1#ifndef _NF_QUEUE_H
2#define _NF_QUEUE_H
3
4#include <linux/ip.h>
5#include <linux/ipv6.h>
6#include <linux/jhash.h>
7
8/* Each queued (to userspace) skbuff has one of these. */
9struct nf_queue_entry {
10	struct list_head	list;
11	struct sk_buff		*skb;
12	unsigned int		id;
13
14	struct nf_hook_ops	*elem;
15	struct nf_hook_state	state;
16	u16			size; /* sizeof(entry) + saved route keys */
17
18	/* extra space to store route keys */
19};
20
21#define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
22
23/* Packet queuing */
24struct nf_queue_handler {
25	int			(*outfn)(struct nf_queue_entry *entry,
26					 unsigned int queuenum);
27	void			(*nf_hook_drop)(struct net *net,
28						struct nf_hook_ops *ops);
29};
30
31void nf_register_queue_handler(const struct nf_queue_handler *qh);
32void nf_unregister_queue_handler(void);
33void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
34
35bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
36void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
37
38static inline void init_hashrandom(u32 *jhash_initval)
39{
40	while (*jhash_initval == 0)
41		*jhash_initval = prandom_u32();
42}
43
44static inline u32 hash_v4(const struct sk_buff *skb, u32 jhash_initval)
45{
46	const struct iphdr *iph = ip_hdr(skb);
47
48	/* packets in either direction go into same queue */
49	if ((__force u32)iph->saddr < (__force u32)iph->daddr)
50		return jhash_3words((__force u32)iph->saddr,
51			(__force u32)iph->daddr, iph->protocol, jhash_initval);
52
53	return jhash_3words((__force u32)iph->daddr,
54			(__force u32)iph->saddr, iph->protocol, jhash_initval);
55}
56
57#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
58static inline u32 hash_v6(const struct sk_buff *skb, u32 jhash_initval)
59{
60	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
61	u32 a, b, c;
62
63	if ((__force u32)ip6h->saddr.s6_addr32[3] <
64	    (__force u32)ip6h->daddr.s6_addr32[3]) {
65		a = (__force u32) ip6h->saddr.s6_addr32[3];
66		b = (__force u32) ip6h->daddr.s6_addr32[3];
67	} else {
68		b = (__force u32) ip6h->saddr.s6_addr32[3];
69		a = (__force u32) ip6h->daddr.s6_addr32[3];
70	}
71
72	if ((__force u32)ip6h->saddr.s6_addr32[1] <
73	    (__force u32)ip6h->daddr.s6_addr32[1])
74		c = (__force u32) ip6h->saddr.s6_addr32[1];
75	else
76		c = (__force u32) ip6h->daddr.s6_addr32[1];
77
78	return jhash_3words(a, b, c, jhash_initval);
79}
80#endif
81
82static inline u32
83nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
84	     u32 jhash_initval)
85{
86	if (family == NFPROTO_IPV4)
87		queue += ((u64) hash_v4(skb, jhash_initval) * queues_total) >> 32;
88#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
89	else if (family == NFPROTO_IPV6)
90		queue += ((u64) hash_v6(skb, jhash_initval) * queues_total) >> 32;
91#endif
92
93	return queue;
94}
95
96#endif /* _NF_QUEUE_H */
97