1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
/*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*/
/*
* Copyright 2020 Tintri by DDN, Inc. All rights reserved.
*/
/*
* Dispatch function for SMB2_CANCEL
*/
#include <smbsrv/smb2_kproto.h>
static void smb2_cancel_async(smb_request_t *);
static void smb2_cancel_sync(smb_request_t *);
/*
* This handles an SMB2_CANCEL request when seen in the reader.
* (See smb2sr_newrq) Handle this immediately, rather than
* going through the normal taskq dispatch mechanism.
* Note that Cancel does NOT get a response.
*
* Any non-zero return causes disconnect.
* SMB2 header is already decoded.
*/
int
smb2_newrq_cancel(smb_request_t *sr)
{
/*
* If we get SMB2 cancel as part of a compound,
* that's a protocol violation. Drop 'em!
*/
if (sr->smb2_next_command != 0)
return (EINVAL);
DTRACE_SMB2_START(op__Cancel, smb_request_t *, sr);
if (sr->smb2_hdr_flags & SMB2_FLAGS_ASYNC_COMMAND)
smb2_cancel_async(sr);
else
smb2_cancel_sync(sr);
DTRACE_SMB2_DONE(op__Cancel, smb_request_t *, sr);
return (0);
}
/*
* Dispatch handler for SMB2_CANCEL.
* Note that Cancel does NOT get a response.
*/
smb_sdrc_t
smb2_cancel(smb_request_t *sr)
{
/*
* If we get SMB2 cancel as part of a compound,
* that's a protocol violation. Drop 'em!
*/
if (sr->smb2_cmd_hdr != 0 || sr->smb2_next_command != 0)
return (SDRC_DROP_VC);
DTRACE_SMB2_START(op__Cancel, smb_request_t *, sr);
if (sr->smb2_hdr_flags & SMB2_FLAGS_ASYNC_COMMAND) {
smb2_cancel_async(sr);
} else {
smb2_cancel_sync(sr);
}
DTRACE_SMB2_DONE(op__Cancel, smb_request_t *, sr);
return (SDRC_NO_REPLY);
}
/*
* SMB2 Cancel (sync) has an inherent race with the request being
* cancelled. The request may have been received but not yet
* executed by a worker thread, in which case we'll mark the
* request state as cancelled, and when a worker thread starts
* on this request we'll cancel everything in the compound.
*/
static void
smb2_cancel_sync(smb_request_t *sr)
{
struct smb_request *req;
struct smb_session *session = sr->session;
int cnt = 0;
if (sr->smb2_messageid == 0 || sr->smb2_messageid == UINT64_MAX)
return;
smb_slist_enter(&session->s_req_list);
for (req = smb_slist_head(&session->s_req_list); req != NULL;
req = smb_slist_next(&session->s_req_list, req)) {
/* never cancel self */
if (req == sr)
continue;
if (sr->smb2_messageid >= req->smb2_first_msgid &&
sr->smb2_messageid < (req->smb2_first_msgid +
req->smb2_total_credits)) {
smb_request_cancel(req);
cnt++;
}
}
smb_slist_exit(&session->s_req_list);
if (cnt != 1) {
DTRACE_PROBE2(smb2__cancel__error,
uint64_t, sr->smb2_messageid, int, cnt);
#ifdef DEBUG
/*
* It's somewhat common that we may see a cancel for a
* request that has already completed, so report that
* only in debug builds.
*/
cmn_err(CE_WARN, "SMB2 cancel failed, "
"client=%s, MID=0x%llx",
sr->session->ip_addr_str,
(u_longlong_t)sr->smb2_messageid);
#endif
}
}
/*
* Note that cancelling an async request doesn't have a race
* because the client doesn't learn about the async ID until we
* send it to them in an interim reply, and by that point the
* request has progressed to the point where smb_cancel can find
* the request and cancel it.
*/
static void
smb2_cancel_async(smb_request_t *sr)
{
struct smb_request *req;
struct smb_session *session = sr->session;
int cnt = 0;
if (sr->smb2_async_id == 0)
return;
smb_slist_enter(&session->s_req_list);
req = smb_slist_head(&session->s_req_list);
while (req) {
ASSERT(req->sr_magic == SMB_REQ_MAGIC);
if ((req != sr) &&
(req->smb2_async_id == sr->smb2_async_id)) {
smb_request_cancel(req);
cnt++;
}
req = smb_slist_next(&session->s_req_list, req);
}
if (cnt != 1) {
DTRACE_PROBE2(smb2__cancel__error,
uint64_t, sr->smb2_async_id, int, cnt);
/*
* Not logging here, as this is normal, i.e.
* when both a cancel and a handle close
* terminates an SMB2_notify request.
*/
}
smb_slist_exit(&session->s_req_list);
}
|
