Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 212 insertions, 0 deletions

diff --git a/source4/ntvfs/posix/pvfs_wait.c b/source4/ntvfs/posix/pvfs_wait.c
new file mode 100644
index 0000000..21ff33e
--- /dev/null
+++ b/source4/ntvfs/posix/pvfs_wait.c
@@ -0,0 +1,212 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   POSIX NTVFS backend - async request wait routines
+
+   Copyright (C) Andrew Tridgell 2004
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "lib/events/events.h"
+#include "../lib/util/dlinklist.h"
+#include "vfs_posix.h"
+#include "samba/service_stream.h"
+#include "lib/messaging/irpc.h"
+
+/* the context for a single wait instance */
+struct pvfs_wait {
+	struct pvfs_wait *next, *prev;
+	struct pvfs_state *pvfs;
+	void (*handler)(void *, enum pvfs_wait_notice);
+	void *private_data;
+	int msg_type;
+	struct imessaging_context *msg_ctx;
+	struct tevent_context *ev;
+	struct ntvfs_request *req;
+	enum pvfs_wait_notice reason;
+};
+
+/*
+  called from the ntvfs layer when we have requested setup of an async
+  call.  this ensures that async calls runs with the right state of
+  previous ntvfs handlers in the chain (such as security context)
+*/
+NTSTATUS pvfs_async_setup(struct ntvfs_module_context *ntvfs,
+			  struct ntvfs_request *req, void *private_data)
+{
+	struct pvfs_wait *pwait = talloc_get_type(private_data,
+						  struct pvfs_wait);
+	pwait->handler(pwait->private_data, pwait->reason);
+	return NT_STATUS_OK;
+}
+
+/*
+  receive a completion message for a wait
+*/
+static void pvfs_wait_dispatch(struct imessaging_context *msg,
+			       void *private_data,
+			       uint32_t msg_type,
+			       struct server_id src,
+			       size_t num_fds,
+			       int *fds,
+			       DATA_BLOB *data)
+{
+	struct pvfs_wait *pwait = talloc_get_type(private_data,
+						  struct pvfs_wait);
+	struct ntvfs_request *req;
+	void *p = NULL;
+
+	if (num_fds != 0) {
+		DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
+		return;
+	}
+
+	/* we need to check that this one is for us. See
+	   imessaging_send_ptr() for the other side of this.
+	 */
+	if (data->length == sizeof(void *)) {
+		void **pp;
+		pp = (void **)data->data;
+		p = *pp;
+	}
+	if (p == NULL || p != pwait->private_data) {
+		return;
+	}
+
+	pwait->reason = PVFS_WAIT_EVENT;
+
+	/* the extra reference here is to ensure that the req
+	   structure is not destroyed when the async request reply is
+	   sent, which would cause problems with the other ntvfs
+	   modules above us */
+	req = talloc_reference(msg, pwait->req);
+	ntvfs_async_setup(pwait->req, pwait);
+	talloc_unlink(msg, req);
+}
+
+
+/*
+  receive a timeout on a message wait
+*/
+static void pvfs_wait_timeout(struct tevent_context *ev, 
+			      struct tevent_timer *te, struct timeval t,
+			      void *private_data)
+{
+	struct pvfs_wait *pwait = talloc_get_type(private_data,
+						  struct pvfs_wait);
+	struct ntvfs_request *req = pwait->req;
+
+	pwait->reason = PVFS_WAIT_TIMEOUT;
+
+	req = talloc_reference(ev, req);
+	if (req != NULL) {
+		ntvfs_async_setup(req, pwait);
+		talloc_unlink(ev, req);
+	}
+}
+
+
+/*
+  destroy a pending wait
+ */
+static int pvfs_wait_destructor(struct pvfs_wait *pwait)
+{
+	if (pwait->msg_type != -1) {
+		imessaging_deregister(pwait->msg_ctx, pwait->msg_type, pwait);
+	}
+	DLIST_REMOVE(pwait->pvfs->wait_list, pwait);
+	return 0;
+}
+
+/*
+  setup a request to wait on a message of type msg_type, with a
+  timeout (given as an expiry time)
+
+  the return value is a handle. To stop waiting talloc_free this
+  handle.
+
+  if msg_type == -1 then no message is registered, and it is assumed
+  that the caller handles any messaging setup needed
+*/
+struct pvfs_wait *pvfs_wait_message(struct pvfs_state *pvfs,
+				    struct ntvfs_request *req,
+				    int msg_type,
+				    struct timeval end_time,
+				    void (*fn)(void *, enum pvfs_wait_notice),
+				    void *private_data)
+{
+	struct pvfs_wait *pwait;
+
+	pwait = talloc(pvfs, struct pvfs_wait);
+	if (pwait == NULL) {
+		return NULL;
+	}
+
+	pwait->private_data = private_data;
+	pwait->handler = fn;
+	pwait->msg_ctx = pvfs->ntvfs->ctx->msg_ctx;
+	pwait->ev = pvfs->ntvfs->ctx->event_ctx;
+	pwait->msg_type = msg_type;
+	pwait->req = talloc_reference(pwait, req);
+	pwait->pvfs = pvfs;
+
+	if (!timeval_is_zero(&end_time)) {
+		/* setup a timer */
+		tevent_add_timer(pwait->ev, pwait, end_time, pvfs_wait_timeout, pwait);
+	}
+
+	/* register with the messaging subsystem for this message
+	   type */
+	if (msg_type != -1) {
+		imessaging_register(pwait->msg_ctx,
+				   pwait,
+				   msg_type,
+				   pvfs_wait_dispatch);
+	}
+
+	/* tell the main smb server layer that we will be replying 
+	   asynchronously */
+	req->async_states->state |= NTVFS_ASYNC_STATE_ASYNC;
+
+	DLIST_ADD(pvfs->wait_list, pwait);
+
+	/* make sure we cleanup the timer and message handler */
+	talloc_set_destructor(pwait, pvfs_wait_destructor);
+
+	return pwait;
+}
+
+
+/*
+  cancel an outstanding async request
+*/
+NTSTATUS pvfs_cancel(struct ntvfs_module_context *ntvfs, struct ntvfs_request *req)
+{
+	struct pvfs_state *pvfs = talloc_get_type(ntvfs->private_data,
+				  struct pvfs_state);
+	struct pvfs_wait *pwait;
+
+	for (pwait=pvfs->wait_list;pwait;pwait=pwait->next) {
+		if (pwait->req == req) {
+			/* trigger a cancel on the request */
+			pwait->reason = PVFS_WAIT_CANCEL;
+			ntvfs_async_setup(pwait->req, pwait);
+			return NT_STATUS_OK;
+		}
+	}
+
+	return NT_STATUS_DOS(ERRDOS, ERRcancelviolation);
+}