SSL_alloc_buffers.3ossl 3.9 KB

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  57. .IX Title "SSL_ALLOC_BUFFERS 3ossl"
  58. .TH SSL_ALLOC_BUFFERS 3ossl 2025-01-17 3.4.0 OpenSSL
  59. .\" For nroff, turn off justification. Always turn off hyphenation; it makes
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  61. .if n .ad l
  62. .nh
  63. .SH NAME
  64. SSL_free_buffers, SSL_alloc_buffers \- manage SSL structure buffers
  65. .SH SYNOPSIS
  66. .IX Header "SYNOPSIS"
  67. .Vb 1
  68. \& #include <openssl/ssl.h>
  69. \&
  70. \& int SSL_free_buffers(SSL *ssl);
  71. \& int SSL_alloc_buffers(SSL *ssl);
  72. .Ve
  73. .SH DESCRIPTION
  74. .IX Header "DESCRIPTION"
  75. \&\fBSSL_free_buffers()\fR frees the read and write buffers of the given \fBssl\fR.
  76. \&\fBSSL_alloc_buffers()\fR allocates the read and write buffers of the given \fBssl\fR.
  77. .PP
  78. The \fBSSL_MODE_RELEASE_BUFFERS\fR mode releases read or write buffers whenever
  79. the buffers have been drained. These functions allow applications to manually
  80. control when buffers are freed and allocated.
  81. .PP
  82. After freeing the buffers, the buffers are automatically reallocated upon a
  83. new read or write. The \fBSSL_alloc_buffers()\fR does not need to be called, but
  84. can be used to make sure the buffers are preallocated. This can be used to
  85. avoid allocation during data processing or with \fBCRYPTO_set_mem_functions()\fR
  86. to control where and how buffers are allocated.
  87. .PP
  88. These functions are no-ops when used with QUIC SSL objects. For QUIC,
  89. \&\fBSSL_free_buffers()\fR always fails, and \fBSSL_alloc_buffers()\fR always succeeds.
  90. .SH "RETURN VALUES"
  91. .IX Header "RETURN VALUES"
  92. The following return values can occur:
  93. .IP "0 (Failure)" 4
  94. .IX Item "0 (Failure)"
  95. The \fBSSL_free_buffers()\fR function returns 0 when there is pending data to be
  96. read or written. The \fBSSL_alloc_buffers()\fR function returns 0 when there is
  97. an allocation failure.
  98. .IP "1 (Success)" 4
  99. .IX Item "1 (Success)"
  100. The \fBSSL_free_buffers()\fR function returns 1 if the buffers have been freed. This
  101. value is also returned if the buffers had been freed before calling
  102. \&\fBSSL_free_buffers()\fR.
  103. The \fBSSL_alloc_buffers()\fR function returns 1 if the buffers have been allocated.
  104. This value is also returned if the buffers had been allocated before calling
  105. \&\fBSSL_alloc_buffers()\fR.
  106. .SH "SEE ALSO"
  107. .IX Header "SEE ALSO"
  108. \&\fBssl\fR\|(7),
  109. \&\fBSSL_free\fR\|(3), \fBSSL_clear\fR\|(3),
  110. \&\fBSSL_new\fR\|(3), \fBSSL_CTX_set_mode\fR\|(3),
  111. \&\fBCRYPTO_set_mem_functions\fR\|(3)
  112. .SH COPYRIGHT
  113. .IX Header "COPYRIGHT"
  114. Copyright 2017\-2023 The OpenSSL Project Authors. All Rights Reserved.
  115. .PP
  116. Licensed under the Apache License 2.0 (the "License"). You may not use
  117. this file except in compliance with the License. You can obtain a copy
  118. in the file LICENSE in the source distribution or at
  119. <https://www.openssl.org/source/license.html>.