1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
  4 *
  5 * Development of this code funded by Astaro AG (http://www.astaro.com/)
  6 */
  7
  8#include <linux/kernel.h>
  9#include <linux/init.h>
 10#include <linux/module.h>
 11#include <linux/netlink.h>
 12#include <linux/netfilter.h>
 13#include <linux/netfilter/nf_tables.h>
 14#include <net/netfilter/nf_tables_core.h>
 15#include <net/netfilter/nf_tables.h>
 16#include <net/netfilter/nf_tables_offload.h>
 17
 18void nft_immediate_eval(const struct nft_expr *expr,
 19			struct nft_regs *regs,
 20			const struct nft_pktinfo *pkt)
 21{
 22	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 23
 24	nft_data_copy(&regs->data[priv->dreg], &priv->data, priv->dlen);
 25}
 26
 27static const struct nla_policy nft_immediate_policy[NFTA_IMMEDIATE_MAX + 1] = {
 28	[NFTA_IMMEDIATE_DREG]	= { .type = NLA_U32 },
 29	[NFTA_IMMEDIATE_DATA]	= { .type = NLA_NESTED },
 30};
 31
 32static int nft_immediate_init(const struct nft_ctx *ctx,
 33			      const struct nft_expr *expr,
 34			      const struct nlattr * const tb[])
 35{
 36	struct nft_immediate_expr *priv = nft_expr_priv(expr);
 37	struct nft_data_desc desc;
 38	int err;
 39
 40	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
 41	    tb[NFTA_IMMEDIATE_DATA] == NULL)
 42		return -EINVAL;
 43
 44	err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
 45			    tb[NFTA_IMMEDIATE_DATA]);
 46	if (err < 0)
 47		return err;
 48
 49	priv->dlen = desc.len;
 50
 51	err = nft_parse_register_store(ctx, tb[NFTA_IMMEDIATE_DREG],
 52				       &priv->dreg, &priv->data, desc.type,
 53				       desc.len);
 54	if (err < 0)
 55		goto err1;
 56
 57	if (priv->dreg == NFT_REG_VERDICT) {
 58		struct nft_chain *chain = priv->data.verdict.chain;
 59
 60		switch (priv->data.verdict.code) {
 61		case NFT_JUMP:
 62		case NFT_GOTO:
 63			if (nft_chain_is_bound(chain)) {
 64				err = -EBUSY;
 65				goto err1;
 66			}
 67			chain->bound = true;
 68			break;
 69		default:
 70			break;
 71		}
 72	}
 73
 74	return 0;
 75
 76err1:
 77	nft_data_release(&priv->data, desc.type);
 78	return err;
 79}
 80
 81static void nft_immediate_activate(const struct nft_ctx *ctx,
 82				   const struct nft_expr *expr)
 83{
 84	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 85
 86	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
 87}
 88
 89static void nft_immediate_deactivate(const struct nft_ctx *ctx,
 90				     const struct nft_expr *expr,
 91				     enum nft_trans_phase phase)
 92{
 93	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
 94
 95	if (phase == NFT_TRANS_COMMIT)
 96		return;
 97
 98	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
 99}
100
101static void nft_immediate_destroy(const struct nft_ctx *ctx,
102				  const struct nft_expr *expr)
103{
104	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
105	const struct nft_data *data = &priv->data;
106	struct nft_rule *rule, *n;
107	struct nft_ctx chain_ctx;
108	struct nft_chain *chain;
109
110	if (priv->dreg != NFT_REG_VERDICT)
111		return;
112
113	switch (data->verdict.code) {
114	case NFT_JUMP:
115	case NFT_GOTO:
116		chain = data->verdict.chain;
117
118		if (!nft_chain_is_bound(chain))
119			break;
120
121		chain_ctx = *ctx;
122		chain_ctx.chain = chain;
123
124		list_for_each_entry_safe(rule, n, &chain->rules, list)
125			nf_tables_rule_release(&chain_ctx, rule);
126
127		nf_tables_chain_destroy(&chain_ctx);
128		break;
129	default:
130		break;
131	}
132}
133
134static int nft_immediate_dump(struct sk_buff *skb, const struct nft_expr *expr)
135{
136	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
137
138	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
139		goto nla_put_failure;
140
141	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
142			     nft_dreg_to_type(priv->dreg), priv->dlen);
143
144nla_put_failure:
145	return -1;
146}
147
148static int nft_immediate_validate(const struct nft_ctx *ctx,
149				  const struct nft_expr *expr,
150				  const struct nft_data **d)
151{
152	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
153	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
154	const struct nft_data *data;
155	int err;
156
157	if (priv->dreg != NFT_REG_VERDICT)
158		return 0;
159
160	data = &priv->data;
161
162	switch (data->verdict.code) {
163	case NFT_JUMP:
164	case NFT_GOTO:
165		pctx->level++;
166		err = nft_chain_validate(ctx, data->verdict.chain);
167		if (err < 0)
168			return err;
169		pctx->level--;
170		break;
171	default:
172		break;
173	}
174
175	return 0;
176}
177
178static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
179					 struct nft_flow_rule *flow,
180					 const struct nft_immediate_expr *priv)
181{
182	struct flow_action_entry *entry;
183	const struct nft_data *data;
184
185	entry = &flow->rule->action.entries[ctx->num_actions++];
186
187	data = &priv->data;
188	switch (data->verdict.code) {
189	case NF_ACCEPT:
190		entry->id = FLOW_ACTION_ACCEPT;
191		break;
192	case NF_DROP:
193		entry->id = FLOW_ACTION_DROP;
194		break;
195	default:
196		return -EOPNOTSUPP;
197	}
198
199	return 0;
200}
201
202static int nft_immediate_offload(struct nft_offload_ctx *ctx,
203				 struct nft_flow_rule *flow,
204				 const struct nft_expr *expr)
205{
206	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
207
208	if (priv->dreg == NFT_REG_VERDICT)
209		return nft_immediate_offload_verdict(ctx, flow, priv);
210
211	memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));
212
213	return 0;
214}
215
216static const struct nft_expr_ops nft_imm_ops = {
217	.type		= &nft_imm_type,
218	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
219	.eval		= nft_immediate_eval,
220	.init		= nft_immediate_init,
221	.activate	= nft_immediate_activate,
222	.deactivate	= nft_immediate_deactivate,
223	.destroy	= nft_immediate_destroy,
224	.dump		= nft_immediate_dump,
225	.validate	= nft_immediate_validate,
226	.offload	= nft_immediate_offload,
227	.offload_flags	= NFT_OFFLOAD_F_ACTION,
228};
229
230struct nft_expr_type nft_imm_type __read_mostly = {
231	.name		= "immediate",
232	.ops		= &nft_imm_ops,
233	.policy		= nft_immediate_policy,
234	.maxattr	= NFTA_IMMEDIATE_MAX,
235	.owner		= THIS_MODULE,
236};