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56517bad PR |
1 | /* |
2 | * Copyright (C) 2011 Red Hat, Inc. All rights reserved. | |
3 | * | |
4 | * This file is part of LVM2. | |
5 | * | |
6 | * This copyrighted material is made available to anyone wishing to use, | |
7 | * modify, copy, or redistribute it subject to the terms and conditions | |
8 | * of the GNU Lesser General Public License v.2.1. | |
9 | * | |
10 | * You should have received a copy of the GNU Lesser General Public License | |
11 | * along with this program; if not, write to the Free Software Foundation, | |
12 | * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
13 | */ | |
14 | ||
dc85d3fb | 15 | #include "daemon-client.h" |
92658f56 | 16 | #include "config.h" // XXX will be in libdevmapper.h later |
dc85d3fb PR |
17 | |
18 | #ifndef _LVM_DAEMON_COMMON_SERVER_H | |
19 | #define _LVM_DAEMON_COMMON_SERVER_H | |
56517bad PR |
20 | |
21 | typedef struct { | |
22 | int socket_fd; /* the fd we use to talk to the client */ | |
23 | pthread_t thread_id; | |
24 | char *read_buf; | |
25 | void *private; /* this holds per-client state */ | |
26 | } client_handle; | |
27 | ||
28 | typedef struct { | |
55e30071 | 29 | struct config_tree *cft; |
92658f56 | 30 | char *buffer; |
dc85d3fb PR |
31 | } request; |
32 | ||
33 | typedef struct { | |
34 | int error; | |
55e30071 | 35 | struct config_tree *cft; |
92658f56 | 36 | char *buffer; |
dc85d3fb PR |
37 | } response; |
38 | ||
39 | struct daemon_state; | |
40 | ||
aaca7f11 PR |
41 | /* |
42 | * Craft a simple reply, without the need to construct a config_tree. See | |
43 | * daemon_send_simple in daemon-client.h for the description of the parameters. | |
44 | */ | |
45 | response daemon_reply_simple(char *id, ...); | |
46 | ||
94bb67ab PR |
47 | static inline int daemon_request_int(request r, const char *path, int def) { |
48 | return find_config_int(r.cft->root, path, def); | |
49 | } | |
50 | ||
51 | static inline const char *daemon_request_str(request r, const char *path, const char *def) { | |
52 | return find_config_str(r.cft->root, path, def); | |
53 | } | |
54 | ||
dc85d3fb PR |
55 | /* |
56 | * The callback. Called once per request issued, in the respective client's | |
57 | * thread. It is presented by a parsed request (in the form of a config tree). | |
58 | * The output is a new config tree that is serialised and sent back to the | |
59 | * client. The client blocks until the request processing is done and reply is | |
60 | * sent. | |
61 | */ | |
62 | typedef response (*handle_request)(struct daemon_state s, client_handle h, request r); | |
63 | ||
64 | typedef struct daemon_state { | |
d7448a72 PR |
65 | /* |
66 | * The maximal stack size for individual daemon threads. This is | |
67 | * essential for daemons that need to be locked into memory, since | |
68 | * pthread's default is 10M per thread. | |
69 | */ | |
70 | int thread_stack_size; | |
71 | ||
72 | /* Flags & attributes affecting the behaviour of the daemon. */ | |
73 | unsigned avoid_oom:1; | |
74 | unsigned foreground:1; | |
75 | const char *name; | |
76 | const char *pidfile; | |
73ffd6e7 | 77 | const char *socket_path; |
dc85d3fb PR |
78 | int log_level; |
79 | handle_request handler; | |
80 | int (*setup_post)(struct daemon_state *st); | |
73ffd6e7 PR |
81 | |
82 | /* Global runtime info maintained by the framework. */ | |
83 | int socket_fd; | |
d7448a72 | 84 | |
56517bad PR |
85 | void *private; /* the global daemon state */ |
86 | } daemon_state; | |
87 | ||
56517bad PR |
88 | /* |
89 | * Start serving the requests. This does all the daemonisation, socket setup | |
d7448a72 PR |
90 | * work and so on. This function takes over the process, and upon failure, it |
91 | * will terminate execution. It may be called at most once. | |
56517bad | 92 | */ |
dc85d3fb | 93 | void daemon_start(daemon_state s); |
56517bad PR |
94 | |
95 | /* | |
96 | * Take over from an already running daemon. This function handles connecting | |
97 | * to the running daemon and telling it we are going to take over. The takeover | |
98 | * request may be customised by passing in a non-NULL request. | |
99 | * | |
100 | * The takeover sequence: the old daemon stops accepting new clients, then it | |
101 | * waits until all current client connections are closed. When that happens, it | |
102 | * serializes its current state and sends that as a reply, which is then | |
103 | * returned by this function (therefore, this function won't return until the | |
104 | * previous instance has shut down). | |
105 | * | |
106 | * The daemon, after calling daemon_takeover is expected to set up its | |
107 | * daemon_state using the reply from this function and call daemon_start as | |
108 | * usual. | |
109 | */ | |
110 | daemon_reply daemon_takeover(daemon_info i, daemon_request r); | |
111 | ||
112 | /* Call this to request a clean shutdown of the daemon. Async safe. */ | |
113 | void daemon_stop(); | |
114 | ||
115 | #endif |