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.  */
  35 static 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
  42 static 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
  72 static 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
  81 static 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
  87 static 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
 100 static 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
 116 int 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 */
 128 void 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
 145 static 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
 154 static 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
 163 static void register_types(void)
 164 {
 165     type_register_static(&char_fd_type_info);
 166 }
 167
 168 type_init(register_types);