ofproto/netflow.c

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