procps/proc/pwcache.c
Jim Warner 827334870d library: exploit enhanced library memory allocation provisions
There were numerous library memory allocation inconsistencies.
Some were checked for failure and others were not.

All library source modules were modified to utilize the alloc.h
memory rouines which are consistent in dealing with errors.
2011-12-11 22:26:55 +11:00

78 lines
1.8 KiB
C

// Copyright (C) 1992-1998 by Michael K. Johnson, johnsonm@redhat.com
// Note: most likely none of his code remains
//
// Copyright 2002, Albert Cahalan
//
// This file is placed under the conditions of the GNU Library
// General Public License, version 2, or any later version.
// See file COPYING for information on distribution conditions.
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <stdlib.h>
#include <pwd.h>
#include "alloc.h"
#include "pwcache.h"
#include <grp.h>
// might as well fill cache lines... else we waste memory anyway
#define HASHSIZE 64 /* power of 2 */
#define HASH(x) ((x) & (HASHSIZE - 1))
static struct pwbuf {
struct pwbuf *next;
uid_t uid;
char name[P_G_SZ];
} *pwhash[HASHSIZE];
char *user_from_uid(uid_t uid) {
struct pwbuf **p;
struct passwd *pw;
p = &pwhash[HASH(uid)];
while (*p) {
if ((*p)->uid == uid)
return((*p)->name);
p = &(*p)->next;
}
*p = (struct pwbuf *) xmalloc(sizeof(struct pwbuf));
(*p)->uid = uid;
pw = getpwuid(uid);
if(!pw || strlen(pw->pw_name) >= P_G_SZ)
sprintf((*p)->name, "%u", uid);
else
strcpy((*p)->name, pw->pw_name);
(*p)->next = NULL;
return((*p)->name);
}
static struct grpbuf {
struct grpbuf *next;
gid_t gid;
char name[P_G_SZ];
} *grphash[HASHSIZE];
char *group_from_gid(gid_t gid) {
struct grpbuf **g;
struct group *gr;
g = &grphash[HASH(gid)];
while (*g) {
if ((*g)->gid == gid)
return((*g)->name);
g = &(*g)->next;
}
*g = (struct grpbuf *) xmalloc(sizeof(struct grpbuf));
(*g)->gid = gid;
gr = getgrgid(gid);
if (!gr || strlen(gr->gr_name) >= P_G_SZ)
sprintf((*g)->name, "%u", gid);
else
strcpy((*g)->name, gr->gr_name);
(*g)->next = NULL;
return((*g)->name);
}