ipv6.c

ucd-snmp源代码

/*
 *  IP MIB group implementation - ipv6.c
 *
 */

#include <config.h>
#if defined(IFNET_NEEDS_KERNEL) && !defined(_KERNEL)
#define _KERNEL 1
#define _I_DEFINED_KERNEL
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
# if HAVE_SYS_SOCKETVAR_H
#  include <sys/socketvar.h>
# endif
#endif

#if STDC_HEADERS
#include <string.h>
#include <stdlib.h>
#else
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_SYS_SYSCTL_H
#ifdef _I_DEFINED_KERNEL
#undef _KERNEL
#endif
#include <sys/sysctl.h>
#ifdef _I_DEFINED_KERNEL
#define _KERNEL 1
#endif
#endif
#if HAVE_SYS_SYSMP_H
#include <sys/sysmp.h>
#endif
#if HAVE_SYS_TCPIPSTATS_H
#include <sys/tcpipstats.h>
#endif
#include <net/if.h>
#if HAVE_NET_IF_VAR_H
#include <net/if_var.h>
#endif
#if HAVE_NET_IF_DL_H
#include <net/if_dl.h>
#endif
#ifdef HAVE_NET_IF_MIB_H
#include <net/if_mib.h>
#endif
#ifdef _I_DEFINED_KERNEL
#undef _KERNEL
#endif
#include <netinet/in_systm.h>
#if HAVE_SYS_HASHING_H
#include <sys/hashing.h>
#endif
#if HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#if HAVE_NETINET6_IN6_VAR_H
#include <netinet6/in6_var.h>
#endif
#include <netinet/ip6.h>
#if HAVE_NETINET_IP_VAR_H
# include <netinet/ip_var.h>
#endif
#if HAVE_NETINET6_IP6_VAR_H
# include <netinet6/ip6_var.h>
#endif
#include <net/route.h>
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
# if HAVE_NETINET_IN_PCB_H
#  include <netinet/in_pcb.h>
# endif
#endif
#if HAVE_NETINET6_IN6_PCB_H
# include <netinet6/in6_pcb.h>
#endif
#if HAVE_NETINET6_TCP6_H
# define TCP6
#endif
#ifndef TCP6
# if HAVE_NETINET_TCP_H
#  include <netinet/tcp.h>
# endif
# if HAVE_NETINET_TCP_TIMER_H
#  include <netinet/tcp_timer.h>
# endif
# if HAVE_NETINET_TCP_VAR_H
#  include <netinet/tcp_var.h>
# endif
# if HAVE_NETINET_TCP_FSM_H
#  include <netinet/tcp_fsm.h>
# endif
#endif
#if HAVE_NETINET6_TCP6_H
# include <netinet6/tcp6.h>
#endif
#if HAVE_NETINET6_TCP6_TIMER_H
#include <netinet6/tcp6_timer.h>
#endif
#if HAVE_NETINET6_TCP6_VAR_H
#include <netinet6/tcp6_var.h>
#endif
#if HAVE_NETINET6_TCP6_FSM_H
#include <netinet6/tcp6_fsm.h>
#endif
#if HAVE_INET_MIB2_H
#include <inet/mib2.h>
#endif
#ifdef HAVE_SYSLOG_H
#include <syslog.h>
#endif

#include "mibincl.h"
#include "kernel.h"

#include "system.h"

#include "util_funcs.h"
#include "auto_nlist.h"

#ifdef MIB_IPCOUNTER_SYMBOL
#include <sys/mib.h>
#include <netinet/mib_kern.h>
#endif /* MIB_IPCOUNTER_SYMBOL */

#include "ipv6.h"
#include "interfaces.h"

static int header_ipv6 __P((register struct variable *, oid *, size_t *, int,
	size_t *, WriteMethod **));
static int header_ipv6_scan __P((register struct variable *, oid *, size_t *,
	int, size_t *, WriteMethod **, int, int));
static int if_initialize __P((void));
static int if_maxifindex __P((void));
static char *if_getname __P((int));
static int if_getindex __P((const char *));

struct variable4 ipv6_variables[] = {
    {IPV6FORWARDING, ASN_INTEGER, RONLY, var_ipv6, 1, {1}},
    {IPV6DEFAULTHOPLIMIT, ASN_INTEGER, RONLY, var_ipv6, 1, {2}},
    {IPV6INTERFACES, ASN_GAUGE, RONLY, var_ipv6, 1, {3}},
    {IPV6IFTBLLASTCHG, ASN_TIMETICKS, RONLY, var_ipv6, 1, {4}},

    {IPV6IFDESCR, ASN_OCTET_STR, RONLY, var_ifv6Entry, 3, {5, 1, 2}},
    {IPV6IFLOWLAYER, ASN_OBJECT_ID, RONLY, var_ifv6Entry, 3, {5, 1, 3}},
    {IPV6IFEFFECTMTU, ASN_UNSIGNED, RONLY, var_ifv6Entry, 3, {5, 1, 4}},
    {IPV6IFREASMMAXSIZE, ASN_UNSIGNED, RONLY, var_ifv6Entry, 3, {5, 1, 5}},

    {IPV6IFTOKEN, ASN_OCTET_STR, RONLY, var_ifv6Entry, 3, {5, 1, 6}},
    {IPV6IFTOKENLEN, ASN_INTEGER, RONLY, var_ifv6Entry, 3, {5, 1, 7}},
    {IPV6IFPHYSADDRESS, ASN_OCTET_STR, RONLY, var_ifv6Entry, 3, {5, 1, 8}},
    {IPV6IFADMSTATUS, ASN_INTEGER, RONLY, var_ifv6Entry, 3, {5, 1, 9}},
    {IPV6IFOPERSTATUS, ASN_INTEGER, RONLY, var_ifv6Entry, 3, {5, 1, 10}},
    {IPV6IFLASTCHANGE, ASN_TIMETICKS, RONLY, var_ifv6Entry, 3, {5, 1, 11}},

    {IPV6IFSTATSINRCVS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 1}},
    {IPV6IFSTATSINHDRERRS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 2}},
    {IPV6IFSTATSTOOBIGERRS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 3}},
    {IPV6IFSTATSINNOROUTES, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 4}},
    {IPV6IFSTATSINADDRERRS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 5}},
    {IPV6IFSTATSINUNKNOWPROTS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 6}},
    {IPV6IFSTATSINTRUNCATPKTS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 7}},
    {IPV6IFSTATSINDISCARDS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 8}},
    {IPV6IFSTATSINDELIVERS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 9}},
    {IPV6IFSTATSOUTFORWDATAS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 10}},
    {IPV6IFSTATSOUTREQS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 11}},
    {IPV6IFSTATSOUTDISCARDS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 12}},
    {IPV6IFSTATSOUTFRAGOKS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 13}},
    {IPV6IFSTATSOUTFRAGFAILS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 14}},
    {IPV6IFSTATSOUTFRAGCREATS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 15}},
    {IPV6IFSTATSOUTREASMREQS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 16}},
    {IPV6IFSTATSOUTREASMOKS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 17}},
    {IPV6IFSTATSOUTREASMFAILS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 18}},
    {IPV6IFSTATSINMCASTPKTS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 19}},
    {IPV6IFSTATSOUTMCASTPKTS, ASN_COUNTER, RONLY, var_ifv6Entry, 3, {6, 1, 20}},

#if 0
    {IPV6ADDRPREFIXONLINKFLG, INTEGER, RONLY, var_ipv6AddrEntry, 3, {7, 1, 3}},
    {IPV6ADDRPREFIXAUTONOMOUSFLAG, INTEGER, RONLY, var_ipv6AddrEntry, 3, {7, 1, 4}},
    {IPV6ADDRPREFIXADVPREFERLIFE, UNSIGNED32, RONLY, var_ipv6AddrEntry, 3, {7, 1, 5}},
    {IPV6ADDRPREFIXVALIDLIFE, UNSIGNED32, RONLY, var_ipv6AddrEntry, 3, {7, 1, 6}},

    {IPV6ADDRPFXLEN, INTEGER, RONLY, var_ipv6AddrEntry, 3, {8, 1, 2}},
    {IPV6ADDRTYPE, INTEGER, RONLY, var_ipv6AddrEntry, 3, {8, 1, 3}},
    {IPV6ADDRANYCASTFLAG, INTEGER, RONLY, var_ipv6AddrEntry, 3, {8, 1, 4}},
    {IPV6ADDRSTATUS, INTEGER, RONLY, var_ipv6AddrEntry, 3, {8, 1, 5}},

    {IPV6ROUTEIFINDEX, IpV6IFINDEX, RONLY, var_ipv6RouteEntry, 3, {11, 1, 4}},
    {IPV6ROUTENEXTHOP, IpV6ADDRESS, RONLY, var_ipv6RouteEntry, 3, {11, 1, 5}},
    {IPV6ROUTETYPE, INTEGER, RONLY, var_ipv6RouteEntry, 3, {11, 1, 6}},
    {IPV6ROUTEPROTOCOL, INTEGER, RONLY, var_ipv6RouteEntry, 3, {11, 1, 7}},
    {IPV6ROUTEPOLICY, UNSIGNED32, RONLY, var_ipv6RouteEntry, 3, {11, 1, 8}},
    {IPV6ROUTEAGE, UNSIGNED32, RONLY, var_ipv6RouteEntry, 3, {11, 1, 9}},
    {IPV6ROUTENEXTHOPRDI, UNSIGNED32, RONLY, var_ipv6RouteEntry, 3, {11, 1, 10}},
    {IPV6ROUTEMETRIC, UNSIGNED32, RONLY, var_ipv6RouteEntry, 3, {11, 1, 11}},
    {IPV6ROUTEWEIGHT, UNSIGNED32, RONLY, var_ipv6RouteEntry, 3, {11, 1, 12}},
    {IPV6ROUTEINFO, OBJID, RONLY, var_ipv6RouteEntry, 3, {11, 1, 13}},
    {IPV6ROUTEVALID, INTEGER, RONLY, var_ipv6RouteEntry, 3, {11, 1, 14}},

    {IPV6NETTOMEDIAPHYADDR, STRING, RONLY, var_ndpEntry, 3, {12, 1, 2}},
    {IPV6NETTOMEDIATYPE, INTEGER, RONLY, var_ndpEntry, 3, {12, 1, 3}},
    {IPV6NETTOMEDIASTATE, INTEGER, RONLY, var_ndpEntry, 3, {12, 1, 4}},
    {IPV6NETTOMEDIALASTUPDATE, TIMETICKS, RONLY, var_ndpEntry, 3, {12, 1, 5}},
    {IPV6NETTOMEDIAVALID, INTEGER, RONLY, var_ndpEntry, 3, {12, 1, 6}},
#endif
};
oid ipv6_variables_oid[] = {SNMP_OID_MIB2,55,1};
#if 0
    config_load_mib(MIB.55.1, 8, ipv6_variables)
    config_add_mib(IPV6-TC)
    config_add_mib(IPV6-MIB)
#endif

struct variable4 ipv6icmp_variables[] = {
    {IPV6IFICMPINMSG, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 1}},
    {IPV6IFICMPINERRORS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 2}},
    {IPV6IFICMPINDSTUNRCHS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 3}},
    {IPV6IFICMPINADMPROHS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 4}},
    {IPV6IFICMPINTIMEXCDS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 5}},
    {IPV6IFICMPINPARMPROBS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 6}},
    {IPV6IFICMPINPKTTOOBIGS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 7}},
    {IPV6IFICMPINECHOS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 8}},
    {IPV6IFICMPINECHOREPS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 9}},
    {IPV6IFICMPINRTRSLICITS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 10}},
    {IPV6IFICMPINRTRADVS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 11}},
    {IPV6IFICMPINNBRSLICITS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 12}},
    {IPV6IFICMPINNBRADVS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 13}},
    {IPV6IFICMPINREDIRECTS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 14}},
    {IPV6IFICMPINGRPMEQERYS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 15}},
    {IPV6IFICMPINGRPMERSPS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 16}},
    {IPV6IFICMPINGRPMEREDCS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 17}},
    {IPV6IFICMPOUTMSG, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 18}},
    {IPV6IFICMPOUTERRORS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 19}},
    {IPV6IFICMPOUTDSTUNRCHS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 20}},
    {IPV6IFICMPOUTADMPROHS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 21}},
    {IPV6IFICMPOUTTIMEXCDS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 22}},
    {IPV6IFICMPOUTPARMPROBS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 23}},
    {IPV6IFICMPOUTPKTTOOBIGS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 24}},
    {IPV6IFICMPOUTECHOS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 25}},
    {IPV6IFICMPOUTECHOREPS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 26}},
    {IPV6IFICMPOUTRTRSLICITS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 27}},
    {IPV6IFICMPOUTRTRADVS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 28}},
    {IPV6IFICMPOUTNBRSLICITS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 29}},
    {IPV6IFICMPOUTNBRADVS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 30}},
    {IPV6IFICMPOUTREDIRECTS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 31}},
    {IPV6IFICMPOUTGRPMEQERYS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 32}},
    {IPV6IFICMPOUTGRPMERSPS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 33}},
    {IPV6IFICMPOUTGRPMEREDCS, ASN_COUNTER, RONLY, var_icmpv6Entry, 3, {1, 1, 34}}
};
oid ipv6icmp_variables_oid[] = {1,3,6,1,2,1,56,1};
#if 0
    config_load_mib(MIB.56.1, 8, ipv6icmp_variables)
    config_add_mib(IPV6-ICMP-MIB)
#endif

struct variable4 ipv6udp_variables[] = {
    {IPV6UDPLOCALADDRESS, ASN_OCTET_STR, RONLY, var_udp6, 2, {1, 1}},
    {IPV6UDPLOCALPORT, ASN_INTEGER, RONLY, var_udp6, 2, {1, 2}},
    {IPV6UDPIFINDEX, ASN_INTEGER, RONLY, var_udp6, 2, {1, 3}}
};
oid ipv6udp_variables_oid[] = {1,3,6,1,2,1,7,6};
#if 0
    config_load_mib(1.3.6.1.3.87.1, 7, ipv6udp_variables)
    config_add_mib(IPV6-UDP-MIB)
#endif

struct variable4 ipv6tcp_variables[] = {
    {IPV6TCPLOCALADDR, ASN_OCTET_STR, RONLY, var_tcp6, 2, {1, 1}},
    {IPV6TCPLOCALPORT, ASN_INTEGER, RONLY, var_tcp6, 2, {1, 2}},
    {IPV6TCPREMOTEADDR, ASN_OCTET_STR, RONLY, var_tcp6, 2, {1, 3}},
    {IPV6TCPREMOTEPORT, ASN_INTEGER, RONLY, var_tcp6, 2, {1, 4}},
    {IPV6TCPIFINDEX, ASN_INTEGER, RONLY, var_tcp6, 2, {1, 5}},
    {IPV6TCPCONNSTATE, ASN_INTEGER, RONLY, var_tcp6, 2, {1, 6}},
};
oid ipv6tcp_variables_oid[] = {1,3,6,1,2,1,6,16};
#if 0
    config_load_mib(1.3.6.1.3.86.1, 7, ipv6tcp_variables)
    config_add_mib(IPV6-TCP-MIB)
#endif

void
init_ipv6()
{
    /* register ourselves with the agent to handle our mib tree */
    REGISTER_MIB("mibII/ipv6", ipv6_variables, variable4, ipv6_variables_oid);
    REGISTER_MIB("mibII/icmpv6", ipv6icmp_variables, variable4,
	ipv6icmp_variables_oid);
    REGISTER_MIB("mibII/ipv6udp", ipv6udp_variables, variable4,
	ipv6udp_variables_oid);
    REGISTER_MIB("mibII/ipv6tcp", ipv6tcp_variables, variable4,
	ipv6tcp_variables_oid);
}

static int
header_ipv6(
    register struct variable *vp,
			/* IN - pointer to variable entry that points here */
    oid *name,		/* IN/OUT - input name requested, output name found */
    size_t *length,	/* IN/OUT - length of input and output oid's */
    int exact,		/* IN - TRUE if an exact match was requested */
    size_t *var_len,	/* OUT - length of variable or 0 if function returned */
    WriteMethod **write_method)
{
    oid newname[MAX_OID_LEN];
    int result;

    DEBUGMSGTL(("mibII/ipv6", "header_ipv6: "));
    DEBUGMSGOID(("mibII/ipv6", name, *length));
    DEBUGMSG(("mibII/ipv6"," %d\n", exact));

    memcpy((char *)newname, (char *)vp->name, (int)vp->namelen * sizeof(oid));
    newname[(int)vp->namelen] = 0;
    result = snmp_oid_compare(name, *length, newname, (int)vp->namelen + 1);
    if ((exact && (result != 0)) || (!exact && (result >= 0)))
        return(MATCH_FAILED);
    memcpy((char *)name, (char *)newname, ((int)vp->namelen + 1) * sizeof(oid));
    *length = vp->namelen + 1;

    *write_method = 0;
    *var_len = sizeof(long);	/* default to 'long' results */
    return(MATCH_SUCCEEDED);
}

static int
header_ipv6_scan(
    register struct variable *vp,
			/* IN - pointer to variable entry that points here */
    oid *name,		/* IN/OUT - input name requested, output name found */
    size_t *length,	/* IN/OUT - length of input and output oid's */
    int exact,		/* IN - TRUE if an exact match was requested */
    size_t *var_len,	/* OUT - length of variable or 0 if function returned */
    WriteMethod **write_method,
    int from,
    int to)
{
    oid newname[MAX_OID_LEN];
    int result;
    int i;

    DEBUGMSGTL(("mibII/ipv6", "header_ipv6_scan: "));
    DEBUGMSGOID(("mibII/ipv6", name, *length));
    DEBUGMSG(("mibII/ipv6"," %d\n", exact));

    memcpy((char *)newname, (char *)vp->name, (int)vp->namelen * sizeof(oid));
    for (i = from; i <= to; i++) {
	newname[(int)vp->namelen] = i;
	result = snmp_oid_compare(name, *length, newname, (int)vp->namelen + 1);
	if (((exact && result == 0) || (!exact && result < 0)) && if_getname(i))
	    break;
    }
    if (to < i)
	return(MATCH_FAILED);
    memcpy((char *)name, (char *)newname, ((int)vp->namelen + 1) * sizeof(oid));
    *length = vp->namelen + 1;
    *write_method = 0;
    *var_len = sizeof(long);	/* default to 'long' results */
    return(MATCH_SUCCEEDED);
}

static struct if_nameindex *ifnames = NULL;

#ifdef linux
static void linux_if_freenameindex(struct if_nameindex *);
static struct if_nameindex *linux_if_nameindex(void);
#endif

static int
if_initialize(void)
{
#ifndef HAVE_IF_NAMEINDEX
    return -1;
#else
#ifndef linux
    if (ifnames) if_freenameindex(ifnames);
    ifnames = if_nameindex();
#else
    if (ifnames) linux_if_freenameindex(ifnames);
    ifnames = linux_if_nameindex();
#endif
    if (!ifnames) {
	ERROR_MSG("if_nameindex() failed");
	return -1;
    }
    return 0;
#endif
}

static int
if_maxifindex(void)
{
#ifndef HAVE_IF_NAMEINDEX
    return -1;
#else
    struct if_nameindex *p;
    int max = 0;

    if (!ifnames) {
	if (if_initialize() < 0)
	    return -1;
    }
    for (p = ifnames; p && p->if_index; p++) {
	if (max < p->if_index)
	    max = p->if_index;
    }
    return max;
#endif
}

static int
if_countifindex(void)
{
#ifndef HAVE_IF_NAMEINDEX
    return -1;
#else
    struct if_nameindex *p;
    int count = 0;

    if (!ifnames) {
	if (if_initialize() < 0)
	    return -1;
    }
    for (p = ifnames; p && p->if_index; p++) {
	count++;
    }
    return count;
#endif
}

static char *
if_getname(int idx)
{
#ifndef HAVE_IF_NAMEINDEX
    return NULL;
#else
    struct if_nameindex *p;
    int max = -1;

    if (!ifnames) {
	if (if_initialize() < 0)
	    return NULL;
    }
    for (p = ifnames; p && p->if_index; p++) {
	if (p->if_index == idx)
	    return p->if_name;
    }
    return NULL;
#endif
}

static int
if_getindex(const char *name)
{
#ifndef HAVE_IF_NAMEINDEX
    return -1;
#else
    struct if_nameindex *p;

    if (!ifnames) {
	if (if_initialize() < 0)
	    return -1;
    }
    for (p = ifnames; p && p->if_index; p++) {
	if (strcmp(name, p->if_name) == 0)
	    return p->if_index;
    }
    return -1;