epan/dfilter/dfilter-macro.c

   1 /* dfilter-macro.c
   2  *
   3  * $Id$
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 2001 Gerald Combs
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  22  */
  23
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <stdio.h>
  30 #include <errno.h>
  31 #include <ctype.h>
  32 #include <string.h>
  33
  34 #include "dfilter-int.h"
  35 #include "dfilter.h"
  36 #include "dfilter-macro.h"
  37 #include <epan/emem.h>
  38 #include <epan/uat.h>
  39 #include <epan/report_err.h>
  40 #include <epan/proto.h>
  41 #include <wsutil/file_util.h>
  42
  43 typedef struct {
  44         const char* name;
  45         gboolean usable;
  46         char* repr;
  47 } fvt_cache_entry_t;
  48
  49 static uat_t* dfilter_macro_uat = NULL;
  50 static dfilter_macro_t* macros = NULL;
  51 static guint num_macros;
  52 static GHashTable* fvt_cache = NULL;
  53
  54 /* #define DUMP_DFILTER_MACRO */
  55 #ifdef DUMP_DFILTER_MACRO
  56 void dump_dfilter_macro_t(const dfilter_macro_t *m, const char *function, const char *file, int line);
  57 #define DUMP_MACRO(m) dump_dfilter_macro_t(m, __func__, __FILE__, __LINE__)
  58 #else
  59 #define DUMP_MACRO(m)
  60 #endif
  61
  62 static gboolean free_value(gpointer k _U_, gpointer v, gpointer u _U_) {
  63         fvt_cache_entry_t* e = v;
  64         if (e->repr) g_free(e->repr);
  65         g_free(e);
  66         return TRUE;
  67 }
  68
  69 static gboolean fvt_cache_cb(proto_node * node, gpointer data _U_) {
  70         field_info* finfo = node->finfo;
  71         fvt_cache_entry_t* e;
  72
  73         if (!finfo) return FALSE;
  74
  75         if ((e = g_hash_table_lookup(fvt_cache,finfo->hfinfo->abbrev))) {
  76                 e->usable = FALSE;
  77         } else if (finfo->value.ftype->val_to_string_repr) {
  78                 switch (finfo->hfinfo->type) {
  79                         case FT_NONE:
  80                         case FT_PROTOCOL:
  81                                 return FALSE;
  82                         default:
  83                                 break;
  84                 }
  85                 e = g_malloc(sizeof(fvt_cache_entry_t));
  86                 e->name = finfo->hfinfo->abbrev,
  87                 e->repr = fvalue_to_string_repr(&(finfo->value), FTREPR_DFILTER, NULL);
  88                 e->usable = TRUE;
  89                 g_hash_table_insert(fvt_cache,(void*)finfo->hfinfo->abbrev,e);
  90         }
  91         return FALSE;
  92 }
  93
  94 void dfilter_macro_build_ftv_cache(void* tree_root) {
  95         g_hash_table_foreach_remove(fvt_cache,free_value,NULL);
  96         proto_tree_traverse_post_order(tree_root, fvt_cache_cb, NULL);
  97 }
  98
  99 void dfilter_macro_foreach(dfilter_macro_cb_t cb, void* data) {
 100         guint i;
 101
 102         for (i = 0; i < num_macros; i++) {
 103                 cb(&(macros[i]),data);
 104         }
 105         return;
 106 }
 107
 108 static void macro_fprint(dfilter_macro_t* m, void* ud) {
 109         FILE* f = ud;
 110
 111         fprintf(f,"%s\t%s\n",m->name,m->text);
 112 }
 113
 114 void dfilter_macro_save(const gchar* filename, gchar** error) {
 115         FILE* f = ws_fopen(filename,"w");
 116
 117         if (!f) {
 118                 *error = ep_strdup_printf("Could not open file: '%s', error: %s\n", filename, strerror(errno) );
 119                 return;
 120         }
 121
 122         dfilter_macro_foreach(macro_fprint, f);
 123
 124         fclose(f);
 125
 126         return;
 127 }
 128
 129 #ifdef DUMP_MACROS
 130 static void macro_dump(dfilter_macro_t* m _U_, void* ud _U_) {
 131         gchar** part = m->parts;
 132         int* args_pos = m->args_pos;
 133
 134         printf("\n->%s\t%s\t%d [%d]\n\t'%s'\n",
 135                    m->name, m->text, m->argc, m->usable, *(part++));
 136
 137         while (*part) {
 138                 printf("\t$%d '%s'\n",*args_pos,*part);
 139
 140                 args_pos++;
 141                 part++;
 142         }
 143 }
 144 #else
 145 #define macro_dump(a,b)
 146 #endif
 147
 148 void dfilter_macro_dump(void) {
 149 #ifdef DUMP_MACROS
 150         dfilter_macro_foreach(macro_dump, NULL);
 151 #endif
 152 }
 153
 154 static gchar* dfilter_macro_resolve(gchar* name, gchar** args, const gchar** error) {
 155         GString* text;
 156         int argc = 0;
 157         dfilter_macro_t* m = NULL;
 158         fvt_cache_entry_t* e;
 159         int* arg_pos_p;
 160         gchar** parts;
 161         gchar* ret;
 162         guint i;
 163
 164         for (i = 0; i < num_macros; i++) {
 165                 dfilter_macro_t* c = &(macros[i]);
 166                 if ( c->usable && g_str_equal(c->name,name) ) {
 167                         m = c;
 168                         break;
 169                 }
 170         }
 171
 172         if (!m) {
 173                 if (fvt_cache && (e = g_hash_table_lookup(fvt_cache,name) )) {
 174                         if(e->usable) {
 175                                 return e->repr;
 176                         } else {
 177                                 *error = ep_strdup_printf("macro '%s' is unusable", name);
 178                                 return NULL;
 179                         }
 180                 } else {
 181                         *error = ep_strdup_printf("macro '%s' does not exist", name);
 182                         return NULL;
 183                 }
 184         }
 185
 186         DUMP_MACRO(m);
 187
 188         if (args) {
 189                 while(args[argc]) argc++;
 190         }
 191
 192         if (argc != m->argc) {
 193                 *error = ep_strdup_printf("wrong number of arguments for macro '%s', expecting %d instead of %d",
 194                                                                   name, m->argc, argc);
 195                 return NULL;
 196         }
 197
 198         arg_pos_p = m->args_pos;
 199         parts = m->parts;
 200
 201         text = g_string_new(*(parts++));
 202
 203         if (args) {
 204                 while (*parts) {
 205                         g_string_append_printf(text,"%s%s",
 206                                                args[*(arg_pos_p++)],
 207                                                *(parts++));
 208                 }
 209         }
 210
 211         ret = ep_strdup(text->str);
 212
 213         g_string_free(text,TRUE);
 214
 215         return ret;
 216 }
 217
 218
 219 gchar* dfilter_macro_apply(const gchar* text, guint depth, const gchar** error) {
 220         enum { OUTSIDE, STARTING, NAME, ARGS } state = OUTSIDE;
 221         GString* out;
 222         GString* name = NULL;
 223         GString* arg = NULL;
 224         GPtrArray* args = NULL;
 225         gchar c;
 226         const gchar* r = text;
 227         gboolean changed = FALSE;
 228
 229         if ( depth > 31) {
 230                 *error = "too much nesting in macros";
 231                 return NULL;
 232         }
 233
 234 #define FGS(n) if (n) g_string_free(n,TRUE); n = NULL
 235
 236 #define FREE_ALL() \
 237         do { \
 238                 FGS(name); \
 239                 FGS(arg); \
 240                 if (args) { \
 241                         while(args->len) { void* p = g_ptr_array_remove_index_fast(args,0); if (p) g_free(p); } \
 242                         g_ptr_array_free(args,TRUE); \
 243                         args = NULL; } } while(0)
 244
 245                 *error = NULL;
 246                 out = g_string_sized_new(64);
 247
 248                 while(1) {
 249                         c = *r++;
 250
 251                         switch(state) {
 252                                 case OUTSIDE: {
 253                                         switch(c) {
 254                                                 case '\0': {
 255                                                         goto finish;
 256                                                 } case '$': {
 257                                                         state = STARTING;
 258                                                         break;
 259                                                 } default: {
 260                                                         g_string_append_c(out,c);
 261                                                         break;
 262                                                 }
 263                                         }
 264                                         break;
 265                                 } case STARTING: {
 266                                         switch (c) {
 267                                                 case '{': {
 268                                                         args = g_ptr_array_new();
 269                                                         arg = g_string_sized_new(32);
 270                                                         name = g_string_sized_new(32);
 271
 272                                                         state = NAME;
 273
 274                                                         break;
 275                                                 } case '\0': {
 276                                                         g_string_append_c(out,'$');
 277
 278                                                         goto finish;
 279                                                 } default: {
 280                                                         g_string_append_c(out,'$');
 281                                                         g_string_append_c(out,c);
 282
 283                                                         state = OUTSIDE;
 284
 285                                                         break;
 286                                                 }
 287                                         }
 288                                         break;
 289                                 } case NAME: {
 290                                         if ( isalnum((int)c) || c == '_' || c == '-' || c == '.' ) {
 291                                                 g_string_append_c(name,c);
 292                                         } else if ( c == ':') {
 293                                                 state = ARGS;
 294                                         } else if ( c == '}') {
 295                                                 gchar* resolved;
 296
 297                                                 g_ptr_array_add(args,NULL);
 298
 299                                                 resolved = dfilter_macro_resolve(name->str, (gchar**)args->pdata, error);
 300                                                 if (*error) goto on_error;
 301
 302                                                 changed = TRUE;
 303
 304                                                 g_string_append(out,resolved);
 305
 306                                                 FREE_ALL();
 307
 308                                                 state = OUTSIDE;
 309                                         } else if ( c == '\0') {
 310                                                 *error = "end of filter in the middle of a macro expression";
 311                                                 goto on_error;
 312                                         } else {
 313                                                 *error = "invalid char in macro name";
 314                                                 goto on_error;
 315                                         }
 316                                         break;
 317                                 } case ARGS: {
 318                                         switch(c) {
 319                                                 case '\0': {
 320                                                         *error = "end of filter in the middle of a macro expression";
 321                                                         goto on_error;
 322                                                 } case ';': {
 323                                                         g_ptr_array_add(args,arg->str);
 324                                                         g_string_free(arg,FALSE);
 325
 326                                                         arg = g_string_sized_new(32);
 327                                                         break;
 328                                                 } case '\\': {
 329                                                         c = *r++;
 330                                                         if (c) {
 331                                                                 g_string_append_c(arg,c);
 332                                                                 break;
 333                                                         } else {
 334                                                                 *error = "end of filter in the middle of a macro expression";
 335                                                                 goto on_error;
 336                                                         }
 337                                                 } default: {
 338                                                         g_string_append_c(arg,c);
 339                                                         break;
 340                                                 } case '}': {
 341                                                         gchar* resolved;
 342                                                         g_ptr_array_add(args,arg->str);
 343                                                         g_ptr_array_add(args,NULL);
 344
 345                                                         g_string_free(arg,FALSE);
 346                                                         arg = NULL;
 347
 348                                                         resolved = dfilter_macro_resolve(name->str, (gchar**)args->pdata, error);
 349                                                         if (*error) goto on_error;
 350
 351                                                         changed = TRUE;
 352
 353                                                         g_string_append(out,resolved);
 354
 355                                                         FREE_ALL();
 356
 357                                                         state = OUTSIDE;
 358                                                         break;
 359                                                 }
 360                                         }
 361                                         break;
 362                                 }
 363                         }
 364                 }
 365
 366 finish:
 367                 {
 368                         FREE_ALL();
 369
 370                         if (changed) {
 371                                 gchar* resolved = dfilter_macro_apply(out->str, depth++, error);
 372                                 g_string_free(out,TRUE);
 373                                 return (*error) ? NULL : resolved;
 374                         } else {
 375                                 gchar* out_str = ep_strdup(out->str);
 376                                 g_string_free(out,TRUE);
 377                                 return out_str;
 378                         }
 379                 }
 380 on_error:
 381                 {
 382                         FREE_ALL();
 383                         if (! *error) *error = "unknown error in macro expression";
 384                         g_string_free(out,TRUE);
 385                         return NULL;
 386                 }
 387 }
 388
 389 static void macro_update(void* mp, const gchar** error) {
 390         dfilter_macro_t* m = mp;
 391         GPtrArray* parts;
 392         GArray* args_pos;
 393         const gchar* r;
 394         gchar* w;
 395         gchar* part;
 396         int argc = 0;
 397         guint i;
 398
 399         DUMP_MACRO(m);
 400
 401         *error = NULL;
 402
 403         for (i = 0; i < num_macros; i++) {
 404                 if (m == &(macros[i])) continue;
 405
 406                 if ( g_str_equal(m->name,macros[i].name) ) {
 407                         *error = ep_strdup_printf("macro '%s' exists already", m->name);
 408                         m->usable = FALSE;
 409                         return;
 410                 }
 411         }
 412
 413         parts = g_ptr_array_new();
 414         args_pos = g_array_new(FALSE,FALSE,sizeof(int));
 415
 416         m->priv = part = w = g_strdup(m->text);
 417         r = m->text;
 418         g_ptr_array_add(parts,part);
 419
 420         while (r && *r) {
 421
 422                 switch (*r) {
 423                         default:
 424                                 *(w++) = *(r++);
 425                                 break;
 426                         case '\0':
 427                                 *(w++) = *(r++);
 428                                 goto done;
 429                         case '\\':
 430                                 *(w++) = *(++r);
 431                                 r++;
 432                                 break;
 433                         case '$': {
 434                                 int cnt = 0;
 435                                 int arg_pos = 0;
 436                                 do {
 437                                         char c = *(r+1);
 438                                         if (c >= '0' && c <= '9') {
 439                                                 cnt++;
 440                                                 r++;
 441                                                 *(w++) = '\0';
 442                                                 arg_pos *= 10;
 443                                                 arg_pos += c - '0';
 444                                         } else {
 445                                                 break;
 446                                         }
 447                                 } while(*r);
 448
 449                                 if (cnt) {
 450                                         *(w++) = '\0';
 451                                         r++;
 452                                         argc = argc < arg_pos ? arg_pos : argc;
 453                                         arg_pos--;
 454                                         g_array_append_val(args_pos,arg_pos);
 455                                         g_ptr_array_add(parts,w);
 456                                 } else {
 457                                         *(w++) = *(r++);
 458                                 }
 459                                 break;
 460                         }
 461                 }
 462
 463         }
 464
 465 done:
 466         g_ptr_array_add(parts,NULL);
 467
 468         if (m->parts) g_free(m->parts);
 469
 470         m->parts = (gchar**)parts->pdata;
 471
 472         if (m->args_pos) g_free(m->args_pos);
 473
 474         m->args_pos = (int*)(void *)args_pos->data;
 475
 476         g_ptr_array_free(parts,FALSE);
 477         g_array_free(args_pos,FALSE);
 478
 479         m->argc = argc;
 480
 481         m->usable = TRUE;
 482
 483         macro_dump(m,NULL);
 484
 485         DUMP_MACRO(m);
 486
 487         return;
 488 }
 489
 490 static void macro_free(void* r) {
 491         dfilter_macro_t* m = r;
 492
 493         DUMP_MACRO(r);
 494
 495         g_free(m->name);
 496         g_free(m->text);
 497         g_free(m->priv);
 498         g_free(m->parts);
 499         g_free(m->args_pos);
 500 }
 501
 502 static void* macro_copy(void* dest, const void* orig, unsigned len _U_) {
 503         dfilter_macro_t* d = dest;
 504         const dfilter_macro_t* m = orig;
 505
 506         DUMP_MACRO(m);
 507
 508         d->name = g_strdup(m->name);
 509         d->text = g_strdup(m->text);
 510         d->usable = m->usable;
 511
 512         if (m->parts) {
 513                 guint nparts = 0;
 514
 515                 /*
 516                  * Copy the contents of m->priv (a "cooked" version
 517                  * of m->text) into d->priv.
 518                  *
 519                  * First we clone m->text into d->priv, this gets
 520                  * us a NUL terminated string of the proper length.
 521                  *
 522                  * Then we loop copying bytes from m->priv into
 523                  * d-priv.  Since m->priv contains internal ACSII NULs
 524                  * we use the length of m->text to stop the copy.
 525                  */
 526
 527                 d->priv = g_strdup(m->text);
 528                 {
 529                         const gchar* oldText = m->text;
 530                         const gchar* oldPriv = m->priv;
 531                         gchar* newPriv = d->priv;
 532                         while(oldText && *oldText) {
 533                                 *(newPriv++) = *(oldPriv++);
 534                                 oldText++;
 535                         }
 536                 }
 537
 538                 /*
 539                  * The contents of the m->parts array contains pointers
 540                  * into various sections of m->priv.  Since it's
 541                  * an argv style array of ponters, this array is
 542                  * actually one larger than the number of parts
 543                  * to hold the final NULL terminator.
 544                  *
 545                  * The following copy clones the original m->parts
 546                  * array into d->parts but then fixes-up the pointers
 547                  * so that they point into the appropriate sections
 548                  * of the d->priv.
 549                  */
 550
 551                 do nparts++; while (m->parts[nparts]);
 552                 d->parts = g_memdup(m->parts,(nparts+1)*sizeof(void*));
 553                 nparts = 0;
 554                 while(m->parts[nparts]) {
 555                         if(nparts) {
 556                                 d->parts[nparts] = d->parts[nparts - 1] + (m->parts[nparts] - m->parts[nparts - 1]);
 557                         } else {
 558                                 d->parts[nparts] = d->priv;
 559                         }
 560                         nparts++;
 561                 }
 562
 563                 /*
 564                  * Clone the contents of m->args_pos into d->args_pos.
 565                  */
 566
 567                 d->args_pos = g_memdup(m->args_pos,(--nparts)*sizeof(int));
 568         }
 569
 570         DUMP_MACRO(d);
 571
 572         return d;
 573 }
 574
 575 static gboolean macro_name_chk(void* r _U_, const char* in_name, unsigned name_len, void* u1 _U_, void* u2 _U_, const char** error) {
 576         guint i;
 577
 578         if (name_len == 0) {
 579                 *error = "invalid name";
 580                 return FALSE;
 581         }
 582
 583         for (i=0; i < name_len; i++) {
 584                 if (!(in_name[i] == '_' || isalnum((guchar)in_name[i]) ) ) {
 585                         *error = "invalid char in name";
 586                         return FALSE;
 587                 }
 588         }
 589
 590         return TRUE;
 591 }
 592
 593 UAT_CSTRING_CB_DEF(macro,name,dfilter_macro_t)
 594 UAT_CSTRING_CB_DEF(macro,text,dfilter_macro_t)
 595
 596 void dfilter_macro_init(void) {
 597         static uat_field_t uat_fields[] =  {
 598                 UAT_FLD_CSTRING_OTHER(macro,name,macro_name_chk,"The name of the macro."),
 599                 UAT_FLD_CSTRING_ISPRINT(macro,text,"The text this macro resolves to."),
 600                 UAT_END_FIELDS
 601         };
 602
 603         dfilter_macro_uat = uat_new("Display Filter Macros",
 604                                     sizeof(dfilter_macro_t),
 605                                     DFILTER_MACRO_FILENAME,
 606                                     TRUE,
 607                                     (void*) &macros,
 608                                     &num_macros,
 609                                     NULL,
 610                                     "ChDisplayFilterMacrosSection",
 611                                     macro_copy,
 612                                     macro_update,
 613                                     macro_free,
 614                                     uat_fields);
 615
 616         fvt_cache = g_hash_table_new(g_str_hash,g_str_equal);
 617 }
 618
 619 void dfilter_macro_get_uat(void** p) {
 620         *p = dfilter_macro_uat;
 621 }
 622
 623 #ifdef DUMP_DFILTER_MACRO
 624 /*
 625  * The dfilter_macro_t has several characteristics that are
 626  * not immediattly obvious. The dump_dfilter_filter_macro_t()
 627  * function can be used to help "visualize" the contents of
 628  * a dfilter_macro_t.
 629  *
 630  * Some non-obvious components of this struct include:
 631  *
 632  *    m->parts is an argv style array of pointers into the
 633  *    m->priv string.
 634  *
 635  *    The last pointer of an m->parts array should contain
 636  *    NULL to indicate the end of the parts pointer array.
 637  *
 638  *    m->priv is a "cooked" copy of the m->text string.
 639  *    Any variable substitution indicators within m->text
 640  *    ("$1", "$2", ...) will have been replaced with ASCII
 641  *    NUL characters within m->priv.
 642  *
 643  *    The first element of m->parts array (m-parts[0]) will
 644  *    usually have the same pointer value as m->priv (unless
 645  *    the dfilter-macro starts off with a variable
 646  *    substitution indicator (e.g. "$1").
 647  */
 648
 649 void dump_dfilter_macro_t(const dfilter_macro_t *m, const char *function, const char *file, int line)
 650 {
 651         printf("\n<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n");
 652
 653         if(m == NULL) {
 654                 printf("  dfilter_macro_t * == NULL! (via: %s(): %s:%d)\n", function, file, line);
 655                 printf("\n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
 656         }
 657
 658         printf("DUMP of dfilter_macro_t: %p (via: %s(): %s:%d)\n", m, function, file, line);
 659
 660         printf("  &dfilter_macro->name     == %p\n", &m->name);
 661         if(m->name == NULL) {
 662                 printf("                ->name     == NULL\n");
 663         } else {
 664                 printf("                ->name     == %p\n", m->name);
 665                 printf("                ->name     == <%s>\n", m->name);
 666         }
 667
 668         printf("  &dfilter_macro->text     == %p\n", &m->text);
 669         if(m->text == NULL) {
 670                 printf("                ->text     == NULL\n");
 671         } else {
 672                 printf("                ->text     == %p\n", m->text);
 673                 printf("                ->text     == <%s>\n", m->text);
 674         }
 675
 676         printf("  &dfilter_macro->usable   == %p\n", &m->usable);
 677         printf("                ->usable   == %u\n", m->usable);
 678
 679         printf("  &dfilter_macro->parts    == %p\n", &m->parts);
 680
 681         if(m->parts == NULL) {
 682                 printf("                ->parts    == NULL\n");
 683         } else {
 684                 int i = 0;
 685
 686                 while (m->parts[i]) {
 687                         printf("                ->parts[%d] == %p\n", i, m->parts[i]);
 688                         printf("                ->parts[%d] == <%s>\n", i, m->parts[i]);
 689                         i++;
 690                 }
 691                 printf("                ->parts[%d] == NULL\n", i);
 692         }
 693
 694         printf("  &dfilter_macro->args_pos == %p\n", &m->args_pos);
 695         if(m->args_pos == NULL) {
 696                 printf("                ->args_pos == NULL\n");
 697         } else {
 698                 printf("                ->args_pos == %p\n", m->args_pos);
 699                 /*printf("                ->args_pos == <%?>\n", m->args_pos);*/
 700         }
 701
 702         printf("  &dfilter_macro->argc     == %p\n", &m->argc);
 703         printf("                ->argc     == %d\n", m->argc);
 704
 705         printf("  &dfilter_macro->priv     == %p\n", &m->priv);
 706         if(m->priv == NULL) {
 707                 printf("                ->priv     == NULL\n");
 708         } else {
 709                 printf("                ->priv     == %p\n", m->priv);
 710                 printf("                ->priv     == <%s>\n", (char *)m->priv);
 711         }
 712
 713         printf("\n>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
 714 }
 715 #endif
 716