LXR linux/include/net/netfilter/nf

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _NF_QUEUE_H
   3#define _NF_QUEUE_H
   4
   5#include <linux/ip.h>
   6#include <linux/ipv6.h>
   7#include <linux/jhash.h>
   8#include <linux/netfilter.h>
   9#include <linux/skbuff.h>
  10
  11/* Each queued (to userspace) skbuff has one of these. */
  12struct nf_queue_entry {
  13        struct list_head        list;
  14        struct sk_buff          *skb;
  15        unsigned int            id;
  16        unsigned int            hook_index;     /* index in hook_entries->hook[] */
  17#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  18        struct net_device       *physin;
  19        struct net_device       *physout;
  20#endif
  21        struct nf_hook_state    state;
  22        u16                     size; /* sizeof(entry) + saved route keys */
  23
  24        /* extra space to store route keys */
  25};
  26
  27#define nf_queue_entry_reroute(x) ((void *)x + sizeof(struct nf_queue_entry))
  28
  29/* Packet queuing */
  30struct nf_queue_handler {
  31        int             (*outfn)(struct nf_queue_entry *entry,
  32                                 unsigned int queuenum);
  33        void            (*nf_hook_drop)(struct net *net);
  34};
  35
  36void nf_register_queue_handler(const struct nf_queue_handler *qh);
  37void nf_unregister_queue_handler(void);
  38void nf_reinject(struct nf_queue_entry *entry, unsigned int verdict);
  39
  40void nf_queue_entry_get_refs(struct nf_queue_entry *entry);
  41void nf_queue_entry_free(struct nf_queue_entry *entry);
  42
  43static inline void init_hashrandom(u32 *jhash_initval)
  44{
  45        while (*jhash_initval == 0)
  46                *jhash_initval = prandom_u32();
  47}
  48
  49static inline u32 hash_v4(const struct iphdr *iph, u32 initval)
  50{
  51        /* packets in either direction go into same queue */
  52        if ((__force u32)iph->saddr < (__force u32)iph->daddr)
  53                return jhash_3words((__force u32)iph->saddr,
  54                        (__force u32)iph->daddr, iph->protocol, initval);
  55
  56        return jhash_3words((__force u32)iph->daddr,
  57                        (__force u32)iph->saddr, iph->protocol, initval);
  58}
  59
  60static inline u32 hash_v6(const struct ipv6hdr *ip6h, u32 initval)
  61{
  62        u32 a, b, c;
  63
  64        if ((__force u32)ip6h->saddr.s6_addr32[3] <
  65            (__force u32)ip6h->daddr.s6_addr32[3]) {
  66                a = (__force u32) ip6h->saddr.s6_addr32[3];
  67                b = (__force u32) ip6h->daddr.s6_addr32[3];
  68        } else {
  69                b = (__force u32) ip6h->saddr.s6_addr32[3];
  70                a = (__force u32) ip6h->daddr.s6_addr32[3];
  71        }
  72
  73        if ((__force u32)ip6h->saddr.s6_addr32[1] <
  74            (__force u32)ip6h->daddr.s6_addr32[1])
  75                c = (__force u32) ip6h->saddr.s6_addr32[1];
  76        else
  77                c = (__force u32) ip6h->daddr.s6_addr32[1];
  78
  79        return jhash_3words(a, b, c, initval);
  80}
  81
  82static inline u32 hash_bridge(const struct sk_buff *skb, u32 initval)
  83{
  84        struct ipv6hdr *ip6h, _ip6h;
  85        struct iphdr *iph, _iph;
  86
  87        switch (eth_hdr(skb)->h_proto) {
  88        case htons(ETH_P_IP):
  89                iph = skb_header_pointer(skb, skb_network_offset(skb),
  90                                         sizeof(*iph), &_iph);
  91                if (iph)
  92                        return hash_v4(iph, initval);
  93                break;
  94        case htons(ETH_P_IPV6):
  95                ip6h = skb_header_pointer(skb, skb_network_offset(skb),
  96                                          sizeof(*ip6h), &_ip6h);
  97                if (ip6h)
  98                        return hash_v6(ip6h, initval);
  99                break;
 100        }
 101
 102        return 0;
 103}
 104
 105static inline u32
 106nfqueue_hash(const struct sk_buff *skb, u16 queue, u16 queues_total, u8 family,
 107             u32 initval)
 108{
 109        switch (family) {
 110        case NFPROTO_IPV4:
 111                queue += reciprocal_scale(hash_v4(ip_hdr(skb), initval),
 112                                          queues_total);
 113                break;
 114        case NFPROTO_IPV6:
 115                queue += reciprocal_scale(hash_v6(ipv6_hdr(skb), initval),
 116                                          queues_total);
 117                break;
 118        case NFPROTO_BRIDGE:
 119                queue += reciprocal_scale(hash_bridge(skb, initval),
 120                                          queues_total);
 121                break;
 122        }
 123
 124        return queue;
 125}
 126
 127int nf_queue(struct sk_buff *skb, struct nf_hook_state *state,
 128             unsigned int index, unsigned int verdict);
 129
 130#endif /* _NF_QUEUE_H */
 131