net/openvswitch/actions.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2007-2017 Nicira, Inc.
   4  */
   5
   6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8 #include <linux/skbuff.h>
   9 #include <linux/in.h>
  10 #include <linux/ip.h>
  11 #include <linux/openvswitch.h>
  12 #include <linux/sctp.h>
  13 #include <linux/tcp.h>
  14 #include <linux/udp.h>
  15 #include <linux/in6.h>
  16 #include <linux/if_arp.h>
  17 #include <linux/if_vlan.h>
  18
  19 #include <net/dst.h>
  20 #include <net/ip.h>
  21 #include <net/ipv6.h>
  22 #include <net/ip6_fib.h>
  23 #include <net/checksum.h>
  24 #include <net/dsfield.h>
  25 #include <net/mpls.h>
  26 #include <net/sctp/checksum.h>
  27
  28 #include "datapath.h"
  29 #include "flow.h"
  30 #include "conntrack.h"
  31 #include "vport.h"
  32 #include "flow_netlink.h"
  33 #include "openvswitch_trace.h"
  34
  35 struct deferred_action {
  36         struct sk_buff *skb;
  37         const struct nlattr *actions;
  38         int actions_len;
  39
  40         /* Store pkt_key clone when creating deferred action. */
  41         struct sw_flow_key pkt_key;
  42 };
  43
  44 #define MAX_L2_LEN      (VLAN_ETH_HLEN + 3 * MPLS_HLEN)
  45 struct ovs_frag_data {
  46         unsigned long dst;
  47         struct vport *vport;
  48         struct ovs_skb_cb cb;
  49         __be16 inner_protocol;
  50         u16 network_offset;     /* valid only for MPLS */
  51         u16 vlan_tci;
  52         __be16 vlan_proto;
  53         unsigned int l2_len;
  54         u8 mac_proto;
  55         u8 l2_data[MAX_L2_LEN];
  56 };
  57
  58 static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
  59
  60 #define DEFERRED_ACTION_FIFO_SIZE 10
  61 #define OVS_RECURSION_LIMIT 5
  62 #define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
  63 struct action_fifo {
  64         int head;
  65         int tail;
  66         /* Deferred action fifo queue storage. */
  67         struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
  68 };
  69
  70 struct action_flow_keys {
  71         struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
  72 };
  73
  74 static struct action_fifo __percpu *action_fifos;
  75 static struct action_flow_keys __percpu *flow_keys;
  76 static DEFINE_PER_CPU(int, exec_actions_level);
  77
  78 /* Make a clone of the 'key', using the pre-allocated percpu 'flow_keys'
  79  * space. Return NULL if out of key spaces.
  80  */
  81 static struct sw_flow_key *clone_key(const struct sw_flow_key *key_)
  82 {
  83         struct action_flow_keys *keys = this_cpu_ptr(flow_keys);
  84         int level = this_cpu_read(exec_actions_level);
  85         struct sw_flow_key *key = NULL;
  86
  87         if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
  88                 key = &keys->key[level - 1];
  89                 *key = *key_;
  90         }
  91
  92         return key;
  93 }
  94
  95 static void action_fifo_init(struct action_fifo *fifo)
  96 {
  97         fifo->head = 0;
  98         fifo->tail = 0;
  99 }
 100
 101 static bool action_fifo_is_empty(const struct action_fifo *fifo)
 102 {
 103         return (fifo->head == fifo->tail);
 104 }
 105
 106 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
 107 {
 108         if (action_fifo_is_empty(fifo))
 109                 return NULL;
 110
 111         return &fifo->fifo[fifo->tail++];
 112 }
 113
 114 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
 115 {
 116         if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
 117                 return NULL;
 118
 119         return &fifo->fifo[fifo->head++];
 120 }
 121
 122 /* Return true if fifo is not full */
 123 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
 124                                     const struct sw_flow_key *key,
 125                                     const struct nlattr *actions,
 126                                     const int actions_len)
 127 {
 128         struct action_fifo *fifo;
 129         struct deferred_action *da;
 130
 131         fifo = this_cpu_ptr(action_fifos);
 132         da = action_fifo_put(fifo);
 133         if (da) {
 134                 da->skb = skb;
 135                 da->actions = actions;
 136                 da->actions_len = actions_len;
 137                 da->pkt_key = *key;
 138         }
 139
 140         return da;
 141 }
 142
 143 static void invalidate_flow_key(struct sw_flow_key *key)
 144 {
 145         key->mac_proto |= SW_FLOW_KEY_INVALID;
 146 }
 147
 148 static bool is_flow_key_valid(const struct sw_flow_key *key)
 149 {
 150         return !(key->mac_proto & SW_FLOW_KEY_INVALID);
 151 }
 152
 153 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
 154                          struct sw_flow_key *key,
 155                          u32 recirc_id,
 156                          const struct nlattr *actions, int len,
 157                          bool last, bool clone_flow_key);
 158
 159 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 160                               struct sw_flow_key *key,
 161                               const struct nlattr *attr, int len);
 162
 163 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 164                      __be32 mpls_lse, __be16 mpls_ethertype, __u16 mac_len)
 165 {
 166         int err;
 167
 168         err = skb_mpls_push(skb, mpls_lse, mpls_ethertype, mac_len, !!mac_len);
 169         if (err)
 170                 return err;
 171
 172         if (!mac_len)
 173                 key->mac_proto = MAC_PROTO_NONE;
 174
 175         invalidate_flow_key(key);
 176         return 0;
 177 }
 178
 179 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 180                     const __be16 ethertype)
 181 {
 182         int err;
 183
 184         err = skb_mpls_pop(skb, ethertype, skb->mac_len,
 185                            ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET);
 186         if (err)
 187                 return err;
 188
 189         if (ethertype == htons(ETH_P_TEB))
 190                 key->mac_proto = MAC_PROTO_ETHERNET;
 191
 192         invalidate_flow_key(key);
 193         return 0;
 194 }
 195
 196 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
 197                     const __be32 *mpls_lse, const __be32 *mask)
 198 {
 199         struct mpls_shim_hdr *stack;
 200         __be32 lse;
 201         int err;
 202
 203         if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN))
 204                 return -ENOMEM;
 205
 206         stack = mpls_hdr(skb);
 207         lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
 208         err = skb_mpls_update_lse(skb, lse);
 209         if (err)
 210                 return err;
 211
 212         flow_key->mpls.lse[0] = lse;
 213         return 0;
 214 }
 215
 216 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 217 {
 218         int err;
 219
 220         err = skb_vlan_pop(skb);
 221         if (skb_vlan_tag_present(skb)) {
 222                 invalidate_flow_key(key);
 223         } else {
 224                 key->eth.vlan.tci = 0;
 225                 key->eth.vlan.tpid = 0;
 226         }
 227         return err;
 228 }
 229
 230 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 231                      const struct ovs_action_push_vlan *vlan)
 232 {
 233         if (skb_vlan_tag_present(skb)) {
 234                 invalidate_flow_key(key);
 235         } else {
 236                 key->eth.vlan.tci = vlan->vlan_tci;
 237                 key->eth.vlan.tpid = vlan->vlan_tpid;
 238         }
 239         return skb_vlan_push(skb, vlan->vlan_tpid,
 240                              ntohs(vlan->vlan_tci) & ~VLAN_CFI_MASK);
 241 }
 242
 243 /* 'src' is already properly masked. */
 244 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
 245 {
 246         u16 *dst = (u16 *)dst_;
 247         const u16 *src = (const u16 *)src_;
 248         const u16 *mask = (const u16 *)mask_;
 249
 250         OVS_SET_MASKED(dst[0], src[0], mask[0]);
 251         OVS_SET_MASKED(dst[1], src[1], mask[1]);
 252         OVS_SET_MASKED(dst[2], src[2], mask[2]);
 253 }
 254
 255 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
 256                         const struct ovs_key_ethernet *key,
 257                         const struct ovs_key_ethernet *mask)
 258 {
 259         int err;
 260
 261         err = skb_ensure_writable(skb, ETH_HLEN);
 262         if (unlikely(err))
 263                 return err;
 264
 265         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 266
 267         ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
 268                                mask->eth_src);
 269         ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
 270                                mask->eth_dst);
 271
 272         skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 273
 274         ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
 275         ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
 276         return 0;
 277 }
 278
 279 /* pop_eth does not support VLAN packets as this action is never called
 280  * for them.
 281  */
 282 static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
 283 {
 284         int err;
 285
 286         err = skb_eth_pop(skb);
 287         if (err)
 288                 return err;
 289
 290         /* safe right before invalidate_flow_key */
 291         key->mac_proto = MAC_PROTO_NONE;
 292         invalidate_flow_key(key);
 293         return 0;
 294 }
 295
 296 static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
 297                     const struct ovs_action_push_eth *ethh)
 298 {
 299         int err;
 300
 301         err = skb_eth_push(skb, ethh->addresses.eth_dst,
 302                            ethh->addresses.eth_src);
 303         if (err)
 304                 return err;
 305
 306         /* safe right before invalidate_flow_key */
 307         key->mac_proto = MAC_PROTO_ETHERNET;
 308         invalidate_flow_key(key);
 309         return 0;
 310 }
 311
 312 static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key,
 313                     const struct nshhdr *nh)
 314 {
 315         int err;
 316
 317         err = nsh_push(skb, nh);
 318         if (err)
 319                 return err;
 320
 321         /* safe right before invalidate_flow_key */
 322         key->mac_proto = MAC_PROTO_NONE;
 323         invalidate_flow_key(key);
 324         return 0;
 325 }
 326
 327 static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key)
 328 {
 329         int err;
 330
 331         err = nsh_pop(skb);
 332         if (err)
 333                 return err;
 334
 335         /* safe right before invalidate_flow_key */
 336         if (skb->protocol == htons(ETH_P_TEB))
 337                 key->mac_proto = MAC_PROTO_ETHERNET;
 338         else
 339                 key->mac_proto = MAC_PROTO_NONE;
 340         invalidate_flow_key(key);
 341         return 0;
 342 }
 343
 344 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
 345                                   __be32 addr, __be32 new_addr)
 346 {
 347         int transport_len = skb->len - skb_transport_offset(skb);
 348
 349         if (nh->frag_off & htons(IP_OFFSET))
 350                 return;
 351
 352         if (nh->protocol == IPPROTO_TCP) {
 353                 if (likely(transport_len >= sizeof(struct tcphdr)))
 354                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 355                                                  addr, new_addr, true);
 356         } else if (nh->protocol == IPPROTO_UDP) {
 357                 if (likely(transport_len >= sizeof(struct udphdr))) {
 358                         struct udphdr *uh = udp_hdr(skb);
 359
 360                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 361                                 inet_proto_csum_replace4(&uh->check, skb,
 362                                                          addr, new_addr, true);
 363                                 if (!uh->check)
 364                                         uh->check = CSUM_MANGLED_0;
 365                         }
 366                 }
 367         }
 368 }
 369
 370 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 371                         __be32 *addr, __be32 new_addr)
 372 {
 373         update_ip_l4_checksum(skb, nh, *addr, new_addr);
 374         csum_replace4(&nh->check, *addr, new_addr);
 375         skb_clear_hash(skb);
 376         *addr = new_addr;
 377 }
 378
 379 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 380                                  __be32 addr[4], const __be32 new_addr[4])
 381 {
 382         int transport_len = skb->len - skb_transport_offset(skb);
 383
 384         if (l4_proto == NEXTHDR_TCP) {
 385                 if (likely(transport_len >= sizeof(struct tcphdr)))
 386                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 387                                                   addr, new_addr, true);
 388         } else if (l4_proto == NEXTHDR_UDP) {
 389                 if (likely(transport_len >= sizeof(struct udphdr))) {
 390                         struct udphdr *uh = udp_hdr(skb);
 391
 392                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 393                                 inet_proto_csum_replace16(&uh->check, skb,
 394                                                           addr, new_addr, true);
 395                                 if (!uh->check)
 396                                         uh->check = CSUM_MANGLED_0;
 397                         }
 398                 }
 399         } else if (l4_proto == NEXTHDR_ICMP) {
 400                 if (likely(transport_len >= sizeof(struct icmp6hdr)))
 401                         inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 402                                                   skb, addr, new_addr, true);
 403         }
 404 }
 405
 406 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
 407                            const __be32 mask[4], __be32 masked[4])
 408 {
 409         masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
 410         masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
 411         masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
 412         masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
 413 }
 414
 415 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 416                           __be32 addr[4], const __be32 new_addr[4],
 417                           bool recalculate_csum)
 418 {
 419         if (recalculate_csum)
 420                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 421
 422         skb_clear_hash(skb);
 423         memcpy(addr, new_addr, sizeof(__be32[4]));
 424 }
 425
 426 static void set_ipv6_dsfield(struct sk_buff *skb, struct ipv6hdr *nh, u8 ipv6_tclass, u8 mask)
 427 {
 428         u8 old_ipv6_tclass = ipv6_get_dsfield(nh);
 429
 430         ipv6_tclass = OVS_MASKED(old_ipv6_tclass, ipv6_tclass, mask);
 431
 432         if (skb->ip_summed == CHECKSUM_COMPLETE)
 433                 csum_replace(&skb->csum, (__force __wsum)(old_ipv6_tclass << 12),
 434                              (__force __wsum)(ipv6_tclass << 12));
 435
 436         ipv6_change_dsfield(nh, ~mask, ipv6_tclass);
 437 }
 438
 439 static void set_ipv6_fl(struct sk_buff *skb, struct ipv6hdr *nh, u32 fl, u32 mask)
 440 {
 441         u32 ofl;
 442
 443         ofl = nh->flow_lbl[0] << 16 |  nh->flow_lbl[1] << 8 |  nh->flow_lbl[2];
 444         fl = OVS_MASKED(ofl, fl, mask);
 445
 446         /* Bits 21-24 are always unmasked, so this retains their values. */
 447         nh->flow_lbl[0] = (u8)(fl >> 16);
 448         nh->flow_lbl[1] = (u8)(fl >> 8);
 449         nh->flow_lbl[2] = (u8)fl;
 450
 451         if (skb->ip_summed == CHECKSUM_COMPLETE)
 452                 csum_replace(&skb->csum, (__force __wsum)htonl(ofl), (__force __wsum)htonl(fl));
 453 }
 454
 455 static void set_ipv6_ttl(struct sk_buff *skb, struct ipv6hdr *nh, u8 new_ttl, u8 mask)
 456 {
 457         new_ttl = OVS_MASKED(nh->hop_limit, new_ttl, mask);
 458
 459         if (skb->ip_summed == CHECKSUM_COMPLETE)
 460                 csum_replace(&skb->csum, (__force __wsum)(nh->hop_limit << 8),
 461                              (__force __wsum)(new_ttl << 8));
 462         nh->hop_limit = new_ttl;
 463 }
 464
 465 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
 466                        u8 mask)
 467 {
 468         new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
 469
 470         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 471         nh->ttl = new_ttl;
 472 }
 473
 474 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
 475                     const struct ovs_key_ipv4 *key,
 476                     const struct ovs_key_ipv4 *mask)
 477 {
 478         struct iphdr *nh;
 479         __be32 new_addr;
 480         int err;
 481
 482         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 483                                   sizeof(struct iphdr));
 484         if (unlikely(err))
 485                 return err;
 486
 487         nh = ip_hdr(skb);
 488
 489         /* Setting an IP addresses is typically only a side effect of
 490          * matching on them in the current userspace implementation, so it
 491          * makes sense to check if the value actually changed.
 492          */
 493         if (mask->ipv4_src) {
 494                 new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
 495
 496                 if (unlikely(new_addr != nh->saddr)) {
 497                         set_ip_addr(skb, nh, &nh->saddr, new_addr);
 498                         flow_key->ipv4.addr.src = new_addr;
 499                 }
 500         }
 501         if (mask->ipv4_dst) {
 502                 new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
 503
 504                 if (unlikely(new_addr != nh->daddr)) {
 505                         set_ip_addr(skb, nh, &nh->daddr, new_addr);
 506                         flow_key->ipv4.addr.dst = new_addr;
 507                 }
 508         }
 509         if (mask->ipv4_tos) {
 510                 ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
 511                 flow_key->ip.tos = nh->tos;
 512         }
 513         if (mask->ipv4_ttl) {
 514                 set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
 515                 flow_key->ip.ttl = nh->ttl;
 516         }
 517
 518         return 0;
 519 }
 520
 521 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
 522 {
 523         return !!(addr[0] | addr[1] | addr[2] | addr[3]);
 524 }
 525
 526 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
 527                     const struct ovs_key_ipv6 *key,
 528                     const struct ovs_key_ipv6 *mask)
 529 {
 530         struct ipv6hdr *nh;
 531         int err;
 532
 533         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 534                                   sizeof(struct ipv6hdr));
 535         if (unlikely(err))
 536                 return err;
 537
 538         nh = ipv6_hdr(skb);
 539
 540         /* Setting an IP addresses is typically only a side effect of
 541          * matching on them in the current userspace implementation, so it
 542          * makes sense to check if the value actually changed.
 543          */
 544         if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
 545                 __be32 *saddr = (__be32 *)&nh->saddr;
 546                 __be32 masked[4];
 547
 548                 mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
 549
 550                 if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
 551                         set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
 552                                       true);
 553                         memcpy(&flow_key->ipv6.addr.src, masked,
 554                                sizeof(flow_key->ipv6.addr.src));
 555                 }
 556         }
 557         if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
 558                 unsigned int offset = 0;
 559                 int flags = IP6_FH_F_SKIP_RH;
 560                 bool recalc_csum = true;
 561                 __be32 *daddr = (__be32 *)&nh->daddr;
 562                 __be32 masked[4];
 563
 564                 mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
 565
 566                 if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
 567                         if (ipv6_ext_hdr(nh->nexthdr))
 568                                 recalc_csum = (ipv6_find_hdr(skb, &offset,
 569                                                              NEXTHDR_ROUTING,
 570                                                              NULL, &flags)
 571                                                != NEXTHDR_ROUTING);
 572
 573                         set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
 574                                       recalc_csum);
 575                         memcpy(&flow_key->ipv6.addr.dst, masked,
 576                                sizeof(flow_key->ipv6.addr.dst));
 577                 }
 578         }
 579         if (mask->ipv6_tclass) {
 580                 set_ipv6_dsfield(skb, nh, key->ipv6_tclass, mask->ipv6_tclass);
 581                 flow_key->ip.tos = ipv6_get_dsfield(nh);
 582         }
 583         if (mask->ipv6_label) {
 584                 set_ipv6_fl(skb, nh, ntohl(key->ipv6_label),
 585                             ntohl(mask->ipv6_label));
 586                 flow_key->ipv6.label =
 587                     *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 588         }
 589         if (mask->ipv6_hlimit) {
 590                 set_ipv6_ttl(skb, nh, key->ipv6_hlimit, mask->ipv6_hlimit);
 591                 flow_key->ip.ttl = nh->hop_limit;
 592         }
 593         return 0;
 594 }
 595
 596 static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
 597                    const struct nlattr *a)
 598 {
 599         struct nshhdr *nh;
 600         size_t length;
 601         int err;
 602         u8 flags;
 603         u8 ttl;
 604         int i;
 605
 606         struct ovs_key_nsh key;
 607         struct ovs_key_nsh mask;
 608
 609         err = nsh_key_from_nlattr(a, &key, &mask);
 610         if (err)
 611                 return err;
 612
 613         /* Make sure the NSH base header is there */
 614         if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN))
 615                 return -ENOMEM;
 616
 617         nh = nsh_hdr(skb);
 618         length = nsh_hdr_len(nh);
 619
 620         /* Make sure the whole NSH header is there */
 621         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 622                                        length);
 623         if (unlikely(err))
 624                 return err;
 625
 626         nh = nsh_hdr(skb);
 627         skb_postpull_rcsum(skb, nh, length);
 628         flags = nsh_get_flags(nh);
 629         flags = OVS_MASKED(flags, key.base.flags, mask.base.flags);
 630         flow_key->nsh.base.flags = flags;
 631         ttl = nsh_get_ttl(nh);
 632         ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl);
 633         flow_key->nsh.base.ttl = ttl;
 634         nsh_set_flags_and_ttl(nh, flags, ttl);
 635         nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr,
 636                                   mask.base.path_hdr);
 637         flow_key->nsh.base.path_hdr = nh->path_hdr;
 638         switch (nh->mdtype) {
 639         case NSH_M_TYPE1:
 640                 for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) {
 641                         nh->md1.context[i] =
 642                             OVS_MASKED(nh->md1.context[i], key.context[i],
 643                                        mask.context[i]);
 644                 }
 645                 memcpy(flow_key->nsh.context, nh->md1.context,
 646                        sizeof(nh->md1.context));
 647                 break;
 648         case NSH_M_TYPE2:
 649                 memset(flow_key->nsh.context, 0,
 650                        sizeof(flow_key->nsh.context));
 651                 break;
 652         default:
 653                 return -EINVAL;
 654         }
 655         skb_postpush_rcsum(skb, nh, length);
 656         return 0;
 657 }
 658
 659 /* Must follow skb_ensure_writable() since that can move the skb data. */
 660 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 661                         __be16 new_port, __sum16 *check)
 662 {
 663         inet_proto_csum_replace2(check, skb, *port, new_port, false);
 664         *port = new_port;
 665 }
 666
 667 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 668                    const struct ovs_key_udp *key,
 669                    const struct ovs_key_udp *mask)
 670 {
 671         struct udphdr *uh;
 672         __be16 src, dst;
 673         int err;
 674
 675         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 676                                   sizeof(struct udphdr));
 677         if (unlikely(err))
 678                 return err;
 679
 680         uh = udp_hdr(skb);
 681         /* Either of the masks is non-zero, so do not bother checking them. */
 682         src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
 683         dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
 684
 685         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 686                 if (likely(src != uh->source)) {
 687                         set_tp_port(skb, &uh->source, src, &uh->check);
 688                         flow_key->tp.src = src;
 689                 }
 690                 if (likely(dst != uh->dest)) {
 691                         set_tp_port(skb, &uh->dest, dst, &uh->check);
 692                         flow_key->tp.dst = dst;
 693                 }
 694
 695                 if (unlikely(!uh->check))
 696                         uh->check = CSUM_MANGLED_0;
 697         } else {
 698                 uh->source = src;
 699                 uh->dest = dst;
 700                 flow_key->tp.src = src;
 701                 flow_key->tp.dst = dst;
 702         }
 703
 704         skb_clear_hash(skb);
 705
 706         return 0;
 707 }
 708
 709 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 710                    const struct ovs_key_tcp *key,
 711                    const struct ovs_key_tcp *mask)
 712 {
 713         struct tcphdr *th;
 714         __be16 src, dst;
 715         int err;
 716
 717         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 718                                   sizeof(struct tcphdr));
 719         if (unlikely(err))
 720                 return err;
 721
 722         th = tcp_hdr(skb);
 723         src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
 724         if (likely(src != th->source)) {
 725                 set_tp_port(skb, &th->source, src, &th->check);
 726                 flow_key->tp.src = src;
 727         }
 728         dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
 729         if (likely(dst != th->dest)) {
 730                 set_tp_port(skb, &th->dest, dst, &th->check);
 731                 flow_key->tp.dst = dst;
 732         }
 733         skb_clear_hash(skb);
 734
 735         return 0;
 736 }
 737
 738 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 739                     const struct ovs_key_sctp *key,
 740                     const struct ovs_key_sctp *mask)
 741 {
 742         unsigned int sctphoff = skb_transport_offset(skb);
 743         struct sctphdr *sh;
 744         __le32 old_correct_csum, new_csum, old_csum;
 745         int err;
 746
 747         err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 748         if (unlikely(err))
 749                 return err;
 750
 751         sh = sctp_hdr(skb);
 752         old_csum = sh->checksum;
 753         old_correct_csum = sctp_compute_cksum(skb, sctphoff);
 754
 755         sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
 756         sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
 757
 758         new_csum = sctp_compute_cksum(skb, sctphoff);
 759
 760         /* Carry any checksum errors through. */
 761         sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 762
 763         skb_clear_hash(skb);
 764         flow_key->tp.src = sh->source;
 765         flow_key->tp.dst = sh->dest;
 766
 767         return 0;
 768 }
 769
 770 static int ovs_vport_output(struct net *net, struct sock *sk,
 771                             struct sk_buff *skb)
 772 {
 773         struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
 774         struct vport *vport = data->vport;
 775
 776         if (skb_cow_head(skb, data->l2_len) < 0) {
 777                 kfree_skb(skb);
 778                 return -ENOMEM;
 779         }
 780
 781         __skb_dst_copy(skb, data->dst);
 782         *OVS_CB(skb) = data->cb;
 783         skb->inner_protocol = data->inner_protocol;
 784         if (data->vlan_tci & VLAN_CFI_MASK)
 785                 __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci & ~VLAN_CFI_MASK);
 786         else
 787                 __vlan_hwaccel_clear_tag(skb);
 788
 789         /* Reconstruct the MAC header.  */
 790         skb_push(skb, data->l2_len);
 791         memcpy(skb->data, &data->l2_data, data->l2_len);
 792         skb_postpush_rcsum(skb, skb->data, data->l2_len);
 793         skb_reset_mac_header(skb);
 794
 795         if (eth_p_mpls(skb->protocol)) {
 796                 skb->inner_network_header = skb->network_header;
 797                 skb_set_network_header(skb, data->network_offset);
 798                 skb_reset_mac_len(skb);
 799         }
 800
 801         ovs_vport_send(vport, skb, data->mac_proto);
 802         return 0;
 803 }
 804
 805 static unsigned int
 806 ovs_dst_get_mtu(const struct dst_entry *dst)
 807 {
 808         return dst->dev->mtu;
 809 }
 810
 811 static struct dst_ops ovs_dst_ops = {
 812         .family = AF_UNSPEC,
 813         .mtu = ovs_dst_get_mtu,
 814 };
 815
 816 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
 817  * ovs_vport_output(), which is called once per fragmented packet.
 818  */
 819 static void prepare_frag(struct vport *vport, struct sk_buff *skb,
 820                          u16 orig_network_offset, u8 mac_proto)
 821 {
 822         unsigned int hlen = skb_network_offset(skb);
 823         struct ovs_frag_data *data;
 824
 825         data = this_cpu_ptr(&ovs_frag_data_storage);
 826         data->dst = skb->_skb_refdst;
 827         data->vport = vport;
 828         data->cb = *OVS_CB(skb);
 829         data->inner_protocol = skb->inner_protocol;
 830         data->network_offset = orig_network_offset;
 831         if (skb_vlan_tag_present(skb))
 832                 data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
 833         else
 834                 data->vlan_tci = 0;
 835         data->vlan_proto = skb->vlan_proto;
 836         data->mac_proto = mac_proto;
 837         data->l2_len = hlen;
 838         memcpy(&data->l2_data, skb->data, hlen);
 839
 840         memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 841         skb_pull(skb, hlen);
 842 }
 843
 844 static void ovs_fragment(struct net *net, struct vport *vport,
 845                          struct sk_buff *skb, u16 mru,
 846                          struct sw_flow_key *key)
 847 {
 848         u16 orig_network_offset = 0;
 849
 850         if (eth_p_mpls(skb->protocol)) {
 851                 orig_network_offset = skb_network_offset(skb);
 852                 skb->network_header = skb->inner_network_header;
 853         }
 854
 855         if (skb_network_offset(skb) > MAX_L2_LEN) {
 856                 OVS_NLERR(1, "L2 header too long to fragment");
 857                 goto err;
 858         }
 859
 860         if (key->eth.type == htons(ETH_P_IP)) {
 861                 struct rtable ovs_rt = { 0 };
 862                 unsigned long orig_dst;
 863
 864                 prepare_frag(vport, skb, orig_network_offset,
 865                              ovs_key_mac_proto(key));
 866                 dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
 867                          DST_OBSOLETE_NONE, DST_NOCOUNT);
 868                 ovs_rt.dst.dev = vport->dev;
 869
 870                 orig_dst = skb->_skb_refdst;
 871                 skb_dst_set_noref(skb, &ovs_rt.dst);
 872                 IPCB(skb)->frag_max_size = mru;
 873
 874                 ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
 875                 refdst_drop(orig_dst);
 876         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 877                 unsigned long orig_dst;
 878                 struct rt6_info ovs_rt;
 879
 880                 prepare_frag(vport, skb, orig_network_offset,
 881                              ovs_key_mac_proto(key));
 882                 memset(&ovs_rt, 0, sizeof(ovs_rt));
 883                 dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
 884                          DST_OBSOLETE_NONE, DST_NOCOUNT);
 885                 ovs_rt.dst.dev = vport->dev;
 886
 887                 orig_dst = skb->_skb_refdst;
 888                 skb_dst_set_noref(skb, &ovs_rt.dst);
 889                 IP6CB(skb)->frag_max_size = mru;
 890
 891                 ipv6_stub->ipv6_fragment(net, skb->sk, skb, ovs_vport_output);
 892                 refdst_drop(orig_dst);
 893         } else {
 894                 WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
 895                           ovs_vport_name(vport), ntohs(key->eth.type), mru,
 896                           vport->dev->mtu);
 897                 goto err;
 898         }
 899
 900         return;
 901 err:
 902         kfree_skb(skb);
 903 }
 904
 905 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
 906                       struct sw_flow_key *key)
 907 {
 908         struct vport *vport = ovs_vport_rcu(dp, out_port);
 909
 910         if (likely(vport)) {
 911                 u16 mru = OVS_CB(skb)->mru;
 912                 u32 cutlen = OVS_CB(skb)->cutlen;
 913
 914                 if (unlikely(cutlen > 0)) {
 915                         if (skb->len - cutlen > ovs_mac_header_len(key))
 916                                 pskb_trim(skb, skb->len - cutlen);
 917                         else
 918                                 pskb_trim(skb, ovs_mac_header_len(key));
 919                 }
 920
 921                 if (likely(!mru ||
 922                            (skb->len <= mru + vport->dev->hard_header_len))) {
 923                         ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
 924                 } else if (mru <= vport->dev->mtu) {
 925                         struct net *net = read_pnet(&dp->net);
 926
 927                         ovs_fragment(net, vport, skb, mru, key);
 928                 } else {
 929                         kfree_skb(skb);
 930                 }
 931         } else {
 932                 kfree_skb(skb);
 933         }
 934 }
 935
 936 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 937                             struct sw_flow_key *key, const struct nlattr *attr,
 938                             const struct nlattr *actions, int actions_len,
 939                             uint32_t cutlen)
 940 {
 941         struct dp_upcall_info upcall;
 942         const struct nlattr *a;
 943         int rem;
 944
 945         memset(&upcall, 0, sizeof(upcall));
 946         upcall.cmd = OVS_PACKET_CMD_ACTION;
 947         upcall.mru = OVS_CB(skb)->mru;
 948
 949         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 950              a = nla_next(a, &rem)) {
 951                 switch (nla_type(a)) {
 952                 case OVS_USERSPACE_ATTR_USERDATA:
 953                         upcall.userdata = a;
 954                         break;
 955
 956                 case OVS_USERSPACE_ATTR_PID:
 957                         if (dp->user_features &
 958                             OVS_DP_F_DISPATCH_UPCALL_PER_CPU)
 959                                 upcall.portid =
 960                                   ovs_dp_get_upcall_portid(dp,
 961                                                            smp_processor_id());
 962                         else
 963                                 upcall.portid = nla_get_u32(a);
 964                         break;
 965
 966                 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 967                         /* Get out tunnel info. */
 968                         struct vport *vport;
 969
 970                         vport = ovs_vport_rcu(dp, nla_get_u32(a));
 971                         if (vport) {
 972                                 int err;
 973
 974                                 err = dev_fill_metadata_dst(vport->dev, skb);
 975                                 if (!err)
 976                                         upcall.egress_tun_info = skb_tunnel_info(skb);
 977                         }
 978
 979                         break;
 980                 }
 981
 982                 case OVS_USERSPACE_ATTR_ACTIONS: {
 983                         /* Include actions. */
 984                         upcall.actions = actions;
 985                         upcall.actions_len = actions_len;
 986                         break;
 987                 }
 988
 989                 } /* End of switch. */
 990         }
 991
 992         return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
 993 }
 994
 995 static int dec_ttl_exception_handler(struct datapath *dp, struct sk_buff *skb,
 996                                      struct sw_flow_key *key,
 997                                      const struct nlattr *attr)
 998 {
 999         /* The first attribute is always 'OVS_DEC_TTL_ATTR_ACTION'. */
1000         struct nlattr *actions = nla_data(attr);
1001
1002         if (nla_len(actions))
1003                 return clone_execute(dp, skb, key, 0, nla_data(actions),
1004                                      nla_len(actions), true, false);
1005
1006         consume_skb(skb);
1007         return 0;
1008 }
1009
1010 /* When 'last' is true, sample() should always consume the 'skb'.
1011  * Otherwise, sample() should keep 'skb' intact regardless what
1012  * actions are executed within sample().
1013  */
1014 static int sample(struct datapath *dp, struct sk_buff *skb,
1015                   struct sw_flow_key *key, const struct nlattr *attr,
1016                   bool last)
1017 {
1018         struct nlattr *actions;
1019         struct nlattr *sample_arg;
1020         int rem = nla_len(attr);
1021         const struct sample_arg *arg;
1022         bool clone_flow_key;
1023
1024         /* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */
1025         sample_arg = nla_data(attr);
1026         arg = nla_data(sample_arg);
1027         actions = nla_next(sample_arg, &rem);
1028
1029         if ((arg->probability != U32_MAX) &&
1030             (!arg->probability || prandom_u32() > arg->probability)) {
1031                 if (last)
1032                         consume_skb(skb);
1033                 return 0;
1034         }
1035
1036         clone_flow_key = !arg->exec;
1037         return clone_execute(dp, skb, key, 0, actions, rem, last,
1038                              clone_flow_key);
1039 }
1040
1041 /* When 'last' is true, clone() should always consume the 'skb'.
1042  * Otherwise, clone() should keep 'skb' intact regardless what
1043  * actions are executed within clone().
1044  */
1045 static int clone(struct datapath *dp, struct sk_buff *skb,
1046                  struct sw_flow_key *key, const struct nlattr *attr,
1047                  bool last)
1048 {
1049         struct nlattr *actions;
1050         struct nlattr *clone_arg;
1051         int rem = nla_len(attr);
1052         bool dont_clone_flow_key;
1053
1054         /* The first action is always 'OVS_CLONE_ATTR_ARG'. */
1055         clone_arg = nla_data(attr);
1056         dont_clone_flow_key = nla_get_u32(clone_arg);
1057         actions = nla_next(clone_arg, &rem);
1058
1059         return clone_execute(dp, skb, key, 0, actions, rem, last,
1060                              !dont_clone_flow_key);
1061 }
1062
1063 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
1064                          const struct nlattr *attr)
1065 {
1066         struct ovs_action_hash *hash_act = nla_data(attr);
1067         u32 hash = 0;
1068
1069         /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
1070         hash = skb_get_hash(skb);
1071         hash = jhash_1word(hash, hash_act->hash_basis);
1072         if (!hash)
1073                 hash = 0x1;
1074
1075         key->ovs_flow_hash = hash;
1076 }
1077
1078 static int execute_set_action(struct sk_buff *skb,
1079                               struct sw_flow_key *flow_key,
1080                               const struct nlattr *a)
1081 {
1082         /* Only tunnel set execution is supported without a mask. */
1083         if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
1084                 struct ovs_tunnel_info *tun = nla_data(a);
1085
1086                 skb_dst_drop(skb);
1087                 dst_hold((struct dst_entry *)tun->tun_dst);
1088                 skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
1089                 return 0;
1090         }
1091
1092         return -EINVAL;
1093 }
1094
1095 /* Mask is at the midpoint of the data. */
1096 #define get_mask(a, type) ((const type)nla_data(a) + 1)
1097
1098 static int execute_masked_set_action(struct sk_buff *skb,
1099                                      struct sw_flow_key *flow_key,
1100                                      const struct nlattr *a)
1101 {
1102         int err = 0;
1103
1104         switch (nla_type(a)) {
1105         case OVS_KEY_ATTR_PRIORITY:
1106                 OVS_SET_MASKED(skb->priority, nla_get_u32(a),
1107                                *get_mask(a, u32 *));
1108                 flow_key->phy.priority = skb->priority;
1109                 break;
1110
1111         case OVS_KEY_ATTR_SKB_MARK:
1112                 OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
1113                 flow_key->phy.skb_mark = skb->mark;
1114                 break;
1115
1116         case OVS_KEY_ATTR_TUNNEL_INFO:
1117                 /* Masked data not supported for tunnel. */
1118                 err = -EINVAL;
1119                 break;
1120
1121         case OVS_KEY_ATTR_ETHERNET:
1122                 err = set_eth_addr(skb, flow_key, nla_data(a),
1123                                    get_mask(a, struct ovs_key_ethernet *));
1124                 break;
1125
1126         case OVS_KEY_ATTR_NSH:
1127                 err = set_nsh(skb, flow_key, a);
1128                 break;
1129
1130         case OVS_KEY_ATTR_IPV4:
1131                 err = set_ipv4(skb, flow_key, nla_data(a),
1132                                get_mask(a, struct ovs_key_ipv4 *));
1133                 break;
1134
1135         case OVS_KEY_ATTR_IPV6:
1136                 err = set_ipv6(skb, flow_key, nla_data(a),
1137                                get_mask(a, struct ovs_key_ipv6 *));
1138                 break;
1139
1140         case OVS_KEY_ATTR_TCP:
1141                 err = set_tcp(skb, flow_key, nla_data(a),
1142                               get_mask(a, struct ovs_key_tcp *));
1143                 break;
1144
1145         case OVS_KEY_ATTR_UDP:
1146                 err = set_udp(skb, flow_key, nla_data(a),
1147                               get_mask(a, struct ovs_key_udp *));
1148                 break;
1149
1150         case OVS_KEY_ATTR_SCTP:
1151                 err = set_sctp(skb, flow_key, nla_data(a),
1152                                get_mask(a, struct ovs_key_sctp *));
1153                 break;
1154
1155         case OVS_KEY_ATTR_MPLS:
1156                 err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1157                                                                     __be32 *));
1158                 break;
1159
1160         case OVS_KEY_ATTR_CT_STATE:
1161         case OVS_KEY_ATTR_CT_ZONE:
1162         case OVS_KEY_ATTR_CT_MARK:
1163         case OVS_KEY_ATTR_CT_LABELS:
1164         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
1165         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
1166                 err = -EINVAL;
1167                 break;
1168         }
1169
1170         return err;
1171 }
1172
1173 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1174                           struct sw_flow_key *key,
1175                           const struct nlattr *a, bool last)
1176 {
1177         u32 recirc_id;
1178
1179         if (!is_flow_key_valid(key)) {
1180                 int err;
1181
1182                 err = ovs_flow_key_update(skb, key);
1183                 if (err)
1184                         return err;
1185         }
1186         BUG_ON(!is_flow_key_valid(key));
1187
1188         recirc_id = nla_get_u32(a);
1189         return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true);
1190 }
1191
1192 static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb,
1193                                  struct sw_flow_key *key,
1194                                  const struct nlattr *attr, bool last)
1195 {
1196         struct ovs_skb_cb *ovs_cb = OVS_CB(skb);
1197         const struct nlattr *actions, *cpl_arg;
1198         int len, max_len, rem = nla_len(attr);
1199         const struct check_pkt_len_arg *arg;
1200         bool clone_flow_key;
1201
1202         /* The first netlink attribute in 'attr' is always
1203          * 'OVS_CHECK_PKT_LEN_ATTR_ARG'.
1204          */
1205         cpl_arg = nla_data(attr);
1206         arg = nla_data(cpl_arg);
1207
1208         len = ovs_cb->mru ? ovs_cb->mru + skb->mac_len : skb->len;
1209         max_len = arg->pkt_len;
1210
1211         if ((skb_is_gso(skb) && skb_gso_validate_mac_len(skb, max_len)) ||
1212             len <= max_len) {
1213                 /* Second netlink attribute in 'attr' is always
1214                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
1215                  */
1216                 actions = nla_next(cpl_arg, &rem);
1217                 clone_flow_key = !arg->exec_for_lesser_equal;
1218         } else {
1219                 /* Third netlink attribute in 'attr' is always
1220                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'.
1221                  */
1222                 actions = nla_next(cpl_arg, &rem);
1223                 actions = nla_next(actions, &rem);
1224                 clone_flow_key = !arg->exec_for_greater;
1225         }
1226
1227         return clone_execute(dp, skb, key, 0, nla_data(actions),
1228                              nla_len(actions), last, clone_flow_key);
1229 }
1230
1231 static int execute_dec_ttl(struct sk_buff *skb, struct sw_flow_key *key)
1232 {
1233         int err;
1234
1235         if (skb->protocol == htons(ETH_P_IPV6)) {
1236                 struct ipv6hdr *nh;
1237
1238                 err = skb_ensure_writable(skb, skb_network_offset(skb) +
1239                                           sizeof(*nh));
1240                 if (unlikely(err))
1241                         return err;
1242
1243                 nh = ipv6_hdr(skb);
1244
1245                 if (nh->hop_limit <= 1)
1246                         return -EHOSTUNREACH;
1247
1248                 key->ip.ttl = --nh->hop_limit;
1249         } else if (skb->protocol == htons(ETH_P_IP)) {
1250                 struct iphdr *nh;
1251                 u8 old_ttl;
1252
1253                 err = skb_ensure_writable(skb, skb_network_offset(skb) +
1254                                           sizeof(*nh));
1255                 if (unlikely(err))
1256                         return err;
1257
1258                 nh = ip_hdr(skb);
1259                 if (nh->ttl <= 1)
1260                         return -EHOSTUNREACH;
1261
1262                 old_ttl = nh->ttl--;
1263                 csum_replace2(&nh->check, htons(old_ttl << 8),
1264                               htons(nh->ttl << 8));
1265                 key->ip.ttl = nh->ttl;
1266         }
1267         return 0;
1268 }
1269
1270 /* Execute a list of actions against 'skb'. */
1271 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1272                               struct sw_flow_key *key,
1273                               const struct nlattr *attr, int len)
1274 {
1275         const struct nlattr *a;
1276         int rem;
1277
1278         for (a = attr, rem = len; rem > 0;
1279              a = nla_next(a, &rem)) {
1280                 int err = 0;
1281
1282                 if (trace_ovs_do_execute_action_enabled())
1283                         trace_ovs_do_execute_action(dp, skb, key, a, rem);
1284
1285                 switch (nla_type(a)) {
1286                 case OVS_ACTION_ATTR_OUTPUT: {
1287                         int port = nla_get_u32(a);
1288                         struct sk_buff *clone;
1289
1290                         /* Every output action needs a separate clone
1291                          * of 'skb', In case the output action is the
1292                          * last action, cloning can be avoided.
1293                          */
1294                         if (nla_is_last(a, rem)) {
1295                                 do_output(dp, skb, port, key);
1296                                 /* 'skb' has been used for output.
1297                                  */
1298                                 return 0;
1299                         }
1300
1301                         clone = skb_clone(skb, GFP_ATOMIC);
1302                         if (clone)
1303                                 do_output(dp, clone, port, key);
1304                         OVS_CB(skb)->cutlen = 0;
1305                         break;
1306                 }
1307
1308                 case OVS_ACTION_ATTR_TRUNC: {
1309                         struct ovs_action_trunc *trunc = nla_data(a);
1310
1311                         if (skb->len > trunc->max_len)
1312                                 OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1313                         break;
1314                 }
1315
1316                 case OVS_ACTION_ATTR_USERSPACE:
1317                         output_userspace(dp, skb, key, a, attr,
1318                                                      len, OVS_CB(skb)->cutlen);
1319                         OVS_CB(skb)->cutlen = 0;
1320                         break;
1321
1322                 case OVS_ACTION_ATTR_HASH:
1323                         execute_hash(skb, key, a);
1324                         break;
1325
1326                 case OVS_ACTION_ATTR_PUSH_MPLS: {
1327                         struct ovs_action_push_mpls *mpls = nla_data(a);
1328
1329                         err = push_mpls(skb, key, mpls->mpls_lse,
1330                                         mpls->mpls_ethertype, skb->mac_len);
1331                         break;
1332                 }
1333                 case OVS_ACTION_ATTR_ADD_MPLS: {
1334                         struct ovs_action_add_mpls *mpls = nla_data(a);
1335                         __u16 mac_len = 0;
1336
1337                         if (mpls->tun_flags & OVS_MPLS_L3_TUNNEL_FLAG_MASK)
1338                                 mac_len = skb->mac_len;
1339
1340                         err = push_mpls(skb, key, mpls->mpls_lse,
1341                                         mpls->mpls_ethertype, mac_len);
1342                         break;
1343                 }
1344                 case OVS_ACTION_ATTR_POP_MPLS:
1345                         err = pop_mpls(skb, key, nla_get_be16(a));
1346                         break;
1347
1348                 case OVS_ACTION_ATTR_PUSH_VLAN:
1349                         err = push_vlan(skb, key, nla_data(a));
1350                         break;
1351
1352                 case OVS_ACTION_ATTR_POP_VLAN:
1353                         err = pop_vlan(skb, key);
1354                         break;
1355
1356                 case OVS_ACTION_ATTR_RECIRC: {
1357                         bool last = nla_is_last(a, rem);
1358
1359                         err = execute_recirc(dp, skb, key, a, last);
1360                         if (last) {
1361                                 /* If this is the last action, the skb has
1362                                  * been consumed or freed.
1363                                  * Return immediately.
1364                                  */
1365                                 return err;
1366                         }
1367                         break;
1368                 }
1369
1370                 case OVS_ACTION_ATTR_SET:
1371                         err = execute_set_action(skb, key, nla_data(a));
1372                         break;
1373
1374                 case OVS_ACTION_ATTR_SET_MASKED:
1375                 case OVS_ACTION_ATTR_SET_TO_MASKED:
1376                         err = execute_masked_set_action(skb, key, nla_data(a));
1377                         break;
1378
1379                 case OVS_ACTION_ATTR_SAMPLE: {
1380                         bool last = nla_is_last(a, rem);
1381
1382                         err = sample(dp, skb, key, a, last);
1383                         if (last)
1384                                 return err;
1385
1386                         break;
1387                 }
1388
1389                 case OVS_ACTION_ATTR_CT:
1390                         if (!is_flow_key_valid(key)) {
1391                                 err = ovs_flow_key_update(skb, key);
1392                                 if (err)
1393                                         return err;
1394                         }
1395
1396                         err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1397                                              nla_data(a));
1398
1399                         /* Hide stolen IP fragments from user space. */
1400                         if (err)
1401                                 return err == -EINPROGRESS ? 0 : err;
1402                         break;
1403
1404                 case OVS_ACTION_ATTR_CT_CLEAR:
1405                         err = ovs_ct_clear(skb, key);
1406                         break;
1407
1408                 case OVS_ACTION_ATTR_PUSH_ETH:
1409                         err = push_eth(skb, key, nla_data(a));
1410                         break;
1411
1412                 case OVS_ACTION_ATTR_POP_ETH:
1413                         err = pop_eth(skb, key);
1414                         break;
1415
1416                 case OVS_ACTION_ATTR_PUSH_NSH: {
1417                         u8 buffer[NSH_HDR_MAX_LEN];
1418                         struct nshhdr *nh = (struct nshhdr *)buffer;
1419
1420                         err = nsh_hdr_from_nlattr(nla_data(a), nh,
1421                                                   NSH_HDR_MAX_LEN);
1422                         if (unlikely(err))
1423                                 break;
1424                         err = push_nsh(skb, key, nh);
1425                         break;
1426                 }
1427
1428                 case OVS_ACTION_ATTR_POP_NSH:
1429                         err = pop_nsh(skb, key);
1430                         break;
1431
1432                 case OVS_ACTION_ATTR_METER:
1433                         if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
1434                                 consume_skb(skb);
1435                                 return 0;
1436                         }
1437                         break;
1438
1439                 case OVS_ACTION_ATTR_CLONE: {
1440                         bool last = nla_is_last(a, rem);
1441
1442                         err = clone(dp, skb, key, a, last);
1443                         if (last)
1444                                 return err;
1445
1446                         break;
1447                 }
1448
1449                 case OVS_ACTION_ATTR_CHECK_PKT_LEN: {
1450                         bool last = nla_is_last(a, rem);
1451
1452                         err = execute_check_pkt_len(dp, skb, key, a, last);
1453                         if (last)
1454                                 return err;
1455
1456                         break;
1457                 }
1458
1459                 case OVS_ACTION_ATTR_DEC_TTL:
1460                         err = execute_dec_ttl(skb, key);
1461                         if (err == -EHOSTUNREACH)
1462                                 return dec_ttl_exception_handler(dp, skb,
1463                                                                  key, a);
1464                         break;
1465                 }
1466
1467                 if (unlikely(err)) {
1468                         kfree_skb(skb);
1469                         return err;
1470                 }
1471         }
1472
1473         consume_skb(skb);
1474         return 0;
1475 }
1476
1477 /* Execute the actions on the clone of the packet. The effect of the
1478  * execution does not affect the original 'skb' nor the original 'key'.
1479  *
1480  * The execution may be deferred in case the actions can not be executed
1481  * immediately.
1482  */
1483 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
1484                          struct sw_flow_key *key, u32 recirc_id,
1485                          const struct nlattr *actions, int len,
1486                          bool last, bool clone_flow_key)
1487 {
1488         struct deferred_action *da;
1489         struct sw_flow_key *clone;
1490
1491         skb = last ? skb : skb_clone(skb, GFP_ATOMIC);
1492         if (!skb) {
1493                 /* Out of memory, skip this action.
1494                  */
1495                 return 0;
1496         }
1497
1498         /* When clone_flow_key is false, the 'key' will not be change
1499          * by the actions, then the 'key' can be used directly.
1500          * Otherwise, try to clone key from the next recursion level of
1501          * 'flow_keys'. If clone is successful, execute the actions
1502          * without deferring.
1503          */
1504         clone = clone_flow_key ? clone_key(key) : key;
1505         if (clone) {
1506                 int err = 0;
1507
1508                 if (actions) { /* Sample action */
1509                         if (clone_flow_key)
1510                                 __this_cpu_inc(exec_actions_level);
1511
1512                         err = do_execute_actions(dp, skb, clone,
1513                                                  actions, len);
1514
1515                         if (clone_flow_key)
1516                                 __this_cpu_dec(exec_actions_level);
1517                 } else { /* Recirc action */
1518                         clone->recirc_id = recirc_id;
1519                         ovs_dp_process_packet(skb, clone);
1520                 }
1521                 return err;
1522         }
1523
1524         /* Out of 'flow_keys' space. Defer actions */
1525         da = add_deferred_actions(skb, key, actions, len);
1526         if (da) {
1527                 if (!actions) { /* Recirc action */
1528                         key = &da->pkt_key;
1529                         key->recirc_id = recirc_id;
1530                 }
1531         } else {
1532                 /* Out of per CPU action FIFO space. Drop the 'skb' and
1533                  * log an error.
1534                  */
1535                 kfree_skb(skb);
1536
1537                 if (net_ratelimit()) {
1538                         if (actions) { /* Sample action */
1539                                 pr_warn("%s: deferred action limit reached, drop sample action\n",
1540                                         ovs_dp_name(dp));
1541                         } else {  /* Recirc action */
1542                                 pr_warn("%s: deferred action limit reached, drop recirc action\n",
1543                                         ovs_dp_name(dp));
1544                         }
1545                 }
1546         }
1547         return 0;
1548 }
1549
1550 static void process_deferred_actions(struct datapath *dp)
1551 {
1552         struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1553
1554         /* Do not touch the FIFO in case there is no deferred actions. */
1555         if (action_fifo_is_empty(fifo))
1556                 return;
1557
1558         /* Finishing executing all deferred actions. */
1559         do {
1560                 struct deferred_action *da = action_fifo_get(fifo);
1561                 struct sk_buff *skb = da->skb;
1562                 struct sw_flow_key *key = &da->pkt_key;
1563                 const struct nlattr *actions = da->actions;
1564                 int actions_len = da->actions_len;
1565
1566                 if (actions)
1567                         do_execute_actions(dp, skb, key, actions, actions_len);
1568                 else
1569                         ovs_dp_process_packet(skb, key);
1570         } while (!action_fifo_is_empty(fifo));
1571
1572         /* Reset FIFO for the next packet.  */
1573         action_fifo_init(fifo);
1574 }
1575
1576 /* Execute a list of actions against 'skb'. */
1577 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1578                         const struct sw_flow_actions *acts,
1579                         struct sw_flow_key *key)
1580 {
1581         int err, level;
1582
1583         level = __this_cpu_inc_return(exec_actions_level);
1584         if (unlikely(level > OVS_RECURSION_LIMIT)) {
1585                 net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1586                                      ovs_dp_name(dp));
1587                 kfree_skb(skb);
1588                 err = -ENETDOWN;
1589                 goto out;
1590         }
1591
1592         OVS_CB(skb)->acts_origlen = acts->orig_len;
1593         err = do_execute_actions(dp, skb, key,
1594                                  acts->actions, acts->actions_len);
1595
1596         if (level == 1)
1597                 process_deferred_actions(dp);
1598
1599 out:
1600         __this_cpu_dec(exec_actions_level);
1601         return err;
1602 }
1603
1604 int action_fifos_init(void)
1605 {
1606         action_fifos = alloc_percpu(struct action_fifo);
1607         if (!action_fifos)
1608                 return -ENOMEM;
1609
1610         flow_keys = alloc_percpu(struct action_flow_keys);
1611         if (!flow_keys) {
1612                 free_percpu(action_fifos);
1613                 return -ENOMEM;
1614         }
1615
1616         return 0;
1617 }
1618
1619 void action_fifos_exit(void)
1620 {
1621         free_percpu(action_fifos);
1622         free_percpu(flow_keys);
1623 }