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
show_error(char * error_buf,const char * fmt,...)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
free_token(char * token)68 static void free_token(char *token)
69 {
70 pevent_free_token(token);
71 }
72
read_token(char ** tok)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
filter_cmp(const void * a,const void * b)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 *
find_filter_type(struct event_filter * filter,int id)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 *
add_filter_type(struct event_filter * filter,int id)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 */
pevent_filter_alloc(struct pevent * pevent)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
allocate_arg(void)192 static struct filter_arg *allocate_arg(void)
193 {
194 return calloc(1, sizeof(struct filter_arg));
195 }
196
free_arg(struct filter_arg * arg)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
add_event(struct event_list ** events,struct event_format * event)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
event_match(struct event_format * event,regex_t * sreg,regex_t * ereg)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
find_event(struct pevent * pevent,struct event_list ** events,char * sys_name,char * event_name)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
free_events(struct event_list * events)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
create_arg_item(struct event_format * event,const char * token,enum event_type type,struct filter_arg ** parg,char * error_str)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 *
create_arg_op(enum filter_op_type btype)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 *
create_arg_exp(enum filter_exp_type etype)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 *
create_arg_cmp(enum filter_exp_type etype)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
add_right(struct filter_arg * op,struct filter_arg * arg,char * error_str)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 *
rotate_op_right(struct filter_arg * a,struct filter_arg * b)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
add_left(struct filter_arg * op,struct filter_arg * arg)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
process_op(const char * token,enum filter_op_type * btype,enum filter_cmp_type * ctype,enum filter_exp_type * etype)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
check_op_done(struct filter_arg * arg)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
reparent_op_arg(struct filter_arg * parent,struct filter_arg * old_child,struct filter_arg * arg,char * error_str)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) */
test_arg(struct filter_arg * parent,struct filter_arg * arg,char * error_str)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 */
collapse_tree(struct filter_arg * arg,struct filter_arg ** arg_collapsed,char * error_str)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
process_filter(struct event_format * event,struct filter_arg ** parg,char * error_str,int not)951 process_filter(struct event_format *event, struct filter_arg **parg,
952 char *error_str, int not)
953 {
954 enum event_type type;
955 char *token = NULL;
956 struct filter_arg *current_op = NULL;
957 struct filter_arg *current_exp = NULL;
958 struct filter_arg *left_item = NULL;
959 struct filter_arg *arg = NULL;
960 enum op_type op_type;
961 enum filter_op_type btype;
962 enum filter_exp_type etype;
963 enum filter_cmp_type ctype;
964 enum pevent_errno ret;
965
966 *parg = NULL;
967
968 do {
969 free(token);
970 type = read_token(&token);
971 switch (type) {
972 case EVENT_SQUOTE:
973 case EVENT_DQUOTE:
974 case EVENT_ITEM:
975 ret = create_arg_item(event, token, type, &arg, error_str);
976 if (ret < 0)
977 goto fail;
978 if (!left_item)
979 left_item = arg;
980 else if (current_exp) {
981 ret = add_right(current_exp, arg, error_str);
982 if (ret < 0)
983 goto fail;
984 left_item = NULL;
985 /* Not's only one one expression */
986 if (not) {
987 arg = NULL;
988 if (current_op)
989 goto fail_syntax;
990 free(token);
991 *parg = current_exp;
992 return 0;
993 }
994 } else
995 goto fail_syntax;
996 arg = NULL;
997 break;
998
999 case EVENT_DELIM:
1000 if (*token == ',') {
1001 show_error(error_str, "Illegal token ','");
1002 ret = PEVENT_ERRNO__ILLEGAL_TOKEN;
1003 goto fail;
1004 }
1005
1006 if (*token == '(') {
1007 if (left_item) {
1008 show_error(error_str,
1009 "Open paren can not come after item");
1010 ret = PEVENT_ERRNO__INVALID_PAREN;
1011 goto fail;
1012 }
1013 if (current_exp) {
1014 show_error(error_str,
1015 "Open paren can not come after expression");
1016 ret = PEVENT_ERRNO__INVALID_PAREN;
1017 goto fail;
1018 }
1019
1020 ret = process_filter(event, &arg, error_str, 0);
1021 if (ret != PEVENT_ERRNO__UNBALANCED_PAREN) {
1022 if (ret == 0) {
1023 show_error(error_str,
1024 "Unbalanced number of '('");
1025 ret = PEVENT_ERRNO__UNBALANCED_PAREN;
1026 }
1027 goto fail;
1028 }
1029 ret = 0;
1030
1031 /* A not wants just one expression */
1032 if (not) {
1033 if (current_op)
1034 goto fail_syntax;
1035 *parg = arg;
1036 return 0;
1037 }
1038
1039 if (current_op)
1040 ret = add_right(current_op, arg, error_str);
1041 else
1042 current_exp = arg;
1043
1044 if (ret < 0)
1045 goto fail;
1046
1047 } else { /* ')' */
1048 if (!current_op && !current_exp)
1049 goto fail_syntax;
1050
1051 /* Make sure everything is finished at this level */
1052 if (current_exp && !check_op_done(current_exp))
1053 goto fail_syntax;
1054 if (current_op && !check_op_done(current_op))
1055 goto fail_syntax;
1056
1057 if (current_op)
1058 *parg = current_op;
1059 else
1060 *parg = current_exp;
1061 free(token);
1062 return PEVENT_ERRNO__UNBALANCED_PAREN;
1063 }
1064 break;
1065
1066 case EVENT_OP:
1067 op_type = process_op(token, &btype, &ctype, &etype);
1068
1069 /* All expect a left arg except for NOT */
1070 switch (op_type) {
1071 case OP_BOOL:
1072 /* Logic ops need a left expression */
1073 if (!current_exp && !current_op)
1074 goto fail_syntax;
1075 /* fall through */
1076 case OP_NOT:
1077 /* logic only processes ops and exp */
1078 if (left_item)
1079 goto fail_syntax;
1080 break;
1081 case OP_EXP:
1082 case OP_CMP:
1083 if (!left_item)
1084 goto fail_syntax;
1085 break;
1086 case OP_NONE:
1087 show_error(error_str,
1088 "Unknown op token %s", token);
1089 ret = PEVENT_ERRNO__UNKNOWN_TOKEN;
1090 goto fail;
1091 }
1092
1093 ret = 0;
1094 switch (op_type) {
1095 case OP_BOOL:
1096 arg = create_arg_op(btype);
1097 if (arg == NULL)
1098 goto fail_alloc;
1099 if (current_op)
1100 ret = add_left(arg, current_op);
1101 else
1102 ret = add_left(arg, current_exp);
1103 current_op = arg;
1104 current_exp = NULL;
1105 break;
1106
1107 case OP_NOT:
1108 arg = create_arg_op(btype);
1109 if (arg == NULL)
1110 goto fail_alloc;
1111 if (current_op)
1112 ret = add_right(current_op, arg, error_str);
1113 if (ret < 0)
1114 goto fail;
1115 current_exp = arg;
1116 ret = process_filter(event, &arg, error_str, 1);
1117 if (ret < 0)
1118 goto fail;
1119 ret = add_right(current_exp, arg, error_str);
1120 if (ret < 0)
1121 goto fail;
1122 break;
1123
1124 case OP_EXP:
1125 case OP_CMP:
1126 if (op_type == OP_EXP)
1127 arg = create_arg_exp(etype);
1128 else
1129 arg = create_arg_cmp(ctype);
1130 if (arg == NULL)
1131 goto fail_alloc;
1132
1133 if (current_op)
1134 ret = add_right(current_op, arg, error_str);
1135 if (ret < 0)
1136 goto fail;
1137 ret = add_left(arg, left_item);
1138 if (ret < 0) {
1139 arg = NULL;
1140 goto fail_syntax;
1141 }
1142 current_exp = arg;
1143 break;
1144 default:
1145 break;
1146 }
1147 arg = NULL;
1148 if (ret < 0)
1149 goto fail_syntax;
1150 break;
1151 case EVENT_NONE:
1152 break;
1153 case EVENT_ERROR:
1154 goto fail_alloc;
1155 default:
1156 goto fail_syntax;
1157 }
1158 } while (type != EVENT_NONE);
1159
1160 if (!current_op && !current_exp)
1161 goto fail_syntax;
1162
1163 if (!current_op)
1164 current_op = current_exp;
1165
1166 ret = collapse_tree(current_op, parg, error_str);
1167 /* collapse_tree() may free current_op, and updates parg accordingly */
1168 current_op = NULL;
1169 if (ret < 0)
1170 goto fail;
1171
1172 free(token);
1173 return 0;
1174
1175 fail_alloc:
1176 show_error(error_str, "failed to allocate filter arg");
1177 ret = PEVENT_ERRNO__MEM_ALLOC_FAILED;
1178 goto fail;
1179 fail_syntax:
1180 show_error(error_str, "Syntax error");
1181 ret = PEVENT_ERRNO__SYNTAX_ERROR;
1182 fail:
1183 free_arg(current_op);
1184 free_arg(current_exp);
1185 free_arg(arg);
1186 free(token);
1187 return ret;
1188 }
1189
1190 static enum pevent_errno
process_event(struct event_format * event,const char * filter_str,struct filter_arg ** parg,char * error_str)1191 process_event(struct event_format *event, const char *filter_str,
1192 struct filter_arg **parg, char *error_str)
1193 {
1194 int ret;
1195
1196 pevent_buffer_init(filter_str, strlen(filter_str));
1197
1198 ret = process_filter(event, parg, error_str, 0);
1199 if (ret < 0)
1200 return ret;
1201
1202 /* If parg is NULL, then make it into FALSE */
1203 if (!*parg) {
1204 *parg = allocate_arg();
1205 if (*parg == NULL)
1206 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1207
1208 (*parg)->type = FILTER_ARG_BOOLEAN;
1209 (*parg)->boolean.value = FILTER_FALSE;
1210 }
1211
1212 return 0;
1213 }
1214
1215 static enum pevent_errno
filter_event(struct event_filter * filter,struct event_format * event,const char * filter_str,char * error_str)1216 filter_event(struct event_filter *filter, struct event_format *event,
1217 const char *filter_str, char *error_str)
1218 {
1219 struct filter_type *filter_type;
1220 struct filter_arg *arg;
1221 enum pevent_errno ret;
1222
1223 if (filter_str) {
1224 ret = process_event(event, filter_str, &arg, error_str);
1225 if (ret < 0)
1226 return ret;
1227
1228 } else {
1229 /* just add a TRUE arg */
1230 arg = allocate_arg();
1231 if (arg == NULL)
1232 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1233
1234 arg->type = FILTER_ARG_BOOLEAN;
1235 arg->boolean.value = FILTER_TRUE;
1236 }
1237
1238 filter_type = add_filter_type(filter, event->id);
1239 if (filter_type == NULL)
1240 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1241
1242 if (filter_type->filter)
1243 free_arg(filter_type->filter);
1244 filter_type->filter = arg;
1245
1246 return 0;
1247 }
1248
filter_init_error_buf(struct event_filter * filter)1249 static void filter_init_error_buf(struct event_filter *filter)
1250 {
1251 /* clear buffer to reset show error */
1252 pevent_buffer_init("", 0);
1253 filter->error_buffer[0] = '\0';
1254 }
1255
1256 /**
1257 * pevent_filter_add_filter_str - add a new filter
1258 * @filter: the event filter to add to
1259 * @filter_str: the filter string that contains the filter
1260 *
1261 * Returns 0 if the filter was successfully added or a
1262 * negative error code. Use pevent_filter_strerror() to see
1263 * actual error message in case of error.
1264 */
pevent_filter_add_filter_str(struct event_filter * filter,const char * filter_str)1265 enum pevent_errno pevent_filter_add_filter_str(struct event_filter *filter,
1266 const char *filter_str)
1267 {
1268 struct pevent *pevent = filter->pevent;
1269 struct event_list *event;
1270 struct event_list *events = NULL;
1271 const char *filter_start;
1272 const char *next_event;
1273 char *this_event;
1274 char *event_name = NULL;
1275 char *sys_name = NULL;
1276 char *sp;
1277 enum pevent_errno rtn = 0; /* PEVENT_ERRNO__SUCCESS */
1278 int len;
1279 int ret;
1280
1281 filter_init_error_buf(filter);
1282
1283 filter_start = strchr(filter_str, ':');
1284 if (filter_start)
1285 len = filter_start - filter_str;
1286 else
1287 len = strlen(filter_str);
1288
1289 do {
1290 next_event = strchr(filter_str, ',');
1291 if (next_event &&
1292 (!filter_start || next_event < filter_start))
1293 len = next_event - filter_str;
1294 else if (filter_start)
1295 len = filter_start - filter_str;
1296 else
1297 len = strlen(filter_str);
1298
1299 this_event = malloc(len + 1);
1300 if (this_event == NULL) {
1301 /* This can only happen when events is NULL, but still */
1302 free_events(events);
1303 return PEVENT_ERRNO__MEM_ALLOC_FAILED;
1304 }
1305 memcpy(this_event, filter_str, len);
1306 this_event[len] = 0;
1307
1308 if (next_event)
1309 next_event++;
1310
1311 filter_str = next_event;
1312
1313 sys_name = strtok_r(this_event, "/", &sp);
1314 event_name = strtok_r(NULL, "/", &sp);
1315
1316 if (!sys_name) {
1317 /* This can only happen when events is NULL, but still */
1318 free_events(events);
1319 free(this_event);
1320 return PEVENT_ERRNO__FILTER_NOT_FOUND;
1321 }
1322
1323 /* Find this event */
1324 ret = find_event(pevent, &events, strim(sys_name), strim(event_name));
1325 if (ret < 0) {
1326 free_events(events);
1327 free(this_event);
1328 return ret;
1329 }
1330 free(this_event);
1331 } while (filter_str);
1332
1333 /* Skip the ':' */
1334 if (filter_start)
1335 filter_start++;
1336
1337 /* filter starts here */
1338 for (event = events; event; event = event->next) {
1339 ret = filter_event(filter, event->event, filter_start,
1340 filter->error_buffer);
1341 /* Failures are returned if a parse error happened */
1342 if (ret < 0)
1343 rtn = ret;
1344
1345 if (ret >= 0 && pevent->test_filters) {
1346 char *test;
1347 test = pevent_filter_make_string(filter, event->event->id);
1348 if (test) {
1349 printf(" '%s: %s'\n", event->event->name, test);
1350 free(test);
1351 }
1352 }
1353 }
1354
1355 free_events(events);
1356
1357 if (rtn >= 0 && pevent->test_filters)
1358 exit(0);
1359
1360 return rtn;
1361 }
1362
free_filter_type(struct filter_type * filter_type)1363 static void free_filter_type(struct filter_type *filter_type)
1364 {
1365 free_arg(filter_type->filter);
1366 }
1367
1368 /**
1369 * pevent_filter_strerror - fill error message in a buffer
1370 * @filter: the event filter contains error
1371 * @err: the error code
1372 * @buf: the buffer to be filled in
1373 * @buflen: the size of the buffer
1374 *
1375 * Returns 0 if message was filled successfully, -1 if error
1376 */
pevent_filter_strerror(struct event_filter * filter,enum pevent_errno err,char * buf,size_t buflen)1377 int pevent_filter_strerror(struct event_filter *filter, enum pevent_errno err,
1378 char *buf, size_t buflen)
1379 {
1380 if (err <= __PEVENT_ERRNO__START || err >= __PEVENT_ERRNO__END)
1381 return -1;
1382
1383 if (strlen(filter->error_buffer) > 0) {
1384 size_t len = snprintf(buf, buflen, "%s", filter->error_buffer);
1385
1386 if (len > buflen)
1387 return -1;
1388 return 0;
1389 }
1390
1391 return pevent_strerror(filter->pevent, err, buf, buflen);
1392 }
1393
1394 /**
1395 * pevent_filter_remove_event - remove a filter for an event
1396 * @filter: the event filter to remove from
1397 * @event_id: the event to remove a filter for
1398 *
1399 * Removes the filter saved for an event defined by @event_id
1400 * from the @filter.
1401 *
1402 * Returns 1: if an event was removed
1403 * 0: if the event was not found
1404 */
pevent_filter_remove_event(struct event_filter * filter,int event_id)1405 int pevent_filter_remove_event(struct event_filter *filter,
1406 int event_id)
1407 {
1408 struct filter_type *filter_type;
1409 unsigned long len;
1410
1411 if (!filter->filters)
1412 return 0;
1413
1414 filter_type = find_filter_type(filter, event_id);
1415
1416 if (!filter_type)
1417 return 0;
1418
1419 free_filter_type(filter_type);
1420
1421 /* The filter_type points into the event_filters array */
1422 len = (unsigned long)(filter->event_filters + filter->filters) -
1423 (unsigned long)(filter_type + 1);
1424
1425 memmove(filter_type, filter_type + 1, len);
1426 filter->filters--;
1427
1428 memset(&filter->event_filters[filter->filters], 0,
1429 sizeof(*filter_type));
1430
1431 return 1;
1432 }
1433
1434 /**
1435 * pevent_filter_reset - clear all filters in a filter
1436 * @filter: the event filter to reset
1437 *
1438 * Removes all filters from a filter and resets it.
1439 */
pevent_filter_reset(struct event_filter * filter)1440 void pevent_filter_reset(struct event_filter *filter)
1441 {
1442 int i;
1443
1444 for (i = 0; i < filter->filters; i++)
1445 free_filter_type(&filter->event_filters[i]);
1446
1447 free(filter->event_filters);
1448 filter->filters = 0;
1449 filter->event_filters = NULL;
1450 }
1451
pevent_filter_free(struct event_filter * filter)1452 void pevent_filter_free(struct event_filter *filter)
1453 {
1454 pevent_unref(filter->pevent);
1455
1456 pevent_filter_reset(filter);
1457
1458 free(filter);
1459 }
1460
1461 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg);
1462
copy_filter_type(struct event_filter * filter,struct event_filter * source,struct filter_type * filter_type)1463 static int copy_filter_type(struct event_filter *filter,
1464 struct event_filter *source,
1465 struct filter_type *filter_type)
1466 {
1467 struct filter_arg *arg;
1468 struct event_format *event;
1469 const char *sys;
1470 const char *name;
1471 char *str;
1472
1473 /* Can't assume that the pevent's are the same */
1474 sys = filter_type->event->system;
1475 name = filter_type->event->name;
1476 event = pevent_find_event_by_name(filter->pevent, sys, name);
1477 if (!event)
1478 return -1;
1479
1480 str = arg_to_str(source, filter_type->filter);
1481 if (!str)
1482 return -1;
1483
1484 if (strcmp(str, "TRUE") == 0 || strcmp(str, "FALSE") == 0) {
1485 /* Add trivial event */
1486 arg = allocate_arg();
1487 if (arg == NULL)
1488 return -1;
1489
1490 arg->type = FILTER_ARG_BOOLEAN;
1491 if (strcmp(str, "TRUE") == 0)
1492 arg->boolean.value = 1;
1493 else
1494 arg->boolean.value = 0;
1495
1496 filter_type = add_filter_type(filter, event->id);
1497 if (filter_type == NULL)
1498 return -1;
1499
1500 filter_type->filter = arg;
1501
1502 free(str);
1503 return 0;
1504 }
1505
1506 filter_event(filter, event, str, NULL);
1507 free(str);
1508
1509 return 0;
1510 }
1511
1512 /**
1513 * pevent_filter_copy - copy a filter using another filter
1514 * @dest - the filter to copy to
1515 * @source - the filter to copy from
1516 *
1517 * Returns 0 on success and -1 if not all filters were copied
1518 */
pevent_filter_copy(struct event_filter * dest,struct event_filter * source)1519 int pevent_filter_copy(struct event_filter *dest, struct event_filter *source)
1520 {
1521 int ret = 0;
1522 int i;
1523
1524 pevent_filter_reset(dest);
1525
1526 for (i = 0; i < source->filters; i++) {
1527 if (copy_filter_type(dest, source, &source->event_filters[i]))
1528 ret = -1;
1529 }
1530 return ret;
1531 }
1532
1533
1534 /**
1535 * pevent_update_trivial - update the trivial filters with the given filter
1536 * @dest - the filter to update
1537 * @source - the filter as the source of the update
1538 * @type - the type of trivial filter to update.
1539 *
1540 * Scan dest for trivial events matching @type to replace with the source.
1541 *
1542 * Returns 0 on success and -1 if there was a problem updating, but
1543 * events may have still been updated on error.
1544 */
pevent_update_trivial(struct event_filter * dest,struct event_filter * source,enum filter_trivial_type type)1545 int pevent_update_trivial(struct event_filter *dest, struct event_filter *source,
1546 enum filter_trivial_type type)
1547 {
1548 struct pevent *src_pevent;
1549 struct pevent *dest_pevent;
1550 struct event_format *event;
1551 struct filter_type *filter_type;
1552 struct filter_arg *arg;
1553 char *str;
1554 int i;
1555
1556 src_pevent = source->pevent;
1557 dest_pevent = dest->pevent;
1558
1559 /* Do nothing if either of the filters has nothing to filter */
1560 if (!dest->filters || !source->filters)
1561 return 0;
1562
1563 for (i = 0; i < dest->filters; i++) {
1564 filter_type = &dest->event_filters[i];
1565 arg = filter_type->filter;
1566 if (arg->type != FILTER_ARG_BOOLEAN)
1567 continue;
1568 if ((arg->boolean.value && type == FILTER_TRIVIAL_FALSE) ||
1569 (!arg->boolean.value && type == FILTER_TRIVIAL_TRUE))
1570 continue;
1571
1572 event = filter_type->event;
1573
1574 if (src_pevent != dest_pevent) {
1575 /* do a look up */
1576 event = pevent_find_event_by_name(src_pevent,
1577 event->system,
1578 event->name);
1579 if (!event)
1580 return -1;
1581 }
1582
1583 str = pevent_filter_make_string(source, event->id);
1584 if (!str)
1585 continue;
1586
1587 /* Don't bother if the filter is trivial too */
1588 if (strcmp(str, "TRUE") != 0 && strcmp(str, "FALSE") != 0)
1589 filter_event(dest, event, str, NULL);
1590 free(str);
1591 }
1592 return 0;
1593 }
1594
1595 /**
1596 * pevent_filter_clear_trivial - clear TRUE and FALSE filters
1597 * @filter: the filter to remove trivial filters from
1598 * @type: remove only true, false, or both
1599 *
1600 * Removes filters that only contain a TRUE or FALES boolean arg.
1601 *
1602 * Returns 0 on success and -1 if there was a problem.
1603 */
pevent_filter_clear_trivial(struct event_filter * filter,enum filter_trivial_type type)1604 int pevent_filter_clear_trivial(struct event_filter *filter,
1605 enum filter_trivial_type type)
1606 {
1607 struct filter_type *filter_type;
1608 int count = 0;
1609 int *ids = NULL;
1610 int i;
1611
1612 if (!filter->filters)
1613 return 0;
1614
1615 /*
1616 * Two steps, first get all ids with trivial filters.
1617 * then remove those ids.
1618 */
1619 for (i = 0; i < filter->filters; i++) {
1620 int *new_ids;
1621
1622 filter_type = &filter->event_filters[i];
1623 if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1624 continue;
1625 switch (type) {
1626 case FILTER_TRIVIAL_FALSE:
1627 if (filter_type->filter->boolean.value)
1628 continue;
1629 case FILTER_TRIVIAL_TRUE:
1630 if (!filter_type->filter->boolean.value)
1631 continue;
1632 default:
1633 break;
1634 }
1635
1636 new_ids = realloc(ids, sizeof(*ids) * (count + 1));
1637 if (!new_ids) {
1638 free(ids);
1639 return -1;
1640 }
1641
1642 ids = new_ids;
1643 ids[count++] = filter_type->event_id;
1644 }
1645
1646 if (!count)
1647 return 0;
1648
1649 for (i = 0; i < count; i++)
1650 pevent_filter_remove_event(filter, ids[i]);
1651
1652 free(ids);
1653 return 0;
1654 }
1655
1656 /**
1657 * pevent_filter_event_has_trivial - return true event contains trivial filter
1658 * @filter: the filter with the information
1659 * @event_id: the id of the event to test
1660 * @type: trivial type to test for (TRUE, FALSE, EITHER)
1661 *
1662 * Returns 1 if the event contains a matching trivial type
1663 * otherwise 0.
1664 */
pevent_filter_event_has_trivial(struct event_filter * filter,int event_id,enum filter_trivial_type type)1665 int pevent_filter_event_has_trivial(struct event_filter *filter,
1666 int event_id,
1667 enum filter_trivial_type type)
1668 {
1669 struct filter_type *filter_type;
1670
1671 if (!filter->filters)
1672 return 0;
1673
1674 filter_type = find_filter_type(filter, event_id);
1675
1676 if (!filter_type)
1677 return 0;
1678
1679 if (filter_type->filter->type != FILTER_ARG_BOOLEAN)
1680 return 0;
1681
1682 switch (type) {
1683 case FILTER_TRIVIAL_FALSE:
1684 return !filter_type->filter->boolean.value;
1685
1686 case FILTER_TRIVIAL_TRUE:
1687 return filter_type->filter->boolean.value;
1688 default:
1689 return 1;
1690 }
1691 }
1692
1693 static int test_filter(struct event_format *event, struct filter_arg *arg,
1694 struct pevent_record *record, enum pevent_errno *err);
1695
1696 static const char *
get_comm(struct event_format * event,struct pevent_record * record)1697 get_comm(struct event_format *event, struct pevent_record *record)
1698 {
1699 const char *comm;
1700 int pid;
1701
1702 pid = pevent_data_pid(event->pevent, record);
1703 comm = pevent_data_comm_from_pid(event->pevent, pid);
1704 return comm;
1705 }
1706
1707 static unsigned long long
get_value(struct event_format * event,struct format_field * field,struct pevent_record * record)1708 get_value(struct event_format *event,
1709 struct format_field *field, struct pevent_record *record)
1710 {
1711 unsigned long long val;
1712
1713 /* Handle our dummy "comm" field */
1714 if (field == &comm) {
1715 const char *name;
1716
1717 name = get_comm(event, record);
1718 return (unsigned long)name;
1719 }
1720
1721 pevent_read_number_field(field, record->data, &val);
1722
1723 if (!(field->flags & FIELD_IS_SIGNED))
1724 return val;
1725
1726 switch (field->size) {
1727 case 1:
1728 return (char)val;
1729 case 2:
1730 return (short)val;
1731 case 4:
1732 return (int)val;
1733 case 8:
1734 return (long long)val;
1735 }
1736 return val;
1737 }
1738
1739 static unsigned long long
1740 get_arg_value(struct event_format *event, struct filter_arg *arg,
1741 struct pevent_record *record, enum pevent_errno *err);
1742
1743 static unsigned long long
get_exp_value(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1744 get_exp_value(struct event_format *event, struct filter_arg *arg,
1745 struct pevent_record *record, enum pevent_errno *err)
1746 {
1747 unsigned long long lval, rval;
1748
1749 lval = get_arg_value(event, arg->exp.left, record, err);
1750 rval = get_arg_value(event, arg->exp.right, record, err);
1751
1752 if (*err) {
1753 /*
1754 * There was an error, no need to process anymore.
1755 */
1756 return 0;
1757 }
1758
1759 switch (arg->exp.type) {
1760 case FILTER_EXP_ADD:
1761 return lval + rval;
1762
1763 case FILTER_EXP_SUB:
1764 return lval - rval;
1765
1766 case FILTER_EXP_MUL:
1767 return lval * rval;
1768
1769 case FILTER_EXP_DIV:
1770 return lval / rval;
1771
1772 case FILTER_EXP_MOD:
1773 return lval % rval;
1774
1775 case FILTER_EXP_RSHIFT:
1776 return lval >> rval;
1777
1778 case FILTER_EXP_LSHIFT:
1779 return lval << rval;
1780
1781 case FILTER_EXP_AND:
1782 return lval & rval;
1783
1784 case FILTER_EXP_OR:
1785 return lval | rval;
1786
1787 case FILTER_EXP_XOR:
1788 return lval ^ rval;
1789
1790 case FILTER_EXP_NOT:
1791 default:
1792 if (!*err)
1793 *err = PEVENT_ERRNO__INVALID_EXP_TYPE;
1794 }
1795 return 0;
1796 }
1797
1798 static unsigned long long
get_arg_value(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1799 get_arg_value(struct event_format *event, struct filter_arg *arg,
1800 struct pevent_record *record, enum pevent_errno *err)
1801 {
1802 switch (arg->type) {
1803 case FILTER_ARG_FIELD:
1804 return get_value(event, arg->field.field, record);
1805
1806 case FILTER_ARG_VALUE:
1807 if (arg->value.type != FILTER_NUMBER) {
1808 if (!*err)
1809 *err = PEVENT_ERRNO__NOT_A_NUMBER;
1810 }
1811 return arg->value.val;
1812
1813 case FILTER_ARG_EXP:
1814 return get_exp_value(event, arg, record, err);
1815
1816 default:
1817 if (!*err)
1818 *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1819 }
1820 return 0;
1821 }
1822
test_num(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1823 static int test_num(struct event_format *event, struct filter_arg *arg,
1824 struct pevent_record *record, enum pevent_errno *err)
1825 {
1826 unsigned long long lval, rval;
1827
1828 lval = get_arg_value(event, arg->num.left, record, err);
1829 rval = get_arg_value(event, arg->num.right, record, err);
1830
1831 if (*err) {
1832 /*
1833 * There was an error, no need to process anymore.
1834 */
1835 return 0;
1836 }
1837
1838 switch (arg->num.type) {
1839 case FILTER_CMP_EQ:
1840 return lval == rval;
1841
1842 case FILTER_CMP_NE:
1843 return lval != rval;
1844
1845 case FILTER_CMP_GT:
1846 return lval > rval;
1847
1848 case FILTER_CMP_LT:
1849 return lval < rval;
1850
1851 case FILTER_CMP_GE:
1852 return lval >= rval;
1853
1854 case FILTER_CMP_LE:
1855 return lval <= rval;
1856
1857 default:
1858 if (!*err)
1859 *err = PEVENT_ERRNO__ILLEGAL_INTEGER_CMP;
1860 return 0;
1861 }
1862 }
1863
get_field_str(struct filter_arg * arg,struct pevent_record * record)1864 static const char *get_field_str(struct filter_arg *arg, struct pevent_record *record)
1865 {
1866 struct event_format *event;
1867 struct pevent *pevent;
1868 unsigned long long addr;
1869 const char *val = NULL;
1870 char hex[64];
1871
1872 /* If the field is not a string convert it */
1873 if (arg->str.field->flags & FIELD_IS_STRING) {
1874 val = record->data + arg->str.field->offset;
1875
1876 /*
1877 * We need to copy the data since we can't be sure the field
1878 * is null terminated.
1879 */
1880 if (*(val + arg->str.field->size - 1)) {
1881 /* copy it */
1882 memcpy(arg->str.buffer, val, arg->str.field->size);
1883 /* the buffer is already NULL terminated */
1884 val = arg->str.buffer;
1885 }
1886
1887 } else {
1888 event = arg->str.field->event;
1889 pevent = event->pevent;
1890 addr = get_value(event, arg->str.field, record);
1891
1892 if (arg->str.field->flags & (FIELD_IS_POINTER | FIELD_IS_LONG))
1893 /* convert to a kernel symbol */
1894 val = pevent_find_function(pevent, addr);
1895
1896 if (val == NULL) {
1897 /* just use the hex of the string name */
1898 snprintf(hex, 64, "0x%llx", addr);
1899 val = hex;
1900 }
1901 }
1902
1903 return val;
1904 }
1905
test_str(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1906 static int test_str(struct event_format *event, struct filter_arg *arg,
1907 struct pevent_record *record, enum pevent_errno *err)
1908 {
1909 const char *val;
1910
1911 if (arg->str.field == &comm)
1912 val = get_comm(event, record);
1913 else
1914 val = get_field_str(arg, record);
1915
1916 switch (arg->str.type) {
1917 case FILTER_CMP_MATCH:
1918 return strcmp(val, arg->str.val) == 0;
1919
1920 case FILTER_CMP_NOT_MATCH:
1921 return strcmp(val, arg->str.val) != 0;
1922
1923 case FILTER_CMP_REGEX:
1924 /* Returns zero on match */
1925 return !regexec(&arg->str.reg, val, 0, NULL, 0);
1926
1927 case FILTER_CMP_NOT_REGEX:
1928 return regexec(&arg->str.reg, val, 0, NULL, 0);
1929
1930 default:
1931 if (!*err)
1932 *err = PEVENT_ERRNO__ILLEGAL_STRING_CMP;
1933 return 0;
1934 }
1935 }
1936
test_op(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1937 static int test_op(struct event_format *event, struct filter_arg *arg,
1938 struct pevent_record *record, enum pevent_errno *err)
1939 {
1940 switch (arg->op.type) {
1941 case FILTER_OP_AND:
1942 return test_filter(event, arg->op.left, record, err) &&
1943 test_filter(event, arg->op.right, record, err);
1944
1945 case FILTER_OP_OR:
1946 return test_filter(event, arg->op.left, record, err) ||
1947 test_filter(event, arg->op.right, record, err);
1948
1949 case FILTER_OP_NOT:
1950 return !test_filter(event, arg->op.right, record, err);
1951
1952 default:
1953 if (!*err)
1954 *err = PEVENT_ERRNO__INVALID_OP_TYPE;
1955 return 0;
1956 }
1957 }
1958
test_filter(struct event_format * event,struct filter_arg * arg,struct pevent_record * record,enum pevent_errno * err)1959 static int test_filter(struct event_format *event, struct filter_arg *arg,
1960 struct pevent_record *record, enum pevent_errno *err)
1961 {
1962 if (*err) {
1963 /*
1964 * There was an error, no need to process anymore.
1965 */
1966 return 0;
1967 }
1968
1969 switch (arg->type) {
1970 case FILTER_ARG_BOOLEAN:
1971 /* easy case */
1972 return arg->boolean.value;
1973
1974 case FILTER_ARG_OP:
1975 return test_op(event, arg, record, err);
1976
1977 case FILTER_ARG_NUM:
1978 return test_num(event, arg, record, err);
1979
1980 case FILTER_ARG_STR:
1981 return test_str(event, arg, record, err);
1982
1983 case FILTER_ARG_EXP:
1984 case FILTER_ARG_VALUE:
1985 case FILTER_ARG_FIELD:
1986 /*
1987 * Expressions, fields and values evaluate
1988 * to true if they return non zero
1989 */
1990 return !!get_arg_value(event, arg, record, err);
1991
1992 default:
1993 if (!*err)
1994 *err = PEVENT_ERRNO__INVALID_ARG_TYPE;
1995 return 0;
1996 }
1997 }
1998
1999 /**
2000 * pevent_event_filtered - return true if event has filter
2001 * @filter: filter struct with filter information
2002 * @event_id: event id to test if filter exists
2003 *
2004 * Returns 1 if filter found for @event_id
2005 * otherwise 0;
2006 */
pevent_event_filtered(struct event_filter * filter,int event_id)2007 int pevent_event_filtered(struct event_filter *filter, int event_id)
2008 {
2009 struct filter_type *filter_type;
2010
2011 if (!filter->filters)
2012 return 0;
2013
2014 filter_type = find_filter_type(filter, event_id);
2015
2016 return filter_type ? 1 : 0;
2017 }
2018
2019 /**
2020 * pevent_filter_match - test if a record matches a filter
2021 * @filter: filter struct with filter information
2022 * @record: the record to test against the filter
2023 *
2024 * Returns: match result or error code (prefixed with PEVENT_ERRNO__)
2025 * FILTER_MATCH - filter found for event and @record matches
2026 * FILTER_MISS - filter found for event and @record does not match
2027 * FILTER_NOT_FOUND - no filter found for @record's event
2028 * NO_FILTER - if no filters exist
2029 * otherwise - error occurred during test
2030 */
pevent_filter_match(struct event_filter * filter,struct pevent_record * record)2031 enum pevent_errno pevent_filter_match(struct event_filter *filter,
2032 struct pevent_record *record)
2033 {
2034 struct pevent *pevent = filter->pevent;
2035 struct filter_type *filter_type;
2036 int event_id;
2037 int ret;
2038 enum pevent_errno err = 0;
2039
2040 filter_init_error_buf(filter);
2041
2042 if (!filter->filters)
2043 return PEVENT_ERRNO__NO_FILTER;
2044
2045 event_id = pevent_data_type(pevent, record);
2046
2047 filter_type = find_filter_type(filter, event_id);
2048 if (!filter_type)
2049 return PEVENT_ERRNO__FILTER_NOT_FOUND;
2050
2051 ret = test_filter(filter_type->event, filter_type->filter, record, &err);
2052 if (err)
2053 return err;
2054
2055 return ret ? PEVENT_ERRNO__FILTER_MATCH : PEVENT_ERRNO__FILTER_MISS;
2056 }
2057
op_to_str(struct event_filter * filter,struct filter_arg * arg)2058 static char *op_to_str(struct event_filter *filter, struct filter_arg *arg)
2059 {
2060 char *str = NULL;
2061 char *left = NULL;
2062 char *right = NULL;
2063 char *op = NULL;
2064 int left_val = -1;
2065 int right_val = -1;
2066 int val;
2067
2068 switch (arg->op.type) {
2069 case FILTER_OP_AND:
2070 op = "&&";
2071 /* fall through */
2072 case FILTER_OP_OR:
2073 if (!op)
2074 op = "||";
2075
2076 left = arg_to_str(filter, arg->op.left);
2077 right = arg_to_str(filter, arg->op.right);
2078 if (!left || !right)
2079 break;
2080
2081 /* Try to consolidate boolean values */
2082 if (strcmp(left, "TRUE") == 0)
2083 left_val = 1;
2084 else if (strcmp(left, "FALSE") == 0)
2085 left_val = 0;
2086
2087 if (strcmp(right, "TRUE") == 0)
2088 right_val = 1;
2089 else if (strcmp(right, "FALSE") == 0)
2090 right_val = 0;
2091
2092 if (left_val >= 0) {
2093 if ((arg->op.type == FILTER_OP_AND && !left_val) ||
2094 (arg->op.type == FILTER_OP_OR && left_val)) {
2095 /* Just return left value */
2096 str = left;
2097 left = NULL;
2098 break;
2099 }
2100 if (right_val >= 0) {
2101 /* just evaluate this. */
2102 val = 0;
2103 switch (arg->op.type) {
2104 case FILTER_OP_AND:
2105 val = left_val && right_val;
2106 break;
2107 case FILTER_OP_OR:
2108 val = left_val || right_val;
2109 break;
2110 default:
2111 break;
2112 }
2113 asprintf(&str, val ? "TRUE" : "FALSE");
2114 break;
2115 }
2116 }
2117 if (right_val >= 0) {
2118 if ((arg->op.type == FILTER_OP_AND && !right_val) ||
2119 (arg->op.type == FILTER_OP_OR && right_val)) {
2120 /* Just return right value */
2121 str = right;
2122 right = NULL;
2123 break;
2124 }
2125 /* The right value is meaningless */
2126 str = left;
2127 left = NULL;
2128 break;
2129 }
2130
2131 asprintf(&str, "(%s) %s (%s)", left, op, right);
2132 break;
2133
2134 case FILTER_OP_NOT:
2135 op = "!";
2136 right = arg_to_str(filter, arg->op.right);
2137 if (!right)
2138 break;
2139
2140 /* See if we can consolidate */
2141 if (strcmp(right, "TRUE") == 0)
2142 right_val = 1;
2143 else if (strcmp(right, "FALSE") == 0)
2144 right_val = 0;
2145 if (right_val >= 0) {
2146 /* just return the opposite */
2147 asprintf(&str, right_val ? "FALSE" : "TRUE");
2148 break;
2149 }
2150 asprintf(&str, "%s(%s)", op, right);
2151 break;
2152
2153 default:
2154 /* ?? */
2155 break;
2156 }
2157 free(left);
2158 free(right);
2159 return str;
2160 }
2161
val_to_str(struct event_filter * filter,struct filter_arg * arg)2162 static char *val_to_str(struct event_filter *filter, struct filter_arg *arg)
2163 {
2164 char *str = NULL;
2165
2166 asprintf(&str, "%lld", arg->value.val);
2167
2168 return str;
2169 }
2170
field_to_str(struct event_filter * filter,struct filter_arg * arg)2171 static char *field_to_str(struct event_filter *filter, struct filter_arg *arg)
2172 {
2173 return strdup(arg->field.field->name);
2174 }
2175
exp_to_str(struct event_filter * filter,struct filter_arg * arg)2176 static char *exp_to_str(struct event_filter *filter, struct filter_arg *arg)
2177 {
2178 char *lstr;
2179 char *rstr;
2180 char *op;
2181 char *str = NULL;
2182
2183 lstr = arg_to_str(filter, arg->exp.left);
2184 rstr = arg_to_str(filter, arg->exp.right);
2185 if (!lstr || !rstr)
2186 goto out;
2187
2188 switch (arg->exp.type) {
2189 case FILTER_EXP_ADD:
2190 op = "+";
2191 break;
2192 case FILTER_EXP_SUB:
2193 op = "-";
2194 break;
2195 case FILTER_EXP_MUL:
2196 op = "*";
2197 break;
2198 case FILTER_EXP_DIV:
2199 op = "/";
2200 break;
2201 case FILTER_EXP_MOD:
2202 op = "%";
2203 break;
2204 case FILTER_EXP_RSHIFT:
2205 op = ">>";
2206 break;
2207 case FILTER_EXP_LSHIFT:
2208 op = "<<";
2209 break;
2210 case FILTER_EXP_AND:
2211 op = "&";
2212 break;
2213 case FILTER_EXP_OR:
2214 op = "|";
2215 break;
2216 case FILTER_EXP_XOR:
2217 op = "^";
2218 break;
2219 default:
2220 op = "[ERROR IN EXPRESSION TYPE]";
2221 break;
2222 }
2223
2224 asprintf(&str, "%s %s %s", lstr, op, rstr);
2225 out:
2226 free(lstr);
2227 free(rstr);
2228
2229 return str;
2230 }
2231
num_to_str(struct event_filter * filter,struct filter_arg * arg)2232 static char *num_to_str(struct event_filter *filter, struct filter_arg *arg)
2233 {
2234 char *lstr;
2235 char *rstr;
2236 char *str = NULL;
2237 char *op = NULL;
2238
2239 lstr = arg_to_str(filter, arg->num.left);
2240 rstr = arg_to_str(filter, arg->num.right);
2241 if (!lstr || !rstr)
2242 goto out;
2243
2244 switch (arg->num.type) {
2245 case FILTER_CMP_EQ:
2246 op = "==";
2247 /* fall through */
2248 case FILTER_CMP_NE:
2249 if (!op)
2250 op = "!=";
2251 /* fall through */
2252 case FILTER_CMP_GT:
2253 if (!op)
2254 op = ">";
2255 /* fall through */
2256 case FILTER_CMP_LT:
2257 if (!op)
2258 op = "<";
2259 /* fall through */
2260 case FILTER_CMP_GE:
2261 if (!op)
2262 op = ">=";
2263 /* fall through */
2264 case FILTER_CMP_LE:
2265 if (!op)
2266 op = "<=";
2267
2268 asprintf(&str, "%s %s %s", lstr, op, rstr);
2269 break;
2270
2271 default:
2272 /* ?? */
2273 break;
2274 }
2275
2276 out:
2277 free(lstr);
2278 free(rstr);
2279 return str;
2280 }
2281
str_to_str(struct event_filter * filter,struct filter_arg * arg)2282 static char *str_to_str(struct event_filter *filter, struct filter_arg *arg)
2283 {
2284 char *str = NULL;
2285 char *op = NULL;
2286
2287 switch (arg->str.type) {
2288 case FILTER_CMP_MATCH:
2289 op = "==";
2290 /* fall through */
2291 case FILTER_CMP_NOT_MATCH:
2292 if (!op)
2293 op = "!=";
2294 /* fall through */
2295 case FILTER_CMP_REGEX:
2296 if (!op)
2297 op = "=~";
2298 /* fall through */
2299 case FILTER_CMP_NOT_REGEX:
2300 if (!op)
2301 op = "!~";
2302
2303 asprintf(&str, "%s %s \"%s\"",
2304 arg->str.field->name, op, arg->str.val);
2305 break;
2306
2307 default:
2308 /* ?? */
2309 break;
2310 }
2311 return str;
2312 }
2313
arg_to_str(struct event_filter * filter,struct filter_arg * arg)2314 static char *arg_to_str(struct event_filter *filter, struct filter_arg *arg)
2315 {
2316 char *str = NULL;
2317
2318 switch (arg->type) {
2319 case FILTER_ARG_BOOLEAN:
2320 asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
2321 return str;
2322
2323 case FILTER_ARG_OP:
2324 return op_to_str(filter, arg);
2325
2326 case FILTER_ARG_NUM:
2327 return num_to_str(filter, arg);
2328
2329 case FILTER_ARG_STR:
2330 return str_to_str(filter, arg);
2331
2332 case FILTER_ARG_VALUE:
2333 return val_to_str(filter, arg);
2334
2335 case FILTER_ARG_FIELD:
2336 return field_to_str(filter, arg);
2337
2338 case FILTER_ARG_EXP:
2339 return exp_to_str(filter, arg);
2340
2341 default:
2342 /* ?? */
2343 return NULL;
2344 }
2345
2346 }
2347
2348 /**
2349 * pevent_filter_make_string - return a string showing the filter
2350 * @filter: filter struct with filter information
2351 * @event_id: the event id to return the filter string with
2352 *
2353 * Returns a string that displays the filter contents.
2354 * This string must be freed with free(str).
2355 * NULL is returned if no filter is found or allocation failed.
2356 */
2357 char *
pevent_filter_make_string(struct event_filter * filter,int event_id)2358 pevent_filter_make_string(struct event_filter *filter, int event_id)
2359 {
2360 struct filter_type *filter_type;
2361
2362 if (!filter->filters)
2363 return NULL;
2364
2365 filter_type = find_filter_type(filter, event_id);
2366
2367 if (!filter_type)
2368 return NULL;
2369
2370 return arg_to_str(filter, filter_type->filter);
2371 }
2372
2373 /**
2374 * pevent_filter_compare - compare two filters and return if they are the same
2375 * @filter1: Filter to compare with @filter2
2376 * @filter2: Filter to compare with @filter1
2377 *
2378 * Returns:
2379 * 1 if the two filters hold the same content.
2380 * 0 if they do not.
2381 */
pevent_filter_compare(struct event_filter * filter1,struct event_filter * filter2)2382 int pevent_filter_compare(struct event_filter *filter1, struct event_filter *filter2)
2383 {
2384 struct filter_type *filter_type1;
2385 struct filter_type *filter_type2;
2386 char *str1, *str2;
2387 int result;
2388 int i;
2389
2390 /* Do the easy checks first */
2391 if (filter1->filters != filter2->filters)
2392 return 0;
2393 if (!filter1->filters && !filter2->filters)
2394 return 1;
2395
2396 /*
2397 * Now take a look at each of the events to see if they have the same
2398 * filters to them.
2399 */
2400 for (i = 0; i < filter1->filters; i++) {
2401 filter_type1 = &filter1->event_filters[i];
2402 filter_type2 = find_filter_type(filter2, filter_type1->event_id);
2403 if (!filter_type2)
2404 break;
2405 if (filter_type1->filter->type != filter_type2->filter->type)
2406 break;
2407 switch (filter_type1->filter->type) {
2408 case FILTER_TRIVIAL_FALSE:
2409 case FILTER_TRIVIAL_TRUE:
2410 /* trivial types just need the type compared */
2411 continue;
2412 default:
2413 break;
2414 }
2415 /* The best way to compare complex filters is with strings */
2416 str1 = arg_to_str(filter1, filter_type1->filter);
2417 str2 = arg_to_str(filter2, filter_type2->filter);
2418 if (str1 && str2)
2419 result = strcmp(str1, str2) != 0;
2420 else
2421 /* bail out if allocation fails */
2422 result = 1;
2423
2424 free(str1);
2425 free(str2);
2426 if (result)
2427 break;
2428 }
2429
2430 if (i < filter1->filters)
2431 return 0;
2432 return 1;
2433 }
2434
2435