CIFS: Separate SMB2 header structure

In order to support compounding and encryption we need to separate
RFC1001 length field and SMB2 header structure because the protocol
treats them differently. This change will allow to simplify parsing
of such complex SMB2 packets further.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 5d456ebb3813..ef8b2a8363b3 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -119,7 +119,9 @@ smb2_get_credits_field(struct TCP_Server_Info *server, const int optype)
 static unsigned int
 smb2_get_credits(struct mid_q_entry *mid)
 {
-	return le16_to_cpu(((struct smb2_hdr *)mid->resp_buf)->CreditRequest);
+	struct smb2_sync_hdr *shdr = get_sync_hdr(mid->resp_buf);
+
+	return le16_to_cpu(shdr->CreditRequest);
 }
 
 static int
@@ -184,10 +186,10 @@ static struct mid_q_entry *
 smb2_find_mid(struct TCP_Server_Info *server, char *buf)
 {
 	struct mid_q_entry *mid;
-	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
-	__u64 wire_mid = le64_to_cpu(hdr->MessageId);
+	struct smb2_sync_hdr *shdr = get_sync_hdr(buf);
+	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
 
-	if (hdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
+	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
 		cifs_dbg(VFS, "encrypted frame parsing not supported yet");
 		return NULL;
 	}
@@ -196,7 +198,7 @@ smb2_find_mid(struct TCP_Server_Info *server, char *buf)
 	list_for_each_entry(mid, &server->pending_mid_q, qhead) {
 		if ((mid->mid == wire_mid) &&
 		    (mid->mid_state == MID_REQUEST_SUBMITTED) &&
-		    (mid->command == hdr->Command)) {
+		    (mid->command == shdr->Command)) {
 			spin_unlock(&GlobalMid_Lock);
 			return mid;
 		}
@@ -209,12 +211,12 @@ static void
 smb2_dump_detail(void *buf)
 {
 #ifdef CONFIG_CIFS_DEBUG2
-	struct smb2_hdr *smb = (struct smb2_hdr *)buf;
+	struct smb2_sync_hdr *shdr = get_sync_hdr(buf);
 
 	cifs_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d\n",
-		 smb->Command, smb->Status, smb->Flags, smb->MessageId,
-		 smb->ProcessId);
-	cifs_dbg(VFS, "smb buf %p len %u\n", smb, smb2_calc_size(smb));
+		 shdr->Command, shdr->Status, shdr->Flags, shdr->MessageId,
+		 shdr->ProcessId);
+	cifs_dbg(VFS, "smb buf %p len %u\n", buf, smb2_calc_size(buf));
 #endif
 }
 
@@ -1002,14 +1004,14 @@ smb2_close_dir(const unsigned int xid, struct cifs_tcon *tcon,
 static bool
 smb2_is_status_pending(char *buf, struct TCP_Server_Info *server, int length)
 {
-	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
+	struct smb2_sync_hdr *shdr = get_sync_hdr(buf);
 
-	if (hdr->Status != STATUS_PENDING)
+	if (shdr->Status != STATUS_PENDING)
 		return false;
 
 	if (!length) {
 		spin_lock(&server->req_lock);
-		server->credits += le16_to_cpu(hdr->CreditRequest);
+		server->credits += le16_to_cpu(shdr->CreditRequest);
 		spin_unlock(&server->req_lock);
 		wake_up(&server->request_q);
 	}