2 * uhttpd - Tiny single-threaded httpd - Lua handler
4 * Copyright (C) 2010 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)
27 char buffer[UH_LIMIT_MSGHEAD];
30 struct timeval timeout;
32 length = luaL_checknumber(L, 1);
34 if( (length > 0) && (length <= sizeof(buffer)) )
37 FD_SET(fileno(stdin), &reader);
41 timeout.tv_usec = 100000;
43 /* check whether fd is readable */
44 if( select(fileno(stdin) + 1, &reader, NULL, NULL, &timeout) > 0 )
47 rlen = read(fileno(stdin), buffer, length);
48 lua_pushnumber(L, rlen);
52 lua_pushlstring(L, buffer, rlen);
59 /* no, timeout and actually no data */
60 lua_pushnumber(L, -2);
65 lua_pushnumber(L, -3);
69 static int uh_lua_send_common(lua_State *L, int chunked)
76 buffer = luaL_checklstring(L, 1, &length);
82 snprintf(chunk, sizeof(chunk), "%X\r\n", length);
83 slen = write(fileno(stdout), chunk, strlen(chunk));
84 slen += write(fileno(stdout), buffer, length);
85 slen += write(fileno(stdout), "\r\n", 2);
89 slen = write(fileno(stdout), "0\r\n\r\n", 5);
94 slen = write(fileno(stdout), buffer, length);
97 lua_pushnumber(L, slen);
101 static int uh_lua_send(lua_State *L)
103 return uh_lua_send_common(L, 0);
106 static int uh_lua_sendc(lua_State *L)
108 return uh_lua_send_common(L, 1);
111 static int uh_lua_str2str(lua_State *L, int (*xlate_func) (char *, int, const char *, int))
116 char outbuf[UH_LIMIT_MSGHEAD];
118 inbuf = luaL_checklstring(L, 1, &inlen);
119 outlen = (* xlate_func)(outbuf, sizeof(outbuf), inbuf, inlen);
121 luaL_error( L, "%s on URL-encode codec",
122 (outlen==-1) ? "buffer overflow" : "malformed string" );
124 lua_pushlstring(L, outbuf, outlen);
128 static int uh_lua_urldecode(lua_State *L)
130 return uh_lua_str2str( L, uh_urldecode );
134 static int uh_lua_urlencode(lua_State *L)
136 return uh_lua_str2str( L, uh_urlencode );
140 lua_State * uh_lua_init(const char *handler)
142 lua_State *L = lua_open();
143 const char *err_str = NULL;
145 /* Load standard libaries */
148 /* build uhttpd api table */
151 /* register global send and receive functions */
152 lua_pushcfunction(L, uh_lua_recv);
153 lua_setfield(L, -2, "recv");
155 lua_pushcfunction(L, uh_lua_send);
156 lua_setfield(L, -2, "send");
158 lua_pushcfunction(L, uh_lua_sendc);
159 lua_setfield(L, -2, "sendc");
161 lua_pushcfunction(L, uh_lua_urldecode);
162 lua_setfield(L, -2, "urldecode");
164 lua_pushcfunction(L, uh_lua_urlencode);
165 lua_setfield(L, -2, "urlencode");
167 /* _G.uhttpd = { ... } */
168 lua_setfield(L, LUA_GLOBALSINDEX, "uhttpd");
171 /* load Lua handler */
172 switch( luaL_loadfile(L, handler) )
176 "Lua handler contains syntax errors, unable to continue\n");
181 "Lua handler ran out of memory, unable to continue\n");
186 "Lua cannot open the handler script, unable to continue\n");
190 /* compile Lua handler */
191 switch( lua_pcall(L, 0, 0, 0) )
194 err_str = luaL_checkstring(L, -1);
196 "Lua handler had runtime error, unable to continue\n"
197 "Error: %s\n", err_str
202 err_str = luaL_checkstring(L, -1);
204 "Lua handler ran out of memory, unable to continue\n"
205 "Error: %s\n", err_str
210 /* test handler function */
211 lua_getglobal(L, UH_LUA_CALLBACK);
213 if( ! lua_isfunction(L, -1) )
216 "Lua handler provides no " UH_LUA_CALLBACK "(), unable to continue\n");
230 void uh_lua_request(struct client *cl, struct http_request *req, lua_State *L)
233 int content_length = 0;
237 const char *prefix = cl->server->conf->lua_prefix;
238 const char *err_str = NULL;
240 int rfd[2] = { 0, 0 };
241 int wfd[2] = { 0, 0 };
243 char buf[UH_LIMIT_MSGHEAD];
251 struct timeval timeout;
254 /* spawn pipes for me->child, child->me */
255 if( (pipe(rfd) < 0) || (pipe(wfd) < 0) )
257 uh_http_sendhf(cl, 500, "Internal Server Error",
258 "Failed to create pipe: %s", strerror(errno));
260 if( rfd[0] > 0 ) close(rfd[0]);
261 if( rfd[1] > 0 ) close(rfd[1]);
262 if( wfd[0] > 0 ) close(wfd[0]);
263 if( wfd[1] > 0 ) close(wfd[1]);
269 switch( (child = fork()) )
272 uh_http_sendhf(cl, 500, "Internal Server Error",
273 "Failed to fork child: %s", strerror(errno));
277 /* restore SIGTERM */
279 sa.sa_handler = SIG_DFL;
280 sigemptyset(&sa.sa_mask);
281 sigaction(SIGTERM, &sa, NULL);
283 /* close loose pipe ends */
287 /* patch stdout and stdin to pipes */
291 /* put handler callback on stack */
292 lua_getglobal(L, UH_LUA_CALLBACK);
294 /* build env table */
300 case UH_HTTP_MSG_GET:
301 lua_pushstring(L, "GET");
304 case UH_HTTP_MSG_HEAD:
305 lua_pushstring(L, "HEAD");
308 case UH_HTTP_MSG_POST:
309 lua_pushstring(L, "POST");
313 lua_setfield(L, -2, "REQUEST_METHOD");
316 lua_pushstring(L, req->url);
317 lua_setfield(L, -2, "REQUEST_URI");
320 lua_pushstring(L, cl->server->conf->lua_prefix);
321 lua_setfield(L, -2, "SCRIPT_NAME");
323 /* query string, path info */
324 if( (query_string = strchr(req->url, '?')) != NULL )
326 lua_pushstring(L, query_string + 1);
327 lua_setfield(L, -2, "QUERY_STRING");
329 if( (int)(query_string - req->url) > strlen(prefix) )
332 &req->url[strlen(prefix)],
333 (int)(query_string - req->url) - strlen(prefix)
336 lua_setfield(L, -2, "PATH_INFO");
339 else if( strlen(req->url) > strlen(prefix) )
341 lua_pushstring(L, &req->url[strlen(prefix)]);
342 lua_setfield(L, -2, "PATH_INFO");
345 /* http protcol version */
346 lua_pushnumber(L, floor(req->version * 10) / 10);
347 lua_setfield(L, -2, "HTTP_VERSION");
349 if( req->version > 1.0 )
350 lua_pushstring(L, "HTTP/1.1");
352 lua_pushstring(L, "HTTP/1.0");
354 lua_setfield(L, -2, "SERVER_PROTOCOL");
357 /* address information */
358 lua_pushstring(L, sa_straddr(&cl->peeraddr));
359 lua_setfield(L, -2, "REMOTE_ADDR");
361 lua_pushinteger(L, sa_port(&cl->peeraddr));
362 lua_setfield(L, -2, "REMOTE_PORT");
364 lua_pushstring(L, sa_straddr(&cl->servaddr));
365 lua_setfield(L, -2, "SERVER_ADDR");
367 lua_pushinteger(L, sa_port(&cl->servaddr));
368 lua_setfield(L, -2, "SERVER_PORT");
370 /* essential env vars */
371 foreach_header(i, req->headers)
373 if( !strcasecmp(req->headers[i], "Content-Length") )
375 lua_pushnumber(L, atoi(req->headers[i+1]));
376 lua_setfield(L, -2, "CONTENT_LENGTH");
378 else if( !strcasecmp(req->headers[i], "Content-Type") )
380 lua_pushstring(L, req->headers[i+1]);
381 lua_setfield(L, -2, "CONTENT_TYPE");
388 foreach_header(i, req->headers)
390 if( strcasecmp(req->headers[i], "Content-Length") &&
391 strcasecmp(req->headers[i], "Content-Type")
393 lua_pushstring(L, req->headers[i+1]);
394 lua_setfield(L, -2, req->headers[i]);
398 lua_setfield(L, -2, "headers");
402 switch( lua_pcall(L, 1, 0, 0) )
406 err_str = luaL_checkstring(L, -1);
409 err_str = "Unknown error";
412 "HTTP/%.1f 500 Internal Server Error\r\n"
413 "Connection: close\r\n"
414 "Content-Type: text/plain\r\n"
415 "Content-Length: %i\r\n\r\n"
416 "Lua raised a runtime error:\n %s\n",
417 req->version, 31 + strlen(err_str), err_str
432 /* parent; handle I/O relaying */
434 /* close unneeded pipe ends */
439 fd_max = max(rfd[0], wfd[1]) + 1;
441 /* find content length */
442 if( req->method == UH_HTTP_MSG_POST )
444 foreach_header(i, req->headers)
446 if( ! strcasecmp(req->headers[i], "Content-Length") )
448 content_length = atoi(req->headers[i+1]);
456 do { if( x < 0 ) goto out; } while(0)
460 timeout.tv_sec = cl->server->conf->script_timeout;
463 /* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */
469 FD_SET(rfd[0], &reader);
470 FD_SET(wfd[1], &writer);
472 /* wait until we can read or write or both */
473 if( select_intr(fd_max, &reader,
474 (content_length > -1) ? &writer : NULL, NULL,
475 (data_sent < 1) ? &timeout : NULL) > 0
477 /* ready to write to Lua child */
478 if( FD_ISSET(wfd[1], &writer) )
480 /* there is unread post data waiting */
481 if( content_length > 0 )
483 /* read it from socket ... */
484 if( (buflen = uh_tcp_recv(cl, buf, min(content_length, sizeof(buf)))) > 0 )
486 /* ... and write it to child's stdin */
487 if( write(wfd[1], buf, buflen) < 0 )
490 content_length -= buflen;
493 /* unexpected eof! */
496 if( write(wfd[1], "", 0) < 0 )
503 /* there is no more post data, close pipe to child's stdin */
504 else if( content_length > -1 )
511 /* ready to read from Lua child */
512 if( FD_ISSET(rfd[0], &reader) )
514 /* read data from child ... */
515 if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 )
517 /* pass through buffer to socket */
518 ensure(uh_tcp_send(cl, buf, buflen));
522 /* looks like eof from child */
527 uh_http_sendhf(cl, 500, "Internal Server Error",
528 "The Lua child did not produce any response");
535 /* timeout exceeded or interrupted by SIGCHLD */
538 if( (errno != EINTR) && ! data_sent )
540 ensure(uh_http_sendhf(cl, 504, "Gateway Timeout",
541 "The Lua script took too long to produce "
553 if( !kill(child, 0) )
555 kill(child, SIGTERM);
556 waitpid(child, NULL, 0);
563 void uh_lua_close(lua_State *L)