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			err = nf_tables_bind_chain(ctx, chain);
80			if (err < 0)
81				goto err1;
82			break;
83		default:
84			break;
85		}
86	}
87
88	return 0;
89
90err1:
91	nft_data_release(&priv->data, desc.type);
92	return err;
93}
94
95static void nft_immediate_activate(const struct nft_ctx *ctx,
96				   const struct nft_expr *expr)
97{
98	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
99	const struct nft_data *data = &priv->data;
100	struct nft_ctx chain_ctx;
101	struct nft_chain *chain;
102	struct nft_rule *rule;
103
104	if (priv->dreg == NFT_REG_VERDICT) {
105		switch (data->verdict.code) {
106		case NFT_JUMP:
107		case NFT_GOTO:
108			chain = data->verdict.chain;
109			if (!nft_chain_binding(chain))
110				break;
111
112			chain_ctx = *ctx;
113			chain_ctx.chain = chain;
114
115			list_for_each_entry(rule, &chain->rules, list)
116				nft_rule_expr_activate(&chain_ctx, rule);
117
118			nft_clear(ctx->net, chain);
119			break;
120		default:
121			break;
122		}
123	}
124
125	return nft_data_hold(&priv->data, nft_dreg_to_type(priv->dreg));
126}
127
128static void nft_immediate_chain_deactivate(const struct nft_ctx *ctx,
129					   struct nft_chain *chain,
130					   enum nft_trans_phase phase)
131{
132	struct nft_ctx chain_ctx;
133	struct nft_rule *rule;
134
135	chain_ctx = *ctx;
136	chain_ctx.chain = chain;
137
138	list_for_each_entry(rule, &chain->rules, list)
139		nft_rule_expr_deactivate(&chain_ctx, rule, phase);
140}
141
142static void nft_immediate_deactivate(const struct nft_ctx *ctx,
143				     const struct nft_expr *expr,
144				     enum nft_trans_phase phase)
145{
146	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
147	const struct nft_data *data = &priv->data;
148	struct nft_chain *chain;
149
150	if (priv->dreg == NFT_REG_VERDICT) {
151		switch (data->verdict.code) {
152		case NFT_JUMP:
153		case NFT_GOTO:
154			chain = data->verdict.chain;
155			if (!nft_chain_binding(chain))
156				break;
157
158			switch (phase) {
159			case NFT_TRANS_PREPARE_ERROR:
160				nf_tables_unbind_chain(ctx, chain);
161				nft_deactivate_next(ctx->net, chain);
162				break;
163			case NFT_TRANS_PREPARE:
164				nft_immediate_chain_deactivate(ctx, chain, phase);
165				nft_deactivate_next(ctx->net, chain);
166				break;
167			default:
168				nft_immediate_chain_deactivate(ctx, chain, phase);
169				nft_chain_del(chain);
170				chain->bound = false;
171				nft_use_dec(&chain->table->use);
172				break;
173			}
174			break;
175		default:
176			break;
177		}
178	}
179
180	if (phase == NFT_TRANS_COMMIT)
181		return;
182
183	return nft_data_release(&priv->data, nft_dreg_to_type(priv->dreg));
184}
185
186static void nft_immediate_destroy(const struct nft_ctx *ctx,
187				  const struct nft_expr *expr)
188{
189	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
190	const struct nft_data *data = &priv->data;
191	struct nft_rule *rule, *n;
192	struct nft_ctx chain_ctx;
193	struct nft_chain *chain;
194
195	if (priv->dreg != NFT_REG_VERDICT)
196		return;
197
198	switch (data->verdict.code) {
199	case NFT_JUMP:
200	case NFT_GOTO:
201		chain = data->verdict.chain;
202
203		if (!nft_chain_binding(chain))
204			break;
205
206		/* Rule construction failed, but chain is already bound:
207		 * let the transaction records release this chain and its rules.
208		 */
209		if (chain->bound) {
210			nft_use_dec(&chain->use);
211			break;
212		}
213
214		/* Rule has been deleted, release chain and its rules. */
215		chain_ctx = *ctx;
216		chain_ctx.chain = chain;
217
218		nft_use_dec(&chain->use);
219		list_for_each_entry_safe(rule, n, &chain->rules, list) {
220			nft_use_dec(&chain->use);
221			list_del(&rule->list);
222			nf_tables_rule_destroy(&chain_ctx, rule);
223		}
224		nf_tables_chain_destroy(&chain_ctx);
225		break;
226	default:
227		break;
228	}
229}
230
231static int nft_immediate_dump(struct sk_buff *skb,
232			      const struct nft_expr *expr, bool reset)
233{
234	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
235
236	if (nft_dump_register(skb, NFTA_IMMEDIATE_DREG, priv->dreg))
237		goto nla_put_failure;
238
239	return nft_data_dump(skb, NFTA_IMMEDIATE_DATA, &priv->data,
240			     nft_dreg_to_type(priv->dreg), priv->dlen);
241
242nla_put_failure:
243	return -1;
244}
245
246static int nft_immediate_validate(const struct nft_ctx *ctx,
247				  const struct nft_expr *expr,
248				  const struct nft_data **d)
249{
250	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
251	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
252	const struct nft_data *data;
253	int err;
254
255	if (priv->dreg != NFT_REG_VERDICT)
256		return 0;
257
258	data = &priv->data;
259
260	switch (data->verdict.code) {
261	case NFT_JUMP:
262	case NFT_GOTO:
263		pctx->level++;
264		err = nft_chain_validate(ctx, data->verdict.chain);
265		if (err < 0)
266			return err;
267		pctx->level--;
268		break;
269	default:
270		break;
271	}
272
273	return 0;
274}
275
276static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
277					 struct nft_flow_rule *flow,
278					 const struct nft_immediate_expr *priv)
279{
280	struct flow_action_entry *entry;
281	const struct nft_data *data;
282
283	entry = &flow->rule->action.entries[ctx->num_actions++];
284
285	data = &priv->data;
286	switch (data->verdict.code) {
287	case NF_ACCEPT:
288		entry->id = FLOW_ACTION_ACCEPT;
289		break;
290	case NF_DROP:
291		entry->id = FLOW_ACTION_DROP;
292		break;
293	default:
294		return -EOPNOTSUPP;
295	}
296
297	return 0;
298}
299
300static int nft_immediate_offload(struct nft_offload_ctx *ctx,
301				 struct nft_flow_rule *flow,
302				 const struct nft_expr *expr)
303{
304	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
305
306	if (priv->dreg == NFT_REG_VERDICT)
307		return nft_immediate_offload_verdict(ctx, flow, priv);
308
309	memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));
310
311	return 0;
312}
313
314static bool nft_immediate_offload_action(const struct nft_expr *expr)
315{
316	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
317
318	if (priv->dreg == NFT_REG_VERDICT)
319		return true;
320
321	return false;
322}
323
324static bool nft_immediate_reduce(struct nft_regs_track *track,
325				 const struct nft_expr *expr)
326{
327	const struct nft_immediate_expr *priv = nft_expr_priv(expr);
328
329	if (priv->dreg != NFT_REG_VERDICT)
330		nft_reg_track_cancel(track, priv->dreg, priv->dlen);
331
332	return false;
333}
334
335static const struct nft_expr_ops nft_imm_ops = {
336	.type		= &nft_imm_type,
337	.size		= NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
338	.eval		= nft_immediate_eval,
339	.init		= nft_immediate_init,
340	.activate	= nft_immediate_activate,
341	.deactivate	= nft_immediate_deactivate,
342	.destroy	= nft_immediate_destroy,
343	.dump		= nft_immediate_dump,
344	.validate	= nft_immediate_validate,
345	.reduce		= nft_immediate_reduce,
346	.offload	= nft_immediate_offload,
347	.offload_action	= nft_immediate_offload_action,
348};
349
350struct nft_expr_type nft_imm_type __read_mostly = {
351	.name		= "immediate",
352	.ops		= &nft_imm_ops,
353	.policy		= nft_immediate_policy,
354	.maxattr	= NFTA_IMMEDIATE_MAX,
355	.owner		= THIS_MODULE,
356};
357