1/*	$NetBSD: env.c,v 1.3 2014/09/05 21:32:37 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 1.3 2014/09/05 21:32:37 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	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
77char **
78env_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: */
123enum 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 */
138int
139load_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
245char *
246env_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