if_var.h

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	From: @(#)if.h	8.1 (Berkeley) 6/10/93
 * $FreeBSD$
 */

#ifndef	_NET_IF_VAR_H_
#define	_NET_IF_VAR_H_

/*
 * Structures defining a network interface, providing a packet
 * transport mechanism (ala level 0 of the PUP protocols).
 *
 * Each interface accepts output datagrams of a specified maximum
 * length, and provides higher level routines with input datagrams
 * received from its medium.
 *
 * Output occurs when the routine if_output is called, with three parameters:
 *	(*ifp->if_output)(ifp, m, dst, rt)
 * Here m is the mbuf chain to be sent and dst is the destination address.
 * The output routine encapsulates the supplied datagram if necessary,
 * and then transmits it on its medium.
 *
 * On input, each interface unwraps the data received by it, and either
 * places it on the input queue of a internetwork datagram routine
 * and posts the associated software interrupt, or passes the datagram to a raw
 * packet input routine.
 *
 * Routines exist for locating interfaces by their addresses
 * or for locating a interface on a certain network, as well as more general
 * routing and gateway routines maintaining information used to locate
 * interfaces.  These routines live in the files if.c and route.c
 */

#ifdef __STDC__
/*
 * Forward structure declarations for function prototypes [sic].
 */
struct	mbuf;
struct	proc;
struct	rtentry;
struct	rt_addrinfo;
struct	socket;
struct	ether_header;
#endif

#include <sys/queue.h>		/* get TAILQ macros */

TAILQ_HEAD(ifnethead, ifnet);	/* we use TAILQs so that the order of */
TAILQ_HEAD(ifaddrhead, ifaddr);	/* instantiation is preserved in the list */
TAILQ_HEAD(ifprefixhead, ifprefix);
LIST_HEAD(ifmultihead, ifmultiaddr);

/*
 * Structure defining a queue for a network interface.
 */
struct	ifqueue {
	struct	mbuf *ifq_head;
	struct	mbuf *ifq_tail;
	int	ifq_len;
	int	ifq_maxlen;
	int	ifq_drops;
};

/*
 * Structure defining a network interface.
 *
 * (Would like to call this struct ``if'', but C isn't PL/1.)
 */

/*
 * NB: For FreeBSD, it is assumed that each NIC driver's softc starts with  
 * one of these structures, typically held within an arpcom structure.   
 * 
 *	struct <foo>_softc {
 *		struct arpcom {
 *			struct  ifnet ac_if;
 *			...
 *		} <arpcom> ;
 *		...   
 *	};
 *
 * The assumption is used in a number of places, including many
 * files in sys/net, device drivers, and sys/dev/mii.c:miibus_attach().
 * 
 * Unfortunately devices' softc are opaque, so we depend on this layout
 * to locate the struct ifnet from the softc in the generic code.
 *
 * Note that not all fields are used by drivers in the FreeBSD source
 * tree. However, who knows what third party software does with fields
 * marked as "unused", such as if_ipending, if_done, and if_poll*,
 * so any attemt to redefine their meaning might end up in binary
 * compatibility problems, even if the size of struct ifnet, and
 * the size and position of its fields do not change.
 * We just have to live with that.
 */
struct ifnet {
	void	*if_softc;		/* pointer to driver state */
	char	*if_name;		/* name, e.g. ``en'' or ``lo'' */
	TAILQ_ENTRY(ifnet) if_link; 	/* all struct ifnets are chained */
	struct	ifaddrhead if_addrhead;	/* linked list of addresses per if */
	int	if_pcount;		/* number of promiscuous listeners */
	struct	bpf_if *if_bpf;		/* packet filter structure */
	u_short	if_index;		/* numeric abbreviation for this if  */
	short	if_unit;		/* sub-unit for lower level driver */
	short	if_timer;		/* time 'til if_watchdog called */
	short	if_flags;		/* up/down, broadcast, etc. */
	int	if_ipending;		/* interrupts pending */
	void	*if_linkmib;		/* link-type-specific MIB data */
	size_t	if_linkmiblen;		/* length of above data */
	struct	if_data if_data;
	struct	ifmultihead if_multiaddrs; /* multicast addresses configured */
	int	if_amcount;		/* number of all-multicast requests */
/* procedure handles */
	int	(*if_output)		/* output routine (enqueue) */
		__P((struct ifnet *, struct mbuf *, struct sockaddr *,
		     struct rtentry *));
	void	(*if_start)		/* initiate output routine */
		__P((struct ifnet *));
	union {
		int	(*if_done)		/* output complete routine */
			__P((struct ifnet *));	/* (XXX not used) */
		int	uif_capabilities;	/* interface capabilities */
	} _u1;
	int	(*if_ioctl)		/* ioctl routine */
		__P((struct ifnet *, u_long, caddr_t));
	void	(*if_watchdog)		/* timer routine */
		__P((struct ifnet *));
	union {
		int	(*if_poll_recv)		/* polled receive routine */
			__P((struct ifnet *, int *));
		int	uif_capenable;		/* enabled features */
	} _u2;
	int	(*if_poll_xmit)		/* polled transmit routine */
		__P((struct ifnet *, int *));
	void	(*if_poll_intren)	/* polled interrupt reenable routine */
		__P((struct ifnet *));
	void	(*if_poll_slowinput)	/* input routine for slow devices */
		__P((struct ifnet *, struct mbuf *));
	void	(*if_init)		/* Init routine */
		__P((void *));
	int	(*if_resolvemulti)	/* validate/resolve multicast */
		__P((struct ifnet *, struct sockaddr **, struct sockaddr *));
	struct	ifqueue if_snd;		/* output queue */
	struct	ifqueue *if_poll_slowq;	/* input queue for slow devices */
	struct	ifprefixhead if_prefixhead; /* list of prefixes per if */
};
typedef void if_init_f_t __P((void *));

/*
 * Binary compatability gunk for 4.x ONLY.
 */
#define if_capabilities	_u1.uif_capabilities
#define if_capenable	_u2.uif_capenable

#define	if_mtu		if_data.ifi_mtu
#define	if_type		if_data.ifi_type
#define if_physical	if_data.ifi_physical
#define	if_addrlen	if_data.ifi_addrlen
#define	if_hdrlen	if_data.ifi_hdrlen
#define	if_metric	if_data.ifi_metric
#define	if_baudrate	if_data.ifi_baudrate
#define	if_hwassist	if_data.ifi_hwassist
#define	if_ipackets	if_data.ifi_ipackets
#define	if_ierrors	if_data.ifi_ierrors
#define	if_opackets	if_data.ifi_opackets
#define	if_oerrors	if_data.ifi_oerrors
#define	if_collisions	if_data.ifi_collisions
#define	if_ibytes	if_data.ifi_ibytes
#define	if_obytes	if_data.ifi_obytes
#define	if_imcasts	if_data.ifi_imcasts
#define	if_omcasts	if_data.ifi_omcasts
#define	if_iqdrops	if_data.ifi_iqdrops
#define	if_noproto	if_data.ifi_noproto
#define	if_lastchange	if_data.ifi_lastchange
#define if_recvquota	if_data.ifi_recvquota
#define	if_xmitquota	if_data.ifi_xmitquota
#define if_rawoutput(if, m, sa) if_output(if, m, sa, (struct rtentry *)0)

/* for compatibility with other BSDs */
#define	if_addrlist	if_addrhead
#define	if_list		if_link

/*
 * Bit values in if_ipending
 */
#define	IFI_RECV	1	/* I want to receive */
#define	IFI_XMIT	2	/* I want to transmit */

/*
 * Output queues (ifp->if_snd) and slow device input queues (*ifp->if_slowq)
 * are queues of messages stored on ifqueue structures
 * (defined above).  Entries are added to and deleted from these structures
 * by these macros, which should be called with ipl raised to splimp().
 */
#define	IF_QFULL(ifq)		((ifq)->ifq_len >= (ifq)->ifq_maxlen)
#define	IF_DROP(ifq)		((ifq)->ifq_drops++)
#define	IF_ENQUEUE(ifq, m) { \
	(m)->m_nextpkt = 0; \
	if ((ifq)->ifq_tail == 0) \
		(ifq)->ifq_head = m; \
	else \
		(ifq)->ifq_tail->m_nextpkt = m; \
	(ifq)->ifq_tail = m; \
	(ifq)->ifq_len++; \
}
#define	IF_PREPEND(ifq, m) { \
	(m)->m_nextpkt = (ifq)->ifq_head; \
	if ((ifq)->ifq_tail == 0) \
		(ifq)->ifq_tail = (m); \
	(ifq)->ifq_head = (m); \
	(ifq)->ifq_len++; \
}
#define	IF_DEQUEUE(ifq, m) { \
	(m) = (ifq)->ifq_head; \
	if (m) { \
		if (((ifq)->ifq_head = (m)->m_nextpkt) == 0) \
			(ifq)->ifq_tail = 0; \
		(m)->m_nextpkt = 0; \
		(ifq)->ifq_len--; \
	} \
}

#ifdef _KERNEL
#define	IF_ENQ_DROP(ifq, m)	if_enq_drop(ifq, m)

#if defined(__GNUC__) && defined(MT_HEADER)
static __inline int
if_queue_drop(struct ifqueue *ifq, struct mbuf *m)
{
	IF_DROP(ifq);
	return 0;
}

static __inline int
if_enq_drop(struct ifqueue *ifq, struct mbuf *m)
{
	if (IF_QFULL(ifq) &&
	    !if_queue_drop(ifq, m))
		return 0;
	IF_ENQUEUE(ifq, m);
	return 1;
}
#else

#ifdef MT_HEADER
int	if_enq_drop __P((struct ifqueue *, struct mbuf *));
#endif

#endif

/*
 * 72 was chosen below because it is the size of a TCP/IP
 * header (40) + the minimum mss (32).
 */
#define	IF_MINMTU	72
#define	IF_MAXMTU	65535

#endif /* _KERNEL */

/*
 * The ifaddr structure contains information about one address
 * of an interface.  They are maintained by the different address families,
 * are allocated and attached when an address is set, and are linked
 * together so all addresses for an interface can be located.
 */
struct ifaddr {
	struct	sockaddr *ifa_addr;	/* address of interface */
	struct	sockaddr *ifa_dstaddr;	/* other end of p-to-p link */
#define	ifa_broadaddr	ifa_dstaddr	/* broadcast address interface */
	struct	sockaddr *ifa_netmask;	/* used to determine subnet */
	struct	if_data if_data;	/* not all members are meaningful */
	struct	ifnet *ifa_ifp;		/* back-pointer to interface */
	TAILQ_ENTRY(ifaddr) ifa_link;	/* queue macro glue */
	void	(*ifa_rtrequest)	/* check or clean routes (+ or -)'d */
		__P((int, struct rtentry *, struct rt_addrinfo *));
	u_short	ifa_flags;		/* mostly rt_flags for cloning */
	u_int	ifa_refcnt;		/* references to this structure */
	int	ifa_metric;		/* cost of going out this interface */
#ifdef notdef
	struct	rtentry *ifa_rt;	/* XXXX for ROUTETOIF ????? */
#endif
	int (*ifa_claim_addr)		/* check if an addr goes to this if */
		__P((struct ifaddr *, struct sockaddr *));

};
#define	IFA_ROUTE	RTF_UP		/* route installed */

/* for compatibility with other BSDs */
#define	ifa_list	ifa_link

/*
 * The prefix structure contains information about one prefix
 * of an interface.  They are maintained by the different address families,
 * are allocated and attached when an prefix or an address is set,
 * and are linked together so all prefixes for an interface can be located.
 */
struct ifprefix {
	struct	sockaddr *ifpr_prefix;	/* prefix of interface */
	struct	ifnet *ifpr_ifp;	/* back-pointer to interface */
	TAILQ_ENTRY(ifprefix) ifpr_list; /* queue macro glue */
	u_char	ifpr_plen;		/* prefix length in bits */
	u_char	ifpr_type;		/* protocol dependent prefix type */
};

/*
 * Multicast address structure.  This is analogous to the ifaddr
 * structure except that it keeps track of multicast addresses.
 * Also, the reference count here is a count of requests for this
 * address, not a count of pointers to this structure.
 */
struct ifmultiaddr {
	LIST_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
	struct	sockaddr *ifma_addr; 	/* address this membership is for */
	struct	sockaddr *ifma_lladdr;	/* link-layer translation, if any */
	struct	ifnet *ifma_ifp;	/* back-pointer to interface */
	u_int	ifma_refcount;		/* reference count */
	void	*ifma_protospec;	/* protocol-specific state, if any */
};

#ifdef _KERNEL
#define	IFAFREE(ifa) \
	do { \
		if ((ifa)->ifa_refcnt <= 0) \
			ifafree(ifa); \
		else \
			(ifa)->ifa_refcnt--; \
	} while (0)

extern	struct ifnethead ifnet;
extern struct	ifnet	**ifindex2ifnet;
extern	int ifqmaxlen;
extern	struct ifnet loif[];
extern	int if_index;
extern	struct ifaddr **ifnet_addrs;

void	ether_ifattach __P((struct ifnet *, int));
void	ether_ifdetach __P((struct ifnet *, int));
void	ether_input __P((struct ifnet *, struct ether_header *, struct mbuf *));
void	ether_demux __P((struct ifnet *, struct ether_header *, struct mbuf *));
int	ether_output __P((struct ifnet *,
	   struct mbuf *, struct sockaddr *, struct rtentry *));
int	ether_output_frame __P((struct ifnet *, struct mbuf *));
int	ether_ioctl __P((struct ifnet *, int, caddr_t));

int	if_addmulti __P((struct ifnet *, struct sockaddr *,
			 struct ifmultiaddr **));
int	if_allmulti __P((struct ifnet *, int));
void	if_attach __P((struct ifnet *));
int	if_delmulti __P((struct ifnet *, struct sockaddr *));
void	if_detach __P((struct ifnet *));
void	if_down __P((struct ifnet *));
void	if_route __P((struct ifnet *, int flag, int fam));
int	if_setlladdr __P((struct ifnet *, const u_char *, int));
void	if_unroute __P((struct ifnet *, int flag, int fam));
void	if_up __P((struct ifnet *));
/*void	ifinit __P((void));*/ /* declared in systm.h for main() */
int	ifioctl __P((struct socket *, u_long, caddr_t, struct proc *));
int	ifpromisc __P((struct ifnet *, int));
struct	ifnet *ifunit __P((const char *));
struct	ifnet *if_withname __P((struct sockaddr *));

int	if_poll_recv_slow __P((struct ifnet *ifp, int *quotap));
void	if_poll_xmit_slow __P((struct ifnet *ifp, int *quotap));
void	if_poll_throttle __P((void));
void	if_poll_unthrottle __P((void *));
void	if_poll_init __P((void));
void	if_poll __P((void));

struct	ifaddr *ifa_ifwithaddr __P((struct sockaddr *));
struct	ifaddr *ifa_ifwithdstaddr __P((struct sockaddr *));
struct	ifaddr *ifa_ifwithnet __P((struct sockaddr *));
struct	ifaddr *ifa_ifwithroute __P((int, struct sockaddr *,
					struct sockaddr *));
struct	ifaddr *ifaof_ifpforaddr __P((struct sockaddr *, struct ifnet *));
void	ifafree __P((struct ifaddr *));

struct	ifmultiaddr *ifmaof_ifpforaddr __P((struct sockaddr *,
					    struct ifnet *));
int	if_simloop __P((struct ifnet *ifp, struct mbuf *m, int af, int hlen));

void	if_clone_attach __P((struct if_clone *));
void	if_clone_detach __P((struct if_clone *));

int	if_clone_create __P((char *, int));
int	if_clone_destroy __P((const char *));

#define IF_LLADDR(ifp)							\
    LLADDR((struct sockaddr_dl *) ifnet_addrs[ifp->if_index - 1]->ifa_addr)

#ifdef DEVICE_POLLING
enum poll_cmd { POLL_ONLY, POLL_AND_CHECK_STATUS, POLL_DEREGISTER };

typedef	void poll_handler_t __P((struct ifnet *ifp,
		enum poll_cmd cmd, int count));
int	ether_poll_register __P((poll_handler_t *h, struct ifnet *ifp));
int	ether_poll_deregister __P((struct ifnet *ifp));
#endif /* DEVICE_POLLING */
#endif /* _KERNEL */

#endif /* !_NET_IF_VAR_H_ */