CIFS: Respect SMB2 header/max header size
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / cifs / smb2ops.c
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1/*
2 * SMB2 version specific operations
3 *
4 * Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
5 *
6 * This library is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License v2 as published
8 * by the Free Software Foundation.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public License
16 * along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include "cifsglob.h"
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21#include "smb2pdu.h"
22#include "smb2proto.h"
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23#include "cifsproto.h"
24#include "cifs_debug.h"
25
26static int
27change_conf(struct TCP_Server_Info *server)
28{
29 server->credits += server->echo_credits + server->oplock_credits;
30 server->oplock_credits = server->echo_credits = 0;
31 switch (server->credits) {
32 case 0:
33 return -1;
34 case 1:
35 server->echoes = false;
36 server->oplocks = false;
37 cERROR(1, "disabling echoes and oplocks");
38 break;
39 case 2:
40 server->echoes = true;
41 server->oplocks = false;
42 server->echo_credits = 1;
43 cFYI(1, "disabling oplocks");
44 break;
45 default:
46 server->echoes = true;
47 server->oplocks = true;
48 server->echo_credits = 1;
49 server->oplock_credits = 1;
50 }
51 server->credits -= server->echo_credits + server->oplock_credits;
52 return 0;
53}
54
55static void
56smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
57 const int optype)
58{
59 int *val, rc = 0;
60 spin_lock(&server->req_lock);
61 val = server->ops->get_credits_field(server, optype);
62 *val += add;
63 server->in_flight--;
64 if (server->in_flight == 0)
65 rc = change_conf(server);
66 spin_unlock(&server->req_lock);
67 wake_up(&server->request_q);
68 if (rc)
69 cifs_reconnect(server);
70}
71
72static void
73smb2_set_credits(struct TCP_Server_Info *server, const int val)
74{
75 spin_lock(&server->req_lock);
76 server->credits = val;
77 spin_unlock(&server->req_lock);
78}
79
80static int *
81smb2_get_credits_field(struct TCP_Server_Info *server, const int optype)
82{
83 switch (optype) {
84 case CIFS_ECHO_OP:
85 return &server->echo_credits;
86 case CIFS_OBREAK_OP:
87 return &server->oplock_credits;
88 default:
89 return &server->credits;
90 }
91}
92
93static unsigned int
94smb2_get_credits(struct mid_q_entry *mid)
95{
96 return le16_to_cpu(((struct smb2_hdr *)mid->resp_buf)->CreditRequest);
97}
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98
99static __u64
100smb2_get_next_mid(struct TCP_Server_Info *server)
101{
102 __u64 mid;
103 /* for SMB2 we need the current value */
104 spin_lock(&GlobalMid_Lock);
105 mid = server->CurrentMid++;
106 spin_unlock(&GlobalMid_Lock);
107 return mid;
108}
1080ef75 109
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110static struct mid_q_entry *
111smb2_find_mid(struct TCP_Server_Info *server, char *buf)
112{
113 struct mid_q_entry *mid;
114 struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
115
116 spin_lock(&GlobalMid_Lock);
117 list_for_each_entry(mid, &server->pending_mid_q, qhead) {
118 if ((mid->mid == hdr->MessageId) &&
119 (mid->mid_state == MID_REQUEST_SUBMITTED) &&
120 (mid->command == hdr->Command)) {
121 spin_unlock(&GlobalMid_Lock);
122 return mid;
123 }
124 }
125 spin_unlock(&GlobalMid_Lock);
126 return NULL;
127}
128
129static void
130smb2_dump_detail(void *buf)
131{
132#ifdef CONFIG_CIFS_DEBUG2
133 struct smb2_hdr *smb = (struct smb2_hdr *)buf;
134
135 cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d",
136 smb->Command, smb->Status, smb->Flags, smb->MessageId,
137 smb->ProcessId);
138 cERROR(1, "smb buf %p len %u", smb, smb2_calc_size(smb));
139#endif
140}
141
1080ef75 142struct smb_version_operations smb21_operations = {
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143 .setup_request = smb2_setup_request,
144 .check_receive = smb2_check_receive,
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145 .add_credits = smb2_add_credits,
146 .set_credits = smb2_set_credits,
147 .get_credits_field = smb2_get_credits_field,
148 .get_credits = smb2_get_credits,
2dc7e1c0 149 .get_next_mid = smb2_get_next_mid,
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150 .find_mid = smb2_find_mid,
151 .check_message = smb2_check_message,
152 .dump_detail = smb2_dump_detail,
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153};
154
155struct smb_version_values smb21_values = {
156 .version_string = SMB21_VERSION_STRING,
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157 .header_size = sizeof(struct smb2_hdr),
158 .max_header_size = MAX_SMB2_HDR_SIZE,
2dc7e1c0 159 .lock_cmd = SMB2_LOCK,
1080ef75 160};