b654da965e1763af9fb9bff54699fcdee6573422
[darkstat] / 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: */