Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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