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