route_write.c

非常不错的网管开发包

#include <config.h>

#include <sys/types.h>
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#if HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#include <sys/socket.h>
#if HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#if HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#if HAVE_SYS_MBUF_H
#include <sys/mbuf.h>
#endif


#if HAVE_SYS_STREAM_H
#include <sys/stream.h>
#endif
#include <net/route.h>
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#include <arpa/inet.h>
#include <netdb.h>

#include <errno.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdio.h>
#include <ctype.h>
#if HAVE_STRING_H
#include <string.h>
#endif
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif

#if HAVE_DMALLOC_H
#include <dmalloc.h>
#endif

#include "asn1.h"
#include "snmp.h"
#include "snmp_api.h"
#include "snmp_impl.h"
#include "snmp_vars.h"
#include "snmp_debug.h"
#include "ip.h"
#include "route_write.h"
#include "snmp_logging.h"

#ifndef STRUCT_RTENTRY_HAS_RT_DST
#define rt_dst rt_nodes->rn_key
#endif
#ifndef STRUCT_RTENTRY_HAS_RT_HASH
#define rt_hash rt_pad1
#endif

#ifdef irix6
#define SIOCADDRT SIOCADDMULTI
#define SIOCDELRT SIOCDELMULTI
#endif

int addRoute(u_long dstip, u_long gwip, u_long iff, u_short flags)
{
    struct sockaddr_in     dst;
    struct sockaddr_in     gateway;
    int                    s;
    RTENTRY  route;

    s = socket(AF_INET, SOCK_RAW, 0);
    if (s<0) {
        snmp_log_perror("socket");
	return 0;
    }
    

    flags |= RTF_UP;

    dst.sin_family       = AF_INET;
    dst.sin_addr.s_addr  = htonl(dstip);


    gateway.sin_family        = AF_INET;
    gateway.sin_addr.s_addr   = htonl(gwip);

    memcpy(&route.rt_dst, &dst, sizeof(struct sockaddr_in));
    memcpy(&route.rt_gateway, &gateway, sizeof(struct sockaddr_in));

    route.rt_flags = flags;
#ifndef RTENTRY_4_4
    route.rt_hash  = iff;
#endif
#ifdef irix6
    return 0;
#else
    return (ioctl(s, SIOCADDRT , (caddr_t)&route));
#endif

}



int delRoute(u_long dstip, u_long gwip, u_long iff, u_short flags)
{


    struct sockaddr_in     dst;
    struct sockaddr_in     gateway;
    int                    s;
    RTENTRY  route;

    s = socket(AF_INET, SOCK_RAW, 0);
    if (s<0) {
        snmp_log_perror("socket");
	return 0;
    }
    

    flags |= RTF_UP;

    dst.sin_family       = AF_INET;
    dst.sin_addr.s_addr  = htonl(dstip);


    gateway.sin_family        = AF_INET;
    gateway.sin_addr.s_addr   = htonl(gwip);

    memcpy(&route.rt_dst, &dst, sizeof(struct  sockaddr_in));
    memcpy(&route.rt_gateway, &gateway, sizeof(struct  sockaddr_in));

    route.rt_flags = flags;
#ifndef RTENTRY_4_4
    route.rt_hash  = iff;
#endif

#ifdef irix6
    return 0;
#else
    return (ioctl(s, SIOCDELRT , (caddr_t)&route));
#endif

}


#ifndef STRUCT_RTENTRY_HAS_RT_DST
#undef rt_dst
#endif


#define  MAX_CACHE   8

struct rtent {

    u_long    in_use;
    u_long    old_dst;
    u_long    old_nextIR;
    u_long    old_ifix;
    u_long    old_flags;

    u_long    rt_dst;            /*  main entries    */
    u_long    rt_ifix;
    u_long    rt_metric1;
    u_long    rt_nextIR;
    u_long    rt_type;
    u_long    rt_proto;


    u_long    xx_dst;            /*  shadow entries  */
    u_long    xx_ifix;
    u_long    xx_metric1;
    u_long    xx_nextIR;
    u_long    xx_type;
    u_long    xx_proto;
};

struct  rtent  rtcache[MAX_CACHE];

struct rtent *findCacheRTE(u_long dst)
{
    int i;

    for (i = 0; i < MAX_CACHE; i++) {
	
	if (rtcache[i].in_use && (rtcache[i].rt_dst == dst)) {  /* valid & match? */
	    return (&rtcache[i]);
	}
    }
    return 0;
}

struct rtent  *newCacheRTE(void)
{

    int i;

    for (i = 0; i < MAX_CACHE; i++) {
	
	if (!rtcache[i].in_use) {
	    rtcache[i].in_use = 1;
	    return (&rtcache[i]);
	}
    }
    return 0;

}

int delCacheRTE(u_long dst)
{
    struct  rtent  *rt;

    rt = findCacheRTE(dst);
    if (!rt) {
	return 0;
    }

    rt->in_use = 0;
    return 1;
}


struct  rtent  *cacheKernelRTE(u_long dst)
{
    return 0;  /* for now */
    /* ...... */
}

/*
 * If statP is non-NULL, the referenced object is at that location.
 * If statP is NULL and ap is non-NULL, the instance exists, but not this variable.
 * If statP is NULL and ap is NULL, then neither this instance nor the variable exists.
 */

int
write_rte(
   int      action,
   u_char   *var_val,
   u_char   var_val_type,
   size_t   var_val_len,
   u_char   *statP,
   oid      *name,
   size_t   length)
{
    struct rtent *rp;
    int var;
    long val;
    u_long  dst;
    char    buf[8];
    u_short  flags;
    int      oldty;

    /*
     * object identifier is of form:
     * 1.3.6.1.2.1.4.21.1.X.A.B.C.D ,  where A.B.C.D is IP address.
     * IPADDR starts at offset 10.
     */

    if (length != 14) {
 snmp_log(LOG_ERR, "length error\n");
	return SNMP_ERR_NOCREATION;
    }

    var = name[9];
    
    dst = *((u_long *) & name[10] );

    rp = findCacheRTE(dst);

    if (!rp) {
	rp = cacheKernelRTE(dst);
    }


    if (action == RESERVE1 && !rp) {

	rp = newCacheRTE();
	if (!rp) {
	    snmp_log(LOG_ERR, "newCacheRTE");
	    return SNMP_ERR_RESOURCEUNAVAILABLE;
	}
	rp->rt_type = rp->xx_type = 2;

    } else if (action == COMMIT){


    } else if (action == FREE) {
	if (rp->rt_type == 2) {  /* was invalid before */
	    delCacheRTE(dst);
	}
    }



    
    switch(var){

	case IPROUTEDEST:
	   
            if (action == RESERVE1){

		if (var_val_type != ASN_OCTET_STR) {
		    snmp_log(LOG_ERR, "not octet");
		    return SNMP_ERR_WRONGTYPE;
		}

                memcpy(buf, var_val, (var_val_len > 8) ? 8 : var_val_len);

		if (var_val_type != ASN_OCTET_STR) {
		    snmp_log(LOG_ERR, "not octet2");
		    return SNMP_ERR_WRONGTYPE;
		}
		
		rp->xx_dst = *((u_long *) buf);
		

	    } else if (action == COMMIT) {
		rp->rt_dst = rp->xx_dst;
	    }
	    break;

	case IPROUTEMETRIC1:

	    if (action == RESERVE1) {
		if (var_val_type != ASN_INTEGER) {
		    snmp_log(LOG_ERR, "not int1");
		    return SNMP_ERR_WRONGTYPE;
		}
		
                val = *((long *) var_val);

		if (val < -1) {
		    snmp_log(LOG_ERR, "not right1");
		    return SNMP_ERR_WRONGVALUE;
		}

		rp->xx_metric1 = val;

	    } else if (action == RESERVE2) {

		if ((rp->xx_metric1 == 1) && (rp->xx_type != 4)) {
		    snmp_log(LOG_ERR, "reserve2 failed\n");
		    return SNMP_ERR_WRONGVALUE;
		}

	    } else if (action == COMMIT) {
		rp->rt_metric1 = rp->xx_metric1;
	    }
	    break;

	case IPROUTEIFINDEX:

	    if (action == RESERVE1) {
		if (var_val_type != ASN_INTEGER) {
                  snmp_log(LOG_ERR, "not right2");
		  return SNMP_ERR_WRONGTYPE;
		}
		
                val = *((long *) var_val);

		if (val <= 0) {
		    snmp_log(LOG_ERR, "not right3");
		    return SNMP_ERR_WRONGVALUE;
		}

		rp->xx_ifix = val;

	    } else if (action == COMMIT) {
		rp->rt_ifix = rp->xx_ifix;
	    }
	    break;	    
	    
	case IPROUTENEXTHOP:
	   
            if (action == RESERVE1){

		if (var_val_type != ASN_OCTET_STR) {
		    snmp_log(LOG_ERR, "not right4");
		  return SNMP_ERR_WRONGTYPE;
		}

                memcpy(buf, var_val, (var_val_len > 8) ? 8 : var_val_len);

		if (var_val_type != ASN_OCTET_STR) {
		    snmp_log(LOG_ERR, "not right5");
		    return SNMP_ERR_WRONGTYPE;
		}
		
		rp->xx_nextIR = *((u_long *) buf);

	    } else if (action == COMMIT) {
		rp->rt_nextIR = rp->xx_nextIR;
	    }
	  

	case IPROUTETYPE:

	    /*
	     *  flag meaning:
	     *
	     *  IPROUTEPROTO (rt_proto): none: (cant set == 3 (netmgmt)) 
	     *
	     *  IPROUTEMETRIC1:  1 iff gateway, 0 otherwise
	     *  IPROUTETYPE:     4 iff gateway, 3 otherwise
	     */

	    if (action == RESERVE1) {
		if (var_val_type != ASN_INTEGER) {
		  return SNMP_ERR_WRONGTYPE;
		}
		
                val = *((long *) var_val);

		if ((val < 2) || (val > 4)) { /* only accept invalid, direct, indirect */
		    snmp_log(LOG_ERR, "not right6");
		    return SNMP_ERR_WRONGVALUE;
		}

		rp->xx_type = val;

	    } else if (action == COMMIT) {
		
		oldty = rp->rt_type;
		rp->rt_type = rp->xx_type;
		
		if (rp->rt_type == 2) {  /* invalid, so delete from kernel */

		    if (delRoute(rp->rt_dst, rp->rt_nextIR, rp->rt_ifix , rp->old_flags ) < 0) {
			snmp_log_perror("delRoute");
		    }

		} else {

		    /* it must be valid now, so flush to kernel */
		    
		    if (oldty != 2) {   /* was the old entry valid ?  */
			if (delRoute(rp->old_dst, rp->old_nextIR, rp->old_ifix , rp->old_flags ) < 0) {
			    snmp_log_perror("delRoute");
			}
		    }

		    /* not invalid, so remove from cache */
		    
		    flags = (rp->rt_type == 4 ? RTF_GATEWAY : 0);

		    if (addRoute(rp->rt_dst, rp->rt_nextIR, rp->rt_ifix , flags) < 0) {
			snmp_log_perror("addRoute");
		    }

		    delCacheRTE( rp->rt_type );
		}
	    }
	    break;


	case IPROUTEPROTO:

	default:
                DEBUGMSGTL(("snmpd", "unknown sub-id %d in write_rte\n", var));
        	return SNMP_ERR_NOCREATION;


    }

    return SNMP_ERR_NOERROR;
}