tools/lib/traceevent/parse-filter.c

   1 /*
   2  * Copyright (C) 2010 Red Hat Inc, Steven Rostedt <[email protected]>
   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 #define CPU "CPU"
  32
  33 static struct format_field comm = {
  34         .name = "COMM",
  35 };
  36
  37 static struct format_field cpu = {
  38         .name = "CPU",
  39 };
  40
  41 struct event_list {
  42         struct event_list       *next;
  43         struct event_format     *event;
  44 };
  45
  46 static void show_error(char *error_buf, const char *fmt, ...)
  47 {
  48         unsigned long long index;
  49         const char *input;
  50         va_list ap;
  51         int len;
  52         int i;
  53
  54         input = pevent_get_input_buf();
  55         index = pevent_get_input_buf_ptr();
  56         len = input ? strlen(input) : 0;
  57
  58         if (len) {
  59                 strcpy(error_buf, input);
  60                 error_buf[len] = '\n';
  61                 for (i = 1; i < len && i < index; i++)
  62                         error_buf[len+i] = ' ';
  63                 error_buf[len + i] = '^';
  64                 error_buf[len + i + 1] = '\n';
  65                 len += i+2;
  66         }
  67
  68         va_start(ap, fmt);
  69         vsnprintf(error_buf + len, PEVENT_FILTER_ERROR_BUFSZ - len, fmt, ap);
  70         va_end(ap);
  71 }
  72
  73 static void free_token(char *token)
  74 {
  75         pevent_free_token(token);
  76 }
  77
  78 static enum event_type read_token(char **tok)
  79 {
  80         enum event_type type;
  81         char *token = NULL;
  82
  83         do {
  84                 free_token(token);
  85                 type = pevent_read_token(&token);
  86         } while (type == EVENT_NEWLINE || type == EVENT_SPACE);
  87
  88         /* If token is = or ! check to see if the next char is ~ */
  89         if (token &&
  90             (strcmp(token, "=") == 0 || strcmp(token, "!") == 0) &&
  91             pevent_peek_char() == '~') {
  92                 /* append it */
  93                 *tok = malloc(3);
  94                 if (*tok == NULL) {
  95                         free_token(token);
  96                         return EVENT_ERROR;
  97                 }
  98                 sprintf(*tok, "%c%c", *token, '~');
  99                 free_token(token);
 100                 /* Now remove the '~' from the buffer */
 101                 pevent_read_token(&token);
 102                 free_token(token);
 103         } else
 104                 *tok = token;
 105
 106         return type;
 107 }
 108
 109 static int filter_cmp(const void *a, const void *b)
 110 {
 111         const struct filter_type *ea = a;
 112         const struct filter_type *eb = b;
 113
 114         if (ea->event_id < eb->event_id)
 115                 return -1;
 116
 117         if (ea->event_id > eb->event_id)
 118                 return 1;
 119
 120         return 0;
 121 }
 122
 123 static struct filter_type *
 124 find_filter_type(struct event_filter *filter, int id)
 125 {
 126         struct filter_type *filter_type;
 127         struct filter_type key;
 128
 129         key.event_id = id;
 130
 131         filter_type = bsearch(&key, filter->event_filters,
 132                               filter->filters,
 133                               sizeof(*filter->event_filters),
 134                               filter_cmp);
 135
 136         return filter_type;
 137 }
 138
 139 static struct filter_type *
 140 add_filter_type(struct event_filter *filter, int id)
 141 {
 142         struct filter_type *filter_type;
 143         int i;
 144
 145         filter_type = find_filter_type(filter, id);
 146         if (filter_type)
 147                 return filter_type;
 148
 149         filter_type = realloc(filter->event_filters,
 150                               sizeof(*filter->event_filters) *
 151                               (filter->filters + 1));
 152         if (!filter_type)
 153                 return NULL;
 154
 155         filter->event_filters = filter_type;
 156
 157         for (i = 0; i < filter->filters; i++) {
 158                 if (filter->event_filters[i].event_id > id)
 159                         break;
 160         }
 161
 162         if (i < filter->filters)
 163                 memmove(&filter->event_filters[i+1],
 164                         &filter->event_filters[i],
 165                         sizeof(*filter->event_filters) *
 166                         (filter->filters - i));
 167
 168         filter_type = &filter->event_filters[i];
 169         filter_type->event_id = id;
 170         filter_type->event = pevent_find_event(filter->pevent, id);
 171         filter_type->filter = NULL;
 172
 173         filter->filters++;
 174
 175         return filter_type;
 176 }
 177
 178 /**
 179  * pevent_filter_alloc - create a new event filter
 180  * @pevent: The pevent that this filter is associated with
 181  */
 182 struct event_filter *pevent_filter_alloc(struct pevent *pevent)
 183 {
 184         struct event_filter *filter;
 185
 186         filter = malloc(sizeof(*filter));
 187         if (filter == NULL)
 188                 return NULL;
 189
 190         memset(filter, 0, sizeof(*filter));
 191         filter->pevent = pevent;
 192         pevent_ref(pevent);
 193
 194         return filter;
 195 }
 196
 197 static struct filter_arg *allocate_arg(void)
 198 {
 199         return calloc(1, sizeof(struct filter_arg));
 200 }
 201
 202 static void free_arg(struct filter_arg *arg)
 203 {
 204         if (!arg)
 205                 return;
 206
 207         switch (arg->type) {
 208         case FILTER_ARG_NONE:
 209         case FILTER_ARG_BOOLEAN:
 210                 break;
 211
 212         case FILTER_ARG_NUM:
 213                 free_arg(arg->num.left);
 214                 free_arg(arg->num.right);
 215                 break;
 216
 217         case FILTER_ARG_EXP:
 218                 free_arg(arg->exp.left);
 219                 free_arg(arg->exp.right);
 220                 break;
 221
 222         case FILTER_ARG_STR:
 223                 free(arg->str.val);
 224                 regfree(&arg->str.reg);
 225                 free(arg->str.buffer);
 226                 break;
 227
 228         case FILTER_ARG_VALUE:
 229                 if (arg->value.type == FILTER_STRING ||
 230                     arg->value.type == FILTER_CHAR)
 231                         free(arg->value.str);
 232                 break;
 233
 234         case FILTER_ARG_OP:
 235                 free_arg(arg->op.left);
 236                 free_arg(arg->op.right);
 237         default:
 238                 break;
 239         }
 240
 241         free(arg);
 242 }
 243
 244 static int add_event(struct event_list **events,
 245                       struct event_format *event)
 246 {
 247         struct event_list *list;
 248
 249         list = malloc(sizeof(*list));
 250         if (list == NULL)
 251                 return -1;
 252
 253         list->next = *events;
 254         *events = list;
 255         list->event = event;
 256         return 0;
 257 }
 258
 259 static int event_match(struct event_format *event,
 260                        regex_t *sreg, regex_t *ereg)
 261 {
 262         if (sreg) {
 263                 return !regexec(sreg, event->system, 0, NULL, 0) &&
 264                         !regexec(ereg, event->name, 0, NULL, 0);
 265         }
 266
 267         return !regexec(ereg, event->system, 0, NULL, 0) ||
 268                 !regexec(ereg, event->name, 0, NULL, 0);
 269 }
 270
 271 static enum pevent_errno
 272 find_event(struct pevent *pevent, struct event_list **events,
 273            char *sys_name, char *event_name)
 274 {
 275         struct event_format *event;
 276         regex_t ereg;
 277         regex_t sreg;
 278         int match = 0;
 279         int fail = 0;
 280         char *reg;
 281         int ret;
 282         int i;
 283
 284         if (!event_name) {
 285                 /* if no name is given, then swap sys and name */
 286                 event_name = sys_name;
 287                 sys_name = NULL;
 288         }
 289
 290         reg = malloc(strlen(event_name) + 3);
 291         if (reg == NULL)
 292                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 293
 294         sprintf(reg, "^%s$", event_name);
 295
 296         ret = regcomp(&ereg, reg, REG_ICASE|REG_NOSUB);
 297         free(reg);
 298
 299         if (ret)
 300                 return PEVENT_ERRNO__INVALID_EVENT_NAME;
 301
 302         if (sys_name) {
 303                 reg = malloc(strlen(sys_name) + 3);
 304                 if (reg == NULL) {
 305                         regfree(&ereg);
 306                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 307                 }
 308
 309                 sprintf(reg, "^%s$", sys_name);
 310                 ret = regcomp(&sreg, reg, REG_ICASE|REG_NOSUB);
 311                 free(reg);
 312                 if (ret) {
 313                         regfree(&ereg);
 314                         return PEVENT_ERRNO__INVALID_EVENT_NAME;
 315                 }
 316         }
 317
 318         for (i = 0; i < pevent->nr_events; i++) {
 319                 event = pevent->events[i];
 320                 if (event_match(event, sys_name ? &sreg : NULL, &ereg)) {
 321                         match = 1;
 322                         if (add_event(events, event) < 0) {
 323                                 fail = 1;
 324                                 break;
 325                         }
 326                 }
 327         }
 328
 329         regfree(&ereg);
 330         if (sys_name)
 331                 regfree(&sreg);
 332
 333         if (!match)
 334                 return PEVENT_ERRNO__EVENT_NOT_FOUND;
 335         if (fail)
 336                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 337
 338         return 0;
 339 }
 340
 341 static void free_events(struct event_list *events)
 342 {
 343         struct event_list *event;
 344
 345         while (events) {
 346                 event = events;
 347                 events = events->next;
 348                 free(event);
 349         }
 350 }
 351
 352 static enum pevent_errno
 353 create_arg_item(struct event_format *event, const char *token,
 354                 enum event_type type, struct filter_arg **parg, char *error_str)
 355 {
 356         struct format_field *field;
 357         struct filter_arg *arg;
 358
 359         arg = allocate_arg();
 360         if (arg == NULL) {
 361                 show_error(error_str, "failed to allocate filter arg");
 362                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 363         }
 364
 365         switch (type) {
 366
 367         case EVENT_SQUOTE:
 368         case EVENT_DQUOTE:
 369                 arg->type = FILTER_ARG_VALUE;
 370                 arg->value.type =
 371                         type == EVENT_DQUOTE ? FILTER_STRING : FILTER_CHAR;
 372                 arg->value.str = strdup(token);
 373                 if (!arg->value.str) {
 374                         free_arg(arg);
 375                         show_error(error_str, "failed to allocate string filter arg");
 376                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 377                 }
 378                 break;
 379         case EVENT_ITEM:
 380                 /* if it is a number, then convert it */
 381                 if (isdigit(token[0])) {
 382                         arg->type = FILTER_ARG_VALUE;
 383                         arg->value.type = FILTER_NUMBER;
 384                         arg->value.val = strtoull(token, NULL, 0);
 385                         break;
 386                 }
 387                 /* Consider this a field */
 388                 field = pevent_find_any_field(event, token);
 389                 if (!field) {
 390                         /* If token is 'COMM' or 'CPU' then it is special */
 391                         if (strcmp(token, COMM) == 0) {
 392                                 field = &comm;
 393                         } else if (strcmp(token, CPU) == 0) {
 394                                 field = &cpu;
 395                         } else {
 396                                 /* not a field, Make it false */
 397                                 arg->type = FILTER_ARG_BOOLEAN;
 398                                 arg->boolean.value = FILTER_FALSE;
 399                                 break;
 400                         }
 401                 }
 402                 arg->type = FILTER_ARG_FIELD;
 403                 arg->field.field = field;
 404                 break;
 405         default:
 406                 free_arg(arg);
 407                 show_error(error_str, "expected a value but found %s", token);
 408                 return PEVENT_ERRNO__UNEXPECTED_TYPE;
 409         }
 410         *parg = arg;
 411         return 0;
 412 }
 413
 414 static struct filter_arg *
 415 create_arg_op(enum filter_op_type btype)
 416 {
 417         struct filter_arg *arg;
 418
 419         arg = allocate_arg();
 420         if (!arg)
 421                 return NULL;
 422
 423         arg->type = FILTER_ARG_OP;
 424         arg->op.type = btype;
 425
 426         return arg;
 427 }
 428
 429 static struct filter_arg *
 430 create_arg_exp(enum filter_exp_type etype)
 431 {
 432         struct filter_arg *arg;
 433
 434         arg = allocate_arg();
 435         if (!arg)
 436                 return NULL;
 437
 438         arg->type = FILTER_ARG_EXP;
 439         arg->op.type = etype;
 440
 441         return arg;
 442 }
 443
 444 static struct filter_arg *
 445 create_arg_cmp(enum filter_exp_type etype)
 446 {
 447         struct filter_arg *arg;
 448
 449         arg = allocate_arg();
 450         if (!arg)
 451                 return NULL;
 452
 453         /* Use NUM and change if necessary */
 454         arg->type = FILTER_ARG_NUM;
 455         arg->op.type = etype;
 456
 457         return arg;
 458 }
 459
 460 static enum pevent_errno
 461 add_right(struct filter_arg *op, struct filter_arg *arg, char *error_str)
 462 {
 463         struct filter_arg *left;
 464         char *str;
 465         int op_type;
 466         int ret;
 467
 468         switch (op->type) {
 469         case FILTER_ARG_EXP:
 470                 if (op->exp.right)
 471                         goto out_fail;
 472                 op->exp.right = arg;
 473                 break;
 474
 475         case FILTER_ARG_OP:
 476                 if (op->op.right)
 477                         goto out_fail;
 478                 op->op.right = arg;
 479                 break;
 480
 481         case FILTER_ARG_NUM:
 482                 if (op->op.right)
 483                         goto out_fail;
 484                 /*
 485                  * The arg must be num, str, or field
 486                  */
 487                 switch (arg->type) {
 488                 case FILTER_ARG_VALUE:
 489                 case FILTER_ARG_FIELD:
 490                         break;
 491                 default:
 492                         show_error(error_str, "Illegal rvalue");
 493                         return PEVENT_ERRNO__ILLEGAL_RVALUE;
 494                 }
 495
 496                 /*
 497                  * Depending on the type, we may need to
 498                  * convert this to a string or regex.
 499                  */
 500                 switch (arg->value.type) {
 501                 case FILTER_CHAR:
 502                         /*
 503                          * A char should be converted to number if
 504                          * the string is 1 byte, and the compare
 505                          * is not a REGEX.
 506                          */
 507                         if (strlen(arg->value.str) == 1 &&
 508                             op->num.type != FILTER_CMP_REGEX &&
 509                             op->num.type != FILTER_CMP_NOT_REGEX) {
 510                                 arg->value.type = FILTER_NUMBER;
 511                                 goto do_int;
 512                         }
 513                         /* fall through */
 514                 case FILTER_STRING:
 515
 516                         /* convert op to a string arg */
 517                         op_type = op->num.type;
 518                         left = op->num.left;
 519                         str = arg->value.str;
 520
 521                         /* reset the op for the new field */
 522                         memset(op, 0, sizeof(*op));
 523
 524                         /*
 525                          * If left arg was a field not found then
 526                          * NULL the entire op.
 527                          */
 528                         if (left->type == FILTER_ARG_BOOLEAN) {
 529                                 free_arg(left);
 530                                 free_arg(arg);
 531                                 op->type = FILTER_ARG_BOOLEAN;
 532                                 op->boolean.value = FILTER_FALSE;
 533                                 break;
 534                         }
 535
 536                         /* Left arg must be a field */
 537                         if (left->type != FILTER_ARG_FIELD) {
 538                                 show_error(error_str,
 539                                            "Illegal lvalue for string comparison");
 540                                 return PEVENT_ERRNO__ILLEGAL_LVALUE;
 541                         }
 542
 543                         /* Make sure this is a valid string compare */
 544                         switch (op_type) {
 545                         case FILTER_CMP_EQ:
 546                                 op_type = FILTER_CMP_MATCH;
 547                                 break;
 548                         case FILTER_CMP_NE:
 549                                 op_type = FILTER_CMP_NOT_MATCH;
 550                                 break;
 551
 552                         case FILTER_CMP_REGEX:
 553                         case FILTER_CMP_NOT_REGEX:
 554                                 ret = regcomp(&op->str.reg, str, REG_ICASE|REG_NOSUB);
 555                                 if (ret) {
 556                                         show_error(error_str,
 557                                                    "RegEx '%s' did not compute",
 558                                                    str);
 559                                         return PEVENT_ERRNO__INVALID_REGEX;
 560                                 }
 561                                 break;
 562                         default:
 563                                 show_error(error_str,
 564                                            "Illegal comparison for string");
 565                                 return PEVENT_ERRNO__ILLEGAL_STRING_CMP;
 566                         }
 567
 568                         op->type = FILTER_ARG_STR;
 569                         op->str.type = op_type;
 570                         op->str.field = left->field.field;
 571                         op->str.val = strdup(str);
 572                         if (!op->str.val) {
 573                                 show_error(error_str, "Failed to allocate string filter");
 574                                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 575                         }
 576                         /*
 577                          * Need a buffer to copy data for tests
 578                          */
 579                         op->str.buffer = malloc(op->str.field->size + 1);
 580                         if (!op->str.buffer) {
 581                                 show_error(error_str, "Failed to allocate string filter");
 582                                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
 583                         }
 584                         /* Null terminate this buffer */
 585                         op->str.buffer[op->str.field->size] = 0;
 586
 587                         /* We no longer have left or right args */
 588                         free_arg(arg);
 589                         free_arg(left);
 590
 591                         break;
 592
 593                 case FILTER_NUMBER:
 594
 595  do_int:
 596                         switch (op->num.type) {
 597                         case FILTER_CMP_REGEX:
 598                         case FILTER_CMP_NOT_REGEX:
 599                                 show_error(error_str,
 600                                            "Op not allowed with integers");
 601                                 return PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
 602
 603                         default:
 604                                 break;
 605                         }
 606
 607                         /* numeric compare */
 608                         op->num.right = arg;
 609                         break;
 610                 default:
 611                         goto out_fail;
 612                 }
 613                 break;
 614         default:
 615                 goto out_fail;
 616         }
 617
 618         return 0;
 619
 620  out_fail:
 621         show_error(error_str, "Syntax error");
 622         return PEVENT_ERRNO__SYNTAX_ERROR;
 623 }
 624
 625 static struct filter_arg *
 626 rotate_op_right(struct filter_arg *a, struct filter_arg *b)
 627 {
 628         struct filter_arg *arg;
 629
 630         arg = a->op.right;
 631         a->op.right = b;
 632         return arg;
 633 }
 634
 635 static enum pevent_errno add_left(struct filter_arg *op, struct filter_arg *arg)
 636 {
 637         switch (op->type) {
 638         case FILTER_ARG_EXP:
 639                 if (arg->type == FILTER_ARG_OP)
 640                         arg = rotate_op_right(arg, op);
 641                 op->exp.left = arg;
 642                 break;
 643
 644         case FILTER_ARG_OP:
 645                 op->op.left = arg;
 646                 break;
 647         case FILTER_ARG_NUM:
 648                 if (arg->type == FILTER_ARG_OP)
 649                         arg = rotate_op_right(arg, op);
 650
 651                 /* left arg of compares must be a field */
 652                 if (arg->type != FILTER_ARG_FIELD &&
 653                     arg->type != FILTER_ARG_BOOLEAN)
 654                         return PEVENT_ERRNO__INVALID_ARG_TYPE;
 655                 op->num.left = arg;
 656                 break;
 657         default:
 658                 return PEVENT_ERRNO__INVALID_ARG_TYPE;
 659         }
 660         return 0;
 661 }
 662
 663 enum op_type {
 664         OP_NONE,
 665         OP_BOOL,
 666         OP_NOT,
 667         OP_EXP,
 668         OP_CMP,
 669 };
 670
 671 static enum op_type process_op(const char *token,
 672                                enum filter_op_type *btype,
 673                                enum filter_cmp_type *ctype,
 674                                enum filter_exp_type *etype)
 675 {
 676         *btype = FILTER_OP_NOT;
 677         *etype = FILTER_EXP_NONE;
 678         *ctype = FILTER_CMP_NONE;
 679
 680         if (strcmp(token, "&&") == 0)
 681                 *btype = FILTER_OP_AND;
 682         else if (strcmp(token, "||") == 0)
 683                 *btype = FILTER_OP_OR;
 684         else if (strcmp(token, "!") == 0)
 685                 return OP_NOT;
 686
 687         if (*btype != FILTER_OP_NOT)
 688                 return OP_BOOL;
 689
 690         /* Check for value expressions */
 691         if (strcmp(token, "+") == 0) {
 692                 *etype = FILTER_EXP_ADD;
 693         } else if (strcmp(token, "-") == 0) {
 694                 *etype = FILTER_EXP_SUB;
 695         } else if (strcmp(token, "*") == 0) {
 696                 *etype = FILTER_EXP_MUL;
 697         } else if (strcmp(token, "/") == 0) {
 698                 *etype = FILTER_EXP_DIV;
 699         } else if (strcmp(token, "%") == 0) {
 700                 *etype = FILTER_EXP_MOD;
 701         } else if (strcmp(token, ">>") == 0) {
 702                 *etype = FILTER_EXP_RSHIFT;
 703         } else if (strcmp(token, "<<") == 0) {
 704                 *etype = FILTER_EXP_LSHIFT;
 705         } else if (strcmp(token, "&") == 0) {
 706                 *etype = FILTER_EXP_AND;
 707         } else if (strcmp(token, "|") == 0) {
 708                 *etype = FILTER_EXP_OR;
 709         } else if (strcmp(token, "^") == 0) {
 710                 *etype = FILTER_EXP_XOR;
 711         } else if (strcmp(token, "~") == 0)
 712                 *etype = FILTER_EXP_NOT;
 713
 714         if (*etype != FILTER_EXP_NONE)
 715                 return OP_EXP;
 716
 717         /* Check for compares */
 718         if (strcmp(token, "==") == 0)
 719                 *ctype = FILTER_CMP_EQ;
 720         else if (strcmp(token, "!=") == 0)
 721                 *ctype = FILTER_CMP_NE;
 722         else if (strcmp(token, "<") == 0)
 723                 *ctype = FILTER_CMP_LT;
 724         else if (strcmp(token, ">") == 0)
 725                 *ctype = FILTER_CMP_GT;
 726         else if (strcmp(token, "<=") == 0)
 727                 *ctype = FILTER_CMP_LE;
 728         else if (strcmp(token, ">=") == 0)
 729                 *ctype = FILTER_CMP_GE;
 730         else if (strcmp(token, "=~") == 0)
 731                 *ctype = FILTER_CMP_REGEX;
 732         else if (strcmp(token, "!~") == 0)
 733                 *ctype = FILTER_CMP_NOT_REGEX;
 734         else
 735                 return OP_NONE;
 736
 737         return OP_CMP;
 738 }
 739
 740 static int check_op_done(struct filter_arg *arg)
 741 {
 742         switch (arg->type) {
 743         case FILTER_ARG_EXP:
 744                 return arg->exp.right != NULL;
 745
 746         case FILTER_ARG_OP:
 747                 return arg->op.right != NULL;
 748
 749         case FILTER_ARG_NUM:
 750                 return arg->num.right != NULL;
 751
 752         case FILTER_ARG_STR:
 753                 /* A string conversion is always done */
 754                 return 1;
 755
 756         case FILTER_ARG_BOOLEAN:
 757                 /* field not found, is ok */
 758                 return 1;
 759
 760         default:
 761                 return 0;
 762         }
 763 }
 764
 765 enum filter_vals {
 766         FILTER_VAL_NORM,
 767         FILTER_VAL_FALSE,
 768         FILTER_VAL_TRUE,
 769 };
 770
 771 static enum pevent_errno
 772 reparent_op_arg(struct filter_arg *parent, struct filter_arg *old_child,
 773                 struct filter_arg *arg, char *error_str)
 774 {
 775         struct filter_arg *other_child;
 776         struct filter_arg **ptr;
 777
 778         if (parent->type != FILTER_ARG_OP &&
 779             arg->type != FILTER_ARG_OP) {
 780                 show_error(error_str, "can not reparent other than OP");
 781                 return PEVENT_ERRNO__REPARENT_NOT_OP;
 782         }
 783
 784         /* Get the sibling */
 785         if (old_child->op.right == arg) {
 786                 ptr = &old_child->op.right;
 787                 other_child = old_child->op.left;
 788         } else if (old_child->op.left == arg) {
 789                 ptr = &old_child->op.left;
 790                 other_child = old_child->op.right;
 791         } else {
 792                 show_error(error_str, "Error in reparent op, find other child");
 793                 return PEVENT_ERRNO__REPARENT_FAILED;
 794         }
 795
 796         /* Detach arg from old_child */
 797         *ptr = NULL;
 798
 799         /* Check for root */
 800         if (parent == old_child) {
 801                 free_arg(other_child);
 802                 *parent = *arg;
 803                 /* Free arg without recussion */
 804                 free(arg);
 805                 return 0;
 806         }
 807
 808         if (parent->op.right == old_child)
 809                 ptr = &parent->op.right;
 810         else if (parent->op.left == old_child)
 811                 ptr = &parent->op.left;
 812         else {
 813                 show_error(error_str, "Error in reparent op");
 814                 return PEVENT_ERRNO__REPARENT_FAILED;
 815         }
 816
 817         *ptr = arg;
 818
 819         free_arg(old_child);
 820         return 0;
 821 }
 822
 823 /* Returns either filter_vals (success) or pevent_errno (failfure) */
 824 static int test_arg(struct filter_arg *parent, struct filter_arg *arg,
 825                     char *error_str)
 826 {
 827         int lval, rval;
 828
 829         switch (arg->type) {
 830
 831                 /* bad case */
 832         case FILTER_ARG_BOOLEAN:
 833                 return FILTER_VAL_FALSE + arg->boolean.value;
 834
 835                 /* good cases: */
 836         case FILTER_ARG_STR:
 837         case FILTER_ARG_VALUE:
 838         case FILTER_ARG_FIELD:
 839                 return FILTER_VAL_NORM;
 840
 841         case FILTER_ARG_EXP:
 842                 lval = test_arg(arg, arg->exp.left, error_str);
 843                 if (lval != FILTER_VAL_NORM)
 844                         return lval;
 845                 rval = test_arg(arg, arg->exp.right, error_str);
 846                 if (rval != FILTER_VAL_NORM)
 847                         return rval;
 848                 return FILTER_VAL_NORM;
 849
 850         case FILTER_ARG_NUM:
 851                 lval = test_arg(arg, arg->num.left, error_str);
 852                 if (lval != FILTER_VAL_NORM)
 853                         return lval;
 854                 rval = test_arg(arg, arg->num.right, error_str);
 855                 if (rval != FILTER_VAL_NORM)
 856                         return rval;
 857                 return FILTER_VAL_NORM;
 858
 859         case FILTER_ARG_OP:
 860                 if (arg->op.type != FILTER_OP_NOT) {
 861                         lval = test_arg(arg, arg->op.left, error_str);
 862                         switch (lval) {
 863                         case FILTER_VAL_NORM:
 864                                 break;
 865                         case FILTER_VAL_TRUE:
 866                                 if (arg->op.type == FILTER_OP_OR)
 867                                         return FILTER_VAL_TRUE;
 868                                 rval = test_arg(arg, arg->op.right, error_str);
 869                                 if (rval != FILTER_VAL_NORM)
 870                                         return rval;
 871
 872                                 return reparent_op_arg(parent, arg, arg->op.right,
 873                                                        error_str);
 874
 875                         case FILTER_VAL_FALSE:
 876                                 if (arg->op.type == FILTER_OP_AND)
 877                                         return FILTER_VAL_FALSE;
 878                                 rval = test_arg(arg, arg->op.right, error_str);
 879                                 if (rval != FILTER_VAL_NORM)
 880                                         return rval;
 881
 882                                 return reparent_op_arg(parent, arg, arg->op.right,
 883                                                        error_str);
 884
 885                         default:
 886                                 return lval;
 887                         }
 888                 }
 889
 890                 rval = test_arg(arg, arg->op.right, error_str);
 891                 switch (rval) {
 892                 case FILTER_VAL_NORM:
 893                 default:
 894                         break;
 895
 896                 case FILTER_VAL_TRUE:
 897                         if (arg->op.type == FILTER_OP_OR)
 898                                 return FILTER_VAL_TRUE;
 899                         if (arg->op.type == FILTER_OP_NOT)
 900                                 return FILTER_VAL_FALSE;
 901
 902                         return reparent_op_arg(parent, arg, arg->op.left,
 903                                                error_str);
 904
 905                 case FILTER_VAL_FALSE:
 906                         if (arg->op.type == FILTER_OP_AND)
 907                                 return FILTER_VAL_FALSE;
 908                         if (arg->op.type == FILTER_OP_NOT)
 909                                 return FILTER_VAL_TRUE;
 910
 911                         return reparent_op_arg(parent, arg, arg->op.left,
 912                                                error_str);
 913                 }
 914
 915                 return rval;
 916         default:
 917                 show_error(error_str, "bad arg in filter tree");
 918                 return PEVENT_ERRNO__BAD_FILTER_ARG;
 919         }
 920         return FILTER_VAL_NORM;
 921 }
 922
 923 /* Remove any unknown event fields */
 924 static int collapse_tree(struct filter_arg *arg,
 925                          struct filter_arg **arg_collapsed, char *error_str)
 926 {
 927         int ret;
 928
 929         ret = test_arg(arg, arg, error_str);
 930         switch (ret) {
 931         case FILTER_VAL_NORM:
 932                 break;
 933
 934         case FILTER_VAL_TRUE:
 935         case FILTER_VAL_FALSE:
 936                 free_arg(arg);
 937                 arg = allocate_arg();
 938                 if (arg) {
 939                         arg->type = FILTER_ARG_BOOLEAN;
 940                         arg->boolean.value = ret == FILTER_VAL_TRUE;
 941                 } else {
 942                         show_error(error_str, "Failed to allocate filter arg");
 943                         ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
 944                 }
 945                 break;
 946
 947         default:
 948                 /* test_arg() already set the error_str */
 949                 free_arg(arg);
 950                 arg = NULL;
 951                 break;
 952         }
 953
 954         *arg_collapsed = arg;
 955         return ret;
 956 }
 957
 958 static enum pevent_errno
 959 process_filter(struct event_format *event, struct filter_arg **parg,
 960                char *error_str, int not)
 961 {
 962         enum event_type type;
 963         char *token = NULL;
 964         struct filter_arg *current_op = NULL;
 965         struct filter_arg *current_exp = NULL;
 966         struct filter_arg *left_item = NULL;
 967         struct filter_arg *arg = NULL;
 968         enum op_type op_type;
 969         enum filter_op_type btype;
 970         enum filter_exp_type etype;
 971         enum filter_cmp_type ctype;
 972         enum pevent_errno ret;
 973
 974         *parg = NULL;
 975
 976         do {
 977                 free(token);
 978                 type = read_token(&token);
 979                 switch (type) {
 980                 case EVENT_SQUOTE:
 981                 case EVENT_DQUOTE:
 982                 case EVENT_ITEM:
 983                         ret = create_arg_item(event, token, type, &arg, error_str);
 984                         if (ret < 0)
 985                                 goto fail;
 986                         if (!left_item)
 987                                 left_item = arg;
 988                         else if (current_exp) {
 989                                 ret = add_right(current_exp, arg, error_str);
 990                                 if (ret < 0)
 991                                         goto fail;
 992                                 left_item = NULL;
 993                                 /* Not's only one one expression */
 994                                 if (not) {
 995                                         arg = NULL;
 996                                         if (current_op)
 997                                                 goto fail_syntax;
 998                                         free(token);
 999                                         *parg = current_exp;
1000                                         return 0;
1001                                 }
1002                         } else
1003                                 goto fail_syntax;
1004                         arg = NULL;
1005                         break;
1006
1007                 case EVENT_DELIM:
1008                         if (*token == ',') {
1009                                 show_error(error_str, "Illegal token ','");
1010                                 ret = PEVENT_ERRNO__ILLEGAL_TOKEN;
1011                                 goto fail;
1012                         }
1013
1014                         if (*token == '(') {
1015                                 if (left_item) {
1016                                         show_error(error_str,
1017                                                    "Open paren can not come after item");
1018                                         ret = PEVENT_ERRNO__INVALID_PAREN;
1019                                         goto fail;
1020                                 }
1021                                 if (current_exp) {
1022                                         show_error(error_str,
1023                                                    "Open paren can not come after expression");
1024                                         ret = PEVENT_ERRNO__INVALID_PAREN;
1025                                         goto fail;
1026                                 }
1027
1028                                 ret = process_filter(event, &arg, error_str, 0);
1029                                 if (ret != PEVENT_ERRNO__UNBALANCED_PAREN) {
1030                                         if (ret == 0) {
1031                                                 show_error(error_str,
1032                                                            "Unbalanced number of '('");
1033                                                 ret = PEVENT_ERRNO__UNBALANCED_PAREN;
1034                                         }
1035                                         goto fail;
1036                                 }
1037                                 ret = 0;
1038
1039                                 /* A not wants just one expression */
1040                                 if (not) {
1041                                         if (current_op)
1042                                                 goto fail_syntax;
1043                                         *parg = arg;
1044                                         return 0;
1045                                 }
1046
1047                                 if (current_op)
1048                                         ret = add_right(current_op, arg, error_str);
1049                                 else
1050                                         current_exp = arg;
1051
1052                                 if (ret < 0)
1053                                         goto fail;
1054
1055                         } else { /* ')' */
1056                                 if (!current_op && !current_exp)
1057                                         goto fail_syntax;
1058
1059                                 /* Make sure everything is finished at this level */
1060                                 if (current_exp && !check_op_done(current_exp))
1061                                         goto fail_syntax;
1062                                 if (current_op && !check_op_done(current_op))
1063                                         goto fail_syntax;
1064
1065                                 if (current_op)
1066                                         *parg = current_op;
1067                                 else
1068                                         *parg = current_exp;
1069                                 free(token);
1070                                 return PEVENT_ERRNO__UNBALANCED_PAREN;
1071                         }
1072                         break;
1073
1074                 case EVENT_OP:
1075                         op_type = process_op(token, &btype, &ctype, &etype);
1076
1077                         /* All expect a left arg except for NOT */
1078                         switch (op_type) {
1079                         case OP_BOOL:
1080                                 /* Logic ops need a left expression */
1081                                 if (!current_exp && !current_op)
1082                                         goto fail_syntax;
1083                                 /* fall through */
1084                         case OP_NOT:
1085                                 /* logic only processes ops and exp */
1086                                 if (left_item)
1087                                         goto fail_syntax;
1088                                 break;
1089                         case OP_EXP:
1090                         case OP_CMP:
1091                                 if (!left_item)
1092                                         goto fail_syntax;
1093                                 break;
1094                         case OP_NONE:
1095                                 show_error(error_str,
1096                                            "Unknown op token %s", token);
1097                                 ret = PEVENT_ERRNO__UNKNOWN_TOKEN;
1098                                 goto fail;
1099                         }
1100
1101                         ret = 0;
1102                         switch (op_type) {
1103                         case OP_BOOL:
1104                                 arg = create_arg_op(btype);
1105                                 if (arg == NULL)
1106                                         goto fail_alloc;
1107                                 if (current_op)
1108                                         ret = add_left(arg, current_op);
1109                                 else
1110                                         ret = add_left(arg, current_exp);
1111                                 current_op = arg;
1112                                 current_exp = NULL;
1113                                 break;
1114
1115                         case OP_NOT:
1116                                 arg = create_arg_op(btype);
1117                                 if (arg == NULL)
1118                                         goto fail_alloc;
1119                                 if (current_op)
1120                                         ret = add_right(current_op, arg, error_str);
1121                                 if (ret < 0)
1122                                         goto fail;
1123                                 current_exp = arg;
1124                                 ret = process_filter(event, &arg, error_str, 1);
1125                                 if (ret < 0)
1126                                         goto fail;
1127                                 ret = add_right(current_exp, arg, error_str);
1128                                 if (ret < 0)
1129                                         goto fail;
1130                                 break;
1131
1132                         case OP_EXP:
1133                         case OP_CMP:
1134                                 if (op_type == OP_EXP)
1135                                         arg = create_arg_exp(etype);
1136                                 else
1137                                         arg = create_arg_cmp(ctype);
1138                                 if (arg == NULL)
1139                                         goto fail_alloc;
1140
1141                                 if (current_op)
1142                                         ret = add_right(current_op, arg, error_str);
1143                                 if (ret < 0)
1144                                         goto fail;
1145                                 ret = add_left(arg, left_item);
1146                                 if (ret < 0) {
1147                                         arg = NULL;
1148                                         goto fail_syntax;
1149                                 }
1150                                 current_exp = arg;
1151                                 break;
1152                         default:
1153                                 break;
1154                         }
1155                         arg = NULL;
1156                         if (ret < 0)
1157                                 goto fail_syntax;
1158                         break;
1159                 case EVENT_NONE:
1160                         break;
1161                 case EVENT_ERROR:
1162                         goto fail_alloc;
1163                 default:
1164                         goto fail_syntax;
1165                 }
1166         } while (type != EVENT_NONE);
1167
1168         if (!current_op && !current_exp)
1169                 goto fail_syntax;
1170
1171         if (!current_op)
1172                 current_op = current_exp;
1173
1174         ret = collapse_tree(current_op, parg, error_str);
1175         /* collapse_tree() may free current_op, and updates parg accordingly */
1176         current_op = NULL;
1177         if (ret < 0)
1178                 goto fail;
1179
1180         free(token);
1181         return 0;
1182
1183  fail_alloc:
1184         show_error(error_str, "failed to allocate filter arg");
1185         ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
1186         goto fail;
1187  fail_syntax:
1188         show_error(error_str, "Syntax error");
1189         ret = PEVENT_ERRNO__SYNTAX_ERROR;
1190  fail:
1191         free_arg(current_op);
1192         free_arg(current_exp);
1193         free_arg(arg);
1194         free(token);
1195         return ret;
1196 }
1197
1198 static enum pevent_errno
1199 process_event(struct event_format *event, const char *filter_str,
1200               struct filter_arg **parg, char *error_str)
1201 {
1202         int ret;
1203
1204         pevent_buffer_init(filter_str, strlen(filter_str));
1205
1206         ret = process_filter(event, parg, error_str, 0);
1207         if (ret < 0)
1208                 return ret;
1209
1210         /* If parg is NULL, then make it into FALSE */
1211         if (!*parg) {
1212                 *parg = allocate_arg();
1213                 if (*parg == NULL)
1214                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1215
1216                 (*parg)->type = FILTER_ARG_BOOLEAN;
1217                 (*parg)->boolean.value = FILTER_FALSE;
1218         }
1219
1220         return 0;
1221 }
1222
1223 static enum pevent_errno
1224 filter_event(struct event_filter *filter, struct event_format *event,
1225              const char *filter_str, char *error_str)
1226 {
1227         struct filter_type *filter_type;
1228         struct filter_arg *arg;
1229         enum pevent_errno ret;
1230
1231         if (filter_str) {
1232                 ret = process_event(event, filter_str, &arg, error_str);
1233                 if (ret < 0)
1234                         return ret;
1235
1236         } else {
1237                 /* just add a TRUE arg */
1238                 arg = allocate_arg();
1239                 if (arg == NULL)
1240                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1241
1242                 arg->type = FILTER_ARG_BOOLEAN;
1243                 arg->boolean.value = FILTER_TRUE;
1244         }
1245
1246         filter_type = add_filter_type(filter, event->id);
1247         if (filter_type == NULL)
1248                 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1249
1250         if (filter_type->filter)
1251                 free_arg(filter_type->filter);
1252         filter_type->filter = arg;
1253
1254         return 0;
1255 }
1256
1257 static void filter_init_error_buf(struct event_filter *filter)
1258 {
1259         /* clear buffer to reset show error */
1260         pevent_buffer_init("", 0);
1261         filter->error_buffer[0] = '\0';
1262 }
1263
1264 /**
1265  * pevent_filter_add_filter_str - add a new filter
1266  * @filter: the event filter to add to
1267  * @filter_str: the filter string that contains the filter
1268  *
1269  * Returns 0 if the filter was successfully added or a
1270  * negative error code.  Use pevent_filter_strerror() to see
1271  * actual error message in case of error.
1272  */
1273 enum pevent_errno pevent_filter_add_filter_str(struct event_filter *filter,
1274                                                const char *filter_str)
1275 {
1276         struct pevent *pevent = filter->pevent;
1277         struct event_list *event;
1278         struct event_list *events = NULL;
1279         const char *filter_start;
1280         const char *next_event;
1281         char *this_event;
1282         char *event_name = NULL;
1283         char *sys_name = NULL;
1284         char *sp;
1285         enum pevent_errno rtn = 0; /* PEVENT_ERRNO__SUCCESS */
1286         int len;
1287         int ret;
1288
1289         filter_init_error_buf(filter);
1290
1291         filter_start = strchr(filter_str, ':');
1292         if (filter_start)
1293                 len = filter_start - filter_str;
1294         else
1295                 len = strlen(filter_str);
1296
1297         do {
1298                 next_event = strchr(filter_str, ',');
1299                 if (next_event &&
1300                     (!filter_start || next_event < filter_start))
1301                         len = next_event - filter_str;
1302                 else if (filter_start)
1303                         len = filter_start - filter_str;
1304                 else
1305                         len = strlen(filter_str);
1306
1307                 this_event = malloc(len + 1);
1308                 if (this_event == NULL) {
1309                         /* This can only happen when events is NULL, but still */
1310                         free_events(events);
1311                         return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1312                 }
1313                 memcpy(this_event, filter_str, len);
1314                 this_event[len] = 0;
1315
1316                 if (next_event)
1317                         next_event++;
1318
1319                 filter_str = next_event;
1320
1321                 sys_name = strtok_r(this_event, "/", &sp);
1322                 event_name = strtok_r(NULL, "/", &sp);
1323
1324                 if (!sys_name) {
1325                         /* This can only happen when events is NULL, but still */
1326                         free_events(events);
1327                         free(this_event);
1328                         return PEVENT_ERRNO__FILTER_NOT_FOUND;
1329                 }
1330
1331                 /* Find this event */
1332                 ret = find_event(pevent, &events, strim(sys_name), strim(event_name));
1333                 if (ret < 0) {
1334                         free_events(events);
1335                         free(this_event);
1336                         return ret;
1337                 }
1338                 free(this_event);
1339         } while (filter_str);
1340
1341         /* Skip the ':' */
1342         if (filter_start)
1343                 filter_start++;
1344
1345         /* filter starts here */
1346         for (event = events; event; event = event->next) {
1347                 ret = filter_event(filter, event->event, filter_start,
1348                                    filter->error_buffer);
1349                 /* Failures are returned if a parse error happened */
1350                 if (ret < 0)
1351                         rtn = ret;
1352
1353                 if (ret >= 0 && pevent->test_filters) {
1354                         char *test;
1355                         test = pevent_filter_make_string(filter, event->event->id);
1356                         if (test) {
1357                                 printf(" '%s: %s'\n", event->event->name, test);
1358                                 free(test);
1359                         }
1360                 }
1361         }
1362
1363         free_events(events);
1364
1365         if (rtn >= 0 && pevent->test_filters)
1366                 exit(0);
1367
1368         return rtn;
1369 }
1370
1371 static void free_filter_type(struct filter_type *filter_type)
1372 {
1373         free_arg(filter_type->filter);
1374 }
1375
1376 /**
1377  * pevent_filter_strerror - fill error message in a buffer
1378  * @filter: the event filter contains error
1379  * @err: the error code
1380  * @buf: the buffer to be filled in
1381  * @buflen: the size of the buffer
1382  *
1383  * Returns 0 if message was filled successfully, -1 if error
1384  */
1385 int pevent_filter_strerror(struct event_filter *filter, enum pevent_errno err,
1386                            char *buf, size_t buflen)
1387 {
1388         if (err <= __PEVENT_ERRNO__START || err >= __PEVENT_ERRNO__END)
1389                 return -1;
1390
1391         if (strlen(filter->error_buffer) > 0) {
1392                 size_t len = snprintf(buf, buflen, "%s", filter->error_buffer);
1393
1394                 if (len > buflen)
1395                         return -1;
1396                 return 0;
1397         }
1398
1399         return pevent_strerror(filter->pevent, err, buf, buflen);
1400 }
1401
1402 /**
1403  * pevent_filter_remove_event - remove a filter for an event
1404  * @filter: the event filter to remove from
1405  * @event_id: the event to remove a filter for
1406  *
1407  * Removes the filter saved for an event defined by @event_id
1408  * from the @filter.
1409  *
1410  * Returns 1: if an event was removed
1411  *   0: if the event was not found
1412  */
1413 int pevent_filter_remove_event(struct event_filter *filter,
1414                                int event_id)
1415 {
1416         struct filter_type *filter_type;
1417         unsigned long len;
1418
1419         if (!filter->filters)
1420                 return 0;
1421
1422         filter_type = find_filter_type(filter, event_id);
1423
1424         if (!filter_type)
1425                 return 0;
1426
1427         free_filter_type(filter_type);
1428
1429         /* The filter_type points into the event_filters array */
1430         len = (unsigned long)(filter->event_filters + filter->filters) -
1431                 (unsigned long)(filter_type + 1);
1432
1433         memmove(filter_type, filter_type + 1, len);
1434         filter->filters--;
1435
1436         memset(&filter->event_filters[filter->filters], 0,
1437                sizeof(*filter_type));
1438
1439         return 1;
1440 }
1441
1442 /**
1443  * pevent_filter_reset - clear all filters in a filter
1444  * @filter: the event filter to reset
1445  *
1446  * Removes all filters from a filter and resets it.
1447  */
1448 void pevent_filter_reset(struct event_filter *filter)
1449 {
1450         int i;
1451
1452         for (i = 0; i < filter->filters; i++)
1453                 free_filter_type(&filter->event_filters[i]);
1454
1455         free(filter->event_filters);
1456         filter->filters = 0;
1457         filter->event_filters = NULL;
1458 }
1459
1460 void pevent_filter_free(struct event_filter *filter)
1461 {
1462         pevent_unref(filter->pevent);
1463
1464         pevent_filter_reset(filter);
1465
1466         free(filter);
1467 }
1468
1469 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg);
1470
1471 static int copy_filter_type(struct event_filter *filter,
1472                              struct event_filter *source,
1473                              struct filter_type *filter_type)
1474 {
1475         struct filter_arg *arg;
1476         struct event_format *event;
1477         const char *sys;
1478         const char *name;
1479         char *str;
1480
1481         /* Can't assume that the pevent's are the same */
1482         sys = filter_type->event->system;
1483         name = filter_type->event->name;
1484         event = pevent_find_event_by_name(filter->pevent, sys, name);
1485         if (!event)
1486                 return -1;
1487
1488         str = arg_to_str(source, filter_type->filter);
1489         if (!str)
1490                 return -1;
1491
1492         if (strcmp(str, "TRUE") == 0 || strcmp(str, "FALSE") == 0) {
1493                 /* Add trivial event */
1494                 arg = allocate_arg();
1495                 if (arg == NULL)
1496                         return -1;
1497
1498                 arg->type = FILTER_ARG_BOOLEAN;
1499                 if (strcmp(str, "TRUE") == 0)
1500                         arg->boolean.value = 1;
1501                 else
1502                         arg->boolean.value = 0;
1503
1504                 filter_type = add_filter_type(filter, event->id);
1505                 if (filter_type == NULL)
1506                         return -1;
1507
1508                 filter_type->filter = arg;
1509
1510                 free(str);
1511                 return 0;
1512         }
1513
1514         filter_event(filter, event, str, NULL);
1515         free(str);
1516
1517         return 0;
1518 }
1519
1520 /**
1521  * pevent_filter_copy - copy a filter using another filter
1522  * @dest - the filter to copy to
1523  * @source - the filter to copy from
1524  *
1525  * Returns 0 on success and -1 if not all filters were copied
1526  */
1527 int pevent_filter_copy(struct event_filter *dest, struct event_filter *source)
1528 {
1529         int ret = 0;
1530         int i;
1531
1532         pevent_filter_reset(dest);
1533
1534         for (i = 0; i < source->filters; i++) {
1535                 if (copy_filter_type(dest, source, &source->event_filters[i]))
1536                         ret = -1;
1537         }
1538         return ret;
1539 }
1540
1541
1542 /**
1543  * pevent_update_trivial - update the trivial filters with the given filter
1544  * @dest - the filter to update
1545  * @source - the filter as the source of the update
1546  * @type - the type of trivial filter to update.
1547  *
1548  * Scan dest for trivial events matching @type to replace with the source.
1549  *
1550  * Returns 0 on success and -1 if there was a problem updating, but
1551  *   events may have still been updated on error.
1552  */
1553 int pevent_update_trivial(struct event_filter *dest, struct event_filter *source,
1554                           enum filter_trivial_type type)
1555 {
1556         struct pevent *src_pevent;
1557         struct pevent *dest_pevent;
1558         struct event_format *event;
1559         struct filter_type *filter_type;
1560         struct filter_arg *arg;
1561         char *str;
1562         int i;
1563
1564         src_pevent = source->pevent;
1565         dest_pevent = dest->pevent;
1566
1567         /* Do nothing if either of the filters has nothing to filter */
1568         if (!dest->filters || !source->filters)
1569                 return 0;
1570
1571         for (i = 0; i < dest->filters; i++) {
1572                 filter_type = &dest->event_filters[i];
1573                 arg = filter_type->filter;
1574                 if (arg->type != FILTER_ARG_BOOLEAN)
1575                         continue;
1576                 if ((arg->boolean.value && type == FILTER_TRIVIAL_FALSE) ||
1577                     (!arg->boolean.value && type == FILTER_TRIVIAL_TRUE))
1578                         continue;
1579
1580                 event = filter_type->event;
1581
1582                 if (src_pevent != dest_pevent) {
1583                         /* do a look up */
1584                         event = pevent_find_event_by_name(src_pevent,
1585                                                           event->system,
1586                                                           event->name);
1587                         if (!event)
1588                                 return -1;
1589                 }
1590
1591                 str = pevent_filter_make_string(source, event->id);
1592                 if (!str)
1593                         continue;
1594
1595                 /* Don't bother if the filter is trivial too */
1596                 if (strcmp(str, "TRUE") != 0 && strcmp(str, "FALSE") != 0)
1597                         filter_event(dest, event, str, NULL);
1598                 free(str);
1599         }
1600         return 0;
1601 }
1602
1603 /**
1604  * pevent_filter_clear_trivial - clear TRUE and FALSE filters
1605  * @filter: the filter to remove trivial filters from
1606  * @type: remove only true, false, or both
1607  *
1608  * Removes filters that only contain a TRUE or FALES boolean arg.
1609  *
1610  * Returns 0 on success and -1 if there was a problem.
1611  */
1612 int pevent_filter_clear_trivial(struct event_filter *filter,
1613                                  enum filter_trivial_type type)
1614 {
1615         struct filter_type *filter_type;
1616         int count = 0;
1617         int *ids = NULL;
1618         int i;
1619
1620         if (!filter->filters)
1621                 return 0;
1622
1623         /*
1624          * Two steps, first get all ids with trivial filters.
1625          *  then remove those ids.
1626          */
1627         for (i = 0; i < filter->filters; i++) {
1628                 int *new_ids;
1629
1630                 filter_type = &filter->event_filters[i];
1631                 if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1632                         continue;
1633                 switch (type) {
1634                 case FILTER_TRIVIAL_FALSE:
1635                         if (filter_type->filter->boolean.value)
1636                                 continue;
1637                 case FILTER_TRIVIAL_TRUE:
1638                         if (!filter_type->filter->boolean.value)
1639                                 continue;
1640                 default:
1641                         break;
1642                 }
1643
1644                 new_ids = realloc(ids, sizeof(*ids) * (count + 1));
1645                 if (!new_ids) {
1646                         free(ids);
1647                         return -1;
1648                 }
1649
1650                 ids = new_ids;
1651                 ids[count++] = filter_type->event_id;
1652         }
1653
1654         if (!count)
1655                 return 0;
1656
1657         for (i = 0; i < count; i++)
1658                 pevent_filter_remove_event(filter, ids[i]);
1659
1660         free(ids);
1661         return 0;
1662 }
1663
1664 /**
1665  * pevent_filter_event_has_trivial - return true event contains trivial filter
1666  * @filter: the filter with the information
1667  * @event_id: the id of the event to test
1668  * @type: trivial type to test for (TRUE, FALSE, EITHER)
1669  *
1670  * Returns 1 if the event contains a matching trivial type
1671  *  otherwise 0.
1672  */
1673 int pevent_filter_event_has_trivial(struct event_filter *filter,
1674                                     int event_id,
1675                                     enum filter_trivial_type type)
1676 {
1677         struct filter_type *filter_type;
1678
1679         if (!filter->filters)
1680                 return 0;
1681
1682         filter_type = find_filter_type(filter, event_id);
1683
1684         if (!filter_type)
1685                 return 0;
1686
1687         if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1688                 return 0;
1689
1690         switch (type) {
1691         case FILTER_TRIVIAL_FALSE:
1692                 return !filter_type->filter->boolean.value;
1693
1694         case FILTER_TRIVIAL_TRUE:
1695                 return filter_type->filter->boolean.value;
1696         default:
1697                 return 1;
1698         }
1699 }
1700
1701 static int test_filter(struct event_format *event, struct filter_arg *arg,
1702                        struct pevent_record *record, enum pevent_errno *err);
1703
1704 static const char *
1705 get_comm(struct event_format *event, struct pevent_record *record)
1706 {
1707         const char *comm;
1708         int pid;
1709
1710         pid = pevent_data_pid(event->pevent, record);
1711         comm = pevent_data_comm_from_pid(event->pevent, pid);
1712         return comm;
1713 }
1714
1715 static unsigned long long
1716 get_value(struct event_format *event,
1717           struct format_field *field, struct pevent_record *record)
1718 {
1719         unsigned long long val;
1720
1721         /* Handle our dummy "comm" field */
1722         if (field == &comm) {
1723                 const char *name;
1724
1725                 name = get_comm(event, record);
1726                 return (unsigned long)name;
1727         }
1728
1729         /* Handle our dummy "cpu" field */
1730         if (field == &cpu)
1731                 return record->cpu;
1732
1733         pevent_read_number_field(field, record->data, &val);
1734
1735         if (!(field->flags & FIELD_IS_SIGNED))
1736                 return val;
1737
1738         switch (field->size) {
1739         case 1:
1740                 return (char)val;
1741         case 2:
1742                 return (short)val;
1743         case 4:
1744                 return (int)val;
1745         case 8:
1746                 return (long long)val;
1747         }
1748         return val;
1749 }
1750
1751 static unsigned long long
1752 get_arg_value(struct event_format *event, struct filter_arg *arg,
1753               struct pevent_record *record, enum pevent_errno *err);
1754
1755 static unsigned long long
1756 get_exp_value(struct event_format *event, struct filter_arg *arg,
1757               struct pevent_record *record, enum pevent_errno *err)
1758 {
1759         unsigned long long lval, rval;
1760
1761         lval = get_arg_value(event, arg->exp.left, record, err);
1762         rval = get_arg_value(event, arg->exp.right, record, err);
1763
1764         if (*err) {
1765                 /*
1766                  * There was an error, no need to process anymore.
1767                  */
1768                 return 0;
1769         }
1770
1771         switch (arg->exp.type) {
1772         case FILTER_EXP_ADD:
1773                 return lval + rval;
1774
1775         case FILTER_EXP_SUB:
1776                 return lval - rval;
1777
1778         case FILTER_EXP_MUL:
1779                 return lval * rval;
1780
1781         case FILTER_EXP_DIV:
1782                 return lval / rval;
1783
1784         case FILTER_EXP_MOD:
1785                 return lval % rval;
1786
1787         case FILTER_EXP_RSHIFT:
1788                 return lval >> rval;
1789
1790         case FILTER_EXP_LSHIFT:
1791                 return lval << rval;
1792
1793         case FILTER_EXP_AND:
1794                 return lval & rval;
1795
1796         case FILTER_EXP_OR:
1797                 return lval | rval;
1798
1799         case FILTER_EXP_XOR:
1800                 return lval ^ rval;
1801
1802         case FILTER_EXP_NOT:
1803         default:
1804                 if (!*err)
1805                         *err = PEVENT_ERRNO__INVALID_EXP_TYPE;
1806         }
1807         return 0;
1808 }
1809
1810 static unsigned long long
1811 get_arg_value(struct event_format *event, struct filter_arg *arg,
1812               struct pevent_record *record, enum pevent_errno *err)
1813 {
1814         switch (arg->type) {
1815         case FILTER_ARG_FIELD:
1816                 return get_value(event, arg->field.field, record);
1817
1818         case FILTER_ARG_VALUE:
1819                 if (arg->value.type != FILTER_NUMBER) {
1820                         if (!*err)
1821                                 *err = PEVENT_ERRNO__NOT_A_NUMBER;
1822                 }
1823                 return arg->value.val;
1824
1825         case FILTER_ARG_EXP:
1826                 return get_exp_value(event, arg, record, err);
1827
1828         default:
1829                 if (!*err)
1830                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1831         }
1832         return 0;
1833 }
1834
1835 static int test_num(struct event_format *event, struct filter_arg *arg,
1836                     struct pevent_record *record, enum pevent_errno *err)
1837 {
1838         unsigned long long lval, rval;
1839
1840         lval = get_arg_value(event, arg->num.left, record, err);
1841         rval = get_arg_value(event, arg->num.right, record, err);
1842
1843         if (*err) {
1844                 /*
1845                  * There was an error, no need to process anymore.
1846                  */
1847                 return 0;
1848         }
1849
1850         switch (arg->num.type) {
1851         case FILTER_CMP_EQ:
1852                 return lval == rval;
1853
1854         case FILTER_CMP_NE:
1855                 return lval != rval;
1856
1857         case FILTER_CMP_GT:
1858                 return lval > rval;
1859
1860         case FILTER_CMP_LT:
1861                 return lval < rval;
1862
1863         case FILTER_CMP_GE:
1864                 return lval >= rval;
1865
1866         case FILTER_CMP_LE:
1867                 return lval <= rval;
1868
1869         default:
1870                 if (!*err)
1871                         *err = PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
1872                 return 0;
1873         }
1874 }
1875
1876 static const char *get_field_str(struct filter_arg *arg, struct pevent_record *record)
1877 {
1878         struct event_format *event;
1879         struct pevent *pevent;
1880         unsigned long long addr;
1881         const char *val = NULL;
1882         char hex[64];
1883
1884         /* If the field is not a string convert it */
1885         if (arg->str.field->flags & FIELD_IS_STRING) {
1886                 val = record->data + arg->str.field->offset;
1887
1888                 /*
1889                  * We need to copy the data since we can't be sure the field
1890                  * is null terminated.
1891                  */
1892                 if (*(val + arg->str.field->size - 1)) {
1893                         /* copy it */
1894                         memcpy(arg->str.buffer, val, arg->str.field->size);
1895                         /* the buffer is already NULL terminated */
1896                         val = arg->str.buffer;
1897                 }
1898
1899         } else {
1900                 event = arg->str.field->event;
1901                 pevent = event->pevent;
1902                 addr = get_value(event, arg->str.field, record);
1903
1904                 if (arg->str.field->flags & (FIELD_IS_POINTER | FIELD_IS_LONG))
1905                         /* convert to a kernel symbol */
1906                         val = pevent_find_function(pevent, addr);
1907
1908                 if (val == NULL) {
1909                         /* just use the hex of the string name */
1910                         snprintf(hex, 64, "0x%llx", addr);
1911                         val = hex;
1912                 }
1913         }
1914
1915         return val;
1916 }
1917
1918 static int test_str(struct event_format *event, struct filter_arg *arg,
1919                     struct pevent_record *record, enum pevent_errno *err)
1920 {
1921         const char *val;
1922
1923         if (arg->str.field == &comm)
1924                 val = get_comm(event, record);
1925         else
1926                 val = get_field_str(arg, record);
1927
1928         switch (arg->str.type) {
1929         case FILTER_CMP_MATCH:
1930                 return strcmp(val, arg->str.val) == 0;
1931
1932         case FILTER_CMP_NOT_MATCH:
1933                 return strcmp(val, arg->str.val) != 0;
1934
1935         case FILTER_CMP_REGEX:
1936                 /* Returns zero on match */
1937                 return !regexec(&arg->str.reg, val, 0, NULL, 0);
1938
1939         case FILTER_CMP_NOT_REGEX:
1940                 return regexec(&arg->str.reg, val, 0, NULL, 0);
1941
1942         default:
1943                 if (!*err)
1944                         *err = PEVENT_ERRNO__ILLEGAL_STRING_CMP;
1945                 return 0;
1946         }
1947 }
1948
1949 static int test_op(struct event_format *event, struct filter_arg *arg,
1950                    struct pevent_record *record, enum pevent_errno *err)
1951 {
1952         switch (arg->op.type) {
1953         case FILTER_OP_AND:
1954                 return test_filter(event, arg->op.left, record, err) &&
1955                         test_filter(event, arg->op.right, record, err);
1956
1957         case FILTER_OP_OR:
1958                 return test_filter(event, arg->op.left, record, err) ||
1959                         test_filter(event, arg->op.right, record, err);
1960
1961         case FILTER_OP_NOT:
1962                 return !test_filter(event, arg->op.right, record, err);
1963
1964         default:
1965                 if (!*err)
1966                         *err = PEVENT_ERRNO__INVALID_OP_TYPE;
1967                 return 0;
1968         }
1969 }
1970
1971 static int test_filter(struct event_format *event, struct filter_arg *arg,
1972                        struct pevent_record *record, enum pevent_errno *err)
1973 {
1974         if (*err) {
1975                 /*
1976                  * There was an error, no need to process anymore.
1977                  */
1978                 return 0;
1979         }
1980
1981         switch (arg->type) {
1982         case FILTER_ARG_BOOLEAN:
1983                 /* easy case */
1984                 return arg->boolean.value;
1985
1986         case FILTER_ARG_OP:
1987                 return test_op(event, arg, record, err);
1988
1989         case FILTER_ARG_NUM:
1990                 return test_num(event, arg, record, err);
1991
1992         case FILTER_ARG_STR:
1993                 return test_str(event, arg, record, err);
1994
1995         case FILTER_ARG_EXP:
1996         case FILTER_ARG_VALUE:
1997         case FILTER_ARG_FIELD:
1998                 /*
1999                  * Expressions, fields and values evaluate
2000                  * to true if they return non zero
2001                  */
2002                 return !!get_arg_value(event, arg, record, err);
2003
2004         default:
2005                 if (!*err)
2006                         *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
2007                 return 0;
2008         }
2009 }
2010
2011 /**
2012  * pevent_event_filtered - return true if event has filter
2013  * @filter: filter struct with filter information
2014  * @event_id: event id to test if filter exists
2015  *
2016  * Returns 1 if filter found for @event_id
2017  *   otherwise 0;
2018  */
2019 int pevent_event_filtered(struct event_filter *filter, int event_id)
2020 {
2021         struct filter_type *filter_type;
2022
2023         if (!filter->filters)
2024                 return 0;
2025
2026         filter_type = find_filter_type(filter, event_id);
2027
2028         return filter_type ? 1 : 0;
2029 }
2030
2031 /**
2032  * pevent_filter_match - test if a record matches a filter
2033  * @filter: filter struct with filter information
2034  * @record: the record to test against the filter
2035  *
2036  * Returns: match result or error code (prefixed with PEVENT_ERRNO__)
2037  * FILTER_MATCH - filter found for event and @record matches
2038  * FILTER_MISS  - filter found for event and @record does not match
2039  * FILTER_NOT_FOUND - no filter found for @record's event
2040  * NO_FILTER - if no filters exist
2041  * otherwise - error occurred during test
2042  */
2043 enum pevent_errno pevent_filter_match(struct event_filter *filter,
2044                                       struct pevent_record *record)
2045 {
2046         struct pevent *pevent = filter->pevent;
2047         struct filter_type *filter_type;
2048         int event_id;
2049         int ret;
2050         enum pevent_errno err = 0;
2051
2052         filter_init_error_buf(filter);
2053
2054         if (!filter->filters)
2055                 return PEVENT_ERRNO__NO_FILTER;
2056
2057         event_id = pevent_data_type(pevent, record);
2058
2059         filter_type = find_filter_type(filter, event_id);
2060         if (!filter_type)
2061                 return PEVENT_ERRNO__FILTER_NOT_FOUND;
2062
2063         ret = test_filter(filter_type->event, filter_type->filter, record, &err);
2064         if (err)
2065                 return err;
2066
2067         return ret ? PEVENT_ERRNO__FILTER_MATCH : PEVENT_ERRNO__FILTER_MISS;
2068 }
2069
2070 static char *op_to_str(struct event_filter *filter, struct filter_arg *arg)
2071 {
2072         char *str = NULL;
2073         char *left = NULL;
2074         char *right = NULL;
2075         char *op = NULL;
2076         int left_val = -1;
2077         int right_val = -1;
2078         int val;
2079
2080         switch (arg->op.type) {
2081         case FILTER_OP_AND:
2082                 op = "&&";
2083                 /* fall through */
2084         case FILTER_OP_OR:
2085                 if (!op)
2086                         op = "||";
2087
2088                 left = arg_to_str(filter, arg->op.left);
2089                 right = arg_to_str(filter, arg->op.right);
2090                 if (!left || !right)
2091                         break;
2092
2093                 /* Try to consolidate boolean values */
2094                 if (strcmp(left, "TRUE") == 0)
2095                         left_val = 1;
2096                 else if (strcmp(left, "FALSE") == 0)
2097                         left_val = 0;
2098
2099                 if (strcmp(right, "TRUE") == 0)
2100                         right_val = 1;
2101                 else if (strcmp(right, "FALSE") == 0)
2102                         right_val = 0;
2103
2104                 if (left_val >= 0) {
2105                         if ((arg->op.type == FILTER_OP_AND && !left_val) ||
2106                             (arg->op.type == FILTER_OP_OR && left_val)) {
2107                                 /* Just return left value */
2108                                 str = left;
2109                                 left = NULL;
2110                                 break;
2111                         }
2112                         if (right_val >= 0) {
2113                                 /* just evaluate this. */
2114                                 val = 0;
2115                                 switch (arg->op.type) {
2116                                 case FILTER_OP_AND:
2117                                         val = left_val && right_val;
2118                                         break;
2119                                 case FILTER_OP_OR:
2120                                         val = left_val || right_val;
2121                                         break;
2122                                 default:
2123                                         break;
2124                                 }
2125                                 asprintf(&str, val ? "TRUE" : "FALSE");
2126                                 break;
2127                         }
2128                 }
2129                 if (right_val >= 0) {
2130                         if ((arg->op.type == FILTER_OP_AND && !right_val) ||
2131                             (arg->op.type == FILTER_OP_OR && right_val)) {
2132                                 /* Just return right value */
2133                                 str = right;
2134                                 right = NULL;
2135                                 break;
2136                         }
2137                         /* The right value is meaningless */
2138                         str = left;
2139                         left = NULL;
2140                         break;
2141                 }
2142
2143                 asprintf(&str, "(%s) %s (%s)", left, op, right);
2144                 break;
2145
2146         case FILTER_OP_NOT:
2147                 op = "!";
2148                 right = arg_to_str(filter, arg->op.right);
2149                 if (!right)
2150                         break;
2151
2152                 /* See if we can consolidate */
2153                 if (strcmp(right, "TRUE") == 0)
2154                         right_val = 1;
2155                 else if (strcmp(right, "FALSE") == 0)
2156                         right_val = 0;
2157                 if (right_val >= 0) {
2158                         /* just return the opposite */
2159                         asprintf(&str, right_val ? "FALSE" : "TRUE");
2160                         break;
2161                 }
2162                 asprintf(&str, "%s(%s)", op, right);
2163                 break;
2164
2165         default:
2166                 /* ?? */
2167                 break;
2168         }
2169         free(left);
2170         free(right);
2171         return str;
2172 }
2173
2174 static char *val_to_str(struct event_filter *filter, struct filter_arg *arg)
2175 {
2176         char *str = NULL;
2177
2178         asprintf(&str, "%lld", arg->value.val);
2179
2180         return str;
2181 }
2182
2183 static char *field_to_str(struct event_filter *filter, struct filter_arg *arg)
2184 {
2185         return strdup(arg->field.field->name);
2186 }
2187
2188 static char *exp_to_str(struct event_filter *filter, struct filter_arg *arg)
2189 {
2190         char *lstr;
2191         char *rstr;
2192         char *op;
2193         char *str = NULL;
2194
2195         lstr = arg_to_str(filter, arg->exp.left);
2196         rstr = arg_to_str(filter, arg->exp.right);
2197         if (!lstr || !rstr)
2198                 goto out;
2199
2200         switch (arg->exp.type) {
2201         case FILTER_EXP_ADD:
2202                 op = "+";
2203                 break;
2204         case FILTER_EXP_SUB:
2205                 op = "-";
2206                 break;
2207         case FILTER_EXP_MUL:
2208                 op = "*";
2209                 break;
2210         case FILTER_EXP_DIV:
2211                 op = "/";
2212                 break;
2213         case FILTER_EXP_MOD:
2214                 op = "%";
2215                 break;
2216         case FILTER_EXP_RSHIFT:
2217                 op = ">>";
2218                 break;
2219         case FILTER_EXP_LSHIFT:
2220                 op = "<<";
2221                 break;
2222         case FILTER_EXP_AND:
2223                 op = "&";
2224                 break;
2225         case FILTER_EXP_OR:
2226                 op = "|";
2227                 break;
2228         case FILTER_EXP_XOR:
2229                 op = "^";
2230                 break;
2231         default:
2232                 op = "[ERROR IN EXPRESSION TYPE]";
2233                 break;
2234         }
2235
2236         asprintf(&str, "%s %s %s", lstr, op, rstr);
2237 out:
2238         free(lstr);
2239         free(rstr);
2240
2241         return str;
2242 }
2243
2244 static char *num_to_str(struct event_filter *filter, struct filter_arg *arg)
2245 {
2246         char *lstr;
2247         char *rstr;
2248         char *str = NULL;
2249         char *op = NULL;
2250
2251         lstr = arg_to_str(filter, arg->num.left);
2252         rstr = arg_to_str(filter, arg->num.right);
2253         if (!lstr || !rstr)
2254                 goto out;
2255
2256         switch (arg->num.type) {
2257         case FILTER_CMP_EQ:
2258                 op = "==";
2259                 /* fall through */
2260         case FILTER_CMP_NE:
2261                 if (!op)
2262                         op = "!=";
2263                 /* fall through */
2264         case FILTER_CMP_GT:
2265                 if (!op)
2266                         op = ">";
2267                 /* fall through */
2268         case FILTER_CMP_LT:
2269                 if (!op)
2270                         op = "<";
2271                 /* fall through */
2272         case FILTER_CMP_GE:
2273                 if (!op)
2274                         op = ">=";
2275                 /* fall through */
2276         case FILTER_CMP_LE:
2277                 if (!op)
2278                         op = "<=";
2279
2280                 asprintf(&str, "%s %s %s", lstr, op, rstr);
2281                 break;
2282
2283         default:
2284                 /* ?? */
2285                 break;
2286         }
2287
2288 out:
2289         free(lstr);
2290         free(rstr);
2291         return str;
2292 }
2293
2294 static char *str_to_str(struct event_filter *filter, struct filter_arg *arg)
2295 {
2296         char *str = NULL;
2297         char *op = NULL;
2298
2299         switch (arg->str.type) {
2300         case FILTER_CMP_MATCH:
2301                 op = "==";
2302                 /* fall through */
2303         case FILTER_CMP_NOT_MATCH:
2304                 if (!op)
2305                         op = "!=";
2306                 /* fall through */
2307         case FILTER_CMP_REGEX:
2308                 if (!op)
2309                         op = "=~";
2310                 /* fall through */
2311         case FILTER_CMP_NOT_REGEX:
2312                 if (!op)
2313                         op = "!~";
2314
2315                 asprintf(&str, "%s %s \"%s\"",
2316                          arg->str.field->name, op, arg->str.val);
2317                 break;
2318
2319         default:
2320                 /* ?? */
2321                 break;
2322         }
2323         return str;
2324 }
2325
2326 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg)
2327 {
2328         char *str = NULL;
2329
2330         switch (arg->type) {
2331         case FILTER_ARG_BOOLEAN:
2332                 asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
2333                 return str;
2334
2335         case FILTER_ARG_OP:
2336                 return op_to_str(filter, arg);
2337
2338         case FILTER_ARG_NUM:
2339                 return num_to_str(filter, arg);
2340
2341         case FILTER_ARG_STR:
2342                 return str_to_str(filter, arg);
2343
2344         case FILTER_ARG_VALUE:
2345                 return val_to_str(filter, arg);
2346
2347         case FILTER_ARG_FIELD:
2348                 return field_to_str(filter, arg);
2349
2350         case FILTER_ARG_EXP:
2351                 return exp_to_str(filter, arg);
2352
2353         default:
2354                 /* ?? */
2355                 return NULL;
2356         }
2357
2358 }
2359
2360 /**
2361  * pevent_filter_make_string - return a string showing the filter
2362  * @filter: filter struct with filter information
2363  * @event_id: the event id to return the filter string with
2364  *
2365  * Returns a string that displays the filter contents.
2366  *  This string must be freed with free(str).
2367  *  NULL is returned if no filter is found or allocation failed.
2368  */
2369 char *
2370 pevent_filter_make_string(struct event_filter *filter, int event_id)
2371 {
2372         struct filter_type *filter_type;
2373
2374         if (!filter->filters)
2375                 return NULL;
2376
2377         filter_type = find_filter_type(filter, event_id);
2378
2379         if (!filter_type)
2380                 return NULL;
2381
2382         return arg_to_str(filter, filter_type->filter);
2383 }
2384
2385 /**
2386  * pevent_filter_compare - compare two filters and return if they are the same
2387  * @filter1: Filter to compare with @filter2
2388  * @filter2: Filter to compare with @filter1
2389  *
2390  * Returns:
2391  *  1 if the two filters hold the same content.
2392  *  0 if they do not.
2393  */
2394 int pevent_filter_compare(struct event_filter *filter1, struct event_filter *filter2)
2395 {
2396         struct filter_type *filter_type1;
2397         struct filter_type *filter_type2;
2398         char *str1, *str2;
2399         int result;
2400         int i;
2401
2402         /* Do the easy checks first */
2403         if (filter1->filters != filter2->filters)
2404                 return 0;
2405         if (!filter1->filters && !filter2->filters)
2406                 return 1;
2407
2408         /*
2409          * Now take a look at each of the events to see if they have the same
2410          * filters to them.
2411          */
2412         for (i = 0; i < filter1->filters; i++) {
2413                 filter_type1 = &filter1->event_filters[i];
2414                 filter_type2 = find_filter_type(filter2, filter_type1->event_id);
2415                 if (!filter_type2)
2416                         break;
2417                 if (filter_type1->filter->type != filter_type2->filter->type)
2418                         break;
2419                 switch (filter_type1->filter->type) {
2420                 case FILTER_TRIVIAL_FALSE:
2421                 case FILTER_TRIVIAL_TRUE:
2422                         /* trivial types just need the type compared */
2423                         continue;
2424                 default:
2425                         break;
2426                 }
2427                 /* The best way to compare complex filters is with strings */
2428                 str1 = arg_to_str(filter1, filter_type1->filter);
2429                 str2 = arg_to_str(filter2, filter_type2->filter);
2430                 if (str1 && str2)
2431                         result = strcmp(str1, str2) != 0;
2432                 else
2433                         /* bail out if allocation fails */
2434                         result = 1;
2435
2436                 free(str1);
2437                 free(str2);
2438                 if (result)
2439                         break;
2440         }
2441
2442         if (i < filter1->filters)
2443                 return 0;
2444         return 1;
2445 }
2446