at.c

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

	    if (snmp_oid_compare(current, olength, name, *length) == 0){
		memcpy( (char *)lowest,(char *)current, olength * sizeof(oid));
		Lowentry = entry;
		Found++;
		break;	/* no need to search further */
	    }
	} else {
	    if (snmp_oid_compare(current, olength, name, *length) > 0
	      && snmp_oid_compare(current, olength, lowest, *length) < 0) {
		/*
		 * if new one is greater than input and closer to input than
		 * previous lowest, and is not equal to it, save this one as the "next" one.
		 */
		memcpy( (char *)lowest,(char *)current, olength * sizeof(oid));
		Lowentry = entry;
		Found++;
	    }
	}
    }
    DEBUGMSGTL(("mibII/at", "... Found = %d\n", Found));
    if (Found == 0)
	return(NULL);
    memcpy( (char *)name,(char *)lowest, olength * sizeof(oid));
    *length = olength;
    *write_method = 0;
    switch(vp->magic){
	case IPMEDIAIFINDEX:
	    *var_len = sizeof long_return;
	    long_return = Interface_Index_By_Name(Lowentry.ipNetToMediaIfIndex.o_bytes,
						  Lowentry.ipNetToMediaIfIndex.o_length);
	    return (u_char *)&long_return;
	case IPMEDIAPHYSADDRESS:
	    *var_len = Lowentry.ipNetToMediaPhysAddress.o_length;
	    (void)memcpy(return_buf, Lowentry.ipNetToMediaPhysAddress.o_bytes, *var_len);
	    return (u_char *)return_buf;
	case IPMEDIANETADDRESS:
	    *var_len = sizeof long_return;
	    long_return = Lowentry.ipNetToMediaNetAddress;
	    return (u_char *)&long_return;
	case IPMEDIATYPE:
	    *var_len = sizeof long_return;
	    long_return = Lowentry.ipNetToMediaType;
	    return (u_char *)&long_return;
	default:
	    DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_atEntry\n", vp->magic));
   }
   return NULL;
}
#endif /* solaris2 */


	/*********************
	 *
	 *  Internal implementation functions
	 *
	 *********************/

#ifndef solaris2

static int arptab_size, arptab_current;
#if CAN_USE_SYSCTL
static char *lim, *rtnext;
static char *at = 0;
#else
#ifdef STRUCT_ARPHD_HAS_AT_NEXT
static struct arphd *at=0;
static struct arptab *at_ptr, at_entry;
static struct arpcom  at_com;
#else
static struct arptab *at=0;
#endif
#endif /* CAN_USE_SYSCTL */

static void ARP_Scan_Init (void)
{
#ifndef CAN_USE_SYSCTL
#ifndef linux
	if (!at) {
	    auto_nlist(ARPTAB_SIZE_SYMBOL, (char *)&arptab_size, sizeof arptab_size);
#ifdef STRUCT_ARPHD_HAS_AT_NEXT
          at = (struct arphd  *) malloc(arptab_size * sizeof(struct arphd));
#else
	    at = (struct arptab *) malloc(arptab_size * sizeof(struct arptab));
#endif
	}

#ifdef STRUCT_ARPHD_HAS_AT_NEXT
        auto_nlist(ARPTAB_SYMBOL, (char *)at, arptab_size * sizeof(struct arphd));
        at_ptr = at[0].at_next;
#else
        auto_nlist(ARPTAB_SYMBOL, (char *)at, arptab_size * sizeof(struct arptab));
#endif
	arptab_current = 0;
#else /* linux */
	FILE *in = fopen ("/proc/net/arp", "r");
	int i, n = 0;
        char line [128];
	int za, zb, zc, zd, ze, zf, zg, zh, zi, zj;
        char ifname[20];

	if (!in) {
	 snmp_log(LOG_ERR, "snmpd: Cannot open /proc/net/arp\n");
		arptab_current = 0;
		return;
	}
	for (n = -1; fgets (line, sizeof(line), in); n++)
		;
	fclose (in);
	in = fopen ("/proc/net/arp", "r");
	fgets(line, sizeof(line), in);	/* skip header */
	if (at) free (at);
	arptab_current = 0; /* it was missing, bug??? */
	arptab_size = n;
	if (arptab_size > 0)
		at = (struct arptab *)
                  malloc (arptab_size * sizeof (struct arptab));
	else
		at = NULL;
	for (i = 0; i < arptab_size; i++) {
		u_long tmp_a;
		while (line == fgets (line, sizeof(line), in) &&
			12 != sscanf (line, "%d.%d.%d.%d 0x%*x 0x%x %x:%x:%x:%x:%x:%x %*[^ ] %20s\n",
			&za, &zb, &zc, &zd, &at[i].at_flags,
			&ze, &zf, &zg, &zh, &zi, &zj, ifname)) {
			snmp_log(LOG_ERR, "Bad line in /proc/net/arp: %s", line);
			continue;
		    }
		at [i].at_enaddr[0] = ze;
		at [i].at_enaddr[1] = zf;
		at [i].at_enaddr[2] = zg;
		at [i].at_enaddr[3] = zh;
		at [i].at_enaddr[4] = zi;
		at [i].at_enaddr[5] = zj;
		tmp_a = ((u_long)za << 24) |
			((u_long)zb << 16) |
			((u_long)zc <<  8) |
			((u_long)zd      ) ;
		at [i].at_iaddr.s_addr = htonl(tmp_a);
		at [i].if_index = Interface_Index_By_Name(ifname, strlen(ifname));
	}
	fclose (in);
#endif /* linux */
#else /* CAN_USE_SYSCTL */
	int mib[6];
	size_t needed;

	mib[0] = CTL_NET;
	mib[1] = PF_ROUTE;
	mib[2] = 0;
	mib[3] = AF_INET;
	mib[4] = NET_RT_FLAGS;
	mib[5] = RTF_LLINFO;

	if (at)
		free(at);
	if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
		snmp_log_perror("route-sysctl-estimate");
	if ((at = malloc(needed ? needed : 1)) == NULL)
		snmp_log_perror("malloc");
	if (sysctl(mib, 6, at, &needed, NULL, 0) < 0)
		snmp_log_perror("actual retrieval of routing table");
	lim = at + needed;
	rtnext = at;
#endif /* CAN_USE_SYSCTL */
}

#ifdef ARP_SCAN_FOUR_ARGUMENTS
static int ARP_Scan_Next(u_long *IPAddr, char *PhysAddr, u_long *ifType, u_short *ifIndex)
#else
static int ARP_Scan_Next(u_long *IPAddr, char *PhysAddr, u_long *ifType)
#endif
{
#ifndef CAN_USE_SYSCTL
#ifdef linux
	if (arptab_current<arptab_size)
	{
		/* copy values */
		*IPAddr= at[arptab_current].at_iaddr.s_addr;
		*ifType= (at[arptab_current].at_flags & ATF_PERM) ? 4/*static*/ : 3/*dynamic*/ ;
		*ifIndex = at[arptab_current].if_index;
		memcpy( PhysAddr, &at[arptab_current].at_enaddr,
				sizeof(at[arptab_current].at_enaddr) );
		
		/* increment to point next entry */
		arptab_current++;
		/* return success */
		return( 1 );
	}
#endif /* linux */
  return 0; /* we need someone with an irix box to fix this section */
#else
#if !defined(ARP_SCAN_FOUR_ARGUMENTS) || defined(hpux)
	register struct arptab *atab;

	while (arptab_current < arptab_size) {
#ifdef STRUCT_ARPHD_HAS_AT_NEXT
              /* The arp table is an array of linked lists of arptab entries.
                 Unused slots have pointers back to the array entry itself */

              if ( at_ptr == (auto_nlist_value(ARPTAB_SYMBOL) +
                              arptab_current*sizeof(struct arphd))) {
                      /* Usused */
                  arptab_current++;
                  at_ptr = at[arptab_current].at_next;
                  continue;
              }

              klookup( at_ptr, (char *)&at_entry, sizeof(struct arptab));
              klookup( at_entry.at_ac, (char *)&at_com, sizeof(struct arpcom));

              at_ptr = at_entry.at_next;
              atab = &at_entry;
              *ifIndex = at_com.ac_if.if_index;       /* not strictly ARPHD */
#else /* STRUCT_ARPHD_HAS_AT_NEXT */
		atab = &at[arptab_current++];
#endif /* STRUCT_ARPHD_HAS_AT_NEXT */
		if (!(atab->at_flags & ATF_COM)) continue;
		*ifType = (atab->at_flags & ATF_PERM) ? 4 : 3 ;
		*IPAddr = atab->at_iaddr.s_addr;
#if defined (sunV3) || defined(sparc) || defined(hpux)
		memcpy( PhysAddr,(char *) &atab->at_enaddr, sizeof(atab->at_enaddr));
#endif
#if defined(mips) || defined(ibm032) 
		memcpy( PhysAddr,(char *)  atab->at_enaddr, sizeof(atab->at_enaddr));
#endif
	return(1);
	}
#else /* !defined(ARP_SCAN_FOUR_ARGUMENTS) || defined(hpux) */
	struct rt_msghdr *rtm;
	struct sockaddr_inarp *sin;
	struct sockaddr_dl *sdl;

	while (rtnext < lim) {
		rtm = (struct rt_msghdr *)rtnext;
		sin = (struct sockaddr_inarp *)(rtm + 1);
		sdl = (struct sockaddr_dl *)(sin + 1);
		rtnext += rtm->rtm_msglen;
		if (sdl->sdl_alen) {
			*IPAddr = sin->sin_addr.s_addr;
			memcpy( PhysAddr,(char *) LLADDR(sdl), sdl->sdl_alen);
			*ifIndex = sdl->sdl_index;
			*ifType = 1;	/* XXX */
			return(1);
		}
	}
#endif /* !defined(ARP_SCAN_FOUR_ARGUMENTS) || defined(hpux) */
	return(0);	    /* "EOF" */
#endif /* !CAN_USE_SYSCTL */
}
#endif /* solaris2 */
#else /* WIN32 */
#include <iphlpapi.h>
u_char *
var_atEntry(struct variable *vp,
            oid *name,
            size_t *length,
            int exact,
            size_t *var_len,
            WriteMethod **write_method)
{
    /*
     * Address Translation table object identifier is of form:
     * 1.3.6.1.2.1.3.1.1.1.interface.1.A.B.C.D,  where A.B.C.D is IP address.
     * Interface is at offset 10,
     * IPADDR starts at offset 12.
     *
     * IP Net to Media table object identifier is of form:
     * 1.3.6.1.2.1.4.22.1.1.1.interface.A.B.C.D,  where A.B.C.D is IP address.
     * Interface is at offset 10,
     * IPADDR starts at offset 11.
     */
    u_char                    *cp;
    oid                            *op;
    oid                            lowest[16];
    oid                            current[16];
    int         oid_length;
    int         lowState = -1; /* Don't have one yet */
    PMIB_IPNETTABLE pIpNetTable = NULL;
    DWORD status = NO_ERROR;
    DWORD dwActualSize = 0;
    UINT i;

    /* fill in object part of name for current (less sizeof instance part) */
    memcpy((char *)current, (char *)vp->name, (int)vp->namelen * sizeof(oid));

    if (current[6] == 3 ) {        /* AT group oid */
       oid_length = 16;
    }
    else {                        /* IP NetToMedia group oid */
       oid_length = 15;
    }
    
    status = GetIpNetTable(pIpNetTable, &dwActualSize, TRUE);
    if (status == ERROR_INSUFFICIENT_BUFFER)
    {
        pIpNetTable = (PMIB_IPNETTABLE) malloc(dwActualSize);
        if(pIpNetTable != NULL){  
            /* Get the sorted IpNet Table */
            status = GetIpNetTable(pIpNetTable, &dwActualSize, TRUE);
        }
    }
    if (current[6] == 3 ) {        /* AT group oid */
        current[11] = 1;
        op = current + 12;
    }
    else {                        /* IP NetToMedia group oid */
        op = current + 11;
    }

    if(status == NO_ERROR)
    {
        for (i = 0; i < pIpNetTable->dwNumEntries; ++i)
        {
            current[10] =  pIpNetTable->table[i].dwIndex;
            
            cp = (u_char *)&pIpNetTable->table[i].dwAddr;
            *op++ = *cp++;
            *op++ = *cp++;
            *op++ = *cp++;
            *op++ = *cp++;

            if (exact){
                if (snmp_oid_compare(current, oid_length, name, *length) == 0){
                    memcpy( (char *)lowest,(char *)current, oid_length * sizeof(oid));
                    lowState = 0;
                    break;        /* no need to search further */
                }
            } else {
                if (snmp_oid_compare(current, oid_length, name, *length) > 0){
                    memcpy( (char *)lowest,(char *)current, oid_length * sizeof(oid));
                    lowState = 0;
                    break; /* As the table is sorted, no need to search further */
                }
            }
        }
    }
    if (lowState < 0){
        free(pIpNetTable);
        return(NULL);
    }
    memcpy( (char *)name,(char *)lowest, oid_length * sizeof(oid));
    *length = oid_length;
    *write_method = 0;
    switch(vp->magic){
        case IPMEDIAIFINDEX:                        /* also ATIFINDEX */
            *var_len = sizeof long_return;
            long_return = pIpNetTable->table[i].dwIndex;
            free(pIpNetTable);
            return (u_char *)&long_return;
        case IPMEDIAPHYSADDRESS:                /* also ATPHYSADDRESS */
            *var_len = pIpNetTable->table[i].dwPhysAddrLen;
            memcpy(return_buf, pIpNetTable->table[i].bPhysAddr, *var_len);
            free(pIpNetTable);
            return (u_char *)return_buf;
        case IPMEDIANETADDRESS:                        /* also ATNETADDRESS */
            *var_len = sizeof long_return;
            long_return = pIpNetTable->table[i].dwAddr;
            free(pIpNetTable);
            return (u_char *)&long_return;
        case IPMEDIATYPE:
            *var_len = sizeof long_return;
            long_return = pIpNetTable->table[i].dwType;
            free(pIpNetTable);
            return (u_char *)&long_return;
        default:
            DEBUGMSGTL(("snmpd", "unknown sub-id %d in var_atEntry\n", vp->magic));
   }
   return NULL;
}
#endif