xref: /netbsd-src/external/bsd/cron/dist/env.c (revision 7edfdcc22150d98be1dc76e9d1a7f9e23e8b4cae)
1 /*	$NetBSD: env.c,v 1.4 2014/09/07 13:35:27 tron Exp $	*/
2 
3 /* Copyright 1988,1990,1993,1994 by Paul Vixie
4  * All rights reserved
5  */
6 
7 /*
8  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
9  * Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
10  *
11  * Permission to use, copy, modify, and distribute this software for any
12  * purpose with or without fee is hereby granted, provided that the above
13  * copyright notice and this permission notice appear in all copies.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
16  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
18  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
19  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
21  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22  */
23 #include <sys/cdefs.h>
24 #if !defined(lint) && !defined(LINT)
25 #if 0
26 static char rcsid[] = "Id: env.c,v 1.10 2004/01/23 18:56:42 vixie Exp";
27 #else
28 __RCSID("$NetBSD: env.c,v 1.4 2014/09/07 13:35:27 tron Exp $");
29 #endif
30 #endif
31 
32 #include "cron.h"
33 
34 char **
env_init(void)35 env_init(void) {
36 	char **p = malloc(sizeof(char **));
37 
38 	if (p != NULL)
39 		p[0] = NULL;
40 	return (p);
41 }
42 
43 void
env_free(char ** envp)44 env_free(char **envp) {
45 	char **p;
46 
47 	for (p = envp; *p != NULL; p++)
48 		free(*p);
49 	free(envp);
50 }
51 
52 char **
env_copy(char ** envp)53 env_copy(char **envp) {
54 	size_t count, i;
55 	int save_errno;
56 	char **p;
57 
58 	for (count = 0; envp[count] != NULL; count++)
59 		continue;
60 	p = malloc((count + 1) * sizeof(*p));  /* 1 for the NULL */
61 	if (p == NULL)
62 		return NULL;
63 	for (i = 0; i < count; i++) {
64 		if ((p[i] = strdup(envp[i])) == NULL) {
65 			save_errno = errno;
66 			for (count = 0; count < i; count++)
67 				free(p[count]);
68 			free(p);
69 			errno = save_errno;
70 			return NULL;
71 		}
72 	}
73 	p[count] = NULL;
74 	return p;
75 }
76 
77 char **
env_set(char ** envp,char * envstr)78 env_set(char **envp, char *envstr) {
79 	size_t count, found;
80 	char **p, *envtmp;
81 
82 	/*
83 	 * count the number of elements, including the null pointer;
84 	 * also set 'found' to -1 or index of entry if already in here.
85 	 */
86 	found = (size_t)-1;
87 	for (count = 0; envp[count] != NULL; count++) {
88 		if (!strcmp_until(envp[count], envstr, '='))
89 			found = count;
90 	}
91 	count++;	/* for the NULL */
92 
93 	if (found != (size_t)-1) {
94 		/*
95 		 * it exists already, so just free the existing setting,
96 		 * save our new one there, and return the existing array.
97 		 */
98 		if ((envtmp = strdup(envstr)) == NULL)
99 			return (NULL);
100 		free(envp[found]);
101 		envp[found] = envtmp;
102 		return (envp);
103 	}
104 
105 	/*
106 	 * it doesn't exist yet, so resize the array, move null pointer over
107 	 * one, save our string over the old null pointer, and return resized
108 	 * array.
109 	 */
110 	if ((envtmp = strdup(envstr)) == NULL)
111 		return (NULL);
112 	p = realloc(envp, (count + 1) * sizeof(*p));
113 	if (p == NULL) {
114 		free(envtmp);
115 		return (NULL);
116 	}
117 	p[count] = p[count-1];
118 	p[count-1] = envtmp;
119 	return (p);
120 }
121 
122 /* The following states are used by load_env(), traversed in order: */
123 enum env_state {
124 	NAMEI,		/* First char of NAME, may be quote */
125 	NAME,		/* Subsequent chars of NAME */
126 	EQ1,		/* After end of name, looking for '=' sign */
127 	EQ2,		/* After '=', skipping whitespace */
128 	VALUEI,		/* First char of VALUE, may be quote */
129 	VALUE,		/* Subsequent chars of VALUE */
130 	FINI,		/* All done, skipping trailing whitespace */
131 	ERROR		/* Error */
132 };
133 
134 /* return	ERR = end of file
135  *		FALSE = not an env setting (file was repositioned)
136  *		TRUE = was an env setting
137  */
138 int
load_env(char * envstr,FILE * f)139 load_env(char *envstr, FILE *f) {
140 	long filepos;
141 	int fileline;
142 	enum env_state state;
143 	char name[MAX_ENVSTR], val[MAX_ENVSTR];
144 	char quotechar, *c, *str;
145 
146 	filepos = ftell(f);
147 	fileline = LineNumber;
148 	skip_comments(f);
149 	if (EOF == get_string(envstr, MAX_ENVSTR, f, "\n"))
150 		return (ERR);
151 
152 	Debug(DPARS, ("load_env, read <%s>\n", envstr));
153 
154 	(void)memset(name, 0, sizeof name);
155 	(void)memset(val, 0, sizeof val);
156 	str = name;
157 	state = NAMEI;
158 	quotechar = '\0';
159 	c = envstr;
160 	while (state != ERROR && *c) {
161 		switch (state) {
162 		case NAMEI:
163 		case VALUEI:
164 			if (*c == '\'' || *c == '"')
165 				quotechar = *c++;
166 			state++;
167 			/* FALLTHROUGH */
168 		case NAME:
169 		case VALUE:
170 			if (quotechar) {
171 				if (*c == quotechar) {
172 					state++;
173 					c++;
174 					break;
175 				}
176 				if (state == NAME && *c == '=') {
177 					state = ERROR;
178 					break;
179 				}
180 			} else {
181 				if (state == NAME) {
182 					if (isspace((unsigned char)*c)) {
183 						c++;
184 						state++;
185 						break;
186 					}
187 					if (*c == '=') {
188 						state++;
189 						break;
190 					}
191 				}
192 			}
193 			*str++ = *c++;
194 			break;
195 
196 		case EQ1:
197 			if (*c == '=') {
198 				state++;
199 				str = val;
200 				quotechar = '\0';
201 			} else {
202 				if (!isspace((unsigned char)*c))
203 					state = ERROR;
204 			}
205 			c++;
206 			break;
207 
208 		case EQ2:
209 		case FINI:
210 			if (isspace((unsigned char)*c))
211 				c++;
212 			else
213 				state++;
214 			break;
215 
216 		default:
217 			abort();
218 		}
219 	}
220 	if (state != FINI && !(state == VALUE && !quotechar)) {
221 		Debug(DPARS, ("load_env, not an env var, state = %d\n", state));
222 		(void)fseek(f, filepos, 0);
223 		Set_LineNum(fileline);
224 		return (FALSE);
225 	}
226 	if (state == VALUE) {
227 		/* End of unquoted value: trim trailing whitespace */
228 		c = val + strlen(val);
229 		while (c > val && isspace((unsigned char)c[-1]))
230 			*(--c) = '\0';
231 	}
232 
233 	/* 2 fields from parser; looks like an env setting */
234 
235 	/*
236 	 * This can't overflow because get_string() limited the size of the
237 	 * name and val fields.  Still, it doesn't hurt to be careful...
238 	 */
239 	if (!glue_strings(envstr, MAX_ENVSTR, name, val, '='))
240 		return (FALSE);
241 	Debug(DPARS, ("load_env, <%s> <%s> -> <%s>\n", name, val, envstr));
242 	return (TRUE);
243 }
244 
245 char *
env_get(const char * name,char ** envp)246 env_get(const char *name, char **envp) {
247 	size_t len = strlen(name);
248 	char *p, *q;
249 
250 	while ((p = *envp++) != NULL) {
251 		if (!(q = strchr(p, '=')))
252 			continue;
253 		if ((size_t)(q - p) == len && !strncmp(p, name, len))
254 			return (q+1);
255 	}
256 	return (NULL);
257 }
258