if_var.h

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/*
 * 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.
 * 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: src/sys/net/if_var.h,v 1.107 2006/06/19 22:20:44 mlaier Exp $
 */
 

#ifndef _NET_IF_VAR_H_
#define _NET_IF_VAR_H_

#include <net/if.h> /* struct if_data */
#include <sys/ioccom.h> /* ioctl_command_t */

/*
 * 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 an 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 an 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
 */

/*
 * Forward structure declarations for function prototypes [sic].
 */
struct  mbuf;
#ifndef __rtems__
struct  thread;
#endif
struct  rtentry;
struct  rt_addrinfo;
struct  socket;
struct  ether_header;
#ifndef __rtems__
struct  carp_if;
#endif

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

/*
 * 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.)
 */
struct ifnet {
        void    *if_softc;              /* pointer to driver state */
        char    *if_name;               /* name, e.g. ``en'' or ``lo'' */
        struct  ifnet *if_next;         /* all struct ifnets are chained */
        struct  ifaddr *if_addrlist;    /* 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 */
        int     if_flags;               /* up/down, broadcast, etc. */
        void    *if_linkmib;            /* link-type-specific MIB data */
        size_t  if_linkmiblen;          /* length of above data */
        struct  if_data if_data;
/* procedure handles */
        int     (*if_output)            /* output routine (enqueue) */
                (struct ifnet *, struct mbuf *, struct sockaddr *,
                     struct rtentry *);
        void    (*if_start)             /* initiate output routine */
                (struct ifnet *);
        int     (*if_ioctl)             /* ioctl routine */
                (struct ifnet *, ioctl_command_t, caddr_t);
        void    (*if_watchdog)          /* timer routine */
                (struct ifnet *);
        int     (*if_poll_recv)         /* polled receive routine */
                (struct ifnet *, int *);
        int     (*if_poll_xmit)         /* polled transmit routine */
                (struct ifnet *, int *);
        void    (*if_poll_intren)       /* polled interrupt reenable routine */
                (struct ifnet *);
        void    (*if_poll_slowinput)    /* input routine for slow devices */
                (struct ifnet *, struct mbuf *);
        void    (*if_init)              /* Init routine */
                (void *);
        int     (*if_tap)               /* Packet filter routine */
                (struct ifnet *, struct ether_header *, struct mbuf *);
        struct  ifqueue if_snd;         /* output queue */
        struct  ifqueue *if_poll_slowq; /* input queue for slow devices */
};

typedef void if_init_f_t(void *);

/*
 * XXX These aliases are terribly dangerous because they could apply
 * to anything.
 */
#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_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 *)NULL)

/*
 * 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) do {                                 \
        (m)->m_nextpkt = NULL; \
        if ((ifq)->ifq_tail == NULL) \
                (ifq)->ifq_head = m; \
        else \
                (ifq)->ifq_tail->m_nextpkt = m; \
        (ifq)->ifq_tail = m; \
        (ifq)->ifq_len++; \
} while (0)

#define IF_PREPEND(ifq, m) do {                                 \
        (m)->m_nextpkt = (ifq)->ifq_head; \
        if ((ifq)->ifq_tail == NULL) \
                (ifq)->ifq_tail = (m); \
        (ifq)->ifq_head = (m); \
        (ifq)->ifq_len++; \
} while (0)

#define IF_DEQUEUE(ifq, m) do {                                 \
        (m) = (ifq)->ifq_head; \
        if (m) { \
                if (((ifq)->ifq_head = (m)->m_nextpkt) == NULL) \
                        (ifq)->ifq_tail = NULL; \
                (m)->m_nextpkt = NULL; \
                (ifq)->ifq_len--; \
        } \
} while (0)

/*
 * 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  ifnet *ifa_ifp;         /* back-pointer to interface */
        struct  ifaddr *ifa_next;       /* next address for interface */
        void    (*ifa_rtrequest)        /* check or clean routes (+ or -)'d */
                (int, struct rtentry *, struct sockaddr *);
        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 */
        int (*ifa_claim_addr)           /* check if an addr goes to this if */
                (struct ifaddr *, struct sockaddr *);

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

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

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

void    if_attach(struct ifnet *);
void    if_down(struct ifnet *);
void    if_up(struct ifnet *);
/*void  ifinit(void);*/ /* declared in systm.h for main() */
int     ifioctl(struct socket *, u_long, caddr_t, struct proc *);
int     ifpromisc(struct ifnet *, int);

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

#endif /* _KERNEL */

#endif /* !_NET_IF_VAR_H_ */