diff options
Diffstat (limited to 'src/openvpn/compstub.c')
| -rw-r--r-- | src/openvpn/compstub.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/src/openvpn/compstub.c b/src/openvpn/compstub.c new file mode 100644 index 0000000..9c6aad2 --- /dev/null +++ b/src/openvpn/compstub.c @@ -0,0 +1,169 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2012 OpenVPN Technologies, Inc. <sales@openvpn.net> + * + * 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 (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#elif defined(_MSC_VER) +#include "config-msvc.h" +#endif + +#include "syshead.h" + +#if defined(USE_COMP) + +#include "comp.h" +#include "error.h" +#include "otime.h" + +#include "memdbg.h" + +static void +stub_compress_init (struct compress_context *compctx) +{ +} + +static void +stub_compress_uninit (struct compress_context *compctx) +{ +} + +static void +stub_compress (struct buffer *buf, struct buffer work, + struct compress_context *compctx, + const struct frame* frame) +{ + if (buf->len <= 0) + return; + if (compctx->flags & COMP_F_SWAP) + { + uint8_t *head = BPTR (buf); + uint8_t *tail = BEND (buf); + ASSERT (buf_safe (buf, 1)); + ++buf->len; + + /* move head byte of payload to tail */ + *tail = *head; + *head = NO_COMPRESS_BYTE_SWAP; + } + else + { + uint8_t *header = buf_prepend (buf, 1); + *header = NO_COMPRESS_BYTE; + } +} + +static void +stub_decompress (struct buffer *buf, struct buffer work, + struct compress_context *compctx, + const struct frame* frame) +{ + uint8_t c; + if (buf->len <= 0) + return; + if (compctx->flags & COMP_F_SWAP) + { + uint8_t *head = BPTR (buf); + c = *head; + --buf->len; + *head = *BEND (buf); + if (c != NO_COMPRESS_BYTE_SWAP) + { + dmsg (D_COMP_ERRORS, "Bad compression stub (swap) decompression header byte: %d", c); + buf->len = 0; + } + } + else + { + c = *BPTR (buf); + ASSERT (buf_advance (buf, 1)); + if (c != NO_COMPRESS_BYTE) + { + dmsg (D_COMP_ERRORS, "Bad compression stub decompression header byte: %d", c); + buf->len = 0; + } + } +} + + +static void +stubv2_compress (struct buffer *buf, struct buffer work, + struct compress_context *compctx, + const struct frame* frame) +{ + if (buf->len <= 0) + return; + + compv2_escape_data_ifneeded (buf); +} + +static void +stubv2_decompress (struct buffer *buf, struct buffer work, + struct compress_context *compctx, + const struct frame* frame) +{ + if (buf->len <= 0) + return; + + uint8_t *head = BPTR (buf); + + /* no compression or packet to short*/ + if (head[0] != COMP_ALGV2_INDICATOR_BYTE) + return; + + /* compression header (0x50) is present */ + buf_advance(buf, 1); + + /* Packet buffer too short (only 1 byte) */ + if (buf->len <= 0) + return; + + head = BPTR (buf); + buf_advance(buf, 1); + + if (head[0] != COMP_ALGV2_UNCOMPRESSED_BYTE) { + dmsg (D_COMP_ERRORS, "Bad compression stubv2 decompression header byte: %d", *head); + buf->len = 0; + return; + } +} + +const struct compress_alg compv2_stub_alg = { + "stubv2", + stub_compress_init, + stub_compress_uninit, + stubv2_compress, + stubv2_decompress +}; + +const struct compress_alg comp_stub_alg = { + "stub", + stub_compress_init, + stub_compress_uninit, + stub_compress, + stub_decompress +}; + +#else +static void dummy(void) {} +#endif /* USE_STUB */ |