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