r17083: - implement SMB2 Cancel in the client

- the 0xffffffffffffffff seqnum is reserved for SMB2 Break (oplock breaks)
  so don't use it in a request. we should someday try to test this...

metze
(This used to be commit 730cdc4475)

source4/libcli/smb2/cancel.c

@@ -0,0 +1,78 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   SMB2 client notify calls
+
+   Copyright (C) Stefan Metzmacher 2006
+   
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "libcli/raw/libcliraw.h"
+#include "libcli/smb2/smb2.h"
+#include "libcli/smb2/smb2_calls.h"
+
+/*
+  send a cancel request
+*/
+NTSTATUS smb2_cancel(struct smb2_request *r)
+{
+	NTSTATUS status;
+	struct smb2_request *c;
+	uint32_t old_timeout;
+	uint64_t old_seqnum;
+
+	/* 
+	 * if we don't get a pending id yet, we just
+	 * mark the request for pending, so that we directly
+	 * send the cancel after getting the pending id
+	 */
+	if (!r->cancel.can_cancel) {
+		r->cancel.do_cancel++;
+		return NT_STATUS_OK;
+	}
+
+	/* we don't want a seqmun for a SMB2 Cancel */
+	old_seqnum = r->transport->seqnum;
+	c = smb2_request_init(r->transport, SMB2_OP_CANCEL, 0x04, False, 0);
+	r->transport->seqnum = old_seqnum;
+	NT_STATUS_HAVE_NO_MEMORY(c);
+	c->seqnum = 0;
+
+	SIVAL(c->out.hdr, SMB2_HDR_FLAGS,	0x00000002);
+	SSVAL(c->out.hdr, SMB2_HDR_UNKNOWN1,	0x0030);
+	SIVAL(c->out.hdr, SMB2_HDR_PID,		r->cancel.pending_id);
+	SBVAL(c->out.hdr, SMB2_HDR_SEQNUM,	c->seqnum);
+	if (r->session) {
+		SBVAL(c->out.hdr, SMB2_HDR_UID,	r->session->uid);
+	}
+
+	SSVAL(c->out.body, 0x02, 0);
+
+	old_timeout = c->transport->options.timeout;
+	c->transport->options.timeout = 0;
+	smb2_transport_send(c);
+	c->transport->options.timeout = old_timeout;
+
+	if (c->state == SMB2_REQUEST_ERROR) {
+		status = c->status;
+	} else {
+		status = NT_STATUS_OK;
+	}
+
+	talloc_free(c);
+	return status;
+}

source4/libcli/smb2/config.mk

@@ -20,5 +20,6 @@ OBJ_FILES = \
 	flush.o \
 	lock.o \
 	notify.o \
+	cancel.o \
 	keepalive.o
 PUBLIC_DEPENDENCIES = LIBCLI_RAW LIBPACKET gensec

source4/libcli/smb2/request.c

@@ -35,6 +35,7 @@ struct smb2_request *smb2_request_init(struct smb2_transport *transport, uint16_
 				       uint32_t body_dynamic_size)
 {
 	struct smb2_request *req;
+	uint64_t seqnum;
 
 	if (body_dynamic_present) {
 		if (body_dynamic_size == 0) {
@@ -47,15 +48,21 @@ struct smb2_request *smb2_request_init(struct smb2_transport *transport, uint16_
 	req = talloc(transport, struct smb2_request);
 	if (req == NULL) return NULL;
 
+	seqnum = transport->seqnum++;
+	if (seqnum == UINT64_MAX) {
+		seqnum = transport->seqnum++;
+	}
+
 	req->state     = SMB2_REQUEST_INIT;
 	req->transport = transport;
 	req->session   = NULL;
 	req->tree      = NULL;
-	req->seqnum    = transport->seqnum++;
+	req->seqnum    = seqnum;
 	req->status    = NT_STATUS_OK;
 	req->async.fn  = NULL;
 	req->next = req->prev = NULL;
 
+	ZERO_STRUCT(req->cancel);
 	ZERO_STRUCT(req->in);
 
 	req->out.size      = SMB2_HDR_BODY+NBT_HDR_SIZE+body_fixed_size;

source4/libcli/smb2/smb2.h

@@ -128,6 +128,12 @@ struct smb2_request {
 
 	uint64_t seqnum;
 
+	struct {
+		BOOL do_cancel;
+		BOOL can_cancel;
+		uint32_t pending_id;
+	} cancel;
+
 	/* the NT status for this request. Set by packet receive code
 	   or code detecting error. */
 	NTSTATUS status;

source4/libcli/smb2/transport.c

@@ -152,8 +152,10 @@ static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob)
 	int len;
 	struct smb2_request *req = NULL;
 	uint64_t seqnum;
+	uint32_t flags;
 	uint16_t buffer_code;
 	uint32_t dynamic_size;
+	uint32_t i;
 
 	buffer = blob.data;
 	len = blob.length;
@@ -165,6 +167,7 @@ static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob)
 		goto error;
 	}
 
+	flags	= IVAL(hdr, SMB2_HDR_FLAGS);
 	seqnum	= BVAL(hdr, SMB2_HDR_SEQNUM);
 
 	/* match the incoming request against the list of pending requests */
@@ -190,8 +193,13 @@ static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob)
 	req->status       = NT_STATUS(IVAL(hdr, SMB2_HDR_STATUS));
 
 	if (NT_STATUS_EQUAL(req->status, STATUS_PENDING)) {
-		/* the server has helpfully told us that this request is still being
-		   processed. how useful :) */
+		if (flags & 0x00000002) {
+			req->cancel.can_cancel = True;
+			req->cancel.pending_id = IVAL(hdr, SMB2_HDR_PID);
+			for (i=0; i< req->cancel.do_cancel; i++) {
+				smb2_cancel(req);
+			}
+		}
 		talloc_free(buffer);
 		return NT_STATUS_OK;
 	}