add lua plugin support

8 files changed, 448 insertions, 8 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d0c1b0..889c32e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,6 +5,7 @@ SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 ADD_DEFINITIONS(-Os -Wall -Werror -Wmissing-declarations --std=gnu99 -g3)
 
 OPTION(TLS_SUPPORT "TLS support" ON)
+OPTION(LUA_SUPPORT "Lua support" ON)
 
 IF(APPLE)
   INCLUDE_DIRECTORIES(/opt/local/include)
@@ -16,7 +17,7 @@ IF(LIBS STREQUAL "LIBS-NOTFOUND")
 	SET(LIBS "")
 ENDIF()
 
-SET(SOURCES main.c listen.c client.c utils.c file.c auth.c cgi.c relay.c proc.c)
+SET(SOURCES main.c listen.c client.c utils.c file.c auth.c cgi.c relay.c proc.c plugin.c)
 IF(TLS_SUPPORT)
 	SET(SOURCES ${SOURCES} tls.c)
 	ADD_DEFINITIONS(-DHAVE_TLS)
@@ -24,3 +25,44 @@ ENDIF()
 
 ADD_EXECUTABLE(uhttpd ${SOURCES})
 TARGET_LINK_LIBRARIES(uhttpd ubox dl ${LIBS})
+
+SET(PLUGINS "")
+IF(LUA_SUPPORT)
+	FIND_PROGRAM(PKG_CONFIG pkg-config)
+
+	IF(NOT LUA_CFLAGS AND PKG_CONFIG)
+		EXECUTE_PROCESS(
+			COMMAND pkg-config --silence-errors --cflags lua5.1
+			OUTPUT_VARIABLE LUA_CFLAGS
+			OUTPUT_STRIP_TRAILING_WHITESPACE
+		)
+	ENDIF()
+
+	IF(NOT LUA_LIBS AND PKG_CONFIG)
+		EXECUTE_PROCESS(
+			COMMAND pkg-config --silence-errors --libs lua5.1
+			OUTPUT_VARIABLE LUA_LIBS
+			OUTPUT_STRIP_TRAILING_WHITESPACE
+		)
+	ENDIF()
+
+	IF(NOT LUA_LIBS)
+		SET(LUA_LIBS "lua")
+	ENDIF()
+
+	SET(PLUGINS ${PLUGINS} uhttpd_lua)
+	ADD_DEFINITIONS(-DHAVE_LUA ${LUA_CFLAGS})
+	ADD_LIBRARY(uhttpd_lua MODULE lua.c)
+	TARGET_LINK_LIBRARIES(uhttpd_lua ${LUA_LIBS} m dl)
+ENDIF()
+
+IF(PLUGINS)
+	SET_TARGET_PROPERTIES(${PLUGINS} PROPERTIES
+		PREFIX ""
+	)
+ENDIF()
+
+INSTALL(TARGETS uhttpd ${PLUGINS}
+	RUNTIME DESTINATION bin
+	LIBRARY DESTINATION lib
+)
diff --git a/cgi.c b/cgi.c
index ad280cd..2b7cffb 100644
--- a/cgi.c
+++ b/cgi.c
@@ -36,7 +36,7 @@ void uh_interpreter_add(const char *ext, const char *path)
 	list_add_tail(&in->list, &interpreters);
 }
 
-static void cgi_main(struct client *cl, struct path_info *pi)
+static void cgi_main(struct client *cl, struct path_info *pi, const char *url)
 {
 	const struct interpreter *ip = pi->ip;
 	struct env_var *var;
@@ -74,7 +74,7 @@ static void cgi_handle_request(struct client *cl, const char *url, struct path_i
 		return;
 	}
 
-	if (!uh_create_process(cl, pi, cgi_main)) {
+	if (!uh_create_process(cl, pi, url, cgi_main)) {
 		uh_client_error(cl, 500, "Internal Server Error",
 				"Failed to create CGI process: %s", strerror(errno));
 		return;
diff --git a/lua.c b/lua.c
new file mode 100644
index 0000000..e404add
--- /dev/null
+++ b/lua.c
@@ -0,0 +1,280 @@
+/*
+ * uhttpd - Tiny single-threaded httpd
+ *
+ *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
+ *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+
+#include <libubox/blobmsg.h>
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+#include <stdio.h>
+#include <poll.h>
+
+#include "uhttpd.h"
+#include "plugin.h"
+
+#define UH_LUA_CB	"handle_request"
+
+static const struct uhttpd_ops *ops;
+static struct config *_conf;
+#define conf (*_conf)
+
+static lua_State *_L;
+
+static int uh_lua_recv(lua_State *L)
+{
+	static struct pollfd pfd = {
+		.fd = STDIN_FILENO,
+		.events = POLLIN,
+	};
+	luaL_Buffer B;
+	int data_len = 0;
+	int len;
+	int r;
+
+	len = luaL_checknumber(L, 1);
+	luaL_buffinit(L, &B);
+	while(len > 0) {
+		char *buf;
+
+		buf = luaL_prepbuffer(&B);
+		r = read(STDIN_FILENO, buf, LUAL_BUFFERSIZE);
+		if (r < 0) {
+			if (errno == EWOULDBLOCK || errno == EAGAIN) {
+				pfd.revents = 0;
+				poll(&pfd, 1, 1000);
+				if (pfd.revents & POLLIN)
+					continue;
+			}
+			if (errno == EINTR)
+				continue;
+
+			if (!data_len)
+				data_len = -1;
+			break;
+		}
+		if (!r)
+			break;
+
+		luaL_addsize(&B, r);
+		data_len += r;
+		if (r != LUAL_BUFFERSIZE)
+			break;
+	}
+
+	luaL_pushresult(&B);
+	lua_pushnumber(L, data_len);
+	if (data_len > 0) {
+		lua_pushvalue(L, -2);
+		lua_remove(L, -3);
+		return 2;
+	} else {
+		lua_remove(L, -2);
+		return 1;
+	}
+}
+
+static int
+uh_lua_strconvert(lua_State *L, int (*convert)(char *, int, const char *, int))
+{
+	const char *in_buf;
+	static char out_buf[4096];
+	size_t in_len;
+	int out_len;
+
+	in_buf = luaL_checklstring(L, 1, &in_len);
+	out_len = convert(out_buf, sizeof(out_buf), in_buf, in_len);
+
+	if (out_len < 0) {
+		const char *error;
+
+		if (out_len == -1)
+			error = "buffer overflow";
+		else
+			error = "malformed string";
+
+		luaL_error(L, "%s on URL conversion\n", error);
+	}
+
+	lua_pushlstring(L, out_buf, out_len);
+	return 1;
+}
+
+static int uh_lua_urldecode(lua_State *L)
+{
+	return uh_lua_strconvert(L, ops->urldecode);
+}
+
+static int uh_lua_urlencode(lua_State *L)
+{
+	return uh_lua_strconvert(L, ops->urlencode);
+}
+
+static lua_State *uh_lua_state_init(void)
+{
+	const char *msg = "(unknown error)";
+	const char *status;
+	lua_State *L;
+	int ret;
+
+	L = lua_open();
+	luaL_openlibs(L);
+
+	/* build uhttpd api table */
+	lua_newtable(L);
+
+	/* 
+	 * use print as send and sendc implementation,
+	 * chunked transfer is handled in the main server
+	 */
+	lua_getglobal(L, "print");
+	lua_pushvalue(L, -1);
+	lua_setfield(L, -3, "send");
+	lua_setfield(L, -2, "sendc");
+
+	lua_pushcfunction(L, uh_lua_recv);
+	lua_setfield(L, -2, "recv");
+
+	lua_pushcfunction(L, uh_lua_urldecode);
+	lua_setfield(L, -2, "urldecode");
+
+	lua_pushcfunction(L, uh_lua_urlencode);
+	lua_setfield(L, -2, "urlencode");
+
+	lua_pushstring(L, conf.docroot);
+	lua_setfield(L, -2, "docroot");
+
+	lua_setglobal(L, "uhttpd");
+
+	ret = luaL_loadfile(L, conf.lua_handler);
+	if (ret) {
+		status = "loading";
+		goto error;
+	}
+
+	ret = lua_pcall(L, 0, 0, 0);
+	if (ret) {
+		status = "initializing";
+		goto error;
+	}
+
+	lua_getglobal(L, UH_LUA_CB);
+	if (!lua_isfunction(L, -1)) {
+		fprintf(stderr, "Error: Lua handler provides no " UH_LUA_CB "() callback.\n");
+		exit(1);
+	}
+
+	return L;
+
+error:
+	if (!lua_isnil(L, -1))
+		msg = lua_tostring(L, -1);
+
+	fprintf(stderr, "Error %s Lua handler: %s\n", status, msg);
+	exit(1);
+	return NULL;
+}
+
+static void lua_main(struct client *cl, struct path_info *pi, const char *url)
+{
+	const char *error;
+	struct env_var *var;
+	lua_State *L = _L;
+	int path_len, prefix_len;
+	char *str;
+
+	lua_getglobal(L, UH_LUA_CB);
+
+	/* new env table for this request */
+	lua_newtable(L);
+
+	prefix_len = strlen(conf.lua_prefix);
+	path_len = strlen(url);
+	str = strchr(url, '?');
+	if (str) {
+		pi->query = str;
+		path_len = str - url;
+	}
+	if (path_len > prefix_len) {
+		lua_pushlstring(L, url + prefix_len,
+				path_len - prefix_len);
+		lua_setfield(L, -2, "PATH_INFO");
+	}
+
+	for (var = ops->get_process_vars(cl, pi); var->name; var++) {
+		if (!var->value)
+			continue;
+
+		lua_pushstring(L, var->value);
+		lua_setfield(L, -2, var->name);
+	}
+
+	lua_pushnumber(L, 0.9 + (cl->request.version / 10.0));
+	lua_setfield(L, -2, "HTTP_VERSION");
+
+	switch(lua_pcall(L, 1, 0, 0)) {
+	case LUA_ERRMEM:
+	case LUA_ERRRUN:
+		error = luaL_checkstring(L, -1);
+		if (!error)
+			error = "(unknown error)";
+
+		printf("Status: 500 Internal Server Error\r\n\r\n"
+	       "Unable to launch the requested Lua program:\n"
+	       "  %s: %s\n", pi->phys, strerror(errno));
+	}
+
+	exit(0);
+}
+
+static void lua_handle_request(struct client *cl, const char *url, struct path_info *pi)
+{
+	static struct path_info _pi;
+
+	pi = &_pi;
+	pi->name = conf.lua_prefix;
+	pi->phys = conf.lua_handler;
+
+	if (!ops->create_process(cl, pi, url, lua_main)) {
+		ops->client_error(cl, 500, "Internal Server Error",
+				  "Failed to create CGI process: %s", strerror(errno));
+	}
+}
+
+static bool check_lua_url(const char *url)
+{
+	return ops->path_match(conf.lua_prefix, url);
+}
+
+static struct dispatch_handler lua_dispatch = {
+	.check_url = check_lua_url,
+	.handle_request = lua_handle_request,
+};
+
+static int lua_plugin_init(const struct uhttpd_ops *o, struct config *c)
+{
+	ops = o;
+	_conf = c;
+	_L = uh_lua_state_init();
+	ops->dispatch_add(&lua_dispatch);
+	return 0;
+}
+
+const struct uhttpd_plugin uhttpd_plugin = {
+	.init = lua_plugin_init,
+};
diff --git a/main.c b/main.c
index 160f932..cefd4ab 100644
--- a/main.c
+++ b/main.c
@@ -329,6 +329,15 @@ int main(int argc, char **argv)
 		case 'K':
 			tls_key = optarg;
 			break;
+#ifdef HAVE_LUA
+		case 'l':
+			conf.lua_prefix = optarg;
+			break;
+
+		case 'L':
+			conf.lua_handler = optarg;
+			break;
+#endif
 		default:
 			return usage(argv[0]);
 		}
@@ -357,6 +366,17 @@ int main(int argc, char **argv)
 #endif
 	}
 
+#ifdef HAVE_LUA
+	if (conf.lua_handler || conf.lua_prefix) {
+		if (!conf.lua_handler || !conf.lua_prefix) {
+			fprintf(stderr, "Need handler and prefix to enable Lua support\n");
+			return 1;
+		}
+		if (uh_plugin_init("uhttpd_lua.so"))
+			return 1;
+	}
+#endif
+
 	/* fork (if not disabled) */
 	if (!nofork) {
 		switch (fork()) {
diff --git a/plugin.c b/plugin.c
new file mode 100644
index 0000000..25a8464
--- /dev/null
+++ b/plugin.c
@@ -0,0 +1,55 @@
+/*
+ * uhttpd - Tiny single-threaded httpd - Main header
+ *
+ *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
+ *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <dlfcn.h>
+#include "uhttpd.h"
+#include "plugin.h"
+
+static const struct uhttpd_ops ops = {
+	.dispatch_add = uh_dispatch_add,
+	.path_match = uh_path_match,
+	.create_process = uh_create_process,
+	.get_process_vars = uh_get_process_vars,
+	.client_error = uh_client_error,
+	.chunk_write = uh_chunk_write,
+	.urlencode = uh_urlencode,
+	.urldecode = uh_urldecode,
+};
+
+int uh_plugin_init(const char *name)
+{
+	struct uhttpd_plugin *p;
+	const char *sym;
+	void *dlh;
+
+	dlh = dlopen(name, RTLD_LAZY | RTLD_LOCAL);
+	if (!dlh) {
+		fprintf(stderr, "Could not open plugin %s: %s\n", name, dlerror());
+		return -ENOENT;
+	}
+
+	sym = "uhttpd_plugin";
+	p = dlsym(dlh, sym);
+	if (!p) {
+		fprintf(stderr, "Could not find symbol '%s' in plugin '%s'\n", sym, name);
+		return -ENOENT;
+	}
+
+	return p->init(&ops, &conf);
+}
diff --git a/plugin.h b/plugin.h
new file mode 100644
index 0000000..dd73c57
--- /dev/null
+++ b/plugin.h
@@ -0,0 +1,39 @@
+/*
+ * uhttpd - Tiny single-threaded httpd - Main header
+ *
+ *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
+ *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "uhttpd.h"
+
+struct uhttpd_ops {
+	void (*dispatch_add)(struct dispatch_handler *d);
+	bool (*path_match)(const char *prefix, const char *url);
+
+	bool (*create_process)(struct client *cl, struct path_info *pi, const char *url,
+			       void (*cb)(struct client *cl, struct path_info *pi, const char *url));
+	struct env_var *(*get_process_vars)(struct client *cl, struct path_info *pi);
+
+	void (*client_error)(struct client *cl, int code, const char *summary, const char *fmt, ...);
+	void (*chunk_write)(struct client *cl, const void *data, int len);
+
+	int (*urlencode)(char *buf, int blen, const char *src, int slen);
+	int (*urldecode)(char *buf, int blen, const char *src, int slen);
+};
+
+struct uhttpd_plugin {
+	int (*init)(const struct uhttpd_ops *ops, struct config *conf);
+};
diff --git a/proc.c b/proc.c
index ad15abb..8680d01 100644
--- a/proc.c
+++ b/proc.c
@@ -296,8 +296,8 @@ static int proc_data_send(struct client *cl, const char *data, int len)
 	return retlen;
 }
 
-bool uh_create_process(struct client *cl, struct path_info *pi,
-		       void (*cb)(struct client *cl, struct path_info *pi))
+bool uh_create_process(struct client *cl, struct path_info *pi, const char *url,
+		       void (*cb)(struct client *cl, struct path_info *pi, const char *url))
 {
 	struct dispatch *d = &cl->dispatch;
 	struct dispatch_proc *proc = &d->proc;
@@ -331,7 +331,7 @@ bool uh_create_process(struct client *cl, struct path_info *pi,
 		close(wfd[1]);
 
 		uh_close_fds();
-		cb(cl, pi);
+		cb(cl, pi, url);
 		exit(0);
 	}
 
diff --git a/uhttpd.h b/uhttpd.h
index 9ed6439..b8dfece 100644
--- a/uhttpd.h
+++ b/uhttpd.h
@@ -49,6 +49,8 @@ struct config {
 	const char *error_handler;
 	const char *cgi_prefix;
 	const char *cgi_path;
+	const char *lua_handler;
+	const char *lua_prefix;
 	int no_symlinks;
 	int no_dirlists;
 	int network_timeout;
@@ -235,7 +237,9 @@ void uh_relay_close(struct relay *r, int ret);
 void uh_relay_free(struct relay *r);
 
 struct env_var *uh_get_process_vars(struct client *cl, struct path_info *pi);
-bool uh_create_process(struct client *cl, struct path_info *pi,
-		       void (*cb)(struct client *cl, struct path_info *pi));
+bool uh_create_process(struct client *cl, struct path_info *pi, const char *url,
+		       void (*cb)(struct client *cl, struct path_info *pi, const char *url));
+
+int uh_plugin_init(const char *name);
 
 #endif