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 "pidfile.h"
  24
  25 #include <assert.h>
  26 #include <errno.h>
  27 #include <inttypes.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <syslog.h>
  33 #include <unistd.h>
  34 #include <pcap.h>
  35
  36 #include "now.h"
  37 time_t now;
  38
  39 #ifndef INADDR_NONE
  40 # define INADDR_NONE (-1) /* Solaris */
  41 #endif
  42
  43 /* --- Signal handling --- */
  44 static volatile int running = 1;
  45 static void sig_shutdown(int signum _unused_) { running = 0; }
  46
  47 static volatile int reset_pending = 0, export_pending = 0;
  48 static void sig_reset(int signum _unused_)
  49 {
  50    reset_pending = 1;
  51    export_pending = 1;
  52 }
  53
  54 static void sig_export(int signum _unused_) { export_pending = 1; }
  55
  56 /* --- Commandline parsing --- */
  57 static unsigned long
  58 parsenum(const char *str, unsigned long max /* 0 for no max */)
  59 {
  60    unsigned long n;
  61    char *end;
  62
  63    errno = 0;
  64    n = strtoul(str, &end, 10);
  65    if (*end != '\0')
  66       errx(1, "\"%s\" is not a valid number", str);
  67    if (errno == ERANGE)
  68       errx(1, "\"%s\" is out of range", str);
  69    if ((max != 0) && (n > max))
  70       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  71    return n;
  72 }
  73
  74 const char *opt_interface = NULL;
  75 static void cb_interface(const char *arg) { opt_interface = arg; }
  76
  77 const char *opt_capfile = NULL;
  78 static void cb_capfile(const char *arg) { opt_capfile = arg; }
  79
  80 int opt_want_snaplen = -1;
  81 static void cb_snaplen(const char *arg)
  82 { opt_want_snaplen = (int)parsenum(arg, 0); }
  83
  84 int opt_want_pppoe = 0;
  85 static void cb_pppoe(const char *arg _unused_) { opt_want_pppoe = 1; }
  86
  87 int opt_want_syslog = 0;
  88 static void cb_syslog(const char *arg _unused_) { opt_want_syslog = 1; }
  89
  90 int opt_want_verbose = 0;
  91 static void cb_verbose(const char *arg _unused_) { opt_want_verbose = 1; }
  92
  93 int opt_want_daemonize = 1;
  94 static void cb_no_daemon(const char *arg _unused_) { opt_want_daemonize = 0; }
  95
  96 int opt_want_promisc = 1;
  97 static void cb_no_promisc(const char *arg _unused_) { opt_want_promisc = 0; }
  98
  99 int opt_want_dns = 1;
 100 static void cb_no_dns(const char *arg _unused_) { opt_want_dns = 0; }
 101
 102 int opt_want_macs = 1;
 103 static void cb_no_macs(const char *arg _unused_) { opt_want_macs = 0; }
 104
 105 int opt_want_lastseen = 1;
 106 static void cb_no_lastseen(const char *arg _unused_) { opt_want_lastseen = 0; }
 107
 108 unsigned short opt_bindport = 667;
 109 static void cb_port(const char *arg)
 110 { opt_bindport = (unsigned short)parsenum(arg, 65536); }
 111
 112 static void cb_bindaddr(const char *arg) { http_add_bindaddr(arg); }
 113
 114 const char *opt_filter = NULL;
 115 static void cb_filter(const char *arg) { opt_filter = arg; }
 116
 117 static int is_localnet_specified = 0;
 118 static void cb_local(const char *arg)
 119 {
 120    acct_init_localnet(arg);
 121    is_localnet_specified = 1;
 122 }
 123
 124 int opt_want_local_only = 0;
 125 static void cb_local_only(const char *arg _unused_)
 126 { opt_want_local_only = 1; }
 127
 128 const char *opt_chroot_dir = NULL;
 129 static void cb_chroot(const char *arg) { opt_chroot_dir = arg; }
 130
 131 const char *opt_privdrop_user = NULL;
 132 static void cb_user(const char *arg) { opt_privdrop_user = arg; }
 133
 134 const char *daylog_fn = NULL;
 135 static void cb_daylog(const char *arg)
 136 {
 137    if (opt_chroot_dir == NULL)
 138       errx(1, "the daylog file is relative to the chroot.\n"
 139       "You must specify a --chroot dir before you can use --daylog.");
 140    else
 141       daylog_fn = arg;
 142 }
 143
 144 const char *import_fn = NULL;
 145 static void cb_import(const char *arg)
 146 {
 147    if (opt_chroot_dir == NULL)
 148       errx(1, "the import file is relative to the chroot.\n"
 149       "You must specify a --chroot dir before you can use --import.");
 150    else
 151       import_fn = arg;
 152 }
 153
 154 const char *export_fn = NULL;
 155 static void cb_export(const char *arg)
 156 {
 157    if ((opt_chroot_dir == NULL) && (opt_capfile == NULL))
 158       errx(1, "the export file is relative to the chroot.\n"
 159       "You must specify a --chroot dir before you can use --export.");
 160    else
 161       export_fn = arg;
 162 }
 163
 164 static const char *pid_fn = NULL;
 165 static void cb_pidfile(const char *arg)
 166 {
 167    if (opt_chroot_dir == NULL)
 168       errx(1, "the pidfile is relative to the chroot.\n"
 169       "You must specify a --chroot dir before you can use --pidfile.");
 170    else
 171       pid_fn = arg;
 172 }
 173
 174 unsigned int opt_hosts_max = 1000;
 175 static void cb_hosts_max(const char *arg)
 176 { opt_hosts_max = parsenum(arg, 0); }
 177
 178 unsigned int opt_hosts_keep = 500;
 179 static void cb_hosts_keep(const char *arg)
 180 { opt_hosts_keep = parsenum(arg, 0); }
 181
 182 unsigned int opt_ports_max = 200;
 183 static void cb_ports_max(const char *arg)
 184 { opt_ports_max = parsenum(arg, 65536); }
 185
 186 unsigned int opt_ports_keep = 30;
 187 static void cb_ports_keep(const char *arg)
 188 { opt_ports_keep = parsenum(arg, 65536); }
 189
 190 unsigned int opt_highest_port = 65535;
 191 static void cb_highest_port(const char *arg)
 192 { opt_highest_port = parsenum(arg, 65535); }
 193
 194 int opt_wait_secs = -1;
 195 static void cb_wait_secs(const char *arg)
 196 { opt_wait_secs = (int)parsenum(arg, 0); }
 197
 198 int opt_want_hexdump = 0;
 199 static void cb_hexdump(const char *arg _unused_)
 200 { opt_want_hexdump = 1; }
 201
 202 int opt_want_help = 0;
 203 static void cb_help(const char *arg _unused_)
 204 { opt_want_help = 1; }
 205 static void cb_version(const char *arg _unused_)
 206 { opt_want_help = -1; }
 207
 208 /* --- */
 209
 210 struct cmdline_arg {
 211    const char *name, *arg_name; /* NULL arg_name means unary */
 212    void (*callback)(const char *arg);
 213    int num_seen;
 214 };
 215
 216 static struct cmdline_arg cmdline_args[] = {
 217    {"-i",             "interface",       cb_interface,    0},
 218    {"-r",             "file",            cb_capfile,      0},
 219    {"-p",             "port",            cb_port,         0},
 220    {"-b",             "bindaddr",        cb_bindaddr,    -1},
 221    {"-f",             "filter",          cb_filter,       0},
 222    {"-l",             "network/netmask", cb_local,        0},
 223    {"--local-only",   NULL,              cb_local_only,   0},
 224    {"--snaplen",      "bytes",           cb_snaplen,      0},
 225    {"--pppoe",        NULL,              cb_pppoe,        0},
 226    {"--syslog",       NULL,              cb_syslog,       0},
 227    {"--verbose",      NULL,              cb_verbose,      0},
 228    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 229    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 230    {"--no-dns",       NULL,              cb_no_dns,       0},
 231    {"--no-macs",      NULL,              cb_no_macs,      0},
 232    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 233    {"--chroot",       "dir",             cb_chroot,       0},
 234    {"--user",         "username",        cb_user,         0},
 235    {"--daylog",       "filename",        cb_daylog,       0},
 236    {"--import",       "filename",        cb_import,       0},
 237    {"--export",       "filename",        cb_export,       0},
 238    {"--pidfile",      "filename",        cb_pidfile,      0},
 239    {"--hosts-max",    "count",           cb_hosts_max,    0},
 240    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 241    {"--ports-max",    "count",           cb_ports_max,    0},
 242    {"--ports-keep",   "count",           cb_ports_keep,   0},
 243    {"--highest-port", "port",            cb_highest_port, 0},
 244    {"--wait",         "secs",            cb_wait_secs,    0},
 245    {"--hexdump",      NULL,              cb_hexdump,      0},
 246    {"--version",      NULL,              cb_version,      0},
 247    {"--help",         NULL,              cb_help,         0},
 248    {NULL,             NULL,              NULL,            0}
 249 };
 250
 251 /*
 252  * We autogenerate the usage statement from the cmdline_args data structure.
 253  */
 254 static void
 255 usage(void)
 256 {
 257    static char intro[] = "usage: darkstat ";
 258    char indent[sizeof(intro)];
 259    struct cmdline_arg *arg;
 260
 261    printf(PACKAGE_STRING " (using %s)\n", pcap_lib_version());
 262    if (opt_want_help == -1) return;
 263
 264    memset(indent, ' ', sizeof(indent));
 265    indent[0] = indent[sizeof(indent) - 1] = 0;
 266
 267    printf("\n%s", intro);
 268    for (arg = cmdline_args; arg->name != NULL; arg++) {
 269       printf("%s[ %s%s%s ]\n",
 270           indent,
 271           arg->name,
 272           arg->arg_name != NULL ? " " : "",
 273           arg->arg_name != NULL ? arg->arg_name : "");
 274       indent[0] = ' ';
 275    }
 276    printf("\n"
 277 "Please refer to the darkstat(8) manual page for further\n"
 278 "documentation and usage examples.\n");
 279 }
 280
 281 static void
 282 parse_sub_cmdline(const int argc, char * const *argv)
 283 {
 284    struct cmdline_arg *arg;
 285
 286    if (argc == 0) return;
 287    for (arg = cmdline_args; arg->name != NULL; arg++)
 288       if (strcmp(argv[0], arg->name) == 0) {
 289          if ((arg->arg_name != NULL) && (argc == 1)) {
 290             fprintf(stderr,
 291                "error: argument \"%s\" requires parameter \"%s\"\n",
 292                arg->name, arg->arg_name);
 293             usage();
 294             exit(EXIT_FAILURE);
 295          }
 296          if (arg->num_seen > 0) {
 297             fprintf(stderr,
 298                "error: already specified argument \"%s\"\n",
 299                arg->name);
 300             usage();
 301             exit(EXIT_FAILURE);
 302          }
 303
 304          if (arg->num_seen != -1) /* accept more than one */
 305             arg->num_seen++;
 306
 307          if (arg->arg_name == NULL) {
 308             arg->callback(NULL);
 309             parse_sub_cmdline(argc-1, argv+1);
 310          } else {
 311             arg->callback(argv[1]);
 312             parse_sub_cmdline(argc-2, argv+2);
 313          }
 314          return;
 315       }
 316
 317    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 318    usage();
 319    exit(EXIT_FAILURE);
 320 }
 321
 322 static void
 323 parse_cmdline(const int argc, char * const *argv)
 324 {
 325    if (argc < 1) {
 326       /* Not enough args. */
 327       usage();
 328       exit(EXIT_FAILURE);
 329    }
 330
 331    parse_sub_cmdline(argc, argv);
 332
 333    if (opt_want_help) {
 334      usage();
 335      exit(EXIT_SUCCESS);
 336    }
 337
 338    /* start syslogging as early as possible */
 339    if (opt_want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 340
 341    /* some default values */
 342    if (opt_chroot_dir == NULL) opt_chroot_dir = CHROOT_DIR;
 343    if (opt_privdrop_user == NULL) opt_privdrop_user = PRIVDROP_USER;
 344
 345    /* sanity check args */
 346    if ((opt_interface == NULL) && (opt_capfile == NULL))
 347       errx(1, "must specify either interface (-i) or capture file (-r)");
 348
 349    if ((opt_interface != NULL) && (opt_capfile != NULL))
 350       errx(1, "can't specify both interface (-i) and capture file (-r)");
 351
 352    if ((opt_hosts_max != 0) && (opt_hosts_keep >= opt_hosts_max)) {
 353       opt_hosts_keep = opt_hosts_max / 2;
 354       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 355          opt_hosts_keep, opt_hosts_max);
 356    }
 357    verbosef("max %u hosts, cutting down to %u when exceeded",
 358       opt_hosts_max, opt_hosts_keep);
 359
 360    if ((opt_ports_max != 0) && (opt_ports_keep >= opt_ports_max)) {
 361       opt_ports_keep = opt_ports_max / 2;
 362       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 363          opt_ports_keep, opt_ports_max);
 364    }
 365    verbosef("max %u ports per host, cutting down to %u when exceeded",
 366       opt_ports_max, opt_ports_keep);
 367
 368    if (opt_want_hexdump && !opt_want_verbose) {
 369       opt_want_verbose = 1;
 370       verbosef("--hexdump implies --verbose");
 371    }
 372
 373    if (opt_want_hexdump && opt_want_daemonize) {
 374       opt_want_daemonize = 0;
 375       verbosef("--hexdump implies --no-daemon");
 376    }
 377
 378    if (opt_want_local_only && !is_localnet_specified)
 379       verbosef("WARNING: --local-only without -l only matches the local host");
 380 }
 381
 382 static void
 383 run_from_capfile(void)
 384 {
 385    graph_init();
 386    hosts_db_init();
 387    cap_from_file(opt_capfile, opt_filter);
 388    cap_stop();
 389    if (export_fn != NULL) db_export(export_fn);
 390    hosts_db_free();
 391    graph_free();
 392 #ifndef PRIu64
 393 #warning "PRIu64 is not defined, using qu instead"
 394 #define PRIu64 "qu"
 395 #endif
 396    verbosef("Total packets: %"PRIu64", bytes: %"PRIu64,
 397       acct_total_packets, acct_total_bytes);
 398 }
 399
 400 /* --- Program body --- */
 401 int
 402 main(int argc, char **argv)
 403 {
 404    test_64order();
 405    parse_cmdline(argc-1, argv+1);
 406
 407    if (opt_capfile) {
 408       /*
 409        * This is very different from a regular run against a network
 410        * interface.
 411        */
 412       run_from_capfile();
 413       return 0;
 414    }
 415
 416    /* must verbosef() before first fork to init lock */
 417    verbosef("starting up");
 418    if (pid_fn) pidfile_create(opt_chroot_dir, pid_fn, opt_privdrop_user);
 419
 420    if (opt_want_daemonize) {
 421       verbosef("daemonizing to run in the background!");
 422       daemonize_start();
 423       verbosef("I am the main process");
 424    }
 425    if (pid_fn) pidfile_write_close();
 426
 427    /* do this first as it forks - minimize memory use */
 428    if (opt_want_dns) dns_init(opt_privdrop_user);
 429    cap_init(opt_interface, opt_filter, opt_want_promisc); /* needs root */
 430    http_listen(opt_bindport);
 431    ncache_init(); /* must do before chroot() */
 432
 433    privdrop(opt_chroot_dir, opt_privdrop_user);
 434
 435    /* Don't need root privs for these: */
 436    now = time(NULL);
 437    if (daylog_fn != NULL) daylog_init(daylog_fn);
 438    graph_init();
 439    hosts_db_init();
 440    if (import_fn != NULL) db_import(import_fn);
 441    localip_init(opt_interface);
 442
 443    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 444       errx(1, "signal(SIGTERM) failed");
 445    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 446       errx(1, "signal(SIGINT) failed");
 447    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 448       errx(1, "signal(SIGUSR1) failed");
 449    if (signal(SIGUSR2, sig_export) == SIG_ERR)
 450       errx(1, "signal(SIGUSR2) failed");
 451
 452    verbosef("entering main loop");
 453    daemonize_finish();
 454
 455    while (running) {
 456       int select_ret, max_fd = -1, use_timeout = 0;
 457       struct timeval timeout;
 458       fd_set rs, ws;
 459
 460       now = time(NULL);
 461
 462       if (export_pending) {
 463          if (export_fn != NULL)
 464             db_export(export_fn);
 465          export_pending = 0;
 466       }
 467
 468       if (reset_pending) {
 469          if (export_pending)
 470             continue; /* export before reset */
 471          hosts_db_reset();
 472          graph_reset();
 473          reset_pending = 0;
 474       }
 475
 476       FD_ZERO(&rs);
 477       FD_ZERO(&ws);
 478
 479       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 480       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 481
 482       select_ret = select(max_fd+1, &rs, &ws, NULL,
 483          (use_timeout) ? &timeout : NULL);
 484
 485       if ((select_ret == 0) && (!use_timeout))
 486             errx(1, "select() erroneously timed out");
 487
 488       if (select_ret == -1) {
 489          if (errno == EINTR)
 490             continue;
 491          else
 492             err(1, "select()");
 493       }
 494       else {
 495          graph_rotate();
 496          cap_poll(&rs);
 497          dns_poll();
 498          http_poll(&rs, &ws);
 499       }
 500    }
 501
 502    verbosef("shutting down");
 503    verbosef("pcap stats: %u packets received, %u packets dropped",
 504       cap_pkts_recv, cap_pkts_drop);
 505    http_stop();
 506    cap_stop();
 507    dns_stop();
 508    if (export_fn != NULL) db_export(export_fn);
 509    hosts_db_free();
 510    graph_free();
 511    if (daylog_fn != NULL) daylog_free();
 512    ncache_free();
 513    if (pid_fn) pidfile_unlink();
 514    verbosef("shut down");
 515    return (EXIT_SUCCESS);
 516 }
 517
 518 /* vim:set ts=3 sw=3 tw=78 expandtab: */