From: Volker Lendecke <vl@samba.org>
Date: Tue, 30 Jul 2019 12:54:18 +0000 (+0200)
Subject: smbd: Add defer_sharing_violation_smb1
X-Git-Tag: tdb-1.4.2~245
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c7e110e51afea9a36a060bff62506c53e86c8aab;p=thirdparty%2Fsamba.git

smbd: Add defer_sharing_violation_smb1

This is close to what Windows SMB1 does: Instead of waiting for the
share entry causing the SHARING_VIOLATION to disappear, retry every
200msec up to one second. Windows does it a little differently: Retry
up to 5 times. But up to one second should be close enough.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---

diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index b8b7ed025cc..f54c8cf6313 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -2567,6 +2567,36 @@ static bool setup_poll_open(
 	return true;
 }
 
+bool defer_smb1_sharing_violation(struct smb_request *req)
+{
+	bool ok;
+	int timeout_usecs;
+
+	if (!lp_defer_sharing_violations()) {
+		return false;
+	}
+
+	/*
+	 * Try every 200msec up to (by default) one second. To be
+	 * precise, according to behaviour note <247> in [MS-CIFS],
+	 * the server tries 5 times. But up to one second should be
+	 * close enough.
+	 */
+
+	timeout_usecs = lp_parm_int(
+		SNUM(req->conn),
+		"smbd",
+		"sharedelay",
+		SHARING_VIOLATION_USEC_WAIT);
+
+	ok = setup_poll_open(
+		req,
+		(struct file_id) {0},
+		(struct timeval) { .tv_usec = timeout_usecs },
+		(struct timeval) { .tv_usec = 200000 });
+	return ok;
+}
+
 /****************************************************************************
  On overwrite open ensure that the attributes match.
 ****************************************************************************/
diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h
index 6d3a10f9d75..0fde9b78fb0 100644
--- a/source3/smbd/proto.h
+++ b/source3/smbd/proto.h
@@ -680,6 +680,7 @@ NTSTATUS send_break_message(struct messaging_context *msg_ctx,
 			    uint16_t break_to);
 struct deferred_open_record;
 bool is_deferred_open_async(const struct deferred_open_record *rec);
+bool defer_smb1_sharing_violation(struct smb_request *req);
 NTSTATUS create_directory(connection_struct *conn, struct smb_request *req,
 			  struct smb_filename *smb_dname);
 void msg_file_was_renamed(struct messaging_context *msg,