LXR linux/include/net/netfilter/nf

   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. */
  10struct 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 */
  25struct 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
  31void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
  32void nf_unregister_queue_handler(struct net *net);
  33void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  34
  35void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  36void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  37
  38static inline void init_hashrandom(u32 *jhash_initval)
  39{
  40        while (*jhash_initval == 0)
  41                *jhash_initval = prandom_u32();
  42}
  43
  44static 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
  55static 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
  77static 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
 100static inline u32
 101nfqueue_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
 122int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
 123             unsigned int index, unsigned int verdict);
 124#endif /* _NF_QUEUE_H */
 125