summaryrefslogtreecommitdiffstats
path: root/urpm/media.pm
blob: b85a13bf431374ee6024cca33cafbbf522c38bdd (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
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
package urpm::media;

# $Id$

use urpm 'file_from_local_url';
use urpm::msg;
use urpm::util;
use urpm::removable;
use urpm::lock;
use MDV::Distribconf;


our @PER_MEDIA_OPT = qw(
    downloader
    hdlist
    ignore
    key-ids
    list
    media_info_dir
    name
    noreconfigure
    priority-upgrade
    removable
    static
    synthesis
    update
    url
    verify-rpm
    virtual
    with_hdlist
    with_synthesis
);

sub get_medium_option {
    my ($urpm, $medium, $option_name) = @_;

    defined $medium->{$option_name} ? $medium->{$option_name} : $urpm->{options}{$option_name};
}

sub only_media_opts {
    my ($m) = @_;
    my %m = map { $_ => $m->{$_} } grep { defined $m->{$_} } @PER_MEDIA_OPT;
    \%m;
}

sub read_private_netrc {
    my ($urpm) = @_;

    my @words = split(/\s+/, scalar cat_($urpm->{private_netrc}));
    my @l;
    my $e;
    while (@words) {
	my $keyword = shift @words;
	if ($keyword eq 'machine') {
	    push @l, $e = { machine => shift(@words) };
	} elsif ($keyword eq 'default') {
	    push @l, $e = { default => '' };
	} elsif ($keyword eq 'login' || $keyword eq 'password' || $keyword eq 'account') {
	    $e->{$keyword} = shift(@words);
	} else {
	    $urpm->{error}("unknown netrc command $keyword");
	}
    }
    @l;
}

sub read_config_add_passwords {
    my ($urpm, $config) = @_;

    my @netrc = read_private_netrc($urpm) or return;
    foreach (@{$config->{media}}) {
	my $u = urpm::download::parse_url_with_login($_->{url}) or next;
	if (my ($e) = grep { ($_->{default} || $_->{machine} eq $u->{machine}) && $_->{login} eq $u->{login} } @netrc) {
	    $_->{url} = sprintf('%s://%s:%s@%s%s', $u->{proto}, $u->{login}, $e->{password}, $u->{machine}, $u->{dir});
	} else {
	    $urpm->{log}(sprintf('no password found for %s@%s', $u->{login}, $u->{machine}));
	}
    }
}

sub remove_passwords_and_write_private_netrc {
    my ($urpm, $config) = @_;

    my @l;
    foreach (@{$config->{media}}) {
	my $u = urpm::download::parse_url_with_login($_->{url}) or next;
	#- check whether a password is visible
	$u->{password} or next;

	push @l, $u;
	$_->{url} = sprintf('%s://%s@%s%s', $u->{proto}, $u->{login}, $u->{machine}, $u->{dir});
    }
    {
	my $fh = urpm::sys::open_safe($urpm, '>', $urpm->{private_netrc}) or return;
	foreach my $u (@l) {
	    printf $fh "machine %s login %s password %s\n", $u->{machine}, $u->{login}, $u->{password};
	}
    }
    chmod 0600, $urpm->{private_netrc};
}

#- handle deprecated way of saving passwords
sub recover_url_from_list {
    my ($urpm, $medium) = @_;

    my $list = delete $medium->{list} or return;
    my $statedir_list = "$urpm->{statedir}/$list";

    #- /./ is end of url marker in list file (typically generated by a
    #- find . -name "*.rpm" > list
    #- for exportable list file.
    if (my @probe = map { m!^(.*)/\./! || m!^(.*)/[^/]*$! } cat_($statedir_list)) {
	$urpm->{log}("recovering url from $statedir_list");
	($medium->{url}) = sort { length($a) <=> length($b) } @probe;
	$urpm->{modified} = 1; #- ensure urpmi.cfg is handled using only partially hidden url + netrc, since file list won't be generated anymore
	unlink $statedir_list;
    }
}

#- Loads /etc/urpmi/urpmi.cfg and performs basic checks.
#- Does not handle old format: <name> <url> [with <path_hdlist>]
#- options :
#-    - nocheck_access : don't check presence of synthesis and other files
sub read_config {
    my ($urpm, $b_nocheck_access) = @_;
    return if $urpm->{media}; #- media already loaded
    $urpm->{media} = [];
    my $config = urpm::cfg::load_config($urpm->{config})
	or $urpm->{fatal}(6, $urpm::cfg::err);

    #- per-media options
    read_config_add_passwords($urpm, $config);

    foreach my $m (@{$config->{media}}) {
	my $medium = only_media_opts($m);

	if (!$medium->{url}) {
	    #- recover the url the old deprecated way...
	    #- only useful for migration, new urpmi.cfg will use netrc
	    recover_url_from_list($urpm, $medium);
	    $medium->{url} or $urpm->{error}("unable to find url in list file $medium->{name}, medium ignored");
	}

	add_existing_medium($urpm, $medium, $b_nocheck_access);
    }

    eval { require urpm::ldap; urpm::ldap::load_ldap_media($urpm) };
}

#- if invalid, set {ignore}
sub check_existing_medium {
    my ($urpm, $medium, $b_nocheck_access) = @_;

    my $err;
    if (!$medium->{url}) { 
	$err = $medium->{virtual} ?
	  N("virtual medium \"%s\" should have a clear url, medium ignored",
			   $medium->{name}) :
	  N("unable to access list file of \"%s\", medium ignored", $medium->{name});
    } elsif (!$b_nocheck_access && !$medium->{ignore} 
	     && !-r any_synthesis($urpm, $medium)) {
	$err = N("unable to access synthesis file of \"%s\", medium ignored", $medium->{name});
    }
    if ($err) {
	$medium->{ignore} = 1;
	$urpm->{error}($err);
    }
}

sub _migrate__with_synthesis {
    my ($medium, $with_synthesis) = @_;

    #- try to migrate to media_info_dir
    my $b = basename($with_synthesis);
    if ($b eq 'synthesis.hdlist.cz' || $b eq 'hdlist.cz') {
	$medium->{media_info_dir} = dirname($with_synthesis);
    } else {
	$with_synthesis =~ s/(synthesis\.)?(hdlist.*\.cz)$/synthesis.$2/;
	$medium->{with_synthesis} = $with_synthesis;
    }
}

#- probe medium to be used, take old medium into account too.
sub add_existing_medium {
    my ($urpm, $medium, $b_nocheck_access) = @_;

    if (name2medium($urpm, $medium->{name})) {
	$urpm->{error}(N("trying to override existing medium \"%s\", skipping", $medium->{name}));
	return;
    }

    if ($medium->{with_hdlist}) {
	_migrate__with_synthesis($medium, delete $medium->{with_hdlist});
	$urpm->{modified} = 1;
    }

    check_existing_medium($urpm, $medium, $b_nocheck_access);

    #- probe removable device.
    probe_removable_device($urpm, $medium);

    #- clear URLs for trailing /es.
    $medium->{url} and $medium->{url} =~ s|(.*?)/*$|$1|;

    push @{$urpm->{media}}, $medium;
}

sub file_from_file_url {
    my ($url) = @_;
    $url =~ m!^(?:file:/)?(/.*)! && $1;
}

sub _url_with_synthesis_basename {
    my ($medium) = @_;

    $medium->{with_synthesis}
      ? basename($medium->{with_synthesis})
      : 'synthesis.hdlist.cz';
}
sub _synthesis_dir {
    my ($medium) = @_;
    my $base = file_from_local_url($medium->{url}) || $medium->{url};
    $medium->{with_synthesis}
      ? reduce_pathname("$base/$medium->{with_synthesis}/..")
      : $medium->{media_info_dir} && reduce_pathname("$base/$medium->{media_info_dir}");
}
sub _url_with_synthesis {
    my ($medium) = @_;

    my $base = file_from_local_url($medium->{url}) || $medium->{url};
    $medium->{with_synthesis}
      ? reduce_pathname("$base/$medium->{with_synthesis}")
      : _synthesis_dir($medium) . "/" . _url_with_synthesis_basename($medium);

}

sub _synthesis {
    my ($medium) = @_;
    $medium->{name} && "synthesis.hdlist.$medium->{name}.cz";
}

sub statedir_synthesis {
    my ($urpm, $medium) = @_;
    "$urpm->{statedir}/" . _synthesis($medium);
}
sub statedir_descriptions {
    my ($urpm, $medium) = @_;
    $medium->{name} && "$urpm->{statedir}/descriptions.$medium->{name}";
}
sub statedir_names {
    my ($urpm, $medium) = @_;
    $medium->{name} && "$urpm->{statedir}/names.$medium->{name}";
}
sub statedir_MD5SUM {
    my ($urpm, $medium) = @_;
    $medium->{name} && "$urpm->{statedir}/MD5SUM.$medium->{name}";
}
sub cachedir_with_synthesis {
    my ($urpm, $medium) = @_;
    _url_with_synthesis($medium) && "$urpm->{cachedir}/partial/" . _url_with_synthesis_basename($medium);
}
sub any_synthesis {
    my ($urpm, $medium) = @_;
    my $f = $medium->{virtual} ? _url_with_synthesis($medium)
      : statedir_synthesis($urpm, $medium);
    -e $f && $f;
}

sub name2medium {
    my ($urpm, $name) = @_;
    my ($medium) = grep { $_->{name} eq $name } @{$urpm->{media}};
    $medium;
}

#- probe device associated with a removable device.
sub probe_removable_device {
    my ($urpm, $medium) = @_;

    if ($medium->{url} && $medium->{url} =~ /^removable/) {
	#- try to find device name in url scheme, this is deprecated, use medium option "removable" instead
	if ($medium->{url} =~ /^removable_?([^_:]*)/) {
	    $medium->{removable} ||= $1 && "/dev/$1";
	}
    } else {
	delete $medium->{removable};
	return;
    }

    #- try to find device to open/close for removable medium.
    if (my $dir = file_from_local_url($medium->{url})) {
	my %infos;
	my @mntpoints = urpm::sys::find_mntpoints($dir, \%infos);
	if (@mntpoints > 1) {	#- return value is suitable for an hash.
	    $urpm->{log}(N("too many mount points for removable medium \"%s\"", $medium->{name}));
	    $urpm->{log}(N("taking removable device as \"%s\"", join ',', map { $infos{$_}{device} } @mntpoints));
	}
	if (urpm::removable::is_iso($medium->{removable})) {
	    $urpm->{log}(N("Medium \"%s\" is an ISO image, will be mounted on-the-fly", $medium->{name}));
	} elsif (@mntpoints) {
	    if ($medium->{removable} && $medium->{removable} ne $infos{$mntpoints[-1]}{device}) {
		$urpm->{log}(N("using different removable device [%s] for \"%s\"",
			       $infos{$mntpoints[-1]}{device}, $medium->{name}));
	    }
	    $medium->{removable} = $infos{$mntpoints[-1]}{device};
	} else {
	    $urpm->{error}(N("unable to retrieve pathname for removable medium \"%s\"", $medium->{name}));
	}
    } else {
	$urpm->{error}(N("unable to retrieve pathname for removable medium \"%s\"", $medium->{name}));
    }
}


#- Writes the urpmi.cfg file.
sub write_urpmi_cfg {
    my ($urpm) = @_;

    #- avoid trashing exiting configuration if it wasn't loaded
    $urpm->{media} or return;

    my $config = {
	#- global config options found in the config file, without the ones
	#- set from the command-line
	global => $urpm->{global_config},
	media => [ map { only_media_opts($_) } grep { !$_->{external} } @{$urpm->{media}} ],
    };
    remove_passwords_and_write_private_netrc($urpm, $config);

    urpm::cfg::dump_config($urpm->{config}, $config)
	or $urpm->{fatal}(6, N("unable to write config file [%s]", $urpm->{config}));

    $urpm->{log}(N("wrote config file [%s]", $urpm->{config}));

    #- everything should be synced now.
    delete $urpm->{modified};
}

sub write_config {
    my ($urpm) = @_;

    write_urpmi_cfg($urpm);
}

sub _tempignore {
    my ($medium, $ignore) = @_;
    $medium->{ignore} = $ignore;
}

#- read urpmi.cfg file as well as necessary synthesis files
#- options :
#-	root (deprecated, set directly $urpm->{root})
#-	cmdline_skiplist
#-      nocheck_access (used by read_config)
#-
#-	callback (urpmf)
#-	need_xml (for urpmf: to be able to have info not available in synthesis)
#-	nodepslist (for urpmq: we don't need the synthesis)
#-	no_skiplist (urpmf)
#-
#-	synthesis (use this synthesis file, and only this synthesis file)
#-
#-	parallel
#-	usedistrib (otherwise uses urpmi.cfg)
#-	  media
#-	  excludemedia
#-	  sortmedia
#-
#-	  update
#-	  searchmedia
sub configure {
    my ($urpm, %options) = @_;

    clean($urpm);

    $options{parallel} && $options{usedistrib} and $urpm->{fatal}(1, N("Can't use parallel mode with use-distrib mode"));

    if ($options{parallel}) {
	require urpm::parallel;
	urpm::parallel::configure($urpm, $options{parallel});

	if (!$options{media} && $urpm->{parallel_handler}{media}) {
	    $options{media} = $urpm->{parallel_handler}{media};
	    $urpm->{log}->(N("using associated media for parallel mode: %s", $options{media}));
	}
    } else {
	#- nb: can't have both parallel and root
	$urpm->{root} = $options{root} if $options{root};
    }

    if ($urpm->{root} && ! -c "$urpm->{root}/dev/null") {
	mkdir "$urpm->{root}/dev";
	system("/bin/cp", "-a", '/dev/null', "$urpm->{root}/dev");
    }

    if ($options{synthesis}) {
	if ($options{synthesis} ne 'none') {
	    #- synthesis take precedence over media, update options.
	    $options{media} || $options{excludemedia} || $options{sortmedia} || $options{update} || $options{usedistrib} || $options{parallel} and
	      $urpm->{fatal}(1, N("--synthesis cannot be used with --media, --excludemedia, --sortmedia, --update, --use-distrib or --parallel"));
	    $urpm->parse_synthesis($options{synthesis});
	    #- synthesis disables the split of transaction (too risky and not useful).
	    $urpm->{options}{'split-length'} = 0;
	}
    } else {
        if ($options{usedistrib}) {
            $urpm->{media} = [];
            add_distrib_media($urpm, "Virtual", $options{usedistrib}, %options, 'virtual' => 1);
        } else {
	    read_config($urpm, $options{nocheck_access});
	    if (!$options{media} && $urpm->{options}{'default-media'}) {
		$options{media} = $urpm->{options}{'default-media'};
	    }
        }
	if ($options{media}) {
	    delete $_->{modified} foreach @{$urpm->{media} || []};
	    select_media($urpm, split /,/, $options{media});
	    foreach (@{$urpm->{media} || []}) {
		_tempignore($_, !$_->{modified});
	    }
	}
	if ($options{searchmedia}) {
	   foreach (select_media_by_name($urpm, [ split /,/, $options{searchmedia} ])) {
	       #- Ensure this media is selected
	       $_->{modified} = 1;
	       _tempignore($_, 0);
	       $_->{searchmedia} = 1;
	   }
	}
	if ($options{excludemedia}) {
	    delete $_->{modified} foreach @{$urpm->{media} || []};
	    foreach (select_media_by_name($urpm, [ split /,/, $options{excludemedia} ])) {
		$_->{modified} = 1;
		#- this is only a local ignore that will not be saved.
		_tempignore($_, 1);
	    }
	}
	if ($options{sortmedia}) {
	    my @sorted_media = map { select_media_by_name($urpm, [$_]) } split(/,/, $options{sortmedia});
	    my @remaining = difference2($urpm->{media}, \@sorted_media);
	    $urpm->{media} = [ @sorted_media, @remaining ];
	}
	_parse_media($urpm, \%options) if !$options{nodepslist};
    }
    #- determine package to withdraw (from skip.list file) only if something should be withdrawn.
    if (!$options{nodepslist}) {
	_compute_flags_for_skiplist($urpm, $options{cmdline_skiplist}) if !$options{no_skiplist};
	_compute_flags_for_instlist($urpm);
    }
}

sub _parse_media {
    my ($urpm, $options) = @_;

    foreach (grep { !$_->{ignore} && (!$options->{update} || $_->{update}) } @{$urpm->{media} || []}) {
	our $currentmedia = $_; #- hack for urpmf
	delete @$_{qw(start end)};
	_parse_synthesis_or_ignore($urpm, $_, $options->{callback});

	if ($options->{need_xml}) {
	    # TODO
	    # _parse_xml_($urpm, $_, any_xml($urpm, $_), $options->{callback});
	}
	if ($_->{searchmedia}) {
	    $urpm->{searchmedia} = 1;
	    $urpm->{log}(N("Search start: %s end: %s", $_->{start}, $_->{end}));
	}
    }
}

sub _compute_flags_for_skiplist {
    my ($urpm, $cmdline_skiplist) = @_;
    my %uniq;
    $urpm->compute_flags(
	urpm::sys::get_packages_list($urpm->{skiplist}, $cmdline_skiplist),
	skip => 1,
	callback => sub {
	    my ($urpm, $pkg) = @_;
	    $pkg->is_arch_compat && ! exists $uniq{$pkg->fullname} or return;
	    $uniq{$pkg->fullname} = undef;
	    $urpm->{log}(N("skipping package %s", scalar($pkg->fullname)));
	},
    );
}

sub _compute_flags_for_instlist {
    my ($urpm) = @_;

    my %uniq;
    $urpm->compute_flags(
	urpm::sys::get_packages_list($urpm->{instlist}),
	disable_obsolete => 1,
	callback => sub {
	    my ($urpm, $pkg) = @_;
	    $pkg->is_arch_compat && ! exists $uniq{$pkg->fullname} or return;
	    $uniq{$pkg->fullname} = undef;
	    $urpm->{log}(N("would install instead of upgrade package %s", scalar($pkg->fullname)));
	},
    );

}

#- add a new medium, sync the config file accordingly.
#- returns the new medium's name. (might be different from the requested
#- name if index_name was specified)
#- options: ignore, index_name, nolock, update, virtual, media_info_dir
sub add_medium {
    my ($urpm, $name, $url, $with_synthesis, %options) = @_;

    #- make sure configuration has been read.
    $urpm->{media} or die "caller should have used ->read_config or ->configure first";

    #- if a medium with that name has already been found, we have to exit now
    if (defined $options{index_name}) {
	my ($i, $basename) = ($options{index_name}, $name);
	while (1) {
	    ++$i;
	    $name = $basename . ($i == 1 ? '' : $i);
	    last if !name2medium($urpm, $name);
	}
    } else {
	name2medium($urpm, $name) and $urpm->{fatal}(5, N("medium \"%s\" already exists", $name));
    }

    $url =~ s,/*$,,; #- clear URLs for trailing /es.

    #- creating the medium info.
    my $medium = { name => $name, 
		url => $url, 
		modified => !$options{ignore}, 
	    };
    foreach (qw(downloader update ignore media_info_dir)) {
	$medium->{$_} = $options{$_} if exists $options{$_};
    }

    if ($options{virtual}) {
	file_from_file_url($url) or $urpm->{fatal}(1, N("virtual medium needs to be local"));
	$medium->{virtual} = 1;
    } else {
	probe_removable_device($urpm, $medium);
    }

    if ($with_synthesis) {
	_migrate__with_synthesis($medium, $with_synthesis);
    }

    #- local media have priority, other are added at the end.
    my $inserted;
    my $ignore_text = $medium->{ignore} ? ' ' . N("(ignored by default)") : '';
    if (file_from_file_url($url)) {
	#- insert before first remote medium
	@{$urpm->{media}} = map {  
	    if (!file_from_file_url($_->{url}) && !$inserted) {
		$inserted = 1;
		$urpm->{info}(N("adding medium \"%s\" before remote medium \"%s\"", $name, $_->{name}) . $ignore_text);
		$medium, $_;
	    } else { $_ }
	} @{$urpm->{media}};
    }
    if (!$inserted) {
	$urpm->{info}(N("adding medium \"%s\"", $name) . $ignore_text);
	push @{$urpm->{media}}, $medium;
    }

    $urpm->{modified} = 1;

    $name;
}

#- add distribution media, according to url given.
#- returns the list of names of added media.
#- options :
#- - initial_number : when adding several numbered media, start with this number
#- - probe_with : force use of rpms instead of using synthesis
#- - ask_media : callback to know whether each media should be added
#- - only_updates : only add "update" media (used by rpmdrake)
#- other options are passed to add_medium(): ignore, nolock, virtual
sub add_distrib_media {
    my ($urpm, $name, $url, %options) = @_;

    #- make sure configuration has been read.
    $urpm->{media} or die "caller should have used ->read_config or ->configure first";

    my $distribconf;

    if (my $dir = file_from_local_url($url)) {
	urpm::removable::try_mounting($urpm, $dir)
	    or $urpm->{error}(N("unable to mount the distribution medium")), return ();
	$distribconf = MDV::Distribconf->new($dir, undef);
	$distribconf->load
	    or $urpm->{error}(N("this location doesn't seem to contain any distribution")), return ();
    } else {
	unlink "$urpm->{cachedir}/partial/media.cfg";

	$distribconf = MDV::Distribconf->new($url, undef);
	$distribconf->settree('mandriva');

	$urpm->{log}(N("retrieving media.cfg file..."));
	if (urpm::download::sync($urpm, undef,
				 [ reduce_pathname($distribconf->getfullpath(undef, 'infodir') . '/media.cfg') ],
				 quiet => 1)) {
	    $distribconf->parse_mediacfg("$urpm->{cachedir}/partial/media.cfg")
		or $urpm->{error}(N("unable to parse media.cfg")), return();
	} else {
	    $urpm->{error}(N("...retrieving failed: %s", $@));
	    $urpm->{error}(N("unable to access the distribution medium (no media.cfg file found)"));
	    return ();
	}
    }

    #- cosmetic update of name if it contains spaces.
    $name =~ /\s/ and $name .= ' ';

    my @newnames;
    #- at this point, we have found a media.cfg file, so parse it
    #- and create all necessary media according to it.
    my $medium_index = $options{initial_number} || 1;

    foreach my $media ($distribconf->listmedia) {
        my $media_name = $distribconf->getvalue($media, 'name') || '';

        if (my $media_arch = $distribconf->getvalue($media, 'arch')) {
            if (!URPM::archscore($media_arch)) {
                $urpm->{log}(N("skipping non compatible media `%s' (for %s)",
			       $media, $media_arch));
                next;
            }
        }
        my $add_by_default = !$distribconf->getvalue($media, 'noauto');
        if ($options{ask_media}) {
            $options{ask_media}->($media_name, $add_by_default) or next;
        } else {
	    my $simple_rpms = !$distribconf->getvalue($media, 'debug_for') && 
	                      !$distribconf->getvalue($media, 'rpms');
	    $add_by_default || $simple_rpms or next;
	}

	my $is_update_media = $distribconf->getvalue($media, 'updates_for');
	if ($options{only_updates}) {
	    $is_update_media or next;
	}

	my $use_copied_synthesis = $urpm->{options}{use_copied_hdlist} || $distribconf->getvalue($media, 'use_copied_hdlist');
	my $with_synthesis = $use_copied_synthesis && offset_pathname(
		$url,
		$distribconf->getpath($media, 'path'),
	    ) . '/' . $distribconf->getpath($media, 'synthesis');

	push @newnames, add_medium($urpm,
	    $name ? "$media_name ($name$medium_index)" : $media_name,
	    reduce_pathname($distribconf->getfullpath($media, 'path')),
	    $with_synthesis, 
	    !$use_copied_synthesis ? (media_info_dir => 'media_info') : (),
	    !$use_copied_synthesis && $options{probe_with} ? ($options{probe_with} => 1) : (),
	    index_name => $name ? undef : 0,
	    $add_by_default ? () : (ignore => 1),
	    %options,
	    # the following override %options
	    update => $is_update_media ? 1 : undef,
	);
	++$medium_index;
    }
    return @newnames;
}

#- deprecated, use select_media_by_name instead
sub select_media {
    my $urpm = shift;
    my $options = {};
    if (ref $_[0]) { $options = shift }
    foreach (select_media_by_name($urpm, [ @_ ], $options->{strict_match})) {
	#- select medium by setting the modified flag, do not check ignore.
	$_->{modified} = 1;
    }
}

sub select_media_by_name {
    my ($urpm, $names, $b_strict_match) = @_;

    my %wanted = map { $_ => 1 } @$names;

    #- first the exact matches
    my @l = grep { delete $wanted{$_->{name}} } @{$urpm->{media}};

    #- check if some arguments don't correspond to the medium name.
    #- in such case, try to find the unique medium (or list candidate
    #- media found).
    foreach (keys %wanted) {
	my $q = quotemeta;
	my (@found, @foundi);
	my $regex  = $b_strict_match ? qr/^$q$/  : qr/$q/;
	my $regexi = $b_strict_match ? qr/^$q$/i : qr/$q/i;
	foreach my $medium (@{$urpm->{media}}) {
	    $medium->{name} =~ $regex  and push @found, $medium;
	    $medium->{name} =~ $regexi and push @foundi, $medium;
	}
	@found = @foundi if !@found;

	if (@found == 0) {
	    $urpm->{error}(N("trying to select nonexistent medium \"%s\"", $_));
	} else {
	    if (@found > 1) {
		$urpm->{log}(N("selecting multiple media: %s", join(", ", map { qq("$_->{name}") } @found)));
	    }
	    #- changed behaviour to select all occurences by default.
	    push @l, @found;
	}
    }
    @l;
}

#- deprecated, use remove_media instead
sub remove_selected_media {
    my ($urpm) = @_;

    remove_media($urpm, [ grep { $_->{modified} } @{$urpm->{media}} ]);
}

sub remove_media {
    my ($urpm, $to_remove) = @_;

    foreach my $medium (@$to_remove) {
	$urpm->{info}(N("removing medium \"%s\"", $medium->{name}));

	#- mark to re-write configuration.
	$urpm->{modified} = 1;

	#- remove files associated with this medium.
	unlink grep { $_ } map { $_->($urpm, $medium) } \&statedir_synthesis, \&statedir_descriptions, \&statedir_names, \&statedir_MD5SUM;

	#- remove proxy settings for this media
	urpm::download::remove_proxy_media($medium->{name});
    }

    $urpm->{media} = [ difference2($urpm->{media}, $to_remove) ];
}

sub _probe_with_try_list {
    my ($urpm, $medium, $f) = @_;

    my @media_info_dirs = ('media_info', '.');

    my $base = file_from_local_url($medium->{url}) || $medium->{url};

    foreach my $media_info_dir (@media_info_dirs) {
	my $url = reduce_pathname("$base/$media_info_dir") . '/synthesis.hdlist.cz';
	if ($f->($url)) {
	    $urpm->{debug} and $urpm->{debug}("found synthesis: $url");
	    $medium->{media_info_dir} = $media_info_dir;
	    return 1;
	}
    }
    undef;
}

sub may_reconfig_urpmi {
    my ($urpm, $medium) = @_;

    my $f;
    if (my $dir = file_from_local_url($medium->{url})) {
	$f = reduce_pathname("$dir/reconfig.urpmi");
    } else {
	unlink($f = "$urpm->{cachedir}/partial/reconfig.urpmi");
	urpm::download::sync($urpm, $medium, [ reduce_pathname("$medium->{url}/reconfig.urpmi") ], quiet => 1);
    }
    if (-s $f) {
	reconfig_urpmi($urpm, $f, $medium);
    }
    unlink $f if !file_from_local_url($medium->{url});
}

#- read a reconfiguration file for urpmi, and reconfigure media accordingly
#- $rfile is the reconfiguration file (local), $name is the media name
#-
#- the format is similar to the RewriteRule of mod_rewrite, so:
#-    PATTERN REPLACEMENT [FLAG]
#- where FLAG can be L or N
#-
#- example of reconfig.urpmi:
#-    # this is an urpmi reconfiguration file
#-    /cooker /cooker/$ARCH
sub reconfig_urpmi {
    my ($urpm, $rfile, $medium) = @_;
    -r $rfile or return;

    $urpm->{log}(N("reconfiguring urpmi for media \"%s\"", $medium->{name}));

    my ($magic, @lines) = cat_($rfile);
    #- the first line of reconfig.urpmi must be magic, to be sure it's not an error file
    $magic =~ /^# this is an urpmi reconfiguration file/ or return undef;

    my @replacements;
    foreach (@lines) {
	chomp;
	s/^\s*//; s/#.*$//; s/\s*$//;
	$_ or next;
	my ($p, $r, $f) = split /\s+/, $_, 3;
	push @replacements, [ quotemeta $p, $r, $f || 1 ];
    }

    my $reconfigured = 0;
    my @reconfigurable = qw(url with_synthesis media_info_dir);

    my %orig = %$medium;

  URLS:
    foreach my $k (@reconfigurable) {
	foreach my $r (@replacements) {
	    if ($medium->{$k} =~ s/$r->[0]/$r->[1]/) {
		$reconfigured = 1;
		#- Flags stolen from mod_rewrite: L(ast), N(ext)
		if ($r->[2] =~ /L/) {
		    last;
		} elsif ($r->[2] =~ /N/) { #- dangerous option
		    redo URLS;
		}
	    }
	}
	#- check that the new url exists before committing changes (local mirrors)
	my $file = file_from_local_url($medium->{$k});
	if ($file && !-e $file) {
	    %$medium = %orig;
	    $reconfigured = 0;
	    $urpm->{log}(N("...reconfiguration failed"));
	    return;
	}
    }

    if ($reconfigured) {
	$urpm->{log}(N("reconfiguration done"));
	$urpm->{modified} = 1;
    }
    $reconfigured;
}

sub _guess_synthesis_suffix {
    my ($url) = @_;
    $url =~ m!\bmedia/(\w+)/*\Z! && $1;
}

sub _synthesis_suffix {
    my ($medium) = @_;
    $medium->{with_synthesis} =~ /synthesis\.hdlist(.*?)(?:\.src)?\.cz$/ ? $1 : '';
}

#- names.<media_name> is used by external progs (namely for bash-completion)
sub generate_medium_names {
    my ($urpm, $medium) = @_;

    unlink statedir_names($urpm, $medium);

    if (my $fh = urpm::sys::open_safe($urpm, ">", statedir_names($urpm, $medium))) {
	foreach ($medium->{start} .. $medium->{end}) {
	    if (defined $urpm->{depslist}[$_]) {
		print $fh $urpm->{depslist}[$_]->name . "\n";
	    } else {
		$urpm->{error}(N("Error generating names file: dependency %d not found", $_));
	    }
	}
    } else {
	$urpm->{error}(N("Error generating names file: Can't write to file (%s)", $!));
    }
}


sub _read_existing_synthesis {
    my ($urpm, $medium) = @_;

    unlink cachedir_with_synthesis($urpm, $medium);

    $urpm->{info}(N("medium \"%s\" is up-to-date", $medium->{name}));

    #- the medium is now considered not modified.
    $medium->{modified} = 0;
    #- XXX we could link the new synthesis to the old one.
    #- (However links need to be managed. see bug #12391.)
    #- as previously done, just read synthesis file here, this is enough.
    _parse_synthesis_or_ignore($urpm, $medium);

    1;
}

sub _parse_synthesis {
    my ($urpm, $medium, $synthesis_file, $o_callback) = @_;

    -e $synthesis_file or return;

    $urpm->{log}(N("examining synthesis file [%s]", $synthesis_file));
    ($medium->{start}, $medium->{end}) = 
      $urpm->parse_synthesis($synthesis_file, $o_callback ? (callback => $o_callback) : @{[]});
}

sub _parse_synthesis_or_ignore {
    my ($urpm, $medium, $o_callback) = @_;

    _parse_synthesis($urpm, $medium, any_synthesis($urpm, $medium), $o_callback) or
      _ignore_medium_on_parse_error($urpm, $medium);
}

sub is_valid_medium {
    my ($medium) = @_;
    defined $medium->{start} && defined $medium->{end};
}

sub _ignore_medium_on_parse_error {
    my ($urpm, $medium) = @_;

    $urpm->{error}(N("problem reading synthesis file of medium \"%s\"", $medium->{name}));
    $medium->{ignore} = 1;
}

sub _get_list_or_pubkey__local {
    my ($urpm, $medium, $name) = @_;

    my $path = _synthesis_dir($medium) . "/$name" . _synthesis_suffix($medium);
    -e $path or $path = file_from_local_url($medium->{url}) . "/media_info/$name";
    if (-e $path) {
	$urpm->{log}(N("copying [%s] for medium \"%s\"...", $path, $medium->{name}));
	copy_and_own($path, "$urpm->{cachedir}/partial/$name")
	  or $urpm->{error}(N("...copying failed")), return;
    }
    1;
}

sub _download_list_or_pubkey {
    my ($urpm, $medium, $name) = @_;

    _download_media_info_file($urpm, $medium, $name, '', 1);
}

sub _download_media_info_file {
    my ($urpm, $medium, $prefix, $suffix, $quiet) = @_;

    my $name = "$prefix$suffix";
    my $found;
    if (_synthesis_suffix($medium)) {
	my $local_name = $prefix . _synthesis_suffix($medium) . $suffix;

	if (urpm::download::sync($urpm, $medium, [_synthesis_dir($medium) . "/$local_name"], 
				 quiet => $quiet)) {
	    rename("$urpm->{cachedir}/partial/$local_name", "$urpm->{cachedir}/partial/$name");
	    $found = 1;
	}
    }
    if (!$found) {
	urpm::download::sync($urpm, $medium, [_synthesis_dir($medium) .  "/$name"], quiet => 1)
	    or unlink "$urpm->{cachedir}/partial/$name";
    }
}

sub get_descriptions_local {
    my ($urpm, $medium) = @_;

    unlink statedir_descriptions($urpm, $medium);

    my $dir = file_from_local_url($medium->{url});
    my $description_file = "$dir/media_info/descriptions"; #- new default location
    -e $description_file or $description_file = "$dir/../descriptions";
    -e $description_file or return;

    $urpm->{log}(N("copying description file of \"%s\"...", $medium->{name}));
    if (copy_and_own($description_file, statedir_descriptions($urpm, $medium))) {
	$urpm->{log}(N("...copying done"));
    } else {
	$urpm->{error}(N("...copying failed"));
	$medium->{ignore} = 1;
    }
}
sub get_descriptions_remote {
    my ($urpm, $medium) = @_;

    unlink "$urpm->{cachedir}/partial/descriptions";

    if (-e statedir_descriptions($urpm, $medium)) {
	urpm::util::move(statedir_descriptions($urpm, $medium), "$urpm->{cachedir}/partial/descriptions");
    }
    urpm::download::sync($urpm, $medium, [ reduce_pathname("$medium->{url}/media_info/descriptions") ], quiet => 1) 
	or #- try older location
	  urpm::download::sync($urpm, $medium, [ reduce_pathname("$medium->{url}/../descriptions") ], quiet => 1);

    if (-e "$urpm->{cachedir}/partial/descriptions") {
	urpm::util::move("$urpm->{cachedir}/partial/descriptions", statedir_descriptions($urpm, $medium));
    }
}
sub get_synthesis__local {
    my ($urpm, $medium, $callback) = @_;

    my $f = cachedir_with_synthesis($urpm, $medium);
    unlink $f;
    $urpm->{log}(N("copying [%s] for medium \"%s\"...", _url_with_synthesis($medium), $medium->{name}));
    $callback and $callback->('copy', $medium->{name});
    if (copy_and_own(_url_with_synthesis($medium), $f)) {
	$callback and $callback->('done', $medium->{name});
	$urpm->{log}(N("...copying done"));
	if (file_size($f) < 20) {
	    $urpm->{error}(N("copy of [%s] failed (file is suspiciously small)", $f));
	    0;
	} else {
	    1;
	}
    } else {
	$callback and $callback->('failed', $medium->{name});
	#- force error, reported afterwards
	unlink $f;
	0;
    }
}
sub get_synthesis__remote {
    my ($urpm, $medium, $callback, $quiet) = @_;

    if (urpm::download::sync($urpm, $medium, [ _url_with_synthesis($medium) ],
			     quiet => $quiet, callback => $callback) &&
			       file_size(cachedir_with_synthesis($urpm, $medium)) >= 20) {
	1;
    } else {
	chomp(my $err = $@);
	$urpm->{error}(N("...retrieving failed: %s", $err));
	0;
    }
}

#- check copied/downloaded file has right signature.
sub check_synthesis_md5sum {
    my ($urpm, $medium) = @_;

    my $wanted_md5sum = urpm::md5sum::from_MD5SUM__or_warn($urpm, "$urpm->{cachedir}/partial/MD5SUM", 'synthesis.hdlist.cz');
    if ($wanted_md5sum) {
	$urpm->{log}(N("computing md5sum of retrieved source synthesis"));
	urpm::md5sum::compute(cachedir_with_synthesis($urpm, $medium)) eq $wanted_md5sum or
	    $urpm->{error}(N("retrieval of [%s] failed (md5sum mismatch)", _url_with_synthesis($medium))), return;
    }
    1;
}

sub _call_genhdlist2 {
    my ($urpm, $medium) = @_;

    !$medium->{with_synthesis} or $urpm->{fatal}(1, 'with_synthesis not handled with --probe-rpms');

    my $dir = file_from_local_url($medium->{url});

    system('genhdlist2', 
	   $urpm->{debug} ? '--verbose' : (), '--no-hdlist',
	   '--media_info-dir', "$urpm->{cachedir}/partial", $dir) == 0 
      or $urpm->{error}(N("genhdlist2 failed on %s", $dir)), return;

    1;
}

sub _is_statedir_MD5SUM_uptodate {
    my ($urpm, $medium, $new_MD5SUM) = @_;

    my $current_MD5SUM = statedir_MD5SUM($urpm, $medium);

    $urpm->{log}(N("comparing %s and %s", $new_MD5SUM, $current_MD5SUM));

    cat_($new_MD5SUM) eq cat_($current_MD5SUM);
}

#- options: callback, force, nomd5sum, probe_with
sub _update_medium__parse_if_unmodified__local {
    my ($urpm, $medium, $options) = @_;

    my $dir = file_from_local_url($medium->{url});

    if (!-d $dir) {
	#- the directory given does not exist and may be accessible
	#- by mounting some other directory. Try to figure it out and mount
	#- everything that might be necessary.
	urpm::removable::try_mounting($urpm,
	    $options->{probe_with} ne 'rpms' && _synthesis_dir($medium)
	      ? _synthesis_dir($medium) : $dir,
	    #- in case of an iso image, pass its name
	    urpm::removable::is_iso($medium->{removable}) && $medium->{removable},
	) or $urpm->{error}(N("unable to access medium \"%s\",
this could happen if you mounted manually the directory when creating the medium.", $medium->{name})), return;
    }

    #- try to probe for possible with_synthesis parameter, unless
    #- it is already defined (and valid).
    if (!_synthesis_dir($medium) && $options->{probe_with} ne 'rpms') {
	_probe_with_try_list($urpm, $medium, sub {
	    my ($url) = @_;
	    -e $url or return;
	    if (file_size($url) >= 20) {
		1;
	    } else {
		$urpm->{error}(N("invalid hdlist file %s for medium \"%s\"", $url, $medium->{name}));
		0;
	    }
	});
    }

    if ($medium->{virtual}) {
	#- syncing a virtual medium is very simple, just try to read the file in order to
	#- determine its type, once a with_synthesis has been found (but is mandatory).
	_parse_synthesis_or_ignore($urpm, $medium);
	1;
    } elsif ($options->{probe_with} eq 'rpms' || !_synthesis_dir($medium)) {
	_call_genhdlist2($urpm, $medium) or return '';
	1;
    } elsif (_synthesis_dir($medium)) {
	my $new_MD5SUM = _synthesis_dir($medium) . '/MD5SUM';
	unlink "$urpm->{cachedir}/partial/MD5SUM";

	if (!$options->{nomd5sum} && file_size($new_MD5SUM) > 32) {	
	    if (!$options->{force} && _is_statedir_MD5SUM_uptodate($urpm, $medium, $new_MD5SUM)) {
		_read_existing_synthesis($urpm, $medium)
		  and return 'unmodified';
	    }

	    $urpm->{log}(N("copying MD5SUM file of \"%s\"...", $medium->{name}));
	    copy_and_own($new_MD5SUM, "$urpm->{cachedir}/partial/MD5SUM");
	}

	my $ok = get_synthesis__local($urpm, $medium, $options->{callback});
	$ok &&= !$options->{force} || check_synthesis_md5sum($urpm, $medium);
	
	if ($ok) {
	    1;
	} elsif ($urpm->{options}{'build-hdlist-on-error'}) {
	    #- if copying synthesis has failed, try to build it directly.
	    _call_genhdlist2($urpm, $medium) or return '';
	    1;
	} else {
	    _ignore_medium_on_parse_error($urpm, $medium);
	    '';
	}
    }
}

sub _download_MD5SUM {
    my ($urpm, $medium) = @_;

    my $cachedir_MD5SUM = "$urpm->{cachedir}/partial/MD5SUM";
    unlink $cachedir_MD5SUM;
    urpm::download::sync($urpm, $medium, 
			       [ reduce_pathname(_synthesis_dir($medium) . '/MD5SUM') ],
			       quiet => 1) && file_size($cachedir_MD5SUM) > 32;
}

#- options: callback, force, nomd5sum, probe_with, quiet
sub _update_medium__parse_if_unmodified__remote {
    my ($urpm, $medium, $options) = @_;

    #- examine if a distant MD5SUM file is available.
    #- this will only be done if $with_synthesis is not empty in order to use
    #- an existing synthesis file, and to check if download was good.
    #- if no MD5SUM is available, do it as before...
    if (_synthesis_dir($medium)) {
	#- we can assume at this point a basename is existing, but it needs
	#- to be checked for being valid, nothing can be deduced if no MD5SUM
	#- file is present.

	if (!$options->{nomd5sum} && _download_MD5SUM($urpm, $medium)) {
	    my $new_MD5SUM = "$urpm->{cachedir}/partial/MD5SUM";
	    if ($options->{force} < 2 && _is_statedir_MD5SUM_uptodate($urpm, $medium, $new_MD5SUM)) {
		_read_existing_synthesis($urpm, $medium)
		  and return 'unmodified';
	    }
	}
    }

    #- try to probe for possible with_synthesis parameter, unless
    #- it is already defined (and valid).
    $urpm->{log}(N("retrieving source synthesis of \"%s\"...", $medium->{name}));
    $options->{callback} and $options->{callback}('retrieve', $medium->{name});
    my $error = sub {
	my ($msg) = @_;
	$urpm->{error}($msg);
	unlink cachedir_with_synthesis($urpm, $medium);
	$options->{callback} and $options->{callback}('failed', $medium->{name});
    };
    my $ok = 1;
    if (!_synthesis_dir($medium)) {
	my $err;
	_probe_with_try_list($urpm, $medium, sub {
	    my ($url) = @_;
	    my $f = "$urpm->{cachedir}/partial/" . basename($url);
	    $options->{force} and unlink $f;
	    if (urpm::download::sync($urpm, $medium, [ $url ],
				     quiet => $options->{quiet}, callback => $options->{callback}) && file_size($f) >= 20) {
		$urpm->{log}(N("found probed synthesis as %s", $url));
		1;
	    } else {
		chomp($err = $@);
		0;
	    }
	}) or do {
	    $error->(N("no synthesis file found for medium \"%s\"", $medium->{name}));
	    $urpm->{error}(N("...retrieving failed: %s", $err));
	    return;
	};

	$options->{nomd5sum} || _download_MD5SUM($urpm, $medium);

    } else {
	if ($options->{force}) {
	    unlink cachedir_with_synthesis($urpm, $medium);
	} else {
	    #- for rsync, try to sync (copy if needed) local copy after restored the previous one.
	    my $previous_synthesis = statedir_synthesis($urpm, $medium);
	    if (-e $previous_synthesis && urpm::protocol_from_url($medium->{url}) eq 'rsync') {
		copy_and_own(
		    $previous_synthesis,
		    cachedir_with_synthesis($urpm, $medium),
		) or $error->(N("...copying failed")), return;
	    }
	}
	$ok = get_synthesis__remote($urpm, $medium, $options->{callback}, $options->{quiet});
    }

    $ok &&= !$options->{force} || check_synthesis_md5sum($urpm, $medium);

    $options->{callback} and $options->{callback}('done', $medium->{name});

    if (!$ok) {
	_ignore_medium_on_parse_error($urpm, $medium);
	return;
    }
    1;
}

sub _get_pubkey_and_descriptions {
    my ($urpm, $medium, $nopubkey) = @_;

    my $local = file_from_local_url($medium->{url});

    ($local ? \&get_descriptions_local : \&get_descriptions_remote)->($urpm, $medium);

    #- examine if a pubkey file is available.
    if (!$nopubkey && !$medium->{'key-ids'}) {
	($local ? \&_get_list_or_pubkey__local : \&_download_list_or_pubkey)->($urpm, $medium, 'pubkey');
    }
}

sub _read_cachedir_pubkey {
    my ($urpm, $medium, $b_wait_lock) = @_;
    -s "$urpm->{cachedir}/partial/pubkey" or return;

    $urpm->{log}(N("examining pubkey file of \"%s\"...", $medium->{name}));

    my $_rpm_lock = urpm::lock::rpm_db($urpm, 'exclusive', wait => $b_wait_lock);
    my $db = urpm::db_open_or_die($urpm, $urpm->{root}, 'rw');

    my %key_ids;
    URPM::import_needed_pubkeys_from_file($db,
	"$urpm->{cachedir}/partial/pubkey",
	sub {
	    my ($id, $imported) = @_;
	    if ($id) {
		$key_ids{$id} = undef;
		$imported and $urpm->{log}(N("...imported key %s from pubkey file of \"%s\"",
					     $id, $medium->{name}));
		$imported or $urpm->{debug}("pubkey $id already imported") if $urpm->{debug};
	    } else {
		$urpm->{error}(N("unable to import pubkey file of \"%s\"", $medium->{name}));
	    }
	});

    unlink "$urpm->{cachedir}/partial/pubkey";
    
    join(',', keys %key_ids);
}

#- options: callback, force, nomd5sum, probe_with, quiet, nopubkey, wait_lock
#- (from _update_medium__parse_if_unmodified__local and _update_medium__parse_if_unmodified__remote)
sub _update_medium_ {
    my ($urpm, $medium, %options) = @_;

    unless ($medium->{modified}) {
	_parse_synthesis_or_ignore($urpm, $medium);
	return 'unmodified';
    }

    #- always delete a remaining list file or pubkey file in cache.
    foreach (qw(list pubkey)) {
	unlink "$urpm->{cachedir}/partial/$_";
    }

    #- check for a reconfig.urpmi file (if not already reconfigured)
    if (!$medium->{noreconfigure}) {
	may_reconfig_urpmi($urpm, $medium);
    }

    {
	my $rc = 
	  file_from_local_url($medium->{url})
	    ? _update_medium__parse_if_unmodified__local($urpm, $medium, \%options)
	    : _update_medium__parse_if_unmodified__remote($urpm, $medium, \%options);

	if (!$rc || $rc eq 'unmodified') {
	    return $rc;
	}
    }

    my $is_updating = -e statedir_synthesis($urpm, $medium);

    if (!$medium->{virtual}) {
	if (file_size(cachedir_with_synthesis($urpm, $medium)) < 20) {
	    $urpm->{error}(N("no synthesis file found for medium \"%s\"", $medium->{name}));
	    return;
	}

	    $options{callback} and $options{callback}('parse', $medium->{name});

	    if (_parse_synthesis($urpm, $medium, cachedir_with_synthesis($urpm, $medium))) {
		$options{callback} && $options{callback}('done', $medium->{name});
	    } else {
		$urpm->{error}(N("unable to parse synthesis file of \"%s\"", $medium->{name}));
		$options{callback} and $options{callback}('failed', $medium->{name});

		#- we have to read back the current synthesis file unmodified.
		_parse_synthesis_or_ignore($urpm, $medium);

		return;
	    }

	    #- use new files

	    unlink statedir_synthesis($urpm, $medium);
	    urpm::util::move(cachedir_with_synthesis($urpm, $medium),
			     statedir_synthesis($urpm, $medium));

	    unlink statedir_MD5SUM($urpm, $medium);
	    if (!$medium->{with_synthesis}) { # no MD5SUM when using with_synthesis, urpmi.update will update everytime!
		urpm::util::move("$urpm->{cachedir}/partial/MD5SUM",
				 statedir_MD5SUM($urpm, $medium)) if -e "$urpm->{cachedir}/partial/MD5SUM";
	    }

    }
    $medium->{modified} = 0;

    _get_pubkey_and_descriptions($urpm, $medium, $options{nopubkey});
    $medium->{'key-ids'} ||= _read_cachedir_pubkey($urpm, $medium, $options{wait_lock});
    generate_medium_names($urpm, $medium);

    $is_updating and $urpm->{info}(N("updated medium \"%s\"", $medium->{name}));

    1;
}

sub _update_medium {
    my ($urpm, $medium, %options) = @_;

    my $rc = _update_medium_($urpm, $medium, %options);

    if (!$rc && !$medium->{virtual}) {
	#- an error has occured for updating the medium, we have to remove temporary files.
	unlink(glob("$urpm->{cachedir}/partial/*"));
    }
    $rc;
}

sub _update_media__handle_some_flags {
    my ($urpm, $forcekey, $all) = @_;

    foreach my $medium (grep { !$_->{ignore} } @{$urpm->{media}}) {
	$forcekey and delete $medium->{'key-ids'};

	if ($medium->{static}) {
	    #- don't ever update static media
	    $medium->{modified} = 0;
	} elsif ($all) {
	    #- if we're rebuilding all media, mark them as modified (except removable ones)
	    $medium->{modified} ||= $medium->{url} !~ m!^removable!;
	}
    }
}

#- Update the urpmi database w.r.t. the current configuration.
#- Takes care of modifications, and tries some tricks to bypass
#- the recomputation of base files.
#- Recognized options :
#-   all         : all medias are being rebuilt
#-   callback    : UI callback
#-   forcekey    : force retrieval of pubkey
#-   force       : try to force rebuilding base files
#-   nomd5sum    : don't verify MD5SUM of retrieved files
#-   nopubkey    : don't use rpm pubkeys
#-   probe_with  : probe synthesis or rpms
#-   quiet       : download synthesis quietly
#-   wait_lock   : block until lock can be acquired
sub update_media {
    my ($urpm, %options) = @_;

    $urpm->{media} or return; # verify that configuration has been read

    $options{nopubkey} ||= $urpm->{options}{nopubkey};

    #- examine each medium to see if one of them needs to be updated.
    #- if this is the case and if not forced, try to use a pre-calculated
    #- synthesis file, else build it from rpm files.
    clean($urpm);

    _update_media__handle_some_flags($urpm, $options{forcekey}, $options{all});

    my %updates_result;
    foreach my $medium (grep { !$_->{ignore} && $_->{modified} } @{$urpm->{media}}) {
	my $rc = _update_medium($urpm, $medium, %options);
	$updates_result{$rc || 'error'}++;
    }

    $urpm->{debug} and $urpm->{debug}('update_medium: ' . join(' ', map { "$_=$updates_result{$_}" } keys %updates_result));

    if ($updates_result{1} == 0) {
	#- only errors/unmodified, leave now
	#- (this ensures buggy added medium is not added to urpmi.cfg)
	return $updates_result{error} == 0;
    }

    if ($urpm->{modified}) {
	#- write config files in any case
	write_config($urpm);
	urpm::download::dump_proxy_config();
    }

    $updates_result{error} == 0;
}

#- clean params and depslist computation zone.
sub clean {
    my ($urpm) = @_;

    $urpm->{depslist} = [];
    $urpm->{provides} = {};

    foreach (@{$urpm->{media} || []}) {
	delete $_->{start};
	delete $_->{end};
    }
}

1;