cifs: simplify SMB header check routine

...just cleanup. There should be no behavior change.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 24 insertions, 22 deletions

diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index a09e077ba925..72e99ece78cf 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -381,29 +381,31 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 }
 
 static int
-checkSMBhdr(struct smb_hdr *smb, __u16 mid)
+check_smb_hdr(struct smb_hdr *smb, __u16 mid)
 {
-        /* Make sure that this really is an SMB, that it is a response,
-           and that the message ids match */
-        if ((*(__le32 *) smb->Protocol == cpu_to_le32(0x424d53ff)) &&
-                (mid == smb->Mid)) {
-                if (smb->Flags & SMBFLG_RESPONSE)
-                        return 0;
-                else {
-                /* only one valid case where server sends us request */
-                        if (smb->Command == SMB_COM_LOCKING_ANDX)
-                                return 0;
-                        else
-                                cERROR(1, "Received Request not response");
-                }
-        } else { /* bad signature or mid */
-                if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff))
-                        cERROR(1, "Bad protocol string signature header %x",
-                                *(unsigned int *) smb->Protocol);
-                if (mid != smb->Mid)
-                        cERROR(1, "Mids do not match");
+        /* does it have the right SMB "signature" ? */
+        if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
+                cERROR(1, "Bad protocol string signature header 0x%x",
+                        *(unsigned int *)smb->Protocol);
+                return 1;
         }
-        cERROR(1, "bad smb detected. The Mid=%d", smb->Mid);
+
+        /* Make sure that message ids match */
+        if (mid != smb->Mid) {
+                cERROR(1, "Mids do not match. received=%u expected=%u",
+                        smb->Mid, mid);
+                return 1;
+        }
+
+        /* if it's a response then accept */
+        if (smb->Flags & SMBFLG_RESPONSE)
+                return 0;
+
+        /* only one valid case where server sends us request */
+        if (smb->Command == SMB_COM_LOCKING_ANDX)
+                return 0;
+
+        cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
         return 1;
 }
 
@@ -448,7 +450,7 @@ checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length)
                 return 1;
         }
 
-        if (checkSMBhdr(smb, mid))
+        if (check_smb_hdr(smb, mid))
                 return 1;
         clc_len = smbCalcSize_LE(smb);