LXR qemu/migration/qemu-file-channel.c

   1/*
   2 * QEMUFile backend for QIOChannel objects
   3 *
   4 * Copyright (c) 2015-2016 Red Hat, Inc
   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-file-channel.h"
  27#include "exec/cpu-common.h"
  28#include "qemu-file.h"
  29#include "io/channel-socket.h"
  30#include "qemu/iov.h"
  31
  32
  33static ssize_t channel_writev_buffer(void *opaque,
  34                                     struct iovec *iov,
  35                                     int iovcnt,
  36                                     int64_t pos)
  37{
  38    QIOChannel *ioc = QIO_CHANNEL(opaque);
  39    ssize_t done = 0;
  40    struct iovec *local_iov = g_new(struct iovec, iovcnt);
  41    struct iovec *local_iov_head = local_iov;
  42    unsigned int nlocal_iov = iovcnt;
  43
  44    nlocal_iov = iov_copy(local_iov, nlocal_iov,
  45                          iov, iovcnt,
  46                          0, iov_size(iov, iovcnt));
  47
  48    while (nlocal_iov > 0) {
  49        ssize_t len;
  50        len = qio_channel_writev(ioc, local_iov, nlocal_iov, NULL);
  51        if (len == QIO_CHANNEL_ERR_BLOCK) {
  52            qio_channel_wait(ioc, G_IO_OUT);
  53            continue;
  54        }
  55        if (len < 0) {
  56            /* XXX handle Error objects */
  57            done = -EIO;
  58            goto cleanup;
  59        }
  60
  61        iov_discard_front(&local_iov, &nlocal_iov, len);
  62        done += len;
  63    }
  64
  65 cleanup:
  66    g_free(local_iov_head);
  67    return done;
  68}
  69
  70
  71static ssize_t channel_get_buffer(void *opaque,
  72                                  uint8_t *buf,
  73                                  int64_t pos,
  74                                  size_t size)
  75{
  76    QIOChannel *ioc = QIO_CHANNEL(opaque);
  77    ssize_t ret;
  78
  79    do {
  80        ret = qio_channel_read(ioc, (char *)buf, size, NULL);
  81        if (ret < 0) {
  82            if (ret == QIO_CHANNEL_ERR_BLOCK) {
  83                qio_channel_yield(ioc, G_IO_IN);
  84            } else {
  85                /* XXX handle Error * object */
  86                return -EIO;
  87            }
  88        }
  89    } while (ret == QIO_CHANNEL_ERR_BLOCK);
  90
  91    return ret;
  92}
  93
  94
  95static int channel_close(void *opaque)
  96{
  97    QIOChannel *ioc = QIO_CHANNEL(opaque);
  98    qio_channel_close(ioc, NULL);
  99    object_unref(OBJECT(ioc));
 100    return 0;
 101}
 102
 103
 104static int channel_shutdown(void *opaque,
 105                            bool rd,
 106                            bool wr)
 107{
 108    QIOChannel *ioc = QIO_CHANNEL(opaque);
 109
 110    if (qio_channel_has_feature(ioc,
 111                                QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 112        QIOChannelShutdown mode;
 113        if (rd && wr) {
 114            mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 115        } else if (rd) {
 116            mode = QIO_CHANNEL_SHUTDOWN_READ;
 117        } else {
 118            mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 119        }
 120        if (qio_channel_shutdown(ioc, mode, NULL) < 0) {
 121            /* XXX handler Error * object */
 122            return -EIO;
 123        }
 124    }
 125    return 0;
 126}
 127
 128
 129static int channel_set_blocking(void *opaque,
 130                                bool enabled)
 131{
 132    QIOChannel *ioc = QIO_CHANNEL(opaque);
 133
 134    if (qio_channel_set_blocking(ioc, enabled, NULL) < 0) {
 135        return -1;
 136    }
 137    return 0;
 138}
 139
 140static QEMUFile *channel_get_input_return_path(void *opaque)
 141{
 142    QIOChannel *ioc = QIO_CHANNEL(opaque);
 143
 144    return qemu_fopen_channel_output(ioc);
 145}
 146
 147static QEMUFile *channel_get_output_return_path(void *opaque)
 148{
 149    QIOChannel *ioc = QIO_CHANNEL(opaque);
 150
 151    return qemu_fopen_channel_input(ioc);
 152}
 153
 154static const QEMUFileOps channel_input_ops = {
 155    .get_buffer = channel_get_buffer,
 156    .close = channel_close,
 157    .shut_down = channel_shutdown,
 158    .set_blocking = channel_set_blocking,
 159    .get_return_path = channel_get_input_return_path,
 160};
 161
 162
 163static const QEMUFileOps channel_output_ops = {
 164    .writev_buffer = channel_writev_buffer,
 165    .close = channel_close,
 166    .shut_down = channel_shutdown,
 167    .set_blocking = channel_set_blocking,
 168    .get_return_path = channel_get_output_return_path,
 169};
 170
 171
 172QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 173{
 174    object_ref(OBJECT(ioc));
 175    return qemu_fopen_ops(ioc, &channel_input_ops);
 176}
 177
 178QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 179{
 180    object_ref(OBJECT(ioc));
 181    return qemu_fopen_ops(ioc, &channel_output_ops);
 182}
 183