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UDP
To connect to a remote UDP server, call the Socketry::UDP::Socket.connect method:
udp_socket = Socketry::UDP::Socket.connect("8.8.8.8", 53)To send a datagram to a remote server, call #send on the Socketry::UDP::Socket instance with a message:
# Make a DNS query with the Ruby standard library's Resolv module
query = Resolv::DNS::Message.new
query.add_question "github.com", Resolv::DNS::Resource::IN::A
# Send the query to the server we connected to earlier
udp_socket.send query.encodeTo receive a response from a remote server, call #recvfrom on a Socketry::UDP::Socket instance with the maximum length of a packet you wish to receive:
datagram = udp_socket.recvfrom(512)This will return a Socketry::UDP::Datagram instance containing the received message.
>> datagram
=> #<Socketry::UDP::Datagram:0x007fd65e0007d0 @message="\x00\x01\x81\x80\x00\x01\x00\x02\x00\x00\x00\x00\x06github\x03com\x00\x00\x01\x00\x01\xC0\f\x00\x01\x00\x01\x00\x00\x00\xB1\x00\x04\xC0\x1E\xFDp\xC0\f\x00\x01\x00\x01\x00\x00\x00\xB1\x00\x04\xC0\x1E\xFDq", @sockaddr=["AF_INET", 53, "8.8.8.8", "8.8.8.8"]>Calling #message on the datagram object returns the underlying message:
>> Resolv::DNS::Message.decode(datagram.message)
=> #<Resolv::DNS::Message:0x007fd65d082ab0 @id=1, @qr=1, @opcode=0, @aa=0, @tc=0, @rd=1, @ra=1, @rcode=0, @question=[[#<Resolv::DNS::Name: github.com.>, Resolv::DNS::Resource::IN::A]], @answer=[[#<Resolv::DNS::Name: github.com.>, 177, #<Resolv::DNS::Resource::IN::A:0x007fd65d0818e0 @address=#<Resolv::IPv4 192.30.253.112>, @ttl=177>], [#<Resolv::DNS::Name: github.com.>, 177, #<Resolv::DNS::Resource::IN::A:0x007fd65d080d50 @address=#<Resolv::IPv4 192.30.253.113>, @ttl=177>]], @authority=[], @additional=[]>
The #addrinfo method returns the source of the received message:
>> datagram.addrinfo
=> #<Addrinfo: 8.8.8.8:53 UDP>
To create a UDP server, call the Socketry::UDP::Socket.bind method with the address and port to bind to:
udp_server = Socketry::UDP::Socket.bind("localhost", 12345)You can now call #recvfrom to receive Socketry::UDP::Datagram messages from clients:
datagram = udp_server.recvfrom(512)To send responses to clients, use the Socketry::UDP::Datagram#addr and #port methods to obtain the destination:
udp_server.send("Response!", host: datagram.remote_addr, port: datagram.remote_port)