unix4lyfe git - darkstat/blob - darkstat.c

   1 /* darkstat 3
   2  * copyright (c) 2001-2010 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 "darkstat.h"
  11 #include "acct.h"
  12 #include "cap.h"
  13 #include "conv.h"
  14 #include "daylog.h"
  15 #include "db.h"
  16 #include "dns.h"
  17 #include "http.h"
  18 #include "hosts_db.h"
  19 #include "localip.h"
  20 #include "ncache.h"
  21 #include "pidfile.h"
  22
  23 #include "err.h"
  24 #include <arpa/inet.h>
  25 #include <sys/socket.h>
  26 #include <netdb.h>
  27 #include <assert.h>
  28 #include <errno.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 #include "now.h"
  38 time_t now;
  39
  40 #ifndef INADDR_NONE
  41 # define INADDR_NONE (-1) /* Solaris */
  42 #endif
  43
  44 /* --- Signal handling --- */
  45 static volatile int running = 1;
  46 static void sig_shutdown(int signum _unused_) { running = 0; }
  47
  48 static volatile int reset_pending = 0, export_pending = 0;
  49 static void sig_reset(int signum _unused_)
  50 {
  51    reset_pending = 1;
  52    export_pending = 1;
  53 }
  54
  55 static void sig_export(int signum _unused_) { export_pending = 1; }
  56
  57 /* --- Commandline parsing --- */
  58 static unsigned long
  59 parsenum(const char *str, unsigned long max /* 0 for no max */)
  60 {
  61    unsigned long n;
  62    char *end;
  63
  64    errno = 0;
  65    n = strtoul(str, &end, 10);
  66    if (*end != '\0')
  67       errx(1, "\"%s\" is not a valid number", str);
  68    if (errno == ERANGE)
  69       errx(1, "\"%s\" is out of range", str);
  70    if ((max != 0) && (n > max))
  71       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  72    return n;
  73 }
  74
  75 const char *interface = NULL;
  76 static void cb_interface(const char *arg) { interface = arg; }
  77
  78 const char *capfile = NULL;
  79 static void cb_capfile(const char *arg) { capfile = arg; }
  80
  81 int want_snaplen = -1;
  82 static void cb_snaplen(const char *arg)
  83 { want_snaplen = (int)parsenum(arg, 0); }
  84
  85 int want_pppoe = 0;
  86 static void cb_pppoe(const char *arg _unused_) { want_pppoe = 1; }
  87
  88 static void cb_syslog(const char *arg _unused_) { want_syslog = 1; }
  89
  90 static void cb_verbose(const char *arg _unused_) { want_verbose = 1; }
  91
  92 int want_daemonize = 1;
  93 static void cb_no_daemon(const char *arg _unused_) { want_daemonize = 0; }
  94
  95 int want_promisc = 1;
  96 static void cb_no_promisc(const char *arg _unused_) { want_promisc = 0; }
  97
  98 int want_dns = 1;
  99 static void cb_no_dns(const char *arg _unused_) { want_dns = 0; }
 100
 101 int want_macs = 1;
 102 static void cb_no_macs(const char *arg _unused_) { want_macs = 0; }
 103
 104 int want_lastseen = 1;
 105 static void cb_no_lastseen(const char *arg _unused_) { want_lastseen = 0; }
 106
 107 unsigned short bindport = 667;
 108 static void cb_port(const char *arg)
 109 { bindport = (unsigned short)parsenum(arg, 65536); }
 110
 111 const char *bindaddr = NULL;
 112 static void cb_bindaddr(const char *arg)
 113 {
 114    struct addrinfo hints, *ai;
 115
 116    memset(&hints, 0, sizeof(hints));
 117    hints.ai_flags = AI_PASSIVE;
 118 #ifdef AI_ADDRCONFIG
 119    hints.ai_flags |= AI_ADDRCONFIG;
 120 #endif
 121    hints.ai_family = AF_UNSPEC;
 122    hints.ai_socktype = SOCK_STREAM;
 123
 124    if (getaddrinfo(arg, NULL, &hints, &ai))
 125       errx(1, "malformed address \"%s\"", arg);
 126
 127    freeaddrinfo(ai);
 128    bindaddr = arg;
 129 }
 130
 131 const char *filter = NULL;
 132 static void cb_filter(const char *arg) { filter = arg; }
 133
 134 static void cb_local(const char *arg) { acct_init_localnet(arg); }
 135
 136 const char *chroot_dir = NULL;
 137 static void cb_chroot(const char *arg) { chroot_dir = arg; }
 138
 139 const char *base = NULL;
 140 static void cb_base(const char *arg) { base = arg; }
 141
 142 const char *privdrop_user = NULL;
 143 static void cb_user(const char *arg) { privdrop_user = arg; }
 144
 145 const char *daylog_fn = NULL;
 146 static void cb_daylog(const char *arg)
 147 {
 148    if (chroot_dir == NULL)
 149       errx(1, "the daylog file is relative to the chroot.\n"
 150       "You must specify a --chroot dir before you can use --daylog.");
 151    else
 152       daylog_fn = arg;
 153 }
 154
 155 const char *import_fn = NULL;
 156 static void cb_import(const char *arg)
 157 {
 158    if (chroot_dir == NULL)
 159       errx(1, "the import file is relative to the chroot.\n"
 160       "You must specify a --chroot dir before you can use --import.");
 161    else
 162       import_fn = arg;
 163 }
 164
 165 const char *export_fn = NULL;
 166 static void cb_export(const char *arg)
 167 {
 168    if ((chroot_dir == NULL) && (capfile == NULL))
 169       errx(1, "the export file is relative to the chroot.\n"
 170       "You must specify a --chroot dir before you can use --export.");
 171    else
 172       export_fn = arg;
 173 }
 174
 175 static const char *pid_fn = NULL;
 176 static void cb_pidfile(const char *arg)
 177 {
 178    if (chroot_dir == NULL)
 179       errx(1, "the pidfile is relative to the chroot.\n"
 180       "You must specify a --chroot dir before you can use --pidfile.");
 181    else
 182       pid_fn = arg;
 183 }
 184
 185 unsigned int hosts_max = 1000;
 186 static void cb_hosts_max(const char *arg)
 187 { hosts_max = parsenum(arg, 0); }
 188
 189 unsigned int hosts_keep = 500;
 190 static void cb_hosts_keep(const char *arg)
 191 { hosts_keep = parsenum(arg, 0); }
 192
 193 unsigned int ports_max = 200;
 194 static void cb_ports_max(const char *arg)
 195 { ports_max = parsenum(arg, 65536); }
 196
 197 unsigned int ports_keep = 30;
 198 static void cb_ports_keep(const char *arg)
 199 { ports_keep = parsenum(arg, 65536); }
 200
 201 unsigned int highest_port = 65535;
 202 static void cb_highest_port(const char *arg)
 203 { highest_port = parsenum(arg, 65535); }
 204
 205 int wait_secs = -1;
 206 static void cb_wait_secs(const char *arg)
 207 { wait_secs = (int)parsenum(arg, 0); }
 208
 209 int want_hexdump = 0;
 210 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 211
 212 /* --- */
 213
 214 struct cmdline_arg {
 215    const char *name, *arg_name; /* NULL arg_name means unary */
 216    void (*callback)(const char *arg);
 217    int num_seen;
 218 };
 219
 220 static struct cmdline_arg cmdline_args[] = {
 221    {"-i",             "interface",       cb_interface,    0},
 222    {"-r",             "file",            cb_capfile,      0},
 223    {"--snaplen",      "bytes",           cb_snaplen,      0},
 224    {"--pppoe",        NULL,              cb_pppoe,        0},
 225    {"--syslog",       NULL,              cb_syslog,       0},
 226    {"--verbose",      NULL,              cb_verbose,      0},
 227    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 228    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 229    {"--no-dns",       NULL,              cb_no_dns,       0},
 230    {"--no-macs",      NULL,              cb_no_macs,      0},
 231    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 232    {"-p",             "port",            cb_port,         0},
 233    {"-b",             "bindaddr",        cb_bindaddr,     0},
 234    {"--base",         "path",            cb_base,         0},
 235    {"-f",             "filter",          cb_filter,       0},
 236    {"-l",             "network/netmask", cb_local,        0},
 237    {"--chroot",       "dir",             cb_chroot,       0},
 238    {"--user",         "username",        cb_user,         0},
 239    {"--daylog",       "filename",        cb_daylog,       0},
 240    {"--import",       "filename",        cb_import,       0},
 241    {"--export",       "filename",        cb_export,       0},
 242    {"--pidfile",      "filename",        cb_pidfile,      0},
 243    {"--hosts-max",    "count",           cb_hosts_max,    0},
 244    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 245    {"--ports-max",    "count",           cb_ports_max,    0},
 246    {"--ports-keep",   "count",           cb_ports_keep,   0},
 247    {"--highest-port", "port",            cb_highest_port, 0},
 248    {"--wait",         "secs",            cb_wait_secs,    0},
 249    {"--hexdump",      NULL,              cb_hexdump,      0},
 250    {NULL,             NULL,              NULL,            0}
 251 };
 252
 253 static void
 254 pad(const int width)
 255 {
 256    int i;
 257    for (i=0; i<width; i++) printf(" ");
 258 }
 259
 260 /*
 261  * We autogenerate the usage statement from the cmdline_args data structure.
 262  */
 263 static void
 264 usage(void)
 265 {
 266    int width, first;
 267    struct cmdline_arg *arg;
 268
 269    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 270       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 271
 272    width = printf("usage: darkstat ");
 273    first = 1;
 274
 275    for (arg = cmdline_args; arg->name != NULL; arg++) {
 276       if (first) first = 0; else pad(width);
 277       printf("[ %s", arg->name);
 278       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 279       printf(" ]\n");
 280    }
 281    printf("\n"
 282 "Please refer to the darkstat(8) manual page for further\n"
 283 "documentation and usage examples.\n");
 284 }
 285
 286 static void
 287 parse_sub_cmdline(const int argc, char * const *argv)
 288 {
 289    struct cmdline_arg *arg;
 290
 291    if (argc == 0) return;
 292    for (arg = cmdline_args; arg->name != NULL; arg++)
 293       if (strcmp(argv[0], arg->name) == 0) {
 294          if ((arg->arg_name != NULL) && (argc == 1)) {
 295             fprintf(stderr,
 296                "error: argument \"%s\" requires parameter \"%s\"\n",
 297                arg->name, arg->arg_name);
 298             usage();
 299             exit(EXIT_FAILURE);
 300          }
 301          if (arg->num_seen > 0) {
 302             fprintf(stderr,
 303                "error: already specified argument \"%s\"\n",
 304                arg->name);
 305             usage();
 306             exit(EXIT_FAILURE);
 307          }
 308
 309          arg->num_seen++;
 310          if (arg->arg_name == NULL) {
 311             arg->callback(NULL);
 312             parse_sub_cmdline(argc-1, argv+1);
 313          } else {
 314             arg->callback(argv[1]);
 315             parse_sub_cmdline(argc-2, argv+2);
 316          }
 317          return;
 318       }
 319
 320    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 321    usage();
 322    exit(EXIT_FAILURE);
 323 }
 324
 325 static void
 326 parse_cmdline(const int argc, char * const *argv)
 327 {
 328    if (argc < 1) {
 329       /* Not enough args. */
 330       usage();
 331       exit(EXIT_FAILURE);
 332    }
 333
 334    parse_sub_cmdline(argc, argv);
 335
 336    /* start syslogging as early as possible */
 337    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 338
 339    /* some default values */
 340    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 341    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 342
 343    /* sanity check args */
 344    if ((interface == NULL) && (capfile == NULL))
 345       errx(1, "must specify either interface (-i) or capture file (-r)");
 346
 347    if ((interface != NULL) && (capfile != NULL))
 348       errx(1, "can't specify both interface (-i) and capture file (-r)");
 349
 350    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 351       hosts_keep = hosts_max / 2;
 352       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 353          hosts_keep, hosts_max);
 354    }
 355    verbosef("max %u hosts, cutting down to %u when exceeded",
 356       hosts_max, hosts_keep);
 357
 358    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 359       ports_keep = ports_max / 2;
 360       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 361          ports_keep, ports_max);
 362    }
 363    verbosef("max %u ports per host, cutting down to %u when exceeded",
 364       ports_max, ports_keep);
 365
 366    if (want_hexdump && !want_verbose) {
 367       want_verbose = 1;
 368       verbosef("--hexdump implies --verbose");
 369    }
 370
 371    if (want_hexdump && want_daemonize) {
 372       want_daemonize = 0;
 373       verbosef("--hexdump implies --no-daemon");
 374    }
 375 }
 376
 377 static void
 378 run_from_capfile(void)
 379 {
 380    graph_init();
 381    hosts_db_init();
 382    cap_from_file(capfile, filter);
 383    cap_stop();
 384    if (export_fn != NULL) db_export(export_fn);
 385    hosts_db_free();
 386    graph_free();
 387    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 388 }
 389
 390 /* --- Program body --- */
 391 int
 392 main(int argc, char **argv)
 393 {
 394    test_64order();
 395    parse_cmdline(argc-1, argv+1);
 396
 397    if (capfile) {
 398       /*
 399        * This is very different from a regular run against a network
 400        * interface.
 401        */
 402       run_from_capfile();
 403       return 0;
 404    }
 405
 406    /* must verbosef() before first fork to init lock */
 407    verbosef("starting up");
 408    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 409
 410    if (want_daemonize) {
 411       verbosef("daemonizing to run in the background!");
 412       daemonize_start();
 413       verbosef("I am the main process");
 414    }
 415    if (pid_fn) pidfile_write_close();
 416
 417    /* do this first as it forks - minimize memory use */
 418    if (want_dns) dns_init(privdrop_user);
 419    cap_init(interface, filter, want_promisc); /* needs root */
 420    http_init(base, bindaddr, bindport, /*maxconn=*/-1);
 421    ncache_init(); /* must do before chroot() */
 422
 423    privdrop(chroot_dir, privdrop_user);
 424
 425    /* Don't need root privs for these: */
 426    now = time(NULL);
 427    if (daylog_fn != NULL) daylog_init(daylog_fn);
 428    graph_init();
 429    hosts_db_init();
 430    if (import_fn != NULL) db_import(import_fn);
 431    localip_init(interface);
 432
 433    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 434       errx(1, "signal(SIGTERM) failed");
 435    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 436       errx(1, "signal(SIGINT) failed");
 437    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 438       errx(1, "signal(SIGUSR1) failed");
 439    if (signal(SIGUSR2, sig_export) == SIG_ERR)
 440       errx(1, "signal(SIGUSR2) failed");
 441
 442    verbosef("entering main loop");
 443    daemonize_finish();
 444
 445    while (running) {
 446       int select_ret, max_fd = -1, use_timeout = 0;
 447       struct timeval timeout;
 448       fd_set rs, ws;
 449
 450       now = time(NULL);
 451
 452       if (export_pending) {
 453          if (export_fn != NULL)
 454             db_export(export_fn);
 455          export_pending = 0;
 456       }
 457
 458       if (reset_pending) {
 459          hosts_db_reset();
 460          graph_reset();
 461          reset_pending = 0;
 462       }
 463
 464       FD_ZERO(&rs);
 465       FD_ZERO(&ws);
 466
 467       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 468       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 469
 470       select_ret = select(max_fd+1, &rs, &ws, NULL,
 471          (use_timeout) ? &timeout : NULL);
 472
 473       if ((select_ret == 0) && (!use_timeout))
 474             errx(1, "select() erroneously timed out");
 475
 476       if (select_ret == -1) {
 477          if (errno == EINTR)
 478             continue;
 479          else
 480             err(1, "select()");
 481       }
 482       else {
 483          graph_rotate();
 484          cap_poll(&rs);
 485          dns_poll();
 486          http_poll(&rs, &ws);
 487       }
 488    }
 489
 490    verbosef("shutting down");
 491    verbosef("pcap stats: %u packets received, %u packets dropped",
 492       pkts_recv, pkts_drop);
 493    http_stop();
 494    cap_stop();
 495    dns_stop();
 496    if (export_fn != NULL) db_export(export_fn);
 497    hosts_db_free();
 498    graph_free();
 499    if (daylog_fn != NULL) daylog_free();
 500    ncache_free();
 501    if (pid_fn) pidfile_unlink();
 502    verbosef("shut down");
 503    return (EXIT_SUCCESS);
 504 }
 505
 506 /* vim:set ts=3 sw=3 tw=78 expandtab: */