projects / ovs.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 */ |