src/common/filter.c

   1 /*
   2  * filter.c
   3  *
   4  * LTTng filter bytecode utilities.
   5  *
   6  * Copyright 2016 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this library; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "filter.h"
  23 #include <stddef.h>
  24
  25 struct bytecode_symbol_iterator {
  26         /* No ownership of bytecode is taken. */
  27         char *bytecode;
  28         size_t offset, len;
  29 };
  30
  31 LTTNG_HIDDEN
  32 struct bytecode_symbol_iterator *bytecode_symbol_iterator_create(
  33                 struct lttng_filter_bytecode *bytecode)
  34 {
  35         struct bytecode_symbol_iterator *it = NULL;
  36
  37         if (!bytecode) {
  38                 goto end;
  39         }
  40
  41         it = zmalloc(sizeof(*it));
  42         if (!it) {
  43                 goto end;
  44         }
  45
  46         it->bytecode = bytecode->data;
  47         it->offset = bytecode->reloc_table_offset;
  48         it->len = bytecode->len;
  49 end:
  50         return it;
  51 }
  52
  53 LTTNG_HIDDEN
  54 int bytecode_symbol_iterator_next(struct bytecode_symbol_iterator *it)
  55 {
  56         int ret;
  57         size_t len;
  58
  59         if (!it || it->offset >= it->len) {
  60                 ret = -1;
  61                 goto end;
  62         }
  63
  64         len = strlen(it->bytecode + it->offset + sizeof(uint16_t)) + 1;
  65         it->offset += len + sizeof(uint16_t);
  66         ret = it->offset >= it->len ? -1 : 0;
  67 end:
  68         return ret;
  69 }
  70
  71 LTTNG_HIDDEN
  72 int bytecode_symbol_iterator_get_type(struct bytecode_symbol_iterator *it)
  73 {
  74         int ret;
  75
  76         if (!it) {
  77                 ret = -1;
  78                 goto end;
  79         }
  80
  81         ret = *((uint16_t *) (it->bytecode + it->offset));
  82 end:
  83         return ret;
  84  }
  85
  86 LTTNG_HIDDEN
  87 const char *bytecode_symbol_iterator_get_name(
  88                 struct bytecode_symbol_iterator *it)
  89 {
  90         const char *ret = NULL;
  91
  92         if (!it) {
  93                 goto end;
  94         }
  95
  96         ret = it->bytecode + it->offset + sizeof(uint16_t);
  97 end:
  98         return ret;
  99 }
 100
 101 LTTNG_HIDDEN
 102 void bytecode_symbol_iterator_destroy(struct bytecode_symbol_iterator *it)
 103 {
 104         free(it);
 105 }