1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 *
25 * Copyright 2017 Nexenta Systems, Inc. All rights reserved.
26 */
27
28 /*
29 * SMB: nt_cancel
30 *
31 * This SMB allows a client to cancel a request currently pending at the
32 * server.
33 *
34 * Client Request Description
35 * ================================== =================================
36 *
37 * UCHAR WordCount; No words are sent (== 0)
38 * USHORT ByteCount; No bytes (==0)
39 *
40 * The Sid, Uid, Pid, Tid, and Mid fields of the SMB are used to locate an
41 * pending server request from this session. If a pending request is
42 * found, it is "hurried along" which may result in success or failure of
43 * the original request. No other response is generated for this SMB.
44 */
45
46 #include <smbsrv/smb_kproto.h>
47
48 smb_sdrc_t
smb_pre_nt_cancel(smb_request_t * sr)49 smb_pre_nt_cancel(smb_request_t *sr)
50 {
51 DTRACE_SMB_START(op__NtCancel, smb_request_t *, sr);
52 return (SDRC_SUCCESS);
53 }
54
55 void
smb_post_nt_cancel(smb_request_t * sr)56 smb_post_nt_cancel(smb_request_t *sr)
57 {
58 DTRACE_SMB_DONE(op__NtCancel, smb_request_t *, sr);
59 }
60
61 /*
62 * Dispatch handler for SMB_COM_NT_CANCEL.
63 * Note that Cancel does NOT get a response.
64 *
65 * SMB NT Cancel has an inherent race with the request being
66 * cancelled. See comments at smb_request_cancel().
67 */
68 smb_sdrc_t
smb_com_nt_cancel(smb_request_t * sr)69 smb_com_nt_cancel(smb_request_t *sr)
70 {
71 struct smb_request *req;
72 struct smb_session *session;
73 int cnt = 0;
74
75 session = sr->session;
76
77 smb_slist_enter(&session->s_req_list);
78 req = smb_slist_head(&session->s_req_list);
79 while (req) {
80 ASSERT(req->sr_magic == SMB_REQ_MAGIC);
81 if ((req != sr) &&
82 (req->smb_uid == sr->smb_uid) &&
83 (req->smb_pid == sr->smb_pid) &&
84 (req->smb_tid == sr->smb_tid) &&
85 (req->smb_mid == sr->smb_mid)) {
86 smb_request_cancel(req);
87 cnt++;
88 }
89 req = smb_slist_next(&session->s_req_list, req);
90 }
91 if (cnt != 1) {
92 DTRACE_PROBE2(smb__ntcancel__error,
93 uint16_t, sr->smb_mid, int, cnt);
94 }
95 smb_slist_exit(&session->s_req_list);
96
97 return (SDRC_NO_REPLY);
98 }
99
100 /*
101 * This handles an SMB_COM_NT_CANCEL request when seen in the reader.
102 * (See smb1sr_newrq) Handle this immediately, rather than
103 * going through the normal taskq dispatch mechanism.
104 * Note that Cancel does NOT get a response.
105 */
106 int
smb1sr_newrq_cancel(smb_request_t * sr)107 smb1sr_newrq_cancel(smb_request_t *sr)
108 {
109 (void) smb_pre_nt_cancel(sr);
110 (void) smb_com_nt_cancel(sr);
111 smb_post_nt_cancel(sr);
112 return (0);
113 }
114