1 /* $OpenBSD: setenv.c,v 1.13 2010/08/23 22:31:50 millert Exp $ */
2 /*
3 * Copyright (c) 1987 Regents of the University of California.
4 * 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. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /* OPENBSD ORIGINAL: lib/libc/stdlib/setenv.c */
32
33 #include "includes.h"
34
35 #if !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV)
36
37 #include <errno.h>
38 #include <stdlib.h>
39 #include <string.h>
40
41 extern char **environ;
42 #ifndef HAVE_SETENV
43 static char **lastenv; /* last value of environ */
44 #endif
45
46 /* OpenSSH Portable: __findenv is from getenv.c rev 1.8, made static */
47 /*
48 * __findenv --
49 * Returns pointer to value associated with name, if any, else NULL.
50 * Starts searching within the environmental array at offset.
51 * Sets offset to be the offset of the name/value combination in the
52 * environmental array, for use by putenv(3), setenv(3) and unsetenv(3).
53 * Explicitly removes '=' in argument name.
54 *
55 * This routine *should* be a static; don't use it.
56 */
57 static char *
__findenv(const char * name,int len,int * offset)58 __findenv(const char *name, int len, int *offset)
59 {
60 extern char **environ;
61 int i;
62 const char *np;
63 char **p, *cp;
64
65 if (name == NULL || environ == NULL)
66 return (NULL);
67 for (p = environ + *offset; (cp = *p) != NULL; ++p) {
68 for (np = name, i = len; i && *cp; i--)
69 if (*cp++ != *np++)
70 break;
71 if (i == 0 && *cp++ == '=') {
72 *offset = p - environ;
73 return (cp);
74 }
75 }
76 return (NULL);
77 }
78
79 #if 0 /* nothing uses putenv */
80 /*
81 * putenv --
82 * Add a name=value string directly to the environmental, replacing
83 * any current value.
84 */
85 int
86 putenv(char *str)
87 {
88 char **P, *cp;
89 size_t cnt;
90 int offset = 0;
91
92 for (cp = str; *cp && *cp != '='; ++cp)
93 ;
94 if (*cp != '=') {
95 errno = EINVAL;
96 return (-1); /* missing `=' in string */
97 }
98
99 if (__findenv(str, (int)(cp - str), &offset) != NULL) {
100 environ[offset++] = str;
101 /* could be set multiple times */
102 while (__findenv(str, (int)(cp - str), &offset)) {
103 for (P = &environ[offset];; ++P)
104 if (!(*P = *(P + 1)))
105 break;
106 }
107 return (0);
108 }
109
110 /* create new slot for string */
111 for (P = environ; *P != NULL; P++)
112 ;
113 cnt = P - environ;
114 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
115 if (!P)
116 return (-1);
117 if (lastenv != environ)
118 memcpy(P, environ, cnt * sizeof(char *));
119 lastenv = environ = P;
120 environ[cnt] = str;
121 environ[cnt + 1] = NULL;
122 return (0);
123 }
124
125 #endif
126
127 #ifndef HAVE_SETENV
128 /*
129 * setenv --
130 * Set the value of the environmental variable "name" to be
131 * "value". If rewrite is set, replace any current value.
132 */
133 int
setenv(const char * name,const char * value,int rewrite)134 setenv(const char *name, const char *value, int rewrite)
135 {
136 char *C, **P;
137 const char *np;
138 int l_value, offset = 0;
139
140 for (np = name; *np && *np != '='; ++np)
141 ;
142 #ifdef notyet
143 if (*np) {
144 errno = EINVAL;
145 return (-1); /* has `=' in name */
146 }
147 #endif
148
149 l_value = strlen(value);
150 if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
151 int tmpoff = offset + 1;
152 if (!rewrite)
153 return (0);
154 #if 0 /* XXX - existing entry may not be writable */
155 if (strlen(C) >= l_value) { /* old larger; copy over */
156 while ((*C++ = *value++))
157 ;
158 return (0);
159 }
160 #endif
161 /* could be set multiple times */
162 while (__findenv(name, (int)(np - name), &tmpoff)) {
163 for (P = &environ[tmpoff];; ++P)
164 if (!(*P = *(P + 1)))
165 break;
166 }
167 } else { /* create new slot */
168 size_t cnt;
169
170 for (P = environ; *P != NULL; P++)
171 ;
172 cnt = P - environ;
173 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
174 if (!P)
175 return (-1);
176 if (lastenv != environ)
177 memcpy(P, environ, cnt * sizeof(char *));
178 lastenv = environ = P;
179 offset = cnt;
180 environ[cnt + 1] = NULL;
181 }
182 if (!(environ[offset] = /* name + `=' + value */
183 malloc((size_t)((int)(np - name) + l_value + 2))))
184 return (-1);
185 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
186 ;
187 for (*C++ = '='; (*C++ = *value++); )
188 ;
189 return (0);
190 }
191
192 #endif /* HAVE_SETENV */
193
194 #ifndef HAVE_UNSETENV
195 /*
196 * unsetenv(name) --
197 * Delete environmental variable "name".
198 */
199 int
unsetenv(const char * name)200 unsetenv(const char *name)
201 {
202 char **P;
203 const char *np;
204 int offset = 0;
205
206 if (!name || !*name) {
207 errno = EINVAL;
208 return (-1);
209 }
210 for (np = name; *np && *np != '='; ++np)
211 ;
212 if (*np) {
213 errno = EINVAL;
214 return (-1); /* has `=' in name */
215 }
216
217 /* could be set multiple times */
218 while (__findenv(name, (int)(np - name), &offset)) {
219 for (P = &environ[offset];; ++P)
220 if (!(*P = *(P + 1)))
221 break;
222 }
223 return (0);
224 }
225 #endif /* HAVE_UNSETENV */
226
227 #endif /* !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) */
228
229