LXR linux/include/net/netfilter/nf

   1#ifndef _NF_QUEUE_H
   2#define _NF_QUEUE_H
   3
   4#include <linux/ip.h>
   5#include <linux/ipv6.h>
   6#include <linux/jhash.h>
   7
   8/* Each queued (to userspace) skbuff has one of these. */
   9struct nf_queue_entry {
  10        struct list_head        list;
  11        struct sk_buff          *skb;
  12        unsigned int            id;
  13
  14        struct nf_hook_ops      *elem;
  15        struct nf_hook_state    state;
  16        u16                     size; /* sizeof(entry) + saved route keys */
  17
  18        /* extra space to store route keys */
  19};
  20
  21#define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
  22
  23/* Packet queuing */
  24struct nf_queue_handler {
  25        int                     (*outfn)(struct nf_queue_entry *entry,
  26                                         unsigned int queuenum);
  27        void                    (*nf_hook_drop)(struct net *net,
  28                                                struct nf_hook_ops *ops);
  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 sk_buff *skb, u32 jhash_initval)
  45{
  46        const struct iphdr *iph = ip_hdr(skb);
  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, jhash_initval);
  52
  53        return jhash_3words((__force u32)iph->daddr,
  54                        (__force u32)iph->saddr, iph->protocol, jhash_initval);
  55}
  56
  57#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
  58static inline u32 hash_v6(const struct sk_buff *skb, u32 jhash_initval)
  59{
  60        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
  61        u32 a, b, c;
  62
  63        if ((__force u32)ip6h->saddr.s6_addr32[3] <
  64            (__force u32)ip6h->daddr.s6_addr32[3]) {
  65                a = (__force u32) ip6h->saddr.s6_addr32[3];
  66                b = (__force u32) ip6h->daddr.s6_addr32[3];
  67        } else {
  68                b = (__force u32) ip6h->saddr.s6_addr32[3];
  69                a = (__force u32) ip6h->daddr.s6_addr32[3];
  70        }
  71
  72        if ((__force u32)ip6h->saddr.s6_addr32[1] <
  73            (__force u32)ip6h->daddr.s6_addr32[1])
  74                c = (__force u32) ip6h->saddr.s6_addr32[1];
  75        else
  76                c = (__force u32) ip6h->daddr.s6_addr32[1];
  77
  78        return jhash_3words(a, b, c, jhash_initval);
  79}
  80#endif
  81
  82static inline u32
  83nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
  84             u32 jhash_initval)
  85{
  86        if (family == NFPROTO_IPV4)
  87                queue += ((u64) hash_v4(skb, jhash_initval) * queues_total) >> 32;
  88#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
  89        else if (family == NFPROTO_IPV6)
  90                queue += ((u64) hash_v6(skb, jhash_initval) * queues_total) >> 32;
  91#endif
  92
  93        return queue;
  94}
  95
  96#endif /* _NF_QUEUE_H */
  97