1 /* 2 * QEMU I/O channels files driver 3 * 4 * Copyright (c) 2015 Red Hat, Inc. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21 #include "qemu/osdep.h" 22 #include "io/channel-file.h" 23 #include "io/channel-watch.h" 24 #include "qapi/error.h" 25 #include "qemu/module.h" 26 #include "qemu/sockets.h" 27 #include "trace.h" 28 29 QIOChannelFile * 30 qio_channel_file_new_fd(int fd) 31 { 32 QIOChannelFile *ioc; 33 34 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 35 36 ioc->fd = fd; 37 38 trace_qio_channel_file_new_fd(ioc, fd); 39 40 return ioc; 41 } 42 43 44 QIOChannelFile * 45 qio_channel_file_new_path(const char *path, 46 int flags, 47 mode_t mode, 48 Error **errp) 49 { 50 QIOChannelFile *ioc; 51 52 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 53 54 ioc->fd = qemu_open_old(path, flags, mode); 55 if (ioc->fd < 0) { 56 object_unref(OBJECT(ioc)); 57 error_setg_errno(errp, errno, 58 "Unable to open %s", path); 59 return NULL; 60 } 61 62 trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd); 63 64 return ioc; 65 } 66 67 68 static void qio_channel_file_init(Object *obj) 69 { 70 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 71 ioc->fd = -1; 72 } 73 74 static void qio_channel_file_finalize(Object *obj) 75 { 76 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 77 if (ioc->fd != -1) { 78 qemu_close(ioc->fd); 79 ioc->fd = -1; 80 } 81 } 82 83 84 static ssize_t qio_channel_file_readv(QIOChannel *ioc, 85 const struct iovec *iov, 86 size_t niov, 87 int **fds, 88 size_t *nfds, 89 int flags, 90 Error **errp) 91 { 92 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 93 ssize_t ret; 94 95 retry: 96 ret = readv(fioc->fd, iov, niov); 97 if (ret < 0) { 98 if (errno == EAGAIN) { 99 return QIO_CHANNEL_ERR_BLOCK; 100 } 101 if (errno == EINTR) { 102 goto retry; 103 } 104 105 error_setg_errno(errp, errno, 106 "Unable to read from file"); 107 return -1; 108 } 109 110 return ret; 111 } 112 113 static ssize_t qio_channel_file_writev(QIOChannel *ioc, 114 const struct iovec *iov, 115 size_t niov, 116 int *fds, 117 size_t nfds, 118 int flags, 119 Error **errp) 120 { 121 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 122 ssize_t ret; 123 124 retry: 125 ret = writev(fioc->fd, iov, niov); 126 if (ret <= 0) { 127 if (errno == EAGAIN) { 128 return QIO_CHANNEL_ERR_BLOCK; 129 } 130 if (errno == EINTR) { 131 goto retry; 132 } 133 error_setg_errno(errp, errno, 134 "Unable to write to file"); 135 return -1; 136 } 137 return ret; 138 } 139 140 static int qio_channel_file_set_blocking(QIOChannel *ioc, 141 bool enabled, 142 Error **errp) 143 { 144 #ifdef WIN32 145 /* not implemented */ 146 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 147 return -1; 148 #else 149 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 150 151 if (!g_unix_set_fd_nonblocking(fioc->fd, !enabled, NULL)) { 152 error_setg_errno(errp, errno, "Failed to set FD nonblocking"); 153 return -1; 154 } 155 return 0; 156 #endif 157 } 158 159 160 static off_t qio_channel_file_seek(QIOChannel *ioc, 161 off_t offset, 162 int whence, 163 Error **errp) 164 { 165 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 166 off_t ret; 167 168 ret = lseek(fioc->fd, offset, whence); 169 if (ret == (off_t)-1) { 170 error_setg_errno(errp, errno, 171 "Unable to seek to offset %lld whence %d in file", 172 (long long int)offset, whence); 173 return -1; 174 } 175 return ret; 176 } 177 178 179 static int qio_channel_file_close(QIOChannel *ioc, 180 Error **errp) 181 { 182 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 183 184 if (qemu_close(fioc->fd) < 0) { 185 error_setg_errno(errp, errno, 186 "Unable to close file"); 187 return -1; 188 } 189 fioc->fd = -1; 190 return 0; 191 } 192 193 194 static void qio_channel_file_set_aio_fd_handler(QIOChannel *ioc, 195 AioContext *ctx, 196 IOHandler *io_read, 197 IOHandler *io_write, 198 void *opaque) 199 { 200 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 201 aio_set_fd_handler(ctx, fioc->fd, false, io_read, io_write, 202 NULL, NULL, opaque); 203 } 204 205 static GSource *qio_channel_file_create_watch(QIOChannel *ioc, 206 GIOCondition condition) 207 { 208 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 209 return qio_channel_create_fd_watch(ioc, 210 fioc->fd, 211 condition); 212 } 213 214 static void qio_channel_file_class_init(ObjectClass *klass, 215 void *class_data G_GNUC_UNUSED) 216 { 217 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); 218 219 ioc_klass->io_writev = qio_channel_file_writev; 220 ioc_klass->io_readv = qio_channel_file_readv; 221 ioc_klass->io_set_blocking = qio_channel_file_set_blocking; 222 ioc_klass->io_seek = qio_channel_file_seek; 223 ioc_klass->io_close = qio_channel_file_close; 224 ioc_klass->io_create_watch = qio_channel_file_create_watch; 225 ioc_klass->io_set_aio_fd_handler = qio_channel_file_set_aio_fd_handler; 226 } 227 228 static const TypeInfo qio_channel_file_info = { 229 .parent = TYPE_QIO_CHANNEL, 230 .name = TYPE_QIO_CHANNEL_FILE, 231 .instance_size = sizeof(QIOChannelFile), 232 .instance_init = qio_channel_file_init, 233 .instance_finalize = qio_channel_file_finalize, 234 .class_init = qio_channel_file_class_init, 235 }; 236 237 static void qio_channel_file_register_types(void) 238 { 239 type_register_static(&qio_channel_file_info); 240 } 241 242 type_init(qio_channel_file_register_types); 243