1 files changed, 103 insertions, 0 deletions
diff --git a/python/gevent/resolver/__init__.py b/python/gevent/resolver/__init__.py
new file mode 100644
index 0000000..3da38e3
--- /dev/null
+++ b/python/gevent/resolver/__init__.py
@@ -0,0 +1,103 @@
+# Copyright (c) 2018  gevent contributors. See LICENSE for details.
+
+from _socket import gaierror
+from _socket import error
+from _socket import getservbyname
+from _socket import getaddrinfo
+
+from gevent._compat import string_types
+from gevent._compat import integer_types
+
+from gevent.socket import SOCK_STREAM
+from gevent.socket import SOCK_DGRAM
+from gevent.socket import SOL_TCP
+from gevent.socket import AI_CANONNAME
+from gevent.socket import EAI_SERVICE
+from gevent.socket import AF_INET
+from gevent.socket import AI_PASSIVE
+
+
+def _lookup_port(port, socktype):
+    # pylint:disable=too-many-branches
+    socktypes = []
+    if isinstance(port, string_types):
+        try:
+            port = int(port)
+        except ValueError:
+            try:
+                if socktype == 0:
+                    origport = port
+                    try:
+                        port = getservbyname(port, 'tcp')
+                        socktypes.append(SOCK_STREAM)
+                    except error:
+                        port = getservbyname(port, 'udp')
+                        socktypes.append(SOCK_DGRAM)
+                    else:
+                        try:
+                            if port == getservbyname(origport, 'udp'):
+                                socktypes.append(SOCK_DGRAM)
+                        except error:
+                            pass
+                elif socktype == SOCK_STREAM:
+                    port = getservbyname(port, 'tcp')
+                elif socktype == SOCK_DGRAM:
+                    port = getservbyname(port, 'udp')
+                else:
+                    raise gaierror(EAI_SERVICE, 'Servname not supported for ai_socktype')
+            except error as ex:
+                if 'not found' in str(ex):
+                    raise gaierror(EAI_SERVICE, 'Servname not supported for ai_socktype')
+                else:
+                    raise gaierror(str(ex))
+            except UnicodeEncodeError:
+                raise error('Int or String expected', port)
+    elif port is None:
+        port = 0
+    elif isinstance(port, integer_types):
+        pass
+    else:
+        raise error('Int or String expected', port, type(port))
+    port = int(port % 65536)
+    if not socktypes and socktype:
+        socktypes.append(socktype)
+    return port, socktypes
+
+hostname_types = tuple(set(string_types + (bytearray, bytes)))
+
+def _resolve_special(hostname, family):
+    if not isinstance(hostname, hostname_types):
+        raise TypeError("argument 1 must be str, bytes or bytearray, not %s" % (type(hostname),))
+
+    if hostname == '':
+        result = getaddrinfo(None, 0, family, SOCK_DGRAM, 0, AI_PASSIVE)
+        if len(result) != 1:
+            raise error('wildcard resolved to multiple address')
+        return result[0][4][0]
+    return hostname
+
+
+class AbstractResolver(object):
+
+    def gethostbyname(self, hostname, family=AF_INET):
+        hostname = _resolve_special(hostname, family)
+        return self.gethostbyname_ex(hostname, family)[-1][0]
+
+    def gethostbyname_ex(self, hostname, family=AF_INET):
+        aliases = self._getaliases(hostname, family)
+        addresses = []
+        tuples = self.getaddrinfo(hostname, 0, family,
+                                  SOCK_STREAM,
+                                  SOL_TCP, AI_CANONNAME)
+        canonical = tuples[0][3]
+        for item in tuples:
+            addresses.append(item[4][0])
+        # XXX we just ignore aliases
+        return (canonical, aliases, addresses)
+
+    def getaddrinfo(self, host, port, family=0, socktype=0, proto=0, flags=0):
+        raise NotImplementedError()
+
+    def _getaliases(self, hostname, family):
+        # pylint:disable=unused-argument
+        return []