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/*
* linux/include/linux/sunrpc/clnt_xprt.h
*
* Declarations for the RPC transport interface.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _LINUX_SUNRPC_XPRT_H
#define _LINUX_SUNRPC_XPRT_H
#include <linux/uio.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/sunrpc/sched.h>
/*
* Maximum number of iov's we use.
*/
#define MAX_IOVEC 10
/*
* The transport code maintains an estimate on the maximum number of out-
* standing RPC requests, using a smoothed version of the congestion
* avoidance implemented in 44BSD. This is basically the Van Jacobson
* slow start algorithm: If a retransmit occurs, the congestion window is
* halved; otherwise, it is incremented by 1/cwnd when
*
* - a reply is received and
* - a full number of requests are outstanding and
* - the congestion window hasn't been updated recently.
*
* Upper procedures may check whether a request would block waiting for
* a free RPC slot by using the RPC_CONGESTED() macro.
*
* Note: on machines with low memory we should probably use a smaller
* MAXREQS value: At 32 outstanding reqs with 8 megs of RAM, fragment
* reassembly will frequently run out of memory.
* Come Linux 2.3, we'll handle fragments directly.
*/
#define RPC_MAXCONG 16
#define RPC_MAXREQS (RPC_MAXCONG + 1)
#define RPC_CWNDSCALE 256
#define RPC_MAXCWND (RPC_MAXCONG * RPC_CWNDSCALE)
#define RPC_INITCWND RPC_CWNDSCALE
#define RPCXPRT_CONGESTED(xprt) \
((xprt)->cong >= (xprt)->cwnd)
/* Default timeout values */
#define RPC_MAX_UDP_TIMEOUT (60*HZ)
#define RPC_MAX_TCP_TIMEOUT (600*HZ)
/* RPC call and reply header size as number of 32bit words (verifier
* size computed separately)
*/
#define RPC_CALLHDRSIZE 6
#define RPC_REPHDRSIZE 4
/*
* This describes a timeout strategy
*/
struct rpc_timeout {
unsigned long to_current, /* current timeout */
to_initval, /* initial timeout */
to_maxval, /* max timeout */
to_increment, /* if !exponential */
to_resrvval; /* reserve timeout */
short to_retries; /* max # of retries */
unsigned char to_exponential;
};
/*
* This is the RPC buffer
*/
struct rpc_iov {
struct iovec io_vec[MAX_IOVEC];
unsigned int io_nr;
unsigned int io_len;
};
/*
* This describes a complete RPC request
*/
struct rpc_rqst {
/*
* This is the user-visible part
*/
struct rpc_xprt * rq_xprt; /* RPC client */
struct rpc_timeout rq_timeout; /* timeout parms */
struct rpc_iov rq_snd_buf; /* send buffer */
struct rpc_iov rq_rcv_buf; /* recv buffer */
/*
* This is the private part
*/
struct rpc_task * rq_task; /* RPC task data */
__u32 rq_xid; /* request XID */
struct rpc_rqst * rq_next; /* free list */
unsigned char rq_damaged; /* reply being received */
/*
* For authentication (e.g. auth_des)
*/
u32 rq_creddata[2];
/*
* Partial send handling
*/
u32 rq_bytes_sent; /* Bytes we have sent */
#ifdef RPC_PROFILE
unsigned long rq_xtime; /* when transmitted */
#endif
};
#define rq_svec rq_snd_buf.io_vec
#define rq_snr rq_snd_buf.io_nr
#define rq_slen rq_snd_buf.io_len
#define rq_rvec rq_rcv_buf.io_vec
#define rq_rnr rq_rcv_buf.io_nr
#define rq_rlen rq_rcv_buf.io_len
struct rpc_xprt {
struct socket * sock; /* BSD socket layer */
struct sock * inet; /* INET layer */
struct rpc_timeout timeout; /* timeout parms */
struct sockaddr_in addr; /* server address */
int prot; /* IP protocol */
unsigned long cong; /* current congestion */
unsigned long cwnd; /* congestion window */
unsigned long congtime; /* hold cwnd until then */
struct rpc_wait_queue sending; /* requests waiting to send */
struct rpc_wait_queue pending; /* requests in flight */
struct rpc_wait_queue backlog; /* waiting for slot */
struct rpc_wait_queue reconn; /* waiting for reconnect */
struct rpc_rqst * free; /* free slots */
struct rpc_rqst slot[RPC_MAXREQS];
unsigned int connected : 1, /* TCP: connected */
write_space: 1, /* TCP: can send */
shutdown : 1, /* being shut down */
nocong : 1, /* no congestion control */
stream : 1, /* TCP */
tcp_more : 1, /* more record fragments */
connecting : 1; /* being reconnected */
/*
* State of TCP reply receive stuff
*/
u32 tcp_recm; /* Fragment header */
u32 tcp_xid; /* Current XID */
unsigned int tcp_reclen, /* fragment length */
tcp_offset, /* fragment offset */
tcp_copied; /* copied to request */
struct list_head rx_pending; /* receive pending list */
/*
* Send stuff
*/
struct rpc_task * snd_task; /* Task blocked in send */
void (*old_data_ready)(struct sock *, int);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
wait_queue_head_t cong_wait;
};
#ifdef __KERNEL__
struct rpc_xprt * xprt_create_proto(int proto, struct sockaddr_in *addr,
struct rpc_timeout *toparms);
int xprt_destroy(struct rpc_xprt *);
void xprt_shutdown(struct rpc_xprt *);
void xprt_default_timeout(struct rpc_timeout *, int);
void xprt_set_timeout(struct rpc_timeout *, unsigned int,
unsigned long);
int xprt_reserve(struct rpc_task *);
void xprt_transmit(struct rpc_task *);
void xprt_receive(struct rpc_task *);
int xprt_adjust_timeout(struct rpc_timeout *);
void xprt_release(struct rpc_task *);
void xprt_reconnect(struct rpc_task *);
int xprt_clear_backlog(struct rpc_xprt *);
void __rpciod_tcp_dispatcher(void);
extern struct list_head rpc_xprt_pending;
static inline
int xprt_tcp_pending(void)
{
return !list_empty(&rpc_xprt_pending);
}
static inline
void rpciod_tcp_dispatcher(void)
{
if (xprt_tcp_pending())
__rpciod_tcp_dispatcher();
}
#endif /* __KERNEL__*/
#endif /* _LINUX_SUNRPC_XPRT_H */
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