1 files changed, 579 insertions, 0 deletions
diff --git a/package/uhttpd/src/uhttpd-lua.c b/package/uhttpd/src/uhttpd-lua.c
new file mode 100644
index 000000000..e11393739
--- /dev/null
+++ b/package/uhttpd/src/uhttpd-lua.c
@@ -0,0 +1,579 @@
+/*
+ * uhttpd - Tiny single-threaded httpd - Lua handler
+ *
+ *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.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"
+#include "uhttpd-utils.h"
+#include "uhttpd-lua.h"
+
+
+static int uh_lua_recv(lua_State *L)
+{
+	size_t length;
+
+	char buffer[UH_LIMIT_MSGHEAD];
+
+	int to = 1;
+	int fd = fileno(stdin);
+	int rlen = 0;
+
+	length = luaL_checknumber(L, 1);
+
+	if ((length > 0) && (length <= sizeof(buffer)))
+	{
+		/* receive data */
+		rlen = uh_raw_recv(fd, buffer, length, to);
+
+		/* data read */
+		if (rlen > 0)
+		{
+			lua_pushnumber(L, rlen);
+			lua_pushlstring(L, buffer, rlen);
+			return 2;
+		}
+
+		/* eof */
+		else if (rlen == 0)
+		{
+			lua_pushnumber(L, 0);
+			return 1;
+		}
+
+		/* no, timeout and actually no data */
+		else
+		{
+			lua_pushnumber(L, -1);
+			return 1;
+		}
+	}
+
+	/* parameter error */
+	lua_pushnumber(L, -2);
+	return 1;
+}
+
+static int uh_lua_send_common(lua_State *L, bool chunked)
+{
+	size_t length;
+
+	char chunk[16];
+	const char *buffer;
+
+	int rv;
+	int to = 1;
+	int fd = fileno(stdout);
+	int slen = 0;
+
+	buffer = luaL_checklstring(L, 1, &length);
+
+	if (chunked)
+	{
+		if (length > 0)
+		{
+			snprintf(chunk, sizeof(chunk), "%X\r\n", length);
+
+			ensure_out(rv = uh_raw_send(fd, chunk, strlen(chunk), to));
+			slen += rv;
+
+			ensure_out(rv = uh_raw_send(fd, buffer, length, to));
+			slen += rv;
+
+			ensure_out(rv = uh_raw_send(fd, "\r\n", 2, to));
+			slen += rv;
+		}
+		else
+		{
+			slen = uh_raw_send(fd, "0\r\n\r\n", 5, to);
+		}
+	}
+	else
+	{
+		slen = uh_raw_send(fd, buffer, length, to);
+	}
+
+out:
+	lua_pushnumber(L, slen);
+	return 1;
+}
+
+static int uh_lua_send(lua_State *L)
+{
+	return uh_lua_send_common(L, false);
+}
+
+static int uh_lua_sendc(lua_State *L)
+{
+	return uh_lua_send_common(L, true);
+}
+
+static int uh_lua_str2str(lua_State *L, int (*xlate_func) (char *, int, const char *, int))
+{
+	size_t inlen;
+	int outlen;
+	const char *inbuf;
+	char outbuf[UH_LIMIT_MSGHEAD];
+
+	inbuf = luaL_checklstring(L, 1, &inlen);
+	outlen = (* xlate_func)(outbuf, sizeof(outbuf), inbuf, inlen);
+	if (outlen < 0)
+		luaL_error(L, "%s on URL-encode codec",
+				   (outlen==-1) ? "buffer overflow" : "malformed string");
+
+	lua_pushlstring(L, outbuf, outlen);
+	return 1;
+}
+
+static int uh_lua_urldecode(lua_State *L)
+{
+	return uh_lua_str2str( L, uh_urldecode );
+}
+
+
+static int uh_lua_urlencode(lua_State *L)
+{
+	return uh_lua_str2str( L, uh_urlencode );
+}
+
+
+lua_State * uh_lua_init(const struct config *conf)
+{
+	lua_State *L = lua_open();
+	const char *err_str = NULL;
+
+	/* Load standard libaries */
+	luaL_openlibs(L);
+
+	/* build uhttpd api table */
+	lua_newtable(L);
+
+	/* register global send and receive functions */
+	lua_pushcfunction(L, uh_lua_recv);
+	lua_setfield(L, -2, "recv");
+
+	lua_pushcfunction(L, uh_lua_send);
+	lua_setfield(L, -2, "send");
+
+	lua_pushcfunction(L, uh_lua_sendc);
+	lua_setfield(L, -2, "sendc");
+
+	lua_pushcfunction(L, uh_lua_urldecode);
+	lua_setfield(L, -2, "urldecode");
+
+	lua_pushcfunction(L, uh_lua_urlencode);
+	lua_setfield(L, -2, "urlencode");
+
+	/* Pass the document-root to the Lua handler by placing it in
+	** uhttpd.docroot.  It could alternatively be placed in env.DOCUMENT_ROOT
+	** which would more closely resemble the CGI protocol; but would mean that
+	** it is not available at the time when the handler-chunk is loaded but
+	** rather not until the handler is called, without any code savings. */
+	lua_pushstring(L, conf->docroot);
+	lua_setfield(L, -2, "docroot");
+
+	/* _G.uhttpd = { ... } */
+	lua_setfield(L, LUA_GLOBALSINDEX, "uhttpd");
+
+
+	/* load Lua handler */
+	switch (luaL_loadfile(L, conf->lua_handler))
+	{
+		case LUA_ERRSYNTAX:
+			fprintf(stderr,
+					"Lua handler contains syntax errors, unable to continue\n");
+			exit(1);
+
+		case LUA_ERRMEM:
+			fprintf(stderr,
+					"Lua handler ran out of memory, unable to continue\n");
+			exit(1);
+
+		case LUA_ERRFILE:
+			fprintf(stderr,
+					"Lua cannot open the handler script, unable to continue\n");
+			exit(1);
+
+		default:
+			/* compile Lua handler */
+			switch (lua_pcall(L, 0, 0, 0))
+			{
+				case LUA_ERRRUN:
+					err_str = luaL_checkstring(L, -1);
+					fprintf(stderr,
+							"Lua handler had runtime error, "
+							"unable to continue\n"
+							"Error: %s\n", err_str);
+					exit(1);
+
+				case LUA_ERRMEM:
+					err_str = luaL_checkstring(L, -1);
+					fprintf(stderr,
+							"Lua handler ran out of memory, "
+							"unable to continue\n"
+							"Error: %s\n", err_str);
+					exit(1);
+
+				default:
+					/* test handler function */
+					lua_getglobal(L, UH_LUA_CALLBACK);
+
+					if (! lua_isfunction(L, -1))
+					{
+						fprintf(stderr,
+								"Lua handler provides no "UH_LUA_CALLBACK"(), "
+								"unable to continue\n");
+						exit(1);
+					}
+
+					lua_pop(L, 1);
+					break;
+			}
+
+			break;
+	}
+
+	return L;
+}
+
+static void uh_lua_shutdown(struct uh_lua_state *state)
+{
+	free(state);
+}
+
+static bool uh_lua_socket_cb(struct client *cl)
+{
+	int len;
+	char buf[UH_LIMIT_MSGHEAD];
+
+	struct uh_lua_state *state = (struct uh_lua_state *)cl->priv;
+
+	/* there is unread post data waiting */
+	while (state->content_length > 0)
+	{
+		/* remaining data in http head buffer ... */
+		if (cl->httpbuf.len > 0)
+		{
+			len = min(state->content_length, cl->httpbuf.len);
+
+			D("Lua: Child(%d) feed %d HTTP buffer bytes\n", cl->proc.pid, len);
+
+			memcpy(buf, cl->httpbuf.ptr, len);
+
+			cl->httpbuf.len -= len;
+			cl->httpbuf.ptr += len;
+		}
+
+		/* read it from socket ... */
+		else
+		{
+			len = uh_tcp_recv(cl, buf, min(state->content_length, sizeof(buf)));
+
+			if ((len < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK)))
+				break;
+
+			D("Lua: Child(%d) feed %d/%d TCP socket bytes\n",
+			  cl->proc.pid, len, min(state->content_length, sizeof(buf)));
+		}
+
+		if (len)
+			state->content_length -= len;
+		else
+			state->content_length = 0;
+
+		/* ... write to Lua process */
+		len = uh_raw_send(cl->wpipe.fd, buf, len,
+						  cl->server->conf->script_timeout);
+
+		/* explicit EOF notification for the child */
+		if (state->content_length <= 0)
+			uh_ufd_remove(&cl->wpipe);
+	}
+
+	/* try to read data from child */
+	while ((len = uh_raw_recv(cl->rpipe.fd, buf, sizeof(buf), -1)) > 0)
+	{
+		/* pass through buffer to socket */
+		D("Lua: Child(%d) relaying %d normal bytes\n", cl->proc.pid, len);
+		ensure_out(uh_tcp_send(cl, buf, len));
+		state->data_sent = true;
+	}
+
+	/* got EOF or read error from child */
+	if ((len == 0) ||
+		((errno != EAGAIN) && (errno != EWOULDBLOCK) && (len == -1)))
+	{
+		D("Lua: Child(%d) presumed dead [%s]\n",
+		  cl->proc.pid, strerror(errno));
+
+		goto out;
+	}
+
+	return true;
+
+out:
+	if (!state->data_sent)
+	{
+		if (cl->timeout.pending)
+			uh_http_sendhf(cl, 502, "Bad Gateway",
+						   "The Lua process did not produce any response\n");
+		else
+			uh_http_sendhf(cl, 504, "Gateway Timeout",
+						   "The Lua process took too long to produce a "
+						   "response\n");
+	}
+
+	uh_lua_shutdown(state);
+	return false;
+}
+
+bool uh_lua_request(struct client *cl, lua_State *L)
+{
+	int i;
+	char *query_string;
+	const char *prefix = cl->server->conf->lua_prefix;
+	const char *err_str = NULL;
+
+	int rfd[2] = { 0, 0 };
+	int wfd[2] = { 0, 0 };
+
+	pid_t child;
+
+	struct uh_lua_state *state;
+	struct http_request *req = &cl->request;
+
+	int content_length = cl->httpbuf.len;
+
+
+	/* allocate state */
+	if (!(state = malloc(sizeof(*state))))
+	{
+		uh_client_error(cl, 500, "Internal Server Error", "Out of memory");
+		return false;
+	}
+
+	/* spawn pipes for me->child, child->me */
+	if ((pipe(rfd) < 0) || (pipe(wfd) < 0))
+	{
+		if (rfd[0] > 0) close(rfd[0]);
+		if (rfd[1] > 0) close(rfd[1]);
+		if (wfd[0] > 0) close(wfd[0]);
+		if (wfd[1] > 0) close(wfd[1]);
+
+		uh_client_error(cl, 500, "Internal Server Error",
+						"Failed to create pipe: %s", strerror(errno));
+
+		return false;
+	}
+
+
+	switch ((child = fork()))
+	{
+	case -1:
+		uh_client_error(cl, 500, "Internal Server Error",
+						"Failed to fork child: %s", strerror(errno));
+
+		return false;
+
+	case 0:
+#ifdef DEBUG
+		sleep(atoi(getenv("UHTTPD_SLEEP_ON_FORK") ?: "0"));
+#endif
+
+		/* do not leak parent epoll descriptor */
+		uloop_done();
+
+		/* close loose pipe ends */
+		close(rfd[0]);
+		close(wfd[1]);
+
+		/* patch stdout and stdin to pipes */
+		dup2(rfd[1], 1);
+		dup2(wfd[0], 0);
+
+		/* avoid leaking our pipe into child-child processes */
+		fd_cloexec(rfd[1]);
+		fd_cloexec(wfd[0]);
+
+		/* put handler callback on stack */
+		lua_getglobal(L, UH_LUA_CALLBACK);
+
+		/* build env table */
+		lua_newtable(L);
+
+		/* request method */
+		lua_pushstring(L, http_methods[req->method]);
+		lua_setfield(L, -2, "REQUEST_METHOD");
+
+		/* request url */
+		lua_pushstring(L, req->url);
+		lua_setfield(L, -2, "REQUEST_URI");
+
+		/* script name */
+		lua_pushstring(L, cl->server->conf->lua_prefix);
+		lua_setfield(L, -2, "SCRIPT_NAME");
+
+		/* query string, path info */
+		if ((query_string = strchr(req->url, '?')) != NULL)
+		{
+			lua_pushstring(L, query_string + 1);
+			lua_setfield(L, -2, "QUERY_STRING");
+
+			if ((int)(query_string - req->url) > strlen(prefix))
+			{
+				lua_pushlstring(L,
+					&req->url[strlen(prefix)],
+					(int)(query_string - req->url) - strlen(prefix)
+				);
+
+				lua_setfield(L, -2, "PATH_INFO");
+			}
+		}
+		else if (strlen(req->url) > strlen(prefix))
+		{
+			lua_pushstring(L, &req->url[strlen(prefix)]);
+			lua_setfield(L, -2, "PATH_INFO");
+		}
+
+		/* http protcol version */
+		lua_pushnumber(L, 0.9 + (req->version / 10.0));
+		lua_setfield(L, -2, "HTTP_VERSION");
+
+		lua_pushstring(L, http_versions[req->version]);
+		lua_setfield(L, -2, "SERVER_PROTOCOL");
+
+
+		/* address information */
+		lua_pushstring(L, sa_straddr(&cl->peeraddr));
+		lua_setfield(L, -2, "REMOTE_ADDR");
+
+		lua_pushinteger(L, sa_port(&cl->peeraddr));
+		lua_setfield(L, -2, "REMOTE_PORT");
+
+		lua_pushstring(L, sa_straddr(&cl->servaddr));
+		lua_setfield(L, -2, "SERVER_ADDR");
+
+		lua_pushinteger(L, sa_port(&cl->servaddr));
+		lua_setfield(L, -2, "SERVER_PORT");
+
+		/* essential env vars */
+		foreach_header(i, req->headers)
+		{
+			if (!strcasecmp(req->headers[i], "Content-Length"))
+			{
+				content_length = atoi(req->headers[i+1]);
+			}
+			else if (!strcasecmp(req->headers[i], "Content-Type"))
+			{
+				lua_pushstring(L, req->headers[i+1]);
+				lua_setfield(L, -2, "CONTENT_TYPE");
+			}
+		}
+
+		lua_pushnumber(L, content_length);
+		lua_setfield(L, -2, "CONTENT_LENGTH");
+
+		/* misc. headers */
+		lua_newtable(L);
+
+		foreach_header(i, req->headers)
+		{
+			if( strcasecmp(req->headers[i], "Content-Length") &&
+				strcasecmp(req->headers[i], "Content-Type"))
+			{
+				lua_pushstring(L, req->headers[i+1]);
+				lua_setfield(L, -2, req->headers[i]);
+			}
+		}
+
+		lua_setfield(L, -2, "headers");
+
+
+		/* call */
+		switch (lua_pcall(L, 1, 0, 0))
+		{
+			case LUA_ERRMEM:
+			case LUA_ERRRUN:
+				err_str = luaL_checkstring(L, -1);
+
+				if (! err_str)
+					err_str = "Unknown error";
+
+				printf("%s 500 Internal Server Error\r\n"
+					   "Connection: close\r\n"
+					   "Content-Type: text/plain\r\n"
+					   "Content-Length: %i\r\n\r\n"
+					   "Lua raised a runtime error:\n  %s\n",
+					   http_versions[req->version],
+					   31 + strlen(err_str), err_str);
+
+				break;
+
+			default:
+				break;
+		}
+
+		close(wfd[0]);
+		close(rfd[1]);
+		exit(0);
+
+		break;
+
+	/* parent; handle I/O relaying */
+	default:
+		memset(state, 0, sizeof(*state));
+
+		cl->rpipe.fd = rfd[0];
+		cl->wpipe.fd = wfd[1];
+		cl->proc.pid = child;
+
+		/* make pipe non-blocking */
+		fd_nonblock(cl->rpipe.fd);
+		fd_nonblock(cl->wpipe.fd);
+
+		/* close unneeded pipe ends */
+		close(rfd[1]);
+		close(wfd[0]);
+
+		D("Lua: Child(%d) created: rfd(%d) wfd(%d)\n", child, rfd[0], wfd[1]);
+
+		state->content_length = cl->httpbuf.len;
+
+		/* find content length */
+		if (req->method == UH_HTTP_MSG_POST)
+		{
+			foreach_header(i, req->headers)
+			{
+				if (!strcasecmp(req->headers[i], "Content-Length"))
+				{
+					state->content_length = atoi(req->headers[i+1]);
+					break;
+				}
+			}
+		}
+
+		cl->cb = uh_lua_socket_cb;
+		cl->priv = state;
+
+		break;
+	}
+
+	return true;
+}
+
+void uh_lua_close(lua_State *L)
+{
+	lua_close(L);
+}