/*	$OpenBSD: svc_simple.c,v 1.11 2010/09/01 14:43:34 millert Exp $ */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * 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.
 */

/* 
 * svc_simple.c
 * Simplified front end to rpc.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <sys/socket.h>
#include <netdb.h>

static struct proglst {
	char *(*p_progname)();
	int  p_prognum;
	int  p_procnum;
	xdrproc_t p_inproc, p_outproc;
	struct proglst *p_nxt;
} *proglst;
static void universal(struct svc_req *, SVCXPRT *);
static SVCXPRT *transp;

int
registerrpc(int prognum, int versnum, int procnum, char *(*progname)(),
    xdrproc_t inproc, xdrproc_t outproc)
{
	struct proglst *pl;
	
	if (procnum == NULLPROC) {
		(void) fprintf(stderr,
		    "can't reassign procedure number %u\n", NULLPROC);
		return (-1);
	}
	if (transp == NULL) {
		transp = svcudp_create(RPC_ANYSOCK);
		if (transp == NULL) {
			(void) fprintf(stderr, "couldn't create an rpc server\n");
			return (-1);
		}
	}
	(void) pmap_unset((u_long)prognum, (u_long)versnum);
	if (!svc_register(transp, (u_long)prognum, (u_long)versnum, 
	    universal, IPPROTO_UDP)) {
	    	(void) fprintf(stderr, "couldn't register prog %d vers %d\n",
		    prognum, versnum);
		return (-1);
	}
	pl = (struct proglst *)malloc(sizeof(struct proglst));
	if (pl == NULL) {
		(void) fprintf(stderr, "registerrpc: out of memory\n");
		return (-1);
	}
	pl->p_progname = progname;
	pl->p_prognum = prognum;
	pl->p_procnum = procnum;
	pl->p_inproc = inproc;
	pl->p_outproc = outproc;
	pl->p_nxt = proglst;
	proglst = pl;
	return (0);
}

static void
universal(struct svc_req *rqstp, SVCXPRT *transp)
{
	int prog, proc;
	char *outdata;
	char xdrbuf[UDPMSGSIZE];
	struct proglst *pl;

	/* 
	 * enforce "procnum 0 is echo" convention
	 */
	if (rqstp->rq_proc == NULLPROC) {
		if (svc_sendreply(transp, xdr_void, NULL) == FALSE) {
			(void) fprintf(stderr, "xxx\n");
			exit(1);
		}
		return;
	}
	prog = rqstp->rq_prog;
	proc = rqstp->rq_proc;
	for (pl = proglst; pl != NULL; pl = pl->p_nxt)
		if (pl->p_prognum == prog && pl->p_procnum == proc) {
			/* decode arguments into a CLEAN buffer */
			memset(xdrbuf, 0, sizeof(xdrbuf)); /* required ! */
			if (!svc_getargs(transp, pl->p_inproc, xdrbuf)) {
				svcerr_decode(transp);
				return;
			}
			outdata = (*(pl->p_progname))(xdrbuf);
			if (outdata == NULL &&
			    pl->p_outproc != xdr_void)
				/* there was an error */
				return;
			if (!svc_sendreply(transp, pl->p_outproc, outdata)) {
				(void) fprintf(stderr,
				    "trouble replying to prog %d\n",
				    pl->p_prognum);
				exit(1);
			}
			/* free the decoded arguments */
			(void)svc_freeargs(transp, pl->p_inproc, xdrbuf);
			return;
		}
	(void) fprintf(stderr, "never registered prog %d\n", prog);
	exit(1);
}