From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: Undefined behaviour of connect(fd, NULL, 0);
Date: Wed, 31 Mar 2010 14:17:32 -0700 (PDT)
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From: Neil Brown <neilb@suse.de>
Date: Thu, 1 Apr 2010 07:24:12 +1100

>> --- a/net/ipv4/af_inet.c	2010-03-31 11:47:01.952910248 -0700
>> +++ b/net/ipv4/af_inet.c	2010-03-31 11:48:09.852938406 -0700
>> @@ -575,7 +575,7 @@ int inet_stream_connect(struct socket *s
>>  
>>  	lock_sock(sk);
>>  
>> -	if (uaddr->sa_family == AF_UNSPEC) {
>> +	if (addr_len < sizeof(sa_family_t) || uaddr->sa_family == AF_UNSPEC) {
>>  		err = sk->sk_prot->disconnect(sk, flags);
>>  		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
>>  		goto out;
> 
> Thanks for the reply.
> 
> The implication of this patch is that
>    connect(fd, NULL, 0)
> is actually a valid way to check if an in-progress connection has completed.
> 
> Is that the intention?

That's not how I read the patch, the result is that connect(fd, NULL...)
will now disconnect the socket.