linux/net/openvswitch/actions.c
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   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/netfilter_ipv6.h>
  26#include <linux/sctp.h>
  27#include <linux/tcp.h>
  28#include <linux/udp.h>
  29#include <linux/in6.h>
  30#include <linux/if_arp.h>
  31#include <linux/if_vlan.h>
  32
  33#include <net/dst.h>
  34#include <net/ip.h>
  35#include <net/ipv6.h>
  36#include <net/ip6_fib.h>
  37#include <net/checksum.h>
  38#include <net/dsfield.h>
  39#include <net/mpls.h>
  40#include <net/sctp/checksum.h>
  41
  42#include "datapath.h"
  43#include "flow.h"
  44#include "conntrack.h"
  45#include "vport.h"
  46
  47static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
  48                              struct sw_flow_key *key,
  49                              const struct nlattr *attr, int len);
  50
  51struct deferred_action {
  52        struct sk_buff *skb;
  53        const struct nlattr *actions;
  54
  55        /* Store pkt_key clone when creating deferred action. */
  56        struct sw_flow_key pkt_key;
  57};
  58
  59#define MAX_L2_LEN      (VLAN_ETH_HLEN + 3 * MPLS_HLEN)
  60struct ovs_frag_data {
  61        unsigned long dst;
  62        struct vport *vport;
  63        struct ovs_skb_cb cb;
  64        __be16 inner_protocol;
  65        __u16 vlan_tci;
  66        __be16 vlan_proto;
  67        unsigned int l2_len;
  68        u8 l2_data[MAX_L2_LEN];
  69};
  70
  71static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
  72
  73#define DEFERRED_ACTION_FIFO_SIZE 10
  74#define OVS_RECURSION_LIMIT 5
  75#define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
  76struct action_fifo {
  77        int head;
  78        int tail;
  79        /* Deferred action fifo queue storage. */
  80        struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
  81};
  82
  83struct recirc_keys {
  84        struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
  85};
  86
  87static struct action_fifo __percpu *action_fifos;
  88static struct recirc_keys __percpu *recirc_keys;
  89static DEFINE_PER_CPU(int, exec_actions_level);
  90
  91static void action_fifo_init(struct action_fifo *fifo)
  92{
  93        fifo->head = 0;
  94        fifo->tail = 0;
  95}
  96
  97static bool action_fifo_is_empty(const struct action_fifo *fifo)
  98{
  99        return (fifo->head == fifo->tail);
 100}
 101
 102static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
 103{
 104        if (action_fifo_is_empty(fifo))
 105                return NULL;
 106
 107        return &fifo->fifo[fifo->tail++];
 108}
 109
 110static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
 111{
 112        if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
 113                return NULL;
 114
 115        return &fifo->fifo[fifo->head++];
 116}
 117
 118/* Return true if fifo is not full */
 119static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
 120                                                    const struct sw_flow_key *key,
 121                                                    const struct nlattr *attr)
 122{
 123        struct action_fifo *fifo;
 124        struct deferred_action *da;
 125
 126        fifo = this_cpu_ptr(action_fifos);
 127        da = action_fifo_put(fifo);
 128        if (da) {
 129                da->skb = skb;
 130                da->actions = attr;
 131                da->pkt_key = *key;
 132        }
 133
 134        return da;
 135}
 136
 137static void invalidate_flow_key(struct sw_flow_key *key)
 138{
 139        key->eth.type = htons(0);
 140}
 141
 142static bool is_flow_key_valid(const struct sw_flow_key *key)
 143{
 144        return !!key->eth.type;
 145}
 146
 147static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
 148                             __be16 ethertype)
 149{
 150        if (skb->ip_summed == CHECKSUM_COMPLETE) {
 151                __be16 diff[] = { ~(hdr->h_proto), ethertype };
 152
 153                skb->csum = ~csum_partial((char *)diff, sizeof(diff),
 154                                        ~skb->csum);
 155        }
 156
 157        hdr->h_proto = ethertype;
 158}
 159
 160static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 161                     const struct ovs_action_push_mpls *mpls)
 162{
 163        struct mpls_shim_hdr *new_mpls_lse;
 164
 165        /* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
 166        if (skb->encapsulation)
 167                return -ENOTSUPP;
 168
 169        if (skb_cow_head(skb, MPLS_HLEN) < 0)
 170                return -ENOMEM;
 171
 172        if (!skb->inner_protocol) {
 173                skb_set_inner_network_header(skb, skb->mac_len);
 174                skb_set_inner_protocol(skb, skb->protocol);
 175        }
 176
 177        skb_push(skb, MPLS_HLEN);
 178        memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
 179                skb->mac_len);
 180        skb_reset_mac_header(skb);
 181        skb_set_network_header(skb, skb->mac_len);
 182
 183        new_mpls_lse = mpls_hdr(skb);
 184        new_mpls_lse->label_stack_entry = mpls->mpls_lse;
 185
 186        skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);
 187
 188        update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
 189        skb->protocol = mpls->mpls_ethertype;
 190
 191        invalidate_flow_key(key);
 192        return 0;
 193}
 194
 195static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 196                    const __be16 ethertype)
 197{
 198        struct ethhdr *hdr;
 199        int err;
 200
 201        err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 202        if (unlikely(err))
 203                return err;
 204
 205        skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);
 206
 207        memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
 208                skb->mac_len);
 209
 210        __skb_pull(skb, MPLS_HLEN);
 211        skb_reset_mac_header(skb);
 212        skb_set_network_header(skb, skb->mac_len);
 213
 214        /* mpls_hdr() is used to locate the ethertype field correctly in the
 215         * presence of VLAN tags.
 216         */
 217        hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
 218        update_ethertype(skb, hdr, ethertype);
 219        if (eth_p_mpls(skb->protocol))
 220                skb->protocol = ethertype;
 221
 222        invalidate_flow_key(key);
 223        return 0;
 224}
 225
 226static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
 227                    const __be32 *mpls_lse, const __be32 *mask)
 228{
 229        struct mpls_shim_hdr *stack;
 230        __be32 lse;
 231        int err;
 232
 233        err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 234        if (unlikely(err))
 235                return err;
 236
 237        stack = mpls_hdr(skb);
 238        lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
 239        if (skb->ip_summed == CHECKSUM_COMPLETE) {
 240                __be32 diff[] = { ~(stack->label_stack_entry), lse };
 241
 242                skb->csum = ~csum_partial((char *)diff, sizeof(diff),
 243                                          ~skb->csum);
 244        }
 245
 246        stack->label_stack_entry = lse;
 247        flow_key->mpls.top_lse = lse;
 248        return 0;
 249}
 250
 251static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 252{
 253        int err;
 254
 255        err = skb_vlan_pop(skb);
 256        if (skb_vlan_tag_present(skb)) {
 257                invalidate_flow_key(key);
 258        } else {
 259                key->eth.vlan.tci = 0;
 260                key->eth.vlan.tpid = 0;
 261        }
 262        return err;
 263}
 264
 265static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 266                     const struct ovs_action_push_vlan *vlan)
 267{
 268        if (skb_vlan_tag_present(skb)) {
 269                invalidate_flow_key(key);
 270        } else {
 271                key->eth.vlan.tci = vlan->vlan_tci;
 272                key->eth.vlan.tpid = vlan->vlan_tpid;
 273        }
 274        return skb_vlan_push(skb, vlan->vlan_tpid,
 275                             ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 276}
 277
 278/* 'src' is already properly masked. */
 279static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
 280{
 281        u16 *dst = (u16 *)dst_;
 282        const u16 *src = (const u16 *)src_;
 283        const u16 *mask = (const u16 *)mask_;
 284
 285        OVS_SET_MASKED(dst[0], src[0], mask[0]);
 286        OVS_SET_MASKED(dst[1], src[1], mask[1]);
 287        OVS_SET_MASKED(dst[2], src[2], mask[2]);
 288}
 289
 290static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
 291                        const struct ovs_key_ethernet *key,
 292                        const struct ovs_key_ethernet *mask)
 293{
 294        int err;
 295
 296        err = skb_ensure_writable(skb, ETH_HLEN);
 297        if (unlikely(err))
 298                return err;
 299
 300        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 301
 302        ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
 303                               mask->eth_src);
 304        ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
 305                               mask->eth_dst);
 306
 307        skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 308
 309        ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
 310        ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
 311        return 0;
 312}
 313
 314static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
 315                                  __be32 addr, __be32 new_addr)
 316{
 317        int transport_len = skb->len - skb_transport_offset(skb);
 318
 319        if (nh->frag_off & htons(IP_OFFSET))
 320                return;
 321
 322        if (nh->protocol == IPPROTO_TCP) {
 323                if (likely(transport_len >= sizeof(struct tcphdr)))
 324                        inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 325                                                 addr, new_addr, true);
 326        } else if (nh->protocol == IPPROTO_UDP) {
 327                if (likely(transport_len >= sizeof(struct udphdr))) {
 328                        struct udphdr *uh = udp_hdr(skb);
 329
 330                        if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 331                                inet_proto_csum_replace4(&uh->check, skb,
 332                                                         addr, new_addr, true);
 333                                if (!uh->check)
 334                                        uh->check = CSUM_MANGLED_0;
 335                        }
 336                }
 337        }
 338}
 339
 340static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 341                        __be32 *addr, __be32 new_addr)
 342{
 343        update_ip_l4_checksum(skb, nh, *addr, new_addr);
 344        csum_replace4(&nh->check, *addr, new_addr);
 345        skb_clear_hash(skb);
 346        *addr = new_addr;
 347}
 348
 349static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 350                                 __be32 addr[4], const __be32 new_addr[4])
 351{
 352        int transport_len = skb->len - skb_transport_offset(skb);
 353
 354        if (l4_proto == NEXTHDR_TCP) {
 355                if (likely(transport_len >= sizeof(struct tcphdr)))
 356                        inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 357                                                  addr, new_addr, true);
 358        } else if (l4_proto == NEXTHDR_UDP) {
 359                if (likely(transport_len >= sizeof(struct udphdr))) {
 360                        struct udphdr *uh = udp_hdr(skb);
 361
 362                        if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 363                                inet_proto_csum_replace16(&uh->check, skb,
 364                                                          addr, new_addr, true);
 365                                if (!uh->check)
 366                                        uh->check = CSUM_MANGLED_0;
 367                        }
 368                }
 369        } else if (l4_proto == NEXTHDR_ICMP) {
 370                if (likely(transport_len >= sizeof(struct icmp6hdr)))
 371                        inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 372                                                  skb, addr, new_addr, true);
 373        }
 374}
 375
 376static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
 377                           const __be32 mask[4], __be32 masked[4])
 378{
 379        masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
 380        masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
 381        masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
 382        masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
 383}
 384
 385static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 386                          __be32 addr[4], const __be32 new_addr[4],
 387                          bool recalculate_csum)
 388{
 389        if (recalculate_csum)
 390                update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 391
 392        skb_clear_hash(skb);
 393        memcpy(addr, new_addr, sizeof(__be32[4]));
 394}
 395
 396static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
 397{
 398        /* Bits 21-24 are always unmasked, so this retains their values. */
 399        OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
 400        OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
 401        OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
 402}
 403
 404static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
 405                       u8 mask)
 406{
 407        new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
 408
 409        csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 410        nh->ttl = new_ttl;
 411}
 412
 413static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
 414                    const struct ovs_key_ipv4 *key,
 415                    const struct ovs_key_ipv4 *mask)
 416{
 417        struct iphdr *nh;
 418        __be32 new_addr;
 419        int err;
 420
 421        err = skb_ensure_writable(skb, skb_network_offset(skb) +
 422                                  sizeof(struct iphdr));
 423        if (unlikely(err))
 424                return err;
 425
 426        nh = ip_hdr(skb);
 427
 428        /* Setting an IP addresses is typically only a side effect of
 429         * matching on them in the current userspace implementation, so it
 430         * makes sense to check if the value actually changed.
 431         */
 432        if (mask->ipv4_src) {
 433                new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
 434
 435                if (unlikely(new_addr != nh->saddr)) {
 436                        set_ip_addr(skb, nh, &nh->saddr, new_addr);
 437                        flow_key->ipv4.addr.src = new_addr;
 438                }
 439        }
 440        if (mask->ipv4_dst) {
 441                new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
 442
 443                if (unlikely(new_addr != nh->daddr)) {
 444                        set_ip_addr(skb, nh, &nh->daddr, new_addr);
 445                        flow_key->ipv4.addr.dst = new_addr;
 446                }
 447        }
 448        if (mask->ipv4_tos) {
 449                ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
 450                flow_key->ip.tos = nh->tos;
 451        }
 452        if (mask->ipv4_ttl) {
 453                set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
 454                flow_key->ip.ttl = nh->ttl;
 455        }
 456
 457        return 0;
 458}
 459
 460static bool is_ipv6_mask_nonzero(const __be32 addr[4])
 461{
 462        return !!(addr[0] | addr[1] | addr[2] | addr[3]);
 463}
 464
 465static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
 466                    const struct ovs_key_ipv6 *key,
 467                    const struct ovs_key_ipv6 *mask)
 468{
 469        struct ipv6hdr *nh;
 470        int err;
 471
 472        err = skb_ensure_writable(skb, skb_network_offset(skb) +
 473                                  sizeof(struct ipv6hdr));
 474        if (unlikely(err))
 475                return err;
 476
 477        nh = ipv6_hdr(skb);
 478
 479        /* Setting an IP addresses is typically only a side effect of
 480         * matching on them in the current userspace implementation, so it
 481         * makes sense to check if the value actually changed.
 482         */
 483        if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
 484                __be32 *saddr = (__be32 *)&nh->saddr;
 485                __be32 masked[4];
 486
 487                mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
 488
 489                if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
 490                        set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
 491                                      true);
 492                        memcpy(&flow_key->ipv6.addr.src, masked,
 493                               sizeof(flow_key->ipv6.addr.src));
 494                }
 495        }
 496        if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
 497                unsigned int offset = 0;
 498                int flags = IP6_FH_F_SKIP_RH;
 499                bool recalc_csum = true;
 500                __be32 *daddr = (__be32 *)&nh->daddr;
 501                __be32 masked[4];
 502
 503                mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
 504
 505                if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
 506                        if (ipv6_ext_hdr(nh->nexthdr))
 507                                recalc_csum = (ipv6_find_hdr(skb, &offset,
 508                                                             NEXTHDR_ROUTING,
 509                                                             NULL, &flags)
 510                                               != NEXTHDR_ROUTING);
 511
 512                        set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
 513                                      recalc_csum);
 514                        memcpy(&flow_key->ipv6.addr.dst, masked,
 515                               sizeof(flow_key->ipv6.addr.dst));
 516                }
 517        }
 518        if (mask->ipv6_tclass) {
 519                ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
 520                flow_key->ip.tos = ipv6_get_dsfield(nh);
 521        }
 522        if (mask->ipv6_label) {
 523                set_ipv6_fl(nh, ntohl(key->ipv6_label),
 524                            ntohl(mask->ipv6_label));
 525                flow_key->ipv6.label =
 526                    *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 527        }
 528        if (mask->ipv6_hlimit) {
 529                OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
 530                               mask->ipv6_hlimit);
 531                flow_key->ip.ttl = nh->hop_limit;
 532        }
 533        return 0;
 534}
 535
 536/* Must follow skb_ensure_writable() since that can move the skb data. */
 537static void set_tp_port(struct sk_buff *skb, __be16 *port,
 538                        __be16 new_port, __sum16 *check)
 539{
 540        inet_proto_csum_replace2(check, skb, *port, new_port, false);
 541        *port = new_port;
 542}
 543
 544static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 545                   const struct ovs_key_udp *key,
 546                   const struct ovs_key_udp *mask)
 547{
 548        struct udphdr *uh;
 549        __be16 src, dst;
 550        int err;
 551
 552        err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 553                                  sizeof(struct udphdr));
 554        if (unlikely(err))
 555                return err;
 556
 557        uh = udp_hdr(skb);
 558        /* Either of the masks is non-zero, so do not bother checking them. */
 559        src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
 560        dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
 561
 562        if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 563                if (likely(src != uh->source)) {
 564                        set_tp_port(skb, &uh->source, src, &uh->check);
 565                        flow_key->tp.src = src;
 566                }
 567                if (likely(dst != uh->dest)) {
 568                        set_tp_port(skb, &uh->dest, dst, &uh->check);
 569                        flow_key->tp.dst = dst;
 570                }
 571
 572                if (unlikely(!uh->check))
 573                        uh->check = CSUM_MANGLED_0;
 574        } else {
 575                uh->source = src;
 576                uh->dest = dst;
 577                flow_key->tp.src = src;
 578                flow_key->tp.dst = dst;
 579        }
 580
 581        skb_clear_hash(skb);
 582
 583        return 0;
 584}
 585
 586static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 587                   const struct ovs_key_tcp *key,
 588                   const struct ovs_key_tcp *mask)
 589{
 590        struct tcphdr *th;
 591        __be16 src, dst;
 592        int err;
 593
 594        err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 595                                  sizeof(struct tcphdr));
 596        if (unlikely(err))
 597                return err;
 598
 599        th = tcp_hdr(skb);
 600        src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
 601        if (likely(src != th->source)) {
 602                set_tp_port(skb, &th->source, src, &th->check);
 603                flow_key->tp.src = src;
 604        }
 605        dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
 606        if (likely(dst != th->dest)) {
 607                set_tp_port(skb, &th->dest, dst, &th->check);
 608                flow_key->tp.dst = dst;
 609        }
 610        skb_clear_hash(skb);
 611
 612        return 0;
 613}
 614
 615static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 616                    const struct ovs_key_sctp *key,
 617                    const struct ovs_key_sctp *mask)
 618{
 619        unsigned int sctphoff = skb_transport_offset(skb);
 620        struct sctphdr *sh;
 621        __le32 old_correct_csum, new_csum, old_csum;
 622        int err;
 623
 624        err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 625        if (unlikely(err))
 626                return err;
 627
 628        sh = sctp_hdr(skb);
 629        old_csum = sh->checksum;
 630        old_correct_csum = sctp_compute_cksum(skb, sctphoff);
 631
 632        sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
 633        sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
 634
 635        new_csum = sctp_compute_cksum(skb, sctphoff);
 636
 637        /* Carry any checksum errors through. */
 638        sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 639
 640        skb_clear_hash(skb);
 641        flow_key->tp.src = sh->source;
 642        flow_key->tp.dst = sh->dest;
 643
 644        return 0;
 645}
 646
 647static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 648{
 649        struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
 650        struct vport *vport = data->vport;
 651
 652        if (skb_cow_head(skb, data->l2_len) < 0) {
 653                kfree_skb(skb);
 654                return -ENOMEM;
 655        }
 656
 657        __skb_dst_copy(skb, data->dst);
 658        *OVS_CB(skb) = data->cb;
 659        skb->inner_protocol = data->inner_protocol;
 660        skb->vlan_tci = data->vlan_tci;
 661        skb->vlan_proto = data->vlan_proto;
 662
 663        /* Reconstruct the MAC header.  */
 664        skb_push(skb, data->l2_len);
 665        memcpy(skb->data, &data->l2_data, data->l2_len);
 666        skb_postpush_rcsum(skb, skb->data, data->l2_len);
 667        skb_reset_mac_header(skb);
 668
 669        ovs_vport_send(vport, skb);
 670        return 0;
 671}
 672
 673static unsigned int
 674ovs_dst_get_mtu(const struct dst_entry *dst)
 675{
 676        return dst->dev->mtu;
 677}
 678
 679static struct dst_ops ovs_dst_ops = {
 680        .family = AF_UNSPEC,
 681        .mtu = ovs_dst_get_mtu,
 682};
 683
 684/* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
 685 * ovs_vport_output(), which is called once per fragmented packet.
 686 */
 687static void prepare_frag(struct vport *vport, struct sk_buff *skb)
 688{
 689        unsigned int hlen = skb_network_offset(skb);
 690        struct ovs_frag_data *data;
 691
 692        data = this_cpu_ptr(&ovs_frag_data_storage);
 693        data->dst = skb->_skb_refdst;
 694        data->vport = vport;
 695        data->cb = *OVS_CB(skb);
 696        data->inner_protocol = skb->inner_protocol;
 697        data->vlan_tci = skb->vlan_tci;
 698        data->vlan_proto = skb->vlan_proto;
 699        data->l2_len = hlen;
 700        memcpy(&data->l2_data, skb->data, hlen);
 701
 702        memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 703        skb_pull(skb, hlen);
 704}
 705
 706static void ovs_fragment(struct net *net, struct vport *vport,
 707                         struct sk_buff *skb, u16 mru, __be16 ethertype)
 708{
 709        if (skb_network_offset(skb) > MAX_L2_LEN) {
 710                OVS_NLERR(1, "L2 header too long to fragment");
 711                goto err;
 712        }
 713
 714        if (ethertype == htons(ETH_P_IP)) {
 715                struct dst_entry ovs_dst;
 716                unsigned long orig_dst;
 717
 718                prepare_frag(vport, skb);
 719                dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
 720                         DST_OBSOLETE_NONE, DST_NOCOUNT);
 721                ovs_dst.dev = vport->dev;
 722
 723                orig_dst = skb->_skb_refdst;
 724                skb_dst_set_noref(skb, &ovs_dst);
 725                IPCB(skb)->frag_max_size = mru;
 726
 727                ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
 728                refdst_drop(orig_dst);
 729        } else if (ethertype == htons(ETH_P_IPV6)) {
 730                const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
 731                unsigned long orig_dst;
 732                struct rt6_info ovs_rt;
 733
 734                if (!v6ops) {
 735                        goto err;
 736                }
 737
 738                prepare_frag(vport, skb);
 739                memset(&ovs_rt, 0, sizeof(ovs_rt));
 740                dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
 741                         DST_OBSOLETE_NONE, DST_NOCOUNT);
 742                ovs_rt.dst.dev = vport->dev;
 743
 744                orig_dst = skb->_skb_refdst;
 745                skb_dst_set_noref(skb, &ovs_rt.dst);
 746                IP6CB(skb)->frag_max_size = mru;
 747
 748                v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
 749                refdst_drop(orig_dst);
 750        } else {
 751                WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
 752                          ovs_vport_name(vport), ntohs(ethertype), mru,
 753                          vport->dev->mtu);
 754                goto err;
 755        }
 756
 757        return;
 758err:
 759        kfree_skb(skb);
 760}
 761
 762static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
 763                      struct sw_flow_key *key)
 764{
 765        struct vport *vport = ovs_vport_rcu(dp, out_port);
 766
 767        if (likely(vport)) {
 768                u16 mru = OVS_CB(skb)->mru;
 769                u32 cutlen = OVS_CB(skb)->cutlen;
 770
 771                if (unlikely(cutlen > 0)) {
 772                        if (skb->len - cutlen > ETH_HLEN)
 773                                pskb_trim(skb, skb->len - cutlen);
 774                        else
 775                                pskb_trim(skb, ETH_HLEN);
 776                }
 777
 778                if (likely(!mru || (skb->len <= mru + ETH_HLEN))) {
 779                        ovs_vport_send(vport, skb);
 780                } else if (mru <= vport->dev->mtu) {
 781                        struct net *net = read_pnet(&dp->net);
 782                        __be16 ethertype = key->eth.type;
 783
 784                        if (!is_flow_key_valid(key)) {
 785                                if (eth_p_mpls(skb->protocol))
 786                                        ethertype = skb->inner_protocol;
 787                                else
 788                                        ethertype = vlan_get_protocol(skb);
 789                        }
 790
 791                        ovs_fragment(net, vport, skb, mru, ethertype);
 792                } else {
 793                        kfree_skb(skb);
 794                }
 795        } else {
 796                kfree_skb(skb);
 797        }
 798}
 799
 800static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 801                            struct sw_flow_key *key, const struct nlattr *attr,
 802                            const struct nlattr *actions, int actions_len,
 803                            uint32_t cutlen)
 804{
 805        struct dp_upcall_info upcall;
 806        const struct nlattr *a;
 807        int rem;
 808
 809        memset(&upcall, 0, sizeof(upcall));
 810        upcall.cmd = OVS_PACKET_CMD_ACTION;
 811        upcall.mru = OVS_CB(skb)->mru;
 812
 813        for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 814                 a = nla_next(a, &rem)) {
 815                switch (nla_type(a)) {
 816                case OVS_USERSPACE_ATTR_USERDATA:
 817                        upcall.userdata = a;
 818                        break;
 819
 820                case OVS_USERSPACE_ATTR_PID:
 821                        upcall.portid = nla_get_u32(a);
 822                        break;
 823
 824                case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 825                        /* Get out tunnel info. */
 826                        struct vport *vport;
 827
 828                        vport = ovs_vport_rcu(dp, nla_get_u32(a));
 829                        if (vport) {
 830                                int err;
 831
 832                                err = dev_fill_metadata_dst(vport->dev, skb);
 833                                if (!err)
 834                                        upcall.egress_tun_info = skb_tunnel_info(skb);
 835                        }
 836
 837                        break;
 838                }
 839
 840                case OVS_USERSPACE_ATTR_ACTIONS: {
 841                        /* Include actions. */
 842                        upcall.actions = actions;
 843                        upcall.actions_len = actions_len;
 844                        break;
 845                }
 846
 847                } /* End of switch. */
 848        }
 849
 850        return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
 851}
 852
 853static int sample(struct datapath *dp, struct sk_buff *skb,
 854                  struct sw_flow_key *key, const struct nlattr *attr,
 855                  const struct nlattr *actions, int actions_len)
 856{
 857        const struct nlattr *acts_list = NULL;
 858        const struct nlattr *a;
 859        int rem;
 860        u32 cutlen = 0;
 861
 862        for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 863                 a = nla_next(a, &rem)) {
 864                u32 probability;
 865
 866                switch (nla_type(a)) {
 867                case OVS_SAMPLE_ATTR_PROBABILITY:
 868                        probability = nla_get_u32(a);
 869                        if (!probability || prandom_u32() > probability)
 870                                return 0;
 871                        break;
 872
 873                case OVS_SAMPLE_ATTR_ACTIONS:
 874                        acts_list = a;
 875                        break;
 876                }
 877        }
 878
 879        rem = nla_len(acts_list);
 880        a = nla_data(acts_list);
 881
 882        /* Actions list is empty, do nothing */
 883        if (unlikely(!rem))
 884                return 0;
 885
 886        /* The only known usage of sample action is having a single user-space
 887         * action, or having a truncate action followed by a single user-space
 888         * action. Treat this usage as a special case.
 889         * The output_userspace() should clone the skb to be sent to the
 890         * user space. This skb will be consumed by its caller.
 891         */
 892        if (unlikely(nla_type(a) == OVS_ACTION_ATTR_TRUNC)) {
 893                struct ovs_action_trunc *trunc = nla_data(a);
 894
 895                if (skb->len > trunc->max_len)
 896                        cutlen = skb->len - trunc->max_len;
 897
 898                a = nla_next(a, &rem);
 899        }
 900
 901        if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE &&
 902                   nla_is_last(a, rem)))
 903                return output_userspace(dp, skb, key, a, actions,
 904                                        actions_len, cutlen);
 905
 906        skb = skb_clone(skb, GFP_ATOMIC);
 907        if (!skb)
 908                /* Skip the sample action when out of memory. */
 909                return 0;
 910
 911        if (!add_deferred_actions(skb, key, a)) {
 912                if (net_ratelimit())
 913                        pr_warn("%s: deferred actions limit reached, dropping sample action\n",
 914                                ovs_dp_name(dp));
 915
 916                kfree_skb(skb);
 917        }
 918        return 0;
 919}
 920
 921static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
 922                         const struct nlattr *attr)
 923{
 924        struct ovs_action_hash *hash_act = nla_data(attr);
 925        u32 hash = 0;
 926
 927        /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
 928        hash = skb_get_hash(skb);
 929        hash = jhash_1word(hash, hash_act->hash_basis);
 930        if (!hash)
 931                hash = 0x1;
 932
 933        key->ovs_flow_hash = hash;
 934}
 935
 936static int execute_set_action(struct sk_buff *skb,
 937                              struct sw_flow_key *flow_key,
 938                              const struct nlattr *a)
 939{
 940        /* Only tunnel set execution is supported without a mask. */
 941        if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
 942                struct ovs_tunnel_info *tun = nla_data(a);
 943
 944                skb_dst_drop(skb);
 945                dst_hold((struct dst_entry *)tun->tun_dst);
 946                skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
 947                return 0;
 948        }
 949
 950        return -EINVAL;
 951}
 952
 953/* Mask is at the midpoint of the data. */
 954#define get_mask(a, type) ((const type)nla_data(a) + 1)
 955
 956static int execute_masked_set_action(struct sk_buff *skb,
 957                                     struct sw_flow_key *flow_key,
 958                                     const struct nlattr *a)
 959{
 960        int err = 0;
 961
 962        switch (nla_type(a)) {
 963        case OVS_KEY_ATTR_PRIORITY:
 964                OVS_SET_MASKED(skb->priority, nla_get_u32(a),
 965                               *get_mask(a, u32 *));
 966                flow_key->phy.priority = skb->priority;
 967                break;
 968
 969        case OVS_KEY_ATTR_SKB_MARK:
 970                OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
 971                flow_key->phy.skb_mark = skb->mark;
 972                break;
 973
 974        case OVS_KEY_ATTR_TUNNEL_INFO:
 975                /* Masked data not supported for tunnel. */
 976                err = -EINVAL;
 977                break;
 978
 979        case OVS_KEY_ATTR_ETHERNET:
 980                err = set_eth_addr(skb, flow_key, nla_data(a),
 981                                   get_mask(a, struct ovs_key_ethernet *));
 982                break;
 983
 984        case OVS_KEY_ATTR_IPV4:
 985                err = set_ipv4(skb, flow_key, nla_data(a),
 986                               get_mask(a, struct ovs_key_ipv4 *));
 987                break;
 988
 989        case OVS_KEY_ATTR_IPV6:
 990                err = set_ipv6(skb, flow_key, nla_data(a),
 991                               get_mask(a, struct ovs_key_ipv6 *));
 992                break;
 993
 994        case OVS_KEY_ATTR_TCP:
 995                err = set_tcp(skb, flow_key, nla_data(a),
 996                              get_mask(a, struct ovs_key_tcp *));
 997                break;
 998
 999        case OVS_KEY_ATTR_UDP:
1000                err = set_udp(skb, flow_key, nla_data(a),
1001                              get_mask(a, struct ovs_key_udp *));
1002                break;
1003
1004        case OVS_KEY_ATTR_SCTP:
1005                err = set_sctp(skb, flow_key, nla_data(a),
1006                               get_mask(a, struct ovs_key_sctp *));
1007                break;
1008
1009        case OVS_KEY_ATTR_MPLS:
1010                err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1011                                                                    __be32 *));
1012                break;
1013
1014        case OVS_KEY_ATTR_CT_STATE:
1015        case OVS_KEY_ATTR_CT_ZONE:
1016        case OVS_KEY_ATTR_CT_MARK:
1017        case OVS_KEY_ATTR_CT_LABELS:
1018                err = -EINVAL;
1019                break;
1020        }
1021
1022        return err;
1023}
1024
1025static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1026                          struct sw_flow_key *key,
1027                          const struct nlattr *a, int rem)
1028{
1029        struct deferred_action *da;
1030        int level;
1031
1032        if (!is_flow_key_valid(key)) {
1033                int err;
1034
1035                err = ovs_flow_key_update(skb, key);
1036                if (err)
1037                        return err;
1038        }
1039        BUG_ON(!is_flow_key_valid(key));
1040
1041        if (!nla_is_last(a, rem)) {
1042                /* Recirc action is the not the last action
1043                 * of the action list, need to clone the skb.
1044                 */
1045                skb = skb_clone(skb, GFP_ATOMIC);
1046
1047                /* Skip the recirc action when out of memory, but
1048                 * continue on with the rest of the action list.
1049                 */
1050                if (!skb)
1051                        return 0;
1052        }
1053
1054        level = this_cpu_read(exec_actions_level);
1055        if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
1056                struct recirc_keys *rks = this_cpu_ptr(recirc_keys);
1057                struct sw_flow_key *recirc_key = &rks->key[level - 1];
1058
1059                *recirc_key = *key;
1060                recirc_key->recirc_id = nla_get_u32(a);
1061                ovs_dp_process_packet(skb, recirc_key);
1062
1063                return 0;
1064        }
1065
1066        da = add_deferred_actions(skb, key, NULL);
1067        if (da) {
1068                da->pkt_key.recirc_id = nla_get_u32(a);
1069        } else {
1070                kfree_skb(skb);
1071
1072                if (net_ratelimit())
1073                        pr_warn("%s: deferred action limit reached, drop recirc action\n",
1074                                ovs_dp_name(dp));
1075        }
1076
1077        return 0;
1078}
1079
1080/* Execute a list of actions against 'skb'. */
1081static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1082                              struct sw_flow_key *key,
1083                              const struct nlattr *attr, int len)
1084{
1085        /* Every output action needs a separate clone of 'skb', but the common
1086         * case is just a single output action, so that doing a clone and
1087         * then freeing the original skbuff is wasteful.  So the following code
1088         * is slightly obscure just to avoid that.
1089         */
1090        int prev_port = -1;
1091        const struct nlattr *a;
1092        int rem;
1093
1094        for (a = attr, rem = len; rem > 0;
1095             a = nla_next(a, &rem)) {
1096                int err = 0;
1097
1098                if (unlikely(prev_port != -1)) {
1099                        struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC);
1100
1101                        if (out_skb)
1102                                do_output(dp, out_skb, prev_port, key);
1103
1104                        OVS_CB(skb)->cutlen = 0;
1105                        prev_port = -1;
1106                }
1107
1108                switch (nla_type(a)) {
1109                case OVS_ACTION_ATTR_OUTPUT:
1110                        prev_port = nla_get_u32(a);
1111                        break;
1112
1113                case OVS_ACTION_ATTR_TRUNC: {
1114                        struct ovs_action_trunc *trunc = nla_data(a);
1115
1116                        if (skb->len > trunc->max_len)
1117                                OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1118                        break;
1119                }
1120
1121                case OVS_ACTION_ATTR_USERSPACE:
1122                        output_userspace(dp, skb, key, a, attr,
1123                                                     len, OVS_CB(skb)->cutlen);
1124                        OVS_CB(skb)->cutlen = 0;
1125                        break;
1126
1127                case OVS_ACTION_ATTR_HASH:
1128                        execute_hash(skb, key, a);
1129                        break;
1130
1131                case OVS_ACTION_ATTR_PUSH_MPLS:
1132                        err = push_mpls(skb, key, nla_data(a));
1133                        break;
1134
1135                case OVS_ACTION_ATTR_POP_MPLS:
1136                        err = pop_mpls(skb, key, nla_get_be16(a));
1137                        break;
1138
1139                case OVS_ACTION_ATTR_PUSH_VLAN:
1140                        err = push_vlan(skb, key, nla_data(a));
1141                        break;
1142
1143                case OVS_ACTION_ATTR_POP_VLAN:
1144                        err = pop_vlan(skb, key);
1145                        break;
1146
1147                case OVS_ACTION_ATTR_RECIRC:
1148                        err = execute_recirc(dp, skb, key, a, rem);
1149                        if (nla_is_last(a, rem)) {
1150                                /* If this is the last action, the skb has
1151                                 * been consumed or freed.
1152                                 * Return immediately.
1153                                 */
1154                                return err;
1155                        }
1156                        break;
1157
1158                case OVS_ACTION_ATTR_SET:
1159                        err = execute_set_action(skb, key, nla_data(a));
1160                        break;
1161
1162                case OVS_ACTION_ATTR_SET_MASKED:
1163                case OVS_ACTION_ATTR_SET_TO_MASKED:
1164                        err = execute_masked_set_action(skb, key, nla_data(a));
1165                        break;
1166
1167                case OVS_ACTION_ATTR_SAMPLE:
1168                        err = sample(dp, skb, key, a, attr, len);
1169                        break;
1170
1171                case OVS_ACTION_ATTR_CT:
1172                        if (!is_flow_key_valid(key)) {
1173                                err = ovs_flow_key_update(skb, key);
1174                                if (err)
1175                                        return err;
1176                        }
1177
1178                        err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1179                                             nla_data(a));
1180
1181                        /* Hide stolen IP fragments from user space. */
1182                        if (err)
1183                                return err == -EINPROGRESS ? 0 : err;
1184                        break;
1185                }
1186
1187                if (unlikely(err)) {
1188                        kfree_skb(skb);
1189                        return err;
1190                }
1191        }
1192
1193        if (prev_port != -1)
1194                do_output(dp, skb, prev_port, key);
1195        else
1196                consume_skb(skb);
1197
1198        return 0;
1199}
1200
1201static void process_deferred_actions(struct datapath *dp)
1202{
1203        struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1204
1205        /* Do not touch the FIFO in case there is no deferred actions. */
1206        if (action_fifo_is_empty(fifo))
1207                return;
1208
1209        /* Finishing executing all deferred actions. */
1210        do {
1211                struct deferred_action *da = action_fifo_get(fifo);
1212                struct sk_buff *skb = da->skb;
1213                struct sw_flow_key *key = &da->pkt_key;
1214                const struct nlattr *actions = da->actions;
1215
1216                if (actions)
1217                        do_execute_actions(dp, skb, key, actions,
1218                                           nla_len(actions));
1219                else
1220                        ovs_dp_process_packet(skb, key);
1221        } while (!action_fifo_is_empty(fifo));
1222
1223        /* Reset FIFO for the next packet.  */
1224        action_fifo_init(fifo);
1225}
1226
1227/* Execute a list of actions against 'skb'. */
1228int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1229                        const struct sw_flow_actions *acts,
1230                        struct sw_flow_key *key)
1231{
1232        int err, level;
1233
1234        level = __this_cpu_inc_return(exec_actions_level);
1235        if (unlikely(level > OVS_RECURSION_LIMIT)) {
1236                net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1237                                     ovs_dp_name(dp));
1238                kfree_skb(skb);
1239                err = -ENETDOWN;
1240                goto out;
1241        }
1242
1243        err = do_execute_actions(dp, skb, key,
1244                                 acts->actions, acts->actions_len);
1245
1246        if (level == 1)
1247                process_deferred_actions(dp);
1248
1249out:
1250        __this_cpu_dec(exec_actions_level);
1251        return err;
1252}
1253
1254int action_fifos_init(void)
1255{
1256        action_fifos = alloc_percpu(struct action_fifo);
1257        if (!action_fifos)
1258                return -ENOMEM;
1259
1260        recirc_keys = alloc_percpu(struct recirc_keys);
1261        if (!recirc_keys) {
1262                free_percpu(action_fifos);
1263                return -ENOMEM;
1264        }
1265
1266        return 0;
1267}
1268
1269void action_fifos_exit(void)
1270{
1271        free_percpu(action_fifos);
1272        free_percpu(recirc_keys);
1273}
1274