mobile: Add initial support for scripting support

Right now the script will be executed once it is loaded. Make sure
to write it into the config file last. Expose various log commands
for logging. Jump through some hoops and get the filename and line
number from lua.

Change-Id: I456f6b6b5e1a14ed6c8cb0dcc5140093d3c61ef6

src/host/layer23/include/osmocom/bb/common/osmocom_data.h

@@ -85,6 +85,9 @@ struct osmocom_ms {
 	struct gsm48_cclayer cclayer;
 	struct osmomncc_entity mncc_entity;
 	struct llist_head trans_list;
+
+	void *lua_state;
+	char *lua_script;
 };
 
 enum osmobb_sig_subsys {

src/host/layer23/include/osmocom/bb/mobile/app_mobile.h

@@ -6,6 +6,7 @@
 extern char *config_dir;
 
 struct osmocom_ms;
+struct vty;
 
 int l23_app_init(int (*mncc_recv)(struct osmocom_ms *ms, int, void *),
 	const char *config_file, const char *vty_ip, uint16_t vty_port);
@@ -20,6 +21,9 @@ int mobile_stop(struct osmocom_ms *ms, int force);
 void mobile_set_started(struct osmocom_ms *ms, bool state);
 void mobile_set_shutdown(struct osmocom_ms *ms, int state);
 
+int script_lua_load(struct vty *vty, struct osmocom_ms *ms, const char *filename);
+int script_lua_close(struct osmocom_ms *ms);
+
 
 /* Internal code. Don't call directly */
 int mobile_exit(struct osmocom_ms *ms, int force);

src/host/layer23/src/mobile/Makefile.am

@@ -12,4 +12,10 @@ bin_PROGRAMS = mobile
 mobile_SOURCES = main.c app_mobile.c
 mobile_LDADD = libmobile.a $(LDADD)
 
-
+# lua support
+if BUILD_LUA
+AM_CPPFLAGS += -DWITH_LUA=1
+libmobile_a_SOURCES += script_lua.c
+else
+libmobile_a_SOURCES += script_nolua.c
+endif

src/host/layer23/src/mobile/script_lua.c

@@ -0,0 +1,146 @@
+/* (C) 2017 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+
+#include <osmocom/bb/common/osmocom_data.h>
+#include <osmocom/bb/common/logging.h>
+
+#include <osmocom/vty/misc.h>
+
+static int lua_osmo_do_log(lua_State *L, int loglevel)
+{
+	int argc = lua_gettop(L);
+	lua_Debug ar = { 0, };
+	int i;
+
+	lua_getstack(L, 1, &ar);
+	lua_getinfo(L, "nSl", &ar);
+
+	for (i = 1; i <= argc; ++i) {
+		if (!lua_isstring(L, i))
+			continue;
+		LOGPSRC(DLUA, loglevel, ar.source, ar.currentline,
+				"%s%s", i > 1 ? "\t" : "", lua_tostring(L, i));
+	}
+	LOGPC(DLUA, loglevel, "\n");
+	return 0;
+}
+
+static int lua_osmo_print(lua_State *L)
+{
+	return lua_osmo_do_log(L, LOGL_NOTICE);
+}
+
+static int lua_osmo_debug(lua_State *L)
+{
+	return lua_osmo_do_log(L, LOGL_DEBUG);
+}
+
+static int lua_osmo_error(lua_State *L)
+{
+	return lua_osmo_do_log(L, LOGL_ERROR);
+}
+
+static int lua_osmo_fatal(lua_State *L)
+{
+	return lua_osmo_do_log(L, LOGL_FATAL);
+}
+
+static const struct luaL_Reg global_runtime[] = {
+	{ "print", 	lua_osmo_print  },
+	{ "log_notice",	lua_osmo_print },
+	{ "log_debug",	lua_osmo_debug  },
+	{ "log_error",	lua_osmo_error  },
+	{ "log_fatal",	lua_osmo_fatal  },
+	{ NULL, NULL },
+};
+
+/*
+ *  Add functions to the global lua scope. Technically these are
+ *  included in the _G table. The following lua code can be used
+ *  to inspect it.
+ *
+ *  > for n in pairs(_G) do print(n) end
+ */
+static void add_globals(lua_State *L)
+{
+	lua_getglobal(L, "_G");
+	luaL_setfuncs(L, global_runtime, 0);
+	lua_pop(L, 1);
+}
+
+static void add_runtime(lua_State *L, struct osmocom_ms *ms)
+{
+	add_globals(L);
+}
+
+static void *talloc_lua_alloc(void *ctx, void *ptr, size_t osize, size_t nsize)
+{
+	if (nsize == 0) {
+		talloc_free(ptr);
+		return NULL;
+	}
+	return talloc_realloc_size(ctx, ptr, nsize);
+}
+
+int script_lua_close(struct osmocom_ms *ms)
+{
+	if (!ms->lua_state)
+		return 0;
+
+	lua_close(ms->lua_state);
+	ms->lua_state = NULL;
+	return 0;
+}
+
+int script_lua_load(struct vty *vty, struct osmocom_ms *ms, const char *filename)
+{
+	int err;
+
+	if (ms->lua_state)
+		lua_close(ms->lua_state);
+	ms->lua_state = lua_newstate(talloc_lua_alloc, ms);
+	if (!ms->lua_state)
+		return -1;
+
+	luaL_openlibs(ms->lua_state);
+	err = luaL_loadfilex(ms->lua_state, filename, NULL);
+	if (err) {
+		vty_out(vty, "%% LUA load error: %s%s",
+				lua_tostring(ms->lua_state, -1), VTY_NEWLINE);
+		lua_pop(ms->lua_state, 1);
+		return -2;
+	}
+
+	add_runtime(ms->lua_state, ms);
+
+	err = lua_pcall(ms->lua_state, 0, 0, 0);
+	if (err) {
+		vty_out(vty, "%% LUA execute error: %s%s",
+				lua_tostring(ms->lua_state, -1), VTY_NEWLINE);
+		lua_pop(ms->lua_state, 1);
+		return 3;
+	}
+
+	return 0;
+}

src/host/layer23/src/mobile/script_nolua.c

@@ -0,0 +1,36 @@
+/* (C) 2017 by Holger Hans Peter Freyther
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <osmocom/bb/common/osmocom_data.h>
+#include <osmocom/bb/common/logging.h>
+
+#include <osmocom/vty/misc.h>
+
+
+int script_lua_load(struct vty *vty, struct osmocom_ms *ms, const char *filename)
+{
+	vty_out(vty, "%% No LUA support compiled into mobile!%s", VTY_NEWLINE);
+	return -1;
+}
+
+int script_lua_close(struct osmocom_ms *ms)
+{
+	return 0;
+}

src/host/layer23/src/mobile/settings.c

@@ -24,6 +24,7 @@
 #include <string.h>
 #include <osmocom/core/talloc.h>
 
+#include <osmocom/bb/mobile/app_mobile.h>
 #include <osmocom/bb/common/logging.h>
 #include <osmocom/bb/common/osmocom_data.h>
 #include <osmocom/bb/common/networks.h>
@@ -143,6 +144,8 @@ int gsm_settings_exit(struct osmocom_ms *ms)
 		talloc_free(abbrev);
 	}
 
+	script_lua_close(ms);
+
 	return 0;
 }
 

src/host/layer23/src/mobile/vty_interface.c

@@ -1531,6 +1531,8 @@ static void config_write_ms(struct vty *vty, struct osmocom_ms *ms)
 	/* no shutdown must be written to config, because shutdown is default */
 	vty_out(vty, " %sshutdown%s", (ms->shutdown != MS_SHUTDOWN_NONE) ? "" : "no ",
 		VTY_NEWLINE);
+	if (ms->lua_script)
+		vty_out(vty, " lua-script %s%s", ms->lua_script, VTY_NEWLINE);
 	vty_out(vty, "!%s", VTY_NEWLINE);
 }
 
@@ -2740,6 +2742,30 @@ DEFUN(cfg_shutdown_force, cfg_ms_shutdown_force_cmd, "shutdown force",
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_ms_script_load_run, cfg_ms_script_load_run_cmd, "lua-script FILENAME",
+	"Load and execute a LUA script\nFilename for lua script")
+{
+	struct osmocom_ms *ms = vty->index;
+
+	osmo_talloc_replace_string(ms, &ms->lua_script, argv[0]);
+	if (!ms->lua_script)
+		return CMD_WARNING;
+
+	script_lua_load(vty, ms, ms->lua_script);
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_ms_no_script_load_run, cfg_ms_no_script_load_run_cmd, "no lua-script",
+	NO_STR "Load and execute LUA script")
+{
+	struct osmocom_ms *ms = vty->index;
+
+	script_lua_close(ms);
+	talloc_free(ms->lua_script);
+	ms->lua_script = NULL;
+	return CMD_SUCCESS;
+}
+
 int ms_vty_go_parent(struct vty *vty)
 {
 	switch (vty->node) {
@@ -2931,6 +2957,8 @@ int ms_vty_init(void)
 	install_element(MS_NODE, &cfg_ms_shutdown_cmd);
 	install_element(MS_NODE, &cfg_ms_shutdown_force_cmd);
 	install_element(MS_NODE, &cfg_ms_no_shutdown_cmd);
+	install_element(MS_NODE, &cfg_ms_script_load_run_cmd);
+	install_element(MS_NODE, &cfg_ms_no_script_load_run_cmd);
 
 	/* Register the talloc context introspection command */
 	osmo_talloc_vty_add_cmds();