xref: /openbmc/qemu/include/io/channel-file.h (revision 4a09d0bb)
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 #ifndef QIO_CHANNEL_FILE_H
22 #define QIO_CHANNEL_FILE_H
23 
24 #include "io/channel.h"
25 
26 #define TYPE_QIO_CHANNEL_FILE "qio-channel-file"
27 #define QIO_CHANNEL_FILE(obj)                                     \
28     OBJECT_CHECK(QIOChannelFile, (obj), TYPE_QIO_CHANNEL_FILE)
29 
30 typedef struct QIOChannelFile QIOChannelFile;
31 
32 /**
33  * QIOChannelFile:
34  *
35  * The QIOChannelFile object provides a channel implementation
36  * that is able to perform I/O on block devices, character
37  * devices, FIFOs, pipes and plain files. While it is technically
38  * able to work on sockets too on the UNIX platform, this is not
39  * portable to Windows and lacks some extra sockets specific
40  * functionality. So the QIOChannelSocket object is recommended
41  * for that use case.
42  *
43  */
44 
45 struct QIOChannelFile {
46     QIOChannel parent;
47     int fd;
48 };
49 
50 
51 /**
52  * qio_channel_file_new_fd:
53  * @fd: the file descriptor
54  *
55  * Create a new IO channel object for a file represented
56  * by the @fd parameter. @fd can be associated with a
57  * block device, character device, fifo, pipe, or a
58  * regular file. For sockets, the QIOChannelSocket class
59  * should be used instead, as this provides greater
60  * functionality and cross platform portability.
61  *
62  * The channel will own the passed in file descriptor
63  * and will take responsibility for closing it, so the
64  * caller must not close it. If appropriate the caller
65  * should dup() its FD before opening the channel.
66  *
67  * Returns: the new channel object
68  */
69 QIOChannelFile *
70 qio_channel_file_new_fd(int fd);
71 
72 /**
73  * qio_channel_file_new_path:
74  * @fd: the file descriptor
75  * @flags: the open flags (O_RDONLY|O_WRONLY|O_RDWR, etc)
76  * @mode: the file creation mode if O_WRONLY is set in @flags
77  * @errp: pointer to initialized error object
78  *
79  * Create a new IO channel object for a file represented
80  * by the @path parameter. @path can point to any
81  * type of file on which sequential I/O can be
82  * performed, whether it be a plain file, character
83  * device or block device.
84  *
85  * Returns: the new channel object
86  */
87 QIOChannelFile *
88 qio_channel_file_new_path(const char *path,
89                           int flags,
90                           mode_t mode,
91                           Error **errp);
92 
93 #endif /* QIO_CHANNEL_FILE_H */
94