var_route.c

包含一下内容: * An extensible agent * An SNMP library * tools to request or set information from SNMP a

/*
 * snmp_var_route.c - return a pointer to the named variable.
 *
 *
 */
/***********************************************************
	Copyright 1988, 1989 by Carnegie Mellon University
	Copyright 1989	TGV, Incorporated

		      All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of CMU and TGV not be used
in advertising or publicity pertaining to distribution of the software
without specific, written prior permission.

CMU AND TGV DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
EVENT SHALL CMU OR TGV BE LIABLE FOR ANY SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
******************************************************************/
/*
 * additions, fixes and enhancements for Linux by Erik Schoenfelder
 * ([e-mail]) 1994/1995.
 * Linux additions taken from CMU to UCD stack by Jennifer Bray of Origin
 * ([e-mail]) 1997
 * Support for system({CTL_NET,PF_ROUTE,...) by Simon Leinen
 * ([e-mail]) 1997
 */

#include <config.h>

#if !defined(CAN_USE_SYSCTL)

#define GATEWAY			/* MultiNet is always configured this way! */
#include <stdio.h>
#include <sys/types.h>
#if HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#if HAVE_SYSLOG_H
#include <syslog.h>
#endif
#if HAVE_MACHINE_PARAM_H
#include <machine/param.h>
#endif
#if HAVE_SYS_MBUF_H
#include <sys/mbuf.h>
#endif
#if HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_NET_IF_VAR_H
#include <net/if_var.h>
#endif
#if HAVE_SYS_HASHING_H
#include <sys/hashing.h>
#endif
#if HAVE_NETINET_IN_VAR_H
#include <netinet/in_var.h>
#endif
#define KERNEL		/* to get routehash and RTHASHSIZ */
#if HAVE_SYS_STREAM_H
#include <sys/stream.h>
#endif
#if HAVE_NET_ROUTE_H
#include <net/route.h>
#endif
#undef	KERNEL
#ifdef RTENTRY_4_4
#ifndef STRUCT_RTENTRY_HAS_RT_UNIT
#define rt_unit rt_refcnt	       /* Reuse this field for device # */
#endif
#ifndef STRUCT_RTENTRY_HAS_RT_DST
#define rt_dst rt_nodes->rn_key
#endif
#else /* RTENTRY_4_3 */
#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
#ifndef STRUCT_RTENTRY_HAS_RT_REFCNT
#ifndef hpux10
#define rt_refcnt rt_pad2
#endif
#endif
#ifndef STRUCT_RTENTRY_HAS_RT_USE
#define rt_use rt_pad3
#endif
#ifndef STRUCT_RTENTRY_HAS_RT_UNIT
#define rt_unit rt_refcnt	       /* Reuse this field for device # */
#endif
#endif
#ifndef NULL
#define NULL 0
#endif
#if HAVE_KVM_OPENFILES
#include <fcntl.h>
#endif
#if HAVE_KVM_H
#include <kvm.h>
#endif

#if HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#if HAVE_INET_MIB2_H
#include <inet/mib2.h>
#endif
#if HAVE_SYS_SYSCTL_H
#include <sys/sysctl.h>
#endif
#if HAVE_NET_IF_DL_H
#include <net/if_dl.h>
#endif
#if HAVE_WINSOCK_H
#include <winsock.h>
#endif

#if HAVE_NLIST_H
#include <nlist.h>
#endif
#include "auto_nlist.h"
#if solaris2
#include "kernel_sunos5.h"
#endif
 
#ifdef HAVE_SYS_SYSCTL_H
# ifdef CTL_NET
#  ifdef PF_ROUTE
#   ifdef NET_RT_DUMP
#    define USE_SYSCTL_ROUTE_DUMP
#   endif
#  endif
# endif
#endif

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


#define CACHE_TIME (120)	    /* Seconds */

#include "mibincl.h"

#include "ip.h"
#include "../kernel.h"
#include "interfaces.h"
#include "struct.h"
#include "util_funcs.h"

#ifndef  MIN
#define  MIN(a,b)                     (((a) < (b)) ? (a) : (b))
#endif


extern WriteMethod write_rte;

#ifndef WIN32
#ifdef USE_SYSCTL_ROUTE_DUMP

static void Route_Scan_Reload (void);

static unsigned char *all_routes = 0;
static unsigned char *all_routes_end;
static size_t all_routes_size;

extern const struct sockaddr * get_address (const void *, int, int);
extern const struct in_addr * get_in_address (const void *, int, int);

/*
  var_ipRouteEntry(...
  Arguments:
  vp	        IN      - pointer to variable entry that points here
  name          IN/OUT  - IN/name requested, OUT/name found
  length        IN/OUT  - length of IN/OUT oid's 
  exact         IN      - TRUE if an exact match was requested
  var_len       OUT     - length of variable or 0 if function returned
  write_method  out     - pointer to function to set variable, otherwise 0
*/
u_char *
var_ipRouteEntry(struct variable *vp,
		 oid *name,
		 size_t *length,
		 int exact,
		 size_t *var_len,
		 WriteMethod **write_method)
{
  /*
   * object identifier is of form:
   * 1.3.6.1.2.1.4.21.1.1.A.B.C.D,  where A.B.C.D is IP address.
   * IPADDR starts at offset 10.
   */
  struct rt_msghdr *rtp, *saveRtp=0;
  register int Save_Valid, result;
  static int saveNameLen=0, saveExact=0;
  static oid saveName[MAX_OID_LEN], Current[MAX_OID_LEN];
  u_char *cp; u_char *ap;
  oid *op;
#if 0
  /** 
  ** this optimisation fails, if there is only a single route avail.
  ** it is a very special case, but better leave it out ...
  **/
#if 0
  if (rtsize <= 1)
    Save_Valid = 0;
  else
#endif /* 0 */
    /*
     *	OPTIMIZATION:
     *
     *	If the name was the same as the last name, with the possible
     *	exception of the [9]th token, then don't read the routing table
     *
     */

    if ((saveNameLen == *length) && (saveExact == exact)) {
      register int temp=name[9];
      name[9] = 0;
      Save_Valid = (snmp_oid_compare(name, *length, saveName, saveNameLen) == 0);
      name[9] = temp;
    } else
      Save_Valid = 0;

  if (Save_Valid && saveRtp) {
    register int temp=name[9];    /* Fix up 'lowest' found entry */
    memcpy( (char *) name,(char *) Current, 14 * sizeof(oid));
    name[9] = temp;
    *length = 14;
    rtp = saveRtp;
  } else {
#endif /* 0 */
    /* fill in object part of name for current (less sizeof instance part) */

    memcpy( (char *)Current,(char *)vp->name, (int)(vp->namelen) * sizeof(oid));

#if 0
    /*
     *  Only reload if this is the start of a wildcard
     */
    if (*length < 14) {
      Route_Scan_Reload();
    }
#else
    Route_Scan_Reload();
#endif
    for(ap = all_routes; ap < all_routes_end; ap += rtp->rtm_msglen) {
      rtp = (struct rt_msghdr *) ap;
      if (rtp->rtm_type == 0)
	break;
      if (rtp->rtm_version != RTM_VERSION)
	{
	  snmp_log(LOG_ERR, "routing socket message version mismatch (%d instead of %d)\n",
		   rtp->rtm_version, RTM_VERSION);
	  break;
	}
      if (rtp->rtm_type != RTM_GET)
	{
	  snmp_log(LOG_ERR, "routing socket returned message other than GET (%d)\n",
		   rtp->rtm_type);
	  continue;
	}
      if (! (rtp->rtm_addrs & RTA_DST))
	continue;
      cp = (u_char *) get_in_address ((struct sockaddr *) (rtp + 1),
				      rtp->rtm_addrs, RTA_DST);
      if (cp == NULL)
        return NULL;
      
      op = Current + 10;
      *op++ = *cp++;
      *op++ = *cp++;
      *op++ = *cp++;
      *op++ = *cp++;

      result = snmp_oid_compare(name, *length, Current, 14);
      if ((exact && (result == 0)) || (!exact && (result < 0)))
	break;
    }
    if (ap >= all_routes_end || rtp->rtm_type == 0)
      return 0;
    /*
     *  Save in the 'cache'
     */
    memcpy( (char *) saveName,(char *) name,
            SNMP_MIN(*length, MAX_OID_LEN) * sizeof(oid));
    saveName[9] = '\0';
    saveNameLen = *length;
    saveExact = exact;
    saveRtp = rtp;
    /*
     *  Return the name
     */
    memcpy( (char *) name,(char *) Current, 14 * sizeof(oid));
    *length = 14;
#if 0
  }
#endif /* 0 */

  *write_method = write_rte;
  *var_len = sizeof(long_return);

  switch(vp->magic){
  case IPROUTEDEST:
    return (u_char *)get_in_address ((struct sockaddr *) (rtp + 1),
				     rtp->rtm_addrs, RTA_DST);
  case IPROUTEIFINDEX:
    long_return = (u_long)rtp->rtm_index;
    return (u_char *)&long_return;
  case IPROUTEMETRIC1:
    long_return = (rtp->rtm_flags & RTF_UP) ? 1 : 0;
    return (u_char *)&long_return;
  case IPROUTEMETRIC2:
#if NO_DUMMY_VALUES
    return NULL;
#endif
    long_return = -1;
    return (u_char *)&long_return;
  case IPROUTEMETRIC3:
#if NO_DUMMY_VALUES
    return NULL;
#endif
    long_return = -1;
    return (u_char *)&long_return;
  case IPROUTEMETRIC4:
#if NO_DUMMY_VALUES
    return NULL;
#endif
    long_return = -1;
    return (u_char *)&long_return;
  case IPROUTEMETRIC5:
#if NO_DUMMY_VALUES
    return NULL;
#endif
    long_return = -1;
    return (u_char *)&long_return;
  case IPROUTENEXTHOP:
    return (u_char *)get_in_address ((struct sockaddr *) (rtp + 1),
				     rtp->rtm_addrs, RTA_GATEWAY);
  case IPROUTETYPE:
    long_return = (rtp->rtm_flags & RTF_UP)
      ? (rtp->rtm_flags & RTF_UP) ? 4 : 3
      : 2;
    return (u_char *)&long_return;
  case IPROUTEPROTO:
    long_return = (rtp->rtm_flags & RTF_DYNAMIC)
      ? 10 : (rtp->rtm_flags & RTF_STATIC)
      ? 2 : (rtp->rtm_flags & RTF_DYNAMIC) ? 4 : 1;
    return (u_char *)&long_return;
  case IPROUTEAGE:
#if NO_DUMMY_VALUES
    return NULL;
#endif
    long_return = 0;
    return (u_char *)&long_return;
  case IPROUTEMASK:
    if (rtp->rtm_flags & RTF_HOST)
      {
	long_return = 0x00000001;
	return (u_char *)&long_return;
      }
    else
      {
	return (u_char *)get_in_address ((struct sockaddr *) (rtp + 1),
					 rtp->rtm_addrs, RTA_NETMASK);
      }
  case IPROUTEINFO:
    *var_len = nullOidLen;
    return (u_char *) nullOid;
  default:
    DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_ipRouteEntry\n", vp->magic));
  }
  return NULL;
}

#else /* not USE_SYSCTL_ROUTE_DUMP */

static void Route_Scan_Reload (void);
static RTENTRY **rthead=0;
static int rtsize=0, rtallocate=0;

#if !(defined(linux) || defined(solaris2))
#define NUM_ROUTE_SYMBOLS 2
static char*  route_symbols[] = {
  RTHOST_SYMBOL,
  RTNET_SYMBOL
};
#endif
#endif

#ifdef USE_SYSCTL_ROUTE_DUMP

void
init_var_route (void)
{
}

static void Route_Scan_Reload (void)
{
  size_t size = 0;
  int name[] = { CTL_NET, PF_ROUTE, 0, 0, NET_RT_DUMP, 0 };

  if (sysctl (name, sizeof (name) / sizeof (int),
	      0, &size, 0, 0) == -1)
    {
      snmp_log(LOG_ERR, "sysctl(CTL_NET,PF_ROUTE,0,0,NET_RT_DUMP,0)\n");
    }
  else
    {
      if (all_routes == 0 || all_routes_size < size)
	{
	  if (all_routes != 0)
	    {
	      free (all_routes);
	      all_routes = 0;
	    }
	  if ((all_routes = malloc (size)) == 0)
	    {
	      snmp_log(LOG_ERR, "out of memory allocating route table\n");
	    }
	  all_routes_size = size;
	}
      else
	{
	  size = all_routes_size;