clnt_udp.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)clnt_udp.c	2.2 88/08/01 4.0 RPCSRC";*/
static char *rcsid = "$FreeBSD: src/lib/libc/rpc/clnt_udp.c,v 1.15 2000/01/27 23:06:36 jasone Exp $";
#endif

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

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <rpc/rpc.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/pmap_clnt.h>
#include <sys/select.h>

/*
 * 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 bool_t           clntudp_control();
static void		clntudp_destroy();

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

/*
 * Private data kept per client handle
 */
struct cu_data {
	int		   cu_sock;
	bool_t		   cu_closeit;
	struct sockaddr_in cu_raddr;
	int		   cu_rlen;
	struct timeval	   cu_wait;
	struct timeval     cu_total;
	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 = NULL;
	struct timeval now;
	struct rpc_msg call_msg;
	static u_int32_t disrupt;

	if (disrupt == 0)
		disrupt = (u_int32_t)(long)raddr;

	cl = (CLIENT *)mem_alloc(sizeof(CLIENT));
	if (cl == NULL) {
		(void) 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) {
		(void) 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_total.tv_sec = -1;
	cu->cu_total.tv_usec = -1;
	cu->cu_sendsz = sendsz;
	cu->cu_recvsz = recvsz;
	call_msg.rm_xid = (++disrupt) ^ 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;
		}
		/* attempt to bind to priv port */
		(void)bindresvport(*sockp, (struct sockaddr_in *)0);
		/* the sockets rpc controls are non-blocking */
		(void)ioctl(*sockp, FIONBIO, (char *) &dontblock);
		cu->cu_closeit = TRUE;
	} else {
		cu->cu_closeit = FALSE;
	}
	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, utimeout)
	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	utimeout;	/* 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 fromlen;
	fd_set *fds, readfds;
	struct sockaddr_in from;
	struct rpc_msg reply_msg;
	XDR reply_xdrs;
	struct timeval time_waited, start, after, tmp1, tmp2, tv;
	bool_t ok;
	int nrefreshes = 2;	/* number of times to refresh cred */
	struct timeval timeout;

	if (cu->cu_total.tv_usec == -1)
		timeout = utimeout;     /* use supplied timeout */
	else
		timeout = cu->cu_total; /* use default timeout */

	if (cu->cu_sock + 1 > FD_SETSIZE) {
		int bytes = howmany(cu->cu_sock + 1, NFDBITS) * sizeof(fd_mask);
		fds = (fd_set *)malloc(bytes);
		if (fds == NULL)
			return (cu->cu_error.re_status = RPC_CANTSEND);
		memset(fds, 0, bytes);
	} else {
		fds = &readfds;
		FD_ZERO(fds);
	}

	timerclear(&time_waited);

call_again:
	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))) {
		if (fds != &readfds)
			free(fds);
		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
	}
	outlen = (int)XDR_GETPOS(xdrs);

send_again:
	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;
		if (fds != &readfds)
			free(fds);
		return (cu->cu_error.re_status = RPC_CANTSEND);
	}

	/*
	 * Hack to provide rpc-based message passing
	 */