Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1088 insertions, 0 deletions

diff --git a/src/basic/compress.c b/src/basic/compress.c
new file mode 100644
index 0000000..ac0bfdf
--- /dev/null
+++ b/src/basic/compress.c
@@ -0,0 +1,1088 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <inttypes.h>
+#include <malloc.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.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 "fileio.h"
+#include "io-util.h"
+#include "macro.h"
+#include "sparse-endian.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "unaligned.h"
+
+#if HAVE_LZ4
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(LZ4F_compressionContext_t, LZ4F_freeCompressionContext, NULL);
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(LZ4F_decompressionContext_t, LZ4F_freeDecompressionContext, NULL);
+#endif
+
+#if HAVE_ZSTD
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(ZSTD_CCtx*, ZSTD_freeCCtx, NULL);
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(ZSTD_DCtx*, ZSTD_freeDCtx, NULL);
+
+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 compression_table[_COMPRESSION_MAX] = {
+        [COMPRESSION_NONE] = "NONE",
+        [COMPRESSION_XZ]   = "XZ",
+        [COMPRESSION_LZ4]  = "LZ4",
+        [COMPRESSION_ZSTD] = "ZSTD",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(compression, Compression);
+
+bool compression_supported(Compression c) {
+        static const unsigned supported =
+                (1U << COMPRESSION_NONE) |
+                (1U << COMPRESSION_XZ) * HAVE_XZ |
+                (1U << COMPRESSION_LZ4) * HAVE_LZ4 |
+                (1U << COMPRESSION_ZSTD) * HAVE_ZSTD;
+
+        return c >= 0 && c < _COMPRESSION_MAX && FLAGS_SET(supported, 1U << c);
+}
+
+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_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_size);
+
+        ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
+        if (ret != LZMA_OK)
+                return -ENOMEM;
+
+        space = MIN(src_size * 2, dst_max ?: SIZE_MAX);
+        if (!greedy_realloc(dst, 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_MAX);
+                if (!greedy_realloc(dst, 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_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_size);
+
+        if (src_size <= 8)
+                return -EBADMSG;
+
+        size = unaligned_read_le64(src);
+        if (size < 0 || (unsigned) size != unaligned_read_le64(src))
+                return -EFBIG;
+        out = greedy_realloc(dst, size, 1);
+        if (!out)
+                return -ENOMEM;
+
+        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_size,
+                size_t dst_max) {
+
+#if HAVE_ZSTD
+        uint64_t size;
+
+        assert(src);
+        assert(src_size > 0);
+        assert(dst);
+        assert(dst_size);
+
+        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, 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 = MALLOC_SIZEOF_SAFE(*dst),
+        };
+
+        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(
+                Compression compression,
+                const void *src,
+                uint64_t src_size,
+                void **dst,
+                size_t* dst_size,
+                size_t dst_max) {
+
+        if (compression == COMPRESSION_XZ)
+                return decompress_blob_xz(
+                                src, src_size,
+                                dst, dst_size, dst_max);
+        else if (compression == COMPRESSION_LZ4)
+                return decompress_blob_lz4(
+                                src, src_size,
+                                dst, dst_size, dst_max);
+        else if (compression == COMPRESSION_ZSTD)
+                return decompress_blob_zstd(
+                                src, src_size,
+                                dst, dst_size, dst_max);
+        else
+                return -EPROTONOSUPPORT;
+}
+
+int decompress_startswith_xz(
+                const void *src,
+                uint64_t src_size,
+                void **buffer,
+                const void *prefix,
+                size_t prefix_len,
+                uint8_t extra) {
+
+#if HAVE_XZ
+        _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT;
+        size_t allocated;
+        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(prefix);
+
+        ret = lzma_stream_decoder(&s, UINT64_MAX, 0);
+        if (ret != LZMA_OK)
+                return -EBADMSG;
+
+        if (!(greedy_realloc(buffer, ALIGN_8(prefix_len + 1), 1)))
+                return -ENOMEM;
+
+        allocated = MALLOC_SIZEOF_SAFE(*buffer);
+
+        s.next_in = src;
+        s.avail_in = src_size;
+
+        s.next_out = *buffer;
+        s.avail_out = allocated;
+
+        for (;;) {
+                ret = lzma_code(&s, LZMA_FINISH);
+
+                if (!IN_SET(ret, LZMA_OK, LZMA_STREAM_END))
+                        return -EBADMSG;
+
+                if (allocated - 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 += allocated;
+
+                if (!(greedy_realloc(buffer, allocated * 2, 1)))
+                        return -ENOMEM;
+
+                allocated = MALLOC_SIZEOF_SAFE(*buffer);
+                s.next_out = *(uint8_t**)buffer + allocated - s.avail_out;
+        }
+
+#else
+        return -EPROTONOSUPPORT;
+#endif
+}
+
+int decompress_startswith_lz4(
+                const void *src,
+                uint64_t src_size,
+                void **buffer,
+                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 */
+
+        size_t allocated;
+        int r;
+
+        assert(src);
+        assert(src_size > 0);
+        assert(buffer);
+        assert(prefix);
+
+        if (src_size <= 8)
+                return -EBADMSG;
+
+        if (!(greedy_realloc(buffer, ALIGN_8(prefix_len + 1), 1)))
+                return -ENOMEM;
+        allocated = MALLOC_SIZEOF_SAFE(*buffer);
+
+        r = LZ4_decompress_safe_partial(
+                        (char*)src + 8,
+                        *buffer,
+                        src_size - 8,
+                        prefix_len + 1,
+                        allocated);
+
+        /* 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, &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,
+                const void *prefix,
+                size_t prefix_len,
+                uint8_t extra) {
+#if HAVE_ZSTD
+        assert(src);
+        assert(src_size > 0);
+        assert(buffer);
+        assert(prefix);
+
+        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, MAX(ZSTD_DStreamOutSize(), prefix_len + 1), 1)))
+                return -ENOMEM;
+
+        ZSTD_inBuffer input = {
+                .src = src,
+                .size = src_size,
+        };
+        ZSTD_outBuffer output = {
+                .dst = *buffer,
+                .size = MALLOC_SIZEOF_SAFE(*buffer),
+        };
+        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(
+                Compression compression,
+                const void *src,
+                uint64_t src_size,
+                void **buffer,
+                const void *prefix,
+                size_t prefix_len,
+                uint8_t extra) {
+
+        if (compression == COMPRESSION_XZ)
+                return decompress_startswith_xz(
+                                src, src_size,
+                                buffer,
+                                prefix, prefix_len,
+                                extra);
+
+        else if (compression == COMPRESSION_LZ4)
+                return decompress_startswith_lz4(
+                                src, src_size,
+                                buffer,
+                                prefix, prefix_len,
+                                extra);
+        else if (compression == COMPRESSION_ZSTD)
+                return decompress_startswith_zstd(
+                                src, src_size,
+                                buffer,
+                                prefix, prefix_len,
+                                extra);
+        else
+                return -EBADMSG;
+}
+
+int compress_stream_xz(int fdf, int fdt, uint64_t max_bytes, uint64_t *ret_uncompressed_size) {
+#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_MAX && (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_MAX) {
+                                        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);
+                        if (k < 0)
+                                return k;
+
+                        if (ret == LZMA_STREAM_END) {
+                                if (ret_uncompressed_size)
+                                        *ret_uncompressed_size = s.total_in;
+
+                                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, uint64_t *ret_uncompressed_size) {
+
+#if HAVE_LZ4
+        LZ4F_errorCode_t c;
+        _cleanup_(LZ4F_freeCompressionContextp) LZ4F_compressionContext_t ctx = NULL;
+        _cleanup_free_ void *in_buff = NULL;
+        _cleanup_free_ char *out_buff = NULL;
+        size_t out_allocsize, n, offset = 0, frame_size;
+        uint64_t total_in = 0, total_out;
+        int r;
+        static const LZ4F_preferences_t preferences = {
+                .frameInfo.blockSizeID = 5,
+        };
+
+        c = LZ4F_createCompressionContext(&ctx, LZ4F_VERSION);
+        if (LZ4F_isError(c))
+                return -ENOMEM;
+
+        frame_size = LZ4F_compressBound(LZ4_BUFSIZE, &preferences);
+        out_allocsize = frame_size + 64*1024; /* add some space for header and trailer */
+        out_buff = malloc(out_allocsize);
+        if (!out_buff)
+                return -ENOMEM;
+
+        in_buff = malloc(LZ4_BUFSIZE);
+        if (!in_buff)
+                return -ENOMEM;
+
+        n = offset = total_out = LZ4F_compressBegin(ctx, out_buff, out_allocsize, &preferences);
+        if (LZ4F_isError(n))
+                return -EINVAL;
+
+        log_debug("Buffer size is %zu bytes, header size %zu bytes.", out_allocsize, n);
+
+        for (;;) {
+                ssize_t k;
+
+                k = loop_read(fdf, in_buff, LZ4_BUFSIZE, true);
+                if (k < 0)
+                        return k;
+                if (k == 0)
+                        break;
+                n = LZ4F_compressUpdate(ctx, out_buff + offset, out_allocsize - offset,
+                                        in_buff, k, NULL);
+                if (LZ4F_isError(n))
+                        return -ENOTRECOVERABLE;
+
+                total_in += k;
+                offset += n;
+                total_out += n;
+
+                if (max_bytes != UINT64_MAX && total_out > (size_t) max_bytes)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EFBIG),
+                                               "Compressed stream longer than %" PRIu64 " bytes", max_bytes);
+
+                if (out_allocsize - offset < frame_size + 4) {
+                        k = loop_write(fdt, out_buff, offset);
+                        if (k < 0)
+                                return k;
+                        offset = 0;
+                }
+        }
+
+        n = LZ4F_compressEnd(ctx, out_buff + offset, out_allocsize - offset, NULL);
+        if (LZ4F_isError(n))
+                return -ENOTRECOVERABLE;
+
+        offset += n;
+        total_out += n;
+        r = loop_write(fdt, out_buff, offset);
+        if (r < 0)
+                return r;
+
+        if (ret_uncompressed_size)
+                *ret_uncompressed_size = total_in;
+
+        log_debug("LZ4 compression finished (%" PRIu64 " -> %" PRIu64 " bytes, %.1f%%)",
+                  total_in, total_out,
+                  (double) total_out / total_in * 100);
+
+        return 0;
+#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_MAX) {
+                                if (max_bytes < (uint64_t) n)
+                                        return -EFBIG;
+
+                                max_bytes -= n;
+                        }
+
+                        k = loop_write(fdt, out, n);
+                        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");
+
+        if (file_offset_beyond_memory_size(st.st_size))
+                return -EFBIG;
+
+        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_MAX && 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);
+                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, uint64_t *ret_uncompressed_size) {
+#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_full(fdt, output.dst, output.pos, USEC_INFINITY);
+                        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 (ret_uncompressed_size)
+                *ret_uncompressed_size = in_bytes;
+
+        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_full(fdt, output.dst, output.pos, USEC_INFINITY);
+                        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;
+}