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);
139 struct client *cl, struct http_request *req,
140 struct path_info *pi, struct interpreter *ip
142 int i, hdroff, bufoff, rv;
146 int content_length = 0;
149 int rfd[2] = { 0, 0 };
150 int wfd[2] = { 0, 0 };
152 char buf[UH_LIMIT_MSGHEAD];
153 char hdr[UH_LIMIT_MSGHEAD];
163 struct timeval timeout;
164 struct http_response *res;
167 /* spawn pipes for me->child, child->me */
168 if( (pipe(rfd) < 0) || (pipe(wfd) < 0) )
170 uh_http_sendhf(cl, 500, "Internal Server Error",
171 "Failed to create pipe: %s", strerror(errno));
173 if( rfd[0] > 0 ) close(rfd[0]);
174 if( rfd[1] > 0 ) close(rfd[1]);
175 if( wfd[0] > 0 ) close(wfd[0]);
176 if( wfd[1] > 0 ) close(wfd[1]);
181 /* fork off child process */
182 switch( (child = fork()) )
186 uh_http_sendhf(cl, 500, "Internal Server Error",
187 "Failed to fork child: %s", strerror(errno));
192 /* unblock signals */
194 sigprocmask(SIG_SETMASK, &ss, NULL);
196 /* restore SIGTERM */
198 sa.sa_handler = SIG_DFL;
199 sigemptyset(&sa.sa_mask);
200 sigaction(SIGTERM, &sa, NULL);
202 /* close loose pipe ends */
206 /* patch stdout and stdin to pipes */
210 /* avoid leaking our pipe into child-child processes */
214 /* check for regular, world-executable file _or_ interpreter */
215 if( ((pi->stat.st_mode & S_IFREG) &&
216 (pi->stat.st_mode & S_IXOTH)) || (ip != NULL)
218 /* build environment */
221 /* common information */
222 setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
223 setenv("SERVER_SOFTWARE", "uHTTPd", 1);
224 setenv("PATH", "/sbin:/usr/sbin:/bin:/usr/bin", 1);
229 setenv("HTTPS", "on", 1);
233 setenv("SERVER_NAME", sa_straddr(&cl->servaddr), 1);
234 setenv("SERVER_ADDR", sa_straddr(&cl->servaddr), 1);
235 setenv("SERVER_PORT", sa_strport(&cl->servaddr), 1);
236 setenv("REMOTE_HOST", sa_straddr(&cl->peeraddr), 1);
237 setenv("REMOTE_ADDR", sa_straddr(&cl->peeraddr), 1);
238 setenv("REMOTE_PORT", sa_strport(&cl->peeraddr), 1);
240 /* path information */
241 setenv("SCRIPT_NAME", pi->name, 1);
242 setenv("SCRIPT_FILENAME", pi->phys, 1);
243 setenv("DOCUMENT_ROOT", pi->root, 1);
244 setenv("QUERY_STRING", pi->query ? pi->query : "", 1);
247 setenv("PATH_INFO", pi->info, 1);
249 /* REDIRECT_STATUS, php-cgi wants it */
250 switch( req->redirect_status )
253 setenv("REDIRECT_STATUS", "404", 1);
257 setenv("REDIRECT_STATUS", "200", 1);
262 if( req->version > 1.0 )
263 setenv("SERVER_PROTOCOL", "HTTP/1.1", 1);
265 setenv("SERVER_PROTOCOL", "HTTP/1.0", 1);
268 switch( req->method )
270 case UH_HTTP_MSG_GET:
271 setenv("REQUEST_METHOD", "GET", 1);
274 case UH_HTTP_MSG_HEAD:
275 setenv("REQUEST_METHOD", "HEAD", 1);
278 case UH_HTTP_MSG_POST:
279 setenv("REQUEST_METHOD", "POST", 1);
284 setenv("REQUEST_URI", req->url, 1);
288 setenv("REMOTE_USER", req->realm->user, 1);
290 /* request message headers */
291 foreach_header(i, req->headers)
293 if( ! strcasecmp(req->headers[i], "Accept") )
294 setenv("HTTP_ACCEPT", req->headers[i+1], 1);
296 else if( ! strcasecmp(req->headers[i], "Accept-Charset") )
297 setenv("HTTP_ACCEPT_CHARSET", req->headers[i+1], 1);
299 else if( ! strcasecmp(req->headers[i], "Accept-Encoding") )
300 setenv("HTTP_ACCEPT_ENCODING", req->headers[i+1], 1);
302 else if( ! strcasecmp(req->headers[i], "Accept-Language") )
303 setenv("HTTP_ACCEPT_LANGUAGE", req->headers[i+1], 1);
305 else if( ! strcasecmp(req->headers[i], "Authorization") )
306 setenv("HTTP_AUTHORIZATION", req->headers[i+1], 1);
308 else if( ! strcasecmp(req->headers[i], "Connection") )
309 setenv("HTTP_CONNECTION", req->headers[i+1], 1);
311 else if( ! strcasecmp(req->headers[i], "Cookie") )
312 setenv("HTTP_COOKIE", req->headers[i+1], 1);
314 else if( ! strcasecmp(req->headers[i], "Host") )
315 setenv("HTTP_HOST", req->headers[i+1], 1);
317 else if( ! strcasecmp(req->headers[i], "Referer") )
318 setenv("HTTP_REFERER", req->headers[i+1], 1);
320 else if( ! strcasecmp(req->headers[i], "User-Agent") )
321 setenv("HTTP_USER_AGENT", req->headers[i+1], 1);
323 else if( ! strcasecmp(req->headers[i], "Content-Type") )
324 setenv("CONTENT_TYPE", req->headers[i+1], 1);
326 else if( ! strcasecmp(req->headers[i], "Content-Length") )
327 setenv("CONTENT_LENGTH", req->headers[i+1], 1);
331 /* execute child code ... */
332 if( chdir(pi->root) )
336 execl(ip->path, ip->path, pi->phys, NULL);
338 execl(pi->phys, pi->phys, NULL);
340 /* in case it fails ... */
342 "Status: 500 Internal Server Error\r\n\r\n"
343 "Unable to launch the requested CGI program:\n"
345 ip ? ip->path : pi->phys, strerror(errno)
353 "Status: 403 Forbidden\r\n\r\n"
354 "Access to this resource is forbidden\n"
364 /* parent; handle I/O relaying */
366 /* close unneeded pipe ends */
371 fd_max = max(rfd[0], wfd[1]) + 1;
373 /* find content length */
374 if( req->method == UH_HTTP_MSG_POST )
376 foreach_header(i, req->headers)
378 if( ! strcasecmp(req->headers[i], "Content-Length") )
380 content_length = atoi(req->headers[i+1]);
387 memset(hdr, 0, sizeof(hdr));
389 /* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */
395 FD_SET(rfd[0], &reader);
396 FD_SET(wfd[1], &writer);
398 timeout.tv_sec = (header_sent < 1) ? cl->server->conf->script_timeout : 3;
401 ensure_out(rv = select_intr(fd_max, &reader,
402 (content_length > -1) ? &writer : NULL, NULL, &timeout));
407 ensure_out(kill(child, 0));
410 /* wait until we can read or write or both */
413 /* ready to write to cgi program */
414 if( FD_ISSET(wfd[1], &writer) )
416 /* there is unread post data waiting */
417 if( content_length > 0 )
419 /* read it from socket ... */
420 ensure_out(buflen = uh_tcp_recv(cl, buf,
421 min(content_length, sizeof(buf))));
425 /* ... and write it to child's stdin */
426 if( write(wfd[1], buf, buflen) < 0 )
429 content_length -= buflen;
432 /* unexpected eof! */
435 if( write(wfd[1], "", 0) < 0 )
442 /* there is no more post data, close pipe to child's stdin */
443 else if( content_length > -1 )
450 /* ready to read from cgi program */
451 if( FD_ISSET(rfd[0], &reader) )
453 /* read data from child ... */
454 if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 )
456 /* we have not pushed out headers yet, parse input */
459 /* head buffer not full and no end yet */
460 if( hdrlen < sizeof(hdr) )
462 bufoff = min(buflen, sizeof(hdr) - hdrlen);
463 memcpy(&hdr[hdrlen], buf, bufoff);
472 /* try to parse header ... */
473 if( (res = uh_cgi_header_parse(hdr, hdrlen, &hdroff)) != NULL )
476 ensure_out(uh_http_sendf(cl, NULL,
477 "HTTP/%.1f %03d %s\r\n"
478 "Connection: close\r\n",
479 req->version, res->statuscode,
482 /* add Content-Type if no Location or Content-Type */
483 if( !uh_cgi_header_lookup(res, "Location") &&
484 !uh_cgi_header_lookup(res, "Content-Type")
486 ensure_out(uh_http_send(cl, NULL,
487 "Content-Type: text/plain\r\n", -1));
490 /* if request was HTTP 1.1 we'll respond chunked */
491 if( (req->version > 1.0) &&
492 !uh_cgi_header_lookup(res, "Transfer-Encoding")
494 ensure_out(uh_http_send(cl, NULL,
495 "Transfer-Encoding: chunked\r\n", -1));
498 /* write headers from CGI program */
499 foreach_header(i, res->headers)
501 ensure_out(uh_http_sendf(cl, NULL, "%s: %s\r\n",
502 res->headers[i], res->headers[i+1]));
505 /* terminate header */
506 ensure_out(uh_http_send(cl, NULL, "\r\n", -1));
508 /* push out remaining head buffer */
509 if( hdroff < hdrlen )
510 ensure_out(uh_http_send(cl, req, &hdr[hdroff], hdrlen - hdroff));
513 /* ... failed and head buffer exceeded */
514 else if( hdrlen >= sizeof(hdr) )
516 ensure_out(uh_cgi_error_500(cl, req,
517 "The CGI program generated an invalid response:\n\n"));
519 ensure_out(uh_http_send(cl, req, hdr, hdrlen));
522 /* ... failed but free buffer space, try again */
528 /* push out remaining read buffer */
529 if( bufoff < buflen )
530 ensure_out(uh_http_send(cl, req, &buf[bufoff], buflen - bufoff));
537 /* headers complete, pass through buffer to socket */
538 ensure_out(uh_http_send(cl, req, buf, buflen));
541 /* looks like eof from child */
544 /* cgi script did not output useful stuff at all */
547 /* I would do this ...
549 * uh_cgi_error_500(cl, req,
550 * "The CGI program generated an "
551 * "invalid response:\n\n");
553 * ... but in order to stay as compatible as possible,
554 * treat whatever we got as text/plain response and
555 * build the required headers here.
558 ensure_out(uh_http_sendf(cl, NULL,
559 "HTTP/%.1f 200 OK\r\n"
560 "Content-Type: text/plain\r\n"
562 req->version, (req->version > 1.0)
563 ? "Transfer-Encoding: chunked\r\n" : ""
566 ensure_out(uh_http_send(cl, req, hdr, hdrlen));
569 /* send final chunk if we're in chunked transfer mode */
570 ensure_out(uh_http_send(cl, req, "", 0));
576 /* timeout exceeded or interrupted by SIGCHLD */
579 if( (errno != EINTR) && ! header_sent )
581 ensure_out(uh_http_sendhf(cl, 504, "Gateway Timeout",
582 "The CGI script took too long to produce "
586 /* send final chunk if we're in chunked transfer mode */
587 ensure_out(uh_http_send(cl, req, "", 0));
597 if( !kill(child, 0) )
599 kill(child, SIGTERM);
600 waitpid(child, NULL, 0);