include/net/netfilter/nf_queue.h

   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. */
   9 struct 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         u16                     size; /* sizeof(entry) + saved route keys */
  16
  17         /* extra space to store route keys */
  18 };
  19
  20 #define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
  21
  22 /* Packet queuing */
  23 struct nf_queue_handler {
  24         int             (*outfn)(struct nf_queue_entry *entry,
  25                                  unsigned int queuenum);
  26         void            (*nf_hook_drop)(struct net *net,
  27                                         const struct nf_hook_entry *hooks);
  28 };
  29
  30 void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
  31 void nf_unregister_queue_handler(struct net *net);
  32 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  33
  34 void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  35 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  36
  37 static inline void init_hashrandom(u32 *jhash_initval)
  38 {
  39         while (*jhash_initval == 0)
  40                 *jhash_initval = prandom_u32();
  41 }
  42
  43 static 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
  54 static 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
  76 static 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
  99 static inline u32
 100 nfqueue_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 */