| /* Copyright (c) 2004-2007, Sara Golemon <sarag@libssh2.org> |
| * Copyright (c) 2010, Daniel Stenberg <daniel@haxx.se> |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, |
| * with or without modification, are permitted provided |
| * that the following conditions are met: |
| * |
| * Redistributions of source code must retain the above |
| * copyright notice, this list of conditions and the |
| * following disclaimer. |
| * |
| * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials |
| * provided with the distribution. |
| * |
| * Neither the name of the copyright holder nor the names |
| * of any other contributors may be used to endorse or |
| * promote products derived from this software without |
| * specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE |
| * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
| * OF SUCH DAMAGE. |
| */ |
| |
| #include "libssh2_priv.h" |
| #ifdef LIBSSH2_HAVE_ZLIB |
| # include <zlib.h> |
| #endif |
| |
| #include "comp.h" |
| |
| /* ******** |
| * none * |
| ******** */ |
| |
| /* |
| * comp_method_none_comp |
| * |
| * Minimalist compression: Absolutely none |
| */ |
| static int |
| comp_method_none_comp(LIBSSH2_SESSION *session, |
| unsigned char *dest, |
| size_t *dest_len, |
| const unsigned char *src, |
| size_t src_len, |
| void **abstract) |
| { |
| (void) session; |
| (void) abstract; |
| (void) dest; |
| (void) dest_len; |
| (void) src; |
| (void) src_len; |
| |
| return 0; |
| } |
| |
| /* |
| * comp_method_none_decomp |
| * |
| * Minimalist decompression: Absolutely none |
| */ |
| static int |
| comp_method_none_decomp(LIBSSH2_SESSION * session, |
| unsigned char **dest, |
| size_t *dest_len, |
| size_t payload_limit, |
| const unsigned char *src, |
| size_t src_len, void **abstract) |
| { |
| (void) session; |
| (void) payload_limit; |
| (void) abstract; |
| *dest = (unsigned char *) src; |
| *dest_len = src_len; |
| return 0; |
| } |
| |
| |
| |
| static const LIBSSH2_COMP_METHOD comp_method_none = { |
| "none", |
| 0, /* not really compressing */ |
| NULL, |
| comp_method_none_comp, |
| comp_method_none_decomp, |
| NULL |
| }; |
| |
| #ifdef LIBSSH2_HAVE_ZLIB |
| /* ******** |
| * zlib * |
| ******** */ |
| |
| /* Memory management wrappers |
| * Yes, I realize we're doing a callback to a callback, |
| * Deal... |
| */ |
| |
| static voidpf |
| comp_method_zlib_alloc(voidpf opaque, uInt items, uInt size) |
| { |
| LIBSSH2_SESSION *session = (LIBSSH2_SESSION *) opaque; |
| |
| return (voidpf) LIBSSH2_ALLOC(session, items * size); |
| } |
| |
| static void |
| comp_method_zlib_free(voidpf opaque, voidpf address) |
| { |
| LIBSSH2_SESSION *session = (LIBSSH2_SESSION *) opaque; |
| |
| LIBSSH2_FREE(session, address); |
| } |
| |
| |
| |
| /* libssh2_comp_method_zlib_init |
| * All your bandwidth are belong to us (so save some) |
| */ |
| static int |
| comp_method_zlib_init(LIBSSH2_SESSION * session, int compr, |
| void **abstract) |
| { |
| z_stream *strm; |
| int status; |
| |
| strm = LIBSSH2_ALLOC(session, sizeof(z_stream)); |
| if (!strm) { |
| return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
| "Unable to allocate memory for " |
| "zlib compression/decompression"); |
| } |
| memset(strm, 0, sizeof(z_stream)); |
| |
| strm->opaque = (voidpf) session; |
| strm->zalloc = (alloc_func) comp_method_zlib_alloc; |
| strm->zfree = (free_func) comp_method_zlib_free; |
| if (compr) { |
| /* deflate */ |
| status = deflateInit(strm, Z_DEFAULT_COMPRESSION); |
| } else { |
| /* inflate */ |
| status = inflateInit(strm); |
| } |
| |
| if (status != Z_OK) { |
| LIBSSH2_FREE(session, strm); |
| _libssh2_debug(session, LIBSSH2_TRACE_TRANS, |
| "unhandled zlib error %d", status); |
| return LIBSSH2_ERROR_COMPRESS; |
| } |
| *abstract = strm; |
| |
| return LIBSSH2_ERROR_NONE; |
| } |
| |
| /* |
| * libssh2_comp_method_zlib_comp |
| * |
| * Compresses source to destination. Without allocation. |
| */ |
| static int |
| comp_method_zlib_comp(LIBSSH2_SESSION *session, |
| unsigned char *dest, |
| |
| /* dest_len is a pointer to allow this function to |
| update it with the final actual size used */ |
| size_t *dest_len, |
| const unsigned char *src, |
| size_t src_len, |
| void **abstract) |
| { |
| z_stream *strm = *abstract; |
| int out_maxlen = *dest_len; |
| int status; |
| |
| strm->next_in = (unsigned char *) src; |
| strm->avail_in = src_len; |
| strm->next_out = dest; |
| strm->avail_out = out_maxlen; |
| |
| status = deflate(strm, Z_PARTIAL_FLUSH); |
| |
| if (status != Z_OK) { |
| _libssh2_debug(session, LIBSSH2_TRACE_TRANS, |
| "unhandled zlib compression error %d", status); |
| return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, |
| "compression failure"); |
| } |
| |
| *dest_len = out_maxlen - strm->avail_out; |
| return 0; |
| } |
| |
| /* |
| * libssh2_comp_method_zlib_decomp |
| * |
| * Decompresses source to destination. Allocates the output memory. |
| */ |
| static int |
| comp_method_zlib_decomp(LIBSSH2_SESSION * session, |
| unsigned char **dest, |
| size_t *dest_len, |
| size_t payload_limit, |
| const unsigned char *src, |
| size_t src_len, void **abstract) |
| { |
| z_stream *strm = *abstract; |
| /* A short-term alloc of a full data chunk is better than a series of |
| reallocs */ |
| char *out; |
| int out_maxlen = 8 * src_len; |
| int limiter = 0; |
| |
| /* If strm is null, then we have not yet been initialized. */ |
| if (strm == NULL) |
| return _libssh2_error(session, LIBSSH2_ERROR_COMPRESS, |
| "decompression unitilized");; |
| |
| /* In practice they never come smaller than this */ |
| if (out_maxlen < 25) |
| out_maxlen = 25; |
| |
| if (out_maxlen > (int) payload_limit) |
| out_maxlen = payload_limit; |
| |
| strm->next_in = (unsigned char *) src; |
| strm->avail_in = src_len; |
| strm->next_out = (unsigned char *) LIBSSH2_ALLOC(session, out_maxlen); |
| out = (char *) strm->next_out; |
| strm->avail_out = out_maxlen; |
| if (!strm->next_out) |
| return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
| "Unable to allocate decompression buffer"); |
| while (strm->avail_in) { |
| int status; |
| |
| status = inflate(strm, Z_PARTIAL_FLUSH); |
| |
| if (status != Z_OK) { |
| LIBSSH2_FREE(session, out); |
| _libssh2_debug(session, LIBSSH2_TRACE_TRANS, |
| "unhandled zlib error %d", status); |
| return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, |
| "decompression failure"); |
| } |
| if (strm->avail_in) { |
| size_t out_ofs = out_maxlen - strm->avail_out; |
| char *newout; |
| |
| out_maxlen += 8 * strm->avail_in; |
| |
| if ((out_maxlen > (int) payload_limit) && limiter++) { |
| LIBSSH2_FREE(session, out); |
| return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, |
| "Excessive growth in decompression phase"); |
| } |
| |
| newout = LIBSSH2_REALLOC(session, out, out_maxlen); |
| if (!newout) { |
| LIBSSH2_FREE(session, out); |
| return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
| "Unable to expand decompression buffer"); |
| } |
| out = newout; |
| strm->next_out = (unsigned char *) out + out_ofs; |
| strm->avail_out += 8 * strm->avail_in; |
| } else |
| while (!strm->avail_out) { |
| /* Done with input, might be a byte or two in internal buffer |
| * during compress. Or potentially many bytes if it's a |
| * decompress |
| */ |
| int grow_size = 2048; |
| char *newout; |
| |
| if (out_maxlen >= (int) payload_limit) { |
| LIBSSH2_FREE(session, out); |
| return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, |
| "Excessive growth in decompression " |
| "phase"); |
| } |
| |
| if (grow_size > (int) (payload_limit - out_maxlen)) { |
| grow_size = payload_limit - out_maxlen; |
| } |
| |
| out_maxlen += grow_size; |
| strm->avail_out = grow_size; |
| |
| newout = LIBSSH2_REALLOC(session, out, out_maxlen); |
| if (!newout) { |
| LIBSSH2_FREE(session, out); |
| return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, |
| "Unable to expand final " |
| "decompress buffer"); |
| } |
| out = newout; |
| strm->next_out = (unsigned char *) out + out_maxlen - |
| grow_size; |
| |
| status = inflate(strm, Z_PARTIAL_FLUSH); |
| |
| if (status != Z_OK) { |
| LIBSSH2_FREE(session, out); |
| _libssh2_debug(session, LIBSSH2_TRACE_TRANS, |
| "unhandled zlib error %d", status); |
| return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, |
| "decompression failure"); |
| } |
| } |
| } |
| |
| *dest = (unsigned char *) out; |
| *dest_len = out_maxlen - strm->avail_out; |
| |
| return 0; |
| } |
| |
| |
| /* libssh2_comp_method_zlib_dtor |
| * All done, no more compression for you |
| */ |
| static int |
| comp_method_zlib_dtor(LIBSSH2_SESSION *session, int compr, void **abstract) |
| { |
| z_stream *strm = *abstract; |
| |
| if (strm) { |
| if (compr) |
| deflateEnd(strm); |
| else |
| inflateEnd(strm); |
| LIBSSH2_FREE(session, strm); |
| } |
| |
| *abstract = NULL; |
| return 0; |
| } |
| |
| static const LIBSSH2_COMP_METHOD comp_method_zlib = { |
| "zlib", |
| 1, /* yes, this compresses */ |
| comp_method_zlib_init, |
| comp_method_zlib_comp, |
| comp_method_zlib_decomp, |
| comp_method_zlib_dtor, |
| }; |
| #endif /* LIBSSH2_HAVE_ZLIB */ |
| |
| /* If compression is enabled by the API, then this array is used which then |
| may allow compression if zlib is available at build time */ |
| static const LIBSSH2_COMP_METHOD *comp_methods[] = { |
| #ifdef LIBSSH2_HAVE_ZLIB |
| &comp_method_zlib, |
| #endif /* LIBSSH2_HAVE_ZLIB */ |
| &comp_method_none, |
| NULL |
| }; |
| |
| /* If compression is disabled by the API, then this array is used */ |
| static const LIBSSH2_COMP_METHOD *no_comp_methods[] = { |
| &comp_method_none, |
| NULL |
| }; |
| |
| const LIBSSH2_COMP_METHOD ** |
| _libssh2_comp_methods(LIBSSH2_SESSION *session) |
| { |
| if(session->flag.compress) |
| return comp_methods; |
| else |
| return no_comp_methods; |
| } |
