stdlib/setenv-fbsd.c

   1 /*
   2  * Copyright (c) 1987, 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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)setenv.c    8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/stdlib/setenv.c,v 1.14 2007/05/01 16:02:41 ache Exp $");
  35
  36 #include <stddef.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39 #include <crt_externs.h>
  40 #include <errno.h>
  41 #include <sys/types.h>
  42 #include <fcntl.h>
  43 #include <malloc/malloc.h>
  44
  45 #define ZONE_OWNS_PTR(zone, ptr)        (malloc_zone_from_ptr((ptr)) == zone)
  46
  47 extern malloc_zone_t *__zone0;
  48 extern void __malloc_check_env_name(const char *);
  49
  50 __private_extern__ char *__findenv(const char *, int *, char **);
  51 __private_extern__ int __setenv(const char *, const char *, int, int, char ***, malloc_zone_t *);
  52 __private_extern__ void __unsetenv(const char *, char **, malloc_zone_t *);
  53 __private_extern__ int init__zone0(int);
  54
  55 /*
  56  * _cthread_init_routine used to be called from crt1.o to initialize threads.
  57  * This is no longer needed, as initialization happens in dylib initializers,
  58  * but is provided to maintain backwards compatibility.  Normally, for 10.5
  59  * or greater, _cthread_init_routine does nothing.
  60  *
  61  * Before 10.5, the _start routine in crt1.o clobbers environ with the original
  62  * stack value, which effectively undoes any environment changes made in
  63  * initializers.  When LEGACY_CRT1_ENVIRON is defined, we replace the
  64  * do-nothing routine with one that attempts to restore the environ value.
  65  * But this only works if the setenv (and family) routines were used
  66  * exclusively, (no direct manipulation of environ).  Note that according to
  67  * SUSv3, direct manipulation of environ may result in undefined behavior in
  68  * setenv and family, so we don't support that (on less than 10.5).
  69  */
  70 #ifdef BUILDING_VARIANT
  71 #  ifdef LEGACY_CRT1_ENVIRON
  72 extern char **_saved_environ;
  73 #  endif /* LEGACY_CRT1_ENVIRON */
  74 #else /* !BUILDING_VARIANT */
  75 #  ifdef LEGACY_CRT1_ENVIRON
  76 __private_extern__ char **_saved_environ = NULL;
  77
  78 static int
  79 _legacy_crt1_environ(void)
  80 {
  81         if (_saved_environ) *_NSGetEnviron() = _saved_environ;
  82         return 0;
  83 }
  84 int (*_cthread_init_routine)(void) = _legacy_crt1_environ;
  85
  86 #  else /* !LEGACY_CRT1_ENVIRON */
  87 static int _do_nothing(void) { return 0; }
  88 int (*_cthread_init_routine)(void) = _do_nothing;
  89 #  endif /* !LEGACY_CRT1_ENVIRON */
  90
  91 /*
  92  * Create the environment malloc zone and give it a recognizable name.
  93  */
  94 __private_extern__ int
  95 init__zone0(int should_set_errno)
  96 {
  97         if (__zone0) return (0);
  98
  99         __zone0 = malloc_create_zone(0, 0);
 100         if (!__zone0) {
 101                 if (should_set_errno) {
 102                         errno = ENOMEM;
 103                 }
 104                 return (-1);
 105         }
 106         malloc_set_zone_name(__zone0, "environ");
 107         return (0);
 108 }
 109
 110 /*
 111  * The copy flag may have 3 values:
 112  *  1 - make a copy of the name/value pair
 113  *  0 - take the name as a user-supplied name=value string
 114  * -1 - like 0, except we copy of the name=value string in name
 115  */
 116 __private_extern__ int
 117 __setenv(name, value, rewrite, copy, environp, envz)
 118         const char *name;
 119         const char *value;
 120         int rewrite, copy;
 121         char ***environp;
 122         malloc_zone_t *envz;
 123 {
 124         char *c;
 125         int offset;
 126
 127         if ((c = __findenv(name, &offset, *environp))) { /* find if already exists */
 128                 char *e;
 129                 if (!rewrite)
 130                         return (0);
 131                 /*
 132                  * In UNIX03, we can overwrite only if we allocated the
 133                  * string.  Then we can realloc it if it is too small.
 134                  */
 135                 e = (*environp)[offset];
 136                 if (copy > 0 && ZONE_OWNS_PTR(envz, e)) {
 137                         size_t l_value = strlen(value);
 138                         if (strlen(c) < l_value) {      /* old smaller; resize*/
 139                                 char *r;
 140                                 size_t len = c - e;
 141                                 if ((r = realloc(e, l_value + len + 1)) == NULL)
 142                                         return (-1);
 143                                 if (r != e) {
 144                                         (*environp)[offset] = r;
 145                                         c = r + len;
 146                                 }
 147                         }
 148                         while ( (*c++ = *value++) );
 149                         return (0);
 150                 }
 151         } else {                                        /* create new slot */
 152                 int cnt;
 153                 char **p;
 154
 155                 for (p = *environp, cnt = 0; *p; ++p, ++cnt);
 156                 if (ZONE_OWNS_PTR(envz, *environp)) {   /* just increase size */
 157                         p = (char **)realloc((char *)*environp,
 158                             (size_t)(sizeof(char *) * (cnt + 2)));
 159                         if (!p)
 160                                 return (-1);
 161                         *environp = p;
 162                 }
 163                 else {                          /* get new space */
 164                                                 /* copy old entries into it */
 165                         p = malloc_zone_malloc(envz, (size_t)(sizeof(char *) * (cnt + 2)));
 166                         if (!p)
 167                                 return (-1);
 168                         bcopy(*environp, p, cnt * sizeof(char *));
 169                         *environp = p;
 170                 }
 171                 (*environp)[cnt + 1] = NULL;
 172                 offset = cnt;
 173         }
 174         /* For non Unix03, or UnixO3 setenv(), we make a copy of the user's
 175          * strings.  For Unix03 putenv(), we put the string directly in
 176          * the environment. */
 177         if (copy > 0) {
 178                 for (c = (char *)name; *c && *c != '='; ++c);   /* no `=' in name */
 179                 if (!((*environp)[offset] =                     /* name + `=' + value */
 180                     malloc_zone_malloc(envz, (size_t)((int)(c - name) + strlen(value) + 2))))
 181                         return (-1);
 182                 for (c = (*environp)[offset]; (*c = *name++) && *c != '='; ++c);
 183                 for (*c++ = '='; (*c++ = *value++); );
 184         } else {
 185                 /* the legacy behavior copies the string */
 186                 if (copy < 0) {
 187                         size_t len = strlen(name);
 188                         if((c = malloc_zone_malloc(envz, len + 1)) == NULL)
 189                                 return (-1);
 190                         memcpy(c, name, len + 1);
 191                         name = c;
 192                 }
 193                 /* if we malloc-ed the previous value, free it first */
 194                 if ((*environp)[offset] != NULL && ZONE_OWNS_PTR(envz, (*environp)[offset]))
 195                         free((*environp)[offset]);
 196                 (*environp)[offset] = (char *)name;
 197         }
 198         return (0);
 199 }
 200
 201 __private_extern__ void
 202 __unsetenv(const char *name, char **environ, malloc_zone_t *envz)
 203 {
 204         char **p;
 205         int offset;
 206
 207         while (__findenv(name, &offset, environ)) { /* if set multiple times */
 208                 /* if we malloc-ed it, free it first */
 209                 if (ZONE_OWNS_PTR(envz, environ[offset]))
 210                         free(environ[offset]);
 211                 for (p = &environ[offset];; ++p)
 212                         if (!(*p = *(p + 1)))
 213                                 break;
 214         }
 215 }
 216
 217 /****************************************************************************/
 218 /*
 219  * _allocenvstate -- SPI that creates a new state (opaque)
 220  */
 221 void *
 222 _allocenvstate(void)
 223 {
 224         malloc_zone_t *zone;
 225         zone = malloc_create_zone(1000 /* unused */, 0 /* unused */);
 226         if (zone) {
 227                 malloc_set_zone_name(zone, "environ");
 228         }
 229         return (void *)zone;
 230 }
 231
 232 /*
 233  * _copyenv -- SPI that copies a NULL-tereminated char * array in a newly
 234  * allocated buffer, compatible with the other SPI env routines.  If env
 235  * is NULL, a char * array composed of a single NULL is returned.  NULL
 236  * is returned on error.  (This isn't needed anymore, as __setenv will
 237  * automatically make a copy in the zone.)
 238  */
 239 char **
 240 _copyenv(char **env)
 241 {
 242         char **p;
 243         int cnt = 1;
 244
 245         if (env)
 246                 for (p = env; *p; ++p, ++cnt);
 247         p = (char **)malloc((size_t)(sizeof(char *) * cnt));
 248         if (!p)
 249                 return (NULL);
 250         if (env)
 251                 bcopy(env, p, cnt * sizeof(char *));
 252         else
 253                 *p = NULL;
 254         return p;
 255 }
 256
 257 /*
 258  * _deallocenvstate -- SPI that frees all the memory associated with the state
 259  * and all allocated strings, including the environment array itself if it
 260  * was copied.
 261  */
 262 int
 263 _deallocenvstate(void *state)
 264 {
 265         malloc_zone_t *envz;
 266
 267         if (!(envz = (malloc_zone_t *)state) || envz == __zone0) {
 268                 errno = EINVAL;
 269                 return -1;
 270         }
 271         malloc_destroy_zone(envz);
 272         return 0;
 273 }
 274
 275 /*
 276  * setenvp -- SPI using an arbitrary pointer to string array and an env state,
 277  * created by _allocenvstate().  Initial checking is not done.
 278  *
 279  *      Set the value of the environmental variable "name" to be
 280  *      "value".  If rewrite is set, replace any current value.
 281  */
 282 int
 283 _setenvp(const char *name, const char *value, int rewrite, char ***envp, void *state)
 284 {
 285         if (init__zone0(1)) return (-1);
 286         return (__setenv(name, value, rewrite, 1, envp, (state ? (malloc_zone_t *)state : __zone0)));
 287 }
 288
 289 /*
 290  * unsetenv(name) -- SPI using an arbitrary pointer to string array and an env
 291  * state, created by _allocenvstate().  Initial checking is not done.
 292  *
 293  *      Delete environmental variable "name".
 294  */
 295 int
 296 _unsetenvp(const char *name, char ***envp, void *state)
 297 {
 298         if (init__zone0(1)) return (-1);
 299         __unsetenv(name, *envp, (state ? (malloc_zone_t *)state : __zone0));
 300         return 0;
 301 }
 302
 303 #endif /* !BUILD_VARIANT */
 304
 305 /*
 306  * setenv --
 307  *      Set the value of the environmental variable "name" to be
 308  *      "value".  If rewrite is set, replace any current value.
 309  */
 310 int
 311 setenv(name, value, rewrite)
 312         const char *name;
 313         const char *value;
 314         int rewrite;
 315 {
 316 #ifdef LEGACY_CRT1_ENVIRON
 317         int ret;
 318 #endif /* LEGACY_CRT1_ENVIRON */
 319
 320         /* no null ptr or empty str */
 321         if(name == NULL || *name == 0) {
 322                 errno = EINVAL;
 323                 return (-1);
 324         }
 325
 326 #if __DARWIN_UNIX03
 327         /* no '=' in name */
 328         if (strchr(name, '=')) {
 329                 errno = EINVAL;
 330                 return (-1);
 331         }
 332 #endif /* __DARWIN_UNIX03 */
 333
 334         if (*value == '=')                      /* no `=' in value */
 335                 ++value;
 336         /* insure __zone0 is set up before calling __malloc_check_env_name */
 337         if (init__zone0(1)) return (-1);
 338         __malloc_check_env_name(name); /* see if we are changing a malloc environment variable */
 339 #ifdef LEGACY_CRT1_ENVIRON
 340         ret = __setenv(name, value, rewrite, 1, _NSGetEnviron(), __zone0);
 341         _saved_environ = *_NSGetEnviron();
 342         return ret;
 343 #else /* !LEGACY_CRT1_ENVIRON */
 344         return (__setenv(name, value, rewrite, 1, _NSGetEnviron(), __zone0));
 345 #endif /* !LEGACY_CRT1_ENVIRON */
 346 }
 347
 348 /*
 349  * unsetenv(name) --
 350  *      Delete environmental variable "name".
 351  */
 352 #if __DARWIN_UNIX03
 353 int
 354 #else /* !__DARWIN_UNIX03 */
 355 void
 356 #endif /* __DARWIN_UNIX03 */
 357 unsetenv(name)
 358         const char *name;
 359 {
 360 #if __DARWIN_UNIX03
 361         /* no null ptr or empty str */
 362         if(name == NULL || *name == 0) {
 363                 errno = EINVAL;
 364                 return (-1);
 365         }
 366
 367         /* no '=' in name */
 368         if (strchr(name, '=')) {
 369                 errno = EINVAL;
 370                 return (-1);
 371         }
 372         /* insure __zone0 is set up before calling __malloc_check_env_name */
 373         if (init__zone0(1)) return (-1);
 374 #else /* !__DARWIN_UNIX03 */
 375         /* no null ptr or empty str */
 376         if(name == NULL || *name == 0)
 377                 return;
 378         /* insure __zone0 is set up before calling __malloc_check_env_name */
 379         if (init__zone0(0)) return;
 380 #endif /* __DARWIN_UNIX03 */
 381         __malloc_check_env_name(name); /* see if we are changing a malloc environment variable */
 382         __unsetenv(name, *_NSGetEnviron(), __zone0);
 383 #if __DARWIN_UNIX03
 384         return 0;
 385 #endif /* __DARWIN_UNIX03 */
 386 }