diff mbox series

[v4,6/8] cifs: deprecate 'enable_negotiate_signing' module param

Message ID 20220929175655.6906-3-ematsumiya@suse.de (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Enzo Matsumiya Sept. 29, 2022, 5:56 p.m. UTC
Deprecate enable_negotiate_signing module parameter as it's irrelevant
since the requested dialect and server support will dictate which
algorithm will actually be used.

Send a negotiate signing context on every SMB 3.1.1 negotiation now.
AES-CMAC will still be used instead, iff, SMB 3.0.x negotiated or
SMB 3.1.1 negotiated, but server doesn't support AES-GMAC.

Warn the user if, for whatever reason, the module was loaded with
'enable_negotiate_signing=0'.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
---
v4: fix checkpatch errors (thanks to Steve)

 fs/cifs/cifsfs.c   | 14 +++++++++++---
 fs/cifs/cifsglob.h |  5 ++++-
 fs/cifs/smb2pdu.c  | 11 ++++-------
 3 files changed, 19 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 8042d7280dec..c46dc9edf6ec 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -65,7 +65,7 @@  bool lookupCacheEnabled = true;
 bool disable_legacy_dialects; /* false by default */
 bool enable_gcm_256 = true;
 bool require_gcm_256; /* false by default */
-bool enable_negotiate_signing; /* false by default */
+bool enable_negotiate_signing = true; /* deprecated -- always true now */
 unsigned int global_secflags = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;
@@ -133,8 +133,12 @@  MODULE_PARM_DESC(enable_gcm_256, "Enable requesting strongest (256 bit) GCM encr
 module_param(require_gcm_256, bool, 0644);
 MODULE_PARM_DESC(require_gcm_256, "Require strongest (256 bit) GCM encryption. Default: n/N/0");
 
-module_param(enable_negotiate_signing, bool, 0644);
-MODULE_PARM_DESC(enable_negotiate_signing, "Enable negotiating packet signing algorithm with server. Default: n/N/0");
+/* XXX: remove this at some point */
+module_param(enable_negotiate_signing, bool, 0);
+MODULE_PARM_DESC(enable_negotiate_signing,
+		 "(deprecated) Enable negotiating packet signing algorithm with the server. "
+		 "This parameter is ignored as cifs.ko will always try to negotiate the signing "
+		 "algorithm on SMB 3.1.1 mounts.");
 
 module_param(disable_legacy_dialects, bool, 0644);
 MODULE_PARM_DESC(disable_legacy_dialects, "To improve security it may be "
@@ -1712,6 +1716,10 @@  init_cifs(void)
 		goto out_init_cifs_idmap;
 	}
 
+	if (!enable_negotiate_signing)
+		pr_warn_once("ignoring deprecated module parameter 'enable_negotiate_signing=0', "
+			     "will try to negotiate signing capabilities anyway...\n");
+
 	return 0;
 
 out_init_cifs_idmap:
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 81a8eff06467..49561e325412 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -2031,7 +2031,10 @@  extern unsigned int global_secflags;	/* if on, session setup sent
 extern unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
 extern bool enable_gcm_256; /* allow optional negotiate of strongest signing (aes-gcm-256) */
 extern bool require_gcm_256; /* require use of strongest signing (aes-gcm-256) */
-extern bool enable_negotiate_signing; /* request use of faster (GMAC) signing if available */
+extern bool enable_negotiate_signing; /*
+				       * request use of faster (GMAC) signing if available
+				       * XXX: deprecated, remove it at some point
+				       */
 extern bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 extern unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 extern unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index d7d6cbe6ba3b..785465873422 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -609,13 +609,10 @@  assemble_neg_contexts(struct smb2_negotiate_req *req,
 		neg_context_count++;
 	}
 
-	if (enable_negotiate_signing) {
-		ctxt_len = build_signing_ctxt((struct smb2_signing_capabilities *)
-				pneg_ctxt);
-		*total_len += ctxt_len;
-		pneg_ctxt += ctxt_len;
-		neg_context_count++;
-	}
+	ctxt_len = build_signing_ctxt((struct smb2_signing_capabilities *)pneg_ctxt);
+	*total_len += ctxt_len;
+	pneg_ctxt += ctxt_len;
+	neg_context_count++;
 
 	/* check for and add transport_capabilities and signing capabilities */
 	req->NegotiateContextCount = cpu_to_le16(neg_context_count);