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 2010 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#include <smbsrv/smb_kproto.h>
29
30/*
31 * The echo request is used to test the connection to the server,
32 * and to see if the server is still responding.  The tid is ignored,
33 * so this request may be sent to the server even if there are no
34 * tree connections to the server.
35 *
36 * Each response echoes the data sent, though ByteCount may indicate
37 * no data. If echo-count is zero, no response is sent.
38 */
39smb_sdrc_t
40smb_pre_echo(smb_request_t *sr)
41{
42	DTRACE_SMB_START(op__Echo, smb_request_t *, sr);
43	return (SDRC_SUCCESS);
44}
45
46void
47smb_post_echo(smb_request_t *sr)
48{
49	DTRACE_SMB_DONE(op__Echo, smb_request_t *, sr);
50}
51
52static unsigned short smb_max_echo = 10;
53
54smb_sdrc_t
55smb_com_echo(struct smb_request *sr)
56{
57	unsigned short necho;
58	unsigned short nbytes;
59	unsigned short i;
60	struct mbuf_chain reply;
61	char *data;
62	uint16_t	pid_hi, pid_lo;
63
64	pid_hi = sr->smb_pid >> 16;
65	pid_lo = (uint16_t)sr->smb_pid;
66
67	if (smbsr_decode_vwv(sr, "w", &necho) != 0)
68		return (SDRC_ERROR);
69
70	/*
71	 * Don't let the client fool us into doing
72	 * more work than is "reasonable".
73	 */
74	if (necho > smb_max_echo)
75		necho = smb_max_echo;
76
77	nbytes = sr->smb_bcc;
78	data = smb_srm_zalloc(sr, nbytes);
79
80	if (smb_mbc_decodef(&sr->smb_data, "#c", nbytes, data))
81		return (SDRC_ERROR);
82
83	for (i = 1; i <= necho; ++i) {
84
85		/*
86		 * According to [MS-CIFS] 3.3.5.32 echo is
87		 * subject to cancellation.
88		 */
89		if (sr->sr_state != SMB_REQ_STATE_ACTIVE)
90			break;
91
92		MBC_INIT(&reply, SMB_HEADER_ED_LEN + 10 + nbytes);
93
94		(void) smb_mbc_encodef(&reply, SMB_HEADER_ED_FMT,
95		    sr->first_smb_com,
96		    sr->smb_rcls,
97		    sr->smb_reh,
98		    sr->smb_err,
99		    sr->smb_flg | SMB_FLAGS_REPLY,
100		    sr->smb_flg2,
101		    pid_hi,
102		    sr->smb_sig,
103		    sr->smb_tid,
104		    pid_lo,
105		    sr->smb_uid,
106		    sr->smb_mid);
107
108		(void) smb_mbc_encodef(&reply, "bww#c", 1, i,
109		    nbytes, nbytes, data);
110
111		if (sr->session->signing.flags & SMB_SIGNING_ENABLED)
112			smb_sign_reply(sr, &reply);
113
114		(void) smb_session_send(sr->session, 0, &reply);
115
116		delay(MSEC_TO_TICK(100));
117	}
118
119	return (SDRC_NO_REPLY);
120}
121