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 #include <linux/netfilter.h>
9 #include <linux/skbuff.h>
10
11 /* Each queued (to userspace) skbuff has one of these. */
12 struct nf_queue_entry {
13 struct list_head list;
14 struct sk_buff *skb;
15 unsigned int id;
16 unsigned int hook_index; /* index in hook_entries->hook[] */
17
18 struct nf_hook_state state;
19 u16 size; /* sizeof(entry) + saved route keys */
20
21 /* extra space to store route keys */
22 };
23
24 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
25
26 /* Packet queuing */
27 struct nf_queue_handler {
28 int (*outfn)(struct nf_queue_entry *entry,
29 unsigned int queuenum);
30 void (*nf_hook_drop)(struct net *net);
31 };
32
33 void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
34 void nf_unregister_queue_handler(struct net *net);
35 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
36
37 void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
38 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
39
init_hashrandom(u32 * jhash_initval)40 static inline void init_hashrandom(u32 *jhash_initval)
41 {
42 while (*jhash_initval == 0)
43 *jhash_initval = prandom_u32();
44 }
45
hash_v4(const struct iphdr * iph,u32 initval)46 static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
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, initval);
52
53 return jhash_3words((__force u32)iph->daddr,
54 (__force u32)iph->saddr, iph->protocol, initval);
55 }
56
hash_v6(const struct ipv6hdr * ip6h,u32 initval)57 static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
58 {
59 u32 a, b, c;
60
61 if ((__force u32)ip6h->saddr.s6_addr32[3] <
62 (__force u32)ip6h->daddr.s6_addr32[3]) {
63 a = (__force u32) ip6h->saddr.s6_addr32[3];
64 b = (__force u32) ip6h->daddr.s6_addr32[3];
65 } else {
66 b = (__force u32) ip6h->saddr.s6_addr32[3];
67 a = (__force u32) ip6h->daddr.s6_addr32[3];
68 }
69
70 if ((__force u32)ip6h->saddr.s6_addr32[1] <
71 (__force u32)ip6h->daddr.s6_addr32[1])
72 c = (__force u32) ip6h->saddr.s6_addr32[1];
73 else
74 c = (__force u32) ip6h->daddr.s6_addr32[1];
75
76 return jhash_3words(a, b, c, initval);
77 }
78
hash_bridge(const struct sk_buff * skb,u32 initval)79 static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
80 {
81 struct ipv6hdr *ip6h, _ip6h;
82 struct iphdr *iph, _iph;
83
84 switch (eth_hdr(skb)->h_proto) {
85 case htons(ETH_P_IP):
86 iph = skb_header_pointer(skb, skb_network_offset(skb),
87 sizeof(*iph), &_iph);
88 if (iph)
89 return hash_v4(iph, initval);
90 break;
91 case htons(ETH_P_IPV6):
92 ip6h = skb_header_pointer(skb, skb_network_offset(skb),
93 sizeof(*ip6h), &_ip6h);
94 if (ip6h)
95 return hash_v6(ip6h, initval);
96 break;
97 }
98
99 return 0;
100 }
101
102 static inline u32
nfqueue_hash(const struct sk_buff * skb,u16 queue,u16 queues_total,u8 family,u32 initval)103 nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
104 u32 initval)
105 {
106 switch (family) {
107 case NFPROTO_IPV4:
108 queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
109 queues_total);
110 break;
111 case NFPROTO_IPV6:
112 queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
113 queues_total);
114 break;
115 case NFPROTO_BRIDGE:
116 queue += reciprocal_scale(hash_bridge(skb, initval),
117 queues_total);
118 break;
119 }
120
121 return queue;
122 }
123
124 int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
125 unsigned int index, unsigned int verdict);
126
127 #endif /* _NF_QUEUE_H */
128
