route.c

开发snmp的开发包有两个开放的SNMP开发库

/*	$OpenBSD: route.c,v 1.66 2004/11/17 01:47:20 itojun Exp $	*/
/*	$NetBSD: route.c,v 1.15 1996/05/07 02:55:06 thorpej Exp $	*/

/*
 * Copyright (c) 1983, 1988, 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. 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.
 */

#ifdef  INHERITED_CODE
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)route.c	8.3 (Berkeley) 3/9/94";
#else
static char *rcsid = "$OpenBSD: route.c,v 1.66 2004/11/17 01:47:20 itojun Exp $";
#endif
#endif /* not lint */
#endif

#include <net-snmp/net-snmp-config.h>

#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include <net-snmp/net-snmp-includes.h>

#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif

#ifndef INET
#define INET
#endif

#include "main.h"
#include "netstat.h"

#define SET_MASK 0x01
#define SET_GWAY 0x02
#define SET_IFNO 0x04
#define SET_TYPE 0x08
#define SET_PRTO 0x10
#define SET_ALL  0x1f

struct route_entry {
    oid             instance[4];
    in_addr_t       destination;
    in_addr_t       mask;
    in_addr_t       gateway;
    int             ifNumber;
    int             type;
    int             proto;
    int             set_bits;
    char            ifname[64];
};

void p_rtnode( struct route_entry *rp );
extern int _ffs(int mask);

/*
 * Print routing tables.
 */
void
routepr(void)
{
    struct route_entry  route, *rp = &route;
    oid    rtcol_oid[]  = { 1,3,6,1,2,1,4,21,1,0 };
    size_t rtcol_len    = OID_LENGTH( rtcol_oid );
    union {
        in_addr_t addr;
        char      data[4];
    } tmpAddr;
    netsnmp_variable_list *var=NULL, *vp;
    char  *cp;
    
    printf("Routing tables\n");
    pr_rthdr(AF_INET);

#define ADD_RTVAR( x ) rtcol_oid[ rtcol_len-1 ] = x; \
    snmp_varlist_add_variable( &var, rtcol_oid, rtcol_len, ASN_NULL, NULL,  0)
    ADD_RTVAR( 2 );                 /* ipRouteIfIndex */
    ADD_RTVAR( 7 );                 /* ipRouteNextHop */
    ADD_RTVAR( 8 );                 /* ipRouteType    */
    ADD_RTVAR( 9 );                 /* ipRouteProto   */
    ADD_RTVAR( 11 );                /* ipRouteMask    */
#undef ADD_RTVAR

        /*
	 * Now walk the ipRouteTable, reporting the various route entries
	 */
    while ( 1 ) {
        if (netsnmp_query_getnext( var, ss ) != SNMP_ERR_NOERROR)
            break;
        rtcol_oid[ rtcol_len-1 ] = 2;	/* ifRouteIfIndex */
        if ( snmp_oid_compare( rtcol_oid, rtcol_len,
                               var->name, rtcol_len) != 0 )
            break;    /* End of Table */
        memset( &route, 0, sizeof( struct route_entry ));
        /* Extract ipRouteDest index value */
        cp = tmpAddr.data;
        cp[0] = var->name[ 10 ] & 0xff;
        cp[1] = var->name[ 11 ] & 0xff;
        cp[2] = var->name[ 12 ] & 0xff;
        cp[3] = var->name[ 13 ] & 0xff;
        rp->destination = tmpAddr.addr;

        for ( vp=var; vp; vp=vp->next_variable ) {
            switch ( vp->name[ 9 ] ) {
            case 2:     /* ifRouteIfIndex */
                rp->ifNumber  = *vp->val.integer;
                rp->set_bits |= SET_IFNO;
                break;
            case 7:                 /* ipRouteNextHop */
                memmove(&rp->gateway, vp->val.string, 4);
                rp->set_bits |= SET_GWAY;
                break;
            case 8:                 /* ipRouteType    */
                rp->type      = *vp->val.integer;
                rp->set_bits |= SET_TYPE;
                break;
            case 9:                 /* ipRouteProto   */
                rp->proto     = *vp->val.integer;
                rp->set_bits |= SET_PRTO;
                break;
            case 11:                /* ipRouteMask    */
                memmove(&rp->mask, vp->val.string, 4);
                rp->set_bits |= SET_MASK;
                break;
            }
        }
        if (rp->set_bits != SET_ALL) {
            continue;   /* Incomplete query */
        }

        p_rtnode( rp );
    }
}



struct iflist {
    int             index;
    char            name[64];
    struct iflist  *next;
}              *Iflist = NULL;

void
get_ifname(char *name, int ifIndex)
{
    oid    ifdescr_oid[]  = { 1,3,6,1,2,1,2,2,1,2,0 };
    size_t ifdescr_len    = OID_LENGTH( ifdescr_oid );
    netsnmp_variable_list *var = NULL;
    struct iflist         *ip;

    for (ip = Iflist; ip; ip = ip->next) {
        if (ip->index == ifIndex)
            break;
    }
    if (ip) {
        strcpy(name, ip->name);
        return;
    }
    ip = (struct iflist *) malloc(sizeof(struct iflist));
    if (ip == NULL)
        return;
    ip->next = Iflist;
    Iflist = ip;
    ip->index = ifIndex;

    ifdescr_oid[ ifdescr_len-1 ] = ifIndex;
    snmp_varlist_add_variable( &var, ifdescr_oid, ifdescr_len,
                               ASN_NULL, NULL,  0);
    if (netsnmp_query_get( var, ss ) == SNMP_ERR_NOERROR) {
        if (var->val_len >= sizeof(ip->name))
            var->val_len  = sizeof(ip->name) - 1;
        memmove(ip->name, var->val.string, var->val_len);
        ip->name[var->val_len] = '\0';
    } else {
        sprintf(ip->name, "if%d", ifIndex);
    }
    strcpy(name, ip->name);
}

/*
 * Print address family header before a section of the routing table.
 */
void
pr_family(int af)
{
	const char *afname;

	switch (af) {
	case AF_INET:
		afname = "Internet";
		break;
#ifdef NETSNMP_ENABLE_IPV6
	case AF_INET6:
		afname = "Internet6";
		break;
#endif
    /*
	case AF_NS:
		afname = "XNS";
		break;
	case AF_IPX:
		afname = "IPX";
		break;
	case AF_CCITT:
		afname = "X.25";
		break;
	case PF_KEY:
		afname = "Encap";
		break;
	case AF_APPLETALK:
		afname = "AppleTalk";
		break;
     */
	default:
		afname = NULL;
		break;
	}
	if (afname)
		printf("\n%s:\n", afname);
	else
		printf("\nProtocol Family %d:\n", af);
}

/* column widths; each followed by one space */
#ifndef NETSNMP_ENABLE_IPV6
#define	WID_DST(af)	26	/* width of destination column */
#define	WID_GW(af)	18	/* width of gateway column */
#else
/* width of destination/gateway column */
#if 1
/* strlen("fe80::aaaa:bbbb:cccc:dddd@gif0") == 30, strlen("/128") == 4 */
#define	WID_DST(af)	((af) == AF_INET6 ? (nflag ? 34 : 26) : 26)
#define	WID_GW(af)	((af) == AF_INET6 ? (nflag ? 30 : 18) : 18)
#else
/* strlen("fe80::aaaa:bbbb:cccc:dddd") == 25, strlen("/128") == 4 */
#define	WID_DST(af)	((af) == AF_INET6 ? (nflag ? 29 : 18) : 18)
#define	WID_GW(af)	((af) == AF_INET6 ? (nflag ? 25 : 18) : 18)
#endif
#endif /* NETSNMP_ENABLE_IPV6 */

/*
 * Print header for routing table columns.
 */
void
pr_rthdr(int af)
{
   /*
	if (Aflag)
		printf("%-*.*s ", PLEN, PLEN, "Address");
	if (Sflag)
		printf("%-*.*s ",
		    WID_DST(af), WID_DST(af), "Source");
    */
	printf("%-*.*s ",
	    WID_DST(af), WID_DST(af), "Destination");
	printf("%-*.*s %-6.6s  %s\n",
	    WID_GW(af), WID_GW(af), "Gateway",
	    "Flags", "Interface");
}

/*
 * Print header for PF_KEY entries.
void
pr_encaphdr(void)
{
	if (Aflag)
		printf("%-*s ", PLEN, "Address");
	printf("%-18s %-5s %-18s %-5s %-5s %-22s\n",
	    "Source", "Port", "Destination",
	    "Port", "Proto", "SA(Address/Proto/Type/Direction)");
}
 */

char *
routename(in_addr_t in)
{
	char *cp;
	static char line[MAXHOSTNAMELEN];
	struct hostent *hp;
	static char domain[MAXHOSTNAMELEN];
	static int first = 1;

	if (first) {
		first = 0;
		if (gethostname(domain, sizeof domain) == 0 &&
		    (cp = strchr(domain, '.')))
			(void) strlcpy(domain, cp + 1, sizeof domain);
		else
			domain[0] = '\0';
	}
	cp = NULL;
	if (!nflag) {
		hp = gethostbyaddr((char *)&in, sizeof (struct in_addr),
		    AF_INET);
		if (hp) {
			if ((cp = strchr(hp->h_name, '.')) &&
			    !strcmp(cp + 1, domain))
				*cp = '\0';
			cp = hp->h_name;
		}
	}
	if (cp) {
		strlcpy(line, cp, sizeof(line));
	} else {
#define C(x)	((x) & 0xff)
		in = ntohl(in);
		snprintf(line, sizeof line, "%u.%u.%u.%u",
		    C(in >> 24), C(in >> 16), C(in >> 8), C(in));
	}
	return (line);
}

/*
 * Return the name of the network whose address is given.
 * The address is assumed to be that of a net or subnet, not a host.
 */
char *
netname(in_addr_t in, in_addr_t mask)
{
	char *cp = NULL;
	static char line[MAXHOSTNAMELEN];
	struct netent *np = NULL;
	int mbits;

	in = ntohl(in);
	mask = ntohl(mask);
	if (!nflag && in != INADDR_ANY) {
		if ((np = getnetbyaddr(in, AF_INET)) != NULL)
			cp = np->n_name;
	}
	mbits = mask ? 33 - _ffs(mask) : 0;
	if (cp) {
		strlcpy(line, cp, sizeof(line));
	} else if (mbits < 9)
		snprintf(line, sizeof line, "%u/%d", C(in >> 24), mbits);
	else if (mbits < 17)
		snprintf(line, sizeof line, "%u.%u/%d",
		    C(in >> 24) , C(in >> 16), mbits);
	else if (mbits < 25)
		snprintf(line, sizeof line, "%u.%u.%u/%d",
		    C(in >> 24), C(in >> 16), C(in >> 8), mbits);
	else
		snprintf(line, sizeof line, "%u.%u.%u.%u/%d", C(in >> 24),
		    C(in >> 16), C(in >> 8), C(in), mbits);
	return (line);
}

#undef NETSNMP_ENABLE_IPV6
#ifdef NETSNMP_ENABLE_IPV6
char *
netname6(struct sockaddr_in6 *sa6, struct in6_addr *mask)
{
	static char line[MAXHOSTNAMELEN + 1];
	struct sockaddr_in6 sin6;
	u_char *p;
	u_char *lim;
	int masklen, final = 0, illegal = 0;
	int i;
	char hbuf[NI_MAXHOST];
	int flag = 0;
	int error;

	sin6 = *sa6;

	masklen = 0;
	lim = (u_char *)(mask + 1);
	i = 0;
	if (mask) {
		for (p = (u_char *)mask; p < lim; p++) {
			if (final && *p) {
				illegal++;
				sin6.sin6_addr.s6_addr[i++] = 0x00;
				continue;
			}

			switch (*p & 0xff) {
			case 0xff:
				masklen += 8;
				break;
			case 0xfe:
				masklen += 7;
				final++;
				break;
			case 0xfc:
				masklen += 6;
				final++;
				break;
			case 0xf8:
				masklen += 5;
				final++;
				break;
			case 0xf0:
				masklen += 4;
				final++;
				break;
			case 0xe0:
				masklen += 3;
				final++;
				break;
			case 0xc0:
				masklen += 2;
				final++;
				break;
			case 0x80:
				masklen += 1;
				final++;
				break;
			case 0x00:
				final++;
				break;
			default:
				final++;
				illegal++;
				break;
			}

			if (!illegal)
				sin6.sin6_addr.s6_addr[i++] &= *p;
			else
				sin6.sin6_addr.s6_addr[i++] = 0x00;
		}
	} else
		masklen = 128;

	if (masklen == 0 && IN6_IS_ADDR_UNSPECIFIED(&sin6.sin6_addr))
		return("default");

	if (illegal)
		fprintf(stderr, "illegal prefixlen\n");

	if (nflag)
		flag |= NI_NUMERICHOST;
	error = getnameinfo((struct sockaddr *)&sin6, sin6.sin6_len,
	    hbuf, sizeof(hbuf), NULL, 0, flag);
	if (error)
		snprintf(hbuf, sizeof(hbuf), "invalid");

	snprintf(line, sizeof(line), "%s/%d", hbuf, masklen);
	return line;
}

char *
routename6(struct sockaddr_in6 *sa6)
{
	static char line[NI_MAXHOST];
	const int niflag = NI_NUMERICHOST;

	if (getnameinfo((struct sockaddr *)sa6, sa6->sin6_len,
	    line, sizeof(line), NULL, 0, niflag) != 0)
		strlcpy(line, "", sizeof line);
	return line;
}
#endif /*NETSNMP_ENABLE_IPV6*/

char *
s_rtflags( struct route_entry *rp )
{
    static char flag_buf[10];
    char  *cp = flag_buf;

    memset( flag_buf, 0, sizeof(flag_buf));
    *cp++ = '<';
    *cp++ = 'U';   /* route is in use */
    if (rp->mask  == 0xffffffff)
        *cp++ = 'H';   /* host */
    if (rp->proto == 4)
        *cp++ = 'D';   /* ICMP redirect */
    if (rp->type  == 4)
        *cp++ = 'G';   /* remote destination/net */
    *cp++ = '>';
    return flag_buf;
}

void
p_rtnode( struct route_entry *rp )
{
    get_ifname(rp->ifname, rp->ifNumber);
    printf("%-*.*s ",
	    WID_DST(AF_INET), WID_DST(AF_INET),
            (rp->destination == INADDR_ANY) ? "default" :
                (rp->set_bits & SET_MASK) ?
                    (rp->mask == 0xffffffff ?
                        routename(rp->destination) :
                        netname(rp->destination, rp->mask)) :
                    netname(rp->destination, 0L));
    printf("%-*.*s %-6.6s  %s\n",
	    WID_GW(af), WID_GW(af),
	    rp->gateway ? routename(rp->gateway) : "*",
            s_rtflags(rp), rp->ifname);
}