diff options
Diffstat (limited to 'package/uhttpd/src/uhttpd-cgi.c')
| -rw-r--r-- | package/uhttpd/src/uhttpd-cgi.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/package/uhttpd/src/uhttpd-cgi.c b/package/uhttpd/src/uhttpd-cgi.c new file mode 100644 index 000000000..5565197ca --- /dev/null +++ b/package/uhttpd/src/uhttpd-cgi.c @@ -0,0 +1,561 @@ +/* + * uhttpd - Tiny single-threaded httpd - CGI handler + * + * Copyright (C) 2010 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-cgi.h" + +static struct http_response * uh_cgi_header_parse(char *buf, int len, int *off) +{ + char *bufptr = NULL; + char *hdrname = NULL; + int hdrcount = 0; + int pos = 0; + + static struct http_response res; + + + if( ((bufptr = strfind(buf, len, "\r\n\r\n", 4)) != NULL) || + ((bufptr = strfind(buf, len, "\n\n", 2)) != NULL) + ) { + *off = (int)(bufptr - buf) + ((bufptr[0] == '\r') ? 4 : 2); + + memset(&res, 0, sizeof(res)); + + res.statuscode = 200; + res.statusmsg = "OK"; + + bufptr = &buf[0]; + + for( pos = 0; pos < len; pos++ ) + { + if( !hdrname && (buf[pos] == ':') ) + { + buf[pos++] = 0; + + if( (pos < len) && (buf[pos] == ' ') ) + pos++; + + if( pos < len ) + { + hdrname = bufptr; + bufptr = &buf[pos]; + } + } + + else if( (buf[pos] == '\r') || (buf[pos] == '\n') ) + { + buf[pos++] = 0; + + if( ! hdrname ) + break; + + if( (pos < len) && (buf[pos] == '\n') ) + pos++; + + if( pos < len ) + { + if( (hdrcount + 1) < array_size(res.headers) ) + { + if( ! strcasecmp(hdrname, "Status") ) + { + res.statuscode = atoi(bufptr); + + if( res.statuscode < 100 ) + res.statuscode = 200; + + if( ((bufptr = strchr(bufptr, ' ')) != NULL) && (&bufptr[1] != 0) ) + res.statusmsg = &bufptr[1]; + } + else + { + res.headers[hdrcount++] = hdrname; + res.headers[hdrcount++] = bufptr; + } + + bufptr = &buf[pos]; + hdrname = NULL; + } + else + { + return NULL; + } + } + } + } + + return &res; + } + + return NULL; +} + +static char * uh_cgi_header_lookup(struct http_response *res, const char *hdrname) +{ + int i; + + foreach_header(i, res->headers) + { + if( ! strcasecmp(res->headers[i], hdrname) ) + return res->headers[i+1]; + } + + return NULL; +} + +static int uh_cgi_error_500(struct client *cl, struct http_request *req, const char *message) +{ + if( uh_http_sendf(cl, NULL, + "HTTP/%.1f 500 Internal Server Error\r\n" + "Content-Type: text/plain\r\n%s\r\n", + req->version, + (req->version > 1.0) + ? "Transfer-Encoding: chunked\r\n" : "" + ) >= 0 + ) { + return uh_http_send(cl, req, message, -1); + } + + return -1; +} + + +void uh_cgi_request(struct client *cl, struct http_request *req, struct path_info *pi) +{ + int i, hdroff, bufoff; + int hdrlen = 0; + int buflen = 0; + int fd_max = 0; + int content_length = 0; + int header_sent = 0; + + int rfd[2] = { 0, 0 }; + int wfd[2] = { 0, 0 }; + + char buf[UH_LIMIT_MSGHEAD]; + char hdr[UH_LIMIT_MSGHEAD]; + + pid_t child; + + fd_set reader; + fd_set writer; + + struct sigaction sa; + struct timeval timeout; + struct http_response *res; + + + /* spawn pipes for me->child, child->me */ + if( (pipe(rfd) < 0) || (pipe(wfd) < 0) ) + { + uh_http_sendhf(cl, 500, "Internal Server Error", + "Failed to create pipe: %s", strerror(errno)); + + 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]); + + return; + } + + /* fork off child process */ + switch( (child = fork()) ) + { + /* oops */ + case -1: + uh_http_sendhf(cl, 500, "Internal Server Error", + "Failed to fork child: %s", strerror(errno)); + return; + + /* exec child */ + case 0: + /* restore SIGTERM */ + sa.sa_flags = 0; + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + sigaction(SIGTERM, &sa, NULL); + + /* close loose pipe ends */ + close(rfd[0]); + close(wfd[1]); + + /* patch stdout and stdin to pipes */ + dup2(rfd[1], 1); + dup2(wfd[0], 0); + + /* check for regular, world-executable file */ + if( (pi->stat.st_mode & S_IFREG) && + (pi->stat.st_mode & S_IXOTH) + ) { + /* build environment */ + clearenv(); + + /* common information */ + setenv("GATEWAY_INTERFACE", "CGI/1.1", 1); + setenv("SERVER_SOFTWARE", "uHTTPd", 1); + setenv("PATH", "/sbin:/usr/sbin:/bin:/usr/bin", 1); + +#ifdef HAVE_TLS + /* https? */ + if( cl->tls ) + setenv("HTTPS", "on", 1); +#endif + + /* addresses */ + setenv("SERVER_NAME", sa_straddr(&cl->servaddr), 1); + setenv("SERVER_ADDR", sa_straddr(&cl->servaddr), 1); + setenv("SERVER_PORT", sa_strport(&cl->servaddr), 1); + setenv("REMOTE_HOST", sa_straddr(&cl->peeraddr), 1); + setenv("REMOTE_ADDR", sa_straddr(&cl->peeraddr), 1); + setenv("REMOTE_PORT", sa_strport(&cl->peeraddr), 1); + + /* path information */ + setenv("SCRIPT_NAME", pi->name, 1); + setenv("SCRIPT_FILENAME", pi->phys, 1); + setenv("DOCUMENT_ROOT", pi->root, 1); + setenv("QUERY_STRING", pi->query ? pi->query : "", 1); + + if( pi->info ) + setenv("PATH_INFO", pi->info, 1); + + + /* http version */ + if( req->version > 1.0 ) + setenv("SERVER_PROTOCOL", "HTTP/1.1", 1); + else + setenv("SERVER_PROTOCOL", "HTTP/1.0", 1); + + /* request method */ + switch( req->method ) + { + case UH_HTTP_MSG_GET: + setenv("REQUEST_METHOD", "GET", 1); + break; + + case UH_HTTP_MSG_HEAD: + setenv("REQUEST_METHOD", "HEAD", 1); + break; + + case UH_HTTP_MSG_POST: + setenv("REQUEST_METHOD", "POST", 1); + break; + } + + /* request url */ + setenv("REQUEST_URI", req->url, 1); + + /* remote user */ + if( req->realm ) + setenv("REMOTE_USER", req->realm->user, 1); + + /* request message headers */ + foreach_header(i, req->headers) + { + if( ! strcasecmp(req->headers[i], "Accept") ) + setenv("HTTP_ACCEPT", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Accept-Charset") ) + setenv("HTTP_ACCEPT_CHARSET", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Accept-Encoding") ) + setenv("HTTP_ACCEPT_ENCODING", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Accept-Language") ) + setenv("HTTP_ACCEPT_LANGUAGE", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Authorization") ) + setenv("HTTP_AUTHORIZATION", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Connection") ) + setenv("HTTP_CONNECTION", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Cookie") ) + setenv("HTTP_COOKIE", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Host") ) + setenv("HTTP_HOST", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Referer") ) + setenv("HTTP_REFERER", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "User-Agent") ) + setenv("HTTP_USER_AGENT", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Content-Type") ) + setenv("CONTENT_TYPE", req->headers[i+1], 1); + + else if( ! strcasecmp(req->headers[i], "Content-Length") ) + setenv("CONTENT_LENGTH", req->headers[i+1], 1); + } + + + /* execute child code ... */ + if( chdir(pi->root) ) + perror("chdir()"); + + execl(pi->phys, pi->phys, NULL); + + /* in case it fails ... */ + printf( + "Status: 500 Internal Server Error\r\n\r\n" + "Unable to launch the requested CGI program:\n" + " %s: %s\n", + pi->phys, strerror(errno) + ); + } + + /* 403 */ + else + { + printf( + "Status: 403 Forbidden\r\n\r\n" + "Access to this resource is forbidden\n" + ); + } + + close(wfd[0]); + close(rfd[1]); + exit(0); + + break; + + /* parent; handle I/O relaying */ + default: + /* close unneeded pipe ends */ + close(rfd[1]); + close(wfd[0]); + + /* max watch fd */ + fd_max = max(rfd[0], wfd[1]) + 1; + + /* find content length */ + if( req->method == UH_HTTP_MSG_POST ) + { + foreach_header(i, req->headers) + { + if( ! strcasecmp(req->headers[i], "Content-Length") ) + { + content_length = atoi(req->headers[i+1]); + break; + } + } + } + + + memset(hdr, 0, sizeof(hdr)); + +#define ensure(x) \ + do { if( x < 0 ) goto out; } while(0) + + /* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */ + while( 1 ) + { + FD_ZERO(&reader); + FD_ZERO(&writer); + + FD_SET(rfd[0], &reader); + FD_SET(wfd[1], &writer); + + timeout.tv_sec = 15; + timeout.tv_usec = 0; + + /* wait until we can read or write or both */ + if( select(fd_max, &reader, (content_length > -1) ? &writer : NULL, NULL, &timeout) > 0 ) + { + /* ready to write to cgi program */ + if( FD_ISSET(wfd[1], &writer) ) + { + /* there is unread post data waiting */ + if( content_length > 0 ) + { + /* read it from socket ... */ + if( (buflen = uh_tcp_recv(cl, buf, min(content_length, sizeof(buf)))) > 0 ) + { + /* ... and write it to child's stdin */ + if( write(wfd[1], buf, buflen) < 0 ) + perror("write()"); + + content_length -= buflen; + } + + /* unexpected eof! */ + else + { + if( write(wfd[1], "", 0) < 0 ) + perror("write()"); + + content_length = 0; + } + } + + /* there is no more post data, close pipe to child's stdin */ + else if( content_length > -1 ) + { + close(wfd[1]); + content_length = -1; + } + } + + /* ready to read from cgi program */ + if( FD_ISSET(rfd[0], &reader) ) + { + /* read data from child ... */ + if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 ) + { + /* we have not pushed out headers yet, parse input */ + if( ! header_sent ) + { + /* head buffer not full and no end yet */ + if( hdrlen < sizeof(hdr) ) + { + bufoff = min(buflen, sizeof(hdr) - hdrlen); + memcpy(&hdr[hdrlen], buf, bufoff); + hdrlen += bufoff; + } + else + { + bufoff = 0; + } + + + /* try to parse header ... */ + if( (res = uh_cgi_header_parse(hdr, hdrlen, &hdroff)) != NULL ) + { + /* write status */ + ensure(uh_http_sendf(cl, NULL, + "HTTP/%.1f %03d %s\r\n" + "Connection: close\r\n", + req->version, res->statuscode, + res->statusmsg)); + + /* add Content-Type if no Location or Content-Type */ + if( !uh_cgi_header_lookup(res, "Location") && + !uh_cgi_header_lookup(res, "Content-Type") + ) { + ensure(uh_http_send(cl, NULL, + "Content-Type: text/plain\r\n", -1)); + } + + /* if request was HTTP 1.1 we'll respond chunked */ + if( (req->version > 1.0) && + !uh_cgi_header_lookup(res, "Transfer-Encoding") + ) { + ensure(uh_http_send(cl, NULL, + "Transfer-Encoding: chunked\r\n", -1)); + } + + /* write headers from CGI program */ + foreach_header(i, res->headers) + { + ensure(uh_http_sendf(cl, NULL, "%s: %s\r\n", + res->headers[i], res->headers[i+1])); + } + + /* terminate header */ + ensure(uh_http_send(cl, NULL, "\r\n", -1)); + + /* push out remaining head buffer */ + if( hdroff < hdrlen ) + ensure(uh_http_send(cl, req, &hdr[hdroff], hdrlen - hdroff)); + } + + /* ... failed and head buffer exceeded */ + else if( hdrlen >= sizeof(hdr) ) + { + ensure(uh_cgi_error_500(cl, req, + "The CGI program generated an invalid response:\n\n")); + + ensure(uh_http_send(cl, req, hdr, hdrlen)); + } + + /* ... failed but free buffer space, try again */ + else + { + continue; + } + + /* push out remaining read buffer */ + if( bufoff < buflen ) + ensure(uh_http_send(cl, req, &buf[bufoff], buflen - bufoff)); + + header_sent = 1; + continue; + } + + + /* headers complete, pass through buffer to socket */ + ensure(uh_http_send(cl, req, buf, buflen)); + } + + /* looks like eof from child */ + else + { + /* cgi script did not output useful stuff at all */ + if( ! header_sent ) + { + /* I would do this ... + * + * uh_cgi_error_500(cl, req, + * "The CGI program generated an " + * "invalid response:\n\n"); + * + * ... but in order to stay as compatible as possible, + * treat whatever we got as text/plain response and + * build the required headers here. + */ + + ensure(uh_http_sendf(cl, NULL, + "HTTP/%.1f 200 OK\r\n" + "Content-Type: text/plain\r\n" + "%s\r\n", + req->version, (req->version > 1.0) + ? "Transfer-Encoding: chunked\r\n" : "" + )); + + ensure(uh_http_send(cl, req, hdr, hdrlen)); + } + + /* send final chunk if we're in chunked transfer mode */ + ensure(uh_http_send(cl, req, "", 0)); + break; + } + } + } + + /* no activity for 15 seconds... looks dead */ + else + { + ensure(uh_http_sendhf(cl, 504, "Gateway Timeout", + "The CGI script took too long to produce a response")); + + break; + } + } + + out: + close(rfd[0]); + close(wfd[1]); + + if( !kill(child, 0) ) + kill(child, SIGTERM); + + break; + } +} + |