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             if (qemu_in_coroutine()) {
  53                 qio_channel_yield(ioc, G_IO_OUT);
  54             } else {
  55                 qio_channel_wait(ioc, G_IO_OUT);
  56             }
  57             continue;
  58         }
  59         if (len < 0) {
  60             /* XXX handle Error objects */
  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 {
  80     QIOChannel *ioc = QIO_CHANNEL(opaque);
  81     ssize_t ret;
  82
  83     do {
  84         ret = qio_channel_read(ioc, (char *)buf, size, NULL);
  85         if (ret < 0) {
  86             if (ret == QIO_CHANNEL_ERR_BLOCK) {
  87                 if (qemu_in_coroutine()) {
  88                     qio_channel_yield(ioc, G_IO_IN);
  89                 } else {
  90                     qio_channel_wait(ioc, G_IO_IN);
  91                 }
  92             } else {
  93                 /* XXX handle Error * object */
  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)
 104 {
 105     QIOChannel *ioc = QIO_CHANNEL(opaque);
 106     qio_channel_close(ioc, NULL);
 107     object_unref(OBJECT(ioc));
 108     return 0;
 109 }
 110
 111
 112 static int channel_shutdown(void *opaque,
 113                             bool rd,
 114                             bool wr)
 115 {
 116     QIOChannel *ioc = QIO_CHANNEL(opaque);
 117
 118     if (qio_channel_has_feature(ioc,
 119                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 120         QIOChannelShutdown mode;
 121         if (rd && wr) {
 122             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 123         } else if (rd) {
 124             mode = QIO_CHANNEL_SHUTDOWN_READ;
 125         } else {
 126             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 127         }
 128         if (qio_channel_shutdown(ioc, mode, NULL) < 0) {
 129             /* XXX handler Error * object */
 130             return -EIO;
 131         }
 132     }
 133     return 0;
 134 }
 135
 136
 137 static int channel_set_blocking(void *opaque,
 138                                 bool enabled)
 139 {
 140     QIOChannel *ioc = QIO_CHANNEL(opaque);
 141
 142     if (qio_channel_set_blocking(ioc, enabled, NULL) < 0) {
 143         return -1;
 144     }
 145     return 0;
 146 }
 147
 148 static QEMUFile *channel_get_input_return_path(void *opaque)
 149 {
 150     QIOChannel *ioc = QIO_CHANNEL(opaque);
 151
 152     return qemu_fopen_channel_output(ioc);
 153 }
 154
 155 static QEMUFile *channel_get_output_return_path(void *opaque)
 156 {
 157     QIOChannel *ioc = QIO_CHANNEL(opaque);
 158
 159     return qemu_fopen_channel_input(ioc);
 160 }
 161
 162 static const QEMUFileOps channel_input_ops = {
 163     .get_buffer = channel_get_buffer,
 164     .close = channel_close,
 165     .shut_down = channel_shutdown,
 166     .set_blocking = channel_set_blocking,
 167     .get_return_path = channel_get_input_return_path,
 168 };
 169
 170
 171 static const QEMUFileOps channel_output_ops = {
 172     .writev_buffer = channel_writev_buffer,
 173     .close = channel_close,
 174     .shut_down = channel_shutdown,
 175     .set_blocking = channel_set_blocking,
 176     .get_return_path = channel_get_output_return_path,
 177 };
 178
 179
 180 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 181 {
 182     object_ref(OBJECT(ioc));
 183     return qemu_fopen_ops(ioc, &channel_input_ops);
 184 }
 185
 186 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 187 {
 188     object_ref(OBJECT(ioc));
 189     return qemu_fopen_ops(ioc, &channel_output_ops);
 190 }