clnt_tcp.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)clnt_tcp.c	4.2      ULTRIX  2/28/91";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/*
 *	Portions of this software have been licensed to 
 *	Digital Equipment Company, Maynard, MA.
 *	Copyright (c) 1986 Sun Microsystems, Inc.  ALL RIGHTS RESERVED.
 */
/* 	Change Log
 *      02/21/91	jhw	picked up SUN 4.0 select change
 *
 *	04/12/89	jhw	integrated SUN 4.0 changes
 *
 *	08/04/89	jhw	removed bindresvport call for V3.0 
 *				binary compatibility
 *
 */
 
/*
 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
 *
 *
 * TCP based RPC supports 'batched calls'.
 * A sequence of calls may be batched-up in a send buffer.  The rpc call
 * return immediately to the client even though the call was not necessarily
 * sent.  The batching occurs iff the results' xdr routine is NULL (0) AND
 * the rpc timeout value is zero (see clnt.h, rpc).
 *
 * Clients should NOT casually batch calls that in fact return results; that is,
 * the server side should be aware that a call is batched and not produce any
 * return message.  Batched calls that produce many result messages can
 * deadlock (netlock) the client and the server....
 *
 * Now go hang yourself.
 */

#include <stdio.h>
#include <rpc/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/clnt.h>
#include <rpc/rpc_msg.h>
#include <rpc/pmap_clnt.h>

#define MCALL_MSG_SIZE 24

char *malloc();
extern int errno;

static int	readtcp();
static int	writetcp();

#include <rpc/pmap_clnt.h>


static enum clnt_stat	clnttcp_call();
static void		clnttcp_abort();
static void		clnttcp_geterr();
static bool_t		clnttcp_freeres();
static bool_t           clnttcp_control();
static void		clnttcp_destroy();

static struct clnt_ops tcp_ops = {
	clnttcp_call,
	clnttcp_abort,
	clnttcp_geterr,
	clnttcp_freeres,
	clnttcp_destroy,
	clnttcp_control
};

struct ct_data {
	int		ct_sock;
	bool_t		ct_closeit;
	struct timeval	ct_wait;
	bool_t          ct_waitset;       /* wait set by clnt_control? */
	struct sockaddr_in ct_addr; 
	struct rpc_err	ct_error;
	char		ct_mcall[MCALL_MSG_SIZE];	/* marshalled callmsg */
	u_int		ct_mpos;			/* pos after marshal */
	XDR		ct_xdrs;
};

/*
 * Create a client handle for a tcp/ip connection.
 * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 * connected to raddr.  If *sockp non-negative then
 * raddr is ignored.  The rpc/tcp package does buffering
 * similar to stdio, so the client must pick send and receive buffer sizes,];
 * 0 => use the default.
 * If raddr->sin_port is 0, then a binder on the remote machine is
 * consulted for the right port number.
 * NB: *sockp is copied into a private area.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 * something more useful.
 */
CLIENT *
clnttcp_create(raddr, prog, vers, sockp, sendsz, recvsz)
	struct sockaddr_in *raddr;
	u_long prog;
	u_long vers;
	register int *sockp;
	u_int sendsz;
	u_int recvsz;
{
	CLIENT *h;
	register struct ct_data *ct;
	struct timeval now;
	struct rpc_msg call_msg;

	h  = (CLIENT *)mem_alloc(0, 0, sizeof(*h), 0);
	if (h == NULL) {
		(void)fprintf(stderr, "clnttcp_create: out of memory\n");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}
	ct = (struct ct_data *)mem_alloc(0, 0, sizeof(*ct), 0);
	if (ct == NULL) {
		(void)fprintf(stderr, "clnttcp_create: out of memory\n");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}

	/*
	 * If no port number given ask the pmap for one
	 */
	if (raddr->sin_port == 0) {
		u_short port;
		if ((port = pmap_getport(raddr, prog, vers, IPPROTO_TCP)) == 0) {
			mem_free((caddr_t)ct, sizeof(struct ct_data));
			mem_free((caddr_t)h, sizeof(CLIENT));
			return ((CLIENT *)NULL);
		}
		raddr->sin_port = htons(port);
	}

	/*
	 * If no socket given, open one
	 */
	if (*sockp < 0) {
		*sockp = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	/*	REMOVED FOR V3.0 BINARY COMPATIBILTY			*/
	/*	(void)bindresvport(*sockp, (struct sockaddr_in *)0);	*/
	/*								*/
		if ((*sockp < 0)
		    || (connect(*sockp, (struct sockaddr *)raddr,
		    sizeof(*raddr)) < 0)) {
			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
			rpc_createerr.cf_error.re_errno = errno;
			(void)close(*sockp);
			goto fooy;
		}
		ct->ct_closeit = TRUE;
	} else {
		ct->ct_closeit = FALSE;
	}

	/*
	 * Set up private data struct
	 */
	ct->ct_sock = *sockp;
	ct->ct_wait.tv_usec = 0;
	ct->ct_waitset = FALSE;
	ct->ct_addr = *raddr;

	/*
	 * Initialize call message
	 */
	(void)gettimeofday(&now, (struct timezone *)0);
	call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
	call_msg.rm_direction = CALL;
	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
	call_msg.rm_call.cb_prog = prog;
	call_msg.rm_call.cb_vers = vers;

	/*
	 * pre-serialize the staic part of the call msg and stash it away
	 */
	xdrmem_create(&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
	    XDR_ENCODE);
	if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
		if (ct->ct_closeit) {
			(void)close(*sockp);
		}
		goto fooy;
	}
	ct->ct_mpos = XDR_GETPOS(&(ct->ct_xdrs));
	XDR_DESTROY(&(ct->ct_xdrs));

	/*
	 * Create a client handle which uses xdrrec for serialization
	 * and authnone for authentication.
	 */
	xdrrec_create(&(ct->ct_xdrs), sendsz, recvsz,
	    (caddr_t)ct, readtcp, writetcp);
	h->cl_ops = &tcp_ops;
	h->cl_private = (caddr_t) ct;
	h->cl_auth = authnone_create();
	return (h);

fooy:
	/*
	 * Something goofed, free stuff and barf
	 */
	mem_free((caddr_t)ct, sizeof(struct ct_data));
	mem_free((caddr_t)h, sizeof(CLIENT));
	return ((CLIENT *)NULL);
}

static enum clnt_stat
clnttcp_call(h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
	register CLIENT *h;
	u_long proc;
	xdrproc_t xdr_args;
	caddr_t args_ptr;
	xdrproc_t xdr_results;
	caddr_t results_ptr;
	struct timeval timeout;
{
	register struct ct_data *ct = (struct ct_data *) h->cl_private;
	register XDR *xdrs = &(ct->ct_xdrs);
	struct rpc_msg reply_msg;
	u_long x_id;
	u_long *msg_x_id = (u_long *)(ct->ct_mcall);	/* yuk */
	register bool_t shipnow;
	int refreshes = 2;

	if (!ct->ct_waitset) {
		ct->ct_wait = timeout;
	}

	shipnow =
	    (xdr_results == (xdrproc_t)0 && timeout.tv_sec == 0
	    && timeout.tv_usec == 0) ? FALSE : TRUE;

call_again:
	xdrs->x_op = XDR_ENCODE;
	ct->ct_error.re_status = RPC_SUCCESS;
	x_id = ntohl(--(*msg_x_id));
	if ((! XDR_PUTBYTES(xdrs, ct->ct_mcall, ct->ct_mpos)) ||
	    (! XDR_PUTLONG(xdrs, (long *)&proc)) ||
	    (! AUTH_MARSHALL(h->cl_auth, xdrs)) ||
	    (! (*xdr_args)(xdrs, args_ptr))) {
		if (ct->ct_error.re_status == RPC_SUCCESS)
			ct->ct_error.re_status = RPC_CANTENCODEARGS;
		(void)xdrrec_endofrecord(xdrs, TRUE);
		return (ct->ct_error.re_status);
	}
	if (! xdrrec_endofrecord(xdrs, shipnow))
		return (ct->ct_error.re_status = RPC_CANTSEND);
	if (! shipnow)
		return (RPC_SUCCESS);
	/*
	 * Hack to provide rpc-based message passing
	 */
	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
		return(ct->ct_error.re_status = RPC_TIMEDOUT);
	}


	/*
	 * Keep receiving until we get a valid transaction id
	 */
	xdrs->x_op = XDR_DECODE;
	while (TRUE) {
		reply_msg.acpted_rply.ar_verf = _null_auth;
		reply_msg.acpted_rply.ar_results.where = NULL;
		reply_msg.acpted_rply.ar_results.proc = xdr_void;
		if (! xdrrec_skiprecord(xdrs))
			return (ct->ct_error.re_status);
		/* now decode and validate the response header */
		if (! xdr_replymsg(xdrs, &reply_msg)) {
			if (ct->ct_error.re_status == RPC_SUCCESS)
				continue;
			return (ct->ct_error.re_status);
		}
		if (reply_msg.rm_xid == x_id)
			break;
	}

	/*
	 * process header
	 */
	_seterr_reply(&reply_msg, &(ct->ct_error));
	if (ct->ct_error.re_status == RPC_SUCCESS) {
		if (! AUTH_VALIDATE(h->cl_auth, &reply_msg.acpted_rply.ar_verf)) {
			ct->ct_error.re_status = RPC_AUTHERROR;
			ct->ct_error.re_why = AUTH_INVALIDRESP;
		} else if (! (*xdr_results)(xdrs, results_ptr)) {
			if (ct->ct_error.re_status == RPC_SUCCESS)
				ct->ct_error.re_status = RPC_CANTDECODERES;
		}
		/* free verifier ... */
		if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
			xdrs->x_op = XDR_FREE;
			(void)xdr_opaque_auth(xdrs, &(reply_msg.acpted_rply.ar_verf));
		}
	}  /* end successful completion */
	else {
		/* maybe our credentials need to be refreshed ... */
		if (refreshes-- && AUTH_REFRESH(h->cl_auth))
			goto call_again;
	}  /* end of unsuccessful completion */
	return (ct->ct_error.re_status);
}

static void
clnttcp_geterr(h, errp)
	CLIENT *h;
	struct rpc_err *errp;
{
	register struct ct_data *ct =
	    (struct ct_data *) h->cl_private;

	*errp = ct->ct_error;
}

static bool_t
clnttcp_freeres(cl, xdr_res, res_ptr)
	CLIENT *cl;
	xdrproc_t xdr_res;
	caddr_t res_ptr;
{
	register struct ct_data *ct = (struct ct_data *)cl->cl_private;
	register XDR *xdrs = &(ct->ct_xdrs);

	xdrs->x_op = XDR_FREE;
	return ((*xdr_res)(xdrs, res_ptr));
}

static void
clnttcp_abort()
{
}

static bool_t
clnttcp_control(cl, request, info)
	CLIENT *cl;
	int request;
	char *info;
{
	register struct ct_data *ct = (struct ct_data *)cl->cl_private;

	switch (request) {
	case CLSET_TIMEOUT:
		ct->ct_wait = *(struct timeval *)info;
		ct->ct_waitset = TRUE;
		break;
	case CLGET_TIMEOUT:
		*(struct timeval *)info = ct->ct_wait;
		break;
	case CLGET_SERVER_ADDR:
		*(struct sockaddr_in *)info = ct->ct_addr;
		break;
	default:
		return (FALSE);
	}
	return (TRUE);
}


static void
clnttcp_destroy(h)
	CLIENT *h;
{
	register struct ct_data *ct =
	    (struct ct_data *) h->cl_private;

	if (ct->ct_closeit) {
		(void)close(ct->ct_sock);
	}
	XDR_DESTROY(&(ct->ct_xdrs));
	mem_free((caddr_t)ct, sizeof(struct ct_data));
	mem_free((caddr_t)h, sizeof(CLIENT));
}

/*
 * Interface between xdr serializer and tcp connection.
 * Behaves like the system calls, read & write, but keeps some error state
 * around for the rpc level.
 */
static int
readtcp(ct, buf, len)
	register struct ct_data *ct;
	caddr_t buf;
	register int len;
{
	fd_set mask;
	fd_set readfds;

	if (len == 0)
		return (0);
	FD_ZERO(&mask);
	FD_SET(ct->ct_sock, &mask);
	while (TRUE) {
		readfds = mask;
		switch (select(_rpc_dtablesize(), &readfds, (int*)NULL, (int*)NULL,
		    &(ct->ct_wait))) {
		case 0:
			ct->ct_error.re_status = RPC_TIMEDOUT;
			return (-1);

		case -1:
			if (errno == EINTR)
				continue;
			ct->ct_error.re_status = RPC_CANTRECV;
			ct->ct_error.re_errno = errno;
			return (-1);
		}
		break;
	}
	switch (len = read(ct->ct_sock, buf, len)) {

	case 0:
		/* premature eof */
		ct->ct_error.re_errno = ECONNRESET;
		ct->ct_error.re_status = RPC_CANTRECV;
		len = -1;  /* it's really an error */
		break;

	case -1:
		ct->ct_error.re_errno = errno;
		ct->ct_error.re_status = RPC_CANTRECV;
		break;
	}
	return (len);
}

static int
writetcp(ct, buf, len)
	struct ct_data *ct;
	caddr_t buf;
	int len;
{
	register int i, cnt;

	for (cnt = len; cnt > 0; cnt -= i, buf += i) {
		if ((i = write(ct->ct_sock, buf, cnt)) == -1) {
			ct->ct_error.re_errno = errno;
			ct->ct_error.re_status = RPC_CANTSEND;
			return (-1);
		}
	}
	return (len);
}