/* 
   Unix SMB/CIFS implementation.

   idmap NSS backend

   Copyright (C) Simo Sorce 2006

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

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

#include "includes.h"
#include "system/passwd.h"
#include "winbindd.h"
#include "nsswitch/winbind_client.h"
#include "idmap.h"
#include "lib/winbind_util.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_IDMAP

/*****************************
 Initialise idmap database.
*****************************/

static NTSTATUS idmap_nss_int_init(struct idmap_domain *dom)
{
	return NT_STATUS_OK;
}

/**********************************
 lookup a set of unix ids.
**********************************/

static NTSTATUS idmap_nss_unixids_to_sids(struct idmap_domain *dom, struct id_map **ids)
{
	int i;

	/* initialize the status to avoid suprise */
	for (i = 0; ids[i]; i++) {
		ids[i]->status = ID_UNKNOWN;
	}

	for (i = 0; ids[i]; i++) {
		struct passwd *pw;
		struct group *gr;
		const char *name;
		enum lsa_SidType type;
		bool ret;

		switch (ids[i]->xid.type) {
		case ID_TYPE_UID:
			pw = getpwuid((uid_t)ids[i]->xid.id);

			if (!pw) {
				ids[i]->status = ID_UNMAPPED;
				continue;
			}
			name = pw->pw_name;
			break;
		case ID_TYPE_GID:
			gr = getgrgid((gid_t)ids[i]->xid.id);

			if (!gr) {
				ids[i]->status = ID_UNMAPPED;
				continue;
			}
			name = gr->gr_name;
			break;
		default: /* ?? */
			ids[i]->status = ID_UNKNOWN;
			continue;
		}

		/* by default calls to winbindd are disabled
		   the following call will not recurse so this is safe */
		(void)winbind_on();
		/* Lookup name from PDC using lsa_lookup_names() */
		ret = winbind_lookup_name(dom->name, name, ids[i]->sid, &type);
		(void)winbind_off();

		if (!ret) {
			/* TODO: how do we know if the name is really not mapped,
			 * or something just failed ? */
			ids[i]->status = ID_UNMAPPED;
			continue;
		}

		switch (type) {
		case SID_NAME_USER:
			if (ids[i]->xid.type == ID_TYPE_UID) {
				ids[i]->status = ID_MAPPED;
			}
			break;

		case SID_NAME_DOM_GRP:
		case SID_NAME_ALIAS:
		case SID_NAME_WKN_GRP:
			if (ids[i]->xid.type == ID_TYPE_GID) {
				ids[i]->status = ID_MAPPED;
			}
			break;

		default:
			ids[i]->status = ID_UNKNOWN;
			break;
		}
	}
	return NT_STATUS_OK;
}

/**********************************
 lookup a set of sids.
**********************************/

static NTSTATUS idmap_nss_sids_to_unixids(struct idmap_domain *dom, struct id_map **ids)
{
	int i;

	/* initialize the status to avoid suprise */
	for (i = 0; ids[i]; i++) {
		ids[i]->status = ID_UNKNOWN;
	}

	for (i = 0; ids[i]; i++) {
		struct group *gr;
		enum lsa_SidType type;
		const char *p = NULL;
		char *name = NULL;
		bool ret;

		/* by default calls to winbindd are disabled
		   the following call will not recurse so this is safe */
		(void)winbind_on();
		ret = winbind_lookup_sid(talloc_tos(), ids[i]->sid, NULL,
					 &p, &type);
		(void)winbind_off();
		name = discard_const_p(char, p);

		if (!ret) {
			/* TODO: how do we know if the name is really not mapped,
			 * or something just failed ? */
			ids[i]->status = ID_UNMAPPED;
			continue;
		}

		switch (type) {
		case SID_NAME_USER: {
			struct passwd *pw;

			/* this will find also all lower case name and use username level */

			pw = Get_Pwnam_alloc(talloc_tos(), name);
			if (pw) {
				ids[i]->xid.id = pw->pw_uid;
				ids[i]->xid.type = ID_TYPE_UID;
				ids[i]->status = ID_MAPPED;
			}
			TALLOC_FREE(pw);
			break;
		}

		case SID_NAME_DOM_GRP:
		case SID_NAME_ALIAS:
		case SID_NAME_WKN_GRP:

			gr = getgrnam(name);
			if (gr) {
				ids[i]->xid.id = gr->gr_gid;
				ids[i]->xid.type = ID_TYPE_GID;
				ids[i]->status = ID_MAPPED;
			}
			break;

		default:
			ids[i]->status = ID_UNKNOWN;
			break;
		}
		TALLOC_FREE(name);
	}
	return NT_STATUS_OK;
}

/**********************************
 Close the idmap tdb instance
**********************************/

static struct idmap_methods nss_methods = {

	.init = idmap_nss_int_init,
	.unixids_to_sids = idmap_nss_unixids_to_sids,
	.sids_to_unixids = idmap_nss_sids_to_unixids,
};

NTSTATUS idmap_nss_init(TALLOC_CTX *mem_ctx)
{
	return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION, "nss", &nss_methods);
}