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 static void cb_base(const char *arg) { http_init_base(arg); }
 138
 139 const char *privdrop_user = NULL;
 140 static void cb_user(const char *arg) { privdrop_user = arg; }
 141
 142 const char *daylog_fn = NULL;
 143 static void cb_daylog(const char *arg)
 144 {
 145    if (chroot_dir == NULL)
 146       errx(1, "the daylog file is relative to the chroot.\n"
 147       "You must specify a --chroot dir before you can use --daylog.");
 148    else
 149       daylog_fn = arg;
 150 }
 151
 152 const char *import_fn = NULL;
 153 static void cb_import(const char *arg)
 154 {
 155    if (chroot_dir == NULL)
 156       errx(1, "the import file is relative to the chroot.\n"
 157       "You must specify a --chroot dir before you can use --import.");
 158    else
 159       import_fn = arg;
 160 }
 161
 162 const char *export_fn = NULL;
 163 static void cb_export(const char *arg)
 164 {
 165    if ((chroot_dir == NULL) && (capfile == NULL))
 166       errx(1, "the export file is relative to the chroot.\n"
 167       "You must specify a --chroot dir before you can use --export.");
 168    else
 169       export_fn = arg;
 170 }
 171
 172 static const char *pid_fn = NULL;
 173 static void cb_pidfile(const char *arg)
 174 {
 175    if (chroot_dir == NULL)
 176       errx(1, "the pidfile is relative to the chroot.\n"
 177       "You must specify a --chroot dir before you can use --pidfile.");
 178    else
 179       pid_fn = arg;
 180 }
 181
 182 unsigned int hosts_max = 1000;
 183 static void cb_hosts_max(const char *arg)
 184 { hosts_max = parsenum(arg, 0); }
 185
 186 unsigned int hosts_keep = 500;
 187 static void cb_hosts_keep(const char *arg)
 188 { hosts_keep = parsenum(arg, 0); }
 189
 190 unsigned int ports_max = 200;
 191 static void cb_ports_max(const char *arg)
 192 { ports_max = parsenum(arg, 65536); }
 193
 194 unsigned int ports_keep = 30;
 195 static void cb_ports_keep(const char *arg)
 196 { ports_keep = parsenum(arg, 65536); }
 197
 198 unsigned int highest_port = 65535;
 199 static void cb_highest_port(const char *arg)
 200 { highest_port = parsenum(arg, 65535); }
 201
 202 int wait_secs = -1;
 203 static void cb_wait_secs(const char *arg)
 204 { wait_secs = parsenum(arg, 0); }
 205
 206 int want_hexdump = 0;
 207 static void cb_hexdump(const char *arg _unused_) { want_hexdump = 1; }
 208
 209 /* --- */
 210
 211 struct cmdline_arg {
 212    const char *name, *arg_name; /* NULL arg_name means unary */
 213    void (*callback)(const char *arg);
 214    int num_seen;
 215 };
 216
 217 static struct cmdline_arg cmdline_args[] = {
 218    {"-i",             "interface",       cb_interface,    0},
 219    {"-r",             "file",            cb_capfile,      0},
 220    {"--snaplen",      "bytes",           cb_snaplen,      0},
 221    {"--pppoe",        NULL,              cb_pppoe,        0},
 222    {"--syslog",       NULL,              cb_syslog,       0},
 223    {"--verbose",      NULL,              cb_verbose,      0},
 224    {"--no-daemon",    NULL,              cb_no_daemon,    0},
 225    {"--no-promisc",   NULL,              cb_no_promisc,   0},
 226    {"--no-dns",       NULL,              cb_no_dns,       0},
 227    {"--no-macs",      NULL,              cb_no_macs,      0},
 228    {"--no-lastseen",  NULL,              cb_no_lastseen,  0},
 229    {"-p",             "port",            cb_port,         0},
 230    {"-b",             "bindaddr",        cb_bindaddr,     0},
 231    {"--base",         "path",            cb_base,         0},
 232    {"-f",             "filter",          cb_filter,       0},
 233    {"-l",             "network/netmask", cb_local,        0},
 234    {"--chroot",       "dir",             cb_chroot,       0},
 235    {"--user",         "username",        cb_user,         0},
 236    {"--daylog",       "filename",        cb_daylog,       0},
 237    {"--import",       "filename",        cb_import,       0},
 238    {"--export",       "filename",        cb_export,       0},
 239    {"--pidfile",      "filename",        cb_pidfile,      0},
 240    {"--hosts-max",    "count",           cb_hosts_max,    0},
 241    {"--hosts-keep",   "count",           cb_hosts_keep,   0},
 242    {"--ports-max",    "count",           cb_ports_max,    0},
 243    {"--ports-keep",   "count",           cb_ports_keep,   0},
 244    {"--highest-port", "port",            cb_highest_port, 0},
 245    {"--wait",         "secs",            cb_wait_secs,    0},
 246    {"--hexdump",      NULL,              cb_hexdump,      0},
 247    {NULL,             NULL,              NULL,            0}
 248 };
 249
 250 static void
 251 pad(const int width)
 252 {
 253    int i;
 254    for (i=0; i<width; i++) printf(" ");
 255 }
 256
 257 /*
 258  * We autogenerate the usage statement from the cmdline_args data structure.
 259  */
 260 static void
 261 usage(void)
 262 {
 263    int width, first;
 264    struct cmdline_arg *arg;
 265
 266    printf(PACKAGE_STRING " (built with libpcap %d.%d)\n\n",
 267       PCAP_VERSION_MAJOR, PCAP_VERSION_MINOR);
 268
 269    width = printf("usage: darkstat ");
 270    first = 1;
 271
 272    for (arg = cmdline_args; arg->name != NULL; arg++) {
 273       if (first) first = 0; else pad(width);
 274       printf("[ %s", arg->name);
 275       if (arg->arg_name != NULL) printf(" %s", arg->arg_name);
 276       printf(" ]\n");
 277    }
 278    printf("\n"
 279 "Please refer to the darkstat(8) manual page for further\n"
 280 "documentation and usage examples.\n");
 281 }
 282
 283 static void
 284 parse_sub_cmdline(const int argc, char * const *argv)
 285 {
 286    struct cmdline_arg *arg;
 287
 288    if (argc == 0) return;
 289    for (arg = cmdline_args; arg->name != NULL; arg++)
 290       if (strcmp(argv[0], arg->name) == 0) {
 291          if ((arg->arg_name != NULL) && (argc == 1)) {
 292             fprintf(stderr,
 293                "error: argument \"%s\" requires parameter \"%s\"\n",
 294                arg->name, arg->arg_name);
 295             usage();
 296             exit(EXIT_FAILURE);
 297          }
 298          if (arg->num_seen > 0) {
 299             fprintf(stderr,
 300                "error: already specified argument \"%s\"\n",
 301                arg->name);
 302             usage();
 303             exit(EXIT_FAILURE);
 304          }
 305
 306          arg->num_seen++;
 307          if (arg->arg_name == NULL) {
 308             arg->callback(NULL);
 309             parse_sub_cmdline(argc-1, argv+1);
 310          } else {
 311             arg->callback(argv[1]);
 312             parse_sub_cmdline(argc-2, argv+2);
 313          }
 314          return;
 315       }
 316
 317    fprintf(stderr, "error: illegal argument: \"%s\"\n", argv[0]);
 318    usage();
 319    exit(EXIT_FAILURE);
 320 }
 321
 322 static void
 323 parse_cmdline(const int argc, char * const *argv)
 324 {
 325    if (argc < 1) {
 326       /* Not enough args. */
 327       usage();
 328       exit(EXIT_FAILURE);
 329    }
 330
 331    parse_sub_cmdline(argc, argv);
 332
 333    /* start syslogging as early as possible */
 334    if (want_syslog) openlog("darkstat", LOG_NDELAY | LOG_PID, LOG_DAEMON);
 335
 336    /* some default values */
 337    if (chroot_dir == NULL) chroot_dir = CHROOT_DIR;
 338    if (privdrop_user == NULL) privdrop_user = PRIVDROP_USER;
 339
 340    /* sanity check args */
 341    if ((interface == NULL) && (capfile == NULL))
 342       errx(1, "must specify either interface (-i) or capture file (-r)");
 343
 344    if ((interface != NULL) && (capfile != NULL))
 345       errx(1, "can't specify both interface (-i) and capture file (-r)");
 346
 347    if ((hosts_max != 0) && (hosts_keep >= hosts_max)) {
 348       hosts_keep = hosts_max / 2;
 349       warnx("reducing --hosts-keep to %u, to be under --hosts-max (%u)",
 350          hosts_keep, hosts_max);
 351    }
 352    verbosef("max %u hosts, cutting down to %u when exceeded",
 353       hosts_max, hosts_keep);
 354
 355    if ((ports_max != 0) && (ports_keep >= ports_max)) {
 356       ports_keep = ports_max / 2;
 357       warnx("reducing --ports-keep to %u, to be under --ports-max (%u)",
 358          ports_keep, ports_max);
 359    }
 360    verbosef("max %u ports per host, cutting down to %u when exceeded",
 361       ports_max, ports_keep);
 362
 363    if (want_hexdump && !want_verbose) {
 364       want_verbose = 1;
 365       verbosef("--hexdump implies --verbose");
 366    }
 367
 368    if (want_hexdump && want_daemonize) {
 369       want_daemonize = 0;
 370       verbosef("--hexdump implies --no-daemon");
 371    }
 372 }
 373
 374 static void
 375 run_from_capfile(void)
 376 {
 377    graph_init();
 378    hosts_db_init();
 379    cap_from_file(capfile, filter);
 380    cap_stop();
 381    if (export_fn != NULL) db_export(export_fn);
 382    hosts_db_free();
 383    graph_free();
 384    verbosef("Total packets: %qu, bytes: %qu", total_packets, total_bytes);
 385 }
 386
 387 /* --- Program body --- */
 388 int
 389 main(int argc, char **argv)
 390 {
 391    test_64order();
 392    parse_cmdline(argc-1, argv+1);
 393
 394    if (capfile) {
 395       /*
 396        * This is very different from a regular run against a network
 397        * interface.
 398        */
 399       run_from_capfile();
 400       return 0;
 401    }
 402
 403    /* must verbosef() before first fork to init lock */
 404    verbosef("starting up");
 405    if (pid_fn) pidfile_create(chroot_dir, pid_fn, privdrop_user);
 406
 407    if (want_daemonize) {
 408       verbosef("daemonizing to run in the background!");
 409       daemonize_start();
 410       verbosef("I am the main process");
 411    }
 412    if (pid_fn) pidfile_write_close();
 413
 414    /* do this first as it forks - minimize memory use */
 415    if (want_dns) dns_init(privdrop_user);
 416    cap_init(interface, filter, want_promisc); /* needs root */
 417    http_init(bindaddr, bindport, /*maxconn=*/ -1); /* low ports need root */
 418    ncache_init(); /* must do before chroot() */
 419
 420    privdrop(chroot_dir, privdrop_user);
 421
 422    /* Don't need root privs for these: */
 423    now = time(NULL);
 424    if (daylog_fn != NULL) daylog_init(daylog_fn);
 425    graph_init();
 426    hosts_db_init();
 427    if (import_fn != NULL) db_import(import_fn);
 428    localip_init(interface);
 429
 430    if (signal(SIGTERM, sig_shutdown) == SIG_ERR)
 431       errx(1, "signal(SIGTERM) failed");
 432    if (signal(SIGINT, sig_shutdown) == SIG_ERR)
 433       errx(1, "signal(SIGINT) failed");
 434    if (signal(SIGUSR1, sig_reset) == SIG_ERR)
 435       errx(1, "signal(SIGUSR1) failed");
 436    if (signal(SIGUSR2, sig_export) == SIG_ERR)
 437       errx(1, "signal(SIGUSR2) failed");
 438
 439    verbosef("entering main loop");
 440    daemonize_finish();
 441
 442    while (running) {
 443       int select_ret, max_fd = -1, use_timeout = 0;
 444       struct timeval timeout;
 445       fd_set rs, ws;
 446
 447       now = time(NULL);
 448
 449       if (export_pending) {
 450          if (export_fn != NULL)
 451             db_export(export_fn);
 452          export_pending = 0;
 453       }
 454
 455       if (reset_pending) {
 456          hosts_db_reset();
 457          graph_reset();
 458          reset_pending = 0;
 459       }
 460
 461       FD_ZERO(&rs);
 462       FD_ZERO(&ws);
 463
 464       cap_fd_set(&rs, &max_fd, &timeout, &use_timeout);
 465       http_fd_set(&rs, &ws, &max_fd, &timeout, &use_timeout);
 466
 467       select_ret = select(max_fd+1, &rs, &ws, NULL,
 468          (use_timeout) ? &timeout : NULL);
 469
 470       if ((select_ret == 0) && (!use_timeout))
 471             errx(1, "select() erroneously timed out");
 472
 473       if (select_ret == -1) {
 474          if (errno == EINTR)
 475             continue;
 476          else
 477             err(1, "select()");
 478       }
 479       else {
 480          graph_rotate();
 481          cap_poll(&rs);
 482          dns_poll();
 483          http_poll(&rs, &ws);
 484       }
 485    }
 486
 487    verbosef("shutting down");
 488    verbosef("pcap stats: %u packets received, %u packets dropped",
 489       pkts_recv, pkts_drop);
 490    cap_stop();
 491    dns_stop();
 492    if (export_fn != NULL) db_export(export_fn);
 493    hosts_db_free();
 494    graph_free();
 495    if (daylog_fn != NULL) daylog_free();
 496    ncache_free();
 497    if (pid_fn) pidfile_unlink();
 498    verbosef("shut down");
 499    return (EXIT_SUCCESS);
 500 }
 501
 502 /* vim:set ts=3 sw=3 tw=78 expandtab: */