/* SNMP support
 * Copyright (C) 1999 Kunihiro Ishiguro <kunihiro@zebra.org>
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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 2, or (at your option) any
 * later version.
 *
 * GNU Zebra 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; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>

#include "smux.h"

#define min(A,B) ((A) < (B) ? (A) : (B))

int oid_compare(const oid *o1, int o1_len, const oid *o2, int o2_len)
{
	int i;

	for (i = 0; i < min(o1_len, o2_len); i++) {
		if (o1[i] < o2[i])
			return -1;
		else if (o1[i] > o2[i])
			return 1;
	}
	if (o1_len < o2_len)
		return -1;
	if (o1_len > o2_len)
		return 1;

	return 0;
}

void *oid_copy(void *dest, const void *src, size_t size)
{
	return memcpy(dest, src, size * sizeof(oid));
}

void oid2in_addr(oid oid[], int len, struct in_addr *addr)
{
	int i;
	uint8_t *pnt;

	if (len == 0)
		return;

	pnt = (uint8_t *)addr;

	for (i = 0; i < len; i++)
		*pnt++ = oid[i];
}

void oid_copy_addr(oid oid[], const struct in_addr *addr, int len)
{
	int i;
	const uint8_t *pnt;

	if (len == 0)
		return;

	pnt = (uint8_t *)addr;

	for (i = 0; i < len; i++)
		oid[i] = *pnt++;
}

int smux_header_generic(struct variable *v, oid *name, size_t *length,
			int exact, size_t *var_len, WriteMethod **write_method)
{
	oid fulloid[MAX_OID_LEN];
	int ret;

	oid_copy(fulloid, v->name, v->namelen);
	fulloid[v->namelen] = 0;
	/* Check against full instance. */
	ret = oid_compare(name, *length, fulloid, v->namelen + 1);

	/* Check single instance. */
	if ((exact && (ret != 0)) || (!exact && (ret >= 0)))
		return MATCH_FAILED;

	/* In case of getnext, fill in full instance. */
	memcpy(name, fulloid, (v->namelen + 1) * sizeof(oid));
	*length = v->namelen + 1;

	*write_method = 0;
	*var_len = sizeof(long); /* default to 'long' results */

	return MATCH_SUCCEEDED;
}

int smux_header_table(struct variable *v, oid *name, size_t *length, int exact,
		      size_t *var_len, WriteMethod **write_method)
{
	/* If the requested OID name is less than OID prefix we
	   handle, adjust it to our prefix. */
	if ((oid_compare(name, *length, v->name, v->namelen)) < 0) {
		if (exact)
			return MATCH_FAILED;
		oid_copy(name, v->name, v->namelen);
		*length = v->namelen;
	}

	*write_method = 0;
	*var_len = sizeof(long);

	return MATCH_SUCCEEDED;
}