s3:smbd: Allow cancel of SMB2 read on ipc handles

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14430

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Andreas Schneider <asn@samba.org>

diff --git a/source3/smbd/smb2_read.c b/source3/smbd/smb2_read.c
index 6c595a7c3406449b225131eb599efa27ee47e624..fc207850c91a92522c83a1a87d48627a6d91e652 100644 (file)
--- a/source3/smbd/smb2_read.c
+++ b/source3/smbd/smb2_read.c
@@ -185,6 +185,7 @@ static void smbd_smb2_request_read_done(struct tevent_req *subreq)
 struct smbd_smb2_read_state {
        struct smbd_smb2_request *smb2req;
        struct smb_request *smbreq;
+       struct tevent_req *ipc_subreq;
        files_struct *fsp;
        uint8_t in_flags;
        uint32_t in_length;
@@ -428,6 +429,22 @@ NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
        return NT_STATUS_OK;
 }
 
+static bool smbd_smb2_read_ipc_cancel(struct tevent_req *req)
+{
+       struct smbd_smb2_read_state *state =
+               tevent_req_data(req,
+               struct smbd_smb2_read_state);
+
+       TALLOC_FREE(state->ipc_subreq);
+       tevent_req_defer_callback(req, state->smb2req->xconn->client->raw_ev_ctx);
+       if (state->fsp->fsp_flags.closing) {
+               tevent_req_nterror(req, NT_STATUS_PIPE_BROKEN);
+       } else {
+               tevent_req_nterror(req, NT_STATUS_CANCELLED);
+       }
+       return true;
+}
+
 static bool smbd_smb2_read_cancel(struct tevent_req *req)
 {
        struct smbd_smb2_read_state *state =
@@ -487,7 +504,7 @@ static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
 
        if (IS_IPC(smbreq->conn)) {
                struct tevent_req *subreq = NULL;
-               bool ok;
+               struct aio_req_fsp_link *aio_lnk = NULL;
 
                state->out_data = data_blob_talloc(state, NULL, in_length);
                if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
@@ -515,12 +532,15 @@ static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
                 * activity so we don't crash on shutdown close.
                 */
 
-               ok = aio_add_req_to_fsp(fsp, req);
-               if (!ok) {
+               aio_lnk = aio_add_req_to_fsp(fsp, req);
+               if (aio_lnk == NULL) {
                        tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
                        return tevent_req_post(req, ev);
                }
+               talloc_move(subreq, &aio_lnk);
 
+               state->ipc_subreq = subreq;
+               tevent_req_set_cancel_fn(req, smbd_smb2_read_ipc_cancel);
                return req;
        }