blob: aaf186ba69f4a64baf37db144b2eb1f773e0859b [file] [log] [blame] [raw]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <inttypes.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#if HAVE_XZ
#include <lzma.h>
#endif
#if HAVE_LZ4
#include <lz4.h>
#include <lz4frame.h>
#endif
#if HAVE_ZSTD
#include <zstd.h>
#include <zstd_errors.h>
#endif
#include "alloc-util.h"
#include "compress.h"
#include "fd-util.h"
#include "io-util.h"
#include "journal-def.h"
#include "macro.h"
#include "sparse-endian.h"
#include "string-table.h"
#include "string-util.h"
#include "unaligned.h"
#include "util.h"
#if HAVE_LZ4
DEFINE_TRIVIAL_CLEANUP_FUNC(LZ4F_compressionContext_t, LZ4F_freeCompressionContext);
DEFINE_TRIVIAL_CLEANUP_FUNC(LZ4F_decompressionContext_t, LZ4F_freeDecompressionContext);
#endif
#if HAVE_ZSTD
DEFINE_TRIVIAL_CLEANUP_FUNC(ZSTD_CCtx *, ZSTD_freeCCtx);
DEFINE_TRIVIAL_CLEANUP_FUNC(ZSTD_DCtx *, ZSTD_freeDCtx);
static int zstd_ret_to_errno(size_t ret) {
switch (ZSTD_getErrorCode(ret)) {
case ZSTD_error_dstSize_tooSmall:
return -ENOBUFS;
case ZSTD_error_memory_allocation:
return -ENOMEM;
default:
return -EBADMSG;
}
}
#endif
#define ALIGN_8(l) ALIGN_TO(l, sizeof(size_t))
static const char* const object_compressed_table[_OBJECT_COMPRESSED_MAX] = {
[OBJECT_COMPRESSED_XZ] = "XZ",
[OBJECT_COMPRESSED_LZ4] = "LZ4",
[OBJECT_COMPRESSED_ZSTD] = "ZSTD",
/* If we add too many more entries here, it's going to grow quite large (and be mostly sparse), since
* the array key is actually a bitmask, not a plain enum */
};
DEFINE_STRING_TABLE_LOOKUP(object_compressed, int);
int compress_blob_xz(const void *src, uint64_t src_size,
void *dst, size_t dst_alloc_size, size_t *dst_size) {
#if HAVE_XZ
static const lzma_options_lzma opt = {
1u << 20u, NULL, 0, LZMA_LC_DEFAULT, LZMA_LP_DEFAULT,
LZMA_PB_DEFAULT, LZMA_MODE_FAST, 128, LZMA_MF_HC3, 4
};
static const lzma_filter filters[] = {
{ LZMA_FILTER_LZMA2, (lzma_options_lzma*) &opt },
{ LZMA_VLI_UNKNOWN, NULL }
};
lzma_ret ret;
size_t out_pos = 0;
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size > 0);
assert(dst_size);
/* Returns < 0 if we couldn't compress the data or the
* compressed result is longer than the original */
if (src_size < 80)
return -ENOBUFS;
ret = lzma_stream_buffer_encode((lzma_filter*) filters, LZMA_CHECK_NONE, NULL,
src, src_size, dst, &out_pos, dst_alloc_size);
if (ret != LZMA_OK)
return -ENOBUFS;
*dst_size = out_pos;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int compress_blob_lz4(const void *src, uint64_t src_size,
void *dst, size_t dst_alloc_size, size_t *dst_size) {
#if HAVE_LZ4
int r;
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size > 0);
assert(dst_size);
/* Returns < 0 if we couldn't compress the data or the
* compressed result is longer than the original */
if (src_size < 9)
return -ENOBUFS;
r = LZ4_compress_default(src, (char*)dst + 8, src_size, (int) dst_alloc_size - 8);
if (r <= 0)
return -ENOBUFS;
unaligned_write_le64(dst, src_size);
*dst_size = r + 8;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int compress_blob_zstd(
const void *src, uint64_t src_size,
void *dst, size_t dst_alloc_size, size_t *dst_size) {
#if HAVE_ZSTD
size_t k;
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size > 0);
assert(dst_size);
k = ZSTD_compress(dst, dst_alloc_size, src, src_size, 0);
if (ZSTD_isError(k))
return zstd_ret_to_errno(k);
*dst_size = k;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_blob_xz(const void *src, uint64_t src_size,
void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
#if HAVE_XZ
_cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
size_t space;
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size);
assert(dst_size);
assert(*dst_alloc_size == 0 || *dst);
ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
if (ret != LZMA_OK)
return -ENOMEM;
space = MIN(src_size * 2, dst_max ?: (size_t) -1);
if (!greedy_realloc(dst, dst_alloc_size, space, 1))
return -ENOMEM;
s.next_in = src;
s.avail_in = src_size;
s.next_out = *dst;
s.avail_out = space;
for (;;) {
size_t used;
ret = lzma_code(&s, LZMA_FINISH);
if (ret == LZMA_STREAM_END)
break;
else if (ret != LZMA_OK)
return -ENOMEM;
if (dst_max > 0 && (space - s.avail_out) >= dst_max)
break;
else if (dst_max > 0 && space == dst_max)
return -ENOBUFS;
used = space - s.avail_out;
space = MIN(2 * space, dst_max ?: (size_t) -1);
if (!greedy_realloc(dst, dst_alloc_size, space, 1))
return -ENOMEM;
s.avail_out = space - used;
s.next_out = *(uint8_t**)dst + used;
}
*dst_size = space - s.avail_out;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_blob_lz4(const void *src, uint64_t src_size,
void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
#if HAVE_LZ4
char* out;
int r, size; /* LZ4 uses int for size */
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size);
assert(dst_size);
assert(*dst_alloc_size == 0 || *dst);
if (src_size <= 8)
return -EBADMSG;
size = unaligned_read_le64(src);
if (size < 0 || (unsigned) size != unaligned_read_le64(src))
return -EFBIG;
if ((size_t) size > *dst_alloc_size) {
out = realloc(*dst, size);
if (!out)
return -ENOMEM;
*dst = out;
*dst_alloc_size = size;
} else
out = *dst;
r = LZ4_decompress_safe((char*)src + 8, out, src_size - 8, size);
if (r < 0 || r != size)
return -EBADMSG;
*dst_size = size;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_blob_zstd(
const void *src, uint64_t src_size,
void **dst, size_t *dst_alloc_size, size_t *dst_size, size_t dst_max) {
#if HAVE_ZSTD
uint64_t size;
assert(src);
assert(src_size > 0);
assert(dst);
assert(dst_alloc_size);
assert(dst_size);
assert(*dst_alloc_size == 0 || *dst);
size = ZSTD_getFrameContentSize(src, src_size);
if (IN_SET(size, ZSTD_CONTENTSIZE_ERROR, ZSTD_CONTENTSIZE_UNKNOWN))
return -EBADMSG;
if (dst_max > 0 && size > dst_max)
size = dst_max;
if (size > SIZE_MAX)
return -E2BIG;
if (!(greedy_realloc(dst, dst_alloc_size, MAX(ZSTD_DStreamOutSize(), size), 1)))
return -ENOMEM;
_cleanup_(ZSTD_freeDCtxp) ZSTD_DCtx *dctx = ZSTD_createDCtx();
if (!dctx)
return -ENOMEM;
ZSTD_inBuffer input = {
.src = src,
.size = src_size,
};
ZSTD_outBuffer output = {
.dst = *dst,
.size = *dst_alloc_size,
};
size_t k = ZSTD_decompressStream(dctx, &output, &input);
if (ZSTD_isError(k)) {
log_debug("ZSTD decoder failed: %s", ZSTD_getErrorName(k));
return zstd_ret_to_errno(k);
}
assert(output.pos >= size);
*dst_size = size;
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_blob(
int compression,
const void *src, uint64_t src_size,
void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max) {
if (compression == OBJECT_COMPRESSED_XZ)
return decompress_blob_xz(
src, src_size,
dst, dst_alloc_size, dst_size, dst_max);
else if (compression == OBJECT_COMPRESSED_LZ4)
return decompress_blob_lz4(
src, src_size,
dst, dst_alloc_size, dst_size, dst_max);
else if (compression == OBJECT_COMPRESSED_ZSTD)
return decompress_blob_zstd(
src, src_size,
dst, dst_alloc_size, dst_size, dst_max);
else
return -EPROTONOSUPPORT;
}
int decompress_startswith_xz(const void *src, uint64_t src_size,
void **buffer, size_t *buffer_size,
const void *prefix, size_t prefix_len,
uint8_t extra) {
#if HAVE_XZ
_cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
/* Checks whether the decompressed blob starts with the
* mentioned prefix. The byte extra needs to follow the
* prefix */
assert(src);
assert(src_size > 0);
assert(buffer);
assert(buffer_size);
assert(prefix);
assert(*buffer_size == 0 || *buffer);
ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
if (ret != LZMA_OK)
return -EBADMSG;
if (!(greedy_realloc(buffer, buffer_size, ALIGN_8(prefix_len + 1), 1)))
return -ENOMEM;
s.next_in = src;
s.avail_in = src_size;
s.next_out = *buffer;
s.avail_out = *buffer_size;
for (;;) {
ret = lzma_code(&s, LZMA_FINISH);
if (!IN_SET(ret, LZMA_OK, LZMA_STREAM_END))
return -EBADMSG;
if (*buffer_size - s.avail_out >= prefix_len + 1)
return memcmp(*buffer, prefix, prefix_len) == 0 &&
((const uint8_t*) *buffer)[prefix_len] == extra;
if (ret == LZMA_STREAM_END)
return 0;
s.avail_out += *buffer_size;
if (!(greedy_realloc(buffer, buffer_size, *buffer_size * 2, 1)))
return -ENOMEM;
s.next_out = *(uint8_t**)buffer + *buffer_size - s.avail_out;
}
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_startswith_lz4(const void *src, uint64_t src_size,
void **buffer, size_t *buffer_size,
const void *prefix, size_t prefix_len,
uint8_t extra) {
#if HAVE_LZ4
/* Checks whether the decompressed blob starts with the
* mentioned prefix. The byte extra needs to follow the
* prefix */
int r;
assert(src);
assert(src_size > 0);
assert(buffer);
assert(buffer_size);
assert(prefix);
assert(*buffer_size == 0 || *buffer);
if (src_size <= 8)
return -EBADMSG;
if (!(greedy_realloc(buffer, buffer_size, ALIGN_8(prefix_len + 1), 1)))
return -ENOMEM;
r = LZ4_decompress_safe_partial((char*)src + 8, *buffer, src_size - 8,
prefix_len + 1, *buffer_size);
/* One lz4 < 1.8.3, we might get "failure" (r < 0), or "success" where
* just a part of the buffer is decompressed. But if we get a smaller
* amount of bytes than requested, we don't know whether there isn't enough
* data to fill the requested size or whether we just got a partial answer.
*/
if (r < 0 || (size_t) r < prefix_len + 1) {
size_t size;
if (LZ4_versionNumber() >= 10803)
/* We trust that the newer lz4 decompresses the number of bytes we
* requested if available in the compressed string. */
return 0;
if (r > 0)
/* Compare what we have first, in case of mismatch we can
* shortcut the full comparison. */
if (memcmp(*buffer, prefix, r) != 0)
return 0;
/* Before version 1.8.3, lz4 always tries to decode full a "sequence",
* so in pathological cases might need to decompress the full field. */
r = decompress_blob_lz4(src, src_size, buffer, buffer_size, &size, 0);
if (r < 0)
return r;
if (size < prefix_len + 1)
return 0;
}
return memcmp(*buffer, prefix, prefix_len) == 0 &&
((const uint8_t*) *buffer)[prefix_len] == extra;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_startswith_zstd(
const void *src, uint64_t src_size,
void **buffer, size_t *buffer_size,
const void *prefix, size_t prefix_len,
uint8_t extra) {
#if HAVE_ZSTD
assert(src);
assert(src_size > 0);
assert(buffer);
assert(buffer_size);
assert(prefix);
assert(*buffer_size == 0 || *buffer);
uint64_t size = ZSTD_getFrameContentSize(src, src_size);
if (IN_SET(size, ZSTD_CONTENTSIZE_ERROR, ZSTD_CONTENTSIZE_UNKNOWN))
return -EBADMSG;
if (size < prefix_len + 1)
return 0; /* Decompressed text too short to match the prefix and extra */
_cleanup_(ZSTD_freeDCtxp) ZSTD_DCtx *dctx = ZSTD_createDCtx();
if (!dctx)
return -ENOMEM;
if (!(greedy_realloc(buffer, buffer_size, MAX(ZSTD_DStreamOutSize(), prefix_len + 1), 1)))
return -ENOMEM;
ZSTD_inBuffer input = {
.src = src,
.size = src_size,
};
ZSTD_outBuffer output = {
.dst = *buffer,
.size = *buffer_size,
};
size_t k;
k = ZSTD_decompressStream(dctx, &output, &input);
if (ZSTD_isError(k)) {
log_debug("ZSTD decoder failed: %s", ZSTD_getErrorName(k));
return zstd_ret_to_errno(k);
}
assert(output.pos >= prefix_len + 1);
return memcmp(*buffer, prefix, prefix_len) == 0 &&
((const uint8_t*) *buffer)[prefix_len] == extra;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_startswith(
int compression,
const void *src, uint64_t src_size,
void **buffer, size_t *buffer_size,
const void *prefix, size_t prefix_len,
uint8_t extra) {
if (compression == OBJECT_COMPRESSED_XZ)
return decompress_startswith_xz(
src, src_size,
buffer, buffer_size,
prefix, prefix_len,
extra);
else if (compression == OBJECT_COMPRESSED_LZ4)
return decompress_startswith_lz4(
src, src_size,
buffer, buffer_size,
prefix, prefix_len,
extra);
else if (compression == OBJECT_COMPRESSED_ZSTD)
return decompress_startswith_zstd(
src, src_size,
buffer, buffer_size,
prefix, prefix_len,
extra);
else
return -EBADMSG;
}
int compress_stream_xz(int fdf, int fdt, uint64_t max_bytes) {
#if HAVE_XZ
_cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
uint8_t buf[BUFSIZ], out[BUFSIZ];
lzma_action action = LZMA_RUN;
assert(fdf >= 0);
assert(fdt >= 0);
ret = lzma_easy_encoder(&s, LZMA_PRESET_DEFAULT, LZMA_CHECK_CRC64);
if (ret != LZMA_OK)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"Failed to initialize XZ encoder: code %u",
ret);
for (;;) {
if (s.avail_in == 0 && action == LZMA_RUN) {
size_t m = sizeof(buf);
ssize_t n;
if (max_bytes != (uint64_t) -1 && (uint64_t) m > max_bytes)
m = (size_t) max_bytes;
n = read(fdf, buf, m);
if (n < 0)
return -errno;
if (n == 0)
action = LZMA_FINISH;
else {
s.next_in = buf;
s.avail_in = n;
if (max_bytes != (uint64_t) -1) {
assert(max_bytes >= (uint64_t) n);
max_bytes -= n;
}
}
}
if (s.avail_out == 0) {
s.next_out = out;
s.avail_out = sizeof(out);
}
ret = lzma_code(&s, action);
if (!IN_SET(ret, LZMA_OK, LZMA_STREAM_END))
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
"Compression failed: code %u",
ret);
if (s.avail_out == 0 || ret == LZMA_STREAM_END) {
ssize_t n, k;
n = sizeof(out) - s.avail_out;
k = loop_write(fdt, out, n, false);
if (k < 0)
return k;
if (ret == LZMA_STREAM_END) {
log_debug("XZ compression finished (%"PRIu64" -> %"PRIu64" bytes, %.1f%%)",
s.total_in, s.total_out,
(double) s.total_out / s.total_in * 100);
return 0;
}
}
}
#else
return -EPROTONOSUPPORT;
#endif
}
#define LZ4_BUFSIZE (512*1024u)
int compress_stream_lz4(int fdf, int fdt, uint64_t max_bytes) {
#if HAVE_LZ4
LZ4F_errorCode_t c;
_cleanup_(LZ4F_freeCompressionContextp) LZ4F_compressionContext_t ctx = NULL;
_cleanup_free_ char *buf = NULL;
char *src = NULL;
size_t size, n, total_in = 0, total_out, offset = 0, frame_size;
struct stat st;
int r;
static const LZ4F_compressOptions_t options = {
.stableSrc = 1,
};
static const LZ4F_preferences_t preferences = {
.frameInfo.blockSizeID = 5,
};
c = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
if (LZ4F_isError(c))
return -ENOMEM;
if (fstat(fdf, &st) < 0)
return log_debug_errno(errno, "fstat() failed: %m");
frame_size = LZ4F_compressBound(LZ4_BUFSIZE, &preferences);
size = frame_size + 64*1024; /* add some space for header and trailer */
buf = malloc(size);
if (!buf)
return -ENOMEM;
n = offset = total_out = LZ4F_compressBegin(ctx, buf, size, &preferences);
if (LZ4F_isError(n))
return -EINVAL;
src = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fdf, 0);
if (src == MAP_FAILED)
return -errno;
log_debug("Buffer size is %zu bytes, header size %zu bytes.", size, n);
while (total_in < (size_t) st.st_size) {
ssize_t k;
k = MIN(LZ4_BUFSIZE, st.st_size - total_in);
n = LZ4F_compressUpdate(ctx, buf + offset, size - offset,
src + total_in, k, &options);
if (LZ4F_isError(n)) {
r = -ENOTRECOVERABLE;
goto cleanup;
}
total_in += k;
offset += n;
total_out += n;
if (max_bytes != (uint64_t) -1 && total_out > (size_t) max_bytes)
return log_debug_errno(SYNTHETIC_ERRNO(EFBIG),
"Compressed stream longer than %" PRIu64 " bytes",
max_bytes);
if (size - offset < frame_size + 4) {
k = loop_write(fdt, buf, offset, false);
if (k < 0) {
r = k;
goto cleanup;
}
offset = 0;
}
}
n = LZ4F_compressEnd(ctx, buf + offset, size - offset, &options);
if (LZ4F_isError(n)) {
r = -ENOTRECOVERABLE;
goto cleanup;
}
offset += n;
total_out += n;
r = loop_write(fdt, buf, offset, false);
if (r < 0)
goto cleanup;
log_debug("LZ4 compression finished (%zu -> %zu bytes, %.1f%%)",
total_in, total_out,
(double) total_out / total_in * 100);
cleanup:
munmap(src, st.st_size);
return r;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_stream_xz(int fdf, int fdt, uint64_t max_bytes) {
#if HAVE_XZ
_cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
lzma_ret ret;
uint8_t buf[BUFSIZ], out[BUFSIZ];
lzma_action action = LZMA_RUN;
assert(fdf >= 0);
assert(fdt >= 0);
ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
if (ret != LZMA_OK)
return log_debug_errno(SYNTHETIC_ERRNO(ENOMEM),
"Failed to initialize XZ decoder: code %u",
ret);
for (;;) {
if (s.avail_in == 0 && action == LZMA_RUN) {
ssize_t n;
n = read(fdf, buf, sizeof(buf));
if (n < 0)
return -errno;
if (n == 0)
action = LZMA_FINISH;
else {
s.next_in = buf;
s.avail_in = n;
}
}
if (s.avail_out == 0) {
s.next_out = out;
s.avail_out = sizeof(out);
}
ret = lzma_code(&s, action);
if (!IN_SET(ret, LZMA_OK, LZMA_STREAM_END))
return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG),
"Decompression failed: code %u",
ret);
if (s.avail_out == 0 || ret == LZMA_STREAM_END) {
ssize_t n, k;
n = sizeof(out) - s.avail_out;
if (max_bytes != (uint64_t) -1) {
if (max_bytes < (uint64_t) n)
return -EFBIG;
max_bytes -= n;
}
k = loop_write(fdt, out, n, false);
if (k < 0)
return k;
if (ret == LZMA_STREAM_END) {
log_debug("XZ decompression finished (%"PRIu64" -> %"PRIu64" bytes, %.1f%%)",
s.total_in, s.total_out,
(double) s.total_out / s.total_in * 100);
return 0;
}
}
}
#else
return log_debug_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT),
"Cannot decompress file. Compiled without XZ support.");
#endif
}
int decompress_stream_lz4(int in, int out, uint64_t max_bytes) {
#if HAVE_LZ4
size_t c;
_cleanup_(LZ4F_freeDecompressionContextp) LZ4F_decompressionContext_t ctx = NULL;
_cleanup_free_ char *buf = NULL;
char *src;
struct stat st;
int r = 0;
size_t total_in = 0, total_out = 0;
c = LZ4F_createDecompressionContext(&ctx, LZ4F_VERSION);
if (LZ4F_isError(c))
return -ENOMEM;
if (fstat(in, &st) < 0)
return log_debug_errno(errno, "fstat() failed: %m");
buf = malloc(LZ4_BUFSIZE);
if (!buf)
return -ENOMEM;
src = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, in, 0);
if (src == MAP_FAILED)
return -errno;
while (total_in < (size_t) st.st_size) {
size_t produced = LZ4_BUFSIZE;
size_t used = st.st_size - total_in;
c = LZ4F_decompress(ctx, buf, &produced, src + total_in, &used, NULL);
if (LZ4F_isError(c)) {
r = -EBADMSG;
goto cleanup;
}
total_in += used;
total_out += produced;
if (max_bytes != (uint64_t) -1 && total_out > (size_t) max_bytes) {
log_debug("Decompressed stream longer than %"PRIu64" bytes", max_bytes);
r = -EFBIG;
goto cleanup;
}
r = loop_write(out, buf, produced, false);
if (r < 0)
goto cleanup;
}
log_debug("LZ4 decompression finished (%zu -> %zu bytes, %.1f%%)",
total_in, total_out,
total_in > 0 ? (double) total_out / total_in * 100 : 0.0);
cleanup:
munmap(src, st.st_size);
return r;
#else
return log_debug_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT),
"Cannot decompress file. Compiled without LZ4 support.");
#endif
}
int compress_stream_zstd(int fdf, int fdt, uint64_t max_bytes) {
#if HAVE_ZSTD
_cleanup_(ZSTD_freeCCtxp) ZSTD_CCtx *cctx = NULL;
_cleanup_free_ void *in_buff = NULL, *out_buff = NULL;
size_t in_allocsize, out_allocsize;
size_t z;
uint64_t left = max_bytes, in_bytes = 0;
assert(fdf >= 0);
assert(fdt >= 0);
/* Create the context and buffers */
in_allocsize = ZSTD_CStreamInSize();
out_allocsize = ZSTD_CStreamOutSize();
in_buff = malloc(in_allocsize);
out_buff = malloc(out_allocsize);
cctx = ZSTD_createCCtx();
if (!cctx || !out_buff || !in_buff)
return -ENOMEM;
z = ZSTD_CCtx_setParameter(cctx, ZSTD_c_checksumFlag, 1);
if (ZSTD_isError(z))
log_debug("Failed to enable ZSTD checksum, ignoring: %s", ZSTD_getErrorName(z));
/* This loop read from the input file, compresses that entire chunk,
* and writes all output produced to the output file.
*/
for (;;) {
bool is_last_chunk;
ZSTD_inBuffer input = {
.src = in_buff,
.size = 0,
.pos = 0
};
ssize_t red;
red = loop_read(fdf, in_buff, in_allocsize, true);
if (red < 0)
return red;
is_last_chunk = red == 0;
in_bytes += (size_t) red;
input.size = (size_t) red;
for (bool finished = false; !finished;) {
ZSTD_outBuffer output = {
.dst = out_buff,
.size = out_allocsize,
.pos = 0
};
size_t remaining;
ssize_t wrote;
/* Compress into the output buffer and write all of the
* output to the file so we can reuse the buffer next
* iteration.
*/
remaining = ZSTD_compressStream2(
cctx, &output, &input,
is_last_chunk ? ZSTD_e_end : ZSTD_e_continue);
if (ZSTD_isError(remaining)) {
log_debug("ZSTD encoder failed: %s", ZSTD_getErrorName(remaining));
return zstd_ret_to_errno(remaining);
}
if (left < output.pos)
return -EFBIG;
wrote = loop_write(fdt, output.dst, output.pos, 1);
if (wrote < 0)
return wrote;
left -= output.pos;
/* If we're on the last chunk we're finished when zstd
* returns 0, which means its consumed all the input AND
* finished the frame. Otherwise, we're finished when
* we've consumed all the input.
*/
finished = is_last_chunk ? (remaining == 0) : (input.pos == input.size);
}
/* zstd only returns 0 when the input is completely consumed */
assert(input.pos == input.size);
if (is_last_chunk)
break;
}
if (in_bytes > 0)
log_debug("ZSTD compression finished (%" PRIu64 " -> %" PRIu64 " bytes, %.1f%%)",
in_bytes, max_bytes - left, (double) (max_bytes - left) / in_bytes * 100);
else
log_debug("ZSTD compression finished (%" PRIu64 " -> %" PRIu64 " bytes)",
in_bytes, max_bytes - left);
return 0;
#else
return -EPROTONOSUPPORT;
#endif
}
int decompress_stream_zstd(int fdf, int fdt, uint64_t max_bytes) {
#if HAVE_ZSTD
_cleanup_(ZSTD_freeDCtxp) ZSTD_DCtx *dctx = NULL;
_cleanup_free_ void *in_buff = NULL, *out_buff = NULL;
size_t in_allocsize, out_allocsize;
size_t last_result = 0;
uint64_t left = max_bytes, in_bytes = 0;
assert(fdf >= 0);
assert(fdt >= 0);
/* Create the context and buffers */
in_allocsize = ZSTD_DStreamInSize();
out_allocsize = ZSTD_DStreamOutSize();
in_buff = malloc(in_allocsize);
out_buff = malloc(out_allocsize);
dctx = ZSTD_createDCtx();
if (!dctx || !out_buff || !in_buff)
return -ENOMEM;
/* This loop assumes that the input file is one or more concatenated
* zstd streams. This example won't work if there is trailing non-zstd
* data at the end, but streaming decompression in general handles this
* case. ZSTD_decompressStream() returns 0 exactly when the frame is
* completed, and doesn't consume input after the frame.
*/
for (;;) {
bool has_error = false;
ZSTD_inBuffer input = {
.src = in_buff,
.size = 0,
.pos = 0
};
ssize_t red;
red = loop_read(fdf, in_buff, in_allocsize, true);
if (red < 0)
return red;
if (red == 0)
break;
in_bytes += (size_t) red;
input.size = (size_t) red;
input.pos = 0;
/* Given a valid frame, zstd won't consume the last byte of the
* frame until it has flushed all of the decompressed data of
* the frame. So input.pos < input.size means frame is not done
* or there is still output available.
*/
while (input.pos < input.size) {
ZSTD_outBuffer output = {
.dst = out_buff,
.size = out_allocsize,
.pos = 0
};
ssize_t wrote;
/* The return code is zero if the frame is complete, but
* there may be multiple frames concatenated together.
* Zstd will automatically reset the context when a
* frame is complete. Still, calling ZSTD_DCtx_reset()
* can be useful to reset the context to a clean state,
* for instance if the last decompression call returned
* an error.
*/
last_result = ZSTD_decompressStream(dctx, &output, &input);
if (ZSTD_isError(last_result)) {
has_error = true;
break;
}
if (left < output.pos)
return -EFBIG;
wrote = loop_write(fdt, output.dst, output.pos, 1);
if (wrote < 0)
return wrote;
left -= output.pos;
}
if (has_error)
break;
}
if (in_bytes == 0)
return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "ZSTD decoder failed: no data read");
if (last_result != 0) {
/* The last return value from ZSTD_decompressStream did not end
* on a frame, but we reached the end of the file! We assume
* this is an error, and the input was truncated.
*/
log_debug("ZSTD decoder failed: %s", ZSTD_getErrorName(last_result));
return zstd_ret_to_errno(last_result);
}
log_debug(
"ZSTD decompression finished (%" PRIu64 " -> %" PRIu64 " bytes, %.1f%%)",
in_bytes,
max_bytes - left,
(double) (max_bytes - left) / in_bytes * 100);
return 0;
#else
return log_debug_errno(SYNTHETIC_ERRNO(EPROTONOSUPPORT),
"Cannot decompress file. Compiled without ZSTD support.");
#endif
}
int decompress_stream(const char *filename, int fdf, int fdt, uint64_t max_bytes) {
if (endswith(filename, ".lz4"))
return decompress_stream_lz4(fdf, fdt, max_bytes);
else if (endswith(filename, ".xz"))
return decompress_stream_xz(fdf, fdt, max_bytes);
else if (endswith(filename, ".zst"))
return decompress_stream_zstd(fdf, fdt, max_bytes);
else
return -EPROTONOSUPPORT;
}