xref: /openbsd-src/usr.sbin/cron/env.c (revision db3296cf5c1dd9058ceecc3a29fe4aaa0bd26000)
1 /*	$OpenBSD: env.c,v 1.15 2003/02/21 16:47:29 millert Exp $	*/
2 
3 /* Copyright 1988,1990,1993,1994 by Paul Vixie
4  * All rights reserved
5  */
6 
7 /*
8  * Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
9  *
10  * Permission to use, copy, modify, and distribute this software for any
11  * purpose with or without fee is hereby granted, provided that the above
12  * copyright notice and this permission notice appear in all copies.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
15  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
17  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
18  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
19  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
20  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
21  * SOFTWARE.
22  */
23 
24 #if !defined(lint) && !defined(LINT)
25 static char const rcsid[] = "$OpenBSD: env.c,v 1.15 2003/02/21 16:47:29 millert Exp $";
26 #endif
27 
28 #include "cron.h"
29 
30 char **
31 env_init(void) {
32 	char **p = (char **) malloc(sizeof(char **));
33 
34 	if (p != NULL)
35 		p[0] = NULL;
36 	return (p);
37 }
38 
39 void
40 env_free(char **envp) {
41 	char **p;
42 
43 	for (p = envp; *p != NULL; p++)
44 		free(*p);
45 	free(envp);
46 }
47 
48 char **
49 env_copy(char **envp) {
50 	int count, i, save_errno;
51 	char **p;
52 
53 	for (count = 0; envp[count] != NULL; count++)
54 		continue;
55 	p = (char **) malloc((count+1) * sizeof(char *));  /* 1 for the NULL */
56 	if (p != NULL) {
57 		for (i = 0; i < count; i++)
58 			if ((p[i] = strdup(envp[i])) == NULL) {
59 				save_errno = errno;
60 				while (--i >= 0)
61 					free(p[i]);
62 				free(p);
63 				errno = save_errno;
64 				return (NULL);
65 			}
66 		p[count] = NULL;
67 	}
68 	return (p);
69 }
70 
71 char **
72 env_set(char **envp, char *envstr) {
73 	int count, found;
74 	char **p, *envtmp;
75 
76 	/*
77 	 * count the number of elements, including the null pointer;
78 	 * also set 'found' to -1 or index of entry if already in here.
79 	 */
80 	found = -1;
81 	for (count = 0; envp[count] != NULL; count++) {
82 		if (!strcmp_until(envp[count], envstr, '='))
83 			found = count;
84 	}
85 	count++;	/* for the NULL */
86 
87 	if (found != -1) {
88 		/*
89 		 * it exists already, so just free the existing setting,
90 		 * save our new one there, and return the existing array.
91 		 */
92 		if ((envtmp = strdup(envstr)) == NULL)
93 			return (NULL);
94 		free(envp[found]);
95 		envp[found] = envtmp;
96 		return (envp);
97 	}
98 
99 	/*
100 	 * it doesn't exist yet, so resize the array, move null pointer over
101 	 * one, save our string over the old null pointer, and return resized
102 	 * array.
103 	 */
104 	if ((envtmp = strdup(envstr)) == NULL)
105 		return (NULL);
106 	p = (char **) realloc((void *) envp,
107 			      (size_t) ((count+1) * sizeof(char **)));
108 	if (p == NULL) {
109 		free(envtmp);
110 		return (NULL);
111 	}
112 	p[count] = p[count-1];
113 	p[count-1] = envtmp;
114 	return (p);
115 }
116 
117 /* The following states are used by load_env(), traversed in order: */
118 enum env_state {
119 	NAMEI,		/* First char of NAME, may be quote */
120 	NAME,		/* Subsequent chars of NAME */
121 	EQ1,		/* After end of name, looking for '=' sign */
122 	EQ2,		/* After '=', skipping whitespace */
123 	VALUEI,		/* First char of VALUE, may be quote */
124 	VALUE,		/* Subsequent chars of VALUE */
125 	FINI,		/* All done, skipping trailing whitespace */
126 	ERROR,		/* Error */
127 };
128 
129 /* return	ERR = end of file
130  *		FALSE = not an env setting (file was repositioned)
131  *		TRUE = was an env setting
132  */
133 int
134 load_env(char *envstr, FILE *f) {
135 	long filepos;
136 	int fileline;
137 	enum env_state state;
138 	char name[MAX_ENVSTR], val[MAX_ENVSTR];
139 	char quotechar, *c, *str;
140 
141 	filepos = ftell(f);
142 	fileline = LineNumber;
143 	skip_comments(f);
144 	if (EOF == get_string(envstr, MAX_ENVSTR, f, "\n"))
145 		return (ERR);
146 
147 	Debug(DPARS, ("load_env, read <%s>\n", envstr))
148 
149 	bzero(name, sizeof name);
150 	bzero(val, sizeof val);
151 	str = name;
152 	state = NAMEI;
153 	quotechar = '\0';
154 	c = envstr;
155 	while (state != ERROR && *c) {
156 		switch (state) {
157 		case NAMEI:
158 		case VALUEI:
159 			if (*c == '\'' || *c == '"')
160 				quotechar = *c++;
161 			state++;
162 			/* FALLTHROUGH */
163 		case NAME:
164 		case VALUE:
165 			if (quotechar) {
166 				if (*c == quotechar) {
167 					state++;
168 					c++;
169 					break;
170 				}
171 				if (state == NAME && *c == '=') {
172 					state = ERROR;
173 					break;
174 				}
175 			} else {
176 				if (state == NAME) {
177 					if (isspace((unsigned char)*c)) {
178 						c++;
179 						state++;
180 						break;
181 					}
182 					if (*c == '=') {
183 						state++;
184 						break;
185 					}
186 				}
187 			}
188 			*str++ = *c++;
189 			break;
190 
191 		case EQ1:
192 			if (*c == '=') {
193 				state++;
194 				str = val;
195 				quotechar = '\0';
196 			} else {
197 				if (!isspace((unsigned char)*c))
198 					state = ERROR;
199 			}
200 			c++;
201 			break;
202 		case EQ2:
203 		case FINI:
204 			if (isspace((unsigned char)*c))
205 				c++;
206 			else
207 				state++;
208 			break;
209 		}
210 	}
211 	if (state != FINI && !(state == VALUE && !quotechar)) {
212 		Debug(DPARS, ("load_env, not an env var, state = %d\n", state))
213 		fseek(f, filepos, 0);
214 		Set_LineNum(fileline);
215 		return (FALSE);
216 	}
217 	if (state == VALUE) {
218 		/* End of unquoted value: trim trailing whitespace */
219 		c = val + strlen(val);
220 		while (c > val && isspace((unsigned char)c[-1]))
221 			*(--c) = '\0';
222 	}
223 
224 	/* 2 fields from parser; looks like an env setting */
225 
226 	/*
227 	 * This can't overflow because get_string() limited the size of the
228 	 * name and val fields.  Still, it doesn't hurt to be careful...
229 	 */
230 	if (!glue_strings(envstr, MAX_ENVSTR, name, val, '='))
231 		return (FALSE);
232 	Debug(DPARS, ("load_env, <%s> <%s> -> <%s>\n", name, val, envstr))
233 	return (TRUE);
234 }
235 
236 char *
237 env_get(char *name, char **envp) {
238 	int len = strlen(name);
239 	char *p, *q;
240 
241 	while ((p = *envp++) != NULL) {
242 		if (!(q = strchr(p, '=')))
243 			continue;
244 		if ((q - p) == len && !strncmp(p, name, len))
245 			return (q+1);
246 	}
247 	return (NULL);
248 }
249