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.  */
  37 static 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
  44 static 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
  74 static 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
  83 static 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
  89 static 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
 102 static 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
 118 int qmp_chardev_open_file_source(char *src, int flags, Error **errp)
 119 {
 120     int fd = -1;
 121
 122     TFR(fd = qemu_open_old(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 */
 130 void 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
 147 static 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
 156 static 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
 165 static void register_types(void)
 166 {
 167     type_register_static(&char_fd_type_info);
 168 }
 169
 170 type_init(register_types);