Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
[qemu.git] / io / channel-file.c
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 "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(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 Error **errp)
90 {
91 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
92 ssize_t ret;
93
94 retry:
95 ret = readv(fioc->fd, iov, niov);
96 if (ret < 0) {
97 if (errno == EAGAIN) {
98 return QIO_CHANNEL_ERR_BLOCK;
99 }
100 if (errno == EINTR) {
101 goto retry;
102 }
103
104 error_setg_errno(errp, errno,
105 "Unable to read from file");
106 return -1;
107 }
108
109 return ret;
110 }
111
112 static ssize_t qio_channel_file_writev(QIOChannel *ioc,
113 const struct iovec *iov,
114 size_t niov,
115 int *fds,
116 size_t nfds,
117 Error **errp)
118 {
119 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
120 ssize_t ret;
121
122 retry:
123 ret = writev(fioc->fd, iov, niov);
124 if (ret <= 0) {
125 if (errno == EAGAIN) {
126 return QIO_CHANNEL_ERR_BLOCK;
127 }
128 if (errno == EINTR) {
129 goto retry;
130 }
131 error_setg_errno(errp, errno,
132 "Unable to write to file");
133 return -1;
134 }
135 return ret;
136 }
137
138 static int qio_channel_file_set_blocking(QIOChannel *ioc,
139 bool enabled,
140 Error **errp)
141 {
142 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
143
144 if (enabled) {
145 qemu_set_block(fioc->fd);
146 } else {
147 qemu_set_nonblock(fioc->fd);
148 }
149 return 0;
150 }
151
152
153 static off_t qio_channel_file_seek(QIOChannel *ioc,
154 off_t offset,
155 int whence,
156 Error **errp)
157 {
158 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
159 off_t ret;
160
161 ret = lseek(fioc->fd, offset, whence);
162 if (ret == (off_t)-1) {
163 error_setg_errno(errp, errno,
164 "Unable to seek to offset %lld whence %d in file",
165 (long long int)offset, whence);
166 return -1;
167 }
168 return ret;
169 }
170
171
172 static int qio_channel_file_close(QIOChannel *ioc,
173 Error **errp)
174 {
175 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
176
177 if (qemu_close(fioc->fd) < 0) {
178 error_setg_errno(errp, errno,
179 "Unable to close file");
180 return -1;
181 }
182 fioc->fd = -1;
183 return 0;
184 }
185
186
187 static void qio_channel_file_set_aio_fd_handler(QIOChannel *ioc,
188 AioContext *ctx,
189 IOHandler *io_read,
190 IOHandler *io_write,
191 void *opaque)
192 {
193 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
194 aio_set_fd_handler(ctx, fioc->fd, false, io_read, io_write, NULL, opaque);
195 }
196
197 static GSource *qio_channel_file_create_watch(QIOChannel *ioc,
198 GIOCondition condition)
199 {
200 QIOChannelFile *fioc = QIO_CHANNEL_FILE(ioc);
201 return qio_channel_create_fd_watch(ioc,
202 fioc->fd,
203 condition);
204 }
205
206 static void qio_channel_file_class_init(ObjectClass *klass,
207 void *class_data G_GNUC_UNUSED)
208 {
209 QIOChannelClass *ioc_klass = QIO_CHANNEL_CLASS(klass);
210
211 ioc_klass->io_writev = qio_channel_file_writev;
212 ioc_klass->io_readv = qio_channel_file_readv;
213 ioc_klass->io_set_blocking = qio_channel_file_set_blocking;
214 ioc_klass->io_seek = qio_channel_file_seek;
215 ioc_klass->io_close = qio_channel_file_close;
216 ioc_klass->io_create_watch = qio_channel_file_create_watch;
217 ioc_klass->io_set_aio_fd_handler = qio_channel_file_set_aio_fd_handler;
218 }
219
220 static const TypeInfo qio_channel_file_info = {
221 .parent = TYPE_QIO_CHANNEL,
222 .name = TYPE_QIO_CHANNEL_FILE,
223 .instance_size = sizeof(QIOChannelFile),
224 .instance_init = qio_channel_file_init,
225 .instance_finalize = qio_channel_file_finalize,
226 .class_init = qio_channel_file_class_init,
227 };
228
229 static void qio_channel_file_register_types(void)
230 {
231 type_register_static(&qio_channel_file_info);
232 }
233
234 type_init(qio_channel_file_register_types);