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if_ether.h revision 1.45
      1 /*	$NetBSD: if_ether.h,v 1.45 2007/03/04 06:03:15 christos 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. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  *
     31  *	@(#)if_ether.h	8.1 (Berkeley) 6/10/93
     32  */
     33 
     34 #ifndef _NET_IF_ETHER_H_
     35 #define _NET_IF_ETHER_H_
     36 
     37 #ifdef _KERNEL
     38 #ifdef _KERNEL_OPT
     39 #include "opt_mbuftrace.h"
     40 #endif
     41 #include <sys/mbuf.h>
     42 #endif
     43 
     44 /*
     45  * Some basic Ethernet constants.
     46  */
     47 #define	ETHER_ADDR_LEN	6	/* length of an Ethernet address */
     48 #define	ETHER_TYPE_LEN	2	/* length of the Ethernet type field */
     49 #define	ETHER_CRC_LEN	4	/* length of the Ethernet CRC */
     50 #define	ETHER_HDR_LEN	((ETHER_ADDR_LEN * 2) + ETHER_TYPE_LEN)
     51 #define	ETHER_MIN_LEN	64	/* minimum frame length, including CRC */
     52 #define	ETHER_MAX_LEN	1518	/* maximum frame length, including CRC */
     53 #define	ETHER_MAX_LEN_JUMBO 9018 /* maximum jumbo frame len, including CRC */
     54 
     55 /*
     56  * Some Ethernet extensions.
     57  */
     58 #define	ETHER_VLAN_ENCAP_LEN 4	/* length of 802.1Q VLAN encapsulation */
     59 
     60 /*
     61  * Ethernet address - 6 octets
     62  * this is only used by the ethers(3) functions.
     63  */
     64 struct ether_addr {
     65 	u_int8_t ether_addr_octet[ETHER_ADDR_LEN];
     66 } __attribute__((__packed__));
     67 
     68 /*
     69  * Structure of a 10Mb/s Ethernet header.
     70  */
     71 struct	ether_header {
     72 	u_int8_t  ether_dhost[ETHER_ADDR_LEN];
     73 	u_int8_t  ether_shost[ETHER_ADDR_LEN];
     74 	u_int16_t ether_type;
     75 } __attribute__((__packed__));
     76 
     77 #include <net/ethertypes.h>
     78 
     79 #define	ETHER_IS_MULTICAST(addr) (*(addr) & 0x01) /* is address mcast/bcast? */
     80 
     81 #define	ETHERMTU_JUMBO	(ETHER_MAX_LEN_JUMBO - ETHER_HDR_LEN - ETHER_CRC_LEN)
     82 #define	ETHERMTU	(ETHER_MAX_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
     83 #define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
     84 
     85 /*
     86  * Compute the maximum frame size based on ethertype (i.e. possible
     87  * encapsulation) and whether or not an FCS is present.
     88  */
     89 #define	ETHER_MAX_FRAME(ifp, etype, hasfcs)				\
     90 	((ifp)->if_mtu + ETHER_HDR_LEN +				\
     91 	 ((hasfcs) ? ETHER_CRC_LEN : 0) +				\
     92 	 (((etype) == ETHERTYPE_VLAN) ? ETHER_VLAN_ENCAP_LEN : 0))
     93 
     94 /*
     95  * Ethernet CRC32 polynomials (big- and little-endian verions).
     96  */
     97 #define	ETHER_CRC_POLY_LE	0xedb88320
     98 #define	ETHER_CRC_POLY_BE	0x04c11db6
     99 
    100 #ifndef _STANDALONE
    101 
    102 /*
    103  * Ethernet-specific mbuf flags.
    104  */
    105 #define	M_HASFCS	M_LINK0	/* FCS included at end of frame */
    106 #define	M_PROMISC	M_LINK1	/* this packet is not for us */
    107 
    108 #ifdef _KERNEL
    109 /*
    110  * Macro to map an IP multicast address to an Ethernet multicast address.
    111  * The high-order 25 bits of the Ethernet address are statically assigned,
    112  * and the low-order 23 bits are taken from the low end of the IP address.
    113  */
    114 #define ETHER_MAP_IP_MULTICAST(ipaddr, enaddr)				\
    115 	/* const struct in_addr *ipaddr; */				\
    116 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
    117 do {									\
    118 	(enaddr)[0] = 0x01;						\
    119 	(enaddr)[1] = 0x00;						\
    120 	(enaddr)[2] = 0x5e;						\
    121 	(enaddr)[3] = ((const u_int8_t *)ipaddr)[1] & 0x7f;		\
    122 	(enaddr)[4] = ((const u_int8_t *)ipaddr)[2];			\
    123 	(enaddr)[5] = ((const u_int8_t *)ipaddr)[3];			\
    124 } while (/*CONSTCOND*/0)
    125 /*
    126  * Macro to map an IP6 multicast address to an Ethernet multicast address.
    127  * The high-order 16 bits of the Ethernet address are statically assigned,
    128  * and the low-order 32 bits are taken from the low end of the IP6 address.
    129  */
    130 #define ETHER_MAP_IPV6_MULTICAST(ip6addr, enaddr)			\
    131 	/* struct in6_addr *ip6addr; */					\
    132 	/* u_int8_t enaddr[ETHER_ADDR_LEN]; */				\
    133 {                                                                       \
    134 	(enaddr)[0] = 0x33;						\
    135 	(enaddr)[1] = 0x33;						\
    136 	(enaddr)[2] = ((const uint8_t *)ip6addr)[12];			\
    137 	(enaddr)[3] = ((const uint8_t *)ip6addr)[13];			\
    138 	(enaddr)[4] = ((const uint8_t *)ip6addr)[14];			\
    139 	(enaddr)[5] = ((const uint8_t *)ip6addr)[15];			\
    140 }
    141 #endif
    142 
    143 /*
    144  * Structure shared between the ethernet driver modules and
    145  * the multicast list code.  For example, each ec_softc or il_softc
    146  * begins with this structure.
    147  */
    148 struct	ethercom {
    149 	struct	ifnet ec_if;			/* network-visible interface */
    150 	LIST_HEAD(, ether_multi) ec_multiaddrs;	/* list of ether multicast
    151 						   addrs */
    152 	int	ec_multicnt;			/* length of ec_multiaddrs
    153 						   list */
    154 	int	ec_capabilities;		/* capabilities, provided by
    155 						   driver */
    156 	int	ec_capenable;			/* tells hardware which
    157 						   capabilities to enable */
    158 
    159 	int	ec_nvlans;			/* # VLANs on this interface */
    160 #ifdef MBUFTRACE
    161 	struct	mowner ec_rx_mowner;		/* mbufs received */
    162 	struct	mowner ec_tx_mowner;		/* mbufs transmitted */
    163 #endif
    164 };
    165 
    166 #define	ETHERCAP_VLAN_MTU	0x00000001	/* VLAN-compatible MTU */
    167 #define	ETHERCAP_VLAN_HWTAGGING	0x00000002	/* hardware VLAN tag support */
    168 #define	ETHERCAP_JUMBO_MTU	0x00000004	/* 9000 byte MTU supported */
    169 
    170 #ifdef	_KERNEL
    171 extern const uint8_t etherbroadcastaddr[ETHER_ADDR_LEN];
    172 extern const uint8_t ethermulticastaddr_slowprotocols[ETHER_ADDR_LEN];
    173 extern const uint8_t ether_ipmulticast_min[ETHER_ADDR_LEN];
    174 extern const uint8_t ether_ipmulticast_max[ETHER_ADDR_LEN];
    175 
    176 int	ether_ioctl(struct ifnet *, u_long, void *);
    177 int	ether_addmulti (struct ifreq *, struct ethercom *);
    178 int	ether_delmulti (struct ifreq *, struct ethercom *);
    179 int	ether_changeaddr (struct ifreq *, struct ethercom *);
    180 int	ether_multiaddr(struct sockaddr *, u_int8_t[], u_int8_t[]);
    181 #endif /* _KERNEL */
    182 
    183 /*
    184  * Ethernet multicast address structure.  There is one of these for each
    185  * multicast address or range of multicast addresses that we are supposed
    186  * to listen to on a particular interface.  They are kept in a linked list,
    187  * rooted in the interface's ethercom structure.
    188  */
    189 struct ether_multi {
    190 	u_int8_t enm_addrlo[ETHER_ADDR_LEN]; /* low  or only address of range */
    191 	u_int8_t enm_addrhi[ETHER_ADDR_LEN]; /* high or only address of range */
    192 	u_int	 enm_refcount;		/* no. claims to this addr/range */
    193 	LIST_ENTRY(ether_multi) enm_list;
    194 };
    195 
    196 /*
    197  * Structure used by macros below to remember position when stepping through
    198  * all of the ether_multi records.
    199  */
    200 struct ether_multistep {
    201 	struct ether_multi  *e_enm;
    202 };
    203 
    204 /*
    205  * Macro for looking up the ether_multi record for a given range of Ethernet
    206  * multicast addresses connected to a given ethercom structure.  If no matching
    207  * record is found, "enm" returns NULL.
    208  */
    209 #define ETHER_LOOKUP_MULTI(addrlo, addrhi, ec, enm)			\
    210 	/* u_int8_t addrlo[ETHER_ADDR_LEN]; */				\
    211 	/* u_int8_t addrhi[ETHER_ADDR_LEN]; */				\
    212 	/* struct ethercom *ec; */					\
    213 	/* struct ether_multi *enm; */					\
    214 {									\
    215 	for ((enm) = LIST_FIRST(&(ec)->ec_multiaddrs);			\
    216 	    (enm) != NULL &&						\
    217 	    (bcmp((enm)->enm_addrlo, (addrlo), ETHER_ADDR_LEN) != 0 ||	\
    218 	     bcmp((enm)->enm_addrhi, (addrhi), ETHER_ADDR_LEN) != 0);	\
    219 		(enm) = LIST_NEXT((enm), enm_list));			\
    220 }
    221 
    222 /*
    223  * Macro to step through all of the ether_multi records, one at a time.
    224  * The current position is remembered in "step", which the caller must
    225  * provide.  ETHER_FIRST_MULTI(), below, must be called to initialize "step"
    226  * and get the first record.  Both macros return a NULL "enm" when there
    227  * are no remaining records.
    228  */
    229 #define ETHER_NEXT_MULTI(step, enm) \
    230 	/* struct ether_multistep step; */  \
    231 	/* struct ether_multi *enm; */  \
    232 { \
    233 	if (((enm) = (step).e_enm) != NULL) \
    234 		(step).e_enm = LIST_NEXT((enm), enm_list); \
    235 }
    236 
    237 #define ETHER_FIRST_MULTI(step, ec, enm) \
    238 	/* struct ether_multistep step; */ \
    239 	/* struct ethercom *ec; */ \
    240 	/* struct ether_multi *enm; */ \
    241 { \
    242 	(step).e_enm = LIST_FIRST(&(ec)->ec_multiaddrs); \
    243 	ETHER_NEXT_MULTI((step), (enm)); \
    244 }
    245 
    246 #ifdef _KERNEL
    247 
    248 /*
    249  * Ethernet 802.1Q VLAN structures.
    250  */
    251 
    252 /* add VLAN tag to input/received packet */
    253 #define	VLAN_INPUT_TAG(ifp, m, vlanid, _errcase)	\
    254 	do {								\
    255                 struct m_tag *mtag =					\
    256                     m_tag_get(PACKET_TAG_VLAN, sizeof(u_int), M_NOWAIT);\
    257                 if (mtag == NULL) {					\
    258 			ifp->if_ierrors++;				\
    259                         printf("%s: unable to allocate VLAN tag\n",	\
    260                             ifp->if_xname);				\
    261                         m_freem(m);					\
    262                         _errcase;					\
    263                 }							\
    264                 *(u_int *)(mtag + 1) = vlanid;				\
    265                 m_tag_prepend(m, mtag);					\
    266 	} while(0)
    267 
    268 /* extract VLAN tag from output/trasmit packet */
    269 #define VLAN_OUTPUT_TAG(ec, m0)			\
    270 	VLAN_ATTACHED(ec) ? m_tag_find((m0), PACKET_TAG_VLAN, NULL) : NULL
    271 
    272 /* extract VLAN ID value from a VLAN tag */
    273 #define VLAN_TAG_VALUE(mtag)	\
    274 	((*(u_int *)(mtag + 1)) & 4095)
    275 
    276 /* test if any VLAN is configured for this interface */
    277 #define VLAN_ATTACHED(ec)	((ec)->ec_nvlans > 0)
    278 
    279 void	ether_ifattach(struct ifnet *, const u_int8_t *);
    280 void	ether_ifdetach(struct ifnet *);
    281 
    282 char	*ether_sprintf(const u_int8_t *);
    283 char	*ether_snprintf(char *, size_t, const u_int8_t *);
    284 
    285 u_int32_t ether_crc32_le(const u_int8_t *, size_t);
    286 u_int32_t ether_crc32_be(const u_int8_t *, size_t);
    287 
    288 int	ether_nonstatic_aton(u_char *, char *);
    289 #else
    290 /*
    291  * Prototype ethers(3) functions.
    292  */
    293 #include <sys/cdefs.h>
    294 __BEGIN_DECLS
    295 char *	ether_ntoa __P((const struct ether_addr *));
    296 struct ether_addr *
    297 	ether_aton __P((const char *));
    298 int	ether_ntohost __P((char *, const struct ether_addr *));
    299 int	ether_hostton __P((const char *, struct ether_addr *));
    300 int	ether_line __P((const char *, struct ether_addr *, char *));
    301 __END_DECLS
    302 #endif
    303 
    304 #endif /* _STANDALONE */
    305 
    306 #endif /* !_NET_IF_ETHER_H_ */
    307