xref: /illumos-gate/usr/src/uts/common/fs/smbsrv/smb_echo.c (revision bde334a8dbd66dfa70ce4d7fc9dcad6e1ae45fe4)
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  */
39 smb_sdrc_t
40 smb_pre_echo(smb_request_t *sr)
41 {
42 	DTRACE_SMB_START(op__Echo, smb_request_t *, sr);
43 	return (SDRC_SUCCESS);
44 }
45 
46 void
47 smb_post_echo(smb_request_t *sr)
48 {
49 	DTRACE_SMB_DONE(op__Echo, smb_request_t *, sr);
50 }
51 
52 static unsigned short smb_max_echo = 10;
53 
54 smb_sdrc_t
55 smb_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