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_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 */
  24 struct 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
  31 void nf_register_queue_handler(struct net *net, const struct nf_queue_handler *qh);
  32 void nf_unregister_queue_handler(struct net *net);
  33 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  34
  35 void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  36 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  37
  38 static inline void init_hashrandom(u32 *jhash_initval)
  39 {
  40         while (*jhash_initval == 0)
  41                 *jhash_initval = prandom_u32();
  42 }
  43
  44 static 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)
  58 static 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
  82 static inline u32
  83 nfqueue_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 */