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 "qemu-file.h"
  28 #include "io/channel-socket.h"
  29 #include "qemu/iov.h"
  30 #include "qemu/yank.h"
  31
  32
  33 static ssize_t channel_writev_buffer(void *opaque,
  34                                      struct iovec *iov,
  35                                      int iovcnt,
  36                                      int64_t pos,
  37                                      Error **errp)
  38 {
  39     QIOChannel *ioc = QIO_CHANNEL(opaque);
  40     ssize_t done = 0;
  41     struct iovec *local_iov = g_new(struct iovec, iovcnt);
  42     struct iovec *local_iov_head = local_iov;
  43     unsigned int nlocal_iov = iovcnt;
  44
  45     nlocal_iov = iov_copy(local_iov, nlocal_iov,
  46                           iov, iovcnt,
  47                           0, iov_size(iov, iovcnt));
  48
  49     while (nlocal_iov > 0) {
  50         ssize_t len;
  51         len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
  52         if (len == QIO_CHANNEL_ERR_BLOCK) {
  53             if (qemu_in_coroutine()) {
  54                 qio_channel_yield(ioc, G_IO_OUT);
  55             } else {
  56                 qio_channel_wait(ioc, G_IO_OUT);
  57             }
  58             continue;
  59         }
  60         if (len < 0) {
  61             done = -EIO;
  62             goto cleanup;
  63         }
  64
  65         iov_discard_front(&local_iov, &nlocal_iov, len);
  66         done += len;
  67     }
  68
  69  cleanup:
  70     g_free(local_iov_head);
  71     return done;
  72 }
  73
  74
  75 static ssize_t channel_get_buffer(void *opaque,
  76                                   uint8_t *buf,
  77                                   int64_t pos,
  78                                   size_t size,
  79                                   Error **errp)
  80 {
  81     QIOChannel *ioc = QIO_CHANNEL(opaque);
  82     ssize_t ret;
  83
  84     do {
  85         ret = qio_channel_read(ioc, (char *)buf, size, errp);
  86         if (ret < 0) {
  87             if (ret == QIO_CHANNEL_ERR_BLOCK) {
  88                 if (qemu_in_coroutine()) {
  89                     qio_channel_yield(ioc, G_IO_IN);
  90                 } else {
  91                     qio_channel_wait(ioc, G_IO_IN);
  92                 }
  93             } else {
  94                 return -EIO;
  95             }
  96         }
  97     } while (ret == QIO_CHANNEL_ERR_BLOCK);
  98
  99     return ret;
 100 }
 101
 102
 103 static int channel_close(void *opaque, Error **errp)
 104 {
 105     int ret;
 106     QIOChannel *ioc = QIO_CHANNEL(opaque);
 107     ret = qio_channel_close(ioc, errp);
 108     if (object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET)
 109         && OBJECT(ioc)->ref == 1) {
 110         yank_unregister_function(MIGRATION_YANK_INSTANCE,
 111                                  yank_generic_iochannel,
 112                                  QIO_CHANNEL(ioc));
 113     }
 114     object_unref(OBJECT(ioc));
 115     return ret;
 116 }
 117
 118
 119 static int channel_shutdown(void *opaque,
 120                             bool rd,
 121                             bool wr,
 122                             Error **errp)
 123 {
 124     QIOChannel *ioc = QIO_CHANNEL(opaque);
 125
 126     if (qio_channel_has_feature(ioc,
 127                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 128         QIOChannelShutdown mode;
 129         if (rd && wr) {
 130             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 131         } else if (rd) {
 132             mode = QIO_CHANNEL_SHUTDOWN_READ;
 133         } else {
 134             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 135         }
 136         if (qio_channel_shutdown(ioc, mode, errp) < 0) {
 137             return -EIO;
 138         }
 139     }
 140     return 0;
 141 }
 142
 143
 144 static int channel_set_blocking(void *opaque,
 145                                 bool enabled,
 146                                 Error **errp)
 147 {
 148     QIOChannel *ioc = QIO_CHANNEL(opaque);
 149
 150     if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
 151         return -1;
 152     }
 153     return 0;
 154 }
 155
 156 static QEMUFile *channel_get_input_return_path(void *opaque)
 157 {
 158     QIOChannel *ioc = QIO_CHANNEL(opaque);
 159
 160     return qemu_fopen_channel_output(ioc);
 161 }
 162
 163 static QEMUFile *channel_get_output_return_path(void *opaque)
 164 {
 165     QIOChannel *ioc = QIO_CHANNEL(opaque);
 166
 167     return qemu_fopen_channel_input(ioc);
 168 }
 169
 170 static const QEMUFileOps channel_input_ops = {
 171     .get_buffer = channel_get_buffer,
 172     .close = channel_close,
 173     .shut_down = channel_shutdown,
 174     .set_blocking = channel_set_blocking,
 175     .get_return_path = channel_get_input_return_path,
 176 };
 177
 178
 179 static const QEMUFileOps channel_output_ops = {
 180     .writev_buffer = channel_writev_buffer,
 181     .close = channel_close,
 182     .shut_down = channel_shutdown,
 183     .set_blocking = channel_set_blocking,
 184     .get_return_path = channel_get_output_return_path,
 185 };
 186
 187
 188 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 189 {
 190     object_ref(OBJECT(ioc));
 191     return qemu_fopen_ops(ioc, &channel_input_ops);
 192 }
 193
 194 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 195 {
 196     object_ref(OBJECT(ioc));
 197     return qemu_fopen_ops(ioc, &channel_output_ops);
 198 }