procps/proc/pwcache.c
Jim Warner 18e684d65d library: eliminate all dependencies on alloc.h/alloc.c
While that old master branch library may utilize those
memory allocation functions found in the alloc module,
it was inappropriate for this newlib branch to subject
callers to a stderr message followed by an early exit.

Of course, the old libprocps offered a message handler
override provision (xalloc_err_handler) but that, too,
would seem to be inappropriate for our modern library.

[ remember the battles fought with that damn libnuma ]

So, this commit will tweak those old inherited sources
setting the stage for standardized return values/errno
settings in connection with a memory allocation error.

------------------------------------------------------
Along the way, we'll address the following miscellany:

. Completely eliminate usage of anything from alloc.h.
This, of course, entails our own error checking of the
alternative allocation calls from stdlib.h & string.h.

. Eliminate use of the strdup function where possible,
as with 'procps_uptime' and 'procps_loadavg' routines.

. Whack some obsolete code (getslabinfo) in sysinfo.c.

Signed-off-by: Jim Warner <james.warner@comcast.net>
2017-12-20 21:18:53 +11:00

97 lines
2.5 KiB
C

/*
* pwcache.c - memory cache passwd file handling
*
* Copyright (C) 1992-1998 by Michael K. Johnson, johnsonm@redhat.com
* Note: most likely none of his code remains
*
* Copyright 2002, Albert Cahalan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <stdlib.h>
#include <pwd.h>
#include <grp.h>
#include "pwcache.h"
#include "procps-private.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 char ERRname[] = "?";
static struct pwbuf {
struct pwbuf *next;
uid_t uid;
char name[P_G_SZ];
} *pwhash[HASHSIZE];
char *pwcache_get_user(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;
}
if (!(*p = (struct pwbuf *)malloc(sizeof(struct pwbuf))))
return ERRname;
(*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 *pwcache_get_group(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;
}
if (!(*g = (struct grpbuf *)malloc(sizeof(struct grpbuf))))
return ERRname;;
(*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);
}