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

1 files changed, 146 insertions, 0 deletions

diff --git a/src/host/layer23/src/mobile/script_lua.c b/src/host/layer23/src/mobile/script_lua.c
new file mode 100644
index 00000000..b3b9c99c
--- /dev/null
+++ b/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;
+}