1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1987, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 2018 Philip Paeps
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1987, 1993, 1994\n\
36 The Regents of the University of California. All rights reserved.\n";
37 #endif /* not lint */
38
39 #ifndef lint
40 static const char sccsid[] = "@(#)last.c 8.2 (Berkeley) 4/2/94";
41 #endif /* not lint */
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44
45 #include <sys/param.h>
46 #include <sys/capsicum.h>
47 #include <sys/queue.h>
48 #include <sys/stat.h>
49
50 #include <capsicum_helpers.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <fcntl.h>
54 #include <langinfo.h>
55 #include <locale.h>
56 #include <paths.h>
57 #include <signal.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <time.h>
62 #include <timeconv.h>
63 #include <unistd.h>
64 #include <utmpx.h>
65
66 #include <libxo/xo.h>
67
68 #define NO 0 /* false/no */
69 #define YES 1 /* true/yes */
70 #define ATOI2(ar) ((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
71
72 typedef struct arg {
73 char *name; /* argument */
74 #define REBOOT_TYPE -1
75 #define HOST_TYPE -2
76 #define TTY_TYPE -3
77 #define USER_TYPE -4
78 int type; /* type of arg */
79 struct arg *next; /* linked list pointer */
80 } ARG;
81 static ARG *arglist; /* head of linked list */
82
83 static SLIST_HEAD(, idtab) idlist;
84
85 struct idtab {
86 time_t logout; /* log out time */
87 char id[sizeof ((struct utmpx *)0)->ut_id]; /* identifier */
88 SLIST_ENTRY(idtab) list;
89 };
90
91 static const char *crmsg; /* cause of last reboot */
92 static time_t currentout; /* current logout value */
93 static long maxrec; /* records to display */
94 static const char *file = NULL; /* utx.log file */
95 static int noctfix = 0; /* locale is C or UTF-8 */
96 static int sflag = 0; /* show delta in seconds */
97 static int width = 5; /* show seconds in delta */
98 static int yflag; /* show year */
99 static int d_first;
100 static int snapfound = 0; /* found snapshot entry? */
101 static time_t snaptime; /* if != 0, we will only
102 * report users logged in
103 * at this snapshot time
104 */
105
106 static void addarg(int, char *);
107 static const char *ctf(const char *);
108 static time_t dateconv(char *);
109 static void doentry(struct utmpx *);
110 static void hostconv(char *);
111 static void printentry(struct utmpx *, struct idtab *);
112 static char *ttyconv(char *);
113 static int want(struct utmpx *);
114 static void usage(void);
115 static void wtmp(void);
116
117 static const char*
ctf(const char * fmt)118 ctf(const char *fmt) {
119 static char buf[31];
120 const char *src, *end;
121 char *dst;
122
123 if (noctfix)
124 return (fmt);
125
126 end = buf + sizeof(buf);
127 for (src = fmt, dst = buf; dst < end; *dst++ = *src++) {
128 if (*src == '\0') {
129 *dst = '\0';
130 break;
131 } else if (*src == '%' && *(src+1) == 's') {
132 *dst++ = '%';
133 *dst++ = 'h';
134 *dst++ = 's';
135 strlcpy(dst, src+2, end - dst);
136 return (buf);
137 }
138 }
139 return (buf);
140 }
141
142 static void
usage(void)143 usage(void)
144 {
145 xo_error(
146 "usage: last [-swy] [-d [[CC]YY][MMDD]hhmm[.SS]] [-f file] [-h host]\n"
147 " [-n maxrec] [-t tty] [user ...]\n");
148 exit(1);
149 }
150
151 int
main(int argc,char * argv[])152 main(int argc, char *argv[])
153 {
154 int ch;
155 char *p;
156
157 (void) setlocale(LC_TIME, "");
158 d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
159
160 (void) setlocale(LC_CTYPE, "");
161 p = nl_langinfo(CODESET);
162 if (strcmp(p, "UTF-8") == 0 || strcmp(p, "US-ASCII") == 0)
163 noctfix = 1;
164
165 argc = xo_parse_args(argc, argv);
166 if (argc < 0)
167 exit(1);
168 atexit(xo_finish_atexit);
169
170 maxrec = -1;
171 snaptime = 0;
172 while ((ch = getopt(argc, argv, "0123456789d:f:h:n:st:wy")) != -1)
173 switch (ch) {
174 case '0': case '1': case '2': case '3': case '4':
175 case '5': case '6': case '7': case '8': case '9':
176 /*
177 * kludge: last was originally designed to take
178 * a number after a dash.
179 */
180 if (maxrec == -1) {
181 p = strchr(argv[optind - 1], ch);
182 if (p == NULL)
183 p = strchr(argv[optind], ch);
184 maxrec = atol(p);
185 if (!maxrec)
186 exit(0);
187 }
188 break;
189 case 'd':
190 snaptime = dateconv(optarg);
191 break;
192 case 'f':
193 file = optarg;
194 break;
195 case 'h':
196 hostconv(optarg);
197 addarg(HOST_TYPE, optarg);
198 break;
199 case 'n':
200 errno = 0;
201 maxrec = strtol(optarg, &p, 10);
202 if (p == optarg || *p != '\0' || errno != 0 ||
203 maxrec <= 0)
204 xo_errx(1, "%s: bad line count", optarg);
205 break;
206 case 's':
207 sflag++; /* Show delta as seconds */
208 break;
209 case 't':
210 addarg(TTY_TYPE, ttyconv(optarg));
211 break;
212 case 'w':
213 width = 8;
214 break;
215 case 'y':
216 yflag++;
217 break;
218 case '?':
219 default:
220 usage();
221 }
222
223 if (caph_limit_stdio() < 0)
224 xo_err(1, "can't limit stdio rights");
225
226 caph_cache_catpages();
227 caph_cache_tzdata();
228
229 /* Cache UTX database. */
230 if (setutxdb(UTXDB_LOG, file) != 0)
231 xo_err(1, "%s", file != NULL ? file : "(default utx db)");
232
233 if (caph_enter() < 0)
234 xo_err(1, "cap_enter");
235
236 if (sflag && width == 8) usage();
237
238 if (argc) {
239 setlinebuf(stdout);
240 for (argv += optind; *argv; ++argv) {
241 if (strcmp(*argv, "reboot") == 0)
242 addarg(REBOOT_TYPE, *argv);
243 #define COMPATIBILITY
244 #ifdef COMPATIBILITY
245 /* code to allow "last p5" to work */
246 addarg(TTY_TYPE, ttyconv(*argv));
247 #endif
248 addarg(USER_TYPE, *argv);
249 }
250 }
251 wtmp();
252 exit(0);
253 }
254
255 /*
256 * wtmp --
257 * read through the utx.log file
258 */
259 static void
wtmp(void)260 wtmp(void)
261 {
262 struct utmpx *buf = NULL;
263 struct utmpx *ut;
264 static unsigned int amount = 0;
265 time_t t;
266 char ct[80];
267 struct tm *tm;
268
269 SLIST_INIT(&idlist);
270 (void)time(&t);
271
272 xo_open_container("last-information");
273
274 /* Load the last entries from the file. */
275 while ((ut = getutxent()) != NULL) {
276 if (amount % 128 == 0) {
277 buf = realloc(buf, (amount + 128) * sizeof *ut);
278 if (buf == NULL)
279 xo_err(1, "realloc");
280 }
281 memcpy(&buf[amount++], ut, sizeof *ut);
282 if (t > ut->ut_tv.tv_sec)
283 t = ut->ut_tv.tv_sec;
284 }
285 endutxent();
286
287 /* Display them in reverse order. */
288 xo_open_list("last");
289 while (amount > 0)
290 doentry(&buf[--amount]);
291 xo_close_list("last");
292 free(buf);
293 tm = localtime(&t);
294 (void) strftime(ct, sizeof(ct), "%+", tm);
295 xo_emit("\n{:utxdb/%s}", (file == NULL) ? "utx.log" : file);
296 xo_attr("seconds", "%lu", (unsigned long) t);
297 xo_emit(ctf(" begins {:begins/%s}\n"), ct);
298 xo_close_container("last-information");
299 }
300
301 /*
302 * doentry --
303 * process a single utx.log entry
304 */
305 static void
doentry(struct utmpx * bp)306 doentry(struct utmpx *bp)
307 {
308 struct idtab *tt;
309
310 /* the machine stopped */
311 if (bp->ut_type == BOOT_TIME || bp->ut_type == SHUTDOWN_TIME) {
312 /* everybody just logged out */
313 while ((tt = SLIST_FIRST(&idlist)) != NULL) {
314 SLIST_REMOVE_HEAD(&idlist, list);
315 free(tt);
316 }
317 currentout = -bp->ut_tv.tv_sec;
318 crmsg = bp->ut_type != SHUTDOWN_TIME ?
319 "crash" : "shutdown";
320 /*
321 * if we're in snapshot mode, we want to exit if this
322 * shutdown/reboot appears while we we are tracking the
323 * active range
324 */
325 if (snaptime && snapfound)
326 exit(0);
327 /*
328 * don't print shutdown/reboot entries unless flagged for
329 */
330 if (!snaptime && want(bp))
331 printentry(bp, NULL);
332 return;
333 }
334 /* date got set */
335 if (bp->ut_type == OLD_TIME || bp->ut_type == NEW_TIME) {
336 if (want(bp) && !snaptime)
337 printentry(bp, NULL);
338 return;
339 }
340
341 if (bp->ut_type != USER_PROCESS && bp->ut_type != DEAD_PROCESS)
342 return;
343
344 /* find associated identifier */
345 SLIST_FOREACH(tt, &idlist, list)
346 if (!memcmp(tt->id, bp->ut_id, sizeof bp->ut_id))
347 break;
348
349 if (tt == NULL) {
350 /* add new one */
351 tt = malloc(sizeof(struct idtab));
352 if (tt == NULL)
353 xo_errx(1, "malloc failure");
354 tt->logout = currentout;
355 memcpy(tt->id, bp->ut_id, sizeof bp->ut_id);
356 SLIST_INSERT_HEAD(&idlist, tt, list);
357 }
358
359 /*
360 * print record if not in snapshot mode and wanted
361 * or in snapshot mode and in snapshot range
362 */
363 if (bp->ut_type == USER_PROCESS && (want(bp) ||
364 (bp->ut_tv.tv_sec < snaptime &&
365 (tt->logout > snaptime || tt->logout < 1)))) {
366 snapfound = 1;
367 printentry(bp, tt);
368 }
369 tt->logout = bp->ut_tv.tv_sec;
370 }
371
372 /*
373 * printentry --
374 * output an entry
375 *
376 * If `tt' is non-NULL, use it and `crmsg' to print the logout time or
377 * logout type (crash/shutdown) as appropriate.
378 */
379 static void
printentry(struct utmpx * bp,struct idtab * tt)380 printentry(struct utmpx *bp, struct idtab *tt)
381 {
382 char ct[80];
383 struct tm *tm;
384 time_t delta; /* time difference */
385 time_t t;
386
387 if (maxrec != -1 && !maxrec--)
388 exit(0);
389 xo_open_instance("last");
390 t = bp->ut_tv.tv_sec;
391 tm = localtime(&t);
392 (void) strftime(ct, sizeof(ct), d_first ?
393 (yflag ? "%a %e %b %Y %R" : "%a %e %b %R") :
394 (yflag ? "%a %b %e %Y %R" : "%a %b %e %R"), tm);
395 switch (bp->ut_type) {
396 case BOOT_TIME:
397 xo_emit("{:user/%-42s/%s}", "boot time");
398 break;
399 case SHUTDOWN_TIME:
400 xo_emit("{:user/%-42s/%s}", "shutdown time");
401 break;
402 case OLD_TIME:
403 xo_emit("{:user/%-42s/%s}", "old time");
404 break;
405 case NEW_TIME:
406 xo_emit("{:user/%-42s/%s}", "new time");
407 break;
408 case USER_PROCESS:
409 xo_emit("{:user/%-10s/%s} {:tty/%-8s/%s} {:from/%-22.22s/%s}",
410 bp->ut_user, bp->ut_line, bp->ut_host);
411 break;
412 }
413 xo_attr("seconds", "%lu", (unsigned long)t);
414 xo_emit(ctf(" {:login-time/%s%c/%s}"), ct, tt == NULL ? '\n' : ' ');
415 if (tt == NULL)
416 goto end;
417 if (!tt->logout) {
418 xo_emit(" {:logout-time/still logged in}\n");
419 goto end;
420 }
421 if (tt->logout < 0) {
422 tt->logout = -tt->logout;
423 xo_emit("- {:logout-reason/%s}", crmsg);
424 } else {
425 tm = localtime(&tt->logout);
426 (void) strftime(ct, sizeof(ct), "%R", tm);
427 xo_attr("seconds", "%lu", (unsigned long)tt->logout);
428 xo_emit(ctf("- {:logout-time/%s}"), ct);
429 }
430 delta = tt->logout - bp->ut_tv.tv_sec;
431 xo_attr("seconds", "%ld", (long)delta);
432 if (sflag) {
433 xo_emit(" ({:session-length/%8ld})\n", (long)delta);
434 } else {
435 tm = gmtime(&delta);
436 (void) strftime(ct, sizeof(ct), width >= 8 ? "%T" : "%R", tm);
437 if (delta < 86400)
438 xo_emit(ctf(" ({:session-length/%s})\n"), ct);
439 else
440 xo_emit(ctf(" ({:session-length/%ld+%s})\n"),
441 (long)delta / 86400, ct);
442 }
443
444 end:
445 xo_close_instance("last");
446 }
447
448 /*
449 * want --
450 * see if want this entry
451 */
452 static int
want(struct utmpx * bp)453 want(struct utmpx *bp)
454 {
455 ARG *step;
456
457 if (snaptime)
458 return (NO);
459
460 if (!arglist)
461 return (YES);
462
463 for (step = arglist; step; step = step->next)
464 switch(step->type) {
465 case REBOOT_TYPE:
466 if (bp->ut_type == BOOT_TIME ||
467 bp->ut_type == SHUTDOWN_TIME)
468 return (YES);
469 break;
470 case HOST_TYPE:
471 if (!strcasecmp(step->name, bp->ut_host))
472 return (YES);
473 break;
474 case TTY_TYPE:
475 if (!strcmp(step->name, bp->ut_line))
476 return (YES);
477 break;
478 case USER_TYPE:
479 if (!strcmp(step->name, bp->ut_user))
480 return (YES);
481 break;
482 }
483 return (NO);
484 }
485
486 /*
487 * addarg --
488 * add an entry to a linked list of arguments
489 */
490 static void
addarg(int type,char * arg)491 addarg(int type, char *arg)
492 {
493 ARG *cur;
494
495 if ((cur = malloc(sizeof(ARG))) == NULL)
496 xo_errx(1, "malloc failure");
497 cur->next = arglist;
498 cur->type = type;
499 cur->name = arg;
500 arglist = cur;
501 }
502
503 /*
504 * hostconv --
505 * convert the hostname to search pattern; if the supplied host name
506 * has a domain attached that is the same as the current domain, rip
507 * off the domain suffix since that's what login(1) does.
508 */
509 static void
hostconv(char * arg)510 hostconv(char *arg)
511 {
512 static int first = 1;
513 static char *hostdot, name[MAXHOSTNAMELEN];
514 char *argdot;
515
516 if (!(argdot = strchr(arg, '.')))
517 return;
518 if (first) {
519 first = 0;
520 if (gethostname(name, sizeof(name)))
521 xo_err(1, "gethostname");
522 hostdot = strchr(name, '.');
523 }
524 if (hostdot && !strcasecmp(hostdot, argdot))
525 *argdot = '\0';
526 }
527
528 /*
529 * ttyconv --
530 * convert tty to correct name.
531 */
532 static char *
ttyconv(char * arg)533 ttyconv(char *arg)
534 {
535 char *mval;
536
537 /*
538 * kludge -- we assume that all tty's end with
539 * a two character suffix.
540 */
541 if (strlen(arg) == 2) {
542 /* either 6 for "ttyxx" or 8 for "console" */
543 if ((mval = malloc(8)) == NULL)
544 xo_errx(1, "malloc failure");
545 if (!strcmp(arg, "co"))
546 (void)strcpy(mval, "console");
547 else {
548 (void)strcpy(mval, "tty");
549 (void)strcpy(mval + 3, arg);
550 }
551 return (mval);
552 }
553 if (!strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1))
554 return (arg + 5);
555 return (arg);
556 }
557
558 /*
559 * dateconv --
560 * Convert the snapshot time in command line given in the format
561 * [[CC]YY]MMDDhhmm[.SS]] to a time_t.
562 * Derived from atime_arg1() in usr.bin/touch/touch.c
563 */
564 static time_t
dateconv(char * arg)565 dateconv(char *arg)
566 {
567 time_t timet;
568 struct tm *t;
569 int yearset;
570 char *p;
571
572 /* Start with the current time. */
573 if (time(&timet) < 0)
574 xo_err(1, "time");
575 if ((t = localtime(&timet)) == NULL)
576 xo_err(1, "localtime");
577
578 /* [[CC]YY]MMDDhhmm[.SS] */
579 if ((p = strchr(arg, '.')) == NULL)
580 t->tm_sec = 0; /* Seconds defaults to 0. */
581 else {
582 if (strlen(p + 1) != 2)
583 goto terr;
584 *p++ = '\0';
585 t->tm_sec = ATOI2(p);
586 }
587
588 yearset = 0;
589 switch (strlen(arg)) {
590 case 12: /* CCYYMMDDhhmm */
591 t->tm_year = ATOI2(arg);
592 t->tm_year *= 100;
593 yearset = 1;
594 /* FALLTHROUGH */
595 case 10: /* YYMMDDhhmm */
596 if (yearset) {
597 yearset = ATOI2(arg);
598 t->tm_year += yearset;
599 } else {
600 yearset = ATOI2(arg);
601 if (yearset < 69)
602 t->tm_year = yearset + 2000;
603 else
604 t->tm_year = yearset + 1900;
605 }
606 t->tm_year -= 1900; /* Convert to UNIX time. */
607 /* FALLTHROUGH */
608 case 8: /* MMDDhhmm */
609 t->tm_mon = ATOI2(arg);
610 --t->tm_mon; /* Convert from 01-12 to 00-11 */
611 t->tm_mday = ATOI2(arg);
612 t->tm_hour = ATOI2(arg);
613 t->tm_min = ATOI2(arg);
614 break;
615 case 4: /* hhmm */
616 t->tm_hour = ATOI2(arg);
617 t->tm_min = ATOI2(arg);
618 break;
619 default:
620 goto terr;
621 }
622 t->tm_isdst = -1; /* Figure out DST. */
623 timet = mktime(t);
624 if (timet == -1)
625 terr: xo_errx(1,
626 "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
627 return timet;
628 }
629