lib/gnutls_mbuffers.h

   1 /*
   2  * Copyright (C) 2009-2012 Free Software Foundation, Inc.
   3  *
   4  * Author: Jonathan Bastien-Filiatrault
   5  *
   6  * This file is part of GNUTLS.
   7  *
   8  * The GNUTLS library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>
  20  *
  21  */
  22
  23 #ifndef GNUTLS_MBUFFERS_H
  24 #define GNUTLS_MBUFFERS_H
  25
  26 #include <gnutls_int.h>
  27 #include <gnutls_errors.h>
  28
  29 void _mbuffer_head_init (mbuffer_head_st * buf);
  30 void _mbuffer_head_clear (mbuffer_head_st * buf);
  31 void _mbuffer_enqueue (mbuffer_head_st * buf, mbuffer_st * bufel);
  32 mbuffer_st* _mbuffer_dequeue (mbuffer_head_st * buf, mbuffer_st * bufel);
  33 int _mbuffer_head_remove_bytes (mbuffer_head_st * buf, size_t bytes);
  34 mbuffer_st *_mbuffer_alloc (size_t payload_size, size_t maximum_size);
  35
  36 mbuffer_st *_mbuffer_head_get_first (mbuffer_head_st * buf, gnutls_datum_t * msg);
  37 mbuffer_st *_mbuffer_head_get_next (mbuffer_st * cur, gnutls_datum_t * msg);
  38
  39 mbuffer_st *
  40 _mbuffer_head_pop_first (mbuffer_head_st * buf);
  41
  42 /* This is dangerous since it will replace bufel with a new
  43  * one.
  44  */
  45 int _mbuffer_append_data (mbuffer_st * bufel, void *newdata,
  46                           size_t newdata_size);
  47 int _mbuffer_linearize (mbuffer_head_st * buf);
  48
  49
  50 /* For "user" use. One can have buffer data and header.
  51  */
  52
  53 inline static void
  54 _mbuffer_set_udata (mbuffer_st * bufel, void *data, size_t data_size)
  55 {
  56   memcpy (bufel->msg.data + bufel->mark + bufel->user_mark, data, data_size);
  57   bufel->msg.size = data_size + bufel->user_mark + bufel->mark;
  58 }
  59
  60 inline static void *
  61 _mbuffer_get_uhead_ptr (mbuffer_st * bufel)
  62 {
  63   return bufel->msg.data + bufel->mark;
  64 }
  65
  66 inline static void *
  67 _mbuffer_get_udata_ptr (mbuffer_st * bufel)
  68 {
  69   return bufel->msg.data + bufel->user_mark + bufel->mark;
  70 }
  71
  72 inline static void
  73 _mbuffer_set_udata_size (mbuffer_st * bufel, size_t size)
  74 {
  75   bufel->msg.size = size + bufel->user_mark + bufel->mark;
  76 }
  77
  78 inline static size_t
  79 _mbuffer_get_udata_size (mbuffer_st * bufel)
  80 {
  81   return bufel->msg.size - bufel->user_mark - bufel->mark;
  82 }
  83
  84 /* discards size bytes from the begging of the buffer */
  85 inline static void
  86 _mbuffer_consume (mbuffer_head_st* buf, mbuffer_st * bufel, size_t size)
  87 {
  88   bufel->user_mark = 0;
  89   if (bufel->mark+size < bufel->msg.size)
  90     bufel->mark += size;
  91   else
  92     bufel->mark = bufel->msg.size;
  93
  94   buf->byte_length -= size;
  95 }
  96
  97 inline static size_t
  98 _mbuffer_get_uhead_size (mbuffer_st * bufel)
  99 {
 100   return bufel->user_mark;
 101 }
 102
 103 inline static void
 104 _mbuffer_set_uhead_size (mbuffer_st * bufel, size_t size)
 105 {
 106   bufel->user_mark = size;
 107 }
 108
 109
 110
 111 inline static mbuffer_st *
 112 _gnutls_handshake_alloc (gnutls_session_t session, size_t size, size_t maximum)
 113 {
 114   mbuffer_st *ret = _mbuffer_alloc (HANDSHAKE_HEADER_SIZE(session) + size,
 115                                     HANDSHAKE_HEADER_SIZE(session) + maximum);
 116
 117   if (!ret)
 118     return NULL;
 119
 120   _mbuffer_set_uhead_size (ret, HANDSHAKE_HEADER_SIZE(session));
 121
 122   return ret;
 123 }
 124
 125 /* Free a segment, if the pointer is not NULL
 126  *
 127  * We take a ** to detect and fix double free bugs (the dangling
 128  * pointer case). It also makes sure the pointer has a known value
 129  * after freeing.
 130  */
 131 inline static void
 132 _mbuffer_xfree (mbuffer_st ** bufel)
 133 {
 134   if (*bufel)
 135     gnutls_free (*bufel);
 136
 137   *bufel = NULL;
 138 }
 139
 140 #endif