1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
/*
* Copyright (C) 2011-2012 Red Hat, Inc.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _LVM_DAEMON_CLIENT_H
#define _LVM_DAEMON_CLIENT_H
#include "libdaemon/client/config-util.h"
typedef struct {
int socket_fd; /* the fd we use to talk to the daemon */
const char *protocol;
int protocol_version; /* version of the protocol the daemon uses */
int error;
} daemon_handle;
typedef struct {
const char *path; /* the binary of the daemon */
const char *socket; /* path to the comms socket */
unsigned autostart:1; /* start the daemon if not running? */
/*
* If the following are not NULL/0, an attempt to talk to a daemon which
* uses a different protocol or version will fail.
*/
const char *protocol;
int protocol_version;
} daemon_info;
typedef struct {
struct buffer buffer;
/*
* The request looks like this:
* request = "id"
* arg_foo = "something"
* arg_bar = 3
* arg_wibble {
* something_special = "here"
* amount = 75
* knobs = [ "twiddle", "tweak" ]
* }
*/
struct dm_config_tree *cft;
} daemon_request;
typedef struct {
int error; /* 0 for success */
struct buffer buffer;
struct dm_config_tree *cft; /* parsed reply, if available */
} daemon_reply;
/*
* Open the communication channel to the daemon. If the daemon is not running,
* it may be autostarted based on the binary path provided in the info (this
* will only happen if autostart is set to true). If the call fails for any
* reason, daemon_handle_valid(h) for the response will return false. Otherwise,
* the connection is good to start serving requests.
*/
daemon_handle daemon_open(daemon_info i);
/*
* Send a request to the daemon, waiting for the reply. All communication with
* the daemon is synchronous. The function handles the IO details and parses the
* response, handling common error conditions. See "daemon_reply" for details.
*
* In case the request contains a non-NULL buffer pointer, this buffer is sent
* *verbatim* to the server. In this case, the cft pointer may be NULL (but will
* be ignored even if non-NULL). If the buffer is NULL, the cft is required to
* be a valid pointer, and is used to build up the request.
*/
daemon_reply daemon_send(daemon_handle h, daemon_request rq);
/*
* A simple interface to daemon_send. This function just takes the command id
* and possibly a list of parameters (of the form "name = %?", "value"). The
* type (string, integer) of the value is indicated by a character substituted
* for ? in %?: d for integer, s for string.
*/
daemon_reply daemon_send_simple(daemon_handle h, const char *id, ...);
daemon_reply daemon_send_simple_v(daemon_handle h, const char *id, va_list ap);
daemon_request daemon_request_make(const char *id);
int daemon_request_extend(daemon_request r, ...);
int daemon_request_extend_v(daemon_request r, va_list ap);
void daemon_request_destroy(daemon_request r);
void daemon_reply_destroy(daemon_reply r);
static inline int64_t daemon_reply_int(daemon_reply r, const char *path, int64_t def)
{
return dm_config_find_int64(r.cft->root, path, def);
}
static inline const char *daemon_reply_str(daemon_reply r, const char *path, const char *def)
{
return dm_config_find_str_allow_empty(r.cft->root, path, def);
}
/* Shut down the communication to the daemon. Compulsory. */
void daemon_close(daemon_handle h);
#endif
|
