1 /* $NetBSD: setenv.c,v 1.34 2010/09/23 17:30:49 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1987, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)setenv.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: setenv.c,v 1.34 2010/09/23 17:30:49 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 43 #include <assert.h> 44 #include <errno.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <bitstring.h> 48 #include "reentrant.h" 49 #include "local.h" 50 51 #ifdef __weak_alias 52 __weak_alias(setenv,_setenv) 53 #endif 54 55 #ifdef _REENTRANT 56 extern rwlock_t __environ_lock; 57 #endif 58 59 extern char **environ; 60 extern bitstr_t *__environ_malloced; 61 62 /* 63 * setenv -- 64 * Set the value of the environmental variable "name" to be 65 * "value". If rewrite is set, replace any current value. 66 */ 67 int 68 setenv(const char *name, const char *value, int rewrite) 69 { 70 static char **saveenv; /* copy of previously allocated space */ 71 char *c, **newenv; 72 const char *cc; 73 size_t l_value, size; 74 int offset; 75 76 _DIAGASSERT(name != NULL); 77 _DIAGASSERT(value != NULL); 78 79 rwlock_wrlock(&__environ_lock); 80 /* find if already exists */ 81 c = __findenv(name, &offset); 82 83 if (__allocenv(offset) == -1) 84 return -1; 85 86 if (*value == '=') /* no `=' in value */ 87 ++value; 88 l_value = strlen(value); 89 90 if (c != NULL) { 91 if (!rewrite) 92 goto good; 93 if (strlen(c) > l_value) /* old larger; copy over */ 94 goto copy; 95 } else { /* create new slot */ 96 size = (size_t)(sizeof(char *) * (offset + 2)); 97 if (saveenv == environ) { /* just increase size */ 98 if ((newenv = realloc(saveenv, size)) == NULL) 99 goto bad; 100 saveenv = newenv; 101 } else { /* get new space */ 102 free(saveenv); 103 if ((saveenv = malloc(size)) == NULL) 104 goto bad; 105 (void)memcpy(saveenv, environ, size - sizeof(char *)); 106 } 107 environ = saveenv; 108 environ[offset + 1] = NULL; 109 } 110 for (cc = name; *cc && *cc != '='; ++cc) /* no `=' in name */ 111 continue; 112 size = cc - name; 113 /* name + `=' + value */ 114 if ((c = malloc(size + l_value + 2)) == NULL) 115 goto bad; 116 environ[offset] = c; 117 (void)memcpy(c, name, size); 118 c += size; 119 *c++ = '='; 120 bit_set(__environ_malloced, offset); 121 copy: 122 (void)memcpy(c, value, l_value + 1); 123 good: 124 rwlock_unlock(&__environ_lock); 125 return 0; 126 bad: 127 rwlock_unlock(&__environ_lock); 128 return -1; 129 } 130