include/net/9p/transport.h

   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 /**
  30  * enum p9_trans_status - different states of underlying transports
  31  * @Connected: transport is connected and healthy
  32  * @Disconnected: transport has been disconnected
  33  * @Hung: transport is connected by wedged
  34  *
  35  * This enumeration details the various states a transport
  36  * instatiation can be in.
  37  */
  38
  39 enum p9_trans_status {
  40         Connected,
  41         Disconnected,
  42         Hung,
  43 };
  44
  45 /**
  46  * struct p9_trans - per-transport state and API
  47  * @status: transport &p9_trans_status
  48  * @msize: negotiated maximum packet size (duplicate from client)
  49  * @extended: negotiated protocol extensions (duplicate from client)
  50  * @priv: transport private data
  51  * @close: member function to disconnect and close the transport
  52  * @rpc: member function to issue a request to the transport
  53  *
  54  * This is the basic API for a transport instance.  It is used as
  55  * a handle by the client to issue requests.  This interface is currently
  56  * in flux during reorganization.
  57  *
  58  * Bugs: there is lots of duplicated data here and its not clear that
  59  * the member functions need to be per-instance versus per transport
  60  * module.
  61  */
  62
  63 struct p9_trans {
  64         enum p9_trans_status status;
  65         int msize;
  66         unsigned char extended;
  67         void *priv;
  68         void (*close) (struct p9_trans *);
  69         int (*rpc) (struct p9_trans *t, struct p9_fcall *tc,
  70                                                         struct p9_fcall **rc);
  71 };
  72
  73 /**
  74  * struct p9_trans_module - transport module interface
  75  * @list: used to maintain a list of currently available transports
  76  * @name: the human-readable name of the transport
  77  * @maxsize: transport provided maximum packet size
  78  * @def: set if this transport should be considered the default
  79  * @create: member function to create a new connection on this transport
  80  *
  81  * This is the basic API for a transport module which is registered by the
  82  * transport module with the 9P core network module and used by the client
  83  * to instantiate a new connection on a transport.
  84  *
  85  * Bugs: the transport module list isn't protected.
  86  */
  87
  88 struct p9_trans_module {
  89         struct list_head list;
  90         char *name;             /* name of transport */
  91         int maxsize;            /* max message size of transport */
  92         int def;                /* this transport should be default */
  93         struct p9_trans * (*create)(const char *, char *, int, unsigned char);
  94 };
  95
  96 void v9fs_register_trans(struct p9_trans_module *m);
  97 struct p9_trans_module *v9fs_match_trans(const substring_t *name);
  98 struct p9_trans_module *v9fs_default_trans(void);
  99 #endif /* NET_9P_TRANSPORT_H */