wiretap/pppdump.c

   1 /* pppdump.c
   2  *
   3  * $Id: pppdump.c,v 1.15 2002/03/04 00:25:35 guy Exp $
   4  *
   5  * Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25 #include "wtap-int.h"
  26 #include "buffer.h"
  27 #include "pppdump.h"
  28 #include "file_wrappers.h"
  29
  30 #include <glib.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <errno.h>
  34 #include <string.h>
  35
  36 /*
  37 pppdump records
  38 Daniel Thompson (STMicroelectronics) <daniel.thompson@st.com>
  39
  40 +------+
  41 | 0x07 +------+------+------+         Reset time
  42 |  t3  |  t2  |  t1  |  t0  |         t = time_t
  43 +------+------+------+------+
  44
  45 +------+
  46 | 0x06 |                              Time step (short)
  47 |  ts  |                              ts = time step (tenths)
  48 +------+
  49
  50 +------+
  51 | 0x05 +------+------+------+         Time step (long)
  52 | ts3  | ts2  | ts1  | ts0  |         ts = time step (tenths)
  53 +------+------+------+------+
  54
  55 +------+
  56 | 0x04 |                              Receive deliminator (not seen in practice)
  57 +------+
  58
  59 +------+
  60 | 0x03 |                              Send deliminator (not seen in practice)
  61 +------+
  62
  63 +------+
  64 | 0x02 +------+                       Received data
  65 |  n1  |  n0  |                       n = number of bytes following
  66 |    data     |
  67 |             |
  68
  69 +------+
  70 | 0x01 +------+                       Sent data
  71 |  n1  |  n0  |                       n = number of bytes following
  72 |    data     |
  73 |             |
  74 */
  75
  76 #define PPPD_SENT_DATA          0x01
  77 #define PPPD_RECV_DATA          0x02
  78 #define PPPD_SEND_DELIM         0x03
  79 #define PPPD_RECV_DELIM         0x04
  80 #define PPPD_TIME_STEP_LONG     0x05
  81 #define PPPD_TIME_STEP_SHORT    0x06
  82 #define PPPD_RESET_TIME         0x07
  83
  84 #define PPPD_NULL               0x00    /* For my own use */
  85
  86 /* this buffer must be at least (2*PPPD_MTU) + sizeof(ppp_header) + sizeof(lcp_header) +
  87  * sizeof(ipcp_header). PPPD_MTU is *very* rarely larger than 1500 so this value is fine
  88  */
  89 #define PPPD_BUF_SIZE           8192
  90
  91 typedef enum {
  92         DIRECTION_SENT,
  93         DIRECTION_RECV
  94 } direction_enum;
  95
  96 static gboolean pppdump_read(wtap *wth, int *err, long *data_offset);
  97 static int pppdump_seek_read(wtap *wth, long seek_off,
  98         union wtap_pseudo_header *pseudo_header, guint8 *pd, int len);
  99
 100 typedef struct {
 101         long            offset;
 102         int             num_saved_states;
 103         direction_enum  dir;
 104 } pkt_id;
 105
 106 typedef struct {
 107         direction_enum  dir;
 108         int             cnt;
 109         gboolean        esc;
 110         guint8          buf[PPPD_BUF_SIZE];
 111         long            id_offset;
 112 } pkt_t;
 113
 114 /* Partial-record state */
 115 typedef struct {
 116         int             num_bytes;
 117         pkt_t           *pkt;
 118 } prec_state;
 119
 120 struct _pppdump_t;
 121
 122 typedef struct _pppdump_t {
 123         time_t                  timestamp;
 124         guint                   tenths;
 125         pkt_t                   spkt;
 126         pkt_t                   rpkt;
 127         long                    offset;
 128         GList                   *precs;
 129         struct _pppdump_t       *seek_state;
 130         GPtrArray               *pids;
 131         guint                   pkt_cnt;
 132         int                     num_saved_states;
 133 } pppdump_t;
 134
 135 static int
 136 process_data(pppdump_t *state, FILE_T fh, pkt_t *pkt, int n, guint8 *pd, int *err,
 137                 gboolean *state_saved);
 138
 139 static gboolean
 140 collate(pppdump_t*, FILE_T fh, int *err, guint8 *pd, int *num_bytes,
 141                 direction_enum *direction, pkt_id *pid);
 142
 143 static void
 144 pppdump_close(wtap *wth);
 145
 146 static void
 147 init_state(pppdump_t *state)
 148 {
 149
 150         state->precs = NULL;
 151
 152         state->spkt.dir = DIRECTION_SENT;
 153         state->spkt.cnt = 0;
 154         state->spkt.esc = FALSE;
 155         state->spkt.id_offset = 0;
 156
 157         state->rpkt.dir = DIRECTION_RECV;
 158         state->rpkt.cnt = 0;
 159         state->rpkt.esc = FALSE;
 160         state->rpkt.id_offset = 0;
 161
 162         state->seek_state = NULL;
 163         state->offset = 0x100000; /* to detect errors during development */
 164 }
 165
 166
 167 int
 168 pppdump_open(wtap *wth, int *err)
 169 {
 170         guint8          buffer[6];      /* Looking for: 0x07 t3 t2 t1 t0 ID */
 171         pppdump_t       *state;
 172
 173         /* There is no file header, only packet records. Fortunately for us,
 174         * timestamp records are separated from packet records, so we should
 175         * find an "initial time stamp" (i.e., a "reset time" record, or
 176         * record type 0x07) at the beginning of the file. We'll check for
 177         * that, plus a valid record following the 0x07 and the four bytes
 178         * representing the timestamp.
 179         */
 180
 181         wtap_file_read_unknown_bytes(buffer, sizeof(buffer), wth->fh, err);
 182
 183         if (buffer[0] == PPPD_RESET_TIME &&
 184                         (buffer[5] == PPPD_SENT_DATA ||
 185                          buffer[5] == PPPD_RECV_DATA ||
 186                          buffer[5] == PPPD_TIME_STEP_LONG ||
 187                          buffer[5] == PPPD_TIME_STEP_SHORT ||
 188                          buffer[5] == PPPD_RESET_TIME)) {
 189
 190                 goto my_file_type;
 191         }
 192         else {
 193                 return 0;
 194         }
 195
 196   my_file_type:
 197
 198         if (file_seek(wth->fh, 5, SEEK_SET) == -1) {
 199                 *err = file_error(wth->fh);
 200                 return -1;
 201         }
 202
 203         state = wth->capture.generic = g_malloc(sizeof(pppdump_t));
 204         state->timestamp = pntohl(&buffer[1]);
 205         state->tenths = 0;
 206
 207         init_state(state);
 208
 209         state->offset = 5;
 210         wth->file_encap = WTAP_ENCAP_PPP_WITH_PHDR;
 211         wth->file_type = WTAP_FILE_PPPDUMP;
 212
 213         wth->snapshot_length = PPPD_BUF_SIZE; /* just guessing */
 214         wth->subtype_read = pppdump_read;
 215         wth->subtype_seek_read = pppdump_seek_read;
 216         wth->subtype_close = pppdump_close;
 217
 218         state->seek_state = g_malloc(sizeof(pppdump_t));
 219
 220         state->pids = g_ptr_array_new();
 221         state->pkt_cnt = 0;
 222         state->num_saved_states = 0;
 223
 224         return 1;
 225 }
 226
 227 /* Find the next packet and parse it; called from wtap_loop(). */
 228 static gboolean
 229 pppdump_read(wtap *wth, int *err, long *data_offset)
 230 {
 231         gboolean        retval;
 232         int             num_bytes;
 233         direction_enum  direction;
 234         guint8          *buf;
 235         pppdump_t       *state;
 236         pkt_id          *pid;
 237
 238         buffer_assure_space(wth->frame_buffer, PPPD_BUF_SIZE);
 239         buf = buffer_start_ptr(wth->frame_buffer);
 240
 241         state = wth->capture.generic;
 242         pid = g_new(pkt_id, 1);
 243         if (!pid) {
 244                 *err = errno;   /* assume a malloc failed and set "errno" */
 245                 return FALSE;
 246         }
 247         pid->offset = 0;
 248         pid->num_saved_states = 0;
 249
 250         retval = collate(state, wth->fh, err, buf, &num_bytes, &direction, pid);
 251
 252         if (!retval) {
 253                 g_free(pid);
 254                 return FALSE;
 255         }
 256
 257         pid->dir = direction;
 258
 259         g_ptr_array_add(state->pids, pid);
 260         /* The user's data_offset is not really an offset, but a packet number. */
 261         *data_offset = state->pkt_cnt;
 262         state->pkt_cnt++;
 263
 264         wth->phdr.len           = num_bytes;
 265         wth->phdr.caplen        = num_bytes;
 266         wth->phdr.ts.tv_sec     = state->timestamp;
 267         wth->phdr.ts.tv_usec    = state->tenths * 100000;
 268         wth->phdr.pkt_encap     = WTAP_ENCAP_PPP_WITH_PHDR;
 269
 270         wth->pseudo_header.p2p.sent = (direction == DIRECTION_SENT ? TRUE : FALSE);
 271
 272         return TRUE;
 273 }
 274
 275 #define PKT(x)  (x)->dir == DIRECTION_SENT ? "SENT" : "RECV"
 276
 277 static gboolean
 278 save_prec_state(pppdump_t *state, int num_bytes, pkt_t *pkt)
 279 {
 280         prec_state      *prec;
 281
 282         prec = g_new(prec_state, 1);
 283         if (!prec) {
 284                 return FALSE;
 285         }
 286         prec->num_bytes = num_bytes;
 287         prec->pkt = pkt;
 288
 289         state->precs = g_list_append(state->precs, prec);
 290         return TRUE;
 291 }
 292
 293 static int
 294 process_data_from_prec_state(pppdump_t *state, FILE_T fh, guint8* pd, int *err,
 295                 gboolean *state_saved, pkt_t **ppkt)
 296 {
 297         prec_state      *prec;
 298
 299         prec = state->precs->data;
 300
 301         state->precs = g_list_remove(state->precs, prec);
 302
 303         *ppkt = prec->pkt;
 304
 305         return process_data(state, fh, prec->pkt, prec->num_bytes, pd, err, state_saved);
 306 }
 307
 308
 309
 310 /* Returns number of bytes copied for record, -1 if failure.
 311  *
 312  * This is modeled after pppdump.c, the utility to parse pppd log files; it comes with the ppp
 313  * distribution.
 314  */
 315 static int
 316 process_data(pppdump_t *state, FILE_T fh, pkt_t *pkt, int n, guint8 *pd, int *err,
 317                 gboolean *state_saved)
 318 {
 319         int     c;
 320         int     num_bytes = n;
 321         int     num_written;
 322
 323         *state_saved = FALSE;
 324         for (; num_bytes > 0; --num_bytes) {
 325                 c = file_getc(fh);
 326                 state->offset++;
 327                 switch (c) {
 328                         case EOF:
 329                                 if (*err == 0) {
 330                                         *err = WTAP_ERR_SHORT_READ;
 331                                 }
 332                                 return -1;
 333                                 break;
 334
 335                         case '~':
 336                                 if (pkt->cnt > 0) {
 337                                         pkt->esc = FALSE;
 338
 339                                         num_written = pkt->cnt;
 340                                         pkt->cnt = 0;
 341                                         if (num_written <= 0) {
 342                                                 return 0;
 343                                         }
 344
 345                                         if (num_written > PPPD_BUF_SIZE) {
 346                                                 *err = WTAP_ERR_UNC_OVERFLOW;
 347                                                 return -1;
 348                                         }
 349
 350                                         memcpy(pd, pkt->buf, num_written);
 351
 352                                         num_bytes--;
 353                                         if (num_bytes > 0) {
 354                                                 if (!save_prec_state(state, num_bytes, pkt)) {
 355                                                         *err = errno;
 356                                                         return -1;
 357                                                 }
 358                                                 *state_saved = TRUE;
 359                                         }
 360                                         return num_written;
 361                                 }
 362                                 break;
 363
 364                         case '}':
 365                                 if (!pkt->esc) {
 366                                         pkt->esc = TRUE;
 367                                         break;
 368                                 }
 369                                 /* else fall through */
 370
 371                         default:
 372                                 if (pkt->esc) {
 373                                         c ^= 0x20;
 374                                         pkt->esc = FALSE;
 375                                 }
 376
 377                                 pkt->buf[pkt->cnt++] = c;
 378                                 if (pkt->cnt > PPPD_BUF_SIZE) {
 379                                         *err = WTAP_ERR_UNC_OVERFLOW;
 380                                         return -1;
 381                                 }
 382                                 break;
 383                 }
 384         }
 385
 386         /* we could have run out of bytes to read */
 387         return 0;
 388
 389 }
 390
 391
 392
 393
 394 /* Returns TRUE if packet data copied, FALSE if error occurred or EOF (no more records). */
 395 static gboolean
 396 collate(pppdump_t* state, FILE_T fh, int *err, guint8 *pd, int *num_bytes,
 397                 direction_enum *direction, pkt_id *pid)
 398 {
 399         int             id;
 400         pkt_t           *pkt = NULL;
 401         int             n, num_written = 0;
 402         gboolean        ss = FALSE;
 403         guint32         time_long;
 404         guint8          time_short;
 405
 406         if (!state->precs) {
 407                 state->num_saved_states = 0;
 408         }
 409         if (pid) {
 410                 pid->num_saved_states = state->num_saved_states;
 411         }
 412
 413
 414         while (state->precs) {
 415                 num_written = process_data_from_prec_state(state, fh, pd, err, &ss, &pkt);
 416                 state->num_saved_states++;
 417                 if (pid) {
 418                         pid->num_saved_states++;
 419                 }
 420
 421                 if (num_written < 0) {
 422                         return FALSE;
 423                 }
 424                 else if (num_written > 0) {
 425                         *num_bytes = num_written;
 426                         *direction = pkt->dir;
 427                         if (pid) {
 428                                 pid->offset = pkt->id_offset;
 429                         }
 430                         if (!ss) {
 431                                 pkt->id_offset = 0;
 432                         }
 433                         return TRUE;
 434                 }
 435                 /* if 0 bytes written, keep processing */
 436         }
 437
 438         while ((id = file_getc(fh)) != EOF) {
 439                 state->offset++;
 440                 switch (id) {
 441                         case PPPD_SENT_DATA:
 442                         case PPPD_RECV_DATA:
 443                                 pkt = id == PPPD_SENT_DATA ? &state->spkt : &state->rpkt;
 444
 445                                 if (pkt->id_offset == 0) {
 446                                         pkt->id_offset = state->offset - 1;
 447                                 }
 448
 449                                 n = file_getc(fh);
 450                                 n = (n << 8) + file_getc(fh);
 451                                 state->offset += 2;
 452
 453                                 num_written = process_data(state, fh, pkt, n, pd, err, &ss);
 454
 455                                 if (num_written < 0) {
 456                                         return FALSE;
 457                                 }
 458                                 else if (num_written > 0) {
 459                                         *num_bytes = num_written;
 460                                         *direction = pkt->dir;
 461                                         if (pid) {
 462                                                 pid->offset = pkt->id_offset;
 463                                         }
 464                                         if (!ss) {
 465                                                 pkt->id_offset = 0;
 466                                         }
 467                                         return TRUE;
 468                                 }
 469                                 /* if 0 bytes written, keep looping */
 470
 471                                 break;
 472
 473                         case PPPD_SEND_DELIM:
 474                         case PPPD_RECV_DELIM:
 475                                 /* What can we do? */
 476                                 break;
 477
 478                         case PPPD_RESET_TIME:
 479                                 wtap_file_read_unknown_bytes(&time_long, sizeof(guint32), fh, err);
 480                                 state->offset += sizeof(guint32);
 481                                 state->timestamp = pntohl(&time_long);
 482                                 state->tenths = 0;
 483                                 break;
 484
 485                         case PPPD_TIME_STEP_LONG:
 486                                 wtap_file_read_unknown_bytes(&time_long, sizeof(guint32), fh, err);
 487                                 state->offset += sizeof(guint32);
 488                                 state->tenths += pntohl(&time_long);
 489
 490                                 if (state->tenths >= 10) {
 491                                         state->timestamp += state->tenths / 10;
 492                                         state->tenths = state->tenths % 10;
 493                                 }
 494
 495                                 break;
 496
 497                         case PPPD_TIME_STEP_SHORT:
 498                                 wtap_file_read_unknown_bytes(&time_short, sizeof(guint8), fh, err);
 499                                 state->offset += sizeof(guint8);
 500                                 state->tenths += time_short;
 501
 502                                 if (state->tenths >= 10) {
 503                                         state->timestamp += state->tenths / 10;
 504                                         state->tenths = state->tenths % 10;
 505                                 }
 506
 507                                 break;
 508
 509                         default:
 510                                 /* XXX - bad file */
 511                                 g_assert_not_reached();
 512                 }
 513
 514         }
 515
 516         return FALSE;
 517 }
 518
 519
 520
 521 /* Used to read packets in random-access fashion */
 522 static int
 523 pppdump_seek_read (wtap *wth,
 524                  long seek_off,
 525                  union wtap_pseudo_header *pseudo_header,
 526                  guint8 *pd,
 527                  int len)
 528 {
 529         int             err = 0;
 530         int             num_bytes;
 531         direction_enum  direction;
 532         gboolean        retval;
 533         pppdump_t       *state;
 534         pkt_id          *pid;
 535         int             i;
 536
 537
 538         state = wth->capture.generic;
 539
 540         pid = g_ptr_array_index(state->pids, seek_off);
 541         if (!pid) {
 542                 return -1;
 543         }
 544
 545         file_seek(wth->random_fh, pid->offset, SEEK_SET);
 546
 547         init_state(state->seek_state);
 548
 549         for (i = 0 ; i <= pid->num_saved_states; i++) {
 550           again:
 551                 retval = collate(state->seek_state, wth->random_fh, &err, pd, &num_bytes,
 552                                 &direction, NULL);
 553
 554                 if (!retval) {
 555                         return -1;
 556                 }
 557
 558                 if (direction != pid->dir) {
 559                         goto again;
 560                 }
 561         }
 562
 563         if (len != num_bytes) {
 564                 return -1;
 565         }
 566
 567         pseudo_header->p2p.sent = (pid->dir == DIRECTION_SENT ? TRUE : FALSE);
 568
 569         return 0;
 570 }
 571
 572 static void
 573 simple_g_free(gpointer data, gpointer dummy _U_)
 574 {
 575         if (data)
 576                 g_free(data);
 577 }
 578
 579 static void
 580 pppdump_close(wtap *wth)
 581 {
 582         pppdump_t       *state;
 583
 584         state = wth->capture.generic;
 585
 586         if (state->precs) {
 587                 g_list_foreach(state->precs, simple_g_free, NULL);
 588                 g_list_free(state->precs);
 589         }
 590
 591         if (state->seek_state) { /* should always be TRUE */
 592                 g_free(state->seek_state);
 593         }
 594
 595         if (state->pids) { /* should always be TRUE */
 596                 unsigned int i;
 597                 for (i = 0; i < g_ptr_array_len(state->pids); i++) {
 598                         g_free(g_ptr_array_index(state->pids, i));
 599                 }
 600                 g_ptr_array_free(state->pids, TRUE);
 601         }
 602
 603         g_free(state);
 604
 605 }