ctrl: completely replace all CTRL commands

The previous commands are not conforming to how the CTRL interface is intended
to work:

  SET enable-ps <IMSI>
  SET disable-ps <IMSI>
  SET status-ps <IMSI>

'status-ps' is a write-only command even though it returns the status.
'enable-ps' / 'disable-ps' indicate the value instead of a variable name of an
entity. The entity <IMSI> takes the place of the variable value.

See also https://lists.osmocom.org/pipermail/openbsc/2017-September/011236.html

Instead, replace with

  SET subscriber.by-imsi-123456.ps-enabled {0,1}
  GET subscriber.by-imsi-123456.ps-enabled

and also provide further CTRL functions while at it:

  {SET,GET} subscriber.by-{imsi,msisdn,id}-123456.{cs,ps}-enabled {0,1}
  GET subscriber.by-{imsi,msisdn,id}-123456.{info,info-aud,info-all}

Provide CTRL tests in the form of transcripts.

Adjust tests/test_subscriber.sql to feature nonzero SQN, to see some values for
SQN in the CTRL transcript tests. (This does not affect the VTY tests, because
that creates its own subscribers, and there's no VTY command to set the SQN.)

This is the first time an application uses CTRL_NODE ids that are defined
outside of libosmocore, see 'Depends' below.

Implementation choice: the first idea was to have a '.' between the 'by-xxx'
and the value, like:

  subscriber.by-xxx.123456.function

but the difficulty with subscribers is that they are not in RAM, and I can't
just point node_data at a struct instance that is always there (like, say, a
global bts[0] struct in osmo-bsc). Instead, I want to store the selector and
later decide whether to read from the DB or whatever. With a '.' separating
things, the only way in a ctrl function to obtain both 'by-xxx' and '123456'
for picking a subscriber record would be to parse the entire variable path
string elements, including 'subscriber' and 'function', which would then also
clumsily fix at which node level we hook these commands; there could have been
separate CTRL_NODE_SUBSCR_BY_{IMSI,MSISDN,ID} parent nodes, but we cannot
introspect the current parent node dynamically within a ctrl function handler
(plus I'm not sure whether it's possible and a good idea to have the same
command under multiple parent nodes).

Rather than that, I store the 'by-foo-123' token in the node_data pointer to
have both bits of information pointed at by a single pointer; I use the
incoming command parsing to get this token pre-separated from surrounding node
names, and no need to re-allocate it, since the vector of tokens lives until
after command execution is complete. Each leaf command obtains this token from
cmd->node (aka node_data), and feeds this token to a common static function to
parse selector and value from it and to retrieve a subscriber record as needed.

(BTW, I have mentioned on the mailing list that this way might be necessary to
avoid numeric-only CTRL node names, but we don't need to, and that is not at
all related to this choice of structure.)

Depends: libosmocore I1bd62ae0d4eefde7e1517db15a2155640a1bab58
         libosmocore Ic9dba0e4a1eb5a7dc3cee2f181b9024ed4fc7005
Change-Id: I98ee6a06b3aa6a67adb868e0b63b0e04eb42eb50
diff --git a/tests/test_subscriber_errors.ctrl b/tests/test_subscriber_errors.ctrl
new file mode 100644
index 0000000..2f64fdb
--- /dev/null
+++ b/tests/test_subscriber_errors.ctrl
@@ -0,0 +1,107 @@
+GET 1 invalid
+ERROR 1 Command not found
+SET 2 invalid nonsense
+ERROR 2 Command not found
+
+GET 3 subscriber.by-imsi-nonsense.info
+ERROR 3 Invalid value part of 'by-xxx-value' selector.
+GET 4 subscriber.by-msisdn-nonsense.info
+ERROR 4 Invalid value part of 'by-xxx-value' selector.
+GET 5 subscriber.by-id-nonsense.info
+ERROR 5 Invalid value part of 'by-xxx-value' selector.
+
+GET 6 subscriber
+ERROR 6 Command not present.
+GET 7 subscriber.
+ERROR 7 Command not present.
+GET 8 subscriber.by-nonsense
+ERROR 8 Command not present.
+GET 9 subscriber.by-nonsense-
+ERROR 9 Command not present.
+GET 10 subscriber.by-nonsense-123456
+ERROR 10 Command not present.
+GET 11 subscriber.by-nonsense-123456.
+ERROR 11 Command not present.
+GET 12 subscriber.by-imsi-
+ERROR 12 Command not present.
+GET 13 subscriber.by-imsi-.
+ERROR 13 Command not present.
+GET 14 subscriber.by-imsi-901990000000003
+ERROR 14 Command not present.
+GET 15 subscriber.by-imsi-901990000000003.
+ERROR 15 Command not present.
+
+GET 16 subscriber.by-nonsense-123456.info
+ERROR 16 Not a known subscriber 'by-xxx-' selector.
+GET 17 subscriber.by-123456.info
+ERROR 17 Not a known subscriber 'by-xxx-' selector.
+
+GET 18 subscriber.by-imsi-.info
+ERROR 18 Invalid value part of 'by-xxx-value' selector.
+GET 19 subscriber.by-imsi--.info
+ERROR 19 Invalid value part of 'by-xxx-value' selector.
+
+GET 20 subscriber.by-imsi-12345678901234567.info
+ERROR 20 Invalid value part of 'by-xxx-value' selector.
+GET 21 subscriber.by-imsi-12345.info
+ERROR 21 Invalid value part of 'by-xxx-value' selector.
+GET 22 subscriber.by-imsi-1234567890123456.info
+ERROR 22 Invalid value part of 'by-xxx-value' selector.
+
+GET 23 subscriber.by-id-99999999999999999999999999.info
+ERROR 23 Invalid value part of 'by-xxx-value' selector.
+GET 24 subscriber.by-id-9223372036854775807.info
+ERROR 24 No such subscriber.
+GET 25 subscriber.by-id-9223372036854775808.info
+ERROR 25 Invalid value part of 'by-xxx-value' selector.
+GET 26 subscriber.by-id--1.info
+ERROR 26 No such subscriber.
+GET 27 subscriber.by-id--9223372036854775808.info
+ERROR 27 No such subscriber.
+GET 28 subscriber.by-id--9223372036854775809.info
+ERROR 28 Invalid value part of 'by-xxx-value' selector.
+
+GET 29 subscriber.by-id-1+1.info
+ERROR 29 Invalid value part of 'by-xxx-value' selector.
+GET 30 subscriber.by-id--.info
+ERROR 30 Invalid value part of 'by-xxx-value' selector.
+GET 31 subscriber.by-id-+1.info
+ERROR 31 Invalid value part of 'by-xxx-value' selector.
+GET 32 subscriber.by-id-+-1.info
+ERROR 32 Invalid value part of 'by-xxx-value' selector.
+GET 33 subscriber.by-id--+1.info
+ERROR 33 Invalid value part of 'by-xxx-value' selector.
+GET 34 subscriber.by-id-++1.info
+ERROR 34 Invalid value part of 'by-xxx-value' selector.
+GET 35 subscriber.by-id---1.info
+ERROR 35 Invalid value part of 'by-xxx-value' selector.
+
+GET 36 subscriber.by-id- 1.info
+ERROR 36 Command not present.
+GET 37 subscriber.by-id-+ 1.info
+ERROR 37 Command not present.
+GET 38 subscriber.by-id-- 1.info
+ERROR 38 Command not present.
+
+
+SET 39 subscriber.by-imsi-901990000000001.info foo
+ERROR 39 Read Only attribute
+SET 40 subscriber.by-imsi-901990000000001.info-aud foo
+ERROR 40 Read Only attribute
+SET 41 subscriber.by-imsi-901990000000001.info-all foo
+ERROR 41 Read Only attribute
+
+SET 42 subscriber.by-imsi-901990000000001.ps-enabled nonsense
+ERROR 42 Value failed verification.
+SET 43 subscriber.by-imsi-901990000000001.cs-enabled nonsense
+ERROR 43 Value failed verification.
+
+SET 44 subscriber.by-imsi-901990000000001.ps-enabled
+ERROR err Command parser error.
+SET 45 subscriber.by-imsi-901990000000001.cs-enabled
+ERROR err Command parser error.
+
+GET 46 subscriber.by-imsi-1234567890123456.ps-enabled
+ERROR 46 Invalid value part of 'by-xxx-value' selector.
+GET 47 subscriber.by-imsi-1234567890123456.cs-enabled
+ERROR 47 Invalid value part of 'by-xxx-value' selector.