def on_packet_recvname(self, data) -> bool:
""" Handle RECV_NAME command, the first packet in a new connection. """
if data[0] != ord('n'):
return self.protocol_error(
"Unexpected packet (expecting RECV_NAME)")
# Read peer distribution version and compare to ours
peer_max_min = (data[1], data[2])
if dist_protocol.dist_version_check(peer_max_min):
return self.protocol_error(
"Dist protocol version have: %s got: %s"
% (str(dist_protocol.DIST_VSN_PAIR), str(peer_max_min)))
self.peer_distr_version_ = peer_max_min
self.peer_flags_ = util.u32(data[3:7])
self.peer_name_ = data[7:].decode("latin1")
LOG.info("RECV_NAME: %s %s", self.peer_distr_version_, self.peer_name_)
# Report
self._send_packet2(b"sok")
self.my_challenge_ = int(random.random() * 0x7fffffff)
self._send_challenge(self.my_challenge_)
self.state_ = self.WAIT_CHALLENGE_REPLY
return True
def query_node(node: str) -> tuple:
""" Query EPMD about the port to the given node.
:param node: String with node "name@ip" or "name@hostname"
:return: Host and port where the node is, or None
:rtype: tuple(str, int)
:throws EPMDClientError: if something is wrong with input
:throws EPMDConnectionError: if connection went wrong
"""
# Trim the host name/IP after the @ and resolve the DNS name
if "@" not in node:
raise EPMDClientError("Node must have @ in it")
(r_name, r_ip_or_hostname) = node.split("@")
r_ip = socket.gethostbyname(r_ip_or_hostname)
port_please2 = bytes([REQ_PORT_PLEASE2]) \
+ bytes(r_name, "utf8") # not sure if latin-1 here
resp = EPMDClient._fire_forget_query(r_ip, port_please2)
# RESP_PORT2
# Response Error structure
# 1 1
# 119 Result > 0
if len(resp) < 2 or resp[0] != RESP_PORT2:
ERROR("EPMD: PORT_PLEASE2 to %s sent wrong response %s" %
(r_ip, resp))
raise EPMDConnectionError("PORT_PLEASE2 wrong response")
if resp[1] != 0:
ERROR("EPMD: PORT_PLEASE2 to %s: error %d" % (r_ip, resp[1]))
raise EPMDConnectionError("PORT_PLEASE2 error %d" % resp[1])
# Response structure
# 1 1 2 1 1 2 ...
# 119 Result PortNo NodeType Protocol HighestVersion ...
# 2 2 Nlen 2 Elen
# LowestVersion Nlen NodeName Elen >Extra
r_port = util.u16(resp, 2)
# node_type = resp[4]
# protocol = resp[5]
versions = (util.u16(resp, 6), util.u16(resp, 8))
if not dist_protocol.dist_version_check(versions):
raise EPMDConnectionError(
"Remote node %s supports protocol version %s and we "
"support %d" % (node, versions, dist_protocol.DIST_VSN))
# ignore node name and extra
return r_ip, r_port