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         /* if we don't need anything. don't do anything */
 138
 139         if ( buffer_size == 0x0 )
 140                 return True;
 141
 142         ps= &buffer->prs;
 143
 144         /* damn, I'm doing the reverse operation of prs_grow() :) */
 145         if (buffer_size < prs_data_size(ps))
 146                 extra_space=0;
 147         else
 148                 extra_space = buffer_size - prs_data_size(ps);
 149
 150         /*
 151          * save the offset and move to the end of the buffer
 152          * prs_grow() checks the extra_space against the offset
 153          */
 154         old_offset=prs_offset(ps);
 155         prs_set_offset(ps, prs_data_size(ps));
 156
 157         if (!prs_grow(ps, extra_space))
 158                 return False;
 159
 160         prs_set_offset(ps, old_offset);
 161
 162         buffer->string_at_end=prs_data_size(ps);
 163
 164         return True;
 165 }
 166
 167 /*******************************************************************
 168  move a BUFFER from the query to the reply.
 169  As the data pointers in RPC_BUFFER are malloc'ed, not talloc'ed,
 170  this is ok. This is an OPTIMIZATION and is not strictly neccessary.
 171  Clears the memory to zero also.
 172 ********************************************************************/
 173
 174 void rpcbuf_move(RPC_BUFFER *src, RPC_BUFFER **dest)
 175 {
 176         SMB_ASSERT( src != NULL );
 177
 178         prs_switch_type(&src->prs, MARSHALL);
 179         if(!prs_set_offset(&src->prs, 0))
 180                 return;
 181         prs_force_dynamic(&src->prs);
 182         prs_mem_clear(&src->prs);
 183         *dest=src;
 184 }
 185
 186 /*******************************************************************
 187  Get the size of a BUFFER struct.
 188 ********************************************************************/
 189
 190 uint32 rpcbuf_get_size(RPC_BUFFER *buffer)
 191 {
 192         return (buffer->size);
 193 }
 194
 195
 196 /*******************************************************************
 197  * write a UNICODE string and its relative pointer.
 198  * used by all the RPC structs passing a buffer
 199  *
 200  * As I'm a nice guy, I'm forcing myself to explain this code.
 201  * MS did a good job in the overall spoolss code except in some
 202  * functions where they are passing the API buffer directly in the
 203  * RPC request/reply. That's to maintain compatiility at the API level.
 204  * They could have done it the good way the first time.
 205  *
 206  * So what happen is: the strings are written at the buffer's end,
 207  * in the reverse order of the original structure. Some pointers to
 208  * the strings are also in the buffer. Those are relative to the
 209  * buffer's start.
 210  *
 211  * If you don't understand or want to change that function,
 212  * first get in touch with me: jfm@samba.org
 213  *
 214  ********************************************************************/
 215
 216 BOOL smb_io_relstr(const char *desc, RPC_BUFFER *buffer, int depth, UNISTR *string)
 217 {
 218         prs_struct *ps=&buffer->prs;
 219
 220         if (MARSHALLING(ps)) {
 221                 uint32 struct_offset = prs_offset(ps);
 222                 uint32 relative_offset;
 223
 224                 buffer->string_at_end -= (size_of_relative_string(string) - 4);
 225                 if(!prs_set_offset(ps, buffer->string_at_end))
 226                         return False;
 227 #if 0   /* JERRY */
 228                 /*
 229                  * Win2k does not align strings in a buffer
 230                  * Tested against WinNT 4.0 SP 6a & 2k SP2  --jerry
 231                  */
 232                 if (!prs_align(ps))
 233                         return False;
 234 #endif
 235                 buffer->string_at_end = prs_offset(ps);
 236
 237                 /* write the string */
 238                 if (!smb_io_unistr(desc, string, ps, depth))
 239                         return False;
 240
 241                 if(!prs_set_offset(ps, struct_offset))
 242                         return False;
 243
 244                 relative_offset=buffer->string_at_end - buffer->struct_start;
 245                 /* write its offset */
 246                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 247                         return False;
 248         }
 249         else {
 250                 uint32 old_offset;
 251
 252                 /* read the offset */
 253                 if (!prs_uint32("offset", ps, depth, &(buffer->string_at_end)))
 254                         return False;
 255
 256                 if (buffer->string_at_end == 0)
 257                         return True;
 258
 259                 old_offset = prs_offset(ps);
 260                 if(!prs_set_offset(ps, buffer->string_at_end+buffer->struct_start))
 261                         return False;
 262
 263                 /* read the string */
 264                 if (!smb_io_unistr(desc, string, ps, depth))
 265                         return False;
 266
 267                 if(!prs_set_offset(ps, old_offset))
 268                         return False;
 269         }
 270         return True;
 271 }
 272
 273 /*******************************************************************
 274  * write a array of UNICODE strings and its relative pointer.
 275  * used by 2 RPC structs
 276  ********************************************************************/
 277
 278 BOOL smb_io_relarraystr(const char *desc, RPC_BUFFER *buffer, int depth, uint16 **string)
 279 {
 280         UNISTR chaine;
 281
 282         prs_struct *ps=&buffer->prs;
 283
 284         if (MARSHALLING(ps)) {
 285                 uint32 struct_offset = prs_offset(ps);
 286                 uint32 relative_offset;
 287                 uint16 *p;
 288                 uint16 *q;
 289                 uint16 zero=0;
 290                 p=*string;
 291                 q=*string;
 292
 293                 /* first write the last 0 */
 294                 buffer->string_at_end -= 2;
 295                 if(!prs_set_offset(ps, buffer->string_at_end))
 296                         return False;
 297
 298                 if(!prs_uint16("leading zero", ps, depth, &zero))
 299                         return False;
 300
 301                 while (p && (*p!=0)) {
 302                         while (*q!=0)
 303                                 q++;
 304
 305                         /* Yes this should be malloc not talloc. Don't change. */
 306
 307                         chaine.buffer = SMB_MALLOC((q-p+1)*sizeof(uint16));
 308                         if (chaine.buffer == NULL)
 309                                 return False;
 310
 311                         memcpy(chaine.buffer, p, (q-p+1)*sizeof(uint16));
 312
 313                         buffer->string_at_end -= (q-p+1)*sizeof(uint16);
 314
 315                         if(!prs_set_offset(ps, buffer->string_at_end)) {
 316                                 SAFE_FREE(chaine.buffer);
 317                                 return False;
 318                         }
 319
 320                         /* write the string */
 321                         if (!smb_io_unistr(desc, &chaine, ps, depth)) {
 322                                 SAFE_FREE(chaine.buffer);
 323                                 return False;
 324                         }
 325                         q++;
 326                         p=q;
 327
 328                         SAFE_FREE(chaine.buffer);
 329                 }
 330
 331                 if(!prs_set_offset(ps, struct_offset))
 332                         return False;
 333
 334                 relative_offset=buffer->string_at_end - buffer->struct_start;
 335                 /* write its offset */
 336                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 337                         return False;
 338
 339         } else {
 340
 341                 /* UNMARSHALLING */
 342
 343                 uint32 old_offset;
 344                 uint16 *chaine2=NULL;
 345                 int l_chaine=0;
 346                 int l_chaine2=0;
 347                 size_t realloc_size = 0;
 348
 349                 *string=NULL;
 350
 351                 /* read the offset */
 352                 if (!prs_uint32("offset", ps, depth, &buffer->string_at_end))
 353                         return False;
 354
 355                 old_offset = prs_offset(ps);
 356                 if(!prs_set_offset(ps, buffer->string_at_end + buffer->struct_start))
 357                         return False;
 358
 359                 do {
 360                         if (!smb_io_unistr(desc, &chaine, ps, depth))
 361                                 return False;
 362
 363                         l_chaine=str_len_uni(&chaine);
 364
 365                         /* we're going to add two more bytes here in case this
 366                            is the last string in the array and we need to add
 367                            an extra NULL for termination */
 368                         if (l_chaine > 0)
 369                         {
 370                                 uint16 *tc2;
 371
 372                                 realloc_size = (l_chaine2+l_chaine+2)*sizeof(uint16);
 373
 374                                 /* Yes this should be realloc - it's freed below. JRA */
 375
 376                                 if((tc2=(uint16 *)SMB_REALLOC(chaine2, realloc_size)) == NULL) {
 377                                         SAFE_FREE(chaine2);
 378                                         return False;
 379                                 }
 380                                 else chaine2 = tc2;
 381                                 memcpy(chaine2+l_chaine2, chaine.buffer, (l_chaine+1)*sizeof(uint16));
 382                                 l_chaine2+=l_chaine+1;
 383                         }
 384
 385                 } while(l_chaine!=0);
 386
 387                 /* the end should be bould NULL terminated so add
 388                    the second one here */
 389                 if (chaine2)
 390                 {
 391                         chaine2[l_chaine2] = '\0';
 392                         *string=(uint16 *)TALLOC_MEMDUP(prs_get_mem_context(ps),chaine2,realloc_size);
 393                         SAFE_FREE(chaine2);
 394                 }
 395
 396                 if(!prs_set_offset(ps, old_offset))
 397                         return False;
 398         }
 399         return True;
 400 }
 401
 402 /*******************************************************************
 403  Parse a DEVMODE structure and its relative pointer.
 404 ********************************************************************/
 405
 406 BOOL smb_io_relsecdesc(const char *desc, RPC_BUFFER *buffer, int depth, SEC_DESC **secdesc)
 407 {
 408         prs_struct *ps= &buffer->prs;
 409
 410         prs_debug(ps, depth, desc, "smb_io_relsecdesc");
 411         depth++;
 412
 413         if (MARSHALLING(ps)) {
 414                 uint32 struct_offset = prs_offset(ps);
 415                 uint32 relative_offset;
 416
 417                 if (! *secdesc) {
 418                         relative_offset = 0;
 419                         if (!prs_uint32("offset", ps, depth, &relative_offset))
 420                                 return False;
 421                         return True;
 422                 }
 423
 424                 if (*secdesc != NULL) {
 425                         buffer->string_at_end -= sec_desc_size(*secdesc);
 426
 427                         if(!prs_set_offset(ps, buffer->string_at_end))
 428                                 return False;
 429                         /* write the secdesc */
 430                         if (!sec_io_desc(desc, secdesc, ps, depth))
 431                                 return False;
 432
 433                         if(!prs_set_offset(ps, struct_offset))
 434                                 return False;
 435                 }
 436
 437                 relative_offset=buffer->string_at_end - buffer->struct_start;
 438                 /* write its offset */
 439
 440                 if (!prs_uint32("offset", ps, depth, &relative_offset))
 441                         return False;
 442         } else {
 443                 uint32 old_offset;
 444
 445                 /* read the offset */
 446                 if (!prs_uint32("offset", ps, depth, &buffer->string_at_end))
 447                         return False;
 448
 449                 old_offset = prs_offset(ps);
 450                 if(!prs_set_offset(ps, buffer->string_at_end + buffer->struct_start))
 451                         return False;
 452
 453                 /* read the sd */
 454                 if (!sec_io_desc(desc, secdesc, ps, depth))
 455                         return False;
 456
 457                 if(!prs_set_offset(ps, old_offset))
 458                         return False;
 459         }
 460         return True;
 461 }
 462
 463
 464
 465 /*******************************************************************
 466  * return the length of a UNICODE string in number of char, includes:
 467  * - the leading zero
 468  * - the relative pointer size
 469  ********************************************************************/
 470
 471 uint32 size_of_relative_string(UNISTR *string)
 472 {
 473         uint32 size=0;
 474
 475         size=str_len_uni(string);       /* the string length       */
 476         size=size+1;                    /* add the trailing zero   */
 477         size=size*2;                    /* convert in char         */
 478         size=size+4;                    /* add the size of the ptr */
 479
 480 #if 0   /* JERRY */
 481         /*
 482          * Do not include alignment as Win2k does not align relative
 483          * strings within a buffer   --jerry
 484          */
 485         /* Ensure size is 4 byte multiple (prs_align is being called...). */
 486         /* size += ((4 - (size & 3)) & 3); */
 487 #endif
 488
 489         return size;
 490 }
 491