if_vlan_var.h revision 112168 
1/*
2 * Copyright 1998 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.  M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose.  It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $FreeBSD: head/sys/net/if_vlan_var.h 112168 2003-03-13 00:30:31Z mux $
30 */
31
32#ifndef _NET_IF_VLAN_VAR_H_
33#define	_NET_IF_VLAN_VAR_H_	1
34
35struct	ether_vlan_header {
36	u_char	evl_dhost[ETHER_ADDR_LEN];
37	u_char	evl_shost[ETHER_ADDR_LEN];
38	u_int16_t evl_encap_proto;
39	u_int16_t evl_tag;
40	u_int16_t evl_proto;
41};
42
43#define	EVL_VLANOFTAG(tag) ((tag) & 4095)
44#define	EVL_PRIOFTAG(tag) (((tag) >> 13) & 7)
45
46/* sysctl(3) tags, for compatibility purposes */
47#define	VLANCTL_PROTO	1
48#define	VLANCTL_MAX	2
49
50/*
51 * Configuration structure for SIOCSETVLAN and SIOCGETVLAN ioctls.
52 */
53struct	vlanreq {
54	char	vlr_parent[IFNAMSIZ];
55	u_short	vlr_tag;
56};
57#define	SIOCSETVLAN	SIOCSIFGENERIC
58#define	SIOCGETVLAN	SIOCGIFGENERIC
59
60#ifdef _KERNEL
61/*
62 * Drivers that are capable of adding and removing the VLAN header
63 * in hardware indicate they support this by marking IFCAP_VLAN_HWTAGGING
64 * in if_capabilities.  Drivers for hardware that is also capable
65 * of handling larger MTU's that may include a software-appended
66 * VLAN header w/o lowering the normal MTU should mark IFCAP_VLA_MTU
67 * in if_capabilities; this notfies the VLAN code it can leave the
68 * MTU on the vlan interface at the normal setting.
69 */
70
71/*
72 * Drivers that support hardware VLAN tagging pass a packet's tag
73 * up through the stack by appending a packet tag with this value.
74 * Output is handled likewise, the driver must locate the packet
75 * tag to extract the VLAN tag.  The following macros are used to
76 * do this work.  On input, do:
77 *
78 *	VLAN_INPUT_TAG(ifp, m, tag,);
79 *
80 * to mark the packet m with the specified VLAN tag.  The last
81 * parameter provides code to execute in case of an error.  On
82 * output the driver should check ifnet to see if any VLANs are
83 * in use and only then check for a packet tag; this is done with:
84 *
85 *	struct m_tag *mtag;
86 *	mtag = VLAN_OUTPUT_TAG(ifp, m);
87 *	if (mtag != NULL) {
88 *		... = VLAN_TAG_VALUE(mtag);
89 *		... pass tag to hardware ...
90 *	}
91 *
92 * Note that a driver must indicate it supports hardware VLAN
93 * tagging by marking IFCAP_VLAN_HWTAGGING in if_capabilities.
94 */
95#define	MTAG_VLAN	1035328035
96#define	MTAG_VLAN_TAG	0		/* tag of VLAN interface */
97
98#define	VLAN_INPUT_TAG(_ifp, _m, _t, _errcase) do {		\
99	struct m_tag *mtag;					\
100	mtag = m_tag_alloc(MTAG_VLAN, MTAG_VLAN_TAG,		\
101			   sizeof (u_int), M_NOWAIT);		\
102	if (mtag == NULL) {					\
103		(_ifp)->if_ierrors++;				\
104		m_freem(_m);					\
105		_errcase;					\
106	}							\
107	*(u_int *)(mtag+1) = (_t);				\
108	m_tag_prepend((_m), mtag);				\
109} while (0)
110
111#define	VLAN_OUTPUT_TAG(_ifp, _m)				\
112	((_ifp)->if_nvlans != 0 ?				\
113		m_tag_locate((_m), MTAG_VLAN, MTAG_VLAN_TAG, NULL) : NULL)
114#define	VLAN_TAG_VALUE(_mt)	(*(u_int *)((_mt)+1))
115#endif /* _KERNEL */
116
117#endif /* _NET_IF_VLAN_VAR_H_ */
118