shadow/libmisc/addgrps.c
Alejandro Colomar e2df287aad Don't redefine errno(3)
It is Undefined Behavior to declare errno (see NOTES in its manual page).
Instead of using the errno dummy declaration, use one that doesn't need
a comment.

Signed-off-by: Alejandro Colomar <alx@kernel.org>
2022-12-22 11:43:29 +01:00

115 lines
2.5 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 "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, *tmp;
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 = (gid_t *) malloc (i * sizeof (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;
}
tmp = (gid_t *) realloc (grouplist, (size_t)(ngroups + 1) * sizeof (GETGROUPS_T));
if (NULL == tmp) {
free (grouplist);
return -1;
}
tmp[ngroups] = grp->gr_gid;
ngroups++;
grouplist = tmp;
added = true;
}
if (added) {
ret = setgroups ((size_t)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 */