Re: Stats Collector Error 7.4beta1 and 7.4beta2 - Mailing list pgsql-hackers

From Jan Wieck
Subject Re: Stats Collector Error 7.4beta1 and 7.4beta2
Date
Msg-id 3F58BA8C.3070108@Yahoo.com
Whole thread Raw
In response to Re: Stats Collector Error 7.4beta1 and 7.4beta2  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Stats Collector Error 7.4beta1 and 7.4beta2
Re: Stats Collector Error 7.4beta1 and 7.4beta2
List pgsql-hackers

Tom Lane wrote:

> Jan Wieck <JanWieck@Yahoo.com> writes:
>> Redhat 7.1 says
>>         The file descriptor sockfd must refer to a socket.  If the
>>         socket is of type SOCK_DGRAM then the serv_addr address is
>>         the address to which datagrams are sent  by  default,  and
>>         the  only  address  from which datagrams are received.  If
> 
>> Looks like the test is obsolete. Any objections to remove it? Do people 
>> agree that it's a bugfix that can go into 7.4?
> 
> The test is not "obsolete"; we understood when we wrote it that it
> should theoretically be redundant with the kernel-level restriction.
> But there may be systems out there that fail to make the check promised
> by the HPUX and Linux manpages.  So I'd prefer to leave it in there if
> we can.  I don't want to rip it out simply because we don't understand
> why it's failing on Adam's setup.
> 
> What I'm wondering about is whether we are comparing the right number of
> bytes ... have both address structs been reported to have the same
> length?  Maybe we need a min().

I disagree. If getsockname(), getpeername() or recvfrom() return 
different address length's, it'd be more an indicator that the addresses 
ARE different anyway. Just because an IPV4 address doesn't have that 
feature is no reason to assume that addresses of different length are 
the same if they match over min() bytes.

If you want to continue to check the addresses and feel that HPUX and 
Linux manpage claims about kernel behaviour aren't enough, then we have 
to make it a specific check per "supported" AF. For now, that'd just be 
AF_INET and AF_INET6, and the default case bailing out with an error.


Jan

-- 
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