1/*	$NetBSD: env.c,v 1.2 2010/05/06 18:53:17 christos 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
26static char rcsid[] = "Id: env.c,v 1.10 2004/01/23 18:56:42 vixie Exp";
27#else
28__RCSID("$NetBSD: env.c,v 1.2 2010/05/06 18:53:17 christos Exp $");
29#endif
30#endif
31
32#include "cron.h"
33
34char **
35env_init(void) {
36	char **p = malloc(sizeof(char **));
37
38	if (p != NULL)
39		p[0] = NULL;
40	return (p);
41}
42
43void
44env_free(char **envp) {
45	char **p;
46
47	for (p = envp; *p != NULL; p++)
48		free(*p);
49	free(envp);
50}
51
52char **
53env_copy(char **envp) {
54	int count, i, save_errno;
55	char **p;
56
57	for (count = 0; envp[count] != NULL; count++)
58		continue;
59	p = malloc((count+1) * sizeof(*p));  /* 1 for the NULL */
60	if (p != NULL) {
61		for (i = 0; i < count; i++)
62			if ((p[i] = strdup(envp[i])) == NULL) {
63				save_errno = errno;
64				while (--i >= 0)
65					free(p[i]);
66				free(p);
67				errno = save_errno;
68				return (NULL);
69			}
70		p[count] = NULL;
71	}
72	return (p);
73}
74
75char **
76env_set(char **envp, char *envstr) {
77	int count, found;
78	char **p, *envtmp;
79
80	/*
81	 * count the number of elements, including the null pointer;
82	 * also set 'found' to -1 or index of entry if already in here.
83	 */
84	found = -1;
85	for (count = 0; envp[count] != NULL; count++) {
86		if (!strcmp_until(envp[count], envstr, '='))
87			found = count;
88	}
89	count++;	/* for the NULL */
90
91	if (found != -1) {
92		/*
93		 * it exists already, so just free the existing setting,
94		 * save our new one there, and return the existing array.
95		 */
96		if ((envtmp = strdup(envstr)) == NULL)
97			return (NULL);
98		free(envp[found]);
99		envp[found] = envtmp;
100		return (envp);
101	}
102
103	/*
104	 * it doesn't exist yet, so resize the array, move null pointer over
105	 * one, save our string over the old null pointer, and return resized
106	 * array.
107	 */
108	if ((envtmp = strdup(envstr)) == NULL)
109		return (NULL);
110	p = realloc(envp, (size_t) ((count+1) * sizeof(*p)));
111	if (p == NULL) {
112		free(envtmp);
113		return (NULL);
114	}
115	p[count] = p[count-1];
116	p[count-1] = envtmp;
117	return (p);
118}
119
120/* The following states are used by load_env(), traversed in order: */
121enum env_state {
122	NAMEI,		/* First char of NAME, may be quote */
123	NAME,		/* Subsequent chars of NAME */
124	EQ1,		/* After end of name, looking for '=' sign */
125	EQ2,		/* After '=', skipping whitespace */
126	VALUEI,		/* First char of VALUE, may be quote */
127	VALUE,		/* Subsequent chars of VALUE */
128	FINI,		/* All done, skipping trailing whitespace */
129	ERROR		/* Error */
130};
131
132/* return	ERR = end of file
133 *		FALSE = not an env setting (file was repositioned)
134 *		TRUE = was an env setting
135 */
136int
137load_env(char *envstr, FILE *f) {
138	long filepos;
139	int fileline;
140	enum env_state state;
141	char name[MAX_ENVSTR], val[MAX_ENVSTR];
142	char quotechar, *c, *str;
143
144	filepos = ftell(f);
145	fileline = LineNumber;
146	skip_comments(f);
147	if (EOF == get_string(envstr, MAX_ENVSTR, f, "\n"))
148		return (ERR);
149
150	Debug(DPARS, ("load_env, read <%s>\n", envstr));
151
152	(void)memset(name, 0, sizeof name);
153	(void)memset(val, 0, sizeof val);
154	str = name;
155	state = NAMEI;
156	quotechar = '\0';
157	c = envstr;
158	while (state != ERROR && *c) {
159		switch (state) {
160		case NAMEI:
161		case VALUEI:
162			if (*c == '\'' || *c == '"')
163				quotechar = *c++;
164			state++;
165			/* FALLTHROUGH */
166		case NAME:
167		case VALUE:
168			if (quotechar) {
169				if (*c == quotechar) {
170					state++;
171					c++;
172					break;
173				}
174				if (state == NAME && *c == '=') {
175					state = ERROR;
176					break;
177				}
178			} else {
179				if (state == NAME) {
180					if (isspace((unsigned char)*c)) {
181						c++;
182						state++;
183						break;
184					}
185					if (*c == '=') {
186						state++;
187						break;
188					}
189				}
190			}
191			*str++ = *c++;
192			break;
193
194		case EQ1:
195			if (*c == '=') {
196				state++;
197				str = val;
198				quotechar = '\0';
199			} else {
200				if (!isspace((unsigned char)*c))
201					state = ERROR;
202			}
203			c++;
204			break;
205
206		case EQ2:
207		case FINI:
208			if (isspace((unsigned char)*c))
209				c++;
210			else
211				state++;
212			break;
213
214		default:
215			abort();
216		}
217	}
218	if (state != FINI && !(state == VALUE && !quotechar)) {
219		Debug(DPARS, ("load_env, not an env var, state = %d\n", state));
220		(void)fseek(f, filepos, 0);
221		Set_LineNum(fileline);
222		return (FALSE);
223	}
224	if (state == VALUE) {
225		/* End of unquoted value: trim trailing whitespace */
226		c = val + strlen(val);
227		while (c > val && isspace((unsigned char)c[-1]))
228			*(--c) = '\0';
229	}
230
231	/* 2 fields from parser; looks like an env setting */
232
233	/*
234	 * This can't overflow because get_string() limited the size of the
235	 * name and val fields.  Still, it doesn't hurt to be careful...
236	 */
237	if (!glue_strings(envstr, MAX_ENVSTR, name, val, '='))
238		return (FALSE);
239	Debug(DPARS, ("load_env, <%s> <%s> -> <%s>\n", name, val, envstr));
240	return (TRUE);
241}
242
243char *
244env_get(const char *name, char **envp) {
245	size_t len = strlen(name);
246	char *p, *q;
247
248	while ((p = *envp++) != NULL) {
249		if (!(q = strchr(p, '=')))
250			continue;
251		if ((size_t)(q - p) == len && !strncmp(p, name, len))
252			return (q+1);
253	}
254	return (NULL);
255}
256