src/src/mime.c

   1 /* $Cambridge: exim/src/src/mime.c,v 1.13 2005/11/15 10:08:25 ph10 Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004 */
   8 /* License: GPL */
   9
  10 #include "exim.h"
  11 #ifdef WITH_CONTENT_SCAN
  12 #include "mime.h"
  13 #include <sys/stat.h>
  14
  15 FILE *mime_stream = NULL;
  16 uschar *mime_current_boundary = NULL;
  17
  18 /*************************************************
  19 * set MIME anomaly level + text                  *
  20 *************************************************/
  21
  22 /* Small wrapper to set the two expandables which
  23    give info on detected "problems" in MIME
  24    encodings. Those are defined in mime.h. */
  25
  26 void mime_set_anomaly(int level, char *text) {
  27   mime_anomaly_level = level;
  28   mime_anomaly_text = US text;
  29 }
  30
  31
  32 /*************************************************
  33 * decode quoted-printable chars                  *
  34 *************************************************/
  35
  36 /* gets called when we hit a =
  37    returns: new pointer position
  38    result code in c:
  39           -2 - decode error
  40           -1 - soft line break, no char
  41            0-255 - char to write
  42 */
  43
  44 unsigned int mime_qp_hstr_i(uschar *cptr) {
  45   unsigned int i, j = 0;
  46   while (cptr && *cptr && isxdigit(*cptr)) {
  47     i = *cptr++ - '0';
  48     if (9 < i) i -= 7;
  49     j <<= 4;
  50     j |= (i & 0x0f);
  51   }
  52   return(j);
  53 }
  54
  55 uschar *mime_decode_qp_char(uschar *qp_p,int *c) {
  56   uschar hex[] = {0,0,0};
  57   int nan = 0;
  58   uschar *initial_pos = qp_p;
  59
  60   /* advance one char */
  61   qp_p++;
  62
  63   REPEAT_FIRST:
  64   if ( (*qp_p == '\t') || (*qp_p == ' ') || (*qp_p == '\r') )  {
  65     /* tab or whitespace may follow
  66        just ignore it, but remember
  67        that this is not a valid hex
  68        encoding any more */
  69     nan = 1;
  70     qp_p++;
  71     goto REPEAT_FIRST;
  72   }
  73   else if ( (('0' <= *qp_p) && (*qp_p <= '9')) || (('A' <= *qp_p) && (*qp_p <= 'F'))  || (('a' <= *qp_p) && (*qp_p <= 'f')) ) {
  74     /* this is a valid hex char, if nan is unset */
  75     if (nan) {
  76       /* this is illegal */
  77       *c = -2;
  78       return initial_pos;
  79     }
  80     else {
  81       hex[0] = *qp_p;
  82       qp_p++;
  83     };
  84   }
  85   else if (*qp_p == '\n') {
  86     /* hit soft line break already, continue */
  87     *c = -1;
  88     return qp_p;
  89   }
  90   else {
  91     /* illegal char here */
  92     *c = -2;
  93     return initial_pos;
  94   };
  95
  96   if ( (('0' <= *qp_p) && (*qp_p <= '9')) || (('A' <= *qp_p) && (*qp_p <= 'F')) || (('a' <= *qp_p) && (*qp_p <= 'f')) ) {
  97     if (hex[0] > 0) {
  98       hex[1] = *qp_p;
  99       /* do hex conversion */
 100       *c = mime_qp_hstr_i(hex);
 101       qp_p++;
 102       return qp_p;
 103     }
 104     else {
 105       /* huh ? */
 106       *c = -2;
 107       return initial_pos;
 108     };
 109   }
 110   else {
 111     /* illegal char */
 112     *c = -2;
 113     return initial_pos;
 114   };
 115 }
 116
 117
 118 uschar *mime_parse_line(uschar *buffer, uschar *data, uschar *encoding, int *num_decoded) {
 119
 120   if (encoding == NULL) {
 121     /* no encoding type at all */
 122     NO_DECODING:
 123     memcpy(data, buffer, Ustrlen(buffer));
 124     data[(Ustrlen(buffer))] = 0;
 125     *num_decoded = Ustrlen(data);
 126     return data;
 127   }
 128   else if (Ustrcmp(encoding,"base64") == 0) {
 129     uschar *p = buffer;
 130     int offset = 0;
 131
 132     /* ----- BASE64 ---------------------------------------------------- */
 133     /* NULL out '\r' and '\n' chars */
 134     while (Ustrrchr(p,'\r') != NULL) {
 135       *(Ustrrchr(p,'\r')) = '\0';
 136     };
 137     while (Ustrrchr(p,'\n') != NULL) {
 138       *(Ustrrchr(p,'\n')) = '\0';
 139     };
 140
 141     while (*(p+offset) != '\0') {
 142       /* hit illegal char ? */
 143       if (mime_b64[*(p+offset)] == 128) {
 144         mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
 145         offset++;
 146       }
 147       else {
 148         *p = mime_b64[*(p+offset)];
 149         p++;
 150       };
 151     };
 152     *p = 255;
 153
 154     /* line is translated, start bit shifting */
 155     p = buffer;
 156     *num_decoded = 0;
 157     while(*p != 255) {
 158       uschar tmp_c;
 159
 160       /* byte 0 ---------------------- */
 161       if (*(p+1) == 255) {
 162         break;
 163       }
 164       data[(*num_decoded)] = *p;
 165       data[(*num_decoded)] <<= 2;
 166       tmp_c = *(p+1);
 167       tmp_c >>= 4;
 168       data[(*num_decoded)] |= tmp_c;
 169       (*num_decoded)++;
 170       p++;
 171       /* byte 1 ---------------------- */
 172       if (*(p+1) == 255) {
 173         break;
 174       }
 175       data[(*num_decoded)] = *p;
 176       data[(*num_decoded)] <<= 4;
 177       tmp_c = *(p+1);
 178       tmp_c >>= 2;
 179       data[(*num_decoded)] |= tmp_c;
 180       (*num_decoded)++;
 181       p++;
 182       /* byte 2 ---------------------- */
 183       if (*(p+1) == 255) {
 184         break;
 185       }
 186       data[(*num_decoded)] = *p;
 187       data[(*num_decoded)] <<= 6;
 188       data[(*num_decoded)] |= *(p+1);
 189       (*num_decoded)++;
 190       p+=2;
 191
 192     };
 193     return data;
 194     /* ----------------------------------------------------------------- */
 195   }
 196   else if (Ustrcmp(encoding,"quoted-printable") == 0) {
 197     uschar *p = buffer;
 198
 199     /* ----- QP -------------------------------------------------------- */
 200     *num_decoded = 0;
 201     while (*p != 0) {
 202       if (*p == '=') {
 203         int decode_qp_result;
 204
 205         p = mime_decode_qp_char(p,&decode_qp_result);
 206
 207         if (decode_qp_result == -2) {
 208           /* Error from decoder. p is unchanged. */
 209           mime_set_anomaly(MIME_ANOMALY_BROKEN_QP);
 210           data[(*num_decoded)] = '=';
 211           (*num_decoded)++;
 212           p++;
 213         }
 214         else if (decode_qp_result == -1) {
 215           break;
 216         }
 217         else if (decode_qp_result >= 0) {
 218           data[(*num_decoded)] = decode_qp_result;
 219           (*num_decoded)++;
 220         };
 221       }
 222       else {
 223         data[(*num_decoded)] = *p;
 224         (*num_decoded)++;
 225         p++;
 226       };
 227     };
 228     return data;
 229     /* ----------------------------------------------------------------- */
 230   }
 231   /* unknown encoding type, just dump as-is */
 232   else goto NO_DECODING;
 233 }
 234
 235
 236 FILE *mime_get_decode_file(uschar *pname, uschar *fname) {
 237   FILE *f = NULL;
 238   uschar *filename;
 239
 240   filename = (uschar *)malloc(2048);
 241
 242   if ((pname != NULL) && (fname != NULL)) {
 243     (void)string_format(filename, 2048, "%s/%s", pname, fname);
 244     f = fopen(CS filename,"wb+");
 245   }
 246   else if (pname == NULL) {
 247     f = fopen(CS fname,"wb+");
 248   }
 249   else if (fname == NULL) {
 250     int file_nr = 0;
 251     int result = 0;
 252
 253     /* must find first free sequential filename */
 254     do {
 255       struct stat mystat;
 256       (void)string_format(filename,2048,"%s/%s-%05u", pname, message_id, file_nr);
 257       file_nr++;
 258       /* security break */
 259       if (file_nr >= 1024)
 260         break;
 261       result = stat(CS filename,&mystat);
 262     }
 263     while(result != -1);
 264     f = fopen(CS filename,"wb+");
 265   };
 266
 267   /* set expansion variable */
 268   mime_decoded_filename = filename;
 269
 270   return f;
 271 }
 272
 273
 274 int mime_decode(uschar **listptr) {
 275   int sep = 0;
 276   uschar *list = *listptr;
 277   uschar *option;
 278   uschar option_buffer[1024];
 279   uschar decode_path[1024];
 280   FILE *decode_file = NULL;
 281   uschar *buffer = NULL;
 282   uschar *decode_buffer = NULL;
 283   long f_pos = 0;
 284   unsigned int size_counter = 0;
 285
 286   if (mime_stream == NULL)
 287     return FAIL;
 288
 289   f_pos = ftell(mime_stream);
 290
 291   /* build default decode path (will exist since MBOX must be spooled up) */
 292   (void)string_format(decode_path,1024,"%s/scan/%s",spool_directory,message_id);
 293
 294   /* reserve a line and decoder buffer to work in */
 295   buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
 296   if (buffer == NULL) {
 297     log_write(0, LOG_PANIC,
 298                  "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
 299     return DEFER;
 300   };
 301
 302   decode_buffer = (uschar *)malloc(MIME_MAX_LINE_LENGTH+1);
 303   if (decode_buffer == NULL) {
 304     log_write(0, LOG_PANIC,
 305                  "decode ACL condition: can't allocate %d bytes of memory.", MIME_MAX_LINE_LENGTH+1);
 306     return DEFER;
 307   };
 308
 309   /* try to find 1st option */
 310   if ((option = string_nextinlist(&list, &sep,
 311                                   option_buffer,
 312                                   sizeof(option_buffer))) != NULL) {
 313
 314     /* parse 1st option */
 315     if ( (Ustrcmp(option,"false") == 0) || (Ustrcmp(option,"0") == 0) ) {
 316       /* explicitly no decoding */
 317       return FAIL;
 318     };
 319
 320     if (Ustrcmp(option,"default") == 0) {
 321       /* explicit default path + file names */
 322       goto DEFAULT_PATH;
 323     };
 324
 325     if (option[0] == '/') {
 326       struct stat statbuf;
 327
 328       memset(&statbuf,0,sizeof(statbuf));
 329
 330       /* assume either path or path+file name */
 331       if ( (stat(CS option, &statbuf) == 0) && S_ISDIR(statbuf.st_mode) )
 332         /* is directory, use it as decode_path */
 333         decode_file = mime_get_decode_file(option, NULL);
 334       else
 335         /* does not exist or is a file, use as full file name */
 336         decode_file = mime_get_decode_file(NULL, option);
 337     }
 338     else
 339       /* assume file name only, use default path */
 340       decode_file = mime_get_decode_file(decode_path, option);
 341   }
 342   else
 343     /* no option? patch default path */
 344     DEFAULT_PATH: decode_file = mime_get_decode_file(decode_path, NULL);
 345
 346   if (decode_file == NULL)
 347     return DEFER;
 348
 349   /* read data linewise and dump it to the file,
 350      while looking for the current boundary */
 351   while(fgets(CS buffer, MIME_MAX_LINE_LENGTH, mime_stream) != NULL) {
 352     uschar *decoded_line = NULL;
 353     int decoded_line_length = 0;
 354
 355     if (mime_current_boundary != NULL) {
 356       /* boundary line must start with 2 dashes */
 357       if (Ustrncmp(buffer,"--",2) == 0) {
 358         if (Ustrncmp((buffer+2),mime_current_boundary,Ustrlen(mime_current_boundary)) == 0)
 359           break;
 360       };
 361     };
 362
 363     decoded_line = mime_parse_line(buffer, decode_buffer, mime_content_transfer_encoding, &decoded_line_length);
 364
 365     /* write line to decode file */
 366     if (fwrite(decoded_line, 1, decoded_line_length, decode_file) < decoded_line_length) {
 367       /* error/short write */
 368       clearerr(mime_stream);
 369       fseek(mime_stream,f_pos,SEEK_SET);
 370       return DEFER;
 371     };
 372     size_counter += decoded_line_length;
 373
 374     if (size_counter > 1023) {
 375       if ((mime_content_size + (size_counter / 1024)) < 65535)
 376         mime_content_size += (size_counter / 1024);
 377       else
 378         mime_content_size = 65535;
 379       size_counter = (size_counter % 1024);
 380     };
 381
 382   }
 383
 384   (void)fclose(decode_file);
 385
 386   clearerr(mime_stream);
 387   fseek(mime_stream,f_pos,SEEK_SET);
 388
 389   /* round up remaining size bytes to one k */
 390   if (size_counter) {
 391     mime_content_size++;
 392   };
 393
 394   return OK;
 395 }
 396
 397 int mime_get_header(FILE *f, uschar *header) {
 398   int c = EOF;
 399   int done = 0;
 400   int header_value_mode = 0;
 401   int header_open_brackets = 0;
 402   int num_copied = 0;
 403
 404   while(!done) {
 405
 406     c = fgetc(f);
 407     if (c == EOF) break;
 408
 409     /* always skip CRs */
 410     if (c == '\r') continue;
 411
 412     if (c == '\n') {
 413       if (num_copied > 0) {
 414         /* look if next char is '\t' or ' ' */
 415         c = fgetc(f);
 416         if (c == EOF) break;
 417         if ( (c == '\t') || (c == ' ') ) continue;
 418         (void)ungetc(c,f);
 419       };
 420       /* end of the header, terminate with ';' */
 421       c = ';';
 422       done = 1;
 423     };
 424
 425     /* skip control characters */
 426     if (c < 32) continue;
 427
 428     if (header_value_mode) {
 429       /* --------- value mode ----------- */
 430       /* skip leading whitespace */
 431       if ( ((c == '\t') || (c == ' ')) && (header_value_mode == 1) )
 432         continue;
 433
 434       /* we have hit a non-whitespace char, start copying value data */
 435       header_value_mode = 2;
 436
 437       /* skip quotes */
 438       if (c == '"') continue;
 439
 440       /* leave value mode on ';' */
 441       if (c == ';') {
 442         header_value_mode = 0;
 443       };
 444       /* -------------------------------- */
 445     }
 446     else {
 447       /* -------- non-value mode -------- */
 448       /* skip whitespace + tabs */
 449       if ( (c == ' ') || (c == '\t') )
 450         continue;
 451       if (c == '\\') {
 452         /* quote next char. can be used
 453         to escape brackets. */
 454         c = fgetc(f);
 455         if (c == EOF) break;
 456       }
 457       else if (c == '(') {
 458         header_open_brackets++;
 459         continue;
 460       }
 461       else if ((c == ')') && header_open_brackets) {
 462         header_open_brackets--;
 463         continue;
 464       }
 465       else if ( (c == '=') && !header_open_brackets ) {
 466         /* enter value mode */
 467         header_value_mode = 1;
 468       };
 469
 470       /* skip chars while we are in a comment */
 471       if (header_open_brackets > 0)
 472         continue;
 473       /* -------------------------------- */
 474     };
 475
 476     /* copy the char to the buffer */
 477     header[num_copied] = (uschar)c;
 478     /* raise counter */
 479     num_copied++;
 480
 481     /* break if header buffer is full */
 482     if (num_copied > MIME_MAX_HEADER_SIZE-1) {
 483       done = 1;
 484     };
 485   };
 486
 487   if ((num_copied > 0) && (header[num_copied-1] != ';')) {
 488     header[num_copied-1] = ';';
 489   };
 490
 491   /* 0-terminate */
 492   header[num_copied] = '\0';
 493
 494   /* return 0 for EOF or empty line */
 495   if ((c == EOF) || (num_copied == 1))
 496     return 0;
 497   else
 498     return 1;
 499 }
 500
 501
 502 int mime_acl_check(uschar *acl, FILE *f, struct mime_boundary_context *context,
 503                    uschar **user_msgptr, uschar **log_msgptr) {
 504   int rc = OK;
 505   uschar *header = NULL;
 506   struct mime_boundary_context nested_context;
 507
 508   /* reserve a line buffer to work in */
 509   header = (uschar *)malloc(MIME_MAX_HEADER_SIZE+1);
 510   if (header == NULL) {
 511     log_write(0, LOG_PANIC,
 512                  "MIME ACL: can't allocate %d bytes of memory.", MIME_MAX_HEADER_SIZE+1);
 513     return DEFER;
 514   };
 515
 516   /* Not actually used at the moment, but will be vital to fixing
 517    * some RFC 2046 nonconformance later... */
 518   nested_context.parent = context;
 519
 520   /* loop through parts */
 521   while(1) {
 522
 523     /* reset all per-part mime variables */
 524     mime_anomaly_level     = 0;
 525     mime_anomaly_text      = NULL;
 526     mime_boundary          = NULL;
 527     mime_charset           = NULL;
 528     mime_decoded_filename  = NULL;
 529     mime_filename          = NULL;
 530     mime_content_description = NULL;
 531     mime_content_disposition = NULL;
 532     mime_content_id        = NULL;
 533     mime_content_transfer_encoding = NULL;
 534     mime_content_type      = NULL;
 535     mime_is_multipart      = 0;
 536     mime_content_size      = 0;
 537
 538     /*
 539     If boundary is null, we assume that *f is positioned on the start of headers (for example,
 540     at the very beginning of a message.
 541     If a boundary is given, we must first advance to it to reach the start of the next header
 542     block.
 543     */
 544
 545     /* NOTE -- there's an error here -- RFC2046 specifically says to
 546      * check for outer boundaries.  This code doesn't do that, and
 547      * I haven't fixed this.
 548      *
 549      * (I have moved partway towards adding support, however, by adding
 550      * a "parent" field to my new boundary-context structure.)
 551      */
 552     if (context != NULL) {
 553       while(fgets(CS header, MIME_MAX_HEADER_SIZE, f) != NULL) {
 554         /* boundary line must start with 2 dashes */
 555         if (Ustrncmp(header,"--",2) == 0) {
 556           if (Ustrncmp((header+2),context->boundary,Ustrlen(context->boundary)) == 0) {
 557             /* found boundary */
 558             if (Ustrncmp((header+2+Ustrlen(context->boundary)),"--",2) == 0) {
 559               /* END boundary found */
 560               debug_printf("End boundary found %s\n", context->boundary);
 561               return rc;
 562             }
 563             else {
 564               debug_printf("Next part with boundary %s\n", context->boundary);
 565             };
 566             /* can't use break here */
 567             goto DECODE_HEADERS;
 568           }
 569         };
 570       }
 571       /* Hit EOF or read error. Ugh. */
 572       debug_printf("Hit EOF ...\n");
 573       return rc;
 574     };
 575
 576     DECODE_HEADERS:
 577     /* parse headers, set up expansion variables */
 578     while(mime_get_header(f,header)) {
 579       int i;
 580       /* loop through header list */
 581       for (i = 0; i < mime_header_list_size; i++) {
 582         uschar *header_value = NULL;
 583         int header_value_len = 0;
 584
 585         /* found an interesting header? */
 586         if (strncmpic(mime_header_list[i].name,header,mime_header_list[i].namelen) == 0) {
 587           uschar *p = header + mime_header_list[i].namelen;
 588           /* yes, grab the value (normalize to lower case)
 589              and copy to its corresponding expansion variable */
 590           while(*p != ';') {
 591             *p = tolower(*p);
 592             p++;
 593           };
 594           header_value_len = (p - (header + mime_header_list[i].namelen));
 595           header_value = (uschar *)malloc(header_value_len+1);
 596           memset(header_value,0,header_value_len+1);
 597           p = header + mime_header_list[i].namelen;
 598           Ustrncpy(header_value, p, header_value_len);
 599           debug_printf("Found %s MIME header, value is '%s'\n", mime_header_list[i].name, header_value);
 600           *((uschar **)(mime_header_list[i].value)) = header_value;
 601
 602           /* make p point to the next character after the closing ';' */
 603           p += (header_value_len+1);
 604
 605           /* grab all param=value tags on the remaining line, check if they are interesting */
 606           NEXT_PARAM_SEARCH: while (*p != 0) {
 607             int j;
 608             for (j = 0; j < mime_parameter_list_size; j++) {
 609               uschar *param_value = NULL;
 610               int param_value_len = 0;
 611
 612               /* found an interesting parameter? */
 613               if (strncmpic(mime_parameter_list[j].name,p,mime_parameter_list[j].namelen) == 0) {
 614                 uschar *q = p + mime_parameter_list[j].namelen;
 615                 /* yes, grab the value and copy to its corresponding expansion variable */
 616                 while(*q != ';') q++;
 617                 param_value_len = (q - (p + mime_parameter_list[j].namelen));
 618                 param_value = (uschar *)malloc(param_value_len+1);
 619                 memset(param_value,0,param_value_len+1);
 620                 q = p + mime_parameter_list[j].namelen;
 621                 Ustrncpy(param_value, q, param_value_len);
 622                 param_value = rfc2047_decode(param_value, check_rfc2047_length, NULL, 32, &param_value_len, &q);
 623                 debug_printf("Found %s MIME parameter in %s header, value is '%s'\n", mime_parameter_list[j].name, mime_header_list[i].name, param_value);
 624                 *((uschar **)(mime_parameter_list[j].value)) = param_value;
 625                 p += (mime_parameter_list[j].namelen + param_value_len + 1);
 626                 goto NEXT_PARAM_SEARCH;
 627               };
 628             }
 629             /* There is something, but not one of our interesting parameters.
 630                Advance to the next semicolon */
 631             while(*p != ';') p++;
 632             p++;
 633           };
 634         };
 635       };
 636     };
 637
 638     /* set additional flag variables (easier access) */
 639     if ( (mime_content_type != NULL) &&
 640          (Ustrncmp(mime_content_type,"multipart",9) == 0) )
 641       mime_is_multipart = 1;
 642
 643     /* Make a copy of the boundary pointer.
 644        Required since mime_boundary is global
 645        and can be overwritten further down in recursion */
 646     nested_context.boundary = mime_boundary;
 647
 648     /* raise global counter */
 649     mime_part_count++;
 650
 651     /* copy current file handle to global variable */
 652     mime_stream = f;
 653     mime_current_boundary = context ? context->boundary : 0;
 654
 655     /* Note the context */
 656     mime_is_coverletter = !(context && context->context == MBC_ATTACHMENT);
 657
 658     /* call ACL handling function */
 659     rc = acl_check(ACL_WHERE_MIME, NULL, acl, user_msgptr, log_msgptr);
 660
 661     mime_stream = NULL;
 662     mime_current_boundary = NULL;
 663
 664     if (rc != OK) break;
 665
 666     /* If we have a multipart entity and a boundary, go recursive */
 667     if ( (mime_content_type != NULL) &&
 668          (nested_context.boundary != NULL) &&
 669          (Ustrncmp(mime_content_type,"multipart",9) == 0) ) {
 670       debug_printf("Entering multipart recursion, boundary '%s'\n", nested_context.boundary);
 671
 672       if (context && context->context == MBC_ATTACHMENT)
 673         nested_context.context = MBC_ATTACHMENT;
 674       else if (!Ustrcmp(mime_content_type,"multipart/alternative")
 675             || !Ustrcmp(mime_content_type,"multipart/related"))
 676         nested_context.context = MBC_COVERLETTER_ALL;
 677       else
 678         nested_context.context = MBC_COVERLETTER_ONESHOT;
 679
 680       rc = mime_acl_check(acl, f, &nested_context, user_msgptr, log_msgptr);
 681       if (rc != OK) break;
 682     }
 683     else if ( (mime_content_type != NULL) &&
 684             (Ustrncmp(mime_content_type,"message/rfc822",14) == 0) ) {
 685       uschar *rfc822name = NULL;
 686       uschar filename[2048];
 687       int file_nr = 0;
 688       int result = 0;
 689
 690       /* must find first free sequential filename */
 691       do {
 692         struct stat mystat;
 693         (void)string_format(filename,2048,"%s/scan/%s/__rfc822_%05u", spool_directory, message_id, file_nr);
 694         file_nr++;
 695         /* security break */
 696         if (file_nr >= 128)
 697           goto NO_RFC822;
 698         result = stat(CS filename,&mystat);
 699       }
 700       while(result != -1);
 701
 702       rfc822name = filename;
 703
 704       /* decode RFC822 attachment */
 705       mime_decoded_filename = NULL;
 706       mime_stream = f;
 707       mime_current_boundary = context ? context->boundary : NULL;
 708       mime_decode(&rfc822name);
 709       mime_stream = NULL;
 710       mime_current_boundary = NULL;
 711       if (mime_decoded_filename == NULL) {
 712         /* decoding failed */
 713         log_write(0, LOG_MAIN,
 714              "mime_regex acl condition warning - could not decode RFC822 MIME part to file.");
 715         return DEFER;
 716       };
 717       mime_decoded_filename = NULL;
 718     };
 719
 720     NO_RFC822:
 721     /* If the boundary of this instance is NULL, we are finished here */
 722     if (context == NULL) break;
 723
 724     if (context->context == MBC_COVERLETTER_ONESHOT)
 725       context->context = MBC_ATTACHMENT;
 726
 727   };
 728
 729   return rc;
 730 }
 731
 732 #endif