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 static char **lastenv; /* last value of environ */
43
44 /* OpenSSH Portable: __findenv is from getenv.c rev 1.8, made static */
45 /*
46 * __findenv --
47 * Returns pointer to value associated with name, if any, else NULL.
48 * Starts searching within the environmental array at offset.
49 * Sets offset to be the offset of the name/value combination in the
50 * environmental array, for use by putenv(3), setenv(3) and unsetenv(3).
51 * Explicitly removes '=' in argument name.
52 *
53 * This routine *should* be a static; don't use it.
54 */
55 static char *
__findenv(const char * name,int len,int * offset)56 __findenv(const char *name, int len, int *offset)
57 {
58 extern char **environ;
59 int i;
60 const char *np;
61 char **p, *cp;
62
63 if (name == NULL || environ == NULL)
64 return (NULL);
65 for (p = environ + *offset; (cp = *p) != NULL; ++p) {
66 for (np = name, i = len; i && *cp; i--)
67 if (*cp++ != *np++)
68 break;
69 if (i == 0 && *cp++ == '=') {
70 *offset = p - environ;
71 return (cp);
72 }
73 }
74 return (NULL);
75 }
76
77 #if 0 /* nothing uses putenv */
78 /*
79 * putenv --
80 * Add a name=value string directly to the environmental, replacing
81 * any current value.
82 */
83 int
84 putenv(char *str)
85 {
86 char **P, *cp;
87 size_t cnt;
88 int offset = 0;
89
90 for (cp = str; *cp && *cp != '='; ++cp)
91 ;
92 if (*cp != '=') {
93 errno = EINVAL;
94 return (-1); /* missing `=' in string */
95 }
96
97 if (__findenv(str, (int)(cp - str), &offset) != NULL) {
98 environ[offset++] = str;
99 /* could be set multiple times */
100 while (__findenv(str, (int)(cp - str), &offset)) {
101 for (P = &environ[offset];; ++P)
102 if (!(*P = *(P + 1)))
103 break;
104 }
105 return (0);
106 }
107
108 /* create new slot for string */
109 for (P = environ; *P != NULL; P++)
110 ;
111 cnt = P - environ;
112 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
113 if (!P)
114 return (-1);
115 if (lastenv != environ)
116 memcpy(P, environ, cnt * sizeof(char *));
117 lastenv = environ = P;
118 environ[cnt] = str;
119 environ[cnt + 1] = NULL;
120 return (0);
121 }
122
123 #endif
124
125 #ifndef HAVE_SETENV
126 /*
127 * setenv --
128 * Set the value of the environmental variable "name" to be
129 * "value". If rewrite is set, replace any current value.
130 */
131 int
setenv(const char * name,const char * value,int rewrite)132 setenv(const char *name, const char *value, int rewrite)
133 {
134 char *C, **P;
135 const char *np;
136 int l_value, offset = 0;
137
138 for (np = name; *np && *np != '='; ++np)
139 ;
140 #ifdef notyet
141 if (*np) {
142 errno = EINVAL;
143 return (-1); /* has `=' in name */
144 }
145 #endif
146
147 l_value = strlen(value);
148 if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
149 int tmpoff = offset + 1;
150 if (!rewrite)
151 return (0);
152 #if 0 /* XXX - existing entry may not be writable */
153 if (strlen(C) >= l_value) { /* old larger; copy over */
154 while ((*C++ = *value++))
155 ;
156 return (0);
157 }
158 #endif
159 /* could be set multiple times */
160 while (__findenv(name, (int)(np - name), &tmpoff)) {
161 for (P = &environ[tmpoff];; ++P)
162 if (!(*P = *(P + 1)))
163 break;
164 }
165 } else { /* create new slot */
166 size_t cnt;
167
168 for (P = environ; *P != NULL; P++)
169 ;
170 cnt = P - environ;
171 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
172 if (!P)
173 return (-1);
174 if (lastenv != environ)
175 memcpy(P, environ, cnt * sizeof(char *));
176 lastenv = environ = P;
177 offset = cnt;
178 environ[cnt + 1] = NULL;
179 }
180 if (!(environ[offset] = /* name + `=' + value */
181 malloc((size_t)((int)(np - name) + l_value + 2))))
182 return (-1);
183 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
184 ;
185 for (*C++ = '='; (*C++ = *value++); )
186 ;
187 return (0);
188 }
189
190 #endif /* HAVE_SETENV */
191
192 #ifndef HAVE_UNSETENV
193 /*
194 * unsetenv(name) --
195 * Delete environmental variable "name".
196 */
197 int
unsetenv(const char * name)198 unsetenv(const char *name)
199 {
200 char **P;
201 const char *np;
202 int offset = 0;
203
204 if (!name || !*name) {
205 errno = EINVAL;
206 return (-1);
207 }
208 for (np = name; *np && *np != '='; ++np)
209 ;
210 if (*np) {
211 errno = EINVAL;
212 return (-1); /* has `=' in name */
213 }
214
215 /* could be set multiple times */
216 while (__findenv(name, (int)(np - name), &offset)) {
217 for (P = &environ[offset];; ++P)
218 if (!(*P = *(P + 1)))
219 break;
220 }
221 return (0);
222 }
223 #endif /* HAVE_UNSETENV */
224
225 #endif /* !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) */
226
227