diff options
Diffstat (limited to 'src/common/torgzip.c')
| -rw-r--r-- | src/common/torgzip.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/src/common/torgzip.c b/src/common/torgzip.c new file mode 100644 index 0000000000..1b3fce2e88 --- /dev/null +++ b/src/common/torgzip.c @@ -0,0 +1,221 @@ +/* Copyright 2004 Roger Dingledine */ +/* See LICENSE for licensing information */ +/* $Id$ */ + +/** + * \file torgzip.c + * + * \brief Simple in-memory gzip implementation. + **/ + +#include "orconfig.h" + + +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> +#include <zlib.h> + +#include "util.h" +#include "log.h" +#include "torgzip.h" + +static int gzip_is_supported = -1; + +int +is_gzip_supported(void) +{ + if (gzip_is_supported >= 0) + return gzip_is_supported; + + if (!strcmpstart(ZLIB_VERSION, "0.") || + !strcmpstart(ZLIB_VERSION, "1.0") || + !strcmpstart(ZLIB_VERSION, "1.1")) + gzip_is_supported = 0; + else + gzip_is_supported = 1; + + return gzip_is_supported; +} + +static INLINE int +method_bits(compress_method_t method) +{ + /* Bits+16 means "use gzip" in zlib >= 1.2 */ + return method == GZIP_METHOD ? 15+16 : 15; +} + +int +tor_gzip_compress(char **out, size_t *out_len, + const char *in, size_t in_len, + compress_method_t method) +{ + struct z_stream_s *stream = NULL; + size_t out_size; + off_t offset; + + tor_assert(out && out_len && in); + + if (method == GZIP_METHOD && !is_gzip_supported()) { + /* Old zlib version don't support gzip in deflateInit2 */ + log_fn(LOG_WARN, "Gzip not supported with zlib %s", ZLIB_VERSION); + return -1; + } + + *out = NULL; + + stream = tor_malloc_zero(sizeof(struct z_stream_s)); + stream->zalloc = Z_NULL; + stream->zfree = Z_NULL; + stream->opaque = NULL; + stream->next_in = (unsigned char*) in; + stream->avail_in = in_len; + + if (deflateInit2(stream, Z_BEST_COMPRESSION, Z_DEFLATED, + method_bits(method), + 8, Z_DEFAULT_STRATEGY) != Z_OK) { + printf("Z"); + log_fn(LOG_WARN, "Error from deflateInit2: %s", + stream->msg?stream->msg:"<no message>"); + goto err; + } + + /* Guess 50% compression. */ + out_size = in_len / 2; + if (out_size < 1024) out_size = 1024; + *out = tor_malloc(out_size); + stream->next_out = *out; + stream->avail_out = out_size; + + while (1) { + switch (deflate(stream, Z_FINISH)) + { + case Z_STREAM_END: + goto done; + case Z_OK: + /* In case zlib doesn't work as I think .... */ + if (stream->avail_out >= stream->avail_in+16) + break; + case Z_BUF_ERROR: + offset = stream->next_out - ((unsigned char*)*out); + out_size *= 2; + *out = tor_realloc(*out, out_size); + stream->next_out = *out + offset; + stream->avail_out = out_size - offset; + break; + default: + log_fn(LOG_WARN, "Gzip compression didn't finish: %s", + stream->msg ? stream->msg : "<no message>"); + goto err; + } + } + done: + *out_len = stream->total_out; + if (deflateEnd(stream)!=Z_OK) { + log_fn(LOG_WARN, "Error freeing gzip structures"); + goto err; + } + tor_free(stream); + + return 0; + err: + if (stream) { + deflateEnd(stream); + tor_free(stream); + } + if (*out) { + tor_free(*out); + } + return -1; +} + +int +tor_gzip_uncompress(char **out, size_t *out_len, + const char *in, size_t in_len, + compress_method_t method) +{ + struct z_stream_s *stream = NULL; + size_t out_size; + off_t offset; + + tor_assert(out && out_len && in); + + if (method == GZIP_METHOD && !is_gzip_supported()) { + /* Old zlib version don't support gzip in inflateInit2 */ + log_fn(LOG_WARN, "Gzip not supported with zlib %s", ZLIB_VERSION); + return -1; + } + + *out = NULL; + + stream = tor_malloc_zero(sizeof(struct z_stream_s)); + stream->zalloc = Z_NULL; + stream->zfree = Z_NULL; + stream->opaque = NULL; + stream->next_in = (unsigned char*) in; + stream->avail_in = in_len; + + if (inflateInit2(stream, + method_bits(method)) != Z_OK) { + log_fn(LOG_WARN, "Error from inflateInit2: %s", + stream->msg?stream->msg:"<no message>"); + goto err; + } + + out_size = in_len * 2; /* guess 50% compression. */ + if (out_size < 1024) out_size = 1024; + + *out = tor_malloc(out_size); + stream->next_out = *out; + stream->avail_out = out_size; + + while (1) { + switch(inflate(stream, Z_FINISH)) + { + case Z_STREAM_END: + goto done; + case Z_OK: + /* In case zlib doesn't work as I think.... */ + if (stream->avail_out >= stream->avail_in+16) + break; + case Z_BUF_ERROR: + offset = stream->next_out - ((unsigned char*)*out); + out_size *= 2; + *out = tor_realloc(*out, out_size); + stream->next_out = *out + offset; + stream->avail_out = out_size - offset; + break; + default: + log_fn(LOG_WARN, "Gzip decompression returned an error: %s", + stream->msg ? stream->msg : "<no message>"); + goto err; + } + + } + done: + *out_len = stream->total_out; + if (inflateEnd(stream)!=Z_OK) { + log_fn(LOG_WARN, "Error freeing gzip structures"); + goto err; + } + tor_free(stream); + + return 0; + err: + if (stream) { + inflateEnd(stream); + tor_free(stream); + } + if (*out) { + tor_free(*out); + } + return -1; +} + +/* + Local Variables: + mode:c + indent-tabs-mode:nil + c-basic-offset:2 + End: +*/ |