aboutsummaryrefslogtreecommitdiffstats
path: root/fetchmail.c
blob: b621c0560290313571f133c297f6a28f35def827 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
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
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
/*
 * fetchmail.c -- main driver module for fetchmail
 *
 * For license terms, see the file COPYING in this directory.
 */

#include <config.h>

#include <stdio.h>
#include <ctype.h>
#if defined(STDC_HEADERS)
#include <stdlib.h>
#endif
#if defined(HAVE_UNISTD_H)
#include <unistd.h>
#endif
#if defined(HAVE_ALLOCA_H)
#include <alloca.h>
#endif
#include <string.h>
#include <signal.h>
#if defined(HAVE_SYSLOG)
#include <syslog.h>
#endif
#include <pwd.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>

#ifdef HAVE_GETHOSTBYNAME
#include <netdb.h>
#endif /* HAVE_GETHOSTBYNAME */

#include "fetchmail.h"
#include "tunable.h"
#include "smtp.h"
#include "getopt.h"
#include "netrc.h"

#define DROPDEAD	6	/* maximum bad socket opens */

/* prototypes for internal functions */
static int load_params(int, char **, int);
static void dump_params (struct query *);
static int query_host(struct query *);
static char *visbuf(const char *);

/* controls the detail level of status/progress messages written to stderr */
int outlevel;    	/* see the O_.* constants above */
int yydebug;		/* enable parse debugging */

/* daemon mode control */
int poll_interval;	/* poll interval in seconds */
int nodetach;		/* if TRUE, don't detach daemon process */
char *logfile;		/* log file for daemon mode */
int use_syslog;		/* if --syslog was set */
int quitmode;		/* if --quit was set */
int check_only;		/* if --probe was set */
char *cmd_logfile;	/* if --logfile was set */

/* miscellaneous global controls */
char *rcfile;		/* path name of rc file */
char *idfile;		/* UID list file */
int versioninfo;	/* emit only version info */
char *user;		/* the name of the invoking user */
char *program_name;	/* the name to prefix error messages with */

static char *lockfile;		/* name of lockfile */
static int querystatus;		/* status of query */
static int lastsig;		/* last signal received */

static void termhook();		/* forward declaration of exit hook */

RETSIGTYPE donothing(sig) int sig; {signal(sig, donothing); lastsig = sig;}

static void unlockit(void)
/* must-do actions for exit (but we can't count on being able to do malloc) */
{
    unlink(lockfile);
}

int main (int argc, char **argv)
{
    int st, bkgd = FALSE;
    int parsestatus, implicitmode;
    char *home, *tmpdir, tmpbuf[BUFSIZ]; 
    struct passwd *pw;
    struct query *ctl;
    FILE	*lockfp;
    netrc_entry *netrc_list;
    char *netrc_file;
    pid_t pid;

    if ((program_name = strrchr(argv[0], '/')) != NULL)
	++program_name;
    else
	program_name = argv[0];

    if ((user = getenv("USER")) == (char *)NULL)
        user = getenv("LOGNAME");

    if ((user == (char *)NULL) || (home = getenv("HOME")) == (char *)NULL)
    {
	if ((pw = getpwuid(getuid())) != NULL)
	{
	    user = pw->pw_name;
	    home = pw->pw_dir;
	}
	else
	{
	    fprintf(stderr,"fetchmail: can't find your name and home directory!\n");
	    exit(PS_UNDEFINED);
	}
    }

    /*
     * Backward-compatibility hack.  If we're called by the name of the
     * ancestral popclient, look for .poprc.  This will actually work 
     * for popclient files that don't use the removed keywords.
     */
    if (strcmp("popclient", argv[0]) == 0)
	tmpdir = ".poprc";
    else
	tmpdir = ".fetchmailrc";

    rcfile = (char *) xmalloc(strlen(home)+strlen(tmpdir)+2);
    strcpy(rcfile, home);
    strcat(rcfile, "/");
    strcat(rcfile, tmpdir);

#define IDFILE_NAME	".fetchids"
    idfile = (char *) xmalloc(strlen(home)+strlen(IDFILE_NAME)+2);
    strcpy(idfile, home);
    strcat(idfile, "/");
    strcat(idfile, IDFILE_NAME);
  
    outlevel = O_NORMAL;

    if ((parsestatus = parsecmdline(argc,argv,&cmd_opts)) < 0)
	exit(PS_SYNTAX);

    /* this hint to stdio should halp messages come out in the right order */
    setvbuf(stdout, NULL, _IOLBF, POPBUFSIZE);

    if (versioninfo)
	printf("This is fetchmail release %s pl %s\n", RELEASE_ID, PATCHLEVEL);

    /* avoid parsing the config file if all we're doing is killing a daemon */ 
    if (!quitmode)
	implicitmode = load_params(argc, argv, optind);

    /* set up to do lock protocol */
    if (!getuid())
	strcpy(tmpbuf, "/var/run/fetchmail.pid");
    else {
	strcpy(tmpbuf, home);
	strcat(tmpbuf, "/.fetchmail");
    }

    /* perhaps we just want to check options? */
    if (versioninfo) {
	printf("Taking options from command line");
	if (access(rcfile, 0))
	    printf("\n");
	else
	    printf(" and %s\n", rcfile);
	if (outlevel == O_VERBOSE)
	    printf("Lockfile at %s\n", tmpbuf);
	for (ctl = querylist; ctl; ctl = ctl->next) {
	    if (ctl->active && !(implicitmode && ctl->server.skip))
		dump_params(ctl);
	}
	if (querylist == NULL)
	    (void) fprintf(stderr,
		"No mailservers set up -- perhaps %s is missing?\n", rcfile);
	exit(0);
    }
    else if (!quitmode && querylist == NULL) {
	(void) fputs("fetchmail: no mailservers have been specified.\n", stderr);
	exit(PS_SYNTAX);
    }

    /* check for another fetchmail running concurrently */
    pid = -1;
    if ((lockfile = (char *) malloc(strlen(tmpbuf) + 1)) == NULL)
    {
	fprintf(stderr,"fetchmail: cannot allocate memory for lock name.\n");
	exit(PS_EXCLUDE);
    }
    else
	(void) strcpy(lockfile, tmpbuf);
    if ((lockfp = fopen(lockfile, "r")) != NULL )
    {
	bkgd = (fscanf(lockfp,"%d %d", &pid, &st) == 2);

	if (kill(pid, 0) == -1) {
	    fprintf(stderr,"fetchmail: removing stale lockfile\n");
	    pid = -1;
	    bkgd = FALSE;
	    unlink(lockfile);
	}
	fclose(lockfp);
    }

    /* perhaps user asked us to kill the other fetchmail */
    if (quitmode)
    {
	if (pid == -1) 
	{
	    fprintf(stderr,"fetchmail: no other fetchmail is running\n");
	    exit(PS_EXCLUDE);
	}
	else if (kill(pid, SIGTERM) < 0)
	{
	    fprintf(stderr,"fetchmail: error killing %s fetchmail at %d.\n",
		    bkgd ? "background" : "foreground", pid);
	    exit(PS_EXCLUDE);
	}
	else
	{
	    fprintf(stderr,"fetchmail: %s fetchmail at %d killed.\n",
		    bkgd ? "background" : "foreground", pid);
	    unlink(lockfile);
	    exit(0);
	}
    }

    /* another fetchmail is running -- wake it up or die */
    if (pid != -1)
    {
	if (check_only)
	{
	    fprintf(stderr,
		 "fetchmail: can't check mail while another fetchmail to same host is running.");
	    return(PS_EXCLUDE);
        }
	else if (!implicitmode)
	{
	    fprintf(stderr,
		 "fetchmail: can't poll specified hosts with another fetchmail running at %d.\n",
		 pid);
		return(PS_EXCLUDE);
	}
	else if (!bkgd)
	{
	    fprintf(stderr,
		 "fetchmail: another foreground fetchmail is running at %d.\n",
		 pid);
		return(PS_EXCLUDE);
	}
	else if (kill(pid, SIGUSR1) == 0)
	{
	    fprintf(stderr,
		    "fetchmail: background fetchmail at %d awakened.\n",
		    pid);
	    return(0);
	}
	else
	{
	    /*
	     * Should never happen -- possible only if a background fetchmail
	     * croaks after the first kill probe above but before the SIGUSR1/SIGHUP
	     * transmission.
	     */
	    fprintf(stderr,
		    "fetchmail: elder sibling at %d died mysteriously.\n",
		    pid);
	    return(PS_UNDEFINED);
	}
    }

    /* parse the ~/.netrc file, for future password lookups. */
    netrc_file = (char *) xmalloc (strlen (home) + 8);
    strcpy (netrc_file, home);
    strcat (netrc_file, "/.netrc");

    netrc_list = parse_netrc (netrc_file);

    /* pick up interactively any passwords we need but don't have */ 
    for (ctl = querylist; ctl; ctl = ctl->next)
	if (ctl->active && !(implicitmode && ctl->server.skip) && !ctl->password)
	{
	    if (ctl->server.authenticate == A_KERBEROS)
		/* Server won't care what the password is, but there
		   must be some non-null string here.  */
		ctl->password = ctl->remotename;
	    else
	    {
		/* Look up the host and account in the .netrc file. */
		netrc_entry *p = search_netrc(netrc_list,ctl->server.names->id);
		while (p && strcmp (p->account, ctl->remotename))
		    p = search_netrc (p->next, ctl->remotename);

		if (p)
		{
		    /* We found the entry, so use the password. */
		    ctl->password = xstrdup(p->password);
		}
	    }

	    if (!ctl->password)
	    {
		(void) sprintf(tmpbuf, "Enter password for %s@%s: ",
			       ctl->remotename, ctl->server.names->id);
		ctl->password = xstrdup((char *)getpassword(tmpbuf));
	    }
	}

    /*
     * Maybe time to go to demon mode...
     */
#if defined(HAVE_SYSLOG)
    if (use_syslog)
    	openlog(program_name, LOG_PID, LOG_MAIL);
#endif

    if (poll_interval && !nodetach)
	daemonize(logfile, termhook);

    /* beyond here we don't want more than one fetchmail running per user */
    umask(0077);
    signal(SIGABRT, termhook);
    signal(SIGINT, termhook);
    signal(SIGTERM, termhook);
    signal(SIGALRM, termhook);
    signal(SIGPIPE, termhook);
    signal(SIGQUIT, termhook);

    /*
     * With this simple hack, we make it possible for a foreground 
     * fetchmail to wake up one in daemon mode.  What we want is the
     * side effect of interrupting any sleep that may be going on,
     * forcing fetchmail to re-poll its hosts.
     */
    signal(SIGUSR1, donothing);

    /* pacify people who think all system daemons wake up on SIGHUP */
    if (poll_interval && !getuid())
	signal(SIGHUP, donothing);

    /* here's the exclusion lock */
    if ( (lockfp = fopen(lockfile,"w")) != NULL ) {
	fprintf(lockfp,"%d",getpid());
	if (poll_interval)
	    fprintf(lockfp," %d", poll_interval);
	fclose(lockfp);
	atexit(unlockit);
    }

    /*
     * Query all hosts. If there's only one, the error return will
     * reflect the status of that transaction.
     */
    do {
#ifdef HAVE_RES_SEARCH
	sethostent(TRUE);	/* use TCP/IP for mailserver queries */
#endif /* HAVE_RES_SEARCH */

	batchcount = 0;
	for (ctl = querylist; ctl; ctl = ctl->next)
	{
	    if (ctl->active && !(implicitmode && ctl->server.skip))
	    {
#ifdef linux
		/* interface_check does its own error logging */
		if (!interface_check(&ctl->server))
		    continue;
#endif /* linux */

#ifdef HAVE_GETHOSTBYNAME
		/*
		 * This functions partly as an optimization and partly
		 * as a probe to make sure our nameserver is still up.
		 * The multidrop case (especially) needs it.
		 */
		if (ctl->server.authenticate == A_KERBEROS || MULTIDROP(ctl))
		{
		    struct hostent	*namerec;

		    /* compute the canonical name of the host */
		    errno = 0;
		    namerec = gethostbyname(ctl->server.names->id);
		    if (namerec == (struct hostent *)NULL)
		    {
			error(0, errno,
				"skipping %s poll, ",
				ctl->server.names->id);
			if (errno)
			{
			    if (errno == ENETUNREACH)
				break;	/* go to sleep */
			}
#ifdef HAVE_HERROR		/* NEXTSTEP doesn't */
			else
			    herror("DNS error");
#endif /* HAVE_HERROR */
			continue;
		    }
		    else
		    {
			free(ctl->server.canonical_name);
			ctl->server.canonical_name = xstrdup((char *)namerec->h_name);
		    }
		}
#endif /* HAVE_GETHOSTBYNAME */

		querystatus = query_host(ctl);
		if (!check_only)
		    update_str_lists(ctl);
	    }
	}

#ifdef HAVE_RES_SEARCH
	endhostent();		/* release TCP/IP connection to nameserver */
#endif /* HAVE_RES_SEARCH */

	/*
	 * Close all SMTP delivery sockets.  For optimum performance
	 * we'd like to hold them open til end of run, but (1) this
	 * loses if our poll interval is longer than the MTA's inactivity
	 * timeout, and (2) some MTAs (like smail) don't deliver after
	 * each message, but rather queue up mail and wait to actually
	 * deliver it until the input socket is closed. 
	 */
	for (ctl = querylist; ctl; ctl = ctl->next)
	    if (ctl->smtp_sockfp)
	    {
		SMTP_quit(ctl->smtp_sockfp);
		fclose(ctl->smtp_sockfp);
		ctl->smtp_sockfp = (FILE *)NULL;
	    }

	/*
	 * OK, we've polled.  Now sleep.
	 */
	if (poll_interval)
	{
	    if (outlevel == O_VERBOSE)
	    {
		time_t	now;

		time(&now);
		fprintf(stderr, "fetchmail: sleeping at %s", ctime(&now));
	    }

	    /*
	     * We can't use sleep(3) here because we need an alarm(3)
	     * equivalent in order to implement server nonresponse timeout.
	     * We'll just assume setitimer(2) is available since fetchmail
	     * has to have a BSDoid socket layer to work at all.
	     */
	    {
		struct itimerval ntimeout;

		ntimeout.it_interval.tv_sec = ntimeout.it_interval.tv_usec = 0;
		ntimeout.it_value.tv_sec  = poll_interval;
		ntimeout.it_value.tv_usec = 0;

		setitimer(ITIMER_REAL,&ntimeout,NULL);
		signal(SIGALRM, donothing);
		pause();
		signal(SIGALRM, SIG_IGN);
		if (lastsig == SIGUSR1
			|| ((poll_interval && !getuid()) && lastsig == SIGHUP))
		{
#ifdef SYS_SIGLIST_DECLARED
		    error(0, 0, "awakened by %s", sys_siglist[lastsig]);
#else
		    error(0, 0, "awakened by signal %d", lastsig);
#endif
		}
	    }

	    if (outlevel == O_VERBOSE)
	    {
		time_t	now;

		time(&now);
		fprintf(stderr, "fetchmail: awakened at %s", ctime(&now));
	    }
	}
    } while
	(poll_interval);

    if (outlevel == O_VERBOSE)
	fprintf(stderr,"fetchmail: normal termination, status %d\n",querystatus);

    termhook(0);
    exit(querystatus);
}

static int load_params(int argc, char **argv, int optind)
{
    int	implicitmode, st;
    struct passwd *pw;
    struct query def_opts, *ctl, *mp;

    memset(&def_opts, '\0', sizeof(struct query));

    def_opts.server.protocol = P_AUTO;
    def_opts.server.timeout = CLIENT_TIMEOUT;
    def_opts.remotename = user;
    def_opts.smtphost = "localhost";

    /* this builds the host list */
    if (prc_parse_file(rcfile) != 0)
	exit(PS_SYNTAX);

    if ((implicitmode = (optind >= argc)))
    {
	for (ctl = querylist; ctl; ctl = ctl->next)
	    ctl->active = TRUE;
    }
    else
	for (; optind < argc; optind++) 
	{
	    /*
	     * If hostname corresponds to a host known from the rc file,
	     * simply declare it active.  Otherwise synthesize a host
	     * record from command line and defaults
	     */
	    for (ctl = querylist; ctl; ctl = ctl->next)
		if (str_in_list(&ctl->server.names, argv[optind]))
		    goto foundit;

	    ctl = hostalloc(&cmd_opts);
	    save_str(&ctl->server.names, -1, argv[optind]);

	foundit:
	    ctl->active = TRUE;
	}

    /* if there's a defaults record, merge it and lose it */ 
    if (querylist && strcmp(querylist->server.names->id, "defaults") == 0)
    {
	for (ctl = querylist->next; ctl; ctl = ctl->next)
	    optmerge(ctl, querylist);
	querylist = querylist->next;
    }

    /* don't allow a defaults record after the first */
    for (ctl = querylist; ctl; ctl = ctl->next)
	if (ctl != querylist && strcmp(ctl->server.names->id, "defaults") == 0)
	    exit(PS_SYNTAX);

    /* merge in wired defaults, do sanity checks and prepare internal fields */
    for (ctl = querylist; ctl; ctl = ctl->next)
    {
	if (ctl->active && !(implicitmode && ctl->server.skip))
	{
	    /* merge in defaults */
	    optmerge(ctl, &def_opts);

	    /* keep lusers from shooting themselves in the foot :-) */
	    if (poll_interval && ctl->limit)
	    {
		fprintf(stderr,"fetchmail: you'd never see large messages!\n");
		exit(PS_SYNTAX);
	    }

	    /* make sure delivery will default to a real local user */
	    if ((pw = getpwnam(user)) == (struct passwd *)NULL)
	    {
		fprintf(stderr,
			"fetchmail: can't set up default delivery to %s\n", user);
		exit(PS_SYNTAX);	/* has to be from bad rc file */
	    }
	    else
	    {
		ctl->uid = pw->pw_uid;	/* for local delivery via MDA */
		if (!ctl->localnames)	/* for local delivery via SMTP */
		    save_str(&ctl->localnames, -1, user);
	    }

#if !defined(HAVE_GETHOSTBYNAME) || !defined(HAVE_RES_SEARCH)
	    /* can't handle multidrop mailboxes unless we can do DNS lookups */
	    if (ctl->localnames && ctl->localnames->next)
	    {
		fputs("fetchmail: can't handle multidrop mailboxes without DNS\n",
			stderr);
		exit(PS_SYNTAX);
	    }
#endif /* !HAVE_GETHOSTBYNAME || !HAVE_RES_SEARCH */

	    /*
	     * Assign SMTP leaders.  We want to allow all query blocks
	     * sharing the same server/SMTP-host pair to use the same
	     * SMTP connection.  To accomplish this, we initialize
	     * each query block's leader field to point to the first
	     * block in the list with a matching server/SMTP-host pair.
	     *
	     * In the typical case, there will be only one SMTP host (the
	     * client machine) and thus just one SMTP leader (and one listener
	     * process) through the entire poll cycle.
	     */
	    if (!ctl->mda)
	    {
		ctl->smtp_sockfp = (FILE *)NULL;
		for (mp = querylist; mp && mp != ctl; mp = mp->next)
		    if (!strcmp(mp->server.names->id, ctl->server.names->id)
			&& !strcmp(mp->smtphost, ctl->smtphost))
		    {
			ctl->lead_smtp = mp->lead_smtp;
			goto no_new_leader;
		    }
		ctl->lead_smtp = ctl;
	    no_new_leader:;
	    }

	    /* similarly, compute server leaders for queries */
	    for (mp = querylist; mp && mp != ctl; mp = mp->next)
		if (strcmp(mp->server.names->id, ctl->server.names->id) == 0)
		{
		    ctl->server.lead_server = mp->server.lead_server;
		    goto no_new_server;
		}
	    ctl->server.lead_server = &(ctl->server);
	no_new_server:;

	    /* plug in the semi-standard way of indicating a mail address */
	    if (ctl->server.envelope == (char *)NULL)
		ctl->server.envelope = "X-Envelope-To:";

#ifdef linux
	    /* interface_check does its own error logging */
	    interface_parse(&ctl->server);
#endif /* linux */

	    /* sanity checks */
	    if (ctl->server.port < 0)
	    {
		(void) fprintf(stderr,
			       "%s configuration invalid, port number cannot be negative",
			       ctl->server.names->id);
		exit(PS_SYNTAX);
	    }
	}
    }

    /* initialize UID handling */
    if ((st = prc_filecheck(idfile)) != 0)
	exit(st);
    else
	initialize_saved_lists(querylist, idfile);

    /* if cmd_logfile was explicitly set, use it to override logfile */
    if (cmd_logfile)
	logfile = cmd_logfile;

    return(implicitmode);
}

void termhook(int sig)
/* to be executed on normal or signal-induced termination */
{
    struct query	*ctl;

    /*
     * Sending SMTP QUIT on signal is theoretically nice, but led to a 
     * subtle bug.  If fetchmail was terminated by signal while it was 
     * shipping message text, it would hang forever waiting for a
     * command acknowledge.  In theory we could disable the QUIT
     * only outside of the message send.  In practice, we don't
     * care.  All mailservers hang up on a dropped TCP/IP connection
     * anyway.
     */

    if (sig != 0)
        error(0, 0, "terminated with signal %d", sig);
    else
	/* terminate all SMTP connections cleanly */
	for (ctl = querylist; ctl; ctl = ctl->next)
	    if (ctl->lead_smtp == ctl && ctl->smtp_sockfp != (FILE *)NULL)
		SMTP_quit(ctl->smtp_sockfp);

    if (!check_only)
	write_saved_lists(querylist, idfile);

    exit(querystatus);
}

static char *showproto(int proto)
/* protocol index to protocol name mapping */
{
    switch (proto)
    {
    case P_AUTO: return("auto"); break;
    case P_POP2: return("POP2"); break;
    case P_POP3: return("POP3"); break;
    case P_IMAP: return("IMAP"); break;
    case P_APOP: return("APOP"); break;
    default: return("unknown?!?"); break;
    }
}

/*
 * Sequence of protocols to try when autoprobing, most capable to least.
 */
static const int autoprobe[] = {P_IMAP, P_POP3, P_POP2};

static int query_host(struct query *ctl)
/* perform fetch transaction with single host */
{
    int i, st;

    if (outlevel == O_VERBOSE)
    {
	time_t now;

	time(&now);
	fprintf(stderr, "Querying %s (protocol %s) at %s",
	    ctl->server.names->id, showproto(ctl->server.protocol), ctime(&now));
    }
    switch (ctl->server.protocol) {
    case P_AUTO:
	for (i = 0; i < sizeof(autoprobe)/sizeof(autoprobe[0]); i++)
	{
	    ctl->server.protocol = autoprobe[i];
	    if ((st = query_host(ctl)) == PS_SUCCESS || st == PS_NOMAIL || st == PS_AUTHFAIL)
		break;
	}
	ctl->server.protocol = P_AUTO;
	return(st);
	break;
    case P_POP2:
	return(doPOP2(ctl));
	break;
    case P_POP3:
    case P_APOP:
	return(doPOP3(ctl));
	break;
    case P_IMAP:
	return(doIMAP(ctl));
	break;
    default:
	error(0, 0, "unsupported protocol selected.");
	return(PS_PROTOCOL);
    }
}

void dump_params (struct query *ctl)
/* display query parameters in English */
{
    printf("Options for retrieving from %s@%s:\n",
	   ctl->remotename, visbuf(ctl->server.names->id));
#ifdef HAVE_GETHOSTBYNAME
    if (ctl->server.canonical_name)
	printf("  Canonical DNS name of server is %s.\n", ctl->server.canonical_name);
#endif /* HAVE_GETHOSTBYNAME */
    if (ctl->server.names->next)
    {
	struct idlist *idp;

	printf("  Predeclared mailserver aliases:");
	for (idp = ctl->server.names->next; idp; idp = idp->next)
	    printf(" %s", idp->id);
	putchar('\n');
    }
    if (ctl->server.skip || outlevel == O_VERBOSE)
	printf("  This host will%s be queried when no host is specified.\n",
	       ctl->server.skip ? " not" : "");
    if (!ctl->password)
	printf("  Password will be prompted for.\n");
    else if (outlevel == O_VERBOSE)
	if (ctl->server.protocol == P_APOP)
	    printf("  APOP secret = '%s'.\n", visbuf(ctl->password));
        else
	    printf("  Password = '%s'.\n", visbuf(ctl->password));
    if (ctl->server.protocol == P_POP3 
		&& ctl->server.port == KPOP_PORT
		&& ctl->server.authenticate == A_KERBEROS)
	printf("  Protocol is KPOP");
    else
	printf("  Protocol is %s", showproto(ctl->server.protocol));
    if (ctl->server.port)
	printf(" (using port %d)", ctl->server.port);
    else if (outlevel == O_VERBOSE)
	printf(" (using default port)");
    putchar('.');
    putchar('\n');
    if (ctl->server.authenticate == A_KERBEROS)
	    printf("  Kerberos authentication enabled.\n");
    printf("  Server nonresponse timeout is %d seconds", ctl->server.timeout);
    if (ctl->server.timeout ==  CLIENT_TIMEOUT)
	printf(" (default).\n");
    else
	printf(".\n");
    if (ctl->server.localdomains)
    {
	struct idlist *idp;

	printf("  Local domains:");
	for (idp = ctl->server.localdomains; idp; idp = idp->next)
	    printf(" %s", idp->id);
	putchar('\n');
    }

    printf("  %s messages will be retrieved (--all %s).\n",
	   ctl->fetchall ? "All" : "Only new",
	   ctl->fetchall ? "on" : "off");
    printf("  Fetched messages will%s be kept on the server (--keep %s).\n",
	   ctl->keep ? "" : " not",
	   ctl->keep ? "on" : "off");
    printf("  Old messages will%s be flushed before message retrieval (--flush %s).\n",
	   ctl->flush ? "" : " not",
	   ctl->flush ? "on" : "off");
    printf("  Rewrite of server-local addresses is %sabled (--norewrite %s).\n",
	   ctl->norewrite ? "dis" : "en",
	   ctl->norewrite ? "on" : "off");
    if (ctl->limit)
	printf("  Message size limit is %d bytes (--limit %d).\n", 
	       ctl->limit, ctl->limit);
    else if (outlevel == O_VERBOSE)
	printf("  No message size limit (--limit 0).\n");
    if (ctl->fetchlimit)
	printf("  Received-message limit is %d (--fetchlimit %d).\n",
	       ctl->fetchlimit, ctl->fetchlimit);
    else if (outlevel == O_VERBOSE)
	printf("  No received-message limit (--fetchlimit 0).\n");
    if (ctl->batchlimit)
	printf("  SMTP message batch limit is %d.\n", ctl->batchlimit);
    else if (outlevel == O_VERBOSE)
	printf("  No SMTP message batch limit.\n");
    if (ctl->mda)
	printf("  Messages will be delivered with '%s.'\n", visbuf(ctl->mda));
    else
	printf("  Messages will be SMTP-forwarded to '%s'.\n", visbuf(ctl->smtphost));
    if (ctl->preconnect)
	printf("  Server connection will be preinitialized with '%s.'\n", visbuf(ctl->preconnect));
    else if (outlevel == O_VERBOSE)
	printf("  No preinitialization command.\n");
    if (!ctl->localnames)
	printf("  No localnames declared for this host.\n");
    else
    {
	struct idlist *idp;
	int count = 0;

	for (idp = ctl->localnames; idp; idp = idp->next)
	    ++count;

	printf("  %d local name(s) recognized%s.\n",
	       count,
	       (count == 1 && !strcmp(ctl->localnames->id, user)) ? " (by default)" : "");
	if (outlevel == O_VERBOSE)
	{
	    for (idp = ctl->localnames; idp; idp = idp->next)
		if (idp->val.id2)
		    printf("\t%s -> %s\n", idp->id, idp->val.id2);
		else
		    printf("\t%s\n", idp->id);
	    if (ctl->wildcard)
		fputs("*\n", stdout);
	}

	if (count > 1)
	    printf("  Envelope header is assumed to be: %s\n", ctl->server.envelope);
    }
#ifdef	linux
    if (ctl->server.interface)
	printf("TCP/IP interface requirements for %s.\n", ctl->server.interface);
    else if (outlevel == O_VERBOSE)
	printf("No TCP/IP interface requirements specified.\n");
    if (ctl->server.monitor)
	printf("Polling loop will monitor %s.\n", ctl->server.monitor);
    else if (outlevel == O_VERBOSE)
	printf("No monitor interface specified.\n");
#endif

    if (ctl->server.protocol > P_POP2)
	if (!ctl->oldsaved)
	    printf("  No UIDs saved from this host.\n");
	else
	{
	    struct idlist *idp;
	    int count = 0;

	    for (idp = ctl->oldsaved; idp; idp = idp->next)
		++count;

	    printf("  %d UIDs saved.\n", count);
	    if (outlevel == O_VERBOSE)
		for (idp = ctl->oldsaved; idp; idp = idp->next)
		    fprintf(stderr, "\t%s\n", idp->id);
	}
}

/* helper functions for string interpretation and display */

void escapes(cp, tp)
/* process standard C-style escape sequences in a string */
const char	*cp;	/* source string with escapes */
char		*tp;	/* target buffer for digested string */
{
    while (*cp)
    {
	int	cval = 0;

	if (*cp == '\\' && strchr("0123456789xX", cp[1]))
	{
	    char *dp, *hex = "00112233445566778899aAbBcCdDeEfF";
	    int dcount = 0;

	    if (*++cp == 'x' || *cp == 'X')
		for (++cp; (dp = strchr(hex, *cp)) && (dcount++ < 2); cp++)
		    cval = (cval * 16) + (dp - hex) / 2;
	    else if (*cp == '0')
		while (strchr("01234567",*cp) != (char*)NULL && (dcount++ < 3))
		    cval = (cval * 8) + (*cp++ - '0');
	    else
		while ((strchr("0123456789",*cp)!=(char*)NULL)&&(dcount++ < 3))
		    cval = (cval * 10) + (*cp++ - '0');
	}
	else if (*cp == '\\')		/* C-style character escapes */
	{
	    switch (*++cp)
	    {
	    case '\\': cval = '\\'; break;
	    case 'n': cval = '\n'; break;
	    case 't': cval = '\t'; break;
	    case 'b': cval = '\b'; break;
	    case 'r': cval = '\r'; break;
	    default: cval = *cp;
	    }
	    cp++;
	}
	else
	    cval = *cp++;
	*tp++ = cval;
    }
    *tp = '\0';
}

static char *visbuf(const char *buf)
/* visibilize a given string */
{
    static char vbuf[BUFSIZ];
    char *tp = vbuf;

    while (*buf)
    {
	if (isprint(*buf) || *buf == ' ')
	    *tp++ = *buf++;
	else if (*buf == '\n')
	{
	    *tp++ = '\\'; *tp++ = 'n';
	    buf++;
	}
	else if (*buf == '\r')
	{
	    *tp++ = '\\'; *tp++ = 'r';
	    buf++;
	}
	else if (*buf == '\b')
	{
	    *tp++ = '\\'; *tp++ = 'b';
	    buf++;
	}
	else if (*buf < ' ')
	{
	    *tp++ = '\\'; *tp++ = '^'; *tp++ = '@' + *buf;
	    buf++;
	}
	else
	{
	    (void) sprintf(tp, "\\0x%02x", *buf++);
	    tp += strlen(tp);
	}
    }
    *tp++ = '\0';
    return(vbuf);
}

/* fetchmail.c ends here */