xref: /linux/include/net/9p/transport.h (revision 5f4123be3cdb1dbd77fa9d6d2bb96bb9689a0a19)
1 /*
2  * include/net/9p/transport.h
3  *
4  * Transport Definition
5  *
6  *  Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
7  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #ifndef NET_9P_TRANSPORT_H
27 #define NET_9P_TRANSPORT_H
28 
29 #include <linux/module.h>
30 
31 /**
32  * enum p9_trans_status - different states of underlying transports
33  * @Connected: transport is connected and healthy
34  * @Disconnected: transport has been disconnected
35  * @Hung: transport is connected by wedged
36  *
37  * This enumeration details the various states a transport
38  * instatiation can be in.
39  */
40 
41 enum p9_trans_status {
42 	Connected,
43 	Disconnected,
44 	Hung,
45 };
46 
47 /**
48  * struct p9_trans - per-transport state and API
49  * @status: transport &p9_trans_status
50  * @msize: negotiated maximum packet size (duplicate from client)
51  * @extended: negotiated protocol extensions (duplicate from client)
52  * @priv: transport private data
53  * @close: member function to disconnect and close the transport
54  * @rpc: member function to issue a request to the transport
55  *
56  * This is the basic API for a transport instance.  It is used as
57  * a handle by the client to issue requests.  This interface is currently
58  * in flux during reorganization.
59  *
60  * Bugs: there is lots of duplicated data here and its not clear that
61  * the member functions need to be per-instance versus per transport
62  * module.
63  */
64 
65 struct p9_trans {
66 	enum p9_trans_status status;
67 	int msize;
68 	unsigned char extended;
69 	void *priv;
70 	void (*close) (struct p9_trans *);
71 	int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
72 							struct p9_fcall **rc);
73 };
74 
75 /**
76  * struct p9_trans_module - transport module interface
77  * @list: used to maintain a list of currently available transports
78  * @name: the human-readable name of the transport
79  * @maxsize: transport provided maximum packet size
80  * @def: set if this transport should be considered the default
81  * @create: member function to create a new connection on this transport
82  *
83  * This is the basic API for a transport module which is registered by the
84  * transport module with the 9P core network module and used by the client
85  * to instantiate a new connection on a transport.
86  *
87  * Bugs: the transport module list isn't protected.
88  */
89 
90 struct p9_trans_module {
91 	struct list_head list;
92 	char *name;		/* name of transport */
93 	int maxsize;		/* max message size of transport */
94 	int def;		/* this transport should be default */
95 	struct p9_trans * (*create)(const char *, char *, int, unsigned char);
96 	struct module *owner;
97 };
98 
99 void v9fs_register_trans(struct p9_trans_module *m);
100 void v9fs_unregister_trans(struct p9_trans_module *m);
101 struct p9_trans_module *v9fs_get_trans_by_name(const substring_t *name);
102 struct p9_trans_module *v9fs_get_default_trans(void);
103 void v9fs_put_trans(struct p9_trans_module *m);
104 #endif /* NET_9P_TRANSPORT_H */
105