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;
  49 static void sig_reset(int signum _unused_) { reset_pending = 1; }
  50
  51 /* --- Commandline parsing --- */
  52 static unsigned long
  53 parsenum(const char *str, unsigned long max /* 0 for no max */)
  54 {
  55    unsigned long n;
  56    char *end;
  57
  58    errno = 0;
  59    n = strtoul(str, &end, 10);
  60    if (*end != '\0')
  61       errx(1, "\"%s\" is not a valid number", str);
  62    if (errno == ERANGE)
  63       errx(1, "\"%s\" is out of range", str);
  64    if ((max != 0) && (n > max))
  65       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  66    return n;
  67 }
  68
  69 const char *interface = NULL;
  70 static void cb_interface(const char *arg) { interface = arg; }
  71
  72 const char *capfile = NULL;
  73 static void cb_capfile(const char *arg) { capfile = arg; }
  74
  75 int want_snaplen = -1;
  76 static void cb_snaplen(const char *arg) { want_snaplen = parsenum(arg, 0); }
  77
  78 int want_pppoe = 0;
  79 static void cb_pppoe(const char *arg _unused_) { want_pppoe = 1; }
  80
  81 static void cb_syslog(const char *arg _unused_) { want_syslog = 1; }
  82
  83 static void cb_verbose(const char *arg _unused_) { want_verbose = 1; }
  84
  85 int want_daemonize = 1;
  86 static void cb_no_daemon(const char *arg _unused_) { want_daemonize = 0; }
  87
  88 int want_promisc = 1;
  89 static void cb_no_promisc(const char *arg _unused_) { want_promisc = 0; }
  90
  91 int want_dns = 1;
  92 static void cb_no_dns(const char *arg _unused_) { want_dns = 0; }
  93
  94 int want_macs = 1;
  95 static void cb_no_macs(const char *arg _unused_) { want_macs = 0; }
  96
  97 int want_lastseen = 1;
  98 static void cb_no_lastseen(const char *arg _unused_) { want_lastseen = 0; }
  99
 100 unsigned short bindport = 667;
 101 static void cb_port(const char *arg) { bindport = parsenum(arg, 65536); }
 102
 103 char * bindaddr = NULL;
 104 static void cb_bindaddr(const char *arg)
 105 {
 106    struct addrinfo hints, *ai;
 107
 108    memset(&hints, '\0', sizeof(hints));
 109    hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
 110    hints.ai_family = AF_UNSPEC;
 111    hints.ai_socktype = SOCK_STREAM;
 112
 113    if (getaddrinfo(arg, NULL, &hints, &ai))
 114       errx(1, "malformed address \"%s\"", arg);
 115
 116    freeaddrinfo(ai);
 117    bindaddr = strdup(arg);
 118 }
 119
 120 const char *filter = NULL;
 121 static void cb_filter(const char *arg) { filter = arg; }
 122
 123 static void cb_local(const char *arg) { acct_init_localnet(arg); }
 124
 125 const char *chroot_dir = NULL;
 126 static void cb_chroot(const char *arg) { chroot_dir = arg; }
 127
 128 const char *privdrop_user = NULL;
 129 static void cb_user(const char *arg) { privdrop_user = arg; }
 130
 131 const char *daylog_fn = NULL;
 132 static void cb_daylog(const char *arg)
 133 {
 134    if (chroot_dir == NULL)
 135       errx(1, "the daylog file is relative to the chroot.\n"
 136       "You must specify a --chroot dir before you can use --daylog.");
 137    else
 138       daylog_fn = arg;
 139 }
 140
 141 const char *import_fn = NULL;
 142 static void cb_import(const char *arg)
 143 {
 144    if (chroot_dir == NULL)
 145       errx(1, "the import file is relative to the chroot.\n"
 146       "You must specify a --chroot dir before you can use --import.");
 147    else
 148       import_fn = arg;
 149 }
 150
 151 const char *export_fn = NULL;
 152 static void cb_export(const char *arg)
 153 {
 154    if ((chroot_dir == NULL) && (capfile == NULL))
 155       errx(1, "the export file is relative to the chroot.\n"
 156       "You must specify a --chroot dir before you can use --export.");
 157    else
 158       export_fn = arg;
 159 }
 160
 161 static const char *pid_fn = NULL;
 162 static void cb_pidfile(const char *arg)
 163 {
 164    if (chroot_dir == NULL)
 165       errx(1, "the pidfile is relative to the chroot.\n"
 166       "You must specify a --chroot dir before you can use --pidfile.");
 167    else
 168       pid_fn = arg;
 169 }
 170
 171 unsigned int hosts_max = 1000;
 172 static void cb_hosts_max(const char *arg)
 173 { hosts_max = parsenum(arg, 0); }
 174
 175 unsigned int hosts_keep = 500;
 176 static void cb_hosts_keep(const char *arg)
 177 { hosts_keep = parsenum(arg, 0); }
 178
 179 unsigned int ports_max = 200;
 180 static void cb_ports_max(const char *arg)
 181 { ports_max = parsenum(arg, 65536); }
 182
 183 unsigned int ports_keep = 30;
 184 static void cb_ports_keep(const char *arg)
 185 { ports_keep = parsenum(arg, 65536); }
 186
 187 unsigned int highest_port = 65535;
 188 static void cb_highest_port(const char *arg)
 189 { highest_port = parsenum(arg, 65535); }
 190
 191 int wait_secs = -1;
 192 static void cb_wait_secs(const char *arg)
 193 { wait_secs = parsenum(arg, 0); }
 194
 195 int want_hexdump = 0;
 196 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 197
 198 /* --- */
 199
 200 struct cmdline_arg {
 201    const char *name, *arg_name; /* NULL arg_name means unary */
 202    void (*callback)(const char *arg);
 203    int num_seen;
 204 };
 205
 206 static struct cmdline_arg cmdline_args[] = {
 207    {"-i",             "interface",       cb_interface,    0},
 208    {"-r",             "file",            cb_capfile,      0},
 209    {"--snaplen",      "bytes",           cb_snaplen,      0},
 210    {"--pppoe",        NULL,              cb_pppoe,        0},
 211    {"--syslog",       NULL,              cb_syslog,       0},
 212    {"--verbose",      NULL,              cb_verbose,      0},
 213    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 214    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 215    {"--no-dns",       NULL,              cb_no_dns,       0},
 216    {"--no-macs",      NULL,              cb_no_macs,      0},
 217    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 218    {"-p",             "port",            cb_port,         0},
 219    {"-b",             "bindaddr",        cb_bindaddr,     0},
 220    {"-f",             "filter",          cb_filter,       0},
 221    {"-l",             "network/netmask", cb_local,        0},
 222    {"--chroot",       "dir",             cb_chroot,       0},
 223    {"--user",         "username",        cb_user,         0},
 224    {"--daylog",       "filename",        cb_daylog,       0},
 225    {"--import",       "filename",        cb_import,       0},
 226    {"--export",       "filename",        cb_export,       0},
 227    {"--pidfile",      "filename",        cb_pidfile,      0},
 228    {"--hosts-max",    "count",           cb_hosts_max,    0},
 229    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 230    {"--ports-max",    "count",           cb_ports_max,    0},
 231    {"--ports-keep",   "count",           cb_ports_keep,   0},
 232    {"--highest-port", "port",            cb_highest_port, 0},
 233    {"--wait",         "secs",            cb_wait_secs,    0},
 234    {"--hexdump",      NULL,              cb_hexdump,      0},
 235    {NULL,             NULL,              NULL,            0}
 236 };
 237
 238 static void
 239 pad(const int width)
 240 {
 241    int i;
 242    for (i=0; i<width; i++) printf(" ");
 243 }
 244
 245 /*
 246  * We autogenerate the usage statement from the cmdline_args data structure.
 247  */
 248 static void
 249 usage(void)
 250 {
 251    int width, first;
 252    struct cmdline_arg *arg;
 253
 254    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 255       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 256
 257    width = printf("usage: darkstat ");
 258    first = 1;
 259
 260    for (arg = cmdline_args; arg->name != NULL; arg++) {
 261       if (first) first = 0; else pad(width);
 262       printf("[ %s", arg->name);
 263       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 264       printf(" ]\n");
 265    }
 266    printf("\n"
 267 "Please refer to the darkstat(8) manual page for further\n"
 268 "documentation and usage examples.\n");
 269 }
 270
 271 static void
 272 parse_sub_cmdline(const int argc, char * const *argv)
 273 {
 274    struct cmdline_arg *arg;
 275
 276    if (argc == 0) return;
 277    for (arg = cmdline_args; arg->name != NULL; arg++)
 278       if (strcmp(argv[0], arg->name) == 0) {
 279          if ((arg->arg_name != NULL) && (argc == 1)) {
 280             fprintf(stderr,
 281                "error: argument \"%s\" requires parameter \"%s\"\n",
 282                arg->name, arg->arg_name);
 283             usage();
 284             exit(EXIT_FAILURE);
 285          }
 286          if (arg->num_seen > 0) {
 287             fprintf(stderr,
 288                "error: already specified argument \"%s\"\n",
 289                arg->name);
 290             usage();
 291             exit(EXIT_FAILURE);
 292          }
 293
 294          arg->num_seen++;
 295          if (arg->arg_name == NULL) {
 296             arg->callback(NULL);
 297             parse_sub_cmdline(argc-1, argv+1);
 298          } else {
 299             arg->callback(argv[1]);
 300             parse_sub_cmdline(argc-2, argv+2);
 301          }
 302          return;
 303       }
 304
 305    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 306    usage();
 307    exit(EXIT_FAILURE);
 308 }
 309
 310 static void
 311 parse_cmdline(const int argc, char * const *argv)
 312 {
 313    if (argc < 1) {
 314       /* Not enough args. */
 315       usage();
 316       exit(EXIT_FAILURE);
 317    }
 318
 319    parse_sub_cmdline(argc, argv);
 320
 321    /* start syslogging as early as possible */
 322    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 323
 324    /* some default values */
 325    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 326    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 327
 328    /* sanity check args */
 329    if ((interface == NULL) && (capfile == NULL))
 330       errx(1, "must specify either interface (-i) or capture file (-r)");
 331
 332    if ((interface != NULL) && (capfile != NULL))
 333       errx(1, "can't specify both interface (-i) and capture file (-r)");
 334
 335    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 336       hosts_keep = hosts_max / 2;
 337       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 338          hosts_keep, hosts_max);
 339    }
 340    verbosef("max %u hosts, cutting down to %u when exceeded",
 341       hosts_max, hosts_keep);
 342
 343    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 344       ports_keep = ports_max / 2;
 345       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 346          ports_keep, ports_max);
 347    }
 348    verbosef("max %u ports per host, cutting down to %u when exceeded",
 349       ports_max, ports_keep);
 350
 351    if (want_hexdump && !want_verbose) {
 352       want_verbose = 1;
 353       verbosef("--hexdump implies --verbose");
 354    }
 355
 356    if (want_hexdump && want_daemonize) {
 357       want_daemonize = 0;
 358       verbosef("--hexdump implies --no-daemon");
 359    }
 360 }
 361
 362 static void
 363 run_from_capfile(void)
 364 {
 365    graph_init();
 366    hosts_db_init();
 367    cap_from_file(capfile, filter);
 368    cap_stop();
 369    if (export_fn != NULL) db_export(export_fn);
 370    hosts_db_free();
 371    graph_free();
 372    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 373 }
 374
 375 /* --- Program body --- */
 376 int
 377 main(int argc, char **argv)
 378 {
 379    test_64order();
 380    parse_cmdline(argc-1, argv+1);
 381
 382    if (capfile) {
 383       /*
 384        * This is very different from a regular run against a network
 385        * interface.
 386        */
 387       run_from_capfile();
 388       return 0;
 389    }
 390
 391    /* must verbosef() before first fork to init lock */
 392    verbosef("starting up");
 393    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 394
 395    if (want_daemonize) {
 396       verbosef("daemonizing to run in the background!");
 397       daemonize_start();
 398       verbosef("I am the main process");
 399    }
 400    if (pid_fn) pidfile_write_close();
 401
 402    /* do this first as it forks - minimize memory use */
 403    if (want_dns) dns_init(privdrop_user);
 404    cap_init(interface, filter, want_promisc); /* needs root */
 405    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 406    ncache_init(); /* must do before chroot() */
 407
 408    privdrop(chroot_dir, privdrop_user);
 409
 410    /* Don't need root privs for these: */
 411    now = time(NULL);
 412    if (daylog_fn != NULL) daylog_init(daylog_fn);
 413    graph_init();
 414    hosts_db_init();
 415    if (import_fn != NULL) db_import(import_fn);
 416    localip_init(interface);
 417
 418    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 419       errx(1, "signal(SIGTERM) failed");
 420    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 421       errx(1, "signal(SIGINT) failed");
 422    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 423       errx(1, "signal(SIGUSR1) failed");
 424
 425    verbosef("entering main loop");
 426    daemonize_finish();
 427
 428    while (running) {
 429       int select_ret, max_fd = -1, use_timeout = 0;
 430       struct timeval timeout;
 431       fd_set rs, ws;
 432
 433       now = time(NULL);
 434
 435       if (reset_pending) {
 436          if (export_fn != NULL) db_export(export_fn); /* FIXME: USR2? */
 437          hosts_db_reset();
 438          graph_reset();
 439          reset_pending = 0;
 440       }
 441
 442       FD_ZERO(&rs);
 443       FD_ZERO(&ws);
 444
 445       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 446       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 447
 448       select_ret = select(max_fd+1, &rs, &ws, NULL,
 449          (use_timeout) ? &timeout : NULL);
 450
 451       if ((select_ret == 0) && (!use_timeout))
 452             errx(1, "select() erroneously timed out");
 453
 454       if (select_ret == -1) {
 455          if (errno == EINTR)
 456             continue;
 457          else
 458             err(1, "select()");
 459       }
 460       else {
 461          graph_rotate();
 462          cap_poll(&rs);
 463          dns_poll();
 464          http_poll(&rs, &ws);
 465       }
 466    }
 467
 468    verbosef("shutting down");
 469    verbosef("pcap stats: %u packets received, %u packets dropped",
 470       pkts_recv, pkts_drop);
 471    cap_stop();
 472    dns_stop();
 473    if (export_fn != NULL) db_export(export_fn);
 474    hosts_db_free();
 475    graph_free();
 476    if (daylog_fn != NULL) daylog_free();
 477    ncache_free();
 478    if (pid_fn) pidfile_unlink();
 479    verbosef("shut down");
 480    return (EXIT_SUCCESS);
 481 }
 482
 483 /* vim:set ts=3 sw=3 tw=78 expandtab: */