diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index f0818e76423058c3ad5d3b7faa09df380477e5b7..7f100c768bfb464ed92dcf38b83ed3469771c07b 100644
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -339,13 +339,10 @@ int ksmbd_conn_handler_loop(void *p)
 		}
 
 		/*
-		 * Check if pdu size is valid (min : smb header size,
-		 * max : 0x00FFFFFF).
+		 * Check maximum pdu size(0x00FFFFFF).
 		 */
-		if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
-		    pdu_size > MAX_STREAM_PROT_LEN) {
+		if (pdu_size > MAX_STREAM_PROT_LEN)
 			break;
-		}
 
 		/* 4 for rfc1002 length field */
 		/* 1 for implied bcc[0] */
diff --git a/fs/ksmbd/server.c b/fs/ksmbd/server.c
index ebd73abbabe3a69d81aa00d51e8f6a36510a808a..b353b3f91ce28310dcfff00b89e7b0bdadb168bc 100644
--- a/fs/ksmbd/server.c
+++ b/fs/ksmbd/server.c
@@ -286,6 +286,7 @@ static void handle_ksmbd_work(struct work_struct *wk)
 static int queue_ksmbd_work(struct ksmbd_conn *conn)
 {
 	struct ksmbd_work *work;
+	int err;
 
 	work = ksmbd_alloc_work_struct();
 	if (!work) {
@@ -297,9 +298,10 @@ static int queue_ksmbd_work(struct ksmbd_conn *conn)
 	work->request_buf = conn->request_buf;
 	conn->request_buf = NULL;
 
-	if (ksmbd_init_smb_server(work)) {
+	err = ksmbd_init_smb_server(work);
+	if (err) {
 		ksmbd_free_work_struct(work);
-		return -EINVAL;
+		return 0;
 	}
 
 	ksmbd_conn_enqueue_request(work);
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index b21ac851345f0f9a54b345632a2a5346e12644d2..6ba7f714c89c1728662783681c60729c3df19071 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -245,9 +245,6 @@ int init_smb2_neg_rsp(struct ksmbd_work *work)
 	struct smb2_negotiate_rsp *rsp;
 	struct ksmbd_conn *conn = work->conn;
 
-	if (conn->need_neg == false)
-		return -EINVAL;
-
 	*(__be32 *)work->response_buf =
 		cpu_to_be32(conn->vals->header_size);
 
diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c
index ff2e738ae7ac0f02eddfb1d69c1658658287b3e4..3a3b2210a590e862739a1f8be94ae97eb74a0f56 100644
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -293,20 +293,124 @@ static int ksmbd_negotiate_smb_dialect(void *buf)
 	return BAD_PROT_ID;
 }
 
-int ksmbd_init_smb_server(struct ksmbd_work *work)
+#define SMB_COM_NEGOTIATE_EX	0x0
+
+/**
+ * get_smb1_cmd_val() - get smb command value from smb header
+ * @work:	smb work containing smb header
+ *
+ * Return:      smb command value
+ */
+static u16 get_smb1_cmd_val(struct ksmbd_work *work)
 {
-	struct ksmbd_conn *conn = work->conn;
+	return SMB_COM_NEGOTIATE_EX;
+}
+
+/**
+ * init_smb1_rsp_hdr() - initialize smb negotiate response header
+ * @work:	smb work containing smb request
+ *
+ * Return:      0 on success, otherwise -EINVAL
+ */
+static int init_smb1_rsp_hdr(struct ksmbd_work *work)
+{
+	struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf;
+	struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf;
 
-	if (conn->need_neg == false)
+	/*
+	 * Remove 4 byte direct TCP header.
+	 */
+	*(__be32 *)work->response_buf =
+		cpu_to_be32(sizeof(struct smb_hdr) - 4);
+
+	rsp_hdr->Command = SMB_COM_NEGOTIATE;
+	*(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER;
+	rsp_hdr->Flags = SMBFLG_RESPONSE;
+	rsp_hdr->Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS |
+		SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME;
+	rsp_hdr->Pid = rcv_hdr->Pid;
+	rsp_hdr->Mid = rcv_hdr->Mid;
+	return 0;
+}
+
+/**
+ * smb1_check_user_session() - check for valid session for a user
+ * @work:	smb work containing smb request buffer
+ *
+ * Return:      0 on success, otherwise error
+ */
+static int smb1_check_user_session(struct ksmbd_work *work)
+{
+	unsigned int cmd = work->conn->ops->get_cmd_val(work);
+
+	if (cmd == SMB_COM_NEGOTIATE_EX)
 		return 0;
 
-	init_smb3_11_server(conn);
+	return -EINVAL;
+}
+
+/**
+ * smb1_allocate_rsp_buf() - allocate response buffer for a command
+ * @work:	smb work containing smb request
+ *
+ * Return:      0 on success, otherwise -ENOMEM
+ */
+static int smb1_allocate_rsp_buf(struct ksmbd_work *work)
+{
+	work->response_buf = kmalloc(MAX_CIFS_SMALL_BUFFER_SIZE,
+			GFP_KERNEL | __GFP_ZERO);
+	work->response_sz = MAX_CIFS_SMALL_BUFFER_SIZE;
+
+	if (!work->response_buf) {
+		pr_err("Failed to allocate %u bytes buffer\n",
+				MAX_CIFS_SMALL_BUFFER_SIZE);
+		return -ENOMEM;
+	}
 
-	if (conn->ops->get_cmd_val(work) != SMB_COM_NEGOTIATE)
-		conn->need_neg = false;
 	return 0;
 }
 
+static struct smb_version_ops smb1_server_ops = {
+	.get_cmd_val = get_smb1_cmd_val,
+	.init_rsp_hdr = init_smb1_rsp_hdr,
+	.allocate_rsp_buf = smb1_allocate_rsp_buf,
+	.check_user_session = smb1_check_user_session,
+};
+
+static int smb1_negotiate(struct ksmbd_work *work)
+{
+	return ksmbd_smb_negotiate_common(work, SMB_COM_NEGOTIATE);
+}
+
+static struct smb_version_cmds smb1_server_cmds[1] = {
+	[SMB_COM_NEGOTIATE_EX]	= { .proc = smb1_negotiate, },
+};
+
+static int init_smb1_server(struct ksmbd_conn *conn)
+{
+	conn->ops = &smb1_server_ops;
+	conn->cmds = smb1_server_cmds;
+	conn->max_cmds = ARRAY_SIZE(smb1_server_cmds);
+	return 0;
+}
+
+int ksmbd_init_smb_server(struct ksmbd_work *work)
+{
+	struct ksmbd_conn *conn = work->conn;
+	__le32 proto;
+
+	proto = *(__le32 *)((struct smb_hdr *)work->request_buf)->Protocol;
+	if (conn->need_neg == false) {
+		if (proto == SMB1_PROTO_NUMBER)
+			return -EINVAL;
+		return 0;
+	}
+
+	if (proto == SMB1_PROTO_NUMBER)
+		return init_smb1_server(conn);
+	return init_smb3_11_server(conn);
+}
+
 int ksmbd_populate_dot_dotdot_entries(struct ksmbd_work *work, int info_level,
 				      struct ksmbd_file *dir,
 				      struct ksmbd_dir_info *d_info,
@@ -442,7 +546,7 @@ int ksmbd_extract_shortname(struct ksmbd_conn *conn, const char *longname,
 
 static int __smb2_negotiate(struct ksmbd_conn *conn)
 {
-	return (conn->dialect >= SMB21_PROT_ID &&
+	return (conn->dialect >= SMB20_PROT_ID &&
 		conn->dialect <= SMB311_PROT_ID);
 }
 
@@ -450,9 +554,16 @@ static int smb_handle_negotiate(struct ksmbd_work *work)
 {
 	struct smb_negotiate_rsp *neg_rsp = work->response_buf;
 
-	ksmbd_debug(SMB, "Unsupported SMB protocol\n");
-	neg_rsp->hdr.Status.CifsError = STATUS_INVALID_LOGON_TYPE;
-	return -EINVAL;
+	ksmbd_debug(SMB, "Unsupported SMB1 protocol\n");
+
+	/* Add 2 byte bcc and 2 byte DialectIndex. */
+	inc_rfc1001_len(work->response_buf, 4);
+	neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS;
+
+	neg_rsp->hdr.WordCount = 1;
+	neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect);
+	neg_rsp->ByteCount = 0;
+	return 0;
 }
 
 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
@@ -465,23 +576,12 @@ int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)
 	ksmbd_debug(SMB, "conn->dialect 0x%x\n", conn->dialect);
 
 	if (command == SMB2_NEGOTIATE_HE) {
-		struct smb2_hdr *smb2_hdr = smb2_get_msg(work->request_buf);
-
-		if (smb2_hdr->ProtocolId != SMB2_PROTO_NUMBER) {
-			ksmbd_debug(SMB, "Downgrade to SMB1 negotiation\n");
-			command = SMB_COM_NEGOTIATE;
-		}
-	}
-
-	if (command == SMB2_NEGOTIATE_HE && __smb2_negotiate(conn)) {
 		ret = smb2_handle_negotiate(work);
-		init_smb2_neg_rsp(work);
 		return ret;
 	}
 
 	if (command == SMB_COM_NEGOTIATE) {
 		if (__smb2_negotiate(conn)) {
-			conn->need_neg = true;
 			init_smb3_11_server(conn);
 			init_smb2_neg_rsp(work);
 			ksmbd_debug(SMB, "Upgrade to SMB2 negotiation\n");
diff --git a/fs/ksmbd/smb_common.h b/fs/ksmbd/smb_common.h
index fe498fd6343c0e12429f74d7a13e92ffc763c2ef..ceb3cacaef1b8cc38295bd5e1d5ce981ace8e4d6 100644
--- a/fs/ksmbd/smb_common.h
+++ b/fs/ksmbd/smb_common.h
@@ -205,8 +205,15 @@
 
 #define SMB1_PROTO_NUMBER		cpu_to_le32(0x424d53ff)
 #define SMB_COM_NEGOTIATE		0x72
-
 #define SMB1_CLIENT_GUID_SIZE		(16)
+
+#define SMBFLG_RESPONSE 0x80	/* this PDU is a response from server */
+
+#define SMBFLG2_IS_LONG_NAME	cpu_to_le16(0x40)
+#define SMBFLG2_EXT_SEC		cpu_to_le16(0x800)
+#define SMBFLG2_ERR_STATUS	cpu_to_le16(0x4000)
+#define SMBFLG2_UNICODE		cpu_to_le16(0x8000)
+
 struct smb_hdr {
 	__be32 smb_buf_length;
 	__u8 Protocol[4];
@@ -246,28 +253,7 @@ struct smb_negotiate_req {
 struct smb_negotiate_rsp {
 	struct smb_hdr hdr;     /* wct = 17 */
 	__le16 DialectIndex; /* 0xFFFF = no dialect acceptable */
-	__u8 SecurityMode;
-	__le16 MaxMpxCount;
-	__le16 MaxNumberVcs;
-	__le32 MaxBufferSize;
-	__le32 MaxRawSize;
-	__le32 SessionKey;
-	__le32 Capabilities;    /* see below */
-	__le32 SystemTimeLow;
-	__le32 SystemTimeHigh;
-	__le16 ServerTimeZone;
-	__u8 EncryptionKeyLength;
 	__le16 ByteCount;
-	union {
-		unsigned char EncryptionKey[8]; /* cap extended security off */
-		/* followed by Domain name - if extended security is off */
-		/* followed by 16 bytes of server GUID */
-		/* then security blob if cap_extended_security negotiated */
-		struct {
-			unsigned char GUID[SMB1_CLIENT_GUID_SIZE];
-			unsigned char SecurityBlob[1];
-		} __packed extended_response;
-	} __packed u;
 } __packed;
 
 struct filesystem_attribute_info {