Date: Tue, 14 Nov 1995 11:16:03 -0500 From: "Garrett A. Wollman" <wollman@lcs.mit.edu> To: Poul-Henning Kamp <phk@critter.tfs.com> Cc: current@freebsd.org Subject: Re: cvs commit: src/sys/kern kern_sysctl.c Message-ID: <9511141616.AA23508@halloran-eldar.lcs.mit.edu> In-Reply-To: <570.816343308@critter.tfs.com> References: <Pine.BSF.3.91.951114041815.243B-100000@jhome.DIALix.COM> <570.816343308@critter.tfs.com>
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<<On Tue, 14 Nov 1995 11:01:48 +0100, Poul-Henning Kamp <phk@critter.tfs.com> said:
>> If you dont do the above change, gethostname(buf, 64) will fail with
>> ENOMEM, and cause gated, amd and mountd to fail.
> Well, what if the hostname actually WAS 255 bytes long then ?
Then you return an error.
> I would rather it fail all the time and we can get the code fixed,
> than having a mismatch between expectations like this...
I would prefer for it to obey the standard.
Digital UNIX 3.2:
The gethostname() function retrieves the standard host name of the local
host. If sufficient space is provided, the returned address parameter is
null-terminated.
System hostnames are limited to MAXHOSTNAMELEN as defined in the
/usr/include/sys/param.h file.
Ultrix 4.2:
The gethostname system call returns the standard host name for the
current processor, as previously set by sethostname. The namelen param-
eter specifies the size of the name array. The returned name is null-
terminated unless insufficient space is provided.
SunOS 4.1.1:
gethostname() returns the standard host name for the current
processor, as previously set by sethostname(). The parame-
ter namelen specifies the size of the array pointed to by
name. The returned name is null-terminated unless insuffi-
cient space is provided.
FreeBSD 2.2:
Gethostname() returns the standard host name for the current processor,
as previously set by sethostname(). The parameter namelen specifies the
size of the name array. The returned name is null-terminated unless in-
sufficient space is provided.
> get some variable
> old buffer too small,
> new buffer correct.
> it should return ENOMEM because it cannot copyout, but should the
> new value be installed ?
No.
> I'm seriously considering allowing only a "get" or a "set" per syscall,
> not both.
> But then again, that is too draconian isn't it ?
Yes. It defeats the whole purpose of having `new' and `old'
parameters in one call, which presently allow you to atomically
get-and-set the value of a variable.
-GAWollman
--
Garrett A. Wollman | Shashish is simple, it's discreet, it's brief. ...
wollman@lcs.mit.edu | Shashish is the bonding of hearts in spite of distance.
Opinions not those of| It is a bond more powerful than absence. We like people
MIT, LCS, ANA, or NSA| who like Shashish. - Claude McKenzie + Florent Vollant
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