epan/tvbuff_real.c

   1 /* tvbuff_real.c
   2  *
   3  * Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11
  12 #include "config.h"
  13
  14 #include "tvbuff.h"
  15 #include "tvbuff-int.h"
  16 #include "proto.h"      /* XXX - only used for DISSECTOR_ASSERT, probably a new header file? */
  17 #include "exceptions.h"
  18
  19 struct tvb_real {
  20         struct tvbuff tvb;
  21
  22         /** Func to call when actually freed */
  23         tvbuff_free_cb_t        free_cb;
  24 };
  25
  26 static void
  27 real_free(tvbuff_t *tvb)
  28 {
  29         struct tvb_real *real_tvb = (struct tvb_real *) tvb;
  30
  31         if (real_tvb->free_cb) {
  32                 /*
  33                  * XXX - do this with a union?
  34                  */
  35                 real_tvb->free_cb((void *)tvb->real_data);
  36         }
  37 }
  38
  39 static unsigned
  40 real_offset(const tvbuff_t *tvb _U_, const unsigned counter)
  41 {
  42         return counter;
  43 }
  44
  45 static const struct tvb_ops tvb_real_ops = {
  46         sizeof(struct tvb_real), /* size */
  47
  48         real_free,            /* free */
  49         real_offset,          /* offset */
  50         NULL,                 /* get_ptr */
  51         NULL,                 /* memcpy */
  52         NULL,                 /* find_uint8 */
  53         NULL,                 /* pbrk_uint8 */
  54         NULL,                 /* clone */
  55 };
  56
  57 tvbuff_t *
  58 tvb_new_real_data(const uint8_t* data, const unsigned length, const int reported_length)
  59 {
  60         tvbuff_t *tvb;
  61         struct tvb_real *real_tvb;
  62
  63         THROW_ON(reported_length < -1, ReportedBoundsError);
  64
  65         tvb = tvb_new(&tvb_real_ops);
  66
  67         tvb->real_data           = data;
  68         tvb->length              = length;
  69         tvb->reported_length     = reported_length;
  70         tvb->contained_length    = reported_length;
  71         tvb->initialized         = true;
  72
  73         /*
  74          * This is the top-level real tvbuff for this data source,
  75          * so its data source tvbuff is itself.
  76          */
  77         tvb->ds_tvb = tvb;
  78
  79         real_tvb = (struct tvb_real *) tvb;
  80         real_tvb->free_cb = NULL;
  81
  82         return tvb;
  83 }
  84
  85 void
  86 tvb_set_free_cb(tvbuff_t *tvb, const tvbuff_free_cb_t func)
  87 {
  88         struct tvb_real *real_tvb = (struct tvb_real *) tvb;
  89
  90         DISSECTOR_ASSERT(tvb);
  91         DISSECTOR_ASSERT(tvb->ops == &tvb_real_ops);
  92         real_tvb->free_cb = func;
  93 }
  94
  95 void
  96 tvb_set_child_real_data_tvbuff(tvbuff_t *parent, tvbuff_t *child)
  97 {
  98         DISSECTOR_ASSERT(parent && child);
  99         DISSECTOR_ASSERT(parent->initialized);
 100         DISSECTOR_ASSERT(child->initialized);
 101         DISSECTOR_ASSERT(child->ops == &tvb_real_ops);
 102         tvb_add_to_chain(parent, child);
 103 }
 104
 105 tvbuff_t *
 106 tvb_new_child_real_data(tvbuff_t *parent, const uint8_t* data, const unsigned length, const int reported_length)
 107 {
 108         tvbuff_t *tvb = tvb_new_real_data(data, length, reported_length);
 109
 110         tvb_set_child_real_data_tvbuff(parent, tvb);
 111
 112         return tvb;
 113 }
 114
 115 /*
 116  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 117  *
 118  * Local variables:
 119  * c-basic-offset: 8
 120  * tab-width: 8
 121  * indent-tabs-mode: t
 122  * End:
 123  *
 124  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 125  * :indentSize=8:tabSize=8:noTabs=false:
 126  */