xref: /openbmc/qemu/chardev/testdev.c (revision f363d039)
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);
131