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