/* Finds the first successor to the value in the table that does matches oid,
* using makeKey to convert the oid to a key for comparison. A successor is
* a value that does not match oid, so if multiple entries match an oid, only
* the first will ever be returned using this method.
* Returns the successor's 1-based index if found, or 0 if not found.
*/
static UINT findNextOidInTable(AsnObjectIdentifier *oid,
struct GenericTable *table, size_t tableEntrySize, oidToKeyFunc makeKey,
compareFunc compare)
{
UINT index = 0;
void *key = HeapAlloc(GetProcessHeap(), 0, tableEntrySize);
if (key)
{
makeKey(oid, key);
index = findValueInTable(key, table, tableEntrySize, compare);
if (index == 0)
{
/* Not found in table. If it's less than the first entry, return
* the first index. Otherwise just return 0 and let the caller
* handle finding the successor.
*/
if (compare(key, table->entries) < 0)
index = 1;
}
else
{
/* Skip any entries that match the same key. This enumeration will
* be incomplete, but it's what Windows appears to do if there are
* multiple entries with the same index in a table, and it avoids
* an infinite loop.
*/
for (++index; index <= table->numEntries && compare(key,
&table->entries[tableEntrySize * (index - 1)]) == 0; ++index)
;
}
HeapFree(GetProcessHeap(), 0, key);
}
return index;
}
/* Finds the first value in the table that matches oid, using makeKey to
* convert the oid to a key for comparison. Returns the value's 1-based
* index if found, or 0 if not found.
*/
static UINT findOidInTable(AsnObjectIdentifier *oid,
struct GenericTable *table, size_t tableEntrySize, oidToKeyFunc makeKey,
compareFunc compare)
{
UINT index = 0;
void *key = HeapAlloc(GetProcessHeap(), 0, tableEntrySize);
if (key)
{
makeKey(oid, key);
index = findValueInTable(key, table, tableEntrySize, compare);
HeapFree(GetProcessHeap(), 0, key);
}
return index;
}
/* Given an OID and a base OID that it must begin with, finds the item and
* element of the table whose IP address matches the instance from the OID.
* E.g., given an OID foo.1.2.3.4.5 and a base OID foo, returns item 1 and the
* index of the entry in the table whose IP address is 2.3.4.5.
* If bPduType is not SNMP_PDU_GETNEXT and either the item or instance is
* missing, returns SNMP_ERRORSTATUS_NOSUCHNAME.
* If bPduType is SNMP_PDU_GETNEXT, returns the successor to the item and
* instance, or item 1, instance 1 if either is missing.
*/
static AsnInteger32 getItemAndIpAddressInstanceFromOid(AsnObjectIdentifier *oid,
AsnObjectIdentifier *base, BYTE bPduType, struct GenericTable *table,
size_t tableEntrySize, oidToKeyFunc makeKey, compareFunc compare,
UINT *item, UINT *instance)
{
AsnInteger32 ret = SNMP_ERRORSTATUS_NOERROR;
if (!table)
return SNMP_ERRORSTATUS_NOSUCHNAME;
switch (bPduType)
{
case SNMP_PDU_GETNEXT:
if (SnmpUtilOidNCmp(oid, base, base->idLength) < 0)
{
/* Return the first item and instance from the table */
*item = 1;
*instance = 1;
}
else if (!SnmpUtilOidNCmp(oid, base, base->idLength) &&
oid->idLength < base->idLength + 5)
{
/* Either the table or an item is specified, but the instance is
* not.
*/
*instance = 1;
if (oid->idLength >= base->idLength + 1)
{
*item = oid->ids[base->idLength];
if (!*item)
*item = 1;
}
else
*item = 1;
}
else if (!SnmpUtilOidNCmp(oid, base, base->idLength) &&
oid->idLength == base->idLength + 5)
{
*item = oid->ids[base->idLength];
if (!*item)
{
*instance = 1;
*item = 1;
}
else
{
AsnObjectIdentifier ipOid = { 4, oid->ids + base->idLength + 1
};
*instance = findValueInTable(&ipOid, table, tableEntrySize,
makeKey, compare) + 1;
if (*instance > table->numEntries)
ret = SNMP_ERRORSTATUS_NOSUCHNAME;
}
}
else
ret = SNMP_ERRORSTATUS_NOSUCHNAME;
break;
default:
if (!SnmpUtilOidNCmp(oid, base, base->idLength) &&
oid->idLength == base->idLength + 5)
{
*item = oid->ids[base->idLength];
if (!*item)
ret = SNMP_ERRORSTATUS_NOSUCHNAME;
else
{
AsnObjectIdentifier ipOid = { 4, oid->ids + base->idLength + 1
};
*instance = findValueInTable(&ipOid, table, tableEntrySize,
makeKey, compare);
if (!*instance)
ret = SNMP_ERRORSTATUS_NOSUCHNAME;
}
}
else
ret = SNMP_ERRORSTATUS_NOSUCHNAME;
}
return ret;
}
