unix4lyfe git - darkstat/blob - darkstat.c

   1 /* darkstat 3
   2  * copyright (c) 2001-2009 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 <assert.h>
  26 #include <errno.h>
  27 #include <signal.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <syslog.h>
  32 #include <unistd.h>
  33 #include <pcap.h>
  34
  35 #include "now.h"
  36 time_t now;
  37
  38 #ifndef INADDR_NONE
  39 # define INADDR_NONE (-1) /* Solaris */
  40 #endif
  41
  42 /* --- Signal handling --- */
  43 static volatile int running = 1;
  44 static void sig_shutdown(int signum _unused_) { running = 0; }
  45
  46 static volatile int reset_pending = 0;
  47 static void sig_reset(int signum _unused_) { reset_pending = 1; }
  48
  49 /* --- Commandline parsing --- */
  50 static unsigned long
  51 parsenum(const char *str, unsigned long max /* 0 for no max */)
  52 {
  53    unsigned long n;
  54    char *end;
  55
  56    errno = 0;
  57    n = strtoul(str, &end, 10);
  58    if (*end != '\0')
  59       errx(1, "\"%s\" is not a valid number", str);
  60    if (errno == ERANGE)
  61       errx(1, "\"%s\" is out of range", str);
  62    if ((max != 0) && (n > max))
  63       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  64    return n;
  65 }
  66
  67 const char *interface = NULL;
  68 static void cb_interface(const char *arg) { interface = arg; }
  69
  70 const char *capfile = NULL;
  71 static void cb_capfile(const char *arg) { capfile = arg; }
  72
  73 int want_snaplen = -1;
  74 static void cb_snaplen(const char *arg) { want_snaplen = parsenum(arg, 0); }
  75
  76 int want_pppoe = 0;
  77 static void cb_pppoe(const char *arg _unused_) { want_pppoe = 1; }
  78
  79 static void cb_syslog(const char *arg _unused_) { want_syslog = 1; }
  80
  81 static void cb_verbose(const char *arg _unused_) { want_verbose = 1; }
  82
  83 int want_daemonize = 1;
  84 static void cb_no_daemon(const char *arg _unused_) { want_daemonize = 0; }
  85
  86 int want_promisc = 1;
  87 static void cb_no_promisc(const char *arg _unused_) { want_promisc = 0; }
  88
  89 int want_dns = 1;
  90 static void cb_no_dns(const char *arg _unused_) { want_dns = 0; }
  91
  92 int want_macs = 1;
  93 static void cb_no_macs(const char *arg _unused_) { want_macs = 0; }
  94
  95 int want_lastseen = 1;
  96 static void cb_no_lastseen(const char *arg _unused_) { want_lastseen = 0; }
  97
  98 unsigned short bindport = 667;
  99 static void cb_port(const char *arg) { bindport = parsenum(arg, 65536); }
 100
 101 in_addr_t bindaddr = INADDR_ANY;
 102 static void cb_bindaddr(const char *arg)
 103 {
 104    bindaddr = inet_addr(arg);
 105    if (bindaddr == (in_addr_t)INADDR_NONE)
 106       errx(1, "malformed address \"%s\"", arg);
 107 }
 108
 109 const char *filter = NULL;
 110 static void cb_filter(const char *arg) { filter = arg; }
 111
 112 static void cb_local(const char *arg) { acct_init_localnet(arg); }
 113
 114 const char *chroot_dir = NULL;
 115 static void cb_chroot(const char *arg) { chroot_dir = arg; }
 116
 117 const char *privdrop_user = NULL;
 118 static void cb_user(const char *arg) { privdrop_user = arg; }
 119
 120 const char *daylog_fn = NULL;
 121 static void cb_daylog(const char *arg)
 122 {
 123    if (chroot_dir == NULL)
 124       errx(1, "the daylog file is relative to the chroot.\n"
 125       "You must specify a --chroot dir before you can use --daylog.");
 126    else
 127       daylog_fn = arg;
 128 }
 129
 130 const char *import_fn = NULL;
 131 static void cb_import(const char *arg)
 132 {
 133    if (chroot_dir == NULL)
 134       errx(1, "the import file is relative to the chroot.\n"
 135       "You must specify a --chroot dir before you can use --import.");
 136    else
 137       import_fn = arg;
 138 }
 139
 140 const char *export_fn = NULL;
 141 static void cb_export(const char *arg)
 142 {
 143    if ((chroot_dir == NULL) && (capfile == NULL))
 144       errx(1, "the export file is relative to the chroot.\n"
 145       "You must specify a --chroot dir before you can use --export.");
 146    else
 147       export_fn = arg;
 148 }
 149
 150 static const char *pid_fn = NULL;
 151 static void cb_pidfile(const char *arg)
 152 {
 153    if (chroot_dir == NULL)
 154       errx(1, "the pidfile is relative to the chroot.\n"
 155       "You must specify a --chroot dir before you can use --pidfile.");
 156    else
 157       pid_fn = arg;
 158 }
 159
 160 unsigned int hosts_max = 1000;
 161 static void cb_hosts_max(const char *arg)
 162 { hosts_max = parsenum(arg, 0); }
 163
 164 unsigned int hosts_keep = 500;
 165 static void cb_hosts_keep(const char *arg)
 166 { hosts_keep = parsenum(arg, 0); }
 167
 168 unsigned int ports_max = 200;
 169 static void cb_ports_max(const char *arg)
 170 { ports_max = parsenum(arg, 65536); }
 171
 172 unsigned int ports_keep = 30;
 173 static void cb_ports_keep(const char *arg)
 174 { ports_keep = parsenum(arg, 65536); }
 175
 176 unsigned int highest_port = 65535;
 177 static void cb_highest_port(const char *arg)
 178 { highest_port = parsenum(arg, 65535); }
 179
 180 int want_hexdump = 0;
 181 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 182
 183 /* --- */
 184
 185 struct cmdline_arg {
 186    const char *name, *arg_name; /* NULL arg_name means unary */
 187    void (*callback)(const char *arg);
 188    int num_seen;
 189 };
 190
 191 static struct cmdline_arg cmdline_args[] = {
 192    {"-i",             "interface",       cb_interface,    0},
 193    {"-r",             "file",            cb_capfile,      0},
 194    {"--snaplen",      "bytes",           cb_snaplen,      0},
 195    {"--pppoe",        NULL,              cb_pppoe,        0},
 196    {"--syslog",       NULL,              cb_syslog,       0},
 197    {"--verbose",      NULL,              cb_verbose,      0},
 198    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 199    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 200    {"--no-dns",       NULL,              cb_no_dns,       0},
 201    {"--no-macs",      NULL,              cb_no_macs,      0},
 202    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 203    {"-p",             "port",            cb_port,         0},
 204    {"-b",             "bindaddr",        cb_bindaddr,     0},
 205    {"-f",             "filter",          cb_filter,       0},
 206    {"-l",             "network/netmask", cb_local,        0},
 207    {"--chroot",       "dir",             cb_chroot,       0},
 208    {"--user",         "username",        cb_user,         0},
 209    {"--daylog",       "filename",        cb_daylog,       0},
 210    {"--import",       "filename",        cb_import,       0},
 211    {"--export",       "filename",        cb_export,       0},
 212    {"--pidfile",      "filename",        cb_pidfile,      0},
 213    {"--hosts-max",    "count",           cb_hosts_max,    0},
 214    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 215    {"--ports-max",    "count",           cb_ports_max,    0},
 216    {"--ports-keep",   "count",           cb_ports_keep,   0},
 217    {"--highest-port", "port",            cb_highest_port, 0},
 218    {"--hexdump",      NULL,              cb_hexdump,      0},
 219    {NULL,             NULL,              NULL,            0}
 220 };
 221
 222 static void
 223 pad(const int width)
 224 {
 225    int i;
 226    for (i=0; i<width; i++) printf(" ");
 227 }
 228
 229 /*
 230  * We autogenerate the usage statement from the cmdline_args data structure.
 231  */
 232 static void
 233 usage(void)
 234 {
 235    int width, first;
 236    struct cmdline_arg *arg;
 237
 238    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 239       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 240
 241    width = printf("usage: darkstat ");
 242    first = 1;
 243
 244    for (arg = cmdline_args; arg->name != NULL; arg++) {
 245       if (first) first = 0; else pad(width);
 246       printf("[ %s", arg->name);
 247       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 248       printf(" ]\n");
 249    }
 250    printf("\n"
 251 "Please refer to the darkstat(8) manual page for further\n"
 252 "documentation and usage examples.\n");
 253 }
 254
 255 static void
 256 parse_sub_cmdline(const int argc, char * const *argv)
 257 {
 258    struct cmdline_arg *arg;
 259
 260    if (argc == 0) return;
 261    for (arg = cmdline_args; arg->name != NULL; arg++)
 262       if (strcmp(argv[0], arg->name) == 0) {
 263          if ((arg->arg_name != NULL) && (argc == 1)) {
 264             fprintf(stderr,
 265                "error: argument \"%s\" requires parameter \"%s\"\n",
 266                arg->name, arg->arg_name);
 267             usage();
 268             exit(EXIT_FAILURE);
 269          }
 270          if (arg->num_seen > 0) {
 271             fprintf(stderr,
 272                "error: already specified argument \"%s\"\n",
 273                arg->name);
 274             usage();
 275             exit(EXIT_FAILURE);
 276          }
 277
 278          arg->num_seen++;
 279          if (arg->arg_name == NULL) {
 280             arg->callback(NULL);
 281             parse_sub_cmdline(argc-1, argv+1);
 282          } else {
 283             arg->callback(argv[1]);
 284             parse_sub_cmdline(argc-2, argv+2);
 285          }
 286          return;
 287       }
 288
 289    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 290    usage();
 291    exit(EXIT_FAILURE);
 292 }
 293
 294 static void
 295 parse_cmdline(const int argc, char * const *argv)
 296 {
 297    if (argc < 1) {
 298       /* Not enough args. */
 299       usage();
 300       exit(EXIT_FAILURE);
 301    }
 302
 303    parse_sub_cmdline(argc, argv);
 304
 305    /* start syslogging as early as possible */
 306    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 307
 308    /* some default values */
 309    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 310    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 311
 312    /* sanity check args */
 313    if ((interface == NULL) && (capfile == NULL))
 314       errx(1, "must specify either interface (-i) or capture file (-r)");
 315
 316    if ((interface != NULL) && (capfile != NULL))
 317       errx(1, "can't specify both interface (-i) and capture file (-r)");
 318
 319    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 320       hosts_keep = hosts_max / 2;
 321       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 322          hosts_keep, hosts_max);
 323    }
 324    verbosef("max %u hosts, cutting down to %u when exceeded",
 325       hosts_max, hosts_keep);
 326
 327    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 328       ports_keep = ports_max / 2;
 329       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 330          ports_keep, ports_max);
 331    }
 332    verbosef("max %u ports per host, cutting down to %u when exceeded",
 333       ports_max, ports_keep);
 334
 335    if (want_hexdump && !want_verbose) {
 336       want_verbose = 1;
 337       verbosef("--hexdump implies --verbose");
 338    }
 339
 340    if (want_hexdump && want_daemonize) {
 341       want_daemonize = 0;
 342       verbosef("--hexdump implies --no-daemon");
 343    }
 344 }
 345
 346 static void
 347 run_from_capfile(void)
 348 {
 349    graph_init();
 350    hosts_db_init();
 351    cap_from_file(capfile, filter);
 352    cap_stop();
 353    if (export_fn != NULL) db_export(export_fn);
 354    hosts_db_free();
 355    graph_free();
 356    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 357 }
 358
 359 /* --- Program body --- */
 360 int
 361 main(int argc, char **argv)
 362 {
 363    test_64order();
 364    parse_cmdline(argc-1, argv+1);
 365
 366    if (capfile) {
 367       /*
 368        * This is very different from a regular run against a network
 369        * interface.
 370        */
 371       run_from_capfile();
 372       return 0;
 373    }
 374
 375    /* must verbosef() before first fork to init lock */
 376    verbosef("starting up");
 377    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 378
 379    if (want_daemonize) {
 380       verbosef("daemonizing to run in the background!");
 381       daemonize_start();
 382       verbosef("I am the main process");
 383    }
 384    if (pid_fn) pidfile_write_close();
 385
 386    /* do this first as it forks - minimize memory use */
 387    if (want_dns) dns_init(privdrop_user);
 388    cap_init(interface, filter, want_promisc); /* needs root */
 389    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 390    ncache_init(); /* must do before chroot() */
 391
 392    privdrop(chroot_dir, privdrop_user);
 393
 394    /* Don't need root privs for these: */
 395    now = time(NULL);
 396    if (daylog_fn != NULL) daylog_init(daylog_fn);
 397    graph_init();
 398    hosts_db_init();
 399    if (import_fn != NULL) db_import(import_fn);
 400    localip_init(interface);
 401
 402    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 403       errx(1, "signal(SIGTERM) failed");
 404    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 405       errx(1, "signal(SIGINT) failed");
 406    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 407       errx(1, "signal(SIGUSR1) failed");
 408
 409    verbosef("entering main loop");
 410    daemonize_finish();
 411
 412    while (running) {
 413       int select_ret, max_fd = -1, use_timeout = 0;
 414       struct timeval timeout;
 415       fd_set rs, ws;
 416
 417       now = time(NULL);
 418
 419       if (reset_pending) {
 420          if (export_fn != NULL) db_export(export_fn); /* FIXME: USR2? */
 421          hosts_db_reset();
 422          graph_reset();
 423          reset_pending = 0;
 424       }
 425
 426       FD_ZERO(&rs);
 427       FD_ZERO(&ws);
 428
 429       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 430       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 431
 432       select_ret = select(max_fd+1, &rs, &ws, NULL,
 433          (use_timeout) ? &timeout : NULL);
 434
 435       if ((select_ret == 0) && (!use_timeout))
 436             errx(1, "select() erroneously timed out");
 437
 438       if (select_ret == -1) {
 439          if (errno == EINTR)
 440             continue;
 441          else
 442             err(1, "select()");
 443       }
 444       else {
 445          graph_rotate();
 446          cap_poll(&rs);
 447          dns_poll();
 448          http_poll(&rs, &ws);
 449       }
 450    }
 451
 452    verbosef("shutting down");
 453    verbosef("pcap stats: %u packets received, %u packets dropped",
 454       pkts_recv, pkts_drop);
 455    cap_stop();
 456    dns_stop();
 457    if (export_fn != NULL) db_export(export_fn);
 458    hosts_db_free();
 459    graph_free();
 460    if (daylog_fn != NULL) daylog_free();
 461    ncache_free();
 462    if (pid_fn) pidfile_unlink();
 463    verbosef("shut down");
 464    return (EXIT_SUCCESS);
 465 }
 466
 467 /* vim:set ts=3 sw=3 tw=78 expandtab: */