[PATCH][SMB3] check for and properly advertise directory lease support

[Steve French]

Although servers will typically ignore unsupported features,
we should advertise the support for directory leases (as
Windows e.g. does) in the negotiate protocol capabilities we
pass to the server, and should check for the server capability
(CAP_DIRECTORY_LEASING) before sending a lease request for an
open of a directory.  This will prevent us from accidentally
sending directory leases to SMB2.1 or SMB2 server for example.

Signed-off-by: Steve French <stfrench at microsoft.com>
CC: Stable <stable at vger.kernel.org>
---
 fs/cifs/smb2ops.c | 10 +++++-----
 fs/cifs/smb2pdu.c |  3 +++
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 32cae6e49ea2..23118b7a2bbc 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3654,7 +3654,7 @@ struct smb_version_values smb21_values = {
 struct smb_version_values smb3any_values = {
     .version_string = SMB3ANY_VERSION_STRING,
     .protocol_id = SMB302_PROT_ID, /* doesn't matter, send protocol array */
-    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION,
+    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION | SMB2_GLOBAL_CAP_DIRECTORY_LEASING,
     .large_lock_type = 0,
     .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
     .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
@@ -3675,7 +3675,7 @@ struct smb_version_values smb3any_values = {
 struct smb_version_values smbdefault_values = {
     .version_string = SMBDEFAULT_VERSION_STRING,
     .protocol_id = SMB302_PROT_ID, /* doesn't matter, send protocol array */
-    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION,
+    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION | SMB2_GLOBAL_CAP_DIRECTORY_LEASING,
     .large_lock_type = 0,
     .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
     .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
@@ -3696,7 +3696,7 @@ struct smb_version_values smbdefault_values = {
 struct smb_version_values smb30_values = {
     .version_string = SMB30_VERSION_STRING,
     .protocol_id = SMB30_PROT_ID,
-    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION,
+    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION | SMB2_GLOBAL_CAP_DIRECTORY_LEASING,
     .large_lock_type = 0,
     .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
     .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
@@ -3717,7 +3717,7 @@ struct smb_version_values smb30_values = {
 struct smb_version_values smb302_values = {
     .version_string = SMB302_VERSION_STRING,
     .protocol_id = SMB302_PROT_ID,
-    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION,
+    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION | SMB2_GLOBAL_CAP_DIRECTORY_LEASING,
     .large_lock_type = 0,
     .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
     .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
@@ -3738,7 +3738,7 @@ struct smb_version_values smb302_values = {
 struct smb_version_values smb311_values = {
     .version_string = SMB311_VERSION_STRING,
     .protocol_id = SMB311_PROT_ID,
-    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION,
+    .req_capabilities = SMB2_GLOBAL_CAP_DFS | SMB2_GLOBAL_CAP_LEASING
| SMB2_GLOBAL_CAP_LARGE_MTU | SMB2_GLOBAL_CAP_PERSISTENT_HANDLES |
SMB2_GLOBAL_CAP_ENCRYPTION | SMB2_GLOBAL_CAP_DIRECTORY_LEASING,
     .large_lock_type = 0,
     .exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE_LOCK,
     .shared_lock_type = SMB2_LOCKFLAG_SHARED_LOCK,
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 2ddee7c9c7bf..f6b27bd9b788 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2178,6 +2178,9 @@ SMB2_open_init(struct cifs_tcon *tcon, struct
smb_rqst *rqst, __u8 *oplock,
     if (!(server->capabilities & SMB2_GLOBAL_CAP_LEASING) ||
         *oplock == SMB2_OPLOCK_LEVEL_NONE)
         req->RequestedOplockLevel = *oplock;
+    else if (!(server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING) &&
+          (oparms->create_options & CREATE_NOT_FILE))
+        req->RequestedOplockLevel = *oplock; /* no srv lease support */
     else {
         rc = add_lease_context(server, iov, &n_iov,
                        oparms->fid->lease_key, oplock);
-- 
2.17.1


-- 
Thanks,

Steve
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-smb3-check-for-and-properly-advertise-directory-leas.patch
Type: text/x-patch
Size: 5169 bytes
Desc: not available
URL: <http://lists.samba.org/pipermail/samba-technical/attachments/20180831/b8926142/0001-smb3-check-for-and-properly-advertise-directory-leas.bin>