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 "io/channel-file.h" 22 #include "io/channel-watch.h" 23 #include "qemu/sockets.h" 24 #include "trace.h" 25 26 QIOChannelFile * 27 qio_channel_file_new_fd(int fd) 28 { 29 QIOChannelFile *ioc; 30 31 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 32 33 ioc->fd = fd; 34 35 trace_qio_channel_file_new_fd(ioc, fd); 36 37 return ioc; 38 } 39 40 41 QIOChannelFile * 42 qio_channel_file_new_path(const char *path, 43 int flags, 44 mode_t mode, 45 Error **errp) 46 { 47 QIOChannelFile *ioc; 48 49 ioc = QIO_CHANNEL_FILE(object_new(TYPE_QIO_CHANNEL_FILE)); 50 51 if (flags & O_WRONLY) { 52 ioc->fd = open(path, flags, mode); 53 } else { 54 ioc->fd = open(path, flags); 55 } 56 if (ioc->fd < 0) { 57 object_unref(OBJECT(ioc)); 58 error_setg_errno(errp, errno, 59 "Unable to open %s", path); 60 return NULL; 61 } 62 63 trace_qio_channel_file_new_path(ioc, path, flags, mode, ioc->fd); 64 65 return ioc; 66 } 67 68 69 static void qio_channel_file_init(Object *obj) 70 { 71 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 72 ioc->fd = -1; 73 } 74 75 static void qio_channel_file_finalize(Object *obj) 76 { 77 QIOChannelFile *ioc = QIO_CHANNEL_FILE(obj); 78 if (ioc->fd != -1) { 79 close(ioc->fd); 80 ioc->fd = -1; 81 } 82 } 83 84 85 static ssize_t qio_channel_file_readv(QIOChannel *ioc, 86 const struct iovec *iov, 87 size_t niov, 88 int **fds, 89 size_t *nfds, 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 errno == EWOULDBLOCK) { 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 errno == EWOULDBLOCK) { 129 return QIO_CHANNEL_ERR_BLOCK; 130 } 131 if (errno == EINTR) { 132 goto retry; 133 } 134 error_setg_errno(errp, errno, 135 "Unable to write to file"); 136 return -1; 137 } 138 return ret; 139 } 140 141 static int qio_channel_file_set_blocking(QIOChannel *ioc, 142 bool enabled, 143 Error **errp) 144 { 145 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 146 147 if (enabled) { 148 qemu_set_block(fioc->fd); 149 } else { 150 qemu_set_nonblock(fioc->fd); 151 } 152 return 0; 153 } 154 155 156 static off_t qio_channel_file_seek(QIOChannel *ioc, 157 off_t offset, 158 int whence, 159 Error **errp) 160 { 161 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 162 off_t ret; 163 164 ret = lseek(fioc->fd, offset, whence); 165 if (ret == (off_t)-1) { 166 error_setg_errno(errp, errno, 167 "Unable to seek to offset %lld whence %d in file", 168 (long long int)offset, whence); 169 return -1; 170 } 171 return ret; 172 } 173 174 175 static int qio_channel_file_close(QIOChannel *ioc, 176 Error **errp) 177 { 178 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 179 180 if (close(fioc->fd) < 0) { 181 error_setg_errno(errp, errno, 182 "Unable to close file"); 183 return -1; 184 } 185 return 0; 186 } 187 188 189 static GSource *qio_channel_file_create_watch(QIOChannel *ioc, 190 GIOCondition condition) 191 { 192 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc); 193 return qio_channel_create_fd_watch(ioc, 194 fioc->fd, 195 condition); 196 } 197 198 static void qio_channel_file_class_init(ObjectClass *klass, 199 void *class_data G_GNUC_UNUSED) 200 { 201 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass); 202 203 ioc_klass->io_writev = qio_channel_file_writev; 204 ioc_klass->io_readv = qio_channel_file_readv; 205 ioc_klass->io_set_blocking = qio_channel_file_set_blocking; 206 ioc_klass->io_seek = qio_channel_file_seek; 207 ioc_klass->io_close = qio_channel_file_close; 208 ioc_klass->io_create_watch = qio_channel_file_create_watch; 209 } 210 211 static const TypeInfo qio_channel_file_info = { 212 .parent = TYPE_QIO_CHANNEL, 213 .name = TYPE_QIO_CHANNEL_FILE, 214 .instance_size = sizeof(QIOChannelFile), 215 .instance_init = qio_channel_file_init, 216 .instance_finalize = qio_channel_file_finalize, 217 .class_init = qio_channel_file_class_init, 218 }; 219 220 static void qio_channel_file_register_types(void) 221 { 222 type_register_static(&qio_channel_file_info); 223 } 224 225 type_init(qio_channel_file_register_types); 226