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_state    state;
  15        struct nf_hook_entry    *hook;
  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        unsigned int    (*nf_hook_drop)(struct net *net);
  28};
  29
  30void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
  31void nf_unregister_queue_handler(struct net *net);
  32void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  33
  34void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  35void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  36
  37static inline void init_hashrandom(u32 *jhash_initval)
  38{
  39        while (*jhash_initval == 0)
  40                *jhash_initval = prandom_u32();
  41}
  42
  43static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
  44{
  45        /* packets in either direction go into same queue */
  46        if ((__force u32)iph->saddr < (__force u32)iph->daddr)
  47                return jhash_3words((__force u32)iph->saddr,
  48                        (__force u32)iph->daddr, iph->protocol, initval);
  49
  50        return jhash_3words((__force u32)iph->daddr,
  51                        (__force u32)iph->saddr, iph->protocol, initval);
  52}
  53
  54static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
  55{
  56        u32 a, b, c;
  57
  58        if ((__force u32)ip6h->saddr.s6_addr32[3] <
  59            (__force u32)ip6h->daddr.s6_addr32[3]) {
  60                a = (__force u32) ip6h->saddr.s6_addr32[3];
  61                b = (__force u32) ip6h->daddr.s6_addr32[3];
  62        } else {
  63                b = (__force u32) ip6h->saddr.s6_addr32[3];
  64                a = (__force u32) ip6h->daddr.s6_addr32[3];
  65        }
  66
  67        if ((__force u32)ip6h->saddr.s6_addr32[1] <
  68            (__force u32)ip6h->daddr.s6_addr32[1])
  69                c = (__force u32) ip6h->saddr.s6_addr32[1];
  70        else
  71                c = (__force u32) ip6h->daddr.s6_addr32[1];
  72
  73        return jhash_3words(a, b, c, initval);
  74}
  75
  76static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
  77{
  78        struct ipv6hdr *ip6h, _ip6h;
  79        struct iphdr *iph, _iph;
  80
  81        switch (eth_hdr(skb)->h_proto) {
  82        case htons(ETH_P_IP):
  83                iph = skb_header_pointer(skb, skb_network_offset(skb),
  84                                         sizeof(*iph), &_iph);
  85                if (iph)
  86                        return hash_v4(iph, initval);
  87                break;
  88        case htons(ETH_P_IPV6):
  89                ip6h = skb_header_pointer(skb, skb_network_offset(skb),
  90                                          sizeof(*ip6h), &_ip6h);
  91                if (ip6h)
  92                        return hash_v6(ip6h, initval);
  93                break;
  94        }
  95
  96        return 0;
  97}
  98
  99static inline u32
 100nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
 101             u32 initval)
 102{
 103        switch (family) {
 104        case NFPROTO_IPV4:
 105                queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
 106                                          queues_total);
 107                break;
 108        case NFPROTO_IPV6:
 109                queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
 110                                          queues_total);
 111                break;
 112        case NFPROTO_BRIDGE:
 113                queue += reciprocal_scale(hash_bridge(skb, initval),
 114                                          queues_total);
 115                break;
 116        }
 117
 118        return queue;
 119}
 120
 121#endif /* _NF_QUEUE_H */
 122