xref: /openbmc/linux/net/netfilter/nft_queue.c (revision ef4290e6)
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,
156 			  const struct nft_expr *expr, bool reset)
157 {
158 	const struct nft_queue *priv = nft_expr_priv(expr);
159 
160 	if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) ||
161 	    nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) ||
162 	    nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
163 		goto nla_put_failure;
164 
165 	return 0;
166 
167 nla_put_failure:
168 	return -1;
169 }
170 
171 static int
172 nft_queue_sreg_dump(struct sk_buff *skb,
173 		    const struct nft_expr *expr, bool reset)
174 {
175 	const struct nft_queue *priv = nft_expr_priv(expr);
176 
177 	if (nft_dump_register(skb, NFTA_QUEUE_SREG_QNUM, priv->sreg_qnum) ||
178 	    nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
179 		goto nla_put_failure;
180 
181 	return 0;
182 
183 nla_put_failure:
184 	return -1;
185 }
186 
187 static struct nft_expr_type nft_queue_type;
188 static const struct nft_expr_ops nft_queue_ops = {
189 	.type		= &nft_queue_type,
190 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_queue)),
191 	.eval		= nft_queue_eval,
192 	.init		= nft_queue_init,
193 	.dump		= nft_queue_dump,
194 	.validate	= nft_queue_validate,
195 	.reduce		= NFT_REDUCE_READONLY,
196 };
197 
198 static const struct nft_expr_ops nft_queue_sreg_ops = {
199 	.type		= &nft_queue_type,
200 	.size		= NFT_EXPR_SIZE(sizeof(struct nft_queue)),
201 	.eval		= nft_queue_sreg_eval,
202 	.init		= nft_queue_sreg_init,
203 	.dump		= nft_queue_sreg_dump,
204 	.validate	= nft_queue_validate,
205 	.reduce		= NFT_REDUCE_READONLY,
206 };
207 
208 static const struct nft_expr_ops *
209 nft_queue_select_ops(const struct nft_ctx *ctx,
210 		     const struct nlattr * const tb[])
211 {
212 	if (tb[NFTA_QUEUE_NUM] && tb[NFTA_QUEUE_SREG_QNUM])
213 		return ERR_PTR(-EINVAL);
214 
215 	init_hashrandom(&jhash_initval);
216 
217 	if (tb[NFTA_QUEUE_NUM])
218 		return &nft_queue_ops;
219 
220 	if (tb[NFTA_QUEUE_SREG_QNUM])
221 		return &nft_queue_sreg_ops;
222 
223 	return ERR_PTR(-EINVAL);
224 }
225 
226 static struct nft_expr_type nft_queue_type __read_mostly = {
227 	.name		= "queue",
228 	.select_ops	= nft_queue_select_ops,
229 	.policy		= nft_queue_policy,
230 	.maxattr	= NFTA_QUEUE_MAX,
231 	.owner		= THIS_MODULE,
232 };
233 
234 static int __init nft_queue_module_init(void)
235 {
236 	return nft_register_expr(&nft_queue_type);
237 }
238 
239 static void __exit nft_queue_module_exit(void)
240 {
241 	nft_unregister_expr(&nft_queue_type);
242 }
243 
244 module_init(nft_queue_module_init);
245 module_exit(nft_queue_module_exit);
246 
247 MODULE_LICENSE("GPL");
248 MODULE_AUTHOR("Eric Leblond <eric@regit.org>");
249 MODULE_ALIAS_NFT_EXPR("queue");
250 MODULE_DESCRIPTION("Netfilter nftables queue module");
251