xref: /openbmc/qemu/include/io/channel-command.h (revision 8fa3b702)
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 #include "qom/object.h"
26 
27 #define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
28 typedef struct QIOChannelCommand QIOChannelCommand;
29 DECLARE_INSTANCE_CHECKER(QIOChannelCommand, QIO_CHANNEL_COMMAND,
30                          TYPE_QIO_CHANNEL_COMMAND)
31 
32 
33 
34 /**
35  * QIOChannelCommand:
36  *
37  * The QIOChannelCommand class provides a channel implementation
38  * that can transport data with an externally running command
39  * via its stdio streams.
40  */
41 
42 struct QIOChannelCommand {
43     QIOChannel parent;
44     int writefd;
45     int readfd;
46     pid_t pid;
47 };
48 
49 
50 /**
51  * qio_channel_command_new_pid:
52  * @writefd: the FD connected to the command's stdin
53  * @readfd: the FD connected to the command's stdout
54  * @pid: the PID of the running child command
55  * @errp: pointer to a NULL-initialized error object
56  *
57  * Create a channel for performing I/O with the
58  * previously spawned command identified by @pid.
59  * The two file descriptors provide the connection
60  * to command's stdio streams, either one or which
61  * may be -1 to indicate that stream is not open.
62  *
63  * The channel will take ownership of the process
64  * @pid and will kill it when closing the channel.
65  * Similarly it will take responsibility for
66  * closing the file descriptors @writefd and @readfd.
67  *
68  * Returns: the command channel object, or NULL on error
69  */
70 QIOChannelCommand *
71 qio_channel_command_new_pid(int writefd,
72                             int readfd,
73                             pid_t pid);
74 
75 /**
76  * qio_channel_command_new_spawn:
77  * @argv: the NULL terminated list of command arguments
78  * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
79  * @errp: pointer to a NULL-initialized error object
80  *
81  * Create a channel for performing I/O with the
82  * command to be spawned with arguments @argv.
83  *
84  * Returns: the command channel object, or NULL on error
85  */
86 QIOChannelCommand *
87 qio_channel_command_new_spawn(const char *const argv[],
88                               int flags,
89                               Error **errp);
90 
91 
92 #endif /* QIO_CHANNEL_COMMAND_H */
93