git.maemo.org Git - presencevnc/blob - libvnc/libvncserver/httpd.c

   1 /*
   2  * httpd.c - a simple HTTP server
   3  */
   4
   5 /*
   6  *  Copyright (C) 2002 RealVNC Ltd.
   7  *  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
   8  *
   9  *  This is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This software is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this software; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
  22  *  USA.
  23  */
  24
  25 #include <rfb/rfb.h>
  26
  27 #include <ctype.h>
  28 #ifdef LIBVNCSERVER_HAVE_UNISTD_H
  29 #include <unistd.h>
  30 #endif
  31 #ifdef LIBVNCSERVER_HAVE_SYS_TYPES_H
  32 #include <sys/types.h>
  33 #endif
  34 #ifdef LIBVNCSERVER_HAVE_FCNTL_H
  35 #include <fcntl.h>
  36 #endif
  37 #include <errno.h>
  38
  39 #ifdef WIN32
  40 #include <winsock.h>
  41 #define close closesocket
  42 #else
  43 #ifdef LIBVNCSERVER_HAVE_SYS_TIME_H
  44 #include <sys/time.h>
  45 #endif
  46 #ifdef LIBVNCSERVER_HAVE_SYS_SOCKET_H
  47 #include <sys/socket.h>
  48 #endif
  49 #ifdef LIBVNCSERVER_HAVE_NETINET_IN_H
  50 #include <netinet/in.h>
  51 #include <netinet/tcp.h>
  52 #include <netdb.h>
  53 #include <arpa/inet.h>
  54 #endif
  55 #include <pwd.h>
  56 #endif
  57
  58 #ifdef USE_LIBWRAP
  59 #include <tcpd.h>
  60 #endif
  61
  62 #define connection_close
  63 #ifndef connection_close
  64
  65 #define NOT_FOUND_STR "HTTP/1.0 404 Not found\r\n\r\n" \
  66     "<HEAD><TITLE>File Not Found</TITLE></HEAD>\n" \
  67     "<BODY><H1>File Not Found</H1></BODY>\n"
  68
  69 #define INVALID_REQUEST_STR "HTTP/1.0 400 Invalid Request\r\n\r\n" \
  70     "<HEAD><TITLE>Invalid Request</TITLE></HEAD>\n" \
  71     "<BODY><H1>Invalid request</H1></BODY>\n"
  72
  73 #define OK_STR "HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n"
  74
  75 #else
  76
  77 #define NOT_FOUND_STR "HTTP/1.0 404 Not found\r\nConnection: close\r\n\r\n" \
  78     "<HEAD><TITLE>File Not Found</TITLE></HEAD>\n" \
  79     "<BODY><H1>File Not Found</H1></BODY>\n"
  80
  81 #define INVALID_REQUEST_STR "HTTP/1.0 400 Invalid Request\r\nConnection: close\r\n\r\n" \
  82     "<HEAD><TITLE>Invalid Request</TITLE></HEAD>\n" \
  83     "<BODY><H1>Invalid request</H1></BODY>\n"
  84
  85 #define OK_STR "HTTP/1.0 200 OK\r\nConnection: close\r\nContent-Type: text/html\r\n\r\n"
  86
  87 #endif
  88
  89 static void httpProcessInput(rfbScreenInfoPtr screen);
  90 static rfbBool compareAndSkip(char **ptr, const char *str);
  91 static rfbBool parseParams(const char *request, char *result, int max_bytes);
  92 static rfbBool validateString(char *str);
  93
  94 #define BUF_SIZE 32768
  95
  96 static char buf[BUF_SIZE];
  97 static size_t buf_filled=0;
  98
  99 /*
 100  * httpInitSockets sets up the TCP socket to listen for HTTP connections.
 101  */
 102
 103 void
 104 rfbHttpInitSockets(rfbScreenInfoPtr rfbScreen)
 105 {
 106     if (rfbScreen->httpInitDone)
 107         return;
 108
 109     rfbScreen->httpInitDone = TRUE;
 110
 111     if (!rfbScreen->httpDir)
 112         return;
 113
 114     if (rfbScreen->httpPort == 0) {
 115         rfbScreen->httpPort = rfbScreen->port-100;
 116     }
 117
 118     rfbLog("Listening for HTTP connections on TCP port %d\n", rfbScreen->httpPort);
 119
 120     rfbLog("  URL http://%s:%d\n",rfbScreen->thisHost,rfbScreen->httpPort);
 121
 122     if ((rfbScreen->httpListenSock =
 123       rfbListenOnTCPPort(rfbScreen->httpPort, rfbScreen->listenInterface)) < 0) {
 124         rfbLogPerror("ListenOnTCPPort");
 125         return;
 126     }
 127
 128    /*AddEnabledDevice(httpListenSock);*/
 129 }
 130
 131 void rfbHttpShutdownSockets(rfbScreenInfoPtr rfbScreen) {
 132     if(rfbScreen->httpSock>-1) {
 133         close(rfbScreen->httpSock);
 134         FD_CLR(rfbScreen->httpSock,&rfbScreen->allFds);
 135         rfbScreen->httpSock=-1;
 136     }
 137 }
 138
 139 /*
 140  * httpCheckFds is called from ProcessInputEvents to check for input on the
 141  * HTTP socket(s).  If there is input to process, httpProcessInput is called.
 142  */
 143
 144 void
 145 rfbHttpCheckFds(rfbScreenInfoPtr rfbScreen)
 146 {
 147     int nfds;
 148     fd_set fds;
 149     struct timeval tv;
 150     struct sockaddr_in addr;
 151     socklen_t addrlen = sizeof(addr);
 152
 153     if (!rfbScreen->httpDir)
 154         return;
 155
 156     if (rfbScreen->httpListenSock < 0)
 157         return;
 158
 159     FD_ZERO(&fds);
 160     FD_SET(rfbScreen->httpListenSock, &fds);
 161     if (rfbScreen->httpSock >= 0) {
 162         FD_SET(rfbScreen->httpSock, &fds);
 163     }
 164     tv.tv_sec = 0;
 165     tv.tv_usec = 0;
 166     nfds = select(max(rfbScreen->httpSock,rfbScreen->httpListenSock) + 1, &fds, NULL, NULL, &tv);
 167     if (nfds == 0) {
 168         return;
 169     }
 170     if (nfds < 0) {
 171 #ifdef WIN32
 172                 errno = WSAGetLastError();
 173 #endif
 174         if (errno != EINTR)
 175                 rfbLogPerror("httpCheckFds: select");
 176         return;
 177     }
 178
 179     if ((rfbScreen->httpSock >= 0) && FD_ISSET(rfbScreen->httpSock, &fds)) {
 180         httpProcessInput(rfbScreen);
 181     }
 182
 183     if (FD_ISSET(rfbScreen->httpListenSock, &fds)) {
 184         int flags;
 185         if (rfbScreen->httpSock >= 0) close(rfbScreen->httpSock);
 186
 187         if ((rfbScreen->httpSock = accept(rfbScreen->httpListenSock,
 188                                (struct sockaddr *)&addr, &addrlen)) < 0) {
 189             rfbLogPerror("httpCheckFds: accept");
 190             return;
 191         }
 192 #ifdef __MINGW32__
 193         rfbErr("O_NONBLOCK on MinGW32 NOT IMPLEMENTED");
 194 #else
 195 #ifdef USE_LIBWRAP
 196         if(!hosts_ctl("vnc",STRING_UNKNOWN,inet_ntoa(addr.sin_addr),
 197                       STRING_UNKNOWN)) {
 198           rfbLog("Rejected HTTP connection from client %s\n",
 199                  inet_ntoa(addr.sin_addr));
 200 #else
 201         flags = fcntl(rfbScreen->httpSock, F_GETFL);
 202
 203         if (flags < 0 || fcntl(rfbScreen->httpSock, F_SETFL, flags | O_NONBLOCK) == -1) {
 204             rfbLogPerror("httpCheckFds: fcntl");
 205 #endif
 206             close(rfbScreen->httpSock);
 207             rfbScreen->httpSock = -1;
 208             return;
 209         }
 210
 211         flags=fcntl(rfbScreen->httpSock,F_GETFL);
 212         if(flags==-1 ||
 213            fcntl(rfbScreen->httpSock,F_SETFL,flags|O_NONBLOCK)==-1) {
 214           rfbLogPerror("httpCheckFds: fcntl");
 215           close(rfbScreen->httpSock);
 216           rfbScreen->httpSock=-1;
 217           return;
 218         }
 219 #endif
 220
 221         /*AddEnabledDevice(httpSock);*/
 222     }
 223 }
 224
 225
 226 static void
 227 httpCloseSock(rfbScreenInfoPtr rfbScreen)
 228 {
 229     close(rfbScreen->httpSock);
 230     rfbScreen->httpSock = -1;
 231     buf_filled = 0;
 232 }
 233
 234 static rfbClientRec cl;
 235
 236 /*
 237  * httpProcessInput is called when input is received on the HTTP socket.
 238  */
 239
 240 static void
 241 httpProcessInput(rfbScreenInfoPtr rfbScreen)
 242 {
 243     struct sockaddr_in addr;
 244     socklen_t addrlen = sizeof(addr);
 245     char fullFname[512];
 246     char params[1024];
 247     char *ptr;
 248     char *fname;
 249     unsigned int maxFnameLen;
 250     FILE* fd;
 251     rfbBool performSubstitutions = FALSE;
 252     char str[256+32];
 253 #ifndef WIN32
 254     char* user=getenv("USER");
 255 #endif
 256
 257     cl.sock=rfbScreen->httpSock;
 258
 259     if (strlen(rfbScreen->httpDir) > 255) {
 260         rfbErr("-httpd directory too long\n");
 261         httpCloseSock(rfbScreen);
 262         return;
 263     }
 264     strcpy(fullFname, rfbScreen->httpDir);
 265     fname = &fullFname[strlen(fullFname)];
 266     maxFnameLen = 511 - strlen(fullFname);
 267
 268     buf_filled=0;
 269
 270     /* Read data from the HTTP client until we get a complete request. */
 271     while (1) {
 272         ssize_t got;
 273
 274         if (buf_filled > sizeof (buf)) {
 275             rfbErr("httpProcessInput: HTTP request is too long\n");
 276             httpCloseSock(rfbScreen);
 277             return;
 278         }
 279
 280         got = read (rfbScreen->httpSock, buf + buf_filled,
 281                             sizeof (buf) - buf_filled - 1);
 282
 283         if (got <= 0) {
 284             if (got == 0) {
 285                 rfbErr("httpd: premature connection close\n");
 286             } else {
 287                 if (errno == EAGAIN) {
 288                     return;
 289                 }
 290                 rfbLogPerror("httpProcessInput: read");
 291             }
 292             httpCloseSock(rfbScreen);
 293             return;
 294         }
 295
 296         buf_filled += got;
 297         buf[buf_filled] = '\0';
 298
 299         /* Is it complete yet (is there a blank line)? */
 300         if (strstr (buf, "\r\r") || strstr (buf, "\n\n") ||
 301             strstr (buf, "\r\n\r\n") || strstr (buf, "\n\r\n\r"))
 302             break;
 303     }
 304
 305
 306     /* Process the request. */
 307     if(rfbScreen->httpEnableProxyConnect) {
 308         const static char* PROXY_OK_STR = "HTTP/1.0 200 OK\r\nContent-Type: octet-stream\r\nPragma: no-cache\r\n\r\n";
 309         if(!strncmp(buf, "CONNECT ", 8)) {
 310             if(atoi(strchr(buf, ':')+1)!=rfbScreen->port) {
 311                 rfbErr("httpd: CONNECT format invalid.\n");
 312                 rfbWriteExact(&cl,INVALID_REQUEST_STR, strlen(INVALID_REQUEST_STR));
 313                 httpCloseSock(rfbScreen);
 314                 return;
 315             }
 316             /* proxy connection */
 317             rfbLog("httpd: client asked for CONNECT\n");
 318             rfbWriteExact(&cl,PROXY_OK_STR,strlen(PROXY_OK_STR));
 319             rfbNewClientConnection(rfbScreen,rfbScreen->httpSock);
 320             rfbScreen->httpSock = -1;
 321             return;
 322         }
 323         if (!strncmp(buf, "GET ",4) && !strncmp(strchr(buf,'/'),"/proxied.connection HTTP/1.", 27)) {
 324             /* proxy connection */
 325             rfbLog("httpd: client asked for /proxied.connection\n");
 326             rfbWriteExact(&cl,PROXY_OK_STR,strlen(PROXY_OK_STR));
 327             rfbNewClientConnection(rfbScreen,rfbScreen->httpSock);
 328             rfbScreen->httpSock = -1;
 329             return;
 330         }
 331     }
 332
 333     if (strncmp(buf, "GET ", 4)) {
 334         rfbErr("httpd: no GET line\n");
 335         httpCloseSock(rfbScreen);
 336         return;
 337     } else {
 338         /* Only use the first line. */
 339         buf[strcspn(buf, "\n\r")] = '\0';
 340     }
 341
 342     if (strlen(buf) > maxFnameLen) {
 343         rfbErr("httpd: GET line too long\n");
 344         httpCloseSock(rfbScreen);
 345         return;
 346     }
 347
 348     if (sscanf(buf, "GET %s HTTP/1.", fname) != 1) {
 349         rfbErr("httpd: couldn't parse GET line\n");
 350         httpCloseSock(rfbScreen);
 351         return;
 352     }
 353
 354     if (fname[0] != '/') {
 355         rfbErr("httpd: filename didn't begin with '/'\n");
 356         rfbWriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
 357         httpCloseSock(rfbScreen);
 358         return;
 359     }
 360
 361     if (strchr(fname+1, '/') != NULL) {
 362         rfbErr("httpd: asking for file in other directory\n");
 363         rfbWriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
 364         httpCloseSock(rfbScreen);
 365         return;
 366     }
 367
 368     getpeername(rfbScreen->httpSock, (struct sockaddr *)&addr, &addrlen);
 369     rfbLog("httpd: get '%s' for %s\n", fname+1,
 370            inet_ntoa(addr.sin_addr));
 371
 372     /* Extract parameters from the URL string if necessary */
 373
 374     params[0] = '\0';
 375     ptr = strchr(fname, '?');
 376     if (ptr != NULL) {
 377        *ptr = '\0';
 378        if (!parseParams(&ptr[1], params, 1024)) {
 379            params[0] = '\0';
 380            rfbErr("httpd: bad parameters in the URL\n");
 381        }
 382     }
 383
 384
 385     /* If we were asked for '/', actually read the file index.vnc */
 386
 387     if (strcmp(fname, "/") == 0) {
 388         strcpy(fname, "/index.vnc");
 389         rfbLog("httpd: defaulting to '%s'\n", fname+1);
 390     }
 391
 392     /* Substitutions are performed on files ending .vnc */
 393
 394     if (strlen(fname) >= 4 && strcmp(&fname[strlen(fname)-4], ".vnc") == 0) {
 395         performSubstitutions = TRUE;
 396     }
 397
 398     /* Open the file */
 399
 400     if ((fd = fopen(fullFname, "r")) == 0) {
 401         rfbLogPerror("httpProcessInput: open");
 402         rfbWriteExact(&cl, NOT_FOUND_STR, strlen(NOT_FOUND_STR));
 403         httpCloseSock(rfbScreen);
 404         return;
 405     }
 406
 407     rfbWriteExact(&cl, OK_STR, strlen(OK_STR));
 408
 409     while (1) {
 410         int n = fread(buf, 1, BUF_SIZE-1, fd);
 411         if (n < 0) {
 412             rfbLogPerror("httpProcessInput: read");
 413             fclose(fd);
 414             httpCloseSock(rfbScreen);
 415             return;
 416         }
 417
 418         if (n == 0)
 419             break;
 420
 421         if (performSubstitutions) {
 422
 423             /* Substitute $WIDTH, $HEIGHT, etc with the appropriate values.
 424                This won't quite work properly if the .vnc file is longer than
 425                BUF_SIZE, but it's reasonable to assume that .vnc files will
 426                always be short. */
 427
 428             char *ptr = buf;
 429             char *dollar;
 430             buf[n] = 0; /* make sure it's null-terminated */
 431
 432             while ((dollar = strchr(ptr, '$'))!=NULL) {
 433                 rfbWriteExact(&cl, ptr, (dollar - ptr));
 434
 435                 ptr = dollar;
 436
 437                 if (compareAndSkip(&ptr, "$WIDTH")) {
 438
 439                     sprintf(str, "%d", rfbScreen->width);
 440                     rfbWriteExact(&cl, str, strlen(str));
 441
 442                 } else if (compareAndSkip(&ptr, "$HEIGHT")) {
 443
 444                     sprintf(str, "%d", rfbScreen->height);
 445                     rfbWriteExact(&cl, str, strlen(str));
 446
 447                 } else if (compareAndSkip(&ptr, "$APPLETWIDTH")) {
 448
 449                     sprintf(str, "%d", rfbScreen->width);
 450                     rfbWriteExact(&cl, str, strlen(str));
 451
 452                 } else if (compareAndSkip(&ptr, "$APPLETHEIGHT")) {
 453
 454                     sprintf(str, "%d", rfbScreen->height + 32);
 455                     rfbWriteExact(&cl, str, strlen(str));
 456
 457                 } else if (compareAndSkip(&ptr, "$PORT")) {
 458
 459                     sprintf(str, "%d", rfbScreen->port);
 460                     rfbWriteExact(&cl, str, strlen(str));
 461
 462                 } else if (compareAndSkip(&ptr, "$DESKTOP")) {
 463
 464                     rfbWriteExact(&cl, rfbScreen->desktopName, strlen(rfbScreen->desktopName));
 465
 466                 } else if (compareAndSkip(&ptr, "$DISPLAY")) {
 467
 468                     sprintf(str, "%s:%d", rfbScreen->thisHost, rfbScreen->port-5900);
 469                     rfbWriteExact(&cl, str, strlen(str));
 470
 471                 } else if (compareAndSkip(&ptr, "$USER")) {
 472 #ifndef WIN32
 473                     if (user) {
 474                         rfbWriteExact(&cl, user,
 475                                    strlen(user));
 476                     } else
 477 #endif
 478                         rfbWriteExact(&cl, "?", 1);
 479                 } else if (compareAndSkip(&ptr, "$PARAMS")) {
 480                     if (params[0] != '\0')
 481                         rfbWriteExact(&cl, params, strlen(params));
 482                 } else {
 483                     if (!compareAndSkip(&ptr, "$$"))
 484                         ptr++;
 485
 486                     if (rfbWriteExact(&cl, "$", 1) < 0) {
 487                         fclose(fd);
 488                         httpCloseSock(rfbScreen);
 489                         return;
 490                     }
 491                 }
 492             }
 493             if (rfbWriteExact(&cl, ptr, (&buf[n] - ptr)) < 0)
 494                 break;
 495
 496         } else {
 497
 498             /* For files not ending .vnc, just write out the buffer */
 499
 500             if (rfbWriteExact(&cl, buf, n) < 0)
 501                 break;
 502         }
 503     }
 504
 505     fclose(fd);
 506     httpCloseSock(rfbScreen);
 507 }
 508
 509
 510 static rfbBool
 511 compareAndSkip(char **ptr, const char *str)
 512 {
 513     if (strncmp(*ptr, str, strlen(str)) == 0) {
 514         *ptr += strlen(str);
 515         return TRUE;
 516     }
 517
 518     return FALSE;
 519 }
 520
 521 /*
 522  * Parse the request tail after the '?' character, and format a sequence
 523  * of <param> tags for inclusion into an HTML page with embedded applet.
 524  */
 525
 526 static rfbBool
 527 parseParams(const char *request, char *result, int max_bytes)
 528 {
 529     char param_request[128];
 530     char param_formatted[196];
 531     const char *tail;
 532     char *delim_ptr;
 533     char *value_str;
 534     int cur_bytes, len;
 535
 536     result[0] = '\0';
 537     cur_bytes = 0;
 538
 539     tail = request;
 540     for (;;) {
 541         /* Copy individual "name=value" string into a buffer */
 542         delim_ptr = strchr((char *)tail, '&');
 543         if (delim_ptr == NULL) {
 544             if (strlen(tail) >= sizeof(param_request)) {
 545                 return FALSE;
 546             }
 547             strcpy(param_request, tail);
 548         } else {
 549             len = delim_ptr - tail;
 550             if (len >= sizeof(param_request)) {
 551                 return FALSE;
 552             }
 553             memcpy(param_request, tail, len);
 554             param_request[len] = '\0';
 555         }
 556
 557         /* Split the request into parameter name and value */
 558         value_str = strchr(&param_request[1], '=');
 559         if (value_str == NULL) {
 560             return FALSE;
 561         }
 562         *value_str++ = '\0';
 563         if (strlen(value_str) == 0) {
 564             return FALSE;
 565         }
 566
 567         /* Validate both parameter name and value */
 568         if (!validateString(param_request) || !validateString(value_str)) {
 569             return FALSE;
 570         }
 571
 572         /* Prepare HTML-formatted representation of the name=value pair */
 573         len = sprintf(param_formatted,
 574                       "<PARAM NAME=\"%s\" VALUE=\"%s\">\n",
 575                       param_request, value_str);
 576         if (cur_bytes + len + 1 > max_bytes) {
 577             return FALSE;
 578         }
 579         strcat(result, param_formatted);
 580         cur_bytes += len;
 581
 582         /* Go to the next parameter */
 583         if (delim_ptr == NULL) {
 584             break;
 585         }
 586         tail = delim_ptr + 1;
 587     }
 588     return TRUE;
 589 }
 590
 591 /*
 592  * Check if the string consists only of alphanumeric characters, '+'
 593  * signs, underscores, and dots. Replace all '+' signs with spaces.
 594  */
 595
 596 static rfbBool
 597 validateString(char *str)
 598 {
 599     char *ptr;
 600
 601     for (ptr = str; *ptr != '\0'; ptr++) {
 602         if (!isalnum(*ptr) && *ptr != '_' && *ptr != '.') {
 603             if (*ptr == '+') {
 604                 *ptr = ' ';
 605             } else {
 606                 return FALSE;
 607             }
 608         }
 609     }
 610     return TRUE;
 611 }
 612