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 "cfg.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     int *fds;                     /* Sockets for NetFlow collectors. */
  97     size_t n_fds;                 /* Number of Netflow collectors. */
  98     bool add_id_to_iface;         /* Put the 7 least signficiant bits of
  99                                    * 'engine_id' into the most signficant
 100                                    * bits of the interface fields. */
 101     uint32_t netflow_cnt;         /* Flow sequence number for NetFlow. */
 102     struct ofpbuf packet;         /* NetFlow packet being accumulated. */
 103 };
 104
 105 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
 106
 107 static int
 108 open_collector(char *dst)
 109 {
 110     char *save_ptr = NULL;
 111     const char *host_name;
 112     const char *port_string;
 113     struct sockaddr_in sin;
 114     int retval;
 115     int fd;
 116
 117     /* Glibc 2.7 has a bug in strtok_r when compiling with optimization that
 118      * can cause segfaults here:
 119      * http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614.
 120      * Using "::" instead of the obvious ":" works around it. */
 121     host_name = strtok_r(dst, ":", &save_ptr);
 122     port_string = strtok_r(NULL, ":", &save_ptr);
 123     if (!host_name) {
 124         ovs_error(0, "%s: bad peer name format", dst);
 125         return -EAFNOSUPPORT;
 126     }
 127     if (!port_string) {
 128         ovs_error(0, "%s: bad port format", dst);
 129         return -EAFNOSUPPORT;
 130     }
 131
 132     memset(&sin, 0, sizeof sin);
 133     sin.sin_family = AF_INET;
 134     if (lookup_ip(host_name, &sin.sin_addr)) {
 135         return -ENOENT;
 136     }
 137     sin.sin_port = htons(atoi(port_string));
 138
 139     fd = socket(AF_INET, SOCK_DGRAM, 0);
 140     if (fd < 0) {
 141         VLOG_ERR("%s: socket: %s", dst, strerror(errno));
 142         return -errno;
 143     }
 144
 145     retval = set_nonblocking(fd);
 146     if (retval) {
 147         close(fd);
 148         return -retval;
 149     }
 150
 151     retval = connect(fd, (struct sockaddr *) &sin, sizeof sin);
 152     if (retval < 0) {
 153         int error = errno;
 154         VLOG_ERR("%s: connect: %s", dst, strerror(error));
 155         close(fd);
 156         return -error;
 157     }
 158
 159     return fd;
 160 }
 161
 162 void
 163 netflow_expire(struct netflow *nf, const struct ofexpired *expired)
 164 {
 165     struct netflow_v5_header *nf_hdr;
 166     struct netflow_v5_record *nf_rec;
 167     struct timeval now;
 168
 169     /* NetFlow only reports on IP packets. */
 170     if (expired->flow.dl_type != htons(ETH_TYPE_IP)) {
 171         return;
 172     }
 173
 174     time_timeval(&now);
 175
 176     if (!nf->packet.size) {
 177         nf_hdr = ofpbuf_put_zeros(&nf->packet, sizeof *nf_hdr);
 178         nf_hdr->version = htons(NETFLOW_V5_VERSION);
 179         nf_hdr->count = htons(0);
 180         nf_hdr->sysuptime = htonl(time_msec() - nf->boot_time);
 181         nf_hdr->unix_secs = htonl(now.tv_sec);
 182         nf_hdr->unix_nsecs = htonl(now.tv_usec * 1000);
 183         nf_hdr->flow_seq = htonl(nf->netflow_cnt++);
 184         nf_hdr->engine_type = nf->engine_type;
 185         nf_hdr->engine_id = nf->engine_id;
 186         nf_hdr->sampling_interval = htons(0);
 187     }
 188
 189     nf_hdr = nf->packet.data;
 190     nf_hdr->count = htons(ntohs(nf_hdr->count) + 1);
 191
 192     nf_rec = ofpbuf_put_zeros(&nf->packet, sizeof *nf_rec);
 193     nf_rec->src_addr = expired->flow.nw_src;
 194     nf_rec->dst_addr = expired->flow.nw_dst;
 195     nf_rec->nexthop = htons(0);
 196     if (nf->add_id_to_iface) {
 197         uint16_t iface = (nf->engine_id & 0x7f) << 9;
 198         nf_rec->input = htons(iface | (expired->flow.in_port & 0x1ff));
 199         nf_rec->output = htons(iface);
 200         printf("input: %x\n", ntohs(nf_rec->input));
 201     } else {
 202         nf_rec->input = htons(expired->flow.in_port);
 203         nf_rec->output = htons(0);
 204     }
 205     nf_rec->packet_count = htonl(MIN(expired->packet_count, UINT32_MAX));
 206     nf_rec->byte_count = htonl(MIN(expired->byte_count, UINT32_MAX));
 207     nf_rec->init_time = htonl(expired->created - nf->boot_time);
 208     nf_rec->used_time = htonl(MAX(expired->created, expired->used)
 209                              - nf->boot_time);
 210     if (expired->flow.nw_proto == IP_TYPE_ICMP) {
 211         /* In NetFlow, the ICMP type and code are concatenated and
 212          * placed in the 'dst_port' field. */
 213         uint8_t type = ntohs(expired->flow.tp_src);
 214         uint8_t code = ntohs(expired->flow.tp_dst);
 215         nf_rec->src_port = htons(0);
 216         nf_rec->dst_port = htons((type << 8) | code);
 217     } else {
 218         nf_rec->src_port = expired->flow.tp_src;
 219         nf_rec->dst_port = expired->flow.tp_dst;
 220     }
 221     nf_rec->tcp_flags = expired->tcp_flags;
 222     nf_rec->ip_proto = expired->flow.nw_proto;
 223     nf_rec->ip_tos = expired->ip_tos;
 224
 225     /* NetFlow messages are limited to 30 records.  A length of 1400
 226      * bytes guarantees that the limit is not exceeded.  */
 227     if (nf->packet.size >= 1400) {
 228         netflow_run(nf);
 229     }
 230 }
 231
 232 void
 233 netflow_run(struct netflow *nf)
 234 {
 235     size_t i;
 236
 237     if (!nf->packet.size) {
 238         return;
 239     }
 240
 241     for (i = 0; i < nf->n_fds; i++) {
 242         if (send(nf->fds[i], nf->packet.data, nf->packet.size, 0) == -1) {
 243             VLOG_WARN_RL(&rl, "netflow message send failed: %s",
 244                          strerror(errno));
 245         }
 246     }
 247     nf->packet.size = 0;
 248 }
 249
 250 static void
 251 clear_collectors(struct netflow *nf)
 252 {
 253     size_t i;
 254
 255     for (i = 0; i < nf->n_fds; i++) {
 256         close(nf->fds[i]);
 257     }
 258     free(nf->fds);
 259     nf->fds = NULL;
 260     nf->n_fds = 0;
 261 }
 262
 263 int
 264 netflow_set_collectors(struct netflow *nf, const struct svec *collectors_)
 265 {
 266     struct svec collectors;
 267     int error = 0;
 268     size_t i;
 269
 270     clear_collectors(nf);
 271
 272     svec_clone(&collectors, collectors_);
 273     svec_sort_unique(&collectors);
 274
 275     nf->fds = xmalloc(sizeof *nf->fds * collectors.n);
 276     for (i = 0; i < collectors.n; i++) {
 277         const char *name = collectors.names[i];
 278         char *tmpname = xstrdup(name);
 279         int fd = open_collector(tmpname);
 280         free(tmpname);
 281         if (fd >= 0) {
 282             nf->fds[nf->n_fds++] = fd;
 283         } else {
 284             VLOG_WARN("couldn't open connection to collector (%s), "
 285                       "ignoring %s\n", strerror(-fd), name);
 286             if (!error) {
 287                 error = -fd;
 288             }
 289         }
 290     }
 291
 292     svec_destroy(&collectors);
 293     return error;
 294 }
 295
 296 void
 297 netflow_set_engine(struct netflow *nf, uint8_t engine_type,
 298         uint8_t engine_id, bool add_id_to_iface)
 299 {
 300     nf->engine_type = engine_type;
 301     nf->engine_id = engine_id;
 302     nf->add_id_to_iface = add_id_to_iface;
 303 }
 304
 305 struct netflow *
 306 netflow_create(void)
 307 {
 308     struct netflow *nf = xmalloc(sizeof *nf);
 309     nf->engine_type = 0;
 310     nf->engine_id = 0;
 311     nf->boot_time = time_msec();
 312     nf->fds = NULL;
 313     nf->n_fds = 0;
 314     nf->add_id_to_iface = false;
 315     nf->netflow_cnt = 0;
 316     ofpbuf_init(&nf->packet, 1500);
 317     return nf;
 318 }
 319
 320 void
 321 netflow_destroy(struct netflow *nf)
 322 {
 323     if (nf) {
 324         ofpbuf_uninit(&nf->packet);
 325         clear_collectors(nf);
 326         free(nf);
 327     }
 328 }