xref: /linux/net/netfilter/nft_queue.c (revision 2da68a77)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2013 Eric Leblond <eric@regit.org>
4  *
5  * Development of this code partly funded by OISF
6  * (http://www.openinfosecfoundation.org/)
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/netlink.h>
13 #include <linux/jhash.h>
14 #include <linux/netfilter.h>
15 #include <linux/netfilter/nf_tables.h>
16 #include <net/netfilter/nf_tables.h>
17 #include <net/netfilter/nf_queue.h>
18 
19 static u32 jhash_initval __read_mostly;
20 
21 struct nft_queue {
22 	u8	sreg_qnum;
23 	u16	queuenum;
24 	u16	queues_total;
25 	u16	flags;
26 };
27 
28 static void nft_queue_eval(const struct nft_expr *expr,
29 			   struct nft_regs *regs,
30 			   const struct nft_pktinfo *pkt)
31 {
32 	struct nft_queue *priv = nft_expr_priv(expr);
33 	u32 queue = priv->queuenum;
34 	u32 ret;
35 
36 	if (priv->queues_total > 1) {
37 		if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) {
38 			int cpu = raw_smp_processor_id();
39 
40 			queue = priv->queuenum + cpu % priv->queues_total;
41 		} else {
42 			queue = nfqueue_hash(pkt->skb, queue,
43 					     priv->queues_total, nft_pf(pkt),
44 					     jhash_initval);
45 		}
46 	}
47 
48 	ret = NF_QUEUE_NR(queue);
49 	if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
50 		ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
51 
52 	regs->verdict.code = ret;
53 }
54 
55 static void nft_queue_sreg_eval(const struct nft_expr *expr,
56 				struct nft_regs *regs,
57 				const struct nft_pktinfo *pkt)
58 {
59 	struct nft_queue *priv = nft_expr_priv(expr);
60 	u32 queue, ret;
61 
62 	queue = regs->data[priv->sreg_qnum];
63 
64 	ret = NF_QUEUE_NR(queue);
65 	if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
66 		ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
67 
68 	regs->verdict.code = ret;
69 }
70 
71 static int nft_queue_validate(const struct nft_ctx *ctx,
72 			      const struct nft_expr *expr,
73 			      const struct nft_data **data)
74 {
75 	static const unsigned int supported_hooks = ((1 << NF_INET_PRE_ROUTING) |
76 						     (1 << NF_INET_LOCAL_IN) |
77 						     (1 << NF_INET_FORWARD) |
78 						     (1 << NF_INET_LOCAL_OUT) |
79 						     (1 << NF_INET_POST_ROUTING));
80 
81 	switch (ctx->family) {
82 	case NFPROTO_IPV4:
83 	case NFPROTO_IPV6:
84 	case NFPROTO_INET:
85 	case NFPROTO_BRIDGE:
86 		break;
87 	case NFPROTO_NETDEV: /* lacks okfn */
88 		fallthrough;
89 	default:
90 		return -EOPNOTSUPP;
91 	}
92 
93 	return nft_chain_validate_hooks(ctx->chain, supported_hooks);
94 }
95 
96 static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = {
97 	[NFTA_QUEUE_NUM]	= { .type = NLA_U16 },
98 	[NFTA_QUEUE_TOTAL]	= { .type = NLA_U16 },
99 	[NFTA_QUEUE_FLAGS]	= { .type = NLA_U16 },
100 	[NFTA_QUEUE_SREG_QNUM]	= { .type = NLA_U32 },
101 };
102 
103 static int nft_queue_init(const struct nft_ctx *ctx,
104 			  const struct nft_expr *expr,
105 			  const struct nlattr * const tb[])
106 {
107 	struct nft_queue *priv = nft_expr_priv(expr);
108 	u32 maxid;
109 
110 	priv->queuenum = ntohs(nla_get_be16(tb[NFTA_QUEUE_NUM]));
111 
112 	if (tb[NFTA_QUEUE_TOTAL])
113 		priv->queues_total = ntohs(nla_get_be16(tb[NFTA_QUEUE_TOTAL]));
114 	else
115 		priv->queues_total = 1;
116 
117 	if (priv->queues_total == 0)
118 		return -EINVAL;
119 
120 	maxid = priv->queues_total - 1 + priv->queuenum;
121 	if (maxid > U16_MAX)
122 		return -ERANGE;
123 
124 	if (tb[NFTA_QUEUE_FLAGS]) {
125 		priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
126 		if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
127 			return -EINVAL;
128 	}
129 	return 0;
130 }
131 
132 static int nft_queue_sreg_init(const struct nft_ctx *ctx,
133 			       const struct nft_expr *expr,
134 			       const struct nlattr * const tb[])
135 {
136 	struct nft_queue *priv = nft_expr_priv(expr);
137 	int err;
138 
139 	err = nft_parse_register_load(tb[NFTA_QUEUE_SREG_QNUM],
140 				      &priv->sreg_qnum, sizeof(u32));
141 	if (err < 0)
142 		return err;
143 
144 	if (tb[NFTA_QUEUE_FLAGS]) {
145 		priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
146 		if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
147 			return -EINVAL;
148 		if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT)
149 			return -EOPNOTSUPP;
150 	}
151 
152 	return 0;
153 }
154 
155 static int nft_queue_dump(struct sk_buff *skb, const struct nft_expr *expr)
156 {
157 	const struct nft_queue *priv = nft_expr_priv(expr);
158 
159 	if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) ||
160 	    nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) ||
161 	    nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
162 		goto nla_put_failure;
163 
164 	return 0;
165 
166 nla_put_failure:
167 	return -1;
168 }
169 
170 static int
171 nft_queue_sreg_dump(struct sk_buff *skb, const struct nft_expr *expr)
172 {
173 	const struct nft_queue *priv = nft_expr_priv(expr);
174 
175 	if (nft_dump_register(skb, NFTA_QUEUE_SREG_QNUM, priv->sreg_qnum) ||
176 	    nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
177 		goto nla_put_failure;
178 
179 	return 0;
180 
181 nla_put_failure:
182 	return -1;
183 }
184 
185 static struct nft_expr_type nft_queue_type;
186 static const struct nft_expr_ops nft_queue_ops = {
187 	.type		= &nft_queue_type,
188 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_queue)),
189 	.eval		= nft_queue_eval,
190 	.init		= nft_queue_init,
191 	.dump		= nft_queue_dump,
192 	.validate	= nft_queue_validate,
193 	.reduce		= NFT_REDUCE_READONLY,
194 };
195 
196 static const struct nft_expr_ops nft_queue_sreg_ops = {
197 	.type		= &nft_queue_type,
198 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_queue)),
199 	.eval		= nft_queue_sreg_eval,
200 	.init		= nft_queue_sreg_init,
201 	.dump		= nft_queue_sreg_dump,
202 	.validate	= nft_queue_validate,
203 	.reduce		= NFT_REDUCE_READONLY,
204 };
205 
206 static const struct nft_expr_ops *
207 nft_queue_select_ops(const struct nft_ctx *ctx,
208 		     const struct nlattr * const tb[])
209 {
210 	if (tb[NFTA_QUEUE_NUM] && tb[NFTA_QUEUE_SREG_QNUM])
211 		return ERR_PTR(-EINVAL);
212 
213 	init_hashrandom(&jhash_initval);
214 
215 	if (tb[NFTA_QUEUE_NUM])
216 		return &nft_queue_ops;
217 
218 	if (tb[NFTA_QUEUE_SREG_QNUM])
219 		return &nft_queue_sreg_ops;
220 
221 	return ERR_PTR(-EINVAL);
222 }
223 
224 static struct nft_expr_type nft_queue_type __read_mostly = {
225 	.name		= "queue",
226 	.select_ops	= nft_queue_select_ops,
227 	.policy		= nft_queue_policy,
228 	.maxattr	= NFTA_QUEUE_MAX,
229 	.owner		= THIS_MODULE,
230 };
231 
232 static int __init nft_queue_module_init(void)
233 {
234 	return nft_register_expr(&nft_queue_type);
235 }
236 
237 static void __exit nft_queue_module_exit(void)
238 {
239 	nft_unregister_expr(&nft_queue_type);
240 }
241 
242 module_init(nft_queue_module_init);
243 module_exit(nft_queue_module_exit);
244 
245 MODULE_LICENSE("GPL");
246 MODULE_AUTHOR("Eric Leblond <eric@regit.org>");
247 MODULE_ALIAS_NFT_EXPR("queue");
248 MODULE_DESCRIPTION("Netfilter nftables queue module");
249