shadow/libmisc/addgrps.c

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#include <config.h>
#ifdef HAVE_SETGROUPS
#include "prototypes.h"
#include "defines.h"
#include <stdio.h>
#include <grp.h>
#include <errno.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;
int i, ngroups, added;
struct group *grp;
char *token;
char buf[1024];
if (strlen (list) >= sizeof (buf)) {
errno = EINVAL;
return -1;
}
strcpy (buf, list);
i = 16;
for (;;) {
grouplist = (gid_t *) malloc (i * sizeof (GETGROUPS_T));
if (!grouplist)
return -1;
ngroups = getgroups (i, grouplist);
if (i > ngroups)
break;
/* not enough room, so try allocating a larger buffer */
free (grouplist);
i *= 2;
}
if (ngroups < 0) {
free (grouplist);
return -1;
}
added = 0;
for (token = strtok (buf, SEP); token; token = strtok (NULL, SEP)) {
grp = getgrnam (token);
if (!grp) {
fprintf (stderr, _("Warning: unknown group %s\n"),
token);
continue;
}
for (i = 0; i < ngroups && grouplist[i] != grp->gr_gid; i++);
if (i < ngroups)
continue;
if (ngroups >= sysconf (_SC_NGROUPS_MAX)) {
fprintf (stderr, _("Warning: too many groups\n"));
break;
}
tmp = (gid_t *) realloc (grouplist, (ngroups + 1) * sizeof (GETGROUPS_T));
if (!tmp) {
free (grouplist);
return -1;
}
tmp[ngroups++] = grp->gr_gid;
grouplist = tmp;
added++;
}
if (added)
return setgroups (ngroups, grouplist);
return 0;
}
#endif