diff options
author | Bernhard Schmidt <berni@debian.org> | 2020-09-01 16:53:26 +0200 |
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committer | Bernhard Schmidt <berni@debian.org> | 2020-09-01 16:53:26 +0200 |
commit | 57f0b7b331088e489e93ae89ee0aed98381d8806 (patch) | |
tree | b86439ebb9e98eb6b81bda4c47f67cd3959d182f /doc/doxygen/doc_memory_management.h | |
parent | 1079962e4c06f88a54e50d997c1b7e84303d30b4 (diff) |
New upstream version 2.5~beta3upstream/2.5_beta3
Diffstat (limited to 'doc/doxygen/doc_memory_management.h')
-rw-r--r-- | doc/doxygen/doc_memory_management.h | 98 |
1 files changed, 0 insertions, 98 deletions
diff --git a/doc/doxygen/doc_memory_management.h b/doc/doxygen/doc_memory_management.h deleted file mode 100644 index 1f16328..0000000 --- a/doc/doxygen/doc_memory_management.h +++ /dev/null @@ -1,98 +0,0 @@ -/* - * OpenVPN -- An application to securely tunnel IP networks - * over a single TCP/UDP port, with support for SSL/TLS-based - * session authentication and key exchange, - * packet encryption, packet authentication, and - * packet compression. - * - * Copyright (C) 2010-2018 Fox Crypto B.V. <openvpn@fox-it.com> - * - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - */ - -/** - * @file - * Memory management strategies documentation file. - */ - -/** - * @page memory_management OpenVPN's memory management strategies - * - * This section describes several implementation details relating to - * OpenVPN's memory management strategies. - * - * During operation, the OpenVPN process performs all kinds of operations - * on blocks of data. Receiving packets, encrypting content, prepending - * headers, etc. To make the programmer's job easier and to decrease the - * likelihood of memory-related bugs, OpenVPN uses its own memory %buffer - * library and garbage collection facilities. These are described in - * brief here. - * - * @section memory_management_buffer The buffer structure - * - * The \c buffer structure is a wrapper around a block of dynamically - * allocated memory which keeps track of the block's capacity \c - * buffer.capacity and location in memory \c buffer.data. This structure - * supports efficient prepending and appending within the allocated memory - * through the use of offset \c buffer.offset and length \c buffer.len - * fields. See the \c buffer documentation for more details on the - * structure itself. - * - * OpenVPN's %buffer library, implemented in the \c buffer.h and \c - * buffer.c files, contains many utility functions for working with \c - * buffer structures. These functions facilitate common operations, such - * as allocating, freeing, reading and writing to \c buffer structures, - * and even offer several more advanced operations, such as string - * matching and creating sub-buffers. - * - * Not only do these utility functions make working with \c buffer - * structures easy, they also perform extensive error checking. Each - * function, where necessary, checks whether enough space is available - * before performing its actions. This minimizes the chance of bugs - * leading to %buffer overflows and other vulnerabilities. - * - * @section memory_management_frame The frame structure - * - * The \c frame structure keeps track of the maximum allowed packet - * geometries of a network connection. - * - * It is used, for example, to determine the size of \c buffer structures - * in which to store data channel packets. This is done by having each - * data channel processing module register the maximum amount of extra - * space it will need for header prepending and content expansion in the - * \c frame structure. Once these parameters are known, \c buffer - * structures can be allocated, based on the \c frame parameters, so that - * they are large enough to allow efficient prepending of headers and - * processing of content. - * - * @section memory_management_garbage Garbage collection - * - * OpenVPN has many sizable functions which perform various actions - * depending on their %context. This makes it difficult to know in advance - * exactly how much memory must be allocated. The garbage collection - * facilities are used to keep track of dynamic allocations, thereby - * allowing easy collective freeing of the allocated memory. - * - * The garbage collection system is implemented by the \c gc_arena and \c - * gc_entry structures. The arena represents a garbage collecting unit, - * and contains a linked list of entries. Each entry represents one block - * of dynamically allocated memory. - * - * The garbage collection system also contains various utility functions - * for working with the garbage collection structures. These include - * functions for initializing new arenas, allocating memory of a given - * size and registering the allocation in an arena, and freeing all the - * allocated memory associated with an arena. - */ |