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List:       kde-core-devel
Subject:    Re: KDE does not start on FreeBSD
From:       Thiago Macieira <thiagom () wanadoo ! fr>
Date:       2002-01-09 17:05:41
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Oswald Buddenhagen wrote:

>>>according to the fbsd header it should be
>>>  strlen(sockname.sun_path) + 1 + offsetof(sun_path, sockaddr_un)
>>>
>>why the +1?  if you do that, then the len is says the structure is 1 byte 
>>bigger than it actually is.


The ending ASCII zero in the pathname might account for that.


> /*
>  * Definitions for UNIX IPC domain.
>  */
> struct  sockaddr_un {
>         u_char  sun_len;                /* sockaddr len including null */
>         u_char  sun_family;             /* AF_UNIX */
>         char    sun_path[104];          /* path name (gag) */
> };
> 
> so how would you interpret this?

Linux defines the length as 108, other systems might define differently. 
That's quite arbitrary anyways. And the longest pathname is quite longer 
than that.

It has been suggested that sun_path should be a zero-sized array, and 
that you should allocate the needed size yourself. KUnixSocketAddress 
has been designed in that way.

Actually, all sockets in the KDE core libraries are malloc()ed with the 
sizes given by the needed functions instead of relying on any sockaddr_* 
structure size, including __sockaddr_storage.

-- 
   Thiago Macieira - UFOT Registry number: 1001
  thiagom@mail.com
    ICQ UIN: 1967141  PGP: 0x8F2978D5 and 0xEA9037A5 (PGP 2.x)
      Registered Linux user #65028

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