linux-user: Add support for a group of btrfs ioctls used for snapshots
[qemu.git] / chardev / testdev.c
1 /*
2 * QEMU Char Device for testsuite control
3 *
4 * Copyright (c) 2014 Red Hat, Inc.
5 *
6 * Author: Paolo Bonzini <pbonzini@redhat.com>
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this software and associated documentation files (the "Software"), to deal
10 * in the Software without restriction, including without limitation the rights
11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 * copies of the Software, and to permit persons to whom the Software is
13 * furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 * THE SOFTWARE.
25 */
26
27 #include "qemu/osdep.h"
28 #include "qemu/module.h"
29 #include "chardev/char.h"
30
31 #define BUF_SIZE 32
32
33 typedef struct {
34 Chardev parent;
35
36 uint8_t in_buf[32];
37 int in_buf_used;
38 } TestdevChardev;
39
40 #define TYPE_CHARDEV_TESTDEV "chardev-testdev"
41 #define TESTDEV_CHARDEV(obj) \
42 OBJECT_CHECK(TestdevChardev, (obj), TYPE_CHARDEV_TESTDEV)
43
44 /* Try to interpret a whole incoming packet */
45 static int testdev_eat_packet(TestdevChardev *testdev)
46 {
47 const uint8_t *cur = testdev->in_buf;
48 int len = testdev->in_buf_used;
49 uint8_t c;
50 int arg;
51
52 #define EAT(c) do { \
53 if (!len--) { \
54 return 0; \
55 } \
56 c = *cur++; \
57 } while (0)
58
59 EAT(c);
60
61 while (isspace(c)) {
62 EAT(c);
63 }
64
65 arg = 0;
66 while (isdigit(c)) {
67 arg = arg * 10 + c - '0';
68 EAT(c);
69 }
70
71 while (isspace(c)) {
72 EAT(c);
73 }
74
75 switch (c) {
76 case 'q':
77 exit((arg << 1) | 1);
78 break;
79 default:
80 break;
81 }
82 return cur - testdev->in_buf;
83 }
84
85 /* The other end is writing some data. Store it and try to interpret */
86 static int testdev_chr_write(Chardev *chr, const uint8_t *buf, int len)
87 {
88 TestdevChardev *testdev = TESTDEV_CHARDEV(chr);
89 int tocopy, eaten, orig_len = len;
90
91 while (len) {
92 /* Complete our buffer as much as possible */
93 tocopy = MIN(len, BUF_SIZE - testdev->in_buf_used);
94
95 memcpy(testdev->in_buf + testdev->in_buf_used, buf, tocopy);
96 testdev->in_buf_used += tocopy;
97 buf += tocopy;
98 len -= tocopy;
99
100 /* Interpret it as much as possible */
101 while (testdev->in_buf_used > 0 &&
102 (eaten = testdev_eat_packet(testdev)) > 0) {
103 memmove(testdev->in_buf, testdev->in_buf + eaten,
104 testdev->in_buf_used - eaten);
105 testdev->in_buf_used -= eaten;
106 }
107 }
108 return orig_len;
109 }
110
111 static void char_testdev_class_init(ObjectClass *oc, void *data)
112 {
113 ChardevClass *cc = CHARDEV_CLASS(oc);
114
115 cc->chr_write = testdev_chr_write;
116 }
117
118 static const TypeInfo char_testdev_type_info = {
119 .name = TYPE_CHARDEV_TESTDEV,
120 .parent = TYPE_CHARDEV,
121 .instance_size = sizeof(TestdevChardev),
122 .class_init = char_testdev_class_init,
123 };
124
125 static void register_types(void)
126 {
127 type_register_static(&char_testdev_type_info);
128 }
129
130 type_init(register_types);