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(dst: &regs->data[priv->dreg], src: &priv->data, len: 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(nla: tb[NFTA_IMMEDIATE_DREG]);
61 err = nft_data_init(ctx, data: &priv->data, desc: &desc, nla: 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, attr: tb[NFTA_IMMEDIATE_DREG],
68 dreg: &priv->dreg, data: &priv->data, type: desc.type,
69 len: 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(data: &priv->data, type: 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(ctx: &chain_ctx, rule);
117
118 nft_clear(ctx->net, chain);
119 break;
120 default:
121 break;
122 }
123 }
124
125 return nft_data_hold(data: &priv->data, type: nft_dreg_to_type(reg: 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(ctx: &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(use: &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(data: &priv->data, type: nft_dreg_to_type(reg: 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(use: &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(use: &chain->use);
219 list_for_each_entry_safe(rule, n, &chain->rules, list) {
220 nft_use_dec(use: &chain->use);
221 list_del(entry: &rule->list);
222 nf_tables_rule_destroy(ctx: &chain_ctx, rule);
223 }
224 nf_tables_chain_destroy(chain);
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, attr: NFTA_IMMEDIATE_DREG, reg: priv->dreg))
237 goto nla_put_failure;
238
239 return nft_data_dump(skb, attr: NFTA_IMMEDIATE_DATA, data: &priv->data,
240 type: nft_dreg_to_type(reg: priv->dreg), len: 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{
249 const struct nft_immediate_expr *priv = nft_expr_priv(expr);
250 struct nft_ctx *pctx = (struct nft_ctx *)ctx;
251 const struct nft_data *data;
252 int err;
253
254 if (priv->dreg != NFT_REG_VERDICT)
255 return 0;
256
257 data = &priv->data;
258
259 switch (data->verdict.code) {
260 case NFT_JUMP:
261 case NFT_GOTO:
262 pctx->level++;
263 err = nft_chain_validate(ctx, chain: data->verdict.chain);
264 if (err < 0)
265 return err;
266 pctx->level--;
267 break;
268 default:
269 break;
270 }
271
272 return 0;
273}
274
275static int nft_immediate_offload_verdict(struct nft_offload_ctx *ctx,
276 struct nft_flow_rule *flow,
277 const struct nft_immediate_expr *priv)
278{
279 struct flow_action_entry *entry;
280 const struct nft_data *data;
281
282 entry = &flow->rule->action.entries[ctx->num_actions++];
283
284 data = &priv->data;
285 switch (data->verdict.code) {
286 case NF_ACCEPT:
287 entry->id = FLOW_ACTION_ACCEPT;
288 break;
289 case NF_DROP:
290 entry->id = FLOW_ACTION_DROP;
291 break;
292 default:
293 return -EOPNOTSUPP;
294 }
295
296 return 0;
297}
298
299static int nft_immediate_offload(struct nft_offload_ctx *ctx,
300 struct nft_flow_rule *flow,
301 const struct nft_expr *expr)
302{
303 const struct nft_immediate_expr *priv = nft_expr_priv(expr);
304
305 if (priv->dreg == NFT_REG_VERDICT)
306 return nft_immediate_offload_verdict(ctx, flow, priv);
307
308 memcpy(&ctx->regs[priv->dreg].data, &priv->data, sizeof(priv->data));
309
310 return 0;
311}
312
313static bool nft_immediate_offload_action(const struct nft_expr *expr)
314{
315 const struct nft_immediate_expr *priv = nft_expr_priv(expr);
316
317 if (priv->dreg == NFT_REG_VERDICT)
318 return true;
319
320 return false;
321}
322
323static bool nft_immediate_reduce(struct nft_regs_track *track,
324 const struct nft_expr *expr)
325{
326 const struct nft_immediate_expr *priv = nft_expr_priv(expr);
327
328 if (priv->dreg != NFT_REG_VERDICT)
329 nft_reg_track_cancel(track, dreg: priv->dreg, len: priv->dlen);
330
331 return false;
332}
333
334static const struct nft_expr_ops nft_imm_ops = {
335 .type = &nft_imm_type,
336 .size = NFT_EXPR_SIZE(sizeof(struct nft_immediate_expr)),
337 .eval = nft_immediate_eval,
338 .init = nft_immediate_init,
339 .activate = nft_immediate_activate,
340 .deactivate = nft_immediate_deactivate,
341 .destroy = nft_immediate_destroy,
342 .dump = nft_immediate_dump,
343 .validate = nft_immediate_validate,
344 .reduce = nft_immediate_reduce,
345 .offload = nft_immediate_offload,
346 .offload_action = nft_immediate_offload_action,
347};
348
349struct nft_expr_type nft_imm_type __read_mostly = {
350 .name = "immediate",
351 .ops = &nft_imm_ops,
352 .policy = nft_immediate_policy,
353 .maxattr = NFTA_IMMEDIATE_MAX,
354 .owner = THIS_MODULE,
355};
356

source code of linux/net/netfilter/nft_immediate.c