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