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6e0ce48e | 1 | /* |
e0edde6f | 2 | * Copyright (c) 2007-2011 Nicira, Inc. |
6e0ce48e | 3 | * |
a9a29d22 JG |
4 | * This program is free software; you can redistribute it and/or |
5 | * modify it under the terms of version 2 of the GNU General Public | |
6 | * License as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
16 | * 02110-1301, USA | |
6e0ce48e JG |
17 | */ |
18 | ||
19 | #ifndef VLAN_H | |
20 | #define VLAN_H 1 | |
21 | ||
22 | #include <linux/if_vlan.h> | |
23 | #include <linux/skbuff.h> | |
24 | #include <linux/version.h> | |
25 | ||
37286523 BP |
26 | /** |
27 | * DOC: VLAN tag manipulation. | |
28 | * | |
29 | * &struct sk_buff handling of VLAN tags has evolved over time: | |
30 | * | |
31 | * In 2.6.26 and earlier, VLAN tags did not have any generic representation in | |
32 | * an skb, other than as a raw 802.1Q header inside the packet data. | |
33 | * | |
34 | * In 2.6.27 &struct sk_buff added a @vlan_tci member. Between 2.6.27 and | |
35 | * 2.6.32, its value was the raw contents of the 802.1Q TCI field, or zero if | |
36 | * no 802.1Q header was present. This worked OK except for the corner case of | |
37 | * an 802.1Q header with an all-0-bits TCI, which could not be represented. | |
38 | * | |
39 | * In 2.6.33, @vlan_tci semantics changed. Now, if an 802.1Q header is | |
40 | * present, then the VLAN_TAG_PRESENT bit is always set. This fixes the | |
41 | * all-0-bits TCI corner case. | |
42 | * | |
43 | * For compatibility we emulate the 2.6.33+ behavior on earlier kernel | |
44 | * versions. The client must not access @vlan_tci directly. Instead, use | |
45 | * vlan_get_tci() to read it or vlan_set_tci() to write it, with semantics | |
46 | * equivalent to those on 2.6.33+. | |
47 | */ | |
48 | ||
6e0ce48e JG |
49 | static inline u16 vlan_get_tci(struct sk_buff *skb) |
50 | { | |
37286523 BP |
51 | #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33) |
52 | if (skb->vlan_tci) | |
53 | return skb->vlan_tci | VLAN_TAG_PRESENT; | |
54 | #endif | |
6e0ce48e JG |
55 | return skb->vlan_tci; |
56 | } | |
57 | ||
58 | static inline void vlan_set_tci(struct sk_buff *skb, u16 vlan_tci) | |
59 | { | |
37286523 BP |
60 | #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,33) |
61 | vlan_tci &= ~VLAN_TAG_PRESENT; | |
62 | #endif | |
6e0ce48e JG |
63 | skb->vlan_tci = vlan_tci; |
64 | } | |
6e0ce48e | 65 | #endif /* vlan.h */ |