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                                 return PEVENT_ERRNO__UNBALANCED_PAREN;
1062                         }
1063                         break;
1064
1065                 case EVENT_OP:
1066                         op_type = process_op(token, &btype, &ctype, &etype);
1067
1068                         /* All expect a left arg except for NOT */
1069                         switch (op_type) {
1070                         case OP_BOOL:
1071                                 /* Logic ops need a left expression */
1072                                 if (!current_exp && !current_op)
1073                                         goto fail_syntax;
1074                                 /* fall through */
1075                         case OP_NOT:
1076                                 /* logic only processes ops and exp */
1077                                 if (left_item)
1078                                         goto fail_syntax;
1079                                 break;
1080                         case OP_EXP:
1081                         case OP_CMP:
1082                                 if (!left_item)
1083                                         goto fail_syntax;
1084                                 break;
1085                         case OP_NONE:
1086                                 show_error(error_str,
1087                                            "Unknown op token %s", token);
1088                                 ret = PEVENT_ERRNO__UNKNOWN_TOKEN;
1089                                 goto fail;
1090                         }
1091
1092                         ret = 0;
1093                         switch (op_type) {
1094                         case OP_BOOL:
1095                                 arg = create_arg_op(btype);
1096                                 if (arg == NULL)
1097                                         goto fail_alloc;
1098                                 if (current_op)
1099                                         ret = add_left(arg, current_op);
1100                                 else
1101                                         ret = add_left(arg, current_exp);
1102                                 current_op = arg;
1103                                 current_exp = NULL;
1104                                 break;
1105
1106                         case OP_NOT:
1107                                 arg = create_arg_op(btype);
1108                                 if (arg == NULL)
1109                                         goto fail_alloc;
1110                                 if (current_op)
1111                                         ret = add_right(current_op, arg, error_str);
1112                                 if (ret < 0)
1113                                         goto fail;
1114                                 current_exp = arg;
1115                                 ret = process_filter(event, &arg, error_str, 1);
1116                                 if (ret < 0)
1117                                         goto fail;
1118                                 ret = add_right(current_exp, arg, error_str);
1119                                 if (ret < 0)
1120                                         goto fail;
1121                                 break;
1122
1123                         case OP_EXP:
1124                         case OP_CMP:
1125                                 if (op_type == OP_EXP)
1126                                         arg = create_arg_exp(etype);
1127                                 else
1128                                         arg = create_arg_cmp(ctype);
1129                                 if (arg == NULL)
1130                                         goto fail_alloc;
1131
1132                                 if (current_op)
1133                                         ret = add_right(current_op, arg, error_str);
1134                                 if (ret < 0)
1135                                         goto fail;
1136                                 ret = add_left(arg, left_item);
1137                                 if (ret < 0) {
1138                                         arg = NULL;
1139                                         goto fail_syntax;
1140                                 }
1141                                 current_exp = arg;
1142                                 break;
1143                         default:
1144                                 break;
1145                         }
1146                         arg = NULL;
1147                         if (ret < 0)
1148                                 goto fail_syntax;
1149                         break;
1150                 case EVENT_NONE:
1151                         break;
1152                 case EVENT_ERROR:
1153                         goto fail_alloc;
1154                 default:
1155                         goto fail_syntax;
1156                 }
1157         } while (type != EVENT_NONE);
1158
1159         if (!current_op && !current_exp)
1160                 goto fail_syntax;
1161
1162         if (!current_op)
1163                 current_op = current_exp;
1164
1165         ret = collapse_tree(current_op, parg, error_str);
1166         if (ret < 0)
1167                 goto fail;
1168
1169         *parg = current_op;
1170
1171         return 0;
1172
1173  fail_alloc:
1174         show_error(error_str, "failed to allocate filter arg");
1175         ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
1176         goto fail;
1177  fail_syntax:
1178         show_error(error_str, "Syntax error");
1179         ret = PEVENT_ERRNO__SYNTAX_ERROR;
1180  fail:
1181         free_arg(current_op);
1182         free_arg(current_exp);
1183         free_arg(arg);
1184         free(token);
1185         return ret;
1186 }
1187
1188 static enum pevent_errno
1189 process_event(struct event_format *event, const char *filter_str,
1190               struct filter_arg **parg, char *error_str)
1191 {
1192         int ret;
1193
1194         pevent_buffer_init(filter_str, strlen(filter_str));
1195
1196         ret = process_filter(event, parg, error_str, 0);
1197         if (ret < 0)
1198                 return ret;
1199
1200         /* If parg is NULL, then make it into FALSE */
1201         if (!*parg) {
1202                 *parg = allocate_arg();
1203                 if (*parg == NULL)
1204                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1205
1206                 (*parg)->type = FILTER_ARG_BOOLEAN;
1207                 (*parg)->boolean.value = FILTER_FALSE;
1208         }
1209
1210         return 0;
1211 }
1212
1213 static enum pevent_errno
1214 filter_event(struct event_filter *filter, struct event_format *event,
1215              const char *filter_str, char *error_str)
1216 {
1217         struct filter_type *filter_type;
1218         struct filter_arg *arg;
1219         enum pevent_errno ret;
1220
1221         if (filter_str) {
1222                 ret = process_event(event, filter_str, &arg, error_str);
1223                 if (ret < 0)
1224                         return ret;
1225
1226         } else {
1227                 /* just add a TRUE arg */
1228                 arg = allocate_arg();
1229                 if (arg == NULL)
1230                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1231
1232                 arg->type = FILTER_ARG_BOOLEAN;
1233                 arg->boolean.value = FILTER_TRUE;
1234         }
1235
1236         filter_type = add_filter_type(filter, event->id);
1237         if (filter_type == NULL)
1238                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1239
1240         if (filter_type->filter)
1241                 free_arg(filter_type->filter);
1242         filter_type->filter = arg;
1243
1244         return 0;
1245 }
1246
1247 static void filter_init_error_buf(struct event_filter *filter)
1248 {
1249         /* clear buffer to reset show error */
1250         pevent_buffer_init("", 0);
1251         filter->error_buffer[0] = '\0';
1252 }
1253
1254 /**
1255  * pevent_filter_add_filter_str - add a new filter
1256  * @filter: the event filter to add to
1257  * @filter_str: the filter string that contains the filter
1258  *
1259  * Returns 0 if the filter was successfully added or a
1260  * negative error code.  Use pevent_filter_strerror() to see
1261  * actual error message in case of error.
1262  */
1263 enum pevent_errno pevent_filter_add_filter_str(struct event_filter *filter,
1264                                                const char *filter_str)
1265 {
1266         struct pevent *pevent = filter->pevent;
1267         struct event_list *event;
1268         struct event_list *events = NULL;
1269         const char *filter_start;
1270         const char *next_event;
1271         char *this_event;
1272         char *event_name = NULL;
1273         char *sys_name = NULL;
1274         char *sp;
1275         enum pevent_errno rtn = 0; /* PEVENT_ERRNO__SUCCESS */
1276         int len;
1277         int ret;
1278
1279         filter_init_error_buf(filter);
1280
1281         filter_start = strchr(filter_str, ':');
1282         if (filter_start)
1283                 len = filter_start - filter_str;
1284         else
1285                 len = strlen(filter_str);
1286
1287         do {
1288                 next_event = strchr(filter_str, ',');
1289                 if (next_event &&
1290                     (!filter_start || next_event < filter_start))
1291                         len = next_event - filter_str;
1292                 else if (filter_start)
1293                         len = filter_start - filter_str;
1294                 else
1295                         len = strlen(filter_str);
1296
1297                 this_event = malloc(len + 1);
1298                 if (this_event == NULL) {
1299                         /* This can only happen when events is NULL, but still */
1300                         free_events(events);
1301                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1302                 }
1303                 memcpy(this_event, filter_str, len);
1304                 this_event[len] = 0;
1305
1306                 if (next_event)
1307                         next_event++;
1308
1309                 filter_str = next_event;
1310
1311                 sys_name = strtok_r(this_event, "/", &sp);
1312                 event_name = strtok_r(NULL, "/", &sp);
1313
1314                 if (!sys_name) {
1315                         /* This can only happen when events is NULL, but still */
1316                         free_events(events);
1317                         free(this_event);
1318                         return PEVENT_ERRNO__FILTER_NOT_FOUND;
1319                 }
1320
1321                 /* Find this event */
1322                 ret = find_event(pevent, &events, strim(sys_name), strim(event_name));
1323                 if (ret < 0) {
1324                         free_events(events);
1325                         free(this_event);
1326                         return ret;
1327                 }
1328                 free(this_event);
1329         } while (filter_str);
1330
1331         /* Skip the ':' */
1332         if (filter_start)
1333                 filter_start++;
1334
1335         /* filter starts here */
1336         for (event = events; event; event = event->next) {
1337                 ret = filter_event(filter, event->event, filter_start,
1338                                    filter->error_buffer);
1339                 /* Failures are returned if a parse error happened */
1340                 if (ret < 0)
1341                         rtn = ret;
1342
1343                 if (ret >= 0 && pevent->test_filters) {
1344                         char *test;
1345                         test = pevent_filter_make_string(filter, event->event->id);
1346                         if (test) {
1347                                 printf(" '%s: %s'\n", event->event->name, test);
1348                                 free(test);
1349                         }
1350                 }
1351         }
1352
1353         free_events(events);
1354
1355         if (rtn >= 0 && pevent->test_filters)
1356                 exit(0);
1357
1358         return rtn;
1359 }
1360
1361 static void free_filter_type(struct filter_type *filter_type)
1362 {
1363         free_arg(filter_type->filter);
1364 }
1365
1366 /**
1367  * pevent_filter_strerror - fill error message in a buffer
1368  * @filter: the event filter contains error
1369  * @err: the error code
1370  * @buf: the buffer to be filled in
1371  * @buflen: the size of the buffer
1372  *
1373  * Returns 0 if message was filled successfully, -1 if error
1374  */
1375 int pevent_filter_strerror(struct event_filter *filter, enum pevent_errno err,
1376                            char *buf, size_t buflen)
1377 {
1378         if (err <= __PEVENT_ERRNO__START || err >= __PEVENT_ERRNO__END)
1379                 return -1;
1380
1381         if (strlen(filter->error_buffer) > 0) {
1382                 size_t len = snprintf(buf, buflen, "%s", filter->error_buffer);
1383
1384                 if (len > buflen)
1385                         return -1;
1386                 return 0;
1387         }
1388
1389         return pevent_strerror(filter->pevent, err, buf, buflen);
1390 }
1391
1392 /**
1393  * pevent_filter_remove_event - remove a filter for an event
1394  * @filter: the event filter to remove from
1395  * @event_id: the event to remove a filter for
1396  *
1397  * Removes the filter saved for an event defined by @event_id
1398  * from the @filter.
1399  *
1400  * Returns 1: if an event was removed
1401  *   0: if the event was not found
1402  */
1403 int pevent_filter_remove_event(struct event_filter *filter,
1404                                int event_id)
1405 {
1406         struct filter_type *filter_type;
1407         unsigned long len;
1408
1409         if (!filter->filters)
1410                 return 0;
1411
1412         filter_type = find_filter_type(filter, event_id);
1413
1414         if (!filter_type)
1415                 return 0;
1416
1417         free_filter_type(filter_type);
1418
1419         /* The filter_type points into the event_filters array */
1420         len = (unsigned long)(filter->event_filters + filter->filters) -
1421                 (unsigned long)(filter_type + 1);
1422
1423         memmove(filter_type, filter_type + 1, len);
1424         filter->filters--;
1425
1426         memset(&filter->event_filters[filter->filters], 0,
1427                sizeof(*filter_type));
1428
1429         return 1;
1430 }
1431
1432 /**
1433  * pevent_filter_reset - clear all filters in a filter
1434  * @filter: the event filter to reset
1435  *
1436  * Removes all filters from a filter and resets it.
1437  */
1438 void pevent_filter_reset(struct event_filter *filter)
1439 {
1440         int i;
1441
1442         for (i = 0; i < filter->filters; i++)
1443                 free_filter_type(&filter->event_filters[i]);
1444
1445         free(filter->event_filters);
1446         filter->filters = 0;
1447         filter->event_filters = NULL;
1448 }
1449
1450 void pevent_filter_free(struct event_filter *filter)
1451 {
1452         pevent_unref(filter->pevent);
1453
1454         pevent_filter_reset(filter);
1455
1456         free(filter);
1457 }
1458
1459 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg);
1460
1461 static int copy_filter_type(struct event_filter *filter,
1462                              struct event_filter *source,
1463                              struct filter_type *filter_type)
1464 {
1465         struct filter_arg *arg;
1466         struct event_format *event;
1467         const char *sys;
1468         const char *name;
1469         char *str;
1470
1471         /* Can't assume that the pevent's are the same */
1472         sys = filter_type->event->system;
1473         name = filter_type->event->name;
1474         event = pevent_find_event_by_name(filter->pevent, sys, name);
1475         if (!event)
1476                 return -1;
1477
1478         str = arg_to_str(source, filter_type->filter);
1479         if (!str)
1480                 return -1;
1481
1482         if (strcmp(str, "TRUE") == 0 || strcmp(str, "FALSE") == 0) {
1483                 /* Add trivial event */
1484                 arg = allocate_arg();
1485                 if (arg == NULL)
1486                         return -1;
1487
1488                 arg->type = FILTER_ARG_BOOLEAN;
1489                 if (strcmp(str, "TRUE") == 0)
1490                         arg->boolean.value = 1;
1491                 else
1492                         arg->boolean.value = 0;
1493
1494                 filter_type = add_filter_type(filter, event->id);
1495                 if (filter_type == NULL)
1496                         return -1;
1497
1498                 filter_type->filter = arg;
1499
1500                 free(str);
1501                 return 0;
1502         }
1503
1504         filter_event(filter, event, str, NULL);
1505         free(str);
1506
1507         return 0;
1508 }
1509
1510 /**
1511  * pevent_filter_copy - copy a filter using another filter
1512  * @dest - the filter to copy to
1513  * @source - the filter to copy from
1514  *
1515  * Returns 0 on success and -1 if not all filters were copied
1516  */
1517 int pevent_filter_copy(struct event_filter *dest, struct event_filter *source)
1518 {
1519         int ret = 0;
1520         int i;
1521
1522         pevent_filter_reset(dest);
1523
1524         for (i = 0; i < source->filters; i++) {
1525                 if (copy_filter_type(dest, source, &source->event_filters[i]))
1526                         ret = -1;
1527         }
1528         return ret;
1529 }
1530
1531
1532 /**
1533  * pevent_update_trivial - update the trivial filters with the given filter
1534  * @dest - the filter to update
1535  * @source - the filter as the source of the update
1536  * @type - the type of trivial filter to update.
1537  *
1538  * Scan dest for trivial events matching @type to replace with the source.
1539  *
1540  * Returns 0 on success and -1 if there was a problem updating, but
1541  *   events may have still been updated on error.
1542  */
1543 int pevent_update_trivial(struct event_filter *dest, struct event_filter *source,
1544                           enum filter_trivial_type type)
1545 {
1546         struct pevent *src_pevent;
1547         struct pevent *dest_pevent;
1548         struct event_format *event;
1549         struct filter_type *filter_type;
1550         struct filter_arg *arg;
1551         char *str;
1552         int i;
1553
1554         src_pevent = source->pevent;
1555         dest_pevent = dest->pevent;
1556
1557         /* Do nothing if either of the filters has nothing to filter */
1558         if (!dest->filters || !source->filters)
1559                 return 0;
1560
1561         for (i = 0; i < dest->filters; i++) {
1562                 filter_type = &dest->event_filters[i];
1563                 arg = filter_type->filter;
1564                 if (arg->type != FILTER_ARG_BOOLEAN)
1565                         continue;
1566                 if ((arg->boolean.value && type == FILTER_TRIVIAL_FALSE) ||
1567                     (!arg->boolean.value && type == FILTER_TRIVIAL_TRUE))
1568                         continue;
1569
1570                 event = filter_type->event;
1571
1572                 if (src_pevent != dest_pevent) {
1573                         /* do a look up */
1574                         event = pevent_find_event_by_name(src_pevent,
1575                                                           event->system,
1576                                                           event->name);
1577                         if (!event)
1578                                 return -1;
1579                 }
1580
1581                 str = pevent_filter_make_string(source, event->id);
1582                 if (!str)
1583                         continue;
1584
1585                 /* Don't bother if the filter is trivial too */
1586                 if (strcmp(str, "TRUE") != 0 && strcmp(str, "FALSE") != 0)
1587                         filter_event(dest, event, str, NULL);
1588                 free(str);
1589         }
1590         return 0;
1591 }
1592
1593 /**
1594  * pevent_filter_clear_trivial - clear TRUE and FALSE filters
1595  * @filter: the filter to remove trivial filters from
1596  * @type: remove only true, false, or both
1597  *
1598  * Removes filters that only contain a TRUE or FALES boolean arg.
1599  *
1600  * Returns 0 on success and -1 if there was a problem.
1601  */
1602 int pevent_filter_clear_trivial(struct event_filter *filter,
1603                                  enum filter_trivial_type type)
1604 {
1605         struct filter_type *filter_type;
1606         int count = 0;
1607         int *ids = NULL;
1608         int i;
1609
1610         if (!filter->filters)
1611                 return 0;
1612
1613         /*
1614          * Two steps, first get all ids with trivial filters.
1615          *  then remove those ids.
1616          */
1617         for (i = 0; i < filter->filters; i++) {
1618                 int *new_ids;
1619
1620                 filter_type = &filter->event_filters[i];
1621                 if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1622                         continue;
1623                 switch (type) {
1624                 case FILTER_TRIVIAL_FALSE:
1625                         if (filter_type->filter->boolean.value)
1626                                 continue;
1627                 case FILTER_TRIVIAL_TRUE:
1628                         if (!filter_type->filter->boolean.value)
1629                                 continue;
1630                 default:
1631                         break;
1632                 }
1633
1634                 new_ids = realloc(ids, sizeof(*ids) * (count + 1));
1635                 if (!new_ids) {
1636                         free(ids);
1637                         return -1;
1638                 }
1639
1640                 ids = new_ids;
1641                 ids[count++] = filter_type->event_id;
1642         }
1643
1644         if (!count)
1645                 return 0;
1646
1647         for (i = 0; i < count; i++)
1648                 pevent_filter_remove_event(filter, ids[i]);
1649
1650         free(ids);
1651         return 0;
1652 }
1653
1654 /**
1655  * pevent_filter_event_has_trivial - return true event contains trivial filter
1656  * @filter: the filter with the information
1657  * @event_id: the id of the event to test
1658  * @type: trivial type to test for (TRUE, FALSE, EITHER)
1659  *
1660  * Returns 1 if the event contains a matching trivial type
1661  *  otherwise 0.
1662  */
1663 int pevent_filter_event_has_trivial(struct event_filter *filter,
1664                                     int event_id,
1665                                     enum filter_trivial_type type)
1666 {
1667         struct filter_type *filter_type;
1668
1669         if (!filter->filters)
1670                 return 0;
1671
1672         filter_type = find_filter_type(filter, event_id);
1673
1674         if (!filter_type)
1675                 return 0;
1676
1677         if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1678                 return 0;
1679
1680         switch (type) {
1681         case FILTER_TRIVIAL_FALSE:
1682                 return !filter_type->filter->boolean.value;
1683
1684         case FILTER_TRIVIAL_TRUE:
1685                 return filter_type->filter->boolean.value;
1686         default:
1687                 return 1;
1688         }
1689 }
1690
1691 static int test_filter(struct event_format *event, struct filter_arg *arg,
1692                        struct pevent_record *record, enum pevent_errno *err);
1693
1694 static const char *
1695 get_comm(struct event_format *event, struct pevent_record *record)
1696 {
1697         const char *comm;
1698         int pid;
1699
1700         pid = pevent_data_pid(event->pevent, record);
1701         comm = pevent_data_comm_from_pid(event->pevent, pid);
1702         return comm;
1703 }
1704
1705 static unsigned long long
1706 get_value(struct event_format *event,
1707           struct format_field *field, struct pevent_record *record)
1708 {
1709         unsigned long long val;
1710
1711         /* Handle our dummy "comm" field */
1712         if (field == &comm) {
1713                 const char *name;
1714
1715                 name = get_comm(event, record);
1716                 return (unsigned long)name;
1717         }
1718
1719         pevent_read_number_field(field, record->data, &val);
1720
1721         if (!(field->flags & FIELD_IS_SIGNED))
1722                 return val;
1723
1724         switch (field->size) {
1725         case 1:
1726                 return (char)val;
1727         case 2:
1728                 return (short)val;
1729         case 4:
1730                 return (int)val;
1731         case 8:
1732                 return (long long)val;
1733         }
1734         return val;
1735 }
1736
1737 static unsigned long long
1738 get_arg_value(struct event_format *event, struct filter_arg *arg,
1739               struct pevent_record *record, enum pevent_errno *err);
1740
1741 static unsigned long long
1742 get_exp_value(struct event_format *event, struct filter_arg *arg,
1743               struct pevent_record *record, enum pevent_errno *err)
1744 {
1745         unsigned long long lval, rval;
1746
1747         lval = get_arg_value(event, arg->exp.left, record, err);
1748         rval = get_arg_value(event, arg->exp.right, record, err);
1749
1750         if (*err) {
1751                 /*
1752                  * There was an error, no need to process anymore.
1753                  */
1754                 return 0;
1755         }
1756
1757         switch (arg->exp.type) {
1758         case FILTER_EXP_ADD:
1759                 return lval + rval;
1760
1761         case FILTER_EXP_SUB:
1762                 return lval - rval;
1763
1764         case FILTER_EXP_MUL:
1765                 return lval * rval;
1766
1767         case FILTER_EXP_DIV:
1768                 return lval / rval;
1769
1770         case FILTER_EXP_MOD:
1771                 return lval % rval;
1772
1773         case FILTER_EXP_RSHIFT:
1774                 return lval >> rval;
1775
1776         case FILTER_EXP_LSHIFT:
1777                 return lval << rval;
1778
1779         case FILTER_EXP_AND:
1780                 return lval & rval;
1781
1782         case FILTER_EXP_OR:
1783                 return lval | rval;
1784
1785         case FILTER_EXP_XOR:
1786                 return lval ^ rval;
1787
1788         case FILTER_EXP_NOT:
1789         default:
1790                 if (!*err)
1791                         *err = PEVENT_ERRNO__INVALID_EXP_TYPE;
1792         }
1793         return 0;
1794 }
1795
1796 static unsigned long long
1797 get_arg_value(struct event_format *event, struct filter_arg *arg,
1798               struct pevent_record *record, enum pevent_errno *err)
1799 {
1800         switch (arg->type) {
1801         case FILTER_ARG_FIELD:
1802                 return get_value(event, arg->field.field, record);
1803
1804         case FILTER_ARG_VALUE:
1805                 if (arg->value.type != FILTER_NUMBER) {
1806                         if (!*err)
1807                                 *err = PEVENT_ERRNO__NOT_A_NUMBER;
1808                 }
1809                 return arg->value.val;
1810
1811         case FILTER_ARG_EXP:
1812                 return get_exp_value(event, arg, record, err);
1813
1814         default:
1815                 if (!*err)
1816                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1817         }
1818         return 0;
1819 }
1820
1821 static int test_num(struct event_format *event, struct filter_arg *arg,
1822                     struct pevent_record *record, enum pevent_errno *err)
1823 {
1824         unsigned long long lval, rval;
1825
1826         lval = get_arg_value(event, arg->num.left, record, err);
1827         rval = get_arg_value(event, arg->num.right, record, err);
1828
1829         if (*err) {
1830                 /*
1831                  * There was an error, no need to process anymore.
1832                  */
1833                 return 0;
1834         }
1835
1836         switch (arg->num.type) {
1837         case FILTER_CMP_EQ:
1838                 return lval == rval;
1839
1840         case FILTER_CMP_NE:
1841                 return lval != rval;
1842
1843         case FILTER_CMP_GT:
1844                 return lval > rval;
1845
1846         case FILTER_CMP_LT:
1847                 return lval < rval;
1848
1849         case FILTER_CMP_GE:
1850                 return lval >= rval;
1851
1852         case FILTER_CMP_LE:
1853                 return lval <= rval;
1854
1855         default:
1856                 if (!*err)
1857                         *err = PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
1858                 return 0;
1859         }
1860 }
1861
1862 static const char *get_field_str(struct filter_arg *arg, struct pevent_record *record)
1863 {
1864         struct event_format *event;
1865         struct pevent *pevent;
1866         unsigned long long addr;
1867         const char *val = NULL;
1868         char hex[64];
1869
1870         /* If the field is not a string convert it */
1871         if (arg->str.field->flags & FIELD_IS_STRING) {
1872                 val = record->data + arg->str.field->offset;
1873
1874                 /*
1875                  * We need to copy the data since we can't be sure the field
1876                  * is null terminated.
1877                  */
1878                 if (*(val + arg->str.field->size - 1)) {
1879                         /* copy it */
1880                         memcpy(arg->str.buffer, val, arg->str.field->size);
1881                         /* the buffer is already NULL terminated */
1882                         val = arg->str.buffer;
1883                 }
1884
1885         } else {
1886                 event = arg->str.field->event;
1887                 pevent = event->pevent;
1888                 addr = get_value(event, arg->str.field, record);
1889
1890                 if (arg->str.field->flags & (FIELD_IS_POINTER | FIELD_IS_LONG))
1891                         /* convert to a kernel symbol */
1892                         val = pevent_find_function(pevent, addr);
1893
1894                 if (val == NULL) {
1895                         /* just use the hex of the string name */
1896                         snprintf(hex, 64, "0x%llx", addr);
1897                         val = hex;
1898                 }
1899         }
1900
1901         return val;
1902 }
1903
1904 static int test_str(struct event_format *event, struct filter_arg *arg,
1905                     struct pevent_record *record, enum pevent_errno *err)
1906 {
1907         const char *val;
1908
1909         if (arg->str.field == &comm)
1910                 val = get_comm(event, record);
1911         else
1912                 val = get_field_str(arg, record);
1913
1914         switch (arg->str.type) {
1915         case FILTER_CMP_MATCH:
1916                 return strcmp(val, arg->str.val) == 0;
1917
1918         case FILTER_CMP_NOT_MATCH:
1919                 return strcmp(val, arg->str.val) != 0;
1920
1921         case FILTER_CMP_REGEX:
1922                 /* Returns zero on match */
1923                 return !regexec(&arg->str.reg, val, 0, NULL, 0);
1924
1925         case FILTER_CMP_NOT_REGEX:
1926                 return regexec(&arg->str.reg, val, 0, NULL, 0);
1927
1928         default:
1929                 if (!*err)
1930                         *err = PEVENT_ERRNO__ILLEGAL_STRING_CMP;
1931                 return 0;
1932         }
1933 }
1934
1935 static int test_op(struct event_format *event, struct filter_arg *arg,
1936                    struct pevent_record *record, enum pevent_errno *err)
1937 {
1938         switch (arg->op.type) {
1939         case FILTER_OP_AND:
1940                 return test_filter(event, arg->op.left, record, err) &&
1941                         test_filter(event, arg->op.right, record, err);
1942
1943         case FILTER_OP_OR:
1944                 return test_filter(event, arg->op.left, record, err) ||
1945                         test_filter(event, arg->op.right, record, err);
1946
1947         case FILTER_OP_NOT:
1948                 return !test_filter(event, arg->op.right, record, err);
1949
1950         default:
1951                 if (!*err)
1952                         *err = PEVENT_ERRNO__INVALID_OP_TYPE;
1953                 return 0;
1954         }
1955 }
1956
1957 static int test_filter(struct event_format *event, struct filter_arg *arg,
1958                        struct pevent_record *record, enum pevent_errno *err)
1959 {
1960         if (*err) {
1961                 /*
1962                  * There was an error, no need to process anymore.
1963                  */
1964                 return 0;
1965         }
1966
1967         switch (arg->type) {
1968         case FILTER_ARG_BOOLEAN:
1969                 /* easy case */
1970                 return arg->boolean.value;
1971
1972         case FILTER_ARG_OP:
1973                 return test_op(event, arg, record, err);
1974
1975         case FILTER_ARG_NUM:
1976                 return test_num(event, arg, record, err);
1977
1978         case FILTER_ARG_STR:
1979                 return test_str(event, arg, record, err);
1980
1981         case FILTER_ARG_EXP:
1982         case FILTER_ARG_VALUE:
1983         case FILTER_ARG_FIELD:
1984                 /*
1985                  * Expressions, fields and values evaluate
1986                  * to true if they return non zero
1987                  */
1988                 return !!get_arg_value(event, arg, record, err);
1989
1990         default:
1991                 if (!*err)
1992                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1993                 return 0;
1994         }
1995 }
1996
1997 /**
1998  * pevent_event_filtered - return true if event has filter
1999  * @filter: filter struct with filter information
2000  * @event_id: event id to test if filter exists
2001  *
2002  * Returns 1 if filter found for @event_id
2003  *   otherwise 0;
2004  */
2005 int pevent_event_filtered(struct event_filter *filter, int event_id)
2006 {
2007         struct filter_type *filter_type;
2008
2009         if (!filter->filters)
2010                 return 0;
2011
2012         filter_type = find_filter_type(filter, event_id);
2013
2014         return filter_type ? 1 : 0;
2015 }
2016
2017 /**
2018  * pevent_filter_match - test if a record matches a filter
2019  * @filter: filter struct with filter information
2020  * @record: the record to test against the filter
2021  *
2022  * Returns: match result or error code (prefixed with PEVENT_ERRNO__)
2023  * FILTER_MATCH - filter found for event and @record matches
2024  * FILTER_MISS  - filter found for event and @record does not match
2025  * FILTER_NOT_FOUND - no filter found for @record's event
2026  * NO_FILTER - if no filters exist
2027  * otherwise - error occurred during test
2028  */
2029 enum pevent_errno pevent_filter_match(struct event_filter *filter,
2030                                       struct pevent_record *record)
2031 {
2032         struct pevent *pevent = filter->pevent;
2033         struct filter_type *filter_type;
2034         int event_id;
2035         int ret;
2036         enum pevent_errno err = 0;
2037
2038         filter_init_error_buf(filter);
2039
2040         if (!filter->filters)
2041                 return PEVENT_ERRNO__NO_FILTER;
2042
2043         event_id = pevent_data_type(pevent, record);
2044
2045         filter_type = find_filter_type(filter, event_id);
2046         if (!filter_type)
2047                 return PEVENT_ERRNO__FILTER_NOT_FOUND;
2048
2049         ret = test_filter(filter_type->event, filter_type->filter, record, &err);
2050         if (err)
2051                 return err;
2052
2053         return ret ? PEVENT_ERRNO__FILTER_MATCH : PEVENT_ERRNO__FILTER_MISS;
2054 }
2055
2056 static char *op_to_str(struct event_filter *filter, struct filter_arg *arg)
2057 {
2058         char *str = NULL;
2059         char *left = NULL;
2060         char *right = NULL;
2061         char *op = NULL;
2062         int left_val = -1;
2063         int right_val = -1;
2064         int val;
2065
2066         switch (arg->op.type) {
2067         case FILTER_OP_AND:
2068                 op = "&&";
2069                 /* fall through */
2070         case FILTER_OP_OR:
2071                 if (!op)
2072                         op = "||";
2073
2074                 left = arg_to_str(filter, arg->op.left);
2075                 right = arg_to_str(filter, arg->op.right);
2076                 if (!left || !right)
2077                         break;
2078
2079                 /* Try to consolidate boolean values */
2080                 if (strcmp(left, "TRUE") == 0)
2081                         left_val = 1;
2082                 else if (strcmp(left, "FALSE") == 0)
2083                         left_val = 0;
2084
2085                 if (strcmp(right, "TRUE") == 0)
2086                         right_val = 1;
2087                 else if (strcmp(right, "FALSE") == 0)
2088                         right_val = 0;
2089
2090                 if (left_val >= 0) {
2091                         if ((arg->op.type == FILTER_OP_AND && !left_val) ||
2092                             (arg->op.type == FILTER_OP_OR && left_val)) {
2093                                 /* Just return left value */
2094                                 str = left;
2095                                 left = NULL;
2096                                 break;
2097                         }
2098                         if (right_val >= 0) {
2099                                 /* just evaluate this. */
2100                                 val = 0;
2101                                 switch (arg->op.type) {
2102                                 case FILTER_OP_AND:
2103                                         val = left_val && right_val;
2104                                         break;
2105                                 case FILTER_OP_OR:
2106                                         val = left_val || right_val;
2107                                         break;
2108                                 default:
2109                                         break;
2110                                 }
2111                                 asprintf(&str, val ? "TRUE" : "FALSE");
2112                                 break;
2113                         }
2114                 }
2115                 if (right_val >= 0) {
2116                         if ((arg->op.type == FILTER_OP_AND && !right_val) ||
2117                             (arg->op.type == FILTER_OP_OR && right_val)) {
2118                                 /* Just return right value */
2119                                 str = right;
2120                                 right = NULL;
2121                                 break;
2122                         }
2123                         /* The right value is meaningless */
2124                         str = left;
2125                         left = NULL;
2126                         break;
2127                 }
2128
2129                 asprintf(&str, "(%s) %s (%s)", left, op, right);
2130                 break;
2131
2132         case FILTER_OP_NOT:
2133                 op = "!";
2134                 right = arg_to_str(filter, arg->op.right);
2135                 if (!right)
2136                         break;
2137
2138                 /* See if we can consolidate */
2139                 if (strcmp(right, "TRUE") == 0)
2140                         right_val = 1;
2141                 else if (strcmp(right, "FALSE") == 0)
2142                         right_val = 0;
2143                 if (right_val >= 0) {
2144                         /* just return the opposite */
2145                         asprintf(&str, right_val ? "FALSE" : "TRUE");
2146                         break;
2147                 }
2148                 asprintf(&str, "%s(%s)", op, right);
2149                 break;
2150
2151         default:
2152                 /* ?? */
2153                 break;
2154         }
2155         free(left);
2156         free(right);
2157         return str;
2158 }
2159
2160 static char *val_to_str(struct event_filter *filter, struct filter_arg *arg)
2161 {
2162         char *str = NULL;
2163
2164         asprintf(&str, "%lld", arg->value.val);
2165
2166         return str;
2167 }
2168
2169 static char *field_to_str(struct event_filter *filter, struct filter_arg *arg)
2170 {
2171         return strdup(arg->field.field->name);
2172 }
2173
2174 static char *exp_to_str(struct event_filter *filter, struct filter_arg *arg)
2175 {
2176         char *lstr;
2177         char *rstr;
2178         char *op;
2179         char *str = NULL;
2180
2181         lstr = arg_to_str(filter, arg->exp.left);
2182         rstr = arg_to_str(filter, arg->exp.right);
2183         if (!lstr || !rstr)
2184                 goto out;
2185
2186         switch (arg->exp.type) {
2187         case FILTER_EXP_ADD:
2188                 op = "+";
2189                 break;
2190         case FILTER_EXP_SUB:
2191                 op = "-";
2192                 break;
2193         case FILTER_EXP_MUL:
2194                 op = "*";
2195                 break;
2196         case FILTER_EXP_DIV:
2197                 op = "/";
2198                 break;
2199         case FILTER_EXP_MOD:
2200                 op = "%";
2201                 break;
2202         case FILTER_EXP_RSHIFT:
2203                 op = ">>";
2204                 break;
2205         case FILTER_EXP_LSHIFT:
2206                 op = "<<";
2207                 break;
2208         case FILTER_EXP_AND:
2209                 op = "&";
2210                 break;
2211         case FILTER_EXP_OR:
2212                 op = "|";
2213                 break;
2214         case FILTER_EXP_XOR:
2215                 op = "^";
2216                 break;
2217         default:
2218                 op = "[ERROR IN EXPRESSION TYPE]";
2219                 break;
2220         }
2221
2222         asprintf(&str, "%s %s %s", lstr, op, rstr);
2223 out:
2224         free(lstr);
2225         free(rstr);
2226
2227         return str;
2228 }
2229
2230 static char *num_to_str(struct event_filter *filter, struct filter_arg *arg)
2231 {
2232         char *lstr;
2233         char *rstr;
2234         char *str = NULL;
2235         char *op = NULL;
2236
2237         lstr = arg_to_str(filter, arg->num.left);
2238         rstr = arg_to_str(filter, arg->num.right);
2239         if (!lstr || !rstr)
2240                 goto out;
2241
2242         switch (arg->num.type) {
2243         case FILTER_CMP_EQ:
2244                 op = "==";
2245                 /* fall through */
2246         case FILTER_CMP_NE:
2247                 if (!op)
2248                         op = "!=";
2249                 /* fall through */
2250         case FILTER_CMP_GT:
2251                 if (!op)
2252                         op = ">";
2253                 /* fall through */
2254         case FILTER_CMP_LT:
2255                 if (!op)
2256                         op = "<";
2257                 /* fall through */
2258         case FILTER_CMP_GE:
2259                 if (!op)
2260                         op = ">=";
2261                 /* fall through */
2262         case FILTER_CMP_LE:
2263                 if (!op)
2264                         op = "<=";
2265
2266                 asprintf(&str, "%s %s %s", lstr, op, rstr);
2267                 break;
2268
2269         default:
2270                 /* ?? */
2271                 break;
2272         }
2273
2274 out:
2275         free(lstr);
2276         free(rstr);
2277         return str;
2278 }
2279
2280 static char *str_to_str(struct event_filter *filter, struct filter_arg *arg)
2281 {
2282         char *str = NULL;
2283         char *op = NULL;
2284
2285         switch (arg->str.type) {
2286         case FILTER_CMP_MATCH:
2287                 op = "==";
2288                 /* fall through */
2289         case FILTER_CMP_NOT_MATCH:
2290                 if (!op)
2291                         op = "!=";
2292                 /* fall through */
2293         case FILTER_CMP_REGEX:
2294                 if (!op)
2295                         op = "=~";
2296                 /* fall through */
2297         case FILTER_CMP_NOT_REGEX:
2298                 if (!op)
2299                         op = "!~";
2300
2301                 asprintf(&str, "%s %s \"%s\"",
2302                          arg->str.field->name, op, arg->str.val);
2303                 break;
2304
2305         default:
2306                 /* ?? */
2307                 break;
2308         }
2309         return str;
2310 }
2311
2312 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg)
2313 {
2314         char *str = NULL;
2315
2316         switch (arg->type) {
2317         case FILTER_ARG_BOOLEAN:
2318                 asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
2319                 return str;
2320
2321         case FILTER_ARG_OP:
2322                 return op_to_str(filter, arg);
2323
2324         case FILTER_ARG_NUM:
2325                 return num_to_str(filter, arg);
2326
2327         case FILTER_ARG_STR:
2328                 return str_to_str(filter, arg);
2329
2330         case FILTER_ARG_VALUE:
2331                 return val_to_str(filter, arg);
2332
2333         case FILTER_ARG_FIELD:
2334                 return field_to_str(filter, arg);
2335
2336         case FILTER_ARG_EXP:
2337                 return exp_to_str(filter, arg);
2338
2339         default:
2340                 /* ?? */
2341                 return NULL;
2342         }
2343
2344 }
2345
2346 /**
2347  * pevent_filter_make_string - return a string showing the filter
2348  * @filter: filter struct with filter information
2349  * @event_id: the event id to return the filter string with
2350  *
2351  * Returns a string that displays the filter contents.
2352  *  This string must be freed with free(str).
2353  *  NULL is returned if no filter is found or allocation failed.
2354  */
2355 char *
2356 pevent_filter_make_string(struct event_filter *filter, int event_id)
2357 {
2358         struct filter_type *filter_type;
2359
2360         if (!filter->filters)
2361                 return NULL;
2362
2363         filter_type = find_filter_type(filter, event_id);
2364
2365         if (!filter_type)
2366                 return NULL;
2367
2368         return arg_to_str(filter, filter_type->filter);
2369 }
2370
2371 /**
2372  * pevent_filter_compare - compare two filters and return if they are the same
2373  * @filter1: Filter to compare with @filter2
2374  * @filter2: Filter to compare with @filter1
2375  *
2376  * Returns:
2377  *  1 if the two filters hold the same content.
2378  *  0 if they do not.
2379  */
2380 int pevent_filter_compare(struct event_filter *filter1, struct event_filter *filter2)
2381 {
2382         struct filter_type *filter_type1;
2383         struct filter_type *filter_type2;
2384         char *str1, *str2;
2385         int result;
2386         int i;
2387
2388         /* Do the easy checks first */
2389         if (filter1->filters != filter2->filters)
2390                 return 0;
2391         if (!filter1->filters && !filter2->filters)
2392                 return 1;
2393
2394         /*
2395          * Now take a look at each of the events to see if they have the same
2396          * filters to them.
2397          */
2398         for (i = 0; i < filter1->filters; i++) {
2399                 filter_type1 = &filter1->event_filters[i];
2400                 filter_type2 = find_filter_type(filter2, filter_type1->event_id);
2401                 if (!filter_type2)
2402                         break;
2403                 if (filter_type1->filter->type != filter_type2->filter->type)
2404                         break;
2405                 switch (filter_type1->filter->type) {
2406                 case FILTER_TRIVIAL_FALSE:
2407                 case FILTER_TRIVIAL_TRUE:
2408                         /* trivial types just need the type compared */
2409                         continue;
2410                 default:
2411                         break;
2412                 }
2413                 /* The best way to compare complex filters is with strings */
2414                 str1 = arg_to_str(filter1, filter_type1->filter);
2415                 str2 = arg_to_str(filter2, filter_type2->filter);
2416                 if (str1 && str2)
2417                         result = strcmp(str1, str2) != 0;
2418                 else
2419                         /* bail out if allocation fails */
2420                         result = 1;
2421
2422                 free(str1);
2423                 free(str2);
2424                 if (result)
2425                         break;
2426         }
2427
2428         if (i < filter1->filters)
2429                 return 0;
2430         return 1;
2431 }
2432