int DNS::connect( const std::string& host, const LogSink& logInstance )
{
struct addrinfo* results = 0;
resolve( &results, host, logInstance );
if( !results )
{
logInstance.err( LogAreaClassDns, "host not found: " + host );
return -ConnDnsError;
}
struct addrinfo* runp = results;
while( runp )
{
int fd = DNS::connect( runp, logInstance );
if( fd >= 0 )
return fd;
runp = runp->ai_next;
}
freeaddrinfo( results );
return -ConnConnectionRefused;
}
void DNS::resolve( struct addrinfo** res, const std::string& service, const std::string& proto,
const std::string& domain, const LogSink& logInstance )
{
logInstance.dbg( LogAreaClassDns, "Resolving: _" + service + "._" + proto + "." + domain );
struct addrinfo hints;
if( proto == "tcp" )
hints.ai_socktype = SOCK_STREAM;
else if( proto == "udp" )
hints.ai_socktype = SOCK_DGRAM;
else
{
logInstance.err( LogAreaClassDns, "Unknown/Invalid protocol: " + proto );
}
memset( &hints, '\0', sizeof( hints ) );
hints.ai_flags = AI_ADDRCONFIG | AI_CANONNAME;
hints.ai_socktype = SOCK_STREAM;
int e = getaddrinfo( domain.c_str(), service.c_str(), &hints, res );
if( e )
logInstance.err( LogAreaClassDns, "getaddrinfo() failed" );
}
