include/rxrpc/peer.h

   1 /* peer.h: Rx RPC per-transport peer record
   2  *
   3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #ifndef _LINUX_RXRPC_PEER_H
  13 #define _LINUX_RXRPC_PEER_H
  14
  15 #include <linux/wait.h>
  16 #include <rxrpc/types.h>
  17 #include <rxrpc/krxtimod.h>
  18
  19 struct rxrpc_peer_ops
  20 {
  21         /* peer record being added */
  22         int (*adding)(struct rxrpc_peer *peer);
  23
  24         /* peer record being discarded from graveyard */
  25         void (*discarding)(struct rxrpc_peer *peer);
  26
  27         /* change of epoch detected on connection */
  28         void (*change_of_epoch)(struct rxrpc_connection *conn);
  29 };
  30
  31 /*****************************************************************************/
  32 /*
  33  * Rx RPC per-transport peer record
  34  * - peers only retain a refcount on the transport when they are active
  35  * - peers with refcount==0 are inactive and reside in the transport's graveyard
  36  */
  37 struct rxrpc_peer
  38 {
  39         atomic_t                usage;
  40         struct rxrpc_peer_ops   *ops;           /* operations on this peer */
  41         struct rxrpc_transport  *trans;         /* owner transport */
  42         struct rxrpc_timer      timeout;        /* timeout for grave destruction */
  43         struct list_head        link;           /* link in transport's peer list */
  44         struct list_head        proc_link;      /* link in /proc list */
  45         rwlock_t                conn_idlock;    /* lock for connection IDs */
  46         struct list_head        conn_idlist;    /* list of connections granted IDs */
  47         uint32_t                conn_idcounter; /* connection ID counter */
  48         rwlock_t                conn_lock;      /* lock for active/dead connections */
  49         struct list_head        conn_active;    /* active connections to/from this peer */
  50         struct list_head        conn_graveyard; /* graveyard for inactive connections */
  51         spinlock_t              conn_gylock;    /* lock for conn_graveyard */
  52         wait_queue_head_t       conn_gy_waitq;  /* wait queue hit when graveyard is empty */
  53         atomic_t                conn_count;     /* number of attached connections */
  54         struct in_addr          addr;           /* remote address */
  55         size_t                  if_mtu;         /* interface MTU for this peer */
  56         spinlock_t              lock;           /* access lock */
  57
  58         void                    *user;          /* application layer data */
  59
  60         /* calculated RTT cache */
  61 #define RXRPC_RTT_CACHE_SIZE 32
  62         suseconds_t             rtt;            /* current RTT estimate (in uS) */
  63         unsigned                rtt_point;      /* next entry at which to insert */
  64         unsigned                rtt_usage;      /* amount of cache actually used */
  65         suseconds_t             rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* calculated RTT cache */
  66 };
  67
  68
  69 extern int rxrpc_peer_lookup(struct rxrpc_transport *trans,
  70                              __be32 addr,
  71                              struct rxrpc_peer **_peer);
  72
  73 static inline void rxrpc_get_peer(struct rxrpc_peer *peer)
  74 {
  75         BUG_ON(atomic_read(&peer->usage)<0);
  76         atomic_inc(&peer->usage);
  77         //printk("rxrpc_get_peer(%p{u=%d})\n",peer,atomic_read(&peer->usage));
  78 }
  79
  80 extern void rxrpc_put_peer(struct rxrpc_peer *peer);
  81
  82 #endif /* _LINUX_RXRPC_PEER_H */