unix4lyfe git - darkstat/blob - darkstat.c

   1 /* darkstat 3
   2  * copyright (c) 2001-2008 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 /* --- */
 172
 173 struct cmdline_arg {
 174    const char *name, *arg_name; /* NULL arg_name means unary */
 175    void (*callback)(const char *arg);
 176    int num_seen;
 177 };
 178
 179 static struct cmdline_arg cmdline_args[] = {
 180    {"-i",             "interface",       cb_interface,    0},
 181    {"-r",             "file",            cb_capfile,      0},
 182    {"--pppoe",        NULL,              cb_pppoe,        0},
 183    {"--verbose",      NULL,              cb_verbose,      0},
 184    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 185    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 186    {"--no-dns",       NULL,              cb_no_dns,       0},
 187    {"--no-macs",      NULL,              cb_no_macs,      0},
 188    {"-p",             "port",            cb_port,         0},
 189    {"-b",             "bindaddr",        cb_bindaddr,     0},
 190    {"-f",             "filter",          cb_filter,       0},
 191    {"-l",             "network/netmask", cb_local,        0},
 192    {"--chroot",       "dir",             cb_chroot,       0},
 193    {"--user",         "username",        cb_user,         0},
 194    {"--daylog",       "filename",        cb_daylog,       0},
 195    {"--import",       "filename",        cb_import,       0},
 196    {"--export",       "filename",        cb_export,       0},
 197    {"--pidfile",      "filename",        cb_pidfile,      0},
 198    {"--hosts-max",    "count",           cb_hosts_max,    0},
 199    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 200    {"--ports-max",    "count",           cb_ports_max,    0},
 201    {"--ports-keep",   "count",           cb_ports_keep,   0},
 202    {"--highest-port", "port",            cb_highest_port, 0},
 203    {NULL,             NULL,              NULL,            0}
 204 };
 205
 206 static void
 207 pad(const int width)
 208 {
 209    int i;
 210    for (i=0; i<width; i++) printf(" ");
 211 }
 212
 213 /*
 214  * We autogenerate the usage statement from the cmdline_args data structure.
 215  */
 216 static void
 217 usage(void)
 218 {
 219    int width, first;
 220    struct cmdline_arg *arg;
 221
 222    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 223       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 224
 225    width = printf("usage: darkstat ");
 226    first = 1;
 227
 228    for (arg = cmdline_args; arg->name != NULL; arg++) {
 229       if (first) first = 0; else pad(width);
 230       printf("[ %s", arg->name);
 231       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 232       printf(" ]\n");
 233    }
 234    printf("\n"
 235 "Please refer to the darkstat(1) manual page for further\n"
 236 "documentation and usage examples.\n");
 237 }
 238
 239 static void
 240 parse_sub_cmdline(const int argc, char * const *argv)
 241 {
 242    struct cmdline_arg *arg;
 243
 244    if (argc == 0) return;
 245    for (arg = cmdline_args; arg->name != NULL; arg++)
 246       if (strcmp(argv[0], arg->name) == 0) {
 247          if ((arg->arg_name != NULL) && (argc == 1)) {
 248             printf("\nerror: argument \"%s\" requires parameter \"%s\"\n",
 249                arg->name, arg->arg_name);
 250             usage();
 251             exit(EXIT_FAILURE);
 252          }
 253          if (arg->num_seen > 0) {
 254             printf("\nerror: already specified argument \"%s\"\n",
 255                arg->name);
 256             usage();
 257             exit(EXIT_FAILURE);
 258          }
 259
 260          arg->num_seen++;
 261          if (arg->arg_name == NULL) {
 262             arg->callback(NULL);
 263             parse_sub_cmdline(argc-1, argv+1);
 264          } else {
 265             arg->callback(argv[1]);
 266             parse_sub_cmdline(argc-2, argv+2);
 267          }
 268          return;
 269       }
 270
 271    printf("\nerror: illegal argument: \"%s\"\n", argv[0]);
 272    usage();
 273    exit(EXIT_FAILURE);
 274 }
 275
 276 static void
 277 parse_cmdline(const int argc, char * const *argv)
 278 {
 279    if (argc < 1) {
 280       /* Not enough args. */
 281       usage();
 282       exit(EXIT_FAILURE);
 283    }
 284
 285    parse_sub_cmdline(argc, argv);
 286
 287    /* some default values */
 288    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 289    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 290
 291    /* sanity check args */
 292    if ((interface == NULL) && (capfile == NULL))
 293       errx(1, "must specify either interface (-i) or capture file (-r)");
 294
 295    if ((interface != NULL) && (capfile != NULL))
 296       errx(1, "can't specify both interface (-i) and capture file (-r)");
 297
 298    if ((hosts_max != 0) && (hosts_keep >= hosts_max))
 299       errx(1, "must keep fewer hosts than --hosts-max (%u)", hosts_max);
 300    verbosef("max %u hosts, cutting down to %u when exceeded",
 301       hosts_max, hosts_keep);
 302
 303    if ((ports_max != 0) && (ports_keep >= ports_max))
 304       errx(1, "must keep fewer ports than --ports-max (%u)", ports_max);
 305    verbosef("max %u ports per host, cutting down to %u when exceeded",
 306       ports_max, ports_keep);
 307 }
 308
 309 static void
 310 run_from_capfile(void)
 311 {
 312    graph_init();
 313    hosts_db_init();
 314    cap_from_file(capfile, filter);
 315    cap_stop();
 316    if (export_fn != NULL) db_export(export_fn);
 317    hosts_db_free();
 318    graph_free();
 319    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 320 }
 321
 322 /* --- Program body --- */
 323 int
 324 main(int argc, char **argv)
 325 {
 326    test_64order();
 327    parse_cmdline(argc-1, argv+1);
 328
 329    if (capfile) {
 330       /*
 331        * This is very different from a regular run against a network
 332        * interface.
 333        */
 334       run_from_capfile();
 335       return 0;
 336    }
 337
 338    /* must verbosef() before first fork to init lock */
 339    verbosef("starting up");
 340    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 341
 342    if (want_daemonize) {
 343       verbosef("daemonizing to run in the background!");
 344       daemonize_start();
 345       verbosef("I am the main process");
 346    }
 347    if (pid_fn) pidfile_write_close();
 348
 349    /* do this first as it forks - minimize memory use */
 350    if (want_dns) dns_init(privdrop_user);
 351    cap_init(interface, filter, want_promisc); /* needs root */
 352    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 353    ncache_init(); /* must do before chroot() */
 354
 355    privdrop(chroot_dir, privdrop_user);
 356
 357    /* Don't need root privs for these: */
 358    now = time(NULL);
 359    if (daylog_fn != NULL) daylog_init(daylog_fn);
 360    graph_init();
 361    hosts_db_init();
 362    if (import_fn != NULL) db_import(import_fn);
 363    localip_init(interface);
 364
 365    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 366       errx(1, "signal(SIGTERM) failed");
 367    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 368       errx(1, "signal(SIGINT) failed");
 369    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 370       errx(1, "signal(SIGUSR1) failed");
 371
 372    verbosef("entering main loop");
 373    daemonize_finish();
 374
 375    while (running) {
 376       int select_ret, max_fd = -1, use_timeout = 0;
 377       struct timeval timeout;
 378       fd_set rs, ws;
 379
 380       now = time(NULL);
 381
 382       if (reset_pending) {
 383          if (export_fn != NULL) db_export(export_fn); /* FIXME: USR2? */
 384          hosts_db_reset();
 385          graph_reset();
 386          reset_pending = 0;
 387       }
 388
 389       FD_ZERO(&rs);
 390       FD_ZERO(&ws);
 391
 392       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 393       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 394
 395       select_ret = select(max_fd+1, &rs, &ws, NULL,
 396          (use_timeout) ? &timeout : NULL);
 397
 398       if ((select_ret == 0) && (!use_timeout))
 399             errx(1, "select() erroneously timed out");
 400
 401       if (select_ret == -1) {
 402          if (errno == EINTR)
 403             continue;
 404          else
 405             err(1, "select()");
 406       }
 407       else {
 408          graph_rotate();
 409          cap_poll(&rs);
 410          dns_poll();
 411          http_poll(&rs, &ws);
 412       }
 413    }
 414
 415    verbosef("shutting down");
 416    verbosef("pcap stats: %u packets received, %u packets dropped",
 417       pkts_recv, pkts_drop);
 418    cap_stop();
 419    dns_stop();
 420    if (export_fn != NULL) db_export(export_fn);
 421    hosts_db_free();
 422    graph_free();
 423    if (daylog_fn != NULL) daylog_free();
 424    ncache_free();
 425    if (pid_fn) pidfile_unlink();
 426    verbosef("shut down");
 427    return (EXIT_SUCCESS);
 428 }
 429
 430 /* vim:set ts=3 sw=3 tw=78 expandtab: */