connections.c 30.9 KB
Newer Older
Linus Tolke Y's avatar
Linus Tolke Y committed
1
/*
2
 * Copyright (C) 1991-2005  Lysator Academic Computer Association.
Linus Tolke Y's avatar
Linus Tolke Y committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
 *
 * 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.
 *
Per Cederqvist's avatar
Per Cederqvist committed
22
 * Please report bugs at http://bugzilla.lysator.liu.se/. 
Linus Tolke Y's avatar
Linus Tolke Y committed
23
 */
Per Cederqvist's avatar
Per Cederqvist committed
24 25 26 27 28 29 30 31
/*
 * 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
32 33 34 35 36

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

Per Cederqvist's avatar
Per Cederqvist committed
37
#include <errno.h>
Per Cederqvist's avatar
Per Cederqvist committed
38
#include <stdio.h>
Per Cederqvist's avatar
Per Cederqvist committed
39
#include <setjmp.h>
Per Cederqvist's avatar
Per Cederqvist committed
40 41 42
#ifdef HAVE_STRING_H
#  include <string.h>
#endif
Per Cederqvist's avatar
Per Cederqvist committed
43
#include <sys/types.h>
Per Cederqvist's avatar
Per Cederqvist committed
44
#include <sys/stat.h>
45
#include "timewrap.h"
46
#include <sys/socket.h>
47
#include <signal.h>
48
#include <assert.h>
49
#include <netdb.h>
Per Cederqvist's avatar
Per Cederqvist committed
50
#include <stdlib.h>
Per Cederqvist's avatar
Per Cederqvist committed
51

52
#include "adns.h"
53 54 55
#include "oop.h"

#include "unused.h"
56
#include "ldifftime.h"
Per Cederqvist's avatar
Per Cederqvist committed
57
#include "misc-types.h"
58
#include "s-string.h"
Per Cederqvist's avatar
Per Cederqvist committed
59
#include "kom-types.h"
60
#include "kom-memory.h"
Per Cederqvist's avatar
Per Cederqvist committed
61
#include "debug.h"
62
#include "isc-interface.h"
Per Cederqvist's avatar
Per Cederqvist committed
63
#include "com.h"
64
#include "async.h"
Per Cederqvist's avatar
Per Cederqvist committed
65
#include "connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
66
#include "internal-connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
67
#include "prot-a-parse-arg.h"
Per Cederqvist's avatar
Per Cederqvist committed
68 69 70 71 72
#include "log.h"
#include "lyskomd.h"
#include "services.h"
#include "isc-parse.h"
#include "prot-a.h"
73
#include "prot-a-parse.h"
Per Cederqvist's avatar
Per Cederqvist committed
74 75 76 77
#include "server/smalloc.h"
#include "end-of-atomic.h"
#include "send-async.h"
#include "cache.h"
78
#include "rfc931.h"
79
#include "param.h"
David Byers's avatar
David Byers committed
80
#include "kom-config.h"
81
#include "kom-errno.h"
Per Cederqvist's avatar
Per Cederqvist committed
82
#include "sigflags.h"
Per Cederqvist's avatar
Per Cederqvist committed
83
#include "server-time.h"
84
#include "aux-items.h"
85
#include "eintr.h"
86
#include "text-garb.h"
87
#include "timeval-util.h"
88
#include "stats.h"
89
#include "string-malloc.h"
90
#include "manipulate.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
/*
 * 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
99
 * privileges issues a `shutdown', or of lyskomd receives a SIGTERM.
Per Cederqvist's avatar
Per Cederqvist committed
100 101
 * 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

Per Cederqvist's avatar
Per Cederqvist committed
138 139
/* head and tail pointers for the wait queue that uses the queue_prev,
   queue_next and on_queue fields of Connection. */
140 141 142
static Connection *queue_first = NULL;
static Connection *queue_last = NULL;

143 144 145
static void busy(void);


Per Cederqvist's avatar
Per Cederqvist committed
146
/* Add c to the end of the wait queue. */
147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
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;
162
    update_stat(STAT_RUN_QUEUE, 1);
163 164
}

Per Cederqvist's avatar
Per Cederqvist committed
165
/* Remove c from the wait queue. Any element on the queue can be removed. */
166 167 168 169 170 171 172 173 174 175 176 177 178 179
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
180
	queue_first = c->queue_next;
Per Cederqvist's avatar
Per Cederqvist committed
181

182 183
    c->queue_prev = NULL;
    c->queue_next = NULL;
184
    update_stat(STAT_RUN_QUEUE, -1);
185 186
}

Per Cederqvist's avatar
Per Cederqvist committed
187
void
188 189
set_time(void)
{
190 191
    struct timeval last_time;
    static int limiter = 0;
192 193

    last_time = current_time;
194 195 196 197 198 199 200 201 202 203 204
    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))
205
    {
Per Cederqvist's avatar
Per Cederqvist committed
206
	kom_log("WARNING: Time moved backward at least %g seconds.\n",
207
		timeval_diff_d(last_time, current_time));
208 209 210
	/* FIXME (bug 62): Should we take more decisive action here? */
    }
}
Per Cederqvist's avatar
Per Cederqvist committed
211

Per Cederqvist's avatar
Per Cederqvist committed
212
static void
Per Cederqvist's avatar
Per Cederqvist committed
213 214 215
logout_client(Connection *cp)
{
    Connection *real_active_connection;
216
    int ret;
Per Cederqvist's avatar
Per Cederqvist committed
217 218 219

    if ( active_connection != NULL )
    {
David Byers's avatar
David Byers committed
220
	kom_log("BUGCHK: logout_client(%ld): connection %ld is active.\n",
Per Cederqvist's avatar
Per Cederqvist committed
221 222 223 224 225
	    cp->session_no, active_connection->session_no);
    }
    
    if ( cp->pers_no != 0 )
    {
226 227 228 229 230 231 232 233 234 235 236 237
	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
238 239 240 241
	active_connection = cp;
	logout();
	active_connection = real_active_connection;
    }
242 243
    else
    {
244
#if 0
245
	/* FIXME (bug 908): send a new async here instead.  This causes the
246 247
	   elisp client to say that a secret (or unknown) person has
	   left the system.  */
248
        async_logout( 0, cp->session_no );
249
#endif
250
    }
Per Cederqvist's avatar
Per Cederqvist committed
251 252 253 254 255 256 257 258 259 260 261 262 263 264

    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");
    }

265 266
    ret = isc_destroy(kom_server_mcb, cp->isc_session);
    if (ret < 0)
David Byers's avatar
David Byers committed
267
	kom_log("logout_client(): isc_destroyed returned %d\n", ret);
268
    cp->isc_session = NULL;
269 270
    if (cp->on_queue)
	queue_remove(cp);
Per Cederqvist's avatar
Per Cederqvist committed
271 272

    kill_client(cp);		/* Free the Connection */
273
    update_stat(STAT_CLIENTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
274 275
}

Per Cederqvist's avatar
Per Cederqvist committed
276 277 278 279 280 281 282 283 284 285 286 287 288 289
/*
 * 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 )
290
	    restart_kom("logout_all_clients(): cant get session %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
291 292 293 294 295 296
			sess);
	else
	    logout_client (conn);
    }

    if ( traverse_connections (0) != 0)
297
	restart_kom("logout_all_clients(): traverse_connections(0) == %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
298 299 300 301
		    traverse_connections(0));
}

    
Per Cederqvist's avatar
Per Cederqvist committed
302 303 304 305 306 307 308 309
    

    
/*
 * 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
310 311
call_function(Connection *client,
	      union result_holder *res)
Per Cederqvist's avatar
Per Cederqvist committed
312 313 314 315 316
{
    Success	status=FAILURE;	/* OK if the call was successful. */

    if ( active_connection != NULL )
    {
317
	kom_log("call_function(%ld): active_connection = %ld\n",
Per Cederqvist's avatar
Per Cederqvist committed
318 319
	    client->session_no, active_connection->session_no);
    }
320 321 322

    if (client->function == illegal_fnc) 
    {
323
        err_stat = 0;
324 325 326 327
	kom_errno = KOM_NOT_IMPL;
	return FAILURE;
    }

Per Cederqvist's avatar
Per Cederqvist committed
328 329
    active_connection = client;

330
    service_statistics[client->function_index]++;
Per Cederqvist's avatar
Per Cederqvist committed
331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353

#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';
354 355
	    isc_puts("%%LysKOM unsupported protocol.\n", client->isc_session);
	    isc_flush(client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
356
	    BUG(("%%%%Unsupported protocol.\n"));
357
	    longjmp(parse_env, KOM_LOGOUT);
Per Cederqvist's avatar
Per Cederqvist committed
358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386
	}
    }

    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
387 388 389
    sfree(client->misc_info_list.misc);
    client->misc_info_list.misc = 0;
    client->misc_info_list.no_of_misc = 0;
390
    s_clear(&client->aux_item.data);
391
    s_clear(&client->dummy_aux_item.data);
392 393 394
    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
395 396
    client->parse_pos = 0;
    client->fnc_parse_pos = 0;
397
    client->array_parse_index = 0;
David Byers's avatar
David Byers committed
398
    client->array_parse_parsed_length = 0;
Per Cederqvist's avatar
Per Cederqvist committed
399 400 401
    client->array_parse_pos = 0;
    client->struct_parse_pos = 0;
    client->string_parse_pos = 0;
David Byers's avatar
David Byers committed
402 403 404
    client->hunt_parse_pos = 0;
    client->array_hunt_num = 0;
    client->array_hunt_depth = 0;
405 406 407
    sfree(client->num_list.data);
    client->num_list.data = NULL;
    client->num_list.length = 0;
408 409
    free_aux_item_list(&client->aux_item_list);
    client->info.highest_aux_no = 0;
Per Cederqvist's avatar
Per Cederqvist committed
410 411 412 413 414 415 416
}

/*
 * Send a reply to a call.
 */
static void
reply(Connection *client,
417 418
      Success status,
      union result_holder *result)
Per Cederqvist's avatar
Per Cederqvist committed
419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434
{
    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.
435 436
 * 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
437
 */
438
static Bool
Per Cederqvist's avatar
Per Cederqvist committed
439 440 441
parse_unparsed(Connection *client)
{
    Success       status;
442
    union result_holder result;
Per Cederqvist's avatar
Per Cederqvist committed
443 444 445 446 447 448
        
    switch ( setjmp(parse_env) )
    {
    case 0 :
	/* Parse message. If message is complete call function and reply. */
	parse_packet(client);
449 450
	if (client->blocked_by_dns)
	    return TRUE;
451 452 453 454
#ifdef DEBUG_CALLS
	if (client->blocked_by_disable_client)
	    return TRUE;
#endif
455
	update_stat(STAT_REQUESTS, 1);
Per Cederqvist's avatar
Per Cederqvist committed
456
	status = call_function(client, &result);
457
	update_stat(STAT_REQUESTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
458
	reply(client, status, &result);
459
	client->penalty += param.penalty_per_call;
Per Cederqvist's avatar
Per Cederqvist committed
460
	free_parsed(client);
461
	end_of_atomic();
462
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
463

464
    case KOM_PROTOCOL_ERR:
Per Cederqvist's avatar
Per Cederqvist committed
465 466
	s_clear(&client->string0);
	free_parsed(client);
467
	isc_puts("%% LysKOM protocol error.\n", client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
468
	BUG(("%%%% Protocol error.\n"));
469
	client->penalty += param.max_penalty;
Per Cederqvist's avatar
Per Cederqvist committed
470 471 472
	s_clear(&client->unparsed);
	client->first_to_parse = 0;
	client->more_to_parse = FALSE;
473
	end_of_atomic();
474
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
475

476
    case KOM_MSG_INCOMPLETE:
Per Cederqvist's avatar
Per Cederqvist committed
477
	client->more_to_parse = FALSE;
478
	return FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
479

480
    case KOM_LOGOUT:
481
	add_to_kill_list(client);
482
	client->more_to_parse = FALSE;
483 484 485
	return TRUE;
    default:
	restart_kom("Bad longjmp return value.\n");
Per Cederqvist's avatar
Per Cederqvist committed
486
    }
487
    /*NOTREACHED*/
Per Cederqvist's avatar
Per Cederqvist committed
488 489 490 491 492
}


/* Return 1 if the named file exists, 0 otherwise */
static int
Per Cederqvist's avatar
Per Cederqvist committed
493
fexists(const char *filename)
Per Cederqvist's avatar
Per Cederqvist committed
494 495 496 497 498 499 500 501 502 503 504 505 506 507
{
    struct stat buf;
    int code;
  
    code = !stat(filename, &buf);
    errno = 0;

    return code;
}


void
dump_statistics(void)
{
508
    static struct timeval last_dump = {0, 0};
Per Cederqvist's avatar
Per Cederqvist committed
509 510 511
    int i;
    FILE *fp;

512
    if ((fp = i_fopen(param.statistic_name, "a")) == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
513
    {
514 515
	kom_log("dump_statistics(): can't open file %s\n",
		param.statistic_name);
Per Cederqvist's avatar
Per Cederqvist committed
516 517 518
	return;
    }

519
    if (timeval_zero(last_dump))
Per Cederqvist's avatar
Per Cederqvist committed
520 521
    {
	fprintf(fp, "RESTART\n");
Per Cederqvist's avatar
Per Cederqvist committed
522
	last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
523 524
    }
    
525 526
    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
527
    fprintf(fp, "STATISTICS:");
528 529 530 531 532

    /* 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
533
    {
534
	fprintf(fp, " %d:%lu", fnc_defs[i].function, service_statistics[i]);
Per Cederqvist's avatar
Per Cederqvist committed
535 536 537 538
	service_statistics[i]=0;
    }

    fprintf(fp, "\n");
539
    i_fclose(fp);
Per Cederqvist's avatar
Per Cederqvist committed
540

Per Cederqvist's avatar
Per Cederqvist committed
541
    last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
542 543
}

544 545
/* List of connections to kill. */

Per Cederqvist's avatar
Per Cederqvist committed
546 547
static Session_no *kill_list = NULL;
static int kill_list_size = 0;
548
static int kill_pending = 0;
549 550 551 552 553

/* Schedule this client for termination. */
void
add_to_kill_list(Connection *conn)
{
554
    oop_source *source;
Per Cederqvist's avatar
Per Cederqvist committed
555 556
    int i;

557
    switch (conn->kill_status)
558
    {
559 560 561
    case ks_pending:
	/* A kill is already pending.  Do nothing--but check that the
	   the client really is present on the kill_list.  */
562 563 564
	for (i = 0; i < kill_list_size; i++)
	    if (kill_list[i] == conn->session_no)
		return;
565

566
	restart_kom("add_to_kill_list(): kill_pending set but not on list.\n");
567 568 569 570 571 572 573 574 575 576
	return;

    case ks_dying:
	/* Don't add this client to the kill list while it is being
	   killed.  */
	return;

    case ks_none:
	/* The normal case.  Do all the work below. */
	break;
577 578
    }

579
    /* Check that the client isn't already present on the kill_list. */
Per Cederqvist's avatar
Per Cederqvist committed
580
    for (i = 0; i < kill_list_size; i++)
581
	if (kill_list[i] == conn->session_no)
582
	    restart_kom("add_to_kill_list(): on list but not kill_pending.\n");
Per Cederqvist's avatar
Per Cederqvist committed
583

584 585 586 587 588 589 590 591 592 593 594 595 596 597 598
    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;
599
    conn->kill_status = ks_pending;
600 601 602

    if (!kill_pending)
    {
603
	source = isc_getoopsource(conn->isc_session);
604 605 606
	source->on_time(source, OOP_TIME_NOW, check_kill_flg, NULL);
	kill_pending = 1;
    }
607
}
Per Cederqvist's avatar
Per Cederqvist committed
608

609

610
static void
611 612 613 614 615 616
dump_connections(void)
{
    Session_no s;
    Connection *conn;
    FILE *fp;

617
    if ((fp = i_fopen(param.connection_status_file_tmp, "w")) == NULL)
618
    {
619 620
	kom_log("dump_connections(): can't open file %s: %s\n",
		param.connection_status_file_tmp, strerror(errno));
621 622 623 624 625 626
	return;
    }

    for (s = 0; (s = traverse_connections(s)) != 0;)
    {
	conn = get_conn_by_number(s);
627 628
	fprintf(fp, "%d %lu %d %s\n", conn->isc_session->fd, conn->session_no,
		handshake_ok(conn, 0),
629 630 631
		conn->peer);
    }

632 633 634 635 636 637
    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");

638
    if (i_fclose(fp) < 0)
639 640 641 642 643
    {
	kom_log("dump_connections(): fclose failed: %s (ignored)\n",
		strerror(errno));
    }

644 645 646
    errno = 0;
    if (i_rename(param.connection_status_file_tmp,
		 param.connection_status_file) < 0)
647
    {
648 649 650 651
	kom_log("dump_connections(): can't rename %s to %s: %s\n",
		param.connection_status_file_tmp,
		param.connection_status_file,
		strerror(errno));
652 653 654 655
    }
}


Per Cederqvist's avatar
Per Cederqvist committed
656 657 658
/*
 * check_kill_flg must NEVER be called inside an atomic call!
 */
659 660 661 662
static void *
check_kill_flg(oop_source *UNUSED(source),
	       struct timeval UNUSED(tv),
	       void *UNUSED(user))
Per Cederqvist's avatar
Per Cederqvist committed
663 664
{
    Connection *conn;
665
    Bool changed = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
666

667 668
    kill_pending = 0;

Per Cederqvist's avatar
Per Cederqvist committed
669 670
    if ( active_connection != NULL )
    {
671
	restart_kom("check_kill_flg: active_connection == %ld",
Per Cederqvist's avatar
Per Cederqvist committed
672 673 674
		    active_connection->session_no);
    }

675
    while (kill_list_size > 0)
Per Cederqvist's avatar
Per Cederqvist committed
676
    {
677 678 679
	--kill_list_size;
	conn = get_conn_by_number (kill_list[kill_list_size]);
	if (conn == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
680
	{
David Byers's avatar
David Byers committed
681
	    kom_log("check_kill_flg(): Connection %ld doesn't exist.\n",
682 683 684 685
		kill_list[kill_list_size]);
	}
	else
	{
686 687
	    assert(conn->kill_status == ks_pending);
	    conn->kill_status = ks_dying;
688 689
	    logout_client(conn);
	    end_of_atomic();
690
	    changed = TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
691 692
	}
    }
693

694 695 696 697 698
    if (kill_list != NULL)
    {
	sfree (kill_list);
	kill_list = NULL;
    }
699 700 701

    if (changed == TRUE)
	dump_connections();
702 703

    return OOP_CONTINUE;
Per Cederqvist's avatar
Per Cederqvist committed
704 705
}

706 707 708 709
static void *
dns_resolution(struct isc_scb *scb,
	       enum isc_resolve_status res,
	       long errcode)
710 711 712
{
    struct timeval after;
    double diff = -1.0;
713 714
    Connection *conn;
    char *hostname = NULL;
715

716
    update_stat(STAT_DNS_QUEUE, -1);
717

718
    conn = scb->udg;
719

720 721 722 723
    conn->dns_done = TRUE;
    if (conn->blocked_by_dns)
    {
	conn->blocked_by_dns = FALSE;
724 725
	if (!conn->on_queue)
	    queue_add(conn);
726 727
    }

728 729 730 731 732 733 734
    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);
735

736 737 738
    busy();

    switch (res)
739
    {
740
    case isc_resolve_h_errno:
741
	if (hostname == NULL)
742 743 744 745 746 747 748 749 750 751
	    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);
752
	else
753 754
	    kom_log("Unknown resolver error %ld looking up %s.\n",
		    errcode, hostname);
755
	break;
756

757
    case isc_resolve_adns_error:
758 759 760
	if (hostname == NULL)
	    hostname = s_crea_c_str(scb->remote);

761 762 763 764 765 766
	/* Misconfigurations of localhost are common and harmless.
	   Don't bother logging them, since that makes the test cases fail. */
	if ((errcode != adns_s_inconsistent && errcode != adns_s_nxdomain)
	    || strcmp(hostname, "127.0.0.1") != 0)
	    kom_log("Error looking up %s: %s\n",
		    hostname, adns_strerror(errcode));
767 768 769 770 771 772 773
	break;

    case isc_resolve_aborted:
	abort();

    case isc_resolve_ok:
	break;
774 775
    }

776 777 778 779 780 781 782 783 784 785 786 787 788 789 790
    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); 

791 792 793
    if (handshake_ok(conn, 0))
	dump_connections();

794
    return OOP_CONTINUE;
795 796
}

797
    
798
static void
799 800
write_err_cb(struct isc_scb *cb_session,
	     int saved_errno)
801
{
802
    Connection  * cp = cb_session->udg;
803
    if (saved_errno != ECONNRESET && saved_errno != EPIPE)
804 805
	kom_log("Failed to write to client %lu from %s: %s\n",
		cp->session_no, cp->peer, strerror(saved_errno));
806
    cp->penalty += param.max_penalty;
807 808 809 810
    add_to_kill_list(cp);
}


811
static void
812
stale_cb(struct isc_scb *cb_session)
813
{
814
    Connection *cp = cb_session->udg;
815 816 817 818 819 820
    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);
}
    
821

822
static void
823
idle_cb(struct isc_scb *cb_session)
824
{
825
    Connection *cp = cb_session->udg;
826 827 828 829 830 831 832
    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
833
static void
834
login_request(struct isc_scb *session)
Per Cederqvist's avatar
Per Cederqvist committed
835 836
{
    Connection  * cp;
837
    const char *realuser;
838 839
    char portbuf[1+2+3*sizeof(long)];
    size_t portlen;
840
    char *remote_ip = NULL;
Per Cederqvist's avatar
Per Cederqvist committed
841 842

    /* Supress logins if /etc/nologin exists */
David Byers's avatar
David Byers committed
843
    if (fexists(param.nologin_file))
Per Cederqvist's avatar
Per Cederqvist committed
844
    {
845 846 847
	isc_puts("%% No logins allowed.\n", session);
	isc_flush(session);
 	isc_destroy(kom_server_mcb, session);
Per Cederqvist's avatar
Per Cederqvist committed
848 849 850
	return;
    }

851 852
    /* Create a Connection, and link the Connection and the
       isc_session together. */
853

854
    cp = new_client();
855 856
    cp->isc_session = session;
    session->udg = cp;
857
    update_stat(STAT_CLIENTS, 1);
858

859 860 861
    /* 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);
862

863
    /* Initiate DNS lookup. */
864
    if (param.use_dns && isc_resolve_remote(session, dns_resolution) == 0)
865
	update_stat(STAT_DNS_QUEUE, 1);
866
    else
867
	s_strcpy(&session->remote, cp->remote_ip);
868

869 870 871 872 873 874
    /* 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);
875

876
    dump_connections();
877

878 879 880 881
    /* 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;
882

883 884 885
    cp->schedule.priority = param.default_priority;
    cp->schedule.weight = param.default_weight;

886 887 888
    /* 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)
889
    {
890 891 892 893 894 895 896 897 898
	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;
899 900
    }

901 902 903 904
    if (realuser != NULL)
	s_crea_str(&cp->ident_user, realuser);

    BUG(("\n[Client %lu from %s is connecting]\n", cp->session_no, remote_ip));
905

906
    isc_set_read_callback(session, data_available_callback, write_err_cb,
907
			  stale_cb, idle_cb);
908
    string_free(remote_ip);
Per Cederqvist's avatar
Per Cederqvist committed
909 910 911
}

static void
912
adjust_penalty(Connection *conn)
Per Cederqvist's avatar
Per Cederqvist committed
913
{
914 915
    unsigned int gens = penalty_generation - conn->penalty_generation;
    if (gens > 0)
916
    {
917 918 919 920 921 922
	/* The weight is in the range 1-0xffff (inclusive).
	   The penalty is in the range 0-0x10000 (inclusive).
	   This means that the multiplication can never overflow. */

	if (conn->penalty <= gens)
	    conn->penalty = 0;
923
	else
924 925 926 927 928 929 930 931 932
	{
	    unsigned int tmp = conn->penalty - gens * conn->schedule.weight;
	    if (tmp < conn->penalty)
		conn->penalty = tmp;
	    else
		conn->penalty = 0;
	}

	conn->penalty_generation = penalty_generation;
933
    }
Per Cederqvist's avatar
Per Cederqvist committed
934 935 936
}