4.3BSD-UWisc/src/lib/libc/rpc/clnt_udp.c

#if defined(LIBC_RCS) && !defined(lint)
static char rcs_id[] = 
	"$Header: clnt_udp.c,v 1.2 86/09/08 14:48:59 tadl Exp $";
#endif
/*
 * RCS info
 *	$Locker:  $
 */
/* NFSSRC @(#)clnt_udp.c	2.1 86/04/14 */
#if defined(SUN_SCCS) && !defined(lint)
static char sccsid[] = "@(#)clnt_udp.c 1.1 86/02/03 Copyr 1984 Sun Micro";
#endif

/*
 * clnt_udp.c, Implements a UPD/IP based, client side RPC.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

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

char *malloc();
extern int errno;

/*
 * UDP bases client side rpc operations
 */
static enum clnt_stat	clntudp_call();
static void		clntudp_abort();
static void		clntudp_geterr();
static bool_t		clntudp_freeres();
static void		clntudp_destroy();

static struct clnt_ops udp_ops = {
	clntudp_call,
	clntudp_abort,
	clntudp_geterr,
	clntudp_freeres,
	clntudp_destroy
};

/* 
 * Private data kept per client handle
 */
struct cu_data {
	int		   cu_sock;
	struct sockaddr_in cu_raddr;
	int		   cu_rlen;
	struct timeval	   cu_wait;
	struct rpc_err	   cu_error;
	XDR		   cu_outxdrs;
	u_int		   cu_xdrpos;
	u_int		   cu_sendsz;
	char		   *cu_outbuf;
	u_int		   cu_recvsz;
	char		   cu_inbuf[1];
};

/*
 * Create a UDP based client handle.
 * If *sockp<0, *sockp is set to a newly created UPD socket.
 * If raddr->sin_port is 0 a binder on the remote machine
 * is consulted for the correct port number.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is initialized to null authentication.
 *     Caller may wish to set this something more useful.
 *
 * wait is the amount of time used between retransmitting a call if
 * no response has been heard;  retransmition occurs until the actual
 * rpc call times out.
 *
 * sendsz and recvsz are the maximum allowable packet sizes that can be
 * sent and received.
 */
CLIENT *
clntudp_bufcreate(raddr, program, version, wait, sockp, sendsz, recvsz)
	struct sockaddr_in *raddr;
	u_long program;
	u_long version;
	struct timeval wait;
	register int *sockp;
	u_int sendsz;
	u_int recvsz;
{
	CLIENT *cl;
	register struct cu_data *cu;
	struct timeval now;
	struct rpc_msg call_msg;

	cl = (CLIENT *)mem_alloc(sizeof(CLIENT));
	if (cl == NULL) {
		fprintf(stderr, "clntudp_create: out of memory\n");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}
	sendsz = ((sendsz + 3) / 4) * 4;
	recvsz = ((recvsz + 3) / 4) * 4;
	cu = (struct cu_data *)mem_alloc(sizeof(*cu) + sendsz + recvsz);
	if (cu == NULL) {
		fprintf(stderr, "clntudp_create: out of memory\n");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}
	cu->cu_outbuf = &cu->cu_inbuf[recvsz];

	(void)gettimeofday(&now, (struct timezone *)0);
	if (raddr->sin_port == 0) {
		u_short port;
		if ((port =
		    pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
			goto fooy;
		}
		raddr->sin_port = htons(port);
	}
	cl->cl_ops = &udp_ops;
	cl->cl_private = (caddr_t)cu;
	cu->cu_raddr = *raddr;
	cu->cu_rlen = sizeof (cu->cu_raddr);
	cu->cu_wait = wait;
	cu->cu_sendsz = sendsz;
	cu->cu_recvsz = recvsz;
	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 = program;
	call_msg.rm_call.cb_vers = version;
	xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
	    sendsz, XDR_ENCODE);
	if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
		goto fooy;
	}
	cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
	if (*sockp < 0) {
		int dontblock = 1;

		*sockp = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
		if (*sockp < 0) {
			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
			rpc_createerr.cf_error.re_errno = errno;
			goto fooy;
		}
		/* the sockets rpc controls are non-blocking */
		(void)ioctl(*sockp, FIONBIO, &dontblock);
	}
	cu->cu_sock = *sockp;
	cl->cl_auth = authnone_create();
	return (cl);
fooy:
	if (cu)
		mem_free((caddr_t)cu, sizeof(*cu) + sendsz + recvsz);
	if (cl)
		mem_free((caddr_t)cl, sizeof(CLIENT));
	return ((CLIENT *)NULL);
}

CLIENT *
clntudp_create(raddr, program, version, wait, sockp)
	struct sockaddr_in *raddr;
	u_long program;
	u_long version;
	struct timeval wait;
	register int *sockp;
{

	return(clntudp_bufcreate(raddr, program, version, wait, sockp,
	    UDPMSGSIZE, UDPMSGSIZE));
}

static enum clnt_stat 
clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, timeout)
	register CLIENT	*cl;		/* client handle */
	u_long		proc;		/* procedure number */
	xdrproc_t	xargs;		/* xdr routine for args */
	caddr_t		argsp;		/* pointer to args */
	xdrproc_t	xresults;	/* xdr routine for results */
	caddr_t		resultsp;	/* pointer to results */
	struct timeval	timeout;	/* seconds to wait before giving up */
{
	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
	register XDR *xdrs;
	register int outlen;
	register int inlen;
	int readfds, fromlen;
	register int mask;
	struct sockaddr_in from;
	struct rpc_msg reply_msg;
	XDR reply_xdrs;
	struct timeval time_waited;
	bool_t ok;

call_again:
	time_waited.tv_sec = 0;
	time_waited.tv_usec = 0;
	xdrs = &(cu->cu_outxdrs);
	xdrs->x_op = XDR_ENCODE;
	XDR_SETPOS(xdrs, cu->cu_xdrpos);
	/*
	 * the transaction is the first thing in the out buffer
	 */
	(*(u_short *)(cu->cu_outbuf))++;
	if ((! XDR_PUTLONG(xdrs, (long *)&proc)) ||
	    (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
	    (! (*xargs)(xdrs, argsp)))
		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
	outlen = (int)XDR_GETPOS(xdrs);
	while (TRUE) {

		if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
		    (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen)
		    != outlen) {
			cu->cu_error.re_errno = errno;
			return (cu->cu_error.re_status = RPC_CANTSEND);
		}
		/*
		 * sub-optimal code appears inside the loop because we have
		 * some clock time to spare while the packets are in flight.
		 * (We assume that this is actually only executed once.)
		 */
		reply_msg.acpted_rply.ar_verf = _null_auth;
		reply_msg.acpted_rply.ar_results.where = resultsp;
		reply_msg.acpted_rply.ar_results.proc = xresults;
		mask = 1 << cu->cu_sock;
rcv_again:
		readfds = mask;
		switch (select(32, &readfds, (int *)NULL, (int *)NULL,
		    &(cu->cu_wait))) {

		case 0:
			time_waited.tv_sec += cu->cu_wait.tv_sec;
			time_waited.tv_usec += cu->cu_wait.tv_usec;
			while (time_waited.tv_usec >= 1000000) {
				time_waited.tv_sec++;
				time_waited.tv_usec -= 1000000;
			}
			if ((time_waited.tv_sec < timeout.tv_sec) ||
				((time_waited.tv_sec == timeout.tv_sec) &&
				(time_waited.tv_usec < timeout.tv_usec)))
				continue;
			return (cu->cu_error.re_status = RPC_TIMEDOUT);

		case -1:
			if (errno == EINTR)
				goto rcv_again;
			cu->cu_error.re_errno = errno;
			return (cu->cu_error.re_status = RPC_CANTRECV);
		}
		if ((readfds & mask) == 0)
			goto rcv_again;
tryagain:
		fromlen = sizeof(struct sockaddr);
		inlen = recvfrom(cu->cu_sock, cu->cu_inbuf, cu->cu_recvsz, 0,
		    (struct sockaddr *)&from, &fromlen);
		if (inlen < 0) {
			if (errno == EINTR)
				goto tryagain;
			if (errno == EWOULDBLOCK)
				goto rcv_again;
			cu->cu_error.re_errno = errno;
			return (cu->cu_error.re_status = RPC_CANTRECV);
		}
		if (inlen < sizeof(u_long))
			goto rcv_again;
		/* see if reply transaction id matches sent id */
		if (*((u_long *)(cu->cu_inbuf)) != *((u_long *)(cu->cu_outbuf)))
			goto rcv_again;
		/* we now assume we have the proper reply */
		break;
	}

	/*
	 * now decode and validate the response
	 */
	xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
	ok = xdr_replymsg(&reply_xdrs, &reply_msg);
	/* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
	if (ok) {
		_seterr_reply(&reply_msg, &(cu->cu_error));
		if (cu->cu_error.re_status == RPC_SUCCESS) {
			if (! AUTH_VALIDATE(cl->cl_auth,
				&reply_msg.acpted_rply.ar_verf)) {
				cu->cu_error.re_status = RPC_AUTHERROR;
				cu->cu_error.re_why = AUTH_INVALIDRESP;
			}
			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 (AUTH_REFRESH(cl->cl_auth))
				goto call_again;
		}  /* end of unsuccessful completion */
	}  /* end of valid reply message */
	else {
		cu->cu_error.re_status = RPC_CANTDECODERES;
	}
	return (cu->cu_error.re_status);
}

static void
clntudp_geterr(cl, errp)
	CLIENT *cl;
	struct rpc_err *errp;
{
	register struct cu_data *cu = (struct cu_data *)cl->cl_private;

	*errp = cu->cu_error;
}


static bool_t
clntudp_freeres(cl, xdr_res, res_ptr)
	CLIENT *cl;
	xdrproc_t xdr_res;
	caddr_t res_ptr;
{
	register struct cu_data *cu = (struct cu_data *)cl->cl_private;
	register XDR *xdrs = &(cu->cu_outxdrs);

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

static void 
clntudp_abort(/*h*/)
	/*CLIENT *h;*/
{
}

static void
clntudp_destroy(cl)
	CLIENT *cl;
{
	register struct cu_data *cu = (struct cu_data *)cl->cl_private;

	XDR_DESTROY(&(cu->cu_outxdrs));
	mem_free((caddr_t)cu, (sizeof(*cu) + cu->cu_sendsz + cu->cu_recvsz));
	mem_free((caddr_t)cl, sizeof(CLIENT));
}