1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 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/list.h>
 11#include <linux/rbtree.h>
 12#include <linux/netlink.h>
 13#include <linux/netfilter.h>
 14#include <linux/netfilter/nf_tables.h>
 15#include <net/netfilter/nf_tables.h>
 16#include <net/netfilter/nf_tables_core.h>
 17
 18struct nft_lookup {
 19	struct nft_set			*set;
 20	u8				sreg;
 21	u8				dreg;
 22	bool				invert;
 23	struct nft_set_binding		binding;
 24};
 25
 26#ifdef CONFIG_RETPOLINE
 27bool nft_set_do_lookup(const struct net *net, const struct nft_set *set,
 28		       const u32 *key, const struct nft_set_ext **ext)
 29{
 30	if (set->ops == &nft_set_hash_fast_type.ops)
 31		return nft_hash_lookup_fast(net, set, key, ext);
 32	if (set->ops == &nft_set_hash_type.ops)
 33		return nft_hash_lookup(net, set, key, ext);
 34
 35	if (set->ops == &nft_set_rhash_type.ops)
 36		return nft_rhash_lookup(net, set, key, ext);
 37
 38	if (set->ops == &nft_set_bitmap_type.ops)
 39		return nft_bitmap_lookup(net, set, key, ext);
 40
 41	if (set->ops == &nft_set_pipapo_type.ops)
 42		return nft_pipapo_lookup(net, set, key, ext);
 43#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
 44	if (set->ops == &nft_set_pipapo_avx2_type.ops)
 45		return nft_pipapo_avx2_lookup(net, set, key, ext);
 46#endif
 47
 48	if (set->ops == &nft_set_rbtree_type.ops)
 49		return nft_rbtree_lookup(net, set, key, ext);
 50
 51	WARN_ON_ONCE(1);
 52	return set->ops->lookup(net, set, key, ext);
 53}
 54EXPORT_SYMBOL_GPL(nft_set_do_lookup);
 55#endif
 56
 57void nft_lookup_eval(const struct nft_expr *expr,
 58		     struct nft_regs *regs,
 59		     const struct nft_pktinfo *pkt)
 60{
 61	const struct nft_lookup *priv = nft_expr_priv(expr);
 62	const struct nft_set *set = priv->set;
 63	const struct nft_set_ext *ext = NULL;
 64	const struct net *net = nft_net(pkt);
 65	bool found;
 66
 67	found =	nft_set_do_lookup(net, set, &regs->data[priv->sreg], &ext) ^
 68				  priv->invert;
 69	if (!found) {
 70		ext = nft_set_catchall_lookup(net, set);
 71		if (!ext) {
 72			regs->verdict.code = NFT_BREAK;
 73			return;
 74		}
 75	}
 76
 77	if (ext) {
 78		if (set->flags & NFT_SET_MAP)
 79			nft_data_copy(&regs->data[priv->dreg],
 80				      nft_set_ext_data(ext), set->dlen);
 81
 82		nft_set_elem_update_expr(ext, regs, pkt);
 83	}
 84}
 85
 86static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = {
 87	[NFTA_LOOKUP_SET]	= { .type = NLA_STRING,
 88				    .len = NFT_SET_MAXNAMELEN - 1 },
 89	[NFTA_LOOKUP_SET_ID]	= { .type = NLA_U32 },
 90	[NFTA_LOOKUP_SREG]	= { .type = NLA_U32 },
 91	[NFTA_LOOKUP_DREG]	= { .type = NLA_U32 },
 92	[NFTA_LOOKUP_FLAGS]	= { .type = NLA_U32 },
 93};
 94
 95static int nft_lookup_init(const struct nft_ctx *ctx,
 96			   const struct nft_expr *expr,
 97			   const struct nlattr * const tb[])
 98{
 99	struct nft_lookup *priv = nft_expr_priv(expr);
100	u8 genmask = nft_genmask_next(ctx->net);
101	struct nft_set *set;
102	u32 flags;
103	int err;
104
105	if (tb[NFTA_LOOKUP_SET] == NULL ||
106	    tb[NFTA_LOOKUP_SREG] == NULL)
107		return -EINVAL;
108
109	set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET],
110				    tb[NFTA_LOOKUP_SET_ID], genmask);
111	if (IS_ERR(set))
112		return PTR_ERR(set);
113
114	err = nft_parse_register_load(tb[NFTA_LOOKUP_SREG], &priv->sreg,
115				      set->klen);
116	if (err < 0)
117		return err;
118
119	if (tb[NFTA_LOOKUP_FLAGS]) {
120		flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS]));
121
122		if (flags & ~NFT_LOOKUP_F_INV)
123			return -EINVAL;
124
125		if (flags & NFT_LOOKUP_F_INV) {
126			if (set->flags & NFT_SET_MAP)
127				return -EINVAL;
128			priv->invert = true;
129		}
130	}
131
132	if (tb[NFTA_LOOKUP_DREG] != NULL) {
133		if (priv->invert)
134			return -EINVAL;
135		if (!(set->flags & NFT_SET_MAP))
136			return -EINVAL;
137
138		err = nft_parse_register_store(ctx, tb[NFTA_LOOKUP_DREG],
139					       &priv->dreg, NULL, set->dtype,
140					       set->dlen);
141		if (err < 0)
142			return err;
143	} else if (set->flags & NFT_SET_MAP)
144		return -EINVAL;
145
146	priv->binding.flags = set->flags & NFT_SET_MAP;
147
148	err = nf_tables_bind_set(ctx, set, &priv->binding);
149	if (err < 0)
150		return err;
151
152	priv->set = set;
153	return 0;
154}
155
156static void nft_lookup_deactivate(const struct nft_ctx *ctx,
157				  const struct nft_expr *expr,
158				  enum nft_trans_phase phase)
159{
160	struct nft_lookup *priv = nft_expr_priv(expr);
161
162	nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
163}
164
165static void nft_lookup_activate(const struct nft_ctx *ctx,
166				const struct nft_expr *expr)
167{
168	struct nft_lookup *priv = nft_expr_priv(expr);
169
170	priv->set->use++;
171}
172
173static void nft_lookup_destroy(const struct nft_ctx *ctx,
174			       const struct nft_expr *expr)
175{
176	struct nft_lookup *priv = nft_expr_priv(expr);
177
178	nf_tables_destroy_set(ctx, priv->set);
179}
180
181static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr)
182{
183	const struct nft_lookup *priv = nft_expr_priv(expr);
184	u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0;
185
186	if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
187		goto nla_put_failure;
188	if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg))
189		goto nla_put_failure;
190	if (priv->set->flags & NFT_SET_MAP)
191		if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg))
192			goto nla_put_failure;
193	if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags)))
194		goto nla_put_failure;
195	return 0;
196
197nla_put_failure:
198	return -1;
199}
200
201static int nft_lookup_validate_setelem(const struct nft_ctx *ctx,
202				       struct nft_set *set,
203				       const struct nft_set_iter *iter,
204				       struct nft_set_elem *elem)
205{
206	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
207	struct nft_ctx *pctx = (struct nft_ctx *)ctx;
208	const struct nft_data *data;
209	int err;
210
211	if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) &&
212	    *nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END)
213		return 0;
214
215	data = nft_set_ext_data(ext);
216	switch (data->verdict.code) {
217	case NFT_JUMP:
218	case NFT_GOTO:
219		pctx->level++;
220		err = nft_chain_validate(ctx, data->verdict.chain);
221		if (err < 0)
222			return err;
223		pctx->level--;
224		break;
225	default:
226		break;
227	}
228
229	return 0;
230}
231
232static int nft_lookup_validate(const struct nft_ctx *ctx,
233			       const struct nft_expr *expr,
234			       const struct nft_data **d)
235{
236	const struct nft_lookup *priv = nft_expr_priv(expr);
237	struct nft_set_iter iter;
238
239	if (!(priv->set->flags & NFT_SET_MAP) ||
240	    priv->set->dtype != NFT_DATA_VERDICT)
241		return 0;
242
243	iter.genmask	= nft_genmask_next(ctx->net);
244	iter.skip	= 0;
245	iter.count	= 0;
246	iter.err	= 0;
247	iter.fn		= nft_lookup_validate_setelem;
248
249	priv->set->ops->walk(ctx, priv->set, &iter);
250	if (iter.err < 0)
251		return iter.err;
252
253	return 0;
254}
255
256static const struct nft_expr_ops nft_lookup_ops = {
257	.type		= &nft_lookup_type,
258	.size		= NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
259	.eval		= nft_lookup_eval,
260	.init		= nft_lookup_init,
261	.activate	= nft_lookup_activate,
262	.deactivate	= nft_lookup_deactivate,
263	.destroy	= nft_lookup_destroy,
264	.dump		= nft_lookup_dump,
265	.validate	= nft_lookup_validate,
266};
267
268struct nft_expr_type nft_lookup_type __read_mostly = {
269	.name		= "lookup",
270	.ops		= &nft_lookup_ops,
271	.policy		= nft_lookup_policy,
272	.maxattr	= NFTA_LOOKUP_MAX,
273	.owner		= THIS_MODULE,
274};