usr/src/lib/gss_mechs/mech_krb5/krb5/posix/setenv.c

   1 #pragma ident   "%Z%%M% %I%     %E% SMI"
   2 /*
   3  * Copyright (c) 1987, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the University of
  17  *      California, Berkeley and its contributors.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 /* based on @(#)setenv.c        8.1 (Berkeley) 6/4/93 */
  36 /* based on @(#)getenv.c        8.1 (Berkeley) 6/4/93 */
  37
  38 #ifndef __STDC__
  39 #define const
  40 #endif
  41
  42 #include <stddef.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #ifndef __P
  47 #define __P(x)  ()
  48 #endif
  49 static char *__findenv __P((const char *, int *));
  50
  51 /*
  52  * setenv --
  53  *      Set the value of the environmental variable "name" to be
  54  *      "value".  If rewrite is set, replace any current value.
  55  */
  56 int
  57 krb5_setenv(name, value, rewrite)
  58         register const char *name;
  59         register const char *value;
  60         int rewrite;
  61 {
  62 #if HAVE_SETENV
  63     return (setenv(name, value, rewrite));
  64 #else
  65         extern char **environ;
  66         static int alloced;                     /* if allocated space before */
  67         register char *c;
  68         int l_value, offset;
  69
  70         if (*value == '=')                      /* no `=' in value */
  71                 ++value;
  72         l_value = strlen(value);
  73         if ((c = __findenv(name, &offset))) {   /* find if already exists */
  74                 if (!rewrite)
  75                         return (0);
  76                 if (strlen(c) >= l_value) {     /* old larger; copy over */
  77                         while ((*c++ = *value++));
  78                         return (0);
  79                 }
  80         } else {                                        /* create new slot */
  81                 register int cnt;
  82                 register char **p;
  83
  84                 for (p = environ, cnt = 0; *p; ++p, ++cnt);
  85                 if (alloced) {                  /* just increase size */
  86                         environ = (char **)realloc((char *)environ,
  87                             (size_t)(sizeof(char *) * (cnt + 2)));
  88                         if (!environ)
  89                                 return (-1);
  90                 }
  91                 else {                          /* get new space */
  92                         alloced = 1;            /* copy old entries into it */
  93                         p = (char **)malloc((size_t)(sizeof(char *) * (cnt + 2)));
  94                         if (!p)
  95                                 return (-1);
  96                         memcpy(p, environ, cnt * sizeof(char *));
  97                         environ = p;
  98                 }
  99                 environ[cnt + 1] = NULL;
 100                 offset = cnt;
 101         }
 102         for (c = (char *)name; *c && *c != '='; ++c);   /* no `=' in name */
 103         if (!(environ[offset] =                 /* name + `=' + value */
 104             malloc((size_t)((int)(c - name) + l_value + 2))))
 105                 return (-1);
 106         /* LINTED */
 107         for (c = environ[offset]; (*c = *name++) && (*c != '='); ++c);
 108         for (*c++ = '='; (*c++ = *value++););
 109         return (0);
 110 #endif
 111 }
 112
 113 /*
 114  * unsetenv(name) --
 115  *      Delete environmental variable "name".
 116  */
 117 void
 118 krb5_unsetenv(name)
 119         const char *name;
 120 {
 121 #if HAVE_UNSETENV
 122     unsetenv(name);
 123 #else
 124         extern char **environ;
 125         register char **p;
 126         int offset;
 127
 128         while (__findenv(name, &offset))        /* if set multiple times */
 129                 for (p = &environ[offset];; ++p)
 130                         /* LINTED */
 131                         if (!(*p = *(p + 1)))
 132                                 break;
 133 #endif
 134 }
 135
 136 /*
 137  * getenv --
 138  *      Returns ptr to value associated with name, if any, else NULL.
 139  */
 140 char *
 141 krb5_getenv(name)
 142         const char *name;
 143 {
 144 #if HAVE_GETENV
 145     return (getenv(name));
 146 #else
 147         int offset;
 148
 149         return (__findenv(name, &offset));
 150 #endif
 151 }
 152
 153 #if (!HAVE_GETENV || !HAVE_SETENV || !HAVE_UNSETENV)
 154 /*
 155  * __findenv --
 156  *      Returns pointer to value associated with name, if any, else NULL.
 157  *      Sets offset to be the offset of the name/value combination in the
 158  *      environmental array, for use by setenv(3) and unsetenv(3).
 159  *      Explicitly removes '=' in argument name.
 160  */
 161 static char *
 162 __findenv(name, offset)
 163         register const char *name;
 164         int *offset;
 165 {
 166         extern char **environ;
 167         register int len;
 168         register const char *np;
 169         register char **p, *c;
 170
 171         if (name == NULL || environ == NULL)
 172                 return (NULL);
 173         for (np = name; *np && *np != '='; ++np)
 174                 continue;
 175         len = np - name;
 176         for (p = environ; (c = *p) != NULL; ++p)
 177                 if (strncmp(c, name, len) == 0 && c[len] == '=') {
 178                         *offset = p - environ;
 179                         return (c + len + 1);
 180                 }
 181         return (NULL);
 182 }
 183 #endif