D-GSM 3/n: implement roaming by mslookup in osmo-hlr
Add mslookup client to find remote home HLRs of unknown IMSIs, and
proxy/forward GSUP for those to the right remote HLR instances.
Add remote_hlr.c to manage one GSUP client per remote HLR GSUP address.
Add proxy.c to keep state about remotely handled IMSIs (remote GSUP address,
MSISDN, and probably more in future patches). The mslookup_server that
determines whether a given MSISDN is attached locally now also needs to look in
the proxy record: it is always the osmo-hlr immediately peering for the MSC
that should respond to mslookup service address queries like SIP and SMPP.
(Only gsup.hlr service is always answered by the home HLR.)
Add dgsm.c to set up an mdns mslookup client, ask for IMSI homes, and to decide
which GSUP is handled locally and which needs to go to a remote HLR.
Add full VTY config and VTY tests.
For a detailed overview of the D-GSM and mslookup related files, please see the
elaborate comment at the top of mslookup.c (already added in an earlier patch).
Change-Id: I2fe453553c90e6ee527ed13a13089900efd488aa
diff --git a/include/osmocom/hlr/remote_hlr.h b/include/osmocom/hlr/remote_hlr.h
new file mode 100644
index 0000000..6a4e8a1
--- /dev/null
+++ b/include/osmocom/hlr/remote_hlr.h
@@ -0,0 +1,59 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/sockaddr_str.h>
+
+struct osmo_gsup_client;
+struct osmo_gsup_message;
+struct osmo_gsup_req;
+struct msgb;
+
+#define LOG_REMOTE_HLR(remote_hlr, level, fmt, args...) \
+ LOGP(DDGSM, level, "(Proxy HLR-" OSMO_SOCKADDR_STR_FMT ") " fmt, \
+ OSMO_SOCKADDR_STR_FMT_ARGS((remote_hlr) ? &(remote_hlr)->addr : NULL), ##args)
+
+#define LOG_REMOTE_HLR_MSG(remote_hlr, gsup_msg, level, fmt, args...) \
+ LOG_REMOTE_HLR(remote_hlr, level, "%s: " fmt, osmo_gsup_message_type_name((gsup_msg)->message_type), ##args)
+
+/* GSUP client link for proxying to a remote HLR. */
+struct remote_hlr {
+ struct llist_head entry;
+ struct osmo_sockaddr_str addr;
+ struct osmo_gsup_client *gsupc;
+ struct llist_head pending_up_callbacks;
+};
+
+/*! Receive a remote_hlr address when connecting succeeded, or remote_hlr == NULL on error.
+ * \param addr GSUP IP address and port for which the connection was requested.
+ * \param remote_hlr The connected remote_hlr ready for sending, or NULL if connecting failed.
+ * \param data Same a passed to remote_hlr_get_or_connect(). */
+typedef void (*remote_hlr_connect_result_cb_t)(const struct osmo_sockaddr_str *addr, struct remote_hlr *remote_hlr, void *data);
+
+struct remote_hlr *remote_hlr_get_or_connect(const struct osmo_sockaddr_str *addr, bool connect,
+ remote_hlr_connect_result_cb_t connect_result_cb, void *data);
+void remote_hlr_destroy(struct remote_hlr *remote_hlr);
+int remote_hlr_msgb_send(struct remote_hlr *remote_hlr, struct msgb *msg);
+void remote_hlr_gsup_forward_to_remote_hlr(struct remote_hlr *remote_hlr, struct osmo_gsup_req *req,
+ struct osmo_gsup_message *modified_gsup);
+
+bool remote_hlr_is_up(struct remote_hlr *remote_hlr);