PATCH] smb3: include current dialect (SMB3.1.1) when version 3 or greater requested on mount

[Steve French]

SMB3.1.1 is the newest, and preferred dialect, and is included in
the requested dialect list by default (ie if no vers= is specified
on mount) but it should also be requested if SMB3 or later is requested
(vers=3 instead of a specific dialect: vers=2.1, vers=3.02 or vers=3.0).

Currently specifying "vers=3" only requests smb3.0 and smb3.02 but this
patch fixes it to also request smb3.1.1 dialect, as it is the newest
and most secure dialect and is a "version 3 or later" dialect (the intent
of "vers=3").

Signed-off-by: Steve French <stfrench at microsoft.com>
Suggested-by: Pavel Shilovsky <pshilov at microsoft.com>
---
 fs/cifs/fs_context.c |  2 +-
 fs/cifs/smb2pdu.c    | 19 +++++++++++++------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 5111aadfdb6b..479c24695281 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -391,7 +391,7 @@ cifs_parse_smb_version(char *value, struct
smb3_fs_context *ctx, bool is_smb3)
  ctx->vals = &smb3any_values;
  break;
  case Smb_default:
- ctx->ops = &smb30_operations; /* currently identical with 3.0 */
+ ctx->ops = &smb30_operations;
  ctx->vals = &smbdefault_values;
  break;
  default:
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 794fc3b68b4f..52625549c3b5 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -814,8 +814,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
     SMB3ANY_VERSION_STRING) == 0) {
  req->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
  req->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
- req->DialectCount = cpu_to_le16(2);
- total_len += 4;
+ req->Dialects[2] = cpu_to_le16(SMB311_PROT_ID);
+ req->DialectCount = cpu_to_le16(3);
+ total_len += 6;
  } else if (strcmp(server->vals->version_string,
     SMBDEFAULT_VERSION_STRING) == 0) {
  req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
@@ -848,6 +849,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
  memcpy(req->ClientGUID, server->client_guid,
  SMB2_CLIENT_GUID_SIZE);
  if ((server->vals->protocol_id == SMB311_PROT_ID) ||
+     (strcmp(server->vals->version_string,
+      SMB3ANY_VERSION_STRING) == 0) ||
      (strcmp(server->vals->version_string,
       SMBDEFAULT_VERSION_STRING) == 0))
  assemble_neg_contexts(req, server, &total_len);
@@ -883,6 +886,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
  cifs_server_dbg(VFS,
  "SMB2.1 dialect returned but not requested\n");
  return -EIO;
+ } else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
+ server->ops = &smb311_operations;
+ server->vals = &smb311_values;
  }
  } else if (strcmp(server->vals->version_string,
     SMBDEFAULT_VERSION_STRING) == 0) {
@@ -1042,10 +1048,11 @@ int smb3_validate_negotiate(const unsigned int
xid, struct cifs_tcon *tcon)
  SMB3ANY_VERSION_STRING) == 0) {
  pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
  pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
- pneg_inbuf->DialectCount = cpu_to_le16(2);
- /* structure is big enough for 3 dialects, sending only 2 */
+ pneg_inbuf->Dialects[2] = cpu_to_le16(SMB311_PROT_ID);
+ pneg_inbuf->DialectCount = cpu_to_le16(3);
+ /* SMB 2.1 not included so subtract one dialect from len */
  inbuflen = sizeof(*pneg_inbuf) -
- (2 * sizeof(pneg_inbuf->Dialects[0]));
+ (sizeof(pneg_inbuf->Dialects[0]));
  } else if (strcmp(server->vals->version_string,
  SMBDEFAULT_VERSION_STRING) == 0) {
  pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
@@ -1053,7 +1060,7 @@ int smb3_validate_negotiate(const unsigned int
xid, struct cifs_tcon *tcon)
  pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
  pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
  pneg_inbuf->DialectCount = cpu_to_le16(4);
- /* structure is big enough for 3 dialects */
+ /* structure is big enough for 4 dialects */
  inbuflen = sizeof(*pneg_inbuf);
  } else {
  /* otherwise specific dialect was requested */

-- 
Thanks,

Steve
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