qemu-e2k/chardev/char-fd.c

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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* 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/module.h"
#include "qemu/sockets.h"
#include "qapi/error.h"
#include "chardev/char.h"
#include "chardev/char-fe.h"
#include "io/channel-file.h"
#include "chardev/char-fd.h"
#include "chardev/char-io.h"
/* Called with chr_write_lock held. */
static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
{
FDChardev *s = FD_CHARDEV(chr);
if (!s->ioc_out) {
return -1;
}
return io_channel_send(s->ioc_out, buf, len);
}
static gboolean fd_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
{
Chardev *chr = CHARDEV(opaque);
FDChardev *s = FD_CHARDEV(opaque);
int len;
uint8_t buf[CHR_READ_BUF_LEN];
ssize_t ret;
len = sizeof(buf);
if (len > s->max_size) {
len = s->max_size;
}
if (len == 0) {
return TRUE;
}
ret = qio_channel_read(
chan, (gchar *)buf, len, NULL);
if (ret == 0) {
remove_fd_in_watch(chr);
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
return FALSE;
}
if (ret > 0) {
qemu_chr_be_write(chr, buf, ret);
}
return TRUE;
}
static int fd_chr_read_poll(void *opaque)
{
Chardev *chr = CHARDEV(opaque);
FDChardev *s = FD_CHARDEV(opaque);
s->max_size = qemu_chr_be_can_write(chr);
return s->max_size;
}
typedef struct FDSource {
GSource parent;
GIOCondition cond;
} FDSource;
static gboolean
fd_source_prepare(GSource *source,
gint *timeout_)
{
FDSource *src = (FDSource *)source;
return src->cond != 0;
}
static gboolean
fd_source_check(GSource *source)
{
FDSource *src = (FDSource *)source;
return src->cond != 0;
}
static gboolean
fd_source_dispatch(GSource *source, GSourceFunc callback,
gpointer user_data)
{
FDSource *src = (FDSource *)source;
FEWatchFunc func = (FEWatchFunc)callback;
gboolean ret = G_SOURCE_CONTINUE;
if (src->cond) {
ret = func(NULL, src->cond, user_data);
src->cond = 0;
}
return ret;
}
static GSourceFuncs fd_source_funcs = {
fd_source_prepare,
fd_source_check,
fd_source_dispatch,
NULL, NULL, NULL
};
static GSource *fd_source_new(FDChardev *chr)
{
return g_source_new(&fd_source_funcs, sizeof(FDSource));
}
static gboolean child_func(GIOChannel *source,
GIOCondition condition,
gpointer data)
{
FDSource *parent = data;
parent->cond |= condition;
return G_SOURCE_CONTINUE;
}
static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
{
FDChardev *s = FD_CHARDEV(chr);
g_autoptr(GSource) source = fd_source_new(s);
if (s->ioc_out) {
g_autoptr(GSource) child = qio_channel_create_watch(s->ioc_out, cond & ~G_IO_IN);
g_source_set_callback(child, (GSourceFunc)child_func, source, NULL);
g_source_add_child_source(source, child);
}
if (s->ioc_in) {
g_autoptr(GSource) child = qio_channel_create_watch(s->ioc_in, cond & ~G_IO_OUT);
g_source_set_callback(child, (GSourceFunc)child_func, source, NULL);
g_source_add_child_source(source, child);
}
return g_steal_pointer(&source);
}
static void fd_chr_update_read_handler(Chardev *chr)
{
FDChardev *s = FD_CHARDEV(chr);
remove_fd_in_watch(chr);
if (s->ioc_in) {
chr->gsource = io_add_watch_poll(chr, s->ioc_in,
fd_chr_read_poll,
fd_chr_read, chr,
chr->gcontext);
}
}
static void char_fd_finalize(Object *obj)
{
Chardev *chr = CHARDEV(obj);
FDChardev *s = FD_CHARDEV(obj);
remove_fd_in_watch(chr);
if (s->ioc_in) {
object_unref(OBJECT(s->ioc_in));
}
if (s->ioc_out) {
object_unref(OBJECT(s->ioc_out));
}
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}
int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
{
int fd = -1;
TFR(fd = qemu_open_old(src, flags, 0666));
if (fd == -1) {
error_setg_file_open(errp, errno, src);
}
return fd;
}
/* open a character device to a unix fd */
void qemu_chr_open_fd(Chardev *chr,
int fd_in, int fd_out)
{
FDChardev *s = FD_CHARDEV(chr);
g_autofree char *name = NULL;
if (fd_out >= 0 && !g_unix_set_fd_nonblocking(fd_out, true, NULL)) {
assert(!"Failed to set FD nonblocking");
}
if (fd_out == fd_in && fd_in >= 0) {
s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
name = g_strdup_printf("chardev-file-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
s->ioc_out = QIO_CHANNEL(object_ref(s->ioc_in));
return;
}
if (fd_in >= 0) {
s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
name = g_strdup_printf("chardev-file-in-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
}
if (fd_out >= 0) {
s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
g_free(name);
name = g_strdup_printf("chardev-file-out-%s", chr->label);
qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
}
}
static void char_fd_class_init(ObjectClass *oc, void *data)
{
ChardevClass *cc = CHARDEV_CLASS(oc);
cc->chr_add_watch = fd_chr_add_watch;
cc->chr_write = fd_chr_write;
cc->chr_update_read_handler = fd_chr_update_read_handler;
}
static const TypeInfo char_fd_type_info = {
.name = TYPE_CHARDEV_FD,
.parent = TYPE_CHARDEV,
.instance_size = sizeof(FDChardev),
.instance_finalize = char_fd_finalize,
.class_init = char_fd_class_init,
.abstract = true,
};
static void register_types(void)
{
type_register_static(&char_fd_type_info);
}
type_init(register_types);