[PATCH v5 14/20] ksmbd: add ksmbd_smb2_cur_pdu_buflen()

[Ralph Boehme <slow@samba.org>]

Cc: Namjae Jeon <linkinjeon@kernel.org>
Cc: Tom Talpey <tom@talpey.com>
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Ralph Boehme <slow@samba.org>
---
 fs/ksmbd/smb2misc.c | 25 +++++++++++++++++++++++++
 fs/ksmbd/smb2pdu.h  |  1 +
 2 files changed, 26 insertions(+)

diff --git a/fs/ksmbd/smb2misc.c b/fs/ksmbd/smb2misc.c
index 2cc031c39514..76f53db7db8d 100644
--- a/fs/ksmbd/smb2misc.c
+++ b/fs/ksmbd/smb2misc.c
@@ -427,3 +427,28 @@ int smb2_negotiate_request(struct ksmbd_work *work)
 {
 	return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE);
 }
+
+/**
+ * ksmbd_smb2_cur_pdu_buflen() - Get len of current SMB2 PDU buffer
+ * This returns the lenght including any possible padding.
+ * @work: smb work containing request buffer
+ */
+unsigned int ksmbd_smb2_cur_pdu_buflen(struct ksmbd_work *work)
+{
+	struct smb2_hdr *hdr = ksmbd_req_buf_next(work);
+	unsigned int buf_len;
+	unsigned int pdu_len;
+
+	if (hdr->NextCommand != 0) {
+		/*
+		 * hdr->NextCommand has already been validated by
+		 * init_chained_smb2_rsp().
+		 */
+		return __le32_to_cpu(hdr->NextCommand);
+	}
+
+	buf_len = get_rfc1002_len(work->request_buf);
+	pdu_len = buf_len - work->next_smb2_rcv_hdr_off;
+	return pdu_len;
+}
+
diff --git a/fs/ksmbd/smb2pdu.h b/fs/ksmbd/smb2pdu.h
index a6dec5ec6a54..c5fa8256b0bb 100644
--- a/fs/ksmbd/smb2pdu.h
+++ b/fs/ksmbd/smb2pdu.h
@@ -1680,6 +1680,7 @@ int smb2_set_rsp_credits(struct ksmbd_work *work);
 
 /* smb2 misc functions */
 int ksmbd_smb2_check_message(struct ksmbd_work *work);
+unsigned int ksmbd_smb2_cur_pdu_buflen(struct ksmbd_work *work);
 
 /* smb2 command handlers */
 int smb2_handle_negotiate(struct ksmbd_work *work);
-- 
2.31.1