LXR qemu/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
  33typedef 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 */
  45static 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 */
  86static 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
 111static 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
 118static 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
 125static void register_types(void)
 126{
 127    type_register_static(&char_testdev_type_info);
 128}
 129
 130type_init(register_types);
 131