qemu/backends/testdev.c

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/*
* QEMU Char Device for testsuite control
*
* Copyright (c) 2014 Red Hat, Inc.
*
* Author: Paolo Bonzini <pbonzini@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "qemu/osdep.h"
#include "qemu-common.h"
#include "sysemu/char.h"
#define BUF_SIZE 32
typedef struct {
CharDriverState *chr;
uint8_t in_buf[32];
int in_buf_used;
} TestdevCharState;
/* Try to interpret a whole incoming packet */
static int testdev_eat_packet(TestdevCharState *testdev)
{
const uint8_t *cur = testdev->in_buf;
int len = testdev->in_buf_used;
uint8_t c;
int arg;
#define EAT(c) do { \
if (!len--) { \
return 0; \
} \
c = *cur++; \
} while (0)
EAT(c);
while (isspace(c)) {
EAT(c);
}
arg = 0;
while (isdigit(c)) {
arg = arg * 10 + c - '0';
EAT(c);
}
while (isspace(c)) {
EAT(c);
}
switch (c) {
case 'q':
exit((arg << 1) | 1);
break;
default:
break;
}
return cur - testdev->in_buf;
}
/* The other end is writing some data. Store it and try to interpret */
static int testdev_write(CharDriverState *chr, const uint8_t *buf, int len)
{
TestdevCharState *testdev = chr->opaque;
int tocopy, eaten, orig_len = len;
while (len) {
/* Complete our buffer as much as possible */
tocopy = MIN(len, BUF_SIZE - testdev->in_buf_used);
memcpy(testdev->in_buf + testdev->in_buf_used, buf, tocopy);
testdev->in_buf_used += tocopy;
buf += tocopy;
len -= tocopy;
/* Interpret it as much as possible */
while (testdev->in_buf_used > 0 &&
(eaten = testdev_eat_packet(testdev)) > 0) {
memmove(testdev->in_buf, testdev->in_buf + eaten,
testdev->in_buf_used - eaten);
testdev->in_buf_used -= eaten;
}
}
return orig_len;
}
static void testdev_close(struct CharDriverState *chr)
{
TestdevCharState *testdev = chr->opaque;
g_free(testdev);
}
static CharDriverState *chr_testdev_init(const char *id,
ChardevBackend *backend,
ChardevReturn *ret,
Error **errp)
{
TestdevCharState *testdev;
CharDriverState *chr;
testdev = g_new0(TestdevCharState, 1);
testdev->chr = chr = g_new0(CharDriverState, 1);
chr->opaque = testdev;
chr->chr_write = testdev_write;
chr->chr_close = testdev_close;
return chr;
}
static void register_types(void)
{
register_char_driver("testdev", CHARDEV_BACKEND_KIND_TESTDEV, NULL,
chr_testdev_init);
}
type_init(register_types);