LXR linux/include/linux/netfilter

   1#ifndef __LINUX_BRIDGE_NETFILTER_H
   2#define __LINUX_BRIDGE_NETFILTER_H
   3
   4#include <uapi/linux/netfilter_bridge.h>
   5
   6
   7enum nf_br_hook_priorities {
   8        NF_BR_PRI_FIRST = INT_MIN,
   9        NF_BR_PRI_NAT_DST_BRIDGED = -300,
  10        NF_BR_PRI_FILTER_BRIDGED = -200,
  11        NF_BR_PRI_BRNF = 0,
  12        NF_BR_PRI_NAT_DST_OTHER = 100,
  13        NF_BR_PRI_FILTER_OTHER = 200,
  14        NF_BR_PRI_NAT_SRC = 300,
  15        NF_BR_PRI_LAST = INT_MAX,
  16};
  17
  18#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
  19
  20#define BRNF_PKT_TYPE                   0x01
  21#define BRNF_BRIDGED_DNAT               0x02
  22#define BRNF_BRIDGED                    0x04
  23#define BRNF_NF_BRIDGE_PREROUTING       0x08
  24#define BRNF_8021Q                      0x10
  25#define BRNF_PPPoE                      0x20
  26
  27static inline unsigned int nf_bridge_encap_header_len(const struct sk_buff *skb)
  28{
  29        switch (skb->protocol) {
  30        case __cpu_to_be16(ETH_P_8021Q):
  31                return VLAN_HLEN;
  32        case __cpu_to_be16(ETH_P_PPP_SES):
  33                return PPPOE_SES_HLEN;
  34        default:
  35                return 0;
  36        }
  37}
  38
  39static inline void nf_bridge_update_protocol(struct sk_buff *skb)
  40{
  41        if (skb->nf_bridge->mask & BRNF_8021Q)
  42                skb->protocol = htons(ETH_P_8021Q);
  43        else if (skb->nf_bridge->mask & BRNF_PPPoE)
  44                skb->protocol = htons(ETH_P_PPP_SES);
  45}
  46
  47/* Fill in the header for fragmented IP packets handled by
  48 * the IPv4 connection tracking code.
  49 *
  50 * Only used in br_forward.c
  51 */
  52static inline int nf_bridge_copy_header(struct sk_buff *skb)
  53{
  54        int err;
  55        unsigned int header_size;
  56
  57        nf_bridge_update_protocol(skb);
  58        header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
  59        err = skb_cow_head(skb, header_size);
  60        if (err)
  61                return err;
  62
  63        skb_copy_to_linear_data_offset(skb, -header_size,
  64                                       skb->nf_bridge->data, header_size);
  65        __skb_push(skb, nf_bridge_encap_header_len(skb));
  66        return 0;
  67}
  68
  69static inline int nf_bridge_maybe_copy_header(struct sk_buff *skb)
  70{
  71        if (skb->nf_bridge &&
  72            skb->nf_bridge->mask & (BRNF_BRIDGED | BRNF_BRIDGED_DNAT))
  73                return nf_bridge_copy_header(skb);
  74        return 0;
  75}
  76
  77static inline unsigned int nf_bridge_mtu_reduction(const struct sk_buff *skb)
  78{
  79        if (unlikely(skb->nf_bridge->mask & BRNF_PPPoE))
  80                return PPPOE_SES_HLEN;
  81        return 0;
  82}
  83
  84int br_handle_frame_finish(struct sk_buff *skb);
  85/* Only used in br_device.c */
  86static inline int br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
  87{
  88        struct nf_bridge_info *nf_bridge = skb->nf_bridge;
  89
  90        skb_pull(skb, ETH_HLEN);
  91        nf_bridge->mask ^= BRNF_BRIDGED_DNAT;
  92        skb_copy_to_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN),
  93                                       skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
  94        skb->dev = nf_bridge->physindev;
  95        return br_handle_frame_finish(skb);
  96}
  97
  98/* This is called by the IP fragmenting code and it ensures there is
  99 * enough room for the encapsulating header (if there is one). */
 100static inline unsigned int nf_bridge_pad(const struct sk_buff *skb)
 101{
 102        if (skb->nf_bridge)
 103                return nf_bridge_encap_header_len(skb);
 104        return 0;
 105}
 106
 107struct bridge_skb_cb {
 108        union {
 109                __be32 ipv4;
 110        } daddr;
 111};
 112
 113static inline void br_drop_fake_rtable(struct sk_buff *skb)
 114{
 115        struct dst_entry *dst = skb_dst(skb);
 116
 117        if (dst && (dst->flags & DST_FAKE_RTABLE))
 118                skb_dst_drop(skb);
 119}
 120
 121#else
 122#define nf_bridge_maybe_copy_header(skb)        (0)
 123#define nf_bridge_pad(skb)                      (0)
 124#define br_drop_fake_rtable(skb)                do { } while (0)
 125#endif /* CONFIG_BRIDGE_NETFILTER */
 126
 127#endif
 128