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authorEric Dumazet <eric.dumazet@gmail.com>2009-10-26 18:40:35 -0700
committerDavid S. Miller <davem@davemloft.net>2009-10-27 01:02:33 -0700
commit05423b241311c9380b7280179295bac7794281b6 (patch)
tree8a84aca48cbc30b142bdf143dbf11fdbab9cad67 /include
parentcan: sja1000: fix bug using library functions for skb allocation (diff)
downloadlinux-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')
-rw-r--r--include/linux/if_vlan.h14
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;