ofproto/netflow.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2013, 2014, 2015 Nicira, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <config.h>
  18 #include "netflow.h"
  19 #include <sys/types.h>
  20 #include <netinet/in.h>
  21 #include <arpa/inet.h>
  22 #include <errno.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include "byte-order.h"
  26 #include "collectors.h"
  27 #include "dpif.h"
  28 #include "flow.h"
  29 #include "lib/netflow.h"
  30 #include "openvswitch/ofpbuf.h"
  31 #include "ofproto.h"
  32 #include "ofproto/netflow.h"
  33 #include "packets.h"
  34 #include "openvswitch/poll-loop.h"
  35 #include "socket-util.h"
  36 #include "timeval.h"
  37 #include "util.h"
  38 #include "openvswitch/vlog.h"
  39
  40 VLOG_DEFINE_THIS_MODULE(netflow);
  41
  42 struct netflow {
  43     uint8_t engine_type;          /* Value of engine_type to use. */
  44     uint8_t engine_id;            /* Value of engine_id to use. */
  45     long long int boot_time;      /* Time when netflow_create() was called. */
  46     struct collectors *collectors; /* NetFlow collectors. */
  47     bool add_id_to_iface;         /* Put the 7 least significiant bits of
  48                                    * 'engine_id' into the most significant
  49                                    * bits of the interface fields. */
  50     uint32_t netflow_cnt;         /* Flow sequence number for NetFlow. */
  51     struct ofpbuf packet;         /* NetFlow packet being accumulated. */
  52     long long int active_timeout; /* Timeout for flows that are still active. */
  53     long long int next_timeout;   /* Next scheduled active timeout. */
  54     long long int reconfig_time;  /* When we reconfigured the timeouts. */
  55
  56     struct hmap flows;            /* Contains 'netflow_flows'. */
  57
  58     struct ovs_refcount ref_cnt;
  59 };
  60
  61 struct netflow_flow {
  62     struct hmap_node hmap_node;
  63
  64     long long int last_expired;   /* Time this flow last timed out. */
  65     long long int created;        /* Time flow was created since time out. */
  66
  67     ofp_port_t output_iface;      /* Output interface index. */
  68     uint16_t tcp_flags;           /* Bitwise-OR of all TCP flags seen. */
  69
  70     ofp_port_t in_port;           /* Input port. */
  71     ovs_be32 nw_src;              /* IPv4 source address. */
  72     ovs_be32 nw_dst;              /* IPv4 destination address. */
  73     uint8_t nw_tos;               /* IP ToS (including DSCP and ECN). */
  74     uint8_t nw_proto;             /* IP protocol. */
  75     ovs_be16 tp_src;              /* TCP/UDP/SCTP source port. */
  76     ovs_be16 tp_dst;              /* TCP/UDP/SCTP destination port. */
  77
  78     uint64_t packet_count;        /* Packets from subrules. */
  79     uint64_t byte_count;          /* Bytes from subrules. */
  80     long long int used;           /* Last-used time (0 if never used). */
  81 };
  82
  83 static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
  84 static atomic_count netflow_count = ATOMIC_COUNT_INIT(0);
  85
  86 static struct netflow_flow *netflow_flow_lookup(const struct netflow *,
  87                                                 const struct flow *)
  88     OVS_REQUIRES(mutex);
  89 static uint32_t netflow_flow_hash(const struct flow *);
  90 static void netflow_expire__(struct netflow *, struct netflow_flow *)
  91     OVS_REQUIRES(mutex);
  92 static void netflow_run__(struct netflow *) OVS_REQUIRES(mutex);
  93
  94 void
  95 netflow_mask_wc(const struct flow *flow, struct flow_wildcards *wc)
  96 {
  97     if (flow->dl_type != htons(ETH_TYPE_IP)) {
  98         return;
  99     }
 100     memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
 101     memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
 102     memset(&wc->masks.nw_dst, 0xff, sizeof wc->masks.nw_dst);
 103     flow_unwildcard_tp_ports(flow, wc);
 104     wc->masks.nw_tos |= IP_DSCP_MASK;
 105 }
 106
 107 static void
 108 gen_netflow_rec(struct netflow *nf, struct netflow_flow *nf_flow,
 109                 uint32_t packet_count, uint32_t byte_count)
 110     OVS_REQUIRES(mutex)
 111 {
 112     struct netflow_v5_header *nf_hdr;
 113     struct netflow_v5_record *nf_rec;
 114
 115     if (!nf->packet.size) {
 116         struct timespec now;
 117
 118         time_wall_timespec(&now);
 119
 120         nf_hdr = ofpbuf_put_zeros(&nf->packet, sizeof *nf_hdr);
 121         nf_hdr->version = htons(NETFLOW_V5_VERSION);
 122         nf_hdr->count = htons(0);
 123         nf_hdr->sysuptime = htonl(time_msec() - nf->boot_time);
 124         nf_hdr->unix_secs = htonl(now.tv_sec);
 125         nf_hdr->unix_nsecs = htonl(now.tv_nsec);
 126         nf_hdr->engine_type = nf->engine_type;
 127         nf_hdr->engine_id = nf->engine_id;
 128         nf_hdr->sampling_interval = htons(0);
 129     }
 130
 131     nf_hdr = nf->packet.data;
 132     nf_hdr->count = htons(ntohs(nf_hdr->count) + 1);
 133     nf_hdr->flow_seq = htonl(nf->netflow_cnt++);
 134
 135     nf_rec = ofpbuf_put_zeros(&nf->packet, sizeof *nf_rec);
 136     nf_rec->src_addr = nf_flow->nw_src;
 137     nf_rec->dst_addr = nf_flow->nw_dst;
 138     nf_rec->nexthop = htonl(0);
 139     if (nf->add_id_to_iface) {
 140         uint16_t iface = (nf->engine_id & 0x7f) << 9;
 141         nf_rec->input = htons(iface | (ofp_to_u16(nf_flow->in_port) & 0x1ff));
 142         nf_rec->output = htons(iface
 143             | (ofp_to_u16(nf_flow->output_iface) & 0x1ff));
 144     } else {
 145         nf_rec->input = htons(ofp_to_u16(nf_flow->in_port));
 146         nf_rec->output = htons(ofp_to_u16(nf_flow->output_iface));
 147     }
 148     nf_rec->packet_count = htonl(packet_count);
 149     nf_rec->byte_count = htonl(byte_count);
 150     nf_rec->init_time = htonl(nf_flow->created - nf->boot_time);
 151     nf_rec->used_time = htonl(MAX(nf_flow->created, nf_flow->used)
 152                              - nf->boot_time);
 153     if (nf_flow->nw_proto == IPPROTO_ICMP) {
 154         /* In NetFlow, the ICMP type and code are concatenated and
 155          * placed in the 'dst_port' field. */
 156         uint8_t type = ntohs(nf_flow->tp_src);
 157         uint8_t code = ntohs(nf_flow->tp_dst);
 158         nf_rec->src_port = htons(0);
 159         nf_rec->dst_port = htons((type << 8) | code);
 160     } else {
 161         nf_rec->src_port = nf_flow->tp_src;
 162         nf_rec->dst_port = nf_flow->tp_dst;
 163     }
 164     nf_rec->tcp_flags = (uint8_t) nf_flow->tcp_flags;
 165     nf_rec->ip_proto = nf_flow->nw_proto;
 166     nf_rec->ip_tos = nf_flow->nw_tos & IP_DSCP_MASK;
 167
 168     /* NetFlow messages are limited to 30 records. */
 169     if (ntohs(nf_hdr->count) >= 30) {
 170         netflow_run__(nf);
 171     }
 172 }
 173
 174 void
 175 netflow_flow_update(struct netflow *nf, const struct flow *flow,
 176                     ofp_port_t output_iface,
 177                     const struct dpif_flow_stats *stats)
 178     OVS_EXCLUDED(mutex)
 179 {
 180     struct netflow_flow *nf_flow;
 181     long long int used;
 182
 183     /* NetFlow only reports on IP packets. */
 184     if (flow->dl_type != htons(ETH_TYPE_IP)) {
 185         return;
 186     }
 187
 188     ovs_mutex_lock(&mutex);
 189     nf_flow = netflow_flow_lookup(nf, flow);
 190     if (!nf_flow) {
 191         nf_flow = xzalloc(sizeof *nf_flow);
 192         nf_flow->in_port = flow->in_port.ofp_port;
 193         nf_flow->nw_src = flow->nw_src;
 194         nf_flow->nw_dst = flow->nw_dst;
 195         nf_flow->nw_tos = flow->nw_tos;
 196         nf_flow->nw_proto = flow->nw_proto;
 197         nf_flow->tp_src = flow->tp_src;
 198         nf_flow->tp_dst = flow->tp_dst;
 199         nf_flow->created = stats->used;
 200         nf_flow->output_iface = output_iface;
 201         hmap_insert(&nf->flows, &nf_flow->hmap_node, netflow_flow_hash(flow));
 202     }
 203
 204     if (nf_flow->output_iface != output_iface) {
 205         netflow_expire__(nf, nf_flow);
 206         nf_flow->created = stats->used;
 207         nf_flow->output_iface = output_iface;
 208     }
 209
 210     nf_flow->packet_count += stats->n_packets;
 211     nf_flow->byte_count += stats->n_bytes;
 212     nf_flow->tcp_flags |= stats->tcp_flags;
 213
 214     used = MAX(nf_flow->used, stats->used);
 215     if (nf_flow->used != used) {
 216         nf_flow->used = used;
 217         if (!nf->active_timeout || !nf_flow->last_expired
 218             || nf->reconfig_time > nf_flow->last_expired) {
 219             /* Keep the time updated to prevent a flood of expiration in
 220              * the future. */
 221             nf_flow->last_expired = time_msec();
 222         }
 223     }
 224
 225     ovs_mutex_unlock(&mutex);
 226 }
 227
 228 static void
 229 netflow_expire__(struct netflow *nf, struct netflow_flow *nf_flow)
 230     OVS_REQUIRES(mutex)
 231 {
 232     uint64_t pkts, bytes;
 233
 234     pkts = nf_flow->packet_count;
 235     bytes = nf_flow->byte_count;
 236
 237     nf_flow->last_expired += nf->active_timeout;
 238
 239     if (pkts == 0) {
 240         return;
 241     }
 242
 243     if ((bytes >> 32) <= 175) {
 244         /* NetFlow v5 records are limited to 32-bit counters.  If we've wrapped
 245          * a counter, send as multiple records so we don't lose track of any
 246          * traffic.  We try to evenly distribute the packet and byte counters,
 247          * so that the bytes-per-packet lengths don't look wonky across the
 248          * records. */
 249         while (bytes) {
 250             int n_recs = (bytes + UINT32_MAX - 1) / UINT32_MAX;
 251             uint32_t pkt_count = pkts / n_recs;
 252             uint32_t byte_count = bytes / n_recs;
 253
 254             gen_netflow_rec(nf, nf_flow, pkt_count, byte_count);
 255
 256             pkts -= pkt_count;
 257             bytes -= byte_count;
 258         }
 259     } else {
 260         /* In 600 seconds, a 10GbE link can theoretically transmit 75 * 10**10
 261          * == 175 * 2**32 bytes.  The byte counter is bigger than that, so it's
 262          * probably a bug--for example, the netdev code uses UINT64_MAX to
 263          * report "unknown value", and perhaps that has leaked through to here.
 264          *
 265          * We wouldn't want to hit the loop above in this case, because it
 266          * would try to send up to UINT32_MAX netflow records, which would take
 267          * a long time.
 268          */
 269         static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 1);
 270
 271         VLOG_WARN_RL(&rl, "impossible byte counter %"PRIu64, bytes);
 272     }
 273
 274     /* Update flow tracking data. */
 275     nf_flow->packet_count = 0;
 276     nf_flow->byte_count = 0;
 277     nf_flow->tcp_flags = 0;
 278 }
 279
 280 void
 281 netflow_flow_clear(struct netflow *nf, const struct flow *flow)
 282     OVS_EXCLUDED(mutex)
 283 {
 284     struct netflow_flow *nf_flow;
 285
 286     ovs_mutex_lock(&mutex);
 287     nf_flow = netflow_flow_lookup(nf, flow);
 288     if (nf_flow) {
 289         netflow_expire__(nf, nf_flow);
 290         hmap_remove(&nf->flows, &nf_flow->hmap_node);
 291         free(nf_flow);
 292     }
 293     ovs_mutex_unlock(&mutex);
 294 }
 295
 296 /* Returns true if it's time to send out a round of NetFlow active timeouts,
 297  * false otherwise. */
 298 static void
 299 netflow_run__(struct netflow *nf) OVS_REQUIRES(mutex)
 300 {
 301     long long int now = time_msec();
 302     struct netflow_flow *nf_flow, *next;
 303
 304     if (nf->packet.size) {
 305         collectors_send(nf->collectors, nf->packet.data, nf->packet.size);
 306         nf->packet.size = 0;
 307     }
 308
 309     if (!nf->active_timeout || now < nf->next_timeout) {
 310         return;
 311     }
 312
 313     nf->next_timeout = now + 1000;
 314
 315     HMAP_FOR_EACH_SAFE (nf_flow, next, hmap_node, &nf->flows) {
 316         if (now > nf_flow->last_expired + nf->active_timeout) {
 317             bool idle = nf_flow->used < nf_flow->last_expired;
 318             netflow_expire__(nf, nf_flow);
 319
 320             if (idle) {
 321                 /* If the netflow_flow hasn't been used in a while, it's
 322                  * possible the upper layer lost track of it. */
 323                 hmap_remove(&nf->flows, &nf_flow->hmap_node);
 324                 free(nf_flow);
 325             }
 326         }
 327     }
 328 }
 329
 330 void
 331 netflow_run(struct netflow *nf)
 332 {
 333     ovs_mutex_lock(&mutex);
 334     netflow_run__(nf);
 335     ovs_mutex_unlock(&mutex);
 336 }
 337
 338 void
 339 netflow_wait(struct netflow *nf) OVS_EXCLUDED(mutex)
 340 {
 341     ovs_mutex_lock(&mutex);
 342     if (nf->active_timeout) {
 343         poll_timer_wait_until(nf->next_timeout);
 344     }
 345     if (nf->packet.size) {
 346         poll_immediate_wake();
 347     }
 348     ovs_mutex_unlock(&mutex);
 349 }
 350
 351 int
 352 netflow_set_options(struct netflow *nf,
 353                     const struct netflow_options *nf_options)
 354     OVS_EXCLUDED(mutex)
 355 {
 356     int error = 0;
 357     long long int old_timeout;
 358
 359     ovs_mutex_lock(&mutex);
 360     nf->engine_type = nf_options->engine_type;
 361     nf->engine_id = nf_options->engine_id;
 362     nf->add_id_to_iface = nf_options->add_id_to_iface;
 363
 364     collectors_destroy(nf->collectors);
 365     collectors_create(&nf_options->collectors, -1, &nf->collectors);
 366
 367     old_timeout = nf->active_timeout;
 368     if (nf_options->active_timeout >= 0) {
 369         nf->active_timeout = nf_options->active_timeout;
 370     } else {
 371         nf->active_timeout = NF_ACTIVE_TIMEOUT_DEFAULT;
 372     }
 373     nf->active_timeout *= 1000;
 374     if (old_timeout != nf->active_timeout) {
 375         nf->reconfig_time = time_msec();
 376         nf->next_timeout = time_msec();
 377     }
 378     ovs_mutex_unlock(&mutex);
 379
 380     return error;
 381 }
 382
 383 struct netflow *
 384 netflow_create(void)
 385 {
 386     struct netflow *nf = xzalloc(sizeof *nf);
 387
 388     nf->engine_type = 0;
 389     nf->engine_id = 0;
 390     nf->boot_time = time_msec();
 391     nf->collectors = NULL;
 392     nf->add_id_to_iface = false;
 393     nf->netflow_cnt = 0;
 394     hmap_init(&nf->flows);
 395     ovs_refcount_init(&nf->ref_cnt);
 396     ofpbuf_init(&nf->packet, 1500);
 397     atomic_count_inc(&netflow_count);
 398     return nf;
 399 }
 400
 401 struct netflow *
 402 netflow_ref(const struct netflow *nf_)
 403 {
 404     struct netflow *nf = CONST_CAST(struct netflow *, nf_);
 405     if (nf) {
 406         ovs_refcount_ref(&nf->ref_cnt);
 407     }
 408     return nf;
 409 }
 410
 411 void
 412 netflow_unref(struct netflow *nf)
 413 {
 414     if (nf && ovs_refcount_unref_relaxed(&nf->ref_cnt) == 1) {
 415         atomic_count_dec(&netflow_count);
 416         collectors_destroy(nf->collectors);
 417         ofpbuf_uninit(&nf->packet);
 418
 419         struct netflow_flow *nf_flow, *next;
 420         HMAP_FOR_EACH_SAFE (nf_flow, next, hmap_node, &nf->flows) {
 421             hmap_remove(&nf->flows, &nf_flow->hmap_node);
 422             free(nf_flow);
 423         }
 424         hmap_destroy(&nf->flows);
 425
 426         free(nf);
 427     }
 428 }
 429
 430 /* Returns true if there exist any netflow objects, false otherwise.
 431  * Callers must cope with transient false positives, i.e., there is no tight
 432  * synchronization with the count and the actual existence of netflow objects.
 433  */
 434 bool
 435 netflow_exists(void)
 436 {
 437     return atomic_count_get(&netflow_count) > 0;
 438 }
 439 \f
 440 /* Helpers. */
 441
 442 static struct netflow_flow *
 443 netflow_flow_lookup(const struct netflow *nf, const struct flow *flow)
 444     OVS_REQUIRES(mutex)
 445 {
 446     struct netflow_flow *nf_flow;
 447
 448     HMAP_FOR_EACH_WITH_HASH (nf_flow, hmap_node, netflow_flow_hash(flow),
 449                              &nf->flows) {
 450         if (flow->in_port.ofp_port == nf_flow->in_port
 451             && flow->nw_src == nf_flow->nw_src
 452             && flow->nw_dst == nf_flow->nw_dst
 453             && flow->nw_tos == nf_flow->nw_tos
 454             && flow->nw_proto == nf_flow->nw_proto
 455             && flow->tp_src == nf_flow->tp_src
 456             && flow->tp_dst == nf_flow->tp_dst) {
 457             return nf_flow;
 458         }
 459     }
 460
 461     return NULL;
 462 }
 463
 464 static uint32_t
 465 netflow_flow_hash(const struct flow *flow)
 466 {
 467     uint32_t hash = 0;
 468
 469     hash = hash_add(hash, (OVS_FORCE uint32_t) flow->in_port.ofp_port);
 470     hash = hash_add(hash, ntohl(flow->nw_src));
 471     hash = hash_add(hash, ntohl(flow->nw_dst));
 472     hash = hash_add(hash, flow->nw_tos);
 473     hash = hash_add(hash, flow->nw_proto);
 474     hash = hash_add(hash, ntohs(flow->tp_src));
 475     hash = hash_add(hash, ntohs(flow->tp_dst));
 476
 477     return hash_finish(hash, 28);
 478 }