On 06/26/2018 01:50 AM, Sowmini Varadhan wrote:
If a socket is bound, I guess the scope_id should be used. So
if a socket is not bound to a link local address and the socket
is used to sent to a link local peer, it should fail.
PF_RDS sockets *MUST* alwasy be bound. See
Documentation/networking/rds.txt:
" Sockets must be bound before you can send or receive data.
This is needed because binding also selects a transport and
attaches it to the socket. Once bound, the transport assignment
does not change."
Also, rds_sendmsg checks this (from net-next, your version
has the equivalent ipv6_addr_any etc check):
if (daddr == 0 || rs->rs_bound_addr == 0) {
release_sock(sk);
ret = -ENOTCONN; /* XXX not a great errno */
goto out;
}
I think you misunderstood what I wrote. The above is in response
to your original question:
--
> And this is even more confusing because the fastpath in rds_sendmsg
> does not take the bound_scope_id into consideration at all:
> 1213 if (rs->rs_conn &&
ipv6_addr_equal(&rs->rs_conn->c_faddr, &daddr))
> 1214 conn = rs->rs_conn;
> 1215 else {
> 1216 conn = rds_conn_create_outgoing( /* .. */, scope_id)
> so if I erroneously passed a msg_name on a connected rds socket, what
> would happen? (see also question about rds_connect() itself, below)
--
My answer to this is that if a socket is not bound to a link
local address (meaning it is bound to a non-link local address)
and it is used to send to a link local peer, I think it should
fail. This is consistent with the scope_id check I mentioned in
the previous mail. If the socket is not bound to a link local
address, the bound_scope_id is 0. So if the socket is used to
send to a link local address (which has a non-zero scope_id), the
check will catch it and fail the call. A new conn should not
be created in this case.
--
K. Poon
ka-cheong.p...@oracle.com
