defaults.c revision d04ccbb3f3163ae5962a8b7465d9796bff6ca434
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <dhcpmsg.h>
#include <stdio.h>
#include <sys/stat.h>
#include <libnvpair.h>
#include "common.h"
#include "defaults.h"
struct dhcp_default {
const char *df_name; /* parameter name */
const char *df_default; /* default value */
int df_min; /* min value if type DF_INTEGER */
int df_max; /* max value if type DF_INTEGER */
};
/*
* note: keep in the same order as tunable parameter constants in defaults.h
*/
static struct dhcp_default defaults[] = {
{ "RELEASE_ON_SIGTERM", "0", 0, 0 },
{ "IGNORE_FAILED_ARP", "1", 0, -1 },
{ "OFFER_WAIT", "3", 1, 20 },
{ "ARP_WAIT", "1000", 0, -1 },
{ "CLIENT_ID", NULL, 0, 0 },
{ "PARAM_REQUEST_LIST", NULL, 0, 0 },
{ "REQUEST_HOSTNAME", "1", 0, 0 },
{ "DEBUG_LEVEL", "0", 0, 3 },
{ "VERBOSE", "0", 0, 0 }
};
/*
* df_build_cache(): builds the defaults nvlist cache
*
* input: void
* output: a pointer to an nvlist of the current defaults, or NULL on failure
*/
static nvlist_t *
df_build_cache(void)
{
char entry[1024];
int i;
char *param, *pastv6, *value, *end;
FILE *fp;
nvlist_t *nvlist;
struct dhcp_default *defp;
if ((fp = fopen(DHCP_AGENT_DEFAULTS, "r")) == NULL)
return (NULL);
if (nvlist_alloc(&nvlist, NV_UNIQUE_NAME, 0) != 0) {
dhcpmsg(MSG_WARNING, "cannot build default value cache; "
"using built-in defaults");
(void) fclose(fp);
return (NULL);
}
while (fgets(entry, sizeof (entry), fp) != NULL) {
for (i = 0; entry[i] == ' '; i++)
;
end = strrchr(entry, '\n');
value = strchr(entry, '=');
if (end == NULL || value == NULL || entry[i] == '#')
continue;
*end = '\0';
*value++ = '\0';
/*
* to be compatible with the old defread()-based code
* which ignored case, store the parameters (except for the
* leading interface name) in upper case.
*/
if ((param = strchr(entry, '.')) == NULL) {
pastv6 = param = entry;
} else {
pastv6 = ++param;
if (strncasecmp(param, "v6.", 3) == 0)
pastv6 += 3;
}
for (defp = defaults;
(char *)defp < (char *)defaults + sizeof (defaults);
defp++) {
if (strcasecmp(pastv6, defp->df_name) == 0) {
if (defp->df_max == -1) {
dhcpmsg(MSG_WARNING, "parameter %s is "
"obsolete; ignored", defp->df_name);
}
break;
}
}
for (; *param != '\0'; param++)
*param = toupper(*param);
if (nvlist_add_string(nvlist, &entry[i], value) != 0) {
dhcpmsg(MSG_WARNING, "cannot build default value cache;"
" using built-in defaults");
nvlist_free(nvlist);
nvlist = NULL;
break;
}
}
(void) fclose(fp);
return (nvlist);
}
/*
* df_get_string(): gets the string value of a given user-tunable parameter
*
* input: const char *: the interface the parameter applies to
* boolean_t: B_TRUE for DHCPv6, B_FALSE for IPv4 DHCP
* uint_t: the parameter number to look up
* output: const char *: the parameter's value, or default if not set
* (must be copied by caller to be kept)
* NOTE: df_get_string() is both used by functions outside this source
* file to retrieve strings from the defaults file, *and*
* internally by other df_get_*() functions.
*/
const char *
df_get_string(const char *if_name, boolean_t isv6, uint_t param)
{
char *value;
char paramstr[256];
char name[256];
struct stat statbuf;
static struct stat df_statbuf;
static boolean_t df_unavail_msg = B_FALSE;
static nvlist_t *df_nvlist = NULL;
if (param >= (sizeof (defaults) / sizeof (*defaults)))
return (NULL);
if (stat(DHCP_AGENT_DEFAULTS, &statbuf) != 0) {
if (!df_unavail_msg) {
dhcpmsg(MSG_WARNING, "cannot access %s; using "
"built-in defaults", DHCP_AGENT_DEFAULTS);
df_unavail_msg = B_TRUE;
}
return (defaults[param].df_default);
}
/*
* if our cached parameters are stale, rebuild.
*/
if (statbuf.st_mtime != df_statbuf.st_mtime ||
statbuf.st_size != df_statbuf.st_size) {
df_statbuf = statbuf;
if (df_nvlist != NULL)
nvlist_free(df_nvlist);
df_nvlist = df_build_cache();
}
if (isv6) {
(void) snprintf(name, sizeof (name), ".V6.%s",
defaults[param].df_name);
(void) snprintf(paramstr, sizeof (paramstr), "%s%s", if_name,
name);
} else {
(void) strlcpy(name, defaults[param].df_name, sizeof (name));
(void) snprintf(paramstr, sizeof (paramstr), "%s.%s", if_name,
name);
}
/*
* first look for `if_name.[v6.]param', then `[v6.]param'. if neither
* has been set, use the built-in default.
*/
if (nvlist_lookup_string(df_nvlist, paramstr, &value) == 0 ||
nvlist_lookup_string(df_nvlist, name, &value) == 0)
return (value);
return (defaults[param].df_default);
}
/*
* df_get_int(): gets the integer value of a given user-tunable parameter
*
* input: const char *: the interface the parameter applies to
* boolean_t: B_TRUE for DHCPv6, B_FALSE for IPv4 DHCP
* uint_t: the parameter number to look up
* output: int: the parameter's value, or default if not set
*/
int
df_get_int(const char *if_name, boolean_t isv6, uint_t param)
{
const char *value;
int value_int;
if (param >= (sizeof (defaults) / sizeof (*defaults)))
return (0);
value = df_get_string(if_name, isv6, param);
if (value == NULL || !isdigit(*value))
goto failure;
value_int = atoi(value);
if (value_int > defaults[param].df_max ||
value_int < defaults[param].df_min)
goto failure;
return (value_int);
failure:
dhcpmsg(MSG_WARNING, "df_get_int: parameter `%s' is not between %d and "
"%d, defaulting to `%s'", defaults[param].df_name,
defaults[param].df_min, defaults[param].df_max,
defaults[param].df_default);
return (atoi(defaults[param].df_default));
}
/*
* df_get_bool(): gets the boolean value of a given user-tunable parameter
*
* input: const char *: the interface the parameter applies to
* boolean_t: B_TRUE for DHCPv6, B_FALSE for IPv4 DHCP
* uint_t: the parameter number to look up
* output: boolean_t: B_TRUE if true, B_FALSE if false, default if not set
*/
boolean_t
df_get_bool(const char *if_name, boolean_t isv6, uint_t param)
{
const char *value;
if (param >= (sizeof (defaults) / sizeof (*defaults)))
return (0);
value = df_get_string(if_name, isv6, param);
if (value != NULL) {
if (strcasecmp(value, "true") == 0 ||
strcasecmp(value, "yes") == 0 || strcmp(value, "1") == 0)
return (B_TRUE);
if (strcasecmp(value, "false") == 0 ||
strcasecmp(value, "no") == 0 || strcmp(value, "0") == 0)
return (B_FALSE);
}
dhcpmsg(MSG_WARNING, "df_get_bool: parameter `%s' has invalid value "
"`%s', defaulting to `%s'", defaults[param].df_name,
value != NULL ? value : "NULL", defaults[param].df_default);
return ((atoi(defaults[param].df_default) == 0) ? B_FALSE : B_TRUE);
}