ofproto/netflow.c

   1 /*
   2  * Copyright (c) 2008, 2009 Nicira Networks.
   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 "collectors.h"
  24 #include "flow.h"
  25 #include "netflow.h"
  26 #include "ofpbuf.h"
  27 #include "ofproto.h"
  28 #include "packets.h"
  29 #include "socket-util.h"
  30 #include "svec.h"
  31 #include "timeval.h"
  32 #include "util.h"
  33 #include "xtoxll.h"
  34
  35 #define THIS_MODULE VLM_netflow
  36 #include "vlog.h"
  37
  38 #define NETFLOW_V5_VERSION 5
  39
  40 /* Every NetFlow v5 message contains the header that follows.  This is
  41  * followed by up to thirty records that describe a terminating flow.
  42  * We only send a single record per NetFlow message.
  43  */
  44 struct netflow_v5_header {
  45     uint16_t version;              /* NetFlow version is 5. */
  46     uint16_t count;                /* Number of records in this message. */
  47     uint32_t sysuptime;            /* System uptime in milliseconds. */
  48     uint32_t unix_secs;            /* Number of seconds since Unix epoch. */
  49     uint32_t unix_nsecs;           /* Number of residual nanoseconds
  50                                       after epoch seconds. */
  51     uint32_t flow_seq;             /* Number of flows since sending
  52                                       messages began. */
  53     uint8_t  engine_type;          /* Engine type. */
  54     uint8_t  engine_id;            /* Engine id. */
  55     uint16_t sampling_interval;    /* Set to zero. */
  56 };
  57 BUILD_ASSERT_DECL(sizeof(struct netflow_v5_header) == 24);
  58
  59 /* A NetFlow v5 description of a terminating flow.  It is preceded by a
  60  * NetFlow v5 header.
  61  */
  62 struct netflow_v5_record {
  63     uint32_t src_addr;             /* Source IP address. */
  64     uint32_t dst_addr;             /* Destination IP address. */
  65     uint32_t nexthop;              /* IP address of next hop.  Set to 0. */
  66     uint16_t input;                /* Input interface index. */
  67     uint16_t output;               /* Output interface index. */
  68     uint32_t packet_count;         /* Number of packets. */
  69     uint32_t byte_count;           /* Number of bytes. */
  70     uint32_t init_time;            /* Value of sysuptime on first packet. */
  71     uint32_t used_time;            /* Value of sysuptime on last packet. */
  72
  73     /* The 'src_port' and 'dst_port' identify the source and destination
  74      * port, respectively, for TCP and UDP.  For ICMP, the high-order
  75      * byte identifies the type and low-order byte identifies the code
  76      * in the 'dst_port' field. */
  77     uint16_t src_port;
  78     uint16_t dst_port;
  79
  80     uint8_t  pad1;
  81     uint8_t  tcp_flags;            /* Union of seen TCP flags. */
  82     uint8_t  ip_proto;             /* IP protocol. */
  83     uint8_t  ip_tos;               /* IP TOS value. */
  84     uint16_t src_as;               /* Source AS ID.  Set to 0. */
  85     uint16_t dst_as;               /* Destination AS ID.  Set to 0. */
  86     uint8_t  src_mask;             /* Source mask bits.  Set to 0. */
  87     uint8_t  dst_mask;             /* Destination mask bits.  Set to 0. */
  88     uint8_t  pad[2];
  89 };
  90 BUILD_ASSERT_DECL(sizeof(struct netflow_v5_record) == 48);
  91
  92 struct netflow {
  93     uint8_t engine_type;          /* Value of engine_type to use. */
  94     uint8_t engine_id;            /* Value of engine_id to use. */
  95     long long int boot_time;      /* Time when netflow_create() was called. */
  96     struct collectors *collectors; /* NetFlow collectors. */
  97     bool add_id_to_iface;         /* Put the 7 least signficiant bits of
  98                                    * 'engine_id' into the most signficant
  99                                    * bits of the interface fields. */
 100     uint32_t netflow_cnt;         /* Flow sequence number for NetFlow. */
 101     struct ofpbuf packet;         /* NetFlow packet being accumulated. */
 102     long long int active_timeout; /* Timeout for flows that are still active. */
 103     long long int reconfig_time;  /* When we reconfigured the timeouts. */
 104 };
 105
 106 void
 107 netflow_expire(struct netflow *nf, struct netflow_flow *nf_flow,
 108                struct ofexpired *expired)
 109 {
 110     struct netflow_v5_header *nf_hdr;
 111     struct netflow_v5_record *nf_rec;
 112     struct timeval now;
 113
 114     nf_flow->last_expired += nf->active_timeout;
 115
 116     /* NetFlow only reports on IP packets and we should only report flows
 117      * that actually have traffic. */
 118     if (expired->flow.dl_type != htons(ETH_TYPE_IP) ||
 119         expired->packet_count - nf_flow->packet_count_off == 0) {
 120         return;
 121     }
 122
 123     time_timeval(&now);
 124
 125     if (!nf->packet.size) {
 126         nf_hdr = ofpbuf_put_zeros(&nf->packet, sizeof *nf_hdr);
 127         nf_hdr->version = htons(NETFLOW_V5_VERSION);
 128         nf_hdr->count = htons(0);
 129         nf_hdr->sysuptime = htonl(time_msec() - nf->boot_time);
 130         nf_hdr->unix_secs = htonl(now.tv_sec);
 131         nf_hdr->unix_nsecs = htonl(now.tv_usec * 1000);
 132         nf_hdr->flow_seq = htonl(nf->netflow_cnt++);
 133         nf_hdr->engine_type = nf->engine_type;
 134         nf_hdr->engine_id = nf->engine_id;
 135         nf_hdr->sampling_interval = htons(0);
 136     }
 137
 138     nf_hdr = nf->packet.data;
 139     nf_hdr->count = htons(ntohs(nf_hdr->count) + 1);
 140
 141     nf_rec = ofpbuf_put_zeros(&nf->packet, sizeof *nf_rec);
 142     nf_rec->src_addr = expired->flow.nw_src;
 143     nf_rec->dst_addr = expired->flow.nw_dst;
 144     nf_rec->nexthop = htons(0);
 145     if (nf->add_id_to_iface) {
 146         uint16_t iface = (nf->engine_id & 0x7f) << 9;
 147         nf_rec->input = htons(iface | (expired->flow.in_port & 0x1ff));
 148         nf_rec->output = htons(iface | (nf_flow->output_iface & 0x1ff));
 149     } else {
 150         nf_rec->input = htons(expired->flow.in_port);
 151         nf_rec->output = htons(nf_flow->output_iface);
 152     }
 153     nf_rec->packet_count = htonl(MIN(expired->packet_count -
 154                                      nf_flow->packet_count_off, UINT32_MAX));
 155     nf_rec->byte_count = htonl(MIN(expired->byte_count -
 156                                    nf_flow->byte_count_off, UINT32_MAX));
 157     nf_rec->init_time = htonl(nf_flow->created - nf->boot_time);
 158     nf_rec->used_time = htonl(MAX(nf_flow->created, expired->used)
 159                              - nf->boot_time);
 160     if (expired->flow.nw_proto == IP_TYPE_ICMP) {
 161         /* In NetFlow, the ICMP type and code are concatenated and
 162          * placed in the 'dst_port' field. */
 163         uint8_t type = ntohs(expired->flow.tp_src);
 164         uint8_t code = ntohs(expired->flow.tp_dst);
 165         nf_rec->src_port = htons(0);
 166         nf_rec->dst_port = htons((type << 8) | code);
 167     } else {
 168         nf_rec->src_port = expired->flow.tp_src;
 169         nf_rec->dst_port = expired->flow.tp_dst;
 170     }
 171     nf_rec->tcp_flags = nf_flow->tcp_flags;
 172     nf_rec->ip_proto = expired->flow.nw_proto;
 173     nf_rec->ip_tos = nf_flow->ip_tos;
 174
 175     /* Update flow tracking data. */
 176     nf_flow->created = 0;
 177     nf_flow->packet_count_off = expired->packet_count;
 178     nf_flow->byte_count_off = expired->byte_count;
 179     nf_flow->tcp_flags = 0;
 180
 181     /* NetFlow messages are limited to 30 records. */
 182     if (ntohs(nf_hdr->count) >= 30) {
 183         netflow_run(nf);
 184     }
 185 }
 186
 187 void
 188 netflow_run(struct netflow *nf)
 189 {
 190     if (nf->packet.size) {
 191         collectors_send(nf->collectors, nf->packet.data, nf->packet.size);
 192         nf->packet.size = 0;
 193     }
 194 }
 195
 196 int
 197 netflow_set_options(struct netflow *nf,
 198                     const struct netflow_options *nf_options)
 199 {
 200     int error = 0;
 201     long long int old_timeout;
 202
 203     nf->engine_type = nf_options->engine_type;
 204     nf->engine_id = nf_options->engine_id;
 205     nf->add_id_to_iface = nf_options->add_id_to_iface;
 206
 207     collectors_destroy(nf->collectors);
 208     collectors_create(&nf_options->collectors, 0, &nf->collectors);
 209
 210     old_timeout = nf->active_timeout;
 211     if (nf_options->active_timeout >= 0) {
 212         nf->active_timeout = nf_options->active_timeout;
 213     } else {
 214         nf->active_timeout = NF_ACTIVE_TIMEOUT_DEFAULT;
 215     }
 216     nf->active_timeout *= 1000;
 217     if (old_timeout != nf->active_timeout) {
 218         nf->reconfig_time = time_msec();
 219     }
 220
 221     return error;
 222 }
 223
 224 struct netflow *
 225 netflow_create(void)
 226 {
 227     struct netflow *nf = xmalloc(sizeof *nf);
 228     nf->engine_type = 0;
 229     nf->engine_id = 0;
 230     nf->boot_time = time_msec();
 231     nf->collectors = NULL;
 232     nf->add_id_to_iface = false;
 233     nf->netflow_cnt = 0;
 234     ofpbuf_init(&nf->packet, 1500);
 235     return nf;
 236 }
 237
 238 void
 239 netflow_destroy(struct netflow *nf)
 240 {
 241     if (nf) {
 242         ofpbuf_uninit(&nf->packet);
 243         collectors_destroy(nf->collectors);
 244         free(nf);
 245     }
 246 }
 247
 248 void
 249 netflow_flow_clear(struct netflow_flow *nf_flow)
 250 {
 251     uint16_t output_iface = nf_flow->output_iface;
 252
 253     memset(nf_flow, 0, sizeof *nf_flow);
 254     nf_flow->output_iface = output_iface;
 255 }
 256
 257 void
 258 netflow_flow_update_time(struct netflow *nf, struct netflow_flow *nf_flow,
 259                          long long int used)
 260 {
 261     if (!nf_flow->created) {
 262         nf_flow->created = used;
 263     }
 264
 265     if (!nf || !nf->active_timeout || !nf_flow->last_expired ||
 266         nf->reconfig_time > nf_flow->last_expired) {
 267         /* Keep the time updated to prevent a flood of expiration in
 268          * the future. */
 269         nf_flow->last_expired = time_msec();
 270     }
 271 }
 272
 273 void
 274 netflow_flow_update_flags(struct netflow_flow *nf_flow, uint8_t ip_tos,
 275                           uint8_t tcp_flags)
 276 {
 277     nf_flow->ip_tos = ip_tos;
 278     nf_flow->tcp_flags |= tcp_flags;
 279 }
 280
 281 bool
 282 netflow_active_timeout_expired(struct netflow *nf, struct netflow_flow *nf_flow)
 283 {
 284     if (nf->active_timeout) {
 285         return time_msec() > nf_flow->last_expired + nf->active_timeout;
 286     }
 287
 288     return false;
 289 }