Ensure we correctly calculate reply credits over all returned

SMB2 replies, and do as Windows does and return the total in the
last SMB2 reply. Fixes an issue found by Christian M Ambach <christian.ambach@de.ibm.com>
(and thanks to Christian for the initial patch this was based on).
(cherry picked from commit 65566dfa8629136eaf0dc1491502dc651d1a4858)

Fix bug #8614 (SMB2: not granting credits for all requests in a compound
request).

diff --git a/source3/smbd/smb2_server.c b/source3/smbd/smb2_server.c
index 0e70983263bf5ca9a166cd9ff1cb6c5da693a3d3..8a5d81f87b227a9dc8e09f59bc1233e39d2eb6fe 100644 (file)
--- a/source3/smbd/smb2_server.c
+++ b/source3/smbd/smb2_server.c
@@ -514,13 +514,24 @@ static void smb2_calculate_credits(const struct smbd_smb2_request *inreq,
                                struct smbd_smb2_request *outreq)
 {
        int count, idx;
+       uint16_t total_credits = 0;
 
        count = outreq->out.vector_count;
 
        for (idx=1; idx < count; idx += 3) {
+               uint8_t *outhdr = (uint8_t *)outreq->out.vector[idx].iov_base;
                smb2_set_operation_credit(outreq->sconn,
                        &inreq->in.vector[idx],
                        &outreq->out.vector[idx]);
+               /* To match Windows, count up what we
+                  just granted. */
+               total_credits += SVAL(outhdr, SMB2_HDR_CREDIT);
+               /* Set to zero in all but the last reply. */
+               if (idx + 3 < count) {
+                       SSVAL(outhdr, SMB2_HDR_CREDIT, 0);
+               } else {
+                       SSVAL(outhdr, SMB2_HDR_CREDIT, total_credits);
+               }
        }
 }
 
@@ -1739,11 +1750,9 @@ static NTSTATUS smbd_smb2_request_reply(struct smbd_smb2_request *req)
 
        smb2_setup_nbt_length(req->out.vector, req->out.vector_count);
 
-       /* Set credit for this operation (zero credits if this
+       /* Set credit for these operations (zero credits if this
           is a final reply for an async operation). */
-       smb2_set_operation_credit(req->sconn,
-                       &req->in.vector[i],
-                       &req->out.vector[i]);
+       smb2_calculate_credits(req, req);
 
        if (req->do_signing) {
                NTSTATUS status;