root/usr/src/boot/include/net/if.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.
 * 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.
 *
 *      @(#)if.h        8.1 (Berkeley) 6/10/93
 * $FreeBSD$
 */

#ifndef _NET_IF_H_
#define _NET_IF_H_

#include <sys/cdefs.h>

#if __BSD_VISIBLE
/*
 * <net/if.h> does not depend on <sys/time.h> on most other systems.  This
 * helps userland compatibility.  (struct timeval ifi_lastchange)
 * The same holds for <sys/socket.h>.  (struct sockaddr ifru_addr)
 */
#ifndef _KERNEL
#include <sys/time.h>
#include <sys/socket.h>
#endif
#endif

/*
 * Length of interface external name, including terminating '\0'.
 * Note: this is the same size as a generic device's external name.
 */
#define         IF_NAMESIZE     16
#if __BSD_VISIBLE
#define         IFNAMSIZ        IF_NAMESIZE
#define         IF_MAXUNIT      0x7fff  /* historical value */
#endif
#if __BSD_VISIBLE

/*
 * Structure used to query names of interface cloners.
 */

struct if_clonereq {
        int     ifcr_total;             /* total cloners (out) */
        int     ifcr_count;             /* room for this many in user buffer */
        char    *ifcr_buffer;           /* buffer for cloner names */
};

/*
 * Structure describing information about an interface
 * which may be of interest to management entities.
 */
struct if_data {
        /* generic interface information */
        uint8_t ifi_type;               /* ethernet, tokenring, etc */
        uint8_t ifi_physical;           /* e.g., AUI, Thinnet, 10base-T, etc */
        uint8_t ifi_addrlen;            /* media address length */
        uint8_t ifi_hdrlen;             /* media header length */
        uint8_t ifi_link_state;         /* current link state */
        uint8_t ifi_vhid;               /* carp vhid */
        uint16_t        ifi_datalen;    /* length of this data struct */
        uint32_t        ifi_mtu;        /* maximum transmission unit */
        uint32_t        ifi_metric;     /* routing metric (external only) */
        uint64_t        ifi_baudrate;   /* linespeed */
        /* volatile statistics */
        uint64_t        ifi_ipackets;   /* packets received on interface */
        uint64_t        ifi_ierrors;    /* input errors on interface */
        uint64_t        ifi_opackets;   /* packets sent on interface */
        uint64_t        ifi_oerrors;    /* output errors on interface */
        uint64_t        ifi_collisions; /* collisions on csma interfaces */
        uint64_t        ifi_ibytes;     /* total number of octets received */
        uint64_t        ifi_obytes;     /* total number of octets sent */
        uint64_t        ifi_imcasts;    /* packets received via multicast */
        uint64_t        ifi_omcasts;    /* packets sent via multicast */
        uint64_t        ifi_iqdrops;    /* dropped on input */
        uint64_t        ifi_oqdrops;    /* dropped on output */
        uint64_t        ifi_noproto;    /* destined for unsupported protocol */
        uint64_t        ifi_hwassist;   /* HW offload capabilities, see IFCAP */

        /* Unions are here to make sizes MI. */
        union {                         /* uptime at attach or stat reset */
                time_t          tt;
                uint64_t        ph;
        } __ifi_epoch;
#define ifi_epoch       __ifi_epoch.tt
        union {                         /* time of last administrative change */
                struct timeval  tv;
                struct {
                        uint64_t ph1;
                        uint64_t ph2;
                } ph;
        } __ifi_lastchange;
#define ifi_lastchange  __ifi_lastchange.tv
};

/*-
 * Interface flags are of two types: network stack owned flags, and driver
 * owned flags.  Historically, these values were stored in the same ifnet
 * flags field, but with the advent of fine-grained locking, they have been
 * broken out such that the network stack is responsible for synchronizing
 * the stack-owned fields, and the device driver the device-owned fields.
 * Both halves can perform lockless reads of the other half's field, subject
 * to accepting the involved races.
 *
 * Both sets of flags come from the same number space, and should not be
 * permitted to conflict, as they are exposed to user space via a single
 * field.
 *
 * The following symbols identify read and write requirements for fields:
 *
 * (i) if_flags field set by device driver before attach, read-only there
 *     after.
 * (n) if_flags field written only by the network stack, read by either the
 *     stack or driver.
 * (d) if_drv_flags field written only by the device driver, read by either
 *     the stack or driver.
 */
#define IFF_UP          0x1             /* (n) interface is up */
#define IFF_BROADCAST   0x2             /* (i) broadcast address valid */
#define IFF_DEBUG       0x4             /* (n) turn on debugging */
#define IFF_LOOPBACK    0x8             /* (i) is a loopback net */
#define IFF_POINTOPOINT 0x10            /* (i) is a point-to-point link */
/*                      0x20               was IFF_SMART */
#define IFF_DRV_RUNNING 0x40            /* (d) resources allocated */
#define IFF_NOARP       0x80            /* (n) no address resolution protocol */
#define IFF_PROMISC     0x100           /* (n) receive all packets */
#define IFF_ALLMULTI    0x200           /* (n) receive all multicast packets */
#define IFF_DRV_OACTIVE 0x400           /* (d) tx hardware queue is full */
#define IFF_SIMPLEX     0x800           /* (i) can't hear own transmissions */
#define IFF_LINK0       0x1000          /* per link layer defined bit */
#define IFF_LINK1       0x2000          /* per link layer defined bit */
#define IFF_LINK2       0x4000          /* per link layer defined bit */
#define IFF_ALTPHYS     IFF_LINK2       /* use alternate physical connection */
#define IFF_MULTICAST   0x8000          /* (i) supports multicast */
#define IFF_CANTCONFIG  0x10000         /* (i) unconfigurable using ioctl(2) */
#define IFF_PPROMISC    0x20000         /* (n) user-requested promisc mode */
#define IFF_MONITOR     0x40000         /* (n) user-requested monitor mode */
#define IFF_STATICARP   0x80000         /* (n) static ARP */
#define IFF_DYING       0x200000        /* (n) interface is winding down */
#define IFF_RENAMING    0x400000        /* (n) interface is being renamed */
/*
 * Old names for driver flags so that user space tools can continue to use
 * the old (portable) names.
 */
#ifndef _KERNEL
#define IFF_RUNNING     IFF_DRV_RUNNING
#define IFF_OACTIVE     IFF_DRV_OACTIVE
#endif

/* flags set internally only: */
#define IFF_CANTCHANGE \
        (IFF_BROADCAST|IFF_POINTOPOINT|IFF_DRV_RUNNING|IFF_DRV_OACTIVE|\
            IFF_SIMPLEX|IFF_MULTICAST|IFF_ALLMULTI|IFF_PROMISC|\
            IFF_DYING|IFF_CANTCONFIG)

/*
 * Values for if_link_state.
 */
#define LINK_STATE_UNKNOWN      0       /* link invalid/unknown */
#define LINK_STATE_DOWN         1       /* link is down */
#define LINK_STATE_UP           2       /* link is up */

/*
 * Some convenience macros used for setting ifi_baudrate.
 * XXX 1000 vs. 1024? --thorpej@netbsd.org
 */
#define IF_Kbps(x)      ((uintmax_t)(x) * 1000) /* kilobits/sec. */
#define IF_Mbps(x)      (IF_Kbps((x) * 1000))   /* megabits/sec. */
#define IF_Gbps(x)      (IF_Mbps((x) * 1000))   /* gigabits/sec. */

/*
 * Capabilities that interfaces can advertise.
 *
 * struct ifnet.if_capabilities
 *   contains the optional features & capabilities a particular interface
 *   supports (not only the driver but also the detected hw revision).
 *   Capabilities are defined by IFCAP_* below.
 * struct ifnet.if_capenable
 *   contains the enabled (either by default or through ifconfig) optional
 *   features & capabilities on this interface.
 *   Capabilities are defined by IFCAP_* below.
 * struct if_data.ifi_hwassist in mbuf CSUM_ flag form, controlled by above
 *   contains the enabled optional feature & capabilites that can be used
 *   individually per packet and are specified in the mbuf pkthdr.csum_flags
 *   field.  IFCAP_* and CSUM_* do not match one to one and CSUM_* may be
 *   more detailed or differenciated than IFCAP_*.
 *   Hwassist features are defined CSUM_* in sys/mbuf.h
 *
 * Capabilities that cannot be arbitrarily changed with ifconfig/ioctl
 * are listed in IFCAP_CANTCHANGE, similar to IFF_CANTCHANGE.
 * This is not strictly necessary because the common code never
 * changes capabilities, and it is left to the individual driver
 * to do the right thing. However, having the filter here
 * avoids replication of the same code in all individual drivers.
 */
#define IFCAP_RXCSUM            0x00001  /* can offload checksum on RX */
#define IFCAP_TXCSUM            0x00002  /* can offload checksum on TX */
#define IFCAP_NETCONS           0x00004  /* can be a network console */
#define IFCAP_VLAN_MTU          0x00008 /* VLAN-compatible MTU */
#define IFCAP_VLAN_HWTAGGING    0x00010 /* hardware VLAN tag support */
#define IFCAP_JUMBO_MTU         0x00020 /* 9000 byte MTU supported */
#define IFCAP_POLLING           0x00040 /* driver supports polling */
#define IFCAP_VLAN_HWCSUM       0x00080 /* can do IFCAP_HWCSUM on VLANs */
#define IFCAP_TSO4              0x00100 /* can do TCP Segmentation Offload */
#define IFCAP_TSO6              0x00200 /* can do TCP6 Segmentation Offload */
#define IFCAP_LRO               0x00400 /* can do Large Receive Offload */
#define IFCAP_WOL_UCAST         0x00800 /* wake on any unicast frame */
#define IFCAP_WOL_MCAST         0x01000 /* wake on any multicast frame */
#define IFCAP_WOL_MAGIC         0x02000 /* wake on any Magic Packet */
#define IFCAP_TOE4              0x04000 /* interface can offload TCP */
#define IFCAP_TOE6              0x08000 /* interface can offload TCP6 */
#define IFCAP_VLAN_HWFILTER     0x10000 /* interface hw can filter vlan tag */
#define IFCAP_POLLING_NOCOUNT   0x20000 /* polling ticks cannot be fragmented */
#define IFCAP_VLAN_HWTSO        0x40000 /* can do IFCAP_TSO on VLANs */
#define IFCAP_LINKSTATE         0x80000 /* the runtime link state is dynamic */
#define IFCAP_NETMAP            0x100000 /* netmap mode supported/enabled */
#define IFCAP_RXCSUM_IPV6       0x200000  /* can offload checksum on IPv6 RX */
#define IFCAP_TXCSUM_IPV6       0x400000  /* can offload checksum on IPv6 TX */
#define IFCAP_HWSTATS           0x800000 /* manages counters internally */

#define IFCAP_HWCSUM_IPV6       (IFCAP_RXCSUM_IPV6 | IFCAP_TXCSUM_IPV6)

#define IFCAP_HWCSUM    (IFCAP_RXCSUM | IFCAP_TXCSUM)
#define IFCAP_TSO       (IFCAP_TSO4 | IFCAP_TSO6)
#define IFCAP_WOL       (IFCAP_WOL_UCAST | IFCAP_WOL_MCAST | IFCAP_WOL_MAGIC)
#define IFCAP_TOE       (IFCAP_TOE4 | IFCAP_TOE6)

#define IFCAP_CANTCHANGE        (IFCAP_NETMAP)

#define IFQ_MAXLEN      50
#define IFNET_SLOWHZ    1               /* granularity is 1 second */

/*
 * Message format for use in obtaining information about interfaces
 * from getkerninfo and the routing socket
 * For the new, extensible interface see struct if_msghdrl below.
 */
struct if_msghdr {
        u_short ifm_msglen;     /* to skip over non-understood messages */
        u_char  ifm_version;    /* future binary compatibility */
        u_char  ifm_type;       /* message type */
        int     ifm_addrs;      /* like rtm_addrs */
        int     ifm_flags;      /* value of if_flags */
        u_short ifm_index;      /* index for associated ifp */
        struct  if_data ifm_data;/* statistics and other data about if */
};

/*
 * The 'l' version shall be used by new interfaces, like NET_RT_IFLISTL.  It is
 * extensible after ifm_data_off or within ifm_data.  Both the if_msghdr and
 * if_data now have a member field detailing the struct length in addition to
 * the routing message length.  Macros are provided to find the start of
 * ifm_data and the start of the socket address strucutres immediately following
 * struct if_msghdrl given a pointer to struct if_msghdrl.
 */
#define IF_MSGHDRL_IFM_DATA(_l) \
    (struct if_data *)((char *)(_l) + (_l)->ifm_data_off)
#define IF_MSGHDRL_RTA(_l) \
    (void *)((uintptr_t)(_l) + (_l)->ifm_len)
struct if_msghdrl {
        u_short ifm_msglen;     /* to skip over non-understood messages */
        u_char  ifm_version;    /* future binary compatibility */
        u_char  ifm_type;       /* message type */
        int     ifm_addrs;      /* like rtm_addrs */
        int     ifm_flags;      /* value of if_flags */
        u_short ifm_index;      /* index for associated ifp */
        u_short _ifm_spare1;    /* spare space to grow if_index, see if_var.h */
        u_short ifm_len;        /* length of if_msghdrl incl. if_data */
        u_short ifm_data_off;   /* offset of if_data from beginning */
        struct  if_data ifm_data;/* statistics and other data about if */
};

/*
 * Message format for use in obtaining information about interface addresses
 * from getkerninfo and the routing socket
 * For the new, extensible interface see struct ifa_msghdrl below.
 */
struct ifa_msghdr {
        u_short ifam_msglen;    /* to skip over non-understood messages */
        u_char  ifam_version;   /* future binary compatibility */
        u_char  ifam_type;      /* message type */
        int     ifam_addrs;     /* like rtm_addrs */
        int     ifam_flags;     /* value of ifa_flags */
        u_short ifam_index;     /* index for associated ifp */
        int     ifam_metric;    /* value of ifa_ifp->if_metric */
};

/*
 * The 'l' version shall be used by new interfaces, like NET_RT_IFLISTL.  It is
 * extensible after ifam_metric or within ifam_data.  Both the ifa_msghdrl and
 * if_data now have a member field detailing the struct length in addition to
 * the routing message length.  Macros are provided to find the start of
 * ifm_data and the start of the socket address strucutres immediately following
 * struct ifa_msghdrl given a pointer to struct ifa_msghdrl.
 */
#define IFA_MSGHDRL_IFAM_DATA(_l) \
    (struct if_data *)((char *)(_l) + (_l)->ifam_data_off)
#define IFA_MSGHDRL_RTA(_l) \
    (void *)((uintptr_t)(_l) + (_l)->ifam_len)
struct ifa_msghdrl {
        u_short ifam_msglen;    /* to skip over non-understood messages */
        u_char  ifam_version;   /* future binary compatibility */
        u_char  ifam_type;      /* message type */
        int     ifam_addrs;     /* like rtm_addrs */
        int     ifam_flags;     /* value of ifa_flags */
        u_short ifam_index;     /* index for associated ifp */
        u_short _ifam_spare1;   /* spare space to grow if_index, see if_var.h */
        u_short ifam_len;       /* length of ifa_msghdrl incl. if_data */
        u_short ifam_data_off;  /* offset of if_data from beginning */
        int     ifam_metric;    /* value of ifa_ifp->if_metric */
        struct  if_data ifam_data;/* statistics and other data about if or
                                 * address */
};

/*
 * Message format for use in obtaining information about multicast addresses
 * from the routing socket
 */
struct ifma_msghdr {
        u_short ifmam_msglen;   /* to skip over non-understood messages */
        u_char  ifmam_version;  /* future binary compatibility */
        u_char  ifmam_type;     /* message type */
        int     ifmam_addrs;    /* like rtm_addrs */
        int     ifmam_flags;    /* value of ifa_flags */
        u_short ifmam_index;    /* index for associated ifp */
};

/*
 * Message format announcing the arrival or departure of a network interface.
 */
struct if_announcemsghdr {
        u_short ifan_msglen;    /* to skip over non-understood messages */
        u_char  ifan_version;   /* future binary compatibility */
        u_char  ifan_type;      /* message type */
        u_short ifan_index;     /* index for associated ifp */
        char    ifan_name[IFNAMSIZ]; /* if name, e.g. "en0" */
        u_short ifan_what;      /* what type of announcement */
};

#define IFAN_ARRIVAL    0       /* interface arrival */
#define IFAN_DEPARTURE  1       /* interface departure */

/*
 * Buffer with length to be used in SIOCGIFDESCR/SIOCSIFDESCR requests
 */
struct ifreq_buffer {
        size_t  length;
        void    *buffer;
};

/*
 * Interface request structure used for socket
 * ioctl's.  All interface ioctl's must have parameter
 * definitions which begin with ifr_name.  The
 * remainder may be interface specific.
 */
struct  ifreq {
        char    ifr_name[IFNAMSIZ];             /* if name, e.g. "en0" */
        union {
                struct  sockaddr ifru_addr;
                struct  sockaddr ifru_dstaddr;
                struct  sockaddr ifru_broadaddr;
                struct  ifreq_buffer ifru_buffer;
                short   ifru_flags[2];
                short   ifru_index;
                int     ifru_jid;
                int     ifru_metric;
                int     ifru_mtu;
                int     ifru_phys;
                int     ifru_media;
                caddr_t ifru_data;
                int     ifru_cap[2];
                u_int   ifru_fib;
        } ifr_ifru;
#define ifr_addr        ifr_ifru.ifru_addr      /* address */
#define ifr_dstaddr     ifr_ifru.ifru_dstaddr   /* other end of p-to-p link */
#define ifr_broadaddr   ifr_ifru.ifru_broadaddr /* broadcast address */
#define ifr_buffer      ifr_ifru.ifru_buffer    /* user supplied buffer with its length */
#define ifr_flags       ifr_ifru.ifru_flags[0]  /* flags (low 16 bits) */
#define ifr_flagshigh   ifr_ifru.ifru_flags[1]  /* flags (high 16 bits) */
#define ifr_jid         ifr_ifru.ifru_jid       /* jail/vnet */
#define ifr_metric      ifr_ifru.ifru_metric    /* metric */
#define ifr_mtu         ifr_ifru.ifru_mtu       /* mtu */
#define ifr_phys        ifr_ifru.ifru_phys      /* physical wire */
#define ifr_media       ifr_ifru.ifru_media     /* physical media */
#define ifr_data        ifr_ifru.ifru_data      /* for use by interface */
#define ifr_reqcap      ifr_ifru.ifru_cap[0]    /* requested capabilities */
#define ifr_curcap      ifr_ifru.ifru_cap[1]    /* current capabilities */
#define ifr_index       ifr_ifru.ifru_index     /* interface index */
#define ifr_fib         ifr_ifru.ifru_fib       /* interface fib */
};

#define _SIZEOF_ADDR_IFREQ(ifr) \
        ((ifr).ifr_addr.sa_len > sizeof(struct sockaddr) ? \
         (sizeof(struct ifreq) - sizeof(struct sockaddr) + \
          (ifr).ifr_addr.sa_len) : sizeof(struct ifreq))

struct ifaliasreq {
        char    ifra_name[IFNAMSIZ];            /* if name, e.g. "en0" */
        struct  sockaddr ifra_addr;
        struct  sockaddr ifra_broadaddr;
        struct  sockaddr ifra_mask;
        int     ifra_vhid;
};

/* 9.x compat */
struct oifaliasreq {
        char    ifra_name[IFNAMSIZ];
        struct  sockaddr ifra_addr;
        struct  sockaddr ifra_broadaddr;
        struct  sockaddr ifra_mask;
};

struct ifmediareq {
        char    ifm_name[IFNAMSIZ];     /* if name, e.g. "en0" */
        int     ifm_current;            /* current media options */
        int     ifm_mask;               /* don't care mask */
        int     ifm_status;             /* media status */
        int     ifm_active;             /* active options */
        int     ifm_count;              /* # entries in ifm_ulist array */
        int     *ifm_ulist;             /* media words */
};

struct  ifdrv {
        char            ifd_name[IFNAMSIZ];     /* if name, e.g. "en0" */
        unsigned long   ifd_cmd;
        size_t          ifd_len;
        void            *ifd_data;
};

/*
 * Structure used to retrieve aux status data from interfaces.
 * Kernel suppliers to this interface should respect the formatting
 * needed by ifconfig(8): each line starts with a TAB and ends with
 * a newline.  The canonical example to copy and paste is in if_tun.c.
 */

#define IFSTATMAX       800             /* 10 lines of text */
struct ifstat {
        char    ifs_name[IFNAMSIZ];     /* if name, e.g. "en0" */
        char    ascii[IFSTATMAX + 1];
};

/*
 * Structure used in SIOCGIFCONF request.
 * Used to retrieve interface configuration
 * for machine (useful for programs which
 * must know all networks accessible).
 */
struct  ifconf {
        int     ifc_len;                /* size of associated buffer */
        union {
                caddr_t ifcu_buf;
                struct  ifreq *ifcu_req;
        } ifc_ifcu;
#define ifc_buf ifc_ifcu.ifcu_buf       /* buffer address */
#define ifc_req ifc_ifcu.ifcu_req       /* array of structures returned */
};

/*
 * interface groups
 */

#define IFG_ALL         "all"           /* group contains all interfaces */
/* XXX: will we implement this? */
#define IFG_EGRESS      "egress"        /* if(s) default route(s) point to */

struct ifg_req {
        union {
                char                     ifgrqu_group[IFNAMSIZ];
                char                     ifgrqu_member[IFNAMSIZ];
        } ifgrq_ifgrqu;
#define ifgrq_group     ifgrq_ifgrqu.ifgrqu_group
#define ifgrq_member    ifgrq_ifgrqu.ifgrqu_member
};

/*
 * Used to lookup groups for an interface
 */
struct ifgroupreq {
        char    ifgr_name[IFNAMSIZ];
        u_int   ifgr_len;
        union {
                char    ifgru_group[IFNAMSIZ];
                struct  ifg_req *ifgru_groups;
        } ifgr_ifgru;
#define ifgr_group      ifgr_ifgru.ifgru_group
#define ifgr_groups     ifgr_ifgru.ifgru_groups
};

/*
 * Structure used to request i2c data
 * from interface transceivers.
 */
struct ifi2creq {
        uint8_t dev_addr;       /* i2c address (0xA0, 0xA2) */
        uint8_t offset;         /* read offset */
        uint8_t len;            /* read length */
        uint8_t spare0;
        uint32_t spare1;
        uint8_t data[8];        /* read buffer */
};

#endif /* __BSD_VISIBLE */

#ifdef _KERNEL
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_IFADDR);
MALLOC_DECLARE(M_IFMADDR);
#endif
#endif

#ifndef _KERNEL
struct if_nameindex {
        unsigned int    if_index;       /* 1, 2, ... */
        char            *if_name;       /* null terminated name: "le0", ... */
};

__BEGIN_DECLS
void                     if_freenameindex(struct if_nameindex *);
char                    *if_indextoname(unsigned int, char *);
struct if_nameindex     *if_nameindex(void);
unsigned int             if_nametoindex(const char *);
__END_DECLS
#endif
#endif /* !_NET_IF_H_ */