LXR qemu/backends/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#include "qemu/osdep.h"
  27#include "qemu-common.h"
  28#include "sysemu/char.h"
  29
  30#define BUF_SIZE 32
  31
  32typedef struct {
  33    CharDriverState *chr;
  34    uint8_t in_buf[32];
  35    int in_buf_used;
  36} TestdevCharState;
  37
  38/* Try to interpret a whole incoming packet */
  39static int testdev_eat_packet(TestdevCharState *testdev)
  40{
  41    const uint8_t *cur = testdev->in_buf;
  42    int len = testdev->in_buf_used;
  43    uint8_t c;
  44    int arg;
  45
  46#define EAT(c) do { \
  47    if (!len--) {   \
  48        return 0;   \
  49    }               \
  50    c = *cur++;     \
  51} while (0)
  52
  53    EAT(c);
  54
  55    while (isspace(c)) {
  56        EAT(c);
  57    }
  58
  59    arg = 0;
  60    while (isdigit(c)) {
  61        arg = arg * 10 + c - '0';
  62        EAT(c);
  63    }
  64
  65    while (isspace(c)) {
  66        EAT(c);
  67    }
  68
  69    switch (c) {
  70    case 'q':
  71        exit((arg << 1) | 1);
  72        break;
  73    default:
  74        break;
  75    }
  76    return cur - testdev->in_buf;
  77}
  78
  79/* The other end is writing some data.  Store it and try to interpret */
  80static int testdev_write(CharDriverState *chr, const uint8_t *buf, int len)
  81{
  82    TestdevCharState *testdev = chr->opaque;
  83    int tocopy, eaten, orig_len = len;
  84
  85    while (len) {
  86        /* Complete our buffer as much as possible */
  87        tocopy = MIN(len, BUF_SIZE - testdev->in_buf_used);
  88
  89        memcpy(testdev->in_buf + testdev->in_buf_used, buf, tocopy);
  90        testdev->in_buf_used += tocopy;
  91        buf += tocopy;
  92        len -= tocopy;
  93
  94        /* Interpret it as much as possible */
  95        while (testdev->in_buf_used > 0 &&
  96               (eaten = testdev_eat_packet(testdev)) > 0) {
  97            memmove(testdev->in_buf, testdev->in_buf + eaten,
  98                    testdev->in_buf_used - eaten);
  99            testdev->in_buf_used -= eaten;
 100        }
 101    }
 102    return orig_len;
 103}
 104
 105static void testdev_close(struct CharDriverState *chr)
 106{
 107    TestdevCharState *testdev = chr->opaque;
 108
 109    g_free(testdev);
 110}
 111
 112static CharDriverState *chr_testdev_init(const char *id,
 113                                         ChardevBackend *backend,
 114                                         ChardevReturn *ret,
 115                                         Error **errp)
 116{
 117    TestdevCharState *testdev;
 118    CharDriverState *chr;
 119
 120    testdev = g_new0(TestdevCharState, 1);
 121    testdev->chr = chr = g_new0(CharDriverState, 1);
 122
 123    chr->opaque = testdev;
 124    chr->chr_write = testdev_write;
 125    chr->chr_close = testdev_close;
 126
 127    return chr;
 128}
 129
 130static void register_types(void)
 131{
 132    register_char_driver("testdev", CHARDEV_BACKEND_KIND_TESTDEV, NULL,
 133                         chr_testdev_init);
 134}
 135
 136type_init(register_types);
 137