clnt_udp.c

/* @(#)clnt_udp.c	2.2 88/08/01 4.0 RPCSRC */
/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *     * Neither the name of the "Oracle America, Inc." nor the names of
 *       its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro";
#endif

/*
 * clnt_udp.c, Implements a UDP/IP based, client side RPC.
 */

#include <stdio.h>
#include <unistd.h>
#include <gssrpc/rpc.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#if defined(sun)
#include <sys/filio.h>
#endif
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <gssrpc/pmap_clnt.h>
#include <port-sockets.h>
#include <errno.h>

#ifndef GETSOCKNAME_ARG3_TYPE
#define GETSOCKNAME_ARG3_TYPE int
#endif

/*
 * UDP bases client side rpc operations
 */
static enum clnt_stat	clntudp_call(CLIENT *, rpcproc_t, xdrproc_t, void *,
				     xdrproc_t, void *, struct timeval);
static void		clntudp_abort(CLIENT *);
static void		clntudp_geterr(CLIENT *, struct rpc_err *);
static bool_t		clntudp_freeres(CLIENT *, xdrproc_t, void *);
static bool_t           clntudp_control(CLIENT *, int, void *);
static void		clntudp_destroy(CLIENT *);

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 {
        SOCKET             cu_sock;
	bool_t		   cu_closeit;
	struct sockaddr_in cu_raddr;
	int		   cu_rlen;
	struct sockaddr_in cu_laddr;
        GETSOCKNAME_ARG3_TYPE  cu_llen;
	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;  retransmission 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(
	struct sockaddr_in *raddr,
	rpcprog_t program,
	rpcvers_t version,
	struct timeval wait,
	int *sockp,
	u_int sendsz,
	u_int recvsz)
{
	CLIENT *cl;
	struct cu_data *cu = 0;
	struct timeval now;
	struct rpc_msg call_msg;

	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 = 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 prov port */
		(void)bindresvport_sa(*sockp, NULL);
		/* the sockets rpc controls are non-blocking */
		(void)ioctl(*sockp, FIONBIO, (char *) &dontblock);
		cu->cu_closeit = TRUE;
	} else {
		cu->cu_closeit = FALSE;
	}
	if (connect(*sockp, (struct sockaddr *)raddr, sizeof(*raddr)) < 0)
	     goto fooy;
	cu->cu_llen = sizeof(cu->cu_laddr);
	if (getsockname(*sockp, (struct sockaddr *)&cu->cu_laddr, &cu->cu_llen) < 0)
	     goto fooy;

	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(
	struct sockaddr_in *raddr,
	rpcprog_t program,
	rpcvers_t version,
	struct timeval wait,
	int *sockp)
{

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

static enum clnt_stat
clntudp_call(
	CLIENT	*cl,			/* client handle */
	rpcproc_t	proc,		/* procedure number */
	xdrproc_t	xargs,		/* xdr routine for args */
	void *		argsp,		/* pointer to args */
	xdrproc_t	xresults,	/* xdr routine for results */
	void *		resultsp,	/* pointer to results */
	struct timeval	utimeout	/* seconds to wait before
					 * giving up */
	)
{
	struct cu_data *cu = (struct cu_data *)cl->cl_private;
	XDR *xdrs;
	int outlen;
	ssize_t inlen;
	GETSOCKNAME_ARG3_TYPE fromlen; /* Assumes recvfrom uses same type */
#ifdef FD_SETSIZE
	fd_set readfds;
	fd_set mask;
#else
	int readfds;
	int mask;
#endif /* def FD_SETSIZE */
	struct sockaddr_in from;
	struct rpc_msg reply_msg;
	XDR reply_xdrs;
	struct timeval time_waited, seltimeout;
	bool_t ok;
	int nrefreshes = 2;	/* number of times to refresh cred */
	struct timeval timeout;
	long procl = proc;

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

	time_waited.tv_sec = 0;
	time_waited.tv_usec = 0;
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
	 */
	(*(uint32_t *)(void *)(cu->cu_outbuf))++;
	if ((! XDR_PUTLONG(xdrs, &procl)) ||
	    (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
	    (! AUTH_WRAP(cl->cl_auth, xdrs, xargs, argsp)))
		return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
	outlen = (int)XDR_GETPOS(xdrs);

send_again:
	if (send(cu->cu_sock, cu->cu_outbuf, (u_int)outlen, 0) != outlen) {
		cu->cu_error.re_errno = errno;
		return (cu->cu_error.re_status = RPC_CANTSEND);
	}

	/*
	 * Hack to provide rpc-based message passing
	 */
	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
		return (cu->cu_error.re_status = RPC_TIMEDOUT);
	}
	/*
	 * sub-optimal code appears here 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 = gssrpc__null_auth;
	reply_msg.acpted_rply.ar_results.where = NULL;
	reply_msg.acpted_rply.ar_results.proc = xdr_void;
#ifdef FD_SETSIZE
	FD_ZERO(&mask);
	FD_SET(cu->cu_sock, &mask);
#else
	mask = 1 << cu->cu_sock;
#endif /* def FD_SETSIZE */
	for (;;) {
		readfds = mask;
		seltimeout = cu->cu_wait;
		switch (select(gssrpc__rpc_dtablesize(), &readfds, (fd_set *)NULL,
			       (fd_set *)NULL, &seltimeout)) {

		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)))
				goto send_again;
			return (cu->cu_error.re_status = RPC_TIMEDOUT);

		/*
		 * buggy in other cases because time_waited is not being
		 * updated.
		 */
		case -1:
			if (errno == EINTR)
				continue;
			cu->cu_error.re_errno = errno;
			return (cu->cu_error.re_status = RPC_CANTRECV);
		}
		do {
			fromlen = sizeof(struct sockaddr);
			inlen = recvfrom(cu->cu_sock, cu->cu_inbuf,
				cu->cu_recvsz, 0,
				(struct sockaddr *)&from, &fromlen);
		} while (inlen < 0 && errno == EINTR);
		if (inlen < 0) {
			if (errno == EWOULDBLOCK)
				continue;
			cu->cu_error.re_errno = errno;
			return (cu->cu_error.re_status = RPC_CANTRECV);
		}
		if ((size_t)inlen < sizeof(uint32_t))
			continue;
		/* see if reply transaction id matches sent id */
		if (*((uint32_t *)(void *)(cu->cu_inbuf)) !=
		    *((uint32_t *)(void *)(cu->cu_outbuf)))
			continue;
		/* 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) {
		gssrpc__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;
			} else if (! AUTH_UNWRAP(cl->cl_auth, &reply_xdrs,
						 xresults, resultsp)) {
			     if (cu->cu_error.re_status == RPC_SUCCESS)
				  cu->cu_error.re_status = RPC_CANTDECODERES;
			}
		}  /* end successful completion */
		else {
			/* maybe our credentials need to be refreshed ... */
			if (nrefreshes > 0 &&
			    AUTH_REFRESH(cl->cl_auth, &reply_msg)) {
				nrefreshes--;
				goto call_again;
			}
		}  /* end of unsuccessful completion */
		/* free verifier */
		if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
		    (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 of valid reply message */
	else {
		/*
		 * It's possible for xdr_replymsg() to fail partway
		 * through its attempt to decode the result from the
		 * server. If this happens, it will leave the reply
		 * structure partially populated with dynamically
		 * allocated memory. (This can happen if someone uses
		 * clntudp_bufcreate() to create a CLIENT handle and
		 * specifies a receive buffer size that is too small.)
		 * This memory must be free()ed to avoid a leak.
		 */
		enum xdr_op op = reply_xdrs.x_op;
		reply_xdrs.x_op = XDR_FREE;
		xdr_replymsg(&reply_xdrs, &reply_msg);
		reply_xdrs.x_op = op;
		cu->cu_error.re_status = RPC_CANTDECODERES;
	}
	return (cu->cu_error.re_status);
}

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

	*errp = cu->cu_error;
}


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

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


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

static bool_t
clntudp_control(
	CLIENT *cl,
	int request,
	void *info)
{
	struct cu_data *cu = cl->cl_private;

	switch (request) {
	case CLSET_TIMEOUT:
		cu->cu_total = *(struct timeval *)info;
		break;
	case CLGET_TIMEOUT:
		*(struct timeval *)info = cu->cu_total;
		break;
	case CLSET_RETRY_TIMEOUT:
		cu->cu_wait = *(struct timeval *)info;
		break;
	case CLGET_RETRY_TIMEOUT:
		*(struct timeval *)info = cu->cu_wait;
		break;
	case CLGET_SERVER_ADDR:
		*(struct sockaddr_in *)info = cu->cu_raddr;
		break;
	case CLGET_LOCAL_ADDR:
		*(struct sockaddr_in *)info = cu->cu_laddr;
		break;
	default:
		return (FALSE);
	}
	return (TRUE);
}

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

	if (cu->cu_closeit)
                (void)closesocket(cu->cu_sock);
	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));
}