2 * uhttpd - Tiny single-threaded httpd - Lua handler
4 * Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
20 #include "uhttpd-utils.h"
21 #include "uhttpd-lua.h"
24 static int uh_lua_recv(lua_State *L)
28 char buffer[UH_LIMIT_MSGHEAD];
31 int fd = fileno(stdin);
34 length = luaL_checknumber(L, 1);
36 if ((length > 0) && (length <= sizeof(buffer)))
39 rlen = uh_raw_recv(fd, buffer, length, to);
44 lua_pushnumber(L, rlen);
45 lua_pushlstring(L, buffer, rlen);
56 /* no, timeout and actually no data */
59 lua_pushnumber(L, -1);
65 lua_pushnumber(L, -2);
69 static int uh_lua_send_common(lua_State *L, int chunked)
78 int fd = fileno(stdout);
81 buffer = luaL_checklstring(L, 1, &length);
87 snprintf(chunk, sizeof(chunk), "%X\r\n", length);
89 ensure_out(rv = uh_raw_send(fd, chunk, strlen(chunk), to));
92 ensure_out(rv = uh_raw_send(fd, buffer, length, to));
95 ensure_out(rv = uh_raw_send(fd, "\r\n", 2, to));
100 slen = uh_raw_send(fd, "0\r\n\r\n", 5, to);
105 slen = uh_raw_send(fd, buffer, length, to);
109 lua_pushnumber(L, slen);
113 static int uh_lua_send(lua_State *L)
115 return uh_lua_send_common(L, 0);
118 static int uh_lua_sendc(lua_State *L)
120 return uh_lua_send_common(L, 1);
123 static int uh_lua_str2str(lua_State *L, int (*xlate_func) (char *, int, const char *, int))
128 char outbuf[UH_LIMIT_MSGHEAD];
130 inbuf = luaL_checklstring(L, 1, &inlen);
131 outlen = (* xlate_func)(outbuf, sizeof(outbuf), inbuf, inlen);
133 luaL_error(L, "%s on URL-encode codec",
134 (outlen==-1) ? "buffer overflow" : "malformed string");
136 lua_pushlstring(L, outbuf, outlen);
140 static int uh_lua_urldecode(lua_State *L)
142 return uh_lua_str2str( L, uh_urldecode );
146 static int uh_lua_urlencode(lua_State *L)
148 return uh_lua_str2str( L, uh_urlencode );
152 lua_State * uh_lua_init(const struct config *conf)
154 lua_State *L = lua_open();
155 const char *err_str = NULL;
157 /* Load standard libaries */
160 /* build uhttpd api table */
163 /* register global send and receive functions */
164 lua_pushcfunction(L, uh_lua_recv);
165 lua_setfield(L, -2, "recv");
167 lua_pushcfunction(L, uh_lua_send);
168 lua_setfield(L, -2, "send");
170 lua_pushcfunction(L, uh_lua_sendc);
171 lua_setfield(L, -2, "sendc");
173 lua_pushcfunction(L, uh_lua_urldecode);
174 lua_setfield(L, -2, "urldecode");
176 lua_pushcfunction(L, uh_lua_urlencode);
177 lua_setfield(L, -2, "urlencode");
179 /* Pass the document-root to the Lua handler by placing it in
180 ** uhttpd.docroot. It could alternatively be placed in env.DOCUMENT_ROOT
181 ** which would more closely resemble the CGI protocol; but would mean that
182 ** it is not available at the time when the handler-chunk is loaded but
183 ** rather not until the handler is called, without any code savings. */
184 lua_pushstring(L, conf->docroot);
185 lua_setfield(L, -2, "docroot");
187 /* _G.uhttpd = { ... } */
188 lua_setfield(L, LUA_GLOBALSINDEX, "uhttpd");
191 /* load Lua handler */
192 switch (luaL_loadfile(L, conf->lua_handler))
196 "Lua handler contains syntax errors, unable to continue\n");
201 "Lua handler ran out of memory, unable to continue\n");
206 "Lua cannot open the handler script, unable to continue\n");
210 /* compile Lua handler */
211 switch (lua_pcall(L, 0, 0, 0))
214 err_str = luaL_checkstring(L, -1);
216 "Lua handler had runtime error, "
217 "unable to continue\n"
218 "Error: %s\n", err_str);
222 err_str = luaL_checkstring(L, -1);
224 "Lua handler ran out of memory, "
225 "unable to continue\n"
226 "Error: %s\n", err_str);
230 /* test handler function */
231 lua_getglobal(L, UH_LUA_CALLBACK);
233 if (! lua_isfunction(L, -1))
236 "Lua handler provides no "UH_LUA_CALLBACK"(), "
237 "unable to continue\n");
251 static void uh_lua_shutdown(struct uh_lua_state *state)
256 static bool uh_lua_socket_cb(struct client *cl)
259 char buf[UH_LIMIT_MSGHEAD];
261 struct uh_lua_state *state = (struct uh_lua_state *)cl->priv;
263 /* there is unread post data waiting */
264 while (state->content_length > 0)
266 /* remaining data in http head buffer ... */
267 if (cl->httpbuf.len > 0)
269 len = min(state->content_length, cl->httpbuf.len);
271 D("Lua: Child(%d) feed %d HTTP buffer bytes\n", cl->proc.pid, len);
273 memcpy(buf, cl->httpbuf.ptr, len);
275 cl->httpbuf.len -= len;
276 cl->httpbuf.ptr += len;
279 /* read it from socket ... */
282 len = uh_tcp_recv(cl, buf, min(state->content_length, sizeof(buf)));
284 if ((len < 0) && ((errno == EAGAIN) || (errno == EWOULDBLOCK)))
287 D("Lua: Child(%d) feed %d/%d TCP socket bytes\n",
288 cl->proc.pid, len, min(state->content_length, sizeof(buf)));
292 state->content_length -= len;
294 state->content_length = 0;
296 /* ... write to Lua process */
297 len = uh_raw_send(cl->wpipe.fd, buf, len,
298 cl->server->conf->script_timeout);
300 /* explicit EOF notification for the child */
301 if (state->content_length <= 0)
302 uh_ufd_remove(&cl->wpipe);
305 /* try to read data from child */
306 while ((len = uh_raw_recv(cl->rpipe.fd, buf, sizeof(buf), -1)) > 0)
308 /* pass through buffer to socket */
309 D("Lua: Child(%d) relaying %d normal bytes\n", cl->proc.pid, len);
310 ensure_out(uh_tcp_send(cl, buf, len));
311 state->data_sent = true;
314 /* got EOF or read error from child */
316 ((errno != EAGAIN) && (errno != EWOULDBLOCK) && (len == -1)))
318 D("Lua: Child(%d) presumed dead [%s]\n",
319 cl->proc.pid, strerror(errno));
327 if (!state->data_sent)
329 if (cl->timeout.pending)
330 uh_http_sendhf(cl, 502, "Bad Gateway",
331 "The Lua process did not produce any response\n");
333 uh_http_sendhf(cl, 504, "Gateway Timeout",
334 "The Lua process took too long to produce a "
338 uh_lua_shutdown(state);
342 bool uh_lua_request(struct client *cl, lua_State *L)
346 const char *prefix = cl->server->conf->lua_prefix;
347 const char *err_str = NULL;
349 int rfd[2] = { 0, 0 };
350 int wfd[2] = { 0, 0 };
354 struct uh_lua_state *state;
355 struct http_request *req = &cl->request;
357 int content_length = cl->httpbuf.len;
361 if (!(state = malloc(sizeof(*state))))
363 uh_client_error(cl, 500, "Internal Server Error", "Out of memory");
367 /* spawn pipes for me->child, child->me */
368 if ((pipe(rfd) < 0) || (pipe(wfd) < 0))
370 if (rfd[0] > 0) close(rfd[0]);
371 if (rfd[1] > 0) close(rfd[1]);
372 if (wfd[0] > 0) close(wfd[0]);
373 if (wfd[1] > 0) close(wfd[1]);
375 uh_client_error(cl, 500, "Internal Server Error",
376 "Failed to create pipe: %s", strerror(errno));
382 switch ((child = fork()))
385 uh_client_error(cl, 500, "Internal Server Error",
386 "Failed to fork child: %s", strerror(errno));
392 sleep(atoi(getenv("UHTTPD_SLEEP_ON_FORK") ?: "0"));
395 /* do not leak parent epoll descriptor */
398 /* close loose pipe ends */
402 /* patch stdout and stdin to pipes */
406 /* avoid leaking our pipe into child-child processes */
410 /* put handler callback on stack */
411 lua_getglobal(L, UH_LUA_CALLBACK);
413 /* build env table */
419 case UH_HTTP_MSG_GET:
420 lua_pushstring(L, "GET");
423 case UH_HTTP_MSG_HEAD:
424 lua_pushstring(L, "HEAD");
427 case UH_HTTP_MSG_POST:
428 lua_pushstring(L, "POST");
432 lua_setfield(L, -2, "REQUEST_METHOD");
435 lua_pushstring(L, req->url);
436 lua_setfield(L, -2, "REQUEST_URI");
439 lua_pushstring(L, cl->server->conf->lua_prefix);
440 lua_setfield(L, -2, "SCRIPT_NAME");
442 /* query string, path info */
443 if ((query_string = strchr(req->url, '?')) != NULL)
445 lua_pushstring(L, query_string + 1);
446 lua_setfield(L, -2, "QUERY_STRING");
448 if ((int)(query_string - req->url) > strlen(prefix))
451 &req->url[strlen(prefix)],
452 (int)(query_string - req->url) - strlen(prefix)
455 lua_setfield(L, -2, "PATH_INFO");
458 else if (strlen(req->url) > strlen(prefix))
460 lua_pushstring(L, &req->url[strlen(prefix)]);
461 lua_setfield(L, -2, "PATH_INFO");
464 /* http protcol version */
465 lua_pushnumber(L, floor(req->version * 10) / 10);
466 lua_setfield(L, -2, "HTTP_VERSION");
468 if (req->version > 1.0)
469 lua_pushstring(L, "HTTP/1.1");
471 lua_pushstring(L, "HTTP/1.0");
473 lua_setfield(L, -2, "SERVER_PROTOCOL");
476 /* address information */
477 lua_pushstring(L, sa_straddr(&cl->peeraddr));
478 lua_setfield(L, -2, "REMOTE_ADDR");
480 lua_pushinteger(L, sa_port(&cl->peeraddr));
481 lua_setfield(L, -2, "REMOTE_PORT");
483 lua_pushstring(L, sa_straddr(&cl->servaddr));
484 lua_setfield(L, -2, "SERVER_ADDR");
486 lua_pushinteger(L, sa_port(&cl->servaddr));
487 lua_setfield(L, -2, "SERVER_PORT");
489 /* essential env vars */
490 foreach_header(i, req->headers)
492 if (!strcasecmp(req->headers[i], "Content-Length"))
494 content_length = atoi(req->headers[i+1]);
496 else if (!strcasecmp(req->headers[i], "Content-Type"))
498 lua_pushstring(L, req->headers[i+1]);
499 lua_setfield(L, -2, "CONTENT_TYPE");
503 lua_pushnumber(L, content_length);
504 lua_setfield(L, -2, "CONTENT_LENGTH");
509 foreach_header(i, req->headers)
511 if( strcasecmp(req->headers[i], "Content-Length") &&
512 strcasecmp(req->headers[i], "Content-Type"))
514 lua_pushstring(L, req->headers[i+1]);
515 lua_setfield(L, -2, req->headers[i]);
519 lua_setfield(L, -2, "headers");
523 switch (lua_pcall(L, 1, 0, 0))
527 err_str = luaL_checkstring(L, -1);
530 err_str = "Unknown error";
532 printf("HTTP/%.1f 500 Internal Server Error\r\n"
533 "Connection: close\r\n"
534 "Content-Type: text/plain\r\n"
535 "Content-Length: %i\r\n\r\n"
536 "Lua raised a runtime error:\n %s\n",
537 req->version, 31 + strlen(err_str), err_str);
551 /* parent; handle I/O relaying */
553 memset(state, 0, sizeof(*state));
555 cl->rpipe.fd = rfd[0];
556 cl->wpipe.fd = wfd[1];
557 cl->proc.pid = child;
559 /* make pipe non-blocking */
560 fd_nonblock(cl->rpipe.fd);
561 fd_nonblock(cl->wpipe.fd);
563 /* close unneeded pipe ends */
567 D("Lua: Child(%d) created: rfd(%d) wfd(%d)\n", child, rfd[0], wfd[1]);
569 state->content_length = cl->httpbuf.len;
571 /* find content length */
572 if (req->method == UH_HTTP_MSG_POST)
574 foreach_header(i, req->headers)
576 if (!strcasecmp(req->headers[i], "Content-Length"))
578 state->content_length = atoi(req->headers[i+1]);
584 cl->cb = uh_lua_socket_cb;
593 void uh_lua_close(lua_State *L)