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/rhashtable-types.h>
10 #include <linux/skbuff.h>
11
12 /* Each queued (to userspace) skbuff has one of these. */
13 struct nf_queue_entry {
14 struct list_head list;
15 struct rhash_head hash_node;
16 struct sk_buff *skb;
17 unsigned int id;
18 unsigned int hook_index; /* index in hook_entries->hook[] */
19 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
20 struct net_device *physin;
21 struct net_device *physout;
22 #endif
23 struct nf_hook_state state;
24 bool nf_ct_is_unconfirmed;
25 u16 size; /* sizeof(entry) + saved route keys */
26 u16 queue_num;
27
28 /* extra space to store route keys */
29 };
30
31 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
32
33 /* Packet queuing */
34 struct nf_queue_handler {
35 int (*outfn)(struct nf_queue_entry *entry,
36 unsigned int queuenum);
37 void (*nf_hook_drop)(struct net *net);
38 };
39
40 void nf_register_queue_handler(const struct nf_queue_handler *qh);
41 void nf_unregister_queue_handler(void);
42
43 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
44 void nf_queue_entry_free(struct nf_queue_entry *entry);
45
init_hashrandom(u32 * jhash_initval)46 static inline void init_hashrandom(u32 *jhash_initval)
47 {
48 while (*jhash_initval == 0)
49 *jhash_initval = get_random_u32();
50 }
51
hash_v4(const struct iphdr * iph,u32 initval)52 static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
53 {
54 /* packets in either direction go into same queue */
55 if ((__force u32)iph->saddr < (__force u32)iph->daddr)
56 return jhash_3words((__force u32)iph->saddr,
57 (__force u32)iph->daddr, iph->protocol, initval);
58
59 return jhash_3words((__force u32)iph->daddr,
60 (__force u32)iph->saddr, iph->protocol, initval);
61 }
62
hash_v6(const struct ipv6hdr * ip6h,u32 initval)63 static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
64 {
65 u32 a, b, c;
66
67 if ((__force u32)ip6h->saddr.s6_addr32[3] <
68 (__force u32)ip6h->daddr.s6_addr32[3]) {
69 a = (__force u32) ip6h->saddr.s6_addr32[3];
70 b = (__force u32) ip6h->daddr.s6_addr32[3];
71 } else {
72 b = (__force u32) ip6h->saddr.s6_addr32[3];
73 a = (__force u32) ip6h->daddr.s6_addr32[3];
74 }
75
76 if ((__force u32)ip6h->saddr.s6_addr32[1] <
77 (__force u32)ip6h->daddr.s6_addr32[1])
78 c = (__force u32) ip6h->saddr.s6_addr32[1];
79 else
80 c = (__force u32) ip6h->daddr.s6_addr32[1];
81
82 return jhash_3words(a, b, c, initval);
83 }
84
hash_bridge(const struct sk_buff * skb,u32 initval)85 static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
86 {
87 struct ipv6hdr *ip6h, _ip6h;
88 struct iphdr *iph, _iph;
89
90 switch (eth_hdr(skb)->h_proto) {
91 case htons(ETH_P_IP):
92 iph = skb_header_pointer(skb, skb_network_offset(skb),
93 sizeof(*iph), &_iph);
94 if (iph)
95 return hash_v4(iph, initval);
96 break;
97 case htons(ETH_P_IPV6):
98 ip6h = skb_header_pointer(skb, skb_network_offset(skb),
99 sizeof(*ip6h), &_ip6h);
100 if (ip6h)
101 return hash_v6(ip6h, initval);
102 break;
103 }
104
105 return 0;
106 }
107
108 static inline u32
nfqueue_hash(const struct sk_buff * skb,u16 queue,u16 queues_total,u8 family,u32 initval)109 nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
110 u32 initval)
111 {
112 switch (family) {
113 case NFPROTO_IPV4:
114 queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
115 queues_total);
116 break;
117 case NFPROTO_IPV6:
118 queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
119 queues_total);
120 break;
121 case NFPROTO_BRIDGE:
122 queue += reciprocal_scale(hash_bridge(skb, initval),
123 queues_total);
124 break;
125 }
126
127 return queue;
128 }
129
130 int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
131 unsigned int index, unsigned int verdict);
132
133 #endif /* _NF_QUEUE_H */
134