string key_str, cur_value;
vector<string> valparts;
- key_str=d_querykey = string( name.rbegin(), name.rend() );
+ key_str=bitFlip(labelReverse(toLower(name)))+"\xff";
key.mv_data = (char *)key_str.c_str();
key.mv_size = key_str.length();
return true;
}
-// Get the zone name and value of the requested zone (reversed) OR the entry
-// just before where it should have been
+// Get the zone name of the requested zone (labelReversed) OR the name of the closest parrent zone
bool LMDBBackend::getAuthZone( string &rev_zone )
{
MDB_val key, data;
// XXX can do this just using char *
- string orig = rev_zone;
- key.mv_data = (char *)rev_zone.c_str();
- key.mv_size = rev_zone.length();
+ string key_str=bitFlip(rev_zone+" ");
+ key.mv_data = (char *)key_str.c_str();
+ key.mv_size = key_str.length();
// Release our transaction and cursors in order to get latest data
mdb_txn_reset( txn );
mdb_cursor_renew( txn, nsecx_cursor );
}
- // Find the nearest record, or the last record if none
- if( mdb_cursor_get(zone_cursor, &key, &data, MDB_SET_RANGE) )
- mdb_cursor_get(zone_cursor, &key, &data, MDB_LAST);
-
- rev_zone.assign( (const char *)key.mv_data, key.mv_size );
-
- /* Only skip this bit if we got an exact hit on the SOA or if the key is a shoter
- * version of rev_zone. Otherwise we have to go back to the previous record */
- if( orig.compare( rev_zone ) != 0 ) { // FIXME detect shorter version
- /* Skip back 1 entry to what should be a substring of what was searched
- * for (or a totally different entry) */
- if( mdb_cursor_get(zone_cursor, &key, &data, MDB_PREV) ) {
- // At beginning of database; therefore didn't actually hit the
- // record. Return false
- return false;
- }
+ // Find the best record
+ if( mdb_cursor_get( zone_cursor, &key, &data, MDB_SET_RANGE ) == 0 && key.mv_size <= key_str.length() ) {
+ // Found a shorter match. Now look if the zones are equal up to key-length-1. If they are check
+ // if position key-length in key_str is a label separator. If all this is true we have a match.
+ if( key_str.compare( 0, key.mv_size-1, (const char *) key.mv_data, key.mv_size-1 ) == 0 && key.mv_size && key_str[key.mv_size-1] == ~' ') {
+ rev_zone.resize( key.mv_size-1 );
+
+ DEBUGLOG("Auth key: " << rev_zone <<endl);
- rev_zone.assign( (const char *)key.mv_data, key.mv_size );
+ return true;
+ }
}
- DEBUGLOG("Auth key: " << rev_zone <<endl);
+ //reset the cursor the data in it is invallid
+ mdb_cursor_renew( txn, zone_cursor );
- return true;
+ return false;
}
bool LMDBBackend::getAuthData( SOAData &soa, DNSPacket *p )
return true;
}
-/* String a is the query key, string b is the result from the database. Trys to
- * be intelegent and only return matching sections (ie up to the last point at
- * which there were .'s in both strings, however because the - character is
- * legal and < . in ascii it does not guarantee to return a section point.
- */
-inline unsigned int compare_domains( const string &a, const string &b ) {
- int aLen = a.length(), bLen = b.length(), n = 0, last_dot = 0;
- const unsigned char *aPtr = (const unsigned char*)a.c_str(),
- *bPtr = (const unsigned char*)b.c_str();
-
- while( 1 ) {
- if( n == aLen ) {
- if( n == bLen || bPtr[n] <= '.' )
- return n;
- else
- return last_dot;
- }
-
- if( n == bLen ) {
- if( n == aLen || aPtr[n] <= '.' )
- return n;
- else
- return last_dot;
- }
-
- if( aPtr[n] != bPtr[n] ) {
- if( aPtr[n] <= '.' && bPtr[n] <= '.' )
- return n;
- else
- return last_dot;
- }
-
- if( aPtr[n] == '.' ) // Therefore bPtr[n] == '.' as from above they are the same
- last_dot = n;
-
- n++;
- }
-
- // Should never get here
- return 0;
-}
-
/* This is a subclass of DNSBackend that, assuming you have your zones reversed
* and stored in an ordered fashion, will be able to look up SOA's much quicker
* than the DNSBackend code. The normal case for a SOA that exists is 1 backend
#undef PC
extern PacketCache PC;
+#if 0
+#undef DLOG
+#define DLOG(x) x
+#endif
+
bool _add_to_negcache( const string &zone ) {
static int negqueryttl=::arg().asNum("negquery-cache-ttl");
// add the zone to the negative query cache and return false
if( !getAuthZone( foundkey ) )
return GET_AUTH_NEG_CACHE;
- unsigned int diff_point = compare_domains( querykey, foundkey );
- DLOG(L<<Logger::Error<<"Queried: " << querykey << " and found record: " <<foundkey << " : diff point is: " << diff_point<<endl);
+ DLOG(L<<Logger::Error<<"Queried: " << querykey << " and found record: " <<foundkey<<endl);
// Got a match from a previous backend that was longer than this - no need
// to continue.
- if( best_match_len && best_match_len >= (int)diff_point ) {
+ if( best_match_len && best_match_len >= (int) foundkey.length() ) {
DLOG(L<<Logger::Error<<"Best match was better from a different client"<<endl);
return GET_AUTH_NEG_DONTCACHE;
}
- // If diff_point is 0 then either strings are totally different OR root
- // zone was returned.
- if( diff_point == 0 && foundkey.length() != 0 )
- return GET_AUTH_NEG_CACHE;
-
- /* If the strings are the same (ie diff_point == querykey.length()) then we
- * have found the exact record.
- *
- * If the strings are the same up to the end of the key we pulled from the
- * database, then we have found the true SOA for this zone. (the string we
- * pulled from the database could be longer than the key we searched for,
- * but if that is the case then it cannot be a sub-key because of the
- * reliance to get the key at the requested position OR before)
- *
- * Otherwise, the strings are different up to a certain point. In this
- * case, we need to retry the query as we may have the case of a subdomain
- * in the database eg a.b.com and b.com SOA records. If we then query for
- * www.b.com we will hit the a.b.com SOA record so we want to trim back to
- * the . before the difference and retry the query (ie b.com). Note that
- * because some legal dns characters come *before* the . in ascii if we try
- * searching for www.a.com our db query may return www-a.com in which case
- * we retry the search from the point at which the strings differ (ie
- * a.com)
- *
- * To speed up future decisions for subdomains, if the negative cache is
- * available we will make a note there if the subdomain we queried for does
- * not exist.
- */
- if( diff_point != querykey.length()
- && diff_point != foundkey.length() ) {
- // XXX If we found some way of getting the exact domain without having
- // to try this (ie walk the database btree up until the point where it
- // differs), we could have a 60% performance improvement in some
- // situations.
-
- string shortzone = inZone.substr( inZone.length() - diff_point, string::npos );
- string shortquerykey = querykey.substr( 0, diff_point );
- DLOG(L<<Logger::Error<<"Retrying for " << shortzone << " querykey: " << shortquerykey<<endl);
-
- int ret = _getAuth( p, soa, shortzone, zoneId, shortquerykey, best_match_len );
-
- if( ret == GET_AUTH_NEG_CACHE )
- _add_to_negcache( shortzone );
-
- return ret;
- }
-
// Found record successfully now, fill in the data.
if( getAuthData( *soa, p ) ) {
/* all the keys are reversed. rather than reversing them again it is
bool DNSReversedBackend::getAuth(DNSPacket *p, SOAData *soa, const string &inZone, int *zoneId, const int best_match_len) {
// Reverse the lowercased query string
string zone = toLower(inZone);
- string querykey( zone.rbegin(), zone.rend() );
+ string querykey = labelReverse(zone);
int ret = _getAuth( p, soa, inZone, zoneId, querykey, best_match_len );
{
// prepare the query string
string zone = toLower( inZone );
- string querykey( zone.rbegin(), zone.rend() );
+ string querykey = labelReverse( zone );
if( !_getSOA( querykey, soa, p ) )
return false;
projects / thirdparty / pdns.git / commitdiff
