int parse_packet( const char str[] ) {
const char *beg;
int port = 0;
/* Find port (required) */
beg = parse_packet_param( str, "Port: ");
if( beg == NULL ) {
return 0;
}
/* Read port */
if( sscanf( beg, "%d\r\n", &port ) != 1 && port > 0 && port < 65536 ) {
return 0;
}
/* Find infohash (optional) */
beg = parse_packet_param( str, "Infohash: " );
if( beg != NULL ) {
/* Read infohash for own request */
if( (strstr(beg, "\r\n") - beg) == SHA1_HEX_LENGTH
&& str_isHex( beg, SHA1_HEX_LENGTH )
&& memcmp( beg, LPD_DEFAULT_INFOHASH, SHA1_HEX_LENGTH ) != 0 ) {
memcpy( g_infohash, beg, SHA1_HEX_LENGTH );
}
}
return port;
}
/*
* Lookup the address of the node that has the given id.
* The port refers to the kad instance.
*/
int kad_lookup_node( const char query[], IP *addr_return ) {
UCHAR id[SHA1_BIN_LENGTH];
struct search *sr;
int i, rc;
if( strlen( query ) != SHA1_HEX_LENGTH || !str_isHex( query, SHA1_HEX_LENGTH ) ) {
return -1;
}
bytes_from_hex( id, query, SHA1_HEX_LENGTH );
dht_lock();
rc = 1;
sr = searches;
while( sr ) {
if( sr->af == gconf->af && id_equal( sr->id, id ) ) {
for( i = 0; i < sr->numnodes; ++i ) {
if( id_equal( sr->nodes[i].id, id ) ) {
memcpy( addr_return, &sr->nodes[i].ss, sizeof(IP) );
rc = 0;
goto done;
}
}
break;
}
sr = sr->next;
}
done:;
dht_unlock();
return rc;
}
/*
* Compute the id of a string using the sha1 digest.
* In case of a 20 Byte hex string, the id converted directly.
*/
void id_compute( UCHAR id[], const char str[] ) {
SHA1_CTX ctx;
size_t size;
size = strlen( str );
if( size == SHA1_HEX_LENGTH && str_isHex( str, SHA1_HEX_LENGTH ) ) {
/* Treat hostname as hex string */
bytes_from_hex( id, str, SHA1_HEX_LENGTH );
} else {
SHA1_Init( &ctx );
SHA1_Update( &ctx, (const UCHAR *) str, size);
SHA1_Final( &ctx, id );
}
}
