ksmbd: add support for SMB3 multichannel

Add support for SMB3 multichannel. It will be enable by setting
'server multi channel support = yes' in smb.conf.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifsd/auth.c

@@ -921,13 +921,14 @@ static int generate_key(struct ksmbd_session *sess, struct kvec label,
 }
 
 static int generate_smb3signingkey(struct ksmbd_session *sess,
+				   struct ksmbd_conn *conn,
 				   const struct derivation *signing)
 {
 	int rc;
 	struct channel *chann;
 	char *key;
 
-	chann = lookup_chann_list(sess);
+	chann = lookup_chann_list(sess, conn);
 	if (!chann)
 		return 0;
 
@@ -953,7 +954,8 @@ static int generate_smb3signingkey(struct ksmbd_session *sess,
 	return 0;
 }
 
-int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess)
+int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess,
+			       struct ksmbd_conn *conn)
 {
 	struct derivation d;
 
@@ -961,22 +963,32 @@ int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess)
 	d.label.iov_len = 12;
 	d.context.iov_base = "SmbSign";
 	d.context.iov_len = 8;
-	d.binding = false;
+	d.binding = conn->binding;
 
-	return generate_smb3signingkey(sess, &d);
+	return generate_smb3signingkey(sess, conn, &d);
 }
 
-int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess)
+int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess,
+				struct ksmbd_conn *conn)
 {
 	struct derivation d;
 
 	d.label.iov_base = "SMBSigningKey";
 	d.label.iov_len = 14;
-	d.context.iov_base = sess->Preauth_HashValue;
+	if (conn->binding) {
+		struct preauth_session *preauth_sess;
+
+		preauth_sess = ksmbd_preauth_session_lookup(conn, sess->id);
+		if (!preauth_sess)
+			return -ENOENT;
+		d.context.iov_base = preauth_sess->Preauth_HashValue;
+	} else {
+		d.context.iov_base = sess->Preauth_HashValue;
+	}
 	d.context.iov_len = 64;
-	d.binding = false;
+	d.binding = conn->binding;
 
-	return generate_smb3signingkey(sess, &d);
+	return generate_smb3signingkey(sess, conn, &d);
 }
 
 struct derivation_twin {
@@ -1148,7 +1160,7 @@ static int ksmbd_get_encryption_key(struct ksmbd_conn *conn, __u64 ses_id,
 	struct ksmbd_session *sess;
 	u8 *ses_enc_key;
 
-	sess = ksmbd_session_lookup(conn, ses_id);
+	sess = ksmbd_session_lookup_all(conn, ses_id);
 	if (!sess)
 		return -EINVAL;
 

fs/cifsd/auth.h

@@ -54,8 +54,10 @@ int ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov,
 			int n_vec, char *sig);
 int ksmbd_sign_smb3_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov,
 			int n_vec, char *sig);
-int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess);
-int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess);
+int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess,
+			       struct ksmbd_conn *conn);
+int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess,
+				struct ksmbd_conn *conn);
 int ksmbd_gen_smb30_encryptionkey(struct ksmbd_session *sess);
 int ksmbd_gen_smb311_encryptionkey(struct ksmbd_session *sess);
 int ksmbd_gen_preauth_integrity_hash(struct ksmbd_conn *conn, char *buf,

fs/cifsd/connection.h

@@ -106,6 +106,7 @@ struct ksmbd_conn {
 	__le16				cipher_type;
 	__le16				compress_algorithm;
 	bool				posix_ext_supported;
+	bool				binding;
 };
 
 struct ksmbd_conn_ops {

fs/cifsd/ksmbd_server.h

@@ -33,6 +33,7 @@ struct ksmbd_heartbeat {
 #define KSMBD_GLOBAL_FLAG_CACHE_TBUF		BIT(1)
 #define KSMBD_GLOBAL_FLAG_CACHE_RBUF		BIT(2)
 #define KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION	BIT(3)
+#define KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL	BIT(4)
 
 struct ksmbd_startup_request {
 	__u32	flags;

fs/cifsd/mgmt/user_session.c

@@ -207,7 +207,8 @@ void ksmbd_sessions_deregister(struct ksmbd_conn *conn)
 	}
 }
 
-bool ksmbd_session_id_match(struct ksmbd_session *sess, unsigned long long id)
+static bool ksmbd_session_id_match(struct ksmbd_session *sess,
+				   unsigned long long id)
 {
 	return sess->id == id;
 }
@@ -250,6 +251,52 @@ struct ksmbd_session *ksmbd_session_lookup_slowpath(unsigned long long id)
 	return sess;
 }
 
+struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
+					       unsigned long long id)
+{
+	struct ksmbd_session *sess;
+
+	sess = ksmbd_session_lookup(conn, id);
+	if (!sess && conn->binding)
+		sess = ksmbd_session_lookup_slowpath(id);
+	return sess;
+}
+
+struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
+						    u64 sess_id)
+{
+	struct preauth_session *sess;
+
+	sess = kmalloc(sizeof(struct preauth_session), GFP_KERNEL);
+	if (!sess)
+		return NULL;
+
+	sess->id = sess_id;
+	memcpy(sess->Preauth_HashValue, conn->preauth_info->Preauth_HashValue,
+	       PREAUTH_HASHVALUE_SIZE);
+	list_add(&sess->preauth_entry, &conn->preauth_sess_table);
+
+	return sess;
+}
+
+static bool ksmbd_preauth_session_id_match(struct preauth_session *sess,
+					   unsigned long long id)
+{
+	return sess->id == id;
+}
+
+struct preauth_session *ksmbd_preauth_session_lookup(struct ksmbd_conn *conn,
+						     unsigned long long id)
+{
+	struct preauth_session *sess = NULL;
+
+	list_for_each_entry(sess, &conn->preauth_sess_table, preauth_entry) {
+		if (ksmbd_preauth_session_id_match(sess, id))
+			return sess;
+	}
+	return NULL;
+}
+
 static int __init_smb2_session(struct ksmbd_session *sess)
 {
 	int id = ksmbd_acquire_smb2_uid(&session_ida);

fs/cifsd/mgmt/user_session.h

@@ -26,8 +26,8 @@ struct channel {
 
 struct preauth_session {
 	__u8			Preauth_HashValue[PREAUTH_HASHVALUE_SIZE];
-	u64			sess_id;
-	struct list_head	list_entry;
+	u64			id;
+	struct list_head	preauth_entry;
 };
 
 struct ksmbd_session {
@@ -82,13 +82,18 @@ struct ksmbd_session *ksmbd_smb2_session_create(void);
 
 void ksmbd_session_destroy(struct ksmbd_session *sess);
 
-bool ksmbd_session_id_match(struct ksmbd_session *sess, unsigned long long id);
 struct ksmbd_session *ksmbd_session_lookup_slowpath(unsigned long long id);
 struct ksmbd_session *ksmbd_session_lookup(struct ksmbd_conn *conn,
 					   unsigned long long id);
 void ksmbd_session_register(struct ksmbd_conn *conn,
 			    struct ksmbd_session *sess);
 void ksmbd_sessions_deregister(struct ksmbd_conn *conn);
+struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
+					       unsigned long long id);
+struct preauth_session *ksmbd_preauth_session_alloc(struct ksmbd_conn *conn,
+						    u64 sess_id);
+struct preauth_session *ksmbd_preauth_session_lookup(struct ksmbd_conn *conn,
+						     unsigned long long id);
 
 int ksmbd_acquire_tree_conn_id(struct ksmbd_session *sess);
 void ksmbd_release_tree_conn_id(struct ksmbd_session *sess, int id);

fs/cifsd/smb2ops.c

@@ -229,6 +229,9 @@ void init_smb3_0_server(struct ksmbd_conn *conn)
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION &&
 	    conn->cli_cap & SMB2_GLOBAL_CAP_ENCRYPTION)
 		conn->vals->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
+
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL)
+		conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL;
 }
 
 /**
@@ -250,6 +253,9 @@ void init_smb3_02_server(struct ksmbd_conn *conn)
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_ENCRYPTION &&
 	    conn->cli_cap & SMB2_GLOBAL_CAP_ENCRYPTION)
 		conn->vals->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
+
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL)
+		conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL;
 }
 
 /**
@@ -271,6 +277,9 @@ int init_smb3_11_server(struct ksmbd_conn *conn)
 	if (conn->cipher_type)
 		conn->vals->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
 
+	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB3_MULTICHANNEL)
+		conn->vals->capabilities |= SMB2_GLOBAL_CAP_MULTI_CHANNEL;
+
 	INIT_LIST_HEAD(&conn->preauth_sess_table);
 	return 0;
 }

fs/cifsd/smb2pdu.h

@@ -1647,7 +1647,8 @@ struct file_lock *smb_flock_init(struct file *f);
 int setup_async_work(struct ksmbd_work *work, void (*fn)(void **),
 		     void **arg);
 void smb2_send_interim_resp(struct ksmbd_work *work, __le32 status);
-struct channel *lookup_chann_list(struct ksmbd_session *sess);
+struct channel *lookup_chann_list(struct ksmbd_session *sess,
+				  struct ksmbd_conn *conn);
 void smb3_preauth_hash_rsp(struct ksmbd_work *work);
 int smb3_is_transform_hdr(void *buf);
 int smb3_decrypt_req(struct ksmbd_work *work);

fs/cifsd/smb_common.h

@@ -479,7 +479,7 @@ struct smb_version_ops {
 	bool (*is_sign_req)(struct ksmbd_work *work, unsigned int command);
 	int (*check_sign_req)(struct ksmbd_work *work);
 	void (*set_sign_rsp)(struct ksmbd_work *work);
-	int (*generate_signingkey)(struct ksmbd_session *sess);
+	int (*generate_signingkey)(struct ksmbd_session *sess, struct ksmbd_conn *conn);
 	int (*generate_encryptionkey)(struct ksmbd_session *sess);
 	int (*is_transform_hdr)(void *buf);
 	int (*decrypt_req)(struct ksmbd_work *work);