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 
nft_immediate_eval(const struct nft_expr * expr,struct nft_regs * regs,const struct nft_pktinfo * pkt)18 void 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 
27 static 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 
nft_immediate_init(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nlattr * const tb[])32 static 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 
76 err1:
77 	nft_data_release(&priv->data, desc.type);
78 	return err;
79 }
80 
nft_immediate_activate(const struct nft_ctx * ctx,const struct nft_expr * expr)81 static 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 
nft_immediate_deactivate(const struct nft_ctx * ctx,const struct nft_expr * expr,enum nft_trans_phase phase)89 static 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 
nft_immediate_destroy(const struct nft_ctx * ctx,const struct nft_expr * expr)101 static 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 
nft_immediate_dump(struct sk_buff * skb,const struct nft_expr * expr)134 static 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 
144 nla_put_failure:
145 	return -1;
146 }
147 
nft_immediate_validate(const struct nft_ctx * ctx,const struct nft_expr * expr,const struct nft_data ** d)148 static 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 
nft_immediate_offload_verdict(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_immediate_expr * priv)178 static 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 
nft_immediate_offload(struct nft_offload_ctx * ctx,struct nft_flow_rule * flow,const struct nft_expr * expr)202 static 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 
216 static 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 
230 struct 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 };
237