path: root/src/expr/dynset.c

/*
 * Copyright (c) 2014, 2015 Patrick McHardy <kaber@trash.net>
 *
 * 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 2 of the License, or
 * (at your option) any later version.
 */

#include "internal.h"

#include <stdio.h>
#include <stdint.h>
#include <inttypes.h>
#include <errno.h>
#include <arpa/inet.h>
#include <libmnl/libmnl.h>
#include <linux/netfilter/nf_tables.h>
#include <libnftnl/rule.h>
#include <libnftnl/expr.h>
#include "data_reg.h"
#include "expr_ops.h"

struct nftnl_expr_dynset {
	enum nft_registers	sreg_key;
	enum nft_registers	sreg_data;
	enum nft_dynset_ops	op;
	uint64_t		timeout;
	struct list_head	expr_list;
	char			*set_name;
	uint32_t		set_id;
	uint32_t		dynset_flags;
};

static int
nftnl_expr_dynset_set(struct nftnl_expr *e, uint16_t type,
			 const void *data, uint32_t data_len)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nftnl_expr *expr, *next;

	switch (type) {
	case NFTNL_EXPR_DYNSET_SREG_KEY:
		memcpy(&dynset->sreg_key, data, sizeof(dynset->sreg_key));
		break;
	case NFTNL_EXPR_DYNSET_SREG_DATA:
		memcpy(&dynset->sreg_data, data, sizeof(dynset->sreg_data));
		break;
	case NFTNL_EXPR_DYNSET_OP:
		memcpy(&dynset->op, data, sizeof(dynset->op));
		break;
	case NFTNL_EXPR_DYNSET_TIMEOUT:
		memcpy(&dynset->timeout, data, sizeof(dynset->timeout));
		break;
	case NFTNL_EXPR_DYNSET_SET_NAME:
		dynset->set_name = strdup((const char *)data);
		if (!dynset->set_name)
			return -1;
		break;
	case NFTNL_EXPR_DYNSET_SET_ID:
		memcpy(&dynset->set_id, data, sizeof(dynset->set_id));
		break;
	case NFTNL_EXPR_DYNSET_EXPR:
		list_for_each_entry_safe(expr, next, &dynset->expr_list, head)
			nftnl_expr_free(expr);

		expr = (void *)data;
		list_add(&expr->head, &dynset->expr_list);
		break;
	case NFTNL_EXPR_DYNSET_FLAGS:
		memcpy(&dynset->dynset_flags, data, sizeof(dynset->dynset_flags));
		break;
	default:
		return -1;
	}
	return 0;
}

static const void *
nftnl_expr_dynset_get(const struct nftnl_expr *e, uint16_t type,
			 uint32_t *data_len)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nftnl_expr *expr;

	switch (type) {
	case NFTNL_EXPR_DYNSET_SREG_KEY:
		*data_len = sizeof(dynset->sreg_key);
		return &dynset->sreg_key;
	case NFTNL_EXPR_DYNSET_SREG_DATA:
		*data_len = sizeof(dynset->sreg_data);
		return &dynset->sreg_data;
	case NFTNL_EXPR_DYNSET_OP:
		*data_len = sizeof(dynset->op);
		return &dynset->op;
	case NFTNL_EXPR_DYNSET_TIMEOUT:
		*data_len = sizeof(dynset->timeout);
		return &dynset->timeout;
	case NFTNL_EXPR_DYNSET_SET_NAME:
		*data_len = strlen(dynset->set_name) + 1;
		return dynset->set_name;
	case NFTNL_EXPR_DYNSET_SET_ID:
		*data_len = sizeof(dynset->set_id);
		return &dynset->set_id;
	case NFTNL_EXPR_DYNSET_EXPR:
		list_for_each_entry(expr, &dynset->expr_list, head)
			break;
		return expr;
	case NFTNL_EXPR_DYNSET_FLAGS:
		*data_len = sizeof(dynset->dynset_flags);
		return &dynset->dynset_flags;
	}
	return NULL;
}

static int nftnl_expr_dynset_cb(const struct nlattr *attr, void *data)
{
	const struct nlattr **tb = data;
	int type = mnl_attr_get_type(attr);

	if (mnl_attr_type_valid(attr, NFTA_SET_MAX) < 0)
		return MNL_CB_OK;

	switch (type) {
	case NFTA_DYNSET_SREG_KEY:
	case NFTA_DYNSET_SREG_DATA:
	case NFTA_DYNSET_SET_ID:
	case NFTA_DYNSET_OP:
	case NFTA_DYNSET_FLAGS:
		if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
			abi_breakage();
		break;
	case NFTA_DYNSET_TIMEOUT:
		if (mnl_attr_validate(attr, MNL_TYPE_U64) < 0)
			abi_breakage();
		break;
	case NFTA_DYNSET_SET_NAME:
		if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
			abi_breakage();
		break;
	case NFTA_DYNSET_EXPR:
		if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0)
			abi_breakage();
		break;
	}

	tb[type] = attr;
	return MNL_CB_OK;
}

static void
nftnl_expr_dynset_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nlattr *nest;
	int num_exprs = 0;

	if (e->flags & (1 << NFTNL_EXPR_DYNSET_SREG_KEY))
		mnl_attr_put_u32(nlh, NFTA_DYNSET_SREG_KEY, htonl(dynset->sreg_key));
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_SREG_DATA))
		mnl_attr_put_u32(nlh, NFTA_DYNSET_SREG_DATA, htonl(dynset->sreg_data));
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_OP))
		mnl_attr_put_u32(nlh, NFTA_DYNSET_OP, htonl(dynset->op));
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_TIMEOUT))
		mnl_attr_put_u64(nlh, NFTA_DYNSET_TIMEOUT, htobe64(dynset->timeout));
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_SET_NAME))
		mnl_attr_put_strz(nlh, NFTA_DYNSET_SET_NAME, dynset->set_name);
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_SET_ID))
		mnl_attr_put_u32(nlh, NFTA_DYNSET_SET_ID, htonl(dynset->set_id));
	if (!list_empty(&dynset->expr_list)) {
		struct nftnl_expr *expr;

		list_for_each_entry(expr, &dynset->expr_list, head)
			num_exprs++;

		if (num_exprs == 1) {
			nest = mnl_attr_nest_start(nlh, NFTA_DYNSET_EXPR);
			list_for_each_entry(expr, &dynset->expr_list, head)
				nftnl_expr_build_payload(nlh, expr);
			mnl_attr_nest_end(nlh, nest);
		} else if (num_exprs > 1) {
			struct nlattr *nest1, *nest2;

			nest1 = mnl_attr_nest_start(nlh, NFTA_DYNSET_EXPRESSIONS);
			list_for_each_entry(expr, &dynset->expr_list, head) {
				nest2 = mnl_attr_nest_start(nlh, NFTA_LIST_ELEM);
				nftnl_expr_build_payload(nlh, expr);
				mnl_attr_nest_end(nlh, nest2);
			}
			mnl_attr_nest_end(nlh, nest1);
		}
	}
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_FLAGS))
		mnl_attr_put_u32(nlh, NFTA_DYNSET_FLAGS,
				 htonl(dynset->dynset_flags));
}

EXPORT_SYMBOL(nftnl_expr_add_expr);
void nftnl_expr_add_expr(struct nftnl_expr *e, uint32_t type,
			 struct nftnl_expr *expr)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);

	list_add_tail(&expr->head, &dynset->expr_list);
}

EXPORT_SYMBOL(nftnl_expr_expr_foreach);
int nftnl_expr_expr_foreach(const struct nftnl_expr *e,
			    int (*cb)(struct nftnl_expr *e, void *data),
			    void *data)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nftnl_expr *cur, *tmp;
	int ret;

	list_for_each_entry_safe(cur, tmp, &dynset->expr_list, head) {
		ret = cb(cur, data);
		if (ret < 0)
			return ret;
	}
	return 0;
}

static int
nftnl_expr_dynset_parse(struct nftnl_expr *e, struct nlattr *attr)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nlattr *tb[NFTA_SET_MAX+1] = {};
	struct nftnl_expr *expr, *next;
	int ret = 0;

	if (mnl_attr_parse_nested(attr, nftnl_expr_dynset_cb, tb) < 0)
		return -1;

	if (tb[NFTA_DYNSET_SREG_KEY]) {
		dynset->sreg_key = ntohl(mnl_attr_get_u32(tb[NFTA_DYNSET_SREG_KEY]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_SREG_KEY);
	}
	if (tb[NFTA_DYNSET_SREG_DATA]) {
		dynset->sreg_data = ntohl(mnl_attr_get_u32(tb[NFTA_DYNSET_SREG_DATA]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_SREG_DATA);
	}
	if (tb[NFTA_DYNSET_OP]) {
		dynset->op = ntohl(mnl_attr_get_u32(tb[NFTA_DYNSET_OP]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_OP);
	}
	if (tb[NFTA_DYNSET_TIMEOUT]) {
		dynset->timeout = be64toh(mnl_attr_get_u64(tb[NFTA_DYNSET_TIMEOUT]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_TIMEOUT);
	}
	if (tb[NFTA_DYNSET_SET_NAME]) {
		dynset->set_name =
			strdup(mnl_attr_get_str(tb[NFTA_DYNSET_SET_NAME]));
		if (!dynset->set_name)
			return -1;
		e->flags |= (1 << NFTNL_EXPR_DYNSET_SET_NAME);
	}
	if (tb[NFTA_DYNSET_SET_ID]) {
		dynset->set_id = ntohl(mnl_attr_get_u32(tb[NFTA_DYNSET_SET_ID]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_SET_ID);
	}
	if (tb[NFTA_DYNSET_EXPR]) {
		expr = nftnl_expr_parse(tb[NFTA_DYNSET_EXPR]);
		if (expr == NULL)
			return -1;

		list_add(&expr->head, &dynset->expr_list);
		e->flags |= (1 << NFTNL_EXPR_DYNSET_EXPR);
	} else if (tb[NFTA_DYNSET_EXPRESSIONS]) {
		struct nlattr *attr2;

		mnl_attr_for_each_nested(attr2, tb[NFTA_DYNSET_EXPRESSIONS]) {
			if (mnl_attr_get_type(attr2) != NFTA_LIST_ELEM)
				goto out_dynset_expr;

			expr = nftnl_expr_parse(attr2);
			if (!expr)
				goto out_dynset_expr;

			list_add_tail(&expr->head, &dynset->expr_list);
		}
		e->flags |= (1 << NFTNL_EXPR_DYNSET_EXPRESSIONS);
	}
	if (tb[NFTA_DYNSET_FLAGS]) {
		dynset->dynset_flags = ntohl(mnl_attr_get_u32(tb[NFTA_DYNSET_FLAGS]));
		e->flags |= (1 << NFTNL_EXPR_DYNSET_FLAGS);
	}

	return ret;
out_dynset_expr:
	list_for_each_entry_safe(expr, next, &dynset->expr_list, head)
		nftnl_expr_free(expr);

	return -1;
}

static const char *op2str_array[] = {
	[NFT_DYNSET_OP_ADD]		= "add",
	[NFT_DYNSET_OP_UPDATE] 		= "update",
	[NFT_DYNSET_OP_DELETE]		= "delete",
};

static const char *op2str(enum nft_dynset_ops op)
{
	if (op > NFT_DYNSET_OP_DELETE)
		return "unknown";
	return op2str_array[op];
}

static int
nftnl_expr_dynset_snprintf(char *buf, size_t remain,
			   uint32_t flags, const struct nftnl_expr *e)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nftnl_expr *expr;
	int offset = 0, ret;

	ret = snprintf(buf, remain, "%s reg_key %u set %s ",
		       op2str(dynset->op), dynset->sreg_key, dynset->set_name);
	SNPRINTF_BUFFER_SIZE(ret, remain, offset);

	if (e->flags & (1 << NFTNL_EXPR_DYNSET_SREG_DATA)) {
		ret = snprintf(buf + offset, remain, "sreg_data %u ",
			       dynset->sreg_data);
		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
	}
	if (e->flags & (1 << NFTNL_EXPR_DYNSET_TIMEOUT)) {
		ret = snprintf(buf + offset, remain, "timeout %"PRIu64"ms ",
			       dynset->timeout);
		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
	}
	list_for_each_entry(expr, &dynset->expr_list, head) {
		ret = snprintf(buf + offset, remain, "expr [ %s ",
			       expr->ops->name);
		SNPRINTF_BUFFER_SIZE(ret, remain, offset);

		ret = nftnl_expr_snprintf(buf + offset, remain, expr,
					     NFTNL_OUTPUT_DEFAULT,
					     NFTNL_OF_EVENT_ANY);
		SNPRINTF_BUFFER_SIZE(ret, remain, offset);

		ret = snprintf(buf + offset, remain, "] ");
		SNPRINTF_BUFFER_SIZE(ret, remain, offset);
	}

	return offset;
}

static void nftnl_expr_dynset_init(const struct nftnl_expr *e)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);

	INIT_LIST_HEAD(&dynset->expr_list);
}

static void nftnl_expr_dynset_free(const struct nftnl_expr *e)
{
	struct nftnl_expr_dynset *dynset = nftnl_expr_data(e);
	struct nftnl_expr *expr, *next;

	xfree(dynset->set_name);
	list_for_each_entry_safe(expr, next, &dynset->expr_list, head)
		nftnl_expr_free(expr);
}

struct expr_ops expr_ops_dynset = {
	.name		= "dynset",
	.alloc_len	= sizeof(struct nftnl_expr_dynset),
	.max_attr	= NFTA_DYNSET_MAX,
	.init		= nftnl_expr_dynset_init,
	.free		= nftnl_expr_dynset_free,
	.set		= nftnl_expr_dynset_set,
	.get		= nftnl_expr_dynset_get,
	.parse		= nftnl_expr_dynset_parse,
	.build		= nftnl_expr_dynset_build,
	.output		= nftnl_expr_dynset_snprintf,
};