nodegit/vendor/libssh2/src/comp.c at master · nodejs-experiments/nodegit · GitHub

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* 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>

#undef compress /* dodge name clash with ZLIB macro */

#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 */

0, /* isn't used in userauth, go figure */

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_CALLOC(session, sizeof(z_stream));

if(!strm) {

return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,

"Unable to allocate memory for "

"zlib compression/decompression");

}

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) && (strm->avail_out > 0)) {

*dest_len = out_maxlen - strm->avail_out;

return 0;

}

_libssh2_debug(session, LIBSSH2_TRACE_TRANS,

"unhandled zlib compression error %d, avail_out",

status, strm->avail_out);

return _libssh2_error(session, LIBSSH2_ERROR_ZLIB, "compression failure");

}

* 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;

size_t out_maxlen = src_len;

if(src_len <= SIZE_MAX / 4)

out_maxlen = src_len * 4;

else

out_maxlen = payload_limit;

/* If strm is null, then we have not yet been initialized. */

if(strm == NULL)

return _libssh2_error(session, LIBSSH2_ERROR_COMPRESS,

"decompression uninitialized");;

/* In practice they never come smaller than this */

if(out_maxlen < 25)

out_maxlen = 25;

if(out_maxlen > 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");

/* Loop until it's all inflated or hit error */

for(;;) {

int status;

size_t out_ofs;

char *newout;

status = inflate(strm, Z_PARTIAL_FLUSH);

if(status == Z_OK) {

if(strm->avail_out > 0)

/* status is OK and the output buffer has not been exhausted

so we're done */

break;

}

else if(status == Z_BUF_ERROR) {

/* the input data has been exhausted so we are done */

break;

}

else {

/* error state */

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(out_maxlen > payload_limit || out_maxlen > SIZE_MAX / 2) {

LIBSSH2_FREE(session, out);

return _libssh2_error(session, LIBSSH2_ERROR_ZLIB,

"Excessive growth in decompression phase");

}

/* If we get here we need to grow the output buffer and try again */

out_ofs = out_maxlen - strm->avail_out;

out_maxlen *= 2;

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 = out_maxlen - out_ofs;

}

*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 */

1, /* do compression during userauth */

comp_method_zlib_init,

comp_method_zlib_comp,

comp_method_zlib_decomp,

comp_method_zlib_dtor,

};

static const LIBSSH2_COMP_METHOD comp_method_zlib_openssh = {

"zlib@openssh.com",

1, /* yes, this compresses */

0, /* don't use compression during userauth */

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,

&comp_method_zlib_openssh,

#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;

}

nodegit/vendor/libssh2/src/comp.c at master · nodejs-experiments/nodegit · GitHub

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