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