2 * uhttpd - Tiny single-threaded httpd - CGI 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-cgi.h"
23 static struct http_response * uh_cgi_header_parse(char *buf, int len, int *off)
30 static struct http_response res;
33 if( ((bufptr = strfind(buf, len, "\r\n\r\n", 4)) != NULL) ||
34 ((bufptr = strfind(buf, len, "\n\n", 2)) != NULL)
36 *off = (int)(bufptr - buf) + ((bufptr[0] == '\r') ? 4 : 2);
38 memset(&res, 0, sizeof(res));
45 for( pos = 0; pos < len; pos++ )
47 if( !hdrname && (buf[pos] == ':') )
51 if( (pos < len) && (buf[pos] == ' ') )
61 else if( (buf[pos] == '\r') || (buf[pos] == '\n') )
68 if( (pos < len) && (buf[pos] == '\n') )
73 if( (hdrcount + 1) < array_size(res.headers) )
75 if( ! strcasecmp(hdrname, "Status") )
77 res.statuscode = atoi(bufptr);
79 if( res.statuscode < 100 )
82 if( ((bufptr = strchr(bufptr, ' ')) != NULL) && (&bufptr[1] != 0) )
83 res.statusmsg = &bufptr[1];
87 res.headers[hdrcount++] = hdrname;
88 res.headers[hdrcount++] = bufptr;
108 static char * uh_cgi_header_lookup(struct http_response *res, const char *hdrname)
112 foreach_header(i, res->headers)
114 if( ! strcasecmp(res->headers[i], hdrname) )
115 return res->headers[i+1];
121 static int uh_cgi_error_500(struct client *cl, struct http_request *req, const char *message)
123 if( uh_http_sendf(cl, NULL,
124 "HTTP/%.1f 500 Internal Server Error\r\n"
125 "Content-Type: text/plain\r\n%s\r\n",
128 ? "Transfer-Encoding: chunked\r\n" : ""
131 return uh_http_send(cl, req, message, -1);
138 void uh_cgi_request(struct client *cl, struct http_request *req, struct path_info *pi)
140 int i, hdroff, bufoff;
144 int content_length = 0;
147 int rfd[2] = { 0, 0 };
148 int wfd[2] = { 0, 0 };
150 char buf[UH_LIMIT_MSGHEAD];
151 char hdr[UH_LIMIT_MSGHEAD];
159 struct timeval timeout;
160 struct http_response *res;
163 /* spawn pipes for me->child, child->me */
164 if( (pipe(rfd) < 0) || (pipe(wfd) < 0) )
166 uh_http_sendhf(cl, 500, "Internal Server Error",
167 "Failed to create pipe: %s", strerror(errno));
169 if( rfd[0] > 0 ) close(rfd[0]);
170 if( rfd[1] > 0 ) close(rfd[1]);
171 if( wfd[0] > 0 ) close(wfd[0]);
172 if( wfd[1] > 0 ) close(wfd[1]);
177 /* fork off child process */
178 switch( (child = fork()) )
182 uh_http_sendhf(cl, 500, "Internal Server Error",
183 "Failed to fork child: %s", strerror(errno));
188 /* restore SIGTERM */
190 sa.sa_handler = SIG_DFL;
191 sigemptyset(&sa.sa_mask);
192 sigaction(SIGTERM, &sa, NULL);
194 /* close loose pipe ends */
198 /* patch stdout and stdin to pipes */
202 /* check for regular, world-executable file */
203 if( (pi->stat.st_mode & S_IFREG) &&
204 (pi->stat.st_mode & S_IXOTH)
206 /* build environment */
209 /* common information */
210 setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
211 setenv("SERVER_SOFTWARE", "uHTTPd", 1);
212 setenv("PATH", "/sbin:/usr/sbin:/bin:/usr/bin", 1);
217 setenv("HTTPS", "on", 1);
221 setenv("SERVER_NAME", sa_straddr(&cl->servaddr), 1);
222 setenv("SERVER_ADDR", sa_straddr(&cl->servaddr), 1);
223 setenv("SERVER_PORT", sa_strport(&cl->servaddr), 1);
224 setenv("REMOTE_HOST", sa_straddr(&cl->peeraddr), 1);
225 setenv("REMOTE_ADDR", sa_straddr(&cl->peeraddr), 1);
226 setenv("REMOTE_PORT", sa_strport(&cl->peeraddr), 1);
228 /* path information */
229 setenv("SCRIPT_NAME", pi->name, 1);
230 setenv("SCRIPT_FILENAME", pi->phys, 1);
231 setenv("DOCUMENT_ROOT", pi->root, 1);
232 setenv("QUERY_STRING", pi->query ? pi->query : "", 1);
235 setenv("PATH_INFO", pi->info, 1);
239 if( req->version > 1.0 )
240 setenv("SERVER_PROTOCOL", "HTTP/1.1", 1);
242 setenv("SERVER_PROTOCOL", "HTTP/1.0", 1);
245 switch( req->method )
247 case UH_HTTP_MSG_GET:
248 setenv("REQUEST_METHOD", "GET", 1);
251 case UH_HTTP_MSG_HEAD:
252 setenv("REQUEST_METHOD", "HEAD", 1);
255 case UH_HTTP_MSG_POST:
256 setenv("REQUEST_METHOD", "POST", 1);
261 setenv("REQUEST_URI", req->url, 1);
265 setenv("REMOTE_USER", req->realm->user, 1);
267 /* request message headers */
268 foreach_header(i, req->headers)
270 if( ! strcasecmp(req->headers[i], "Accept") )
271 setenv("HTTP_ACCEPT", req->headers[i+1], 1);
273 else if( ! strcasecmp(req->headers[i], "Accept-Charset") )
274 setenv("HTTP_ACCEPT_CHARSET", req->headers[i+1], 1);
276 else if( ! strcasecmp(req->headers[i], "Accept-Encoding") )
277 setenv("HTTP_ACCEPT_ENCODING", req->headers[i+1], 1);
279 else if( ! strcasecmp(req->headers[i], "Accept-Language") )
280 setenv("HTTP_ACCEPT_LANGUAGE", req->headers[i+1], 1);
282 else if( ! strcasecmp(req->headers[i], "Authorization") )
283 setenv("HTTP_AUTHORIZATION", req->headers[i+1], 1);
285 else if( ! strcasecmp(req->headers[i], "Connection") )
286 setenv("HTTP_CONNECTION", req->headers[i+1], 1);
288 else if( ! strcasecmp(req->headers[i], "Cookie") )
289 setenv("HTTP_COOKIE", req->headers[i+1], 1);
291 else if( ! strcasecmp(req->headers[i], "Host") )
292 setenv("HTTP_HOST", req->headers[i+1], 1);
294 else if( ! strcasecmp(req->headers[i], "Referer") )
295 setenv("HTTP_REFERER", req->headers[i+1], 1);
297 else if( ! strcasecmp(req->headers[i], "User-Agent") )
298 setenv("HTTP_USER_AGENT", req->headers[i+1], 1);
300 else if( ! strcasecmp(req->headers[i], "Content-Type") )
301 setenv("CONTENT_TYPE", req->headers[i+1], 1);
303 else if( ! strcasecmp(req->headers[i], "Content-Length") )
304 setenv("CONTENT_LENGTH", req->headers[i+1], 1);
308 /* execute child code ... */
309 if( chdir(pi->root) )
312 execl(pi->phys, pi->phys, NULL);
314 /* in case it fails ... */
316 "Status: 500 Internal Server Error\r\n\r\n"
317 "Unable to launch the requested CGI program:\n"
319 pi->phys, strerror(errno)
327 "Status: 403 Forbidden\r\n\r\n"
328 "Access to this resource is forbidden\n"
338 /* parent; handle I/O relaying */
340 /* close unneeded pipe ends */
345 fd_max = max(rfd[0], wfd[1]) + 1;
347 /* find content length */
348 if( req->method == UH_HTTP_MSG_POST )
350 foreach_header(i, req->headers)
352 if( ! strcasecmp(req->headers[i], "Content-Length") )
354 content_length = atoi(req->headers[i+1]);
361 memset(hdr, 0, sizeof(hdr));
364 do { if( x < 0 ) goto out; } while(0)
366 /* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */
372 FD_SET(rfd[0], &reader);
373 FD_SET(wfd[1], &writer);
378 /* wait until we can read or write or both */
379 if( select(fd_max, &reader, (content_length > -1) ? &writer : NULL, NULL, &timeout) > 0 )
381 /* ready to write to cgi program */
382 if( FD_ISSET(wfd[1], &writer) )
384 /* there is unread post data waiting */
385 if( content_length > 0 )
387 /* read it from socket ... */
388 if( (buflen = uh_tcp_recv(cl, buf, min(content_length, sizeof(buf)))) > 0 )
390 /* ... and write it to child's stdin */
391 if( write(wfd[1], buf, buflen) < 0 )
394 content_length -= buflen;
397 /* unexpected eof! */
400 if( write(wfd[1], "", 0) < 0 )
407 /* there is no more post data, close pipe to child's stdin */
408 else if( content_length > -1 )
415 /* ready to read from cgi program */
416 if( FD_ISSET(rfd[0], &reader) )
418 /* read data from child ... */
419 if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 )
421 /* we have not pushed out headers yet, parse input */
424 /* head buffer not full and no end yet */
425 if( hdrlen < sizeof(hdr) )
427 bufoff = min(buflen, sizeof(hdr) - hdrlen);
428 memcpy(&hdr[hdrlen], buf, bufoff);
437 /* try to parse header ... */
438 if( (res = uh_cgi_header_parse(hdr, hdrlen, &hdroff)) != NULL )
441 ensure(uh_http_sendf(cl, NULL,
442 "HTTP/%.1f %03d %s\r\n"
443 "Connection: close\r\n",
444 req->version, res->statuscode,
447 /* add Content-Type if no Location or Content-Type */
448 if( !uh_cgi_header_lookup(res, "Location") &&
449 !uh_cgi_header_lookup(res, "Content-Type")
451 ensure(uh_http_send(cl, NULL,
452 "Content-Type: text/plain\r\n", -1));
455 /* if request was HTTP 1.1 we'll respond chunked */
456 if( (req->version > 1.0) &&
457 !uh_cgi_header_lookup(res, "Transfer-Encoding")
459 ensure(uh_http_send(cl, NULL,
460 "Transfer-Encoding: chunked\r\n", -1));
463 /* write headers from CGI program */
464 foreach_header(i, res->headers)
466 ensure(uh_http_sendf(cl, NULL, "%s: %s\r\n",
467 res->headers[i], res->headers[i+1]));
470 /* terminate header */
471 ensure(uh_http_send(cl, NULL, "\r\n", -1));
473 /* push out remaining head buffer */
474 if( hdroff < hdrlen )
475 ensure(uh_http_send(cl, req, &hdr[hdroff], hdrlen - hdroff));
478 /* ... failed and head buffer exceeded */
479 else if( hdrlen >= sizeof(hdr) )
481 ensure(uh_cgi_error_500(cl, req,
482 "The CGI program generated an invalid response:\n\n"));
484 ensure(uh_http_send(cl, req, hdr, hdrlen));
487 /* ... failed but free buffer space, try again */
493 /* push out remaining read buffer */
494 if( bufoff < buflen )
495 ensure(uh_http_send(cl, req, &buf[bufoff], buflen - bufoff));
502 /* headers complete, pass through buffer to socket */
503 ensure(uh_http_send(cl, req, buf, buflen));
506 /* looks like eof from child */
509 /* cgi script did not output useful stuff at all */
512 /* I would do this ...
514 * uh_cgi_error_500(cl, req,
515 * "The CGI program generated an "
516 * "invalid response:\n\n");
518 * ... but in order to stay as compatible as possible,
519 * treat whatever we got as text/plain response and
520 * build the required headers here.
523 ensure(uh_http_sendf(cl, NULL,
524 "HTTP/%.1f 200 OK\r\n"
525 "Content-Type: text/plain\r\n"
527 req->version, (req->version > 1.0)
528 ? "Transfer-Encoding: chunked\r\n" : ""
531 ensure(uh_http_send(cl, req, hdr, hdrlen));
534 /* send final chunk if we're in chunked transfer mode */
535 ensure(uh_http_send(cl, req, "", 0));
541 /* no activity for 15 seconds... looks dead */
544 ensure(uh_http_sendhf(cl, 504, "Gateway Timeout",
545 "The CGI script took too long to produce a response"));
555 if( !kill(child, 0) )
556 kill(child, SIGTERM);