libs/sgi-webuci/src/cgi.c

   1 /*
   2  * CGI routines for luci
   3  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   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 version 2
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 /*
  16  * Based on code from cgilib:
  17  *
  18  *   cgi.c - Some simple routines for CGI programming
  19  *   Copyright (c) 1996-9,2007,8  Martin Schulze <joey@infodrom.org>
  20  *
  21  *   This program is free software; you can redistribute it and/or modify
  22  *   it under the terms of the GNU General Public License as published by
  23  *   the Free Software Foundation; either version 2 of the License, or
  24  *   (at your option) any later version.
  25  *
  26  *   This program is distributed in the hope that it will be useful,
  27  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  29  *   GNU General Public License for more details.
  30  *
  31  *   You should have received a copy of the GNU General Public License
  32  *   along with this program; if not, write to the Free Software Foundation
  33  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  34  */
  35
  36 #define _GNU_SOURCE 1
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41 #include <string.h>
  42 #include <stdbool.h>
  43 #include <strings.h>
  44 #include <ctype.h>
  45 #include <lauxlib.h>
  46
  47 #define BUFSIZE 128
  48
  49 static char *
  50 cgiGetLine (FILE *stream)
  51 {
  52         static char *line = NULL;
  53         static size_t size = 0;
  54         char buf[BUFSIZE];
  55         char *cp;
  56
  57         if (!line) {
  58                 if ((line = (char *)malloc (BUFSIZE)) == NULL)
  59                         return NULL;
  60                 size = BUFSIZE;
  61         }
  62         line[0] = '\0';
  63
  64         while (!feof (stream)) {
  65                 if ((cp = fgets (buf, sizeof (buf), stream)) == NULL)
  66                         return NULL;
  67
  68                 if (strlen(line)+strlen(buf)+1 > size) {
  69                         if ((cp = (char *)realloc (line, size + BUFSIZE)) == NULL)
  70                                 return line;
  71                         size += BUFSIZE;
  72                         line = cp;
  73                 }
  74
  75                 strcat (line, buf);
  76                 if (line[strlen(line)-1] == '\n') {
  77                         line[strlen(line)-1] = '\0';
  78                         if (line[strlen(line)-1] == '\r')
  79                                 line[strlen(line)-1] = '\0';
  80                         return line;
  81                 }
  82         }
  83
  84         return NULL;
  85 }
  86
  87
  88 static const char *
  89 luci_getenv(lua_State *L, const char *name)
  90 {
  91         const char *ret;
  92
  93         lua_getfield(L, lua_upvalueindex(2), name);
  94         ret = lua_tostring(L, -1);
  95         lua_pop(L, 1);
  96         return ret;
  97 }
  98
  99 static void
 100 luci_setvar(lua_State *L, const char *name, const char *value, bool append)
 101 {
 102         /* Check if there is an existing value already */
 103         lua_getfield(L, lua_upvalueindex(1), name);
 104         if (lua_isnil(L, -1)) {
 105                 /* nope, we're safe - add a new one */
 106                 lua_pushstring(L, value);
 107                 lua_setfield(L, lua_upvalueindex(1), name);
 108         } else if (lua_istable(L, -1) && append) {
 109                 /* it's a table already, but appending is requested
 110                  * take the last element and append the new string to it */
 111                 int tlast = lua_objlen(L, -1);
 112                 lua_rawgeti(L, -1, tlast);
 113                 lua_pushstring(L, value);
 114                 lua_pushstring(L, "\n");
 115                 lua_concat(L, 3);
 116                 lua_rawseti(L, -2, tlast);
 117         } else if (lua_istable(L, -1)) {
 118                 /* it's a table, which means we already have two
 119                  * or more entries, add the next one */
 120
 121                 int tnext = lua_objlen(L, -1) + 1; /* next entry */
 122
 123                 lua_pushstring(L, value);
 124                 luaL_setn(L, -2, tnext);
 125                 lua_rawseti(L, -2, tnext);
 126         } else if (lua_isstring(L, -1) && append) {
 127                 /* append the new string to the existing variable */
 128                 lua_pushstring(L, value);
 129                 lua_pushstring(L, "\n");
 130                 lua_concat(L, 3);
 131                 lua_setfield(L, lua_upvalueindex(1), name);
 132         } else if (lua_isstring(L, -1)) {
 133                 /* we're trying to add a variable that already has
 134                  * a string value. convert the string value to a
 135                  * table and add our new value to the table as well
 136                  */
 137                 lua_createtable(L, 2, 0);
 138                 lua_pushvalue(L, -2); /* copy of the initial string value */
 139                 lua_rawseti(L, -2, 1);
 140
 141                 lua_pushstring(L, value);
 142                 lua_rawseti(L, -2, 2);
 143                 lua_setfield(L, lua_upvalueindex(1), name);
 144         } else {
 145                 luaL_error(L, "Invalid table entry type for index '%s'", name);
 146         }
 147 }
 148
 149 char *cgiDecodeString (char *text)
 150 {
 151         char *cp, *xp;
 152
 153         for (cp=text,xp=text; *cp; cp++) {
 154                 if (*cp == '%') {
 155                         if (strchr("0123456789ABCDEFabcdef", *(cp+1))
 156                                 && strchr("0123456789ABCDEFabcdef", *(cp+2))) {
 157                                 if (islower(*(cp+1)))
 158                                         *(cp+1) = toupper(*(cp+1));
 159                                 if (islower(*(cp+2)))
 160                                         *(cp+2) = toupper(*(cp+2));
 161                                 *(xp) = (*(cp+1) >= 'A' ? *(cp+1) - 'A' + 10 : *(cp+1) - '0' ) * 16
 162                                         + (*(cp+2) >= 'A' ? *(cp+2) - 'A' + 10 : *(cp+2) - '0');
 163                                 xp++;cp+=2;
 164                         }
 165                 } else {
 166                         *(xp++) = *cp;
 167                 }
 168         }
 169         memset(xp, 0, cp-xp);
 170         return text;
 171 }
 172
 173 #if 0
 174 /* cgiReadFile()
 175  *
 176  * Read and save a file fro a multipart request
 177  */
 178 #include <errno.h>
 179 char *cgiReadFile (FILE *stream, char *boundary)
 180 {
 181         char *crlfboundary, *buf;
 182         size_t boundarylen;
 183         int c;
 184         unsigned int pivot;
 185         char *cp;
 186         char template[]= "/tmp/cgilibXXXXXX";
 187         FILE *tmpfile;
 188         int fd;
 189
 190         boundarylen = strlen(boundary)+3;
 191         if ((crlfboundary = (char *)malloc (boundarylen)) == NULL)
 192                 return NULL;
 193         sprintf (crlfboundary, "\r\n%s", boundary);
 194
 195         if ((buf = (char *)malloc (boundarylen)) == NULL) {
 196                 free (crlfboundary);
 197                 return NULL;
 198         }
 199         memset (buf, 0, boundarylen);
 200         pivot = 0;
 201
 202         if ((fd = mkstemp (template)) == -1) {
 203                 free (crlfboundary);
 204                 free (buf);
 205                 return NULL;
 206         }
 207
 208         if ((tmpfile = fdopen (fd, "w")) == NULL) {
 209                 free (crlfboundary);
 210                 free (buf);
 211                 unlink (template);
 212                 return NULL;
 213         }
 214
 215         while (!feof (stream)) {
 216                 c = fgetc (stream);
 217
 218                 if (c == 0) {
 219                         if (strlen (buf)) {
 220                                 for (cp=buf; *cp; cp++)
 221                                         putc (*cp, tmpfile);
 222                                 memset (buf, 0, boundarylen);
 223                                 pivot = 0;
 224                         }
 225                         putc (c, tmpfile);
 226                         continue;
 227                 }
 228
 229                 if (strlen (buf)) {
 230                         if (crlfboundary[pivot+1] == c) {
 231                                 buf[++pivot] = c;
 232
 233                                 if (strlen (buf) == strlen (crlfboundary))
 234                                         break;
 235                                 else
 236                                         continue;
 237                         } else {
 238                                 for (cp=buf; *cp; cp++)
 239                                         putc (*cp, tmpfile);
 240                                 memset (buf, 0, boundarylen);
 241                                 pivot = 0;
 242                         }
 243                 }
 244
 245                 if (crlfboundary[0] == c) {
 246                         buf[0] = c;
 247                 } else {
 248                         fputc (c, tmpfile);
 249                 }
 250         }
 251
 252         if (!feof (stream))
 253                 fgets (buf, boundarylen, stream);
 254
 255         fclose (tmpfile);
 256
 257         free (crlfboundary);
 258         free (buf);
 259
 260         return strdup (template);
 261 }
 262 #endif
 263
 264 /*
 265  * Decode multipart/form-data
 266  */
 267 #define MULTIPART_DELTA 5
 268 void luci_parse_multipart (lua_State *L, char *boundary)
 269 {
 270         char *line;
 271         char *cp, *xp;
 272         char *name = NULL, *type = NULL;
 273         char *fname = NULL;
 274         int header = 1;
 275         bool append = false;
 276
 277         while ((line = cgiGetLine (stdin)) != NULL) {
 278                 if (!strncmp (line, boundary, strlen(boundary))) {
 279                         header = 1;
 280                         if (name)
 281                                 free(name);
 282                         if (type)
 283                                 free(type);
 284                         name = NULL;
 285                         type = NULL;
 286                         append = false;
 287                 } else if (header && !name && !strncasecmp (line, "Content-Disposition: form-data; ", 32)) {
 288                         if ((cp = strstr (line, "name=\"")) == NULL)
 289                                 continue;
 290                         cp += 6;
 291                         if ((xp = strchr (cp, '\"')) == NULL)
 292                                 continue;
 293                         name = malloc(xp-cp + 1);
 294                         strncpy(name, cp, xp-cp);
 295                         name[xp-cp] = 0;
 296                         cgiDecodeString (name);
 297
 298                         if ((cp = strstr (line, "filename=\"")) == NULL)
 299                                 continue;
 300                         cp += 10;
 301                         if ((xp = strchr (cp, '\"')) == NULL)
 302                                 continue;
 303                         fname = malloc(xp-cp + 1);
 304                         strncpy(fname, cp, xp-cp);
 305                         fname[xp-cp] = 0;
 306                         cgiDecodeString (fname);
 307                 } else if (header && !type && !strncasecmp (line, "Content-Type: ", 14)) {
 308                         cp = line + 14;
 309                         type = strdup (cp);
 310                 } else if (header) {
 311                         if (!strlen(line)) {
 312                                 header = 0;
 313
 314                                 if (fname) {
 315 #if 0
 316                                         header = 1;
 317                                         tmpfile = cgiReadFile (stdin, boundary);
 318
 319                                         if (!tmpfile) {
 320                                                 free (name);
 321                                                 free (fname);
 322                                                 if (type)
 323                                                         free (type);
 324                                                 name = fname = type = NULL;
 325                                         }
 326
 327                                         cgiDebugOutput (2, "Wrote %s (%s) to file: %s", name, fname, tmpfile);
 328
 329                                         if (!strlen (fname)) {
 330                                                 cgiDebugOutput (3, "Found empty filename, removing");
 331                                                 unlink (tmpfile);
 332                                                 free (tmpfile);
 333                                                 free (name);
 334                                                 free (fname);
 335                                                 if (type)
 336                                                         free (type);
 337                                                 name = fname = type = NULL;
 338                                         } else {
 339                                                 if ((file = (s_file *)malloc (sizeof (s_file))) == NULL) {
 340                                                         cgiDebugOutput (3, "malloc failed, ignoring %s=%s", name, fname);
 341                                                         unlink (tmpfile);
 342                                                         free (tmpfile);
 343                                                         free (name);
 344                                                         free (fname);
 345                                                         if (type)
 346                                                                 free (type);
 347                                                         name = fname = type = NULL;
 348                                                         continue;
 349                                                 }
 350
 351                                                 file->name = name;
 352                                                 file->type = type;
 353                                                 file->tmpfile = tmpfile;
 354                                                 if ((cp = rindex (fname, '/')) == NULL)
 355                                                         file->filename = fname;
 356                                                 else {
 357                                                         file->filename = strdup (++cp);
 358                                                         free (fname);
 359                                                 }
 360                                                 name = type = fname = NULL;
 361
 362                                                 if (!files) {
 363                                                         if ((files = (s_file **)malloc(2*sizeof (s_file *))) == NULL) {
 364                                                                 cgiDebugOutput (3, "malloc failed, ignoring %s=%s", name, fname);
 365                                                                 unlink (tmpfile);
 366                                                                 free (tmpfile);
 367                                                                 free (name);
 368                                                                 name = NULL;
 369                                                                 if (type) {
 370                                                                         free (type);
 371                                                                         type = NULL;
 372                                                                 }
 373                                                                 free (file->filename);
 374                                                                 free (file);
 375                                                                 continue;
 376                                                         }
 377                                                         memset (files, 0, 2*sizeof (s_file *));
 378                                                         index = 0;
 379                                                 } else {
 380                                                         for (index=0; files[index]; index++);
 381                                                         if ((tmpf = (s_file **)realloc(files, (index+2)*sizeof (s_file *))) == NULL) {
 382                                                                 cgiDebugOutput (3, "realloc failed, ignoring %s=%s", name, fname);
 383                                                                 unlink (tmpfile);
 384                                                                 free (tmpfile);
 385                                                                 free (name);
 386                                                                 if (type)
 387                                                                         free (type);
 388                                                                 free (file->filename);
 389                                                                 free (file);
 390                                                                 name = type = fname = NULL;
 391                                                                 continue;
 392                                                         }
 393                                                         files = tmpf;
 394                                                         memset (files + index, 0, 2*sizeof (s_file *));
 395                                                 }
 396                                                 files[index] = file;
 397                                         }
 398 #else
 399                                         free(fname);
 400                                         fname = NULL;
 401 #endif
 402                                 }
 403                         }
 404                 } else {
 405                         if (!name)
 406                                 return;
 407
 408                         cgiDecodeString(line);
 409                         luci_setvar(L, name, line, append);
 410                         if (!append) /* beginning of variable contents */
 411                                 append = true;
 412                 }
 413         }
 414 }
 415
 416 /* parse the request header and store variables
 417  * in the array supplied as function argument 1 on the stack
 418  */
 419 int luci_parse_header (lua_State *L)
 420 {
 421         int length;
 422         char *line = NULL;
 423         int numargs;
 424         char *cp = NULL, *ip = NULL, *esp = NULL;
 425         const char *ct, *il;
 426         int i;
 427
 428         if (!lua_istable(L, lua_upvalueindex(1)))
 429                 luaL_error(L, "Invalid argument");
 430
 431         if (!lua_istable(L, lua_upvalueindex(2)))
 432                 luaL_error(L, "Invalid argument");
 433
 434         ct = luci_getenv(L, "content_type");
 435         if (ct) {
 436                 ct = cp = strdup(ct);
 437         }
 438         if (cp && strstr(cp, "multipart/form-data") && strstr(cp, "boundary=")) {
 439                 cp = strstr(cp, "boundary=") + strlen ("boundary=") - 2;
 440                 *cp = *(cp+1) = '-';
 441                 luci_parse_multipart(L, cp);
 442                 free((char *) ct);
 443                 return 0;
 444         }
 445         free((char *) ct);
 446
 447         ct = luci_getenv(L, "request_method");
 448         il = luci_getenv(L, "content_length");
 449
 450         if (!ct) {
 451                 fprintf(stderr, "no request method!\n");
 452                 return 0;
 453         }
 454
 455         if (!strcmp(ct, "POST")) {
 456                 if (il) {
 457                         length = atoi(il);
 458                         if (length <= 0)
 459                                 return 0;
 460                         line = (char *)malloc (length+2);
 461                         if (line)
 462                                 fgets(line, length+1, stdin);
 463                 }
 464         } else if (!strcmp(ct, "GET")) {
 465                 ct = luci_getenv(L, "query_string");
 466                 if (ct)
 467                         esp = strdup(ct);
 468                 if (esp && strlen(esp)) {
 469                         line = (char *)malloc (strlen(esp)+2);
 470                         if (line)
 471                                 strcpy (line, esp);
 472                 }
 473                 free(esp);
 474         }
 475
 476         if (!line)
 477                 return 0;
 478
 479         /*
 480          *  From now on all cgi variables are stored in the variable line
 481          *  and look like  foo=bar&foobar=barfoo&foofoo=
 482          */
 483         for (cp=line; *cp; cp++)
 484                 if (*cp == '+')
 485                         *cp = ' ';
 486
 487         if (strlen(line)) {
 488                 for (numargs=1,cp=line; *cp; cp++)
 489                         if (*cp == '&' || *cp == ';' ) numargs++;
 490         } else
 491                 numargs = 0;
 492
 493         cp = line;
 494         i=0;
 495         while (*cp) {
 496                 char *name;
 497                 char *value;
 498
 499                 if ((ip = (char *)strchr(cp, '&')) != NULL) {
 500                         *ip = '\0';
 501                 } else if ((ip = (char *)strchr(cp, ';')) != NULL) {
 502                         *ip = '\0';
 503                 } else
 504                         ip = cp + strlen(cp);
 505
 506                 if ((esp=(char *)strchr(cp, '=')) == NULL)
 507                         goto skip;
 508
 509                 if (!strlen(esp))
 510                         goto skip;
 511
 512                 if (i >= numargs)
 513                         goto skip;
 514
 515                 esp[0] = 0;
 516                 name = cp;
 517                 cgiDecodeString (name);
 518
 519                 cp = ++esp;
 520                 value = cp;
 521                 cgiDecodeString (value);
 522
 523                 luci_setvar(L, name, value, false);
 524 skip:
 525                 cp = ++ip;
 526         }
 527         free(line);
 528         return 0;
 529 }
 530