diff options
Diffstat (limited to 'pkg/copy/copy.go')
-rw-r--r-- | pkg/copy/copy.go | 220 |
1 files changed, 0 insertions, 220 deletions
diff --git a/pkg/copy/copy.go b/pkg/copy/copy.go deleted file mode 100644 index 13893deb2..000000000 --- a/pkg/copy/copy.go +++ /dev/null @@ -1,220 +0,0 @@ -package copy - -import ( - "io" - "os" - "path/filepath" - "strings" - - buildahCopiah "github.com/containers/buildah/copier" - "github.com/containers/storage/pkg/archive" - securejoin "github.com/cyphar/filepath-securejoin" - "github.com/pkg/errors" -) - -// ********************************* NOTE ************************************* -// -// Most security bugs are caused by attackers playing around with symlinks -// trying to escape from the container onto the host and/or trick into data -// corruption on the host. Hence, file operations on containers (including -// *stat) should always be handled by `github.com/containers/buildah/copier` -// which makes sure to evaluate files in a chroot'ed environment. -// -// Please make sure to add verbose comments when changing code to make the -// lives of future readers easier. -// -// **************************************************************************** - -// Copier copies data from a source to a destination CopyItem. -type Copier struct { - copyFunc func() error - cleanUpFuncs []deferFunc -} - -// cleanUp releases resources the Copier may hold open. -func (c *Copier) cleanUp() { - for _, f := range c.cleanUpFuncs { - f() - } -} - -// Copy data from a source to a destination CopyItem. -func (c *Copier) Copy() error { - defer c.cleanUp() - return c.copyFunc() -} - -// GetCopiers returns a Copier to copy the source item to destination. Use -// extract to untar the source if it's a tar archive. -func GetCopier(source *CopyItem, destination *CopyItem, extract bool) (*Copier, error) { - copier := &Copier{} - - // First, do the man-page dance. See podman-cp(1) for details. - if err := enforceCopyRules(source, destination); err != nil { - return nil, err - } - - // Destination is a stream (e.g., stdout or an http body). - if destination.info.IsStream { - // Source is a stream (e.g., stdin or an http body). - if source.info.IsStream { - copier.copyFunc = func() error { - _, err := io.Copy(destination.writer, source.reader) - return err - } - return copier, nil - } - root, glob, err := source.buildahGlobs() - if err != nil { - return nil, err - } - copier.copyFunc = func() error { - return buildahCopiah.Get(root, "", source.getOptions(), []string{glob}, destination.writer) - } - return copier, nil - } - - // Destination is either a file or a directory. - if source.info.IsStream { - copier.copyFunc = func() error { - return buildahCopiah.Put(destination.root, destination.resolved, source.putOptions(), source.reader) - } - return copier, nil - } - - tarOptions := &archive.TarOptions{ - Compression: archive.Uncompressed, - CopyPass: true, - } - - root := destination.root - dir := destination.resolved - if !source.info.IsDir { - // When copying a file, make sure to rename the - // destination base path. - nameMap := make(map[string]string) - nameMap[filepath.Base(source.resolved)] = filepath.Base(destination.resolved) - tarOptions.RebaseNames = nameMap - dir = filepath.Dir(dir) - } - - var tarReader io.ReadCloser - if extract && archive.IsArchivePath(source.resolved) { - if !destination.info.IsDir { - return nil, errors.Errorf("cannot extract archive %q to file %q", source.original, destination.original) - } - - reader, err := os.Open(source.resolved) - if err != nil { - return nil, err - } - copier.cleanUpFuncs = append(copier.cleanUpFuncs, func() { reader.Close() }) - - // The stream from stdin may be compressed (e.g., via gzip). - decompressedStream, err := archive.DecompressStream(reader) - if err != nil { - return nil, err - } - - copier.cleanUpFuncs = append(copier.cleanUpFuncs, func() { decompressedStream.Close() }) - tarReader = decompressedStream - } else { - reader, err := archive.TarWithOptions(source.resolved, tarOptions) - if err != nil { - return nil, err - } - copier.cleanUpFuncs = append(copier.cleanUpFuncs, func() { reader.Close() }) - tarReader = reader - } - - copier.copyFunc = func() error { - return buildahCopiah.Put(root, dir, source.putOptions(), tarReader) - } - return copier, nil -} - -// enforceCopyRules enforces the rules for copying from a source to a -// destination as mentioned in the podman-cp(1) man page. Please refer to the -// man page and/or the inline comments for further details. Note that source -// and destination are passed by reference and the their data may be changed. -func enforceCopyRules(source, destination *CopyItem) error { - if source.statError != nil { - return source.statError - } - - // We can copy everything to a stream. - if destination.info.IsStream { - return nil - } - - if source.info.IsStream { - if !(destination.info.IsDir || destination.info.IsStream) { - return errors.New("destination must be a directory or stream when copying from a stream") - } - return nil - } - - // Source is a *directory*. - if source.info.IsDir { - if destination.statError != nil { - // It's okay if the destination does not exist. We - // made sure before that it's parent exists, so it - // would be created while copying. - if os.IsNotExist(destination.statError) { - return nil - } - // Could be a permission error. - return destination.statError - } - - // If the destination exists and is not a directory, we have a - // problem. - if !destination.info.IsDir { - return errors.Errorf("cannot copy directory %q to file %q", source.original, destination.original) - } - - // If the destination exists and is a directory, we need to - // append the source base directory to it. This makes sure - // that copying "/foo/bar" "/tmp" will copy to "/tmp/bar" (and - // not "/tmp"). - newDestination, err := securejoin.SecureJoin(destination.resolved, filepath.Base(source.resolved)) - if err != nil { - return err - } - destination.resolved = newDestination - return nil - } - - // Source is a *file*. - if destination.statError != nil { - // It's okay if the destination does not exist, unless it ends - // with "/". - if !os.IsNotExist(destination.statError) { - return destination.statError - } else if strings.HasSuffix(destination.resolved, "/") { - // Note: this is practically unreachable code as the - // existence of parent directories is enforced early - // on. It's left here as an extra security net. - return errors.Errorf("destination directory %q must exist (trailing %q)", destination.original, "/") - } - // Does not exist and does not end with "/". - return nil - } - - // If the destination is a file, we're good. We will overwrite the - // contents while copying. - if !destination.info.IsDir { - return nil - } - - // If the destination exists and is a directory, we need to append the - // source base directory to it. This makes sure that copying - // "/foo/bar" "/tmp" will copy to "/tmp/bar" (and not "/tmp"). - newDestination, err := securejoin.SecureJoin(destination.resolved, filepath.Base(source.resolved)) - if err != nil { - return err - } - - destination.resolved = newDestination - return nil -} |