unix4lyfe git - darkstat-debian/blob - darkstat.c

   1 /* darkstat 3
   2  * copyright (c) 2001-2011 Emil Mikulic.
   3  *
   4  * darkstat.c: signals, cmdline parsing, program body.
   5  *
   6  * You may use, modify and redistribute this file under the terms of the
   7  * GNU General Public License version 2. (see COPYING.GPL)
   8  */
   9
  10 #include "acct.h"
  11 #include "cap.h"
  12 #include "cdefs.h"
  13 #include "config.h"
  14 #include "conv.h"
  15 #include "daylog.h"
  16 #include "db.h"
  17 #include "dns.h"
  18 #include "err.h"
  19 #include "http.h"
  20 #include "hosts_db.h"
  21 #include "localip.h"
  22 #include "ncache.h"
  23 #include "now.h"
  24 #include "pidfile.h"
  25
  26 #include <assert.h>
  27 #include <errno.h>
  28 #include <inttypes.h>
  29 #include <signal.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <syslog.h>
  34 #include <unistd.h>
  35 #include <pcap.h>
  36
  37 #ifndef INADDR_NONE
  38 # define INADDR_NONE (-1) /* Solaris */
  39 #endif
  40
  41 /* --- Signal handling --- */
  42 static volatile int running = 1;
  43 static void sig_shutdown(int signum _unused_) { running = 0; }
  44
  45 static volatile int reset_pending = 0, export_pending = 0;
  46 static void sig_reset(int signum _unused_) {
  47    reset_pending = 1;
  48    export_pending = 1;
  49 }
  50
  51 static void sig_export(int signum _unused_) { export_pending = 1; }
  52
  53 /* --- Commandline parsing --- */
  54 static unsigned long parsenum(const char *str,
  55                               unsigned long max /* 0 for no max */) {
  56    unsigned long n;
  57    char *end;
  58
  59    errno = 0;
  60    n = strtoul(str, &end, 10);
  61    if (*end != '\0')
  62       errx(1, "\"%s\" is not a valid number", str);
  63    if (errno == ERANGE)
  64       errx(1, "\"%s\" is out of range", str);
  65    if ((max != 0) && (n > max))
  66       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  67    return n;
  68 }
  69
  70 static int opt_iface_seen = 0;
  71 static void cb_interface(const char *arg) {
  72    cap_add_ifname(arg);
  73    opt_iface_seen = 1;
  74 }
  75
  76 static void cb_filter(const char *arg) { cap_add_filter(arg); }
  77
  78 const char *opt_capfile = NULL;
  79 static void cb_capfile(const char *arg) { opt_capfile = arg; }
  80
  81 int opt_want_snaplen = -1;
  82 static void cb_snaplen(const char *arg)
  83 { opt_want_snaplen = (int)parsenum(arg, 0); }
  84
  85 int opt_want_pppoe = 0;
  86 static void cb_pppoe(const char *arg _unused_) { opt_want_pppoe = 1; }
  87
  88 int opt_want_syslog = 0;
  89 static void cb_syslog(const char *arg _unused_) { opt_want_syslog = 1; }
  90
  91 int opt_want_verbose = 0;
  92 static void cb_verbose(const char *arg _unused_) { opt_want_verbose = 1; }
  93
  94 int opt_want_daemonize = 1;
  95 static void cb_no_daemon(const char *arg _unused_) { opt_want_daemonize = 0; }
  96
  97 int opt_want_promisc = 1;
  98 static void cb_no_promisc(const char *arg _unused_) { opt_want_promisc = 0; }
  99
 100 int opt_want_dns = 1;
 101 static void cb_no_dns(const char *arg _unused_) { opt_want_dns = 0; }
 102
 103 int opt_want_macs = 1;
 104 static void cb_no_macs(const char *arg _unused_) { opt_want_macs = 0; }
 105
 106 int opt_want_lastseen = 1;
 107 static void cb_no_lastseen(const char *arg _unused_) { opt_want_lastseen = 0; }
 108
 109 unsigned short opt_bindport = 667;
 110 static void cb_port(const char *arg)
 111 { opt_bindport = (unsigned short)parsenum(arg, 65536); }
 112
 113 static void cb_bindaddr(const char *arg) { http_add_bindaddr(arg); }
 114
 115 static int is_localnet_specified = 0;
 116 static void cb_local(const char *arg)
 117 {
 118    acct_init_localnet(arg);
 119    is_localnet_specified = 1;
 120 }
 121
 122 int opt_want_local_only = 0;
 123 static void cb_local_only(const char *arg _unused_)
 124 { opt_want_local_only = 1; }
 125
 126 const char *opt_chroot_dir = NULL;
 127 static void cb_chroot(const char *arg) { opt_chroot_dir = arg; }
 128
 129 const char *opt_privdrop_user = NULL;
 130 static void cb_user(const char *arg) { opt_privdrop_user = arg; }
 131
 132 const char *daylog_fn = NULL;
 133 static void cb_daylog(const char *arg)
 134 {
 135    if (opt_chroot_dir == NULL)
 136       errx(1, "the daylog file is relative to the chroot.\n"
 137       "You must specify a --chroot dir before you can use --daylog.");
 138    else
 139       daylog_fn = arg;
 140 }
 141
 142 const char *import_fn = NULL;
 143 static void cb_import(const char *arg)
 144 {
 145    if (opt_chroot_dir == NULL)
 146       errx(1, "the import file is relative to the chroot.\n"
 147       "You must specify a --chroot dir before you can use --import.");
 148    else
 149       import_fn = arg;
 150 }
 151
 152 const char *export_fn = NULL;
 153 static void cb_export(const char *arg)
 154 {
 155    if ((opt_chroot_dir == NULL) && (opt_capfile == NULL))
 156       errx(1, "the export file is relative to the chroot.\n"
 157       "You must specify a --chroot dir before you can use --export.");
 158    else
 159       export_fn = arg;
 160 }
 161
 162 static const char *pid_fn = NULL;
 163 static void cb_pidfile(const char *arg)
 164 {
 165    if (opt_chroot_dir == NULL)
 166       errx(1, "the pidfile is relative to the chroot.\n"
 167       "You must specify a --chroot dir before you can use --pidfile.");
 168    else
 169       pid_fn = arg;
 170 }
 171
 172 unsigned int opt_hosts_max = 1000;
 173 static void cb_hosts_max(const char *arg)
 174 { opt_hosts_max = parsenum(arg, 0); }
 175
 176 unsigned int opt_hosts_keep = 500;
 177 static void cb_hosts_keep(const char *arg)
 178 { opt_hosts_keep = parsenum(arg, 0); }
 179
 180 unsigned int opt_ports_max = 200;
 181 static void cb_ports_max(const char *arg)
 182 { opt_ports_max = parsenum(arg, 65536); }
 183
 184 unsigned int opt_ports_keep = 30;
 185 static void cb_ports_keep(const char *arg)
 186 { opt_ports_keep = parsenum(arg, 65536); }
 187
 188 unsigned int opt_highest_port = 65535;
 189 static void cb_highest_port(const char *arg)
 190 { opt_highest_port = parsenum(arg, 65535); }
 191
 192 int opt_wait_secs = -1;
 193 static void cb_wait_secs(const char *arg)
 194 { opt_wait_secs = (int)parsenum(arg, 0); }
 195
 196 int opt_want_hexdump = 0;
 197 static void cb_hexdump(const char *arg _unused_)
 198 { opt_want_hexdump = 1; }
 199
 200 int opt_want_help = 0;
 201 static void cb_help(const char *arg _unused_)
 202 { opt_want_help = 1; }
 203 static void cb_version(const char *arg _unused_)
 204 { opt_want_help = -1; }
 205
 206 /* --- */
 207
 208 struct cmdline_arg {
 209    const char *name, *arg_name; /* NULL arg_name means unary */
 210    void (*callback)(const char *arg);
 211    int num_seen;
 212 };
 213
 214 static struct cmdline_arg cmdline_args[] = {
 215    {"-i",             "interface",       cb_interface,   -1},
 216    {"-f",             "filter",          cb_filter,      -1},
 217    {"-r",             "capfile",         cb_capfile,      0},
 218    {"-p",             "port",            cb_port,         0},
 219    {"-b",             "bindaddr",        cb_bindaddr,    -1},
 220    {"-l",             "network/netmask", cb_local,        0},
 221    {"--local-only",   NULL,              cb_local_only,   0},
 222    {"--snaplen",      "bytes",           cb_snaplen,      0},
 223    {"--pppoe",        NULL,              cb_pppoe,        0},
 224    {"--syslog",       NULL,              cb_syslog,       0},
 225    {"--verbose",      NULL,              cb_verbose,      0},
 226    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 227    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 228    {"--no-dns",       NULL,              cb_no_dns,       0},
 229    {"--no-macs",      NULL,              cb_no_macs,      0},
 230    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 231    {"--chroot",       "dir",             cb_chroot,       0},
 232    {"--user",         "username",        cb_user,         0},
 233    {"--daylog",       "filename",        cb_daylog,       0},
 234    {"--import",       "filename",        cb_import,       0},
 235    {"--export",       "filename",        cb_export,       0},
 236    {"--pidfile",      "filename",        cb_pidfile,      0},
 237    {"--hosts-max",    "count",           cb_hosts_max,    0},
 238    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 239    {"--ports-max",    "count",           cb_ports_max,    0},
 240    {"--ports-keep",   "count",           cb_ports_keep,   0},
 241    {"--highest-port", "port",            cb_highest_port, 0},
 242    {"--wait",         "secs",            cb_wait_secs,    0},
 243    {"--hexdump",      NULL,              cb_hexdump,      0},
 244    {"--version",      NULL,              cb_version,      0},
 245    {"--help",         NULL,              cb_help,         0},
 246    {NULL,             NULL,              NULL,            0}
 247 };
 248
 249 /* We autogenerate the usage statement from the cmdline_args data structure. */
 250 static void usage(void) {
 251    static char intro[] = "usage: darkstat ";
 252    char indent[sizeof(intro)];
 253    struct cmdline_arg *arg;
 254
 255    printf(PACKAGE_STRING " (using %s)\n", pcap_lib_version());
 256    if (opt_want_help == -1) return;
 257
 258    memset(indent, ' ', sizeof(indent));
 259    indent[0] = indent[sizeof(indent) - 1] = 0;
 260
 261    printf("\n%s", intro);
 262    for (arg = cmdline_args; arg->name != NULL; arg++) {
 263       printf("%s[ %s%s%s ]\n",
 264           indent,
 265           arg->name,
 266           arg->arg_name != NULL ? " " : "",
 267           arg->arg_name != NULL ? arg->arg_name : "");
 268       indent[0] = ' ';
 269    }
 270    printf("\n"
 271 "Please refer to the darkstat(8) manual page for further\n"
 272 "documentation and usage examples.\n");
 273 }
 274
 275 static void parse_sub_cmdline(const int argc, char * const *argv) {
 276    struct cmdline_arg *arg;
 277
 278    if (argc == 0) return;
 279    for (arg = cmdline_args; arg->name != NULL; arg++)
 280       if (strcmp(argv[0], arg->name) == 0) {
 281          if ((arg->arg_name != NULL) && (argc == 1)) {
 282             fprintf(stderr,
 283                "error: argument \"%s\" requires parameter \"%s\"\n",
 284                arg->name, arg->arg_name);
 285             usage();
 286             exit(EXIT_FAILURE);
 287          }
 288          if (arg->num_seen > 0) {
 289             fprintf(stderr,
 290                "error: already specified argument \"%s\"\n",
 291                arg->name);
 292             usage();
 293             exit(EXIT_FAILURE);
 294          }
 295
 296          if (arg->num_seen != -1) /* accept more than one */
 297             arg->num_seen++;
 298
 299          if (arg->arg_name == NULL) {
 300             arg->callback(NULL);
 301             parse_sub_cmdline(argc-1, argv+1);
 302          } else {
 303             arg->callback(argv[1]);
 304             parse_sub_cmdline(argc-2, argv+2);
 305          }
 306          return;
 307       }
 308
 309    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 310    usage();
 311    exit(EXIT_FAILURE);
 312 }
 313
 314 static void parse_cmdline(const int argc, char * const *argv) {
 315    if (argc < 1) {
 316       /* Not enough args. */
 317       usage();
 318       exit(EXIT_FAILURE);
 319    }
 320
 321    parse_sub_cmdline(argc, argv);
 322
 323    if (opt_want_help) {
 324      usage();
 325      exit(EXIT_SUCCESS);
 326    }
 327
 328    /* start syslogging as early as possible */
 329    if (opt_want_syslog)
 330       openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 331
 332    /* some default values */
 333    if (opt_chroot_dir == NULL)
 334       opt_chroot_dir = CHROOT_DIR;
 335    if (opt_privdrop_user == NULL)
 336       opt_privdrop_user = PRIVDROP_USER;
 337
 338    /* sanity check args */
 339    if (!opt_iface_seen && opt_capfile == NULL)
 340       errx(1, "must specify either interface (-i) or capture file (-r)");
 341
 342    if (opt_iface_seen && opt_capfile != NULL)
 343       errx(1, "can't specify both interface (-i) and capture file (-r)");
 344
 345    if ((opt_hosts_max != 0) && (opt_hosts_keep >= opt_hosts_max)) {
 346       opt_hosts_keep = opt_hosts_max / 2;
 347       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 348          opt_hosts_keep, opt_hosts_max);
 349    }
 350    verbosef("max %u hosts, cutting down to %u when exceeded",
 351       opt_hosts_max, opt_hosts_keep);
 352
 353    if ((opt_ports_max != 0) && (opt_ports_keep >= opt_ports_max)) {
 354       opt_ports_keep = opt_ports_max / 2;
 355       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 356          opt_ports_keep, opt_ports_max);
 357    }
 358    verbosef("max %u ports per host, cutting down to %u when exceeded",
 359       opt_ports_max, opt_ports_keep);
 360
 361    if (opt_want_hexdump && !opt_want_verbose) {
 362       opt_want_verbose = 1;
 363       verbosef("--hexdump implies --verbose");
 364    }
 365
 366    if (opt_want_hexdump && opt_want_daemonize) {
 367       opt_want_daemonize = 0;
 368       verbosef("--hexdump implies --no-daemon");
 369    }
 370
 371    if (opt_want_local_only && !is_localnet_specified)
 372       verbosef("WARNING: --local-only without -l only matches the local host");
 373 }
 374
 375 static void run_from_capfile(void) {
 376    now_init();
 377    graph_init();
 378    hosts_db_init();
 379    cap_from_file(opt_capfile);
 380    if (export_fn != NULL) db_export(export_fn);
 381    hosts_db_free();
 382    graph_free();
 383    verbosef("Total packets: %llu, bytes: %llu",
 384             (unsigned long long)acct_total_packets,
 385             (unsigned long long)acct_total_bytes);
 386 }
 387
 388 /* --- Program body --- */
 389 int
 390 main(int argc, char **argv)
 391 {
 392    test_64order();
 393    parse_cmdline(argc-1, argv+1);
 394
 395    if (opt_capfile) {
 396       run_from_capfile();
 397       return 0;
 398    }
 399
 400    /* must verbosef() before first fork to init lock */
 401    verbosef("starting up");
 402    if (pid_fn) pidfile_create(opt_chroot_dir, pid_fn, opt_privdrop_user);
 403
 404    if (opt_want_daemonize) {
 405       verbosef("daemonizing to run in the background!");
 406       daemonize_start();
 407       verbosef("I am the main process");
 408    }
 409    if (pid_fn) pidfile_write_close();
 410
 411    /* do this first as it forks - minimize memory use */
 412    if (opt_want_dns) dns_init(opt_privdrop_user);
 413    cap_start(opt_want_promisc); /* needs root */
 414    http_listen(opt_bindport);
 415    ncache_init(); /* must do before chroot() */
 416
 417    privdrop(opt_chroot_dir, opt_privdrop_user);
 418
 419    /* Don't need root privs for these: */
 420    now_init();
 421    if (daylog_fn != NULL) daylog_init(daylog_fn);
 422    graph_init();
 423    hosts_db_init();
 424    if (import_fn != NULL) db_import(import_fn);
 425
 426    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 427       errx(1, "signal(SIGTERM) failed");
 428    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 429       errx(1, "signal(SIGINT) failed");
 430    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 431       errx(1, "signal(SIGUSR1) failed");
 432    if (signal(SIGUSR2, sig_export) == SIG_ERR)
 433       errx(1, "signal(SIGUSR2) failed");
 434
 435    verbosef("entering main loop");
 436    daemonize_finish();
 437
 438    while (running) {
 439       int select_ret, max_fd = -1, use_timeout = 0;
 440       struct timeval timeout;
 441       struct timespec t;
 442       fd_set rs, ws;
 443
 444       FD_ZERO(&rs);
 445       FD_ZERO(&ws);
 446       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 447       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 448
 449       select_ret = select(max_fd+1, &rs, &ws, NULL,
 450          (use_timeout) ? &timeout : NULL);
 451       if (select_ret == 0 && !use_timeout)
 452             errx(1, "select() erroneously timed out");
 453       if (select_ret == -1) {
 454          if (errno == EINTR)
 455             continue;
 456          else
 457             err(1, "select()");
 458       }
 459
 460       timer_start(&t);
 461       now_update();
 462
 463       if (export_pending) {
 464          if (export_fn != NULL)
 465             db_export(export_fn);
 466          export_pending = 0;
 467       }
 468
 469       if (reset_pending) {
 470          if (export_pending)
 471             continue; /* export before reset */
 472          hosts_db_reset();
 473          graph_reset();
 474          reset_pending = 0;
 475       }
 476
 477       graph_rotate();
 478       cap_poll(&rs);
 479       dns_poll();
 480       http_poll(&rs, &ws);
 481       timer_stop(&t, 1000000000, "event processing took longer than a second");
 482    }
 483
 484    verbosef("shutting down");
 485    verbosef("pcap stats: %u packets received, %u packets dropped",
 486       cap_pkts_recv, cap_pkts_drop);
 487    http_stop();
 488    cap_stop();
 489    dns_stop();
 490    if (export_fn != NULL) db_export(export_fn);
 491    hosts_db_free();
 492    graph_free();
 493    if (daylog_fn != NULL) daylog_free();
 494    ncache_free();
 495    if (pid_fn) pidfile_unlink();
 496    verbosef("shut down");
 497    return (EXIT_SUCCESS);
 498 }
 499
 500 /* vim:set ts=3 sw=3 tw=78 expandtab: */