cifs: convert send_nt_cancel into a version specific op

For SMB2, this should be a no-op. Obviously if we wanted to do something
for the SMB2 case, we could also define an operation here for it.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>

1 files changed, 41 insertions, 0 deletions

diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index d2850d194eb5..fa486f0ca8b2 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -18,8 +18,49 @@
  */
 
 #include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+
+/*
+ * An NT cancel request header looks just like the original request except:
+ *
+ * The Command is SMB_COM_NT_CANCEL
+ * The WordCount is zeroed out
+ * The ByteCount is zeroed out
+ *
+ * This function mangles an existing request buffer into a
+ * SMB_COM_NT_CANCEL request and then sends it.
+ */
+static int
+send_nt_cancel(struct TCP_Server_Info *server, void *buf,
+               struct mid_q_entry *mid)
+{
+        int rc = 0;
+        struct smb_hdr *in_buf = (struct smb_hdr *)buf;
+
+        /* -4 for RFC1001 length and +2 for BCC field */
+        in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4  + 2);
+        in_buf->Command = SMB_COM_NT_CANCEL;
+        in_buf->WordCount = 0;
+        put_bcc(0, in_buf);
+
+        mutex_lock(&server->srv_mutex);
+        rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
+        if (rc) {
+                mutex_unlock(&server->srv_mutex);
+                return rc;
+        }
+        rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
+        mutex_unlock(&server->srv_mutex);
+
+        cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
+                in_buf->Mid, rc);
+
+        return rc;
+}
 
 struct smb_version_operations smb1_operations = {
+        .send_cancel = send_nt_cancel,
 };
 
 struct smb_version_values smb1_values = {