The Tcpdump Group git mirrors - libpcap/blob - pcap-snf.c

   1 #ifdef HAVE_CONFIG_H
   2 #include "config.h"
   3 #endif
   4
   5 #include <sys/param.h>
   6
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <errno.h>
  10
  11 #include <ctype.h>
  12 #include <netinet/in.h>
  13 #include <sys/mman.h>
  14 #include <sys/socket.h>
  15 #include <sys/types.h>
  16 #include <unistd.h>
  17
  18 #include <snf.h>
  19
  20 #include "pcap-int.h"
  21 #include "pcap-snf.h"
  22
  23 /*
  24  * Private data for capturing on SNF devices.
  25  */
  26 struct pcap_snf {
  27         snf_handle_t snf_handle; /* opaque device handle */
  28         snf_ring_t   snf_ring;   /* opaque device ring handle */
  29         int          snf_timeout;
  30         int          snf_boardnum;
  31 };
  32
  33 static int
  34 snf_set_datalink(pcap_t *p, int dlt)
  35 {
  36         p->linktype = dlt;
  37         return (0);
  38 }
  39
  40 static int
  41 snf_pcap_stats(pcap_t *p, struct pcap_stat *ps)
  42 {
  43         struct snf_ring_stats stats;
  44         int rc;
  45
  46         if ((rc = snf_ring_getstats(ps->snf_ring, &stats))) {
  47                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snf_get_stats: %s",
  48                          pcap_strerror(rc));
  49                 return -1;
  50         }
  51         ps->ps_recv = stats.ring_pkt_recv + stats.ring_pkt_overflow;
  52         ps->ps_drop = stats.ring_pkt_overflow;
  53         ps->ps_ifdrop = stats.nic_pkt_overflow + stats.nic_pkt_bad;
  54         return 0;
  55 }
  56
  57 static void
  58 snf_platform_cleanup(pcap_t *p)
  59 {
  60         struct pcap_snf *ps = p->priv;
  61
  62         if (p == NULL)
  63                 return;
  64
  65         snf_ring_close(ps->snf_ring);
  66         snf_close(ps->snf_handle);
  67         pcap_cleanup_live_common(p);
  68 }
  69
  70 static int
  71 snf_getnonblock(pcap_t *p, char *errbuf)
  72 {
  73         struct pcap_snf *ps = p->priv;
  74
  75         return (ps->snf_timeout == 0);
  76 }
  77
  78 static int
  79 snf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
  80 {
  81         struct pcap_snf *ps = p->priv;
  82
  83         if (nonblock)
  84                 ps->snf_timeout = 0;
  85         else {
  86                 if (p->opt.timeout <= 0)
  87                         ps->snf_timeout = -1; /* forever */
  88                 else
  89                         ps->snf_timeout = p->opt.timeout;
  90         }
  91         return (0);
  92 }
  93
  94 #define _NSEC_PER_SEC 1000000000
  95
  96 static inline
  97 struct timeval
  98 snf_timestamp_to_timeval(const int64_t ts_nanosec)
  99 {
 100         struct timeval tv;
 101         int32_t rem;
 102         if (ts_nanosec == 0)
 103                 return (struct timeval) { 0, 0 };
 104         tv.tv_sec = ts_nanosec / _NSEC_PER_SEC;
 105         tv.tv_usec = (ts_nanosec % _NSEC_PER_SEC) / 1000;
 106         return tv;
 107 }
 108
 109 static int
 110 snf_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 111 {
 112         struct pcap_snf *ps = p->priv;
 113         struct pcap_pkthdr hdr;
 114         int i, flags, err, caplen, n;
 115         struct snf_recv_req req;
 116
 117         if (!p || cnt == 0)
 118                 return -1;
 119
 120         n = 0;
 121         while (n < cnt || PACKET_COUNT_IS_UNLIMITED(cnt)) {
 122                 /*
 123                  * Has "pcap_breakloop()" been called?
 124                  */
 125                 if (p->break_loop) {
 126                         if (n == 0) {
 127                                 p->break_loop = 0;
 128                                 return (-2);
 129                         } else {
 130                                 return (n);
 131                         }
 132                 }
 133
 134                 err = snf_ring_recv(ps->snf_ring, ps->snf_timeout, &req);
 135
 136                 if (err) {
 137                         if (err == EBUSY || err == EAGAIN)
 138                                 return (0);
 139                         if (err == EINTR)
 140                                 continue;
 141                         if (err != 0) {
 142                                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snf_read: %s",
 143                                          pcap_strerror(err));
 144                                 return -1;
 145                         }
 146                 }
 147
 148                 caplen = req.length;
 149                 if (caplen > p->snapshot)
 150                         caplen = p->snapshot;
 151
 152                 if ((p->fcode.bf_insns == NULL) ||
 153                      bpf_filter(p->fcode.bf_insns, req.pkt_addr, req.length, caplen)) {
 154                         hdr.ts = snf_timestamp_to_timeval(req.timestamp);
 155                         hdr.caplen = caplen;
 156                         hdr.len = req.length;
 157                         callback(user, &hdr, req.pkt_addr);
 158                 }
 159                 n++;
 160         }
 161         return (n);
 162 }
 163
 164 static int
 165 snf_setfilter(pcap_t *p, struct bpf_program *fp)
 166 {
 167         if (!p)
 168                 return -1;
 169         if (!fp) {
 170                 strncpy(p->errbuf, "setfilter: No filter specified",
 171                         sizeof(p->errbuf));
 172                 return -1;
 173         }
 174
 175         /* Make our private copy of the filter */
 176
 177         if (install_bpf_program(p, fp) < 0)
 178                 return -1;
 179
 180         return (0);
 181 }
 182
 183 static int
 184 snf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
 185 {
 186         strlcpy(p->errbuf, "Sending packets isn't supported with snf",
 187             PCAP_ERRBUF_SIZE);
 188         return (-1);
 189 }
 190
 191 static int
 192 snf_activate(pcap_t* p)
 193 {
 194         struct pcap_snf *ps = p->priv;
 195         char *device = p->opt.source;
 196         const char *nr = NULL;
 197         int err;
 198         int flags = 0;
 199
 200         if (device == NULL) {
 201                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 202                          "device is NULL: %s", pcap_strerror(errno));
 203                 return -1;
 204         }
 205
 206         /* In Libpcap, we set pshared by default if NUM_RINGS is set to > 1.
 207          * Since libpcap isn't thread-safe */
 208         if ((nr = getenv("SNF_NUM_RINGS")) && *nr && atoi(nr) > 1)
 209                 flags |= SNF_F_PSHARED;
 210         else
 211                 nr = NULL;
 212
 213         err = snf_open(ps->snf_boardnum,
 214                         0, /* let SNF API parse SNF_NUM_RINGS, if set */
 215                         NULL, /* default RSS, or use SNF_RSS_FLAGS env */
 216                         0, /* default to SNF_DATARING_SIZE from env */
 217                         flags, /* may want pshared */
 218                         &ps->snf_handle);
 219         if (err != 0) {
 220                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 221                          "snf_open failed: %s", pcap_strerror(err));
 222                 return -1;
 223         }
 224
 225         err = snf_ring_open(ps->snf_handle, &ps->snf_ring);
 226         if (err != 0) {
 227                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 228                          "snf_ring_open failed: %s", pcap_strerror(err));
 229                 return -1;
 230         }
 231
 232         if (p->opt.timeout <= 0)
 233                 ps->snf_timeout = -1;
 234         else
 235                 ps->snf_timeout = p->opt.timeout;
 236
 237         err = snf_start(ps->snf_handle);
 238         if (err != 0) {
 239                 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
 240                          "snf_start failed: %s", pcap_strerror(err));
 241                 return -1;
 242         }
 243
 244         /*
 245          * "select()" and "poll()" don't work on snf descriptors.
 246          */
 247         p->selectable_fd = -1;
 248         p->linktype = DLT_EN10MB;
 249         p->read_op = snf_read;
 250         p->inject_op = snf_inject;
 251         p->setfilter_op = snf_setfilter;
 252         p->setdirection_op = NULL; /* Not implemented.*/
 253         p->set_datalink_op = snf_set_datalink;
 254         p->getnonblock_op = snf_getnonblock;
 255         p->setnonblock_op = snf_setnonblock;
 256         p->stats_op = snf_pcap_stats;
 257         p->cleanup_op = snf_platform_cleanup;
 258         return 0;
 259 }
 260
 261 int
 262 snf_findalldevs(pcap_if_t **devlistp, char *errbuf)
 263 {
 264         /*
 265          * There are no platform-specific devices since each device
 266          * exists as a regular Ethernet device.
 267          */
 268         return 0;
 269 }
 270
 271 pcap_t *
 272 snf_create(const char *device, char *ebuf, int *is_ours)
 273 {
 274         pcap_t *p;
 275         int boardnum = -1;
 276         struct snf_ifaddrs *ifaddrs, *ifa;
 277         size_t devlen;
 278         struct pcap_snf *ps;
 279
 280         if (snf_init(SNF_VERSION_API)) {
 281                 /* Can't initialize the API, so no SNF devices */
 282                 *is_ours = 0;
 283                 return NULL;
 284         }
 285
 286         /*
 287          * Match a given interface name to our list of interface names, from
 288          * which we can obtain the intended board number
 289          */
 290         if (snf_getifaddrs(&ifaddrs) || ifaddrs == NULL) {
 291                 /* Can't get SNF addresses */
 292                 *is_ours = 0;
 293                 return NULL;
 294         }
 295         devlen = strlen(device) + 1;
 296         ifa = ifaddrs;
 297         while (ifa) {
 298                 if (!strncmp(device, ifa->snf_ifa_name, devlen)) {
 299                         boardnum = ifa->snf_ifa_boardnum;
 300                         break;
 301                 }
 302                 ifa = ifa->snf_ifa_next;
 303         }
 304         snf_freeifaddrs(ifaddrs);
 305
 306         if (ifa == NULL) {
 307                 /*
 308                  * If we can't find the device by name, support the name "snfX"
 309                  * and "snf10gX" where X is the board number.
 310                  */
 311                 if (sscanf(device, "snf10g%d", &boardnum) != 1 &&
 312                     sscanf(device, "snf%d", &boardnum) != 1) {
 313                         /* Nope, not a supported name */
 314                         *is_ours = 0;
 315                         return NULL;
 316                     }
 317         }
 318
 319         /* OK, it's probably ours. */
 320         *is_ours = 1;
 321
 322         p = pcap_create_common(device, ebuf, sizeof (struct pcap_snf));
 323         if (p == NULL)
 324                 return NULL;
 325         ps = p->priv;
 326
 327         p->activate_op = snf_activate;
 328         ps->snf_boardnum = boardnum;
 329         return p;
 330 }