ofproto/ofproto-dpif-sflow.c

   1 /*
   2  * Copyright (c) 2009, 2010, 2011, 2012, 2013, 2014 Nicira, Inc.
   3  * Copyright (c) 2009 InMon Corp.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at:
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <config.h>
  19 #include "ofproto-dpif-sflow.h"
  20 #include <inttypes.h>
  21 #include <sys/socket.h>
  22 #include <net/if.h>
  23 #include <stdlib.h>
  24 #include "collectors.h"
  25 #include "compiler.h"
  26 #include "dpif.h"
  27 #include "hash.h"
  28 #include "hmap.h"
  29 #include "netdev.h"
  30 #include "netlink.h"
  31 #include "ofpbuf.h"
  32 #include "ofproto.h"
  33 #include "packets.h"
  34 #include "poll-loop.h"
  35 #include "ovs-router.h"
  36 #include "route-table.h"
  37 #include "sflow_api.h"
  38 #include "socket-util.h"
  39 #include "timeval.h"
  40 #include "vlog.h"
  41 #include "lib/odp-util.h"
  42 #include "ofproto-provider.h"
  43
  44 VLOG_DEFINE_THIS_MODULE(sflow);
  45
  46 static struct ovs_mutex mutex;
  47
  48 struct dpif_sflow_port {
  49     struct hmap_node hmap_node; /* In struct dpif_sflow's "ports" hmap. */
  50     SFLDataSource_instance dsi; /* sFlow library's notion of port number. */
  51     struct ofport *ofport;      /* To retrive port stats. */
  52     odp_port_t odp_port;
  53 };
  54
  55 struct dpif_sflow {
  56     struct collectors *collectors;
  57     SFLAgent *sflow_agent;
  58     struct ofproto_sflow_options *options;
  59     time_t next_tick;
  60     size_t n_flood, n_all;
  61     struct hmap ports;          /* Contains "struct dpif_sflow_port"s. */
  62     uint32_t probability;
  63     struct ovs_refcount ref_cnt;
  64 };
  65
  66 static void dpif_sflow_del_port__(struct dpif_sflow *,
  67                                   struct dpif_sflow_port *);
  68
  69 #define RECEIVER_INDEX 1
  70
  71 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  72
  73 static bool
  74 nullable_string_is_equal(const char *a, const char *b)
  75 {
  76     return a ? b && !strcmp(a, b) : !b;
  77 }
  78
  79 static bool
  80 ofproto_sflow_options_equal(const struct ofproto_sflow_options *a,
  81                          const struct ofproto_sflow_options *b)
  82 {
  83     return (sset_equals(&a->targets, &b->targets)
  84             && a->sampling_rate == b->sampling_rate
  85             && a->polling_interval == b->polling_interval
  86             && a->header_len == b->header_len
  87             && a->sub_id == b->sub_id
  88             && nullable_string_is_equal(a->agent_device, b->agent_device)
  89             && nullable_string_is_equal(a->control_ip, b->control_ip));
  90 }
  91
  92 static struct ofproto_sflow_options *
  93 ofproto_sflow_options_clone(const struct ofproto_sflow_options *old)
  94 {
  95     struct ofproto_sflow_options *new = xmemdup(old, sizeof *old);
  96     sset_clone(&new->targets, &old->targets);
  97     new->agent_device = old->agent_device ? xstrdup(old->agent_device) : NULL;
  98     new->control_ip = old->control_ip ? xstrdup(old->control_ip) : NULL;
  99     return new;
 100 }
 101
 102 static void
 103 ofproto_sflow_options_destroy(struct ofproto_sflow_options *options)
 104 {
 105     if (options) {
 106         sset_destroy(&options->targets);
 107         free(options->agent_device);
 108         free(options->control_ip);
 109         free(options);
 110     }
 111 }
 112
 113 /* sFlow library callback to allocate memory. */
 114 static void *
 115 sflow_agent_alloc_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
 116                      size_t bytes)
 117 {
 118     return calloc(1, bytes);
 119 }
 120
 121 /* sFlow library callback to free memory. */
 122 static int
 123 sflow_agent_free_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
 124                     void *obj)
 125 {
 126     free(obj);
 127     return 0;
 128 }
 129
 130 /* sFlow library callback to report error. */
 131 static void
 132 sflow_agent_error_cb(void *magic OVS_UNUSED, SFLAgent *agent OVS_UNUSED,
 133                      char *msg)
 134 {
 135     VLOG_WARN("sFlow agent error: %s", msg);
 136 }
 137
 138 /* sFlow library callback to send datagram. */
 139 static void
 140 sflow_agent_send_packet_cb(void *ds_, SFLAgent *agent OVS_UNUSED,
 141                            SFLReceiver *receiver OVS_UNUSED, u_char *pkt,
 142                            uint32_t pktLen)
 143 {
 144     struct dpif_sflow *ds = ds_;
 145     collectors_send(ds->collectors, pkt, pktLen);
 146 }
 147
 148 static struct dpif_sflow_port *
 149 dpif_sflow_find_port(const struct dpif_sflow *ds, odp_port_t odp_port)
 150     OVS_REQUIRES(mutex)
 151 {
 152     struct dpif_sflow_port *dsp;
 153
 154     HMAP_FOR_EACH_IN_BUCKET (dsp, hmap_node, hash_odp_port(odp_port),
 155                              &ds->ports) {
 156         if (dsp->odp_port == odp_port) {
 157             return dsp;
 158         }
 159     }
 160     return NULL;
 161 }
 162
 163 static void
 164 sflow_agent_get_counters(void *ds_, SFLPoller *poller,
 165                          SFL_COUNTERS_SAMPLE_TYPE *cs)
 166     OVS_REQUIRES(mutex)
 167 {
 168     struct dpif_sflow *ds = ds_;
 169     SFLCounters_sample_element elem;
 170     enum netdev_features current;
 171     struct dpif_sflow_port *dsp;
 172     SFLIf_counters *counters;
 173     struct netdev_stats stats;
 174     enum netdev_flags flags;
 175
 176     dsp = dpif_sflow_find_port(ds, u32_to_odp(poller->bridgePort));
 177     if (!dsp) {
 178         return;
 179     }
 180
 181     elem.tag = SFLCOUNTERS_GENERIC;
 182     counters = &elem.counterBlock.generic;
 183     counters->ifIndex = SFL_DS_INDEX(poller->dsi);
 184     counters->ifType = 6;
 185     if (!netdev_get_features(dsp->ofport->netdev, &current, NULL, NULL, NULL)) {
 186         /* The values of ifDirection come from MAU MIB (RFC 2668): 0 = unknown,
 187            1 = full-duplex, 2 = half-duplex, 3 = in, 4=out */
 188         counters->ifSpeed = netdev_features_to_bps(current, 0);
 189         counters->ifDirection = (netdev_features_is_full_duplex(current)
 190                                  ? 1 : 2);
 191     } else {
 192         counters->ifSpeed = 100000000;
 193         counters->ifDirection = 0;
 194     }
 195     if (!netdev_get_flags(dsp->ofport->netdev, &flags) && flags & NETDEV_UP) {
 196         counters->ifStatus = 1; /* ifAdminStatus up. */
 197         if (netdev_get_carrier(dsp->ofport->netdev)) {
 198             counters->ifStatus |= 2; /* ifOperStatus us. */
 199         }
 200     } else {
 201         counters->ifStatus = 0;  /* Down. */
 202     }
 203
 204     /* XXX
 205        1. Is the multicast counter filled in?
 206        2. Does the multicast counter include broadcasts?
 207        3. Does the rx_packets counter include multicasts/broadcasts?
 208     */
 209     ofproto_port_get_stats(dsp->ofport, &stats);
 210     counters->ifInOctets = stats.rx_bytes;
 211     counters->ifInUcastPkts = stats.rx_packets;
 212     counters->ifInMulticastPkts = stats.multicast;
 213     counters->ifInBroadcastPkts = -1;
 214     counters->ifInDiscards = stats.rx_dropped;
 215     counters->ifInErrors = stats.rx_errors;
 216     counters->ifInUnknownProtos = -1;
 217     counters->ifOutOctets = stats.tx_bytes;
 218     counters->ifOutUcastPkts = stats.tx_packets;
 219     counters->ifOutMulticastPkts = -1;
 220     counters->ifOutBroadcastPkts = -1;
 221     counters->ifOutDiscards = stats.tx_dropped;
 222     counters->ifOutErrors = stats.tx_errors;
 223     counters->ifPromiscuousMode = 0;
 224
 225     SFLADD_ELEMENT(cs, &elem);
 226     sfl_poller_writeCountersSample(poller, cs);
 227 }
 228
 229 /* Obtains an address to use for the local sFlow agent and stores it into
 230  * '*agent_addr'.  Returns true if successful, false on failure.
 231  *
 232  * The sFlow agent address should be a local IP address that is persistent and
 233  * reachable over the network, if possible.  The IP address associated with
 234  * 'agent_device' is used if it has one, and otherwise 'control_ip', the IP
 235  * address used to talk to the controller.  If the agent device is not
 236  * specified then it is figured out by taking a look at the routing table based
 237  * on 'targets'. */
 238 static bool
 239 sflow_choose_agent_address(const char *agent_device,
 240                            const struct sset *targets,
 241                            const char *control_ip,
 242                            SFLAddress *agent_addr)
 243 {
 244     const char *target;
 245     struct in_addr in4;
 246
 247     memset(agent_addr, 0, sizeof *agent_addr);
 248     agent_addr->type = SFLADDRESSTYPE_IP_V4;
 249
 250     if (agent_device) {
 251         if (!netdev_get_in4_by_name(agent_device, &in4)) {
 252             goto success;
 253         }
 254     }
 255
 256     SSET_FOR_EACH (target, targets) {
 257         union {
 258             struct sockaddr_storage ss;
 259             struct sockaddr_in sin;
 260         } sa;
 261         char name[IFNAMSIZ];
 262
 263         if (inet_parse_active(target, SFL_DEFAULT_COLLECTOR_PORT, &sa.ss)
 264             && sa.ss.ss_family == AF_INET) {
 265             ovs_be32 gw;
 266
 267             if (ovs_router_lookup(sa.sin.sin_addr.s_addr, name, &gw)
 268                 && !netdev_get_in4_by_name(name, &in4)) {
 269                 goto success;
 270             }
 271         }
 272     }
 273
 274     if (control_ip && !lookup_ip(control_ip, &in4)) {
 275         goto success;
 276     }
 277
 278     VLOG_ERR("could not determine IP address for sFlow agent");
 279     return false;
 280
 281 success:
 282     agent_addr->address.ip_v4.addr = (OVS_FORCE uint32_t) in4.s_addr;
 283     return true;
 284 }
 285
 286 static void
 287 dpif_sflow_clear__(struct dpif_sflow *ds) OVS_REQUIRES(mutex)
 288 {
 289     if (ds->sflow_agent) {
 290         sfl_agent_release(ds->sflow_agent);
 291         free(ds->sflow_agent);
 292         ds->sflow_agent = NULL;
 293     }
 294     collectors_destroy(ds->collectors);
 295     ds->collectors = NULL;
 296     ofproto_sflow_options_destroy(ds->options);
 297     ds->options = NULL;
 298
 299     /* Turn off sampling to save CPU cycles. */
 300     ds->probability = 0;
 301 }
 302
 303 void
 304 dpif_sflow_clear(struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 305 {
 306     ovs_mutex_lock(&mutex);
 307     dpif_sflow_clear__(ds);
 308     ovs_mutex_unlock(&mutex);
 309 }
 310
 311 bool
 312 dpif_sflow_is_enabled(const struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 313 {
 314     bool enabled;
 315
 316     ovs_mutex_lock(&mutex);
 317     enabled = ds->collectors != NULL;
 318     ovs_mutex_unlock(&mutex);
 319     return enabled;
 320 }
 321
 322 struct dpif_sflow *
 323 dpif_sflow_create(void)
 324 {
 325     static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
 326     struct dpif_sflow *ds;
 327
 328     if (ovsthread_once_start(&once)) {
 329         ovs_mutex_init_recursive(&mutex);
 330         ovsthread_once_done(&once);
 331     }
 332
 333     ds = xcalloc(1, sizeof *ds);
 334     ds->next_tick = time_now() + 1;
 335     hmap_init(&ds->ports);
 336     ds->probability = 0;
 337     route_table_register();
 338     ovs_refcount_init(&ds->ref_cnt);
 339
 340     return ds;
 341 }
 342
 343 struct dpif_sflow *
 344 dpif_sflow_ref(const struct dpif_sflow *ds_)
 345 {
 346     struct dpif_sflow *ds = CONST_CAST(struct dpif_sflow *, ds_);
 347     if (ds) {
 348         ovs_refcount_ref(&ds->ref_cnt);
 349     }
 350     return ds;
 351 }
 352
 353 /* 32-bit fraction of packets to sample with.  A value of 0 samples no packets,
 354  * a value of %UINT32_MAX samples all packets and intermediate values sample
 355  * intermediate fractions of packets. */
 356 uint32_t
 357 dpif_sflow_get_probability(const struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 358 {
 359     uint32_t probability;
 360     ovs_mutex_lock(&mutex);
 361     probability = ds->probability;
 362     ovs_mutex_unlock(&mutex);
 363     return probability;
 364 }
 365
 366 void
 367 dpif_sflow_unref(struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 368 {
 369     if (ds && ovs_refcount_unref_relaxed(&ds->ref_cnt) == 1) {
 370         struct dpif_sflow_port *dsp, *next;
 371
 372         route_table_unregister();
 373         dpif_sflow_clear(ds);
 374         HMAP_FOR_EACH_SAFE (dsp, next, hmap_node, &ds->ports) {
 375             dpif_sflow_del_port__(ds, dsp);
 376         }
 377         hmap_destroy(&ds->ports);
 378         free(ds);
 379     }
 380 }
 381
 382 static void
 383 dpif_sflow_add_poller(struct dpif_sflow *ds, struct dpif_sflow_port *dsp)
 384     OVS_REQUIRES(mutex)
 385 {
 386     SFLPoller *poller = sfl_agent_addPoller(ds->sflow_agent, &dsp->dsi, ds,
 387                                             sflow_agent_get_counters);
 388     sfl_poller_set_sFlowCpInterval(poller, ds->options->polling_interval);
 389     sfl_poller_set_sFlowCpReceiver(poller, RECEIVER_INDEX);
 390     sfl_poller_set_bridgePort(poller, odp_to_u32(dsp->odp_port));
 391 }
 392
 393 void
 394 dpif_sflow_add_port(struct dpif_sflow *ds, struct ofport *ofport,
 395                     odp_port_t odp_port) OVS_EXCLUDED(mutex)
 396 {
 397     struct dpif_sflow_port *dsp;
 398     int ifindex;
 399
 400     ovs_mutex_lock(&mutex);
 401     dpif_sflow_del_port(ds, odp_port);
 402
 403     ifindex = netdev_get_ifindex(ofport->netdev);
 404
 405     if (ifindex <= 0) {
 406         /* Not an ifindex port, so do not add a cross-reference to it here */
 407         goto out;
 408     }
 409
 410     /* Add to table of ports. */
 411     dsp = xmalloc(sizeof *dsp);
 412     dsp->ofport = ofport;
 413     dsp->odp_port = odp_port;
 414     SFL_DS_SET(dsp->dsi, SFL_DSCLASS_IFINDEX, ifindex, 0);
 415     hmap_insert(&ds->ports, &dsp->hmap_node, hash_odp_port(odp_port));
 416
 417     /* Add poller. */
 418     if (ds->sflow_agent) {
 419         dpif_sflow_add_poller(ds, dsp);
 420     }
 421
 422 out:
 423     ovs_mutex_unlock(&mutex);
 424 }
 425
 426 static void
 427 dpif_sflow_del_port__(struct dpif_sflow *ds, struct dpif_sflow_port *dsp)
 428     OVS_REQUIRES(mutex)
 429 {
 430     if (ds->sflow_agent) {
 431         sfl_agent_removePoller(ds->sflow_agent, &dsp->dsi);
 432         sfl_agent_removeSampler(ds->sflow_agent, &dsp->dsi);
 433     }
 434     hmap_remove(&ds->ports, &dsp->hmap_node);
 435     free(dsp);
 436 }
 437
 438 void
 439 dpif_sflow_del_port(struct dpif_sflow *ds, odp_port_t odp_port)
 440     OVS_EXCLUDED(mutex)
 441 {
 442     struct dpif_sflow_port *dsp;
 443
 444     ovs_mutex_lock(&mutex);
 445     dsp = dpif_sflow_find_port(ds, odp_port);
 446     if (dsp) {
 447         dpif_sflow_del_port__(ds, dsp);
 448     }
 449     ovs_mutex_unlock(&mutex);
 450 }
 451
 452 void
 453 dpif_sflow_set_options(struct dpif_sflow *ds,
 454                        const struct ofproto_sflow_options *options)
 455     OVS_EXCLUDED(mutex)
 456 {
 457     struct dpif_sflow_port *dsp;
 458     bool options_changed;
 459     SFLReceiver *receiver;
 460     SFLAddress agentIP;
 461     time_t now;
 462     SFLDataSource_instance dsi;
 463     uint32_t dsIndex;
 464     SFLSampler *sampler;
 465
 466     ovs_mutex_lock(&mutex);
 467     if (sset_is_empty(&options->targets) || !options->sampling_rate) {
 468         /* No point in doing any work if there are no targets or nothing to
 469          * sample. */
 470         dpif_sflow_clear__(ds);
 471         goto out;
 472     }
 473
 474     options_changed = (!ds->options
 475                        || !ofproto_sflow_options_equal(options, ds->options));
 476
 477     /* Configure collectors if options have changed or if we're shortchanged in
 478      * collectors (which indicates that opening one or more of the configured
 479      * collectors failed, so that we should retry). */
 480     if (options_changed
 481         || collectors_count(ds->collectors) < sset_count(&options->targets)) {
 482         collectors_destroy(ds->collectors);
 483         collectors_create(&options->targets, SFL_DEFAULT_COLLECTOR_PORT,
 484                           &ds->collectors);
 485         if (ds->collectors == NULL) {
 486             VLOG_WARN_RL(&rl, "no collectors could be initialized, "
 487                          "sFlow disabled");
 488             dpif_sflow_clear__(ds);
 489             goto out;
 490         }
 491     }
 492
 493     /* Choose agent IP address and agent device (if not yet setup) */
 494     if (!sflow_choose_agent_address(options->agent_device,
 495                                     &options->targets,
 496                                     options->control_ip, &agentIP)) {
 497         dpif_sflow_clear__(ds);
 498         goto out;
 499     }
 500
 501     /* Avoid reconfiguring if options didn't change. */
 502     if (!options_changed) {
 503         goto out;
 504     }
 505     ofproto_sflow_options_destroy(ds->options);
 506     ds->options = ofproto_sflow_options_clone(options);
 507
 508     /* Create agent. */
 509     VLOG_INFO("creating sFlow agent %d", options->sub_id);
 510     if (ds->sflow_agent) {
 511         sfl_agent_release(ds->sflow_agent);
 512     }
 513     ds->sflow_agent = xcalloc(1, sizeof *ds->sflow_agent);
 514     now = time_wall();
 515     sfl_agent_init(ds->sflow_agent,
 516                    &agentIP,
 517                    options->sub_id,
 518                    now,         /* Boot time. */
 519                    now,         /* Current time. */
 520                    ds,          /* Pointer supplied to callbacks. */
 521                    sflow_agent_alloc_cb,
 522                    sflow_agent_free_cb,
 523                    sflow_agent_error_cb,
 524                    sflow_agent_send_packet_cb);
 525
 526     receiver = sfl_agent_addReceiver(ds->sflow_agent);
 527     sfl_receiver_set_sFlowRcvrOwner(receiver, "Open vSwitch sFlow");
 528     sfl_receiver_set_sFlowRcvrTimeout(receiver, 0xffffffff);
 529
 530     /* Set the sampling_rate down in the datapath. */
 531     ds->probability = MAX(1, UINT32_MAX / ds->options->sampling_rate);
 532
 533     /* Add a single sampler for the bridge. This appears as a PHYSICAL_ENTITY
 534        because it is associated with the hypervisor, and interacts with the server
 535        hardware directly.  The sub_id is used to distinguish this sampler from
 536        others on other bridges within the same agent. */
 537     dsIndex = 1000 + options->sub_id;
 538     SFL_DS_SET(dsi, SFL_DSCLASS_PHYSICAL_ENTITY, dsIndex, 0);
 539     sampler = sfl_agent_addSampler(ds->sflow_agent, &dsi);
 540     sfl_sampler_set_sFlowFsPacketSamplingRate(sampler, ds->options->sampling_rate);
 541     sfl_sampler_set_sFlowFsMaximumHeaderSize(sampler, ds->options->header_len);
 542     sfl_sampler_set_sFlowFsReceiver(sampler, RECEIVER_INDEX);
 543
 544     /* Add pollers for the currently known ifindex-ports */
 545     HMAP_FOR_EACH (dsp, hmap_node, &ds->ports) {
 546         dpif_sflow_add_poller(ds, dsp);
 547     }
 548
 549
 550 out:
 551     ovs_mutex_unlock(&mutex);
 552 }
 553
 554 int
 555 dpif_sflow_odp_port_to_ifindex(const struct dpif_sflow *ds,
 556                                odp_port_t odp_port) OVS_EXCLUDED(mutex)
 557 {
 558     struct dpif_sflow_port *dsp;
 559     int ret;
 560
 561     ovs_mutex_lock(&mutex);
 562     dsp = dpif_sflow_find_port(ds, odp_port);
 563     ret = dsp ? SFL_DS_INDEX(dsp->dsi) : 0;
 564     ovs_mutex_unlock(&mutex);
 565     return ret;
 566 }
 567
 568 void
 569 dpif_sflow_received(struct dpif_sflow *ds, const struct ofpbuf *packet,
 570                     const struct flow *flow, odp_port_t odp_in_port,
 571                     const union user_action_cookie *cookie)
 572     OVS_EXCLUDED(mutex)
 573 {
 574     SFL_FLOW_SAMPLE_TYPE fs;
 575     SFLFlow_sample_element hdrElem;
 576     SFLSampled_header *header;
 577     SFLFlow_sample_element switchElem;
 578     SFLSampler *sampler;
 579     struct dpif_sflow_port *in_dsp;
 580     ovs_be16 vlan_tci;
 581
 582     ovs_mutex_lock(&mutex);
 583     sampler = ds->sflow_agent->samplers;
 584     if (!sampler) {
 585         goto out;
 586     }
 587
 588     /* Build a flow sample. */
 589     memset(&fs, 0, sizeof fs);
 590
 591     /* Look up the input ifIndex if this port has one. Otherwise just
 592      * leave it as 0 (meaning 'unknown') and continue. */
 593     in_dsp = dpif_sflow_find_port(ds, odp_in_port);
 594     if (in_dsp) {
 595         fs.input = SFL_DS_INDEX(in_dsp->dsi);
 596     }
 597
 598     /* Make the assumption that the random number generator in the datapath converges
 599      * to the configured mean, and just increment the samplePool by the configured
 600      * sampling rate every time. */
 601     sampler->samplePool += sfl_sampler_get_sFlowFsPacketSamplingRate(sampler);
 602
 603     /* Sampled header. */
 604     memset(&hdrElem, 0, sizeof hdrElem);
 605     hdrElem.tag = SFLFLOW_HEADER;
 606     header = &hdrElem.flowType.header;
 607     header->header_protocol = SFLHEADER_ETHERNET_ISO8023;
 608     /* The frame_length should include the Ethernet FCS (4 bytes),
 609      * but it has already been stripped,  so we need to add 4 here. */
 610     header->frame_length = ofpbuf_size(packet) + 4;
 611     /* Ethernet FCS stripped off. */
 612     header->stripped = 4;
 613     header->header_length = MIN(ofpbuf_size(packet),
 614                                 sampler->sFlowFsMaximumHeaderSize);
 615     header->header_bytes = ofpbuf_data(packet);
 616
 617     /* Add extended switch element. */
 618     memset(&switchElem, 0, sizeof(switchElem));
 619     switchElem.tag = SFLFLOW_EX_SWITCH;
 620     switchElem.flowType.sw.src_vlan = vlan_tci_to_vid(flow->vlan_tci);
 621     switchElem.flowType.sw.src_priority = vlan_tci_to_pcp(flow->vlan_tci);
 622
 623     /* Retrieve data from user_action_cookie. */
 624     vlan_tci = cookie->sflow.vlan_tci;
 625     switchElem.flowType.sw.dst_vlan = vlan_tci_to_vid(vlan_tci);
 626     switchElem.flowType.sw.dst_priority = vlan_tci_to_pcp(vlan_tci);
 627
 628     fs.output = cookie->sflow.output;
 629
 630     /* Submit the flow sample to be encoded into the next datagram. */
 631     SFLADD_ELEMENT(&fs, &hdrElem);
 632     SFLADD_ELEMENT(&fs, &switchElem);
 633     sfl_sampler_writeFlowSample(sampler, &fs);
 634
 635 out:
 636     ovs_mutex_unlock(&mutex);
 637 }
 638
 639 void
 640 dpif_sflow_run(struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 641 {
 642     ovs_mutex_lock(&mutex);
 643     if (ds->collectors != NULL) {
 644         time_t now = time_now();
 645         route_table_run();
 646         if (now >= ds->next_tick) {
 647             sfl_agent_tick(ds->sflow_agent, time_wall());
 648             ds->next_tick = now + 1;
 649         }
 650     }
 651     ovs_mutex_unlock(&mutex);
 652 }
 653
 654 void
 655 dpif_sflow_wait(struct dpif_sflow *ds) OVS_EXCLUDED(mutex)
 656 {
 657     ovs_mutex_lock(&mutex);
 658     if (ds->collectors != NULL) {
 659         poll_timer_wait_until(ds->next_tick * 1000LL);
 660     }
 661     ovs_mutex_unlock(&mutex);
 662 }