xref: /openbmc/qemu/chardev/testdev.c (revision b8116f4c)
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 #include "qom/object.h"
31 
32 #define BUF_SIZE 32
33 
34 struct TestdevChardev {
35     Chardev parent;
36 
37     uint8_t in_buf[32];
38     int in_buf_used;
39 };
40 typedef struct TestdevChardev TestdevChardev;
41 
42 #define TYPE_CHARDEV_TESTDEV "chardev-testdev"
43 DECLARE_INSTANCE_CHECKER(TestdevChardev, TESTDEV_CHARDEV,
44                          TYPE_CHARDEV_TESTDEV)
45 
46 /* Try to interpret a whole incoming packet */
47 static int testdev_eat_packet(TestdevChardev *testdev)
48 {
49     const uint8_t *cur = testdev->in_buf;
50     int len = testdev->in_buf_used;
51     uint8_t c;
52     int arg;
53 
54 #define EAT(c) do { \
55     if (!len--) {   \
56         return 0;   \
57     }               \
58     c = *cur++;     \
59 } while (0)
60 
61     EAT(c);
62 
63     while (isspace(c)) {
64         EAT(c);
65     }
66 
67     arg = 0;
68     while (isdigit(c)) {
69         arg = arg * 10 + c - '0';
70         EAT(c);
71     }
72 
73     while (isspace(c)) {
74         EAT(c);
75     }
76 
77     switch (c) {
78     case 'q':
79         exit((arg << 1) | 1);
80         break;
81     default:
82         break;
83     }
84     return cur - testdev->in_buf;
85 }
86 
87 /* The other end is writing some data.  Store it and try to interpret */
88 static int testdev_chr_write(Chardev *chr, const uint8_t *buf, int len)
89 {
90     TestdevChardev *testdev = TESTDEV_CHARDEV(chr);
91     int tocopy, eaten, orig_len = len;
92 
93     while (len) {
94         /* Complete our buffer as much as possible */
95         tocopy = MIN(len, BUF_SIZE - testdev->in_buf_used);
96 
97         memcpy(testdev->in_buf + testdev->in_buf_used, buf, tocopy);
98         testdev->in_buf_used += tocopy;
99         buf += tocopy;
100         len -= tocopy;
101 
102         /* Interpret it as much as possible */
103         while (testdev->in_buf_used > 0 &&
104                (eaten = testdev_eat_packet(testdev)) > 0) {
105             memmove(testdev->in_buf, testdev->in_buf + eaten,
106                     testdev->in_buf_used - eaten);
107             testdev->in_buf_used -= eaten;
108         }
109     }
110     return orig_len;
111 }
112 
113 static void char_testdev_class_init(ObjectClass *oc, void *data)
114 {
115     ChardevClass *cc = CHARDEV_CLASS(oc);
116 
117     cc->chr_write = testdev_chr_write;
118 }
119 
120 static const TypeInfo char_testdev_type_info = {
121     .name = TYPE_CHARDEV_TESTDEV,
122     .parent = TYPE_CHARDEV,
123     .instance_size = sizeof(TestdevChardev),
124     .class_init = char_testdev_class_init,
125 };
126 
127 static void register_types(void)
128 {
129     type_register_static(&char_testdev_type_info);
130 }
131 
132 type_init(register_types);
133