Commit 05423b24 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

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: default avatarGertjan Hofman <gertjan_hofman@yahoo.com>
Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9dbb58d8
......@@ -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;
......
......@@ -89,7 +89,7 @@ static inline u32 vlan_get_ingress_priority(struct net_device *dev,
{
struct vlan_dev_info *vip = vlan_dev_info(dev);
return vip->ingress_priority_map[(vlan_tci >> 13) & 0x7];
return vip->ingress_priority_map[(vlan_tci >> VLAN_PRIO_SHIFT) & 0x7];
}
#ifdef CONFIG_VLAN_8021Q_GVRP
......
......@@ -393,7 +393,7 @@ int vlan_dev_set_egress_priority(const struct net_device *dev,
struct vlan_dev_info *vlan = vlan_dev_info(dev);
struct vlan_priority_tci_mapping *mp = NULL;
struct vlan_priority_tci_mapping *np;
u32 vlan_qos = (vlan_prio << 13) & 0xE000;
u32 vlan_qos = (vlan_prio << VLAN_PRIO_SHIFT) & VLAN_PRIO_MASK;
/* See if a priority mapping exists.. */
mp = vlan->egress_priority_map[skb_prio & 0xF];
......
......@@ -2300,7 +2300,7 @@ int netif_receive_skb(struct sk_buff *skb)
if (!skb->tstamp.tv64)
net_timestamp(skb);
if (skb->vlan_tci && vlan_hwaccel_do_receive(skb))
if (vlan_tx_tag_present(skb) && vlan_hwaccel_do_receive(skb))
return NET_RX_SUCCESS;
/* if we've gotten here through NAPI, check netpoll */
......
......@@ -79,6 +79,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/if_vlan.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
......@@ -766,7 +767,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
getnstimeofday(&ts);
h.h2->tp_sec = ts.tv_sec;
h.h2->tp_nsec = ts.tv_nsec;
h.h2->tp_vlan_tci = skb->vlan_tci;
h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
hdrlen = sizeof(*h.h2);
break;
default:
......@@ -1493,7 +1494,7 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
aux.tp_snaplen = skb->len;
aux.tp_mac = 0;
aux.tp_net = skb_network_offset(skb);
aux.tp_vlan_tci = skb->vlan_tci;
aux.tp_vlan_tci = vlan_tx_tag_get(skb);
put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
}
......
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