LXR qemu/chardev/char-fd.c

   1/*
   2 * QEMU System Emulator
   3 *
   4 * Copyright (c) 2003-2008 Fabrice Bellard
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24#include "qemu/osdep.h"
  25#include "qemu/sockets.h"
  26#include "qapi/error.h"
  27#include "qemu-common.h"
  28#include "chardev/char.h"
  29#include "io/channel-file.h"
  30
  31#include "chardev/char-fd.h"
  32#include "chardev/char-io.h"
  33
  34/* Called with chr_write_lock held.  */
  35static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
  36{
  37    FDChardev *s = FD_CHARDEV(chr);
  38
  39    return io_channel_send(s->ioc_out, buf, len);
  40}
  41
  42static gboolean fd_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
  43{
  44    Chardev *chr = CHARDEV(opaque);
  45    FDChardev *s = FD_CHARDEV(opaque);
  46    int len;
  47    uint8_t buf[CHR_READ_BUF_LEN];
  48    ssize_t ret;
  49
  50    len = sizeof(buf);
  51    if (len > s->max_size) {
  52        len = s->max_size;
  53    }
  54    if (len == 0) {
  55        return TRUE;
  56    }
  57
  58    ret = qio_channel_read(
  59        chan, (gchar *)buf, len, NULL);
  60    if (ret == 0) {
  61        remove_fd_in_watch(chr);
  62        qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
  63        return FALSE;
  64    }
  65    if (ret > 0) {
  66        qemu_chr_be_write(chr, buf, ret);
  67    }
  68
  69    return TRUE;
  70}
  71
  72static int fd_chr_read_poll(void *opaque)
  73{
  74    Chardev *chr = CHARDEV(opaque);
  75    FDChardev *s = FD_CHARDEV(opaque);
  76
  77    s->max_size = qemu_chr_be_can_write(chr);
  78    return s->max_size;
  79}
  80
  81static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
  82{
  83    FDChardev *s = FD_CHARDEV(chr);
  84    return qio_channel_create_watch(s->ioc_out, cond);
  85}
  86
  87static void fd_chr_update_read_handler(Chardev *chr)
  88{
  89    FDChardev *s = FD_CHARDEV(chr);
  90
  91    remove_fd_in_watch(chr);
  92    if (s->ioc_in) {
  93        chr->gsource = io_add_watch_poll(chr, s->ioc_in,
  94                                           fd_chr_read_poll,
  95                                           fd_chr_read, chr,
  96                                           chr->gcontext);
  97    }
  98}
  99
 100static void char_fd_finalize(Object *obj)
 101{
 102    Chardev *chr = CHARDEV(obj);
 103    FDChardev *s = FD_CHARDEV(obj);
 104
 105    remove_fd_in_watch(chr);
 106    if (s->ioc_in) {
 107        object_unref(OBJECT(s->ioc_in));
 108    }
 109    if (s->ioc_out) {
 110        object_unref(OBJECT(s->ioc_out));
 111    }
 112
 113    qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 114}
 115
 116int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
 117{
 118    int fd = -1;
 119
 120    TFR(fd = qemu_open(src, flags, 0666));
 121    if (fd == -1) {
 122        error_setg_file_open(errp, errno, src);
 123    }
 124    return fd;
 125}
 126
 127/* open a character device to a unix fd */
 128void qemu_chr_open_fd(Chardev *chr,
 129                      int fd_in, int fd_out)
 130{
 131    FDChardev *s = FD_CHARDEV(chr);
 132    char *name;
 133
 134    s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
 135    name = g_strdup_printf("chardev-file-in-%s", chr->label);
 136    qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
 137    g_free(name);
 138    s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
 139    name = g_strdup_printf("chardev-file-out-%s", chr->label);
 140    qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
 141    g_free(name);
 142    qemu_set_nonblock(fd_out);
 143}
 144
 145static void char_fd_class_init(ObjectClass *oc, void *data)
 146{
 147    ChardevClass *cc = CHARDEV_CLASS(oc);
 148
 149    cc->chr_add_watch = fd_chr_add_watch;
 150    cc->chr_write = fd_chr_write;
 151    cc->chr_update_read_handler = fd_chr_update_read_handler;
 152}
 153
 154static const TypeInfo char_fd_type_info = {
 155    .name = TYPE_CHARDEV_FD,
 156    .parent = TYPE_CHARDEV,
 157    .instance_size = sizeof(FDChardev),
 158    .instance_finalize = char_fd_finalize,
 159    .class_init = char_fd_class_init,
 160    .abstract = true,
 161};
 162
 163static void register_types(void)
 164{
 165    type_register_static(&char_fd_type_info);
 166}
 167
 168type_init(register_types);
 169