usr/src/lib/libc/port/gen/ttyslot.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 /*
  33  * Return the number of the slot in the utmp file
  34  * corresponding to the current user: try for file 0, 1, 2.
  35  * Returns -1 if slot not found.
  36  */
  37
  38 #include "lint.h"
  39 #include <string.h>
  40 #include <stdio.h>
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <unistd.h>
  44 #include <utmpx.h>
  45 #include <stdlib.h>
  46 #include <pthread.h>
  47
  48 #ifndef TRUE
  49 #define TRUE 1
  50 #define FALSE 0
  51 #endif
  52
  53 int
  54 ttyslot(void)
  55 {
  56         struct futmpx ubuf;
  57         char *p;
  58         int s;
  59         int ret = -1;
  60         int console = FALSE;
  61         char ttynm[128];
  62         FILE *fp;
  63         int cancel_state;
  64
  65         /*
  66          * The UNIX98 Posix conformance test suite requires
  67          * ttyslot() to not be a cancellation point.
  68          */
  69         (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
  70
  71         if ((p = ttyname_r(0, ttynm, 128)) != NULL ||
  72             (p = ttyname_r(1, ttynm, 128)) != NULL ||
  73             (p = ttyname_r(2, ttynm, 128)) != NULL) {
  74                 if (strncmp(p, "/dev/", 5) == 0)
  75                         p += 5;
  76                 if (strcmp(p, "console") == 0)
  77                         console = TRUE;
  78                 s = 0;
  79                 if ((fp = fopen(UTMPX_FILE, "rF")) != NULL) {
  80                         while ((fread(&ubuf, sizeof (ubuf), 1, fp)) == 1) {
  81                                 if ((ubuf.ut_type == INIT_PROCESS ||
  82                                     ubuf.ut_type == LOGIN_PROCESS ||
  83                                     ubuf.ut_type == USER_PROCESS) &&
  84                                     strncmp(p, ubuf.ut_line,
  85                                     sizeof (ubuf.ut_line)) == 0) {
  86                                         ret = s;
  87                                         if (!console ||
  88                                             strncmp(ubuf.ut_host, ":0", 2) == 0)
  89                                                 break;
  90                                 }
  91                                 s++;
  92                         }
  93                         (void) fclose(fp);
  94                 }
  95         }
  96
  97         (void) pthread_setcancelstate(cancel_state, NULL);
  98         return (ret);
  99 }