unable to invoke socket.connect with AF_UNSPEC

[RomanValov]

BPO	18095
Nosy	@giampaolo

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2013-05-29.14:07:24.704>
labels = ['type-bug', 'expert-IO']
title = 'unable to invoke socket.connect with AF_UNSPEC'
updated_at = <Date 2013-07-06.18:42:10.099>
user = 'https://proxy-ga.blitzz.co/proxy/123456/bugs.python.org/RomanValov'

bugs.python.org fields:

activity = <Date 2013-07-06.18:42:10.099>
actor = 'giampaolo.rodola'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['IO']
creation = <Date 2013-05-29.14:07:24.704>
creator = 'Roman.Valov'
dependencies = []
files = []
hgrepos = []
issue_num = 18095
keywords = []
message_count = 2.0
messages = ['190308', '192479']
nosy_count = 3.0
nosy_names = ['giampaolo.rodola', 'Roman.Valov', 'marto1']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'behavior'
url = 'https://proxy-ga.blitzz.co/proxy/123456/bugs.python.org/issue18095'
versions = ['Python 3.3']

[RomanValov]

There is a way to "disconnect" UDP socket
that was previously "connected" to specific
remote endpoint in C:

struct sockaddr_in sin;        
  memset((char \*)&sin, 0, sizeof(sin));
  sin.sin_family = AF_UNSPEC;
  connect(fd, (struct sockaddr \*)&sin, sizeof(sin));

However in this is not available in python, since connect
accepts only (host, port) as a parameter for UDP socket.

It's possible to drop "port" connection with port=0,
however I can't find a way to drop "host" connection.

[marto1]

--- a/Modules/socketmodule.c	Tue Jul 02 09:07:53 2013 -0400
+++ b/Modules/socketmodule.c	Sat Jul 06 21:08:40 2013 +0300
@@ -3673,6 +3673,15 @@
 {
     int how;
     int res;
+    struct sockaddr_in sin;
+    if (s->sock_type == SOCK_DGRAM){
+        memset((char *)&sin, 0, sizeof(sin));
+        sin.sin_family = AF_UNSPEC;
+        Py_BEGIN_ALLOW_THREADS
+        res = connect(s->sock_fd, (struct sockaddr *)&sin, sizeof(sin));
+        Py_END_ALLOW_THREADS
+        return Py_None;
+    }
 
     how = _PyLong_AsInt(arg);
     if (how == -1 && PyErr_Occurred())

The shutdown method seems a suitable candidate, but a disconnect() method(which is semantically more correct) could be introduced.

[vinipsmaker]

The shutdown method seems a suitable candidate, but a disconnect() method(which is semantically more correct) could be introduced.

I think a separate disconnect() method is more appropriate. That's what I did in my own network framework.