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/*
* Copyright (c) 1984 through 2008, William LeFebvre
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of William LeFebvre nor the names of other
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*/
/*
* Top users/processes display for Unix
* Version 3
*/
/*
* Username translation code for top.
*
* These routines handle uid to username mapping. They use a hash table to
* reduce reading overhead. Entries are refreshed every EXPIRETIME seconds.
*
* The old ad-hoc hash functions have been replaced with something a little
* more formal and (hopefully) more robust (found in hash.c)
*/
#include "os.h"
#include <pwd.h>
#include "top.h"
#include "utils.h"
#include "hash.h"
#include "username.h"
#define EXPIRETIME (60 * 5)
/* we need some sort of idea how long usernames can be */
#ifndef MAXLOGNAME
#ifdef _POSIX_LOGIN_NAME_MAX
#define MAXLOGNAME _POSIX_LOGIN_NAME_MAX
#else
#define MAXLOGNAME 9
#endif
#endif
struct hash_data {
int uid;
char name[MAXLOGNAME]; /* big enough? */
time_t expire;
};
hash_table *userhash;
void
init_username(void)
{
userhash = hash_create(211);
}
char *
username(int xuid)
{
struct hash_data *data;
struct passwd *pw;
time_t now;
/* what time is it? */
now = time(NULL);
/* get whatever is in the cache */
data = hash_lookup_uint(userhash, (unsigned int)xuid);
/* if we had a cache miss, then create space for a new entry */
if (data == NULL)
{
/* make space */
data = emalloc(sizeof(struct hash_data));
/* fill in some data, including an already expired time */
data->uid = xuid;
data->expire = (time_t)0;
/* add it to the hash: the rest gets filled in later */
hash_add_uint(userhash, xuid, data);
}
/* Now data points to the correct hash entry for "xuid". If this is
a new entry, then expire is 0 and the next test will be true. */
if (data->expire <= now)
{
if ((pw = getpwuid(xuid)) != NULL)
{
strncpy(data->name, pw->pw_name, MAXLOGNAME-1);
data->expire = now + EXPIRETIME;
dprintf("username: updating %d with %s, expires %d\n",
data->uid, data->name, data->expire);
}
else
{
/* username doesnt exist ... so invent one */
snprintf(data->name, sizeof(data->name), "%d", xuid);
data->expire = now + EXPIRETIME;
dprintf("username: updating %d with %s, expires %d\n",
data->uid, data->name, data->expire);
}
}
/* return what we have */
return data->name;
}
int
userid(char *xusername)
{
struct passwd *pwd;
if ((pwd = getpwnam(xusername)) == NULL)
{
return(-1);
}
/* return our result */
return(pwd->pw_uid);
}
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