freebsd-dev/lib/libc/gen/pwcache.c
Ed Schouten dc29acd1a9 Don't let the C library depend on <utmp.h>.
The maximum length of a username has nothing to do with the size of the
username in the utmp files. Use MAXLOGNAME, which is defined as 17
(UT_USERSIZE + 1).
2009-12-05 19:04:21 +00:00

114 lines
3.3 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 4. 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)pwcache.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#define NCACHE 64 /* power of 2 */
#define MASK (NCACHE - 1) /* bits to store with */
const char *
user_from_uid(uid_t uid, int nouser)
{
static struct ncache {
uid_t uid;
int found;
char name[MAXLOGNAME];
} c_uid[NCACHE];
static int pwopen;
struct passwd *pw;
struct ncache *cp;
cp = c_uid + (uid & MASK);
if (cp->uid != uid || !*cp->name) {
if (pwopen == 0) {
setpassent(1);
pwopen = 1;
}
pw = getpwuid(uid);
cp->uid = uid;
if (pw != NULL) {
cp->found = 1;
(void)strncpy(cp->name, pw->pw_name, MAXLOGNAME - 1);
cp->name[MAXLOGNAME - 1] = '\0';
} else {
cp->found = 0;
(void)snprintf(cp->name, MAXLOGNAME - 1, "%u", uid);
if (nouser)
return (NULL);
}
}
return ((nouser && !cp->found) ? NULL : cp->name);
}
const char *
group_from_gid(gid_t gid, int nogroup)
{
static struct ncache {
gid_t gid;
int found;
char name[MAXLOGNAME];
} c_gid[NCACHE];
static int gropen;
struct group *gr;
struct ncache *cp;
cp = c_gid + (gid & MASK);
if (cp->gid != gid || !*cp->name) {
if (gropen == 0) {
setgroupent(1);
gropen = 1;
}
gr = getgrgid(gid);
cp->gid = gid;
if (gr != NULL) {
cp->found = 1;
(void)strncpy(cp->name, gr->gr_name, MAXLOGNAME - 1);
cp->name[MAXLOGNAME - 1] = '\0';
} else {
cp->found = 0;
(void)snprintf(cp->name, MAXLOGNAME - 1, "%u", gid);
if (nogroup)
return (NULL);
}
}
return ((nogroup && !cp->found) ? NULL : cp->name);
}