LXR linux-bk/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
  19struct 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 */
  37struct 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
  69extern int rxrpc_peer_lookup(struct rxrpc_transport *trans,
  70                             __be32 addr,
  71                             struct rxrpc_peer **_peer);
  72
  73static 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
  80extern void rxrpc_put_peer(struct rxrpc_peer *peer);
  81
  82#endif /* _LINUX_RXRPC_PEER_H */
  83