From: Andrew Lunn <andrew@lunn.ch>
To: Sturle Mastberg <sturle.mastberg@tandberg.net>
Cc: Gary Thomas <gary@mlbassoc.com>,
eCos Discussion <ecos-discuss@ecos.sourceware.org>
Subject: Re: [ECOS] Possible fix for duplicated ARP entries in the FreeBSD stack
Date: Fri, 17 Jun 2005 11:30:00 -0000 [thread overview]
Message-ID: <20050617112810.GA4982@lunn.ch> (raw)
In-Reply-To: <42B2ACAD.5030608@tandberg.net>
On Fri, Jun 17, 2005 at 12:57:49PM +0200, Sturle Mastberg wrote:
> Gary Thomas wrote:
> >On Fri, 2005-06-17 at 10:52 +0200, Sturle Mastberg wrote:
> >
> >>Hello,
> >>
> >>For some time I've had problem with duplicated ARP entries that have
> >>caused all sorts of problems. I searched the archive and discovered that
> >>the problem had been reported before:
> >>
> >>
> >>http://sourceware.org/ml/ecos-discuss/2004-11/msg00097.html
> >>
> >>
> >>My proposal to a fix is to make the sockaddr_inarp struct
> >>(include/netinet/if_ether.h) equal in size to the sockaddr struct by
> >>padding it at the end. This is exactly what is done to the sockaddr_in
> >>struct (include/netinet/in.h) for different reasons.
> >>
> >>
> >>I reached this conclusion after I discovered that two virutally
> >>identical calls to rtalloc1 (net/route.c) returned different results.
> >>The first instance appears in arplookup (netinet/if_ether.c) where the
> >>first parameter to rtalloc1 is a struct sockaddr_inarp cast to a struct
> >>sockaddr. The second instance appears in ip_output (netinet/ip_output)
> >>via rtalloc_ign (net/route.c) where the first parameter to rtalloc1 is
> >>an actual struct sockaddr. The rtalloc1 function does a radix tree
> >>search with a call to the rn_match function (net/radix.c). A closer look
> >>at this code reveals that it does indeed depend on the size of the
> >>supplied struct.
> >>
> >>
> >>The only conclusion a can draw from this is that the three structs:
> >>sockaddr, sockaddr_in and sockaddr_inarp must all be of equal size. I
> >>have checked the FreeBSD source repository that this is the case for the
> >>original code.
> >>
> >>
> >>While browsing the FreeBSD source repository I discovered that the
> >>sa_data character array member of the sockaddr struct was increased in
> >>size in the eCos FreeBSD stack. Does anyone know why this increase was
> >>introduced in eCos?
I beleave Nick did this for IPv6. This bigger size allows an IPv6
address to be placed into a sockaddr which you cannot normally do.
Andrew
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next prev parent reply other threads:[~2005-06-17 11:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-17 8:52 Sturle Mastberg
2005-06-17 10:01 ` Gary Thomas
2005-06-17 10:58 ` Sturle Mastberg
2005-06-17 11:30 ` Andrew Lunn [this message]
2005-06-17 12:53 ` Nick Garnett
2005-06-17 12:57 ` Gary Thomas
2005-06-20 9:05 ` [ECOS] RE : [ECOS] Possible fix for duplicated ARP entries in the FreeBSDstack Arnaud Chataignier
2005-06-20 10:12 ` [ECOS] " Sturle Mastberg
2005-06-20 10:26 ` [ECOS] " Nick Garnett
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