SO_BSDCOMPAT MESSAGE

[Danny Mayer]

Mark Andrews wrote:
>>Hi Everybody , 
>> 
>>            I installed bind 9.3.1 on fedora core 3 and When I start named
>>it's giving an message like this  " dns2 kernel: process `named' is using
>>obsolete setsockopt SO_BSDCOMPAT " I check mailing list and history but I
>>couldn't find any information for solve it , also on google. Do you have any
>>idea why this message anonced by kernel ? one time named are stopped , any
>>relation with this message ? 
>> 
>>Thanks
>>Best Regards 
>> 
>>Vahric MUHTARYAN
>>Sistem Mühendisi/System Engineer
>>DorukNet
>>Tel / Phone : +90 212 326 92 00
>>Fax : +90 212 227 28 11
>>E-mail : vahric.muhtaryan at doruk.net.tr 
>>http://www.doruk.net.tr 
>>http://www.doruk.net.tr/english.html
> 
> 
> 	Complain to the Linux kernel developers.  They should remove
> 	the message or the #define.
> 
> 	I suspect that all usage instances are actually protected
> 	with a #ifdef SO_BSDCOMPAT because it is not in early versions
> 	of the kernel.
> 
> 	e.g.
> 
> #ifdef SO_BSDCOMPAT
>         if (type != isc_sockettype_unix &&
>             setsockopt(sock->fd, SOL_SOCKET, SO_BSDCOMPAT,
>                        (void *)&on, sizeof(on)) < 0) {
>                 isc__strerror(errno, strbuf, sizeof(strbuf));
>                 UNEXPECTED_ERROR(__FILE__, __LINE__,
>                                  "setsockopt(%d, SO_BSDCOMPAT) %s: %s",
>                                  sock->fd,
>                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
>                                                 ISC_MSG_FAILED, "failed"),
>                                  strbuf);
>                 /* Press on... */
>         }
> #endif
> 
> 	Do they really expect application developers to try to
> 	workout what kernel version is running to see if they need
> 	to set SO_BSDCOMPAT especially when some kernel versions
> 	need the option turned on?
> 
> 	As to why it was that the Linux kernel developers thought
> 	that making unconnected UDP sockets return errors after
> 	getting a ICMP message would be good.  Unfortunately this
> 	is only really useful in the case where a connected UDP
> 	socket could be used (always talking to the same end point).
> 	There is not enough information to do anything with the
> 	error code when you are talking to thousands of different
> 	clients a second.
> 

They probably decided to follow Microsoft's example in Windows 2000 and
when they put out a fix for it, instead of fixing the code, the provided
a WSAIoctl() option for programmers to fix themselves Microsoft's broken
code. See Q263823 for the harrowing details.

Danny

> 	They then came up with this socket option to restore the
> 	BSD Socket API behaviour (SO_BSDCOMPAT) and not pass the
> 	error information back up the stack.
> 
> 	They then decided to change the default to be the BSD Socket
> 	API behaviour so the setsockopt(SO_BSDCOMPAT) call was no
> 	longer necessary and decided to make the kernel complain
> 	about all such calls but also did not remove the #define for
> 	SO_BSDCOMPAT.
> 
> 	Mark
> --
> Mark Andrews, ISC
> 1 Seymour St., Dundas Valley, NSW 2117, Australia
> PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org
> 
> 
>