/*
   Unix SMB/CIFS implementation.

   AIX loadable authentication module, providing identification
   routines against Samba winbind/Windows NT Domain

   Copyright (C) Aaron Collins 2003
   Copyright (C) Timur I. Bakeyev 2013

   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 3 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
   Library General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "winbind_client.h"

/* Make sure that the module gets registered needed by freebsd 5.1 */
extern enum nss_status _nss_winbind_getgrent_r(struct group *, char *, size_t,
    int *);
extern enum nss_status _nss_winbind_getgrnam_r(const char *, struct group *,
    char *, size_t, int *);
extern enum nss_status _nss_winbind_getgrgid_r(gid_t gid, struct group *, char *,
    size_t, int *);
extern enum nss_status _nss_winbind_setgrent(void);
extern enum nss_status _nss_winbind_endgrent(void);
extern enum nss_status _nss_winbind_initgroups_dyn(char *, gid_t, long int *,
    long int *, gid_t **, long int , int *);

extern enum nss_status _nss_winbind_getpwent_r(struct passwd *, char *, size_t,
    int *);
extern enum nss_status _nss_winbind_getpwnam_r(const char *, struct passwd *,
    char *, size_t, int *);
extern enum nss_status _nss_winbind_getpwuid_r(gid_t gid, struct passwd *, char *,
    size_t, int *);
extern enum nss_status _nss_winbind_setpwent(void);
extern enum nss_status _nss_winbind_endpwent(void);
ns_mtab *nss_module_register(const char *, unsigned int *, nss_module_unregister_fn *);

NSS_METHOD_PROTOTYPE(__nss_compat_getgrnam_r);
NSS_METHOD_PROTOTYPE(__nss_compat_getgrgid_r);
NSS_METHOD_PROTOTYPE(__nss_compat_getgrent_r);
NSS_METHOD_PROTOTYPE(__nss_compat_setgrent);
NSS_METHOD_PROTOTYPE(__nss_compat_endgrent);

NSS_METHOD_PROTOTYPE(__nss_compat_getpwnam_r);
NSS_METHOD_PROTOTYPE(__nss_compat_getpwuid_r);
NSS_METHOD_PROTOTYPE(__nss_compat_getpwent_r);
NSS_METHOD_PROTOTYPE(__nss_compat_setpwent);
NSS_METHOD_PROTOTYPE(__nss_compat_endpwent);
NSS_METHOD_PROTOTYPE(__nss_compat_endpwent);

NSS_METHOD_PROTOTYPE(__freebsd_getgroupmembership);

static ns_mtab methods[] = {
{ NSDB_GROUP, "getgrnam_r", __nss_compat_getgrnam_r, _nss_winbind_getgrnam_r },
{ NSDB_GROUP, "getgrgid_r", __nss_compat_getgrgid_r, _nss_winbind_getgrgid_r },
{ NSDB_GROUP, "getgrent_r", __nss_compat_getgrent_r, _nss_winbind_getgrent_r },
{ NSDB_GROUP, "setgrent",   __nss_compat_setgrent,   _nss_winbind_setgrent },
{ NSDB_GROUP, "endgrent",   __nss_compat_endgrent,   _nss_winbind_endgrent },
{ NSDB_GROUP, "getgroupmembership", __freebsd_getgroupmembership, NULL },

{ NSDB_PASSWD, "getpwnam_r", __nss_compat_getpwnam_r, _nss_winbind_getpwnam_r },
{ NSDB_PASSWD, "getpwuid_r", __nss_compat_getpwuid_r, _nss_winbind_getpwuid_r },
{ NSDB_PASSWD, "getpwent_r", __nss_compat_getpwent_r, _nss_winbind_getpwent_r },
{ NSDB_PASSWD, "setpwent",   __nss_compat_setpwent,   _nss_winbind_setpwent },
{ NSDB_PASSWD, "endpwent",   __nss_compat_endpwent,   _nss_winbind_endpwent },

};

/* Taken from libc */
static int
gr_addgid(gid_t gid, gid_t *groups, int maxgrp, int *grpcnt)
{
	int	ret, dupc;

	/* skip duplicates */
	for (dupc = 0; dupc < MIN(maxgrp, *grpcnt); dupc++) {
		if (groups[dupc] == gid)
			return 1;
	}

	ret = 1;
	if (*grpcnt < maxgrp)			/* add this gid */
		groups[*grpcnt] = gid;
	else
		ret = 0;

	(*grpcnt)++;

	return ret;
}

/*
    rv = _nsdispatch(NULL, dtab, NSDB_GROUP, "getgroupmembership",
	            defaultsrc, uname, agroup, groups, maxgrp, grpcnt);
*/

int
__freebsd_getgroupmembership(void *retval, void *mdata, va_list ap)
{
	const char 	*uname  = va_arg(ap, const char *);
	gid_t		 group  = va_arg(ap, gid_t);
	gid_t		*groups = va_arg(ap, gid_t *);
	int		 maxgrp = va_arg(ap, int);
	int		*groupc = va_arg(ap, int *);

	NSS_STATUS ret;
	long int lcount, lsize;
	int i, errnop;
	gid_t *tmpgroups;

	/* Can be realloc() inside _nss_winbind_initgroups_dyn() */
	if ((tmpgroups=calloc(maxgrp, sizeof(gid_t))) == NULL) {
		errno = ENOMEM;
		return NS_TRYAGAIN;
	}

	lcount = 0;
	lsize = maxgrp;
	/* insert primary membership(possibly already there) */
	gr_addgid(group, groups, maxgrp, groupc);
	/* Don't limit number of groups, we want to know total size */
	ret = _nss_winbind_initgroups_dyn(uname, group, &lcount, &lsize,
		&tmpgroups, 0, &errnop);
	if (ret == NSS_STATUS_SUCCESS) {
		/* lcount potentially can be bigger than maxgrp, so would groupc */
		for (i = 0; i < lcount; i++)
			 gr_addgid(tmpgroups[i], groups, maxgrp, groupc);
	}
	free(tmpgroups);
	/* Let following nsswitch backend(s) add more groups(?) */
	return NSS_STATUS_NOTFOUND;
}

ns_mtab *
nss_module_register(const char *source, unsigned int *mtabsize,
    nss_module_unregister_fn *unreg)
{
        *mtabsize = sizeof(methods)/sizeof(methods[0]);
        *unreg = NULL;
        return (methods);
}
