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};
  28
  29void nf_register_queue_handler(const struct nf_queue_handler *qh);
  30void nf_unregister_queue_handler(void);
  31void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  32
  33bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  34void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  35
  36static inline void init_hashrandom(u32 *jhash_initval)
  37{
  38        while (*jhash_initval == 0)
  39                *jhash_initval = prandom_u32();
  40}
  41
  42static inline u32 hash_v4(const struct sk_buff *skb, u32 jhash_initval)
  43{
  44        const struct iphdr *iph = ip_hdr(skb);
  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, jhash_initval);
  50
  51        return jhash_3words((__force u32)iph->daddr,
  52                        (__force u32)iph->saddr, iph->protocol, jhash_initval);
  53}
  54
  55#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
  56static inline u32 hash_v6(const struct sk_buff *skb, u32 jhash_initval)
  57{
  58        const struct ipv6hdr *ip6h = ipv6_hdr(skb);
  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, jhash_initval);
  77}
  78#endif
  79
  80static inline u32
  81nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
  82             u32 jhash_initval)
  83{
  84        if (family == NFPROTO_IPV4)
  85                queue += ((u64) hash_v4(skb, jhash_initval) * queues_total) >> 32;
  86#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
  87        else if (family == NFPROTO_IPV6)
  88                queue += ((u64) hash_v6(skb, jhash_initval) * queues_total) >> 32;
  89#endif
  90
  91        return queue;
  92}
  93
  94#endif /* _NF_QUEUE_H */
  95