connections.c 26.6 KB
Newer Older
Linus Tolke's avatar
Linus Tolke committed
1
/*
Per Cederqvist's avatar
Per Cederqvist committed
2
 * $Id: connections.c,v 0.118 2003/08/06 22:30:35 ceder Exp $
Per Cederqvist's avatar
Per Cederqvist committed
3
 * Copyright (C) 1991-2002  Lysator Academic Computer Association.
Linus Tolke's avatar
Linus Tolke committed
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
 *
 * This file is part of the LysKOM server.
 * 
 * LysKOM is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by 
 * the Free Software Foundation; either version 1, or (at your option) 
 * any later version.
 * 
 * LysKOM is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with LysKOM; see the file COPYING.  If not, write to
 * Lysator, c/o ISY, Linkoping University, S-581 83 Linkoping, SWEDEN,
 * or the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, 
 * MA 02139, USA.
 *
 * Please mail bug reports to bug-lyskom@lysator.liu.se. 
 */
Per Cederqvist's avatar
Per Cederqvist committed
25
26
27
28
29
30
31
32
/*
 * connections.c
 *
 * Denna fil inneh}ller niv}n ovanf|r isc.
 *
 * Created by Willf|r 31/3-90. Mostly written by ceder.
 */

David Byers's avatar
David Byers committed
33
34
35
36
37

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

Per Cederqvist's avatar
Per Cederqvist committed
38
#include <errno.h>
Per Cederqvist's avatar
Per Cederqvist committed
39
#include <stdio.h>
Per Cederqvist's avatar
Per Cederqvist committed
40
#include <setjmp.h>
Per Cederqvist's avatar
Per Cederqvist committed
41
42
43
#ifdef HAVE_STRING_H
#  include <string.h>
#endif
Per Cederqvist's avatar
Per Cederqvist committed
44
#include <sys/types.h>
Per Cederqvist's avatar
Per Cederqvist committed
45
#include <sys/stat.h>
46
#include "timewrap.h"
47
#include <sys/socket.h>
48
#include <signal.h>
49
#include <assert.h>
50
#include <netdb.h>
Per Cederqvist's avatar
Per Cederqvist committed
51
#include <stdlib.h>
Per Cederqvist's avatar
Per Cederqvist committed
52

53
#include "adns.h"
54
55
56
#include "oop.h"

#include "unused.h"
57
#include "ldifftime.h"
Per Cederqvist's avatar
Per Cederqvist committed
58
#include "misc-types.h"
59
#include "s-string.h"
Per Cederqvist's avatar
Per Cederqvist committed
60
#include "kom-types.h"
61
#include "kom-memory.h"
Per Cederqvist's avatar
Per Cederqvist committed
62
#include "debug.h"
63
#include "isc-interface.h"
Per Cederqvist's avatar
Per Cederqvist committed
64
#include "com.h"
65
#include "async.h"
Per Cederqvist's avatar
Per Cederqvist committed
66
#include "connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
67
#include "internal-connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
68
#include "prot-a-parse-arg.h"
Per Cederqvist's avatar
Per Cederqvist committed
69
70
71
72
73
#include "log.h"
#include "lyskomd.h"
#include "services.h"
#include "isc-parse.h"
#include "prot-a.h"
74
#include "prot-a-parse.h"
Per Cederqvist's avatar
Per Cederqvist committed
75
76
77
78
#include "server/smalloc.h"
#include "end-of-atomic.h"
#include "send-async.h"
#include "cache.h"
79
#include "rfc931.h"
80
#include "param.h"
David Byers's avatar
David Byers committed
81
#include "kom-config.h"
82
#include "kom-errno.h"
Per Cederqvist's avatar
Per Cederqvist committed
83
#include "sigflags.h"
Per Cederqvist's avatar
Per Cederqvist committed
84
#include "server-time.h"
85
#include "aux-items.h"
86
#include "eintr.h"
87
#include "text-garb.h"
88
#include "timeval-util.h"
89
#include "stats.h"
90
#include "string-malloc.h"
Per Cederqvist's avatar
Per Cederqvist committed
91

92
93
oop_source_sys * kom_server_oop_src = NULL;
struct isc_mcb * kom_server_mcb    = NULL;
Per Cederqvist's avatar
Per Cederqvist committed
94
95
Connection     * active_connection = NULL;

Per Cederqvist's avatar
Per Cederqvist committed
96
97
98
99
100
101
/*
 * This is set TRUE when the server should be closed. It is checked
 * each time around the main loop. It is set if someone with enough
 * privileges issues a `shutdown', or of lyskomd receives a SIGHUP.
 * This not an abort: all data is saved before we exit.
 */
102
Bool go_and_die = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
103
104

/*
105
106
107
108
109
110
111
112
113
 * The number of times that the session penalties has been averaged.
 * Beware: this number will wrap around.
 */
static unsigned int penalty_generation = 0;

/*
 * These state variables are used to find out if we are busy or not.
 * When a packet arrives, data_available_callback() will set work_done
 * to TRUE and is_idle to FALSE.
Per Cederqvist's avatar
Per Cederqvist committed
114
 */
115
116
static Bool work_done = FALSE;
static Bool is_idle = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
117
118
119
120
121
122
123
124

jmp_buf 	 parse_env;


const Fnc_descriptor fnc_defs[]={
#include "fnc-def-init.incl"
};

125
const int num_fnc_defs = sizeof (fnc_defs) / sizeof (Fnc_descriptor);
126

Per Cederqvist's avatar
Per Cederqvist committed
127
unsigned long service_statistics[sizeof (fnc_defs) / sizeof (Fnc_descriptor)];
Per Cederqvist's avatar
Per Cederqvist committed
128
129
130

BUGDECL;

131
132
133
static oop_call_fd data_available_callback;
static oop_call_time check_kill_flg;
static oop_call_time check_idle_callback;
134
135
136
static isc_write_error_cb write_err_cb;
static isc_stale_output_cb stale_cb;
static isc_stale_output_cb idle_cb;
137
138
139
140

static Connection *queue_first = NULL;
static Connection *queue_last = NULL;

141
142
143
static void busy(void);


144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
static void
queue_add(Connection *c)
{
    assert(c->on_queue == FALSE);
    c->on_queue = TRUE;

    c->queue_prev = queue_last;
    c->queue_next = NULL;

    if (queue_first == NULL)
	queue_first = c;
    else
	queue_last->queue_next = c;

    queue_last = c;
159
    update_stat(STAT_RUN_QUEUE, 1);
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
}

static void
queue_remove(Connection *c)
{
    assert(c->on_queue == TRUE);
    c->on_queue = FALSE;

    if (c->queue_next != NULL)
	c->queue_next->queue_prev = c->queue_prev;
    else
	queue_last = c->queue_prev;
    
    if (c->queue_prev != NULL)
	c->queue_prev->queue_next = c->queue_next;
    else
176
	queue_first = c->queue_next;
Per Cederqvist's avatar
Per Cederqvist committed
177

178
179
    c->queue_prev = NULL;
    c->queue_next = NULL;
180
    update_stat(STAT_RUN_QUEUE, -1);
181
182
}

Per Cederqvist's avatar
Per Cederqvist committed
183
void
184
185
set_time(void)
{
186
187
    struct timeval last_time;
    static int limiter = 0;
188
189

    last_time = current_time;
190
191
192
193
194
195
196
197
198
199
200
    if (gettimeofday(&current_time, NULL) < 0)
    {
	if (limiter < 50)
	{
	    kom_log("WARNING: gettimeofday failed: %s\n", strerror(errno));
	    if (++limiter == 50)
		kom_log("WARNING: will not log the above message again.\n");
	}
    }

    if (timeval_less(current_time, last_time))
201
202
203
204
205
    {
	kom_log("WARNING: Time is moving in the wrong direction.\n");
	/* FIXME (bug 62): Should we take more decisive action here? */
    }
}
Per Cederqvist's avatar
Per Cederqvist committed
206

Per Cederqvist's avatar
Per Cederqvist committed
207
static void
Per Cederqvist's avatar
Per Cederqvist committed
208
209
210
logout_client(Connection *cp)
{
    Connection *real_active_connection;
211
    int ret;
Per Cederqvist's avatar
Per Cederqvist committed
212
213
214

    if ( active_connection != NULL )
    {
David Byers's avatar
David Byers committed
215
	kom_log("BUGCHK: logout_client(%ld): connection %ld is active.\n",
Per Cederqvist's avatar
Per Cederqvist committed
216
217
218
219
220
	    cp->session_no, active_connection->session_no);
    }
    
    if ( cp->pers_no != 0 )
    {
221
222
223
224
225
226
227
228
229
230
231
232
	int ctr = 0;

	if (active_connection != NULL)
	{
	    kom_log("WNG: logout_client(): active_connection != NULL\n");
	    if (ctr < 100)
		ctr++;
	    else
		kom_log("WNG: won't log the above message more\n");
	}

	real_active_connection = active_connection;
Per Cederqvist's avatar
Per Cederqvist committed
233
234
235
236
	active_connection = cp;
	logout();
	active_connection = real_active_connection;
    }
237
238
    else
    {
239
#if 0
240
	/* FIXME (bug 908): send a new async here instead.  This causes the
241
242
	   elisp client to say that a secret (or unknown) person has
	   left the system.  */
243
        async_logout( 0, cp->session_no );
244
#endif
245
    }
Per Cederqvist's avatar
Per Cederqvist committed
246
247
248
249
250
251
252
253
254
255
256
257
258
259

    switch(cp->protocol)
    {
    case 0:			/* Hasn't yet allocated any protocol. */
	break;
	
    case 'A':
	prot_a_destruct(cp);
	break;
	
    default:
	restart_kom("logout_client(): Bad protocol.\n");
    }

260
261
    ret = isc_destroy(kom_server_mcb, cp->isc_session);
    if (ret < 0)
David Byers's avatar
David Byers committed
262
	kom_log("logout_client(): isc_destroyed returned %d\n", ret);
263
    cp->isc_session = NULL;
264
265
    if (cp->on_queue)
	queue_remove(cp);
Per Cederqvist's avatar
Per Cederqvist committed
266
267

    kill_client(cp);		/* Free the Connection */
268
    update_stat(STAT_CLIENTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
269
270
}

Per Cederqvist's avatar
Per Cederqvist committed
271
272
273
274
275
276
277
278
279
280
281
282
283
284
/*
 * This function is part of the shutdown tidy-up sequence.
 */
void
logout_all_clients(void)
{
    Session_no sess = 0;
    Connection *conn;
    
    while ( (sess = traverse_connections (sess)) != 0)
    {
	conn = get_conn_by_number (sess);

	if ( conn == NULL )
285
	    restart_kom("logout_all_clients(): cant get session %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
286
287
288
289
290
291
			sess);
	else
	    logout_client (conn);
    }

    if ( traverse_connections (0) != 0)
292
	restart_kom("logout_all_clients(): traverse_connections(0) == %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
293
294
295
296
		    traverse_connections(0));
}

    
Per Cederqvist's avatar
Per Cederqvist committed
297
298
299
300
301
302
303
304
    

    
/*
 * Call a function in services.c. A pointer to the result is returned.
 * The pointer points to static data which is overwritten on each call.
 */
static Success
305
306
call_function(Connection *client,
	      union result_holder *res)
Per Cederqvist's avatar
Per Cederqvist committed
307
308
309
310
311
{
    Success	status=FAILURE;	/* OK if the call was successful. */

    if ( active_connection != NULL )
    {
312
	kom_log("call_function(%ld): active_connection = %ld\n",
Per Cederqvist's avatar
Per Cederqvist committed
313
314
	    client->session_no, active_connection->session_no);
    }
315
316
317

    if (client->function == illegal_fnc) 
    {
318
        err_stat = 0;
319
320
321
322
	kom_errno = KOM_NOT_IMPL;
	return FAILURE;
    }

Per Cederqvist's avatar
Per Cederqvist committed
323
324
    active_connection = client;

325
    service_statistics[client->function_index]++;
Per Cederqvist's avatar
Per Cederqvist committed
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348

#include "call-switch.incl"

    active_connection = NULL;

    return status;
}


static void
parse_packet(Connection *client)
{
    if ( client->protocol == '\0' ) /* Not known yet. */
    {
	client->protocol = parse_char(client);
	switch(client->protocol)
	{
	case 'A':
	    prot_a_init(client);
	    break;

	default:
	    client->protocol = '\0';
349
350
	    isc_puts("%%LysKOM unsupported protocol.\n", client->isc_session);
	    isc_flush(client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
351
	    BUG(("%%%%Unsupported protocol.\n"));
352
	    longjmp(parse_env, KOM_LOGOUT);
Per Cederqvist's avatar
Per Cederqvist committed
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
	}
    }

    switch(client->protocol)
    {
    case 'A':
	prot_a_parse_packet(client);
	break;

    default:
	restart_kom("parse_packet(): Bad protocol.\n");
	break;
    }
}

/*
 * Free all parsed areas which are no longer needed. Re-initialize all
 * parse_pos fields so that the parse will expect a new function.
 *
 * This function is called
 *	when a parse error occurs
 *	when a parse is complete and the function has executed.
 */
static void
free_parsed(Connection *client)
{
    s_clear(&client->c_string0);
    s_clear(&client->c_string1);
    client->string0 = EMPTY_STRING; /* So that no one frees it. */
David Byers's avatar
David Byers committed
382
383
384
    sfree(client->misc_info_list.misc);
    client->misc_info_list.misc = 0;
    client->misc_info_list.no_of_misc = 0;
385
    s_clear(&client->aux_item.data);
386
    s_clear(&client->dummy_aux_item.data);
Per Cederqvist's avatar
Per Cederqvist committed
387
388
    sfree( client->c_local_text_no_p);
    client->c_local_text_no_p = NULL;
389
390
391
    sfree(client->read_range_list.ranges);
    client->read_range_list.ranges = NULL;
    client->read_range_list.length = 0;
Per Cederqvist's avatar
Per Cederqvist committed
392
393
    client->parse_pos = 0;
    client->fnc_parse_pos = 0;
394
    client->array_parse_index = 0;
David Byers's avatar
David Byers committed
395
    client->array_parse_parsed_length = 0;
Per Cederqvist's avatar
Per Cederqvist committed
396
397
398
    client->array_parse_pos = 0;
    client->struct_parse_pos = 0;
    client->string_parse_pos = 0;
David Byers's avatar
David Byers committed
399
400
401
    client->hunt_parse_pos = 0;
    client->array_hunt_num = 0;
    client->array_hunt_depth = 0;
402
403
404
    sfree(client->num_list.data);
    client->num_list.data = NULL;
    client->num_list.length = 0;
405
406
    free_aux_item_list(&client->aux_item_list);
    client->info.highest_aux_no = 0;
Per Cederqvist's avatar
Per Cederqvist committed
407
408
409
410
411
412
413
}

/*
 * Send a reply to a call.
 */
static void
reply(Connection *client,
414
415
      Success status,
      union result_holder *result)
Per Cederqvist's avatar
Per Cederqvist committed
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
{
    switch(client->protocol)
    {
    case 'A':
	prot_a_reply(client, status, result);
	break;

    default:
	restart_kom("reply(): Bad protocol.\n");
	break;
    }
}


/*
 * Try to parse enough data from client->unparsed to call a function.
432
433
 * If more data is needed set client->more_to_parse to FALSE.  Returns
 * TRUE if anything was (or might have been) written to the client.
Per Cederqvist's avatar
Per Cederqvist committed
434
 */
435
static Bool
Per Cederqvist's avatar
Per Cederqvist committed
436
437
438
parse_unparsed(Connection *client)
{
    Success       status;
439
    union result_holder result;
Per Cederqvist's avatar
Per Cederqvist committed
440
441
442
443
444
445
        
    switch ( setjmp(parse_env) )
    {
    case 0 :
	/* Parse message. If message is complete call function and reply. */
	parse_packet(client);
446
447
	if (client->blocked_by_dns)
	    return TRUE;
448
	update_stat(STAT_REQUESTS, 1);
Per Cederqvist's avatar
Per Cederqvist committed
449
	status = call_function(client, &result);
450
	update_stat(STAT_REQUESTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
451
	reply(client, status, &result);
452
	client->penalty += param.penalty_per_call;
Per Cederqvist's avatar
Per Cederqvist committed
453
	free_parsed(client);
454
	end_of_atomic();
455
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
456

457
    case KOM_PROTOCOL_ERR:
Per Cederqvist's avatar
Per Cederqvist committed
458
459
	s_clear(&client->string0);
	free_parsed(client);
460
	isc_puts("%% LysKOM protocol error.\n", client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
461
	BUG(("%%%% Protocol error.\n"));
462
	client->penalty += param.max_penalty;
Per Cederqvist's avatar
Per Cederqvist committed
463
464
465
	s_clear(&client->unparsed);
	client->first_to_parse = 0;
	client->more_to_parse = FALSE;
466
	end_of_atomic();
467
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
468

469
    case KOM_MSG_INCOMPLETE:
Per Cederqvist's avatar
Per Cederqvist committed
470
	client->more_to_parse = FALSE;
471
	return FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
472

473
    case KOM_LOGOUT:
474
	add_to_kill_list(client);
475
	client->more_to_parse = FALSE;
476
477
478
	return TRUE;
    default:
	restart_kom("Bad longjmp return value.\n");
Per Cederqvist's avatar
Per Cederqvist committed
479
    }
480
    /*NOTREACHED*/
Per Cederqvist's avatar
Per Cederqvist committed
481
482
483
484
485
}


/* Return 1 if the named file exists, 0 otherwise */
static int
Per Cederqvist's avatar
Per Cederqvist committed
486
fexists(const char *filename)
Per Cederqvist's avatar
Per Cederqvist committed
487
488
489
490
491
492
493
494
495
496
497
498
499
500
{
    struct stat buf;
    int code;
  
    code = !stat(filename, &buf);
    errno = 0;

    return code;
}


void
dump_statistics(void)
{
501
    static struct timeval last_dump = {0, 0};
Per Cederqvist's avatar
Per Cederqvist committed
502
503
504
    int i;
    FILE *fp;

505
    if ((fp = i_fopen(param.statistic_name, "a")) == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
506
    {
507
508
	kom_log("dump_statistics(): can't open file %s\n",
		param.statistic_name);
Per Cederqvist's avatar
Per Cederqvist committed
509
510
511
	return;
    }

512
    if (timeval_zero(last_dump))
Per Cederqvist's avatar
Per Cederqvist committed
513
514
    {
	fprintf(fp, "RESTART\n");
Per Cederqvist's avatar
Per Cederqvist committed
515
	last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
516
517
    }
    
518
519
    fprintf(fp, "TIME: %s", ctime(&current_time.tv_sec));
    fprintf(fp, "SECONDS: %ld\n", timeval_diff_sec(current_time, last_dump));
Per Cederqvist's avatar
Per Cederqvist committed
520
    fprintf(fp, "STATISTICS:");
521
522
523
524
525

    /* The last entry corresponds to the dummy entry that is used to
       skip arguments to unimplemented requests.  Skip that, since it
       contains no useful statistics.  */
    for (i = 0; i < num_fnc_defs - 1; i++)
Per Cederqvist's avatar
Per Cederqvist committed
526
    {
527
	fprintf(fp, " %d:%lu", fnc_defs[i].function, service_statistics[i]);
Per Cederqvist's avatar
Per Cederqvist committed
528
529
530
531
	service_statistics[i]=0;
    }

    fprintf(fp, "\n");
532
    i_fclose(fp);
Per Cederqvist's avatar
Per Cederqvist committed
533

Per Cederqvist's avatar
Per Cederqvist committed
534
    last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
535
536
}

537
538
/* List of connections to kill. */

Per Cederqvist's avatar
Per Cederqvist committed
539
540
static Session_no *kill_list = NULL;
static int kill_list_size = 0;
541
static int kill_pending = 0;
542
543
544
545
546

/* Schedule this client for termination. */
void
add_to_kill_list(Connection *conn)
{
547
    oop_source *source;
Per Cederqvist's avatar
Per Cederqvist committed
548
549
    int i;

550
551
552
553
554
555
556
557
    if (conn->kill_pending)
    {
	for (i = 0; i < kill_list_size; i++)
	    if (kill_list[i] == conn->session_no)
		return;
	restart_kom("add_to_kill_list(): kill_pending set but not on list.\n");
    }

Per Cederqvist's avatar
Per Cederqvist committed
558
    for (i = 0; i < kill_list_size; i++)
559
	if (kill_list[i] == conn->session_no)
560
	    restart_kom("add_to_kill_list(): on list but not kill_pending.\n");
Per Cederqvist's avatar
Per Cederqvist committed
561

562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
    if (kill_list == NULL)
    {
	if (kill_list_size != 0)
	    restart_kom("add_to_kill_list(): size = %d\n", kill_list_size);

	kill_list_size = 1;
	kill_list = smalloc(sizeof(Session_no));
    }
    else
    {
	kill_list_size++;
	kill_list = srealloc(kill_list, kill_list_size * sizeof(Session_no));
    }

    kill_list[kill_list_size-1] = conn->session_no;
577
    conn->kill_pending = TRUE;
578
579
580

    if (!kill_pending)
    {
581
	source = isc_getoopsource(conn->isc_session);
582
583
584
	source->on_time(source, OOP_TIME_NOW, check_kill_flg, NULL);
	kill_pending = 1;
    }
585
}
Per Cederqvist's avatar
Per Cederqvist committed
586

587
588
589
590
591
592
593
594

void
dump_connections(void)
{
    Session_no s;
    Connection *conn;
    FILE *fp;

595
    if ((fp = i_fopen(param.connection_status_file_tmp, "w")) == NULL)
596
    {
597
598
	kom_log("dump_connections(): can't open file %s: %s\n",
		param.connection_status_file_tmp, strerror(errno));
599
600
601
602
603
604
	return;
    }

    for (s = 0; (s = traverse_connections(s)) != 0;)
    {
	conn = get_conn_by_number(s);
605
606
	fprintf(fp, "%d %lu %d %s\n", conn->isc_session->fd, conn->session_no,
		handshake_ok(conn, 0),
607
608
609
		conn->peer);
    }

610
611
612
613
614
615
    if (fflush(fp) != 0)
	kom_log("dump_connections(): fflush() says an error has occured.\n");
	
    if (ferror(fp))
	kom_log("dump_connections(): ferror() says an error has occured.\n");

616
    if (i_fclose(fp) < 0)
617
618
619
620
621
    {
	kom_log("dump_connections(): fclose failed: %s (ignored)\n",
		strerror(errno));
    }

622
    errno = 0;
623
624
    if (i_rename(param.connection_status_file_tmp,
		 param.connection_status_file) < 0)
625
    {
626
	kom_log("dump_connections(): can't rename %s to %s: %s\n",
627
		param.connection_status_file_tmp,
628
629
		param.connection_status_file,
		strerror(errno));
630
631
632
633
    }
}


Per Cederqvist's avatar
Per Cederqvist committed
634
635
636
/*
 * check_kill_flg must NEVER be called inside an atomic call!
 */
637
638
639
640
static void *
check_kill_flg(oop_source *UNUSED(source),
	       struct timeval UNUSED(tv),
	       void *UNUSED(user))
Per Cederqvist's avatar
Per Cederqvist committed
641
642
{
    Connection *conn;
643
    Bool changed = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
644

645
646
    kill_pending = 0;

Per Cederqvist's avatar
Per Cederqvist committed
647
648
    if ( active_connection != NULL )
    {
649
	restart_kom("check_kill_flg: active_connection == %ld",
Per Cederqvist's avatar
Per Cederqvist committed
650
651
652
		    active_connection->session_no);
    }

653
    while (kill_list_size > 0)
Per Cederqvist's avatar
Per Cederqvist committed
654
    {
655
656
657
	--kill_list_size;
	conn = get_conn_by_number (kill_list[kill_list_size]);
	if (conn == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
658
	{
David Byers's avatar
David Byers committed
659
	    kom_log("check_kill_flg(): Connection %ld doesn't exist.\n",
660
661
662
663
		kill_list[kill_list_size]);
	}
	else
	{
664
665
	    assert(conn->kill_pending);
	    conn->kill_pending = FALSE;
666
667
	    logout_client(conn);
	    end_of_atomic();
668
	    changed = TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
669
670
	}
    }
671

672
673
674
675
676
    if (kill_list != NULL)
    {
	sfree (kill_list);
	kill_list = NULL;
    }
677
678
679

    if (changed == TRUE)
	dump_connections();
680
681

    return OOP_CONTINUE;
Per Cederqvist's avatar
Per Cederqvist committed
682
683
}

684
685
686
687
static void *
dns_resolution(struct isc_scb *scb,
	       enum isc_resolve_status res,
	       long errcode)
688
689
690
{
    struct timeval after;
    double diff = -1.0;
691
692
    Connection *conn;
    char *hostname = NULL;
693

694
    update_stat(STAT_DNS_QUEUE, -1);
695

696
    conn = scb->udg;
697

698
699
700
701
    conn->dns_done = TRUE;
    if (conn->blocked_by_dns)
    {
	conn->blocked_by_dns = FALSE;
702
703
	if (!conn->on_queue)
	    queue_add(conn);
704
705
    }

706
707
708
709
710
711
712
    if (res == isc_resolve_aborted)
	return OOP_CONTINUE;

    if (gettimeofday(&after, NULL) < 0)
	kom_log("gettimeofday failed: %s\n", strerror(errno));

    diff = timeval_diff_d(after, conn->connect_time);
713

714
715
716
    busy();

    switch (res)
717
    {
718
    case isc_resolve_h_errno:
719
	if (hostname == NULL)
720
721
722
723
724
725
726
727
728
729
	    hostname = s_crea_c_str(scb->remote);

	if (errcode == HOST_NOT_FOUND)
	    kom_log("No hostname found for %s.\n", hostname);
	else if (errcode == TRY_AGAIN)
	    kom_log("Lookup of %s timed out.\n", hostname);
	else if (errcode == NO_RECOVERY)
	    kom_log("Non-recoverable error looking up %s.\n", hostname);
	else if (errcode == NO_ADDRESS)
	    kom_log("Got NO_ADDRESS error looking up %s.\n", hostname);
730
	else
731
732
	    kom_log("Unknown resolver error %ld looking up %s.\n",
		    errcode, hostname);
733
	break;
734

735
    case isc_resolve_adns_error:
736
737
738
739
	if (hostname == NULL)
	    hostname = s_crea_c_str(scb->remote);

	kom_log("Error looking up %s: %s\n", hostname, adns_strerror(errcode));
740
741
742
743
744
745
746
	break;

    case isc_resolve_aborted:
	abort();

    case isc_resolve_ok:
	break;
747
748
    }

749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
    if (diff > param.dns_log_threshold)
    {
	if (hostname == NULL)
	    hostname = s_crea_c_str(scb->remote);

	if (res == isc_resolve_ok)
	    kom_log("Slow DNS: got %s after %f seconds\n", hostname, diff);
	else
	    kom_log("Slow bad DNS: %s failed after %f seconds\n",
		    hostname, diff);
   }

    if (hostname != NULL)
	string_free(hostname); 

    return OOP_CONTINUE;
765
766
}

767
    
768
static void
769
770
write_err_cb(struct isc_scb *cb_session,
	     int saved_errno)
771
{
772
    Connection  * cp = cb_session->udg;
773
    if (saved_errno != ECONNRESET && saved_errno != EPIPE)
774
775
	kom_log("Failed to write to client %lu from %s: %s\n",
		cp->session_no, cp->peer, strerror(saved_errno));
776
    cp->penalty += param.max_penalty;
777
778
779
780
    add_to_kill_list(cp);
}


781
static void
782
stale_cb(struct isc_scb *cb_session)
783
{
784
    Connection *cp = cb_session->udg;
785
786
787
788
789
790
    kom_log("Client %lu from %s has stalled.  Killing it.\n",
	    cp->session_no, cp->peer);
    cp->penalty += param.max_penalty;
    add_to_kill_list(cp);
}
    
791

792
static void
793
idle_cb(struct isc_scb *cb_session)
794
{
795
    Connection *cp = cb_session->udg;
796
797
798
799
800
801
802
    kom_log("Client %lu from %s has been idle too long.  Killing it.\n",
	    cp->session_no, cp->peer);
    cp->penalty += param.max_penalty;
    add_to_kill_list(cp);
}


Per Cederqvist's avatar
Per Cederqvist committed
803
static void
804
login_request(struct isc_scb *session)
Per Cederqvist's avatar
Per Cederqvist committed
805
806
{
    Connection  * cp;
807
    const char *realuser;
808
809
    char portbuf[1+2+3*sizeof(long)];
    size_t portlen;
810
    char *remote_ip = NULL;
Per Cederqvist's avatar
Per Cederqvist committed
811
812

    /* Supress logins if /etc/nologin exists */
David Byers's avatar
David Byers committed
813
    if (fexists(param.nologin_file))
Per Cederqvist's avatar
Per Cederqvist committed
814
    {
815
816
817
	isc_puts("%% No logins allowed.\n", session);
	isc_flush(session);
 	isc_destroy(kom_server_mcb, session);
Per Cederqvist's avatar
Per Cederqvist committed
818
819
820
	return;
    }

821
822
    /* Create a Connection, and link the Connection and the
       isc_session together. */
823

824
    cp = new_client();
825
826
    cp->isc_session = session;
    session->udg = cp;
827
    update_stat(STAT_CLIENTS, 1);
828

829
830
831
    /* Store the IP address in readable form. */
    s_crea_str(&cp->remote_ip, isc_getipnum(session->raddr, NULL, 0));
    remote_ip = s_crea_c_str(cp->remote_ip);
832

833
    /* Initiate DNS lookup. */
834
    if (param.use_dns && isc_resolve_remote(session, dns_resolution) == 0)
835
	update_stat(STAT_DNS_QUEUE, 1);
836
    else
837
	s_strcpy(&session->remote, cp->remote_ip);
838

839
840
841
842
843
844
    /* Update the status file that contains all connection. */
    sprintf(portbuf, " %d", isc_getportnum(session->raddr));
    portlen = strlen(portbuf);
    cp->peer = smalloc(s_strlen(cp->remote_ip) + portlen + 1);
    strcpy(cp->peer, remote_ip);
    strcpy(cp->peer + s_strlen(cp->remote_ip), portbuf);
845

846
    dump_connections();
847

848
849
850
851
    /* Start with max penalty, so that it doesn't pay to make a lot of
       new connections.  */
    cp->penalty = param.max_penalty;
    cp->penalty_generation = penalty_generation;
852

853
854
855
    /* Get the real user name, as returned by the Ident protocol (rfc 931). */
    realuser = get_real_username(session, remote_ip);
    if (realuser == NULL && param.authentication_level == 2)
856
    {
857
858
859
860
861
862
863
864
865
	kom_log("Connection from %s rejected - no IDENT available.\n", 
		remote_ip);

	isc_puts("%% No IDENT server reachable at your site.\n",
		 session);
	isc_flush(session);
	logout_client(cp);
	string_free(remote_ip);
	return;
866
867
    }

868
869
870
871
    if (realuser != NULL)
	s_crea_str(&cp->ident_user, realuser);

    BUG(("\n[Client %lu from %s is connecting]\n", cp->session_no, remote_ip));
872

873
    isc_set_read_callback(session, data_available_callback, write_err_cb,
874
			  stale_cb, idle_cb);
875
    string_free(remote_ip);
Per Cederqvist's avatar
Per Cederqvist committed
876
877
878
}

static void
879
adjust_penalty(Connection *conn)
Per Cederqvist's avatar
Per Cederqvist committed
880
{
881
882
883
884
885
886
887
888
    while (penalty_generation - conn->penalty_generation > 0)
    {
	conn->penalty /= 2;
	if (conn->penalty == 0)
	    conn->penalty_generation = penalty_generation;
	else
	    conn->penalty_generation++;
    }
Per Cederqvist's avatar
Per Cederqvist committed
889
890
891
892
}


static void
893
read_from_connection(Connection *conn)
Per Cederqvist's avatar
Per Cederqvist committed
894
{
895
    Bool would_block = FALSE;
896
    Bool need_flush = FALSE;
897
    String_size pre;
Per Cederqvist's avatar
Per Cederqvist committed
898

899
900
    adjust_penalty(conn);

901
    while (!would_block && !go_and_die && conn->penalty < param.max_penalty
902
	   && !conn->kill_pending && !conn->blocked_by_dns)
903
    {
904
	pre = s_strlen(conn->unparsed) - conn->first_to_parse;
905
	while (conn->more_to_parse
906
	       && !go_and_die && conn->penalty < param.max_penalty
907
	       && !conn->kill_pending && !conn->blocked_by_dns)
908
	    need_flush |= parse_unparsed(conn);
909
910
	update_stat(STAT_RECV_QUEUE,
		    s_strlen(conn->unparsed) - conn->first_to_parse - pre);
911

912
	if (go_and_die || conn->penalty >= param.max_penalty
913
	    || conn->kill_pending || conn->blocked_by_dns)
914
915
916
917
	    break;

	if (!conn->more_to_parse)
	{
918
	    pre = s_strlen(conn->unparsed) - conn->first_to_parse;
919
920
921
922
923
	    switch (isc_read_data(conn->isc_session,
				  &conn->unparsed,
				  &conn->first_to_parse))
	    {
	    case ISC_READ_DATA:
924
925
926
		update_stat(STAT_RECV_QUEUE,
			    s_strlen(conn->unparsed) - conn->first_to_parse
			    - pre);
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
		conn->penalty += param.penalty_per_read;
		conn->more_to_parse = TRUE;
		break;
	    case ISC_READ_ERROR:
		if (errno != ECONNRESET)
		    kom_log("Error reading from client: %s\n",
			    strerror(errno));
		/*FALLTHROUGH*/
	    case ISC_READ_LOGOUT:
		add_to_kill_list(conn);
		break;
	    case ISC_READ_WOULDBLOCK:
		would_block = TRUE;
		break;
	    case ISC_READ_NOMEM:
		restart_kom("isc_read_data() reports no memory\n");
	    }

	    if (!conn->more_to_parse)
		break;
	}
    }
949

950
    if (need_flush)
951
952
	isc_flush(conn->isc_session);

953
954
955
956
957
    /* Delete the parsed part of 'unparsed' */
    if (s_trim_left(&conn->unparsed, conn->first_to_parse) != OK)
	restart_kom("parse_unparsed: s_trim_left\n");
    conn->first_to_parse = 0;

958
    if (conn->penalty >= param.max_penalty && !conn->blocked_by_dns)
959
    {
960
961
962
963
964
	/* isc_disable() will fail if we have received EPIPE on
	   this socket.  In that case will soon close it, since
	   write_err_cb() has added it to the kill list. */
	if (isc_disable(conn->isc_session) == 0)
	    queue_add(conn);
965
    }
Per Cederqvist's avatar
Per Cederqvist committed
966
967
}

968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984

static void
enable_idle_check(void)
{
    oop_source *source = oop_sys_source(kom_server_oop_src);

    source->on_time(source, OOP_TIME_NOW, check_idle_callback, NULL);
}


static void *
check_idle_callback(oop_source *UNUSED(source),
		    struct timeval UNUSED(tv),
		    void *UNUSED(user))
{
    Connection *c;
    Connection *next;
985
986
    Connection *head = NULL;
    Connection *tail = NULL;
987
988
989
990
991
992
993
994
995

    set_time();
    is_idle = !work_done;
    work_done = FALSE;

    if (is_idle && queue_first != NULL)
    {
	is_idle = FALSE;
	++penalty_generation;
996

997
	for (next = queue_first; next != NULL; )
Per Cederqvist's avatar
Per Cederqvist committed
998
	{
999
1000
1001
1002
	    c = next;
	    next = next->queue_next;
	    adjust_penalty(c);
	    if (c->penalty < param.low_penalty)
Per Cederqvist's avatar
Per Cederqvist committed
1003
	    {
1004
		queue_remove(c);
1005
1006
1007
1008
1009
1010

		if (head == NULL)
		    head = c;
		else
		    tail->queue_next = c;
		tail = c;
Per Cederqvist's avatar
Per Cederqvist committed
1011
	    }
1012
1013
1014
	}
    }

1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
    for (next = head; next != NULL; )
    {
	c = next;
	next = next->queue_next;
	c->queue_next = NULL;
	if (isc_enable(c->isc_session) < 0)
	    restart_kom("failed to re-enable session\n");

	/* The call to read_from_connection() might add the
	   connection to the queue.  That's why we remove all entries
	   first, and use a private queue within this function.  */
	if (!go_and_die)
	    read_from_connection(c);
    }

1030
1031
1032
    if (!is_idle)
	enable_idle_check();

1033
1034
    /* Check if a client issued a shutdown command.  */
    return go_and_die ? OOP_HALT : OOP_CONTINUE;
1035
1036
1037
}

static void *
Per Cederqvist's avatar
Per Cederqvist committed
1038
saver_callback(oop_source *source,
1039
1040
1041
	       struct timeval UNUSED(tv),
	       void *user)
{
1042
    struct timeval timeout;
1043
    struct timeval *next_timer = user;
1044

1045
    timeout = end_of_atomic();
1046
1047
    if (setup_timer(next_timer, timeout) < 0)
	kom_log("gettimeofday failed: %s\n", strerror(errno));
Per Cederqvist's avatar
Per Cederqvist committed
1048

1049
1050
1051
    source->on_time(source, *next_timer, saver_callback, user);
    return OOP_CONTINUE;
}
Per Cederqvist's avatar
Per Cederqvist committed
1052
1053


1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
static void
busy(void)
{
    /* Something arrived, so we are busy.  */
    if (is_idle)
    {
	is_idle = FALSE;
	enable_idle_check();
    }
	
    work_done = TRUE;
}

1067
1068
1069
1070
1071
1072
static void *
data_available_callback(oop_source *source,
			int fd,
			oop_event event,
			void *user)
{
1073
    Connection *conn = ((struct isc_scb*)user)->udg;
1074
1075
1076

    assert(event == OOP_READ);
    assert(conn->isc_session->fd == fd);
1077
    assert(isc_getoopsource(conn->isc_session) == source);
1078
    assert(conn->on_queue == FALSE);
1079

1080
    busy();
1081
1082
1083
1084
1085
1086
1087
1088
1089
    set_time();
    read_from_connection(conn);

    /* Check if the client issued a shutdown command.  */
    return go_and_die ? OOP_HALT : OOP_CONTINUE;
}


void *
1090
handle_accept_event(struct isc_scb *UNUSED(accepting_session),
1091
1092
		    struct isc_scb *new_session)
{
1093
    new_session->udg = NULL;
1094

1095
1096
    set_time();

1097
1098
1099
1100
1101
    if (new_session->fd <= PROTECTED_FDS || new_session->fd >= fd_ceiling)
    {
	BUG(("Connection attempt rejected.\n"));
	isc_puts("%% No connections left.\n", new_session);
	isc_flush(new_session);
1102
	isc_destroy(new_session->master, new_session);
Per Cederqvist's avatar
Per Cederqvist committed
1103

1104
	async_rejected_connection();
Per Cederqvist's avatar
Per Cederqvist committed
1105
    }
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
    else
	login_request(new_session);

    return OOP_CONTINUE;
}


void
toploop(void)
{
    struct timeval saver_timer;

    void *exit_reason;
    oop_source *source = oop_sys_source(kom_server_oop_src);

    /* Start the garb right away. */
Per Cederqvist's avatar
Per Cederqvist committed
1122
    start_garb_thread(source);
1123
1124

    /* Hack to find out when we are idle. */
1125
    enable_idle_check();
1126
1127
1128
1129
1130
1131