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 #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);