364 lines
9.3 KiB
C
364 lines
9.3 KiB
C
/*
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* VLAN An implementation of 802.1Q VLAN tagging.
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*
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* Authors: Ben Greear <greearb@candelatech.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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*/
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#ifndef _LINUX_IF_VLAN_H_
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#define _LINUX_IF_VLAN_H_
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#include <linux/netdevice.h>
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#include <linux/etherdevice.h>
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#include <linux/rtnetlink.h>
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#include <linux/bug.h>
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#include <uapi/linux/if_vlan.h>
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#define VLAN_HLEN 4 /* The additional bytes required by VLAN
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* (in addition to the Ethernet header)
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*/
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#define VLAN_ETH_HLEN 18 /* Total octets in header. */
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#define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
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/*
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* According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
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*/
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#define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
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#define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
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/*
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* struct vlan_hdr - vlan header
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* @h_vlan_TCI: priority and VLAN ID
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* @h_vlan_encapsulated_proto: packet type ID or len
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*/
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struct vlan_hdr {
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__be16 h_vlan_TCI;
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__be16 h_vlan_encapsulated_proto;
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};
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/**
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* struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
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* @h_dest: destination ethernet address
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* @h_source: source ethernet address
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* @h_vlan_proto: ethernet protocol (always 0x8100)
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* @h_vlan_TCI: priority and VLAN ID
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* @h_vlan_encapsulated_proto: packet type ID or len
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*/
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struct vlan_ethhdr {
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unsigned char h_dest[ETH_ALEN];
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unsigned char h_source[ETH_ALEN];
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__be16 h_vlan_proto;
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__be16 h_vlan_TCI;
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__be16 h_vlan_encapsulated_proto;
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};
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#include <linux/skbuff.h>
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static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
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{
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return (struct vlan_ethhdr *)skb_mac_header(skb);
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}
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#define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
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#define VLAN_PRIO_SHIFT 13
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#define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
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#define VLAN_TAG_PRESENT VLAN_CFI_MASK
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#define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
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#define VLAN_N_VID 4096
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/* found in socket.c */
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extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
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static inline int is_vlan_dev(struct net_device *dev)
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{
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return dev->priv_flags & IFF_802_1Q_VLAN;
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}
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#define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
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#define vlan_tx_nonzero_tag_present(__skb) \
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(vlan_tx_tag_present(__skb) && ((__skb)->vlan_tci & VLAN_VID_MASK))
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#define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
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#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
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extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
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u16 vlan_id);
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extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
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extern u16 vlan_dev_vlan_id(const struct net_device *dev);
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extern bool vlan_do_receive(struct sk_buff **skb);
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extern struct sk_buff *vlan_untag(struct sk_buff *skb);
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extern int vlan_vid_add(struct net_device *dev, unsigned short vid);
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extern void vlan_vid_del(struct net_device *dev, unsigned short vid);
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extern int vlan_vids_add_by_dev(struct net_device *dev,
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const struct net_device *by_dev);
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extern void vlan_vids_del_by_dev(struct net_device *dev,
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const struct net_device *by_dev);
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extern bool vlan_uses_dev(const struct net_device *dev);
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#else
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static inline struct net_device *
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__vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
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{
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return NULL;
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}
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static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
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{
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BUG();
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return NULL;
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}
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static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
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{
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BUG();
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return 0;
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}
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static inline bool vlan_do_receive(struct sk_buff **skb)
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{
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return false;
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}
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static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
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{
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return skb;
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}
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static inline int vlan_vid_add(struct net_device *dev, unsigned short vid)
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{
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return 0;
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}
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static inline void vlan_vid_del(struct net_device *dev, unsigned short vid)
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{
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}
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static inline int vlan_vids_add_by_dev(struct net_device *dev,
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const struct net_device *by_dev)
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{
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return 0;
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}
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static inline void vlan_vids_del_by_dev(struct net_device *dev,
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const struct net_device *by_dev)
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{
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}
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static inline bool vlan_uses_dev(const struct net_device *dev)
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{
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return false;
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}
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#endif
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/**
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* vlan_insert_tag - regular VLAN tag inserting
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* @skb: skbuff to tag
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* @vlan_tci: VLAN TCI to insert
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*
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* Inserts the VLAN tag into @skb as part of the payload
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* Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
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*
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* Following the skb_unshare() example, in case of error, the calling function
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* doesn't have to worry about freeing the original skb.
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*
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* Does not change skb->protocol so this function can be used during receive.
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*/
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static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
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{
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struct vlan_ethhdr *veth;
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if (skb_cow_head(skb, VLAN_HLEN) < 0) {
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kfree_skb(skb);
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return NULL;
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}
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veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
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/* Move the mac addresses to the beginning of the new header. */
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memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
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skb->mac_header -= VLAN_HLEN;
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/* first, the ethernet type */
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veth->h_vlan_proto = htons(ETH_P_8021Q);
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/* now, the TCI */
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veth->h_vlan_TCI = htons(vlan_tci);
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return skb;
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}
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/**
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* __vlan_put_tag - regular VLAN tag inserting
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* @skb: skbuff to tag
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* @vlan_tci: VLAN TCI to insert
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*
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* Inserts the VLAN tag into @skb as part of the payload
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* Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
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*
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* Following the skb_unshare() example, in case of error, the calling function
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* doesn't have to worry about freeing the original skb.
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*/
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static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
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{
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skb = vlan_insert_tag(skb, vlan_tci);
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if (skb)
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skb->protocol = htons(ETH_P_8021Q);
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return skb;
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}
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/**
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* __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
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* @skb: skbuff to tag
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* @vlan_tci: VLAN TCI to insert
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*
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* Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
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*/
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static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
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u16 vlan_tci)
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{
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skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
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return skb;
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}
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#define HAVE_VLAN_PUT_TAG
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/**
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* vlan_put_tag - inserts VLAN tag according to device features
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* @skb: skbuff to tag
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* @vlan_tci: VLAN TCI to insert
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*
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* Assumes skb->dev is the target that will xmit this frame.
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* Returns a VLAN tagged skb.
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*/
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static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
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{
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if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
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return __vlan_hwaccel_put_tag(skb, vlan_tci);
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} else {
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return __vlan_put_tag(skb, vlan_tci);
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}
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}
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/**
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* __vlan_get_tag - get the VLAN ID that is part of the payload
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* @skb: skbuff to query
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* @vlan_tci: buffer to store vlaue
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*
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* Returns error if the skb is not of VLAN type
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*/
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static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
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{
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struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
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if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
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return -EINVAL;
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}
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*vlan_tci = ntohs(veth->h_vlan_TCI);
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return 0;
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}
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/**
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* __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
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* @skb: skbuff to query
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* @vlan_tci: buffer to store vlaue
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*
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* Returns error if @skb->vlan_tci is not set correctly
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*/
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static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
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u16 *vlan_tci)
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{
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if (vlan_tx_tag_present(skb)) {
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*vlan_tci = vlan_tx_tag_get(skb);
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return 0;
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} else {
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*vlan_tci = 0;
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return -EINVAL;
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}
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}
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#define HAVE_VLAN_GET_TAG
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/**
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* vlan_get_tag - get the VLAN ID from the skb
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* @skb: skbuff to query
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* @vlan_tci: buffer to store vlaue
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*
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* Returns error if the skb is not VLAN tagged
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*/
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static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
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{
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if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
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return __vlan_hwaccel_get_tag(skb, vlan_tci);
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} else {
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return __vlan_get_tag(skb, vlan_tci);
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}
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}
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/**
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* vlan_get_protocol - get protocol EtherType.
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* @skb: skbuff to query
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*
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* Returns the EtherType of the packet, regardless of whether it is
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* vlan encapsulated (normal or hardware accelerated) or not.
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*/
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static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
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{
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__be16 protocol = 0;
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if (vlan_tx_tag_present(skb) ||
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skb->protocol != cpu_to_be16(ETH_P_8021Q))
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protocol = skb->protocol;
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else {
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__be16 proto, *protop;
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protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
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h_vlan_encapsulated_proto),
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sizeof(proto), &proto);
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if (likely(protop))
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protocol = *protop;
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}
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return protocol;
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}
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static inline void vlan_set_encap_proto(struct sk_buff *skb,
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struct vlan_hdr *vhdr)
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{
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__be16 proto;
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unsigned short *rawp;
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/*
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* Was a VLAN packet, grab the encapsulated protocol, which the layer
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* three protocols care about.
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*/
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proto = vhdr->h_vlan_encapsulated_proto;
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if (ntohs(proto) >= 1536) {
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skb->protocol = proto;
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return;
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}
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rawp = (unsigned short *)(vhdr + 1);
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if (*rawp == 0xFFFF)
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/*
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* This is a magic hack to spot IPX packets. Older Novell
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* breaks the protocol design and runs IPX over 802.3 without
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* an 802.2 LLC layer. We look for FFFF which isn't a used
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* 802.2 SSAP/DSAP. This won't work for fault tolerant netware
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* but does for the rest.
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*/
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skb->protocol = htons(ETH_P_802_3);
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else
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/*
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* Real 802.2 LLC
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*/
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skb->protocol = htons(ETH_P_802_2);
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}
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#endif /* !(_LINUX_IF_VLAN_H_) */
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