xref: /illumos-gate/usr/src/boot/libsa/environment.c (revision 22028508)
15fae793bSToomas Soome /*
2199767f8SToomas Soome  * Copyright (c) 1998 Michael Smith.
3199767f8SToomas Soome  * All rights reserved.
4199767f8SToomas Soome  *
5199767f8SToomas Soome  * Redistribution and use in source and binary forms, with or without
6199767f8SToomas Soome  * modification, are permitted provided that the following conditions
7199767f8SToomas Soome  * are met:
8199767f8SToomas Soome  * 1. Redistributions of source code must retain the above copyright
9199767f8SToomas Soome  *    notice, this list of conditions and the following disclaimer.
10199767f8SToomas Soome  * 2. Redistributions in binary form must reproduce the above copyright
11199767f8SToomas Soome  *    notice, this list of conditions and the following disclaimer in the
12199767f8SToomas Soome  *    documentation and/or other materials provided with the distribution.
13199767f8SToomas Soome  *
14199767f8SToomas Soome  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15199767f8SToomas Soome  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16199767f8SToomas Soome  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17199767f8SToomas Soome  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18199767f8SToomas Soome  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19199767f8SToomas Soome  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20199767f8SToomas Soome  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21199767f8SToomas Soome  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22199767f8SToomas Soome  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23199767f8SToomas Soome  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24199767f8SToomas Soome  * SUCH DAMAGE.
25199767f8SToomas Soome  */
26199767f8SToomas Soome 
27199767f8SToomas Soome #include <sys/cdefs.h>
28199767f8SToomas Soome 
29199767f8SToomas Soome /*
30199767f8SToomas Soome  * Manage an environment-like space in which string variables may be stored.
31199767f8SToomas Soome  * Provide support for some method-like operations for setting/retrieving
32199767f8SToomas Soome  * variables in order to allow some type strength.
33199767f8SToomas Soome  */
34199767f8SToomas Soome 
35199767f8SToomas Soome #include "stand.h"
36199767f8SToomas Soome 
37199767f8SToomas Soome #include <string.h>
38199767f8SToomas Soome 
395fae793bSToomas Soome struct env_var *environ = NULL;
40199767f8SToomas Soome 
41199767f8SToomas Soome /*
42199767f8SToomas Soome  * Look up (name) and return it's env_var structure.
43199767f8SToomas Soome  */
44199767f8SToomas Soome struct env_var	*
env_getenv(const char * name)45199767f8SToomas Soome env_getenv(const char *name)
46199767f8SToomas Soome {
475fae793bSToomas Soome 	struct env_var	*ev;
485fae793bSToomas Soome 
495fae793bSToomas Soome 	for (ev = environ; ev != NULL; ev = ev->ev_next)
505fae793bSToomas Soome 		if (strcmp(ev->ev_name, name) == 0)
515fae793bSToomas Soome 			break;
525fae793bSToomas Soome 	return (ev);
53199767f8SToomas Soome }
54199767f8SToomas Soome 
55199767f8SToomas Soome /*
56199767f8SToomas Soome  * Some notes:
57199767f8SToomas Soome  *
58199767f8SToomas Soome  * If the EV_VOLATILE flag is set, a copy of the variable is made.
59199767f8SToomas Soome  * If EV_DYNAMIC is set, the variable has been allocated with
60199767f8SToomas Soome  * malloc and ownership transferred to the environment.
61199767f8SToomas Soome  * If (value) is NULL, the variable is set but has no value.
62199767f8SToomas Soome  */
63199767f8SToomas Soome int
env_setenv(const char * name,int flags,const void * value,ev_sethook_t sethook,ev_unsethook_t unsethook)64199767f8SToomas Soome env_setenv(const char *name, int flags, const void *value,
655fae793bSToomas Soome     ev_sethook_t sethook, ev_unsethook_t unsethook)
66199767f8SToomas Soome {
675fae793bSToomas Soome 	struct env_var	*ev, *curr, *last;
685fae793bSToomas Soome 
695fae793bSToomas Soome 	if ((ev = env_getenv(name)) != NULL) {
705fae793bSToomas Soome 		/*
715fae793bSToomas Soome 		 * If there's a set hook, let it do the work
725fae793bSToomas Soome 		 * (unless we are working for one already).
735fae793bSToomas Soome 		 */
745fae793bSToomas Soome 		if ((ev->ev_sethook != NULL) && !(flags & EV_NOHOOK))
755fae793bSToomas Soome 			return (ev->ev_sethook(ev, flags, value));
765fae793bSToomas Soome 
775fae793bSToomas Soome 		/* If there is data in the variable, discard it. */
785fae793bSToomas Soome 		if (ev->ev_value != NULL && (ev->ev_flags & EV_DYNAMIC) != 0)
795fae793bSToomas Soome 			free(ev->ev_value);
805fae793bSToomas Soome 		ev->ev_value = NULL;
815fae793bSToomas Soome 		ev->ev_flags &= ~EV_DYNAMIC;
825fae793bSToomas Soome 
835fae793bSToomas Soome 	} else {
845fae793bSToomas Soome 		/*
855fae793bSToomas Soome 		 * New variable; create and sort into list
865fae793bSToomas Soome 		 */
875fae793bSToomas Soome 		ev = malloc(sizeof (struct env_var));
885fae793bSToomas Soome 		ev->ev_name = strdup(name);
895fae793bSToomas Soome 		ev->ev_value = NULL;
905fae793bSToomas Soome 		ev->ev_flags = 0;
915fae793bSToomas Soome 		/* hooks can only be set when the variable is instantiated */
925fae793bSToomas Soome 		ev->ev_sethook = sethook;
935fae793bSToomas Soome 		ev->ev_unsethook = unsethook;
945fae793bSToomas Soome 
955fae793bSToomas Soome 		/* Sort into list */
965fae793bSToomas Soome 		ev->ev_prev = NULL;
975fae793bSToomas Soome 		ev->ev_next = NULL;
985fae793bSToomas Soome 		/* Search for the record to insert before */
995fae793bSToomas Soome 		for (last = NULL, curr = environ; curr != NULL;
1005fae793bSToomas Soome 		    last = curr, curr = curr->ev_next) {
1015fae793bSToomas Soome 
1025fae793bSToomas Soome 			if (strcmp(ev->ev_name, curr->ev_name) < 0) {
1035fae793bSToomas Soome 				if (curr->ev_prev) {
1045fae793bSToomas Soome 					curr->ev_prev->ev_next = ev;
1055fae793bSToomas Soome 				} else {
1065fae793bSToomas Soome 					environ = ev;
1075fae793bSToomas Soome 				}
1085fae793bSToomas Soome 				ev->ev_next = curr;
1095fae793bSToomas Soome 				ev->ev_prev = curr->ev_prev;
1105fae793bSToomas Soome 				curr->ev_prev = ev;
1115fae793bSToomas Soome 				break;
1125fae793bSToomas Soome 			}
1135fae793bSToomas Soome 		}
1145fae793bSToomas Soome 		if (curr == NULL) {
1155fae793bSToomas Soome 			if (last == NULL) {
1165fae793bSToomas Soome 				environ = ev;
1175fae793bSToomas Soome 			} else {
1185fae793bSToomas Soome 				last->ev_next = ev;
1195fae793bSToomas Soome 				ev->ev_prev = last;
1205fae793bSToomas Soome 			}
121199767f8SToomas Soome 		}
122199767f8SToomas Soome 	}
1235fae793bSToomas Soome 
1245fae793bSToomas Soome 	/* If we have a new value, use it */
1255fae793bSToomas Soome 	if (flags & EV_VOLATILE) {
1265fae793bSToomas Soome 		ev->ev_value = strdup(value);
1275fae793bSToomas Soome 		ev->ev_flags |= EV_DYNAMIC;
1285fae793bSToomas Soome 	} else {
1295fae793bSToomas Soome 		ev->ev_value = (char *)value;
1305fae793bSToomas Soome 		ev->ev_flags |= flags & EV_DYNAMIC;
131199767f8SToomas Soome 	}
1325fae793bSToomas Soome 
1335fae793bSToomas Soome 	return (0);
134199767f8SToomas Soome }
135199767f8SToomas Soome 
136199767f8SToomas Soome char *
getenv(const char * name)137199767f8SToomas Soome getenv(const char *name)
138199767f8SToomas Soome {
1395fae793bSToomas Soome 	struct env_var	*ev;
1405fae793bSToomas Soome 
1415fae793bSToomas Soome 	/* Set but no value gives empty string */
1425fae793bSToomas Soome 	if ((ev = env_getenv(name)) != NULL) {
1435fae793bSToomas Soome 		if (ev->ev_value != NULL)
1445fae793bSToomas Soome 			return (ev->ev_value);
1455fae793bSToomas Soome 		return ("");
1465fae793bSToomas Soome 	}
1475fae793bSToomas Soome 	return (NULL);
148199767f8SToomas Soome }
149199767f8SToomas Soome 
150199767f8SToomas Soome int
setenv(const char * name,const char * value,int overwrite)151199767f8SToomas Soome setenv(const char *name, const char *value, int overwrite)
152199767f8SToomas Soome {
1535fae793bSToomas Soome 	/* No guarantees about state, always assume volatile */
1545fae793bSToomas Soome 	if (overwrite || (env_getenv(name) == NULL))
1555fae793bSToomas Soome 		return (env_setenv(name, EV_VOLATILE, value, NULL, NULL));
1565fae793bSToomas Soome 	return (0);
157199767f8SToomas Soome }
158199767f8SToomas Soome 
159199767f8SToomas Soome int
putenv(const char * string)160199767f8SToomas Soome putenv(const char *string)
161199767f8SToomas Soome {
1625fae793bSToomas Soome 	char	*value, *copy;
1635fae793bSToomas Soome 	int	result;
1645fae793bSToomas Soome 
1655fae793bSToomas Soome 	copy = strdup(string);
1665fae793bSToomas Soome 	if ((value = strchr(copy, '=')) != NULL)
1675fae793bSToomas Soome 		*(value++) = 0;
1685fae793bSToomas Soome 	result = setenv(copy, value, 1);
1695fae793bSToomas Soome 	free(copy);
1705fae793bSToomas Soome 	return (result);
171199767f8SToomas Soome }
172199767f8SToomas Soome 
173199767f8SToomas Soome int
unsetenv(const char * name)174199767f8SToomas Soome unsetenv(const char *name)
175199767f8SToomas Soome {
1765fae793bSToomas Soome 	struct env_var	*ev;
1775fae793bSToomas Soome 	int		err;
1785fae793bSToomas Soome 
1795fae793bSToomas Soome 	err = 0;
1805fae793bSToomas Soome 	if ((ev = env_getenv(name)) == NULL) {
1815fae793bSToomas Soome 		err = ENOENT;
1825fae793bSToomas Soome 	} else {
1835fae793bSToomas Soome 		if (ev->ev_unsethook != NULL)
1845fae793bSToomas Soome 			err = ev->ev_unsethook(ev);
1855fae793bSToomas Soome 		if (err == 0) {
1865fae793bSToomas Soome 			env_discard(ev);
1875fae793bSToomas Soome 		}
188199767f8SToomas Soome 	}
1895fae793bSToomas Soome 	return (err);
190199767f8SToomas Soome }
191199767f8SToomas Soome 
1925fae793bSToomas Soome void
env_discard(struct env_var * ev)193199767f8SToomas Soome env_discard(struct env_var *ev)
194199767f8SToomas Soome {
1955fae793bSToomas Soome 	if (ev->ev_prev)
1965fae793bSToomas Soome 		ev->ev_prev->ev_next = ev->ev_next;
1975fae793bSToomas Soome 	if (ev->ev_next)
1985fae793bSToomas Soome 		ev->ev_next->ev_prev = ev->ev_prev;
1995fae793bSToomas Soome 	if (environ == ev)
2005fae793bSToomas Soome 		environ = ev->ev_next;
2015fae793bSToomas Soome 	free(ev->ev_name);
2025fae793bSToomas Soome 	if (ev->ev_value != NULL && (ev->ev_flags & EV_DYNAMIC) != 0)
2035fae793bSToomas Soome 		free(ev->ev_value);
2045fae793bSToomas Soome 	free(ev);
205199767f8SToomas Soome }
206199767f8SToomas Soome 
207199767f8SToomas Soome int
env_noset(struct env_var * ev __unused,int flags __unused,const void * value __unused)208199767f8SToomas Soome env_noset(struct env_var *ev __unused, int flags __unused,
209199767f8SToomas Soome     const void *value __unused)
210199767f8SToomas Soome {
2115fae793bSToomas Soome 	return (EPERM);
212199767f8SToomas Soome }
213199767f8SToomas Soome 
214199767f8SToomas Soome int
env_nounset(struct env_var * ev __unused)215199767f8SToomas Soome env_nounset(struct env_var *ev __unused)
216199767f8SToomas Soome {
2175fae793bSToomas Soome 	return (EPERM);
218199767f8SToomas Soome }
219