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 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
18 struct net_device *physin;
19 struct net_device *physout;
20 #endif
21 struct nf_hook_state state;
22 u16 size; /* sizeof(entry) + saved route keys */
23
24 /* extra space to store route keys */
25 };
26
27 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
28
29 /* Packet queuing */
30 struct nf_queue_handler {
31 int (*outfn)(struct nf_queue_entry *entry,
32 unsigned int queuenum);
33 void (*nf_hook_drop)(struct net *net);
34 };
35
36 void nf_register_queue_handler(const struct nf_queue_handler *qh);
37 void nf_unregister_queue_handler(void);
38 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
39
40 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
41 void nf_queue_entry_free(struct nf_queue_entry *entry);
42
init_hashrandom(u32 * jhash_initval)43 static inline void init_hashrandom(u32 *jhash_initval)
44 {
45 while (*jhash_initval == 0)
46 *jhash_initval = get_random_u32();
47 }
48
hash_v4(const struct iphdr * iph,u32 initval)49 static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
50 {
51 /* packets in either direction go into same queue */
52 if ((__force u32)iph->saddr < (__force u32)iph->daddr)
53 return jhash_3words((__force u32)iph->saddr,
54 (__force u32)iph->daddr, iph->protocol, initval);
55
56 return jhash_3words((__force u32)iph->daddr,
57 (__force u32)iph->saddr, iph->protocol, initval);
58 }
59
hash_v6(const struct ipv6hdr * ip6h,u32 initval)60 static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
61 {
62 u32 a, b, c;
63
64 if ((__force u32)ip6h->saddr.s6_addr32[3] <
65 (__force u32)ip6h->daddr.s6_addr32[3]) {
66 a = (__force u32) ip6h->saddr.s6_addr32[3];
67 b = (__force u32) ip6h->daddr.s6_addr32[3];
68 } else {
69 b = (__force u32) ip6h->saddr.s6_addr32[3];
70 a = (__force u32) ip6h->daddr.s6_addr32[3];
71 }
72
73 if ((__force u32)ip6h->saddr.s6_addr32[1] <
74 (__force u32)ip6h->daddr.s6_addr32[1])
75 c = (__force u32) ip6h->saddr.s6_addr32[1];
76 else
77 c = (__force u32) ip6h->daddr.s6_addr32[1];
78
79 return jhash_3words(a, b, c, initval);
80 }
81
hash_bridge(const struct sk_buff * skb,u32 initval)82 static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
83 {
84 struct ipv6hdr *ip6h, _ip6h;
85 struct iphdr *iph, _iph;
86
87 switch (eth_hdr(skb)->h_proto) {
88 case htons(ETH_P_IP):
89 iph = skb_header_pointer(skb, skb_network_offset(skb),
90 sizeof(*iph), &_iph);
91 if (iph)
92 return hash_v4(iph, initval);
93 break;
94 case htons(ETH_P_IPV6):
95 ip6h = skb_header_pointer(skb, skb_network_offset(skb),
96 sizeof(*ip6h), &_ip6h);
97 if (ip6h)
98 return hash_v6(ip6h, initval);
99 break;
100 }
101
102 return 0;
103 }
104
105 static inline u32
nfqueue_hash(const struct sk_buff * skb,u16 queue,u16 queues_total,u8 family,u32 initval)106 nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
107 u32 initval)
108 {
109 switch (family) {
110 case NFPROTO_IPV4:
111 queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
112 queues_total);
113 break;
114 case NFPROTO_IPV6:
115 queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
116 queues_total);
117 break;
118 case NFPROTO_BRIDGE:
119 queue += reciprocal_scale(hash_bridge(skb, initval),
120 queues_total);
121 break;
122 }
123
124 return queue;
125 }
126
127 int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
128 unsigned int index, unsigned int verdict);
129
130 #endif /* _NF_QUEUE_H */
131