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 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 "qemu/sockets.h" 25 #include "trace.h" 26 27 QIOChannelFile * 28 qio_channel_file_new_fd(int fd) 29 { 30 QIOChannelFile *ioc; 31 32 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 33 34 ioc->fd = fd; 35 36 trace_qio_channel_file_new_fd(ioc, fd); 37 38 return ioc; 39 } 40 41 42 QIOChannelFile * 43 qio_channel_file_new_path(const char *path, 44 int flags, 45 mode_t mode, 46 Error **errp) 47 { 48 QIOChannelFile *ioc; 49 50 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 51 52 if (flags & O_WRONLY) { 53 ioc->fd = open(path, flags, mode); 54 } else { 55 ioc->fd = open(path, flags); 56 } 57 if (ioc->fd < 0) { 58 object_unref(OBJECT(ioc)); 59 error_setg_errno(errp, errno, 60 "Unable to open %s", path); 61 return NULL; 62 } 63 64 trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd); 65 66 return ioc; 67 } 68 69 70 static void qio_channel_file_init(Object *obj) 71 { 72 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 73 ioc->fd = -1; 74 } 75 76 static void qio_channel_file_finalize(Object *obj) 77 { 78 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 79 if (ioc->fd != -1) { 80 close(ioc->fd); 81 ioc->fd = -1; 82 } 83 } 84 85 86 static ssize_t qio_channel_file_readv(QIOChannel *ioc, 87 const struct iovec *iov, 88 size_t niov, 89 int **fds, 90 size_t *nfds, 91 Error **errp) 92 { 93 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 94 ssize_t ret; 95 96 retry: 97 ret = readv(fioc->fd, iov, niov); 98 if (ret < 0) { 99 if (errno == EAGAIN) { 100 return QIO_CHANNEL_ERR_BLOCK; 101 } 102 if (errno == EINTR) { 103 goto retry; 104 } 105 106 error_setg_errno(errp, errno, 107 "Unable to read from file"); 108 return -1; 109 } 110 111 return ret; 112 } 113 114 static ssize_t qio_channel_file_writev(QIOChannel *ioc, 115 const struct iovec *iov, 116 size_t niov, 117 int *fds, 118 size_t nfds, 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 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 145 146 if (enabled) { 147 qemu_set_block(fioc->fd); 148 } else { 149 qemu_set_nonblock(fioc->fd); 150 } 151 return 0; 152 } 153 154 155 static off_t qio_channel_file_seek(QIOChannel *ioc, 156 off_t offset, 157 int whence, 158 Error **errp) 159 { 160 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 161 off_t ret; 162 163 ret = lseek(fioc->fd, offset, whence); 164 if (ret == (off_t)-1) { 165 error_setg_errno(errp, errno, 166 "Unable to seek to offset %lld whence %d in file", 167 (long long int)offset, whence); 168 return -1; 169 } 170 return ret; 171 } 172 173 174 static int qio_channel_file_close(QIOChannel *ioc, 175 Error **errp) 176 { 177 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 178 179 if (close(fioc->fd) < 0) { 180 error_setg_errno(errp, errno, 181 "Unable to close file"); 182 return -1; 183 } 184 return 0; 185 } 186 187 188 static GSource *qio_channel_file_create_watch(QIOChannel *ioc, 189 GIOCondition condition) 190 { 191 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 192 return qio_channel_create_fd_watch(ioc, 193 fioc->fd, 194 condition); 195 } 196 197 static void qio_channel_file_class_init(ObjectClass *klass, 198 void *class_data G_GNUC_UNUSED) 199 { 200 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); 201 202 ioc_klass->io_writev = qio_channel_file_writev; 203 ioc_klass->io_readv = qio_channel_file_readv; 204 ioc_klass->io_set_blocking = qio_channel_file_set_blocking; 205 ioc_klass->io_seek = qio_channel_file_seek; 206 ioc_klass->io_close = qio_channel_file_close; 207 ioc_klass->io_create_watch = qio_channel_file_create_watch; 208 } 209 210 static const TypeInfo qio_channel_file_info = { 211 .parent = TYPE_QIO_CHANNEL, 212 .name = TYPE_QIO_CHANNEL_FILE, 213 .instance_size = sizeof(QIOChannelFile), 214 .instance_init = qio_channel_file_init, 215 .instance_finalize = qio_channel_file_finalize, 216 .class_init = qio_channel_file_class_init, 217 }; 218 219 static void qio_channel_file_register_types(void) 220 { 221 type_register_static(&qio_channel_file_info); 222 } 223 224 type_init(qio_channel_file_register_types); 225