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 <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 wait_secs = -1;
 181 static void cb_wait_secs(const char *arg)
 182 { wait_secs = parsenum(arg, 0); }
 183
 184 int want_hexdump = 0;
 185 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 186
 187 /* --- */
 188
 189 struct cmdline_arg {
 190    const char *name, *arg_name; /* NULL arg_name means unary */
 191    void (*callback)(const char *arg);
 192    int num_seen;
 193 };
 194
 195 static struct cmdline_arg cmdline_args[] = {
 196    {"-i",             "interface",       cb_interface,    0},
 197    {"-r",             "file",            cb_capfile,      0},
 198    {"--snaplen",      "bytes",           cb_snaplen,      0},
 199    {"--pppoe",        NULL,              cb_pppoe,        0},
 200    {"--syslog",       NULL,              cb_syslog,       0},
 201    {"--verbose",      NULL,              cb_verbose,      0},
 202    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 203    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 204    {"--no-dns",       NULL,              cb_no_dns,       0},
 205    {"--no-macs",      NULL,              cb_no_macs,      0},
 206    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 207    {"-p",             "port",            cb_port,         0},
 208    {"-b",             "bindaddr",        cb_bindaddr,     0},
 209    {"-f",             "filter",          cb_filter,       0},
 210    {"-l",             "network/netmask", cb_local,        0},
 211    {"--chroot",       "dir",             cb_chroot,       0},
 212    {"--user",         "username",        cb_user,         0},
 213    {"--daylog",       "filename",        cb_daylog,       0},
 214    {"--import",       "filename",        cb_import,       0},
 215    {"--export",       "filename",        cb_export,       0},
 216    {"--pidfile",      "filename",        cb_pidfile,      0},
 217    {"--hosts-max",    "count",           cb_hosts_max,    0},
 218    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 219    {"--ports-max",    "count",           cb_ports_max,    0},
 220    {"--ports-keep",   "count",           cb_ports_keep,   0},
 221    {"--highest-port", "port",            cb_highest_port, 0},
 222    {"--wait",         "secs",            cb_wait_secs,    0},
 223    {"--hexdump",      NULL,              cb_hexdump,      0},
 224    {NULL,             NULL,              NULL,            0}
 225 };
 226
 227 static void
 228 pad(const int width)
 229 {
 230    int i;
 231    for (i=0; i<width; i++) printf(" ");
 232 }
 233
 234 /*
 235  * We autogenerate the usage statement from the cmdline_args data structure.
 236  */
 237 static void
 238 usage(void)
 239 {
 240    int width, first;
 241    struct cmdline_arg *arg;
 242
 243    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 244       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 245
 246    width = printf("usage: darkstat ");
 247    first = 1;
 248
 249    for (arg = cmdline_args; arg->name != NULL; arg++) {
 250       if (first) first = 0; else pad(width);
 251       printf("[ %s", arg->name);
 252       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 253       printf(" ]\n");
 254    }
 255    printf("\n"
 256 "Please refer to the darkstat(8) manual page for further\n"
 257 "documentation and usage examples.\n");
 258 }
 259
 260 static void
 261 parse_sub_cmdline(const int argc, char * const *argv)
 262 {
 263    struct cmdline_arg *arg;
 264
 265    if (argc == 0) return;
 266    for (arg = cmdline_args; arg->name != NULL; arg++)
 267       if (strcmp(argv[0], arg->name) == 0) {
 268          if ((arg->arg_name != NULL) && (argc == 1)) {
 269             fprintf(stderr,
 270                "error: argument \"%s\" requires parameter \"%s\"\n",
 271                arg->name, arg->arg_name);
 272             usage();
 273             exit(EXIT_FAILURE);
 274          }
 275          if (arg->num_seen > 0) {
 276             fprintf(stderr,
 277                "error: already specified argument \"%s\"\n",
 278                arg->name);
 279             usage();
 280             exit(EXIT_FAILURE);
 281          }
 282
 283          arg->num_seen++;
 284          if (arg->arg_name == NULL) {
 285             arg->callback(NULL);
 286             parse_sub_cmdline(argc-1, argv+1);
 287          } else {
 288             arg->callback(argv[1]);
 289             parse_sub_cmdline(argc-2, argv+2);
 290          }
 291          return;
 292       }
 293
 294    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 295    usage();
 296    exit(EXIT_FAILURE);
 297 }
 298
 299 static void
 300 parse_cmdline(const int argc, char * const *argv)
 301 {
 302    if (argc < 1) {
 303       /* Not enough args. */
 304       usage();
 305       exit(EXIT_FAILURE);
 306    }
 307
 308    parse_sub_cmdline(argc, argv);
 309
 310    /* start syslogging as early as possible */
 311    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 312
 313    /* some default values */
 314    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 315    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 316
 317    /* sanity check args */
 318    if ((interface == NULL) && (capfile == NULL))
 319       errx(1, "must specify either interface (-i) or capture file (-r)");
 320
 321    if ((interface != NULL) && (capfile != NULL))
 322       errx(1, "can't specify both interface (-i) and capture file (-r)");
 323
 324    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 325       hosts_keep = hosts_max / 2;
 326       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 327          hosts_keep, hosts_max);
 328    }
 329    verbosef("max %u hosts, cutting down to %u when exceeded",
 330       hosts_max, hosts_keep);
 331
 332    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 333       ports_keep = ports_max / 2;
 334       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 335          ports_keep, ports_max);
 336    }
 337    verbosef("max %u ports per host, cutting down to %u when exceeded",
 338       ports_max, ports_keep);
 339
 340    if (want_hexdump && !want_verbose) {
 341       want_verbose = 1;
 342       verbosef("--hexdump implies --verbose");
 343    }
 344
 345    if (want_hexdump && want_daemonize) {
 346       want_daemonize = 0;
 347       verbosef("--hexdump implies --no-daemon");
 348    }
 349 }
 350
 351 static void
 352 run_from_capfile(void)
 353 {
 354    graph_init();
 355    hosts_db_init();
 356    cap_from_file(capfile, filter);
 357    cap_stop();
 358    if (export_fn != NULL) db_export(export_fn);
 359    hosts_db_free();
 360    graph_free();
 361    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 362 }
 363
 364 /* --- Program body --- */
 365 int
 366 main(int argc, char **argv)
 367 {
 368    test_64order();
 369    parse_cmdline(argc-1, argv+1);
 370
 371    if (capfile) {
 372       /*
 373        * This is very different from a regular run against a network
 374        * interface.
 375        */
 376       run_from_capfile();
 377       return 0;
 378    }
 379
 380    /* must verbosef() before first fork to init lock */
 381    verbosef("starting up");
 382    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 383
 384    if (want_daemonize) {
 385       verbosef("daemonizing to run in the background!");
 386       daemonize_start();
 387       verbosef("I am the main process");
 388    }
 389    if (pid_fn) pidfile_write_close();
 390
 391    /* do this first as it forks - minimize memory use */
 392    if (want_dns) dns_init(privdrop_user);
 393    cap_init(interface, filter, want_promisc); /* needs root */
 394    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 395    ncache_init(); /* must do before chroot() */
 396
 397    privdrop(chroot_dir, privdrop_user);
 398
 399    /* Don't need root privs for these: */
 400    now = time(NULL);
 401    if (daylog_fn != NULL) daylog_init(daylog_fn);
 402    graph_init();
 403    hosts_db_init();
 404    if (import_fn != NULL) db_import(import_fn);
 405    localip_init(interface);
 406
 407    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 408       errx(1, "signal(SIGTERM) failed");
 409    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 410       errx(1, "signal(SIGINT) failed");
 411    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 412       errx(1, "signal(SIGUSR1) failed");
 413
 414    verbosef("entering main loop");
 415    daemonize_finish();
 416
 417    while (running) {
 418       int select_ret, max_fd = -1, use_timeout = 0;
 419       struct timeval timeout;
 420       fd_set rs, ws;
 421
 422       now = time(NULL);
 423
 424       if (reset_pending) {
 425          if (export_fn != NULL) db_export(export_fn); /* FIXME: USR2? */
 426          hosts_db_reset();
 427          graph_reset();
 428          reset_pending = 0;
 429       }
 430
 431       FD_ZERO(&rs);
 432       FD_ZERO(&ws);
 433
 434       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 435       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 436
 437       select_ret = select(max_fd+1, &rs, &ws, NULL,
 438          (use_timeout) ? &timeout : NULL);
 439
 440       if ((select_ret == 0) && (!use_timeout))
 441             errx(1, "select() erroneously timed out");
 442
 443       if (select_ret == -1) {
 444          if (errno == EINTR)
 445             continue;
 446          else
 447             err(1, "select()");
 448       }
 449       else {
 450          graph_rotate();
 451          cap_poll(&rs);
 452          dns_poll();
 453          http_poll(&rs, &ws);
 454       }
 455    }
 456
 457    verbosef("shutting down");
 458    verbosef("pcap stats: %u packets received, %u packets dropped",
 459       pkts_recv, pkts_drop);
 460    cap_stop();
 461    dns_stop();
 462    if (export_fn != NULL) db_export(export_fn);
 463    hosts_db_free();
 464    graph_free();
 465    if (daylog_fn != NULL) daylog_free();
 466    ncache_free();
 467    if (pid_fn) pidfile_unlink();
 468    verbosef("shut down");
 469    return (EXIT_SUCCESS);
 470 }
 471
 472 /* vim:set ts=3 sw=3 tw=78 expandtab: */