LibTar: Create LibTar and TarStream

TarStream parses the contents of a tar file from an InputStream
2025-07-27 05:27:45 +00:00 · 2020-10-01 22:22:40 -07:00 · 2020-10-01 22:22:40 -07:00 · 99ee93149c
commit 99ee93149c
parent 1f90e4ab8d
5 changed files with 312 additions and 0 deletions
--- a/Libraries/LibTar/Tar.h
+++ b/Libraries/LibTar/Tar.h
@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2020, Peter Elliott <pelliott@ualberta.ca>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <AK/StringView.h>
+#include <sys/types.h>
+
+namespace Tar {
+
+enum FileType {
+    NormalFile = '0',
+    AlternateNormalFile = '\0',
+    HardLink = '1',
+    SymLink = '2',
+    CharacterSpecialFile = '3',
+    BlockSpecialFile = '4',
+    Directory = '5',
+    FIFO = '6',
+    ContiguousFile = '7',
+    GlobalExtendedHeader = 'g',
+    ExtendedHeader = 'x'
+};
+
+constexpr size_t block_size = 512;
+
+class Header {
+public:
+    // FIXME: support ustar filename prefix
+    const StringView file_name() const { return m_file_name; }
+    mode_t mode() const { return get_tar_field(m_mode); }
+    uid_t uid() const { return get_tar_field(m_uid); }
+    gid_t gid() const { return get_tar_field(m_gid); }
+    // FIXME: support 2001-star size encoding
+    size_t size() const { return get_tar_field(m_size); }
+    time_t timestamp() const { return get_tar_field(m_timestamp); }
+    FileType type_flag() const { return FileType(m_type_flag); }
+    const StringView link_name() const { return m_link_name; }
+    const StringView magic() const { return m_magic; }
+    const StringView version() const { return m_version; }
+    const StringView owner_name() const { return m_owner_name; }
+    const StringView group_name() const { return m_group_name; }
+    int major() const { return get_tar_field(m_major); }
+    int minor() const { return get_tar_field(m_minor); }
+
+    //private:
+    char m_file_name[100];
+    char m_mode[8];
+    char m_uid[8];
+    char m_gid[8];
+    char m_size[12];
+    char m_timestamp[12];
+    char m_checksum[8];
+    char m_type_flag;
+    char m_link_name[100];
+    char m_magic[6];
+    char m_version[2];
+    char m_owner_name[32];
+    char m_group_name[32];
+    char m_major[8];
+    char m_minor[8];
+    char m_prefix[155];
+
+    template<size_t N>
+    static size_t get_tar_field(const char (&field)[N]);
+};
+
+template<size_t N>
+size_t Header::get_tar_field(const char (&field)[N])
+{
+    size_t value = 0;
+    for (size_t i = 0; i < N; ++i) {
+        if (field[i] == 0)
+            break;
+
+        ASSERT(field[i] >= '0' && field[i] <= '7');
+        value *= 8;
+        value += field[i] - '0';
+    }
+    return value;
+}
+
+}