release/src/router/samba3/source/web/cgi.c

   1 /*
   2    some simple CGI helper routines
   3    Copyright (C) Andrew Tridgell 1997-1998
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18 */
  19
  20
  21 #include "includes.h"
  22 #include "web/swat_proto.h"
  23 #include "secrets.h"
  24
  25 #define MAX_VARIABLES 10000
  26
  27 /* set the expiry on fixed pages */
  28 #define EXPIRY_TIME (60*60*24*7)
  29
  30 #ifdef DEBUG_COMMENTS
  31 extern void print_title(char *fmt, ...);
  32 #endif
  33
  34 struct cgi_var {
  35         char *name;
  36         char *value;
  37 };
  38
  39 static struct cgi_var variables[MAX_VARIABLES];
  40 static int num_variables;
  41 static int content_length;
  42 static int request_post;
  43 static char *query_string;
  44 static const char *baseurl;
  45 static char *pathinfo;
  46 static char *C_user;
  47 static char *C_pass;
  48 static BOOL inetd_server;
  49 static BOOL got_request;
  50
  51 static char *grab_line(FILE *f, int *cl)
  52 {
  53         char *ret = NULL;
  54         int i = 0;
  55         int len = 0;
  56
  57         while ((*cl)) {
  58                 int c;
  59
  60                 if (i == len) {
  61                         char *ret2;
  62                         if (len == 0) len = 1024;
  63                         else len *= 2;
  64                         ret2 = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR(ret, len);
  65                         if (!ret2) return ret;
  66                         ret = ret2;
  67                 }
  68
  69                 c = fgetc(f);
  70                 (*cl)--;
  71
  72                 if (c == EOF) {
  73                         (*cl) = 0;
  74                         break;
  75                 }
  76
  77                 if (c == '\r') continue;
  78
  79                 if (strchr_m("\n&", c)) break;
  80
  81                 ret[i++] = c;
  82
  83         }
  84
  85         if (ret) {
  86                 ret[i] = 0;
  87         }
  88         return ret;
  89 }
  90
  91 /**
  92  URL encoded strings can have a '+', which should be replaced with a space
  93
  94  (This was in rfc1738_unescape(), but that broke the squid helper)
  95 **/
  96
  97 static void plus_to_space_unescape(char *buf)
  98 {
  99         char *p=buf;
 100
 101         while ((p=strchr_m(p,'+')))
 102                 *p = ' ';
 103 }
 104
 105 /***************************************************************************
 106   load all the variables passed to the CGI program. May have multiple variables
 107   with the same name and the same or different values. Takes a file parameter
 108   for simulating CGI invocation eg loading saved preferences.
 109   ***************************************************************************/
 110 void cgi_load_variables(void)
 111 {
 112         static char *line;
 113         char *p, *s, *tok;
 114         int len, i;
 115         FILE *f = stdin;
 116
 117 #ifdef DEBUG_COMMENTS
 118         char dummy[100]="";
 119         print_title(dummy);
 120         d_printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
 121 #endif
 122
 123         if (!content_length) {
 124                 p = getenv("CONTENT_LENGTH");
 125                 len = p?atoi(p):0;
 126         } else {
 127                 len = content_length;
 128         }
 129
 130
 131         if (len > 0 &&
 132             (request_post ||
 133              ((s=getenv("REQUEST_METHOD")) &&
 134               strequal(s,"POST")))) {
 135                 while (len && (line=grab_line(f, &len))) {
 136                         p = strchr_m(line,'=');
 137                         if (!p) continue;
 138
 139                         *p = 0;
 140
 141                         variables[num_variables].name = SMB_STRDUP(line);
 142                         variables[num_variables].value = SMB_STRDUP(p+1);
 143
 144                         SAFE_FREE(line);
 145
 146                         if (!variables[num_variables].name ||
 147                             !variables[num_variables].value)
 148                                 continue;
 149
 150                         plus_to_space_unescape(variables[num_variables].value);
 151                         rfc1738_unescape(variables[num_variables].value);
 152                         plus_to_space_unescape(variables[num_variables].name);
 153                         rfc1738_unescape(variables[num_variables].name);
 154
 155 #ifdef DEBUG_COMMENTS
 156                         printf("<!== POST var %s has value \"%s\"  ==>\n",
 157                                variables[num_variables].name,
 158                                variables[num_variables].value);
 159 #endif
 160
 161                         num_variables++;
 162                         if (num_variables == MAX_VARIABLES) break;
 163                 }
 164         }
 165
 166         fclose(stdin);
 167         open("/dev/null", O_RDWR);
 168
 169         if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
 170                 for (tok=strtok(s,"&;");tok;tok=strtok(NULL,"&;")) {
 171                         p = strchr_m(tok,'=');
 172                         if (!p) continue;
 173
 174                         *p = 0;
 175
 176                         variables[num_variables].name = SMB_STRDUP(tok);
 177                         variables[num_variables].value = SMB_STRDUP(p+1);
 178
 179                         if (!variables[num_variables].name ||
 180                             !variables[num_variables].value)
 181                                 continue;
 182
 183                         plus_to_space_unescape(variables[num_variables].value);
 184                         rfc1738_unescape(variables[num_variables].value);
 185                         plus_to_space_unescape(variables[num_variables].name);
 186                         rfc1738_unescape(variables[num_variables].name);
 187
 188 #ifdef DEBUG_COMMENTS
 189                         printf("<!== Commandline var %s has value \"%s\"  ==>\n",
 190                                variables[num_variables].name,
 191                                variables[num_variables].value);
 192 #endif
 193                         num_variables++;
 194                         if (num_variables == MAX_VARIABLES) break;
 195                 }
 196
 197         }
 198 #ifdef DEBUG_COMMENTS
 199         printf("<!== End dump in cgi_load_variables() ==>\n");
 200 #endif
 201
 202         /* variables from the client are in UTF-8 - convert them
 203            to our internal unix charset before use */
 204         for (i=0;i<num_variables;i++) {
 205                 pstring dest;
 206
 207                 convert_string(CH_UTF8, CH_UNIX,
 208                                variables[i].name, -1,
 209                                dest, sizeof(dest), True);
 210                 free(variables[i].name);
 211                 variables[i].name = SMB_STRDUP(dest);
 212
 213                 convert_string(CH_UTF8, CH_UNIX,
 214                                variables[i].value, -1,
 215                                dest, sizeof(dest), True);
 216                 free(variables[i].value);
 217                 variables[i].value = SMB_STRDUP(dest);
 218         }
 219 }
 220
 221
 222 /***************************************************************************
 223   find a variable passed via CGI
 224   Doesn't quite do what you think in the case of POST text variables, because
 225   if they exist they might have a value of "" or even " ", depending on the
 226   browser. Also doesn't allow for variables[] containing multiple variables
 227   with the same name and the same or different values.
 228   ***************************************************************************/
 229
 230 const char *cgi_variable(const char *name)
 231 {
 232         int i;
 233
 234         for (i=0;i<num_variables;i++)
 235                 if (strcmp(variables[i].name, name) == 0)
 236                         return variables[i].value;
 237         return NULL;
 238 }
 239
 240 /***************************************************************************
 241  Version of the above that can't return a NULL pointer.
 242 ***************************************************************************/
 243
 244 const char *cgi_variable_nonull(const char *name)
 245 {
 246         const char *var = cgi_variable(name);
 247         if (var) {
 248                 return var;
 249         } else {
 250                 return "";
 251         }
 252 }
 253
 254 /***************************************************************************
 255 tell a browser about a fatal error in the http processing
 256   ***************************************************************************/
 257 static void cgi_setup_error(const char *err, const char *header, const char *info)
 258 {
 259         if (!got_request) {
 260                 /* damn browsers don't like getting cut off before they give a request */
 261                 char line[1024];
 262                 while (fgets(line, sizeof(line)-1, stdin)) {
 263                         if (strnequal(line,"GET ", 4) ||
 264                             strnequal(line,"POST ", 5) ||
 265                             strnequal(line,"PUT ", 4)) {
 266                                 break;
 267                         }
 268                 }
 269         }
 270
 271         d_printf("HTTP/1.0 %s\r\n%sConnection: close\r\nContent-Type: text/html\r\n\r\n<HTML><HEAD><TITLE>%s</TITLE></HEAD><BODY><H1>%s</H1>%s<p></BODY></HTML>\r\n\r\n", err, header, err, err, info);
 272         fclose(stdin);
 273         fclose(stdout);
 274         exit(0);
 275 }
 276
 277
 278 /***************************************************************************
 279 tell a browser about a fatal authentication error
 280   ***************************************************************************/
 281 static void cgi_auth_error(void)
 282 {
 283         if (inetd_server) {
 284                 cgi_setup_error("401 Authorization Required",
 285                                 "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
 286                                 "You must be authenticated to use this service");
 287         } else {
 288                 printf("Content-Type: text/html\r\n");
 289
 290                 printf("\r\n<HTML><HEAD><TITLE>SWAT</TITLE></HEAD>\n");
 291                 printf("<BODY><H1>Installation Error</H1>\n");
 292                 printf("SWAT must be installed via inetd. It cannot be run as a CGI script<p>\n");
 293                 printf("</BODY></HTML>\r\n");
 294         }
 295         exit(0);
 296 }
 297
 298 /***************************************************************************
 299 authenticate when we are running as a CGI
 300   ***************************************************************************/
 301 static void cgi_web_auth(void)
 302 {
 303         const char *user = getenv("REMOTE_USER");
 304         struct passwd *pwd;
 305         const char *head = "Content-Type: text/html\r\n\r\n<HTML><BODY><H1>SWAT installation Error</H1>\n";
 306         const char *tail = "</BODY></HTML>\r\n";
 307
 308         if (!user) {
 309                 printf("%sREMOTE_USER not set. Not authenticated by web server.<br>%s\n",
 310                        head, tail);
 311                 exit(0);
 312         }
 313
 314         pwd = getpwnam_alloc(NULL, user);
 315         if (!pwd) {
 316                 printf("%sCannot find user %s<br>%s\n", head, user, tail);
 317                 exit(0);
 318         }
 319
 320         C_user = SMB_STRDUP(user);
 321
 322         if (!setuid(0)) {
 323                 C_pass = secrets_fetch_generic("root", "SWAT");
 324                 if (C_pass == NULL) {
 325                         char *tmp_pass = NULL;
 326                         tmp_pass = generate_random_str(16);
 327                         if (tmp_pass == NULL) {
 328                                 printf("%sFailed to create random nonce for "
 329                                        "SWAT session\n<br>%s\n", head, tail);
 330                                 exit(0);
 331                         }
 332                         secrets_store_generic("root", "SWAT", tmp_pass);
 333                         C_pass = SMB_STRDUP(tmp_pass);
 334                 }
 335         }
 336         setuid(pwd->pw_uid);
 337         if (geteuid() != pwd->pw_uid || getuid() != pwd->pw_uid) {
 338                 printf("%sFailed to become user %s - uid=%d/%d<br>%s\n",
 339                        head, user, (int)geteuid(), (int)getuid(), tail);
 340                 exit(0);
 341         }
 342         TALLOC_FREE(pwd);
 343 }
 344
 345
 346 /***************************************************************************
 347 handle a http authentication line
 348   ***************************************************************************/
 349 static BOOL cgi_handle_authorization(char *line)
 350 {
 351         char *p;
 352         fstring user, user_pass;
 353         struct passwd *pass = NULL;
 354
 355         if (!strnequal(line,"Basic ", 6)) {
 356                 goto err;
 357         }
 358         line += 6;
 359         while (line[0] == ' ') line++;
 360         base64_decode_inplace(line);
 361         if (!(p=strchr_m(line,':'))) {
 362                 /*
 363                  * Always give the same error so a cracker
 364                  * cannot tell why we fail.
 365                  */
 366                 goto err;
 367         }
 368         *p = 0;
 369
 370         convert_string(CH_UTF8, CH_UNIX,
 371                        line, -1,
 372                        user, sizeof(user), True);
 373
 374         convert_string(CH_UTF8, CH_UNIX,
 375                        p+1, -1,
 376                        user_pass, sizeof(user_pass), True);
 377
 378         /*
 379          * Try and get the user from the UNIX password file.
 380          */
 381
 382         pass = getpwnam_alloc(NULL, user);
 383
 384         /*
 385          * Validate the password they have given.
 386          */
 387
 388         if NT_STATUS_IS_OK(pass_check(pass, user, user_pass,
 389                       strlen(user_pass), NULL, False)) {
 390
 391                 if (pass) {
 392                         /*
 393                          * Password was ok.
 394                          */
 395
 396                         if ( initgroups(pass->pw_name, pass->pw_gid) != 0 )
 397                                 goto err;
 398
 399                         become_user_permanently(pass->pw_uid, pass->pw_gid);
 400
 401                         /* Save the users name */
 402                         C_user = SMB_STRDUP(user);
 403                         C_pass = SMB_STRDUP(user_pass);
 404                         TALLOC_FREE(pass);
 405                         return True;
 406                 }
 407         }
 408
 409 err:
 410         cgi_setup_error("401 Bad Authorization",
 411                         "WWW-Authenticate: Basic realm=\"SWAT\"\r\n",
 412                         "username or password incorrect");
 413
 414         TALLOC_FREE(pass);
 415         return False;
 416 }
 417
 418 /***************************************************************************
 419 is this root?
 420   ***************************************************************************/
 421 BOOL am_root(void)
 422 {
 423         if (geteuid() == 0) {
 424                 return( True);
 425         } else {
 426                 return( False);
 427         }
 428 }
 429
 430 /***************************************************************************
 431 return a ptr to the users name
 432   ***************************************************************************/
 433 char *cgi_user_name(void)
 434 {
 435         return(C_user);
 436 }
 437
 438 /***************************************************************************
 439 return a ptr to the users password
 440   ***************************************************************************/
 441 char *cgi_user_pass(void)
 442 {
 443         return(C_pass);
 444 }
 445
 446 /***************************************************************************
 447 handle a file download
 448   ***************************************************************************/
 449 static void cgi_download(char *file)
 450 {
 451         SMB_STRUCT_STAT st;
 452         char buf[1024];
 453         int fd, l, i;
 454         char *p;
 455         char *lang;
 456
 457         /* sanitise the filename */
 458         for (i=0;file[i];i++) {
 459                 if (!isalnum((int)file[i]) && !strchr_m("/.-_", file[i])) {
 460                         cgi_setup_error("404 File Not Found","",
 461                                         "Illegal character in filename");
 462                 }
 463         }
 464
 465         if (sys_stat(file, &st) != 0)
 466         {
 467                 cgi_setup_error("404 File Not Found","",
 468                                 "The requested file was not found");
 469         }
 470
 471         if (S_ISDIR(st.st_mode))
 472         {
 473                 snprintf(buf, sizeof(buf), "%s/index.html", file);
 474                 if (!file_exist(buf, &st) || !S_ISREG(st.st_mode))
 475                 {
 476                         cgi_setup_error("404 File Not Found","",
 477                                         "The requested file was not found");
 478                 }
 479         }
 480         else if (S_ISREG(st.st_mode))
 481         {
 482                 snprintf(buf, sizeof(buf), "%s", file);
 483         }
 484         else
 485         {
 486                 cgi_setup_error("404 File Not Found","",
 487                                 "The requested file was not found");
 488         }
 489
 490         fd = web_open(buf,O_RDONLY,0);
 491         if (fd == -1) {
 492                 cgi_setup_error("404 File Not Found","",
 493                                 "The requested file was not found");
 494         }
 495         printf("HTTP/1.0 200 OK\r\n");
 496         if ((p=strrchr_m(buf, '.'))) {
 497                 if (strcmp(p,".gif")==0) {
 498                         printf("Content-Type: image/gif\r\n");
 499                 } else if (strcmp(p,".jpg")==0) {
 500                         printf("Content-Type: image/jpeg\r\n");
 501                 } else if (strcmp(p,".png")==0) {
 502                         printf("Content-Type: image/png\r\n");
 503                 } else if (strcmp(p,".css")==0) {
 504                         printf("Content-Type: text/css\r\n");
 505                 } else if (strcmp(p,".txt")==0) {
 506                         printf("Content-Type: text/plain\r\n");
 507                 } else {
 508                         printf("Content-Type: text/html\r\n");
 509                 }
 510         }
 511         printf("Expires: %s\r\n", http_timestring(time(NULL)+EXPIRY_TIME));
 512
 513         lang = lang_tdb_current();
 514         if (lang) {
 515                 printf("Content-Language: %s\r\n", lang);
 516         }
 517
 518         printf("Content-Length: %d\r\n\r\n", (int)st.st_size);
 519         while ((l=read(fd,buf,sizeof(buf)))>0) {
 520                 fwrite(buf, 1, l, stdout);
 521         }
 522         close(fd);
 523         exit(0);
 524 }
 525
 526
 527
 528
 529 /**
 530  * @brief Setup the CGI framework.
 531  *
 532  * Setup the cgi framework, handling the possibility that this program
 533  * is either run as a true CGI program with a gateway to a web server, or
 534  * is itself a mini web server.
 535  **/
 536 void cgi_setup(const char *rootdir, int auth_required)
 537 {
 538         BOOL authenticated = False;
 539         char line[1024];
 540         char *url=NULL;
 541         char *p;
 542         char *lang;
 543
 544         if (chdir(rootdir)) {
 545                 cgi_setup_error("500 Server Error", "",
 546                                 "chdir failed - the server is not configured correctly");
 547         }
 548
 549         /* Handle the possibility we might be running as non-root */
 550         sec_init();
 551
 552         if ((lang=getenv("HTTP_ACCEPT_LANGUAGE"))) {
 553                 /* if running as a cgi program */
 554                 web_set_lang(lang);
 555         }
 556
 557         /* maybe we are running under a web server */
 558         if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
 559                 if (auth_required) {
 560                         cgi_web_auth();
 561                 }
 562                 return;
 563         }
 564
 565         inetd_server = True;
 566
 567         if (!check_access(1, lp_hostsallow(-1), lp_hostsdeny(-1))) {
 568                 cgi_setup_error("403 Forbidden", "",
 569                                 "Samba is configured to deny access from this client\n<br>Check your \"hosts allow\" and \"hosts deny\" options in smb.conf ");
 570         }
 571
 572         /* we are a mini-web server. We need to read the request from stdin
 573            and handle authentication etc */
 574         while (fgets(line, sizeof(line)-1, stdin)) {
 575                 if (line[0] == '\r' || line[0] == '\n') break;
 576                 if (strnequal(line,"GET ", 4)) {
 577                         got_request = True;
 578                         url = SMB_STRDUP(&line[4]);
 579                 } else if (strnequal(line,"POST ", 5)) {
 580                         got_request = True;
 581                         request_post = 1;
 582                         url = SMB_STRDUP(&line[5]);
 583                 } else if (strnequal(line,"PUT ", 4)) {
 584                         got_request = True;
 585                         cgi_setup_error("400 Bad Request", "",
 586                                         "This server does not accept PUT requests");
 587                 } else if (strnequal(line,"Authorization: ", 15)) {
 588                         authenticated = cgi_handle_authorization(&line[15]);
 589                 } else if (strnequal(line,"Content-Length: ", 16)) {
 590                         content_length = atoi(&line[16]);
 591                 } else if (strnequal(line,"Accept-Language: ", 17)) {
 592                         web_set_lang(&line[17]);
 593                 }
 594                 /* ignore all other requests! */
 595         }
 596
 597         if (auth_required && !authenticated) {
 598                 cgi_auth_error();
 599         }
 600
 601         if (!url) {
 602                 cgi_setup_error("400 Bad Request", "",
 603                                 "You must specify a GET or POST request");
 604         }
 605
 606         /* trim the URL */
 607         if ((p = strchr_m(url,' ')) || (p=strchr_m(url,'\t'))) {
 608                 *p = 0;
 609         }
 610         while (*url && strchr_m("\r\n",url[strlen(url)-1])) {
 611                 url[strlen(url)-1] = 0;
 612         }
 613
 614         /* anything following a ? in the URL is part of the query string */
 615         if ((p=strchr_m(url,'?'))) {
 616                 query_string = p+1;
 617                 *p = 0;
 618         }
 619
 620         string_sub(url, "/swat/", "", 0);
 621
 622         if (url[0] != '/' && strstr(url,"..")==0) {
 623                 cgi_download(url);
 624         }
 625
 626         printf("HTTP/1.0 200 OK\r\nConnection: close\r\n");
 627         printf("Date: %s\r\n", http_timestring(time(NULL)));
 628         baseurl = "";
 629         pathinfo = url+1;
 630 }
 631
 632
 633 /***************************************************************************
 634 return the current pages URL
 635   ***************************************************************************/
 636 const char *cgi_baseurl(void)
 637 {
 638         if (inetd_server) {
 639                 return baseurl;
 640         }
 641         return getenv("SCRIPT_NAME");
 642 }
 643
 644 /***************************************************************************
 645 return the current pages path info
 646   ***************************************************************************/
 647 const char *cgi_pathinfo(void)
 648 {
 649         char *r;
 650         if (inetd_server) {
 651                 return pathinfo;
 652         }
 653         r = getenv("PATH_INFO");
 654         if (!r) return "";
 655         if (*r == '/') r++;
 656         return r;
 657 }
 658
 659 /***************************************************************************
 660 return the hostname of the client
 661   ***************************************************************************/
 662 char *cgi_remote_host(void)
 663 {
 664         if (inetd_server) {
 665                 return get_peer_name(1,False);
 666         }
 667         return getenv("REMOTE_HOST");
 668 }
 669
 670 /***************************************************************************
 671 return the hostname of the client
 672   ***************************************************************************/
 673 char *cgi_remote_addr(void)
 674 {
 675         if (inetd_server) {
 676                 return get_peer_addr(1);
 677         }
 678         return getenv("REMOTE_ADDR");
 679 }
 680
 681
 682 /***************************************************************************
 683 return True if the request was a POST
 684   ***************************************************************************/
 685 BOOL cgi_waspost(void)
 686 {
 687         if (inetd_server) {
 688                 return request_post;
 689         }
 690         return strequal(getenv("REQUEST_METHOD"), "POST");
 691 }