lib/libc/gen/utmpx.c

   1 /*      $NetBSD: utmpx.c,v 1.35 2015/05/23 11:48:13 christos Exp $       */
   2
   3 /*-
   4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Christos Zoulas.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 #include <sys/cdefs.h>
  32
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 __RCSID("$NetBSD: utmpx.c,v 1.35 2015/05/23 11:48:13 christos Exp $");
  35 #endif /* LIBC_SCCS and not lint */
  36
  37 #include "namespace.h"
  38 #include <sys/types.h>
  39 #include <sys/param.h>
  40 #include <sys/socket.h>
  41 #include <sys/stat.h>
  42 #include <sys/time.h>
  43 #include <sys/wait.h>
  44
  45 #include <assert.h>
  46 #include <db.h>
  47 #include <errno.h>
  48 #include <fcntl.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <unistd.h>
  53 #include <utmp.h>
  54 #include <utmpx.h>
  55 #include <vis.h>
  56
  57 static FILE *fp;
  58 static int readonly = 0;
  59 static int version = 1;
  60 static struct utmpx ut;
  61 static char utfile[MAXPATHLEN] = _PATH_UTMPX;
  62
  63 static struct utmpx *utmp_update(const struct utmpx *);
  64
  65 static const char vers[] = "utmpx-2.00";
  66
  67 struct otimeval {
  68         long tv_sec;
  69         long tv_usec;
  70 };
  71
  72 static void
  73 old2new(struct utmpx *utx)
  74 {
  75         struct otimeval otv;
  76         struct timeval *tv = &utx->ut_tv;
  77         (void)memcpy(&otv, tv, sizeof(otv));
  78         tv->tv_sec = otv.tv_sec;
  79         tv->tv_usec = (suseconds_t)otv.tv_usec;
  80 }
  81
  82 static void
  83 new2old(struct utmpx *utx)
  84 {
  85         struct otimeval otv;
  86         struct timeval *tv = &utx->ut_tv;
  87
  88         otv.tv_sec = (long)tv->tv_sec;
  89         otv.tv_usec = (long)tv->tv_usec;
  90         (void)memcpy(tv, &otv, sizeof(otv));
  91 }
  92
  93 void
  94 setutxent(void)
  95 {
  96
  97         (void)memset(&ut, 0, sizeof(ut));
  98         if (fp == NULL)
  99                 return;
 100         (void)fseeko(fp, (off_t)sizeof(ut), SEEK_SET);
 101 }
 102
 103
 104 void
 105 endutxent(void)
 106 {
 107
 108         (void)memset(&ut, 0, sizeof(ut));
 109         if (fp != NULL) {
 110                 (void)fclose(fp);
 111                 fp = NULL;
 112                 readonly = 0;
 113         }
 114 }
 115
 116
 117 struct utmpx *
 118 getutxent(void)
 119 {
 120
 121         if (fp == NULL) {
 122                 struct stat st;
 123
 124                 if ((fp = fopen(utfile, "re+")) == NULL)
 125                         if ((fp = fopen(utfile, "we+")) == NULL) {
 126                                 if ((fp = fopen(utfile, "re")) == NULL)
 127                                         goto fail;
 128                                 else
 129                                         readonly = 1;
 130                         }
 131
 132
 133                 /* get file size in order to check if new file */
 134                 if (fstat(fileno(fp), &st) == -1)
 135                         goto failclose;
 136
 137                 if (st.st_size == 0) {
 138                         /* new file, add signature record */
 139                         (void)memset(&ut, 0, sizeof(ut));
 140                         ut.ut_type = SIGNATURE;
 141                         (void)memcpy(ut.ut_user, vers, sizeof(vers));
 142                         if (fwrite(&ut, sizeof(ut), 1, fp) != 1)
 143                                 goto failclose;
 144                 } else {
 145                         /* old file, read signature record */
 146                         if (fread(&ut, sizeof(ut), 1, fp) != 1)
 147                                 goto failclose;
 148                         if (memcmp(ut.ut_user, vers, 5) != 0 ||
 149                             ut.ut_type != SIGNATURE)
 150                                 goto failclose;
 151                 }
 152                 version = ut.ut_user[6] - '0';
 153         }
 154
 155         if (fread(&ut, sizeof(ut), 1, fp) != 1)
 156                 goto fail;
 157         if (version == 1)
 158                 old2new(&ut);
 159
 160         return &ut;
 161 failclose:
 162         (void)fclose(fp);
 163 fail:
 164         (void)memset(&ut, 0, sizeof(ut));
 165         return NULL;
 166 }
 167
 168
 169 struct utmpx *
 170 getutxid(const struct utmpx *utx)
 171 {
 172
 173         _DIAGASSERT(utx != NULL);
 174
 175         if (utx->ut_type == EMPTY)
 176                 return NULL;
 177
 178         do {
 179                 if (ut.ut_type == EMPTY)
 180                         continue;
 181                 switch (utx->ut_type) {
 182                 case EMPTY:
 183                         return NULL;
 184                 case RUN_LVL:
 185                 case BOOT_TIME:
 186                 case OLD_TIME:
 187                 case NEW_TIME:
 188                         if (ut.ut_type == utx->ut_type)
 189                                 return &ut;
 190                         break;
 191                 case INIT_PROCESS:
 192                 case LOGIN_PROCESS:
 193                 case USER_PROCESS:
 194                 case DEAD_PROCESS:
 195                         switch (ut.ut_type) {
 196                         case INIT_PROCESS:
 197                         case LOGIN_PROCESS:
 198                         case USER_PROCESS:
 199                         case DEAD_PROCESS:
 200                                 if (memcmp(ut.ut_id, utx->ut_id,
 201                                     sizeof(ut.ut_id)) == 0)
 202                                         return &ut;
 203                                 break;
 204                         default:
 205                                 break;
 206                         }
 207                         break;
 208                 default:
 209                         return NULL;
 210                 }
 211         } while (getutxent() != NULL);
 212         return NULL;
 213 }
 214
 215
 216 struct utmpx *
 217 getutxline(const struct utmpx *utx)
 218 {
 219
 220         _DIAGASSERT(utx != NULL);
 221
 222         do {
 223                 switch (ut.ut_type) {
 224                 case EMPTY:
 225                         break;
 226                 case LOGIN_PROCESS:
 227                 case USER_PROCESS:
 228                         if (strncmp(ut.ut_line, utx->ut_line,
 229                             sizeof(ut.ut_line)) == 0)
 230                                 return &ut;
 231                         break;
 232                 default:
 233                         break;
 234                 }
 235         } while (getutxent() != NULL);
 236         return NULL;
 237 }
 238
 239
 240 struct utmpx *
 241 pututxline(const struct utmpx *utx)
 242 {
 243         struct utmpx temp, *u = NULL;
 244         int gotlock = 0;
 245
 246         _DIAGASSERT(utx != NULL);
 247
 248         if (utx == NULL)
 249                 return NULL;
 250
 251         if (strcmp(_PATH_UTMPX, utfile) == 0) {
 252                 if (geteuid() == 0) {
 253                         if (fp != NULL && readonly)
 254                                 endutxent();
 255                 } else {
 256                         if (fp == NULL || readonly)
 257                                 return utmp_update(utx);
 258                 }
 259         }
 260
 261
 262         (void)memcpy(&temp, utx, sizeof(temp));
 263
 264         if (fp == NULL) {
 265                 (void)getutxent();
 266                 if (fp == NULL || readonly)
 267                         return NULL;
 268         }
 269
 270         if (getutxid(&temp) == NULL) {
 271                 setutxent();
 272                 if (getutxid(&temp) == NULL) {
 273                         if (lockf(fileno(fp), F_LOCK, (off_t)0) == -1)
 274                                 return NULL;
 275                         gotlock++;
 276                         if (fseeko(fp, (off_t)0, SEEK_END) == -1)
 277                                 goto fail;
 278                 }
 279         }
 280
 281         if (!gotlock) {
 282                 /* we are not appending */
 283                 if (fseeko(fp, -(off_t)sizeof(ut), SEEK_CUR) == -1)
 284                         return NULL;
 285         }
 286
 287         if (version == 1)
 288                 new2old(&temp);
 289         if (fwrite(&temp, sizeof (temp), 1, fp) != 1)
 290                 goto fail;
 291
 292         if (fflush(fp) == -1)
 293                 goto fail;
 294
 295         u = memcpy(&ut, &temp, sizeof(ut));
 296 fail:
 297         if (gotlock) {
 298                 if (lockf(fileno(fp), F_ULOCK, (off_t)0) == -1)
 299                         return NULL;
 300         }
 301         return u;
 302 }
 303
 304
 305 static struct utmpx *
 306 utmp_update(const struct utmpx *utx)
 307 {
 308         char buf[sizeof(*utx) * 4 + 1];
 309         pid_t pid;
 310         int status;
 311
 312         _DIAGASSERT(utx != NULL);
 313
 314         (void)strvisx(buf, (const char *)(const void *)utx, sizeof(*utx),
 315             VIS_WHITE | VIS_NOLOCALE);
 316         switch (pid = fork()) {
 317         case 0:
 318                 (void)execl(_PATH_UTMP_UPDATE,
 319                     strrchr(_PATH_UTMP_UPDATE, '/') + 1, buf, NULL);
 320                 _exit(1);
 321                 /*NOTREACHED*/
 322         case -1:
 323                 return NULL;
 324         default:
 325                 if (waitpid(pid, &status, 0) == -1)
 326                         return NULL;
 327                 if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
 328                         return memcpy(&ut, utx, sizeof(ut));
 329                 return NULL;
 330         }
 331
 332 }
 333
 334 /*
 335  * The following are extensions and not part of the X/Open spec.
 336  */
 337 int
 338 updwtmpx(const char *file, const struct utmpx *utx)
 339 {
 340         int fd;
 341         int saved_errno;
 342
 343         _DIAGASSERT(file != NULL);
 344         _DIAGASSERT(utx != NULL);
 345
 346         fd = open(file, O_WRONLY|O_APPEND|O_SHLOCK|O_CLOEXEC);
 347
 348         if (fd == -1) {
 349                 if ((fd = open(file, O_CREAT|O_WRONLY|O_EXLOCK|O_CLOEXEC, 0644)) == -1)
 350                         return -1;
 351                 (void)memset(&ut, 0, sizeof(ut));
 352                 ut.ut_type = SIGNATURE;
 353                 (void)memcpy(ut.ut_user, vers, sizeof(vers));
 354                 if (write(fd, &ut, sizeof(ut)) == -1)
 355                         goto failed;
 356         }
 357         if (write(fd, utx, sizeof(*utx)) == -1)
 358                 goto failed;
 359         if (close(fd) == -1)
 360                 return -1;
 361         return 0;
 362
 363   failed:
 364         saved_errno = errno;
 365         (void) close(fd);
 366         errno = saved_errno;
 367         return -1;
 368 }
 369
 370
 371 int
 372 utmpxname(const char *fname)
 373 {
 374         size_t len;
 375
 376         _DIAGASSERT(fname != NULL);
 377
 378         len = strlen(fname);
 379
 380         if (len >= sizeof(utfile))
 381                 return 0;
 382
 383         /* must end in x! */
 384         if (fname[len - 1] != 'x')
 385                 return 0;
 386
 387         (void)strlcpy(utfile, fname, sizeof(utfile));
 388         endutxent();
 389         return 1;
 390 }
 391
 392
 393 void
 394 getutmp(const struct utmpx *ux, struct utmp *u)
 395 {
 396
 397         _DIAGASSERT(ux != NULL);
 398         _DIAGASSERT(u != NULL);
 399
 400         (void)memcpy(u->ut_name, ux->ut_name, sizeof(u->ut_name));
 401         (void)memcpy(u->ut_line, ux->ut_line, sizeof(u->ut_line));
 402         (void)memcpy(u->ut_host, ux->ut_host, sizeof(u->ut_host));
 403         u->ut_time = ux->ut_tv.tv_sec;
 404 }
 405
 406 void
 407 getutmpx(const struct utmp *u, struct utmpx *ux)
 408 {
 409
 410         _DIAGASSERT(ux != NULL);
 411         _DIAGASSERT(u != NULL);
 412
 413         (void)memcpy(ux->ut_name, u->ut_name, sizeof(u->ut_name));
 414         (void)memcpy(ux->ut_line, u->ut_line, sizeof(u->ut_line));
 415         (void)memcpy(ux->ut_host, u->ut_host, sizeof(u->ut_host));
 416         ux->ut_tv.tv_sec = u->ut_time;
 417         ux->ut_tv.tv_usec = 0;
 418         (void)memset(&ux->ut_ss, 0, sizeof(ux->ut_ss));
 419         ux->ut_pid = 0;
 420         ux->ut_type = USER_PROCESS;
 421         ux->ut_session = 0;
 422         ux->ut_exit.e_termination = 0;
 423         ux->ut_exit.e_exit = 0;
 424 }
 425
 426 struct lastlogx *
 427 getlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
 428 {
 429         DBT key, data;
 430         DB *db;
 431
 432         _DIAGASSERT(fname != NULL);
 433         _DIAGASSERT(ll != NULL);
 434
 435         db = dbopen(fname, O_RDONLY|O_SHLOCK|O_CLOEXEC, 0, DB_HASH, NULL);
 436
 437         if (db == NULL)
 438                 return NULL;
 439
 440         key.data = &uid;
 441         key.size = sizeof(uid);
 442
 443         if ((db->get)(db, &key, &data, 0) != 0)
 444                 goto error;
 445
 446         if (data.size != sizeof(*ll)) {
 447                 errno = EFTYPE;
 448                 goto error;
 449         }
 450
 451         if (ll == NULL)
 452                 if ((ll = malloc(sizeof(*ll))) == NULL)
 453                         goto done;
 454
 455         (void)memcpy(ll, data.data, sizeof(*ll));
 456         goto done;
 457 error:
 458         ll = NULL;
 459 done:
 460         (db->close)(db);
 461         return ll;
 462 }
 463
 464 int
 465 updlastlogx(const char *fname, uid_t uid, struct lastlogx *ll)
 466 {
 467         DBT key, data;
 468         int error = 0;
 469         DB *db;
 470
 471         _DIAGASSERT(fname != NULL);
 472         _DIAGASSERT(ll != NULL);
 473
 474         db = dbopen(fname, O_RDWR|O_CREAT|O_EXLOCK|O_CLOEXEC, 0644, DB_HASH, NULL);
 475
 476         if (db == NULL)
 477                 return -1;
 478
 479         key.data = &uid;
 480         key.size = sizeof(uid);
 481         data.data = ll;
 482         data.size = sizeof(*ll);
 483         if ((db->put)(db, &key, &data, 0) != 0)
 484                 error = -1;
 485
 486         (db->close)(db);
 487         return error;
 488 }