Re: [PATCH v4] net/ceph/messenger: support IPv6 Link-Local with scope identifier

Hi Max,

The core issue from v3 is still present: sin6_scope_id is a local
ifindex and must not go on the wire. v4 adds ceph_addr_equal_no_scope()
for banner comparisons, but peer_addr still carries the scope from
inet_pton_with_scope() and gets encoded into the msgr2 HELLO and
client-ident. A peer with scope 0 or a different ifindex will still fail
identity checks.

v4 also introduces new issues: the monmap update path drops scope when
installing decoded addresses, so reconnect to link-local monitors breaks
after the first map; ceph_addr_equal_no_type() still memcmps full
addresses including scope, breaking monmap lookup; and
ceph_addr_clear_scope() does an unaligned write through a cast on a
const-qualified pointer.

The fix needs a clean wire/local split: scope lives only in the sockaddr
used for kernel_connect(), cleared in everything that touches wire
identity.

--
Alex Markuze