ttl_utils.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* DESCRIPTION: Contains utilities relating to TTL calculation.
*/
#include <unistd.h>
#include <syslog.h>
#include <errno.h>
#include <strings.h>
#include <ndbm.h>
#include "ypsym.h"
#include "ypdefs.h"
#include "shim.h"
#include "yptol.h"
#include "../ldap_util.h"
/*
* Constants used in time calculations
*/
#define MILLION 1000000
/*
* Decs
*/
suc_code is_greater_timeval(struct timeval *, struct timeval *);
suc_code add_to_timeval(struct timeval *, int);
/*
* FUNCTION: has_entry_expired()
*
* DESCRIPTION: Determines if an individual entry has expired.
*
* INPUTS: Map control structure for an open map
* Entry key
*
* OUTPUTS: TRUE = Entry has expired or cannot be found this will cause
* missing entries to be pulled out of the DIT.
* FALSE = Entry has not expired
*
*/
bool_t
has_entry_expired(map_ctrl *map, datum *key)
{
datum ttl;
struct timeval now;
struct timeval old_time;
char *key_name;
char *myself = "has_entry_expired";
if ((map == NULL) || (map->ttl == NULL))
return (FALSE);
/* Get expiry time entry for key */
ttl = dbm_fetch(map->ttl, *key);
if (NULL == ttl.dptr) {
/*
* If we failed to get a map expiry key, which must always be
* present, then something is seriously wrong. Try to recreate
* the map.
*/
if ((key->dsize == strlen(MAP_EXPIRY_KEY)) &&
(0 == strncmp(key->dptr, MAP_EXPIRY_KEY, key->dsize))) {
logmsg(MSG_NOTIMECHECK, LOG_ERR, "Cannot find %s TTL "
"for map %s. Will attempt to recreate map",
MAP_EXPIRY_KEY, map->map_name);
return (TRUE);
}
/*
* Not a problem just no TTL entry for this entry. Maybe it has
* not yet been downloaded. Maybe it will be handled by a
* service other than NIS. Check if the entire map has expired.
* This prevents repeated LDAP reads when requests are made for
* nonexistant entries.
*/
if (has_map_expired(map)) {
/* Kick of a map update */
update_map_if_required(map, FALSE);
}
/* Don't update the entry */
return (FALSE);
}
if (ttl.dsize != sizeof (struct timeval)) {
/*
* Need to malloc some memory before can syslog the key name
* but this may fail. Solution log a simple message first THEn
* a more detailed one if it works.
*/
logmsg(MSG_NOTIMECHECK, LOG_ERR,
"Invalid TTL key in map %s. error %d",
map->map_name, dbm_error(map->ttl));
/* Log the key name */
key_name = (char *)am(myself, key->dsize + 1);
if (NULL == key_name) {
logmsg(MSG_NOMEM, LOG_ERR,
"Could not alloc memory for keyname");
} else {
strncpy(key_name, key->dptr, key->dsize);
key_name[key->dsize] = '\0';
logmsg(MSG_NOTIMECHECK, LOG_ERR,
"Key name was %s", key_name);
sfree(key_name);
}
/* Update it Anyway */
return (TRUE);
}
/* Get current time */
gettimeofday(&now, NULL);
/*
* Because dptr may not be int aligned need to build an int
* out of what it points to or will get a bus error
*/
bcopy(ttl.dptr, &old_time, sizeof (struct timeval));
return (is_greater_timeval(&now, &old_time));
}
/*
* FUNCTION: has_map_expired()
*
* DESCRIPTION: Determines if an entire map has expire
*
* INPUTS: Map control structure for an open map
*
* OUTPUTS: TRUE = Map has expired
* FALSE Map has not expired
*
*/
bool_t
has_map_expired(map_ctrl *map)
{
datum key;
/* Set up datum with magic expiry key */
key.dsize = strlen(MAP_EXPIRY_KEY);
key.dptr = MAP_EXPIRY_KEY;
/* Call has_entry_expired() with magic map expiry key */
return (has_entry_expired(map, &key));
}
/*
* FUNCTION: update_entry_ttl()
*
* DESCRIPTION: Updates the TTL for one map entry
*
* INPUTS: Map control structure for an open map
* Entry key
* Flag indication if TTL should be max, min or random
*
* OUTPUTS: SUCCESS = TTL updated
* FAILURE = TTL not updated
*
*/
suc_code
update_entry_ttl(map_ctrl *map, datum *key, TTL_TYPE type)
{
datum expire;
struct timeval now;
int ttl;
/* Get current time */
gettimeofday(&now, NULL);
/* Get TTL from mapping file */
ttl = get_ttl_value(map, type);
if (FAILURE == add_to_timeval(&now, ttl))
return (FAILURE);
/* Convert time into a datum */
expire.dsize = sizeof (struct timeval);
expire.dptr = (char *)&now;
/* Set expiry time entry for key */
errno = 0;
if (0 > dbm_store(map->ttl, *key, expire, DBM_REPLACE)) {
logmsg(MSG_NOTIMECHECK, LOG_ERR, "Could not write TTL entry "
"(errno=%d)", errno);
return (FAILURE);
}
return (SUCCESS);
}
/*
* FUNCTION: update_map_ttl()
*
* DESCRIPTION: Updates the TTL for entire map. This can be called either with
* the map open (map_ctrl DBM pointer set up) or the map closed
* (map_ctrl DBM pointers not set). The latter case will occur
* when we have just created a new map.
*
* This function must open the TTL map but, in either case, must
* return with the map_ctrl in it's original state.
*
* INPUTS: Map control structure for an open map
*
* OUTPUTS: SUCCESS = TTL updated
* FAILURE = TTL not updated
*
*/
suc_code
update_map_ttl(map_ctrl *map)
{
datum key;
bool_t map_was_open = TRUE;
suc_code ret;
/* Set up datum with magic expiry key */
key.dsize = strlen(MAP_EXPIRY_KEY);
key.dptr = MAP_EXPIRY_KEY;
/* If TTL not open open it */
if (NULL == map->ttl) {
map->ttl = dbm_open(map->ttl_path, O_RDWR, 0644);
if (NULL == map->ttl)
return (FAILURE);
map_was_open = FALSE;
}
/* Call update_entry_ttl() with magic map expiry key */
ret = update_entry_ttl(map, &key, TTL_MIN);
/* If we had to open TTL file close it */
if (!map_was_open) {
dbm_close(map->ttl);
map->ttl_path = NULL;
}
return (ret);
}
/*
* FUNCTION: add_to_timeval()
*
* DESCRIPTION: Adds an int to a timeval
*
* NOTE : Seems strange that there is not a library function to do this
* if one exists then this function can be removed.
*
* NOTE : Does not handle UNIX clock wrap round but this is a much bigger
* problem.
*
* INPUTS: Time value to add to
* Time value to add in seconds
*
* OUTPUTS: SUCCESS = Addition successful
* FAILURE = Addition failed (probably wrapped)
*
*/
suc_code
add_to_timeval(struct timeval *t1, int t2)
{
long usec;
struct timeval oldval;
oldval.tv_sec = t1->tv_sec;
/* Add seconds part */
t1->tv_sec += t2;
/* Check for clock wrap */
if (!(t1->tv_sec >= oldval.tv_sec)) {
logmsg(MSG_NOTIMECHECK, LOG_ERR,
"Wrap when adding %d to %d", t2, oldval.tv_sec);
return (FAILURE);
}
return (SUCCESS);
}
/*
* FUNCTION: is_greater_timeval()
*
* DESCRIPTION: Compares two timevals
*
* NOTE : Seems strange that there is not a library function to do this
* if one exists then this function can be removed.
*
* INPUTS: First time value
* Time value to compare it with
*
* OUTPUTS: TRUE t1 > t2
* FALSE t1 <= t2
*
*/
suc_code
is_greater_timeval(struct timeval *t1, struct timeval *t2)
{
if (t1->tv_sec > t2->tv_sec)
return (TRUE);
if (t1->tv_sec == t2->tv_sec) {
if (t1->tv_usec > t2->tv_usec)
return (TRUE);
else
return (FALSE);
}
return (FALSE);
}