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 };
  28
  29 void nf_register_queue_handler(const struct nf_queue_handler *qh);
  30 void nf_unregister_queue_handler(void);
  31 void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  32
  33 bool nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  34 void nf_queue_entry_release_refs(struct nf_queue_entry *entry);
  35
  36 static inline void init_hashrandom(u32 *jhash_initval)
  37 {
  38         while (*jhash_initval == 0)
  39                 *jhash_initval = prandom_u32();
  40 }
  41
  42 static 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)
  56 static 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
  80 static inline u32
  81 nfqueue_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 */