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 <sys/socket.h>
  26 #include <netdb.h>
  27 #include <assert.h>
  28 #include <errno.h>
  29 #include <signal.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <syslog.h>
  34 #include <unistd.h>
  35 #include <pcap.h>
  36
  37 #include "now.h"
  38 time_t now;
  39
  40 #ifndef INADDR_NONE
  41 # define INADDR_NONE (-1) /* Solaris */
  42 #endif
  43
  44 /* --- Signal handling --- */
  45 static volatile int running = 1;
  46 static void sig_shutdown(int signum _unused_) { running = 0; }
  47
  48 static volatile int reset_pending = 0, export_pending = 0;
  49 static void sig_reset(int signum _unused_)
  50 {
  51    reset_pending = 1;
  52    export_pending = 1;
  53 }
  54
  55 static void sig_export(int signum _unused_) { export_pending = 1; }
  56
  57 /* --- Commandline parsing --- */
  58 static unsigned long
  59 parsenum(const char *str, unsigned long max /* 0 for no max */)
  60 {
  61    unsigned long n;
  62    char *end;
  63
  64    errno = 0;
  65    n = strtoul(str, &end, 10);
  66    if (*end != '\0')
  67       errx(1, "\"%s\" is not a valid number", str);
  68    if (errno == ERANGE)
  69       errx(1, "\"%s\" is out of range", str);
  70    if ((max != 0) && (n > max))
  71       errx(1, "\"%s\" is out of range (max %lu)", str, max);
  72    return n;
  73 }
  74
  75 const char *interface = NULL;
  76 static void cb_interface(const char *arg) { interface = arg; }
  77
  78 const char *capfile = NULL;
  79 static void cb_capfile(const char *arg) { capfile = arg; }
  80
  81 int want_snaplen = -1;
  82 static void cb_snaplen(const char *arg) { want_snaplen = parsenum(arg, 0); }
  83
  84 int want_pppoe = 0;
  85 static void cb_pppoe(const char *arg _unused_) { want_pppoe = 1; }
  86
  87 static void cb_syslog(const char *arg _unused_) { want_syslog = 1; }
  88
  89 static void cb_verbose(const char *arg _unused_) { want_verbose = 1; }
  90
  91 int want_daemonize = 1;
  92 static void cb_no_daemon(const char *arg _unused_) { want_daemonize = 0; }
  93
  94 int want_promisc = 1;
  95 static void cb_no_promisc(const char *arg _unused_) { want_promisc = 0; }
  96
  97 int want_dns = 1;
  98 static void cb_no_dns(const char *arg _unused_) { want_dns = 0; }
  99
 100 int want_macs = 1;
 101 static void cb_no_macs(const char *arg _unused_) { want_macs = 0; }
 102
 103 int want_lastseen = 1;
 104 static void cb_no_lastseen(const char *arg _unused_) { want_lastseen = 0; }
 105
 106 unsigned short bindport = 667;
 107 static void cb_port(const char *arg) { bindport = parsenum(arg, 65536); }
 108
 109 const char *bindaddr = NULL;
 110 static void cb_bindaddr(const char *arg)
 111 {
 112    struct addrinfo hints, *ai;
 113
 114    memset(&hints, 0, sizeof(hints));
 115    hints.ai_flags = AI_PASSIVE;
 116 #ifdef AI_ADDRCONFIG
 117    hints.ai_flags |= AI_ADDRCONFIG;
 118 #endif
 119    hints.ai_family = AF_UNSPEC;
 120    hints.ai_socktype = SOCK_STREAM;
 121
 122    if (getaddrinfo(arg, NULL, &hints, &ai))
 123       errx(1, "malformed address \"%s\"", arg);
 124
 125    freeaddrinfo(ai);
 126    bindaddr = arg;
 127 }
 128
 129 const char *filter = NULL;
 130 static void cb_filter(const char *arg) { filter = arg; }
 131
 132 static void cb_local(const char *arg) { acct_init_localnet(arg); }
 133
 134 const char *chroot_dir = NULL;
 135 static void cb_chroot(const char *arg) { chroot_dir = arg; }
 136
 137 const char *privdrop_user = NULL;
 138 static void cb_user(const char *arg) { privdrop_user = arg; }
 139
 140 const char *daylog_fn = NULL;
 141 static void cb_daylog(const char *arg)
 142 {
 143    if (chroot_dir == NULL)
 144       errx(1, "the daylog file is relative to the chroot.\n"
 145       "You must specify a --chroot dir before you can use --daylog.");
 146    else
 147       daylog_fn = arg;
 148 }
 149
 150 const char *import_fn = NULL;
 151 static void cb_import(const char *arg)
 152 {
 153    if (chroot_dir == NULL)
 154       errx(1, "the import file is relative to the chroot.\n"
 155       "You must specify a --chroot dir before you can use --import.");
 156    else
 157       import_fn = arg;
 158 }
 159
 160 const char *export_fn = NULL;
 161 static void cb_export(const char *arg)
 162 {
 163    if ((chroot_dir == NULL) && (capfile == NULL))
 164       errx(1, "the export file is relative to the chroot.\n"
 165       "You must specify a --chroot dir before you can use --export.");
 166    else
 167       export_fn = arg;
 168 }
 169
 170 static const char *pid_fn = NULL;
 171 static void cb_pidfile(const char *arg)
 172 {
 173    if (chroot_dir == NULL)
 174       errx(1, "the pidfile is relative to the chroot.\n"
 175       "You must specify a --chroot dir before you can use --pidfile.");
 176    else
 177       pid_fn = arg;
 178 }
 179
 180 unsigned int hosts_max = 1000;
 181 static void cb_hosts_max(const char *arg)
 182 { hosts_max = parsenum(arg, 0); }
 183
 184 unsigned int hosts_keep = 500;
 185 static void cb_hosts_keep(const char *arg)
 186 { hosts_keep = parsenum(arg, 0); }
 187
 188 unsigned int ports_max = 200;
 189 static void cb_ports_max(const char *arg)
 190 { ports_max = parsenum(arg, 65536); }
 191
 192 unsigned int ports_keep = 30;
 193 static void cb_ports_keep(const char *arg)
 194 { ports_keep = parsenum(arg, 65536); }
 195
 196 unsigned int highest_port = 65535;
 197 static void cb_highest_port(const char *arg)
 198 { highest_port = parsenum(arg, 65535); }
 199
 200 int wait_secs = -1;
 201 static void cb_wait_secs(const char *arg)
 202 { wait_secs = parsenum(arg, 0); }
 203
 204 int want_hexdump = 0;
 205 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 206
 207 /* --- */
 208
 209 struct cmdline_arg {
 210    const char *name, *arg_name; /* NULL arg_name means unary */
 211    void (*callback)(const char *arg);
 212    int num_seen;
 213 };
 214
 215 static struct cmdline_arg cmdline_args[] = {
 216    {"-i",             "interface",       cb_interface,    0},
 217    {"-r",             "file",            cb_capfile,      0},
 218    {"--snaplen",      "bytes",           cb_snaplen,      0},
 219    {"--pppoe",        NULL,              cb_pppoe,        0},
 220    {"--syslog",       NULL,              cb_syslog,       0},
 221    {"--verbose",      NULL,              cb_verbose,      0},
 222    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 223    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 224    {"--no-dns",       NULL,              cb_no_dns,       0},
 225    {"--no-macs",      NULL,              cb_no_macs,      0},
 226    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 227    {"-p",             "port",            cb_port,         0},
 228    {"-b",             "bindaddr",        cb_bindaddr,     0},
 229    {"-f",             "filter",          cb_filter,       0},
 230    {"-l",             "network/netmask", cb_local,        0},
 231    {"--chroot",       "dir",             cb_chroot,       0},
 232    {"--user",         "username",        cb_user,         0},
 233    {"--daylog",       "filename",        cb_daylog,       0},
 234    {"--import",       "filename",        cb_import,       0},
 235    {"--export",       "filename",        cb_export,       0},
 236    {"--pidfile",      "filename",        cb_pidfile,      0},
 237    {"--hosts-max",    "count",           cb_hosts_max,    0},
 238    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 239    {"--ports-max",    "count",           cb_ports_max,    0},
 240    {"--ports-keep",   "count",           cb_ports_keep,   0},
 241    {"--highest-port", "port",            cb_highest_port, 0},
 242    {"--wait",         "secs",            cb_wait_secs,    0},
 243    {"--hexdump",      NULL,              cb_hexdump,      0},
 244    {NULL,             NULL,              NULL,            0}
 245 };
 246
 247 static void
 248 pad(const int width)
 249 {
 250    int i;
 251    for (i=0; i<width; i++) printf(" ");
 252 }
 253
 254 /*
 255  * We autogenerate the usage statement from the cmdline_args data structure.
 256  */
 257 static void
 258 usage(void)
 259 {
 260    int width, first;
 261    struct cmdline_arg *arg;
 262
 263    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 264       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 265
 266    width = printf("usage: darkstat ");
 267    first = 1;
 268
 269    for (arg = cmdline_args; arg->name != NULL; arg++) {
 270       if (first) first = 0; else pad(width);
 271       printf("[ %s", arg->name);
 272       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 273       printf(" ]\n");
 274    }
 275    printf("\n"
 276 "Please refer to the darkstat(8) manual page for further\n"
 277 "documentation and usage examples.\n");
 278 }
 279
 280 static void
 281 parse_sub_cmdline(const int argc, char * const *argv)
 282 {
 283    struct cmdline_arg *arg;
 284
 285    if (argc == 0) return;
 286    for (arg = cmdline_args; arg->name != NULL; arg++)
 287       if (strcmp(argv[0], arg->name) == 0) {
 288          if ((arg->arg_name != NULL) && (argc == 1)) {
 289             fprintf(stderr,
 290                "error: argument \"%s\" requires parameter \"%s\"\n",
 291                arg->name, arg->arg_name);
 292             usage();
 293             exit(EXIT_FAILURE);
 294          }
 295          if (arg->num_seen > 0) {
 296             fprintf(stderr,
 297                "error: already specified argument \"%s\"\n",
 298                arg->name);
 299             usage();
 300             exit(EXIT_FAILURE);
 301          }
 302
 303          arg->num_seen++;
 304          if (arg->arg_name == NULL) {
 305             arg->callback(NULL);
 306             parse_sub_cmdline(argc-1, argv+1);
 307          } else {
 308             arg->callback(argv[1]);
 309             parse_sub_cmdline(argc-2, argv+2);
 310          }
 311          return;
 312       }
 313
 314    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 315    usage();
 316    exit(EXIT_FAILURE);
 317 }
 318
 319 static void
 320 parse_cmdline(const int argc, char * const *argv)
 321 {
 322    if (argc < 1) {
 323       /* Not enough args. */
 324       usage();
 325       exit(EXIT_FAILURE);
 326    }
 327
 328    parse_sub_cmdline(argc, argv);
 329
 330    /* start syslogging as early as possible */
 331    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 332
 333    /* some default values */
 334    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 335    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 336
 337    /* sanity check args */
 338    if ((interface == NULL) && (capfile == NULL))
 339       errx(1, "must specify either interface (-i) or capture file (-r)");
 340
 341    if ((interface != NULL) && (capfile != NULL))
 342       errx(1, "can't specify both interface (-i) and capture file (-r)");
 343
 344    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 345       hosts_keep = hosts_max / 2;
 346       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 347          hosts_keep, hosts_max);
 348    }
 349    verbosef("max %u hosts, cutting down to %u when exceeded",
 350       hosts_max, hosts_keep);
 351
 352    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 353       ports_keep = ports_max / 2;
 354       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 355          ports_keep, ports_max);
 356    }
 357    verbosef("max %u ports per host, cutting down to %u when exceeded",
 358       ports_max, ports_keep);
 359
 360    if (want_hexdump && !want_verbose) {
 361       want_verbose = 1;
 362       verbosef("--hexdump implies --verbose");
 363    }
 364
 365    if (want_hexdump && want_daemonize) {
 366       want_daemonize = 0;
 367       verbosef("--hexdump implies --no-daemon");
 368    }
 369 }
 370
 371 static void
 372 run_from_capfile(void)
 373 {
 374    graph_init();
 375    hosts_db_init();
 376    cap_from_file(capfile, filter);
 377    cap_stop();
 378    if (export_fn != NULL) db_export(export_fn);
 379    hosts_db_free();
 380    graph_free();
 381    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 382 }
 383
 384 /* --- Program body --- */
 385 int
 386 main(int argc, char **argv)
 387 {
 388    test_64order();
 389    parse_cmdline(argc-1, argv+1);
 390
 391    if (capfile) {
 392       /*
 393        * This is very different from a regular run against a network
 394        * interface.
 395        */
 396       run_from_capfile();
 397       return 0;
 398    }
 399
 400    /* must verbosef() before first fork to init lock */
 401    verbosef("starting up");
 402    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 403
 404    if (want_daemonize) {
 405       verbosef("daemonizing to run in the background!");
 406       daemonize_start();
 407       verbosef("I am the main process");
 408    }
 409    if (pid_fn) pidfile_write_close();
 410
 411    /* do this first as it forks - minimize memory use */
 412    if (want_dns) dns_init(privdrop_user);
 413    cap_init(interface, filter, want_promisc); /* needs root */
 414    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 415    ncache_init(); /* must do before chroot() */
 416
 417    privdrop(chroot_dir, privdrop_user);
 418
 419    /* Don't need root privs for these: */
 420    now = time(NULL);
 421    if (daylog_fn != NULL) daylog_init(daylog_fn);
 422    graph_init();
 423    hosts_db_init();
 424    if (import_fn != NULL) db_import(import_fn);
 425    localip_init(interface);
 426
 427    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 428       errx(1, "signal(SIGTERM) failed");
 429    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 430       errx(1, "signal(SIGINT) failed");
 431    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 432       errx(1, "signal(SIGUSR1) failed");
 433    if (signal(SIGUSR2, sig_export) == SIG_ERR)
 434       errx(1, "signal(SIGUSR2) failed");
 435
 436    verbosef("entering main loop");
 437    daemonize_finish();
 438
 439    while (running) {
 440       int select_ret, max_fd = -1, use_timeout = 0;
 441       struct timeval timeout;
 442       fd_set rs, ws;
 443
 444       now = time(NULL);
 445
 446       if (export_pending) {
 447          if (export_fn != NULL)
 448             db_export(export_fn);
 449          export_pending = 0;
 450       }
 451
 452       if (reset_pending) {
 453          hosts_db_reset();
 454          graph_reset();
 455          reset_pending = 0;
 456       }
 457
 458       FD_ZERO(&rs);
 459       FD_ZERO(&ws);
 460
 461       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 462       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 463
 464       select_ret = select(max_fd+1, &rs, &ws, NULL,
 465          (use_timeout) ? &timeout : NULL);
 466
 467       if ((select_ret == 0) && (!use_timeout))
 468             errx(1, "select() erroneously timed out");
 469
 470       if (select_ret == -1) {
 471          if (errno == EINTR)
 472             continue;
 473          else
 474             err(1, "select()");
 475       }
 476       else {
 477          graph_rotate();
 478          cap_poll(&rs);
 479          dns_poll();
 480          http_poll(&rs, &ws);
 481       }
 482    }
 483
 484    verbosef("shutting down");
 485    verbosef("pcap stats: %u packets received, %u packets dropped",
 486       pkts_recv, pkts_drop);
 487    cap_stop();
 488    dns_stop();
 489    if (export_fn != NULL) db_export(export_fn);
 490    hosts_db_free();
 491    graph_free();
 492    if (daylog_fn != NULL) daylog_free();
 493    ncache_free();
 494    if (pid_fn) pidfile_unlink();
 495    verbosef("shut down");
 496    return (EXIT_SUCCESS);
 497 }
 498
 499 /* vim:set ts=3 sw=3 tw=78 expandtab: */