linux/include/linux/if_vlan.h

/*
 * VLAN		An implementation of 802.1Q VLAN tagging.
 *
 * Authors:	Ben Greear <greearb@candelatech.com>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 */

#ifndef _LINUX_IF_VLAN_H_
#define _LINUX_IF_VLAN_H_

#ifdef __KERNEL__
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>

#define VLAN_HLEN	4		/* The additional bytes (on top of the Ethernet header)
					 * that VLAN requires.
					 */
#define VLAN_ETH_ALEN	6		/* Octets in one ethernet addr	 */
#define VLAN_ETH_HLEN	18		/* Total octets in header.	 */
#define VLAN_ETH_ZLEN	64		/* Min. octets in frame sans FCS */

/*
 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
 */
#define VLAN_ETH_DATA_LEN	1500	/* Max. octets in payload	 */
#define VLAN_ETH_FRAME_LEN	1518	/* Max. octets in frame sans FCS */

/*
 * 	struct vlan_hdr - vlan header
 * 	@h_vlan_TCI: priority and VLAN ID
 *	@h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_hdr {
	__be16	h_vlan_TCI;
	__be16	h_vlan_encapsulated_proto;
};

/**
 *	struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
 *	@h_dest: destination ethernet address
 *	@h_source: source ethernet address
 *	@h_vlan_proto: ethernet protocol (always 0x8100)
 *	@h_vlan_TCI: priority and VLAN ID
 *	@h_vlan_encapsulated_proto: packet type ID or len
 */
struct vlan_ethhdr {
	unsigned char	h_dest[ETH_ALEN];
	unsigned char	h_source[ETH_ALEN];
	__be16		h_vlan_proto;
	__be16		h_vlan_TCI;
	__be16		h_vlan_encapsulated_proto;
};

#include <linux/skbuff.h>

static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
{
	return (struct vlan_ethhdr *)skb_mac_header(skb);
}

#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 */
#define VLAN_N_VID		4096

/* found in socket.c */
extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));

/* if this changes, algorithm will have to be reworked because this
 * depends on completely exhausting the VLAN identifier space.  Thus
 * it gives constant time look-up, but in many cases it wastes memory.
 */
#define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
#define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_N_VID/VLAN_GROUP_ARRAY_SPLIT_PARTS)

struct vlan_group {
	struct net_device	*real_dev; /* The ethernet(like) device
					    * the vlan is attached to.
					    */
	unsigned int		nr_vlans;
	struct hlist_node	hlist;	/* linked list */
	struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
	struct rcu_head		rcu;
};

static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
						       u16 vlan_id)
{
	struct net_device **array;
	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
	return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
}

static inline void vlan_group_set_device(struct vlan_group *vg,
					 u16 vlan_id,
					 struct net_device *dev)
{
	struct net_device **array;
	if (!vg)
		return;
	array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
	array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
}

#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)
/* Must be invoked with rcu_read_lock or with RTNL. */
static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
					       u16 vlan_id)
{
	struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);

	if (grp)
		return vlan_group_get_device(grp, vlan_id);

	return NULL;
}

extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
extern u16 vlan_dev_vlan_id(const struct net_device *dev);

extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
			     u16 vlan_tci, int polling);
extern bool vlan_do_receive(struct sk_buff **skb);
extern struct sk_buff *vlan_untag(struct sk_buff *skb);
extern gro_result_t
vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
		 unsigned int vlan_tci, struct sk_buff *skb);
extern gro_result_t
vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
	       unsigned int vlan_tci);

#else
static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
					       u16 vlan_id)
{
	return NULL;
}

static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
{
	BUG();
	return NULL;
}

static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
{
	BUG();
	return 0;
}

static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
				    u16 vlan_tci, int polling)
{
	BUG();
	return NET_XMIT_SUCCESS;
}

static inline bool vlan_do_receive(struct sk_buff **skb)
{
	if ((*skb)->vlan_tci & VLAN_VID_MASK)
		(*skb)->pkt_type = PACKET_OTHERHOST;
	return false;
}

static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
{
	return skb;
}

static inline gro_result_t
vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
		 unsigned int vlan_tci, struct sk_buff *skb)
{
	return GRO_DROP;
}

static inline gro_result_t
vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
	       unsigned int vlan_tci)
{
	return GRO_DROP;
}
#endif

/**
 * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 * @skb: buffer
 * @grp: vlan group
 * @vlan_tci: VLAN TCI as received from the card
 */
static inline int vlan_hwaccel_rx(struct sk_buff *skb,
				  struct vlan_group *grp,
				  u16 vlan_tci)
{
	return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
}

/**
 * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 * @skb: buffer
 * @grp: vlan group
 * @vlan_tci: VLAN TCI as received from the card
 */
static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
					   struct vlan_group *grp,
					   u16 vlan_tci)
{
	return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
}

/**
 * __vlan_put_tag - regular VLAN tag inserting
 * @skb: skbuff to tag
 * @vlan_tci: VLAN TCI to insert
 *
 * Inserts the VLAN tag into @skb as part of the payload
 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 *
 * Following the skb_unshare() example, in case of error, the calling function
 * doesn't have to worry about freeing the original skb.
 */
static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
{
	struct vlan_ethhdr *veth;

	if (skb_cow_head(skb, VLAN_HLEN) < 0) {
		kfree_skb(skb);
		return NULL;
	}
	veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);

	/* Move the mac addresses to the beginning of the new header. */
	memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
	skb->mac_header -= VLAN_HLEN;

	/* first, the ethernet type */
	veth->h_vlan_proto = htons(ETH_P_8021Q);

	/* now, the TCI */
	veth->h_vlan_TCI = htons(vlan_tci);

	skb->protocol = htons(ETH_P_8021Q);

	return skb;
}

/**
 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 * @skb: skbuff to tag
 * @vlan_tci: VLAN TCI to insert
 *
 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 */
static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
						     u16 vlan_tci)
{
	skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
	return skb;
}

#define HAVE_VLAN_PUT_TAG

/**
 * vlan_put_tag - inserts VLAN tag according to device features
 * @skb: skbuff to tag
 * @vlan_tci: VLAN TCI to insert
 *
 * Assumes skb->dev is the target that will xmit this frame.
 * Returns a VLAN tagged skb.
 */
static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
{
	if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
		return __vlan_hwaccel_put_tag(skb, vlan_tci);
	} else {
		return __vlan_put_tag(skb, vlan_tci);
	}
}

/**
 * __vlan_get_tag - get the VLAN ID that is part of the payload
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if the skb is not of VLAN type
 */
static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
	struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;

	if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
		return -EINVAL;
	}

	*vlan_tci = ntohs(veth->h_vlan_TCI);
	return 0;
}

/**
 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if @skb->vlan_tci is not set correctly
 */
static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
					 u16 *vlan_tci)
{
	if (vlan_tx_tag_present(skb)) {
		*vlan_tci = vlan_tx_tag_get(skb);
		return 0;
	} else {
		*vlan_tci = 0;
		return -EINVAL;
	}
}

#define HAVE_VLAN_GET_TAG

/**
 * vlan_get_tag - get the VLAN ID from the skb
 * @skb: skbuff to query
 * @vlan_tci: buffer to store vlaue
 *
 * Returns error if the skb is not VLAN tagged
 */
static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
{
	if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
		return __vlan_hwaccel_get_tag(skb, vlan_tci);
	} else {
		return __vlan_get_tag(skb, vlan_tci);
	}
}

/**
 * vlan_get_protocol - get protocol EtherType.
 * @skb: skbuff to query
 *
 * Returns the EtherType of the packet, regardless of whether it is
 * vlan encapsulated (normal or hardware accelerated) or not.
 */
static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
{
	__be16 protocol = 0;

	if (vlan_tx_tag_present(skb) ||
	     skb->protocol != cpu_to_be16(ETH_P_8021Q))
		protocol = skb->protocol;
	else {
		__be16 proto, *protop;
		protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
						h_vlan_encapsulated_proto),
						sizeof(proto), &proto);
		if (likely(protop))
			protocol = *protop;
	}

	return protocol;
}
#endif /* __KERNEL__ */

/* VLAN IOCTLs are found in sockios.h */

/* Passed in vlan_ioctl_args structure to determine behaviour. */
enum vlan_ioctl_cmds {
	ADD_VLAN_CMD,
	DEL_VLAN_CMD,
	SET_VLAN_INGRESS_PRIORITY_CMD,
	SET_VLAN_EGRESS_PRIORITY_CMD,
	GET_VLAN_INGRESS_PRIORITY_CMD,
	GET_VLAN_EGRESS_PRIORITY_CMD,
	SET_VLAN_NAME_TYPE_CMD,
	SET_VLAN_FLAG_CMD,
	GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
	GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
};

enum vlan_flags {
	VLAN_FLAG_REORDER_HDR	= 0x1,
	VLAN_FLAG_GVRP		= 0x2,
	VLAN_FLAG_LOOSE_BINDING	= 0x4,
};

enum vlan_name_types {
	VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
	VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
	VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
	VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
	VLAN_NAME_TYPE_HIGHEST
};

struct vlan_ioctl_args {
	int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
	char device1[24];

        union {
		char device2[24];
		int VID;
		unsigned int skb_priority;
		unsigned int name_type;
		unsigned int bind_type;
		unsigned int flag; /* Matches vlan_dev_info flags */
        } u;

	short vlan_qos;   
};

#endif /* !(_LINUX_IF_VLAN_H_) */