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 "smb.h"
  23
  24 #define MAX_VARIABLES 10000
  25
  26 /* set the expiry on fixed pages */
  27 #define EXPIRY_TIME (60*60*24*7)
  28
  29 #define CGI_LOGGING 0
  30
  31 #ifdef DEBUG_COMMENTS
  32 extern void print_title(char *fmt, ...);
  33 #endif
  34
  35 struct var {
  36         char *name;
  37         char *value;
  38 };
  39
  40 static struct var variables[MAX_VARIABLES];
  41 static int num_variables;
  42 static int content_length;
  43 static int request_post;
  44 static int request_get;
  45 static char *query_string;
  46 static char *baseurl;
  47 static char *pathinfo;
  48
  49 static void unescape(char *buf)
  50 {
  51         char *p=buf;
  52
  53         while ((p=strchr(p,'+')))
  54                 *p = ' ';
  55
  56         p = buf;
  57
  58         while (p && *p && (p=strchr(p,'%'))) {
  59                 int c1 = p[1];
  60                 int c2 = p[2];
  61
  62                 if (c1 >= '0' && c1 <= '9')
  63                         c1 = c1 - '0';
  64                 else if (c1 >= 'A' && c1 <= 'F')
  65                         c1 = 10 + c1 - 'A';
  66                 else if (c1 >= 'a' && c1 <= 'f')
  67                         c1 = 10 + c1 - 'a';
  68                 else {p++; continue;}
  69
  70                 if (c2 >= '0' && c2 <= '9')
  71                         c2 = c2 - '0';
  72                 else if (c2 >= 'A' && c2 <= 'F')
  73                         c2 = 10 + c2 - 'A';
  74                 else if (c2 >= 'a' && c2 <= 'f')
  75                         c2 = 10 + c2 - 'a';
  76                 else {p++; continue;}
  77
  78                 *p = (c1<<4) | c2;
  79
  80                 memcpy(p+1, p+3, strlen(p+3)+1);
  81                 p++;
  82         }
  83 }
  84
  85
  86 static char *grab_line(FILE *f, int *cl)
  87 {
  88         char *ret;
  89         int i = 0;
  90         int len = 1024;
  91
  92         ret = (char *)malloc(len);
  93         if (!ret) return NULL;
  94
  95
  96         while ((*cl)) {
  97                 int c = fgetc(f);
  98                 (*cl)--;
  99
 100                 if (c == EOF) {
 101                         (*cl) = 0;
 102                         break;
 103                 }
 104
 105                 if (c == '\r') continue;
 106
 107                 if (strchr("\n&", c)) break;
 108
 109                 ret[i++] = c;
 110
 111                 if (i == len-1) {
 112                         char *ret2;
 113                         ret2 = (char *)realloc(ret, len*2);
 114                         if (!ret2) return ret;
 115                         len *= 2;
 116                         ret = ret2;
 117                 }
 118         }
 119
 120
 121         ret[i] = 0;
 122         return ret;
 123 }
 124
 125 /***************************************************************************
 126   load all the variables passed to the CGI program. May have multiple variables
 127   with the same name and the same or different values. Takes a file parameter
 128   for simulating CGI invocation eg loading saved preferences.
 129   ***************************************************************************/
 130 void cgi_load_variables(FILE *f1)
 131 {
 132         FILE *f = f1;
 133         static char *line;
 134         char *p, *s, *tok;
 135         int len;
 136
 137 #ifdef DEBUG_COMMENTS
 138         char dummy[100]="";
 139         print_title(dummy);
 140         printf("<!== Start dump in cgi_load_variables() %s ==>\n",__FILE__);
 141 #endif
 142
 143         if (!f1) {
 144                 f = stdin;
 145                 if (!content_length) {
 146                         p = getenv("CONTENT_LENGTH");
 147                         len = p?atoi(p):0;
 148                 } else {
 149                         len = content_length;
 150                 }
 151         } else {
 152                 fseek(f, 0, SEEK_END);
 153                 len = ftell(f);
 154                 fseek(f, 0, SEEK_SET);
 155         }
 156
 157
 158         if (len > 0 &&
 159             (f1 || request_post ||
 160              ((s=getenv("REQUEST_METHOD")) &&
 161               strcasecmp(s,"POST")==0))) {
 162                 while (len && (line=grab_line(f, &len))) {
 163                         p = strchr(line,'=');
 164                         if (!p) continue;
 165
 166                         *p = 0;
 167
 168                         variables[num_variables].name = strdup(line);
 169                         variables[num_variables].value = strdup(p+1);
 170
 171                         free(line);
 172
 173                         if (!variables[num_variables].name ||
 174                             !variables[num_variables].value)
 175                                 continue;
 176
 177                         unescape(variables[num_variables].value);
 178                         unescape(variables[num_variables].name);
 179
 180 #ifdef DEBUG_COMMENTS
 181                         printf("<!== POST var %s has value \"%s\"  ==>\n",
 182                                variables[num_variables].name,
 183                                variables[num_variables].value);
 184 #endif
 185
 186                         num_variables++;
 187                         if (num_variables == MAX_VARIABLES) break;
 188                 }
 189         }
 190
 191         if (f1) {
 192 #ifdef DEBUG_COMMENTS
 193                 printf("<!== End dump in cgi_load_variables() ==>\n");
 194 #endif
 195                 return;
 196         }
 197
 198         fclose(stdin);
 199
 200         if ((s=query_string) || (s=getenv("QUERY_STRING"))) {
 201                 for (tok=strtok(s,"&;");tok;tok=strtok(NULL,"&;")) {
 202                         p = strchr(tok,'=');
 203                         if (!p) continue;
 204
 205                         *p = 0;
 206
 207                         variables[num_variables].name = strdup(tok);
 208                         variables[num_variables].value = strdup(p+1);
 209
 210                         if (!variables[num_variables].name ||
 211                             !variables[num_variables].value)
 212                                 continue;
 213
 214                         unescape(variables[num_variables].value);
 215                         unescape(variables[num_variables].name);
 216
 217 #ifdef DEBUG_COMMENTS
 218                         printf("<!== Commandline var %s has value \"%s\"  ==>\n",
 219                                variables[num_variables].name,
 220                                variables[num_variables].value);
 221 #endif
 222                         num_variables++;
 223                         if (num_variables == MAX_VARIABLES) break;
 224                 }
 225
 226         }
 227 #ifdef DEBUG_COMMENTS
 228         printf("<!== End dump in cgi_load_variables() ==>\n");
 229 #endif
 230 }
 231
 232
 233 /***************************************************************************
 234   find a variable passed via CGI
 235   Doesn't quite do what you think in the case of POST text variables, because
 236   if they exist they might have a value of "" or even " ", depending on the
 237   browser. Also doesn't allow for variables[] containing multiple variables
 238   with the same name and the same or different values.
 239   ***************************************************************************/
 240 char *cgi_variable(char *name)
 241 {
 242         int i;
 243
 244         for (i=0;i<num_variables;i++)
 245                 if (strcmp(variables[i].name, name) == 0)
 246                         return variables[i].value;
 247         return NULL;
 248 }
 249
 250 /***************************************************************************
 251 return a particular cgi variable
 252   ***************************************************************************/
 253 char *cgi_vnum(int i, char **name)
 254 {
 255         if (i < 0 || i >= num_variables) return NULL;
 256         *name = variables[i].name;
 257         return variables[i].value;
 258 }
 259
 260 /***************************************************************************
 261   return the value of a CGI boolean variable.
 262   ***************************************************************************/
 263 int cgi_boolean(char *name, int def)
 264 {
 265         char *p = cgi_variable(name);
 266
 267         if (!p) return def;
 268
 269         return strcmp(p, "1") == 0;
 270 }
 271
 272 /***************************************************************************
 273 like strdup() but quotes < > and &
 274   ***************************************************************************/
 275 char *quotedup(char *s)
 276 {
 277         int i, n=0;
 278         int len;
 279         char *ret;
 280         char *d;
 281
 282         if (!s) return strdup("");
 283
 284         len = strlen(s);
 285
 286         for (i=0;i<len;i++)
 287                 if (s[i] == '<' || s[i] == '>' || s[i] == '&')
 288                         n++;
 289
 290         ret = malloc(len + n*6 + 1);
 291
 292         if (!ret) return NULL;
 293
 294         d = ret;
 295
 296         for (i=0;i<len;i++) {
 297                 switch (s[i]) {
 298                 case '<':
 299                         strcpy(d, "&lt;");
 300                         d += 4;
 301                         break;
 302
 303                 case '>':
 304                         strcpy(d, "&gt;");
 305                         d += 4;
 306                         break;
 307
 308                 case '&':
 309                         strcpy(d, "&amp;");
 310                         d += 5;
 311                         break;
 312
 313                 default:
 314                         *d++ = s[i];
 315                 }
 316         }
 317
 318         *d = 0;
 319
 320         return ret;
 321 }
 322
 323
 324 /***************************************************************************
 325 like strdup() but quotes a wide range of characters
 326   ***************************************************************************/
 327 char *urlquote(char *s)
 328 {
 329         int i, n=0;
 330         int len;
 331         char *ret;
 332         char *d;
 333         char *qlist = "\"\n\r'&<> \t+;";
 334
 335         if (!s) return strdup("");
 336
 337         len = strlen(s);
 338
 339         for (i=0;i<len;i++)
 340                 if (strchr(qlist, s[i])) n++;
 341
 342         ret = malloc(len + n*2 + 1);
 343
 344         if (!ret) return NULL;
 345
 346         d = ret;
 347
 348         for (i=0;i<len;i++) {
 349                 if (strchr(qlist,s[i])) {
 350                         sprintf(d, "%%%02X", (int)s[i]);
 351                         d += 3;
 352                 } else {
 353                         *d++ = s[i];
 354                 }
 355         }
 356
 357         *d = 0;
 358
 359         return ret;
 360 }
 361
 362
 363 /***************************************************************************
 364 like strdup() but quotes " characters
 365   ***************************************************************************/
 366 char *quotequotes(char *s)
 367 {
 368         int i, n=0;
 369         int len;
 370         char *ret;
 371         char *d;
 372
 373         if (!s) return strdup("");
 374
 375         len = strlen(s);
 376
 377         for (i=0;i<len;i++)
 378                 if (s[i] == '"')
 379                         n++;
 380
 381         ret = malloc(len + n*6 + 1);
 382
 383         if (!ret) return NULL;
 384
 385         d = ret;
 386
 387         for (i=0;i<len;i++) {
 388                 switch (s[i]) {
 389                 case '"':
 390                         strcpy(d, "&quot;");
 391                         d += 6;
 392                         break;
 393
 394                 default:
 395                         *d++ = s[i];
 396                 }
 397         }
 398
 399         *d = 0;
 400
 401         return ret;
 402 }
 403
 404
 405 /***************************************************************************
 406 quote spaces in a buffer
 407   ***************************************************************************/
 408 void quote_spaces(char *buf)
 409 {
 410         while (*buf) {
 411                 if (*buf == ' ') *buf = '+';
 412                 buf++;
 413         }
 414 }
 415
 416
 417
 418 /***************************************************************************
 419 tell a browser about a fatal error in the http processing
 420   ***************************************************************************/
 421 static void cgi_setup_error(char *err, char *header, char *info)
 422 {
 423         printf("HTTP/1.1 %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", err, header, err, err, info);
 424         exit(0);
 425 }
 426
 427
 428 /***************************************************************************
 429 decode a base64 string in-place - simple and slow algorithm
 430   ***************************************************************************/
 431 static void base64_decode(char *s)
 432 {
 433         char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 434         int bit_offset, byte_offset, idx, i;
 435         unsigned char *d = (unsigned char *)s;
 436         char *p;
 437
 438         i=0;
 439
 440         while (*s && (p=strchr(b64,*s))) {
 441                 idx = (int)(p - b64);
 442                 byte_offset = (i*6)/8;
 443                 bit_offset = (i*6)%8;
 444                 d[byte_offset] &= ~((1<<(8-bit_offset))-1);
 445                 if (bit_offset < 3) {
 446                         d[byte_offset] |= (idx << (2-bit_offset));
 447                 } else {
 448                         d[byte_offset] |= (idx >> (bit_offset-2));
 449                         d[byte_offset+1] = 0;
 450                         d[byte_offset+1] |= (idx << (8-(bit_offset-2))) & 0xFF;
 451                 }
 452                 s++; i++;
 453         }
 454 }
 455
 456
 457 /***************************************************************************
 458 handle a http authentication line
 459   ***************************************************************************/
 460 static int cgi_handle_authorization(char *line)
 461 {
 462         char *p, *user, *pass;
 463
 464         if (strncasecmp(line,"Basic ", 6)) {
 465                 cgi_setup_error("401 Bad Authorization", "",
 466                                 "Only basic authorization is understood");
 467         }
 468         line += 6;
 469         while (line[0] == ' ') line++;
 470         base64_decode(line);
 471         if (!(p=strchr(line,':'))) {
 472                 cgi_setup_error("401 Bad Authorization", "",
 473                                 "username/password must be supplied");
 474         }
 475         *p = 0;
 476         user = line;
 477         pass = p+1;
 478
 479         /* currently only allow connections as root */
 480         if (strcmp(user,"root")) {
 481                 cgi_setup_error("401 Bad Authorization", "",
 482                                 "incorrect username/password");
 483         }
 484
 485
 486         return password_ok(user, pass, strlen(pass), NULL);
 487 }
 488
 489
 490 /***************************************************************************
 491 handle a file download
 492   ***************************************************************************/
 493 static void cgi_download(char *file)
 494 {
 495         struct stat st;
 496         char buf[1024];
 497         int fd, l, i;
 498         char *p;
 499
 500         /* sanitise the filename */
 501         for (i=0;file[i];i++) {
 502                 if (!isalnum(file[i]) && !strchr("/.-_", file[i])) {
 503                         cgi_setup_error("404 File Not Found","",
 504                                         "Illegal character in filename");
 505                 }
 506         }
 507
 508         if (!file_exist(file, &st)) {
 509                 cgi_setup_error("404 File Not Found","",
 510                                 "The requested file was not found");
 511         }
 512         fd = open(file,O_RDONLY);
 513         if (fd == -1) {
 514                 cgi_setup_error("404 File Not Found","",
 515                                 "The requested file was not found");
 516         }
 517         printf("HTTP/1.1 200 OK\r\n");
 518         if ((p=strrchr(file,'.'))) {
 519                 if (strcmp(p,".gif")==0) {
 520                         printf("Content-Type: image/gif\r\n");
 521                 } else if (strcmp(p,".jpg")==0) {
 522                         printf("Content-Type: image/jpeg\r\n");
 523                 } else {
 524                         printf("Content-Type: text/html\r\n");
 525                 }
 526         }
 527         printf("Expires: %s\r\n", http_timestring(time(NULL)+EXPIRY_TIME));
 528
 529         printf("Content-Length: %d\r\n\r\n", (int)st.st_size);
 530         while ((l=read(fd,buf,sizeof(buf)))>0) {
 531                 fwrite(buf, 1, l, stdout);
 532         }
 533         close(fd);
 534         exit(0);
 535 }
 536
 537
 538 /***************************************************************************
 539 setup the cgi framework, handling the possability that this program is either
 540 run as a true cgi program by a web browser or is itself a mini web server
 541   ***************************************************************************/
 542 void cgi_setup(char *rootdir, int auth_required)
 543 {
 544         int authenticated = 0;
 545         char line[1024];
 546         char *url=NULL;
 547         char *p;
 548 #if CGI_LOGGING
 549         FILE *f;
 550 #endif
 551
 552         if (chdir(rootdir)) {
 553                 cgi_setup_error("400 Server Error", "",
 554                                 "chdir failed - the server is not configured correctly");
 555         }
 556
 557         if (getenv("CONTENT_LENGTH") || getenv("REQUEST_METHOD")) {
 558                 /* assume we are running under a real web server */
 559                 return;
 560         }
 561
 562 #if CGI_LOGGING
 563         f = fopen("/tmp/cgi.log", "a");
 564         if (f) fprintf(f,"\n[Date: %s   %s (%s)]\n",
 565                        http_timestring(time(NULL)),
 566                        client_name(1), client_addr(1));
 567 #endif
 568
 569         /* we are a mini-web server. We need to read the request from stdin
 570            and handle authentication etc */
 571         while (fgets(line, sizeof(line)-1, stdin)) {
 572 #if CGI_LOGGING
 573                 if (f) fputs(line, f);
 574 #endif
 575                 if (line[0] == '\r' || line[0] == '\n') break;
 576                 if (strncasecmp(line,"GET ", 4)==0) {
 577                         request_get = 1;
 578                         url = strdup(&line[4]);
 579                 } else if (strncasecmp(line,"POST ", 5)==0) {
 580                         request_post = 1;
 581                         url = strdup(&line[5]);
 582                 } else if (strncasecmp(line,"PUT ", 4)==0) {
 583                         cgi_setup_error("400 Bad Request", "",
 584                                         "This server does not accept PUT requests");
 585                 } else if (strncasecmp(line,"Authorization: ", 15)==0) {
 586                         authenticated = cgi_handle_authorization(&line[15]);
 587                 } else if (strncasecmp(line,"Content-Length: ", 16)==0) {
 588                         content_length = atoi(&line[16]);
 589                 }
 590                 /* ignore all other requests! */
 591         }
 592 #if CGI_LOGGING
 593         if (f) fclose(f);
 594 #endif
 595
 596         if (auth_required && !authenticated) {
 597                 cgi_setup_error("401 Authorization Required",
 598                                 "WWW-Authenticate: Basic realm=\"root\"\r\n",
 599                                 "You must be authenticated to use this service");
 600         }
 601
 602         if (!url) {
 603                 cgi_setup_error("400 Bad Request", "",
 604                                 "You must specify a GET or POST request");
 605         }
 606
 607         /* trim the URL */
 608         if ((p = strchr(url,' ')) || (p=strchr(url,'\t'))) {
 609                 *p = 0;
 610         }
 611         while (*url && strchr("\r\n",url[strlen(url)-1])) {
 612                 url[strlen(url)-1] = 0;
 613         }
 614
 615         /* anything following a ? in the URL is part of the query string */
 616         if ((p=strchr(url,'?'))) {
 617                 query_string = p+1;
 618                 *p = 0;
 619         }
 620
 621         if (strstr(url+1,"..")==0 && file_exist(url+1, NULL)) {
 622                 cgi_download(url+1);
 623         }
 624
 625         printf("HTTP/1.1 200 OK\r\nConnection: close\r\n");
 626         printf("Date: %s\r\n", http_timestring(time(NULL)));
 627         baseurl = "";
 628         pathinfo = url+1;
 629 }
 630
 631
 632 /***************************************************************************
 633 return the current pages URL
 634   ***************************************************************************/
 635 char *cgi_baseurl(void)
 636 {
 637         if (baseurl) {
 638                 return baseurl;
 639         }
 640         return getenv("SCRIPT_NAME");
 641 }
 642
 643 /***************************************************************************
 644 return the root URL for images etc
 645   ***************************************************************************/
 646 char *cgi_rooturl(void)
 647 {
 648         if (baseurl) {
 649                 return "/";
 650         }
 651         return "/swat/";
 652 }
 653
 654
 655 /***************************************************************************
 656 return the current pages path info
 657   ***************************************************************************/
 658 char *cgi_pathinfo(void)
 659 {
 660         char *r;
 661         if (pathinfo) {
 662                 return pathinfo;
 663         }
 664         r = getenv("PATH_INFO");
 665         if (!r) return "";
 666         if (*r == '/') r++;
 667         return r;
 668 }
 669
 670 /***************************************************************************
 671 return the hostname of the client
 672   ***************************************************************************/
 673 char *cgi_remote_host(void)
 674 {
 675         if (baseurl) {
 676                 return client_name(1);
 677         }
 678         return getenv("REMOTE_HOST");
 679 }
 680
 681 /***************************************************************************
 682 return the hostname of the client
 683   ***************************************************************************/
 684 char *cgi_remote_addr(void)
 685 {
 686         if (baseurl) {
 687                 return client_addr(1);
 688         }
 689         return getenv("REMOTE_ADDR");
 690 }
 691
 692
 693 /***************************************************************************
 694 return True if the request was a POST
 695   ***************************************************************************/
 696 BOOL cgi_waspost(void)
 697 {
 698         if (baseurl) {
 699                 return request_post;
 700         }
 701         return strequal(getenv("REQUEST_METHOD"), "POST");
 702 }