import: split out compression logic, so that we can share it with between import and pull calls

1 files changed, 194 insertions, 0 deletions

diff --git a/src/import/import-compress.c b/src/import/import-compress.c
new file mode 100644
index 0000000000..629605a44c
--- /dev/null
+++ b/src/import/import-compress.c
@@ -0,0 +1,194 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2015 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "util.h"
+#include "import-compress.h"
+
+void import_compress_free(ImportCompress *c) {
+        assert(c);
+
+        if (c->type == IMPORT_COMPRESS_XZ)
+                lzma_end(&c->xz);
+        else if (c->type == IMPORT_COMPRESS_GZIP)
+                inflateEnd(&c->gzip);
+        else if (c->type == IMPORT_COMPRESS_BZIP2)
+                BZ2_bzDecompressEnd(&c->bzip2);
+
+        c->type = IMPORT_COMPRESS_UNKNOWN;
+}
+
+int import_uncompress_detect(ImportCompress *c, const void *data, size_t size) {
+        static const uint8_t xz_signature[] = {
+                0xfd, '7', 'z', 'X', 'Z', 0x00
+        };
+        static const uint8_t gzip_signature[] = {
+                0x1f, 0x8b
+        };
+        static const uint8_t bzip2_signature[] = {
+                'B', 'Z', 'h'
+        };
+
+        int r;
+
+        assert(c);
+
+        if (c->type != IMPORT_COMPRESS_UNKNOWN)
+                return 1;
+
+        if (size < MAX3(sizeof(xz_signature),
+                        sizeof(gzip_signature),
+                        sizeof(bzip2_signature)))
+                return 0;
+
+        assert(data);
+
+        if (memcmp(data, xz_signature, sizeof(xz_signature)) == 0) {
+                lzma_ret xzr;
+
+                xzr = lzma_stream_decoder(&c->xz, UINT64_MAX, LZMA_TELL_UNSUPPORTED_CHECK);
+                if (xzr != LZMA_OK)
+                        return -EIO;
+
+                c->type = IMPORT_COMPRESS_XZ;
+
+        } else if (memcmp(data, gzip_signature, sizeof(gzip_signature)) == 0) {
+                r = inflateInit2(&c->gzip, 15+16);
+                if (r != Z_OK)
+                        return -EIO;
+
+                c->type = IMPORT_COMPRESS_GZIP;
+
+        } else if (memcmp(data, bzip2_signature, sizeof(bzip2_signature)) == 0) {
+                r = BZ2_bzDecompressInit(&c->bzip2, 0, 0);
+                if (r != BZ_OK)
+                        return -EIO;
+
+                c->type = IMPORT_COMPRESS_BZIP2;
+        } else
+                c->type = IMPORT_COMPRESS_UNCOMPRESSED;
+
+        return 1;
+}
+
+int import_uncompress(ImportCompress *c, const void *data, size_t size, ImportCompressCallback callback, void *userdata) {
+        int r;
+
+        assert(c);
+        assert(callback);
+
+        r = import_uncompress_detect(c, data, size);
+        if (r <= 0)
+                return r;
+
+        if (size <= 0)
+                return 1;
+
+        assert(data);
+
+        switch (c->type) {
+
+        case IMPORT_COMPRESS_UNCOMPRESSED:
+                r = callback(data, size, userdata);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case IMPORT_COMPRESS_XZ:
+                c->xz.next_in = data;
+                c->xz.avail_in = size;
+
+                while (c->xz.avail_in > 0) {
+                        uint8_t buffer[16 * 1024];
+                        lzma_ret lzr;
+
+                        c->xz.next_out = buffer;
+                        c->xz.avail_out = sizeof(buffer);
+
+                        lzr = lzma_code(&c->xz, LZMA_RUN);
+                        if (lzr != LZMA_OK && lzr != LZMA_STREAM_END)
+                                return -EIO;
+
+                        r = callback(buffer, sizeof(buffer) - c->xz.avail_out, userdata);
+                        if (r < 0)
+                                return r;
+                }
+
+                break;
+
+        case IMPORT_COMPRESS_GZIP:
+                c->gzip.next_in = (void*) data;
+                c->gzip.avail_in = size;
+
+                while (c->gzip.avail_in > 0) {
+                        uint8_t buffer[16 * 1024];
+
+                        c->gzip.next_out = buffer;
+                        c->gzip.avail_out = sizeof(buffer);
+
+                        r = inflate(&c->gzip, Z_NO_FLUSH);
+                        if (r != Z_OK && r != Z_STREAM_END)
+                                return -EIO;
+
+                        r = callback(buffer, sizeof(buffer) - c->gzip.avail_out, userdata);
+                        if (r < 0)
+                                return r;
+                }
+
+                break;
+
+        case IMPORT_COMPRESS_BZIP2:
+                c->bzip2.next_in = (void*) data;
+                c->bzip2.avail_in = size;
+
+                while (c->bzip2.avail_in > 0) {
+                        uint8_t buffer[16 * 1024];
+
+                        c->bzip2.next_out = (char*) buffer;
+                        c->bzip2.avail_out = sizeof(buffer);
+
+                        r = BZ2_bzDecompress(&c->bzip2);
+                        if (r != BZ_OK && r != BZ_STREAM_END)
+                                return -EIO;
+
+                        r = callback(buffer, sizeof(buffer) - c->bzip2.avail_out, userdata);
+                        if (r < 0)
+                                return r;
+                }
+
+                break;
+
+        default:
+                assert_not_reached("Unknown compression");
+        }
+
+        return 1;
+}
+
+static const char* const import_compress_type_table[_IMPORT_COMPRESS_TYPE_MAX] = {
+        [IMPORT_COMPRESS_UNKNOWN] = "unknown",
+        [IMPORT_COMPRESS_UNCOMPRESSED] = "uncompressed",
+        [IMPORT_COMPRESS_XZ] = "xz",
+        [IMPORT_COMPRESS_GZIP] = "gzip",
+        [IMPORT_COMPRESS_BZIP2] = "bzip2",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(import_compress_type, ImportCompressType);