gen/FreeBSD/getlogin.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)getlogin.c  8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/getlogin.c,v 1.9 2003/10/29 10:45:01 tjr Exp $");
  39
  40 #include <sys/param.h>
  41 #include <errno.h>
  42 #include <pwd.h>
  43 #include <utmp.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 #include "namespace.h"
  48 #include <pthread.h>
  49 #include "un-namespace.h"
  50
  51 #include "libc_private.h"
  52
  53 #define THREAD_LOCK()   if (__isthreaded) _pthread_mutex_lock(&logname_mutex)
  54 #define THREAD_UNLOCK() if (__isthreaded) _pthread_mutex_unlock(&logname_mutex)
  55
  56 extern int              _getlogin(char *, int);
  57
  58 int                     _logname_valid;         /* known to setlogin() */
  59 static pthread_mutex_t  logname_mutex = PTHREAD_MUTEX_INITIALIZER;
  60
  61 static char *
  62 getlogin_basic(int *status)
  63 {
  64         static char logname[MAXLOGNAME];
  65
  66         if (_logname_valid == 0) {
  67                 if (_getlogin(logname, sizeof(logname)) < 0) {
  68                         *status = errno;
  69                         return (NULL);
  70                 }
  71                 _logname_valid = 1;
  72         }
  73         *status = 0;
  74         return (*logname ? logname : NULL);
  75 }
  76
  77 char *
  78 getlogin(void)
  79 {
  80         char    *result;
  81         int     status;
  82
  83         THREAD_LOCK();
  84         result = getlogin_basic(&status);
  85         THREAD_UNLOCK();
  86         return (result);
  87 }
  88
  89 int
  90 getlogin_r(char *logname, int namelen)
  91 {
  92         char    *result;
  93         int     len;
  94         int     status;
  95
  96         THREAD_LOCK();
  97         result = getlogin_basic(&status);
  98         if (status == 0) {
  99                 if ((len = strlen(result) + 1) > namelen)
 100                         status = ERANGE;
 101                 else
 102                         strncpy(logname, result, len);
 103         }
 104         THREAD_UNLOCK();
 105         return (status);
 106 }