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      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 **
     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
     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 **
     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 **
     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
    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 *
    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