net/openvswitch/actions.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
clone_key
action_fifo_init
action_fifo_is_empty
action_fifo_get
action_fifo_put
add_deferred_actions
invalidate_flow_key
is_flow_key_valid
push_mpls
pop_mpls
set_mpls
pop_vlan
push_vlan
ether_addr_copy_masked
set_eth_addr
pop_eth
push_eth
push_nsh
pop_nsh
update_ip_l4_checksum
set_ip_addr
update_ipv6_checksum
mask_ipv6_addr
set_ipv6_addr
set_ipv6_fl
set_ip_ttl
set_ipv4
is_ipv6_mask_nonzero
set_ipv6
set_nsh
set_tp_port
set_udp
set_tcp
set_sctp
ovs_vport_output
ovs_dst_get_mtu
prepare_frag
ovs_fragment
do_output
output_userspace
sample
clone
execute_hash
execute_set_action
execute_masked_set_action
execute_recirc
execute_check_pkt_len
do_execute_actions
clone_execute
process_deferred_actions
ovs_execute_actions
action_fifos_init
action_fifos_exit
   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/netfilter_ipv6.h>
  13 #include <linux/sctp.h>
  14 #include <linux/tcp.h>
  15 #include <linux/udp.h>
  16 #include <linux/in6.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/if_vlan.h>
  19 
  20 #include <net/dst.h>
  21 #include <net/ip.h>
  22 #include <net/ipv6.h>
  23 #include <net/ip6_fib.h>
  24 #include <net/checksum.h>
  25 #include <net/dsfield.h>
  26 #include <net/mpls.h>
  27 #include <net/sctp/checksum.h>
  28 
  29 #include "datapath.h"
  30 #include "flow.h"
  31 #include "conntrack.h"
  32 #include "vport.h"
  33 #include "flow_netlink.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                      const struct ovs_action_push_mpls *mpls)
 165 {
 166         int err;
 167 
 168         err = skb_mpls_push(skb, mpls->mpls_lse, mpls->mpls_ethertype,
 169                             skb->mac_len,
 170                             ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET);
 171         if (err)
 172                 return err;
 173 
 174         invalidate_flow_key(key);
 175         return 0;
 176 }
 177 
 178 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 179                     const __be16 ethertype)
 180 {
 181         int err;
 182 
 183         err = skb_mpls_pop(skb, ethertype, skb->mac_len,
 184                            ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET);
 185         if (err)
 186                 return err;
 187 
 188         invalidate_flow_key(key);
 189         return 0;
 190 }
 191 
 192 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
 193                     const __be32 *mpls_lse, const __be32 *mask)
 194 {
 195         struct mpls_shim_hdr *stack;
 196         __be32 lse;
 197         int err;
 198 
 199         stack = mpls_hdr(skb);
 200         lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
 201         err = skb_mpls_update_lse(skb, lse);
 202         if (err)
 203                 return err;
 204 
 205         flow_key->mpls.top_lse = lse;
 206         return 0;
 207 }
 208 
 209 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 210 {
 211         int err;
 212 
 213         err = skb_vlan_pop(skb);
 214         if (skb_vlan_tag_present(skb)) {
 215                 invalidate_flow_key(key);
 216         } else {
 217                 key->eth.vlan.tci = 0;
 218                 key->eth.vlan.tpid = 0;
 219         }
 220         return err;
 221 }
 222 
 223 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 224                      const struct ovs_action_push_vlan *vlan)
 225 {
 226         if (skb_vlan_tag_present(skb)) {
 227                 invalidate_flow_key(key);
 228         } else {
 229                 key->eth.vlan.tci = vlan->vlan_tci;
 230                 key->eth.vlan.tpid = vlan->vlan_tpid;
 231         }
 232         return skb_vlan_push(skb, vlan->vlan_tpid,
 233                              ntohs(vlan->vlan_tci) & ~VLAN_CFI_MASK);
 234 }
 235 
 236 /* 'src' is already properly masked. */
 237 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
 238 {
 239         u16 *dst = (u16 *)dst_;
 240         const u16 *src = (const u16 *)src_;
 241         const u16 *mask = (const u16 *)mask_;
 242 
 243         OVS_SET_MASKED(dst[0], src[0], mask[0]);
 244         OVS_SET_MASKED(dst[1], src[1], mask[1]);
 245         OVS_SET_MASKED(dst[2], src[2], mask[2]);
 246 }
 247 
 248 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
 249                         const struct ovs_key_ethernet *key,
 250                         const struct ovs_key_ethernet *mask)
 251 {
 252         int err;
 253 
 254         err = skb_ensure_writable(skb, ETH_HLEN);
 255         if (unlikely(err))
 256                 return err;
 257 
 258         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 259 
 260         ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
 261                                mask->eth_src);
 262         ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
 263                                mask->eth_dst);
 264 
 265         skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 266 
 267         ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
 268         ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
 269         return 0;
 270 }
 271 
 272 /* pop_eth does not support VLAN packets as this action is never called
 273  * for them.
 274  */
 275 static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
 276 {
 277         skb_pull_rcsum(skb, ETH_HLEN);
 278         skb_reset_mac_header(skb);
 279         skb_reset_mac_len(skb);
 280 
 281         /* safe right before invalidate_flow_key */
 282         key->mac_proto = MAC_PROTO_NONE;
 283         invalidate_flow_key(key);
 284         return 0;
 285 }
 286 
 287 static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
 288                     const struct ovs_action_push_eth *ethh)
 289 {
 290         struct ethhdr *hdr;
 291 
 292         /* Add the new Ethernet header */
 293         if (skb_cow_head(skb, ETH_HLEN) < 0)
 294                 return -ENOMEM;
 295 
 296         skb_push(skb, ETH_HLEN);
 297         skb_reset_mac_header(skb);
 298         skb_reset_mac_len(skb);
 299 
 300         hdr = eth_hdr(skb);
 301         ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
 302         ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
 303         hdr->h_proto = skb->protocol;
 304 
 305         skb_postpush_rcsum(skb, hdr, ETH_HLEN);
 306 
 307         /* safe right before invalidate_flow_key */
 308         key->mac_proto = MAC_PROTO_ETHERNET;
 309         invalidate_flow_key(key);
 310         return 0;
 311 }
 312 
 313 static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key,
 314                     const struct nshhdr *nh)
 315 {
 316         int err;
 317 
 318         err = nsh_push(skb, nh);
 319         if (err)
 320                 return err;
 321 
 322         /* safe right before invalidate_flow_key */
 323         key->mac_proto = MAC_PROTO_NONE;
 324         invalidate_flow_key(key);
 325         return 0;
 326 }
 327 
 328 static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key)
 329 {
 330         int err;
 331 
 332         err = nsh_pop(skb);
 333         if (err)
 334                 return err;
 335 
 336         /* safe right before invalidate_flow_key */
 337         if (skb->protocol == htons(ETH_P_TEB))
 338                 key->mac_proto = MAC_PROTO_ETHERNET;
 339         else
 340                 key->mac_proto = MAC_PROTO_NONE;
 341         invalidate_flow_key(key);
 342         return 0;
 343 }
 344 
 345 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
 346                                   __be32 addr, __be32 new_addr)
 347 {
 348         int transport_len = skb->len - skb_transport_offset(skb);
 349 
 350         if (nh->frag_off & htons(IP_OFFSET))
 351                 return;
 352 
 353         if (nh->protocol == IPPROTO_TCP) {
 354                 if (likely(transport_len >= sizeof(struct tcphdr)))
 355                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
 356                                                  addr, new_addr, true);
 357         } else if (nh->protocol == IPPROTO_UDP) {
 358                 if (likely(transport_len >= sizeof(struct udphdr))) {
 359                         struct udphdr *uh = udp_hdr(skb);
 360 
 361                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 362                                 inet_proto_csum_replace4(&uh->check, skb,
 363                                                          addr, new_addr, true);
 364                                 if (!uh->check)
 365                                         uh->check = CSUM_MANGLED_0;
 366                         }
 367                 }
 368         }
 369 }
 370 
 371 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
 372                         __be32 *addr, __be32 new_addr)
 373 {
 374         update_ip_l4_checksum(skb, nh, *addr, new_addr);
 375         csum_replace4(&nh->check, *addr, new_addr);
 376         skb_clear_hash(skb);
 377         *addr = new_addr;
 378 }
 379 
 380 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
 381                                  __be32 addr[4], const __be32 new_addr[4])
 382 {
 383         int transport_len = skb->len - skb_transport_offset(skb);
 384 
 385         if (l4_proto == NEXTHDR_TCP) {
 386                 if (likely(transport_len >= sizeof(struct tcphdr)))
 387                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
 388                                                   addr, new_addr, true);
 389         } else if (l4_proto == NEXTHDR_UDP) {
 390                 if (likely(transport_len >= sizeof(struct udphdr))) {
 391                         struct udphdr *uh = udp_hdr(skb);
 392 
 393                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
 394                                 inet_proto_csum_replace16(&uh->check, skb,
 395                                                           addr, new_addr, true);
 396                                 if (!uh->check)
 397                                         uh->check = CSUM_MANGLED_0;
 398                         }
 399                 }
 400         } else if (l4_proto == NEXTHDR_ICMP) {
 401                 if (likely(transport_len >= sizeof(struct icmp6hdr)))
 402                         inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
 403                                                   skb, addr, new_addr, true);
 404         }
 405 }
 406 
 407 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
 408                            const __be32 mask[4], __be32 masked[4])
 409 {
 410         masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
 411         masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
 412         masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
 413         masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
 414 }
 415 
 416 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
 417                           __be32 addr[4], const __be32 new_addr[4],
 418                           bool recalculate_csum)
 419 {
 420         if (recalculate_csum)
 421                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
 422 
 423         skb_clear_hash(skb);
 424         memcpy(addr, new_addr, sizeof(__be32[4]));
 425 }
 426 
 427 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
 428 {
 429         /* Bits 21-24 are always unmasked, so this retains their values. */
 430         OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
 431         OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
 432         OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
 433 }
 434 
 435 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
 436                        u8 mask)
 437 {
 438         new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
 439 
 440         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
 441         nh->ttl = new_ttl;
 442 }
 443 
 444 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
 445                     const struct ovs_key_ipv4 *key,
 446                     const struct ovs_key_ipv4 *mask)
 447 {
 448         struct iphdr *nh;
 449         __be32 new_addr;
 450         int err;
 451 
 452         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 453                                   sizeof(struct iphdr));
 454         if (unlikely(err))
 455                 return err;
 456 
 457         nh = ip_hdr(skb);
 458 
 459         /* Setting an IP addresses is typically only a side effect of
 460          * matching on them in the current userspace implementation, so it
 461          * makes sense to check if the value actually changed.
 462          */
 463         if (mask->ipv4_src) {
 464                 new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
 465 
 466                 if (unlikely(new_addr != nh->saddr)) {
 467                         set_ip_addr(skb, nh, &nh->saddr, new_addr);
 468                         flow_key->ipv4.addr.src = new_addr;
 469                 }
 470         }
 471         if (mask->ipv4_dst) {
 472                 new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
 473 
 474                 if (unlikely(new_addr != nh->daddr)) {
 475                         set_ip_addr(skb, nh, &nh->daddr, new_addr);
 476                         flow_key->ipv4.addr.dst = new_addr;
 477                 }
 478         }
 479         if (mask->ipv4_tos) {
 480                 ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
 481                 flow_key->ip.tos = nh->tos;
 482         }
 483         if (mask->ipv4_ttl) {
 484                 set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
 485                 flow_key->ip.ttl = nh->ttl;
 486         }
 487 
 488         return 0;
 489 }
 490 
 491 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
 492 {
 493         return !!(addr[0] | addr[1] | addr[2] | addr[3]);
 494 }
 495 
 496 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
 497                     const struct ovs_key_ipv6 *key,
 498                     const struct ovs_key_ipv6 *mask)
 499 {
 500         struct ipv6hdr *nh;
 501         int err;
 502 
 503         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 504                                   sizeof(struct ipv6hdr));
 505         if (unlikely(err))
 506                 return err;
 507 
 508         nh = ipv6_hdr(skb);
 509 
 510         /* Setting an IP addresses is typically only a side effect of
 511          * matching on them in the current userspace implementation, so it
 512          * makes sense to check if the value actually changed.
 513          */
 514         if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
 515                 __be32 *saddr = (__be32 *)&nh->saddr;
 516                 __be32 masked[4];
 517 
 518                 mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
 519 
 520                 if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
 521                         set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
 522                                       true);
 523                         memcpy(&flow_key->ipv6.addr.src, masked,
 524                                sizeof(flow_key->ipv6.addr.src));
 525                 }
 526         }
 527         if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
 528                 unsigned int offset = 0;
 529                 int flags = IP6_FH_F_SKIP_RH;
 530                 bool recalc_csum = true;
 531                 __be32 *daddr = (__be32 *)&nh->daddr;
 532                 __be32 masked[4];
 533 
 534                 mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
 535 
 536                 if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
 537                         if (ipv6_ext_hdr(nh->nexthdr))
 538                                 recalc_csum = (ipv6_find_hdr(skb, &offset,
 539                                                              NEXTHDR_ROUTING,
 540                                                              NULL, &flags)
 541                                                != NEXTHDR_ROUTING);
 542 
 543                         set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
 544                                       recalc_csum);
 545                         memcpy(&flow_key->ipv6.addr.dst, masked,
 546                                sizeof(flow_key->ipv6.addr.dst));
 547                 }
 548         }
 549         if (mask->ipv6_tclass) {
 550                 ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
 551                 flow_key->ip.tos = ipv6_get_dsfield(nh);
 552         }
 553         if (mask->ipv6_label) {
 554                 set_ipv6_fl(nh, ntohl(key->ipv6_label),
 555                             ntohl(mask->ipv6_label));
 556                 flow_key->ipv6.label =
 557                     *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
 558         }
 559         if (mask->ipv6_hlimit) {
 560                 OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
 561                                mask->ipv6_hlimit);
 562                 flow_key->ip.ttl = nh->hop_limit;
 563         }
 564         return 0;
 565 }
 566 
 567 static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
 568                    const struct nlattr *a)
 569 {
 570         struct nshhdr *nh;
 571         size_t length;
 572         int err;
 573         u8 flags;
 574         u8 ttl;
 575         int i;
 576 
 577         struct ovs_key_nsh key;
 578         struct ovs_key_nsh mask;
 579 
 580         err = nsh_key_from_nlattr(a, &key, &mask);
 581         if (err)
 582                 return err;
 583 
 584         /* Make sure the NSH base header is there */
 585         if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN))
 586                 return -ENOMEM;
 587 
 588         nh = nsh_hdr(skb);
 589         length = nsh_hdr_len(nh);
 590 
 591         /* Make sure the whole NSH header is there */
 592         err = skb_ensure_writable(skb, skb_network_offset(skb) +
 593                                        length);
 594         if (unlikely(err))
 595                 return err;
 596 
 597         nh = nsh_hdr(skb);
 598         skb_postpull_rcsum(skb, nh, length);
 599         flags = nsh_get_flags(nh);
 600         flags = OVS_MASKED(flags, key.base.flags, mask.base.flags);
 601         flow_key->nsh.base.flags = flags;
 602         ttl = nsh_get_ttl(nh);
 603         ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl);
 604         flow_key->nsh.base.ttl = ttl;
 605         nsh_set_flags_and_ttl(nh, flags, ttl);
 606         nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr,
 607                                   mask.base.path_hdr);
 608         flow_key->nsh.base.path_hdr = nh->path_hdr;
 609         switch (nh->mdtype) {
 610         case NSH_M_TYPE1:
 611                 for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) {
 612                         nh->md1.context[i] =
 613                             OVS_MASKED(nh->md1.context[i], key.context[i],
 614                                        mask.context[i]);
 615                 }
 616                 memcpy(flow_key->nsh.context, nh->md1.context,
 617                        sizeof(nh->md1.context));
 618                 break;
 619         case NSH_M_TYPE2:
 620                 memset(flow_key->nsh.context, 0,
 621                        sizeof(flow_key->nsh.context));
 622                 break;
 623         default:
 624                 return -EINVAL;
 625         }
 626         skb_postpush_rcsum(skb, nh, length);
 627         return 0;
 628 }
 629 
 630 /* Must follow skb_ensure_writable() since that can move the skb data. */
 631 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 632                         __be16 new_port, __sum16 *check)
 633 {
 634         inet_proto_csum_replace2(check, skb, *port, new_port, false);
 635         *port = new_port;
 636 }
 637 
 638 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 639                    const struct ovs_key_udp *key,
 640                    const struct ovs_key_udp *mask)
 641 {
 642         struct udphdr *uh;
 643         __be16 src, dst;
 644         int err;
 645 
 646         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 647                                   sizeof(struct udphdr));
 648         if (unlikely(err))
 649                 return err;
 650 
 651         uh = udp_hdr(skb);
 652         /* Either of the masks is non-zero, so do not bother checking them. */
 653         src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
 654         dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
 655 
 656         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
 657                 if (likely(src != uh->source)) {
 658                         set_tp_port(skb, &uh->source, src, &uh->check);
 659                         flow_key->tp.src = src;
 660                 }
 661                 if (likely(dst != uh->dest)) {
 662                         set_tp_port(skb, &uh->dest, dst, &uh->check);
 663                         flow_key->tp.dst = dst;
 664                 }
 665 
 666                 if (unlikely(!uh->check))
 667                         uh->check = CSUM_MANGLED_0;
 668         } else {
 669                 uh->source = src;
 670                 uh->dest = dst;
 671                 flow_key->tp.src = src;
 672                 flow_key->tp.dst = dst;
 673         }
 674 
 675         skb_clear_hash(skb);
 676 
 677         return 0;
 678 }
 679 
 680 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 681                    const struct ovs_key_tcp *key,
 682                    const struct ovs_key_tcp *mask)
 683 {
 684         struct tcphdr *th;
 685         __be16 src, dst;
 686         int err;
 687 
 688         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
 689                                   sizeof(struct tcphdr));
 690         if (unlikely(err))
 691                 return err;
 692 
 693         th = tcp_hdr(skb);
 694         src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
 695         if (likely(src != th->source)) {
 696                 set_tp_port(skb, &th->source, src, &th->check);
 697                 flow_key->tp.src = src;
 698         }
 699         dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
 700         if (likely(dst != th->dest)) {
 701                 set_tp_port(skb, &th->dest, dst, &th->check);
 702                 flow_key->tp.dst = dst;
 703         }
 704         skb_clear_hash(skb);
 705 
 706         return 0;
 707 }
 708 
 709 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
 710                     const struct ovs_key_sctp *key,
 711                     const struct ovs_key_sctp *mask)
 712 {
 713         unsigned int sctphoff = skb_transport_offset(skb);
 714         struct sctphdr *sh;
 715         __le32 old_correct_csum, new_csum, old_csum;
 716         int err;
 717 
 718         err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 719         if (unlikely(err))
 720                 return err;
 721 
 722         sh = sctp_hdr(skb);
 723         old_csum = sh->checksum;
 724         old_correct_csum = sctp_compute_cksum(skb, sctphoff);
 725 
 726         sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
 727         sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
 728 
 729         new_csum = sctp_compute_cksum(skb, sctphoff);
 730 
 731         /* Carry any checksum errors through. */
 732         sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
 733 
 734         skb_clear_hash(skb);
 735         flow_key->tp.src = sh->source;
 736         flow_key->tp.dst = sh->dest;
 737 
 738         return 0;
 739 }
 740 
 741 static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 742 {
 743         struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
 744         struct vport *vport = data->vport;
 745 
 746         if (skb_cow_head(skb, data->l2_len) < 0) {
 747                 kfree_skb(skb);
 748                 return -ENOMEM;
 749         }
 750 
 751         __skb_dst_copy(skb, data->dst);
 752         *OVS_CB(skb) = data->cb;
 753         skb->inner_protocol = data->inner_protocol;
 754         if (data->vlan_tci & VLAN_CFI_MASK)
 755                 __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci & ~VLAN_CFI_MASK);
 756         else
 757                 __vlan_hwaccel_clear_tag(skb);
 758 
 759         /* Reconstruct the MAC header.  */
 760         skb_push(skb, data->l2_len);
 761         memcpy(skb->data, &data->l2_data, data->l2_len);
 762         skb_postpush_rcsum(skb, skb->data, data->l2_len);
 763         skb_reset_mac_header(skb);
 764 
 765         if (eth_p_mpls(skb->protocol)) {
 766                 skb->inner_network_header = skb->network_header;
 767                 skb_set_network_header(skb, data->network_offset);
 768                 skb_reset_mac_len(skb);
 769         }
 770 
 771         ovs_vport_send(vport, skb, data->mac_proto);
 772         return 0;
 773 }
 774 
 775 static unsigned int
 776 ovs_dst_get_mtu(const struct dst_entry *dst)
 777 {
 778         return dst->dev->mtu;
 779 }
 780 
 781 static struct dst_ops ovs_dst_ops = {
 782         .family = AF_UNSPEC,
 783         .mtu = ovs_dst_get_mtu,
 784 };
 785 
 786 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
 787  * ovs_vport_output(), which is called once per fragmented packet.
 788  */
 789 static void prepare_frag(struct vport *vport, struct sk_buff *skb,
 790                          u16 orig_network_offset, u8 mac_proto)
 791 {
 792         unsigned int hlen = skb_network_offset(skb);
 793         struct ovs_frag_data *data;
 794 
 795         data = this_cpu_ptr(&ovs_frag_data_storage);
 796         data->dst = skb->_skb_refdst;
 797         data->vport = vport;
 798         data->cb = *OVS_CB(skb);
 799         data->inner_protocol = skb->inner_protocol;
 800         data->network_offset = orig_network_offset;
 801         if (skb_vlan_tag_present(skb))
 802                 data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
 803         else
 804                 data->vlan_tci = 0;
 805         data->vlan_proto = skb->vlan_proto;
 806         data->mac_proto = mac_proto;
 807         data->l2_len = hlen;
 808         memcpy(&data->l2_data, skb->data, hlen);
 809 
 810         memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
 811         skb_pull(skb, hlen);
 812 }
 813 
 814 static void ovs_fragment(struct net *net, struct vport *vport,
 815                          struct sk_buff *skb, u16 mru,
 816                          struct sw_flow_key *key)
 817 {
 818         u16 orig_network_offset = 0;
 819 
 820         if (eth_p_mpls(skb->protocol)) {
 821                 orig_network_offset = skb_network_offset(skb);
 822                 skb->network_header = skb->inner_network_header;
 823         }
 824 
 825         if (skb_network_offset(skb) > MAX_L2_LEN) {
 826                 OVS_NLERR(1, "L2 header too long to fragment");
 827                 goto err;
 828         }
 829 
 830         if (key->eth.type == htons(ETH_P_IP)) {
 831                 struct dst_entry ovs_dst;
 832                 unsigned long orig_dst;
 833 
 834                 prepare_frag(vport, skb, orig_network_offset,
 835                              ovs_key_mac_proto(key));
 836                 dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
 837                          DST_OBSOLETE_NONE, DST_NOCOUNT);
 838                 ovs_dst.dev = vport->dev;
 839 
 840                 orig_dst = skb->_skb_refdst;
 841                 skb_dst_set_noref(skb, &ovs_dst);
 842                 IPCB(skb)->frag_max_size = mru;
 843 
 844                 ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
 845                 refdst_drop(orig_dst);
 846         } else if (key->eth.type == htons(ETH_P_IPV6)) {
 847                 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
 848                 unsigned long orig_dst;
 849                 struct rt6_info ovs_rt;
 850 
 851                 if (!v6ops)
 852                         goto err;
 853 
 854                 prepare_frag(vport, skb, orig_network_offset,
 855                              ovs_key_mac_proto(key));
 856                 memset(&ovs_rt, 0, sizeof(ovs_rt));
 857                 dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
 858                          DST_OBSOLETE_NONE, DST_NOCOUNT);
 859                 ovs_rt.dst.dev = vport->dev;
 860 
 861                 orig_dst = skb->_skb_refdst;
 862                 skb_dst_set_noref(skb, &ovs_rt.dst);
 863                 IP6CB(skb)->frag_max_size = mru;
 864 
 865                 v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
 866                 refdst_drop(orig_dst);
 867         } else {
 868                 WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
 869                           ovs_vport_name(vport), ntohs(key->eth.type), mru,
 870                           vport->dev->mtu);
 871                 goto err;
 872         }
 873 
 874         return;
 875 err:
 876         kfree_skb(skb);
 877 }
 878 
 879 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
 880                       struct sw_flow_key *key)
 881 {
 882         struct vport *vport = ovs_vport_rcu(dp, out_port);
 883 
 884         if (likely(vport)) {
 885                 u16 mru = OVS_CB(skb)->mru;
 886                 u32 cutlen = OVS_CB(skb)->cutlen;
 887 
 888                 if (unlikely(cutlen > 0)) {
 889                         if (skb->len - cutlen > ovs_mac_header_len(key))
 890                                 pskb_trim(skb, skb->len - cutlen);
 891                         else
 892                                 pskb_trim(skb, ovs_mac_header_len(key));
 893                 }
 894 
 895                 if (likely(!mru ||
 896                            (skb->len <= mru + vport->dev->hard_header_len))) {
 897                         ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
 898                 } else if (mru <= vport->dev->mtu) {
 899                         struct net *net = read_pnet(&dp->net);
 900 
 901                         ovs_fragment(net, vport, skb, mru, key);
 902                 } else {
 903                         kfree_skb(skb);
 904                 }
 905         } else {
 906                 kfree_skb(skb);
 907         }
 908 }
 909 
 910 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
 911                             struct sw_flow_key *key, const struct nlattr *attr,
 912                             const struct nlattr *actions, int actions_len,
 913                             uint32_t cutlen)
 914 {
 915         struct dp_upcall_info upcall;
 916         const struct nlattr *a;
 917         int rem;
 918 
 919         memset(&upcall, 0, sizeof(upcall));
 920         upcall.cmd = OVS_PACKET_CMD_ACTION;
 921         upcall.mru = OVS_CB(skb)->mru;
 922 
 923         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
 924                  a = nla_next(a, &rem)) {
 925                 switch (nla_type(a)) {
 926                 case OVS_USERSPACE_ATTR_USERDATA:
 927                         upcall.userdata = a;
 928                         break;
 929 
 930                 case OVS_USERSPACE_ATTR_PID:
 931                         upcall.portid = nla_get_u32(a);
 932                         break;
 933 
 934                 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
 935                         /* Get out tunnel info. */
 936                         struct vport *vport;
 937 
 938                         vport = ovs_vport_rcu(dp, nla_get_u32(a));
 939                         if (vport) {
 940                                 int err;
 941 
 942                                 err = dev_fill_metadata_dst(vport->dev, skb);
 943                                 if (!err)
 944                                         upcall.egress_tun_info = skb_tunnel_info(skb);
 945                         }
 946 
 947                         break;
 948                 }
 949 
 950                 case OVS_USERSPACE_ATTR_ACTIONS: {
 951                         /* Include actions. */
 952                         upcall.actions = actions;
 953                         upcall.actions_len = actions_len;
 954                         break;
 955                 }
 956 
 957                 } /* End of switch. */
 958         }
 959 
 960         return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
 961 }
 962 
 963 /* When 'last' is true, sample() should always consume the 'skb'.
 964  * Otherwise, sample() should keep 'skb' intact regardless what
 965  * actions are executed within sample().
 966  */
 967 static int sample(struct datapath *dp, struct sk_buff *skb,
 968                   struct sw_flow_key *key, const struct nlattr *attr,
 969                   bool last)
 970 {
 971         struct nlattr *actions;
 972         struct nlattr *sample_arg;
 973         int rem = nla_len(attr);
 974         const struct sample_arg *arg;
 975         bool clone_flow_key;
 976 
 977         /* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */
 978         sample_arg = nla_data(attr);
 979         arg = nla_data(sample_arg);
 980         actions = nla_next(sample_arg, &rem);
 981 
 982         if ((arg->probability != U32_MAX) &&
 983             (!arg->probability || prandom_u32() > arg->probability)) {
 984                 if (last)
 985                         consume_skb(skb);
 986                 return 0;
 987         }
 988 
 989         clone_flow_key = !arg->exec;
 990         return clone_execute(dp, skb, key, 0, actions, rem, last,
 991                              clone_flow_key);
 992 }
 993 
 994 /* When 'last' is true, clone() should always consume the 'skb'.
 995  * Otherwise, clone() should keep 'skb' intact regardless what
 996  * actions are executed within clone().
 997  */
 998 static int clone(struct datapath *dp, struct sk_buff *skb,
 999                  struct sw_flow_key *key, const struct nlattr *attr,
1000                  bool last)
1001 {
1002         struct nlattr *actions;
1003         struct nlattr *clone_arg;
1004         int rem = nla_len(attr);
1005         bool dont_clone_flow_key;
1006 
1007         /* The first action is always 'OVS_CLONE_ATTR_ARG'. */
1008         clone_arg = nla_data(attr);
1009         dont_clone_flow_key = nla_get_u32(clone_arg);
1010         actions = nla_next(clone_arg, &rem);
1011 
1012         return clone_execute(dp, skb, key, 0, actions, rem, last,
1013                              !dont_clone_flow_key);
1014 }
1015 
1016 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
1017                          const struct nlattr *attr)
1018 {
1019         struct ovs_action_hash *hash_act = nla_data(attr);
1020         u32 hash = 0;
1021 
1022         /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
1023         hash = skb_get_hash(skb);
1024         hash = jhash_1word(hash, hash_act->hash_basis);
1025         if (!hash)
1026                 hash = 0x1;
1027 
1028         key->ovs_flow_hash = hash;
1029 }
1030 
1031 static int execute_set_action(struct sk_buff *skb,
1032                               struct sw_flow_key *flow_key,
1033                               const struct nlattr *a)
1034 {
1035         /* Only tunnel set execution is supported without a mask. */
1036         if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
1037                 struct ovs_tunnel_info *tun = nla_data(a);
1038 
1039                 skb_dst_drop(skb);
1040                 dst_hold((struct dst_entry *)tun->tun_dst);
1041                 skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
1042                 return 0;
1043         }
1044 
1045         return -EINVAL;
1046 }
1047 
1048 /* Mask is at the midpoint of the data. */
1049 #define get_mask(a, type) ((const type)nla_data(a) + 1)
1050 
1051 static int execute_masked_set_action(struct sk_buff *skb,
1052                                      struct sw_flow_key *flow_key,
1053                                      const struct nlattr *a)
1054 {
1055         int err = 0;
1056 
1057         switch (nla_type(a)) {
1058         case OVS_KEY_ATTR_PRIORITY:
1059                 OVS_SET_MASKED(skb->priority, nla_get_u32(a),
1060                                *get_mask(a, u32 *));
1061                 flow_key->phy.priority = skb->priority;
1062                 break;
1063 
1064         case OVS_KEY_ATTR_SKB_MARK:
1065                 OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
1066                 flow_key->phy.skb_mark = skb->mark;
1067                 break;
1068 
1069         case OVS_KEY_ATTR_TUNNEL_INFO:
1070                 /* Masked data not supported for tunnel. */
1071                 err = -EINVAL;
1072                 break;
1073 
1074         case OVS_KEY_ATTR_ETHERNET:
1075                 err = set_eth_addr(skb, flow_key, nla_data(a),
1076                                    get_mask(a, struct ovs_key_ethernet *));
1077                 break;
1078 
1079         case OVS_KEY_ATTR_NSH:
1080                 err = set_nsh(skb, flow_key, a);
1081                 break;
1082 
1083         case OVS_KEY_ATTR_IPV4:
1084                 err = set_ipv4(skb, flow_key, nla_data(a),
1085                                get_mask(a, struct ovs_key_ipv4 *));
1086                 break;
1087 
1088         case OVS_KEY_ATTR_IPV6:
1089                 err = set_ipv6(skb, flow_key, nla_data(a),
1090                                get_mask(a, struct ovs_key_ipv6 *));
1091                 break;
1092 
1093         case OVS_KEY_ATTR_TCP:
1094                 err = set_tcp(skb, flow_key, nla_data(a),
1095                               get_mask(a, struct ovs_key_tcp *));
1096                 break;
1097 
1098         case OVS_KEY_ATTR_UDP:
1099                 err = set_udp(skb, flow_key, nla_data(a),
1100                               get_mask(a, struct ovs_key_udp *));
1101                 break;
1102 
1103         case OVS_KEY_ATTR_SCTP:
1104                 err = set_sctp(skb, flow_key, nla_data(a),
1105                                get_mask(a, struct ovs_key_sctp *));
1106                 break;
1107 
1108         case OVS_KEY_ATTR_MPLS:
1109                 err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1110                                                                     __be32 *));
1111                 break;
1112 
1113         case OVS_KEY_ATTR_CT_STATE:
1114         case OVS_KEY_ATTR_CT_ZONE:
1115         case OVS_KEY_ATTR_CT_MARK:
1116         case OVS_KEY_ATTR_CT_LABELS:
1117         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
1118         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
1119                 err = -EINVAL;
1120                 break;
1121         }
1122 
1123         return err;
1124 }
1125 
1126 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1127                           struct sw_flow_key *key,
1128                           const struct nlattr *a, bool last)
1129 {
1130         u32 recirc_id;
1131 
1132         if (!is_flow_key_valid(key)) {
1133                 int err;
1134 
1135                 err = ovs_flow_key_update(skb, key);
1136                 if (err)
1137                         return err;
1138         }
1139         BUG_ON(!is_flow_key_valid(key));
1140 
1141         recirc_id = nla_get_u32(a);
1142         return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true);
1143 }
1144 
1145 static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb,
1146                                  struct sw_flow_key *key,
1147                                  const struct nlattr *attr, bool last)
1148 {
1149         const struct nlattr *actions, *cpl_arg;
1150         const struct check_pkt_len_arg *arg;
1151         int rem = nla_len(attr);
1152         bool clone_flow_key;
1153 
1154         /* The first netlink attribute in 'attr' is always
1155          * 'OVS_CHECK_PKT_LEN_ATTR_ARG'.
1156          */
1157         cpl_arg = nla_data(attr);
1158         arg = nla_data(cpl_arg);
1159 
1160         if (skb->len <= arg->pkt_len) {
1161                 /* Second netlink attribute in 'attr' is always
1162                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
1163                  */
1164                 actions = nla_next(cpl_arg, &rem);
1165                 clone_flow_key = !arg->exec_for_lesser_equal;
1166         } else {
1167                 /* Third netlink attribute in 'attr' is always
1168                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'.
1169                  */
1170                 actions = nla_next(cpl_arg, &rem);
1171                 actions = nla_next(actions, &rem);
1172                 clone_flow_key = !arg->exec_for_greater;
1173         }
1174 
1175         return clone_execute(dp, skb, key, 0, nla_data(actions),
1176                              nla_len(actions), last, clone_flow_key);
1177 }
1178 
1179 /* Execute a list of actions against 'skb'. */
1180 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1181                               struct sw_flow_key *key,
1182                               const struct nlattr *attr, int len)
1183 {
1184         const struct nlattr *a;
1185         int rem;
1186 
1187         for (a = attr, rem = len; rem > 0;
1188              a = nla_next(a, &rem)) {
1189                 int err = 0;
1190 
1191                 switch (nla_type(a)) {
1192                 case OVS_ACTION_ATTR_OUTPUT: {
1193                         int port = nla_get_u32(a);
1194                         struct sk_buff *clone;
1195 
1196                         /* Every output action needs a separate clone
1197                          * of 'skb', In case the output action is the
1198                          * last action, cloning can be avoided.
1199                          */
1200                         if (nla_is_last(a, rem)) {
1201                                 do_output(dp, skb, port, key);
1202                                 /* 'skb' has been used for output.
1203                                  */
1204                                 return 0;
1205                         }
1206 
1207                         clone = skb_clone(skb, GFP_ATOMIC);
1208                         if (clone)
1209                                 do_output(dp, clone, port, key);
1210                         OVS_CB(skb)->cutlen = 0;
1211                         break;
1212                 }
1213 
1214                 case OVS_ACTION_ATTR_TRUNC: {
1215                         struct ovs_action_trunc *trunc = nla_data(a);
1216 
1217                         if (skb->len > trunc->max_len)
1218                                 OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1219                         break;
1220                 }
1221 
1222                 case OVS_ACTION_ATTR_USERSPACE:
1223                         output_userspace(dp, skb, key, a, attr,
1224                                                      len, OVS_CB(skb)->cutlen);
1225                         OVS_CB(skb)->cutlen = 0;
1226                         break;
1227 
1228                 case OVS_ACTION_ATTR_HASH:
1229                         execute_hash(skb, key, a);
1230                         break;
1231 
1232                 case OVS_ACTION_ATTR_PUSH_MPLS:
1233                         err = push_mpls(skb, key, nla_data(a));
1234                         break;
1235 
1236                 case OVS_ACTION_ATTR_POP_MPLS:
1237                         err = pop_mpls(skb, key, nla_get_be16(a));
1238                         break;
1239 
1240                 case OVS_ACTION_ATTR_PUSH_VLAN:
1241                         err = push_vlan(skb, key, nla_data(a));
1242                         break;
1243 
1244                 case OVS_ACTION_ATTR_POP_VLAN:
1245                         err = pop_vlan(skb, key);
1246                         break;
1247 
1248                 case OVS_ACTION_ATTR_RECIRC: {
1249                         bool last = nla_is_last(a, rem);
1250 
1251                         err = execute_recirc(dp, skb, key, a, last);
1252                         if (last) {
1253                                 /* If this is the last action, the skb has
1254                                  * been consumed or freed.
1255                                  * Return immediately.
1256                                  */
1257                                 return err;
1258                         }
1259                         break;
1260                 }
1261 
1262                 case OVS_ACTION_ATTR_SET:
1263                         err = execute_set_action(skb, key, nla_data(a));
1264                         break;
1265 
1266                 case OVS_ACTION_ATTR_SET_MASKED:
1267                 case OVS_ACTION_ATTR_SET_TO_MASKED:
1268                         err = execute_masked_set_action(skb, key, nla_data(a));
1269                         break;
1270 
1271                 case OVS_ACTION_ATTR_SAMPLE: {
1272                         bool last = nla_is_last(a, rem);
1273 
1274                         err = sample(dp, skb, key, a, last);
1275                         if (last)
1276                                 return err;
1277 
1278                         break;
1279                 }
1280 
1281                 case OVS_ACTION_ATTR_CT:
1282                         if (!is_flow_key_valid(key)) {
1283                                 err = ovs_flow_key_update(skb, key);
1284                                 if (err)
1285                                         return err;
1286                         }
1287 
1288                         err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1289                                              nla_data(a));
1290 
1291                         /* Hide stolen IP fragments from user space. */
1292                         if (err)
1293                                 return err == -EINPROGRESS ? 0 : err;
1294                         break;
1295 
1296                 case OVS_ACTION_ATTR_CT_CLEAR:
1297                         err = ovs_ct_clear(skb, key);
1298                         break;
1299 
1300                 case OVS_ACTION_ATTR_PUSH_ETH:
1301                         err = push_eth(skb, key, nla_data(a));
1302                         break;
1303 
1304                 case OVS_ACTION_ATTR_POP_ETH:
1305                         err = pop_eth(skb, key);
1306                         break;
1307 
1308                 case OVS_ACTION_ATTR_PUSH_NSH: {
1309                         u8 buffer[NSH_HDR_MAX_LEN];
1310                         struct nshhdr *nh = (struct nshhdr *)buffer;
1311 
1312                         err = nsh_hdr_from_nlattr(nla_data(a), nh,
1313                                                   NSH_HDR_MAX_LEN);
1314                         if (unlikely(err))
1315                                 break;
1316                         err = push_nsh(skb, key, nh);
1317                         break;
1318                 }
1319 
1320                 case OVS_ACTION_ATTR_POP_NSH:
1321                         err = pop_nsh(skb, key);
1322                         break;
1323 
1324                 case OVS_ACTION_ATTR_METER:
1325                         if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
1326                                 consume_skb(skb);
1327                                 return 0;
1328                         }
1329                         break;
1330 
1331                 case OVS_ACTION_ATTR_CLONE: {
1332                         bool last = nla_is_last(a, rem);
1333 
1334                         err = clone(dp, skb, key, a, last);
1335                         if (last)
1336                                 return err;
1337 
1338                         break;
1339                 }
1340 
1341                 case OVS_ACTION_ATTR_CHECK_PKT_LEN: {
1342                         bool last = nla_is_last(a, rem);
1343 
1344                         err = execute_check_pkt_len(dp, skb, key, a, last);
1345                         if (last)
1346                                 return err;
1347 
1348                         break;
1349                 }
1350                 }
1351 
1352                 if (unlikely(err)) {
1353                         kfree_skb(skb);
1354                         return err;
1355                 }
1356         }
1357 
1358         consume_skb(skb);
1359         return 0;
1360 }
1361 
1362 /* Execute the actions on the clone of the packet. The effect of the
1363  * execution does not affect the original 'skb' nor the original 'key'.
1364  *
1365  * The execution may be deferred in case the actions can not be executed
1366  * immediately.
1367  */
1368 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
1369                          struct sw_flow_key *key, u32 recirc_id,
1370                          const struct nlattr *actions, int len,
1371                          bool last, bool clone_flow_key)
1372 {
1373         struct deferred_action *da;
1374         struct sw_flow_key *clone;
1375 
1376         skb = last ? skb : skb_clone(skb, GFP_ATOMIC);
1377         if (!skb) {
1378                 /* Out of memory, skip this action.
1379                  */
1380                 return 0;
1381         }
1382 
1383         /* When clone_flow_key is false, the 'key' will not be change
1384          * by the actions, then the 'key' can be used directly.
1385          * Otherwise, try to clone key from the next recursion level of
1386          * 'flow_keys'. If clone is successful, execute the actions
1387          * without deferring.
1388          */
1389         clone = clone_flow_key ? clone_key(key) : key;
1390         if (clone) {
1391                 int err = 0;
1392 
1393                 if (actions) { /* Sample action */
1394                         if (clone_flow_key)
1395                                 __this_cpu_inc(exec_actions_level);
1396 
1397                         err = do_execute_actions(dp, skb, clone,
1398                                                  actions, len);
1399 
1400                         if (clone_flow_key)
1401                                 __this_cpu_dec(exec_actions_level);
1402                 } else { /* Recirc action */
1403                         clone->recirc_id = recirc_id;
1404                         ovs_dp_process_packet(skb, clone);
1405                 }
1406                 return err;
1407         }
1408 
1409         /* Out of 'flow_keys' space. Defer actions */
1410         da = add_deferred_actions(skb, key, actions, len);
1411         if (da) {
1412                 if (!actions) { /* Recirc action */
1413                         key = &da->pkt_key;
1414                         key->recirc_id = recirc_id;
1415                 }
1416         } else {
1417                 /* Out of per CPU action FIFO space. Drop the 'skb' and
1418                  * log an error.
1419                  */
1420                 kfree_skb(skb);
1421 
1422                 if (net_ratelimit()) {
1423                         if (actions) { /* Sample action */
1424                                 pr_warn("%s: deferred action limit reached, drop sample action\n",
1425                                         ovs_dp_name(dp));
1426                         } else {  /* Recirc action */
1427                                 pr_warn("%s: deferred action limit reached, drop recirc action\n",
1428                                         ovs_dp_name(dp));
1429                         }
1430                 }
1431         }
1432         return 0;
1433 }
1434 
1435 static void process_deferred_actions(struct datapath *dp)
1436 {
1437         struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1438 
1439         /* Do not touch the FIFO in case there is no deferred actions. */
1440         if (action_fifo_is_empty(fifo))
1441                 return;
1442 
1443         /* Finishing executing all deferred actions. */
1444         do {
1445                 struct deferred_action *da = action_fifo_get(fifo);
1446                 struct sk_buff *skb = da->skb;
1447                 struct sw_flow_key *key = &da->pkt_key;
1448                 const struct nlattr *actions = da->actions;
1449                 int actions_len = da->actions_len;
1450 
1451                 if (actions)
1452                         do_execute_actions(dp, skb, key, actions, actions_len);
1453                 else
1454                         ovs_dp_process_packet(skb, key);
1455         } while (!action_fifo_is_empty(fifo));
1456 
1457         /* Reset FIFO for the next packet.  */
1458         action_fifo_init(fifo);
1459 }
1460 
1461 /* Execute a list of actions against 'skb'. */
1462 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1463                         const struct sw_flow_actions *acts,
1464                         struct sw_flow_key *key)
1465 {
1466         int err, level;
1467 
1468         level = __this_cpu_inc_return(exec_actions_level);
1469         if (unlikely(level > OVS_RECURSION_LIMIT)) {
1470                 net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1471                                      ovs_dp_name(dp));
1472                 kfree_skb(skb);
1473                 err = -ENETDOWN;
1474                 goto out;
1475         }
1476 
1477         OVS_CB(skb)->acts_origlen = acts->orig_len;
1478         err = do_execute_actions(dp, skb, key,
1479                                  acts->actions, acts->actions_len);
1480 
1481         if (level == 1)
1482                 process_deferred_actions(dp);
1483 
1484 out:
1485         __this_cpu_dec(exec_actions_level);
1486         return err;
1487 }
1488 
1489 int action_fifos_init(void)
1490 {
1491         action_fifos = alloc_percpu(struct action_fifo);
1492         if (!action_fifos)
1493                 return -ENOMEM;
1494 
1495         flow_keys = alloc_percpu(struct action_flow_keys);
1496         if (!flow_keys) {
1497                 free_percpu(action_fifos);
1498                 return -ENOMEM;
1499         }
1500 
1501         return 0;
1502 }
1503 
1504 void action_fifos_exit(void)
1505 {
1506         free_percpu(action_fifos);
1507         free_percpu(flow_keys);
1508 }
/* [<][>][^][v][top][bottom][index][help] */
root/net/openvswitch/actions.c

DEFINITIONS
