kernel/tools/lib/traceevent/parse-filter.c

   1 /*
   2  * Copyright (C) 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
   3  *
   4  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation;
   8  * version 2.1 of the License (not later!)
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this program; if not,  see <http://www.gnu.org/licenses>
  17  *
  18  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  19  */
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <stdarg.h>
  24 #include <errno.h>
  25 #include <sys/types.h>
  26
  27 #include "event-parse.h"
  28 #include "event-utils.h"
  29
  30 #define COMM "COMM"
  31
  32 static struct format_field comm = {
  33         .name = "COMM",
  34 };
  35
  36 struct event_list {
  37         struct event_list       *next;
  38         struct event_format     *event;
  39 };
  40
  41 static void show_error(char *error_buf, const char *fmt, ...)
  42 {
  43         unsigned long long index;
  44         const char *input;
  45         va_list ap;
  46         int len;
  47         int i;
  48
  49         input = pevent_get_input_buf();
  50         index = pevent_get_input_buf_ptr();
  51         len = input ? strlen(input) : 0;
  52
  53         if (len) {
  54                 strcpy(error_buf, input);
  55                 error_buf[len] = '\n';
  56                 for (i = 1; i < len && i < index; i++)
  57                         error_buf[len+i] = ' ';
  58                 error_buf[len + i] = '^';
  59                 error_buf[len + i + 1] = '\n';
  60                 len += i+2;
  61         }
  62
  63         va_start(ap, fmt);
  64         vsnprintf(error_buf + len, PEVENT_FILTER_ERROR_BUFSZ - len, fmt, ap);
  65         va_end(ap);
  66 }
  67
  68 static void free_token(char *token)
  69 {
  70         pevent_free_token(token);
  71 }
  72
  73 static enum event_type read_token(char **tok)
  74 {
  75         enum event_type type;
  76         char *token = NULL;
  77
  78         do {
  79                 free_token(token);
  80                 type = pevent_read_token(&token);
  81         } while (type == EVENT_NEWLINE || type == EVENT_SPACE);
  82
  83         /* If token is = or ! check to see if the next char is ~ */
  84         if (token &&
  85             (strcmp(token, "=") == 0 || strcmp(token, "!") == 0) &&
  86             pevent_peek_char() == '~') {
  87                 /* append it */
  88                 *tok = malloc(3);
  89                 if (*tok == NULL) {
  90                         free_token(token);
  91                         return EVENT_ERROR;
  92                 }
  93                 sprintf(*tok, "%c%c", *token, '~');
  94                 free_token(token);
  95                 /* Now remove the '~' from the buffer */
  96                 pevent_read_token(&token);
  97                 free_token(token);
  98         } else
  99                 *tok = token;
 100
 101         return type;
 102 }
 103
 104 static int filter_cmp(const void *a, const void *b)
 105 {
 106         const struct filter_type *ea = a;
 107         const struct filter_type *eb = b;
 108
 109         if (ea->event_id < eb->event_id)
 110                 return -1;
 111
 112         if (ea->event_id > eb->event_id)
 113                 return 1;
 114
 115         return 0;
 116 }
 117
 118 static struct filter_type *
 119 find_filter_type(struct event_filter *filter, int id)
 120 {
 121         struct filter_type *filter_type;
 122         struct filter_type key;
 123
 124         key.event_id = id;
 125
 126         filter_type = bsearch(&key, filter->event_filters,
 127                               filter->filters,
 128                               sizeof(*filter->event_filters),
 129                               filter_cmp);
 130
 131         return filter_type;
 132 }
 133
 134 static struct filter_type *
 135 add_filter_type(struct event_filter *filter, int id)
 136 {
 137         struct filter_type *filter_type;
 138         int i;
 139
 140         filter_type = find_filter_type(filter, id);
 141         if (filter_type)
 142                 return filter_type;
 143
 144         filter_type = realloc(filter->event_filters,
 145                               sizeof(*filter->event_filters) *
 146                               (filter->filters + 1));
 147         if (!filter_type)
 148                 return NULL;
 149
 150         filter->event_filters = filter_type;
 151
 152         for (i = 0; i < filter->filters; i++) {
 153                 if (filter->event_filters[i].event_id > id)
 154                         break;
 155         }
 156
 157         if (i < filter->filters)
 158                 memmove(&filter->event_filters[i+1],
 159                         &filter->event_filters[i],
 160                         sizeof(*filter->event_filters) *
 161                         (filter->filters - i));
 162
 163         filter_type = &filter->event_filters[i];
 164         filter_type->event_id = id;
 165         filter_type->event = pevent_find_event(filter->pevent, id);
 166         filter_type->filter = NULL;
 167
 168         filter->filters++;
 169
 170         return filter_type;
 171 }
 172
 173 /**
 174  * pevent_filter_alloc - create a new event filter
 175  * @pevent: The pevent that this filter is associated with
 176  */
 177 struct event_filter *pevent_filter_alloc(struct pevent *pevent)
 178 {
 179         struct event_filter *filter;
 180
 181         filter = malloc(sizeof(*filter));
 182         if (filter == NULL)
 183                 return NULL;
 184
 185         memset(filter, 0, sizeof(*filter));
 186         filter->pevent = pevent;
 187         pevent_ref(pevent);
 188
 189         return filter;
 190 }
 191
 192 static struct filter_arg *allocate_arg(void)
 193 {
 194         return calloc(1, sizeof(struct filter_arg));
 195 }
 196
 197 static void free_arg(struct filter_arg *arg)
 198 {
 199         if (!arg)
 200                 return;
 201
 202         switch (arg->type) {
 203         case FILTER_ARG_NONE:
 204         case FILTER_ARG_BOOLEAN:
 205                 break;
 206
 207         case FILTER_ARG_NUM:
 208                 free_arg(arg->num.left);
 209                 free_arg(arg->num.right);
 210                 break;
 211
 212         case FILTER_ARG_EXP:
 213                 free_arg(arg->exp.left);
 214                 free_arg(arg->exp.right);
 215                 break;
 216
 217         case FILTER_ARG_STR:
 218                 free(arg->str.val);
 219                 regfree(&arg->str.reg);
 220                 free(arg->str.buffer);
 221                 break;
 222
 223         case FILTER_ARG_VALUE:
 224                 if (arg->value.type == FILTER_STRING ||
 225                     arg->value.type == FILTER_CHAR)
 226                         free(arg->value.str);
 227                 break;
 228
 229         case FILTER_ARG_OP:
 230                 free_arg(arg->op.left);
 231                 free_arg(arg->op.right);
 232         default:
 233                 break;
 234         }
 235
 236         free(arg);
 237 }
 238
 239 static int add_event(struct event_list **events,
 240                       struct event_format *event)
 241 {
 242         struct event_list *list;
 243
 244         list = malloc(sizeof(*list));
 245         if (list == NULL)
 246                 return -1;
 247
 248         list->next = *events;
 249         *events = list;
 250         list->event = event;
 251         return 0;
 252 }
 253
 254 static int event_match(struct event_format *event,
 255                        regex_t *sreg, regex_t *ereg)
 256 {
 257         if (sreg) {
 258                 return !regexec(sreg, event->system, 0, NULL, 0) &&
 259                         !regexec(ereg, event->name, 0, NULL, 0);
 260         }
 261
 262         return !regexec(ereg, event->system, 0, NULL, 0) ||
 263                 !regexec(ereg, event->name, 0, NULL, 0);
 264 }
 265
 266 static enum pevent_errno
 267 find_event(struct pevent *pevent, struct event_list **events,
 268            char *sys_name, char *event_name)
 269 {
 270         struct event_format *event;
 271         regex_t ereg;
 272         regex_t sreg;
 273         int match = 0;
 274         int fail = 0;
 275         char *reg;
 276         int ret;
 277         int i;
 278
 279         if (!event_name) {
 280                 /* if no name is given, then swap sys and name */
 281                 event_name = sys_name;
 282                 sys_name = NULL;
 283         }
 284
 285         reg = malloc(strlen(event_name) + 3);
 286         if (reg == NULL)
 287                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 288
 289         sprintf(reg, "^%s$", event_name);
 290
 291         ret = regcomp(&ereg, reg, REG_ICASE|REG_NOSUB);
 292         free(reg);
 293
 294         if (ret)
 295                 return PEVENT_ERRNO__INVALID_EVENT_NAME;
 296
 297         if (sys_name) {
 298                 reg = malloc(strlen(sys_name) + 3);
 299                 if (reg == NULL) {
 300                         regfree(&ereg);
 301                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 302                 }
 303
 304                 sprintf(reg, "^%s$", sys_name);
 305                 ret = regcomp(&sreg, reg, REG_ICASE|REG_NOSUB);
 306                 free(reg);
 307                 if (ret) {
 308                         regfree(&ereg);
 309                         return PEVENT_ERRNO__INVALID_EVENT_NAME;
 310                 }
 311         }
 312
 313         for (i = 0; i < pevent->nr_events; i++) {
 314                 event = pevent->events[i];
 315                 if (event_match(event, sys_name ? &sreg : NULL, &ereg)) {
 316                         match = 1;
 317                         if (add_event(events, event) < 0) {
 318                                 fail = 1;
 319                                 break;
 320                         }
 321                 }
 322         }
 323
 324         regfree(&ereg);
 325         if (sys_name)
 326                 regfree(&sreg);
 327
 328         if (!match)
 329                 return PEVENT_ERRNO__EVENT_NOT_FOUND;
 330         if (fail)
 331                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 332
 333         return 0;
 334 }
 335
 336 static void free_events(struct event_list *events)
 337 {
 338         struct event_list *event;
 339
 340         while (events) {
 341                 event = events;
 342                 events = events->next;
 343                 free(event);
 344         }
 345 }
 346
 347 static enum pevent_errno
 348 create_arg_item(struct event_format *event, const char *token,
 349                 enum event_type type, struct filter_arg **parg, char *error_str)
 350 {
 351         struct format_field *field;
 352         struct filter_arg *arg;
 353
 354         arg = allocate_arg();
 355         if (arg == NULL) {
 356                 show_error(error_str, "failed to allocate filter arg");
 357                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 358         }
 359
 360         switch (type) {
 361
 362         case EVENT_SQUOTE:
 363         case EVENT_DQUOTE:
 364                 arg->type = FILTER_ARG_VALUE;
 365                 arg->value.type =
 366                         type == EVENT_DQUOTE ? FILTER_STRING : FILTER_CHAR;
 367                 arg->value.str = strdup(token);
 368                 if (!arg->value.str) {
 369                         free_arg(arg);
 370                         show_error(error_str, "failed to allocate string filter arg");
 371                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 372                 }
 373                 break;
 374         case EVENT_ITEM:
 375                 /* if it is a number, then convert it */
 376                 if (isdigit(token[0])) {
 377                         arg->type = FILTER_ARG_VALUE;
 378                         arg->value.type = FILTER_NUMBER;
 379                         arg->value.val = strtoull(token, NULL, 0);
 380                         break;
 381                 }
 382                 /* Consider this a field */
 383                 field = pevent_find_any_field(event, token);
 384                 if (!field) {
 385                         if (strcmp(token, COMM) != 0) {
 386                                 /* not a field, Make it false */
 387                                 arg->type = FILTER_ARG_BOOLEAN;
 388                                 arg->boolean.value = FILTER_FALSE;
 389                                 break;
 390                         }
 391                         /* If token is 'COMM' then it is special */
 392                         field = &comm;
 393                 }
 394                 arg->type = FILTER_ARG_FIELD;
 395                 arg->field.field = field;
 396                 break;
 397         default:
 398                 free_arg(arg);
 399                 show_error(error_str, "expected a value but found %s", token);
 400                 return PEVENT_ERRNO__UNEXPECTED_TYPE;
 401         }
 402         *parg = arg;
 403         return 0;
 404 }
 405
 406 static struct filter_arg *
 407 create_arg_op(enum filter_op_type btype)
 408 {
 409         struct filter_arg *arg;
 410
 411         arg = allocate_arg();
 412         if (!arg)
 413                 return NULL;
 414
 415         arg->type = FILTER_ARG_OP;
 416         arg->op.type = btype;
 417
 418         return arg;
 419 }
 420
 421 static struct filter_arg *
 422 create_arg_exp(enum filter_exp_type etype)
 423 {
 424         struct filter_arg *arg;
 425
 426         arg = allocate_arg();
 427         if (!arg)
 428                 return NULL;
 429
 430         arg->type = FILTER_ARG_EXP;
 431         arg->op.type = etype;
 432
 433         return arg;
 434 }
 435
 436 static struct filter_arg *
 437 create_arg_cmp(enum filter_exp_type etype)
 438 {
 439         struct filter_arg *arg;
 440
 441         arg = allocate_arg();
 442         if (!arg)
 443                 return NULL;
 444
 445         /* Use NUM and change if necessary */
 446         arg->type = FILTER_ARG_NUM;
 447         arg->op.type = etype;
 448
 449         return arg;
 450 }
 451
 452 static enum pevent_errno
 453 add_right(struct filter_arg *op, struct filter_arg *arg, char *error_str)
 454 {
 455         struct filter_arg *left;
 456         char *str;
 457         int op_type;
 458         int ret;
 459
 460         switch (op->type) {
 461         case FILTER_ARG_EXP:
 462                 if (op->exp.right)
 463                         goto out_fail;
 464                 op->exp.right = arg;
 465                 break;
 466
 467         case FILTER_ARG_OP:
 468                 if (op->op.right)
 469                         goto out_fail;
 470                 op->op.right = arg;
 471                 break;
 472
 473         case FILTER_ARG_NUM:
 474                 if (op->op.right)
 475                         goto out_fail;
 476                 /*
 477                  * The arg must be num, str, or field
 478                  */
 479                 switch (arg->type) {
 480                 case FILTER_ARG_VALUE:
 481                 case FILTER_ARG_FIELD:
 482                         break;
 483                 default:
 484                         show_error(error_str, "Illegal rvalue");
 485                         return PEVENT_ERRNO__ILLEGAL_RVALUE;
 486                 }
 487
 488                 /*
 489                  * Depending on the type, we may need to
 490                  * convert this to a string or regex.
 491                  */
 492                 switch (arg->value.type) {
 493                 case FILTER_CHAR:
 494                         /*
 495                          * A char should be converted to number if
 496                          * the string is 1 byte, and the compare
 497                          * is not a REGEX.
 498                          */
 499                         if (strlen(arg->value.str) == 1 &&
 500                             op->num.type != FILTER_CMP_REGEX &&
 501                             op->num.type != FILTER_CMP_NOT_REGEX) {
 502                                 arg->value.type = FILTER_NUMBER;
 503                                 goto do_int;
 504                         }
 505                         /* fall through */
 506                 case FILTER_STRING:
 507
 508                         /* convert op to a string arg */
 509                         op_type = op->num.type;
 510                         left = op->num.left;
 511                         str = arg->value.str;
 512
 513                         /* reset the op for the new field */
 514                         memset(op, 0, sizeof(*op));
 515
 516                         /*
 517                          * If left arg was a field not found then
 518                          * NULL the entire op.
 519                          */
 520                         if (left->type == FILTER_ARG_BOOLEAN) {
 521                                 free_arg(left);
 522                                 free_arg(arg);
 523                                 op->type = FILTER_ARG_BOOLEAN;
 524                                 op->boolean.value = FILTER_FALSE;
 525                                 break;
 526                         }
 527
 528                         /* Left arg must be a field */
 529                         if (left->type != FILTER_ARG_FIELD) {
 530                                 show_error(error_str,
 531                                            "Illegal lvalue for string comparison");
 532                                 return PEVENT_ERRNO__ILLEGAL_LVALUE;
 533                         }
 534
 535                         /* Make sure this is a valid string compare */
 536                         switch (op_type) {
 537                         case FILTER_CMP_EQ:
 538                                 op_type = FILTER_CMP_MATCH;
 539                                 break;
 540                         case FILTER_CMP_NE:
 541                                 op_type = FILTER_CMP_NOT_MATCH;
 542                                 break;
 543
 544                         case FILTER_CMP_REGEX:
 545                         case FILTER_CMP_NOT_REGEX:
 546                                 ret = regcomp(&op->str.reg, str, REG_ICASE|REG_NOSUB);
 547                                 if (ret) {
 548                                         show_error(error_str,
 549                                                    "RegEx '%s' did not compute",
 550                                                    str);
 551                                         return PEVENT_ERRNO__INVALID_REGEX;
 552                                 }
 553                                 break;
 554                         default:
 555                                 show_error(error_str,
 556                                            "Illegal comparison for string");
 557                                 return PEVENT_ERRNO__ILLEGAL_STRING_CMP;
 558                         }
 559
 560                         op->type = FILTER_ARG_STR;
 561                         op->str.type = op_type;
 562                         op->str.field = left->field.field;
 563                         op->str.val = strdup(str);
 564                         if (!op->str.val) {
 565                                 show_error(error_str, "Failed to allocate string filter");
 566                                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 567                         }
 568                         /*
 569                          * Need a buffer to copy data for tests
 570                          */
 571                         op->str.buffer = malloc(op->str.field->size + 1);
 572                         if (!op->str.buffer) {
 573                                 show_error(error_str, "Failed to allocate string filter");
 574                                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 575                         }
 576                         /* Null terminate this buffer */
 577                         op->str.buffer[op->str.field->size] = 0;
 578
 579                         /* We no longer have left or right args */
 580                         free_arg(arg);
 581                         free_arg(left);
 582
 583                         break;
 584
 585                 case FILTER_NUMBER:
 586
 587  do_int:
 588                         switch (op->num.type) {
 589                         case FILTER_CMP_REGEX:
 590                         case FILTER_CMP_NOT_REGEX:
 591                                 show_error(error_str,
 592                                            "Op not allowed with integers");
 593                                 return PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
 594
 595                         default:
 596                                 break;
 597                         }
 598
 599                         /* numeric compare */
 600                         op->num.right = arg;
 601                         break;
 602                 default:
 603                         goto out_fail;
 604                 }
 605                 break;
 606         default:
 607                 goto out_fail;
 608         }
 609
 610         return 0;
 611
 612  out_fail:
 613         show_error(error_str, "Syntax error");
 614         return PEVENT_ERRNO__SYNTAX_ERROR;
 615 }
 616
 617 static struct filter_arg *
 618 rotate_op_right(struct filter_arg *a, struct filter_arg *b)
 619 {
 620         struct filter_arg *arg;
 621
 622         arg = a->op.right;
 623         a->op.right = b;
 624         return arg;
 625 }
 626
 627 static enum pevent_errno add_left(struct filter_arg *op, struct filter_arg *arg)
 628 {
 629         switch (op->type) {
 630         case FILTER_ARG_EXP:
 631                 if (arg->type == FILTER_ARG_OP)
 632                         arg = rotate_op_right(arg, op);
 633                 op->exp.left = arg;
 634                 break;
 635
 636         case FILTER_ARG_OP:
 637                 op->op.left = arg;
 638                 break;
 639         case FILTER_ARG_NUM:
 640                 if (arg->type == FILTER_ARG_OP)
 641                         arg = rotate_op_right(arg, op);
 642
 643                 /* left arg of compares must be a field */
 644                 if (arg->type != FILTER_ARG_FIELD &&
 645                     arg->type != FILTER_ARG_BOOLEAN)
 646                         return PEVENT_ERRNO__INVALID_ARG_TYPE;
 647                 op->num.left = arg;
 648                 break;
 649         default:
 650                 return PEVENT_ERRNO__INVALID_ARG_TYPE;
 651         }
 652         return 0;
 653 }
 654
 655 enum op_type {
 656         OP_NONE,
 657         OP_BOOL,
 658         OP_NOT,
 659         OP_EXP,
 660         OP_CMP,
 661 };
 662
 663 static enum op_type process_op(const char *token,
 664                                enum filter_op_type *btype,
 665                                enum filter_cmp_type *ctype,
 666                                enum filter_exp_type *etype)
 667 {
 668         *btype = FILTER_OP_NOT;
 669         *etype = FILTER_EXP_NONE;
 670         *ctype = FILTER_CMP_NONE;
 671
 672         if (strcmp(token, "&&") == 0)
 673                 *btype = FILTER_OP_AND;
 674         else if (strcmp(token, "||") == 0)
 675                 *btype = FILTER_OP_OR;
 676         else if (strcmp(token, "!") == 0)
 677                 return OP_NOT;
 678
 679         if (*btype != FILTER_OP_NOT)
 680                 return OP_BOOL;
 681
 682         /* Check for value expressions */
 683         if (strcmp(token, "+") == 0) {
 684                 *etype = FILTER_EXP_ADD;
 685         } else if (strcmp(token, "-") == 0) {
 686                 *etype = FILTER_EXP_SUB;
 687         } else if (strcmp(token, "*") == 0) {
 688                 *etype = FILTER_EXP_MUL;
 689         } else if (strcmp(token, "/") == 0) {
 690                 *etype = FILTER_EXP_DIV;
 691         } else if (strcmp(token, "%") == 0) {
 692                 *etype = FILTER_EXP_MOD;
 693         } else if (strcmp(token, ">>") == 0) {
 694                 *etype = FILTER_EXP_RSHIFT;
 695         } else if (strcmp(token, "<<") == 0) {
 696                 *etype = FILTER_EXP_LSHIFT;
 697         } else if (strcmp(token, "&") == 0) {
 698                 *etype = FILTER_EXP_AND;
 699         } else if (strcmp(token, "|") == 0) {
 700                 *etype = FILTER_EXP_OR;
 701         } else if (strcmp(token, "^") == 0) {
 702                 *etype = FILTER_EXP_XOR;
 703         } else if (strcmp(token, "~") == 0)
 704                 *etype = FILTER_EXP_NOT;
 705
 706         if (*etype != FILTER_EXP_NONE)
 707                 return OP_EXP;
 708
 709         /* Check for compares */
 710         if (strcmp(token, "==") == 0)
 711                 *ctype = FILTER_CMP_EQ;
 712         else if (strcmp(token, "!=") == 0)
 713                 *ctype = FILTER_CMP_NE;
 714         else if (strcmp(token, "<") == 0)
 715                 *ctype = FILTER_CMP_LT;
 716         else if (strcmp(token, ">") == 0)
 717                 *ctype = FILTER_CMP_GT;
 718         else if (strcmp(token, "<=") == 0)
 719                 *ctype = FILTER_CMP_LE;
 720         else if (strcmp(token, ">=") == 0)
 721                 *ctype = FILTER_CMP_GE;
 722         else if (strcmp(token, "=~") == 0)
 723                 *ctype = FILTER_CMP_REGEX;
 724         else if (strcmp(token, "!~") == 0)
 725                 *ctype = FILTER_CMP_NOT_REGEX;
 726         else
 727                 return OP_NONE;
 728
 729         return OP_CMP;
 730 }
 731
 732 static int check_op_done(struct filter_arg *arg)
 733 {
 734         switch (arg->type) {
 735         case FILTER_ARG_EXP:
 736                 return arg->exp.right != NULL;
 737
 738         case FILTER_ARG_OP:
 739                 return arg->op.right != NULL;
 740
 741         case FILTER_ARG_NUM:
 742                 return arg->num.right != NULL;
 743
 744         case FILTER_ARG_STR:
 745                 /* A string conversion is always done */
 746                 return 1;
 747
 748         case FILTER_ARG_BOOLEAN:
 749                 /* field not found, is ok */
 750                 return 1;
 751
 752         default:
 753                 return 0;
 754         }
 755 }
 756
 757 enum filter_vals {
 758         FILTER_VAL_NORM,
 759         FILTER_VAL_FALSE,
 760         FILTER_VAL_TRUE,
 761 };
 762
 763 static enum pevent_errno
 764 reparent_op_arg(struct filter_arg *parent, struct filter_arg *old_child,
 765                 struct filter_arg *arg, char *error_str)
 766 {
 767         struct filter_arg *other_child;
 768         struct filter_arg **ptr;
 769
 770         if (parent->type != FILTER_ARG_OP &&
 771             arg->type != FILTER_ARG_OP) {
 772                 show_error(error_str, "can not reparent other than OP");
 773                 return PEVENT_ERRNO__REPARENT_NOT_OP;
 774         }
 775
 776         /* Get the sibling */
 777         if (old_child->op.right == arg) {
 778                 ptr = &old_child->op.right;
 779                 other_child = old_child->op.left;
 780         } else if (old_child->op.left == arg) {
 781                 ptr = &old_child->op.left;
 782                 other_child = old_child->op.right;
 783         } else {
 784                 show_error(error_str, "Error in reparent op, find other child");
 785                 return PEVENT_ERRNO__REPARENT_FAILED;
 786         }
 787
 788         /* Detach arg from old_child */
 789         *ptr = NULL;
 790
 791         /* Check for root */
 792         if (parent == old_child) {
 793                 free_arg(other_child);
 794                 *parent = *arg;
 795                 /* Free arg without recussion */
 796                 free(arg);
 797                 return 0;
 798         }
 799
 800         if (parent->op.right == old_child)
 801                 ptr = &parent->op.right;
 802         else if (parent->op.left == old_child)
 803                 ptr = &parent->op.left;
 804         else {
 805                 show_error(error_str, "Error in reparent op");
 806                 return PEVENT_ERRNO__REPARENT_FAILED;
 807         }
 808
 809         *ptr = arg;
 810
 811         free_arg(old_child);
 812         return 0;
 813 }
 814
 815 /* Returns either filter_vals (success) or pevent_errno (failfure) */
 816 static int test_arg(struct filter_arg *parent, struct filter_arg *arg,
 817                     char *error_str)
 818 {
 819         int lval, rval;
 820
 821         switch (arg->type) {
 822
 823                 /* bad case */
 824         case FILTER_ARG_BOOLEAN:
 825                 return FILTER_VAL_FALSE + arg->boolean.value;
 826
 827                 /* good cases: */
 828         case FILTER_ARG_STR:
 829         case FILTER_ARG_VALUE:
 830         case FILTER_ARG_FIELD:
 831                 return FILTER_VAL_NORM;
 832
 833         case FILTER_ARG_EXP:
 834                 lval = test_arg(arg, arg->exp.left, error_str);
 835                 if (lval != FILTER_VAL_NORM)
 836                         return lval;
 837                 rval = test_arg(arg, arg->exp.right, error_str);
 838                 if (rval != FILTER_VAL_NORM)
 839                         return rval;
 840                 return FILTER_VAL_NORM;
 841
 842         case FILTER_ARG_NUM:
 843                 lval = test_arg(arg, arg->num.left, error_str);
 844                 if (lval != FILTER_VAL_NORM)
 845                         return lval;
 846                 rval = test_arg(arg, arg->num.right, error_str);
 847                 if (rval != FILTER_VAL_NORM)
 848                         return rval;
 849                 return FILTER_VAL_NORM;
 850
 851         case FILTER_ARG_OP:
 852                 if (arg->op.type != FILTER_OP_NOT) {
 853                         lval = test_arg(arg, arg->op.left, error_str);
 854                         switch (lval) {
 855                         case FILTER_VAL_NORM:
 856                                 break;
 857                         case FILTER_VAL_TRUE:
 858                                 if (arg->op.type == FILTER_OP_OR)
 859                                         return FILTER_VAL_TRUE;
 860                                 rval = test_arg(arg, arg->op.right, error_str);
 861                                 if (rval != FILTER_VAL_NORM)
 862                                         return rval;
 863
 864                                 return reparent_op_arg(parent, arg, arg->op.right,
 865                                                        error_str);
 866
 867                         case FILTER_VAL_FALSE:
 868                                 if (arg->op.type == FILTER_OP_AND)
 869                                         return FILTER_VAL_FALSE;
 870                                 rval = test_arg(arg, arg->op.right, error_str);
 871                                 if (rval != FILTER_VAL_NORM)
 872                                         return rval;
 873
 874                                 return reparent_op_arg(parent, arg, arg->op.right,
 875                                                        error_str);
 876
 877                         default:
 878                                 return lval;
 879                         }
 880                 }
 881
 882                 rval = test_arg(arg, arg->op.right, error_str);
 883                 switch (rval) {
 884                 case FILTER_VAL_NORM:
 885                 default:
 886                         break;
 887
 888                 case FILTER_VAL_TRUE:
 889                         if (arg->op.type == FILTER_OP_OR)
 890                                 return FILTER_VAL_TRUE;
 891                         if (arg->op.type == FILTER_OP_NOT)
 892                                 return FILTER_VAL_FALSE;
 893
 894                         return reparent_op_arg(parent, arg, arg->op.left,
 895                                                error_str);
 896
 897                 case FILTER_VAL_FALSE:
 898                         if (arg->op.type == FILTER_OP_AND)
 899                                 return FILTER_VAL_FALSE;
 900                         if (arg->op.type == FILTER_OP_NOT)
 901                                 return FILTER_VAL_TRUE;
 902
 903                         return reparent_op_arg(parent, arg, arg->op.left,
 904                                                error_str);
 905                 }
 906
 907                 return rval;
 908         default:
 909                 show_error(error_str, "bad arg in filter tree");
 910                 return PEVENT_ERRNO__BAD_FILTER_ARG;
 911         }
 912         return FILTER_VAL_NORM;
 913 }
 914
 915 /* Remove any unknown event fields */
 916 static int collapse_tree(struct filter_arg *arg,
 917                          struct filter_arg **arg_collapsed, char *error_str)
 918 {
 919         int ret;
 920
 921         ret = test_arg(arg, arg, error_str);
 922         switch (ret) {
 923         case FILTER_VAL_NORM:
 924                 break;
 925
 926         case FILTER_VAL_TRUE:
 927         case FILTER_VAL_FALSE:
 928                 free_arg(arg);
 929                 arg = allocate_arg();
 930                 if (arg) {
 931                         arg->type = FILTER_ARG_BOOLEAN;
 932                         arg->boolean.value = ret == FILTER_VAL_TRUE;
 933                 } else {
 934                         show_error(error_str, "Failed to allocate filter arg");
 935                         ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
 936                 }
 937                 break;
 938
 939         default:
 940                 /* test_arg() already set the error_str */
 941                 free_arg(arg);
 942                 arg = NULL;
 943                 break;
 944         }
 945
 946         *arg_collapsed = arg;
 947         return ret;
 948 }
 949
 950 static enum pevent_errno
 951 process_filter(struct event_format *event, struct filter_arg **parg,
 952                char *error_str, int not)
 953 {
 954         enum event_type type;
 955         char *token = NULL;
 956         struct filter_arg *current_op = NULL;
 957         struct filter_arg *current_exp = NULL;
 958         struct filter_arg *left_item = NULL;
 959         struct filter_arg *arg = NULL;
 960         enum op_type op_type;
 961         enum filter_op_type btype;
 962         enum filter_exp_type etype;
 963         enum filter_cmp_type ctype;
 964         enum pevent_errno ret;
 965
 966         *parg = NULL;
 967
 968         do {
 969                 free(token);
 970                 type = read_token(&token);
 971                 switch (type) {
 972                 case EVENT_SQUOTE:
 973                 case EVENT_DQUOTE:
 974                 case EVENT_ITEM:
 975                         ret = create_arg_item(event, token, type, &arg, error_str);
 976                         if (ret < 0)
 977                                 goto fail;
 978                         if (!left_item)
 979                                 left_item = arg;
 980                         else if (current_exp) {
 981                                 ret = add_right(current_exp, arg, error_str);
 982                                 if (ret < 0)
 983                                         goto fail;
 984                                 left_item = NULL;
 985                                 /* Not's only one one expression */
 986                                 if (not) {
 987                                         arg = NULL;
 988                                         if (current_op)
 989                                                 goto fail_syntax;
 990                                         free(token);
 991                                         *parg = current_exp;
 992                                         return 0;
 993                                 }
 994                         } else
 995                                 goto fail_syntax;
 996                         arg = NULL;
 997                         break;
 998
 999                 case EVENT_DELIM:
1000                         if (*token == ',') {
1001                                 show_error(error_str, "Illegal token ','");
1002                                 ret = PEVENT_ERRNO__ILLEGAL_TOKEN;
1003                                 goto fail;
1004                         }
1005
1006                         if (*token == '(') {
1007                                 if (left_item) {
1008                                         show_error(error_str,
1009                                                    "Open paren can not come after item");
1010                                         ret = PEVENT_ERRNO__INVALID_PAREN;
1011                                         goto fail;
1012                                 }
1013                                 if (current_exp) {
1014                                         show_error(error_str,
1015                                                    "Open paren can not come after expression");
1016                                         ret = PEVENT_ERRNO__INVALID_PAREN;
1017                                         goto fail;
1018                                 }
1019
1020                                 ret = process_filter(event, &arg, error_str, 0);
1021                                 if (ret != PEVENT_ERRNO__UNBALANCED_PAREN) {
1022                                         if (ret == 0) {
1023                                                 show_error(error_str,
1024                                                            "Unbalanced number of '('");
1025                                                 ret = PEVENT_ERRNO__UNBALANCED_PAREN;
1026                                         }
1027                                         goto fail;
1028                                 }
1029                                 ret = 0;
1030
1031                                 /* A not wants just one expression */
1032                                 if (not) {
1033                                         if (current_op)
1034                                                 goto fail_syntax;
1035                                         *parg = arg;
1036                                         return 0;
1037                                 }
1038
1039                                 if (current_op)
1040                                         ret = add_right(current_op, arg, error_str);
1041                                 else
1042                                         current_exp = arg;
1043
1044                                 if (ret < 0)
1045                                         goto fail;
1046
1047                         } else { /* ')' */
1048                                 if (!current_op && !current_exp)
1049                                         goto fail_syntax;
1050
1051                                 /* Make sure everything is finished at this level */
1052                                 if (current_exp && !check_op_done(current_exp))
1053                                         goto fail_syntax;
1054                                 if (current_op && !check_op_done(current_op))
1055                                         goto fail_syntax;
1056
1057                                 if (current_op)
1058                                         *parg = current_op;
1059                                 else
1060                                         *parg = current_exp;
1061                                 free(token);
1062                                 return PEVENT_ERRNO__UNBALANCED_PAREN;
1063                         }
1064                         break;
1065
1066                 case EVENT_OP:
1067                         op_type = process_op(token, &btype, &ctype, &etype);
1068
1069                         /* All expect a left arg except for NOT */
1070                         switch (op_type) {
1071                         case OP_BOOL:
1072                                 /* Logic ops need a left expression */
1073                                 if (!current_exp && !current_op)
1074                                         goto fail_syntax;
1075                                 /* fall through */
1076                         case OP_NOT:
1077                                 /* logic only processes ops and exp */
1078                                 if (left_item)
1079                                         goto fail_syntax;
1080                                 break;
1081                         case OP_EXP:
1082                         case OP_CMP:
1083                                 if (!left_item)
1084                                         goto fail_syntax;
1085                                 break;
1086                         case OP_NONE:
1087                                 show_error(error_str,
1088                                            "Unknown op token %s", token);
1089                                 ret = PEVENT_ERRNO__UNKNOWN_TOKEN;
1090                                 goto fail;
1091                         }
1092
1093                         ret = 0;
1094                         switch (op_type) {
1095                         case OP_BOOL:
1096                                 arg = create_arg_op(btype);
1097                                 if (arg == NULL)
1098                                         goto fail_alloc;
1099                                 if (current_op)
1100                                         ret = add_left(arg, current_op);
1101                                 else
1102                                         ret = add_left(arg, current_exp);
1103                                 current_op = arg;
1104                                 current_exp = NULL;
1105                                 break;
1106
1107                         case OP_NOT:
1108                                 arg = create_arg_op(btype);
1109                                 if (arg == NULL)
1110                                         goto fail_alloc;
1111                                 if (current_op)
1112                                         ret = add_right(current_op, arg, error_str);
1113                                 if (ret < 0)
1114                                         goto fail;
1115                                 current_exp = arg;
1116                                 ret = process_filter(event, &arg, error_str, 1);
1117                                 if (ret < 0)
1118                                         goto fail;
1119                                 ret = add_right(current_exp, arg, error_str);
1120                                 if (ret < 0)
1121                                         goto fail;
1122                                 break;
1123
1124                         case OP_EXP:
1125                         case OP_CMP:
1126                                 if (op_type == OP_EXP)
1127                                         arg = create_arg_exp(etype);
1128                                 else
1129                                         arg = create_arg_cmp(ctype);
1130                                 if (arg == NULL)
1131                                         goto fail_alloc;
1132
1133                                 if (current_op)
1134                                         ret = add_right(current_op, arg, error_str);
1135                                 if (ret < 0)
1136                                         goto fail;
1137                                 ret = add_left(arg, left_item);
1138                                 if (ret < 0) {
1139                                         arg = NULL;
1140                                         goto fail_syntax;
1141                                 }
1142                                 current_exp = arg;
1143                                 break;
1144                         default:
1145                                 break;
1146                         }
1147                         arg = NULL;
1148                         if (ret < 0)
1149                                 goto fail_syntax;
1150                         break;
1151                 case EVENT_NONE:
1152                         break;
1153                 case EVENT_ERROR:
1154                         goto fail_alloc;
1155                 default:
1156                         goto fail_syntax;
1157                 }
1158         } while (type != EVENT_NONE);
1159
1160         if (!current_op && !current_exp)
1161                 goto fail_syntax;
1162
1163         if (!current_op)
1164                 current_op = current_exp;
1165
1166         ret = collapse_tree(current_op, parg, error_str);
1167         if (ret < 0)
1168                 goto fail;
1169
1170         *parg = current_op;
1171
1172         free(token);
1173         return 0;
1174
1175  fail_alloc:
1176         show_error(error_str, "failed to allocate filter arg");
1177         ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
1178         goto fail;
1179  fail_syntax:
1180         show_error(error_str, "Syntax error");
1181         ret = PEVENT_ERRNO__SYNTAX_ERROR;
1182  fail:
1183         free_arg(current_op);
1184         free_arg(current_exp);
1185         free_arg(arg);
1186         free(token);
1187         return ret;
1188 }
1189
1190 static enum pevent_errno
1191 process_event(struct event_format *event, const char *filter_str,
1192               struct filter_arg **parg, char *error_str)
1193 {
1194         int ret;
1195
1196         pevent_buffer_init(filter_str, strlen(filter_str));
1197
1198         ret = process_filter(event, parg, error_str, 0);
1199         if (ret < 0)
1200                 return ret;
1201
1202         /* If parg is NULL, then make it into FALSE */
1203         if (!*parg) {
1204                 *parg = allocate_arg();
1205                 if (*parg == NULL)
1206                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1207
1208                 (*parg)->type = FILTER_ARG_BOOLEAN;
1209                 (*parg)->boolean.value = FILTER_FALSE;
1210         }
1211
1212         return 0;
1213 }
1214
1215 static enum pevent_errno
1216 filter_event(struct event_filter *filter, struct event_format *event,
1217              const char *filter_str, char *error_str)
1218 {
1219         struct filter_type *filter_type;
1220         struct filter_arg *arg;
1221         enum pevent_errno ret;
1222
1223         if (filter_str) {
1224                 ret = process_event(event, filter_str, &arg, error_str);
1225                 if (ret < 0)
1226                         return ret;
1227
1228         } else {
1229                 /* just add a TRUE arg */
1230                 arg = allocate_arg();
1231                 if (arg == NULL)
1232                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1233
1234                 arg->type = FILTER_ARG_BOOLEAN;
1235                 arg->boolean.value = FILTER_TRUE;
1236         }
1237
1238         filter_type = add_filter_type(filter, event->id);
1239         if (filter_type == NULL)
1240                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1241
1242         if (filter_type->filter)
1243                 free_arg(filter_type->filter);
1244         filter_type->filter = arg;
1245
1246         return 0;
1247 }
1248
1249 static void filter_init_error_buf(struct event_filter *filter)
1250 {
1251         /* clear buffer to reset show error */
1252         pevent_buffer_init("", 0);
1253         filter->error_buffer[0] = '\0';
1254 }
1255
1256 /**
1257  * pevent_filter_add_filter_str - add a new filter
1258  * @filter: the event filter to add to
1259  * @filter_str: the filter string that contains the filter
1260  *
1261  * Returns 0 if the filter was successfully added or a
1262  * negative error code.  Use pevent_filter_strerror() to see
1263  * actual error message in case of error.
1264  */
1265 enum pevent_errno pevent_filter_add_filter_str(struct event_filter *filter,
1266                                                const char *filter_str)
1267 {
1268         struct pevent *pevent = filter->pevent;
1269         struct event_list *event;
1270         struct event_list *events = NULL;
1271         const char *filter_start;
1272         const char *next_event;
1273         char *this_event;
1274         char *event_name = NULL;
1275         char *sys_name = NULL;
1276         char *sp;
1277         enum pevent_errno rtn = 0; /* PEVENT_ERRNO__SUCCESS */
1278         int len;
1279         int ret;
1280
1281         filter_init_error_buf(filter);
1282
1283         filter_start = strchr(filter_str, ':');
1284         if (filter_start)
1285                 len = filter_start - filter_str;
1286         else
1287                 len = strlen(filter_str);
1288
1289         do {
1290                 next_event = strchr(filter_str, ',');
1291                 if (next_event &&
1292                     (!filter_start || next_event < filter_start))
1293                         len = next_event - filter_str;
1294                 else if (filter_start)
1295                         len = filter_start - filter_str;
1296                 else
1297                         len = strlen(filter_str);
1298
1299                 this_event = malloc(len + 1);
1300                 if (this_event == NULL) {
1301                         /* This can only happen when events is NULL, but still */
1302                         free_events(events);
1303                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1304                 }
1305                 memcpy(this_event, filter_str, len);
1306                 this_event[len] = 0;
1307
1308                 if (next_event)
1309                         next_event++;
1310
1311                 filter_str = next_event;
1312
1313                 sys_name = strtok_r(this_event, "/", &sp);
1314                 event_name = strtok_r(NULL, "/", &sp);
1315
1316                 if (!sys_name) {
1317                         /* This can only happen when events is NULL, but still */
1318                         free_events(events);
1319                         free(this_event);
1320                         return PEVENT_ERRNO__FILTER_NOT_FOUND;
1321                 }
1322
1323                 /* Find this event */
1324                 ret = find_event(pevent, &events, strim(sys_name), strim(event_name));
1325                 if (ret < 0) {
1326                         free_events(events);
1327                         free(this_event);
1328                         return ret;
1329                 }
1330                 free(this_event);
1331         } while (filter_str);
1332
1333         /* Skip the ':' */
1334         if (filter_start)
1335                 filter_start++;
1336
1337         /* filter starts here */
1338         for (event = events; event; event = event->next) {
1339                 ret = filter_event(filter, event->event, filter_start,
1340                                    filter->error_buffer);
1341                 /* Failures are returned if a parse error happened */
1342                 if (ret < 0)
1343                         rtn = ret;
1344
1345                 if (ret >= 0 && pevent->test_filters) {
1346                         char *test;
1347                         test = pevent_filter_make_string(filter, event->event->id);
1348                         if (test) {
1349                                 printf(" '%s: %s'\n", event->event->name, test);
1350                                 free(test);
1351                         }
1352                 }
1353         }
1354
1355         free_events(events);
1356
1357         if (rtn >= 0 && pevent->test_filters)
1358                 exit(0);
1359
1360         return rtn;
1361 }
1362
1363 static void free_filter_type(struct filter_type *filter_type)
1364 {
1365         free_arg(filter_type->filter);
1366 }
1367
1368 /**
1369  * pevent_filter_strerror - fill error message in a buffer
1370  * @filter: the event filter contains error
1371  * @err: the error code
1372  * @buf: the buffer to be filled in
1373  * @buflen: the size of the buffer
1374  *
1375  * Returns 0 if message was filled successfully, -1 if error
1376  */
1377 int pevent_filter_strerror(struct event_filter *filter, enum pevent_errno err,
1378                            char *buf, size_t buflen)
1379 {
1380         if (err <= __PEVENT_ERRNO__START || err >= __PEVENT_ERRNO__END)
1381                 return -1;
1382
1383         if (strlen(filter->error_buffer) > 0) {
1384                 size_t len = snprintf(buf, buflen, "%s", filter->error_buffer);
1385
1386                 if (len > buflen)
1387                         return -1;
1388                 return 0;
1389         }
1390
1391         return pevent_strerror(filter->pevent, err, buf, buflen);
1392 }
1393
1394 /**
1395  * pevent_filter_remove_event - remove a filter for an event
1396  * @filter: the event filter to remove from
1397  * @event_id: the event to remove a filter for
1398  *
1399  * Removes the filter saved for an event defined by @event_id
1400  * from the @filter.
1401  *
1402  * Returns 1: if an event was removed
1403  *   0: if the event was not found
1404  */
1405 int pevent_filter_remove_event(struct event_filter *filter,
1406                                int event_id)
1407 {
1408         struct filter_type *filter_type;
1409         unsigned long len;
1410
1411         if (!filter->filters)
1412                 return 0;
1413
1414         filter_type = find_filter_type(filter, event_id);
1415
1416         if (!filter_type)
1417                 return 0;
1418
1419         free_filter_type(filter_type);
1420
1421         /* The filter_type points into the event_filters array */
1422         len = (unsigned long)(filter->event_filters + filter->filters) -
1423                 (unsigned long)(filter_type + 1);
1424
1425         memmove(filter_type, filter_type + 1, len);
1426         filter->filters--;
1427
1428         memset(&filter->event_filters[filter->filters], 0,
1429                sizeof(*filter_type));
1430
1431         return 1;
1432 }
1433
1434 /**
1435  * pevent_filter_reset - clear all filters in a filter
1436  * @filter: the event filter to reset
1437  *
1438  * Removes all filters from a filter and resets it.
1439  */
1440 void pevent_filter_reset(struct event_filter *filter)
1441 {
1442         int i;
1443
1444         for (i = 0; i < filter->filters; i++)
1445                 free_filter_type(&filter->event_filters[i]);
1446
1447         free(filter->event_filters);
1448         filter->filters = 0;
1449         filter->event_filters = NULL;
1450 }
1451
1452 void pevent_filter_free(struct event_filter *filter)
1453 {
1454         pevent_unref(filter->pevent);
1455
1456         pevent_filter_reset(filter);
1457
1458         free(filter);
1459 }
1460
1461 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg);
1462
1463 static int copy_filter_type(struct event_filter *filter,
1464                              struct event_filter *source,
1465                              struct filter_type *filter_type)
1466 {
1467         struct filter_arg *arg;
1468         struct event_format *event;
1469         const char *sys;
1470         const char *name;
1471         char *str;
1472
1473         /* Can't assume that the pevent's are the same */
1474         sys = filter_type->event->system;
1475         name = filter_type->event->name;
1476         event = pevent_find_event_by_name(filter->pevent, sys, name);
1477         if (!event)
1478                 return -1;
1479
1480         str = arg_to_str(source, filter_type->filter);
1481         if (!str)
1482                 return -1;
1483
1484         if (strcmp(str, "TRUE") == 0 || strcmp(str, "FALSE") == 0) {
1485                 /* Add trivial event */
1486                 arg = allocate_arg();
1487                 if (arg == NULL)
1488                         return -1;
1489
1490                 arg->type = FILTER_ARG_BOOLEAN;
1491                 if (strcmp(str, "TRUE") == 0)
1492                         arg->boolean.value = 1;
1493                 else
1494                         arg->boolean.value = 0;
1495
1496                 filter_type = add_filter_type(filter, event->id);
1497                 if (filter_type == NULL)
1498                         return -1;
1499
1500                 filter_type->filter = arg;
1501
1502                 free(str);
1503                 return 0;
1504         }
1505
1506         filter_event(filter, event, str, NULL);
1507         free(str);
1508
1509         return 0;
1510 }
1511
1512 /**
1513  * pevent_filter_copy - copy a filter using another filter
1514  * @dest - the filter to copy to
1515  * @source - the filter to copy from
1516  *
1517  * Returns 0 on success and -1 if not all filters were copied
1518  */
1519 int pevent_filter_copy(struct event_filter *dest, struct event_filter *source)
1520 {
1521         int ret = 0;
1522         int i;
1523
1524         pevent_filter_reset(dest);
1525
1526         for (i = 0; i < source->filters; i++) {
1527                 if (copy_filter_type(dest, source, &source->event_filters[i]))
1528                         ret = -1;
1529         }
1530         return ret;
1531 }
1532
1533
1534 /**
1535  * pevent_update_trivial - update the trivial filters with the given filter
1536  * @dest - the filter to update
1537  * @source - the filter as the source of the update
1538  * @type - the type of trivial filter to update.
1539  *
1540  * Scan dest for trivial events matching @type to replace with the source.
1541  *
1542  * Returns 0 on success and -1 if there was a problem updating, but
1543  *   events may have still been updated on error.
1544  */
1545 int pevent_update_trivial(struct event_filter *dest, struct event_filter *source,
1546                           enum filter_trivial_type type)
1547 {
1548         struct pevent *src_pevent;
1549         struct pevent *dest_pevent;
1550         struct event_format *event;
1551         struct filter_type *filter_type;
1552         struct filter_arg *arg;
1553         char *str;
1554         int i;
1555
1556         src_pevent = source->pevent;
1557         dest_pevent = dest->pevent;
1558
1559         /* Do nothing if either of the filters has nothing to filter */
1560         if (!dest->filters || !source->filters)
1561                 return 0;
1562
1563         for (i = 0; i < dest->filters; i++) {
1564                 filter_type = &dest->event_filters[i];
1565                 arg = filter_type->filter;
1566                 if (arg->type != FILTER_ARG_BOOLEAN)
1567                         continue;
1568                 if ((arg->boolean.value && type == FILTER_TRIVIAL_FALSE) ||
1569                     (!arg->boolean.value && type == FILTER_TRIVIAL_TRUE))
1570                         continue;
1571
1572                 event = filter_type->event;
1573
1574                 if (src_pevent != dest_pevent) {
1575                         /* do a look up */
1576                         event = pevent_find_event_by_name(src_pevent,
1577                                                           event->system,
1578                                                           event->name);
1579                         if (!event)
1580                                 return -1;
1581                 }
1582
1583                 str = pevent_filter_make_string(source, event->id);
1584                 if (!str)
1585                         continue;
1586
1587                 /* Don't bother if the filter is trivial too */
1588                 if (strcmp(str, "TRUE") != 0 && strcmp(str, "FALSE") != 0)
1589                         filter_event(dest, event, str, NULL);
1590                 free(str);
1591         }
1592         return 0;
1593 }
1594
1595 /**
1596  * pevent_filter_clear_trivial - clear TRUE and FALSE filters
1597  * @filter: the filter to remove trivial filters from
1598  * @type: remove only true, false, or both
1599  *
1600  * Removes filters that only contain a TRUE or FALES boolean arg.
1601  *
1602  * Returns 0 on success and -1 if there was a problem.
1603  */
1604 int pevent_filter_clear_trivial(struct event_filter *filter,
1605                                  enum filter_trivial_type type)
1606 {
1607         struct filter_type *filter_type;
1608         int count = 0;
1609         int *ids = NULL;
1610         int i;
1611
1612         if (!filter->filters)
1613                 return 0;
1614
1615         /*
1616          * Two steps, first get all ids with trivial filters.
1617          *  then remove those ids.
1618          */
1619         for (i = 0; i < filter->filters; i++) {
1620                 int *new_ids;
1621
1622                 filter_type = &filter->event_filters[i];
1623                 if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1624                         continue;
1625                 switch (type) {
1626                 case FILTER_TRIVIAL_FALSE:
1627                         if (filter_type->filter->boolean.value)
1628                                 continue;
1629                 case FILTER_TRIVIAL_TRUE:
1630                         if (!filter_type->filter->boolean.value)
1631                                 continue;
1632                 default:
1633                         break;
1634                 }
1635
1636                 new_ids = realloc(ids, sizeof(*ids) * (count + 1));
1637                 if (!new_ids) {
1638                         free(ids);
1639                         return -1;
1640                 }
1641
1642                 ids = new_ids;
1643                 ids[count++] = filter_type->event_id;
1644         }
1645
1646         if (!count)
1647                 return 0;
1648
1649         for (i = 0; i < count; i++)
1650                 pevent_filter_remove_event(filter, ids[i]);
1651
1652         free(ids);
1653         return 0;
1654 }
1655
1656 /**
1657  * pevent_filter_event_has_trivial - return true event contains trivial filter
1658  * @filter: the filter with the information
1659  * @event_id: the id of the event to test
1660  * @type: trivial type to test for (TRUE, FALSE, EITHER)
1661  *
1662  * Returns 1 if the event contains a matching trivial type
1663  *  otherwise 0.
1664  */
1665 int pevent_filter_event_has_trivial(struct event_filter *filter,
1666                                     int event_id,
1667                                     enum filter_trivial_type type)
1668 {
1669         struct filter_type *filter_type;
1670
1671         if (!filter->filters)
1672                 return 0;
1673
1674         filter_type = find_filter_type(filter, event_id);
1675
1676         if (!filter_type)
1677                 return 0;
1678
1679         if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1680                 return 0;
1681
1682         switch (type) {
1683         case FILTER_TRIVIAL_FALSE:
1684                 return !filter_type->filter->boolean.value;
1685
1686         case FILTER_TRIVIAL_TRUE:
1687                 return filter_type->filter->boolean.value;
1688         default:
1689                 return 1;
1690         }
1691 }
1692
1693 static int test_filter(struct event_format *event, struct filter_arg *arg,
1694                        struct pevent_record *record, enum pevent_errno *err);
1695
1696 static const char *
1697 get_comm(struct event_format *event, struct pevent_record *record)
1698 {
1699         const char *comm;
1700         int pid;
1701
1702         pid = pevent_data_pid(event->pevent, record);
1703         comm = pevent_data_comm_from_pid(event->pevent, pid);
1704         return comm;
1705 }
1706
1707 static unsigned long long
1708 get_value(struct event_format *event,
1709           struct format_field *field, struct pevent_record *record)
1710 {
1711         unsigned long long val;
1712
1713         /* Handle our dummy "comm" field */
1714         if (field == &comm) {
1715                 const char *name;
1716
1717                 name = get_comm(event, record);
1718                 return (unsigned long)name;
1719         }
1720
1721         pevent_read_number_field(field, record->data, &val);
1722
1723         if (!(field->flags & FIELD_IS_SIGNED))
1724                 return val;
1725
1726         switch (field->size) {
1727         case 1:
1728                 return (char)val;
1729         case 2:
1730                 return (short)val;
1731         case 4:
1732                 return (int)val;
1733         case 8:
1734                 return (long long)val;
1735         }
1736         return val;
1737 }
1738
1739 static unsigned long long
1740 get_arg_value(struct event_format *event, struct filter_arg *arg,
1741               struct pevent_record *record, enum pevent_errno *err);
1742
1743 static unsigned long long
1744 get_exp_value(struct event_format *event, struct filter_arg *arg,
1745               struct pevent_record *record, enum pevent_errno *err)
1746 {
1747         unsigned long long lval, rval;
1748
1749         lval = get_arg_value(event, arg->exp.left, record, err);
1750         rval = get_arg_value(event, arg->exp.right, record, err);
1751
1752         if (*err) {
1753                 /*
1754                  * There was an error, no need to process anymore.
1755                  */
1756                 return 0;
1757         }
1758
1759         switch (arg->exp.type) {
1760         case FILTER_EXP_ADD:
1761                 return lval + rval;
1762
1763         case FILTER_EXP_SUB:
1764                 return lval - rval;
1765
1766         case FILTER_EXP_MUL:
1767                 return lval * rval;
1768
1769         case FILTER_EXP_DIV:
1770                 return lval / rval;
1771
1772         case FILTER_EXP_MOD:
1773                 return lval % rval;
1774
1775         case FILTER_EXP_RSHIFT:
1776                 return lval >> rval;
1777
1778         case FILTER_EXP_LSHIFT:
1779                 return lval << rval;
1780
1781         case FILTER_EXP_AND:
1782                 return lval & rval;
1783
1784         case FILTER_EXP_OR:
1785                 return lval | rval;
1786
1787         case FILTER_EXP_XOR:
1788                 return lval ^ rval;
1789
1790         case FILTER_EXP_NOT:
1791         default:
1792                 if (!*err)
1793                         *err = PEVENT_ERRNO__INVALID_EXP_TYPE;
1794         }
1795         return 0;
1796 }
1797
1798 static unsigned long long
1799 get_arg_value(struct event_format *event, struct filter_arg *arg,
1800               struct pevent_record *record, enum pevent_errno *err)
1801 {
1802         switch (arg->type) {
1803         case FILTER_ARG_FIELD:
1804                 return get_value(event, arg->field.field, record);
1805
1806         case FILTER_ARG_VALUE:
1807                 if (arg->value.type != FILTER_NUMBER) {
1808                         if (!*err)
1809                                 *err = PEVENT_ERRNO__NOT_A_NUMBER;
1810                 }
1811                 return arg->value.val;
1812
1813         case FILTER_ARG_EXP:
1814                 return get_exp_value(event, arg, record, err);
1815
1816         default:
1817                 if (!*err)
1818                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1819         }
1820         return 0;
1821 }
1822
1823 static int test_num(struct event_format *event, struct filter_arg *arg,
1824                     struct pevent_record *record, enum pevent_errno *err)
1825 {
1826         unsigned long long lval, rval;
1827
1828         lval = get_arg_value(event, arg->num.left, record, err);
1829         rval = get_arg_value(event, arg->num.right, record, err);
1830
1831         if (*err) {
1832                 /*
1833                  * There was an error, no need to process anymore.
1834                  */
1835                 return 0;
1836         }
1837
1838         switch (arg->num.type) {
1839         case FILTER_CMP_EQ:
1840                 return lval == rval;
1841
1842         case FILTER_CMP_NE:
1843                 return lval != rval;
1844
1845         case FILTER_CMP_GT:
1846                 return lval > rval;
1847
1848         case FILTER_CMP_LT:
1849                 return lval < rval;
1850
1851         case FILTER_CMP_GE:
1852                 return lval >= rval;
1853
1854         case FILTER_CMP_LE:
1855                 return lval <= rval;
1856
1857         default:
1858                 if (!*err)
1859                         *err = PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
1860                 return 0;
1861         }
1862 }
1863
1864 static const char *get_field_str(struct filter_arg *arg, struct pevent_record *record)
1865 {
1866         struct event_format *event;
1867         struct pevent *pevent;
1868         unsigned long long addr;
1869         const char *val = NULL;
1870         char hex[64];
1871
1872         /* If the field is not a string convert it */
1873         if (arg->str.field->flags & FIELD_IS_STRING) {
1874                 val = record->data + arg->str.field->offset;
1875
1876                 /*
1877                  * We need to copy the data since we can't be sure the field
1878                  * is null terminated.
1879                  */
1880                 if (*(val + arg->str.field->size - 1)) {
1881                         /* copy it */
1882                         memcpy(arg->str.buffer, val, arg->str.field->size);
1883                         /* the buffer is already NULL terminated */
1884                         val = arg->str.buffer;
1885                 }
1886
1887         } else {
1888                 event = arg->str.field->event;
1889                 pevent = event->pevent;
1890                 addr = get_value(event, arg->str.field, record);
1891
1892                 if (arg->str.field->flags & (FIELD_IS_POINTER | FIELD_IS_LONG))
1893                         /* convert to a kernel symbol */
1894                         val = pevent_find_function(pevent, addr);
1895
1896                 if (val == NULL) {
1897                         /* just use the hex of the string name */
1898                         snprintf(hex, 64, "0x%llx", addr);
1899                         val = hex;
1900                 }
1901         }
1902
1903         return val;
1904 }
1905
1906 static int test_str(struct event_format *event, struct filter_arg *arg,
1907                     struct pevent_record *record, enum pevent_errno *err)
1908 {
1909         const char *val;
1910
1911         if (arg->str.field == &comm)
1912                 val = get_comm(event, record);
1913         else
1914                 val = get_field_str(arg, record);
1915
1916         switch (arg->str.type) {
1917         case FILTER_CMP_MATCH:
1918                 return strcmp(val, arg->str.val) == 0;
1919
1920         case FILTER_CMP_NOT_MATCH:
1921                 return strcmp(val, arg->str.val) != 0;
1922
1923         case FILTER_CMP_REGEX:
1924                 /* Returns zero on match */
1925                 return !regexec(&arg->str.reg, val, 0, NULL, 0);
1926
1927         case FILTER_CMP_NOT_REGEX:
1928                 return regexec(&arg->str.reg, val, 0, NULL, 0);
1929
1930         default:
1931                 if (!*err)
1932                         *err = PEVENT_ERRNO__ILLEGAL_STRING_CMP;
1933                 return 0;
1934         }
1935 }
1936
1937 static int test_op(struct event_format *event, struct filter_arg *arg,
1938                    struct pevent_record *record, enum pevent_errno *err)
1939 {
1940         switch (arg->op.type) {
1941         case FILTER_OP_AND:
1942                 return test_filter(event, arg->op.left, record, err) &&
1943                         test_filter(event, arg->op.right, record, err);
1944
1945         case FILTER_OP_OR:
1946                 return test_filter(event, arg->op.left, record, err) ||
1947                         test_filter(event, arg->op.right, record, err);
1948
1949         case FILTER_OP_NOT:
1950                 return !test_filter(event, arg->op.right, record, err);
1951
1952         default:
1953                 if (!*err)
1954                         *err = PEVENT_ERRNO__INVALID_OP_TYPE;
1955                 return 0;
1956         }
1957 }
1958
1959 static int test_filter(struct event_format *event, struct filter_arg *arg,
1960                        struct pevent_record *record, enum pevent_errno *err)
1961 {
1962         if (*err) {
1963                 /*
1964                  * There was an error, no need to process anymore.
1965                  */
1966                 return 0;
1967         }
1968
1969         switch (arg->type) {
1970         case FILTER_ARG_BOOLEAN:
1971                 /* easy case */
1972                 return arg->boolean.value;
1973
1974         case FILTER_ARG_OP:
1975                 return test_op(event, arg, record, err);
1976
1977         case FILTER_ARG_NUM:
1978                 return test_num(event, arg, record, err);
1979
1980         case FILTER_ARG_STR:
1981                 return test_str(event, arg, record, err);
1982
1983         case FILTER_ARG_EXP:
1984         case FILTER_ARG_VALUE:
1985         case FILTER_ARG_FIELD:
1986                 /*
1987                  * Expressions, fields and values evaluate
1988                  * to true if they return non zero
1989                  */
1990                 return !!get_arg_value(event, arg, record, err);
1991
1992         default:
1993                 if (!*err)
1994                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1995                 return 0;
1996         }
1997 }
1998
1999 /**
2000  * pevent_event_filtered - return true if event has filter
2001  * @filter: filter struct with filter information
2002  * @event_id: event id to test if filter exists
2003  *
2004  * Returns 1 if filter found for @event_id
2005  *   otherwise 0;
2006  */
2007 int pevent_event_filtered(struct event_filter *filter, int event_id)
2008 {
2009         struct filter_type *filter_type;
2010
2011         if (!filter->filters)
2012                 return 0;
2013
2014         filter_type = find_filter_type(filter, event_id);
2015
2016         return filter_type ? 1 : 0;
2017 }
2018
2019 /**
2020  * pevent_filter_match - test if a record matches a filter
2021  * @filter: filter struct with filter information
2022  * @record: the record to test against the filter
2023  *
2024  * Returns: match result or error code (prefixed with PEVENT_ERRNO__)
2025  * FILTER_MATCH - filter found for event and @record matches
2026  * FILTER_MISS  - filter found for event and @record does not match
2027  * FILTER_NOT_FOUND - no filter found for @record's event
2028  * NO_FILTER - if no filters exist
2029  * otherwise - error occurred during test
2030  */
2031 enum pevent_errno pevent_filter_match(struct event_filter *filter,
2032                                       struct pevent_record *record)
2033 {
2034         struct pevent *pevent = filter->pevent;
2035         struct filter_type *filter_type;
2036         int event_id;
2037         int ret;
2038         enum pevent_errno err = 0;
2039
2040         filter_init_error_buf(filter);
2041
2042         if (!filter->filters)
2043                 return PEVENT_ERRNO__NO_FILTER;
2044
2045         event_id = pevent_data_type(pevent, record);
2046
2047         filter_type = find_filter_type(filter, event_id);
2048         if (!filter_type)
2049                 return PEVENT_ERRNO__FILTER_NOT_FOUND;
2050
2051         ret = test_filter(filter_type->event, filter_type->filter, record, &err);
2052         if (err)
2053                 return err;
2054
2055         return ret ? PEVENT_ERRNO__FILTER_MATCH : PEVENT_ERRNO__FILTER_MISS;
2056 }
2057
2058 static char *op_to_str(struct event_filter *filter, struct filter_arg *arg)
2059 {
2060         char *str = NULL;
2061         char *left = NULL;
2062         char *right = NULL;
2063         char *op = NULL;
2064         int left_val = -1;
2065         int right_val = -1;
2066         int val;
2067
2068         switch (arg->op.type) {
2069         case FILTER_OP_AND:
2070                 op = "&&";
2071                 /* fall through */
2072         case FILTER_OP_OR:
2073                 if (!op)
2074                         op = "||";
2075
2076                 left = arg_to_str(filter, arg->op.left);
2077                 right = arg_to_str(filter, arg->op.right);
2078                 if (!left || !right)
2079                         break;
2080
2081                 /* Try to consolidate boolean values */
2082                 if (strcmp(left, "TRUE") == 0)
2083                         left_val = 1;
2084                 else if (strcmp(left, "FALSE") == 0)
2085                         left_val = 0;
2086
2087                 if (strcmp(right, "TRUE") == 0)
2088                         right_val = 1;
2089                 else if (strcmp(right, "FALSE") == 0)
2090                         right_val = 0;
2091
2092                 if (left_val >= 0) {
2093                         if ((arg->op.type == FILTER_OP_AND && !left_val) ||
2094                             (arg->op.type == FILTER_OP_OR && left_val)) {
2095                                 /* Just return left value */
2096                                 str = left;
2097                                 left = NULL;
2098                                 break;
2099                         }
2100                         if (right_val >= 0) {
2101                                 /* just evaluate this. */
2102                                 val = 0;
2103                                 switch (arg->op.type) {
2104                                 case FILTER_OP_AND:
2105                                         val = left_val && right_val;
2106                                         break;
2107                                 case FILTER_OP_OR:
2108                                         val = left_val || right_val;
2109                                         break;
2110                                 default:
2111                                         break;
2112                                 }
2113                                 asprintf(&str, val ? "TRUE" : "FALSE");
2114                                 break;
2115                         }
2116                 }
2117                 if (right_val >= 0) {
2118                         if ((arg->op.type == FILTER_OP_AND && !right_val) ||
2119                             (arg->op.type == FILTER_OP_OR && right_val)) {
2120                                 /* Just return right value */
2121                                 str = right;
2122                                 right = NULL;
2123                                 break;
2124                         }
2125                         /* The right value is meaningless */
2126                         str = left;
2127                         left = NULL;
2128                         break;
2129                 }
2130
2131                 asprintf(&str, "(%s) %s (%s)", left, op, right);
2132                 break;
2133
2134         case FILTER_OP_NOT:
2135                 op = "!";
2136                 right = arg_to_str(filter, arg->op.right);
2137                 if (!right)
2138                         break;
2139
2140                 /* See if we can consolidate */
2141                 if (strcmp(right, "TRUE") == 0)
2142                         right_val = 1;
2143                 else if (strcmp(right, "FALSE") == 0)
2144                         right_val = 0;
2145                 if (right_val >= 0) {
2146                         /* just return the opposite */
2147                         asprintf(&str, right_val ? "FALSE" : "TRUE");
2148                         break;
2149                 }
2150                 asprintf(&str, "%s(%s)", op, right);
2151                 break;
2152
2153         default:
2154                 /* ?? */
2155                 break;
2156         }
2157         free(left);
2158         free(right);
2159         return str;
2160 }
2161
2162 static char *val_to_str(struct event_filter *filter, struct filter_arg *arg)
2163 {
2164         char *str = NULL;
2165
2166         asprintf(&str, "%lld", arg->value.val);
2167
2168         return str;
2169 }
2170
2171 static char *field_to_str(struct event_filter *filter, struct filter_arg *arg)
2172 {
2173         return strdup(arg->field.field->name);
2174 }
2175
2176 static char *exp_to_str(struct event_filter *filter, struct filter_arg *arg)
2177 {
2178         char *lstr;
2179         char *rstr;
2180         char *op;
2181         char *str = NULL;
2182
2183         lstr = arg_to_str(filter, arg->exp.left);
2184         rstr = arg_to_str(filter, arg->exp.right);
2185         if (!lstr || !rstr)
2186                 goto out;
2187
2188         switch (arg->exp.type) {
2189         case FILTER_EXP_ADD:
2190                 op = "+";
2191                 break;
2192         case FILTER_EXP_SUB:
2193                 op = "-";
2194                 break;
2195         case FILTER_EXP_MUL:
2196                 op = "*";
2197                 break;
2198         case FILTER_EXP_DIV:
2199                 op = "/";
2200                 break;
2201         case FILTER_EXP_MOD:
2202                 op = "%";
2203                 break;
2204         case FILTER_EXP_RSHIFT:
2205                 op = ">>";
2206                 break;
2207         case FILTER_EXP_LSHIFT:
2208                 op = "<<";
2209                 break;
2210         case FILTER_EXP_AND:
2211                 op = "&";
2212                 break;
2213         case FILTER_EXP_OR:
2214                 op = "|";
2215                 break;
2216         case FILTER_EXP_XOR:
2217                 op = "^";
2218                 break;
2219         default:
2220                 op = "[ERROR IN EXPRESSION TYPE]";
2221                 break;
2222         }
2223
2224         asprintf(&str, "%s %s %s", lstr, op, rstr);
2225 out:
2226         free(lstr);
2227         free(rstr);
2228
2229         return str;
2230 }
2231
2232 static char *num_to_str(struct event_filter *filter, struct filter_arg *arg)
2233 {
2234         char *lstr;
2235         char *rstr;
2236         char *str = NULL;
2237         char *op = NULL;
2238
2239         lstr = arg_to_str(filter, arg->num.left);
2240         rstr = arg_to_str(filter, arg->num.right);
2241         if (!lstr || !rstr)
2242                 goto out;
2243
2244         switch (arg->num.type) {
2245         case FILTER_CMP_EQ:
2246                 op = "==";
2247                 /* fall through */
2248         case FILTER_CMP_NE:
2249                 if (!op)
2250                         op = "!=";
2251                 /* fall through */
2252         case FILTER_CMP_GT:
2253                 if (!op)
2254                         op = ">";
2255                 /* fall through */
2256         case FILTER_CMP_LT:
2257                 if (!op)
2258                         op = "<";
2259                 /* fall through */
2260         case FILTER_CMP_GE:
2261                 if (!op)
2262                         op = ">=";
2263                 /* fall through */
2264         case FILTER_CMP_LE:
2265                 if (!op)
2266                         op = "<=";
2267
2268                 asprintf(&str, "%s %s %s", lstr, op, rstr);
2269                 break;
2270
2271         default:
2272                 /* ?? */
2273                 break;
2274         }
2275
2276 out:
2277         free(lstr);
2278         free(rstr);
2279         return str;
2280 }
2281
2282 static char *str_to_str(struct event_filter *filter, struct filter_arg *arg)
2283 {
2284         char *str = NULL;
2285         char *op = NULL;
2286
2287         switch (arg->str.type) {
2288         case FILTER_CMP_MATCH:
2289                 op = "==";
2290                 /* fall through */
2291         case FILTER_CMP_NOT_MATCH:
2292                 if (!op)
2293                         op = "!=";
2294                 /* fall through */
2295         case FILTER_CMP_REGEX:
2296                 if (!op)
2297                         op = "=~";
2298                 /* fall through */
2299         case FILTER_CMP_NOT_REGEX:
2300                 if (!op)
2301                         op = "!~";
2302
2303                 asprintf(&str, "%s %s \"%s\"",
2304                          arg->str.field->name, op, arg->str.val);
2305                 break;
2306
2307         default:
2308                 /* ?? */
2309                 break;
2310         }
2311         return str;
2312 }
2313
2314 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg)
2315 {
2316         char *str = NULL;
2317
2318         switch (arg->type) {
2319         case FILTER_ARG_BOOLEAN:
2320                 asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
2321                 return str;
2322
2323         case FILTER_ARG_OP:
2324                 return op_to_str(filter, arg);
2325
2326         case FILTER_ARG_NUM:
2327                 return num_to_str(filter, arg);
2328
2329         case FILTER_ARG_STR:
2330                 return str_to_str(filter, arg);
2331
2332         case FILTER_ARG_VALUE:
2333                 return val_to_str(filter, arg);
2334
2335         case FILTER_ARG_FIELD:
2336                 return field_to_str(filter, arg);
2337
2338         case FILTER_ARG_EXP:
2339                 return exp_to_str(filter, arg);
2340
2341         default:
2342                 /* ?? */
2343                 return NULL;
2344         }
2345
2346 }
2347
2348 /**
2349  * pevent_filter_make_string - return a string showing the filter
2350  * @filter: filter struct with filter information
2351  * @event_id: the event id to return the filter string with
2352  *
2353  * Returns a string that displays the filter contents.
2354  *  This string must be freed with free(str).
2355  *  NULL is returned if no filter is found or allocation failed.
2356  */
2357 char *
2358 pevent_filter_make_string(struct event_filter *filter, int event_id)
2359 {
2360         struct filter_type *filter_type;
2361
2362         if (!filter->filters)
2363                 return NULL;
2364
2365         filter_type = find_filter_type(filter, event_id);
2366
2367         if (!filter_type)
2368                 return NULL;
2369
2370         return arg_to_str(filter, filter_type->filter);
2371 }
2372
2373 /**
2374  * pevent_filter_compare - compare two filters and return if they are the same
2375  * @filter1: Filter to compare with @filter2
2376  * @filter2: Filter to compare with @filter1
2377  *
2378  * Returns:
2379  *  1 if the two filters hold the same content.
2380  *  0 if they do not.
2381  */
2382 int pevent_filter_compare(struct event_filter *filter1, struct event_filter *filter2)
2383 {
2384         struct filter_type *filter_type1;
2385         struct filter_type *filter_type2;
2386         char *str1, *str2;
2387         int result;
2388         int i;
2389
2390         /* Do the easy checks first */
2391         if (filter1->filters != filter2->filters)
2392                 return 0;
2393         if (!filter1->filters && !filter2->filters)
2394                 return 1;
2395
2396         /*
2397          * Now take a look at each of the events to see if they have the same
2398          * filters to them.
2399          */
2400         for (i = 0; i < filter1->filters; i++) {
2401                 filter_type1 = &filter1->event_filters[i];
2402                 filter_type2 = find_filter_type(filter2, filter_type1->event_id);
2403                 if (!filter_type2)
2404                         break;
2405                 if (filter_type1->filter->type != filter_type2->filter->type)
2406                         break;
2407                 switch (filter_type1->filter->type) {
2408                 case FILTER_TRIVIAL_FALSE:
2409                 case FILTER_TRIVIAL_TRUE:
2410                         /* trivial types just need the type compared */
2411                         continue;
2412                 default:
2413                         break;
2414                 }
2415                 /* The best way to compare complex filters is with strings */
2416                 str1 = arg_to_str(filter1, filter_type1->filter);
2417                 str2 = arg_to_str(filter2, filter_type2->filter);
2418                 if (str1 && str2)
2419                         result = strcmp(str1, str2) != 0;
2420                 else
2421                         /* bail out if allocation fails */
2422                         result = 1;
2423
2424                 free(str1);
2425                 free(str2);
2426                 if (result)
2427                         break;
2428         }
2429
2430         if (i < filter1->filters)
2431                 return 0;
2432         return 1;
2433 }
2434