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 struct bytecode_symbol_iterator *bytecode_symbol_iterator_create(
  32                 struct lttng_filter_bytecode *bytecode)
  33 {
  34         struct bytecode_symbol_iterator *it = NULL;
  35
  36         if (!bytecode) {
  37                 goto end;
  38         }
  39
  40         it = zmalloc(sizeof(*it));
  41         if (!it) {
  42                 goto end;
  43         }
  44
  45         it->bytecode = bytecode->data;
  46         it->offset = bytecode->reloc_table_offset;
  47         it->len = bytecode->len;
  48 end:
  49         return it;
  50 }
  51
  52 int bytecode_symbol_iterator_next(struct bytecode_symbol_iterator *it)
  53 {
  54         int ret;
  55         size_t len;
  56
  57         if (!it || it->offset >= it->len) {
  58                 ret = -1;
  59                 goto end;
  60         }
  61
  62         len = strlen(it->bytecode + it->offset + sizeof(uint16_t)) + 1;
  63         it->offset += len + sizeof(uint16_t);
  64         ret = it->offset >= it->len ? -1 : 0;
  65 end:
  66         return ret;
  67 }
  68
  69 int bytecode_symbol_iterator_get_type(struct bytecode_symbol_iterator *it)
  70 {
  71         int ret;
  72
  73         if (!it) {
  74                 ret = -1;
  75                 goto end;
  76         }
  77
  78         ret = *((uint16_t *) (it->bytecode + it->offset));
  79 end:
  80         return ret;
  81  }
  82
  83 const char *bytecode_symbol_iterator_get_name(
  84                 struct bytecode_symbol_iterator *it)
  85 {
  86         const char *ret = NULL;
  87
  88         if (!it) {
  89                 goto end;
  90         }
  91
  92         ret = it->bytecode + it->offset + sizeof(uint16_t);
  93 end:
  94         return ret;
  95 }
  96
  97 void bytecode_symbol_iterator_destroy(struct bytecode_symbol_iterator *it)
  98 {
  99         free(it);
 100 }