/*

 * Hash expression definitions.

 *

 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include <nftables.h>

#include <expression.h>

#include <datatype.h>

#include <gmputil.h>

#include <hash.h>

#include <utils.h>

static void hash_expr_print(const struct expr *expr, struct output_ctx *octx)

{

	switch (expr->hash.type) {

	case NFT_HASH_SYM:

		nft_print(octx, "symhash");

		break;

	case NFT_HASH_JENKINS:

	default:

		nft_print(octx, "jhash ");

		expr_print(expr->hash.expr, octx);

	}

	nft_print(octx, " mod %u", expr->hash.mod);

	if (expr->hash.seed_set)

		nft_print(octx, " seed 0x%x", expr->hash.seed);

	if (expr->hash.offset)

		nft_print(octx, " offset %u", expr->hash.offset);

}

static bool hash_expr_cmp(const struct expr *e1, const struct expr *e2)

{

	return (!e1->hash.expr ||

		expr_cmp(e1->hash.expr, e2->hash.expr)) &&

	       e1->hash.mod == e2->hash.mod &&

	       e1->hash.seed_set == e2->hash.seed_set &&

	       e1->hash.seed == e2->hash.seed &&

	       e1->hash.offset == e2->hash.offset &&

	       e1->hash.type == e2->hash.type;

}

static void hash_expr_clone(struct expr *new, const struct expr *expr)

{

	if (expr->hash.expr)

		new->hash.expr = expr_clone(expr->hash.expr);

	new->hash.mod = expr->hash.mod;

	new->hash.seed_set = expr->hash.seed_set;

	new->hash.seed = expr->hash.seed;

	new->hash.offset = expr->hash.offset;

	new->hash.type = expr->hash.type;

}

static void hash_expr_destroy(struct expr *expr)

{

	expr_free(expr->hash.expr);

}

const struct expr_ops hash_expr_ops = {

	.type		= EXPR_HASH,

	.name		= "hash",

	.print		= hash_expr_print,

	.json		= hash_expr_json,

	.cmp		= hash_expr_cmp,

	.clone		= hash_expr_clone,

	.destroy	= hash_expr_destroy,

};

struct expr *hash_expr_alloc(const struct location *loc,

			     uint32_t mod,

			     bool seed_set, uint32_t seed,

			     uint32_t offset,

			     enum nft_hash_types type)

{

	struct expr *expr;

	expr = expr_alloc(loc, EXPR_HASH, &integer_type,

			  BYTEORDER_HOST_ENDIAN, 4 * BITS_PER_BYTE);

	expr->hash.mod  = mod;

	expr->hash.seed_set = seed_set;

	expr->hash.seed = seed;

	expr->hash.offset = offset;

	expr->hash.type = type;

	return expr;

}