wiretap/k12text.l

   1 %top {
   2 /* Include this before everything else, for various large-file definitions */
   3 #include "config.h"
   4 #include <wireshark.h>
   5 }
   6
   7 /*
   8  * We want a reentrant scanner.
   9  */
  10 %option reentrant
  11
  12 /*
  13  * We don't use input, so don't generate code for it.
  14  */
  15 %option noinput
  16
  17 /*
  18  * We don't use unput, so don't generate code for it.
  19  */
  20 %option nounput
  21
  22 /*
  23  * We don't read interactively from the terminal.
  24  */
  25 %option never-interactive
  26
  27 /*
  28  * We want to stop processing when we get to the end of the input.
  29  */
  30 %option noyywrap
  31
  32 /*
  33  * The type for the state we keep for a scanner.
  34  */
  35 %option extra-type="k12text_state_t *"
  36
  37 /*
  38  * Prefix scanner routines with "k12text_" rather than "yy", so this scanner
  39  * can coexist with other scanners.
  40  */
  41 %option prefix="k12text_"
  42
  43 /* Options useful for debugging                         */
  44 /* noline:  Prevent generation of #line directives      */
  45 /*          Seems to be required when using the         */
  46 /*          Windows VS debugger so as to be able        */
  47 /*          to properly step through the code and       */
  48 /*          set breakpoints & etc using the             */
  49 /*          k12text.c file rather than the              */
  50 /*          k12text.l file                              */
  51 /*      XXX: %option noline gives an error message:     */
  52 /*          "unrecognized %option: line"                */
  53 /*          with flex 2.5.35; the --noline              */
  54 /*          command-line option works OK.               */
  55 /*                                                      */
  56 /* debug:   Do output of "rule acceptance" info         */
  57 /*          during parse                                */
  58 /*                                                      */
  59 /* %option noline  */
  60 /* %option debug   */
  61
  62 /*
  63  * We have to override the memory allocators so that we don't get
  64  * "unused argument" warnings from the yyscanner argument (which
  65  * we don't use, as we have a global memory allocator).
  66  *
  67  * We provide, as macros, our own versions of the routines generated by Flex,
  68  * which just call malloc()/realloc()/free() (as the Flex versions do),
  69  * discarding the extra argument.
  70  */
  71 %option noyyalloc
  72 %option noyyrealloc
  73 %option noyyfree
  74
  75 %{
  76 /* k12text.l
  77  *
  78  * Wiretap Library
  79  * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
  80  *
  81  * SPDX-License-Identifier: GPL-2.0-or-later
  82  */
  83
  84  /*
  85   * TODO:
  86   *   - fix timestamps after midnight
  87   *   - verify encapsulations
  88   */
  89
  90 #include <stdlib.h>
  91 #include <string.h>
  92 #include <errno.h>
  93 #include <time.h>
  94 #include "wtap-int.h"
  95 #include "wtap.h"
  96 #include "file_wrappers.h"
  97 #include <wsutil/buffer.h>
  98 #include "k12.h"
  99
 100 #ifndef HAVE_UNISTD_H
 101 #define YY_NO_UNISTD_H
 102 #endif
 103
 104 /*
 105  * Disable diagnostics in the code generated by Flex.
 106  */
 107 DIAG_OFF_FLEX()
 108
 109 /*
 110  * State kept by the scanner.
 111  */
 112 typedef struct {
 113         FILE_T fh;
 114         int err;
 115         char *err_info;
 116         int start_state;
 117
 118         unsigned g_h;
 119         unsigned g_m;
 120         unsigned g_s;
 121         unsigned g_ms;
 122         unsigned g_ns;
 123         int g_encap;
 124         uint8_t *bb;
 125         unsigned ii;
 126         bool is_k12text;
 127         bool at_eof;
 128         unsigned junk_chars;
 129         char* error_str;
 130         uint64_t file_bytes_read;
 131         bool ok_frame;
 132 } k12text_state_t;
 133
 134 #define KERROR(text) do { yyextra->error_str = g_strdup(text); yyterminate(); } while(0)
 135 #define SET_HOURS(text) yyextra->g_h = (unsigned) strtoul(text,NULL,10)
 136 #define SET_MINUTES(text) yyextra->g_m = (unsigned) strtoul(text,NULL,10)
 137 #define SET_SECONDS(text) yyextra->g_s = (unsigned) strtoul(text,NULL,10)
 138 #define SET_MS(text) yyextra->g_ms = (unsigned) strtoul(text,NULL,10)
 139 #define SET_NS(text) yyextra->g_ns = (unsigned) strtoul(text,NULL,10)
 140 #define ADD_BYTE(text) do {if (yyextra->ii >= WTAP_MAX_PACKET_SIZE_STANDARD) {KERROR("frame too large");} yyextra->bb[yyextra->ii++] = (uint8_t)strtoul(text,NULL,16); } while(0)
 141 #define FINALIZE_FRAME() do { yyextra->ok_frame = true; } while (0)
 142 /*~ #define ECHO*/
 143 #define YY_USER_ACTION yyextra->file_bytes_read += yyleng;
 144 #define YY_USER_INIT { \
 145         k12text_state_t *scanner_state = k12text_get_extra(yyscanner); \
 146         BEGIN(scanner_state->start_state); \
 147 }
 148 #define YY_INPUT(buf,result,max_size) { \
 149         k12text_state_t *scanner_state = k12text_get_extra(yyscanner); \
 150         int c = file_getc(scanner_state->fh); \
 151         if (c == EOF) { \
 152                 scanner_state->err = file_error(scanner_state->fh, \
 153                     &scanner_state->err_info); \
 154                 if (scanner_state->err == 0) \
 155                         scanner_state->err = WTAP_ERR_SHORT_READ; \
 156                 result = YY_NULL; \
 157         } else { \
 158                 buf[0] = c; \
 159                 result = 1; \
 160         } \
 161 }
 162 #define MAX_JUNK 400000
 163 #define ECHO
 164
 165 /*
 166  * Private per-file data.
 167  */
 168 typedef struct {
 169         /*
 170          * The file position after the end of the previous frame processed by
 171          * k12text_read.
 172          *
 173          * We need to keep this around, and seek to it at the beginning of
 174          * each call to k12text_read(), since the lexer undoubtedly did some
 175          * amount of look-ahead when processing the previous frame.
 176          */
 177         int64_t next_frame_offset;
 178 } k12text_t;
 179
 180 /*
 181  * Sleazy hack to suppress compiler warnings in yy_fatal_error().
 182  */
 183 #define YY_EXIT_FAILURE ((void)yyscanner, 2)
 184
 185 /*
 186  * Macros for the allocators, to discard the extra argument.
 187  */
 188 #define k12text_alloc(size, yyscanner)          (void *)malloc(size)
 189 #define k12text_realloc(ptr, size, yyscanner)   (void *)realloc((char *)(ptr), (size))
 190 #define k12text_free(ptr, yyscanner)            free((char *)ptr)
 191
 192 static int k12text_file_type_subtype = -1;
 193
 194 void register_k12text(void);
 195
 196 %}
 197 start_timestamp \053[\055]{9}\053[\055]{15,100}\053[\055]{10,100}\053
 198 oneormoredigits [0-9]+:
 199 twodigits [0-9][0-9]
 200 colon :
 201 comma ,
 202 threedigits [0-9][0-9][0-9]
 203 start_bytes \174\060\040\040\040\174
 204 bytes_junk \174[A-F0-9][A-F0-9\040][A-F0-9\040][A-F0-9\040]\174
 205 byte [a-f0-9][a-f0-9]\174
 206 end_bytes \015?\012\015?\012
 207 eth ETHER
 208 mtp2 MTP-L2
 209 sscop SSCOP
 210 sscfnni SSCF
 211 hdlc HDLC
 212
 213 %START MAGIC NEXT_FRAME HOURS MINUTES M2S SECONDS S2M MS M2N NS ENCAP STARTBYTES BYTE
 214 %%
 215 <MAGIC>{start_timestamp}  { yyextra->is_k12text = true; yyterminate(); }
 216
 217 <MAGIC>. { if (++ yyextra->junk_chars > MAX_JUNK) { yyextra->is_k12text = false;  yyterminate(); } }
 218
 219 <NEXT_FRAME>{start_timestamp} {BEGIN(HOURS); }
 220 <HOURS>{oneormoredigits} { SET_HOURS(yytext); BEGIN(MINUTES); }
 221 <MINUTES>{twodigits} { SET_MINUTES(yytext); BEGIN(M2S);}
 222 <M2S>{colon} { BEGIN(SECONDS);}
 223 <SECONDS>{twodigits} { SET_SECONDS(yytext); BEGIN(S2M); }
 224 <S2M>{comma}  { BEGIN(MS); }
 225 <MS>{threedigits} { SET_MS(yytext); BEGIN(M2N);  }
 226 <M2N>{comma}  { BEGIN(NS); }
 227 <NS>{threedigits} { SET_NS(yytext); BEGIN(ENCAP);}
 228 <ENCAP>{eth} {yyextra->g_encap = WTAP_ENCAP_ETHERNET; BEGIN(STARTBYTES); }
 229 <ENCAP>{mtp2} {yyextra->g_encap = WTAP_ENCAP_MTP2; BEGIN(STARTBYTES); }
 230 <ENCAP>{sscop} {yyextra->g_encap = WTAP_ENCAP_ATM_PDUS; BEGIN(STARTBYTES); }
 231 <ENCAP>{sscfnni} {yyextra->g_encap = WTAP_ENCAP_MTP3; BEGIN(STARTBYTES); }
 232 <ENCAP>{hdlc} {yyextra->g_encap = WTAP_ENCAP_CHDLC; BEGIN(STARTBYTES); }
 233 <ENCAP,STARTBYTES>{start_bytes} { BEGIN(BYTE); }
 234 <BYTE>{byte} { ADD_BYTE(yytext); }
 235 <BYTE>{bytes_junk} ;
 236 <BYTE>{end_bytes} { FINALIZE_FRAME(); yyterminate(); }
 237
 238 . {  if (++yyextra->junk_chars > MAX_JUNK) { KERROR("too much junk");  } }
 239 <<EOF>> { yyextra->at_eof = true; yyterminate(); }
 240
 241 %%
 242
 243 /*
 244  * Turn diagnostics back on, so we check the code that we've written.
 245  */
 246 DIAG_ON_FLEX()
 247
 248 /* Fill in pkthdr */
 249
 250 static bool
 251 k12text_set_headers(wtap_rec *rec, k12text_state_t *state,
 252     int *err, char **err_info)
 253 {
 254         rec->rec_type = REC_TYPE_PACKET;
 255         rec->block = wtap_block_create(WTAP_BLOCK_PACKET);
 256         rec->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
 257
 258         rec->ts.secs = 946681200 + (3600*state->g_h) + (60*state->g_m) + state->g_s;
 259         rec->ts.nsecs = 1000000*state->g_ms + 1000*state->g_ns;
 260
 261         rec->rec_header.packet_header.caplen = rec->rec_header.packet_header.len = state->ii;
 262
 263         rec->rec_header.packet_header.pkt_encap = state->g_encap;
 264
 265         /* The file-encap is WTAP_ENCAP_PER_PACKET */
 266         switch(state->g_encap) {
 267             case WTAP_ENCAP_ETHERNET:
 268                     rec->rec_header.packet_header.pseudo_header.eth.fcs_len = 0;
 269                     break;
 270             case WTAP_ENCAP_MTP3:
 271             case WTAP_ENCAP_CHDLC:
 272                     /* no pseudo_header to fill in for these types */
 273                     break;
 274             case WTAP_ENCAP_MTP2:      /* not (yet) supported           */
 275                     /* XXX: I don't know how to fill in the             */
 276                     /* pseudo_header for these types.                   */
 277                     *err = WTAP_ERR_UNSUPPORTED;
 278                     *err_info = g_strdup("k12text: MTP2 packets not yet supported");
 279                     return false;
 280             case WTAP_ENCAP_ATM_PDUS:  /* not (yet) supported           */
 281                     /* XXX: I don't know how to fill in the             */
 282                     /* pseudo_header for these types.                   */
 283                     *err = WTAP_ERR_UNSUPPORTED;
 284                     *err_info = g_strdup("k12text: SSCOP packets not yet supported");
 285                     return false;
 286             default:
 287                     *err = WTAP_ERR_UNSUPPORTED;
 288                     *err_info = g_strdup("k12text: unknown encapsulation type");
 289                     return false;
 290         }
 291         return true;
 292 }
 293
 294 /* Note: k12text_reset is called each time data is to be processed from */
 295 /*       a file. This ensures that no "state" from a previous read is   */
 296 /*       used (such as the lexer look-ahead buffer, file_handle, file   */
 297 /*       position and so on. This allows a single lexer buffer to be    */
 298 /*       used even when multiple files are open simultaneously (as for  */
 299 /*       a file merge).                                                 */
 300
 301 static bool
 302 k12text_run_scanner(k12text_state_t *state, FILE_T fh, int start_state,
 303     int *err, char **err_info)
 304 {
 305         yyscan_t scanner = NULL;
 306
 307         if (yylex_init(&scanner) != 0) {
 308                 /* errno is set if this fails */
 309                 *err = errno;
 310                 *err_info = NULL;
 311                 return false;
 312         }
 313         state->fh = fh;
 314         state->err = 0;
 315         state->err_info = NULL;
 316         state->start_state = start_state;
 317
 318         state->g_encap = WTAP_ENCAP_UNKNOWN;
 319         state->ok_frame = false;
 320         state->is_k12text = false;
 321         state->at_eof = false;
 322         state->junk_chars = 0;
 323         state->error_str = NULL;
 324         state->file_bytes_read=0;
 325         state->g_h=0;
 326         state->g_m=0;
 327         state->g_s=0;
 328         state->g_ns=0;
 329         state->g_ms=0;
 330         state->ii=0;
 331
 332         /* Associate the state with the scanner */
 333         k12text_set_extra(state, scanner);
 334
 335         yylex(scanner);
 336         yylex_destroy(scanner);
 337         if (state->err != 0 && state->err != WTAP_ERR_SHORT_READ) {
 338                 /* I/O error. */
 339                 *err = state->err;
 340                 *err_info = state->err_info;
 341                 return false;
 342         }
 343         return true;
 344 }
 345
 346 static bool
 347 k12text_read(wtap *wth, wtap_rec *rec, Buffer *buf, int *err, char ** err_info, int64_t *data_offset)
 348 {
 349         k12text_t *k12text = (k12text_t *)wth->priv;
 350         k12text_state_t state;
 351
 352         /*
 353          * We seek to the file position after the end of the previous frame
 354          * processed by k12text_read(), since the lexer undoubtedly did some
 355          * amount of look-ahead when processing the previous frame.
 356          *
 357          * We also clear out any lexer state (eg: look-ahead buffer) and
 358          * init vars set by lexer.
 359          */
 360
 361         if ( file_seek(wth->fh, k12text->next_frame_offset, SEEK_SET, err) == -1) {
 362                 return false;
 363         }
 364         state.bb = (uint8_t*)g_malloc(WTAP_MAX_PACKET_SIZE_STANDARD);
 365
 366         if (!k12text_run_scanner(&state, wth->fh, NEXT_FRAME, err, err_info)) {
 367                 g_free(state.bb);
 368                 return false;
 369         }
 370
 371         if (state.ok_frame == false) {
 372                 if (state.at_eof) {
 373                         *err = 0;
 374                         *err_info = NULL;
 375                 } else {
 376                         *err = WTAP_ERR_BAD_FILE;
 377                         *err_info = state.error_str;
 378                 }
 379                 g_free(state.bb);
 380                 return false;
 381         }
 382
 383         *data_offset = k12text->next_frame_offset;           /* file position for beginning of this frame   */
 384         k12text->next_frame_offset += state.file_bytes_read; /* file position after end of this frame       */
 385
 386         if (!k12text_set_headers(rec, &state, err, err_info)) {
 387                 g_free(state.bb);
 388                 return false;
 389         }
 390         ws_buffer_assure_space(buf, rec->rec_header.packet_header.caplen);
 391         memcpy(ws_buffer_start_ptr(buf), state.bb, rec->rec_header.packet_header.caplen);
 392
 393         g_free(state.bb);
 394         return true;
 395 }
 396
 397 static bool
 398 k12text_seek_read(wtap *wth, int64_t seek_off, wtap_rec *rec, Buffer *buf, int *err, char **err_info)
 399 {
 400         k12text_state_t state;
 401
 402         if ( file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1) {
 403                 return false;
 404         }
 405         state.bb = (uint8_t*)g_malloc(WTAP_MAX_PACKET_SIZE_STANDARD);
 406
 407         if (!k12text_run_scanner(&state, wth->random_fh, NEXT_FRAME, err, err_info)) {
 408                 g_free(state.bb);
 409                 return false;
 410         }
 411
 412         if (state.ok_frame == false) {
 413                 *err = WTAP_ERR_BAD_FILE;
 414                 if (state.at_eof) {
 415                         /* What happened ? The desired frame was previously read without a problem */
 416                         *err_info = g_strdup("Unexpected EOF (program error ?)");
 417                 } else {
 418                         *err_info = state.error_str;
 419                 }
 420                 g_free(state.bb);
 421                 return false;
 422         }
 423
 424         if (!k12text_set_headers(rec, &state, err, err_info)) {
 425                 g_free(state.bb);
 426                 return false;
 427         }
 428         ws_buffer_assure_space(buf, rec->rec_header.packet_header.caplen);
 429         memcpy(ws_buffer_start_ptr(buf), state.bb, rec->rec_header.packet_header.caplen);
 430
 431         g_free(state.bb);
 432         return true;
 433 }
 434
 435 wtap_open_return_val
 436 k12text_open(wtap *wth, int *err, char **err_info)
 437 {
 438         k12text_t *k12text;
 439         k12text_state_t state;
 440
 441         state.bb = (uint8_t*)g_malloc(WTAP_MAX_PACKET_SIZE_STANDARD);
 442         if (!k12text_run_scanner(&state, wth->fh, MAGIC, err, err_info)) {
 443                 g_free(state.bb);
 444                 return WTAP_OPEN_ERROR;
 445         }
 446
 447         if (!state.is_k12text) {
 448                 /* *err might have been set to WTAP_ERR_SHORT_READ */
 449                 *err = 0;
 450                 g_free(state.bb);
 451                 return WTAP_OPEN_NOT_MINE;
 452         }
 453
 454         if ( file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
 455                 g_free(state.bb);
 456                 return WTAP_OPEN_ERROR;
 457         }
 458
 459         k12text = g_new(k12text_t, 1);
 460         wth->priv = (void *)k12text;
 461         k12text->next_frame_offset = 0;
 462         wth->file_type_subtype = k12text_file_type_subtype;
 463         wth->file_encap = WTAP_ENCAP_PER_PACKET;
 464         wth->snapshot_length = 0;
 465         wth->subtype_read = k12text_read;
 466         wth->subtype_seek_read = k12text_seek_read;
 467         wth->file_tsprec = WTAP_TSPREC_NSEC;
 468
 469         g_free(state.bb);
 470         return WTAP_OPEN_MINE;
 471 }
 472
 473
 474 static const struct { int e; const char* s; } encaps[] = {
 475         { WTAP_ENCAP_ETHERNET, "ETHER" },
 476         { WTAP_ENCAP_MTP2, "MTP-L2" },
 477         { WTAP_ENCAP_ATM_PDUS, "SSCOP" },
 478         { WTAP_ENCAP_MTP3, "SSCF" },
 479         { WTAP_ENCAP_CHDLC, "HDLC" },
 480         /* ... */
 481         { 0, NULL }
 482 };
 483
 484 static bool
 485 k12text_dump(wtap_dumper *wdh, const wtap_rec *rec,
 486              const uint8_t *pd, int *err, char **err_info _U_) {
 487 #define K12BUF_SIZE 196808
 488         char *buf;
 489         size_t left = K12BUF_SIZE;
 490         size_t wl;
 491         char *p;
 492         const char* str_enc;
 493         unsigned i;
 494         unsigned ns;
 495         unsigned ms;
 496         bool ret;
 497         struct tm *tmp;
 498
 499         /* Don't write anything bigger than we're willing to read. */
 500         if (rec->rec_header.packet_header.caplen > WTAP_MAX_PACKET_SIZE_STANDARD) {
 501                 *err = WTAP_ERR_PACKET_TOO_LARGE;
 502                 return false;
 503         }
 504
 505         str_enc = NULL;
 506         for(i=0; encaps[i].s; i++) {
 507                 if (rec->rec_header.packet_header.pkt_encap == encaps[i].e) {
 508                         str_enc = encaps[i].s;
 509                         break;
 510                 }
 511         }
 512         if (str_enc == NULL) {
 513                 /*
 514                  * That encapsulation type is not supported.  Fail.
 515                  */
 516                 *err = WTAP_ERR_UNWRITABLE_ENCAP;
 517                 return false;
 518         }
 519
 520         buf = (char *)g_malloc(K12BUF_SIZE);
 521         p = buf;
 522
 523         ms = rec->ts.nsecs / 1000000;
 524         ns = (rec->ts.nsecs - (1000000*ms))/1000;
 525
 526         tmp = gmtime(&rec->ts.secs);
 527         if (tmp == NULL)
 528                 snprintf(p, 90, "+---------+---------------+----------+\r\nXX:XX:XX,");
 529         else
 530                 strftime(p, 90, "+---------+---------------+----------+\r\n%H:%M:%S,", tmp);
 531         wl = strlen(p);
 532         p += wl;
 533         left -= wl;
 534
 535         wl = snprintf(p, left, "%.3d,%.3d   %s\r\n|0   |", ms, ns, str_enc);
 536         p += wl;
 537         left -= wl;
 538
 539         for(i = 0; i < rec->rec_header.packet_header.caplen && left > 2; i++) {
 540                 wl = snprintf(p, left, "%.2x|", pd[i]);
 541                 p += wl;
 542                 left -= wl;
 543         }
 544
 545         wl = snprintf(p, left, "\r\n\r\n");
 546         left -= wl;
 547
 548         ret = wtap_dump_file_write(wdh, buf, K12BUF_SIZE - left, err);
 549
 550         g_free(buf);
 551         return ret;
 552 }
 553
 554
 555 static bool
 556 k12text_dump_open(wtap_dumper *wdh, int *err _U_, char **err_info _U_)
 557 {
 558     wdh->subtype_write = k12text_dump;
 559
 560     return true;
 561 }
 562
 563 static int
 564 k12text_dump_can_write_encap(int encap)
 565 {
 566     switch (encap) {
 567         case WTAP_ENCAP_PER_PACKET:
 568         case WTAP_ENCAP_ETHERNET:
 569         case WTAP_ENCAP_MTP3:
 570         case WTAP_ENCAP_CHDLC:
 571                 return 0;
 572         case WTAP_ENCAP_MTP2:
 573         case WTAP_ENCAP_ATM_PDUS:
 574         default:
 575                 return WTAP_ERR_UNWRITABLE_ENCAP;
 576     }
 577 }
 578
 579 static const struct supported_block_type k12text_blocks_supported[] = {
 580     /*
 581      * We support packet blocks, with no comments or other options.
 582      */
 583     { WTAP_BLOCK_PACKET, MULTIPLE_BLOCKS_SUPPORTED, NO_OPTIONS_SUPPORTED }
 584 };
 585
 586 static const struct file_type_subtype_info k12text_info = {
 587     "K12 text file", "k12text", "txt", NULL,
 588     false, BLOCKS_SUPPORTED(k12text_blocks_supported),
 589     k12text_dump_can_write_encap, k12text_dump_open, NULL
 590 };
 591
 592 void register_k12text(void)
 593 {
 594     k12text_file_type_subtype = wtap_register_file_type_subtype(&k12text_info);
 595
 596     /*
 597      * Register name for backwards compatibility with the
 598      * wtap_filetypes table in Lua.
 599      */
 600     wtap_register_backwards_compatibility_lua_name("K12TEXT",
 601                                                    k12text_file_type_subtype);
 602 }