Fix import cycle issue

server/filesystem/compress.go

@@ -6,16 +6,23 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"sync/atomic"
 	"time"
+
+	"github.com/mholt/archiver/v3"
+	"github.com/pterodactyl/wings/server/backup"
+	"github.com/pterodactyl/wings/system"
 )
 
-// Compresses all of the files matching the given paths in the specified directory. This function
-// also supports passing nested paths to only compress certain files and folders when working in
-// a larger directory. This effectively creates a local backup, but rather than ignoring specific
-// files and folders, it takes an allow-list of files and folders.
+// CompressFiles compresses all of the files matching the given paths in the
+// specified directory. This function also supports passing nested paths to only
+// compress certain files and folders when working in a larger directory. This
+// effectively creates a local backup, but rather than ignoring specific files
+// and folders, it takes an allow-list of files and folders.
 //
-// All paths are relative to the dir that is passed in as the first argument, and the compressed
-// file will be placed at that location named `archive-{date}.tar.gz`.
+// All paths are relative to the dir that is passed in as the first argument,
+// and the compressed file will be placed at that location named
+// `archive-{date}.tar.gz`.
 func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, error) {
 	cleanedRootDir, err := fs.SafePath(dir)
 	if err != nil {
@@ -32,7 +39,7 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
 		return nil, err
 	}
 
-	a := &Archive{BasePath: cleanedRootDir, Files: cleaned}
+	a := &backup.Archive{BasePath: cleanedRootDir, Files: cleaned}
 	d := path.Join(
 		cleanedRootDir,
 		fmt.Sprintf("archive-%s.tar.gz", strings.ReplaceAll(time.Now().Format(time.RFC3339), ":", "")),
@@ -57,3 +64,86 @@ func (fs *Filesystem) CompressFiles(dir string, paths []string) (os.FileInfo, er
 
 	return f, nil
 }
+
+// SpaceAvailableForDecompression looks through a given archive and determines
+// if decompressing it would put the server over its allocated disk space limit.
+func (fs *Filesystem) SpaceAvailableForDecompression(dir string, file string) error {
+	// Don't waste time trying to determine this if we know the server will have the space for
+	// it since there is no limit.
+	if fs.MaxDisk() <= 0 {
+		return nil
+	}
+
+	source, err := fs.SafePath(filepath.Join(dir, file))
+	if err != nil {
+		return err
+	}
+
+	// Get the cached size in a parallel process so that if it is not cached we are not
+	// waiting an unnecessary amount of time on this call.
+	dirSize, err := fs.DiskUsage(false)
+
+	var size int64
+	// Walk over the archive and figure out just how large the final output would be from unarchiving it.
+	err = archiver.Walk(source, func(f archiver.File) error {
+		if atomic.AddInt64(&size, f.Size())+dirSize > fs.MaxDisk() {
+			return &Error{code: ErrCodeDiskSpace}
+		}
+		return nil
+	})
+	if err != nil {
+		if strings.HasPrefix(err.Error(), "format ") {
+			return &Error{code: ErrCodeUnknownArchive}
+		}
+		return err
+	}
+	return err
+}
+
+// DecompressFile will decompress a file in a given directory by using the
+// archiver tool to infer the file type and go from there. This will walk over
+// all of the files within the given archive and ensure that there is not a
+// zip-slip attack being attempted by validating that the final path is within
+// the server data directory.
+func (fs *Filesystem) DecompressFile(dir string, file string) error {
+	source, err := fs.SafePath(filepath.Join(dir, file))
+	if err != nil {
+		return err
+	}
+	// Ensure that the source archive actually exists on the system.
+	if _, err := os.Stat(source); err != nil {
+		return err
+	}
+
+	// Walk over all of the files spinning up an additional go-routine for each file we've encountered
+	// and then extract that file from the archive and write it to the disk. If any part of this process
+	// encounters an error the entire process will be stopped.
+	err = archiver.Walk(source, func(f archiver.File) error {
+		// Don't waste time with directories, we don't need to create them if they have no contents, and
+		// we will ensure the directory exists when opening the file for writing anyways.
+		if f.IsDir() {
+			return nil
+		}
+		name, err := system.ExtractArchiveSourceName(f, dir)
+		if err != nil {
+			return WrapError(err, filepath.Join(dir, f.Name()))
+		}
+		p := filepath.Join(dir, name)
+		// If it is ignored, just don't do anything with the file and skip over it.
+		if err := fs.IsIgnored(p); err != nil {
+			return nil
+		}
+		if err := fs.Writefile(p, f); err != nil {
+			return &Error{code: ErrCodeUnknownError, err: err, resolved: source}
+		}
+		return nil
+	})
+	if err != nil {
+		if strings.HasPrefix(err.Error(), "format ") {
+			return &Error{code: ErrCodeUnknownArchive}
+		}
+		return err
+	}
+	return nil
+}
+