1 files changed, 292 insertions, 0 deletions
diff --git a/src/Mapper.cxx b/src/Mapper.cxx
new file mode 100644
index 000000000..e2d082122
--- /dev/null
+++ b/src/Mapper.cxx
@@ -0,0 +1,292 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * Maps directory and song objects to file system paths.
+ */
+
+#include "config.h"
+#include "Mapper.hxx"
+#include "Directory.hxx"
+#include "Song.hxx"
+#include "fs/Path.hxx"
+#include "fs/FileSystem.hxx"
+#include "fs/DirectoryReader.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <dirent.h>
+
+static constexpr Domain mapper_domain("mapper");
+
+/**
+ * The absolute path of the music directory encoded in UTF-8.
+ */
+static char *music_dir_utf8;
+static size_t music_dir_utf8_length;
+
+/**
+ * The absolute path of the music directory encoded in the filesystem
+ * character set.
+ */
+static Path music_dir_fs = Path::Null();
+static size_t music_dir_fs_length;
+
+/**
+ * The absolute path of the playlist directory encoded in the
+ * filesystem character set.
+ */
+static Path playlist_dir_fs = Path::Null();
+
+/**
+ * Duplicate a string, chop all trailing slashes.
+ */
+static char *
+strdup_chop_slash(const char *path_fs)
+{
+	size_t length = strlen(path_fs);
+
+	while (length > 0 && path_fs[length - 1] == G_DIR_SEPARATOR)
+		--length;
+
+	return g_strndup(path_fs, length);
+}
+
+static void
+check_directory(const char *path_utf8, const Path &path_fs)
+{
+	struct stat st;
+	if (!StatFile(path_fs, st)) {
+		FormatErrno(mapper_domain,
+			    "Failed to stat directory \"%s\"",
+			    path_utf8);
+		return;
+	}
+
+	if (!S_ISDIR(st.st_mode)) {
+		FormatError(mapper_domain,
+			    "Not a directory: %s", path_utf8);
+		return;
+	}
+
+#ifndef WIN32
+	const Path x = Path::Build(path_fs, ".");
+	if (!StatFile(x, st) && errno == EACCES)
+		FormatError(mapper_domain,
+			    "No permission to traverse (\"execute\") directory: %s",
+			    path_utf8);
+#endif
+
+	const DirectoryReader reader(path_fs);
+	if (reader.HasFailed() && errno == EACCES)
+		FormatError(mapper_domain,
+			    "No permission to read directory: %s", path_utf8);
+}
+
+static void
+mapper_set_music_dir(Path &&path)
+{
+	assert(!path.IsNull());
+
+	music_dir_fs = std::move(path);
+	music_dir_fs_length = music_dir_fs.length();
+
+	const auto utf8 = music_dir_fs.ToUTF8();
+	music_dir_utf8 = strdup_chop_slash(utf8.c_str());
+	music_dir_utf8_length = strlen(music_dir_utf8);
+
+	check_directory(music_dir_utf8, music_dir_fs);
+}
+
+static void
+mapper_set_playlist_dir(Path &&path)
+{
+	assert(!path.IsNull());
+
+	playlist_dir_fs = std::move(path);
+
+	const auto utf8 = playlist_dir_fs.ToUTF8();
+	check_directory(utf8.c_str(), playlist_dir_fs);
+}
+
+void
+mapper_init(Path &&_music_dir, Path &&_playlist_dir)
+{
+	if (!_music_dir.IsNull())
+		mapper_set_music_dir(std::move(_music_dir));
+
+	if (!_playlist_dir.IsNull())
+		mapper_set_playlist_dir(std::move(_playlist_dir));
+}
+
+void mapper_finish(void)
+{
+	g_free(music_dir_utf8);
+}
+
+const char *
+mapper_get_music_directory_utf8(void)
+{
+	return music_dir_utf8;
+}
+
+const Path &
+mapper_get_music_directory_fs(void)
+{
+	return music_dir_fs;
+}
+
+const char *
+map_to_relative_path(const char *path_utf8)
+{
+	return music_dir_utf8 != NULL &&
+		memcmp(path_utf8, music_dir_utf8,
+		       music_dir_utf8_length) == 0 &&
+		G_IS_DIR_SEPARATOR(path_utf8[music_dir_utf8_length])
+		? path_utf8 + music_dir_utf8_length + 1
+		: path_utf8;
+}
+
+Path
+map_uri_fs(const char *uri)
+{
+	assert(uri != NULL);
+	assert(*uri != '/');
+
+	if (music_dir_fs.IsNull())
+		return Path::Null();
+
+	const Path uri_fs = Path::FromUTF8(uri);
+	if (uri_fs.IsNull())
+		return Path::Null();
+
+	return Path::Build(music_dir_fs, uri_fs);
+}
+
+Path
+map_directory_fs(const Directory *directory)
+{
+	assert(music_dir_utf8 != NULL);
+	assert(!music_dir_fs.IsNull());
+
+	if (directory->IsRoot())
+		return music_dir_fs;
+
+	return map_uri_fs(directory->GetPath());
+}
+
+Path
+map_directory_child_fs(const Directory *directory, const char *name)
+{
+	assert(music_dir_utf8 != NULL);
+	assert(!music_dir_fs.IsNull());
+
+	/* check for invalid or unauthorized base names */
+	if (*name == 0 || strchr(name, '/') != NULL ||
+	    strcmp(name, ".") == 0 || strcmp(name, "..") == 0)
+		return Path::Null();
+
+	const Path parent_fs = map_directory_fs(directory);
+	if (parent_fs.IsNull())
+		return Path::Null();
+
+	const Path name_fs = Path::FromUTF8(name);
+	if (name_fs.IsNull())
+		return Path::Null();
+
+	return Path::Build(parent_fs, name_fs);
+}
+
+/**
+ * Map a song object that was created by song_dup_detached().  It does
+ * not have a real parent directory, only the dummy object
+ * #detached_root.
+ */
+static Path
+map_detached_song_fs(const char *uri_utf8)
+{
+	Path uri_fs = Path::FromUTF8(uri_utf8);
+	if (uri_fs.IsNull())
+		return Path::Null();
+
+	return Path::Build(music_dir_fs, uri_fs);
+}
+
+Path
+map_song_fs(const Song *song)
+{
+	assert(song->IsFile());
+
+	if (song->IsInDatabase())
+		return song->IsDetached()
+			? map_detached_song_fs(song->uri)
+			: map_directory_child_fs(song->parent, song->uri);
+	else
+		return Path::FromUTF8(song->uri);
+}
+
+char *
+map_fs_to_utf8(const char *path_fs)
+{
+	if (!music_dir_fs.IsNull() &&
+	    strncmp(path_fs, music_dir_fs.c_str(), music_dir_fs_length) == 0 &&
+	    G_IS_DIR_SEPARATOR(path_fs[music_dir_fs_length]))
+		/* remove musicDir prefix */
+		path_fs += music_dir_fs_length + 1;
+	else if (G_IS_DIR_SEPARATOR(path_fs[0]))
+		/* not within musicDir */
+		return NULL;
+
+	while (path_fs[0] == G_DIR_SEPARATOR)
+		++path_fs;
+
+	const std::string path_utf8 = Path::ToUTF8(path_fs);
+	if (path_utf8.empty())
+		return nullptr;
+
+	return g_strdup(path_utf8.c_str());
+}
+
+const Path &
+map_spl_path(void)
+{
+	return playlist_dir_fs;
+}
+
+Path
+map_spl_utf8_to_fs(const char *name)
+{
+	if (playlist_dir_fs.IsNull())
+		return Path::Null();
+
+	char *filename_utf8 = g_strconcat(name, PLAYLIST_FILE_SUFFIX, NULL);
+	const Path filename_fs = Path::FromUTF8(filename_utf8);
+	g_free(filename_utf8);
+	if (filename_fs.IsNull())
+		return Path::Null();
+
+	return Path::Build(playlist_dir_fs, filename_fs);
+}