1/*
2 * Copyright (c) 2013 Eric Leblond <eric@regit.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * Development of this code partly funded by OISF
9 * (http://www.openinfosecfoundation.org/)
10 */
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/netlink.h>
16#include <linux/jhash.h>
17#include <linux/netfilter.h>
18#include <linux/netfilter/nf_tables.h>
19#include <net/netfilter/nf_tables.h>
20#include <net/netfilter/nf_queue.h>
21
22static u32 jhash_initval __read_mostly;
23
24struct nft_queue {
25	u16	queuenum;
26	u16	queues_total;
27	u16	flags;
28};
29
30static void nft_queue_eval(const struct nft_expr *expr,
31			   struct nft_regs *regs,
32			   const struct nft_pktinfo *pkt)
33{
34	struct nft_queue *priv = nft_expr_priv(expr);
35	u32 queue = priv->queuenum;
36	u32 ret;
37
38	if (priv->queues_total > 1) {
39		if (priv->flags & NFT_QUEUE_FLAG_CPU_FANOUT) {
40			int cpu = smp_processor_id();
41
42			queue = priv->queuenum + cpu % priv->queues_total;
43		} else {
44			queue = nfqueue_hash(pkt->skb, queue,
45					     priv->queues_total, pkt->pf,
46					     jhash_initval);
47		}
48	}
49
50	ret = NF_QUEUE_NR(queue);
51	if (priv->flags & NFT_QUEUE_FLAG_BYPASS)
52		ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
53
54	regs->verdict.code = ret;
55}
56
57static const struct nla_policy nft_queue_policy[NFTA_QUEUE_MAX + 1] = {
58	[NFTA_QUEUE_NUM]	= { .type = NLA_U16 },
59	[NFTA_QUEUE_TOTAL]	= { .type = NLA_U16 },
60	[NFTA_QUEUE_FLAGS]	= { .type = NLA_U16 },
61};
62
63static int nft_queue_init(const struct nft_ctx *ctx,
64			   const struct nft_expr *expr,
65			   const struct nlattr * const tb[])
66{
67	struct nft_queue *priv = nft_expr_priv(expr);
68
69	if (tb[NFTA_QUEUE_NUM] == NULL)
70		return -EINVAL;
71
72	init_hashrandom(&jhash_initval);
73	priv->queuenum = ntohs(nla_get_be16(tb[NFTA_QUEUE_NUM]));
74
75	if (tb[NFTA_QUEUE_TOTAL] != NULL)
76		priv->queues_total = ntohs(nla_get_be16(tb[NFTA_QUEUE_TOTAL]));
77	if (tb[NFTA_QUEUE_FLAGS] != NULL) {
78		priv->flags = ntohs(nla_get_be16(tb[NFTA_QUEUE_FLAGS]));
79		if (priv->flags & ~NFT_QUEUE_FLAG_MASK)
80			return -EINVAL;
81	}
82	return 0;
83}
84
85static int nft_queue_dump(struct sk_buff *skb, const struct nft_expr *expr)
86{
87	const struct nft_queue *priv = nft_expr_priv(expr);
88
89	if (nla_put_be16(skb, NFTA_QUEUE_NUM, htons(priv->queuenum)) ||
90	    nla_put_be16(skb, NFTA_QUEUE_TOTAL, htons(priv->queues_total)) ||
91	    nla_put_be16(skb, NFTA_QUEUE_FLAGS, htons(priv->flags)))
92		goto nla_put_failure;
93
94	return 0;
95
96nla_put_failure:
97	return -1;
98}
99
100static struct nft_expr_type nft_queue_type;
101static const struct nft_expr_ops nft_queue_ops = {
102	.type		= &nft_queue_type,
103	.size		= NFT_EXPR_SIZE(sizeof(struct nft_queue)),
104	.eval		= nft_queue_eval,
105	.init		= nft_queue_init,
106	.dump		= nft_queue_dump,
107};
108
109static struct nft_expr_type nft_queue_type __read_mostly = {
110	.name		= "queue",
111	.ops		= &nft_queue_ops,
112	.policy		= nft_queue_policy,
113	.maxattr	= NFTA_QUEUE_MAX,
114	.owner		= THIS_MODULE,
115};
116
117static int __init nft_queue_module_init(void)
118{
119	return nft_register_expr(&nft_queue_type);
120}
121
122static void __exit nft_queue_module_exit(void)
123{
124	nft_unregister_expr(&nft_queue_type);
125}
126
127module_init(nft_queue_module_init);
128module_exit(nft_queue_module_exit);
129
130MODULE_LICENSE("GPL");
131MODULE_AUTHOR("Eric Leblond <eric@regit.org>");
132MODULE_ALIAS_NFT_EXPR("queue");
133