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     object_unref(OBJECT(ioc));
 111     return ret;
 112 }
 113
 114
 115 static int channel_shutdown(void *opaque,
 116                             bool rd,
 117                             bool wr,
 118                             Error **errp)
 119 {
 120     QIOChannel *ioc = QIO_CHANNEL(opaque);
 121
 122     if (qio_channel_has_feature(ioc,
 123                                 QIO_CHANNEL_FEATURE_SHUTDOWN)) {
 124         QIOChannelShutdown mode;
 125         if (rd && wr) {
 126             mode = QIO_CHANNEL_SHUTDOWN_BOTH;
 127         } else if (rd) {
 128             mode = QIO_CHANNEL_SHUTDOWN_READ;
 129         } else {
 130             mode = QIO_CHANNEL_SHUTDOWN_WRITE;
 131         }
 132         if (qio_channel_shutdown(ioc, mode, errp) < 0) {
 133             return -EIO;
 134         }
 135     }
 136     return 0;
 137 }
 138
 139
 140 static int channel_set_blocking(void *opaque,
 141                                 bool enabled,
 142                                 Error **errp)
 143 {
 144     QIOChannel *ioc = QIO_CHANNEL(opaque);
 145
 146     if (qio_channel_set_blocking(ioc, enabled, errp) < 0) {
 147         return -1;
 148     }
 149     return 0;
 150 }
 151
 152 static QEMUFile *channel_get_input_return_path(void *opaque)
 153 {
 154     QIOChannel *ioc = QIO_CHANNEL(opaque);
 155
 156     return qemu_fopen_channel_output(ioc);
 157 }
 158
 159 static QEMUFile *channel_get_output_return_path(void *opaque)
 160 {
 161     QIOChannel *ioc = QIO_CHANNEL(opaque);
 162
 163     return qemu_fopen_channel_input(ioc);
 164 }
 165
 166 static const QEMUFileOps channel_input_ops = {
 167     .get_buffer = channel_get_buffer,
 168     .close = channel_close,
 169     .shut_down = channel_shutdown,
 170     .set_blocking = channel_set_blocking,
 171     .get_return_path = channel_get_input_return_path,
 172 };
 173
 174
 175 static const QEMUFileOps channel_output_ops = {
 176     .writev_buffer = channel_writev_buffer,
 177     .close = channel_close,
 178     .shut_down = channel_shutdown,
 179     .set_blocking = channel_set_blocking,
 180     .get_return_path = channel_get_output_return_path,
 181 };
 182
 183
 184 QEMUFile *qemu_fopen_channel_input(QIOChannel *ioc)
 185 {
 186     object_ref(OBJECT(ioc));
 187     return qemu_fopen_ops(ioc, &channel_input_ops, true);
 188 }
 189
 190 QEMUFile *qemu_fopen_channel_output(QIOChannel *ioc)
 191 {
 192     object_ref(OBJECT(ioc));
 193     return qemu_fopen_ops(ioc, &channel_output_ops, true);
 194 }