xref: /openbmc/qemu/include/io/channel-command.h (revision 84a3a53c)
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 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 
26 #define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
27 #define QIO_CHANNEL_COMMAND(obj)                                     \
28     OBJECT_CHECK(QIOChannelCommand, (obj), TYPE_QIO_CHANNEL_COMMAND)
29 
30 typedef struct QIOChannelCommand QIOChannelCommand;
31 
32 
33 /**
34  * QIOChannelCommand:
35  *
36  * The QIOChannelCommand class provides a channel implementation
37  * that can transport data with an externally running command
38  * via its stdio streams.
39  */
40 
41 struct QIOChannelCommand {
42     QIOChannel parent;
43     int writefd;
44     int readfd;
45     pid_t pid;
46 };
47 
48 
49 /**
50  * qio_channel_command_new_pid:
51  * @writefd: the FD connected to the command's stdin
52  * @readfd: the FD connected to the command's stdout
53  * @pid: the PID of the running child command
54  * @errp: pointer to an uninitialized error object
55  *
56  * Create a channel for performing I/O with the
57  * previously spawned command identified by @pid.
58  * The two file descriptors provide the connection
59  * to command's stdio streams, either one or which
60  * may be -1 to indicate that stream is not open.
61  *
62  * The channel will take ownership of the process
63  * @pid and will kill it when closing the channel.
64  * Similarly it will take responsibility for
65  * closing the file descriptors @writefd and @readfd.
66  *
67  * Returns: the command channel object, or NULL on error
68  */
69 QIOChannelCommand *
70 qio_channel_command_new_pid(int writefd,
71                             int readfd,
72                             pid_t pid);
73 
74 /**
75  * qio_channel_command_new_spawn:
76  * @argv: the NULL terminated list of command arguments
77  * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
78  * @errp: pointer to an uninitialized error object
79  *
80  * Create a channel for performing I/O with the
81  * command to be spawned with arguments @argv.
82  *
83  * Returns: the command channel object, or NULL on error
84  */
85 QIOChannelCommand *
86 qio_channel_command_new_spawn(const char *const argv[],
87                               int flags,
88                               Error **errp);
89 
90 
91 #endif /* QIO_CHANNEL_COMMAND_H__ */
92