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
  31
  32 static ssize_t channel_writev_buffer(void *opaque,
  33                                      struct iovec *iov,
  34                                      int iovcnt,
  35                                      int64_t pos,
  36                                      Error **errp)
  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, errp);
  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             done = -EIO;
  61             goto cleanup;
  62         }
  63
  64         iov_discard_front(&local_iov, &nlocal_iov, len);
  65         done += len;
  66     }
  67
  68  cleanup:
  69     g_free(local_iov_head);
  70     return done;
  71 }
  72
  73
  74 static ssize_t channel_get_buffer(void *opaque,
  75                                   uint8_t *buf,
  76                                   int64_t pos,
  77                                   size_t size,
  78                                   Error **errp)
  79 {
  80     QIOChannel *ioc = QIO_CHANNEL(opaque);
  81     ssize_t ret;
  82
  83     do {
  84         ret = qio_channel_read(ioc, (char *)buf, size, errp);
  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                 return -EIO;
  94             }
  95         }
  96     } while (ret == QIO_CHANNEL_ERR_BLOCK);
  97
  98     return ret;
  99 }
 100
 101
 102 static int channel_close(void *opaque, Error **errp)
 103 {
 104     int ret;
 105     QIOChannel *ioc = QIO_CHANNEL(opaque);
 106     ret = qio_channel_close(ioc, errp);
 107     object_unref(OBJECT(ioc));
 108     return ret;
 109 }
 110
 111
 112 static int channel_shutdown(void *opaque,
 113                             bool rd,
 114                             bool wr,
 115                             Error **errp)
 116 {
 117     QIOChannel *ioc = QIO_CHANNEL(opaque);
 118
 119     if (qio_channel_has_feature(ioc,
 120                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 121         QIOChannelShutdown mode;
 122         if (rd && wr) {
 123             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 124         } else if (rd) {
 125             mode = QIO_CHANNEL_SHUTDOWN_READ;
 126         } else {
 127             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 128         }
 129         if (qio_channel_shutdown(ioc, mode, errp) < 0) {
 130             return -EIO;
 131         }
 132     }
 133     return 0;
 134 }
 135
 136
 137 static int channel_set_blocking(void *opaque,
 138                                 bool enabled,
 139                                 Error **errp)
 140 {
 141     QIOChannel *ioc = QIO_CHANNEL(opaque);
 142
 143     if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
 144         return -1;
 145     }
 146     return 0;
 147 }
 148
 149 static QEMUFile *channel_get_input_return_path(void *opaque)
 150 {
 151     QIOChannel *ioc = QIO_CHANNEL(opaque);
 152
 153     return qemu_fopen_channel_output(ioc);
 154 }
 155
 156 static QEMUFile *channel_get_output_return_path(void *opaque)
 157 {
 158     QIOChannel *ioc = QIO_CHANNEL(opaque);
 159
 160     return qemu_fopen_channel_input(ioc);
 161 }
 162
 163 static const QEMUFileOps channel_input_ops = {
 164     .get_buffer = channel_get_buffer,
 165     .close = channel_close,
 166     .shut_down = channel_shutdown,
 167     .set_blocking = channel_set_blocking,
 168     .get_return_path = channel_get_input_return_path,
 169 };
 170
 171
 172 static const QEMUFileOps channel_output_ops = {
 173     .writev_buffer = channel_writev_buffer,
 174     .close = channel_close,
 175     .shut_down = channel_shutdown,
 176     .set_blocking = channel_set_blocking,
 177     .get_return_path = channel_get_output_return_path,
 178 };
 179
 180
 181 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 182 {
 183     object_ref(OBJECT(ioc));
 184     return qemu_fopen_ops(ioc, &channel_input_ops);
 185 }
 186
 187 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 188 {
 189     object_ref(OBJECT(ioc));
 190     return qemu_fopen_ops(ioc, &channel_output_ops);
 191 }