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#include <archive.h>
#include <archive_entry.h>
#include <gtest/gtest.h>
#include "lix/libutil/tarfile.hh"
#include "lix/libstore/temporary-dir.hh"
#include "lix/libutil/async-io.hh"
#include "lix/libutil/file-system.hh"
#include "lix/libutil/serialise.hh"
namespace nix {
class TarWriter
{
std::unique_ptr<struct archive, decltype([](auto * a) { archive_write_free(a); })> archive;
Sink * sink;
static int callback_open(struct archive * archive, void * self)
{
return ARCHIVE_OK;
}
static ssize_t
callback_write(struct archive * archive, void * self_, const void * buf, size_t len)
{
auto * self = static_cast<TarWriter *>(self_);
try {
(*self->sink)(std::string_view{static_cast<const char *>(buf), len});
return len;
} catch (std::exception & err) { // NOLINT(lix-foreign-exceptions)
// NOLINTNEXTLINE(lix-unsafe-c-calls): what() is a c string
archive_set_error(archive, EIO, "Sink threw exception: %s", err.what());
return -1;
}
}
static int callback_close(struct archive * archive, void * self)
{
return ARCHIVE_OK;
}
void check(int err, const std::string & reason);
public:
TarWriter(Sink & sink) : archive(archive_write_new()), sink(&sink)
{
check(archive_write_add_filter_gzip(archive.get()), "add filter gzip (%s)");
check(archive_write_set_format_gnutar(archive.get()), "set format tar (%s)");
archive_write_set_option(archive.get(), nullptr, "mac-ext", nullptr);
check(
archive_write_open(
archive.get(),
static_cast<void *>(this),
callback_open,
callback_write,
callback_close
),
"opening archive (%s)"
);
}
void close() &&
{
check(archive_write_close(archive.get()), "closing archive (%s)");
}
using EntryPtr = std::unique_ptr<struct archive_entry, decltype([](auto * entry) {
archive_entry_free(entry);
})>;
EntryPtr newEntry()
{
return EntryPtr{archive_entry_new()};
}
EntryPtr header(const char * path, mode_t mode, unsigned int filetype)
{
auto entry = newEntry();
// NOLINTNEXTLINE(lix-unsafe-c-calls): test code lol
archive_entry_set_pathname(entry.get(), path);
archive_entry_set_mode(entry.get(), mode);
archive_entry_set_filetype(entry.get(), filetype);
return entry;
}
void writeHeader(EntryPtr && entry)
{
check(archive_write_header(archive.get(), entry.get()), "write header (%s)");
}
void file(const char * path, std::string content, mode_t mode = 0700)
{
auto entry = header(path, mode, AE_IFREG);
archive_entry_set_size(entry.get(), content.length());
writeHeader(std::move(entry));
ssize_t written = archive_write_data(archive.get(), content.data(), content.length());
if (written < 0) {
check(written, "write data (%s)");
}
}
void dir(const char * path, mode_t mode = 0700)
{
auto entry = header(path, mode, AE_IFDIR);
writeHeader(std::move(entry));
}
void symlink(const char * path, const char * target, mode_t mode = 0700)
{
auto entry = header(path, mode, AE_IFLNK);
// NOLINTNEXTLINE(lix-unsafe-c-calls): test code lol
archive_entry_set_symlink(entry.get(), target);
writeHeader(std::move(entry));
}
void hardlink(const char * path, const char * target, mode_t mode = 0700)
{
auto entry = header(path, mode, AE_IFLNK);
// NOLINTNEXTLINE(lix-unsafe-c-calls): test code lol
archive_entry_set_hardlink(entry.get(), target);
writeHeader(std::move(entry));
}
};
void TarWriter::check(int err, const std::string & reason)
{
if (err == ARCHIVE_EOF) {
throw EndOfFile("reached end of archive");
} else if (err != ARCHIVE_OK) {
throw Error(reason, archive_error_string(this->archive.get()));
}
}
/** Abstracted file status operations (for e.g. being able to replace it with a NAR or something
* else without blowing up all the tests) */
struct FileChecker
{
Path baseDir;
bool fileExists(std::string subpath)
{
return nix::pathExists(this->baseDir + "/" + subpath);
}
};
struct TarFixture : testing::Test
{
Path tmpDir;
AutoDelete deleter;
StringSink sink;
std::unique_ptr<TarWriter> writer;
TarFixture()
: tmpDir{createTempDir()}
, deleter{tmpDir, true}
, sink{}
, writer{std::make_unique<TarWriter>(sink)}
{
}
void finish()
{
if (writer) {
std::move(*writer).close();
writer = nullptr;
}
}
FileChecker extract();
};
FileChecker TarFixture::extract()
{
finish();
AsyncIoRoot aio;
auto stream = AsyncStringInputStream{sink.s};
aio.blockOn(unpackTarfile(stream, tmpDir));
return FileChecker{tmpDir};
}
TEST_F(TarFixture, readTrivial)
{
writer->dir("foo");
writer->file("foo/bar", "blah");
auto result = extract();
ASSERT_TRUE(result.fileExists("foo/bar"));
}
TEST_F(TarFixture, dotdotShouldFail)
{
writer->dir("../foo");
writer->file("../foo/bar", "blah");
writer->dir("bar");
writer->file("bar/nya", "kitty");
ASSERT_THROW(extract(), ArchiveError);
}
TEST_F(TarFixture, okayHardlinkWorks)
{
writer->dir("somedir");
writer->file("somedir/somefile", "mrrp");
writer->hardlink("somedir/link", "somedir/somefile");
auto result = extract();
ASSERT_TRUE(result.fileExists("somedir/somefile"));
ASSERT_TRUE(result.fileExists("somedir/link"));
}
TEST_F(TarFixture, badHardlinkOrderFails)
{
writer->dir("somedir");
writer->hardlink("somedir/link", "somedir/somefile");
writer->file("somedir/somefile", "mrrp");
ASSERT_THROW(extract(), ArchiveError);
}
TEST_F(TarFixture, okaySymlinkWorksIncludingInFunnyOrder)
{
writer->dir("somedir");
writer->symlink("somedir/link", "somedir/somefile");
writer->file("somedir/somefile", "mrrp");
auto result = extract();
ASSERT_TRUE(result.fileExists("somedir/somefile"));
ASSERT_TRUE(result.fileExists("somedir/link"));
}
TEST_F(TarFixture, badFileOnTopOfFile)
{
writer->dir("somedir");
writer->file("somedir/file", "ohno");
writer->file("somedir/file/mrrp", "mrrp");
ASSERT_THROW(extract(), ArchiveError);
}
TEST_F(TarFixture, badHardlinkTraversalOverFile)
{
writer->dir("somedir");
writer->file("somedir/file", "ohno");
writer->hardlink("somedir/link", "somedir/file/mrrp");
ASSERT_THROW(extract(), ArchiveError);
}
}
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