allow/disallow 2G/3G wip

Add DB storage for enabling / disabling arbitrary RAT types.

So far we have only GERAN-A and UTRAN-Iu, but to be future compatible,
implement an arbitrary length list of RAT types: add DB table subscriber_rat.

Backwards compatibility: if there is no entry in subscriber_rat, all RAT types
shall be allowed. As soon as there is an entry, it can either be false to
forbid a RAT or true to still allow a RAT type.

Depends: I93850710ab55a605bf61b95063a69682a2899bb1 (libosmocore)
Change-Id: I3e399ca8a85421f77a9a15e608413d1507722955

8 files changed, 300 insertions, 7 deletions

diff --git a/sql/hlr.sql b/sql/hlr.sql
index 9ff9867..3c65cd5 100644
--- a/sql/hlr.sql
+++ b/sql/hlr.sql
@@ -70,8 +70,17 @@ CREATE TABLE auc_3g (
 	ind_bitlen	INTEGER NOT NULL DEFAULT 5	-- nr of index bits at lower SQN end
 );
 
+-- Optional: add subscriber entries to allow or disallow specific RATs (2G or 3G or ...).
+-- If a subscriber has no entry, that means that all RATs are allowed (backwards compat).
+CREATE TABLE subscriber_rat (
+	subscriber_id	INTEGER,		-- subscriber.id
+	rat		TEXT CHECK(rat in ('GERAN-A', 'UTRAN-Iu')) NOT NULL,	-- Radio Access Technology, see enum ran_type
+	allowed		BOOLEAN CHECK(allowed in (0, 1)) NOT NULL DEFAULT 0
+);
+
 CREATE UNIQUE INDEX idx_subscr_imsi ON subscriber (imsi);
+CREATE UNIQUE INDEX idx_subscr_rat_flag ON subscriber_rat (subscriber_id, rat);
 
 -- Set HLR database schema version number
 -- Note: This constant is currently duplicated in src/db.c and must be kept in sync!
-PRAGMA user_version = 1;
+PRAGMA user_version = 2;
diff --git a/sql/upgrade_v1_to_v2.sql b/sql/upgrade_v1_to_v2.sql
new file mode 100644
index 0000000..7d09bad
--- /dev/null
+++ b/sql/upgrade_v1_to_v2.sql
@@ -0,0 +1,8 @@
+
+CREATE TABLE subscriber_rat (
+	subscriber_id	INTEGER,		-- subscriber.id
+	rat		TEXT CHECK(rat in ('GERAN-A', 'UTRAN-Iu')) NOT NULL,	-- Radio Access Technology, see enum ran_type
+	allowed		BOOLEAN NOT NULL DEFAULT 0,
+);
+
+PRAGMA user_version = 2;
diff --git a/src/db.c b/src/db.c
index f7cbace..0a51178 100644
--- a/src/db.c
+++ b/src/db.c
@@ -28,7 +28,7 @@
 #include "db_bootstrap.h"
 
 /* This constant is currently duplicated in sql/hlr.sql and must be kept in sync! */
-#define CURRENT_SCHEMA_VERSION	1
+#define CURRENT_SCHEMA_VERSION	2
 
 #define SEL_COLUMNS \
 	"id," \
@@ -76,6 +76,12 @@ static const char *stmt_sql[] = {
 		" VALUES($subscriber_id, $algo_id_3g, $k, $op, $opc, $ind_bitlen)",
 	[DB_STMT_AUC_3G_DELETE] = "DELETE FROM auc_3g WHERE subscriber_id = $subscriber_id",
 	[DB_STMT_SET_LAST_LU_SEEN] = "UPDATE subscriber SET last_lu_seen = datetime($val, 'unixepoch') WHERE id = $subscriber_id",
+	[DB_STMT_UPD_RAT_FLAG] = "INSERT OR REPLACE INTO subscriber_rat (subscriber_id, rat, allowed)"
+		" VALUES ($subscriber_id, $rat, $allowed)",
+	[DB_STMT_RAT_BY_ID] =
+		"SELECT rat, allowed"
+		" FROM subscriber_rat"
+		" WHERE subscriber_id = $subscriber_id",
 };
 
 static void sql3_error_log_cb(void *arg, int err_code, const char *msg)
@@ -290,6 +296,51 @@ db_upgrade_v1(struct db_context *dbc)
 	return rc;
 }
 
+static int db_upgrade_v2(struct db_context *dbc)
+{
+	int i;
+	const char *stmts[] = {
+		"CREATE TABLE subscriber_rat",
+		"CREATE UNIQUE INDEX idx_subscr_rat_flag",
+		NULL
+	};
+	sqlite3_stmt *stmt = NULL;
+
+	for (i = 0; i < ARRAY_SIZE(stmts); i++) {
+		int rc;
+		int j;
+		const char *stmt_sql = NULL;
+
+		if (stmts[i] != NULL) {
+			for (j = 0; j < ARRAY_SIZE(stmt_bootstrap_sql); j++) {
+				if (strstr(stmt_bootstrap_sql[j], stmts[i])) {
+					/* make sure we have a unique match, hence also not break; here */
+					OSMO_ASSERT(!stmt_sql);
+					stmt_sql = stmt_bootstrap_sql[j];
+				}
+			}
+		} else
+			stmt_sql = "PRAGMA user_version = 2";
+		OSMO_ASSERT(stmt_sql);
+
+		rc = sqlite3_prepare_v2(dbc->db, stmt_sql, -1, &stmt, NULL);
+		if (rc != SQLITE_OK) {
+			LOGP(DDB, LOGL_ERROR, "Unable to prepare SQL statement '%s'\n", stmt_sql);
+			return rc;
+		}
+		rc = sqlite3_step(stmt);
+		db_remove_reset(stmt);
+		sqlite3_finalize(stmt);
+		if (rc != SQLITE_DONE) {
+			LOGP(DDB, LOGL_ERROR, "Unable to update HLR database schema to version 2: '%s'\n",
+			     stmt_sql);
+			return rc;
+		}
+	}
+
+	return SQLITE_DONE;
+}
+
 static int db_get_user_version(struct db_context *dbc)
 {
 	const char *user_version_sql = "PRAGMA user_version";
@@ -390,6 +441,8 @@ struct db_context *db_open(void *ctx, const char *fname, bool enable_sqlite_logg
 	LOGP(DDB, LOGL_NOTICE, "Database '%s' has HLR DB schema version %d\n", dbc->fname, version);
 
 	if (version < CURRENT_SCHEMA_VERSION && allow_upgrade) {
+		int orig_version = version;
+
 		switch (version) {
 		case 0:
 			rc = db_upgrade_v1(dbc);
@@ -400,21 +453,30 @@ struct db_context *db_open(void *ctx, const char *fname, bool enable_sqlite_logg
 			}
 			version = 1;
 			/* fall through */
+		case 1:
+			rc = db_upgrade_v2(dbc);
+			if (rc != SQLITE_DONE) {
+				LOGP(DDB, LOGL_ERROR, "Failed to upgrade HLR DB schema to version 2: (rc=%d) %s\n",
+				     rc, sqlite3_errmsg(dbc->db));
+				goto out_free;
+			}
+			version = 2;
+			/* fall through */
 		/* case N: ... */
 		default:
 			break;
 		}
-		LOGP(DDB, LOGL_NOTICE, "Database '%s' has been upgraded to HLR DB schema version %d\n",
-		     dbc->fname, version);
+		LOGP(DDB, LOGL_NOTICE, "Database '%s' has been upgraded from HLR DB schema version %d to %d\n",
+		     dbc->fname, orig_version, version);
 	}
 
 	if (version != CURRENT_SCHEMA_VERSION) {
 		if (version < CURRENT_SCHEMA_VERSION) {
 			LOGP(DDB, LOGL_NOTICE, "HLR DB schema version %d is outdated\n", version);
 			if (!allow_upgrade) {
-				LOGP(DDB, LOGL_ERROR, "Not upgrading HLR database to schema version %d; "
+				LOGP(DDB, LOGL_ERROR, "Not upgrading HLR database from schema version %d to %d; "
 				     "use the --db-upgrade option to allow HLR database upgrades\n",
-				     CURRENT_SCHEMA_VERSION);
+				     version, CURRENT_SCHEMA_VERSION);
 			}
 		} else
 			LOGP(DDB, LOGL_ERROR, "HLR DB schema version %d is unknown\n", version);
diff --git a/src/db.h b/src/db.h
index ae592fb..6fd33ee 100644
--- a/src/db.h
+++ b/src/db.h
@@ -3,6 +3,8 @@
 #include <stdbool.h>
 #include <sqlite3.h>
 
+#include <osmocom/gsm/gsm_utils.h>
+
 struct hlr;
 
 enum stmt_idx {
@@ -26,6 +28,8 @@ enum stmt_idx {
 	DB_STMT_AUC_3G_INSERT,
 	DB_STMT_AUC_3G_DELETE,
 	DB_STMT_SET_LAST_LU_SEEN,
+	DB_STMT_UPD_RAT_FLAG,
+	DB_STMT_RAT_BY_ID,
 	_NUM_DB_STMT
 };
 
@@ -85,8 +89,13 @@ struct hlr_subscriber {
 	bool		ms_purged_cs;
 	bool		ms_purged_ps;
 	time_t		last_lu_seen;
+	bool		rat_types[OSMO_RAT_COUNT];
 };
 
+static const struct hlr_subscriber hlr_subscriber_empty = {
+		.rat_types = { true, true, true },
+	};
+
 /* A format string for use with strptime(3). This format string is
  * used to parse the last_lu_seen column stored in the HLR database.
  * See https://sqlite.org/lang_datefunc.html, function datetime(). */
@@ -138,6 +147,10 @@ int db_subscr_purge(struct db_context *dbc, const char *by_imsi,
 
 int hlr_subscr_nam(struct hlr *hlr, struct hlr_subscriber *subscr, bool nam_val, bool is_ps);
 
+int db_subscr_set_rat_type_flag(struct db_context *dbc, int64_t subscr_id, enum osmo_rat_type rat, bool allowed);
+int db_subscr_get_rat_types(struct db_context *dbc, struct hlr_subscriber *subscr);
+int hlr_subscr_rat_flag(struct hlr *hlr, struct hlr_subscriber *subscr, enum osmo_rat_type rat, bool allowed);
+
 /*! Call sqlite3_column_text() and copy result to a char[].
  * \param[out] buf  A char[] used as sizeof() arg(!) and osmo_strlcpy() target.
  * \param[in] stmt  An sqlite3_stmt*.
diff --git a/src/db_hlr.c b/src/db_hlr.c
index c97cd82..f546e46 100644
--- a/src/db_hlr.c
+++ b/src/db_hlr.c
@@ -409,7 +409,7 @@ static int db_sel(struct db_context *dbc, sqlite3_stmt *stmt, struct hlr_subscri
 	if (!subscr)
 		goto out;
 
-	*subscr = (struct hlr_subscriber){};
+	*subscr = hlr_subscriber_empty;
 
 	/* obtain the various columns */
 	subscr->id = sqlite3_column_int64(stmt, 0);
@@ -444,6 +444,9 @@ static int db_sel(struct db_context *dbc, sqlite3_stmt *stmt, struct hlr_subscri
 out:
 	db_remove_reset(stmt);
 
+	if (ret == 0)
+		db_subscr_get_rat_types(dbc, subscr);
+
 	switch (ret) {
 	case 0:
 		*err = NULL;
@@ -782,3 +785,119 @@ int hlr_subscr_nam(struct hlr *hlr, struct hlr_subscriber *subscr, bool nam_val,
 	}
 	return 0;
 }
+
+int db_subscr_set_rat_type_flag(struct db_context *dbc, int64_t subscr_id, enum osmo_rat_type rat, bool allowed)
+{
+	int rc;
+	int ret = 0;
+	sqlite3_stmt *stmt = dbc->stmt[DB_STMT_UPD_RAT_FLAG];
+
+	if (!db_bind_int64(stmt, "$subscriber_id", subscr_id))
+		return -EIO;
+
+	OSMO_ASSERT(rat >= 0 && rat < OSMO_RAT_COUNT);
+	if (!db_bind_text(stmt, "$rat", osmo_rat_type_name(rat)))
+		return -EIO;
+
+	if (!db_bind_int(stmt, "$allowed", allowed ? 1 : 0))
+		return -EIO;
+
+	/* execute the statement */
+	rc = sqlite3_step(stmt);
+	if (rc != SQLITE_DONE) {
+		LOGP(DDB, LOGL_ERROR, "%s %s: SQL error: %s\n",
+		     allowed ? "enable" : "disable", osmo_rat_type_name(rat),
+		     sqlite3_errmsg(dbc->db));
+		ret = -EIO;
+		goto out;
+	}
+
+	/* verify execution result */
+	rc = sqlite3_changes(dbc->db);
+	if (!rc) {
+		LOGP(DDB, LOGL_ERROR, "Cannot %s %s: no such subscriber: ID=%" PRIu64 "\n",
+		     allowed ? "enable" : "disable", osmo_rat_type_name(rat),
+		     subscr_id);
+		ret = -ENOENT;
+		goto out;
+	} else if (rc != 1) {
+		LOGP(DDB, LOGL_ERROR, "%s %s: SQL modified %d rows (expected 1)\n",
+		     allowed ? "enable" : "disable", osmo_rat_type_name(rat),
+		     rc);
+		ret = -EIO;
+	}
+
+out:
+	db_remove_reset(stmt);
+	return ret;
+}
+
+int db_subscr_get_rat_types(struct db_context *dbc, struct hlr_subscriber *subscr)
+{
+	int rc;
+	int ret = 0;
+	int i;
+	sqlite3_stmt *stmt = dbc->stmt[DB_STMT_RAT_BY_ID];
+
+	if (!db_bind_int64(stmt, "$subscriber_id", subscr->id))
+		return -EIO;
+
+	for (i = 0; i < OSMO_RAT_COUNT; i++)
+		subscr->rat_types[i] = true;
+
+	/* execute the statement */
+	while (1) {
+		enum osmo_rat_type rat;
+		bool allowed;
+
+		rc = sqlite3_step(stmt);
+
+		if (rc == SQLITE_DONE)
+			break;
+		if (rc != SQLITE_ROW)
+			return -rc;
+
+		rc = get_string_value(osmo_rat_type_names, (const char*)sqlite3_column_text(stmt, 0));
+		if (rc == -EINVAL) {
+			ret = -EINVAL;
+			goto out;
+		}
+		if (rc <= 0 || rc >= OSMO_RAT_COUNT) {
+			ret = -EINVAL;
+			goto out;
+		}
+		rat = rc;
+
+		allowed = sqlite3_column_int(stmt, 1);
+
+		subscr->rat_types[rat] = allowed;
+		LOGP(DAUC, LOGL_DEBUG, "db: imsi='%s' %s %s\n",
+		     subscr->imsi, osmo_rat_type_name(rat), allowed ? "allowed" : "forbidden");
+	}
+
+out:
+	db_remove_reset(stmt);
+	return ret;
+}
+
+int hlr_subscr_rat_flag(struct hlr *hlr, struct hlr_subscriber *subscr, enum osmo_rat_type rat, bool allowed)
+{
+	int rc;
+	OSMO_ASSERT(rat >= 0 && rat < OSMO_RAT_COUNT);
+
+	db_subscr_get_rat_types(hlr->dbc, subscr);
+
+	if (subscr->rat_types[rat] == allowed) {
+		LOGHLR(subscr->imsi, LOGL_DEBUG, "Already has the requested value when asked to %s %s\n",
+		       allowed ? "enable" : "disable", osmo_rat_type_name(rat));
+		return -ENOEXEC;
+	}
+
+	rc = db_subscr_set_rat_type_flag(hlr->dbc, subscr->id, rat, allowed);
+	if (rc)
+		return rc > 0? -rc : rc;
+
+	/* FIXME: If we're disabling, send message to VLR to detach subscriber */
+
+	return 0;
+}
diff --git a/src/hlr.c b/src/hlr.c
index 4873a66..098b934 100644
--- a/src/hlr.c
+++ b/src/hlr.c
@@ -263,6 +263,9 @@ static int rx_upd_loc_req(struct osmo_gsup_conn *conn,
 {
 	struct hlr_subscriber *subscr;
 	struct lu_operation *luop = lu_op_alloc_conn(conn);
+	int i;
+	bool allowed;
+
 	if (!luop) {
 		LOGP(DMAIN, LOGL_ERROR, "LU REQ from conn without addr?\n");
 		return -EINVAL;
@@ -308,6 +311,34 @@ static int rx_upd_loc_req(struct osmo_gsup_conn *conn,
 		return 0;
 	}
 
+	/* Check if any available RAT type is allowed. See 3GPP TS 29.010 3.2 'Routeing area updating' and 3.8 'Location
+	 * update' for the "No Suitable cells in location area" error code. */
+	allowed = false;
+	LOGP(DAUC, LOGL_DEBUG, "LU: IMSI='%s' on %s sent RAT types: %zu\n", subscr->imsi,
+	     gsup->cn_domain == OSMO_GSUP_CN_DOMAIN_CS ? "CS" : "PS", gsup->rat_types_len);
+	for (i = 0; i < gsup->rat_types_len; i++) {
+		enum osmo_rat_type rat = gsup->rat_types[i];
+		if (rat <= 0 || rat >= OSMO_RAT_COUNT) {
+			lu_op_tx_error(luop, GMM_CAUSE_COND_IE_ERR);
+			return 0;
+		}
+		if (luop->subscr.rat_types[rat]) {
+			allowed = true;
+			LOGP(DAUC, LOGL_DEBUG, "LU: IMSI='%s' allowed on %s\n",
+			     subscr->imsi, osmo_rat_type_name(rat));
+		} else {
+			LOGP(DAUC, LOGL_DEBUG, "LU: IMSI='%s' not allowed on %s\n",
+			     subscr->imsi, osmo_rat_type_name(rat));
+		}
+	}
+	if (!allowed && gsup->rat_types_len > 0) {
+		LOGP(DAUC, LOGL_DEBUG, "ISMI='%s' not allowed on %s%s\n",
+		     subscr->imsi, osmo_rat_type_name(gsup->rat_types[0]),
+		     gsup->rat_types_len > 1 ? " (nor on the other available RAT types)" : "");
+		lu_op_tx_error(luop, GMM_CAUSE_NO_SUIT_CELL_IN_LA);
+		return 0;
+	}
+
 	/* TODO: Set subscriber tracing = deactive in VLR/SGSN */
 
 #if 0
diff --git a/src/hlr_vty_subscr.c b/src/hlr_vty_subscr.c
index c2359d4..21296ff 100644
--- a/src/hlr_vty_subscr.c
+++ b/src/hlr_vty_subscr.c
@@ -27,6 +27,7 @@
 #include <osmocom/vty/vty.h>
 #include <osmocom/vty/command.h>
 #include <osmocom/core/utils.h>
+#include <osmocom/gsm/gsm_utils.h>
 
 #include "hlr.h"
 #include "db.h"
@@ -49,6 +50,7 @@ static char *get_datestr(const time_t *t)
 static void subscr_dump_full_vty(struct vty *vty, struct hlr_subscriber *subscr)
 {
 	int rc;
+	int i;
 	struct osmo_sub_auth_data aud2g;
 	struct osmo_sub_auth_data aud3g;
 
@@ -78,6 +80,12 @@ static void subscr_dump_full_vty(struct vty *vty, struct hlr_subscriber *subscr)
 		vty_out(vty, "    PS purged%s", VTY_NEWLINE);
 	if (subscr->last_lu_seen)
 		vty_out(vty, "    last LU seen: %s%s", get_datestr(&subscr->last_lu_seen), VTY_NEWLINE);
+	for (i = OSMO_RAT_UNKNOWN + 1; i < ARRAY_SIZE(subscr->rat_types); i++) {
+		vty_out(vty, "    %s: %s%s", osmo_rat_type_name(i), subscr->rat_types[i] ? "allowed" : "forbidden",
+			VTY_NEWLINE);
+	}
+	if (subscr->ms_purged_cs)
+		vty_out(vty, "    CS purged%s", VTY_NEWLINE);
 
 	if (!*subscr->imsi)
 		return;
@@ -506,6 +514,45 @@ DEFUN(subscriber_aud3g,
 	return CMD_SUCCESS;
 }
 
+DEFUN(subscriber_rat,
+      subscriber_rat_cmd,
+      SUBSCR_UPDATE "rat (geran-a|utran-iu) (allowed|forbidden)",
+      SUBSCR_UPDATE_HELP
+      "Allow or forbid specific Radio Access Types\n"
+      "Set access to GERAN-A\n"
+      "Set access to UTRAN-Iu\n"
+      "Allow access\n"
+      "Forbid access\n")
+{
+	struct hlr_subscriber subscr;
+	const char *id_type = argv[0];
+	const char *id = argv[1];
+	const char *rat_str = argv[2];
+	const char *allowed_forbidden = argv[3];
+	enum osmo_rat_type rat;
+	bool allowed;
+	int rc;
+
+	if (strcmp(rat_str, "geran-a") == 0)
+		rat = OSMO_RAT_GERAN_A;
+	else if (strcmp(rat_str, "utran-iu") == 0)
+		rat = OSMO_RAT_UTRAN_IU;
+
+	allowed = (strcmp(allowed_forbidden, "allowed") == 0);
+
+	if (get_subscr_by_argv(vty, id_type, id, &subscr))
+		return CMD_WARNING;
+
+	rc = hlr_subscr_rat_flag(g_hlr, &subscr, rat, allowed);
+
+	if (rc && rc != -ENOEXEC) {
+		vty_out(vty, "%% Error: cannot set %s to %s%s",
+			osmo_rat_type_name(rat), allowed ? "allowed" : "forbidden", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	return CMD_SUCCESS;
+}
+
 void hlr_vty_subscriber_init(void)
 {
 	install_element_ve(&subscriber_show_cmd);
@@ -517,4 +564,5 @@ void hlr_vty_subscriber_init(void)
 	install_element(ENABLE_NODE, &subscriber_aud2g_cmd);
 	install_element(ENABLE_NODE, &subscriber_no_aud3g_cmd);
 	install_element(ENABLE_NODE, &subscriber_aud3g_cmd);
+	install_element(ENABLE_NODE, &subscriber_rat_cmd);
 }
diff --git a/src/luop.h b/src/luop.h
index f96593b..5a79722 100644
--- a/src/luop.h
+++ b/src/luop.h
@@ -54,6 +54,9 @@ struct lu_operation {
 	enum lu_state state;
 	/*! CS (false) or PS (true) Location Update? */
 	bool is_ps;
+	/*! RAT type indicator: coming in on GERAN-A? UTRAN-Iu? */
+	enum osmo_rat_type via_rat;
+
 	/*! currently running timer */
 	struct osmo_timer_list timer;