Annotation of embedaddon/sudo/src/utmp.c, revision 1.1.1.3

1.1       misho       1: /*
                      2:  * Copyright (c) 2011 Todd C. Miller <Todd.Miller@courtesan.com>
                      3:  *
                      4:  * Permission to use, copy, modify, and distribute this software for any
                      5:  * purpose with or without fee is hereby granted, provided that the above
                      6:  * copyright notice and this permission notice appear in all copies.
                      7:  *
                      8:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
                      9:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
                     10:  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
                     11:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     12:  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
                     13:  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
                     14:  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
                     15:  */
                     16: 
                     17: #include <config.h>
                     18: 
                     19: #include <sys/types.h>
                     20: #include <sys/param.h>
                     21: #include <sys/time.h>
                     22: #include <sys/wait.h>
                     23: #include <stdio.h>
                     24: #ifdef STDC_HEADERS
                     25: # include <stdlib.h>
                     26: # include <stddef.h>
                     27: #else
                     28: # ifdef HAVE_STDLIB_H
                     29: #  include <stdlib.h>
                     30: # endif
                     31: #endif /* STDC_HEADERS */
                     32: #ifdef HAVE_STRING_H
                     33: # if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS)
                     34: #  include <memory.h>
                     35: # endif
                     36: # include <string.h>
                     37: #endif /* HAVE_STRING_H */
                     38: #ifdef HAVE_STRINGS_H
                     39: # include <strings.h>
                     40: #endif /* HAVE_STRINGS_H */
                     41: #ifdef HAVE_UNISTD_H
                     42: # include <unistd.h>
                     43: #endif /* HAVE_UNISTD_H */
                     44: #if TIME_WITH_SYS_TIME
                     45: # include <time.h>
                     46: #endif
                     47: #ifdef HAVE_UTMPX_H
                     48: # include <utmpx.h>
                     49: #else
                     50: # include <utmp.h>
                     51: #endif /* HAVE_UTMPX_H */
                     52: #ifdef HAVE_GETTTYENT
                     53: # include <ttyent.h>
                     54: #endif
                     55: #include <fcntl.h>
1.1.1.3 ! misho      56: #include <signal.h>
1.1       misho      57: 
                     58: #include "sudo.h"
                     59: #include "sudo_exec.h"
                     60: 
                     61: /*
                     62:  * Simplify handling of utmp vs. utmpx
                     63:  */
                     64: #if !defined(HAVE_GETUTXID) && defined(HAVE_GETUTID)
                     65: # define getutxline(u) getutline(u)
                     66: # define pututxline(u) pututline(u)
1.1.1.2   misho      67: # define setutxent()   setutent()
                     68: # define endutxent()   endutent()
1.1       misho      69: #endif /* !HAVE_GETUTXID && HAVE_GETUTID */
                     70: 
                     71: #ifdef HAVE_GETUTXID
                     72: typedef struct utmpx sudo_utmp_t;
                     73: #else
                     74: typedef struct utmp sudo_utmp_t;
                     75: /* Older systems have ut_name, not us_user */
                     76: # if !defined(HAVE_STRUCT_UTMP_UT_USER) && !defined(ut_user)
                     77: #  define ut_user ut_name
                     78: # endif
                     79: #endif
                     80: 
                     81: /* HP-UX has __e_termination and __e_exit, others lack the __ */
                     82: #if defined(HAVE_STRUCT_UTMPX_UT_EXIT_E_TERMINATION) || defined(HAVE_STRUCT_UTMP_UT_EXIT_E_TERMINATION)
                     83: # undef  __e_termination
                     84: # define __e_termination       e_termination
                     85: # undef  __e_exit
                     86: # define __e_exit              e_exit
                     87: #endif
                     88: 
                     89: #if defined(HAVE_GETUTXID) || defined(HAVE_GETUTID)
                     90: /*
                     91:  * Create ut_id from the new ut_line and the old ut_id.
                     92:  */
                     93: static void
                     94: utmp_setid(sudo_utmp_t *old, sudo_utmp_t *new)
                     95: {
                     96:     const char *line = new->ut_line;
                     97:     size_t idlen;
1.1.1.2   misho      98:     debug_decl(utmp_setid, SUDO_DEBUG_UTMP)
1.1       misho      99: 
                    100:     /* Skip over "tty" in the id if old entry did too. */
                    101:     if (old != NULL) {
                    102:        if (strncmp(line, "tty", 3) == 0) {
                    103:            idlen = MIN(sizeof(old->ut_id), 3);
                    104:            if (strncmp(old->ut_id, "tty", idlen) != 0)
                    105:                line += 3;
                    106:        }
                    107:     }
                    108:     
                    109:     /* Store as much as will fit, skipping parts of the beginning as needed. */
                    110:     idlen = strlen(line);
                    111:     if (idlen > sizeof(new->ut_id)) {
                    112:        line += idlen - sizeof(new->ut_id);
                    113:        idlen = sizeof(new->ut_id);
                    114:     }
                    115:     strncpy(new->ut_id, line, idlen);
1.1.1.2   misho     116: 
                    117:     debug_return;
1.1       misho     118: }
                    119: #endif /* HAVE_GETUTXID || HAVE_GETUTID */
                    120: 
                    121: /*
                    122:  * Store time in utmp structure.
                    123:  */
                    124: static void
                    125: utmp_settime(sudo_utmp_t *ut)
                    126: {
                    127:     struct timeval tv;
1.1.1.2   misho     128:     debug_decl(utmp_settime, SUDO_DEBUG_UTMP)
1.1       misho     129: 
                    130:     gettimeofday(&tv, NULL);
                    131: 
                    132: #if defined(HAVE_STRUCT_UTMP_UT_TV) || defined(HAVE_STRUCT_UTMPX_UT_TV)
                    133:     ut->ut_tv.tv_sec = tv.tv_sec;
                    134:     ut->ut_tv.tv_usec = tv.tv_usec;
                    135: #else
                    136:     ut->ut_time = tv.tv_sec;
                    137: #endif
1.1.1.2   misho     138: 
                    139:     debug_return;
1.1       misho     140: }
                    141: 
                    142: /*
                    143:  * Fill in a utmp entry, using an old entry as a template if there is one.
                    144:  */
                    145: static void
                    146: utmp_fill(const char *line, const char *user, sudo_utmp_t *ut_old,
                    147:     sudo_utmp_t *ut_new)
                    148: {
1.1.1.2   misho     149:     debug_decl(utmp_file, SUDO_DEBUG_UTMP)
                    150: 
1.1       misho     151:     if (ut_old == NULL) {
                    152:        memset(ut_new, 0, sizeof(*ut_new));
                    153:        if (user == NULL) {
                    154:            strncpy(ut_new->ut_user, user_details.username,
                    155:                sizeof(ut_new->ut_user));
                    156:        }
                    157:     } else if (ut_old != ut_new) {
                    158:        memcpy(ut_new, ut_old, sizeof(*ut_new));
                    159:     }
                    160:     if (user != NULL)
                    161:        strncpy(ut_new->ut_user, user, sizeof(ut_new->ut_user));
                    162:     strncpy(ut_new->ut_line, line, sizeof(ut_new->ut_line));
                    163: #if defined(HAVE_STRUCT_UTMPX_UT_ID) || defined(HAVE_STRUCT_UTMP_UT_ID)
                    164:     utmp_setid(ut_old, ut_new);
                    165: #endif
                    166: #if defined(HAVE_STRUCT_UTMPX_UT_PID) || defined(HAVE_STRUCT_UTMP_UT_PID)
                    167:     ut_new->ut_pid = getpid();
                    168: #endif
                    169:     utmp_settime(ut_new);
                    170: #if defined(HAVE_STRUCT_UTMPX_UT_TYPE) || defined(HAVE_STRUCT_UTMP_UT_TYPE)
                    171:     ut_new->ut_type = USER_PROCESS;
                    172: #endif
1.1.1.2   misho     173:     debug_return;
1.1       misho     174: }
                    175: 
                    176: /*
                    177:  * There are two basic utmp file types:
                    178:  *
                    179:  *  POSIX:  sequential access with new entries appended to the end.
                    180:  *         Manipulated via {get,put}utent()/{get,put}getutxent().
                    181:  *
                    182:  *  Legacy: sparse file indexed by ttyslot() * sizeof(struct utmp)
                    183:  */
                    184: #if defined(HAVE_GETUTXID) || defined(HAVE_GETUTID)
1.1.1.2   misho     185: bool
1.1       misho     186: utmp_login(const char *from_line, const char *to_line, int ttyfd,
                    187:     const char *user)
                    188: {
                    189:     sudo_utmp_t utbuf, *ut_old = NULL;
1.1.1.2   misho     190:     bool rval = false;
                    191:     debug_decl(utmp_login, SUDO_DEBUG_UTMP)
1.1       misho     192: 
                    193:     /* Strip off /dev/ prefix from line as needed. */
                    194:     if (strncmp(to_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    195:        to_line += sizeof(_PATH_DEV) - 1;
                    196:     setutxent();
                    197:     if (from_line != NULL) {
                    198:        if (strncmp(from_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    199:            from_line += sizeof(_PATH_DEV) - 1;
                    200: 
                    201:        /* Lookup old line. */
                    202:        memset(&utbuf, 0, sizeof(utbuf));
                    203:        strncpy(utbuf.ut_line, from_line, sizeof(utbuf.ut_line));
                    204:        ut_old = getutxline(&utbuf);
                    205:     }
                    206:     utmp_fill(to_line, user, ut_old, &utbuf);
                    207:     if (pututxline(&utbuf) != NULL)
1.1.1.2   misho     208:        rval = true;
1.1       misho     209:     endutxent();
                    210: 
1.1.1.2   misho     211:     debug_return_bool(rval);
1.1       misho     212: }
                    213: 
1.1.1.2   misho     214: bool
1.1       misho     215: utmp_logout(const char *line, int status)
                    216: {
1.1.1.2   misho     217:     bool rval = false;
1.1       misho     218:     sudo_utmp_t *ut, utbuf;
1.1.1.2   misho     219:     debug_decl(utmp_logout, SUDO_DEBUG_UTMP)
1.1       misho     220: 
                    221:     /* Strip off /dev/ prefix from line as needed. */
                    222:     if (strncmp(line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    223:        line += sizeof(_PATH_DEV) - 1;
                    224:    
                    225:     memset(&utbuf, 0, sizeof(utbuf));
                    226:     strncpy(utbuf.ut_line, line, sizeof(utbuf.ut_line));
                    227:     if ((ut = getutxline(&utbuf)) != NULL) {
                    228:        memset(ut->ut_user, 0, sizeof(ut->ut_user));
                    229: # if defined(HAVE_STRUCT_UTMPX_UT_TYPE) || defined(HAVE_STRUCT_UTMP_UT_TYPE)
                    230:        ut->ut_type = DEAD_PROCESS;
                    231: # endif
                    232: # if defined(HAVE_STRUCT_UTMPX_UT_EXIT) || defined(HAVE_STRUCT_UTMP_UT_EXIT)
                    233:        ut->ut_exit.__e_exit = WEXITSTATUS(status);
                    234:        ut->ut_exit.__e_termination = WIFEXITED(status) ? WEXITSTATUS(status) : 0;
                    235: # endif
                    236:        utmp_settime(ut);
                    237:        if (pututxline(ut) != NULL)
1.1.1.2   misho     238:            rval = true;
1.1       misho     239:     }
1.1.1.2   misho     240:     debug_return_bool(rval);
1.1       misho     241: }
                    242: 
                    243: #else /* !HAVE_GETUTXID && !HAVE_GETUTID */
                    244: 
                    245: /*
                    246:  * Find the slot for the specified line (tty name and file descriptor).
                    247:  * Returns a slot suitable for seeking into utmp on success or <= 0 on error.
                    248:  * If getttyent() is available we can use that to compute the slot.
                    249:  */
                    250: # ifdef HAVE_GETTTYENT
                    251: static int
                    252: utmp_slot(const char *line, int ttyfd)
                    253: {
                    254:     int slot = 1;
                    255:     struct ttyent *tty;
1.1.1.2   misho     256:     debug_decl(utmp_slot, SUDO_DEBUG_UTMP)
1.1       misho     257: 
                    258:     setttyent();
                    259:     while ((tty = getttyent()) != NULL) {
                    260:        if (strcmp(line, tty->ty_name) == 0)
                    261:            break;
                    262:        slot++;
                    263:     }
                    264:     endttyent();
1.1.1.2   misho     265:     debug_return_int(tty ? slot : 0);
1.1       misho     266: }
                    267: # else
                    268: static int
                    269: utmp_slot(const char *line, int ttyfd)
                    270: {
                    271:     int sfd, slot;
1.1.1.2   misho     272:     debug_decl(utmp_slot, SUDO_DEBUG_UTMP)
1.1       misho     273: 
                    274:     /*
                    275:      * Temporarily point stdin to the tty since ttyslot()
                    276:      * doesn't take an argument.
                    277:      */
                    278:     if ((sfd = dup(STDIN_FILENO)) == -1)
                    279:        error(1, _("unable to save stdin"));
                    280:     if (dup2(ttyfd, STDIN_FILENO) == -1)
                    281:        error(1, _("unable to dup2 stdin"));
                    282:     slot = ttyslot();
                    283:     if (dup2(sfd, STDIN_FILENO) == -1)
                    284:        error(1, _("unable to restore stdin"));
                    285:     close(sfd);
                    286: 
1.1.1.2   misho     287:     debug_return_int(slot);
1.1       misho     288: }
                    289: # endif /* HAVE_GETTTYENT */
                    290: 
1.1.1.2   misho     291: bool
1.1       misho     292: utmp_login(const char *from_line, const char *to_line, int ttyfd,
                    293:     const char *user)
                    294: {
                    295:     sudo_utmp_t utbuf, *ut_old = NULL;
1.1.1.2   misho     296:     bool rval = false;
                    297:     int slot;
1.1       misho     298:     FILE *fp;
1.1.1.2   misho     299:     debug_decl(utmp_login, SUDO_DEBUG_UTMP)
1.1       misho     300: 
                    301:     /* Strip off /dev/ prefix from line as needed. */
                    302:     if (strncmp(to_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    303:        to_line += sizeof(_PATH_DEV) - 1;
                    304: 
                    305:     /* Find slot for new entry. */
                    306:     slot = utmp_slot(to_line, ttyfd);
                    307:     if (slot <= 0)
                    308:        goto done;
                    309: 
                    310:     if ((fp = fopen(_PATH_UTMP, "r+")) == NULL)
                    311:        goto done;
                    312: 
                    313:     if (from_line != NULL) {
                    314:        if (strncmp(from_line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    315:            from_line += sizeof(_PATH_DEV) - 1;
                    316: 
                    317:        /* Lookup old line. */
                    318:        while (fread(&utbuf, sizeof(utbuf), 1, fp) == 1) {
                    319: # ifdef HAVE_STRUCT_UTMP_UT_ID
                    320:            if (utbuf.ut_type != LOGIN_PROCESS && utbuf.ut_type != USER_PROCESS)
                    321:                continue;
                    322: # endif
                    323:            if (utbuf.ut_user[0] &&
                    324:                !strncmp(utbuf.ut_line, from_line, sizeof(utbuf.ut_line))) {
                    325:                ut_old = &utbuf;
                    326:                break;
                    327:            }
                    328:        }
                    329:     }
                    330:     utmp_fill(to_line, user, ut_old, &utbuf);
1.1.1.3 ! misho     331: #ifdef HAVE_FSEEKO
        !           332:     if (fseeko(fp, slot * (off_t)sizeof(utbuf), SEEK_SET) == 0) {
        !           333: #else
1.1       misho     334:     if (fseek(fp, slot * (long)sizeof(utbuf), SEEK_SET) == 0) {
1.1.1.3 ! misho     335: #endif
1.1       misho     336:        if (fwrite(&utbuf, sizeof(utbuf), 1, fp) == 1)
1.1.1.2   misho     337:            rval = true;
1.1       misho     338:     }
                    339:     fclose(fp);
                    340: 
                    341: done:
1.1.1.2   misho     342:     debug_return_bool(rval);
1.1       misho     343: }
                    344: 
1.1.1.2   misho     345: bool
1.1       misho     346: utmp_logout(const char *line, int status)
                    347: {
                    348:     sudo_utmp_t utbuf;
1.1.1.2   misho     349:     bool rval = false;
1.1       misho     350:     FILE *fp;
1.1.1.2   misho     351:     debug_decl(utmp_logout, SUDO_DEBUG_UTMP)
1.1       misho     352: 
                    353:     if ((fp = fopen(_PATH_UTMP, "r+")) == NULL)
1.1.1.2   misho     354:        debug_return_int(rval);
1.1       misho     355: 
                    356:     /* Strip off /dev/ prefix from line as needed. */
                    357:     if (strncmp(line, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
                    358:        line += sizeof(_PATH_DEV) - 1;
                    359:    
                    360:     while (fread(&utbuf, sizeof(utbuf), 1, fp) == 1) {
                    361:        if (!strncmp(utbuf.ut_line, line, sizeof(utbuf.ut_line))) {
                    362:            memset(utbuf.ut_user, 0, sizeof(utbuf.ut_user));
                    363: # if defined(HAVE_STRUCT_UTMP_UT_TYPE)
                    364:            utbuf.ut_type = DEAD_PROCESS;
                    365: # endif
                    366:            utmp_settime(&utbuf);
                    367:            /* Back up and overwrite record. */
1.1.1.3 ! misho     368: #ifdef HAVE_FSEEKO
        !           369:            if (fseeko(fp, (off_t)0 - (off_t)sizeof(utbuf), SEEK_CUR) == 0) {
        !           370: #else
1.1       misho     371:            if (fseek(fp, 0L - (long)sizeof(utbuf), SEEK_CUR) == 0) {
1.1.1.3 ! misho     372: #endif
1.1       misho     373:                if (fwrite(&utbuf, sizeof(utbuf), 1, fp) == 1)
1.1.1.2   misho     374:                    rval = true;
1.1       misho     375:            }
                    376:            break;
                    377:        }
                    378:     }
                    379:     fclose(fp);
                    380: 
1.1.1.2   misho     381:     debug_return_bool(rval);
1.1       misho     382: }
                    383: #endif /* HAVE_GETUTXID || HAVE_GETUTID */

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>