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/* $OpenBSD: cache.c,v 1.23 2016/08/26 04:08:18 guenther Exp $ */
/* $NetBSD: cache.c,v 1.4 1995/03/21 09:07:10 cgd Exp $ */
/*-
* Copyright (c) 1992 Keith Muller.
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Keith Muller of the University of California, San Diego.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pax.h"
#include "extern.h"
/*
* Constants and data structures used to implement group and password file
* caches. Traditional passwd/group cache routines perform quite poorly with
* archives. The chances of hitting a valid lookup with an archive is quite a
* bit worse than with files already resident on the file system. These misses
* create a MAJOR performance cost. To address this problem, these routines
* cache both hits and misses.
*
* NOTE: name lengths must be as large as those stored in ANY PROTOCOL and
* as stored in the passwd and group files. CACHE SIZES MUST BE PRIME
*/
#define UNMLEN 32 /* >= user name found in any protocol */
#define GNMLEN 32 /* >= group name found in any protocol */
#define UNM_SZ 317 /* size of uid_name() cache */
#define GNM_SZ 317 /* size of gid_name() cache */
#define VALID 1 /* entry and name are valid */
#define INVALID 2 /* entry valid, name NOT valid */
/*
* Node structures used in the user, group, uid, and gid caches.
*/
typedef struct uidc {
int valid; /* is this a valid or a miss entry */
char name[UNMLEN]; /* uid name */
uid_t uid; /* cached uid */
} UIDC;
typedef struct gidc {
int valid; /* is this a valid or a miss entry */
char name[GNMLEN]; /* gid name */
gid_t gid; /* cached gid */
} GIDC;
/*
* routines that control user, group, uid and gid caches (for the archive
* member print routine).
* IMPORTANT:
* these routines cache BOTH hits and misses, a major performance improvement
*/
static int pwopn = 0; /* is password file open */
static int gropn = 0; /* is group file open */
static UIDC **usrtb = NULL; /* user name to uid cache */
static GIDC **grptb = NULL; /* group name to gid cache */
/*
* usrtb_start
* creates an empty usrtb
* Return:
* 0 if ok, -1 otherwise
*/
int
usrtb_start(void)
{
static int fail = 0;
if (usrtb != NULL)
return(0);
if (fail)
return(-1);
if ((usrtb = calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
++fail;
paxwarn(1, "Unable to allocate memory for user name cache table");
return(-1);
}
return(0);
}
/*
* grptb_start
* creates an empty grptb
* Return:
* 0 if ok, -1 otherwise
*/
int
grptb_start(void)
{
static int fail = 0;
if (grptb != NULL)
return(0);
if (fail)
return(-1);
if ((grptb = calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
++fail;
paxwarn(1,"Unable to allocate memory for group name cache table");
return(-1);
}
return(0);
}
/*
* uid_name()
* caches the uid for a given user name. We use a simple hash table.
* Return
* the uid (if any) for a user name, or a -1 if no match can be found
*/
int
uid_name(char *name, uid_t *uid)
{
struct passwd *pw;
UIDC *ptr;
int namelen;
/*
* return -1 for mangled names
*/
if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
return(-1);
if ((usrtb == NULL) && (usrtb_start() < 0))
return(-1);
/*
* look up in hash table, if found and valid return the uid,
* if found and invalid, return a -1
*/
ptr = usrtb[st_hash(name, namelen, UNM_SZ)];
if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
if (ptr->valid == INVALID)
return(-1);
*uid = ptr->uid;
return(0);
}
if (!pwopn) {
setpassent(1);
++pwopn;
}
if (ptr == NULL)
ptr = usrtb[st_hash(name, namelen, UNM_SZ)] =
malloc(sizeof(UIDC));
/*
* no match, look it up, if no match store it as an invalid entry,
* or store the matching uid
*/
if (ptr == NULL) {
if ((pw = getpwnam(name)) == NULL)
return(-1);
*uid = pw->pw_uid;
return(0);
}
(void)strlcpy(ptr->name, name, sizeof(ptr->name));
if ((pw = getpwnam(name)) == NULL) {
ptr->valid = INVALID;
return(-1);
}
ptr->valid = VALID;
*uid = ptr->uid = pw->pw_uid;
return(0);
}
/*
* gid_name()
* caches the gid for a given group name. We use a simple hash table.
* Return
* the gid (if any) for a group name, or a -1 if no match can be found
*/
int
gid_name(char *name, gid_t *gid)
{
struct group *gr;
GIDC *ptr;
int namelen;
/*
* return -1 for mangled names
*/
if (((namelen = strlen(name)) == 0) || (name[0] == '\0'))
return(-1);
if ((grptb == NULL) && (grptb_start() < 0))
return(-1);
/*
* look up in hash table, if found and valid return the uid,
* if found and invalid, return a -1
*/
ptr = grptb[st_hash(name, namelen, GNM_SZ)];
if ((ptr != NULL) && (ptr->valid > 0) && !strcmp(name, ptr->name)) {
if (ptr->valid == INVALID)
return(-1);
*gid = ptr->gid;
return(0);
}
if (!gropn) {
setgroupent(1);
++gropn;
}
if (ptr == NULL)
ptr = grptb[st_hash(name, namelen, GNM_SZ)] =
malloc(sizeof(GIDC));
/*
* no match, look it up, if no match store it as an invalid entry,
* or store the matching gid
*/
if (ptr == NULL) {
if ((gr = getgrnam(name)) == NULL)
return(-1);
*gid = gr->gr_gid;
return(0);
}
(void)strlcpy(ptr->name, name, sizeof(ptr->name));
if ((gr = getgrnam(name)) == NULL) {
ptr->valid = INVALID;
return(-1);
}
ptr->valid = VALID;
*gid = ptr->gid = gr->gr_gid;
return(0);
}
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