Add support for multiple APN profiles for subscriber data

Previously the HLR sent in the Insert Subscriber Data call only the
wildcard APN as a single entry.
This violates the spec because the first entry (with the lowest context_id) is
always the default APN, but it is forbidden to have a wildcard APN as default apn.

Introduce a default template/profile which can contain multiple APNs.
This profile is always sent out to the SGSN/MME as part of Insert-Subscriber-Data.
In the future a subscriber might have a profile template name written into the
database which will resolve to a "pdp-profile premium" in the configuration.

To be backward compatible, if the pdp-profile default section is missing,
the HLR will send out only a wildcard APN.

Config example:

hlr
 ps
  pdp-profile default
   profile 1
    apn internet
   profile 2
    apn *

Changes to the apn list will be only handed out to subscribers
when the subscriber do a location update.

Related: SYS#6391
Change-Id: I540132ee5dcfd09f4816e02e702927e1074ca50f

include/osmocom/hlr/hlr.h

@@ -58,6 +58,14 @@ struct hlr {
 	struct hlr_euse *euse_default;
 	enum gsm48_gmm_cause reject_cause;
 	enum gsm48_gmm_cause no_proxy_reject_cause;
+	/* PS: APN default configuration used by Subscription Data on ISR */
+	struct {
+		struct {
+			bool enabled;
+			struct osmo_gsup_pdp_info pdp_infos[OSMO_GSUP_MAX_NUM_PDP_INFO];
+			size_t num_pdp_infos;
+		} pdp_profile;
+	} ps;
 
 	/* NCSS (call independent) session guard timeout value */
 	int ncss_guard_timeout;

include/osmocom/hlr/hlr_vty.h

@@ -35,6 +35,9 @@ enum hlr_vty_node {
 	MSLOOKUP_SERVER_NODE,
 	MSLOOKUP_SERVER_MSC_NODE,
 	MSLOOKUP_CLIENT_NODE,
+	PS_NODE,
+	PS_PDP_PROFILES_NODE,
+	PS_PDP_PROFILES_PROFILE_NODE,
 };