include/linux/sunrpc/xprt.h

   1 /*
   2  *  linux/include/linux/sunrpc/clnt_xprt.h
   3  *
   4  *  Declarations for the RPC transport interface.
   5  *
   6  *  Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifndef _LINUX_SUNRPC_XPRT_H
  10 #define _LINUX_SUNRPC_XPRT_H
  11
  12 #include <linux/uio.h>
  13 #include <linux/socket.h>
  14 #include <linux/in.h>
  15 #include <linux/sunrpc/sched.h>
  16 #include <linux/sunrpc/xdr.h>
  17
  18 /*
  19  * The transport code maintains an estimate on the maximum number of out-
  20  * standing RPC requests, using a smoothed version of the congestion
  21  * avoidance implemented in 44BSD. This is basically the Van Jacobson
  22  * congestion algorithm: If a retransmit occurs, the congestion window is
  23  * halved; otherwise, it is incremented by 1/cwnd when
  24  *
  25  *      -       a reply is received and
  26  *      -       a full number of requests are outstanding and
  27  *      -       the congestion window hasn't been updated recently.
  28  *
  29  * Upper procedures may check whether a request would block waiting for
  30  * a free RPC slot by using the RPC_CONGESTED() macro.
  31  */
  32 extern unsigned int xprt_udp_slot_table_entries;
  33 extern unsigned int xprt_tcp_slot_table_entries;
  34
  35 #define RPC_MIN_SLOT_TABLE      (2U)
  36 #define RPC_DEF_SLOT_TABLE      (16U)
  37 #define RPC_MAX_SLOT_TABLE      (128U)
  38
  39 #define RPC_CWNDSHIFT           (8U)
  40 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  41 #define RPC_INITCWND            RPC_CWNDSCALE
  42 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  43 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  44
  45 /* Default timeout values */
  46 #define RPC_MAX_UDP_TIMEOUT     (60*HZ)
  47 #define RPC_MAX_TCP_TIMEOUT     (600*HZ)
  48
  49 /*
  50  * Wait duration for an RPC TCP connection to be established.  Solaris
  51  * NFS over TCP uses 60 seconds, for example, which is in line with how
  52  * long a server takes to reboot.
  53  */
  54 #define RPC_CONNECT_TIMEOUT     (60*HZ)
  55
  56 /*
  57  * Delay an arbitrary number of seconds before attempting to reconnect
  58  * after an error.
  59  */
  60 #define RPC_REESTABLISH_TIMEOUT (15*HZ)
  61
  62 /* RPC call and reply header size as number of 32bit words (verifier
  63  * size computed separately)
  64  */
  65 #define RPC_CALLHDRSIZE         6
  66 #define RPC_REPHDRSIZE          4
  67
  68 /*
  69  * This describes a timeout strategy
  70  */
  71 struct rpc_timeout {
  72         unsigned long           to_initval,             /* initial timeout */
  73                                 to_maxval,              /* max timeout */
  74                                 to_increment;           /* if !exponential */
  75         unsigned int            to_retries;             /* max # of retries */
  76         unsigned char           to_exponential;
  77 };
  78
  79 /*
  80  * This describes a complete RPC request
  81  */
  82 struct rpc_rqst {
  83         /*
  84          * This is the user-visible part
  85          */
  86         struct rpc_xprt *       rq_xprt;                /* RPC client */
  87         struct xdr_buf          rq_snd_buf;             /* send buffer */
  88         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  89
  90         /*
  91          * This is the private part
  92          */
  93         struct rpc_task *       rq_task;        /* RPC task data */
  94         __u32                   rq_xid;         /* request XID */
  95         int                     rq_cong;        /* has incremented xprt->cong */
  96         int                     rq_received;    /* receive completed */
  97         u32                     rq_seqno;       /* gss seq no. used on req. */
  98
  99         struct list_head        rq_list;
 100
 101         struct xdr_buf          rq_private_buf;         /* The receive buffer
 102                                                          * used in the softirq.
 103                                                          */
 104         unsigned long           rq_majortimeo;  /* major timeout alarm */
 105         unsigned long           rq_timeout;     /* Current timeout value */
 106         unsigned int            rq_retries;     /* # of retries */
 107         /*
 108          * For authentication (e.g. auth_des)
 109          */
 110         u32                     rq_creddata[2];
 111
 112         /*
 113          * Partial send handling
 114          */
 115
 116         u32                     rq_bytes_sent;  /* Bytes we have sent */
 117
 118         unsigned long           rq_xtime;       /* when transmitted */
 119         int                     rq_ntrans;
 120 };
 121 #define rq_svec                 rq_snd_buf.head
 122 #define rq_slen                 rq_snd_buf.len
 123
 124 #define XPRT_LAST_FRAG          (1 << 0)
 125 #define XPRT_COPY_RECM          (1 << 1)
 126 #define XPRT_COPY_XID           (1 << 2)
 127 #define XPRT_COPY_DATA          (1 << 3)
 128
 129 struct rpc_xprt {
 130         struct socket *         sock;           /* BSD socket layer */
 131         struct sock *           inet;           /* INET layer */
 132
 133         struct rpc_timeout      timeout;        /* timeout parms */
 134         struct sockaddr_in      addr;           /* server address */
 135         int                     prot;           /* IP protocol */
 136
 137         unsigned long           cong;           /* current congestion */
 138         unsigned long           cwnd;           /* congestion window */
 139
 140         unsigned int            rcvsize,        /* socket receive buffer size */
 141                                 sndsize;        /* socket send buffer size */
 142
 143         size_t                  max_payload;    /* largest RPC payload size,
 144                                                    in bytes */
 145
 146         struct rpc_wait_queue   sending;        /* requests waiting to send */
 147         struct rpc_wait_queue   resend;         /* requests waiting to resend */
 148         struct rpc_wait_queue   pending;        /* requests in flight */
 149         struct rpc_wait_queue   backlog;        /* waiting for slot */
 150         struct list_head        free;           /* free slots */
 151         struct rpc_rqst *       slot;           /* slot table storage */
 152         unsigned int            max_reqs;       /* total slots */
 153         unsigned long           sockstate;      /* Socket state */
 154         unsigned char           shutdown   : 1, /* being shut down */
 155                                 nocong     : 1, /* no congestion control */
 156                                 resvport   : 1, /* use a reserved port */
 157                                 stream     : 1; /* TCP */
 158
 159         /*
 160          * XID
 161          */
 162         __u32                   xid;            /* Next XID value to use */
 163
 164         /*
 165          * State of TCP reply receive stuff
 166          */
 167         u32                     tcp_recm,       /* Fragment header */
 168                                 tcp_xid,        /* Current XID */
 169                                 tcp_reclen,     /* fragment length */
 170                                 tcp_offset;     /* fragment offset */
 171         unsigned long           tcp_copied,     /* copied to request */
 172                                 tcp_flags;
 173         /*
 174          * Connection of sockets
 175          */
 176         struct work_struct      sock_connect;
 177         unsigned short          port;
 178         /*
 179          * Disconnection of idle sockets
 180          */
 181         struct work_struct      task_cleanup;
 182         struct timer_list       timer;
 183         unsigned long           last_used;
 184
 185         /*
 186          * Send stuff
 187          */
 188         spinlock_t              sock_lock;      /* lock socket info */
 189         spinlock_t              xprt_lock;      /* lock xprt info */
 190         struct rpc_task *       snd_task;       /* Task blocked in send */
 191
 192         struct list_head        recv;
 193
 194
 195         void                    (*old_data_ready)(struct sock *, int);
 196         void                    (*old_state_change)(struct sock *);
 197         void                    (*old_write_space)(struct sock *);
 198
 199         wait_queue_head_t       cong_wait;
 200 };
 201
 202 #ifdef __KERNEL__
 203
 204 struct rpc_xprt *       xprt_create_proto(int proto, struct sockaddr_in *addr,
 205                                         struct rpc_timeout *toparms);
 206 int                     xprt_destroy(struct rpc_xprt *);
 207 void                    xprt_set_timeout(struct rpc_timeout *, unsigned int,
 208                                         unsigned long);
 209
 210 void                    xprt_reserve(struct rpc_task *);
 211 int                     xprt_prepare_transmit(struct rpc_task *);
 212 void                    xprt_transmit(struct rpc_task *);
 213 void                    xprt_receive(struct rpc_task *);
 214 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 215 void                    xprt_release(struct rpc_task *);
 216 void                    xprt_connect(struct rpc_task *);
 217 void                    xprt_sock_setbufsize(struct rpc_xprt *);
 218
 219 #define XPRT_LOCKED     0
 220 #define XPRT_CONNECT    1
 221 #define XPRT_CONNECTING 2
 222
 223 #define xprt_connected(xp)              (test_bit(XPRT_CONNECT, &(xp)->sockstate))
 224 #define xprt_set_connected(xp)          (set_bit(XPRT_CONNECT, &(xp)->sockstate))
 225 #define xprt_test_and_set_connected(xp) (test_and_set_bit(XPRT_CONNECT, &(xp)->sockstate))
 226 #define xprt_test_and_clear_connected(xp) \
 227                                         (test_and_clear_bit(XPRT_CONNECT, &(xp)->sockstate))
 228 #define xprt_clear_connected(xp)        (clear_bit(XPRT_CONNECT, &(xp)->sockstate))
 229
 230 #endif /* __KERNEL__*/
 231
 232 #endif /* _LINUX_SUNRPC_XPRT_H */