xref: /openbmc/qemu/include/io/channel-command.h (revision 9f6df01d)
1 /*
2  * QEMU I/O channels external command 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 #ifndef QIO_CHANNEL_COMMAND_H
22 #define QIO_CHANNEL_COMMAND_H
23 
24 #include "io/channel.h"
25 #include "qom/object.h"
26 
27 #define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
28 OBJECT_DECLARE_SIMPLE_TYPE(QIOChannelCommand, QIO_CHANNEL_COMMAND)
29 
30 
31 
32 /**
33  * QIOChannelCommand:
34  *
35  * The QIOChannelCommand class provides a channel implementation
36  * that can transport data with an externally running command
37  * via its stdio streams.
38  */
39 
40 struct QIOChannelCommand {
41     QIOChannel parent;
42     int writefd;
43     int readfd;
44     pid_t pid;
45 };
46 
47 
48 /**
49  * qio_channel_command_new_pid:
50  * @writefd: the FD connected to the command's stdin
51  * @readfd: the FD connected to the command's stdout
52  * @pid: the PID of the running child command
53  * @errp: pointer to a NULL-initialized error object
54  *
55  * Create a channel for performing I/O with the
56  * previously spawned command identified by @pid.
57  * The two file descriptors provide the connection
58  * to command's stdio streams, either one or which
59  * may be -1 to indicate that stream is not open.
60  *
61  * The channel will take ownership of the process
62  * @pid and will kill it when closing the channel.
63  * Similarly it will take responsibility for
64  * closing the file descriptors @writefd and @readfd.
65  *
66  * Returns: the command channel object, or NULL on error
67  */
68 QIOChannelCommand *
69 qio_channel_command_new_pid(int writefd,
70                             int readfd,
71                             pid_t pid);
72 
73 /**
74  * qio_channel_command_new_spawn:
75  * @argv: the NULL terminated list of command arguments
76  * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
77  * @errp: pointer to a NULL-initialized error object
78  *
79  * Create a channel for performing I/O with the
80  * command to be spawned with arguments @argv.
81  *
82  * Returns: the command channel object, or NULL on error
83  */
84 QIOChannelCommand *
85 qio_channel_command_new_spawn(const char *const argv[],
86                               int flags,
87                               Error **errp);
88 
89 
90 #endif /* QIO_CHANNEL_COMMAND_H */
91