shadow/libmisc/addgrps.c
Alejandro Colomar efbbcade43 Use safer allocation macros
Use of these macros, apart from the benefits mentioned in the commit
that adds the macros, has some other good side effects:

-  Consistency in getting the size of the object from sizeof(type),
   instead of a mix of sizeof(type) sometimes and sizeof(*p) other
   times.

-  More readable code: no casts, and no sizeof(), so also shorter lines
   that we don't need to cut.

-  Consistency in using array allocation calls for allocations of arrays
   of objects, even when the object size is 1.

Cc: Valentin V. Bartenev <vbartenev@gmail.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-02-23 20:28:43 -06:00

115 lines
2.4 KiB
C

/*
* SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2001 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2009, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#if defined (HAVE_SETGROUPS) && ! defined (USE_PAM)
#include "prototypes.h"
#include "defines.h"
#include <stdio.h>
#include <grp.h>
#include <errno.h>
#include "alloc.h"
#include "shadowlog.h"
#ident "$Id$"
#define SEP ",:"
/*
* Add groups with names from LIST (separated by commas or colons)
* to the supplementary group set. Silently ignore groups which are
* already there. Warning: uses strtok().
*/
int add_groups (const char *list)
{
GETGROUPS_T *grouplist;
size_t i;
int ngroups;
bool added;
char *token;
char buf[1024];
int ret;
FILE *shadow_logfd = log_get_logfd();
if (strlen (list) >= sizeof (buf)) {
errno = EINVAL;
return -1;
}
strcpy (buf, list);
i = 16;
for (;;) {
grouplist = MALLOCARRAY (i, GETGROUPS_T);
if (NULL == grouplist) {
return -1;
}
ngroups = getgroups (i, grouplist);
if ( ( (-1 == ngroups)
&& (EINVAL != errno))
|| (i > (size_t)ngroups)) {
/* Unexpected failure of getgroups or successful
* reception of the groups */
break;
}
/* not enough room, so try allocating a larger buffer */
free (grouplist);
i *= 2;
}
if (ngroups < 0) {
free (grouplist);
return -1;
}
added = false;
for (token = strtok (buf, SEP); NULL != token; token = strtok (NULL, SEP)) {
struct group *grp;
grp = getgrnam (token); /* local, no need for xgetgrnam */
if (NULL == grp) {
fprintf (shadow_logfd, _("Warning: unknown group %s\n"),
token);
continue;
}
for (i = 0; i < (size_t)ngroups && grouplist[i] != grp->gr_gid; i++);
if (i < (size_t)ngroups) {
continue;
}
if (ngroups >= sysconf (_SC_NGROUPS_MAX)) {
fputs (_("Warning: too many groups\n"), shadow_logfd);
break;
}
grouplist = REALLOCARRAYF(grouplist, (size_t) ngroups + 1, GETGROUPS_T);
if (grouplist == NULL) {
return -1;
}
grouplist[ngroups] = grp->gr_gid;
ngroups++;
added = true;
}
if (added) {
ret = setgroups (ngroups, grouplist);
free (grouplist);
return ret;
}
free (grouplist);
return 0;
}
#else /* HAVE_SETGROUPS && !USE_PAM */
extern int ISO_C_forbids_an_empty_translation_unit;
#endif /* HAVE_SETGROUPS && !USE_PAM */