net/netfilter/nft_immediate.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  *
  * Development of this code funded by Astaro AG (http://www.astaro.com/)
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/netlink.h>
 #include <linux/netfilter.h>
 #include <linux/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_core.h>
 #include <net/netfilter/nf_tables.h>
 #include <net/netfilter/nf_tables_offload.h>

 void nft_immediate_eval(const struct nft_expr *expr,
 			struct nft_regs *regs,
 			const struct nft_pktinfo *pkt)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

 	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
 }

 static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
 	[NFTA_IMMEDIATE_DREG]	= { .type = NLA_U32 },
 	[NFTA_IMMEDIATE_DATA]	= { .type = NLA_NESTED },
 };

 static enum nft_data_types nft_reg_to_type(const struct nlattr *nla)
 {
 	enum nft_data_types type;
 	u8 reg;

 	reg = ntohl(nla_get_be32(nla));
 	if (reg == NFT_REG_VERDICT)
 		type = NFT_DATA_VERDICT;
 	else
 		type = NFT_DATA_VALUE;

 	return type;
 }

 static int nft_immediate_init(const struct nft_ctx *ctx,
 			      const struct nft_expr *expr,
 			      const struct nlattr * const tb[])
 {
 	struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	struct nft_data_desc desc = {
 		.size	= sizeof(priv->data),
 	};
 	int err;

 	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
 	    tb[NFTA_IMMEDIATE_DATA] == NULL)
 		return -EINVAL;

 	desc.type = nft_reg_to_type(tb[NFTA_IMMEDIATE_DREG]);
 	err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]);
 	if (err < 0)
 		return err;

 	priv->dlen = desc.len;

 	err = nft_parse_register_store(ctx, tb[NFTA_IMMEDIATE_DREG],
 				       &priv->dreg, &priv->data, desc.type,
 				       desc.len);
 	if (err < 0)
 		goto err1;

 	if (priv->dreg == NFT_REG_VERDICT) {
 		struct nft_chain *chain = priv->data.verdict.chain;

 		switch (priv->data.verdict.code) {
 		case NFT_JUMP:
 		case NFT_GOTO:
 			err = nf_tables_bind_chain(ctx, chain);
 			if (err < 0)
 				goto err1;
 			break;
 		default:
 			break;
 		}
 	}

 	return 0;

 err1:
 	nft_data_release(&priv->data, desc.type);
 	return err;
 }

 static void nft_immediate_activate(const struct nft_ctx *ctx,
 				   const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	const struct nft_data *data = &priv->data;
 	struct nft_ctx chain_ctx;
 	struct nft_chain *chain;
 	struct nft_rule *rule;

 	if (priv->dreg == NFT_REG_VERDICT) {
 		switch (data->verdict.code) {
 		case NFT_JUMP:
 		case NFT_GOTO:
 			chain = data->verdict.chain;
 			if (!nft_chain_binding(chain))
 				break;

 			chain_ctx = *ctx;
 			chain_ctx.chain = chain;

 			list_for_each_entry(rule, &chain->rules, list)
 				nft_rule_expr_activate(&chain_ctx, rule);

 			nft_clear(ctx->net, chain);
 			break;
 		default:
 			break;
 		}
 	}

 	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
 }

 static void nft_immediate_chain_deactivate(const struct nft_ctx *ctx,
 					   struct nft_chain *chain,
 					   enum nft_trans_phase phase)
 {
 	struct nft_ctx chain_ctx;
 	struct nft_rule *rule;

 	chain_ctx = *ctx;
 	chain_ctx.chain = chain;

 	list_for_each_entry(rule, &chain->rules, list)
 		nft_rule_expr_deactivate(&chain_ctx, rule, phase);
 }

 static void nft_immediate_deactivate(const struct nft_ctx *ctx,
 				     const struct nft_expr *expr,
 				     enum nft_trans_phase phase)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	const struct nft_data *data = &priv->data;
 	struct nft_chain *chain;

 	if (priv->dreg == NFT_REG_VERDICT) {
 		switch (data->verdict.code) {
 		case NFT_JUMP:
 		case NFT_GOTO:
 			chain = data->verdict.chain;
 			if (!nft_chain_binding(chain))
 				break;

 			switch (phase) {
 			case NFT_TRANS_PREPARE_ERROR:
 				nf_tables_unbind_chain(ctx, chain);
 				nft_deactivate_next(ctx->net, chain);
 				break;
 			case NFT_TRANS_PREPARE:
 				nft_immediate_chain_deactivate(ctx, chain, phase);
 				nft_deactivate_next(ctx->net, chain);
 				break;
 			default:
 				nft_immediate_chain_deactivate(ctx, chain, phase);
 				nft_chain_del(chain);
 				chain->bound = false;
 				nft_use_dec(&chain->table->use);
 				break;
 			}
 			break;
 		default:
 			break;
 		}
 	}

 	if (phase == NFT_TRANS_COMMIT)
 		return;

 	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
 }

 static void nft_immediate_destroy(const struct nft_ctx *ctx,
 				  const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	const struct nft_data *data = &priv->data;
 	struct nft_rule *rule, *n;
 	struct nft_ctx chain_ctx;
 	struct nft_chain *chain;

 	if (priv->dreg != NFT_REG_VERDICT)
 		return;

 	switch (data->verdict.code) {
 	case NFT_JUMP:
 	case NFT_GOTO:
 		chain = data->verdict.chain;

 		if (!nft_chain_binding(chain))
 			break;

 		/* Rule construction failed, but chain is already bound:
 		 * let the transaction records release this chain and its rules.
 		 */
 		if (chain->bound) {
 			nft_use_dec(&chain->use);
 			break;
 		}

 		/* Rule has been deleted, release chain and its rules. */
 		chain_ctx = *ctx;
 		chain_ctx.chain = chain;

 		nft_use_dec(&chain->use);
 		list_for_each_entry_safe(rule, n, &chain->rules, list) {
 			nft_use_dec(&chain->use);
 			list_del(&rule->list);
 			nf_tables_rule_destroy(&chain_ctx, rule);
 		}
 		nf_tables_chain_destroy(chain);
 		break;
 	default:
 		break;
 	}
 }

 static int nft_immediate_dump(struct sk_buff *skb,
 			      const struct nft_expr *expr, bool reset)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

 	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
 		goto nla_put_failure;

 	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
 			     nft_dreg_to_type(priv->dreg), priv->dlen);

 nla_put_failure:
 	return -1;
 }

 static int nft_immediate_validate(const struct nft_ctx *ctx,
 				  const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
 	const struct nft_data *data;
 	int err;

 	if (priv->dreg != NFT_REG_VERDICT)
 		return 0;

 	data = &priv->data;

 	switch (data->verdict.code) {
 	case NFT_JUMP:
 	case NFT_GOTO:
 		pctx->level++;
 		err = nft_chain_validate(ctx, data->verdict.chain);
 		if (err < 0)
 			return err;
 		pctx->level--;
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
 					 struct nft_flow_rule *flow,
 					 const struct nft_immediate_expr *priv)
 {
 	struct flow_action_entry *entry;
 	const struct nft_data *data;

 	entry = &flow->rule->action.entries[ctx->num_actions++];

 	data = &priv->data;
 	switch (data->verdict.code) {
 	case NF_ACCEPT:
 		entry->id = FLOW_ACTION_ACCEPT;
 		break;
 	case NF_DROP:
 		entry->id = FLOW_ACTION_DROP;
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}

 	return 0;
 }

 static int nft_immediate_offload(struct nft_offload_ctx *ctx,
 				 struct nft_flow_rule *flow,
 				 const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

 	if (priv->dreg == NFT_REG_VERDICT)
 		return nft_immediate_offload_verdict(ctx, flow, priv);

 	memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));

 	return 0;
 }

 static bool nft_immediate_offload_action(const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

 	if (priv->dreg == NFT_REG_VERDICT)
 		return true;

 	return false;
 }

 static bool nft_immediate_reduce(struct nft_regs_track *track,
 				 const struct nft_expr *expr)
 {
 	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

 	if (priv->dreg != NFT_REG_VERDICT)
 		nft_reg_track_cancel(track, priv->dreg, priv->dlen);

 	return false;
 }

 static const struct nft_expr_ops nft_imm_ops = {
 	.type		= &nft_imm_type,
 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
 	.eval		= nft_immediate_eval,
 	.init		= nft_immediate_init,
 	.activate	= nft_immediate_activate,
 	.deactivate	= nft_immediate_deactivate,
 	.destroy	= nft_immediate_destroy,
 	.dump		= nft_immediate_dump,
 	.validate	= nft_immediate_validate,
 	.reduce		= nft_immediate_reduce,
 	.offload	= nft_immediate_offload,
 	.offload_action	= nft_immediate_offload_action,
 };

 struct nft_expr_type nft_imm_type __read_mostly = {
 	.name		= "immediate",
 	.ops		= &nft_imm_ops,
 	.policy		= nft_immediate_policy,
 	.maxattr	= NFTA_IMMEDIATE_MAX,
 	.owner		= THIS_MODULE,
 };
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
	*
	* Development of this code funded by Astaro AG (http://www.astaro.com/)
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/netlink.h>
	#include <linux/netfilter.h>
	#include <linux/netfilter/nf_tables.h>
	#include <net/netfilter/nf_tables_core.h>
	#include <net/netfilter/nf_tables.h>
	#include <net/netfilter/nf_tables_offload.h>

	void nft_immediate_eval(const struct nft_expr *expr,
	struct nft_regs *regs,
	const struct nft_pktinfo *pkt)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
	}

	static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
	[NFTA_IMMEDIATE_DREG] = { .type = NLA_U32 },
	[NFTA_IMMEDIATE_DATA] = { .type = NLA_NESTED },
	};

	static enum nft_data_types nft_reg_to_type(const struct nlattr *nla)
	{
	enum nft_data_types type;
	u8 reg;

	reg = ntohl(nla_get_be32(nla));
	if (reg == NFT_REG_VERDICT)
	type = NFT_DATA_VERDICT;
	else
	type = NFT_DATA_VALUE;

	return type;
	}

	static int nft_immediate_init(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	const struct nlattr * const tb[])
	{
	struct nft_immediate_expr *priv = nft_expr_priv(expr);
	struct nft_data_desc desc = {
	.size = sizeof(priv->data),
	};
	int err;

	if (tb[NFTA_IMMEDIATE_DREG] == NULL \|\|
	tb[NFTA_IMMEDIATE_DATA] == NULL)
	return -EINVAL;

	desc.type = nft_reg_to_type(tb[NFTA_IMMEDIATE_DREG]);
	err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]);
	if (err < 0)
	return err;

	priv->dlen = desc.len;

	err = nft_parse_register_store(ctx, tb[NFTA_IMMEDIATE_DREG],
	&priv->dreg, &priv->data, desc.type,
	desc.len);
	if (err < 0)
	goto err1;

	if (priv->dreg == NFT_REG_VERDICT) {
	struct nft_chain *chain = priv->data.verdict.chain;

	switch (priv->data.verdict.code) {
	case NFT_JUMP:
	case NFT_GOTO:
	err = nf_tables_bind_chain(ctx, chain);
	if (err < 0)
	goto err1;
	break;
	default:
	break;
	}
	}

	return 0;

	err1:
	nft_data_release(&priv->data, desc.type);
	return err;
	}

	static void nft_immediate_activate(const struct nft_ctx *ctx,
	const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
	const struct nft_data *data = &priv->data;
	struct nft_ctx chain_ctx;
	struct nft_chain *chain;
	struct nft_rule *rule;

	if (priv->dreg == NFT_REG_VERDICT) {
	switch (data->verdict.code) {
	case NFT_JUMP:
	case NFT_GOTO:
	chain = data->verdict.chain;
	if (!nft_chain_binding(chain))
	break;

	chain_ctx = *ctx;
	chain_ctx.chain = chain;

	list_for_each_entry(rule, &chain->rules, list)
	nft_rule_expr_activate(&chain_ctx, rule);

	nft_clear(ctx->net, chain);
	break;
	default:
	break;
	}
	}

	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
	}

	static void nft_immediate_chain_deactivate(const struct nft_ctx *ctx,
	struct nft_chain *chain,
	enum nft_trans_phase phase)
	{
	struct nft_ctx chain_ctx;
	struct nft_rule *rule;

	chain_ctx = *ctx;
	chain_ctx.chain = chain;

	list_for_each_entry(rule, &chain->rules, list)
	nft_rule_expr_deactivate(&chain_ctx, rule, phase);
	}

	static void nft_immediate_deactivate(const struct nft_ctx *ctx,
	const struct nft_expr *expr,
	enum nft_trans_phase phase)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
	const struct nft_data *data = &priv->data;
	struct nft_chain *chain;

	if (priv->dreg == NFT_REG_VERDICT) {
	switch (data->verdict.code) {
	case NFT_JUMP:
	case NFT_GOTO:
	chain = data->verdict.chain;
	if (!nft_chain_binding(chain))
	break;

	switch (phase) {
	case NFT_TRANS_PREPARE_ERROR:
	nf_tables_unbind_chain(ctx, chain);
	nft_deactivate_next(ctx->net, chain);
	break;
	case NFT_TRANS_PREPARE:
	nft_immediate_chain_deactivate(ctx, chain, phase);
	nft_deactivate_next(ctx->net, chain);
	break;
	default:
	nft_immediate_chain_deactivate(ctx, chain, phase);
	nft_chain_del(chain);
	chain->bound = false;
	nft_use_dec(&chain->table->use);
	break;
	}
	break;
	default:
	break;
	}
	}

	if (phase == NFT_TRANS_COMMIT)
	return;

	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
	}

	static void nft_immediate_destroy(const struct nft_ctx *ctx,
	const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
	const struct nft_data *data = &priv->data;
	struct nft_rule rule, n;
	struct nft_ctx chain_ctx;
	struct nft_chain *chain;

	if (priv->dreg != NFT_REG_VERDICT)
	return;

	switch (data->verdict.code) {
	case NFT_JUMP:
	case NFT_GOTO:
	chain = data->verdict.chain;

	if (!nft_chain_binding(chain))
	break;

	/* Rule construction failed, but chain is already bound:
	* let the transaction records release this chain and its rules.
	*/
	if (chain->bound) {
	nft_use_dec(&chain->use);
	break;
	}

	/* Rule has been deleted, release chain and its rules. */
	chain_ctx = *ctx;
	chain_ctx.chain = chain;

	nft_use_dec(&chain->use);
	list_for_each_entry_safe(rule, n, &chain->rules, list) {
	nft_use_dec(&chain->use);
	list_del(&rule->list);
	nf_tables_rule_destroy(&chain_ctx, rule);
	}
	nf_tables_chain_destroy(chain);
	break;
	default:
	break;
	}
	}

	static int nft_immediate_dump(struct sk_buff *skb,
	const struct nft_expr *expr, bool reset)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
	goto nla_put_failure;

	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
	nft_dreg_to_type(priv->dreg), priv->dlen);

	nla_put_failure:
	return -1;
	}

	static int nft_immediate_validate(const struct nft_ctx *ctx,
	const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
	struct nft_ctx pctx = (struct nft_ctx )ctx;
	const struct nft_data *data;
	int err;

	if (priv->dreg != NFT_REG_VERDICT)
	return 0;

	data = &priv->data;

	switch (data->verdict.code) {
	case NFT_JUMP:
	case NFT_GOTO:
	pctx->level++;
	err = nft_chain_validate(ctx, data->verdict.chain);
	if (err < 0)
	return err;
	pctx->level--;
	break;
	default:
	break;
	}

	return 0;
	}

	static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
	struct nft_flow_rule *flow,
	const struct nft_immediate_expr *priv)
	{
	struct flow_action_entry *entry;
	const struct nft_data *data;

	entry = &flow->rule->action.entries[ctx->num_actions++];

	data = &priv->data;
	switch (data->verdict.code) {
	case NF_ACCEPT:
	entry->id = FLOW_ACTION_ACCEPT;
	break;
	case NF_DROP:
	entry->id = FLOW_ACTION_DROP;
	break;
	default:
	return -EOPNOTSUPP;
	}

	return 0;
	}

	static int nft_immediate_offload(struct nft_offload_ctx *ctx,
	struct nft_flow_rule *flow,
	const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

	if (priv->dreg == NFT_REG_VERDICT)
	return nft_immediate_offload_verdict(ctx, flow, priv);

	memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));

	return 0;
	}

	static bool nft_immediate_offload_action(const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

	if (priv->dreg == NFT_REG_VERDICT)
	return true;

	return false;
	}

	static bool nft_immediate_reduce(struct nft_regs_track *track,
	const struct nft_expr *expr)
	{
	const struct nft_immediate_expr *priv = nft_expr_priv(expr);

	if (priv->dreg != NFT_REG_VERDICT)
	nft_reg_track_cancel(track, priv->dreg, priv->dlen);

	return false;
	}

	static const struct nft_expr_ops nft_imm_ops = {
	.type = &nft_imm_type,
	.size = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
	.eval = nft_immediate_eval,
	.init = nft_immediate_init,
	.activate = nft_immediate_activate,
	.deactivate = nft_immediate_deactivate,
	.destroy = nft_immediate_destroy,
	.dump = nft_immediate_dump,
	.validate = nft_immediate_validate,
	.reduce = nft_immediate_reduce,
	.offload = nft_immediate_offload,
	.offload_action = nft_immediate_offload_action,
	};

	struct nft_expr_type nft_imm_type __read_mostly = {
	.name = "immediate",
	.ops = &nft_imm_ops,
	.policy = nft_immediate_policy,
	.maxattr = NFTA_IMMEDIATE_MAX,
	.owner = THIS_MODULE,
	};