shadow/lib/sgetgrent.c
Alex Colomar 0d9799de04 Don't test for NULL before calling free(3)
free(3) accepts NULL, since the oldest ISO C.  I guess the
paranoid code was taking care of prehistoric implementations of
free(3).  I've never known of an implementation that doesn't
conform to this, so let's simplify this.

Remove xfree(3), which was effectively an equivalent of free(3).

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-09-29 16:03:53 +02:00

130 lines
2.8 KiB
C

/*
* SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2005 , Tomasz Kłoczko
* SPDX-FileCopyrightText: 2008 , Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#ident "$Id$"
#include <stdio.h>
#include <sys/types.h>
#include <grp.h>
#include "defines.h"
#include "prototypes.h"
#define NFIELDS 4
/*
* list - turn a comma-separated string into an array of (char *)'s
*
* list() converts the comma-separated list of member names into
* an array of character pointers.
*
* WARNING: I profiled this once with and without strchr() calls
* and found that using a register variable and an explicit loop
* works best. For large /etc/group files, this is a major win.
*
* FINALLY added dynamic allocation. Still need to fix sgetsgent().
* --marekm
*/
static char **list (char *s)
{
static char **members = 0;
static int size = 0; /* max members + 1 */
int i;
char **rbuf;
i = 0;
for (;;) {
/* check if there is room for another pointer (to a group
member name, or terminating NULL). */
if (i >= size) {
size = i + 100; /* at least: i + 1 */
if (members) {
rbuf =
realloc (members, size * sizeof (char *));
} else {
/* for old (before ANSI C) implementations of
realloc() that don't handle NULL properly */
rbuf = malloc (size * sizeof (char *));
}
if (!rbuf) {
free (members);
members = 0;
size = 0;
return (char **) 0;
}
members = rbuf;
}
if (!s || s[0] == '\0')
break;
members[i++] = s;
while (('\0' != *s) && (',' != *s)) {
s++;
}
if ('\0' != *s) {
*s++ = '\0';
}
}
members[i] = (char *) 0;
return members;
}
struct group *sgetgrent (const char *buf)
{
static char *grpbuf = 0;
static size_t size = 0;
static char *grpfields[NFIELDS];
static struct group grent;
int i;
char *cp;
if (strlen (buf) + 1 > size) {
/* no need to use realloc() here - just free it and
allocate a larger block */
free (grpbuf);
size = strlen (buf) + 1000; /* at least: strlen(buf) + 1 */
grpbuf = malloc (size);
if (!grpbuf) {
size = 0;
return 0;
}
}
strcpy (grpbuf, buf);
cp = strrchr (grpbuf, '\n');
if (NULL != cp) {
*cp = '\0';
}
for (cp = grpbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) {
grpfields[i] = cp;
cp = strchr (cp, ':');
if (NULL != cp) {
*cp = '\0';
cp++;
}
}
if (i < (NFIELDS - 1) || *grpfields[2] == '\0' || cp != NULL) {
return (struct group *) 0;
}
grent.gr_name = grpfields[0];
grent.gr_passwd = grpfields[1];
if (get_gid (grpfields[2], &grent.gr_gid) == 0) {
return (struct group *) 0;
}
grent.gr_mem = list (grpfields[3]);
if (NULL == grent.gr_mem) {
return (struct group *) 0; /* out of memory */
}
return &grent;
}