = MASKED(nh->ttl, new_ttl, mask);
 370
 371         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 372         nh->ttl = new_ttl;
 373 }
 374
 375 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
 376                     const struct ovs_key_ipv4 *key,
 377                     const struct ovs_key_ipv4 *mask)
 378 {
 379         struct iphdr *nh;
 380         __be32 new_addr;
 381         int err;
 382
 383         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 384                                   sizeof(struct iphdr));
 385         if (unlikely(err))
 386                 return err;
 387
 388         nh = ip_hdr(skb);
 389
 390         /* Setting an IP addresses is typically only a side effect of
 391          * matching on them in the current userspace implementation, so it
 392          * makes sense to check if the value actually changed.
 393          */
 394         if (mask->ipv4_src) {
 395                 new_addr = MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
 396
 397                 if (unlikely(new_addr != nh->saddr)) {
 398                         set_ip_addr(skb, nh, &nh->saddr, new_addr);
 399                         flow_key->ipv4.addr.src = new_addr;
 400                 }
 401         }
 402         if (mask->ipv4_dst) {
 403                 new_addr = MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
 404
 405                 if (unlikely(new_addr != nh->daddr)) {
 406                         set_ip_addr(skb, nh, &nh->daddr, new_addr);
 407                         flow_key->ipv4.addr.dst = new_addr;
 408                 }
 409         }
 410         if (mask->ipv4_tos) {
 411                 ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
 412                 flow_key->ip.tos = nh->tos;
 413         }
 414         if (mask->ipv4_ttl) {
 415                 set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
 416                 flow_key->ip.ttl = nh->ttl;
 417         }
 418
 419         return 0;
 420 }
 421
 422 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
 423 {
 424         return !!(addr[0] | addr[1] | addr[2] | addr[3]);
 425 }
 426
 427 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
 428                     const struct ovs_key_ipv6 *key,
 429                     const struct ovs_key_ipv6 *mask)
 430 {
 431         struct ipv6hdr *nh;
 432         int err;
 433
 434         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 435                                   sizeof(struct ipv6hdr));
 436         if (unlikely(err))
 437                 return err;
 438
 439         nh = ipv6_hdr(skb);
 440
 441         /* Setting an IP addresses is typically only a side effect of
 442          * matching on them in the current userspace implementation, so it
 443          * makes sense to check if the value actually changed.
 444          */
 445         if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
 446                 __be32 *saddr = (__be32 *)&nh->saddr;
 447                 __be32 masked[4];
 448
 449                 mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
 450
 451                 if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
 452                         set_ipv6_addr(skb, key->ipv6_proto, saddr, masked,
 453                                       true);
 454                         memcpy(&flow_key->ipv6.addr.src, masked,
 455                                sizeof(flow_key->ipv6.addr.src));
 456                 }
 457         }
 458         if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
 459                 unsigned int offset = 0;
 460                 int flags = IP6_FH_F_SKIP_RH;
 461                 bool recalc_csum = true;
 462                 __be32 *daddr = (__be32 *)&nh->daddr;
 463                 __be32 masked[4];
 464
 465                 mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
 466
 467                 if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
 468                         if (ipv6_ext_hdr(nh->nexthdr))
 469                                 recalc_csum = (ipv6_find_hdr(skb, &offset,
 470                                                              NEXTHDR_ROUTING,
 471                                                              NULL, &flags)
 472                                                != NEXTHDR_ROUTING);
 473
 474                         set_ipv6_addr(skb, key->ipv6_proto, daddr, masked,
 475                                       recalc_csum);
 476                         memcpy(&flow_key->ipv6.addr.dst, masked,
 477                                sizeof(flow_key->ipv6.addr.dst));
 478                 }
 479         }
 480         if (mask->ipv6_tclass) {
 481                 ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
 482                 flow_key->ip.tos = ipv6_get_dsfield(nh);
 483         }
 484         if (mask->ipv6_label) {
 485                 set_ipv6_fl(nh, ntohl(key->ipv6_label),
 486                             ntohl(mask->ipv6_label));
 487                 flow_key->ipv6.label =
 488                     *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 489         }
 490         if (mask->ipv6_hlimit) {
 491                 SET_MASKED(nh->hop_limit, key->ipv6_hlimit, mask->ipv6_hlimit);
 492                 flow_key->ip.ttl = nh->hop_limit;
 493         }
 494         return 0;
 495 }
 496
 497 /* Must follow skb_ensure_writable() since that can move the skb data. */
 498 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 499                         __be16 new_port, __sum16 *check)
 500 {
 501         inet_proto_csum_replace2(check, skb, *port, new_port, 0);
 502         *port = new_port;
 503 }
 504
 505 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 506                    const struct ovs_key_udp *key,
 507                    const struct ovs_key_udp *mask)
 508 {
 509         struct udphdr *uh;
 510         __be16 src, dst;
 511         int err;
 512
 513         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 514                                   sizeof(struct udphdr));
 515         if (unlikely(err))
 516                 return err;
 517
 518         uh = udp_hdr(skb);
 519         /* Either of the masks is non-zero, so do not bother checking them. */
 520         src = MASKED(uh->source, key->udp_src, mask->udp_src);
 521         dst = MASKED(uh->dest, key->udp_dst, mask->udp_dst);
 522
 523         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 524                 if (likely(src != uh->source)) {
 525                         set_tp_port(skb, &uh->source, src, &uh->check);
 526                         flow_key->tp.src = src;
 527                 }
 528                 if (likely(dst != uh->dest)) {
 529                         set_tp_port(skb, &uh->dest, dst, &uh->check);
 530                         flow_key->tp.dst = dst;
 531                 }
 532
 533                 if (unlikely(!uh->check))
 534                         uh->check = CSUM_MANGLED_0;
 535         } else {
 536                 uh->source = src;
 537                 uh->dest = dst;
 538                 flow_key->tp.src = src;
 539                 flow_key->tp.dst = dst;
 540         }
 541
 542         skb_clear_hash(skb);
 543
 544         return 0;
 545 }
 546
 547 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 548                    const struct ovs_key_tcp *key,
 549                    const struct ovs_key_tcp *mask)
 550 {
 551         struct tcphdr *th;
 552         __be16 src, dst;
 553         int err;
 554
 555         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 556                                   sizeof(struct tcphdr));
 557         if (unlikely(err))
 558                 return err;
 559
 560         th = tcp_hdr(skb);
 561         src = MASKED(th->source, key->tcp_src, mask->tcp_src);
 562         if (likely(src != th->source)) {
 563                 set_tp_port(skb, &th->source, src, &th->check);
 564                 flow_key->tp.src = src;
 565         }
 566         dst = MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
 567         if (likely(dst != th->dest)) {
 568                 set_tp_port(skb, &th->dest, dst, &th->check);
 569                 flow_key->tp.dst = dst;
 570         }
 571         skb_clear_hash(skb);
 572
 573         return 0;
 574 }
 575
 576 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 577                     const struct ovs_key_sctp *key,
 578                     const struct ovs_key_sctp *mask)
 579 {
 580         unsigned int sctphoff = skb_transport_offset(skb);
 581         struct sctphdr *sh;
 582         __le32 old_correct_csum, new_csum, old_csum;
 583         int err;
 584
 585         err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 586         if (unlikely(err))
 587                 return err;
 588
 589         sh = sctp_hdr(skb);
 590         old_csum = sh->checksum;
 591         old_correct_csum = sctp_compute_cksum(skb, sctphoff);
 592
 593         sh->source = MASKED(sh->source, key->sctp_src, mask->sctp_src);
 594         sh->dest = MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
 595
 596         new_csum = sctp_compute_cksum(skb, sctphoff);
 597
 598         /* Carry any checksum errors through. */
 599         sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 600
 601         skb_clear_hash(skb);
 602         flow_key->tp.src = sh->source;
 603         flow_key->tp.dst = sh->dest;
 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                             const struct nlattr *actions, int actions_len)
 621 {
 622         struct ovs_tunnel_info info;
 623         struct dp_upcall_info upcall;
 624         const struct nlattr *a;
 625         int rem;
 626
 627         memset(&upcall, 0, sizeof(upcall));
 628         upcall.cmd = OVS_PACKET_CMD_ACTION;
 629
 630         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 631                  a = nla_next(a, &rem)) {
 632                 switch (nla_type(a)) {
 633                 case OVS_USERSPACE_ATTR_USERDATA:
 634                         upcall.userdata = a;
 635                         break;
 636
 637                 case OVS_USERSPACE_ATTR_PID:
 638                         upcall.portid = nla_get_u32(a);
 639                         break;
 640
 641                 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 642                         /* Get out tunnel info. */
 643                         struct vport *vport;
 644
 645                         vport = ovs_vport_rcu(dp, nla_get_u32(a));
 646                         if (vport) {
 647                                 int err;
 648
 649                                 err = ovs_vport_get_egress_tun_info(vport, skb,
 650                                                                     &info);
 651                                 if (!err)
 652                                         upcall.egress_tun_info = &info;
 653                         }
 654                         break;
 655                 }
 656
 657                 case OVS_USERSPACE_ATTR_ACTIONS: {
 658                         /* Include actions. */
 659                         upcall.actions = actions;
 660                         upcall.actions_len = actions_len;
 661                         break;
 662                 }
 663
 664                 } /* End of switch. */
 665         }
 666
 667         return ovs_dp_upcall(dp, skb, key, &upcall);
 668 }
 669
 670 static int sample(struct datapath *dp, struct sk_buff *skb,
 671                   struct sw_flow_key *key, const struct nlattr *attr,
 672                   const struct nlattr *actions, int actions_len)
 673 {
 674         const struct nlattr *acts_list = NULL;
 675         const struct nlattr *a;
 676         int rem;
 677
 678         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 679                  a = nla_next(a, &rem)) {
 680                 switch (nla_type(a)) {
 681                 case OVS_SAMPLE_ATTR_PROBABILITY:
 682                         if (prandom_u32() >= nla_get_u32(a))
 683                                 return 0;
 684                         break;
 685
 686                 case OVS_SAMPLE_ATTR_ACTIONS:
 687                         acts_list = a;
 688                         break;
 689                 }
 690         }
 691
 692         rem = nla_len(acts_list);
 693         a = nla_data(acts_list);
 694
 695         /* Actions list is empty, do nothing */
 696         if (unlikely(!rem))
 697                 return 0;
 698
 699         /* The only known usage of sample action is having a single user-space
 700          * action. Treat this usage as a special case.
 701          * The output_userspace() should clone the skb to be sent to the
 702          * user space. This skb will be consumed by its caller.
 703          */
 704         if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
 705                    nla_is_last(a, rem)))
 706                 return output_userspace(dp, skb, key, a, actions, actions_len);
 707
 708         skb = skb_clone(skb, GFP_ATOMIC);
 709         if (!skb)
 710                 /* Skip the sample action when out of memory. */
 711                 return 0;
 712
 713         if (!add_deferred_actions(skb, key, a)) {
 714                 if (net_ratelimit())
 715                         pr_warn("%s: deferred actions limit reached, dropping sample action\n",
 716                                 ovs_dp_name(dp));
 717
 718                 kfree_skb(skb);
 719         }
 720         return 0;
 721 }
 722
 723 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
 724                          const struct nlattr *attr)
 725 {
 726         struct ovs_action_hash *hash_act = nla_data(attr);
 727         u32 hash = 0;
 728
 729         /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
 730         hash = skb_get_hash(skb);
 731         hash = jhash_1word(hash, hash_act->hash_basis);
 732         if (!hash)
 733                 hash = 0x1;
 734
 735         key->ovs_flow_hash = hash;
 736 }
 737
 738 static int execute_set_action(struct sk_buff *skb,
 739                               struct sw_flow_key *flow_key,
 740                               const struct nlattr *a)
 741 {
 742         /* Only tunnel set execution is supported without a mask. */
 743         if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
 744                 OVS_CB(skb)->egress_tun_info = nla_data(a);
 745                 return 0;
 746         }
 747
 748         return -EINVAL;
 749 }
 750
 751 /* Mask is at the midpoint of the data. */
 752 #define get_mask(a, type) ((const type)nla_data(a) + 1)
 753
 754 static int execute_masked_set_action(struct sk_buff *skb,
 755                                      struct sw_flow_key *flow_key,
 756                                      const struct nlattr *a)
 757 {
 758         int err = 0;
 759
 760         switch (nla_type(a)) {
 761         case OVS_KEY_ATTR_PRIORITY:
 762                 SET_MASKED(skb->priority, nla_get_u32(a), *get_mask(a, u32 *));
 763                 flow_key->phy.priority = skb->priority;
 764                 break;
 765
 766         case OVS_KEY_ATTR_SKB_MARK:
 767                 SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
 768                 flow_key->phy.skb_mark = skb->mark;
 769                 break;
 770
 771         case OVS_KEY_ATTR_TUNNEL_INFO:
 772                 /* Masked data not supported for tunnel. */
 773                 err = -EINVAL;
 774                 break;
 775
 776         case OVS_KEY_ATTR_ETHERNET:
 777                 err = set_eth_addr(skb, flow_key, nla_data(a),
 778                                    get_mask(a, struct ovs_key_ethernet *));
 779                 break;
 780
 781         case OVS_KEY_ATTR_IPV4:
 782                 err = set_ipv4(skb, flow_key, nla_data(a),
 783                                get_mask(a, struct ovs_key_ipv4 *));
 784                 break;
 785
 786         case OVS_KEY_ATTR_IPV6:
 787                 err = set_ipv6(skb, flow_key, nla_data(a),
 788                                get_mask(a, struct ovs_key_ipv6 *));
 789                 break;
 790
 791         case OVS_KEY_ATTR_TCP:
 792                 err = set_tcp(skb, flow_key, nla_data(a),
 793                               get_mask(a, struct ovs_key_tcp *));
 794                 break;
 795
 796         case OVS_KEY_ATTR_UDP:
 797                 err = set_udp(skb, flow_key, nla_data(a),
 798                               get_mask(a, struct ovs_key_udp *));
 799                 break;
 800
 801         case OVS_KEY_ATTR_SCTP:
 802                 err = set_sctp(skb, flow_key, nla_data(a),
 803                                get_mask(a, struct ovs_key_sctp *));
 804                 break;
 805
 806         case OVS_KEY_ATTR_MPLS:
 807                 err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
 808                                                                     __be32 *));
 809                 break;
 810         }
 811
 812         return err;
 813 }
 814
 815 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
 816                           struct sw_flow_key *key,
 817                           const struct nlattr *a, int rem)
 818 {
 819         struct deferred_action *da;
 820
 821         if (!is_flow_key_valid(key)) {
 822                 int err;
 823
 824                 err = ovs_flow_key_update(skb, key);
 825                 if (err)
 826                         return err;
 827         }
 828         BUG_ON(!is_flow_key_valid(key));
 829
 830         if (!nla_is_last(a, rem)) {
 831                 /* Recirc action is the not the last action
 832                  * of the action list, need to clone the skb.
 833                  */
 834                 skb = skb_clone(skb, GFP_ATOMIC);
 835
 836                 /* Skip the recirc action when out of memory, but
 837                  * continue on with the rest of the action list.
 838                  */
 839                 if (!skb)
 840                         return 0;
 841         }
 842
 843         da = add_deferred_actions(skb, key, NULL);
 844         if (da) {
 845                 da->pkt_key.recirc_id = nla_get_u32(a);
 846         } else {
 847                 kfree_skb(skb);
 848
 849                 if (net_ratelimit())
 850                         pr_warn("%s: deferred action limit reached, drop recirc action\n",
 851                                 ovs_dp_name(dp));
 852         }
 853
 854         return 0;
 855 }
 856
 857 /* Execute a list of actions against 'skb'. */
 858 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 859                               struct sw_flow_key *key,
 860                               const struct nlattr *attr, int len)
 861 {
 862         /* Every output action needs a separate clone of 'skb', but the common
 863          * case is just a single output action, so that doing a clone and
 864          * then freeing the original skbuff is wasteful.  So the following code
 865          * is slightly obscure just to avoid that.
 866          */
 867         int prev_port = -1;
 868         const struct nlattr *a;
 869         int rem;
 870
 871         for (a = attr, rem = len; rem > 0;
 872              a = nla_next(a, &rem)) {
 873                 int err = 0;
 874
 875                 if (unlikely(prev_port != -1)) {
 876                         struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
 877
 878                         if (out_skb)
 879                                 do_output(dp, out_skb, prev_port);
 880
 881                         prev_port = -1;
 882                 }
 883
 884                 switch (nla_type(a)) {
 885                 case OVS_ACTION_ATTR_OUTPUT:
 886                         prev_port = nla_get_u32(a);
 887                         break;
 888
 889                 case OVS_ACTION_ATTR_USERSPACE:
 890                         output_userspace(dp, skb, key, a, attr, len);
 891                         break;
 892
 893                 case OVS_ACTION_ATTR_HASH:
 894                         execute_hash(skb, key, a);
 895                         break;
 896
 897                 case OVS_ACTION_ATTR_PUSH_MPLS:
 898                         err = push_mpls(skb, key, nla_data(a));
 899                         break;
 900
 901                 case OVS_ACTION_ATTR_POP_MPLS:
 902                         err = pop_mpls(skb, key, nla_get_be16(a));
 903                         break;
 904
 905                 case OVS_ACTION_ATTR_PUSH_VLAN:
 906                         err = push_vlan(skb, key, nla_data(a));
 907                         break;
 908
 909                 case OVS_ACTION_ATTR_POP_VLAN:
 910                         err = pop_vlan(skb, key);
 911                         break;
 912
 913                 case OVS_ACTION_ATTR_RECIRC:
 914                         err = execute_recirc(dp, skb, key, a, rem);
 915                         if (nla_is_last(a, rem)) {
 916                                 /* If this is the last action, the skb has
 917                                  * been consumed or freed.
 918                                  * Return immediately.
 919                                  */
 920                                 return err;
 921                         }
 922                         break;
 923
 924                 case OVS_ACTION_ATTR_SET:
 925                         err = execute_set_action(skb, key, nla_data(a));
 926                         break;
 927
 928                 case OVS_ACTION_ATTR_SET_MASKED:
 929                 case OVS_ACTION_ATTR_SET_TO_MASKED:
 930                         err = execute_masked_set_action(skb, key, nla_data(a));
 931                         break;
 932
 933                 case OVS_ACTION_ATTR_SAMPLE:
 934                         err = sample(dp, skb, key, a, attr, len);
 935                         break;
 936                 }
 937
 938                 if (unlikely(err)) {
 939                         kfree_skb(skb);
 940                         return err;
 941                 }
 942         }
 943
 944         if (prev_port != -1)
 945                 do_output(dp, skb, prev_port);
 946         else
 947                 consume_skb(skb);
 948
 949         return 0;
 950 }
 951
 952 static void process_deferred_actions(struct datapath *dp)
 953 {
 954         struct action_fifo *fifo = this_cpu_ptr(action_fifos);
 955
 956         /* Do not touch the FIFO in case there is no deferred actions. */
 957         if (action_fifo_is_empty(fifo))
 958                 return;
 959
 960         /* Finishing executing all deferred actions. */
 961         do {
 962                 struct deferred_action *da = action_fifo_get(fifo);
 963                 struct sk_buff *skb = da->skb;
 964                 struct sw_flow_key *key = &da->pkt_key;
 965                 const struct nlattr *actions = da->actions;
 966
 967                 if (actions)
 968                         do_execute_actions(dp, skb, key, actions,
 969                                            nla_len(actions));
 970                 else
 971                         ovs_dp_process_packet(skb, key);
 972         } while (!action_fifo_is_empty(fifo));
 973
 974         /* Reset FIFO for the next packet.  */
 975         action_fifo_init(fifo);
 976 }
 977
 978 /* Execute a list of actions against 'skb'. */
 979 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 980                         const struct sw_flow_actions *acts,
 981                         struct sw_flow_key *key)
 982 {
 983         int level = this_cpu_read(exec_actions_level);
 984         int err;
 985
 986         this_cpu_inc(exec_actions_level);
 987         OVS_CB(skb)->egress_tun_info = NULL;
 988         err = do_execute_actions(dp, skb, key,
 989                                  acts->actions, acts->actions_len);
 990
 991         if (!level)
 992                 process_deferred_actions(dp);
 993
 994         this_cpu_dec(exec_actions_level);
 995         return err;
 996 }
 997
 998 int action_fifos_init(void)
 999 {
1000         action_fifos = alloc_percpu(struct action_fifo);
1001         if (!action_fifos)
1002                 return -ENOMEM;
1003
1004         return 0;
1005 }
1006
1007 void action_fifos_exit(void)
1008 {
1009         free_percpu(action_fifos);
1010 }