HDFS-15372. Files in snapshots no longer see attribute provider permissions. Contributed by Stephen O'Donnell.

Signed-off-by: Wei-Chiu Chuang <weichiu@apache.org>
This commit is contained in:
Stephen O'Donnell 2020-06-16 15:58:16 -07:00 committed by Wei-Chiu Chuang
parent 81d8a887b0
commit 730a39d138
4 changed files with 199 additions and 20 deletions

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@ -73,7 +73,6 @@
import java.io.Closeable;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
@ -2032,7 +2031,20 @@ INodeAttributes getAttributes(INodesInPath iip)
// first empty component for the root. however file status
// related calls are expected to strip out the root component according
// to TestINodeAttributeProvider.
byte[][] components = iip.getPathComponents();
// Due to HDFS-15372 the attribute provider should received the resolved
// snapshot path. Ie, rather than seeing /d/.snapshot/sn/data it should
// see /d/data. However, for the path /d/.snapshot/sn it should see this
// full path. Node.getPathComponents always resolves the path to the
// original location, so we need to check if ".snapshot/sn" is the last
// path to ensure the provider receives the correct components.
byte[][] components;
if (iip.isSnapshot() && !iip.isDotSnapshotDirPrefix()) {
// For snapshot paths, node.getPathComponents unless the last component
// is like ".snapshot/sn"
components = node.getPathComponents();
} else {
components = iip.getPathComponents();
}
components = Arrays.copyOfRange(components, 1, components.length);
nodeAttrs = ap.getAttributes(components, nodeAttrs);
}

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@ -19,11 +19,14 @@
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Stack;
import com.google.common.base.Preconditions;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
import org.apache.hadoop.ipc.CallerContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -207,7 +210,7 @@ void checkPermission(INodesInPath inodesInPath, boolean doCheckOwner,
final INodeAttributes[] inodeAttrs = new INodeAttributes[inodes.length];
final byte[][] components = inodesInPath.getPathComponents();
for (int i = 0; i < inodes.length && inodes[i] != null; i++) {
inodeAttrs[i] = getINodeAttrs(components, i, inodes[i], snapshotId);
inodeAttrs[i] = getINodeAttrs(inodes[i], snapshotId);
}
String path = inodesInPath.getPath();
@ -257,8 +260,7 @@ void checkPermission(INodesInPath inodesInPath, boolean doCheckOwner,
void checkPermission(INode inode, int snapshotId, FsAction access)
throws AccessControlException {
byte[][] pathComponents = inode.getPathComponents();
INodeAttributes nodeAttributes = getINodeAttrs(pathComponents,
pathComponents.length - 1, inode, snapshotId);
INodeAttributes nodeAttributes = getINodeAttrs(inode, snapshotId);
try {
INodeAttributes[] iNodeAttr = {nodeAttributes};
AccessControlEnforcer enforcer = getAccessControlEnforcer();
@ -367,23 +369,31 @@ public void checkPermissionWithContext(
authzContext.getSubAccess(), authzContext.isIgnoreEmptyDir());
}
private INodeAttributes getINodeAttrs(byte[][] pathByNameArr, int pathIdx,
INode inode, int snapshotId) {
private INodeAttributes getINodeAttrs(INode inode, int snapshotId) {
INodeAttributes inodeAttrs = inode.getSnapshotINode(snapshotId);
if (getAttributesProvider() != null) {
String[] elements = new String[pathIdx + 1];
/**
* {@link INode#getPathComponents(String)} returns a null component
* for the root only path "/". Assign an empty string if so.
* This logic is similar to {@link FSDirectory#getAttributes()} and it
* ensures that the attribute provider sees snapshot paths resolved to their
* original location. This means the attributeProvider can apply permissions
* to the snapshot paths in the same was as the live paths. See HDFS-15372.
*/
if (pathByNameArr.length == 1 && pathByNameArr[0] == null) {
elements[0] = "";
} else {
for (int i = 0; i < elements.length; i++) {
elements[i] = DFSUtil.bytes2String(pathByNameArr[i]);
}
}
inodeAttrs = getAttributesProvider().getAttributes(elements, inodeAttrs);
if (getAttributesProvider() != null) {
/**
* If we have an inode representing a path like /d/.snapshot/snap1
* then calling inode.getPathComponents returns [null, d, snap1]. If we
* call inode.getFullPathName() it will return /d/.snapshot/snap1. For
* this special path (snapshot root) the attribute provider should see:
*
* [null, d, .snapshot/snap1]
*
* Using IIP.resolveFromRoot, it will take the inode fullPathName and
* construct an IIP object that give the correct components as above.
*/
INodesInPath iip = INodesInPath.resolveFromRoot(inode);
byte[][] components = iip.getPathComponents();
components = Arrays.copyOfRange(components, 1, components.length);
inodeAttrs = getAttributesProvider()
.getAttributes(components, inodeAttrs);
}
return inodeAttrs;
}
@ -439,7 +449,7 @@ private void checkSubAccess(byte[][] components, int pathIdx,
if (!(cList.isEmpty() && ignoreEmptyDir)) {
//TODO have to figure this out with inodeattribute provider
INodeAttributes inodeAttr =
getINodeAttrs(components, pathIdx, d, snapshotId);
getINodeAttrs(d, snapshotId);
if (!hasPermission(inodeAttr, access)) {
throw new AccessControlException(
toAccessControlString(inodeAttr, d.getFullPathName(), access));
@ -457,7 +467,7 @@ private void checkSubAccess(byte[][] components, int pathIdx,
if (inodeAttr.getFsPermission().getStickyBit()) {
for (INode child : cList) {
INodeAttributes childInodeAttr =
getINodeAttrs(components, pathIdx, child, snapshotId);
getINodeAttrs(child, snapshotId);
if (isStickyBitViolated(inodeAttr, childInodeAttr)) {
List<byte[]> allComponentList = new ArrayList<>();
for (int i = 0; i <= pathIdx; ++i) {

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@ -46,6 +46,20 @@ private static boolean isDotSnapshotDir(byte[] pathComponent) {
Arrays.equals(HdfsServerConstants.DOT_SNAPSHOT_DIR_BYTES, pathComponent);
}
/**
* Returns true if the given path component starts with the same byte stream
* as {@link HdfsConstants#DOT_SNAPSHOT_DIR}, indicating the component
* starts with a DotSnapshot directory.
* @param pathComponent Bytes representing the pathComponent
* @return True is the component starts with
* {@link HdfsConstants#DOT_SNAPSHOT_DIR} and false otherwise.
*/
private static boolean isDotSnapshotDirPrefix(byte[] pathComponent) {
return pathComponent != null &&
isDotSnapshotDir(Arrays.copyOf(
pathComponent, HdfsServerConstants.DOT_SNAPSHOT_DIR_BYTES.length));
}
private static INode[] getINodes(final INode inode) {
int depth = 0, index;
INode tmp = inode;
@ -135,6 +149,27 @@ static INodesInPath resolve(final INodeDirectory startingDir,
return resolve(startingDir, components, false);
}
/**
* Retrieves the existing INodes from a path, starting at the root directory.
* The root directory is located by following the parent link in the inode
* recursively until the final root inode is found.
* The inodes returned will depend upon the output of inode.getFullPathName().
* For a snapshot path, like /data/.snapshot/snap1, it will be resolved to:
* [null, data, .snapshot/snap1]
* For a file in the snapshot, as inode.getFullPathName resolves the snapshot
* information, the returned inodes for a path like /data/.snapshot/snap1/d1
* would be:
* [null, data, d1]
* @param inode the {@link INode} to be resolved
* @return INodesInPath
*/
static INodesInPath resolveFromRoot(INode inode) {
INode[] inodes = getINodes(inode);
byte[][] paths = INode.getPathComponents(inode.getFullPathName());
INodeDirectory rootDir = inodes[0].asDirectory();
return resolve(rootDir, paths);
}
static INodesInPath resolve(final INodeDirectory startingDir,
byte[][] components, final boolean isRaw) {
Preconditions.checkArgument(startingDir.compareTo(components[0]) == 0);
@ -462,6 +497,13 @@ boolean isDotSnapshotDir() {
return isDotSnapshotDir(getLastLocalName());
}
/**
* @return Return true if .snapshot is the prefix of the last path component.
*/
boolean isDotSnapshotDirPrefix() {
return isDotSnapshotDirPrefix(getLastLocalName());
}
/**
* @return if this is a /.reserved/raw path.
*/

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@ -33,6 +33,7 @@
import org.apache.hadoop.fs.XAttr;
import org.apache.hadoop.fs.permission.*;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.security.AccessControlException;
@ -80,6 +81,7 @@ public void checkPermission(String fsOwner, String supergroup,
ancestorAccess, parentAccess, access, subAccess, ignoreEmptyDir);
}
CALLED.add("checkPermission|" + ancestorAccess + "|" + parentAccess + "|" + access);
CALLED.add("checkPermission|" + path);
}
@Override
@ -93,6 +95,7 @@ public void checkPermissionWithContext(
CALLED.add("checkPermission|" + authzContext.getAncestorAccess()
+ "|" + authzContext.getParentAccess() + "|" + authzContext
.getAccess());
CALLED.add("checkPermission|" + authzContext.getPath());
}
}
@ -109,7 +112,12 @@ public void stop() {
@Override
public INodeAttributes getAttributes(String[] pathElements,
final INodeAttributes inode) {
String fullPath = String.join("/", pathElements);
if (!fullPath.startsWith("/")) {
fullPath = "/" + fullPath;
}
CALLED.add("getAttributes");
CALLED.add("getAttributes|"+fullPath);
final boolean useDefault = useDefault(pathElements);
final boolean useNullAcl = useNullAclFeature(pathElements);
return new INodeAttributes() {
@ -485,4 +493,111 @@ public Void run() throws Exception {
}
});
}
@Test
// HDFS-15372 - Attribute provider should not see the snapshot path as it
// should be resolved into the original path name before it hits the provider.
public void testAttrProviderSeesResolvedSnapahotPaths() throws Exception {
FileSystem fs = FileSystem.get(miniDFS.getConfiguration(0));
DistributedFileSystem hdfs = miniDFS.getFileSystem();
final Path userPath = new Path("/user");
final Path authz = new Path("/user/authz");
final Path authzChild = new Path("/user/authz/child2");
fs.mkdirs(userPath);
fs.setPermission(userPath, new FsPermission(HDFS_PERMISSION));
fs.mkdirs(authz);
hdfs.allowSnapshot(userPath);
fs.setPermission(authz, new FsPermission(HDFS_PERMISSION));
fs.mkdirs(authzChild);
fs.setPermission(authzChild, new FsPermission(HDFS_PERMISSION));
fs.createSnapshot(userPath, "snapshot_1");
UserGroupInformation ugi = UserGroupInformation.createUserForTesting("u1",
new String[]{"g1"});
ugi.doAs(new PrivilegedExceptionAction<Void>() {
@Override
public Void run() throws Exception {
FileSystem fs = FileSystem.get(miniDFS.getConfiguration(0));
final Path snapChild =
new Path("/user/.snapshot/snapshot_1/authz/child2");
// Run various methods on the path to access the attributes etc.
fs.getAclStatus(snapChild);
fs.getContentSummary(snapChild);
fs.getFileStatus(snapChild);
Assert.assertFalse(CALLED.contains("getAttributes|" +
snapChild.toString()));
Assert.assertTrue(CALLED.contains("getAttributes|/user/authz/child2"));
// The snapshot path should be seen by the permission checker, but when
// it checks access, the paths will be resolved so the attributeProvider
// only sees the resolved path.
Assert.assertTrue(
CALLED.contains("checkPermission|" + snapChild.toString()));
CALLED.clear();
fs.getAclStatus(new Path("/"));
Assert.assertTrue(CALLED.contains("checkPermission|/"));
Assert.assertTrue(CALLED.contains("getAttributes|/"));
CALLED.clear();
fs.getFileStatus(new Path("/user"));
Assert.assertTrue(CALLED.contains("checkPermission|/user"));
Assert.assertTrue(CALLED.contains("getAttributes|/user"));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot"));
Assert.assertTrue(CALLED.contains("checkPermission|/user/.snapshot"));
// attribute provider never sees the .snapshot path directly.
Assert.assertFalse(CALLED.contains("getAttributes|/user/.snapshot"));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot/snapshot_1"));
Assert.assertTrue(
CALLED.contains("checkPermission|/user/.snapshot/snapshot_1"));
Assert.assertTrue(
CALLED.contains("getAttributes|/user/.snapshot/snapshot_1"));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot/snapshot_1/authz"));
Assert.assertTrue(CALLED
.contains("checkPermission|/user/.snapshot/snapshot_1/authz"));
Assert.assertTrue(CALLED.contains("getAttributes|/user/authz"));
CALLED.clear();
fs.getFileStatus(new Path("/user/authz"));
Assert.assertTrue(CALLED.contains("checkPermission|/user/authz"));
Assert.assertTrue(CALLED.contains("getAttributes|/user/authz"));
return null;
}
});
// Delete the files / folders covered by the snapshot, then re-check they
// are all readable correctly.
fs.delete(authz, true);
ugi.doAs(new PrivilegedExceptionAction<Void>() {
@Override
public Void run() throws Exception {
FileSystem fs = FileSystem.get(miniDFS.getConfiguration(0));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot"));
Assert.assertTrue(CALLED.contains("checkPermission|/user/.snapshot"));
// attribute provider never sees the .snapshot path directly.
Assert.assertFalse(CALLED.contains("getAttributes|/user/.snapshot"));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot/snapshot_1"));
Assert.assertTrue(
CALLED.contains("checkPermission|/user/.snapshot/snapshot_1"));
Assert.assertTrue(
CALLED.contains("getAttributes|/user/.snapshot/snapshot_1"));
CALLED.clear();
fs.getFileStatus(new Path("/user/.snapshot/snapshot_1/authz"));
Assert.assertTrue(CALLED
.contains("checkPermission|/user/.snapshot/snapshot_1/authz"));
Assert.assertTrue(CALLED.contains("getAttributes|/user/authz"));
return null;
}
});
}
}