cifs: move smb version mount options into fs_context.c

This and related patches which move mount related
code to fs_context.c has the advantage of
shriking the code in fs/cifs/connect.c (which had
the second most lines of code of any of the files
in cifs.ko and was getting harder to read due
to its size) and will also make it easier to
switch over to the new mount API in the future.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index deb1168ed8af..ad6c2fed4055 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -10,6 +10,91 @@
 #include "cifs_debug.h"
 #include "fs_context.h"
 
+static const match_table_t cifs_smb_version_tokens = {
+	{ Smb_1, SMB1_VERSION_STRING },
+	{ Smb_20, SMB20_VERSION_STRING},
+	{ Smb_21, SMB21_VERSION_STRING },
+	{ Smb_30, SMB30_VERSION_STRING },
+	{ Smb_302, SMB302_VERSION_STRING },
+	{ Smb_302, ALT_SMB302_VERSION_STRING },
+	{ Smb_311, SMB311_VERSION_STRING },
+	{ Smb_311, ALT_SMB311_VERSION_STRING },
+	{ Smb_3any, SMB3ANY_VERSION_STRING },
+	{ Smb_default, SMBDEFAULT_VERSION_STRING },
+	{ Smb_version_err, NULL }
+};
+
+int
+cifs_parse_smb_version(char *value, struct smb_vol *vol, bool is_smb3)
+{
+	substring_t args[MAX_OPT_ARGS];
+
+	switch (match_token(value, cifs_smb_version_tokens, args)) {
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
+	case Smb_1:
+		if (disable_legacy_dialects) {
+			cifs_dbg(VFS, "mount with legacy dialect disabled\n");
+			return 1;
+		}
+		if (is_smb3) {
+			cifs_dbg(VFS, "vers=1.0 (cifs) not permitted when mounting with smb3\n");
+			return 1;
+		}
+		cifs_dbg(VFS, "Use of the less secure dialect vers=1.0 is not recommended unless required for access to very old servers\n");
+		vol->ops = &smb1_operations;
+		vol->vals = &smb1_values;
+		break;
+	case Smb_20:
+		if (disable_legacy_dialects) {
+			cifs_dbg(VFS, "mount with legacy dialect disabled\n");
+			return 1;
+		}
+		if (is_smb3) {
+			cifs_dbg(VFS, "vers=2.0 not permitted when mounting with smb3\n");
+			return 1;
+		}
+		vol->ops = &smb20_operations;
+		vol->vals = &smb20_values;
+		break;
+#else
+	case Smb_1:
+		cifs_dbg(VFS, "vers=1.0 (cifs) mount not permitted when legacy dialects disabled\n");
+		return 1;
+	case Smb_20:
+		cifs_dbg(VFS, "vers=2.0 mount not permitted when legacy dialects disabled\n");
+		return 1;
+#endif /* CIFS_ALLOW_INSECURE_LEGACY */
+	case Smb_21:
+		vol->ops = &smb21_operations;
+		vol->vals = &smb21_values;
+		break;
+	case Smb_30:
+		vol->ops = &smb30_operations;
+		vol->vals = &smb30_values;
+		break;
+	case Smb_302:
+		vol->ops = &smb30_operations; /* currently identical with 3.0 */
+		vol->vals = &smb302_values;
+		break;
+	case Smb_311:
+		vol->ops = &smb311_operations;
+		vol->vals = &smb311_values;
+		break;
+	case Smb_3any:
+		vol->ops = &smb30_operations; /* currently identical with 3.0 */
+		vol->vals = &smb3any_values;
+		break;
+	case Smb_default:
+		vol->ops = &smb30_operations; /* currently identical with 3.0 */
+		vol->vals = &smbdefault_values;
+		break;
+	default:
+		cifs_dbg(VFS, "Unknown vers= option specified: %s\n", value);
+		return 1;
+	}
+	return 0;
+}
+
 static const match_table_t cifs_secflavor_tokens = {
 	{ Opt_sec_krb5, "krb5" },
 	{ Opt_sec_krb5i, "krb5i" },