main.c 29.9 KB
Newer Older
1
/* Copyright 2001,2002,2003 Roger Dingledine, Matej Pfajfar. */
2
3
/* See LICENSE for licensing information */
/* $Id$ */
Roger Dingledine's avatar
Roger Dingledine committed
4

5
6
7
8
/*****
 * main.c: Tor main loop and startup functions.
 *****/

Roger Dingledine's avatar
Roger Dingledine committed
9
10
#include "or.h"

11
/********* PROTOTYPES **********/
Roger Dingledine's avatar
Roger Dingledine committed
12

13
static void dumpstats(int severity); /* log stats */
14
static int init_from_config(int argc, char **argv);
Roger Dingledine's avatar
Roger Dingledine committed
15

Roger Dingledine's avatar
Roger Dingledine committed
16
17
/********* START VARIABLES **********/

18
/* declared in connection.c */
19
extern char *conn_state_to_string[][_CONN_TYPE_MAX+1];
20

21
or_options_t options; /* command-line and config-file options */
22
int global_read_bucket; /* max number of bytes I can read this second */
Roger Dingledine's avatar
Roger Dingledine committed
23

24
25
/* What was the read bucket before the last call to prepare_for_pool?
 * (used to determine how many bytes we've read). */
26
static int stats_prev_global_read_bucket;
27
/* How many bytes have we read since we started the process? */
28
static uint64_t stats_n_bytes_read = 0;
29
/* How many seconds have we been running? */
30
31
static long stats_n_seconds_reading = 0;

32
33
/* Array of all open connections; each element corresponds to the element of
 * poll_array in the same position.  The first nfds elements are valid. */
Roger Dingledine's avatar
Roger Dingledine committed
34
static connection_t *connection_array[MAXCONNECTIONS] =
Roger Dingledine's avatar
Roger Dingledine committed
35
36
        { NULL };

37
/* Array of pollfd objects for calls to poll(). */
Nick Mathewson's avatar
Nick Mathewson committed
38
static struct pollfd poll_array[MAXCONNECTIONS];
Roger Dingledine's avatar
Roger Dingledine committed
39

Roger Dingledine's avatar
Roger Dingledine committed
40
static int nfds=0; /* number of connections currently active */
Roger Dingledine's avatar
Roger Dingledine committed
41

42
#ifndef MS_WINDOWS /* do signal stuff only on unix */
43
static int please_dumpstats=0; /* whether we should dump stats during the loop */
44
45
static int please_reset=0; /* whether we just got a sighup */
static int please_reap_children=0; /* whether we should waitpid for exited children */
46
#endif /* signal stuff */
47

48
/* we set this to 1 when we've fetched a dir, to know whether to complain
49
50
 * yet about unrecognized nicknames in entrynodes, exitnodes, etc.
 * Also, we don't try building circuits unless this is 1. */
51
int has_fetched_directory=0;
52
53
54

/* we set this to 1 when we've opened a circuit, so we can print a log
 * entry to inform the user that Tor is working. */
55
int has_completed_circuit=0;
56

Roger Dingledine's avatar
Roger Dingledine committed
57
58
/********* END VARIABLES ************/

Roger Dingledine's avatar
Roger Dingledine committed
59
60
61
62
63
64
65
66
/****************************************************************************
*
* This section contains accessors and other methods on the connection_array
* and poll_array variables (which are global within this file and unavailable
* outside it).
*
****************************************************************************/

67
68
69
70
/* Add 'conn' to the array of connections that we can poll on.  The
 * connection's socket must be set; the connection starts out
 * non-reading and non-writing.
 */
Roger Dingledine's avatar
Roger Dingledine committed
71
int connection_add(connection_t *conn) {
Roger Dingledine's avatar
Roger Dingledine committed
72
  tor_assert(conn);
73
  tor_assert(conn->s >= 0);
Roger Dingledine's avatar
Roger Dingledine committed
74

75
  if(nfds >= options.MaxConn-1) {
76
    log_fn(LOG_WARN,"failing because nfds is too high.");
Roger Dingledine's avatar
Roger Dingledine committed
77
78
    return -1;
  }
Roger Dingledine's avatar
Roger Dingledine committed
79

Roger Dingledine's avatar
Roger Dingledine committed
80
81
82
83
  conn->poll_index = nfds;
  connection_array[nfds] = conn;

  /* zero these out here, because otherwise we'll inherit values from the previously freed one */
84
  poll_array[nfds].fd = conn->s;
Roger Dingledine's avatar
Roger Dingledine committed
85
86
87
88
89
  poll_array[nfds].events = 0;
  poll_array[nfds].revents = 0;

  nfds++;

90
  log_fn(LOG_INFO,"new conn type %s, socket %d, nfds %d.",
Roger Dingledine's avatar
Roger Dingledine committed
91
      CONN_TYPE_TO_STRING(conn->type), conn->s, nfds);
Roger Dingledine's avatar
Roger Dingledine committed
92
93
94
95

  return 0;
}

Roger Dingledine's avatar
Roger Dingledine committed
96
/* Remove the connection from the global list, and remove the
Nick Mathewson's avatar
Nick Mathewson committed
97
98
99
 * corresponding poll entry.  Calling this function will shift the last
 * connection (if any) into the position occupied by conn.
 */
Roger Dingledine's avatar
Roger Dingledine committed
100
101
102
int connection_remove(connection_t *conn) {
  int current_index;

Roger Dingledine's avatar
Roger Dingledine committed
103
104
  tor_assert(conn);
  tor_assert(nfds>0);
Roger Dingledine's avatar
Roger Dingledine committed
105

106
  log_fn(LOG_INFO,"removing socket %d (type %s), nfds now %d",
Roger Dingledine's avatar
Roger Dingledine committed
107
         conn->s, CONN_TYPE_TO_STRING(conn->type), nfds-1);
Roger Dingledine's avatar
Roger Dingledine committed
108
109
110
111
112
  /* if it's an edge conn, remove it from the list
   * of conn's on this circuit. If it's not on an edge,
   * flush and send destroys for all circuits on this conn
   */
  circuit_about_to_close_connection(conn);
Roger Dingledine's avatar
Roger Dingledine committed
113
114
115
116
117

  current_index = conn->poll_index;
  if(current_index == nfds-1) { /* this is the end */
    nfds--;
    return 0;
Roger Dingledine's avatar
Roger Dingledine committed
118
  }
Roger Dingledine's avatar
Roger Dingledine committed
119

120
  /* replace this one with the one at the end */
Roger Dingledine's avatar
Roger Dingledine committed
121
  nfds--;
Roger Dingledine's avatar
Roger Dingledine committed
122
  poll_array[current_index].fd = poll_array[nfds].fd;
Roger Dingledine's avatar
Roger Dingledine committed
123
124
125
126
127
  poll_array[current_index].events = poll_array[nfds].events;
  poll_array[current_index].revents = poll_array[nfds].revents;
  connection_array[current_index] = connection_array[nfds];
  connection_array[current_index]->poll_index = current_index;

Roger Dingledine's avatar
Roger Dingledine committed
128
  return 0;
Roger Dingledine's avatar
Roger Dingledine committed
129
130
}

131
132
133
/* Set *array to an array of all connections, and *n to the length
 * of the array.  *array and *n must not be modified.
 */
134
135
136
void get_connection_array(connection_t ***array, int *n) {
  *array = connection_array;
  *n = nfds;
137
138
}

139
140
141
/* Set the event mask on 'conn' to 'events'.  (The form of the event mask is
 * as for poll().)
 */
Roger Dingledine's avatar
Roger Dingledine committed
142
143
void connection_watch_events(connection_t *conn, short events) {

Roger Dingledine's avatar
Roger Dingledine committed
144
  tor_assert(conn && conn->poll_index < nfds);
Roger Dingledine's avatar
Roger Dingledine committed
145
146
147
148

  poll_array[conn->poll_index].events = events;
}

149
/* Return true iff the 'conn' is listening for read events. */
Roger Dingledine's avatar
Roger Dingledine committed
150
151
152
153
int connection_is_reading(connection_t *conn) {
  return poll_array[conn->poll_index].events & POLLIN;
}

154
/* Tell the main loop to stop notifying 'conn' of any read events. */
155
156
void connection_stop_reading(connection_t *conn) {

Roger Dingledine's avatar
Roger Dingledine committed
157
  tor_assert(conn && conn->poll_index < nfds);
158

159
  log(LOG_DEBUG,"connection_stop_reading() called.");
160
161
162
163
  if(poll_array[conn->poll_index].events & POLLIN)
    poll_array[conn->poll_index].events -= POLLIN;
}

164
/* Tell the main loop to start notifying 'conn' of any read events. */
165
166
void connection_start_reading(connection_t *conn) {

Roger Dingledine's avatar
Roger Dingledine committed
167
  tor_assert(conn && conn->poll_index < nfds);
168
169
170
171

  poll_array[conn->poll_index].events |= POLLIN;
}

172
/* Return true iff the 'conn' is listening for write events. */
173
174
175
176
int connection_is_writing(connection_t *conn) {
  return poll_array[conn->poll_index].events & POLLOUT;
}

177
/* Tell the main loop to stop notifying 'conn' of any write events. */
178
179
void connection_stop_writing(connection_t *conn) {

Roger Dingledine's avatar
Roger Dingledine committed
180
  tor_assert(conn && conn->poll_index < nfds);
181
182
183
184
185

  if(poll_array[conn->poll_index].events & POLLOUT)
    poll_array[conn->poll_index].events -= POLLOUT;
}

186
/* Tell the main loop to start notifying 'conn' of any write events. */
187
188
void connection_start_writing(connection_t *conn) {

Roger Dingledine's avatar
Roger Dingledine committed
189
  tor_assert(conn && conn->poll_index < nfds);
190
191
192
193

  poll_array[conn->poll_index].events |= POLLOUT;
}

194
195
196
197
/* Called when the connection at connection_array[i] has a read event:
 * checks for validity, catches numerous errors, and dispatches to
 * connection_handle_read.
 */
Roger Dingledine's avatar
Roger Dingledine committed
198
static void conn_read(int i) {
199
  connection_t *conn = connection_array[i];
Roger Dingledine's avatar
Roger Dingledine committed
200

Roger Dingledine's avatar
Roger Dingledine committed
201
202
203
  if (conn->marked_for_close)
    return;

204
205
  /* see http://www.greenend.org.uk/rjk/2001/06/poll.html for
   * discussion of POLLIN vs POLLHUP */
206
  if(!(poll_array[i].revents & (POLLIN|POLLHUP|POLLERR)))
Nick Mathewson's avatar
Nick Mathewson committed
207
208
    if(!connection_is_reading(conn) ||
       !connection_has_pending_tls_data(conn))
209
      return; /* this conn should not read */
210

211
  log_fn(LOG_DEBUG,"socket %d wants to read.",conn->s);
Roger Dingledine's avatar
Roger Dingledine committed
212

213
  assert_connection_ok(conn, time(NULL));
214
  assert_all_pending_dns_resolves_ok();
215

216
  if(
217
    /* XXX does POLLHUP also mean it's definitely broken? */
218
#ifdef MS_WINDOWS
219
    (poll_array[i].revents & POLLERR) ||
220
#endif
221
    connection_handle_read(conn) < 0) {
222
223
224
      if (!conn->marked_for_close) {
        /* this connection is broken. remove it */
        /* XXX This shouldn't ever happen anymore. */
225
        /* XXX but it'll clearly happen on MS_WINDOWS from POLLERR, right? */
226
        log_fn(LOG_ERR,"Unhandled error on read for %s connection (fd %d); removing",
227
               CONN_TYPE_TO_STRING(conn->type), conn->s);
228
229
        connection_mark_for_close(conn,0);
      }
230
231
232
  }
  assert_connection_ok(conn, time(NULL));
  assert_all_pending_dns_resolves_ok();
Roger Dingledine's avatar
Roger Dingledine committed
233
234
}

235
236
237
238
/* Called when the connection at connection_array[i] has a write event:
 * checks for validity, catches numerous errors, and dispatches to
 * connection_handle_write.
 */
Roger Dingledine's avatar
Roger Dingledine committed
239
static void conn_write(int i) {
Roger Dingledine's avatar
Roger Dingledine committed
240
241
  connection_t *conn;

242
243
244
  if(!(poll_array[i].revents & POLLOUT))
    return; /* this conn doesn't want to write */

Roger Dingledine's avatar
Roger Dingledine committed
245
  conn = connection_array[i];
246
  log_fn(LOG_DEBUG,"socket %d wants to write.",conn->s);
247
248
  if (conn->marked_for_close)
    return;
Roger Dingledine's avatar
Roger Dingledine committed
249

250
  assert_connection_ok(conn, time(NULL));
251
  assert_all_pending_dns_resolves_ok();
252

253
254
255
  if (connection_handle_write(conn) < 0) {
    if (!conn->marked_for_close) {
      /* this connection is broken. remove it. */
Roger Dingledine's avatar
Roger Dingledine committed
256
      log_fn(LOG_WARN,"Unhandled error on read for %s connection (fd %d); removing",
257
             CONN_TYPE_TO_STRING(conn->type), conn->s);
258
      conn->has_sent_end = 1; /* otherwise we cry wolf about duplicate close */
259
260
      connection_mark_for_close(conn,0);
    }
261
262
  }
  assert_connection_ok(conn, time(NULL));
263
  assert_all_pending_dns_resolves_ok();
Roger Dingledine's avatar
Roger Dingledine committed
264
265
}

266
267
268
269
270
271
272
273
274
/* If the connection at connection_array[i] is marked for close, then:
 *    - If it has data that it wants to flush, try to flush it.
 *    - If it _still_ has data to flush, and conn->hold_open_until_flushed is
 *      true, then leave the connection open and return.
 *    - Otherwise, remove the connection from connection_array and from
 *      all other lists, close it, and free it.
 * If we remove the connection, then call conn_closed_if_marked at the new
 * connection at position i.
 */
Nick Mathewson's avatar
Nick Mathewson committed
275
static void conn_close_if_marked(int i) {
Roger Dingledine's avatar
Roger Dingledine committed
276
  connection_t *conn;
277
  int retval;
Roger Dingledine's avatar
Roger Dingledine committed
278
279

  conn = connection_array[i];
280
  assert_connection_ok(conn, time(NULL));
281
  assert_all_pending_dns_resolves_ok();
282
283
284
285
286
287
288
289
  if(!conn->marked_for_close)
    return; /* nothing to see here, move along */

  log_fn(LOG_INFO,"Cleaning up connection (fd %d).",conn->s);
  if(conn->s >= 0 && connection_wants_to_flush(conn)) {
    /* -1 means it's an incomplete edge connection, or that the socket
     * has already been closed as unflushable. */
    if(!conn->hold_open_until_flushed)
290
      log_fn(LOG_WARN,
291
        "Conn (fd %d, type %s, state %d) marked, but wants to flush %d bytes. "
292
        "(Marked at %s:%d)",
293
        conn->s, CONN_TYPE_TO_STRING(conn->type), conn->state,
294
295
296
297
298
299
        conn->outbuf_flushlen, conn->marked_for_close_file, conn->marked_for_close);
    if(connection_speaks_cells(conn)) {
      if(conn->state == OR_CONN_STATE_OPEN) {
        retval = flush_buf_tls(conn->tls, conn->outbuf, &conn->outbuf_flushlen);
        /* XXX actually, some non-zero results are maybe ok. which ones? */
      } else
300
        retval = -1; /* never flush non-open broken tls connections */
301
302
303
    } else {
      retval = flush_buf(conn->s, conn->outbuf, &conn->outbuf_flushlen);
    }
Roger Dingledine's avatar
Roger Dingledine committed
304
    if(retval >= 0 &&
305
306
307
308
       conn->hold_open_until_flushed && connection_wants_to_flush(conn)) {
      log_fn(LOG_INFO,"Holding conn (fd %d) open for more flushing.",conn->s);
      /* XXX should we reset timestamp_lastwritten here? */
      return;
309
    }
310
    if(connection_wants_to_flush(conn)) {
311
312
313
314
      log_fn(LOG_WARN,"Conn (fd %d, type %s, state %d) still wants to flush. Losing %d bytes! (Marked at %s:%d)",
             conn->s, CONN_TYPE_TO_STRING(conn->type), conn->state,
             (int)buf_datalen(conn->outbuf), conn->marked_for_close_file,
             conn->marked_for_close);
Roger Dingledine's avatar
Roger Dingledine committed
315
316
    }
  }
317
  connection_remove(conn);
318
319
320
  if(conn->type == CONN_TYPE_EXIT) {
    assert_connection_edge_not_dns_pending(conn);
  }
321
322
323
324
325
  connection_free(conn);
  if(i<nfds) { /* we just replaced the one at i with a new one.
                  process it too. */
    conn_close_if_marked(i);
  }
Roger Dingledine's avatar
Roger Dingledine committed
326
327
}

328
/* This function is called whenever we successfully pull down a directory */
329
330
void directory_has_arrived(void) {

331
  log_fn(LOG_INFO, "A directory has arrived.");
332

333
  /* just for testing */
Roger Dingledine's avatar
tabs    
Roger Dingledine committed
334
335
//  directory_initiate_command(router_pick_directory_server(),
//                             DIR_PURPOSE_FETCH_RENDDESC, "foo", 3);
336

337
338
339
340
341
  has_fetched_directory=1;

  if(options.ORPort) { /* connect to them all */
    router_retry_connections();
  }
342
343
}

Roger Dingledine's avatar
Roger Dingledine committed
344
/* Perform regular maintenance tasks for a single connection.  This
Nick Mathewson's avatar
Nick Mathewson committed
345
346
347
348
349
 * function gets run once per second per connection by run_housekeeping.
 */
static void run_connection_housekeeping(int i, time_t now) {
  cell_t cell;
  connection_t *conn = connection_array[i];
Roger Dingledine's avatar
Roger Dingledine committed
350

351
  /* Expire any directory connections that haven't sent anything for 5 min */
352
  if(conn->type == CONN_TYPE_DIR &&
353
     !conn->marked_for_close &&
354
355
     conn->timestamp_lastwritten + 5*60 < now) {
    log_fn(LOG_WARN,"Expiring wedged directory conn (purpose %d)", conn->purpose);
356
    connection_mark_for_close(conn,0);
357
    /* XXXX Does this next part make sense, really? */
358
    conn->hold_open_until_flushed = 1; /* give it a last chance */
359
360
361
    return;
  }

Nick Mathewson's avatar
Nick Mathewson committed
362
363
364
365
  /* check connections to see whether we should send a keepalive, expire, or wait */
  if(!connection_speaks_cells(conn))
    return;

366
367
  /* If we haven't written to an OR connection for a while, then either nuke
     the connection or send a keepalive, depending. */
Nick Mathewson's avatar
Nick Mathewson committed
368
  if(now >= conn->timestamp_lastwritten + options.KeepalivePeriod) {
369
    if((!options.ORPort && !circuit_get_by_conn(conn)) ||
Nick Mathewson's avatar
Nick Mathewson committed
370
371
372
373
       (!connection_state_is_open(conn))) {
      /* we're an onion proxy, with no circuits; or our handshake has expired. kill it. */
      log_fn(LOG_INFO,"Expiring connection to %d (%s:%d).",
             i,conn->address, conn->port);
374
      /* flush anything waiting, e.g. a destroy for a just-expired circ */
375
      connection_mark_for_close(conn,CLOSE_REASON_UNUSED_OR_CONN);
376
      conn->hold_open_until_flushed = 1;
Nick Mathewson's avatar
Nick Mathewson committed
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
    } else {
      /* either a full router, or we've got a circuit. send a padding cell. */
      log_fn(LOG_DEBUG,"Sending keepalive to (%s:%d)",
             conn->address, conn->port);
      memset(&cell,0,sizeof(cell_t));
      cell.command = CELL_PADDING;
      connection_or_write_cell_to_buf(&cell, conn);
    }
  }
}

/* Perform regular maintenance tasks.  This function gets run once per
 * second by prepare_for_poll.
 */
static void run_scheduled_events(time_t now) {
392
  static long time_to_fetch_directory = 0;
393
  static time_t last_uploaded_services = 0;
394
  static time_t last_rotated_certificate = 0;
Nick Mathewson's avatar
Nick Mathewson committed
395
  int i;
396

397
398
399
400
401
402

  /* 1a. Every MIN_ONION_KEY_LIFETIME seconds, rotate the onion keys,
   *  shut down and restart all cpuworkers, and update the directory if
   *  necessary.
   */
  if (options.ORPort && get_onion_key_set_at()+MIN_ONION_KEY_LIFETIME < now) {
403
    log_fn(LOG_INFO,"Rotating onion key.");
404
405
406
407
408
409
410
411
    rotate_onion_key();
    cpuworkers_rotate();
    if (router_rebuild_descriptor()<0) {
      log_fn(LOG_WARN, "Couldn't rebuild router descriptor");
    }
    router_upload_dir_desc_to_dirservers();
  }

Roger Dingledine's avatar
Roger Dingledine committed
412
  /* 1b. Every MAX_SSL_KEY_LIFETIME seconds, we change our TLS context. */
413
414
415
  if (!last_rotated_certificate)
    last_rotated_certificate = now;
  if (options.ORPort && last_rotated_certificate+MAX_SSL_KEY_LIFETIME < now) {
416
    log_fn(LOG_INFO,"Rotating tls context.");
417
418
419
420
421
422
423
424
425
426
    if (tor_tls_context_new(get_identity_key(), 1, options.Nickname,
                            MAX_SSL_KEY_LIFETIME) < 0) {
      log_fn(LOG_WARN, "Error reinitializing TLS context");
    }
    last_rotated_certificate = now;
    /* XXXX We should rotate TLS connections as well; this code doesn't change
     * XXXX them at all. */
  }

  /* 1c. Every DirFetchPostPeriod seconds, we get a new directory and upload
Nick Mathewson's avatar
Nick Mathewson committed
427
428
429
   *    our descriptor (if any). */
  if(time_to_fetch_directory < now) {
    /* it's time to fetch a new directory and/or post our descriptor */
430
    if(options.ORPort) {
Nick Mathewson's avatar
Nick Mathewson committed
431
      router_rebuild_descriptor();
432
      router_upload_dir_desc_to_dirservers();
Nick Mathewson's avatar
Nick Mathewson committed
433
434
435
436
437
    }
    if(!options.DirPort) {
      /* NOTE directory servers do not currently fetch directories.
       * Hope this doesn't bite us later. */
      directory_initiate_command(router_pick_directory_server(),
438
                                 DIR_PURPOSE_FETCH_DIR, NULL, 0);
439
440
441
    } else {
      /* We're a directory; dump any old descriptors. */
      dirserv_remove_old_servers();
Nick Mathewson's avatar
Nick Mathewson committed
442
    }
443
444
    /* Force an upload of our descriptors every DirFetchPostPeriod seconds. */
    rend_services_upload(1);
445
    last_uploaded_services = now;
Nick Mathewson's avatar
Nick Mathewson committed
446
    rend_cache_clean(); /* should this go elsewhere? */
Nick Mathewson's avatar
Nick Mathewson committed
447
448
    time_to_fetch_directory = now + options.DirFetchPostPeriod;
  }
449

450

451
  /* 2. Every second, we examine pending circuits and prune the
452
   *    ones which have been pending for more than a few seconds.
453
454
455
   *    We do this before step 3, so it can try building more if
   *    it's not comfortable with the number of available circuits.
   */
456
  circuit_expire_building(now);
457

458
459
460
461
462
463
464
  /* 2b. Also look at pending streams and prune the ones that 'began'
   *     a long time ago but haven't gotten a 'connected' yet.
   *     Do this before step 3, so we can put them back into pending
   *     state to be picked up by the new circuit.
   */
  connection_ap_expire_beginning();

465

466
  /* 2c. And expire connections that we've held open for too long.
467
468
469
   */
  connection_expire_held_open();

470
  /* 3. Every second, we try a new circuit if there are no valid
471
472
473
   *    circuits. Every NewCircuitPeriod seconds, we expire circuits
   *    that became dirty more than NewCircuitPeriod seconds ago,
   *    and we make a new circ if there are no clean circuits.
Nick Mathewson's avatar
Nick Mathewson committed
474
   */
475
  if(has_fetched_directory)
476
    circuit_build_needed_circs(now);
477

478
  /* 4. We do housekeeping for each connection... */
Nick Mathewson's avatar
Nick Mathewson committed
479
480
481
  for(i=0;i<nfds;i++) {
    run_connection_housekeeping(i, now);
  }
482

483
  /* 5. And remove any marked circuits... */
484
485
  circuit_close_all_marked();

486
487
  /* 6. And upload service descriptors for any services whose intro points
   *    have changed in the last second. */
488
489
490
491
  if (last_uploaded_services < now-5) {
    rend_services_upload(0);
    last_uploaded_services = now;
  }
492

493
494
495
  /* 6. and blow away any connections that need to die. have to do this now,
   * because if we marked a conn for close and left its socket -1, then
   * we'll pass it to poll/select and bad things will happen.
Nick Mathewson's avatar
Nick Mathewson committed
496
497
498
499
   */
  for(i=0;i<nfds;i++)
    conn_close_if_marked(i);
}
500

501
502
503
504
/* Called every time we're about to call tor_poll.  Increments statistics,
 * and adjusts token buckets.  Returns the number of milliseconds to use for
 * the poll() timeout.
 */
Nick Mathewson's avatar
Nick Mathewson committed
505
506
507
508
509
static int prepare_for_poll(void) {
  static long current_second = 0; /* from previous calls to gettimeofday */
  connection_t *conn;
  struct timeval now;
  int i;
510

Nick Mathewson's avatar
Nick Mathewson committed
511
  tor_gettimeofday(&now);
512

513
514
  /* Check how much bandwidth we've consumed, and increment the token
   * buckets. */
515
516
517
518
  stats_n_bytes_read += stats_prev_global_read_bucket-global_read_bucket;
  connection_bucket_refill(&now);
  stats_prev_global_read_bucket = global_read_bucket;

Nick Mathewson's avatar
Nick Mathewson committed
519
  if(now.tv_sec > current_second) { /* the second has rolled over. check more stuff. */
520

Nick Mathewson's avatar
Nick Mathewson committed
521
    ++stats_n_seconds_reading;
522
    assert_all_pending_dns_resolves_ok();
Nick Mathewson's avatar
Nick Mathewson committed
523
    run_scheduled_events(now.tv_sec);
524
    assert_all_pending_dns_resolves_ok();
525

526
    current_second = now.tv_sec; /* remember which second it is, for next time */
527
528
  }

529
530
  for(i=0;i<nfds;i++) {
    conn = connection_array[i];
531
532
    if(connection_has_pending_tls_data(conn) &&
       connection_is_reading(conn)) {
533
534
535
536
537
538
      log_fn(LOG_DEBUG,"sock %d has pending bytes.",conn->s);
      return 0; /* has pending bytes to read; don't let poll wait. */
    }
  }

  return (1000 - (now.tv_usec / 1000)); /* how many milliseconds til the next second? */
539
540
}

541
542
543
/* Configure the Tor process from the command line arguments and from the
 * configuration file.
 */
544
static int init_from_config(int argc, char **argv) {
545
  /* read the configuration file. */
546
547
548
549
550
  if(getconfig(argc,argv,&options)) {
    log_fn(LOG_ERR,"Reading config failed. For usage, try -h.");
    return -1;
  }
  close_logs(); /* we'll close, then open with correct loglevel if necessary */
551

552
  /* Setuid/setgid as appropriate */
553
554
555
556
557
558
  if(options.User || options.Group) {
    if(switch_id(options.User, options.Group) != 0) {
      return -1;
    }
  }

559
  /* Start backgrounding the process, if requested. */
560
561
562
563
  if (options.RunAsDaemon) {
    start_daemon(options.DataDirectory);
  }

564
  /* Configure the log(s) */
565
566
  if(!options.LogFile && !options.RunAsDaemon)
    add_stream_log(options.loglevel, "<stdout>", stdout);
567
  if(options.LogFile) {
568
569
570
571
572
    if (add_file_log(options.loglevel, options.LogFile) != 0) {
      /* opening the log file failed!  Use stderr and log a warning */
      add_stream_log(options.loglevel, "<stderr>", stderr);
      log_fn(LOG_WARN, "Cannot write to LogFile '%s': %s.", options.LogFile, strerror(errno));
    }
573
    log_fn(LOG_NOTICE, "Successfully opened LogFile '%s', redirecting output.",
574
575
576
           options.LogFile);
  }
  if(options.DebugLogFile) {
577
    if (add_file_log(LOG_DEBUG, options.DebugLogFile) != 0)
578
579
580
      log_fn(LOG_WARN, "Cannot write to DebugLogFile '%s': %s.", options.DebugLogFile, strerror(errno));
    log_fn(LOG_DEBUG, "Successfully opened DebugLogFile '%s'.", options.DebugLogFile);
  }
581

582
  /* Set up our buckets */
583
  connection_bucket_init();
584
585
  stats_prev_global_read_bucket = global_read_bucket;

586
  /* Finish backgrounding the process */
587
588
589
  if(options.RunAsDaemon) {
    /* XXXX Can we delay this any more? */
    finish_daemon();
590
591
  }

592
593
  /* Write our pid to the pid file. if we do not have write permissions we
   * will log a warning */
594
595
  if(options.PidFile)
    write_pidfile(options.PidFile);
596

597
598
599
  return 0;
}

600
601
/* Called when we get a SIGHUP: reload configuration files and keys,
 * retry all connections, re-upload all descriptors, and so on. */
602
603
604
static int do_hup(void) {
  char keydir[512];

605
  log_fn(LOG_NOTICE,"Received sighup. Reloading config.");
606
  has_completed_circuit=0;
607
608
609
610
611
  /* first, reload config variables, in case they've changed */
  /* no need to provide argc/v, they've been cached inside init_from_config */
  if (init_from_config(0, NULL) < 0) {
    exit(1);
  }
612
  /* reload keys as needed for rendezvous services. */
613
  if (rend_service_load_keys()<0) {
614
615
616
    log_fn(LOG_ERR,"Error reloading rendezvous service keys");
    exit(1);
  }
617
618
619
620
621
622
623
624
625
626
627
  if(retry_all_connections() < 0) {
    log_fn(LOG_ERR,"Failed to bind one of the listener ports.");
    return -1;
  }
  if(options.DirPort) {
    /* reload the approved-routers file */
    sprintf(keydir,"%s/approved-routers", options.DataDirectory);
    log_fn(LOG_INFO,"Reloading approved fingerprints from %s...",keydir);
    if(dirserv_parse_fingerprint_file(keydir) < 0) {
      log_fn(LOG_WARN, "Error reloading fingerprints. Continuing with old list.");
    }
628
629
    /* Since we aren't fetching a directory, we won't retry rendezvous points
     * when it gets in.  Try again now. */
630
    rend_services_introduce();
631
632
  } else {
    /* fetch a new directory */
Roger Dingledine's avatar
Roger Dingledine committed
633
    directory_initiate_command(router_pick_directory_server(),
634
                               DIR_PURPOSE_FETCH_DIR, NULL, 0);
635
636
637
638
639
640
641
642
643
644
645
646
  }
  if(options.ORPort) {
    router_rebuild_descriptor();
    sprintf(keydir,"%s/router.desc", options.DataDirectory);
    log_fn(LOG_INFO,"Dumping descriptor to %s...",keydir);
    if (write_str_to_file(keydir, router_get_my_descriptor())) {
      return -1;
    }
  }
  return 0;
}

647
/* Tor main loop. */
648
649
650
651
static int do_main_loop(void) {
  int i;
  int timeout;
  int poll_result;
Roger Dingledine's avatar
Roger Dingledine committed
652

653
654
  /* Initialize the history structures. */
  rep_hist_init();
655
  /* Intialize the service cache. */
Nick Mathewson's avatar
Nick Mathewson committed
656
  rend_cache_init();
657

658
659
  /* load the private keys, if we're supposed to have them, and set up the
   * TLS context. */
660
  if (init_keys() < 0 || rend_service_load_keys() < 0) {
661
662
663
664
    log_fn(LOG_ERR,"Error initializing keys; exiting");
    return -1;
  }

665
666
667
668
669
670
671
  /* load the routers file */
  if(options.RouterFile &&
     router_set_routerlist_from_file(options.RouterFile) < 0) {
    log_fn(LOG_ERR,"Error loading router list.");
    return -1;
  }

672
673
674
675
676
  if(options.DirPort) { /* the directory is already here, run startup things */
    has_fetched_directory = 1;
    directory_has_arrived();
  }

677
  if(options.ORPort) {
678
    cpu_init(); /* launch cpuworkers. Need to do this *after* we've read the onion key. */
Roger Dingledine's avatar
Roger Dingledine committed
679
  }
Roger Dingledine's avatar
Roger Dingledine committed
680

681
682
  /* start up the necessary connections based on which ports are
   * non-zero. This is where we try to connect to all the other ORs,
683
   * and start the listeners.
684
   */
685
686
687
688
  if(retry_all_connections() < 0) {
    log_fn(LOG_ERR,"Failed to bind one of the listener ports.");
    return -1;
  }
Roger Dingledine's avatar
Roger Dingledine committed
689
690

  for(;;) {
691
#ifndef MS_WINDOWS /* do signal stuff only on unix */
692
    if(please_dumpstats) {
693
694
      /* prefer to log it at INFO, but make sure we always see it */
      dumpstats(options.loglevel>LOG_INFO ? options.loglevel : LOG_INFO);
695
696
      please_dumpstats = 0;
    }
697
    if(please_reset) {
698
      do_hup();
699
      please_reset = 0;
700
    }
Roger Dingledine's avatar
Roger Dingledine committed
701
702
703
704
    if(please_reap_children) {
      while(waitpid(-1,NULL,WNOHANG)) ; /* keep reaping until no more zombies */
      please_reap_children = 0;
    }
705
#endif /* signal stuff */
706

707
708
709
    timeout = prepare_for_poll();

    /* poll until we have an event, or the second ends */
710
    poll_result = tor_poll(poll_array, nfds, timeout);
711

712
    /* let catch() handle things like ^c, and otherwise don't worry about it */
713
    if(poll_result < 0) {
714
715
716
      /* let the program survive things like ^z */
      if(tor_socket_errno(-1) != EINTR) {
        log_fn(LOG_ERR,"poll failed: %s [%d]",
717
718
               tor_socket_strerror(tor_socket_errno(-1)),
               tor_socket_errno(-1));
719
        return -1;
720
      } else {
Nick Mathewson's avatar
Nick Mathewson committed
721
        log_fn(LOG_DEBUG,"poll interrupted.");
722
      }
723
    }
Roger Dingledine's avatar
Roger Dingledine committed
724

725
726
    /* do all the reads and errors first, so we can detect closed sockets */
    for(i=0;i<nfds;i++)
727
      conn_read(i); /* this also marks broken connections */
Roger Dingledine's avatar
Roger Dingledine committed
728

729
730
731
732
733
734
    /* then do the writes */
    for(i=0;i<nfds;i++)
      conn_write(i);

    /* any of the conns need to be closed now? */
    for(i=0;i<nfds;i++)
Roger Dingledine's avatar
Roger Dingledine committed
735
      conn_close_if_marked(i);
Roger Dingledine's avatar
Roger Dingledine committed
736

737
738
739
    /* refilling buckets and sending cells happens at the beginning of the
     * next iteration of the loop, inside prepare_for_poll()
     */
Roger Dingledine's avatar
Roger Dingledine committed
740
741
742
  }
}

743
/* Unix signal handler. */
744
static void catch(int the_signal) {
Roger Dingledine's avatar
Roger Dingledine committed
745

746
#ifndef MS_WINDOWS /* do signal stuff only on unix */
747
  switch(the_signal) {
748
//    case SIGABRT:
749
750
    case SIGTERM:
    case SIGINT:
751
      log(LOG_ERR,"Catching signal %d, exiting cleanly.", the_signal);
752
753
      /* we don't care if there was an error when we unlink, nothing
         we could do about it anyways */
754
755
      if(options.PidFile)
        unlink(options.PidFile);
756
      exit(0);
757
758
759
    case SIGPIPE:
      log(LOG_WARN,"Bug: caught sigpipe. Ignoring.");
      break;
760
    case SIGHUP:
761
      please_reset = 1;
762
763
764
765
      break;
    case SIGUSR1:
      please_dumpstats = 1;
      break;
Roger Dingledine's avatar
Roger Dingledine committed
766
767
    case SIGCHLD:
      please_reap_children = 1;
Roger Dingledine's avatar
Roger Dingledine committed
768
      break;
769
    default:
Roger Dingledine's avatar
Roger Dingledine committed
770
      log(LOG_WARN,"Caught signal %d that we can't handle??", the_signal);
771
  }
772
#endif /* signal stuff */
773
774
}

775
static void dumpstats(int severity) {
776
777
  int i;
  connection_t *conn;
778
  time_t now = time(NULL);
779

780
  log(severity, "Dumping stats:");
781
782
783

  for(i=0;i<nfds;i++) {
    conn = connection_array[i];
Roger Dingledine's avatar
Roger Dingledine committed
784
    log(severity, "Conn %d (socket %d) type %d (%s), state %d (%s), created %d secs ago",
785
      i, conn->s, conn->type, CONN_TYPE_TO_STRING(conn->type),
Roger Dingledine's avatar
Roger Dingledine committed
786
      conn->state, conn_state_to_string[conn->type][conn->state], (int)(now - conn->timestamp_created));
787
    if(!connection_is_listener(conn)) {
788
      log(severity,"Conn %d is to '%s:%d'.",i,conn->address, conn->port);
Roger Dingledine's avatar
Roger Dingledine committed
789
      log(severity,"Conn %d: %d bytes waiting on inbuf (last read %d secs ago)",i,
790
             (int)buf_datalen(conn->inbuf),
Roger Dingledine's avatar
Roger Dingledine committed
791
792
793
             (int)(now - conn->timestamp_lastread));
      log(severity,"Conn %d: %d bytes waiting on outbuf (last written %d secs ago)",i,
             (int)buf_datalen(conn->outbuf), (int)(now - conn->timestamp_lastwritten));
794
    }
795
    circuit_dump_by_conn(conn, severity); /* dump info about all the circuits using this conn */
796
  }
797
798
  log(severity,
         "Cells processed: %10lu padding\n"
799
800
801
802
803
         "                 %10lu create\n"
         "                 %10lu created\n"
         "                 %10lu relay\n"
         "                        (%10lu relayed)\n"
         "                        (%10lu delivered)\n"
804
         "                 %10lu destroy",
805
806
807
808
809
810
811
812
         stats_n_padding_cells_processed,
         stats_n_create_cells_processed,
         stats_n_created_cells_processed,
         stats_n_relay_cells_processed,
         stats_n_relay_cells_relayed,
         stats_n_relay_cells_delivered,
         stats_n_destroy_cells_processed);
  if (stats_n_data_cells_packaged)
813
    log(severity,"Average packaged cell fullness: %2.3f%%",
Roger Dingledine's avatar
Roger Dingledine committed
814
           100*(((double)stats_n_data_bytes_packaged) /
815
                (stats_n_data_cells_packaged*RELAY_PAYLOAD_SIZE)) );
816
  if (stats_n_data_cells_received)
817
    log(severity,"Average delivered cell fullness: %2.3f%%",
Roger Dingledine's avatar
Roger Dingledine committed
818
           100*(((double)stats_n_data_bytes_received) /
819
                (stats_n_data_cells_received*RELAY_PAYLOAD_SIZE)) );
Roger Dingledine's avatar
Roger Dingledine committed
820

821
  if (stats_n_seconds_reading)
822
    log(severity,"Average bandwidth used: %d bytes/sec",
823
           (int) (stats_n_bytes_read/stats_n_seconds_reading));
824
825

  rep_hist_dump_stats(now,severity);
826
  rend_service_dump_stats(severity);
827
828
}

829
830
831
832
833
834
835
836
837
int network_init(void)
{
#ifdef MS_WINDOWS
  /* This silly exercise is necessary before windows will allow gethostbyname to work.
   */
  WSADATA WSAData;
  int r;
  r = WSAStartup(0x101,&WSAData);
  if (r) {
Roger Dingledine's avatar
Roger Dingledine committed
838
839
    log_fn(LOG_WARN,"Error initializing windows network layer: code was %d",r);
    return -1;
840
841
842
843
844
845
846
847
848
849
850
851
852
  }
  /* XXXX We should call WSACleanup on exit, I think. */
#endif
  return 0;
}

void exit_function(void)
{
#ifdef MS_WINDOWS
  WSACleanup();
#endif
}

853
int tor_main(int argc, char *argv[]) {
Roger Dingledine's avatar
Roger Dingledine committed
854

855
856
  /* give it somewhere to log to initially */
  add_stream_log(LOG_INFO, "<stdout>", stdout);
857
  log_fn(LOG_NOTICE,"Tor v%s. This is experimental software. Do not use it if you need anonymity.",VERSION);
858

859
  if (network_init()<0) {
Roger Dingledine's avatar
Roger Dingledine committed
860
861
    log_fn(LOG_ERR,"Error initializing network; exiting.");
    return 1;
862
863
864
  }
  atexit(exit_function);

865
866
867
  if (init_from_config(argc,argv) < 0)
    return -1;

868
869
870
871
#ifndef MS_WINDOWS
  if(geteuid()==0)
    log_fn(LOG_WARN,"You are running Tor as root. You don't need to, and you probably shouldn't.");
#endif
872

873
  if(options.ORPort) { /* only spawn dns handlers if we're a router */
874
    dns_init(); /* initialize the dns resolve tree, and spawn workers */
875
  }
Roger Dingledine's avatar
Roger Dingledine committed
876
877
878
  if(options.SocksPort) {
    client_dns_init(); /* init the client dns cache */
  }
879

880
#ifndef MS_WINDOWS /* do signal stuff only on unix */
881
882
883
884
885
886
887
888
889
890
891
892
893
{
  struct sigaction action;
  action.sa_flags = 0;
  sigemptyset(&action.sa_mask);

  action.sa_handler = catch;
  sigaction(SIGINT,  &action, NULL);
  sigaction(SIGTERM, &action, NULL);
  sigaction(SIGPIPE, &action, NULL);
  sigaction(SIGUSR1, &action, NULL);
  sigaction(SIGHUP,  &action, NULL); /* to reload config, retry conns, etc */
  sigaction(SIGCHLD, &action, NULL); /* handle dns/cpu workers that exit */
}
894
#endif /* signal stuff */
895
896

  crypto_global_init();
Nick Mathewson's avatar
Nick Mathewson committed
897
  crypto_seed_rng();
898
  do_main_loop();
899
  crypto_global_cleanup();
900
  return -1;
Roger Dingledine's avatar
Roger Dingledine committed
901
902
}

903
904
905
906
907
908
909
/*
  Local Variables:
  mode:c
  indent-tabs-mode:nil
  c-basic-offset:2
  End:
*/