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 "io/channel-tls.h"
  30 #include "qemu/iov.h"
  31 #include "qemu/yank.h"
  32 #include "yank_functions.h"
  33
  34
  35 static ssize_t channel_writev_buffer(void *opaque,
  36                                      struct iovec *iov,
  37                                      int iovcnt,
  38                                      int64_t pos,
  39                                      Error **errp)
  40 {
  41     QIOChannel *ioc = QIO_CHANNEL(opaque);
  42     ssize_t done = 0;
  43     struct iovec *local_iov = g_new(struct iovec, iovcnt);
  44     struct iovec *local_iov_head = local_iov;
  45     unsigned int nlocal_iov = iovcnt;
  46
  47     nlocal_iov = iov_copy(local_iov, nlocal_iov,
  48                           iov, iovcnt,
  49                           0, iov_size(iov, iovcnt));
  50
  51     while (nlocal_iov > 0) {
  52         ssize_t len;
  53         len = qio_channel_writev(ioc, local_iov, nlocal_iov, errp);
  54         if (len == QIO_CHANNEL_ERR_BLOCK) {
  55             if (qemu_in_coroutine()) {
  56                 qio_channel_yield(ioc, G_IO_OUT);
  57             } else {
  58                 qio_channel_wait(ioc, G_IO_OUT);
  59             }
  60             continue;
  61         }
  62         if (len < 0) {
  63             done = -EIO;
  64             goto cleanup;
  65         }
  66
  67         iov_discard_front(&local_iov, &nlocal_iov, len);
  68         done += len;
  69     }
  70
  71  cleanup:
  72     g_free(local_iov_head);
  73     return done;
  74 }
  75
  76
  77 static ssize_t channel_get_buffer(void *opaque,
  78                                   uint8_t *buf,
  79                                   int64_t pos,
  80                                   size_t size,
  81                                   Error **errp)
  82 {
  83     QIOChannel *ioc = QIO_CHANNEL(opaque);
  84     ssize_t ret;
  85
  86     do {
  87         ret = qio_channel_read(ioc, (char *)buf, size, errp);
  88         if (ret < 0) {
  89             if (ret == QIO_CHANNEL_ERR_BLOCK) {
  90                 if (qemu_in_coroutine()) {
  91                     qio_channel_yield(ioc, G_IO_IN);
  92                 } else {
  93                     qio_channel_wait(ioc, G_IO_IN);
  94                 }
  95             } else {
  96                 return -EIO;
  97             }
  98         }
  99     } while (ret == QIO_CHANNEL_ERR_BLOCK);
 100
 101     return ret;
 102 }
 103
 104
 105 static int channel_close(void *opaque, Error **errp)
 106 {
 107     int ret;
 108     QIOChannel *ioc = QIO_CHANNEL(opaque);
 109     ret = qio_channel_close(ioc, errp);
 110     if ((object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_SOCKET) ||
 111          object_dynamic_cast(OBJECT(ioc), TYPE_QIO_CHANNEL_TLS))
 112         && OBJECT(ioc)->ref == 1) {
 113         yank_unregister_function(MIGRATION_YANK_INSTANCE,
 114                                  migration_yank_iochannel,
 115                                  QIO_CHANNEL(ioc));
 116     }
 117     object_unref(OBJECT(ioc));
 118     return ret;
 119 }
 120
 121
 122 static int channel_shutdown(void *opaque,
 123                             bool rd,
 124                             bool wr,
 125                             Error **errp)
 126 {
 127     QIOChannel *ioc = QIO_CHANNEL(opaque);
 128
 129     if (qio_channel_has_feature(ioc,
 130                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 131         QIOChannelShutdown mode;
 132         if (rd && wr) {
 133             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 134         } else if (rd) {
 135             mode = QIO_CHANNEL_SHUTDOWN_READ;
 136         } else {
 137             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 138         }
 139         if (qio_channel_shutdown(ioc, mode, errp) < 0) {
 140             return -EIO;
 141         }
 142     }
 143     return 0;
 144 }
 145
 146
 147 static int channel_set_blocking(void *opaque,
 148                                 bool enabled,
 149                                 Error **errp)
 150 {
 151     QIOChannel *ioc = QIO_CHANNEL(opaque);
 152
 153     if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
 154         return -1;
 155     }
 156     return 0;
 157 }
 158
 159 static QEMUFile *channel_get_input_return_path(void *opaque)
 160 {
 161     QIOChannel *ioc = QIO_CHANNEL(opaque);
 162
 163     return qemu_fopen_channel_output(ioc);
 164 }
 165
 166 static QEMUFile *channel_get_output_return_path(void *opaque)
 167 {
 168     QIOChannel *ioc = QIO_CHANNEL(opaque);
 169
 170     return qemu_fopen_channel_input(ioc);
 171 }
 172
 173 static const QEMUFileOps channel_input_ops = {
 174     .get_buffer = channel_get_buffer,
 175     .close = channel_close,
 176     .shut_down = channel_shutdown,
 177     .set_blocking = channel_set_blocking,
 178     .get_return_path = channel_get_input_return_path,
 179 };
 180
 181
 182 static const QEMUFileOps channel_output_ops = {
 183     .writev_buffer = channel_writev_buffer,
 184     .close = channel_close,
 185     .shut_down = channel_shutdown,
 186     .set_blocking = channel_set_blocking,
 187     .get_return_path = channel_get_output_return_path,
 188 };
 189
 190
 191 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 192 {
 193     object_ref(OBJECT(ioc));
 194     return qemu_fopen_ops(ioc, &channel_input_ops);
 195 }
 196
 197 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 198 {
 199     object_ref(OBJECT(ioc));
 200     return qemu_fopen_ops(ioc, &channel_output_ops);
 201 }