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 enum nft_data_types nft_reg_to_type(const struct nlattr *nla)
 33{
 34	enum nft_data_types type;
 35	u8 reg;
 36
 37	reg = ntohl(nla_get_be32(nla));
 38	if (reg == NFT_REG_VERDICT)
 39		type = NFT_DATA_VERDICT;
 40	else
 41		type = NFT_DATA_VALUE;
 42
 43	return type;
 44}
 45
 46static int nft_immediate_init(const struct nft_ctx *ctx,
 47			      const struct nft_expr *expr,
 48			      const struct nlattr * const tb[])
 49{
 50	struct nft_immediate_expr *priv = nft_expr_priv(expr);
 51	struct nft_data_desc desc = {
 52		.size	= sizeof(priv->data),
 53	};
 54	int err;
 55
 56	if (tb[NFTA_IMMEDIATE_DREG] == NULL ||
 57	    tb[NFTA_IMMEDIATE_DATA] == NULL)
 58		return -EINVAL;
 59
 60	desc.type = nft_reg_to_type(tb[NFTA_IMMEDIATE_DREG]);
 61	err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]);
 62	if (err < 0)
 63		return err;
 64
 65	priv->dlen = desc.len;
 66
 67	err = nft_parse_register_store(ctx, tb[NFTA_IMMEDIATE_DREG],
 68				       &priv->dreg, &priv->data, desc.type,
 69				       desc.len);
 70	if (err < 0)
 71		goto err1;
 72
 73	if (priv->dreg == NFT_REG_VERDICT) {
 74		struct nft_chain *chain = priv->data.verdict.chain;
 75
 76		switch (priv->data.verdict.code) {
 77		case NFT_JUMP:
 78		case NFT_GOTO:
 79			if (nft_chain_is_bound(chain)) {
 80				err = -EBUSY;
 81				goto err1;
 82			}
 83			chain->bound = true;
 84			break;
 85		default:
 86			break;
 87		}
 88	}
 89
 90	return 0;
 91
 92err1:
 93	nft_data_release(&priv->data, desc.type);
 94	return err;
 95}
 96
 97static void nft_immediate_activate(const struct nft_ctx *ctx,
 98				   const struct nft_expr *expr)
 99{
100	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
101
102	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
103}
104
105static void nft_immediate_deactivate(const struct nft_ctx *ctx,
106				     const struct nft_expr *expr,
107				     enum nft_trans_phase phase)
108{
109	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
110
111	if (phase == NFT_TRANS_COMMIT)
112		return;
113
114	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
115}
116
117static void nft_immediate_destroy(const struct nft_ctx *ctx,
118				  const struct nft_expr *expr)
119{
120	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
121	const struct nft_data *data = &priv->data;
122	struct nft_rule *rule, *n;
123	struct nft_ctx chain_ctx;
124	struct nft_chain *chain;
125
126	if (priv->dreg != NFT_REG_VERDICT)
127		return;
128
129	switch (data->verdict.code) {
130	case NFT_JUMP:
131	case NFT_GOTO:
132		chain = data->verdict.chain;
133
134		if (!nft_chain_is_bound(chain))
135			break;
136
137		chain_ctx = *ctx;
138		chain_ctx.chain = chain;
139
140		list_for_each_entry_safe(rule, n, &chain->rules, list)
141			nf_tables_rule_release(&chain_ctx, rule);
142
143		nf_tables_chain_destroy(&chain_ctx);
144		break;
145	default:
146		break;
147	}
148}
149
150static int nft_immediate_dump(struct sk_buff *skb,
151			      const struct nft_expr *expr, bool reset)
152{
153	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
154
155	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
156		goto nla_put_failure;
157
158	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
159			     nft_dreg_to_type(priv->dreg), priv->dlen);
160
161nla_put_failure:
162	return -1;
163}
164
165static int nft_immediate_validate(const struct nft_ctx *ctx,
166				  const struct nft_expr *expr,
167				  const struct nft_data **d)
168{
169	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
170	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
171	const struct nft_data *data;
172	int err;
173
174	if (priv->dreg != NFT_REG_VERDICT)
175		return 0;
176
177	data = &priv->data;
178
179	switch (data->verdict.code) {
180	case NFT_JUMP:
181	case NFT_GOTO:
182		pctx->level++;
183		err = nft_chain_validate(ctx, data->verdict.chain);
184		if (err < 0)
185			return err;
186		pctx->level--;
187		break;
188	default:
189		break;
190	}
191
192	return 0;
193}
194
195static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
196					 struct nft_flow_rule *flow,
197					 const struct nft_immediate_expr *priv)
198{
199	struct flow_action_entry *entry;
200	const struct nft_data *data;
201
202	entry = &flow->rule->action.entries[ctx->num_actions++];
203
204	data = &priv->data;
205	switch (data->verdict.code) {
206	case NF_ACCEPT:
207		entry->id = FLOW_ACTION_ACCEPT;
208		break;
209	case NF_DROP:
210		entry->id = FLOW_ACTION_DROP;
211		break;
212	default:
213		return -EOPNOTSUPP;
214	}
215
216	return 0;
217}
218
219static int nft_immediate_offload(struct nft_offload_ctx *ctx,
220				 struct nft_flow_rule *flow,
221				 const struct nft_expr *expr)
222{
223	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
224
225	if (priv->dreg == NFT_REG_VERDICT)
226		return nft_immediate_offload_verdict(ctx, flow, priv);
227
228	memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));
229
230	return 0;
231}
232
233static bool nft_immediate_offload_action(const struct nft_expr *expr)
234{
235	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
236
237	if (priv->dreg == NFT_REG_VERDICT)
238		return true;
239
240	return false;
241}
242
243static bool nft_immediate_reduce(struct nft_regs_track *track,
244				 const struct nft_expr *expr)
245{
246	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
247
248	if (priv->dreg != NFT_REG_VERDICT)
249		nft_reg_track_cancel(track, priv->dreg, priv->dlen);
250
251	return false;
252}
253
254static const struct nft_expr_ops nft_imm_ops = {
255	.type		= &nft_imm_type,
256	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
257	.eval		= nft_immediate_eval,
258	.init		= nft_immediate_init,
259	.activate	= nft_immediate_activate,
260	.deactivate	= nft_immediate_deactivate,
261	.destroy	= nft_immediate_destroy,
262	.dump		= nft_immediate_dump,
263	.validate	= nft_immediate_validate,
264	.reduce		= nft_immediate_reduce,
265	.offload	= nft_immediate_offload,
266	.offload_action	= nft_immediate_offload_action,
267};
268
269struct nft_expr_type nft_imm_type __read_mostly = {
270	.name		= "immediate",
271	.ops		= &nft_imm_ops,
272	.policy		= nft_immediate_policy,
273	.maxattr	= NFTA_IMMEDIATE_MAX,
274	.owner		= THIS_MODULE,
275};