On Mon, 28 Jan 2013 15:34:49 -0500 Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > On Jan 28, 2013, at 3:26 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > > > On Mon, 28 Jan 2013 12:16:17 -0800 (PST) > > Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > > > >> > >> On Jan 28, 2013, at 3:05 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > >> > >>> On Mon, 28 Jan 2013 11:51:13 -0800 (PST) > >>> Chuck Lever <chuck.lever@xxxxxxxxxx> wrote: > >>> > >>>> > >>>> On Jan 28, 2013, at 2:41 PM, Jeff Layton <jlayton@xxxxxxxxxx> wrote: > >>>> > >>>>> Currently, it only stores the first 16 bytes of any address. struct > >>>>> sockaddr_in6 is 28 bytes however, so we're currently ignoring the last > >>>>> 12 bytes of the address. > >>>>> > >>>>> Expand the c_addr field to a sockaddr_in6, > >>>> > >>>> What do you do about link-local addresses? > >>>> > >>> > >>> I use rpc_cmp_addr() which should handle the scope correctly for > >>> link-local addrs. Now that you mention it though, I think we may have a > >>> bug in __rpc_copy_addr6. It doesn't touch the scope_id at all -- > >>> shouldn't we be setting the scopeid in that function as well? > >> > >> It looks like rpc_copy_addr() is invoked to copy only source addresses, so the scope ID probably doesn't apply. The comment over rpc_copy_addr() says it explicitly ignores port and scope ID. > >> > > > > Well, it copies the source address of the client, but all of the > > callers are in nfsd code. So I think it probably does matter: > > > > Consider a server that has 2 interfaces, and 2 clients with identical > > link-local addresses hitting the link local address of each interface. > > The only way to distinguish them at that point is to look at their > > scope_ids. > > Yes, but we want to use the server's scope IDs in this case, don't we? Copying the client's scope IDs may not be the right thing to do. That's why __rpc_copy_addr6() doesn't copy the scope ID. > Is there any real distinction between the two? Whenever we start discussing scopeids I mentally substitute "interface index", since it's the same thing on linux. AIUI, scopeids only have a meaning on the host itself. When a link-local address gets used, the sockaddr_in6 in question gets the sin6_scope_id set to the index of the interface to which it is associated. So if we have a client and server "pair" using link-local addresses, then they should have equivalent scope IDs since they are associated with the same interface on the local machine. -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
