mon: Monitor: match command module caps against what's on MonCommands.h

We were checking the command's permissions against what we perceived as
the 'module' from parsing the command's "prefix" (specified by the
client).  This caused troubles with cap checks for commands without a
submodule clearly defined, such as 'status' or 'health' (vs 'mon dump'
or 'osd pool set', which are of submodule 'mon' and 'osd' respectively).

As such, we now grab the command's submodule (right now solely for caps
checks) from the monitor's internal representation of the commands
(defined in mon/MonCommands.h and built at compile time and stashed in
'mon_commands').  Given that commands such as 'health', 'fsid' or
'status' have properly defined modules in MonCommands.h, we simply rely
on that representation for all commands.  Which is what we should have
been doing from the start anyway, because we shouldn't be relying on the
client to point us to what we want to authenticate against.

Signed-off-by: Joao Eduardo Luis <joao@redhat.com>
mon: MonCap: add new profiles

Adds three new profiles:

  read-only:  able to issue all read-only (MON_CAP_R) commands.  Any
  command that may take additional caps (MON_CAP_W or MON_CAP_X) won't
  be allowed.

  read-write: able to issue all read-write (MON_CAP_R | MON_CAP_W)
  commands.  Commands that require MON_CAP_X will not be allowed.

  role-definer: solely able to issue commands on the 'auth' subsystem,
  to which all caps are given (MON_CAP_R | MON_CAP_W | MON_CAP_X).

Fixes: #8899

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
qa/workunits: cephtool: test auth profiles

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
test: mon: test-mon-msg: Check which msgs the mons handle and reply to

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
mon: Monitor: create logical divisions on dispatch() based on msg nature

Instead of a single switch(), have multiple switch() and order them by
increasing necessity of privileges.

This patch thus divides the big switch into:

- messages not requiring auth/caps checks at all
- messages which caps shall be checked somewhere else
- messages the Monitor class needs to deal with but only require a
  client to have enough caps for the monitor to consider handling them
- messages that only a monitor is allowed to send.

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
mon: Monitor: check caps and source before dispatching messages

Only dispatch messages that a client may send if said client has at
least MON_CAP_R, and only dispatch internal monitor messages if peer is
a monitor.

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
mon: Monitor: remove redudant call to osdmon's dispatch

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>
mon: OSDMonitor: add broader cap checks for osdmon's pool ops

Instead of checking caps solely for pool creation, check caps for any
pool ops during preprocess_pool_op()

Signed-off-by: Joao Eduardo Luis <joao.luis@inktank.com>