/* Copyright 1988,1990,1993,1994 by Paul Vixie

/* $NetBSD: env.c,v 1.4 2014/09/07 13:35:27 tron Exp $ */

/* Copyright 1988,1990,1993,1994 by Paul Vixie
* All rights reserved
*/

/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1997,2000 by Internet Software Consortium, Inc.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/cdefs.h>
#if !defined(lint) && !defined(LINT)
#if 0
static char rcsid[] = "Id: env.c,v 1.10 2004/01/23 18:56:42 vixie Exp";
#else
__RCSID("$NetBSD: env.c,v 1.4 2014/09/07 13:35:27 tron Exp $");
#endif
#endif

#include "cron.h"

char **
env_init(void) {
char **p = malloc(sizeof(char **));

if (p != NULL)
p[0] = NULL;
return (p);
}

void
env_free(char **envp) {
char **p;

for (p = envp; *p != NULL; p++)
free(*p);
free(envp);
}

char **
env_copy(char **envp) {
size_t count, i;
int save_errno;
char **p;

for (count = 0; envp[count] != NULL; count++)
continue;
p = malloc((count + 1) * sizeof(*p)); /* 1 for the NULL */
if (p == NULL)
return NULL;
for (i = 0; i < count; i++) {
if ((p[i] = strdup(envp[i])) == NULL) {
save_errno = errno;
for (count = 0; count < i; count++)
free(p[count]);
free(p);
errno = save_errno;
return NULL;
}
}
p[count] = NULL;
return p;
}

char **
env_set(char **envp, char *envstr) {
size_t count, found;
char **p, *envtmp;

/*
* count the number of elements, including the null pointer;
* also set 'found' to -1 or index of entry if already in here.
*/
found = (size_t)-1;
for (count = 0; envp[count] != NULL; count++) {
if (!strcmp_until(envp[count], envstr, '='))
found = count;
}
count++; /* for the NULL */

if (found != (size_t)-1) {
/*
* it exists already, so just free the existing setting,
* save our new one there, and return the existing array.
*/
if ((envtmp = strdup(envstr)) == NULL)
return (NULL);
free(envp[found]);
envp[found] = envtmp;
return (envp);
}

/*
* it doesn't exist yet, so resize the array, move null pointer over
* one, save our string over the old null pointer, and return resized
* array.
*/
if ((envtmp = strdup(envstr)) == NULL)
return (NULL);
p = realloc(envp, (count + 1) * sizeof(*p));
if (p == NULL) {
free(envtmp);
return (NULL);
}
p[count] = p[count-1];
p[count-1] = envtmp;
return (p);
}

/* The following states are used by load_env(), traversed in order: */
enum env_state {
NAMEI, /* First char of NAME, may be quote */
NAME, /* Subsequent chars of NAME */
EQ1, /* After end of name, looking for '=' sign */
EQ2, /* After '=', skipping whitespace */
VALUEI, /* First char of VALUE, may be quote */
VALUE, /* Subsequent chars of VALUE */
FINI, /* All done, skipping trailing whitespace */
ERROR /* Error */
};

/* return ERR = end of file
* FALSE = not an env setting (file was repositioned)
* TRUE = was an env setting
*/
int
load_env(char *envstr, FILE *f) {
long filepos;
int fileline;
enum env_state state;
char name[MAX_ENVSTR], val[MAX_ENVSTR];
char quotechar, *c, *str;

filepos = ftell(f);
fileline = LineNumber;
skip_comments(f);
if (EOF == get_string(envstr, MAX_ENVSTR, f, "\n"))
return (ERR);

Debug(DPARS, ("load_env, read <%s>\n", envstr));

(void)memset(name, 0, sizeof name);
(void)memset(val, 0, sizeof val);
str = name;
state = NAMEI;
quotechar = '\0';
c = envstr;
while (state != ERROR && *c) {
switch (state) {
case NAMEI:
case VALUEI:
if (*c == '\'' || *c == '"')
quotechar = *c++;
state++;
/* FALLTHROUGH */
case NAME:
case VALUE:
if (quotechar) {
if (*c == quotechar) {
state++;
c++;
break;
}
if (state == NAME && *c == '=') {
state = ERROR;
break;
}
} else {
if (state == NAME) {
if (isspace((unsigned char)*c)) {
c++;
state++;
break;
}
if (*c == '=') {
state++;
break;
}
}
}
*str++ = *c++;
break;

case EQ1:
if (*c == '=') {
state++;
str = val;
quotechar = '\0';
} else {
if (!isspace((unsigned char)*c))
state = ERROR;
}
c++;
break;

case EQ2:
case FINI:
if (isspace((unsigned char)*c))
c++;
else
state++;
break;

default:
abort();
}
}
if (state != FINI && !(state == VALUE && !quotechar)) {
Debug(DPARS, ("load_env, not an env var, state = %d\n", state));
(void)fseek(f, filepos, 0);
Set_LineNum(fileline);
return (FALSE);
}
if (state == VALUE) {
/* End of unquoted value: trim trailing whitespace */
c = val + strlen(val);
while (c > val && isspace((unsigned char)c[-1]))
*(--c) = '\0';
}

/* 2 fields from parser; looks like an env setting */

/*
* This can't overflow because get_string() limited the size of the
* name and val fields. Still, it doesn't hurt to be careful...
*/
if (!glue_strings(envstr, MAX_ENVSTR, name, val, '='))
return (FALSE);
Debug(DPARS, ("load_env, <%s> <%s> -> <%s>\n", name, val, envstr));
return (TRUE);
}

char *
env_get(const char *name, char **envp) {
size_t len = strlen(name);
char *p, *q;

while ((p = *envp++) != NULL) {
if (!(q = strchr(p, '=')))
continue;
if ((size_t)(q - p) == len && !strncmp(p, name, len))
return (q+1);
}
return (NULL);
}