From: Jeff Garzik <jeff@garzik•org>
To: Chuck Lever <chuck.lever@oracle•com>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 0/4] RFC: raw IPv6 address parsing in NFS client
Date: Mon, 19 May 2008 14:56:20 -0400 [thread overview]
Message-ID: <4831CD54.9050004@garzik.org> (raw)
In-Reply-To: <BA7B3AE0-E0BA-4535-8641-5DC4A3A41F64@oracle.com>
Chuck Lever wrote:
> On May 18, 2008, at 10:13 PM, Jeff Garzik wrote:
>> Chuck Lever wrote:
>>> Hi-
>>> I'm interested in some review of the following four patches which add to
>>> the kernel's NFS client the ability to parse IPv6 addresses in
>>> presentation
>>> format.
>>> Namely, it adds the following:
>>> 1. If the user passes in an IPv6 address as the server name, the colons
>>> in the address will confuse the logic that splits the device name
>>> into a server hostname and an export path. We'll use square
>>> brackets
>>> around IPv6 server addresses to "escape" the colons, as does Solaris.
>>> 2. If the user passes in a link-local IPv6 address as the server name,
>>> an interface index is also necessary. We'll use the "%id" suffix on
>>> the address to pass in the index, and plant that in the sockaddr's
>>> sin6_scope_id field.
>>> In addition to the following patches in email, a git repo with these
>>> same patches already applied can be found here:
>>> linux-nfs.org:exports/cel-2.6.git
>>> The basic questions:
>>> Are these reasonable conventions to follow? Is the parsing logic
>>> adequate?
>>> Is there anything I'm forgetting?
>>
>> I would take a look at the underlying components of glibc's
>> getnameinfo(), which must parse IPv6 addresses according to POSIX
>> specifications, IIRC.
>>
>> Comments:
>>
>> 1) bracket escaping seems reasonably common. browsers and other apps
>> sometimes use that convention too.
>>
>> 2) an interface name rather than index should be used
>
> If you give a raw IPv6 address with an interface name to mount.nfs, it
> passes the whole thing to getaddrinfo(3) which maps the name to an
> index. The address with index is then passed on to the kernel via
> mount(2) via the normal "addr=" mount option.
>
> Is there a way the kernel can do that mapping for itself?
The kernel certainly knows the interface names... IMO that is a bit
more natural than interface index.
You certainly do not want to _store_ interface index or encourage its
use, since it might change during runtime if network interfaces change.
I don't know precisely your intended usage, nor where your
kernel/userland divide is here, but looking at dev_get_by_name() might
be a start, for accessing netdev via ifname?
Jeff
next prev parent reply other threads:[~2008-05-19 18:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-18 21:19 [PATCH 0/4] RFC: raw IPv6 address parsing in NFS client Chuck Lever
2008-05-18 21:20 ` [PATCH 1/4] NFS: Use common device name parsing logic for NFSv4 and NFSv2/v3 Chuck Lever
2008-05-18 21:20 ` [PATCH 2/4] NFS: Support raw IPv6 address hostnames during NFS mount operation Chuck Lever
2008-05-18 22:23 ` Trond Myklebust
2008-05-19 14:48 ` Chuck Lever
2008-05-18 21:20 ` [PATCH 3/4] NFS: Add string length argument to nfs_parse_server_address Chuck Lever
2008-05-18 21:20 ` [PATCH 4/4] NFS: handle interface identifiers in incoming IPv6 addresses Chuck Lever
2008-05-19 2:13 ` [PATCH 0/4] RFC: raw IPv6 address parsing in NFS client Jeff Garzik
2008-05-19 14:15 ` Chuck Lever
2008-05-19 18:56 ` Jeff Garzik [this message]
2008-05-19 19:46 ` Chuck Lever
2008-05-19 20:32 ` Brian Haley
2008-05-19 17:55 ` Chuck Lever
2008-05-19 18:58 ` Jeff Garzik
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