xref: /freebsd/sys/net/if_vlan_var.h (revision 6780ab54325a71e7e70112b11657973edde8655e)
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  * $FreeBSD$
30  */
31 
32 #ifndef _NET_IF_VLAN_VAR_H_
33 #define	_NET_IF_VLAN_VAR_H_	1
34 
35 struct	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  */
53 struct	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