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	u_int8_t		pf;
16	u16			size; /* sizeof(entry) + saved route keys */
17	unsigned int		hook;
18	struct net_device	*indev;
19	struct net_device	*outdev;
20	int			(*okfn)(struct sk_buff *);
21
22	/* extra space to store route keys */
23};
24
25#define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
26
27/* Packet queuing */
28struct nf_queue_handler {
29	int			(*outfn)(struct nf_queue_entry *entry,
30					 unsigned int queuenum);
31};
32
33void nf_register_queue_handler(const struct nf_queue_handler *qh);
34void nf_unregister_queue_handler(void);
35void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
36
37bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
38void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
39
40static inline void init_hashrandom(u32 *jhash_initval)
41{
42	while (*jhash_initval == 0)
43		*jhash_initval = prandom_u32();
44}
45
46static inline u32 hash_v4(const struct sk_buff *skb, u32 jhash_initval)
47{
48	const struct iphdr *iph = ip_hdr(skb);
49
50	/* packets in either direction go into same queue */
51	if ((__force u32)iph->saddr < (__force u32)iph->daddr)
52		return jhash_3words((__force u32)iph->saddr,
53			(__force u32)iph->daddr, iph->protocol, jhash_initval);
54
55	return jhash_3words((__force u32)iph->daddr,
56			(__force u32)iph->saddr, iph->protocol, jhash_initval);
57}
58
59#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
60static inline u32 hash_v6(const struct sk_buff *skb, u32 jhash_initval)
61{
62	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
63	u32 a, b, c;
64
65	if ((__force u32)ip6h->saddr.s6_addr32[3] <
66	    (__force u32)ip6h->daddr.s6_addr32[3]) {
67		a = (__force u32) ip6h->saddr.s6_addr32[3];
68		b = (__force u32) ip6h->daddr.s6_addr32[3];
69	} else {
70		b = (__force u32) ip6h->saddr.s6_addr32[3];
71		a = (__force u32) ip6h->daddr.s6_addr32[3];
72	}
73
74	if ((__force u32)ip6h->saddr.s6_addr32[1] <
75	    (__force u32)ip6h->daddr.s6_addr32[1])
76		c = (__force u32) ip6h->saddr.s6_addr32[1];
77	else
78		c = (__force u32) ip6h->daddr.s6_addr32[1];
79
80	return jhash_3words(a, b, c, jhash_initval);
81}
82#endif
83
84static inline u32
85nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
86	     u32 jhash_initval)
87{
88	if (family == NFPROTO_IPV4)
89		queue += ((u64) hash_v4(skb, jhash_initval) * queues_total) >> 32;
90#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
91	else if (family == NFPROTO_IPV6)
92		queue += ((u64) hash_v6(skb, jhash_initval) * queues_total) >> 32;
93#endif
94
95	return queue;
96}
97
98#endif /* _NF_QUEUE_H */
99