openwrt/package/uci/patches/120-uci_trigger.patch

--- /dev/null
+++ b/trigger/Makefile
@@ -0,0 +1,44 @@
+include ../Makefile.inc
+LUA_VERSION=5.1
+PREFIX_SEARCH=/usr /usr/local /opt/local
+LUA_PLUGINDIR=$(firstword \
+	$(foreach ldir,$(subst ;, ,$(shell lua -e 'print(package.cpath)')), \
+		$(if $(findstring lib/lua/,$(ldir)),$(patsubst %/?.so,%,$(ldir))) \
+	) \
+)
+
+# find lua prefix
+LUA_PREFIX=$(firstword \
+	$(foreach prefix,$(PREFIX_SEARCH),\
+		$(if $(wildcard $(prefix)/include/lua.h),$(prefix)) \
+	) \
+)
+
+libdir=$(prefix)/libs
+luadir=$(if $(LUA_PLUGINDIR),$(LUA_PLUGINDIR),$(libdir)/lua/$(LUA_VERSION))
+luainc=$(shell pkg-config --silence-errors --cflags lua$(LUA_VERSION))
+
+CPPFLAGS=-I.. $(if $(luainc),$(luainc), -I$(LUA_PREFIX)/include)
+LIBS=-L.. -luci $(shell pkg-config --silence-errors --libs lua$(LUA_VERSION))
+
+PLUGIN_LD=$(CC)
+ifeq ($(OS),Darwin)
+  PLUGIN_LDFLAGS=-bundle
+else
+  PLUGIN_LDFLAGS=-shared -Wl,-soname,$(SHLIB_FILE)
+endif
+
+all: uci_trigger.so
+
+uci_trigger.so: uci_trigger.o
+	$(PLUGIN_LD) $(PLUGIN_LDFLAGS) -o $@ $^ $(LIBS)
+
+%.o: %.c
+	$(CC) $(CPPFLAGS) $(CFLAGS) $(FPIC) -c -o $@ $<
+
+install:
+	mkdir -p $(DESTDIR)$(luadir)
+	$(INSTALL) -m0644 uci_trigger.so $(DESTDIR)$(luadir)/
+
+clean:
+	rm -f *.so *.o uci_trigger.so
--- /dev/null
+++ b/trigger/uci_trigger.c
@@ -0,0 +1,132 @@
+#include <sys/types.h>
+#include <sys/time.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdio.h>
+#include <lualib.h>
+#include <lauxlib.h>
+#include "uci.h"
+
+// #define DEBUG
+
+static int refcount = 0;
+static lua_State *gL = NULL;
+static bool prepared = false;
+
+struct trigger_set_op {
+	struct uci_package *p;
+	struct uci_delta *h;
+};
+
+static int trigger_set(lua_State *L)
+{
+	struct trigger_set_op *so =
+		(struct trigger_set_op *)lua_touserdata(L, 1);
+	struct uci_package *p = so->p;
+	struct uci_delta *h = so->h;
+	struct uci_context *ctx = p->ctx;
+
+	/* ignore non-standard savedirs/configdirs
+	 * in order to not trigger events on uci state changes */
+	if (strcmp(ctx->savedir, UCI_SAVEDIR) ||
+		strcmp(ctx->confdir, UCI_CONFDIR))
+		return 0;
+
+	if (!prepared) {
+		lua_getglobal(L, "require");
+		lua_pushstring(L, "uci.trigger");
+		lua_call(L, 1, 0);
+
+		lua_getglobal(L, "uci");
+		lua_getfield(L, -1, "trigger");
+		lua_getfield(L, -1, "load_modules");
+		lua_call(L, 0, 0);
+		prepared = true;
+	} else {
+		lua_getglobal(L, "uci");
+		lua_getfield(L, -1, "trigger");
+	}
+
+	lua_getfield(L, -1, "set");
+	lua_createtable(L, 4, 0);
+
+	lua_pushstring(L, p->e.name);
+	lua_rawseti(L, -2, 1);
+	if (h->section) {
+		lua_pushstring(L, h->section);
+		lua_rawseti(L, -2, 2);
+	}
+	if (h->e.name) {
+		lua_pushstring(L, h->e.name);
+		lua_rawseti(L, -2, 3);
+	}
+	if (h->value) {
+		lua_pushstring(L, h->value);
+		lua_rawseti(L, -2, 4);
+	}
+	lua_call(L, 1, 0);
+	lua_pop(L, 2);
+	return 0;
+}
+
+#ifdef DEBUG
+
+static int report (lua_State *L, int status) {
+	if (status && !lua_isnil(L, -1)) {
+		const char *msg = lua_tostring(L, -1);
+		if (msg == NULL) msg = "(error object is not a string)";
+		fprintf(stderr, "ERROR: %s\n", msg);
+		lua_pop(L, 1);
+	}
+	return status;
+}
+
+#else
+
+static inline int report(lua_State *L, int status) {
+	return status;
+}
+
+#endif
+
+static void trigger_set_hook(const struct uci_hook_ops *ops, struct uci_package *p, struct uci_delta *h)
+{
+	struct trigger_set_op so;
+
+	so.p = p;
+	so.h = h;
+	report(gL, lua_cpcall(gL, &trigger_set, &so));
+}
+
+static struct uci_hook_ops hook = {
+	.set = trigger_set_hook,
+};
+
+static int trigger_attach(struct uci_context *ctx)
+{
+	if (!gL) {
+		gL = luaL_newstate();
+		if (!gL)
+			return -1;
+		luaL_openlibs(gL);
+
+		refcount++;
+	}
+	uci_add_hook(ctx, &hook);
+	return 0;
+}
+
+static void trigger_detach(struct uci_context *ctx)
+{
+	if (gL && (--refcount <= 0)) {
+		lua_close(gL);
+		gL = NULL;
+		refcount = 0;
+		prepared = false;
+	}
+}
+
+struct uci_plugin_ops uci_plugin = {
+	.attach = trigger_attach,
+	.detach = trigger_detach,
+};