source/rpc_parse/parse_buffer.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  RPC Pipe client / server routines
   4  *
   5  *  Copyright (C) Andrew Tridgell              1992-2000,
   6  *  Copyright (C) Luke Kenneth Casson Leighton 1996-2000,
   7  *  Copyright (C) Jean François Micouleau      1998-2000,
   8  *  Copyright (C) Gerald Carter                2000-2005,
   9  *  Copyright (C) Tim Potter                   2001-2002.
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to the Free Software
  23  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include "includes.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_RPC_PARSE
  30
  31 /**********************************************************************
  32  Initialize a new spoolss buff for use by a client rpc
  33 **********************************************************************/
  34 void rpcbuf_init(RPC_BUFFER *buffer, uint32 size, TALLOC_CTX *ctx)
  35 {
  36         buffer->size = size;
  37         buffer->string_at_end = size;
  38         prs_init(&buffer->prs, size, ctx, MARSHALL);
  39         buffer->struct_start = prs_offset(&buffer->prs);
  40 }
  41
  42 /*******************************************************************
  43  Read/write a RPC_BUFFER struct.
  44 ********************************************************************/
  45
  46 BOOL prs_rpcbuffer(const char *desc, prs_struct *ps, int depth, RPC_BUFFER *buffer)
  47 {
  48         prs_debug(ps, depth, desc, "prs_rpcbuffer");
  49         depth++;
  50
  51         /* reading */
  52         if (UNMARSHALLING(ps)) {
  53                 buffer->size=0;
  54                 buffer->string_at_end=0;
  55
  56                 if (!prs_uint32("size", ps, depth, &buffer->size))
  57                         return False;
  58
  59                 /*
  60                  * JRA. I'm not sure if the data in here is in big-endian format if
  61                  * the client is big-endian. Leave as default (little endian) for now.
  62                  */
  63
  64                 if (!prs_init(&buffer->prs, buffer->size, prs_get_mem_context(ps), UNMARSHALL))
  65                         return False;
  66
  67                 if (!prs_append_some_prs_data(&buffer->prs, ps, prs_offset(ps), buffer->size))
  68                         return False;
  69
  70                 if (!prs_set_offset(&buffer->prs, 0))
  71                         return False;
  72
  73                 if (!prs_set_offset(ps, buffer->size+prs_offset(ps)))
  74                         return False;
  75
  76                 buffer->string_at_end=buffer->size;
  77
  78                 return True;
  79         }
  80         else {
  81                 BOOL ret = False;
  82
  83                 if (!prs_uint32("size", ps, depth, &buffer->size))
  84                         goto out;
  85
  86                 if (!prs_append_some_prs_data(ps, &buffer->prs, 0, buffer->size))
  87                         goto out;
  88
  89                 ret = True;
  90         out:
  91
  92                 /* We have finished with the data in buffer->prs - free it. */
  93                 prs_mem_free(&buffer->prs);
  94
  95                 return ret;
  96         }
  97 }
  98
  99 /*******************************************************************
 100  Read/write an RPC_BUFFER* struct.(allocate memory if unmarshalling)
 101 ********************************************************************/
 102
 103 BOOL prs_rpcbuffer_p(const char *desc, prs_struct *ps, int depth, RPC_BUFFER **buffer)
 104 {
 105         uint32 data_p;
 106
 107         /* caputure the pointer value to stream */
 108
 109         data_p = (uint32) *buffer;
 110
 111         if ( !prs_uint32("ptr", ps, depth, &data_p ))
 112                 return False;
 113
 114         /* we're done if there is no data */
 115
 116         if ( !data_p )
 117                 return True;
 118
 119         if ( UNMARSHALLING(ps) ) {
 120                 if ( !(*buffer = PRS_ALLOC_MEM(ps, RPC_BUFFER, 1)) )
 121                         return False;
 122         }
 123
 124         return prs_rpcbuffer( desc, ps, depth, *buffer);
 125 }
 126
 127 /****************************************************************************
 128  Allocate more memory for a RPC_BUFFER.
 129 ****************************************************************************/
 130
 131 BOOL rpcbuf_alloc_size(RPC_BUFFER *buffer, uint32 buffer_size)
 132 {
 133         prs_struct *ps;
 134         uint32 extra_space;
 135         uint32 old_offset;
 136
 137         ps= &buffer->prs;
 138
 139         /* damn, I'm doing the reverse operation of prs_grow() :) */
 140         if (buffer_size < prs_data_size(ps))
 141                 extra_space=0;
 142         else
 143                 extra_space = buffer_size - prs_data_size(ps);
 144
 145         /*
 146          * save the offset and move to the end of the buffer
 147          * prs_grow() checks the extra_space against the offset
 148          */
 149         old_offset=prs_offset(ps);
 150         prs_set_offset(ps, prs_data_size(ps));
 151
 152         if (!prs_grow(ps, extra_space))
 153                 return False;
 154
 155         prs_set_offset(ps, old_offset);
 156
 157         buffer->string_at_end=prs_data_size(ps);
 158
 159         return True;
 160 }
 161
 162 /*******************************************************************
 163  move a BUFFER from the query to the reply.
 164  As the data pointers in RPC_BUFFER are malloc'ed, not talloc'ed,
 165  this is ok. This is an OPTIMIZATION and is not strictly neccessary.
 166  Clears the memory to zero also.
 167 ********************************************************************/
 168
 169 void rpcbuf_move(RPC_BUFFER *src, RPC_BUFFER **dest)
 170 {
 171         SMB_ASSERT( src != NULL );
 172
 173         prs_switch_type(&src->prs, MARSHALL);
 174         if(!prs_set_offset(&src->prs, 0))
 175                 return;
 176         prs_force_dynamic(&src->prs);
 177         prs_mem_clear(&src->prs);
 178         *dest=src;
 179 }
 180
 181 /*******************************************************************
 182  Get the size of a BUFFER struct.
 183 ********************************************************************/
 184
 185 uint32 rpcbuf_get_size(RPC_BUFFER *buffer)
 186 {
 187         return (buffer->size);
 188 }
 189
 190
 191 /*******************************************************************
 192  * write a UNICODE string and its relative pointer.
 193  * used by all the RPC structs passing a buffer
 194  *
 195  * As I'm a nice guy, I'm forcing myself to explain this code.
 196  * MS did a good job in the overall spoolss code except in some
 197  * functions where they are passing the API buffer directly in the
 198  * RPC request/reply. That's to maintain compatiility at the API level.
 199  * They could have done it the good way the first time.
 200  *
 201  * So what happen is: the strings are written at the buffer's end,
 202  * in the reverse order of the original structure. Some pointers to
 203  * the strings are also in the buffer. Those are relative to the
 204  * buffer's start.
 205  *
 206  * If you don't understand or want to change that function,
 207  * first get in touch with me: jfm@samba.org
 208  *
 209  ********************************************************************/
 210
 211 BOOL smb_io_relstr(const char *desc, RPC_BUFFER *buffer, int depth, UNISTR *string)
 212 {
 213         prs_struct *ps=&buffer->prs;
 214
 215         if (MARSHALLING(ps)) {
 216                 uint32 struct_offset = prs_offset(ps);
 217                 uint32 relative_offset;
 218
 219                 buffer->string_at_end -= (size_of_relative_string(string) - 4);
 220                 if(!prs_set_offset(ps, buffer->string_at_end))
 221                         return False;
 222 #if 0   /* JERRY */
 223                 /*
 224                  * Win2k does not align strings in a buffer
 225                  * Tested against WinNT 4.0 SP 6a & 2k SP2  --jerry
 226                  */
 227                 if (!prs_align(ps))
 228                         return False;
 229 #endif
 230                 buffer->string_at_end = prs_offset(ps);
 231
 232                 /* write the string */
 233                 if (!smb_io_unistr(desc, string, ps, depth))
 234                         return False;
 235
 236                 if(!prs_set_offset(ps, struct_offset))
 237                         return False;
 238
 239                 relative_offset=buffer->string_at_end - buffer->struct_start;
 240                 /* write its offset */
 241                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 242                         return False;
 243         }
 244         else {
 245                 uint32 old_offset;
 246
 247                 /* read the offset */
 248                 if (!prs_uint32("offset", ps, depth, &(buffer->string_at_end)))
 249                         return False;
 250
 251                 if (buffer->string_at_end == 0)
 252                         return True;
 253
 254                 old_offset = prs_offset(ps);
 255                 if(!prs_set_offset(ps, buffer->string_at_end+buffer->struct_start))
 256                         return False;
 257
 258                 /* read the string */
 259                 if (!smb_io_unistr(desc, string, ps, depth))
 260                         return False;
 261
 262                 if(!prs_set_offset(ps, old_offset))
 263                         return False;
 264         }
 265         return True;
 266 }
 267
 268 /*******************************************************************
 269  * write a array of UNICODE strings and its relative pointer.
 270  * used by 2 RPC structs
 271  ********************************************************************/
 272
 273 BOOL smb_io_relarraystr(const char *desc, RPC_BUFFER *buffer, int depth, uint16 **string)
 274 {
 275         UNISTR chaine;
 276
 277         prs_struct *ps=&buffer->prs;
 278
 279         if (MARSHALLING(ps)) {
 280                 uint32 struct_offset = prs_offset(ps);
 281                 uint32 relative_offset;
 282                 uint16 *p;
 283                 uint16 *q;
 284                 uint16 zero=0;
 285                 p=*string;
 286                 q=*string;
 287
 288                 /* first write the last 0 */
 289                 buffer->string_at_end -= 2;
 290                 if(!prs_set_offset(ps, buffer->string_at_end))
 291                         return False;
 292
 293                 if(!prs_uint16("leading zero", ps, depth, &zero))
 294                         return False;
 295
 296                 while (p && (*p!=0)) {
 297                         while (*q!=0)
 298                                 q++;
 299
 300                         /* Yes this should be malloc not talloc. Don't change. */
 301
 302                         chaine.buffer = SMB_MALLOC((q-p+1)*sizeof(uint16));
 303                         if (chaine.buffer == NULL)
 304                                 return False;
 305
 306                         memcpy(chaine.buffer, p, (q-p+1)*sizeof(uint16));
 307
 308                         buffer->string_at_end -= (q-p+1)*sizeof(uint16);
 309
 310                         if(!prs_set_offset(ps, buffer->string_at_end)) {
 311                                 SAFE_FREE(chaine.buffer);
 312                                 return False;
 313                         }
 314
 315                         /* write the string */
 316                         if (!smb_io_unistr(desc, &chaine, ps, depth)) {
 317                                 SAFE_FREE(chaine.buffer);
 318                                 return False;
 319                         }
 320                         q++;
 321                         p=q;
 322
 323                         SAFE_FREE(chaine.buffer);
 324                 }
 325
 326                 if(!prs_set_offset(ps, struct_offset))
 327                         return False;
 328
 329                 relative_offset=buffer->string_at_end - buffer->struct_start;
 330                 /* write its offset */
 331                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 332                         return False;
 333
 334         } else {
 335
 336                 /* UNMARSHALLING */
 337
 338                 uint32 old_offset;
 339                 uint16 *chaine2=NULL;
 340                 int l_chaine=0;
 341                 int l_chaine2=0;
 342                 size_t realloc_size = 0;
 343
 344                 *string=NULL;
 345
 346                 /* read the offset */
 347                 if (!prs_uint32("offset", ps, depth, &buffer->string_at_end))
 348                         return False;
 349
 350                 old_offset = prs_offset(ps);
 351                 if(!prs_set_offset(ps, buffer->string_at_end + buffer->struct_start))
 352                         return False;
 353
 354                 do {
 355                         if (!smb_io_unistr(desc, &chaine, ps, depth))
 356                                 return False;
 357
 358                         l_chaine=str_len_uni(&chaine);
 359
 360                         /* we're going to add two more bytes here in case this
 361                            is the last string in the array and we need to add
 362                            an extra NULL for termination */
 363                         if (l_chaine > 0)
 364                         {
 365                                 uint16 *tc2;
 366
 367                                 realloc_size = (l_chaine2+l_chaine+2)*sizeof(uint16);
 368
 369                                 /* Yes this should be realloc - it's freed below. JRA */
 370
 371                                 if((tc2=(uint16 *)SMB_REALLOC(chaine2, realloc_size)) == NULL) {
 372                                         SAFE_FREE(chaine2);
 373                                         return False;
 374                                 }
 375                                 else chaine2 = tc2;
 376                                 memcpy(chaine2+l_chaine2, chaine.buffer, (l_chaine+1)*sizeof(uint16));
 377                                 l_chaine2+=l_chaine+1;
 378                         }
 379
 380                 } while(l_chaine!=0);
 381
 382                 /* the end should be bould NULL terminated so add
 383                    the second one here */
 384                 if (chaine2)
 385                 {
 386                         chaine2[l_chaine2] = '\0';
 387                         *string=(uint16 *)TALLOC_MEMDUP(prs_get_mem_context(ps),chaine2,realloc_size);
 388                         SAFE_FREE(chaine2);
 389                 }
 390
 391                 if(!prs_set_offset(ps, old_offset))
 392                         return False;
 393         }
 394         return True;
 395 }
 396
 397 /*******************************************************************
 398  Parse a DEVMODE structure and its relative pointer.
 399 ********************************************************************/
 400
 401 BOOL smb_io_relsecdesc(const char *desc, RPC_BUFFER *buffer, int depth, SEC_DESC **secdesc)
 402 {
 403         prs_struct *ps= &buffer->prs;
 404
 405         prs_debug(ps, depth, desc, "smb_io_relsecdesc");
 406         depth++;
 407
 408         if (MARSHALLING(ps)) {
 409                 uint32 struct_offset = prs_offset(ps);
 410                 uint32 relative_offset;
 411
 412                 if (! *secdesc) {
 413                         relative_offset = 0;
 414                         if (!prs_uint32("offset", ps, depth, &relative_offset))
 415                                 return False;
 416                         return True;
 417                 }
 418
 419                 if (*secdesc != NULL) {
 420                         buffer->string_at_end -= sec_desc_size(*secdesc);
 421
 422                         if(!prs_set_offset(ps, buffer->string_at_end))
 423                                 return False;
 424                         /* write the secdesc */
 425                         if (!sec_io_desc(desc, secdesc, ps, depth))
 426                                 return False;
 427
 428                         if(!prs_set_offset(ps, struct_offset))
 429                                 return False;
 430                 }
 431
 432                 relative_offset=buffer->string_at_end - buffer->struct_start;
 433                 /* write its offset */
 434
 435                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 436                         return False;
 437         } else {
 438                 uint32 old_offset;
 439
 440                 /* read the offset */
 441                 if (!prs_uint32("offset", ps, depth, &buffer->string_at_end))
 442                         return False;
 443
 444                 old_offset = prs_offset(ps);
 445                 if(!prs_set_offset(ps, buffer->string_at_end + buffer->struct_start))
 446                         return False;
 447
 448                 /* read the sd */
 449                 if (!sec_io_desc(desc, secdesc, ps, depth))
 450                         return False;
 451
 452                 if(!prs_set_offset(ps, old_offset))
 453                         return False;
 454         }
 455         return True;
 456 }
 457
 458
 459
 460 /*******************************************************************
 461  * return the length of a UNICODE string in number of char, includes:
 462  * - the leading zero
 463  * - the relative pointer size
 464  ********************************************************************/
 465
 466 uint32 size_of_relative_string(UNISTR *string)
 467 {
 468         uint32 size=0;
 469
 470         size=str_len_uni(string);       /* the string length       */
 471         size=size+1;                    /* add the trailing zero   */
 472         size=size*2;                    /* convert in char         */
 473         size=size+4;                    /* add the size of the ptr */
 474
 475 #if 0   /* JERRY */
 476         /*
 477          * Do not include alignment as Win2k does not align relative
 478          * strings within a buffer   --jerry
 479          */
 480         /* Ensure size is 4 byte multiple (prs_align is being called...). */
 481         /* size += ((4 - (size & 3)) & 3); */
 482 #endif
 483
 484         return size;
 485 }
 486