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);