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
  33 static 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
  71 static 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
  95 static 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
 104 static 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
 129 static 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
 140 static 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
 147 static 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
 154 static 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
 163 static 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
 172 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 173 {
 174     object_ref(OBJECT(ioc));
 175     return qemu_fopen_ops(ioc, &channel_input_ops);
 176 }
 177
 178 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 179 {
 180     object_ref(OBJECT(ioc));
 181     return qemu_fopen_ops(ioc, &channel_output_ops);
 182 }