Re: [PATCH] Revert "mountd: handle allocation failures in auth_unix_ip upcall"

["J. Bruce Fields" <bfields@fieldses.org>]

On Mon, Nov 26, 2012 at 05:05:22PM -0500, Chuck Lever wrote:
> 
> On Nov 26, 2012, at 5:03 PM, "J. Bruce Fields" <bfields@fieldses.org> wrote:
> 
> > From: "J. Bruce Fields" <bfields@redhat.com>
> > 
> > This reverts commit 485f7a21e1649797f29317b865cbb094c1f6a71d.  The
> > failures handled there could be any sort of name resolution failure, not
> > just an allocation, and failing to downcall (hence leaving the client
> > hanging) is not the correct thing to do in those cases.
> 
> The problem is in the kernel, then: a downcall should be allowed to fail, IMO.

In this case, after a revert, a failure here will result in the downcall
passing down a client named "DEFAULT".  Presumably that won't be
permitted access to the export, so the client will end up getting an
error.

But I may not understand your objection.

--b.

> 
> > Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> > ---
> > utils/mountd/cache.c | 12 +++---------
> > 1 file changed, 3 insertions(+), 9 deletions(-)
> > 
> > diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
> > index 8f14032..6710eca 100644
> > --- a/utils/mountd/cache.c
> > +++ b/utils/mountd/cache.c
> > @@ -84,6 +84,7 @@ static void auth_unix_ip(FILE *f)
> > 	char ipaddr[INET6_ADDRSTRLEN];
> > 	char *client = NULL;
> > 	struct addrinfo *tmp = NULL;
> > +	struct addrinfo *ai = NULL;
> > 	if (readline(fileno(f), &lbuf, &lbuflen) != 1)
> > 		return;
> > 
> > @@ -106,16 +107,12 @@ static void auth_unix_ip(FILE *f)
> > 
> > 	/* addr is a valid, interesting address, find the domain name... */
> > 	if (!use_ipaddr) {
> > -		struct addrinfo *ai = NULL;
> > -
> > 		ai = client_resolve(tmp->ai_addr);
> > -		if (ai == NULL)
> > -			goto out;
> > 		client = client_compose(ai);
> > 		freeaddrinfo(ai);
> > -		if (!client)
> > -			goto out;
> > 	}
> > +	freeaddrinfo(tmp);
> > +
> > 	qword_print(f, "nfsd");
> > 	qword_print(f, ipaddr);
> > 	qword_printuint(f, time(0) + DEFAULT_TTL);
> > @@ -127,9 +124,6 @@ static void auth_unix_ip(FILE *f)
> > 	xlog(D_CALL, "auth_unix_ip: client %p '%s'", client, client?client: "DEFAULT");
> > 
> > 	free(client);
> > -out:
> > -	freeaddrinfo(tmp);
> > -
> > }
> > 
> > static void auth_unix_gid(FILE *f)
> > -- 
> > 1.7.11.7
> > 
> > --
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> 
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
> 
> 
>