1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NF_QUEUE_H
3 #define _NF_QUEUE_H
4
5 #include <linux/ip.h>
6 #include <linux/ipv6.h>
7 #include <linux/jhash.h>
8
9 /* Each queued (to userspace) skbuff has one of these. */
10 struct nf_queue_entry {
11 struct list_head list;
12 struct sk_buff *skb;
13 unsigned int id;
14 unsigned int hook_index; /* index in hook_entries->hook[] */
15
16 struct nf_hook_state state;
17 u16 size; /* sizeof(entry) + saved route keys */
18
19 /* extra space to store route keys */
20 };
21
22 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
23
24 /* Packet queuing */
25 struct nf_queue_handler {
26 int (*outfn)(struct nf_queue_entry *entry,
27 unsigned int queuenum);
28 void (*nf_hook_drop)(struct net *net);
29 };
30
31 void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
32 void nf_unregister_queue_handler(struct net *net);
33 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
34
35 void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
36 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
37
init_hashrandom(u32 * jhash_initval)38 static inline void init_hashrandom(u32 *jhash_initval)
39 {
40 while (*jhash_initval == 0)
41 *jhash_initval = prandom_u32();
42 }
43
hash_v4(const struct iphdr * iph,u32 initval)44 static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
45 {
46 /* packets in either direction go into same queue */
47 if ((__force u32)iph->saddr < (__force u32)iph->daddr)
48 return jhash_3words((__force u32)iph->saddr,
49 (__force u32)iph->daddr, iph->protocol, initval);
50
51 return jhash_3words((__force u32)iph->daddr,
52 (__force u32)iph->saddr, iph->protocol, initval);
53 }
54
hash_v6(const struct ipv6hdr * ip6h,u32 initval)55 static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
56 {
57 u32 a, b, c;
58
59 if ((__force u32)ip6h->saddr.s6_addr32[3] <
60 (__force u32)ip6h->daddr.s6_addr32[3]) {
61 a = (__force u32) ip6h->saddr.s6_addr32[3];
62 b = (__force u32) ip6h->daddr.s6_addr32[3];
63 } else {
64 b = (__force u32) ip6h->saddr.s6_addr32[3];
65 a = (__force u32) ip6h->daddr.s6_addr32[3];
66 }
67
68 if ((__force u32)ip6h->saddr.s6_addr32[1] <
69 (__force u32)ip6h->daddr.s6_addr32[1])
70 c = (__force u32) ip6h->saddr.s6_addr32[1];
71 else
72 c = (__force u32) ip6h->daddr.s6_addr32[1];
73
74 return jhash_3words(a, b, c, initval);
75 }
76
hash_bridge(const struct sk_buff * skb,u32 initval)77 static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
78 {
79 struct ipv6hdr *ip6h, _ip6h;
80 struct iphdr *iph, _iph;
81
82 switch (eth_hdr(skb)->h_proto) {
83 case htons(ETH_P_IP):
84 iph = skb_header_pointer(skb, skb_network_offset(skb),
85 sizeof(*iph), &_iph);
86 if (iph)
87 return hash_v4(iph, initval);
88 break;
89 case htons(ETH_P_IPV6):
90 ip6h = skb_header_pointer(skb, skb_network_offset(skb),
91 sizeof(*ip6h), &_ip6h);
92 if (ip6h)
93 return hash_v6(ip6h, initval);
94 break;
95 }
96
97 return 0;
98 }
99
100 static inline u32
nfqueue_hash(const struct sk_buff * skb,u16 queue,u16 queues_total,u8 family,u32 initval)101 nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
102 u32 initval)
103 {
104 switch (family) {
105 case NFPROTO_IPV4:
106 queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
107 queues_total);
108 break;
109 case NFPROTO_IPV6:
110 queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
111 queues_total);
112 break;
113 case NFPROTO_BRIDGE:
114 queue += reciprocal_scale(hash_bridge(skb, initval),
115 queues_total);
116 break;
117 }
118
119 return queue;
120 }
121
122 #endif /* _NF_QUEUE_H */
123
