contrib/package/uhttpd/src/uhttpd-cgi.c

   1 #include "uhttpd.h"
   2 #include "uhttpd-cgi.h"
   3 #include "uhttpd-utils.h"
   4
   5 static struct http_response * uh_cgi_header_parse(char *buf, int len, int *off)
   6 {
   7         char *bufptr = NULL;
   8         char *hdrname = NULL;
   9         int hdrcount = 0;
  10         int pos = 0;
  11
  12         static struct http_response res;
  13
  14
  15         if( (bufptr = strfind(buf, len, "\r\n\r\n", 4)) != NULL )
  16         {
  17                 *off = (int)(bufptr - buf) + 4;
  18
  19                 memset(&res, 0, sizeof(res));
  20
  21                 res.statuscode = 200;
  22                 res.statusmsg  = "OK";
  23
  24                 bufptr = &buf[0];
  25
  26                 for( pos = 0; pos < len; pos++ )
  27                 {
  28                         if( !hdrname && (buf[pos] == ':') )
  29                         {
  30                                 buf[pos++] = 0;
  31
  32                                 if( (pos < len) && (buf[pos] == ' ') )
  33                                         pos++;
  34
  35                                 if( pos < len )
  36                                 {
  37                                         hdrname = bufptr;
  38                                         bufptr = &buf[pos];
  39                                 }
  40                         }
  41
  42                         else if( (buf[pos] == '\r') || (buf[pos] == '\n') )
  43                         {
  44                                 buf[pos++] = 0;
  45
  46                                 if( ! hdrname )
  47                                         break;
  48
  49                                 if( (pos < len) && (buf[pos] == '\n') )
  50                                         pos++;
  51
  52                                 if( pos < len )
  53                                 {
  54                                         if( (hdrcount + 1) < array_size(res.headers) )
  55                                         {
  56                                                 if( ! strcasecmp(hdrname, "Status") )
  57                                                 {
  58                                                         res.statuscode = atoi(bufptr);
  59
  60                                                         if( res.statuscode < 100 )
  61                                                                 res.statuscode = 200;
  62
  63                                                         if( ((bufptr = strchr(bufptr, ' ')) != NULL) && (&bufptr[1] != 0) )
  64                                                                 res.statusmsg = &bufptr[1];
  65                                                 }
  66                                                 else
  67                                                 {
  68                                                         res.headers[hdrcount++] = hdrname;
  69                                                         res.headers[hdrcount++] = bufptr;
  70                                                 }
  71
  72                                                 bufptr = &buf[pos];
  73                                                 hdrname = NULL;
  74                                         }
  75                                         else
  76                                         {
  77                                                 return NULL;
  78                                         }
  79                                 }
  80                         }
  81                 }
  82
  83                 return &res;
  84         }
  85
  86         return NULL;
  87 }
  88
  89 static char * uh_cgi_header_lookup(struct http_response *res, const char *hdrname)
  90 {
  91         int i;
  92
  93         foreach_header(i, res->headers)
  94         {
  95                 if( ! strcasecmp(res->headers[i], hdrname) )
  96                         return res->headers[i+1];
  97         }
  98
  99         return NULL;
 100 }
 101
 102 static void uh_cgi_error_500(struct client *cl, struct http_request *req, const char *message)
 103 {
 104         uh_http_sendf(cl, NULL,
 105                 "HTTP/%.1f 500 Internal Server Error\r\n"
 106                 "Content-Type: text/plain\r\n%s\r\n",
 107                         req->version,
 108                         (req->version > 1.0)
 109                                 ? "Transfer-Encoding: chunked\r\n" : ""
 110         );
 111
 112         uh_http_send(cl, req, message, -1);
 113 }
 114
 115
 116 void uh_cgi_request(struct client *cl, struct http_request *req)
 117 {
 118         int i, hdroff, bufoff;
 119         int hdrlen = 0;
 120         int buflen = 0;
 121         int fd_max = 0;
 122         int content_length = 0;
 123         int header_sent = 0;
 124
 125         int rfd[2] = { 0, 0 };
 126         int wfd[2] = { 0, 0 };
 127
 128         char buf[UH_LIMIT_MSGHEAD];
 129         char hdr[UH_LIMIT_MSGHEAD];
 130
 131         fd_set reader;
 132         fd_set writer;
 133
 134         struct timeval timeout;
 135         struct http_response *res;
 136         struct uh_path_info *pi;
 137
 138
 139         /* spawn pipes for me->child, child->me */
 140         if( (pipe(rfd) < 0) || (pipe(wfd) < 0) )
 141         {
 142                 uh_http_sendhf(cl, 500, "Internal Server Error",
 143                         "Failed to create pipe: %s", strerror(errno));
 144
 145                 if( rfd[0] > 0 ) close(rfd[0]);
 146                 if( rfd[1] > 0 ) close(rfd[1]);
 147                 if( wfd[0] > 0 ) close(wfd[0]);
 148                 if( wfd[1] > 0 ) close(wfd[1]);
 149
 150                 return;
 151         }
 152
 153         /* fork off child process */
 154         switch( fork() )
 155         {
 156                 /* oops */
 157                 case -1:
 158                         uh_http_sendhf(cl, 500, "Internal Server Error",
 159                                 "Failed to fork child: %s", strerror(errno));
 160                         return;
 161
 162                 /* exec child */
 163                 case 0:
 164                         /* child */
 165                         close(rfd[0]);
 166                         close(wfd[1]);
 167
 168                         /* patch stdout and stdin to pipes */
 169                         dup2(rfd[1], 1);
 170                         dup2(wfd[0], 0);
 171
 172                         if( (pi = uh_path_lookup(cl, req->url)) != NULL )
 173                         {
 174                                 /* check for regular, world-executable file */
 175                                 if( (pi->stat.st_mode & S_IFREG) &&
 176                                     (pi->stat.st_mode & S_IXOTH)
 177                                 ) {
 178                                         /* build environment */
 179                                         clearenv();
 180
 181                                         /* common information */
 182                                         setenv("GATEWAY_INTERFACE", "CGI/1.1", 1);
 183                                         setenv("SERVER_SOFTWARE", "uHTTPd", 1);
 184                                         setenv("PATH", "/usr/bin:/bin", 1);
 185
 186 #ifdef HAVE_TLS
 187                                         /* https? */
 188                                         if( cl->tls )
 189                                                 setenv("HTTPS", "on", 1);
 190 #endif
 191
 192                                         /* addresses */
 193                                         setenv("SERVER_NAME", sa_straddr(&cl->servaddr), 1);
 194                                         setenv("SERVER_ADDR", sa_straddr(&cl->servaddr), 1);
 195                                         setenv("SERVER_PORT", sa_strport(&cl->servaddr), 1);
 196                                         setenv("REMOTE_HOST", sa_straddr(&cl->peeraddr), 1);
 197                                         setenv("REMOTE_ADDR", sa_straddr(&cl->peeraddr), 1);
 198                                         setenv("REMOTE_PORT", sa_strport(&cl->peeraddr), 1);
 199
 200                                         /* path information */
 201                                         setenv("SCRIPT_NAME", pi->name, 1);
 202                                         setenv("SCRIPT_FILENAME", pi->phys, 1);
 203                                         setenv("SCRIPT_WORKDIR", pi->wdir, 1);  /* nonstandard */
 204                                         setenv("DOCUMENT_ROOT", pi->root, 1);
 205                                         setenv("QUERY_STRING", pi->query ? pi->query : "", 1);
 206
 207                                         if( pi->info )
 208                                                 setenv("PATH_INFO", pi->info, 1);
 209
 210
 211                                         /* http version */
 212                                         if( req->version > 1.0 )
 213                                                 setenv("SERVER_PROTOCOL", "HTTP/1.1", 1);
 214                                         else
 215                                                 setenv("SERVER_PROTOCOL", "HTTP/1.0", 1);
 216
 217                                         /* request method */
 218                                         switch( req->method )
 219                                         {
 220                                                 case UH_HTTP_MSG_GET:
 221                                                         setenv("REQUEST_METHOD", "GET", 1);
 222                                                         break;
 223
 224                                                 case UH_HTTP_MSG_HEAD:
 225                                                         setenv("REQUEST_METHOD", "HEAD", 1);
 226                                                         break;
 227
 228                                                 case UH_HTTP_MSG_POST:
 229                                                         setenv("REQUEST_METHOD", "POST", 1);
 230                                                         break;
 231                                         }
 232
 233                                         /* request url */
 234                                         setenv("REQUEST_URI", req->url, 1);
 235
 236                                         /* request message headers */
 237                                         foreach_header(i, req->headers)
 238                                         {
 239                                                 if( ! strcasecmp(req->headers[i], "Accept") )
 240                                                         setenv("HTTP_ACCEPT", req->headers[i+1], 1);
 241
 242                                                 else if( ! strcasecmp(req->headers[i], "Accept-Charset") )
 243                                                         setenv("HTTP_ACCEPT_CHARSET", req->headers[i+1], 1);
 244
 245                                                 else if( ! strcasecmp(req->headers[i], "Accept-Encoding") )
 246                                                         setenv("HTTP_ACCEPT_ENCODING", req->headers[i+1], 1);
 247
 248                                                 else if( ! strcasecmp(req->headers[i], "Accept-Language") )
 249                                                         setenv("HTTP_ACCEPT_LANGUAGE", req->headers[i+1], 1);
 250
 251                                                 else if( ! strcasecmp(req->headers[i], "Authorization") )
 252                                                         setenv("HTTP_AUTHORIZATION", req->headers[i+1], 1);
 253
 254                                                 else if( ! strcasecmp(req->headers[i], "Connection") )
 255                                                         setenv("HTTP_CONNECTION", req->headers[i+1], 1);
 256
 257                                                 else if( ! strcasecmp(req->headers[i], "Cookie") )
 258                                                         setenv("HTTP_COOKIE", req->headers[i+1], 1);
 259
 260                                                 else if( ! strcasecmp(req->headers[i], "Host") )
 261                                                         setenv("HTTP_HOST", req->headers[i+1], 1);
 262
 263                                                 else if( ! strcasecmp(req->headers[i], "Referer") )
 264                                                         setenv("HTTP_REFERER", req->headers[i+1], 1);
 265
 266                                                 else if( ! strcasecmp(req->headers[i], "User-Agent") )
 267                                                         setenv("HTTP_USER_AGENT", req->headers[i+1], 1);
 268
 269                                                 else if( ! strcasecmp(req->headers[i], "Content-Type") )
 270                                                         setenv("CONTENT_TYPE", req->headers[i+1], 1);
 271
 272                                                 else if( ! strcasecmp(req->headers[i], "Content-Length") )
 273                                                         setenv("CONTENT_LENGTH", req->headers[i+1], 1);
 274                                         }
 275
 276
 277                                         /* execute child code ... */
 278                                         if( chdir(pi->wdir) )
 279                                                 perror("chdir()");
 280
 281                                         execl(pi->phys, pi->phys, NULL);
 282
 283                                         /* in case it fails ... */
 284                                         printf(
 285                                                 "Status: 500 Internal Server Error\r\n\r\n"
 286                                                 "Unable to launch the requested CGI program:\n"
 287                                                 "  %s: %s\n",
 288                                                         pi->phys, strerror(errno)
 289                                         );
 290                                 }
 291
 292                                 /* 403 */
 293                                 else
 294                                 {
 295                                         printf(
 296                                                 "Status: 403 Forbidden\r\n\r\n"
 297                                                 "Access to this resource is forbidden\n"
 298                                         );
 299                                 }
 300                         }
 301
 302                         /* 404 */
 303                         else
 304                         {
 305                                 printf(
 306                                         "Status: 404 Not Found\r\n\r\n"
 307                                         "Unable to launch the requested CGI program:\n"
 308                                         "  No such file or directory\n"
 309                                 );
 310                         }
 311
 312                         close(wfd[0]);
 313                         close(rfd[1]);
 314                         exit(0);
 315
 316                         break;
 317
 318                 /* parent; handle I/O relaying */
 319                 default:
 320                         /* close unneeded pipe ends */
 321                         close(rfd[1]);
 322                         close(wfd[0]);
 323
 324                         /* max watch fd */
 325                         fd_max = max(rfd[0], wfd[1]) + 1;
 326
 327                         /* find content length */
 328                         if( req->method == UH_HTTP_MSG_POST )
 329                         {
 330                                 foreach_header(i, req->headers)
 331                                 {
 332                                         if( ! strcasecmp(req->headers[i], "Content-Length") )
 333                                         {
 334                                                 content_length = atoi(req->headers[i+1]);
 335                                                 break;
 336                                         }
 337                                 }
 338                         }
 339
 340
 341                         memset(hdr, 0, sizeof(hdr));
 342
 343                         /* I/O loop, watch our pipe ends and dispatch child reads/writes from/to socket */
 344                         while( 1 )
 345                         {
 346                                 FD_ZERO(&reader);
 347                                 FD_ZERO(&writer);
 348
 349                                 FD_SET(rfd[0], &reader);
 350                                 FD_SET(wfd[1], &writer);
 351
 352                                 timeout.tv_sec = 3;
 353                                 timeout.tv_usec = 0;
 354
 355                                 /* wait until we can read or write or both */
 356                                 if( select(fd_max, &reader, (content_length > -1) ? &writer : NULL, NULL, &timeout) > 0 )
 357                                 {
 358                                         /* ready to write to cgi program */
 359                                         if( FD_ISSET(wfd[1], &writer) )
 360                                         {
 361                                                 /* there is unread post data waiting */
 362                                                 if( content_length > 0 )
 363                                                 {
 364                                                         /* read it from socket ... */
 365                                                         if( (buflen = uh_tcp_recv(cl, buf, min(content_length, sizeof(buf)))) > 0 )
 366                                                         {
 367                                                                 /* ... and write it to child's stdin */
 368                                                                 if( write(wfd[1], buf, buflen) < 0 )
 369                                                                         perror("write()");
 370
 371                                                                 content_length -= buflen;
 372                                                         }
 373
 374                                                         /* unexpected eof! */
 375                                                         else
 376                                                         {
 377                                                                 if( write(wfd[1], "", 0) < 0 )
 378                                                                         perror("write()");
 379
 380                                                                 content_length = 0;
 381                                                         }
 382                                                 }
 383
 384                                                 /* there is no more post data, close pipe to child's stdin */
 385                                                 else
 386                                                 {
 387                                                         close(wfd[1]);
 388                                                         content_length = -1;
 389                                                 }
 390                                         }
 391
 392                                         /* ready to read from cgi program */
 393                                         if( FD_ISSET(rfd[0], &reader) )
 394                                         {
 395                                                 /* read data from child ... */
 396                                                 if( (buflen = read(rfd[0], buf, sizeof(buf))) > 0 )
 397                                                 {
 398                                                         /* we have not pushed out headers yet, parse input */
 399                                                         if( ! header_sent )
 400                                                         {
 401                                                                 /* head buffer not full and no end yet */
 402                                                                 if( hdrlen < sizeof(hdr) )
 403                                                                 {
 404                                                                         bufoff = min(buflen, sizeof(hdr) - hdrlen);
 405                                                                         memcpy(&hdr[hdrlen], buf, bufoff);
 406                                                                         hdrlen += bufoff;
 407                                                                 }
 408                                                                 else
 409                                                                 {
 410                                                                         bufoff = 0;
 411                                                                 }
 412
 413
 414                                                                 /* try to parse header ... */
 415                                                                 if( (res = uh_cgi_header_parse(hdr, hdrlen, &hdroff)) != NULL )
 416                                                                 {
 417                                                                         /* write status */
 418                                                                         uh_http_sendf(cl, NULL, "HTTP/%.1f %03d %s\r\n",
 419                                                                                 req->version, res->statuscode, res->statusmsg);
 420
 421                                                                         /* add Content-Type if no Location or Content-Type */
 422                                                                         if( !uh_cgi_header_lookup(res, "Location") &&
 423                                                                             !uh_cgi_header_lookup(res, "Content-Type")
 424                                                                         ) {
 425                                                                                 uh_http_send(cl, NULL,
 426                                                                                         "Content-Type: text/plain\r\n", -1);
 427                                                                         }
 428
 429                                                                         /* if request was HTTP 1.1 we'll respond chunked */
 430                                                                         if( (req->version > 1.0) &&
 431                                                                             !uh_cgi_header_lookup(res, "Transfer-Encoding")
 432                                                                         ) {
 433                                                                                 uh_http_send(cl, NULL,
 434                                                                                         "Transfer-Encoding: chunked\r\n", -1);
 435                                                                         }
 436
 437                                                                         /* write headers from CGI program */
 438                                                                         foreach_header(i, res->headers)
 439                                                                         {
 440                                                                                 uh_http_sendf(cl, NULL, "%s: %s\r\n",
 441                                                                                         res->headers[i], res->headers[i+1]);
 442                                                                         }
 443
 444                                                                         /* terminate header */
 445                                                                         uh_http_send(cl, NULL, "\r\n", -1);
 446
 447                                                                         /* push out remaining head buffer */
 448                                                                         if( hdroff < hdrlen )
 449                                                                                 uh_http_send(cl, req, &hdr[hdroff], hdrlen - hdroff);
 450                                                                 }
 451
 452                                                                 /* ... failed and head buffer exceeded */
 453                                                                 else if( hdrlen >= sizeof(hdr) )
 454                                                                 {
 455                                                                         uh_cgi_error_500(cl, req,
 456                                                                                 "The CGI program generated an invalid response:\n\n");
 457
 458                                                                         uh_http_send(cl, req, hdr, hdrlen);
 459                                                                 }
 460
 461                                                                 /* ... failed but free buffer space, try again */
 462                                                                 else
 463                                                                 {
 464                                                                         continue;
 465                                                                 }
 466
 467                                                                 /* push out remaining read buffer */
 468                                                                 if( bufoff < buflen )
 469                                                                         uh_http_send(cl, req, &buf[bufoff], buflen - bufoff);
 470
 471                                                                 header_sent = 1;
 472                                                                 continue;
 473                                                         }
 474
 475
 476                                                         /* headers complete, pass through buffer to socket */
 477                                                         uh_http_send(cl, req, buf, buflen);
 478                                                 }
 479
 480                                                 /* looks like eof from child */
 481                                                 else
 482                                                 {
 483                                                         /* send final chunk if we're in chunked transfer mode */
 484                                                         uh_http_send(cl, req, "", 0);
 485                                                         break;
 486                                                 }
 487                                         }
 488                                 }
 489
 490                                 /* no activity for 3 seconds... looks dead */
 491                                 else
 492                                 {
 493                                         uh_http_sendhf(cl, 504, "Gateway Timeout",
 494                                                 "The CGI script took too long to produce a response");
 495
 496                                         break;
 497                                 }
 498                         }
 499
 500                         close(rfd[0]);
 501                         close(wfd[1]);
 502
 503                         break;
 504         }
 505 }
 506