Re: misc/39327

["Martin S. Weber" <Ephaeton%gmx.net@localhost>]

The following reply was made to PR misc/39327; it has been noted by GNATS.

From: "Martin S. Weber" <Ephaeton%gmx.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: misc-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: misc/39327
Date: Fri, 22 May 2009 13:14:03 -0400

 On Fri, May 22, 2009 at 05:05:03PM +0000, Jukka Ruohonen wrote:
 > The following reply was made to PR misc/39327; it has been noted by GNATS.
 > 
 > From: Jukka Ruohonen <jruohonen%iki.fi@localhost>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc: 
 > Subject: Re: misc/39327
 > Date: Fri, 22 May 2009 20:04:48 +0300
 > 
 >  5AOn Fri, May 22, 2009 at 11:09:07AM -0400, Martin S. Weber wrote:
 >  > Well, it's true that it shouldn't be "the DARPA internet" anylonger, but
 >  > what about the other part of the fix suggestion, i.e. document in 
 >  > /etc/procotols which domain (by socket(2) parlese) the protocol is for?
 >  
 >  I am not sure whether I follow you with the other part.
 >  
 >  1. I think it is not so easy nor reasonable for a single operating system to
 >  change '/etc/protocols' because it comes from IANA, a.k.a. the Internet
 >  Assigned Numbers Authority. Functions like getprotobyname(3) also use
 >  '/etc/protocols' as a lookup; changing it will break a lot of things.
 >  
 
 I understand that, but on the other hand even the IANA will not block
 an improvement in a file they provide, will they?
 
 >  2. Generally the file is not meant as a reference for the domain-parameter
 >  in socket(2), but rather as a reference for the number in the protocol-field
 >  of IPv4 header (or next header -field in IPv6), as described also in the
 >  file itsef. Even if such change would be made, there is no mapping between
 >  the AF_-constants and the file (surely e.g. TCP can be used both with
 >  AF_INET and AF_INET6).
 >  
 
 I think there's some confusion here. I wasn't talking about the domain
 parameter of socket(), but about its protocol parameter:
 
  int
  socket(int domain, int type, int protocol);
 
 The domain parameter can be PF_INET, PF_INET6 and a lot of others, for
 the _protocol_ parameter the manpage says, "The protocol number to use is 
 particular to the communication domain in which communication is to 
 take place; see protocols(5).".
 
 That makes me think: There exists a mapping of domain parameters to
 a set of usable protocol parameters. Look at protocols(5) (and thus
 at /etc/protocols) to find out which. But /etc/protocols only documents
 the possible protocols at all. Now if /etc/protocols had also a field
 for the "communication domain in which communication is to take place",
 there would be no doubt about usable protocols. Take "icmp 1 ICMP" for
 instance. If it read "icmp 1 ICMP PF_INET" instead, it would be obvious
 that icmp is not for PF_INET6. Actually even expanding the comment instead
 of adding a new field to improve documentation on where this procotol 
 "belongs" would improve the situation in my opinion.
 
 
 >  3. Moreover, I think the socket(2) manual page does not rightly give any
 >  impression that one should look to '/etc/protocols' for the AF_-constants.
 >  
 
 AF_ ? The socket(2) man page only talks about PF_ constants (besides, I
 personally never understood THEIR distinction but that is outside the scope
 of this PR.)
 
 -Martin