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| author |   Eric Dumazet <eric.dumazet@gmail.com> | 2009-10-26 18:40:35 -0700 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2009-10-27 01:02:33 -0700 |
| commit | 05423b241311c9380b7280179295bac7794281b6 (patch) | |
| tree | 8a84aca48cbc30b142bdf143dbf11fdbab9cad67 /include/linux/if_vlan.h | |
| parent | can: sja1000: fix bug using library functions for skb allocation (diff) | |
| download | linux-dev-05423b241311c9380b7280179295bac7794281b6.tar.xz linux-dev-05423b241311c9380b7280179295bac7794281b6.zip | |
vlan: allow null VLAN ID to be used
We currently use a 16 bit field (vlan_tci) to store VLAN ID/PRIO on a skb.
Null value is used as a special value, meaning vlan tagging not enabled.
This forbids use of null vlan ID.
As pointed by David, some drivers use the 3 high order bits (PRIO)
As VLAN ID is 12 bits, we can use the remaining bit (CFI) as a flag, and
allow null VLAN ID.
In case future code really wants to use VLAN_CFI_MASK, we'll have to use
a bit outside of vlan_tci.
#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
#define VLAN_PRIO_SHIFT 13
#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
#define VLAN_TAG_PRESENT VLAN_CFI_MASK
#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
Reported-by: Gertjan Hofman <gertjan_hofman@yahoo.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/if_vlan.h')
| -rw-r--r-- | include/linux/if_vlan.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 7ff9af1d0f05..8898cbebcf34 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -63,7 +63,11 @@ static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) return (struct vlan_ethhdr *)skb_mac_header(skb); } -#define VLAN_VID_MASK 0xfff +#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ +#define VLAN_PRIO_SHIFT 13 +#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */ +#define VLAN_TAG_PRESENT VLAN_CFI_MASK +#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */ /* found in socket.c */ extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); @@ -105,8 +109,8 @@ static inline void vlan_group_set_device(struct vlan_group *vg, array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev; } -#define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci) -#define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci) +#define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) +#define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); @@ -231,7 +235,7 @@ static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, u16 vlan_tci) { - skb->vlan_tci = vlan_tci; + skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci; return skb; } @@ -284,7 +288,7 @@ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, u16 *vlan_tci) { if (vlan_tx_tag_present(skb)) { - *vlan_tci = skb->vlan_tci; + *vlan_tci = vlan_tx_tag_get(skb); return 0; } else { *vlan_tci = 0; |