-
Notifications
You must be signed in to change notification settings - Fork 1.2k
/
last.c
1079 lines (967 loc) · 26.3 KB
/
last.c
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
/*
* last(1) from sysvinit project, merged into util-linux in Aug 2013.
*
* Copyright (C) 1991-2004 Miquel van Smoorenburg.
* Copyright (C) 2013 Ondrej Oprala <ooprala@redhat.com>
* Karel Zak <kzak@redhat.com>
*
* Re-implementation of the 'last' command, this time for Linux. Yes I know
* there is BSD last, but I just felt like writing this. No thanks :-). Also,
* this version gives lots more info (especially with -x)
*
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <time.h>
#include <stdio.h>
#include <ctype.h>
#include <utmpx.h>
#include <pwd.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <getopt.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <libgen.h>
#include "c.h"
#include "nls.h"
#include "optutils.h"
#include "pathnames.h"
#include "xalloc.h"
#include "closestream.h"
#include "carefulputc.h"
#include "strutils.h"
#include "timeutils.h"
#include "monotonic.h"
#include "fileutils.h"
#ifdef FUZZ_TARGET
#include "fuzz.h"
#endif
#ifndef SHUTDOWN_TIME
# define SHUTDOWN_TIME 254
#endif
#ifndef LAST_LOGIN_LEN
# define LAST_LOGIN_LEN 8
#endif
#ifndef LAST_DOMAIN_LEN
# define LAST_DOMAIN_LEN 16
#endif
#ifndef LAST_TIMESTAMP_LEN
# define LAST_TIMESTAMP_LEN 32
#endif
#define UCHUNKSIZE 16384 /* How much we read at once. */
struct last_control {
unsigned int lastb :1, /* Is this command 'lastb' */
extended :1, /* Lots of info */
showhost :1, /* Show hostname */
altlist :1, /* Hostname at the end */
usedns :1, /* Use DNS to lookup the hostname */
useip :1; /* Print IP address in number format */
unsigned int name_len; /* Number of login name characters to print */
unsigned int domain_len; /* Number of domain name characters to print */
unsigned int maxrecs; /* Maximum number of records to list */
char **show; /* Match search list */
struct timeval boot_time; /* system boot time */
time_t since; /* at what time to start displaying the file */
time_t until; /* at what time to stop displaying the file */
time_t present; /* who where present at time_t */
unsigned int time_fmt; /* time format */
};
/* Double linked list of struct utmp's */
struct utmplist {
struct utmpx ut;
struct utmplist *next;
struct utmplist *prev;
};
/* Types of listing */
enum {
R_CRASH = 1, /* No logout record, system boot in between */
R_DOWN, /* System brought down in decent way */
R_NORMAL, /* Normal */
R_NOW, /* Still logged in */
R_REBOOT, /* Reboot record. */
R_PHANTOM, /* No logout record but session is stale. */
R_TIMECHANGE /* NEW_TIME or OLD_TIME */
};
enum {
LAST_TIMEFTM_NONE = 0,
LAST_TIMEFTM_SHORT,
LAST_TIMEFTM_CTIME,
LAST_TIMEFTM_ISO8601,
LAST_TIMEFTM_HHMM, /* non-public */
};
struct last_timefmt {
const char *name;
int in_len; /* log-in */
int in_fmt;
int out_len; /* log-out */
int out_fmt;
};
static struct last_timefmt timefmts[] = {
[LAST_TIMEFTM_NONE] = { .name = "notime" },
[LAST_TIMEFTM_SHORT] = {
.name = "short",
.in_len = 16,
.out_len = 7,
.in_fmt = LAST_TIMEFTM_CTIME,
.out_fmt = LAST_TIMEFTM_HHMM
},
[LAST_TIMEFTM_CTIME] = {
.name = "full",
.in_len = 24,
.out_len = 26,
.in_fmt = LAST_TIMEFTM_CTIME,
.out_fmt = LAST_TIMEFTM_CTIME
},
[LAST_TIMEFTM_ISO8601] = {
.name = "iso",
.in_len = 25,
.out_len = 27,
.in_fmt = LAST_TIMEFTM_ISO8601,
.out_fmt = LAST_TIMEFTM_ISO8601
}
};
/* Global variables */
static unsigned int recsdone; /* Number of records listed */
static time_t lastdate; /* Last date we've seen */
static time_t currentdate; /* date when we started processing the file */
#ifndef FUZZ_TARGET
/* --time-format=option parser */
static int which_time_format(const char *s)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(timefmts); i++) {
if (strcmp(timefmts[i].name, s) == 0)
return i;
}
errx(EXIT_FAILURE, _("unknown time format: %s"), s);
}
#endif
/*
* Read one utmp entry, return in new format.
* Automatically reposition file pointer.
*/
static int uread(FILE *fp, struct utmpx *u, int *quit, const char *filename)
{
static int utsize;
static char buf[UCHUNKSIZE];
char tmp[1024];
static off_t fpos;
static int bpos;
off_t o;
if (quit == NULL && u != NULL) {
/*
* Normal read.
*/
return fread(u, sizeof(struct utmpx), 1, fp);
}
if (u == NULL) {
/*
* Initialize and position.
*/
utsize = sizeof(struct utmpx);
fseeko(fp, 0, SEEK_END);
fpos = ftello(fp);
if (fpos == 0)
return 0;
o = ((fpos - 1) / UCHUNKSIZE) * UCHUNKSIZE;
if (fseeko(fp, o, SEEK_SET) < 0) {
warn(_("seek on %s failed"), filename);
return 0;
}
bpos = (int)(fpos - o);
if (fread(buf, bpos, 1, fp) != 1) {
warn(_("cannot read %s"), filename);
return 0;
}
fpos = o;
return 1;
}
/*
* Read one struct. From the buffer if possible.
*/
bpos -= utsize;
if (bpos >= 0) {
memcpy(u, buf + bpos, sizeof(struct utmpx));
return 1;
}
/*
* Oops we went "below" the buffer. We should be able to
* seek back UCHUNKSIZE bytes.
*/
fpos -= UCHUNKSIZE;
if (fpos < 0)
return 0;
/*
* Copy whatever is left in the buffer.
*/
memcpy(tmp + (-bpos), buf, utsize + bpos);
if (fseeko(fp, fpos, SEEK_SET) < 0) {
warn(_("seek on %s failed"), filename);
return 0;
}
/*
* Read another UCHUNKSIZE bytes.
*/
if (fread(buf, UCHUNKSIZE, 1, fp) != 1) {
warn(_("cannot read %s"), filename);
return 0;
}
/*
* The end of the UCHUNKSIZE byte buffer should be the first
* few bytes of the current struct utmp.
*/
memcpy(tmp, buf + UCHUNKSIZE + bpos, -bpos);
bpos += UCHUNKSIZE;
memcpy(u, tmp, sizeof(struct utmpx));
return 1;
}
#ifndef FUZZ_TARGET
/*
* SIGINT handler
*/
static void int_handler(int sig __attribute__((unused)))
{
ul_sig_err(EXIT_FAILURE, "Interrupted");
}
/*
* SIGQUIT handler
*/
static void quit_handler(int sig __attribute__((unused)))
{
ul_sig_warn("Interrupted");
signal(SIGQUIT, quit_handler);
}
#endif
/*
* Lookup a host with DNS.
*/
static int dns_lookup(char *result, int size, int useip, int32_t *a)
{
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
struct sockaddr *sa;
int salen, flags;
int mapped = 0;
flags = useip ? NI_NUMERICHOST : 0;
/*
* IPv4 or IPv6 ?
* 1. If last 3 4bytes are 0, must be IPv4
* 2. If IPv6 in IPv4, handle as IPv4
* 3. Anything else is IPv6
*
* Ugly.
*/
if (a[0] == 0 && a[1] == 0 && a[2] == (int32_t)htonl (0xffff))
mapped = 1;
if (mapped || (a[1] == 0 && a[2] == 0 && a[3] == 0)) {
/* IPv4 */
sin.sin_family = AF_INET;
sin.sin_port = 0;
sin.sin_addr.s_addr = mapped ? a[3] : a[0];
sa = (struct sockaddr *)&sin;
salen = sizeof(sin);
} else {
/* IPv6 */
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_port = 0;
memcpy(sin6.sin6_addr.s6_addr, a, 16);
sa = (struct sockaddr *)&sin6;
salen = sizeof(sin6);
}
return getnameinfo(sa, salen, result, size, NULL, 0, flags);
}
static int time_formatter(int fmt, char *dst, size_t dlen, time_t *when)
{
int ret = 0;
switch (fmt) {
case LAST_TIMEFTM_NONE:
*dst = 0;
break;
case LAST_TIMEFTM_HHMM:
{
struct tm tm;
localtime_r(when, &tm);
if (!snprintf(dst, dlen, "%02d:%02d", tm.tm_hour, tm.tm_min))
ret = -1;
break;
}
case LAST_TIMEFTM_CTIME:
{
char buf[CTIME_BUFSIZ];
ctime_r(when, buf);
snprintf(dst, dlen, "%s", buf);
ret = rtrim_whitespace((unsigned char *) dst);
break;
}
case LAST_TIMEFTM_ISO8601:
ret = strtime_iso(when, ISO_TIMESTAMP_T, dst, dlen);
break;
default:
abort();
}
return ret;
}
/*
* Remove trailing spaces from a string.
*/
static void trim_trailing_spaces(char *s)
{
char *p;
for (p = s; *p; ++p)
continue;
while (p > s && isspace(*--p))
continue;
if (p > s)
++p;
*p++ = '\n';
*p = '\0';
}
/*
* Show one line of information on screen
*/
static int list(const struct last_control *ctl, struct utmpx *p, time_t logout_time, int what)
{
time_t secs, utmp_time;
char logintime[LAST_TIMESTAMP_LEN];
char logouttime[LAST_TIMESTAMP_LEN];
char length[LAST_TIMESTAMP_LEN];
char final[512];
char utline[sizeof(p->ut_line) + 1];
char domain[256];
int mins, hours, days;
int r, len;
struct last_timefmt *fmt;
/*
* uucp and ftp have special-type entries
*/
mem2strcpy(utline, p->ut_line, sizeof(p->ut_line), sizeof(utline));
if (strncmp(utline, "ftp", 3) == 0 && isdigit(utline[3]))
utline[3] = 0;
if (strncmp(utline, "uucp", 4) == 0 && isdigit(utline[4]))
utline[4] = 0;
/*
* Is this something we want to show?
*/
if (ctl->show) {
char **walk;
for (walk = ctl->show; *walk; walk++) {
if (strncmp(p->ut_user, *walk, sizeof(p->ut_user)) == 0 ||
strcmp(utline, *walk) == 0 ||
(strncmp(utline, "tty", 3) == 0 &&
strcmp(utline + 3, *walk) == 0)) break;
}
if (*walk == NULL) return 0;
}
/*
* Calculate times
*/
fmt = &timefmts[ctl->time_fmt];
utmp_time = p->ut_tv.tv_sec;
if (ctl->present) {
if (ctl->present < utmp_time)
return 0;
if (0 < logout_time && logout_time < ctl->present)
return 0;
}
/* log-in time */
if (time_formatter(fmt->in_fmt, logintime,
sizeof(logintime), &utmp_time) < 0)
errx(EXIT_FAILURE, _("preallocation size exceeded"));
/* log-out time */
secs = logout_time - utmp_time; /* Under strange circumstances, secs < 0 can happen */
mins = (secs / 60) % 60;
hours = (secs / 3600) % 24;
days = secs / 86400;
strcpy(logouttime, "- ");
if (time_formatter(fmt->out_fmt, logouttime + 2,
sizeof(logouttime) - 2, &logout_time) < 0)
errx(EXIT_FAILURE, _("preallocation size exceeded"));
if (logout_time == currentdate) {
if (ctl->time_fmt > LAST_TIMEFTM_SHORT) {
snprintf(logouttime, sizeof(logouttime), " still running");
length[0] = 0;
} else {
snprintf(logouttime, sizeof(logouttime), " still");
snprintf(length, sizeof(length), "running");
}
} else if (days) {
snprintf(length, sizeof(length), "(%d+%02d:%02d)", days, abs(hours), abs(mins)); /* hours and mins always shown as positive (w/o minus sign!) even if secs < 0 */
} else if (hours) {
snprintf(length, sizeof(length), " (%02d:%02d)", hours, abs(mins)); /* mins always shown as positive (w/o minus sign!) even if secs < 0 */
} else if (secs >= 0) {
snprintf(length, sizeof(length), " (%02d:%02d)", hours, mins);
} else {
snprintf(length, sizeof(length), " (-00:%02d)", abs(mins)); /* mins always shown as positive (w/o minus sign!) even if secs < 0 */
}
switch(what) {
case R_CRASH:
snprintf(logouttime, sizeof(logouttime), "- crash");
break;
case R_DOWN:
snprintf(logouttime, sizeof(logouttime), "- down ");
break;
case R_NOW:
if (ctl->time_fmt > LAST_TIMEFTM_SHORT) {
snprintf(logouttime, sizeof(logouttime), " still logged in");
length[0] = 0;
} else {
snprintf(logouttime, sizeof(logouttime), " still");
snprintf(length, sizeof(length), "logged in");
}
break;
case R_PHANTOM:
if (ctl->time_fmt > LAST_TIMEFTM_SHORT) {
snprintf(logouttime, sizeof(logouttime), " gone - no logout");
length[0] = 0;
} else if (ctl->time_fmt == LAST_TIMEFTM_SHORT) {
snprintf(logouttime, sizeof(logouttime), " gone");
snprintf(length, sizeof(length), "- no logout");
} else {
logouttime[0] = 0;
snprintf(length, sizeof(length), "no logout");
}
break;
case R_TIMECHANGE:
logouttime[0] = 0;
length[0] = 0;
break;
case R_NORMAL:
case R_REBOOT:
break;
default:
abort();
}
/*
* Look up host with DNS if needed.
*/
r = -1;
if (ctl->usedns || ctl->useip)
r = dns_lookup(domain, sizeof(domain), ctl->useip, (int32_t*)p->ut_addr_v6);
if (r < 0)
mem2strcpy(domain, p->ut_host, sizeof(p->ut_host), sizeof(domain));
if (ctl->showhost) {
if (!ctl->altlist) {
len = snprintf(final, sizeof(final),
"%-8.*s %-12.12s %-16.*s %-*.*s %-*.*s %s\n",
ctl->name_len, p->ut_user, utline,
ctl->domain_len, domain,
fmt->in_len, fmt->in_len, logintime, fmt->out_len, fmt->out_len,
logouttime, length);
} else {
len = snprintf(final, sizeof(final),
"%-8.*s %-12.12s %-*.*s %-*.*s %-12.12s %s\n",
ctl->name_len, p->ut_user, utline,
fmt->in_len, fmt->in_len, logintime, fmt->out_len, fmt->out_len,
logouttime, length, domain);
}
} else
len = snprintf(final, sizeof(final),
"%-8.*s %-12.12s %-*.*s %-*.*s %s\n",
ctl->name_len, p->ut_user, utline,
fmt->in_len, fmt->in_len, logintime, fmt->out_len, fmt->out_len,
logouttime, length);
#if defined(__GLIBC__)
# if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0)
final[sizeof(final)-1] = '\0';
# endif
#endif
trim_trailing_spaces(final);
/*
* Print out "final" string safely.
*/
fputs_careful(final, stdout, '*', false);
if (len < 0 || (size_t)len >= sizeof(final))
putchar('\n');
recsdone++;
if (ctl->maxrecs && ctl->maxrecs <= recsdone)
return 1;
return 0;
}
#ifndef FUZZ_TARGET
static void __attribute__((__noreturn__)) usage(const struct last_control *ctl)
{
FILE *out = stdout;
fputs(USAGE_HEADER, out);
fprintf(out, _(
" %s [options] [<username>...] [<tty>...]\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, out);
fputs(_("Show a listing of last logged in users.\n"), out);
fputs(USAGE_OPTIONS, out);
fputs(_(" -<number> how many lines to show\n"), out);
fputs(_(" -a, --hostlast display hostnames in the last column\n"), out);
fputs(_(" -d, --dns translate the IP number back into a hostname\n"), out);
fprintf(out,
_(" -f, --file <file> use a specific file instead of %s\n"), ctl->lastb ? _PATH_BTMP : _PATH_WTMP);
fputs(_(" -F, --fulltimes print full login and logout times and dates\n"), out);
fputs(_(" -i, --ip display IP numbers in numbers-and-dots notation\n"), out);
fputs(_(" -n, --limit <number> how many lines to show\n"), out);
fputs(_(" -R, --nohostname don't display the hostname field\n"), out);
fputs(_(" -s, --since <time> display the lines since the specified time\n"), out);
fputs(_(" -t, --until <time> display the lines until the specified time\n"), out);
fputs(_(" -p, --present <time> display who were present at the specified time\n"), out);
fputs(_(" -w, --fullnames display full user and domain names\n"), out);
fputs(_(" -x, --system display system shutdown entries and run level changes\n"), out);
fputs(_(" --time-format <format> show timestamps in the specified <format>:\n"
" notime|short|full|iso\n"), out);
fputs(USAGE_SEPARATOR, out);
printf(USAGE_HELP_OPTIONS(22));
printf(USAGE_MAN_TAIL("last(1)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
#endif
static int is_phantom(const struct last_control *ctl, struct utmpx *ut)
{
struct passwd *pw;
char path[sizeof(ut->ut_line) + 16];
char user[sizeof(ut->ut_user) + 1];
int ret = 0;
if (ut->ut_tv.tv_sec < ctl->boot_time.tv_sec)
return 1;
mem2strcpy(user, ut->ut_user, sizeof(ut->ut_user), sizeof(user));
pw = getpwnam(user);
if (!pw)
return 1;
snprintf(path, sizeof(path), "/proc/%u/loginuid", ut->ut_pid);
if (access(path, R_OK) == 0) {
unsigned int loginuid;
FILE *f = NULL;
if (!(f = fopen(path, "r")))
return 1;
if (fscanf(f, "%u", &loginuid) != 1)
ret = 1;
fclose(f);
if (!ret && pw->pw_uid != loginuid)
return 1;
} else {
struct stat st;
char utline[sizeof(ut->ut_line) + 1];
mem2strcpy(utline, ut->ut_line, sizeof(ut->ut_line), sizeof(utline));
snprintf(path, sizeof(path), "/dev/%s", utline);
if (stat(path, &st))
return 1;
if (pw->pw_uid != st.st_uid)
return 1;
}
return ret;
}
static void process_wtmp_file(const struct last_control *ctl,
const char *filename)
{
FILE *fp; /* File pointer of wtmp file */
struct utmpx ut; /* Current utmp entry */
struct utmplist *ulist = NULL; /* All entries */
struct utmplist *p; /* Pointer into utmplist */
struct utmplist *next; /* Pointer into utmplist */
time_t lastboot = 0; /* Last boottime */
time_t lastrch = 0; /* Last run level change */
time_t lastdown; /* Last downtime */
time_t begintime; /* When wtmp begins */
int whydown = 0; /* Why we went down: crash or shutdown */
int c, x; /* Scratch */
struct stat st; /* To stat the [uw]tmp file */
int quit = 0; /* Flag */
int down = 0; /* Down flag */
#ifndef FUZZ_TARGET
time(&lastdown);
#else
lastdown = 1596001948;
#endif
/*
* Fill in 'lastdate'
*/
lastdate = currentdate = lastrch = lastdown;
#ifndef FUZZ_TARGET
/*
* Install signal handlers
*/
signal(SIGINT, int_handler);
signal(SIGQUIT, quit_handler);
#endif
/*
* Open the utmp file
*/
if ((fp = fopen(filename, "r")) == NULL)
err(EXIT_FAILURE, _("cannot open %s"), filename);
/*
* Optimize the buffer size.
*/
setvbuf(fp, NULL, _IOFBF, UCHUNKSIZE);
/*
* Read first structure to capture the time field
*/
if (uread(fp, &ut, NULL, filename) == 1)
begintime = ut.ut_tv.tv_sec;
else {
if (fstat(fileno(fp), &st) != 0)
err(EXIT_FAILURE, _("stat of %s failed"), filename);
begintime = st.st_ctime;
quit = 1;
}
/*
* Go to end of file minus one structure
* and/or initialize utmp reading code.
*/
uread(fp, NULL, NULL, filename);
/*
* Read struct after struct backwards from the file.
*/
while (!quit) {
if (uread(fp, &ut, &quit, filename) != 1)
break;
if (ctl->since && ut.ut_tv.tv_sec < ctl->since)
continue;
if (ctl->until && ctl->until < ut.ut_tv.tv_sec)
continue;
lastdate = ut.ut_tv.tv_sec;
if (ctl->lastb) {
quit = list(ctl, &ut, ut.ut_tv.tv_sec, R_NORMAL);
continue;
}
/*
* Set ut_type to the correct type.
*/
if (strncmp(ut.ut_line, "~", 1) == 0) {
if (strncmp(ut.ut_user, "shutdown", 8) == 0)
ut.ut_type = SHUTDOWN_TIME;
else if (strncmp(ut.ut_user, "reboot", 6) == 0)
ut.ut_type = BOOT_TIME;
else if (strncmp(ut.ut_user, "runlevel", 8) == 0)
ut.ut_type = RUN_LVL;
}
#if 1 /*def COMPAT*/
/*
* For stupid old applications that don't fill in
* ut_type correctly.
*/
else {
if (ut.ut_type != DEAD_PROCESS &&
ut.ut_user[0] && ut.ut_line[0] &&
strncmp(ut.ut_user, "LOGIN", 5) != 0)
ut.ut_type = USER_PROCESS;
/*
* Even worse, applications that write ghost
* entries: ut_type set to USER_PROCESS but
* empty ut_user...
*/
if (ut.ut_user[0] == 0)
ut.ut_type = DEAD_PROCESS;
/*
* Clock changes.
*/
if (strncmp(ut.ut_user, "date", 4) == 0) {
if (ut.ut_line[0] == '|')
ut.ut_type = OLD_TIME;
if (ut.ut_line[0] == '{')
ut.ut_type = NEW_TIME;
}
}
#endif
switch (ut.ut_type) {
case SHUTDOWN_TIME:
if (ctl->extended) {
strcpy(ut.ut_line, "system down");
quit = list(ctl, &ut, lastboot, R_NORMAL);
}
lastdown = lastrch = ut.ut_tv.tv_sec;
down = 1;
break;
case OLD_TIME:
case NEW_TIME:
if (ctl->extended) {
strcpy(ut.ut_line,
ut.ut_type == NEW_TIME ? "new time" :
"old time");
quit = list(ctl, &ut, lastdown, R_TIMECHANGE);
}
break;
case BOOT_TIME:
strcpy(ut.ut_line, "system boot");
quit = list(ctl, &ut, lastdown, R_REBOOT);
lastboot = ut.ut_tv.tv_sec;
down = 1;
break;
case RUN_LVL:
x = ut.ut_pid & 255;
if (ctl->extended) {
snprintf(ut.ut_line, sizeof(ut.ut_line), "(to lvl %c)", x);
quit = list(ctl, &ut, lastrch, R_NORMAL);
}
if (x == '0' || x == '6') {
lastdown = ut.ut_tv.tv_sec;
down = 1;
ut.ut_type = SHUTDOWN_TIME;
}
lastrch = ut.ut_tv.tv_sec;
break;
case USER_PROCESS:
/*
* This was a login - show the first matching
* logout record and delete all records with
* the same ut_line.
*/
c = 0;
for (p = ulist; p; p = next) {
next = p->next;
if (strncmp(p->ut.ut_line, ut.ut_line,
sizeof(ut.ut_line)) == 0) {
/* Show it */
if (c == 0) {
quit = list(ctl, &ut, p->ut.ut_tv.tv_sec, R_NORMAL);
c = 1;
}
if (p->next)
p->next->prev = p->prev;
if (p->prev)
p->prev->next = p->next;
else
ulist = p->next;
free(p);
}
}
/*
* Not found? Then crashed, down, still
* logged in, or missing logout record.
*/
if (c == 0) {
if (!lastboot) {
c = R_NOW;
/* Is process still alive? */
if (is_phantom(ctl, &ut))
c = R_PHANTOM;
} else
c = whydown;
quit = list(ctl, &ut, lastboot, c);
}
/* fallthrough */
case DEAD_PROCESS:
/*
* Just store the data if it is
* interesting enough.
*/
if (ut.ut_line[0] == 0)
break;
p = xmalloc(sizeof(struct utmplist));
memcpy(&p->ut, &ut, sizeof(struct utmpx));
p->next = ulist;
p->prev = NULL;
if (ulist)
ulist->prev = p;
ulist = p;
break;
case EMPTY:
case INIT_PROCESS:
case LOGIN_PROCESS:
#ifdef ACCOUNTING
case ACCOUNTING:
#endif
/* ignored ut_types */
break;
default:
warnx("unrecognized ut_type: %d", ut.ut_type);
}
/*
* If we saw a shutdown/reboot record we can remove
* the entire current ulist.
*/
if (down) {
lastboot = ut.ut_tv.tv_sec;
whydown = (ut.ut_type == SHUTDOWN_TIME) ? R_DOWN : R_CRASH;
for (p = ulist; p; p = next) {
next = p->next;
free(p);
}
ulist = NULL;
down = 0;
}
}
if (ctl->time_fmt != LAST_TIMEFTM_NONE) {
struct last_timefmt *fmt;
char timestr[LAST_TIMESTAMP_LEN];
char *tmp = xstrdup(filename);
fmt = &timefmts[ctl->time_fmt];
if (time_formatter(fmt->in_fmt, timestr,
sizeof(timestr), &begintime) < 0)
errx(EXIT_FAILURE, _("preallocation size exceeded"));
printf(_("\n%s begins %s\n"), basename(tmp), timestr);
free(tmp);
}
fclose(fp);
for (p = ulist; p; p = next) {
next = p->next;
free(p);
}
}
#ifdef FUZZ_TARGET
# include "all-io.h"
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
struct last_control ctl = {
.showhost = TRUE,
.name_len = LAST_LOGIN_LEN,
.time_fmt = LAST_TIMEFTM_SHORT,
.domain_len = LAST_DOMAIN_LEN,
.boot_time = {
.tv_sec = 1595978419,
.tv_usec = 816074
}
};
char name[] = "/tmp/test-last-fuzz.XXXXXX";
int fd;
fd = mkstemp_cloexec(name);
if (fd < 0)
err(EXIT_FAILURE, "mkstemp() failed");
if (write_all(fd, data, size) != 0)
err(EXIT_FAILURE, "write() failed");
process_wtmp_file(&ctl, name);
close(fd);
unlink(name);
return 0;
}
#else
int main(int argc, char **argv)
{
struct last_control ctl = {
.showhost = TRUE,
.name_len = LAST_LOGIN_LEN,
.time_fmt = LAST_TIMEFTM_SHORT,
.domain_len = LAST_DOMAIN_LEN
};
char **files = NULL;
size_t i, nfiles = 0;
int c;
usec_t p;
enum {
OPT_TIME_FORMAT = CHAR_MAX + 1
};
static const struct option long_opts[] = {
{ "limit", required_argument, NULL, 'n' },
{ "help", no_argument, NULL, 'h' },
{ "file", required_argument, NULL, 'f' },
{ "nohostname", no_argument, NULL, 'R' },
{ "version", no_argument, NULL, 'V' },
{ "hostlast", no_argument, NULL, 'a' },
{ "since", required_argument, NULL, 's' },
{ "until", required_argument, NULL, 't' },
{ "present", required_argument, NULL, 'p' },
{ "system", no_argument, NULL, 'x' },
{ "dns", no_argument, NULL, 'd' },
{ "ip", no_argument, NULL, 'i' },
{ "fulltimes", no_argument, NULL, 'F' },
{ "fullnames", no_argument, NULL, 'w' },
{ "time-format", required_argument, NULL, OPT_TIME_FORMAT },
{ NULL, 0, NULL, 0 }
};
static const ul_excl_t excl[] = { /* rows and cols in ASCII order */
{ 'F', OPT_TIME_FORMAT }, /* fulltime, time-format */
{ 0 }
};
int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
/*
* Which file do we want to read?
*/
ctl.lastb = strcmp(program_invocation_short_name, "lastb") == 0 ? 1 : 0;
while ((c = getopt_long(argc, argv,
"hVf:n:RxadFit:p:s:0123456789w", long_opts, NULL)) != -1) {
err_exclusive_options(c, long_opts, excl, excl_st);
switch(c) {
case 'h':
usage(&ctl);