Libraries: Rename LibTar to LibArchive

This is in preparation for a new implementation of zip archive
extraction and creation.

4 files changed, 424 insertions, 0 deletions

diff --git a/Userland/Libraries/LibArchive/CMakeLists.txt b/Userland/Libraries/LibArchive/CMakeLists.txt
new file mode 100644
index 0000000000..29dce137b0
--- /dev/null
+++ b/Userland/Libraries/LibArchive/CMakeLists.txt
@@ -0,0 +1,6 @@
+set(SOURCES
+    TarStream.cpp
+)
+
+serenity_lib(LibArchive archive)
+target_link_libraries(LibArchive LibCore)
diff --git a/Userland/Libraries/LibArchive/Tar.h b/Userland/Libraries/LibArchive/Tar.h
new file mode 100644
index 0000000000..cdd001c23f
--- /dev/null
+++ b/Userland/Libraries/LibArchive/Tar.h
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2020, Peter Elliott <pelliott@ualberta.ca>
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@gmail.com>
+ * 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/String.h>
+#include <AK/StringView.h>
+#include <string.h>
+#include <sys/types.h>
+
+namespace Archive {
+
+enum class TarFileType : char {
+    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;
+constexpr const char* gnu_magic = "ustar ";  // gnu format magic
+constexpr const char* gnu_version = " ";     // gnu format version
+constexpr const char* ustar_magic = "ustar"; // ustar format magic
+constexpr const char* ustar_version = "00";  // ustar format version
+
+class [[gnu::packed]] TarFileHeader {
+public:
+    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); }
+    TarFileType type_flag() const { return TarFileType(m_type_flag); }
+    const StringView link_name() const { return m_link_name; }
+    const StringView magic() const { return StringView(m_magic, min(__builtin_strlen(m_magic), sizeof(m_magic))); }         // in some cases this is a null terminated string, in others its not
+    const StringView version() const { return StringView(m_version, min(__builtin_strlen(m_version), sizeof(m_version))); } // in some cases this is a null terminated string, in others its not
+    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); }
+    // FIXME: support ustar filename prefix
+    const StringView prefix() const { return m_prefix; }
+
+    void set_file_name(const String& file_name) { VERIFY(file_name.copy_characters_to_buffer(m_file_name, sizeof(m_file_name))); }
+    void set_mode(mode_t mode) { VERIFY(String::formatted("{:o}", mode).copy_characters_to_buffer(m_mode, sizeof(m_mode))); }
+    void set_uid(uid_t uid) { VERIFY(String::formatted("{:o}", uid).copy_characters_to_buffer(m_uid, sizeof(m_uid))); }
+    void set_gid(gid_t gid) { VERIFY(String::formatted("{:o}", gid).copy_characters_to_buffer(m_gid, sizeof(m_gid))); }
+    void set_size(size_t size) { VERIFY(String::formatted("{:o}", size).copy_characters_to_buffer(m_size, sizeof(m_size))); }
+    void set_timestamp(time_t timestamp) { VERIFY(String::formatted("{:o}", timestamp).copy_characters_to_buffer(m_timestamp, sizeof(m_timestamp))); }
+    void set_type_flag(TarFileType type) { m_type_flag = static_cast<char>(type); }
+    void set_link_name(const String& link_name) { VERIFY(link_name.copy_characters_to_buffer(m_link_name, sizeof(m_link_name))); }
+    void set_magic(const char* magic) { memcpy(m_magic, magic, sizeof(m_magic)); }           // magic doesnt necessarily include a null byte
+    void set_version(const char* version) { memcpy(m_version, version, sizeof(m_version)); } // version doesnt necessarily include a null byte
+    void set_owner_name(const String& owner_name) { VERIFY(owner_name.copy_characters_to_buffer(m_owner_name, sizeof(m_owner_name))); }
+    void set_group_name(const String& group_name) { VERIFY(group_name.copy_characters_to_buffer(m_group_name, sizeof(m_group_name))); }
+    void set_major(int major) { VERIFY(String::formatted("{:o}", major).copy_characters_to_buffer(m_major, sizeof(m_major))); }
+    void set_minor(int minor) { VERIFY(String::formatted("{:o}", minor).copy_characters_to_buffer(m_minor, sizeof(m_minor))); }
+    void set_prefix(const String& prefix) { VERIFY(prefix.copy_characters_to_buffer(m_prefix, sizeof(m_prefix))); }
+
+    void calculate_checksum();
+
+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]; // an uninitialized header's checksum is filled with spaces
+    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]; // zero out the prefix for archiving
+
+    template<size_t N>
+    static size_t get_tar_field(const char (&field)[N]);
+};
+
+template<size_t N>
+size_t TarFileHeader::get_tar_field(const char (&field)[N])
+{
+    size_t value = 0;
+    for (size_t i = 0; i < N; ++i) {
+        if (field[i] == 0)
+            break;
+
+        VERIFY(field[i] >= '0' && field[i] <= '7');
+        value *= 8;
+        value += field[i] - '0';
+    }
+    return value;
+}
+void TarFileHeader::calculate_checksum()
+{
+    memset(m_checksum, ' ', sizeof(m_checksum));
+    auto checksum = 0u;
+    for (auto i = 0u; i < sizeof(TarFileHeader); ++i) {
+        checksum += ((unsigned char*)this)[i];
+    }
+    VERIFY(String::formatted("{:o}", checksum).copy_characters_to_buffer(m_checksum, sizeof(m_checksum)));
+}
+
+}
diff --git a/Userland/Libraries/LibArchive/TarStream.cpp b/Userland/Libraries/LibArchive/TarStream.cpp
new file mode 100644
index 0000000000..b3763bef17
--- /dev/null
+++ b/Userland/Libraries/LibArchive/TarStream.cpp
@@ -0,0 +1,190 @@
+/*
+ * Copyright (c) 2020, Peter Elliott <pelliott@ualberta.ca>
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@gmail.com>
+ * 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.
+ */
+
+#include <LibArchive/TarStream.h>
+#include <string.h>
+
+namespace Archive {
+TarFileStream::TarFileStream(TarInputStream& tar_stream)
+    : m_tar_stream(tar_stream)
+    , m_generation(tar_stream.m_generation)
+{
+}
+
+size_t TarFileStream::read(Bytes bytes)
+{
+    // verify that the stream has not advanced
+    VERIFY(m_tar_stream.m_generation == m_generation);
+
+    if (has_any_error())
+        return 0;
+
+    auto to_read = min(bytes.size(), m_tar_stream.header().size() - m_tar_stream.m_file_offset);
+
+    auto nread = m_tar_stream.m_stream.read(bytes.trim(to_read));
+    m_tar_stream.m_file_offset += nread;
+    return nread;
+}
+
+bool TarFileStream::unreliable_eof() const
+{
+    // verify that the stream has not advanced
+    VERIFY(m_tar_stream.m_generation == m_generation);
+
+    return m_tar_stream.m_stream.unreliable_eof()
+        || m_tar_stream.m_file_offset >= m_tar_stream.header().size();
+}
+
+bool TarFileStream::read_or_error(Bytes bytes)
+{
+    // verify that the stream has not advanced
+    VERIFY(m_tar_stream.m_generation == m_generation);
+
+    if (read(bytes) < bytes.size()) {
+        set_fatal_error();
+        return false;
+    }
+
+    return true;
+}
+
+bool TarFileStream::discard_or_error(size_t count)
+{
+    // verify that the stream has not advanced
+    VERIFY(m_tar_stream.m_generation == m_generation);
+
+    if (count > m_tar_stream.header().size() - m_tar_stream.m_file_offset) {
+        return false;
+    }
+    m_tar_stream.m_file_offset += count;
+    return m_tar_stream.m_stream.discard_or_error(count);
+}
+
+TarInputStream::TarInputStream(InputStream& stream)
+    : m_stream(stream)
+{
+    if (!m_stream.read_or_error(Bytes(&m_header, sizeof(m_header)))) {
+        m_finished = true;
+        m_stream.handle_any_error(); // clear out errors so we dont assert
+        return;
+    }
+    VERIFY(m_stream.discard_or_error(block_size - sizeof(TarFileHeader)));
+}
+
+static constexpr unsigned long block_ceiling(unsigned long offset)
+{
+    return block_size * (1 + ((offset - 1) / block_size));
+}
+
+void TarInputStream::advance()
+{
+    if (m_finished)
+        return;
+
+    m_generation++;
+    VERIFY(m_stream.discard_or_error(block_ceiling(m_header.size()) - m_file_offset));
+    m_file_offset = 0;
+
+    if (!m_stream.read_or_error(Bytes(&m_header, sizeof(m_header)))) {
+        m_finished = true;
+        return;
+    }
+    if (!valid()) {
+        m_finished = true;
+        return;
+    }
+
+    VERIFY(m_stream.discard_or_error(block_size - sizeof(TarFileHeader)));
+}
+
+bool TarInputStream::valid() const
+{
+    auto& header_magic = header().magic();
+    auto& header_version = header().version();
+    return (header_magic == gnu_magic && header_version == gnu_version) || (header_magic == ustar_magic && header_version == ustar_version);
+}
+
+TarFileStream TarInputStream::file_contents()
+{
+    VERIFY(!m_finished);
+    return TarFileStream(*this);
+}
+
+TarOutputStream::TarOutputStream(OutputStream& stream)
+    : m_stream(stream)
+{
+}
+
+void TarOutputStream::add_directory(const String& path, mode_t mode)
+{
+    VERIFY(!m_finished);
+    TarFileHeader header;
+    memset(&header, 0, sizeof(header));
+    header.set_size(0);
+    header.set_file_name(String::formatted("{}/", path)); // Old tar implementations assume directory names end with a /
+    header.set_type_flag(TarFileType::Directory);
+    header.set_mode(mode);
+    header.set_magic(gnu_magic);
+    header.set_version(gnu_version);
+    header.calculate_checksum();
+    VERIFY(m_stream.write_or_error(Bytes { &header, sizeof(header) }));
+    u8 padding[block_size] = { 0 };
+    VERIFY(m_stream.write_or_error(Bytes { &padding, block_size - sizeof(header) }));
+}
+
+void TarOutputStream::add_file(const String& path, mode_t mode, const ReadonlyBytes& bytes)
+{
+    VERIFY(!m_finished);
+    TarFileHeader header;
+    memset(&header, 0, sizeof(header));
+    header.set_size(bytes.size());
+    header.set_file_name(path);
+    header.set_type_flag(TarFileType::NormalFile);
+    header.set_mode(mode);
+    header.set_magic(gnu_magic);
+    header.set_version(gnu_version);
+    header.calculate_checksum();
+    VERIFY(m_stream.write_or_error(Bytes { &header, sizeof(header) }));
+    u8 padding[block_size] = { 0 };
+    VERIFY(m_stream.write_or_error(Bytes { &padding, block_size - sizeof(header) }));
+    size_t n_written = 0;
+    while (n_written < bytes.size()) {
+        n_written += m_stream.write(bytes.slice(n_written, min(bytes.size() - n_written, block_size)));
+    }
+    VERIFY(m_stream.write_or_error(Bytes { &padding, block_size - (n_written % block_size) }));
+}
+
+void TarOutputStream::finish()
+{
+    VERIFY(!m_finished);
+    u8 padding[block_size] = { 0 };
+    m_stream.write_or_error(Bytes { &padding, block_size }); // 2 empty records that are used to signify the end of the archive
+    m_stream.write_or_error(Bytes { &padding, block_size });
+    m_finished = true;
+}
+
+}
diff --git a/Userland/Libraries/LibArchive/TarStream.h b/Userland/Libraries/LibArchive/TarStream.h
new file mode 100644
index 0000000000..9a486b9efe
--- /dev/null
+++ b/Userland/Libraries/LibArchive/TarStream.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2020, Peter Elliott <pelliott@ualberta.ca>
+ * Copyright (c) 2021, Idan Horowitz <idan.horowitz@gmail.com>
+ * 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/Span.h>
+#include <AK/Stream.h>
+#include <LibArchive/Tar.h>
+
+namespace Archive {
+
+class TarInputStream;
+
+class TarFileStream : public InputStream {
+public:
+    size_t read(Bytes) override;
+    bool unreliable_eof() const override;
+
+    bool read_or_error(Bytes) override;
+    bool discard_or_error(size_t count) override;
+
+private:
+    TarFileStream(TarInputStream& stream);
+    TarInputStream& m_tar_stream;
+    int m_generation;
+
+    friend class TarInputStream;
+};
+
+class TarInputStream {
+public:
+    TarInputStream(InputStream&);
+    void advance();
+    bool finished() const { return m_finished; }
+    bool valid() const;
+    const TarFileHeader& header() const { return m_header; }
+    TarFileStream file_contents();
+
+private:
+    TarFileHeader m_header;
+    InputStream& m_stream;
+    unsigned long m_file_offset { 0 };
+    int m_generation { 0 };
+    bool m_finished { false };
+
+    friend class TarFileStream;
+};
+
+class TarOutputStream {
+public:
+    TarOutputStream(OutputStream&);
+    void add_file(const String& path, mode_t, const ReadonlyBytes&);
+    void add_directory(const String& path, mode_t);
+    void finish();
+
+private:
+    OutputStream& m_stream;
+    bool m_finished { false };
+
+    friend class TarFileStream;
+};
+
+}