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if_ether.h revision 1.21
      1 /*	$NetBSD: if_ether.h,v 1.21 2000/11/17 19:21:53 bouyer Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)if_ether.h	8.1 (Berkeley) 6/10/93
     36  */
     37 
     38 #ifndef _NET_IF_ETHER_H_
     39 #define _NET_IF_ETHER_H_
     40 
     41 /*
     42  * Some basic Ethernet constants.
     43  */
     44 #define	ETHER_ADDR_LEN	6	/* length of an Ethernet address */
     45 #define	ETHER_TYPE_LEN	2	/* length of the Ethernet type field */
     46 #define	ETHER_CRC_LEN	4	/* length of the Ethernet CRC */
     47 #define	ETHER_HDR_LEN	((ETHER_ADDR_LEN * 2) + ETHER_TYPE_LEN)
     48 #define	ETHER_MIN_LEN	64	/* minimum frame length, including CRC */
     49 #define	ETHER_MAX_LEN	1518	/* maximum frame length, including CRC */
     50 
     51 /*
     52  * Some Ethernet extensions.
     53  */
     54 #define	ETHER_VLAN_ENCAP_LEN 4	/* length of 802.1Q VLAN encapsulation */
     55 
     56 /*
     57  * Ethernet address - 6 octets
     58  * this is only used by the ethers(3) functions.
     59  */
     60 struct ether_addr {
     61 	u_int8_t ether_addr_octet[ETHER_ADDR_LEN];
     62 } __attribute__((__packed__));
     63 
     64 /*
     65  * Structure of a 10Mb/s Ethernet header.
     66  */
     67 struct	ether_header {
     68 	u_int8_t  ether_dhost[ETHER_ADDR_LEN];
     69 	u_int8_t  ether_shost[ETHER_ADDR_LEN];
     70 	u_int16_t ether_type;
     71 } __attribute__((__packed__));
     72 
     73 #include <net/ethertypes.h>
     74 
     75 #define	ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
     76 
     77 #define	ETHERMTU	(ETHER_MAX_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
     78 #define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
     79 
     80 /*
     81  * Compute the maximum frame size based on ethertype (i.e. possible
     82  * encapsulation) and whether or not an FCS is present.
     83  */
     84 #define	ETHER_MAX_FRAME(etype, hasfcs)					\
     85 	(ETHERMTU + ETHER_HDR_LEN +					\
     86 	 ((hasfcs) ? ETHER_CRC_LEN : 0) +				\
     87 	 (((etype) == ETHERTYPE_VLAN) ? ETHER_VLAN_ENCAP_LEN : 0))
     88 
     89 /*
     90  * Ethernet CRC32 polynomials (big- and little-endian verions).
     91  */
     92 #define	ETHER_CRC_POLY_LE	0xedb88320
     93 #define	ETHER_CRC_POLY_BE	0x04c11db6
     94 
     95 #ifndef _STANDALONE
     96 
     97 /*
     98  * Ethernet-specific mbuf flags.
     99  */
    100 #define	M_HASFCS	M_LINK0		/* FCS included at end of frame */
    101 
    102 #ifdef _KERNEL
    103 /*
    104  * Macro to map an IP multicast address to an Ethernet multicast address.
    105  * The high-order 25 bits of the Ethernet address are statically assigned,
    106  * and the low-order 23 bits are taken from the low end of the IP address.
    107  */
    108 #define ETHER_MAP_IP_MULTICAST(ipaddr, enaddr)				\
    109 	/* struct in_addr *ipaddr; */					\
    110 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
    111 {									\
    112 	(enaddr)[0] = 0x01;						\
    113 	(enaddr)[1] = 0x00;						\
    114 	(enaddr)[2] = 0x5e;						\
    115 	(enaddr)[3] = ((u_int8_t *)ipaddr)[1] & 0x7f;			\
    116 	(enaddr)[4] = ((u_int8_t *)ipaddr)[2];				\
    117 	(enaddr)[5] = ((u_int8_t *)ipaddr)[3];				\
    118 }
    119 /*
    120  * Macro to map an IP6 multicast address to an Ethernet multicast address.
    121  * The high-order 16 bits of the Ethernet address are statically assigned,
    122  * and the low-order 32 bits are taken from the low end of the IP6 address.
    123  */
    124 #define ETHER_MAP_IPV6_MULTICAST(ip6addr, enaddr)			\
    125 	/* struct in6_addr *ip6addr; */					\
    126 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
    127 {                                                                       \
    128 	(enaddr)[0] = 0x33;						\
    129 	(enaddr)[1] = 0x33;						\
    130 	(enaddr)[2] = ((u_int8_t *)ip6addr)[12];			\
    131 	(enaddr)[3] = ((u_int8_t *)ip6addr)[13];			\
    132 	(enaddr)[4] = ((u_int8_t *)ip6addr)[14];			\
    133 	(enaddr)[5] = ((u_int8_t *)ip6addr)[15];			\
    134 }
    135 #endif
    136 
    137 /*
    138  * Structure shared between the ethernet driver modules and
    139  * the multicast list code.  For example, each ec_softc or il_softc
    140  * begins with this structure.
    141  */
    142 struct	ethercom {
    143 	struct	 ifnet ec_if;			/* network-visible interface */
    144 	LIST_HEAD(, ether_multi) ec_multiaddrs;	/* list of ether multicast
    145 						   addrs */
    146 	int	 ec_multicnt;			/* length of ec_multiaddrs
    147 						   list */
    148 	int	 ec_capabilities;		/* capabilities, provided by
    149 						   driver */
    150 	int	 ec_capenable;			/* tells hardware which
    151 						   capabilities to enable */
    152 
    153 	int	 ec_nvlans;			/* # VLANs on this interface */
    154 };
    155 
    156 #define	ETHERCAP_VLAN_MTU	0x00000001	/* VLAN-compatible MTU */
    157 #define	ETHERCAP_VLAN_HWTAGGING	0x00000002	/* hardware VLAN tag support */
    158 
    159 #ifdef	_KERNEL
    160 extern u_int8_t etherbroadcastaddr[ETHER_ADDR_LEN];
    161 extern u_int8_t ether_ipmulticast_min[ETHER_ADDR_LEN];
    162 extern u_int8_t ether_ipmulticast_max[ETHER_ADDR_LEN];
    163 
    164 int	ether_ioctl(struct ifnet *, u_long, caddr_t);
    165 int	ether_addmulti (struct ifreq *, struct ethercom *);
    166 int	ether_delmulti (struct ifreq *, struct ethercom *);
    167 int	ether_changeaddr (struct ifreq *, struct ethercom *);
    168 int	ether_multiaddr(struct sockaddr *, u_int8_t[], u_int8_t[]);
    169 #endif /* _KERNEL */
    170 
    171 /*
    172  * Ethernet multicast address structure.  There is one of these for each
    173  * multicast address or range of multicast addresses that we are supposed
    174  * to listen to on a particular interface.  They are kept in a linked list,
    175  * rooted in the interface's ethercom structure.
    176  */
    177 struct ether_multi {
    178 	u_int8_t enm_addrlo[ETHER_ADDR_LEN]; /* low  or only address of range */
    179 	u_int8_t enm_addrhi[ETHER_ADDR_LEN]; /* high or only address of range */
    180 	struct	 ethercom *enm_ec;	/* back pointer to ethercom */
    181 	u_int	 enm_refcount;		/* no. claims to this addr/range */
    182 	LIST_ENTRY(ether_multi) enm_list;
    183 };
    184 
    185 /*
    186  * Structure used by macros below to remember position when stepping through
    187  * all of the ether_multi records.
    188  */
    189 struct ether_multistep {
    190 	struct ether_multi  *e_enm;
    191 };
    192 
    193 /*
    194  * Macro for looking up the ether_multi record for a given range of Ethernet
    195  * multicast addresses connected to a given ethercom structure.  If no matching
    196  * record is found, "enm" returns NULL.
    197  */
    198 #define ETHER_LOOKUP_MULTI(addrlo, addrhi, ec, enm)			\
    199 	/* u_int8_t addrlo[ETHER_ADDR_LEN]; */				\
    200 	/* u_int8_t addrhi[ETHER_ADDR_LEN]; */				\
    201 	/* struct ethercom *ec; */					\
    202 	/* struct ether_multi *enm; */					\
    203 {									\
    204 	for ((enm) = (ec)->ec_multiaddrs.lh_first;			\
    205 	    (enm) != NULL &&						\
    206 	    (bcmp((enm)->enm_addrlo, (addrlo), ETHER_ADDR_LEN) != 0 ||	\
    207 	     bcmp((enm)->enm_addrhi, (addrhi), ETHER_ADDR_LEN) != 0);	\
    208 		(enm) = (enm)->enm_list.le_next);			\
    209 }
    210 
    211 /*
    212  * Macro to step through all of the ether_multi records, one at a time.
    213  * The current position is remembered in "step", which the caller must
    214  * provide.  ETHER_FIRST_MULTI(), below, must be called to initialize "step"
    215  * and get the first record.  Both macros return a NULL "enm" when there
    216  * are no remaining records.
    217  */
    218 #define ETHER_NEXT_MULTI(step, enm) \
    219 	/* struct ether_multistep step; */  \
    220 	/* struct ether_multi *enm; */  \
    221 { \
    222 	if (((enm) = (step).e_enm) != NULL) \
    223 		(step).e_enm = (enm)->enm_list.le_next; \
    224 }
    225 
    226 #define ETHER_FIRST_MULTI(step, ec, enm) \
    227 	/* struct ether_multistep step; */ \
    228 	/* struct ethercom *ec; */ \
    229 	/* struct ether_multi *enm; */ \
    230 { \
    231 	(step).e_enm = (ec)->ec_multiaddrs.lh_first; \
    232 	ETHER_NEXT_MULTI((step), (enm)); \
    233 }
    234 
    235 #ifdef _KERNEL
    236 u_int32_t ether_crc32_le (const u_int8_t *, size_t);
    237 u_int32_t ether_crc32_be (const u_int8_t *, size_t);
    238 #else
    239 /*
    240  * Prototype ethers(3) functions.
    241  */
    242 #include <sys/cdefs.h>
    243 __BEGIN_DECLS
    244 char *	ether_ntoa __P((struct ether_addr *));
    245 struct ether_addr *
    246 	ether_aton __P((const char *));
    247 int	ether_ntohost __P((char *, struct ether_addr *));
    248 int	ether_hostton __P((const char *, struct ether_addr *));
    249 int	ether_line __P((const char *, struct ether_addr *, char *));
    250 __END_DECLS
    251 #endif
    252 
    253 #endif /* _STANDALONE */
    254 
    255 #endif /* _NET_IF_ETHER_H_ */
    256