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
  25#include "qemu/osdep.h"
  26#include "qemu-common.h"
  27#include "qemu/module.h"
  28#include "qemu/sockets.h"
  29#include "qapi/error.h"
  30#include "chardev/char.h"
  31#include "io/channel-file.h"
  32
  33#include "chardev/char-fd.h"
  34#include "chardev/char-io.h"
  35
  36/* Called with chr_write_lock held.  */
  37static int fd_chr_write(Chardev *chr, const uint8_t *buf, int len)
  38{
  39    FDChardev *s = FD_CHARDEV(chr);
  40
  41    return io_channel_send(s->ioc_out, buf, len);
  42}
  43
  44static gboolean fd_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
  45{
  46    Chardev *chr = CHARDEV(opaque);
  47    FDChardev *s = FD_CHARDEV(opaque);
  48    int len;
  49    uint8_t buf[CHR_READ_BUF_LEN];
  50    ssize_t ret;
  51
  52    len = sizeof(buf);
  53    if (len > s->max_size) {
  54        len = s->max_size;
  55    }
  56    if (len == 0) {
  57        return TRUE;
  58    }
  59
  60    ret = qio_channel_read(
  61        chan, (gchar *)buf, len, NULL);
  62    if (ret == 0) {
  63        remove_fd_in_watch(chr);
  64        qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
  65        return FALSE;
  66    }
  67    if (ret > 0) {
  68        qemu_chr_be_write(chr, buf, ret);
  69    }
  70
  71    return TRUE;
  72}
  73
  74static int fd_chr_read_poll(void *opaque)
  75{
  76    Chardev *chr = CHARDEV(opaque);
  77    FDChardev *s = FD_CHARDEV(opaque);
  78
  79    s->max_size = qemu_chr_be_can_write(chr);
  80    return s->max_size;
  81}
  82
  83static GSource *fd_chr_add_watch(Chardev *chr, GIOCondition cond)
  84{
  85    FDChardev *s = FD_CHARDEV(chr);
  86    return qio_channel_create_watch(s->ioc_out, cond);
  87}
  88
  89static void fd_chr_update_read_handler(Chardev *chr)
  90{
  91    FDChardev *s = FD_CHARDEV(chr);
  92
  93    remove_fd_in_watch(chr);
  94    if (s->ioc_in) {
  95        chr->gsource = io_add_watch_poll(chr, s->ioc_in,
  96                                           fd_chr_read_poll,
  97                                           fd_chr_read, chr,
  98                                           chr->gcontext);
  99    }
 100}
 101
 102static void char_fd_finalize(Object *obj)
 103{
 104    Chardev *chr = CHARDEV(obj);
 105    FDChardev *s = FD_CHARDEV(obj);
 106
 107    remove_fd_in_watch(chr);
 108    if (s->ioc_in) {
 109        object_unref(OBJECT(s->ioc_in));
 110    }
 111    if (s->ioc_out) {
 112        object_unref(OBJECT(s->ioc_out));
 113    }
 114
 115    qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
 116}
 117
 118int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
 119{
 120    int fd = -1;
 121
 122    TFR(fd = qemu_open(src, flags, 0666));
 123    if (fd == -1) {
 124        error_setg_file_open(errp, errno, src);
 125    }
 126    return fd;
 127}
 128
 129/* open a character device to a unix fd */
 130void qemu_chr_open_fd(Chardev *chr,
 131                      int fd_in, int fd_out)
 132{
 133    FDChardev *s = FD_CHARDEV(chr);
 134    char *name;
 135
 136    s->ioc_in = QIO_CHANNEL(qio_channel_file_new_fd(fd_in));
 137    name = g_strdup_printf("chardev-file-in-%s", chr->label);
 138    qio_channel_set_name(QIO_CHANNEL(s->ioc_in), name);
 139    g_free(name);
 140    s->ioc_out = QIO_CHANNEL(qio_channel_file_new_fd(fd_out));
 141    name = g_strdup_printf("chardev-file-out-%s", chr->label);
 142    qio_channel_set_name(QIO_CHANNEL(s->ioc_out), name);
 143    g_free(name);
 144    qemu_set_nonblock(fd_out);
 145}
 146
 147static void char_fd_class_init(ObjectClass *oc, void *data)
 148{
 149    ChardevClass *cc = CHARDEV_CLASS(oc);
 150
 151    cc->chr_add_watch = fd_chr_add_watch;
 152    cc->chr_write = fd_chr_write;
 153    cc->chr_update_read_handler = fd_chr_update_read_handler;
 154}
 155
 156static const TypeInfo char_fd_type_info = {
 157    .name = TYPE_CHARDEV_FD,
 158    .parent = TYPE_CHARDEV,
 159    .instance_size = sizeof(FDChardev),
 160    .instance_finalize = char_fd_finalize,
 161    .class_init = char_fd_class_init,
 162    .abstract = true,
 163};
 164
 165static void register_types(void)
 166{
 167    type_register_static(&char_fd_type_info);
 168}
 169
 170type_init(register_types);
 171