A more meaningful error handling

aiosocks/__init__.py

@@ -7,7 +7,7 @@ __version__ = '0.1.1'
 
 __all__ = ('Socks4Protocol', 'Socks5Protocol', 'Socks4Auth',
            'Socks5Auth', 'Socks4Addr', 'Socks5Addr', 'SocksError',
-           'NoAcceptableAuthMethods', 'LoginAuthenticationFailed',
+           'NoAcceptableAuthMethods', 'LoginAuthenticationFailed', 'SocksConnectionError',
            'InvalidServerVersion', 'InvalidServerReply', 'create_connection')
 
 
@@ -46,11 +46,19 @@ async def create_connection(protocol_factory, proxy, proxy_auth, dst, *, remote_
             proxy=proxy, proxy_auth=proxy_auth, dst=dst,
             remote_resolve=remote_resolve, loop=loop)
 
-    transport, protocol = await loop.create_connection(
-        socks_factory, proxy.host, proxy.port, ssl=ssl, family=family, proto=proto,
-        flags=flags, sock=sock, local_addr=local_addr, server_hostname=server_hostname)
+    try:
+        transport, protocol = await loop.create_connection(
+            socks_factory, proxy.host, proxy.port, ssl=ssl, family=family, proto=proto,
+            flags=flags, sock=sock, local_addr=local_addr, server_hostname=server_hostname)
+    except OSError as exc:
+        raise SocksConnectionError('[Errno %s] Can not connect to proxy %s:%d [%s]' %
+                                   (exc.errno, proxy.host, proxy.port, exc.strerror)) from exc
 
-    await protocol.negotiate_done()
+    try:
+        await protocol.negotiate_done()
+    except SocksError as exc:
+        raise SocksError('Can not connect to %s:%s [%s]' %
+                         (dst[0], dst[1], exc))
 
     sock = transport.get_extra_info('socket')
 

aiosocks/connector.py

@@ -1,4 +1,9 @@
+import socket
+
 import aiohttp
+import ipaddress
+from aiohttp.errors import ProxyConnectionError
+from .errors import SocksError, SocksConnectionError
 from . import create_connection
 
 __all__ = ('SocksConnector',)
@@ -46,9 +51,14 @@ class SocksConnector(aiohttp.TCPConnector):
                     proto=hinfo['proto'], flags=hinfo['flags'], local_addr=self._local_addr)
 
                 return transp, proto
-            except OSError as e:
+            except (OSError, SocksError, SocksConnectionError) as e:
                 exc = e
         else:
-            raise aiohttp.ClientOSError(exc.errno,
-                                        'Can not connect to %s:%s [%s]' %
-                                        (req.host, req.port, exc.strerror)) from exc
+            if isinstance(exc, SocksConnectionError):
+                raise ProxyConnectionError(*exc.args)
+            if isinstance(exc, SocksError):
+                raise exc
+            else:
+                raise aiohttp.ClientOSError(exc.errno,
+                                            'Can not connect to %s:%s [%s]' %
+                                            (req.host, req.port, exc.strerror)) from exc

aiosocks/errors.py

@@ -16,3 +16,7 @@ class InvalidServerVersion(SocksError):
 
 class InvalidServerReply(SocksError):
     pass
+
+
+class SocksConnectionError(OSError):
+    pass

aiosocks/protocols.py

@@ -106,7 +106,7 @@ class Socks4Protocol(SocksProtocol):
             raise InvalidServerReply('SOCKS4 proxy server sent invalid data')
         if resp[1] != c.SOCKS4_GRANTED:
             error = c.SOCKS4_ERRORS.get(resp[1], 'Unknown error')
-            raise SocksError('{0:#04x}: {1}'.format(resp[1], error))
+            raise SocksError('[Errno {0:#04x}]: {1}'.format(resp[1], error))
 
         binded = socket.inet_ntoa(resp[4:]), struct.unpack('>H', resp[2:4])[0]
         return (host, port), binded
@@ -138,7 +138,7 @@ class Socks5Protocol(SocksProtocol):
         chosen_auth = await self.read_response(2)
 
         if chosen_auth[0] != c.SOCKS_VER5:
-            raise InvalidServerVersion
+            raise InvalidServerVersion('SOCKS5 proxy server sent invalid version')
 
         if chosen_auth[1] == c.SOCKS5_AUTH_UNAME_PWD:
             req = [0x01, chr(len(self._auth.login)).encode(), self._auth.login,
@@ -149,11 +149,11 @@ class Socks5Protocol(SocksProtocol):
             if auth_status[0] != 0x01:
                 raise InvalidServerReply('SOCKS5 proxy server sent invalid data')
             if auth_status[1] != c.SOCKS5_GRANTED:
-                raise LoginAuthenticationFailed
+                raise LoginAuthenticationFailed('SOCKS5 authentication failed')
         # offered auth methods rejected
         elif chosen_auth[1] != c.SOCKS5_AUTH_ANONYMOUS:
             if chosen_auth[1] == c.SOCKS5_AUTH_NO_ACCEPTABLE_METHODS:
-                raise NoAcceptableAuthMethods
+                raise NoAcceptableAuthMethods('All offered SOCKS5 authentication methods were rejected')
             else:
                 raise InvalidServerReply('SOCKS5 proxy server sent invalid data')
 
@@ -165,10 +165,10 @@ class Socks5Protocol(SocksProtocol):
         resp = await self.read_response(3)
 
         if resp[0] != c.SOCKS_VER5:
-            raise InvalidServerVersion
+            raise InvalidServerVersion('SOCKS5 proxy server sent invalid version')
         if resp[1] != c.SOCKS5_GRANTED:
             error = c.SOCKS5_ERRORS.get(resp[1], 'Unknown error')
-            raise SocksError('{0:#04x}: {1}'.format(resp[1], error))
+            raise SocksError('[Errno {0:#04x}]: {1}'.format(resp[1], error))
 
         binded = await self.read_address()