connections.c 25.4 KB
Newer Older
Linus Tolke Y's avatar
Linus Tolke Y committed
1
/*
2
 * $Id: connections.c,v 0.113 2003/08/02 20:45:09 ceder Exp $
Per Cederqvist's avatar
Per Cederqvist committed
3
 * Copyright (C) 1991-2002  Lysator Academic Computer Association.
Linus Tolke Y's avatar
Linus Tolke Y 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>
Per Cederqvist's avatar
Per Cederqvist committed
50

51 52 53
#include "oop.h"

#include "unused.h"
54
#include "ldifftime.h"
Per Cederqvist's avatar
Per Cederqvist committed
55
#include "misc-types.h"
56
#include "s-string.h"
Per Cederqvist's avatar
Per Cederqvist committed
57
#include "kom-types.h"
58
#include "kom-memory.h"
Per Cederqvist's avatar
Per Cederqvist committed
59
#include "debug.h"
60
#include "isc-interface.h"
Per Cederqvist's avatar
Per Cederqvist committed
61
#include "com.h"
62
#include "async.h"
Per Cederqvist's avatar
Per Cederqvist committed
63
#include "connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
64
#include "internal-connections.h"
Per Cederqvist's avatar
Per Cederqvist committed
65
#include "prot-a-parse-arg.h"
Per Cederqvist's avatar
Per Cederqvist committed
66 67 68 69 70
#include "log.h"
#include "lyskomd.h"
#include "services.h"
#include "isc-parse.h"
#include "prot-a.h"
71
#include "prot-a-parse.h"
Per Cederqvist's avatar
Per Cederqvist committed
72 73 74 75
#include "server/smalloc.h"
#include "end-of-atomic.h"
#include "send-async.h"
#include "cache.h"
76
#include "rfc931.h"
77
#include "param.h"
David Byers's avatar
David Byers committed
78
#include "kom-config.h"
79
#include "kom-errno.h"
Per Cederqvist's avatar
Per Cederqvist committed
80
#include "sigflags.h"
Per Cederqvist's avatar
Per Cederqvist committed
81
#include "server-time.h"
82
#include "aux-items.h"
83
#include "eintr.h"
84
#include "text-garb.h"
85
#include "timeval-util.h"
86
#include "stats.h"
Per Cederqvist's avatar
Per Cederqvist committed
87

88 89
oop_source_sys * kom_server_oop_src = NULL;
struct isc_mcb * kom_server_mcb    = NULL;
Per Cederqvist's avatar
Per Cederqvist committed
90 91
Connection     * active_connection = NULL;

Per Cederqvist's avatar
Per Cederqvist committed
92 93 94 95 96 97
/*
 * 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.
 */
98
Bool go_and_die = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
99 100

/*
101 102 103 104 105 106 107 108 109
 * 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
110
 */
111 112
static Bool work_done = FALSE;
static Bool is_idle = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
113 114 115 116 117 118 119 120

jmp_buf 	 parse_env;


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

121
const int num_fnc_defs = sizeof (fnc_defs) / sizeof (Fnc_descriptor);
122

Per Cederqvist's avatar
Per Cederqvist committed
123
unsigned long service_statistics[sizeof (fnc_defs) / sizeof (Fnc_descriptor)];
Per Cederqvist's avatar
Per Cederqvist committed
124 125 126

BUGDECL;

127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
static oop_call_fd data_available_callback;
static oop_call_time check_kill_flg;
static oop_call_time check_idle_callback;

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

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;
149
    update_stat(STAT_RUN_QUEUE, 1);
150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165
}

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
166
	queue_first = c->queue_next;
Per Cederqvist's avatar
Per Cederqvist committed
167

168 169
    c->queue_prev = NULL;
    c->queue_next = NULL;
170
    update_stat(STAT_RUN_QUEUE, -1);
171 172
}

Per Cederqvist's avatar
Per Cederqvist committed
173
void
174 175
set_time(void)
{
176 177
    struct timeval last_time;
    static int limiter = 0;
178 179

    last_time = current_time;
180 181 182 183 184 185 186 187 188 189 190
    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))
191 192 193 194 195
    {
	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
196

Per Cederqvist's avatar
Per Cederqvist committed
197
static void
Per Cederqvist's avatar
Per Cederqvist committed
198 199 200
logout_client(Connection *cp)
{
    Connection *real_active_connection;
201
    int ret;
Per Cederqvist's avatar
Per Cederqvist committed
202 203 204

    if ( active_connection != NULL )
    {
David Byers's avatar
David Byers committed
205
	kom_log("BUGCHK: logout_client(%ld): connection %ld is active.\n",
Per Cederqvist's avatar
Per Cederqvist committed
206 207 208 209 210
	    cp->session_no, active_connection->session_no);
    }
    
    if ( cp->pers_no != 0 )
    {
211 212 213 214 215 216 217 218 219 220 221 222
	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
223 224 225 226
	active_connection = cp;
	logout();
	active_connection = real_active_connection;
    }
227 228
    else
    {
229
#if 0
230
	/* FIXME (bug 908): send a new async here instead.  This causes the
231 232
	   elisp client to say that a secret (or unknown) person has
	   left the system.  */
233
        async_logout( 0, cp->session_no );
234
#endif
235
    }
Per Cederqvist's avatar
Per Cederqvist committed
236 237 238 239 240 241 242 243 244 245 246 247 248 249

    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");
    }

250 251
    ret = isc_destroy(kom_server_mcb, cp->isc_session);
    if (ret < 0)
David Byers's avatar
David Byers committed
252
	kom_log("logout_client(): isc_destroyed returned %d\n", ret);
253
    cp->isc_session = NULL;
254 255
    if (cp->on_queue)
	queue_remove(cp);
Per Cederqvist's avatar
Per Cederqvist committed
256 257

    kill_client(cp);		/* Free the Connection */
258
    update_stat(STAT_CLIENTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
259 260
}

Per Cederqvist's avatar
Per Cederqvist committed
261 262 263 264 265 266 267 268 269 270 271 272 273 274
/*
 * 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 )
275
	    restart_kom("logout_all_clients(): cant get session %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
276 277 278 279 280 281
			sess);
	else
	    logout_client (conn);
    }

    if ( traverse_connections (0) != 0)
282
	restart_kom("logout_all_clients(): traverse_connections(0) == %ld.\n",
Per Cederqvist's avatar
Per Cederqvist committed
283 284 285 286
		    traverse_connections(0));
}

    
Per Cederqvist's avatar
Per Cederqvist committed
287 288 289 290 291 292 293 294
    

    
/*
 * 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
295 296
call_function(Connection *client,
	      union result_holder *res)
Per Cederqvist's avatar
Per Cederqvist committed
297 298 299 300 301
{
    Success	status=FAILURE;	/* OK if the call was successful. */

    if ( active_connection != NULL )
    {
302
	kom_log("call_function(%ld): active_connection = %ld\n",
Per Cederqvist's avatar
Per Cederqvist committed
303 304
	    client->session_no, active_connection->session_no);
    }
305 306 307

    if (client->function == illegal_fnc) 
    {
308
        err_stat = 0;
309 310 311 312
	kom_errno = KOM_NOT_IMPL;
	return FAILURE;
    }

Per Cederqvist's avatar
Per Cederqvist committed
313 314
    active_connection = client;

315
    service_statistics[client->function_index]++;
Per Cederqvist's avatar
Per Cederqvist committed
316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338

#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';
339 340
	    isc_puts("%%LysKOM unsupported protocol.\n", client->isc_session);
	    isc_flush(client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
341
	    BUG(("%%%%Unsupported protocol.\n"));
342
	    longjmp(parse_env, KOM_LOGOUT);
Per Cederqvist's avatar
Per Cederqvist committed
343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371
	}
    }

    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
372 373 374
    sfree(client->misc_info_list.misc);
    client->misc_info_list.misc = 0;
    client->misc_info_list.no_of_misc = 0;
375
    s_clear(&client->aux_item.data);
376
    s_clear(&client->dummy_aux_item.data);
Per Cederqvist's avatar
Per Cederqvist committed
377 378
    sfree( client->c_local_text_no_p);
    client->c_local_text_no_p = NULL;
379 380 381
    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
382 383
    client->parse_pos = 0;
    client->fnc_parse_pos = 0;
384
    client->array_parse_index = 0;
David Byers's avatar
David Byers committed
385
    client->array_parse_parsed_length = 0;
Per Cederqvist's avatar
Per Cederqvist committed
386 387 388
    client->array_parse_pos = 0;
    client->struct_parse_pos = 0;
    client->string_parse_pos = 0;
David Byers's avatar
David Byers committed
389 390 391
    client->hunt_parse_pos = 0;
    client->array_hunt_num = 0;
    client->array_hunt_depth = 0;
392 393 394
    sfree(client->num_list.data);
    client->num_list.data = NULL;
    client->num_list.length = 0;
395 396
    free_aux_item_list(&client->aux_item_list);
    client->info.highest_aux_no = 0;
Per Cederqvist's avatar
Per Cederqvist committed
397 398 399 400 401 402 403
}

/*
 * Send a reply to a call.
 */
static void
reply(Connection *client,
404 405
      Success status,
      union result_holder *result)
Per Cederqvist's avatar
Per Cederqvist committed
406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421
{
    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.
422 423
 * 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
424
 */
425
static Bool
Per Cederqvist's avatar
Per Cederqvist committed
426 427 428
parse_unparsed(Connection *client)
{
    Success       status;
429
    union result_holder result;
Per Cederqvist's avatar
Per Cederqvist committed
430 431 432 433 434 435
        
    switch ( setjmp(parse_env) )
    {
    case 0 :
	/* Parse message. If message is complete call function and reply. */
	parse_packet(client);
436
	update_stat(STAT_REQUESTS, 1);
Per Cederqvist's avatar
Per Cederqvist committed
437
	status = call_function(client, &result);
438
	update_stat(STAT_REQUESTS, -1);
Per Cederqvist's avatar
Per Cederqvist committed
439
	reply(client, status, &result);
440
	client->penalty += param.penalty_per_call;
Per Cederqvist's avatar
Per Cederqvist committed
441
	free_parsed(client);
442
	end_of_atomic();
443
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
444

445
    case KOM_PROTOCOL_ERR:
Per Cederqvist's avatar
Per Cederqvist committed
446 447
	s_clear(&client->string0);
	free_parsed(client);
448
	isc_puts("%% LysKOM protocol error.\n", client->isc_session);
Per Cederqvist's avatar
Per Cederqvist committed
449
	BUG(("%%%% Protocol error.\n"));
450
	client->penalty += param.max_penalty;
Per Cederqvist's avatar
Per Cederqvist committed
451 452 453
	s_clear(&client->unparsed);
	client->first_to_parse = 0;
	client->more_to_parse = FALSE;
454
	end_of_atomic();
455
	return TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
456

457
    case KOM_MSG_INCOMPLETE:
Per Cederqvist's avatar
Per Cederqvist committed
458
	client->more_to_parse = FALSE;
459
	return FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
460

461
    case KOM_LOGOUT:
462
	add_to_kill_list(client);
463
	client->more_to_parse = FALSE;
464 465 466
	return TRUE;
    default:
	restart_kom("Bad longjmp return value.\n");
Per Cederqvist's avatar
Per Cederqvist committed
467
    }
468
    /*NOTREACHED*/
Per Cederqvist's avatar
Per Cederqvist committed
469 470 471 472 473
}


/* Return 1 if the named file exists, 0 otherwise */
static int
Per Cederqvist's avatar
Per Cederqvist committed
474
fexists(const char *filename)
Per Cederqvist's avatar
Per Cederqvist committed
475 476 477 478 479 480 481 482 483 484 485 486 487 488
{
    struct stat buf;
    int code;
  
    code = !stat(filename, &buf);
    errno = 0;

    return code;
}


void
dump_statistics(void)
{
489
    static struct timeval last_dump = {0, 0};
Per Cederqvist's avatar
Per Cederqvist committed
490 491 492
    int i;
    FILE *fp;

493
    if ((fp = i_fopen(param.statistic_name, "a")) == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
494
    {
495 496
	kom_log("dump_statistics(): can't open file %s\n",
		param.statistic_name);
Per Cederqvist's avatar
Per Cederqvist committed
497 498 499
	return;
    }

500
    if (timeval_zero(last_dump))
Per Cederqvist's avatar
Per Cederqvist committed
501 502
    {
	fprintf(fp, "RESTART\n");
Per Cederqvist's avatar
Per Cederqvist committed
503
	last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
504 505
    }
    
506 507
    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
508
    fprintf(fp, "STATISTICS:");
509 510 511 512 513

    /* 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
514
    {
515
	fprintf(fp, " %d:%lu", fnc_defs[i].function, service_statistics[i]);
Per Cederqvist's avatar
Per Cederqvist committed
516 517 518 519
	service_statistics[i]=0;
    }

    fprintf(fp, "\n");
520
    i_fclose(fp);
Per Cederqvist's avatar
Per Cederqvist committed
521

Per Cederqvist's avatar
Per Cederqvist committed
522
    last_dump = current_time;
Per Cederqvist's avatar
Per Cederqvist committed
523 524
}

525 526
/* List of connections to kill. */

Per Cederqvist's avatar
Per Cederqvist committed
527 528
static Session_no *kill_list = NULL;
static int kill_list_size = 0;
529
static int kill_pending = 0;
530 531 532 533 534

/* Schedule this client for termination. */
void
add_to_kill_list(Connection *conn)
{
535
    oop_source *source;
Per Cederqvist's avatar
Per Cederqvist committed
536 537
    int i;

538 539 540 541 542 543 544 545
    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
546
    for (i = 0; i < kill_list_size; i++)
547
	if (kill_list[i] == conn->session_no)
548
	    restart_kom("add_to_kill_list(): on list but not kill_pending.\n");
Per Cederqvist's avatar
Per Cederqvist committed
549

550 551 552 553 554 555 556 557 558 559 560 561 562 563 564
    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;
565
    conn->kill_pending = TRUE;
566 567 568

    if (!kill_pending)
    {
569
	source = isc_getoopsource(conn->isc_session);
570 571 572
	source->on_time(source, OOP_TIME_NOW, check_kill_flg, NULL);
	kill_pending = 1;
    }
573
}
Per Cederqvist's avatar
Per Cederqvist committed
574

575 576 577 578 579 580 581 582

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

583
    if ((fp = i_fopen(param.connection_status_file_tmp, "w")) == NULL)
584
    {
585 586
	kom_log("dump_connections(): can't open file %s: %s\n",
		param.connection_status_file_tmp, strerror(errno));
587 588 589 590 591 592 593 594 595 596
	return;
    }

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

597 598 599 600 601 602
    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");

603
    if (i_fclose(fp) < 0)
604 605 606 607 608
    {
	kom_log("dump_connections(): fclose failed: %s (ignored)\n",
		strerror(errno));
    }

609
    errno = 0;
610 611
    if (i_rename(param.connection_status_file_tmp,
		 param.connection_status_file) < 0)
612
    {
613
	kom_log("dump_connections(): can't rename %s to %s: %s\n",
614
		param.connection_status_file_tmp,
615 616
		param.connection_status_file,
		strerror(errno));
617 618 619 620
    }
}


Per Cederqvist's avatar
Per Cederqvist committed
621 622 623
/*
 * check_kill_flg must NEVER be called inside an atomic call!
 */
624 625 626 627
static void *
check_kill_flg(oop_source *UNUSED(source),
	       struct timeval UNUSED(tv),
	       void *UNUSED(user))
Per Cederqvist's avatar
Per Cederqvist committed
628 629
{
    Connection *conn;
630
    Bool changed = FALSE;
Per Cederqvist's avatar
Per Cederqvist committed
631

632 633
    kill_pending = 0;

Per Cederqvist's avatar
Per Cederqvist committed
634 635
    if ( active_connection != NULL )
    {
636
	restart_kom("check_kill_flg: active_connection == %ld",
Per Cederqvist's avatar
Per Cederqvist committed
637 638 639
		    active_connection->session_no);
    }

640
    while (kill_list_size > 0)
Per Cederqvist's avatar
Per Cederqvist committed
641
    {
642 643 644
	--kill_list_size;
	conn = get_conn_by_number (kill_list[kill_list_size]);
	if (conn == NULL)
Per Cederqvist's avatar
Per Cederqvist committed
645
	{
David Byers's avatar
David Byers committed
646
	    kom_log("check_kill_flg(): Connection %ld doesn't exist.\n",
647 648 649 650
		kill_list[kill_list_size]);
	}
	else
	{
651 652
	    assert(conn->kill_pending);
	    conn->kill_pending = FALSE;
653 654
	    logout_client(conn);
	    end_of_atomic();
655
	    changed = TRUE;
Per Cederqvist's avatar
Per Cederqvist committed
656 657
	}
    }
658

659 660 661 662 663
    if (kill_list != NULL)
    {
	sfree (kill_list);
	kill_list = NULL;
    }
664 665 666

    if (changed == TRUE)
	dump_connections();
667 668

    return OOP_CONTINUE;
Per Cederqvist's avatar
Per Cederqvist committed
669 670
}

671 672

static char *
673
get_host_name(union isc_address *addr)
674 675 676 677 678 679 680 681 682 683 684 685
{
    char *res = NULL;
    char *hostname = NULL;
    struct timeval before;
    struct timeval after;
    double diff = -1.0;

    if (param.use_dns)
    {
	if (gettimeofday(&before, NULL) < 0)
	    kom_log("gettimeofday failed: %s\n", strerror(errno));

686 687
	update_stat(STAT_DNS_QUEUE, 1);
	
688 689
	res = hostname = isc_gethostname(addr, NULL, 0);

690 691
	update_stat(STAT_DNS_QUEUE, -1);

692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712
	if (gettimeofday(&after, NULL) < 0)
	    kom_log("gettimeofday failed: %s\n", strerror(errno));

	diff = (after.tv_sec - before.tv_sec
		+ 1e-6 * (after.tv_usec - before.tv_usec));
    }

    if (res == NULL)
	res = isc_getipnum(addr, NULL, 0);

    if (param.use_dns && diff > param.dns_log_threshold)
    {
	if (hostname == NULL)
	    kom_log("Slow bad DNS: %s failed after %f seconds\n", res, diff);
	else
	    kom_log("Slow DNS: got %s after %f seconds\n", res, diff);
    }

    return res;
}

713 714 715 716 717 718 719
static void
write_err_cb(struct isc_mcb *UNUSED(cb_mcb),
	     struct isc_scb *UNUSED(cb_session),
	     int saved_errno,
	     void *user)
{
    Connection  * cp = user;
720
    if (saved_errno != ECONNRESET && saved_errno != EPIPE)
721 722
	kom_log("Failed to write to client %lu from %s: %s\n",
		cp->session_no, cp->peer, strerror(saved_errno));
723
    cp->penalty += param.max_penalty;
724 725 726 727
    add_to_kill_list(cp);
}


728 729 730 731 732 733 734 735 736 737 738 739
static void
stale_cb(struct isc_mcb *UNUSED(cb_mcb),
	 struct isc_scb *UNUSED(cb_session),
	 void *user)
{
    Connection *cp = user;
    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);
}
    
740

741 742 743 744 745 746 747 748 749 750 751 752 753
static void
idle_cb(struct isc_mcb *UNUSED(cb_mcb),
	struct isc_scb *UNUSED(cb_session),
	void *user)
{
    Connection *cp = user;
    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
754
static void
755
login_request(struct isc_scb *session)
Per Cederqvist's avatar
Per Cederqvist committed
756 757
{
    Connection  * cp;
758
    const char *realuser;
759
    char *hostname = NULL;
760
    char peername[256];
761 762 763
    char portbuf[1+2+3*sizeof(long)];
    size_t hostlen;
    size_t portlen;
Per Cederqvist's avatar
Per Cederqvist committed
764 765

    /* Supress logins if /etc/nologin exists */
David Byers's avatar
David Byers committed
766
    if (fexists(param.nologin_file))
Per Cederqvist's avatar
Per Cederqvist committed
767
    {
768 769 770
	isc_puts("%% No logins allowed.\n", session);
	isc_flush(session);
 	isc_destroy(kom_server_mcb, session);
Per Cederqvist's avatar
Per Cederqvist committed
771 772 773
	return;
    }

774
    hostname = get_host_name(session->raddr);
775
    if (hostname == NULL)
David Byers's avatar
David Byers committed
776
	kom_log("WNG: login_request(): unknown hostid.\n");
777

778
    /* Get the real user name, as returned by the Ident protocol (rfc 931). */
779
    realuser = get_real_username(session, hostname);
780
    if (realuser == NULL && param.authentication_level == 2)
Per Cederqvist's avatar
Per Cederqvist committed
781
    {
David Byers's avatar
David Byers committed
782
	kom_log("Connection from %s rejected - no IDENT available.\n", 
783
	     hostname);
Per Cederqvist's avatar
Per Cederqvist committed
784

785
	isc_puts("%% No IDENT server reachable at your site.\n",
786 787 788
		 session);
	isc_flush(session);
	isc_destroy(kom_server_mcb, session);
789
	return;
Per Cederqvist's avatar
Per Cederqvist committed
790
    }
791

792 793
    /* Create a Connection, and link the Connection and the
       isc_session together. */
794

795
    cp = new_client();
796 797
    cp->isc_session = session;
    session->udg = cp;
798

799 800 801 802 803
    /* 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;

804 805
    if (hostname == NULL)
	s_crea_str(&cp->hostname, "unknown");
806
    else
807 808 809 810 811 812
	s_crea_str(&cp->hostname, hostname);

    if (realuser != NULL)
	s_crea_str(&cp->ident_user, realuser);

    BUG(("\n[Client %lu from %s is connecting]\n", cp->session_no, hostname));
813 814


815
    isc_getipnum(session->raddr, peername, sizeof(peername));
816 817
    hostlen = strlen(peername);
    if (hostlen >= sizeof(peername)-1)
818 819 820 821
    {
	kom_log("login_request(): truncated remote peer address %s.\n",
		peername);
    }
822
    sprintf(portbuf, " %d", isc_getportnum(session->raddr));
823 824
    portlen = strlen(portbuf);
    cp->peer = smalloc(hostlen + portlen + 1);
825
    strcpy(cp->peer, peername);
826
    strcpy(cp->peer + hostlen, portbuf);
827

828
    update_stat(STAT_CLIENTS, 1);
829
    dump_connections();
830

831
    isc_set_read_callback(session, data_available_callback, write_err_cb,
832
			  stale_cb, idle_cb, cp);
Per Cederqvist's avatar
Per Cederqvist committed
833 834 835
}

static void
836
adjust_penalty(Connection *conn)
Per Cederqvist's avatar
Per Cederqvist committed
837
{
838 839 840 841 842 843 844 845
    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
846 847 848 849
}


static void
850
read_from_connection(Connection *conn)
Per Cederqvist's avatar
Per Cederqvist committed
851
{
852
    Bool would_block = FALSE;
853
    Bool need_flush = FALSE;
854
    String_size pre;
Per Cederqvist's avatar
Per Cederqvist committed
855

856 857
    adjust_penalty(conn);

858 859
    while (!would_block && !go_and_die && conn->penalty < param.max_penalty
	   && !conn->kill_pending)
860
    {
861
	pre = s_strlen(conn->unparsed) - conn->first_to_parse;
862
	while (conn->more_to_parse
863 864
	       && !go_and_die && conn->penalty < param.max_penalty
	       && !conn->kill_pending)
865
	    need_flush |= parse_unparsed(conn);
866 867
	update_stat(STAT_RECV_QUEUE,
		    s_strlen(conn->unparsed) - conn->first_to_parse - pre);
868

869 870
	if (go_and_die || conn->penalty >= param.max_penalty
	    || conn->kill_pending)
871 872 873 874
	    break;

	if (!conn->more_to_parse)
	{
875
	    pre = s_strlen(conn->unparsed) - conn->first_to_parse;
876 877 878 879 880
	    switch (isc_read_data(conn->isc_session,
				  &conn->unparsed,
				  &conn->first_to_parse))
	    {
	    case ISC_READ_DATA:
881 882 883
		update_stat(STAT_RECV_QUEUE,
			    s_strlen(conn->unparsed) - conn->first_to_parse
			    - pre);
884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905
		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;
	}
    }
906

907
    if (need_flush)
908 909
	isc_flush(conn->isc_session);

910 911 912 913 914 915 916
    /* 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;

    if (conn->penalty >= param.max_penalty)
    {
917 918 919 920 921
	/* 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);
922
    }
Per Cederqvist's avatar
Per Cederqvist committed
923 924
}

925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941

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;
942 943
    Connection *head = NULL;
    Connection *tail = NULL;
944 945 946 947 948 949 950 951 952

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

    if (is_idle && queue_first != NULL)
    {
	is_idle = FALSE;
	++penalty_generation;
953

954
	for (next = queue_first; next != NULL; )
Per Cederqvist's avatar
Per Cederqvist committed
955
	{
956 957 958 959
	    c = next;
	    next = next->queue_next;
	    adjust_penalty(c);
	    if (c->penalty < param.low_penalty)
Per Cederqvist's avatar
Per Cederqvist committed
960
	    {
961
		queue_remove(c);
962 963 964 965 966 967

		if (head == NULL)
		    head = c;
		else
		    tail->queue_next = c;
		tail = c;
Per Cederqvist's avatar
Per Cederqvist committed
968
	    }
969 970 971
	}
    }

972 973 974 975 976 977 978 979 980 981 982 983 984 985 986
    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);
    }

987 988 989
    if (!is_idle)
	enable_idle_check();

990 991
    /* Check if a client issued a shutdown command.  */
    return go_and_die ? OOP_HALT : OOP_CONTINUE;
992 993 994
}

static void *