/*
 * Copyright (c) 2009, Sun Microsystems, 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 Sun Microsystems, 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.
 */
/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
 */

#include "config.h"
#include <sys/cdefs.h>

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

/*
 * This interface creates a virtual listener for all the services
 * started thru rpc_reg(). It listens on the same endpoint for
 * all the services and then executes the corresponding service
 * for the given prognum and procnum.
 */
#include <pthread.h>
#include <reentrant.h>
#include <sys/types.h>
#include <rpc/rpc.h>
#include <rpc/nettype.h>
#include <rpc/svc_auth.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>

#include "rpc_com.h"

static void universal(struct svc_req *);

static struct proglst {
	char *(*p_progname) (char *);
	rpcprog_t p_prognum;
	rpcvers_t p_versnum;
	rpcproc_t p_procnum;
	SVCXPRT *p_transp;
	char *p_netid;
	char *p_xdrbuf;
	int p_recvsz;
	xdrproc_t p_inproc, p_outproc;
	struct proglst *p_nxt;
} *proglst;

static const char rpc_reg_err[] = "%s: %s";
static const char rpc_reg_msg[] = "rpc_reg: ";
static const char __reg_err1[] = "can't find appropriate transport";
static const char __reg_err2[] = "can't get protocol info";
static const char __reg_err3[] = "unsupported transport size";

/*
 * For simplified, easy to use kind of rpc interfaces.
 * nettype indicates the type of transport on which the service will be
 * listening. Used for conservation of the system resource. Only one
 * handle is created for all the services (actually one of each netid)
 * and same xdrbuf is used for same netid. The size of the arguments
 * is also limited by the recvsize for that transport, even if it is
 * a COTS transport. This may be wrong, but for cases like these, they
 * should not use the simplified interfaces like this.
 */

int
rpc_reg(rpcprog_t prognum, rpcvers_t versnum, rpcproc_t procnum,
	char *(*progname) (char *), xdrproc_t inproc, xdrproc_t outproc,
	char *nettype)
{
	struct netconfig *nconf;
	int done = false;
	void *handle;
	extern mutex_t proglst_lock;

	if (procnum == NULLPROC) {
		__warnx(TIRPC_DEBUG_FLAG_ERROR,
			"%s can't reassign procedure number %u", rpc_reg_msg,
			NULLPROC);
		return (-1);
	}

	if (nettype == NULL)
		nettype = "netpath";	/* The default behavior */
	handle = __rpc_setconf(nettype);
	if (!handle) {
		__warnx(TIRPC_DEBUG_FLAG_ERROR, rpc_reg_err, rpc_reg_msg,
			__reg_err1);
		return (-1);
	}
	/* VARIABLES PROTECTED BY proglst_lock: proglst */
	mutex_lock(&proglst_lock);
	while ((nconf = __rpc_getconf(handle)) != NULL) {
		struct proglst *pl;
		SVCXPRT *svcxprt;
		int madenow;
		u_int recvsz;
		char *xdrbuf;
		char *netid;

		madenow = false;
		svcxprt = NULL;
		recvsz = 0;
		xdrbuf = netid = NULL;
		for (pl = proglst; pl; pl = pl->p_nxt) {
			if (strcmp(pl->p_netid, nconf->nc_netid) == 0) {
				svcxprt = pl->p_transp;
				xdrbuf = pl->p_xdrbuf;
				recvsz = pl->p_recvsz;
				netid = pl->p_netid;
				break;
			}
		}

		if (svcxprt == NULL) {
			struct __rpc_sockinfo si;

			svcxprt = svc_tli_ncreate(RPC_ANYFD, nconf, NULL, 0, 0);
			if (svcxprt == NULL)
				continue;
			if (!__rpc_fd2sockinfo(svcxprt->xp_fd, &si)) {
				__warnx(TIRPC_DEBUG_FLAG_ERROR, rpc_reg_err,
					rpc_reg_msg, __reg_err2);
				SVC_DESTROY(svcxprt);
				continue;
			}
			recvsz = __rpc_get_t_size(si.si_af, si.si_proto, 0);
			if (recvsz == 0) {
				__warnx(TIRPC_DEBUG_FLAG_ERROR, rpc_reg_err,
					rpc_reg_msg, __reg_err3);
				SVC_DESTROY(svcxprt);
				continue;
			}
			xdrbuf = mem_alloc((unsigned)recvsz);
			netid = mem_strdup(nconf->nc_netid);
			madenow = true;
		}
		/*
		 * Check if this (program, version, netid) had already been
		 * registered.  The check may save a few RPC calls to rpcbind
		 */
		for (pl = proglst; pl; pl = pl->p_nxt)
			if ((pl->p_prognum == prognum)
			    && (pl->p_versnum == versnum)
			    && (strcmp(pl->p_netid, netid) == 0))
				break;
		if (pl == NULL) {	/* Not yet */
			(void)rpcb_unset(prognum, versnum, nconf);
		} else {
			/* so that svc_reg does not call rpcb_set() */
			nconf = NULL;
		}

		if (!svc_reg(svcxprt, prognum, versnum, universal, nconf)) {
			__warnx(TIRPC_DEBUG_FLAG_ERROR,
				"%s couldn't register prog %u vers %u for %s",
				rpc_reg_msg, (unsigned)prognum,
				(unsigned)versnum, netid);
			if (madenow) {
				SVC_DESTROY(svcxprt);
				mem_free(xdrbuf, (unsigned)recvsz);
				mem_free(netid, 0);
			}
			continue;
		}

		pl = mem_alloc(sizeof(struct proglst));
		pl->p_progname = progname;
		pl->p_prognum = prognum;
		pl->p_versnum = versnum;
		pl->p_procnum = procnum;
		pl->p_inproc = inproc;
		pl->p_outproc = outproc;
		pl->p_transp = svcxprt;
		pl->p_xdrbuf = xdrbuf;
		pl->p_recvsz = recvsz;
		pl->p_netid = netid;
		pl->p_nxt = proglst;
		proglst = pl;
		done = true;
	}
	__rpc_endconf(handle);
	mutex_unlock(&proglst_lock);

	if (done == false) {
		__warnx(TIRPC_DEBUG_FLAG_ERROR,
			"%s cant find suitable transport for %s", rpc_reg_msg,
			nettype);
		return (-1);
	}
	return (0);
}

/*
 * The universal handler for the services registered using svc_reg.
 * It handles both the connectionless and the connection oriented cases.
 */

static void
universal(struct svc_req *req)
{
	rpcprog_t prog;
	rpcvers_t vers;
	rpcproc_t proc;
	char *outdata;
	char *xdrbuf;
	struct proglst *pl;
	extern mutex_t proglst_lock;

	/*
	 * enforce "procnum 0 is echo" convention
	 */
	if (req->rq_msg.cb_proc == NULLPROC) {
		req->rq_msg.RPCM_ack.ar_results.where = NULL;
		req->rq_msg.RPCM_ack.ar_results.proc = (xdrproc_t) xdr_void;
		if (svc_sendreply(req) >= XPRT_DIED) {
			__warnx(TIRPC_DEBUG_FLAG_ERROR, "svc_sendreply failed");
		}
		return;
	}
	prog = req->rq_msg.cb_prog;
	vers = req->rq_msg.cb_vers;
	proc = req->rq_msg.cb_proc;
	mutex_lock(&proglst_lock);
	for (pl = proglst; pl; pl = pl->p_nxt)
		if (pl->p_prognum == prog && pl->p_procnum == proc
		    && pl->p_versnum == vers
		    && (strcmp(pl->p_netid, req->rq_xprt->xp_netid) == 0)) {
			/* decode arguments into a CLEAN buffer */
			xdrbuf = pl->p_xdrbuf;
			/* Zero the arguments: reqd ! */
			(void)memset(xdrbuf, 0, sizeof(pl->p_recvsz));
			/*
			 * Assuming that sizeof (xdrbuf) would be enough
			 * for the arguments; if not then the program
			 * may bomb. BEWARE!
			 */
			req->rq_msg.rm_xdr.where = xdrbuf;
			req->rq_msg.rm_xdr.proc = pl->p_inproc;
			if (!SVCAUTH_CHECKSUM(req)) {
				__warnx(TIRPC_DEBUG_FLAG_ERROR,
					"rpc: SVCAUTH_CHECKSUM failed prog %u vers %u",
					(unsigned)prog, (unsigned)vers);
				xdr_free(pl->p_inproc, xdrbuf);
				svcerr_decode(req);
				mutex_unlock(&proglst_lock);
				return;
			}

			outdata = (*(pl->p_progname)) (xdrbuf);
			if (outdata == NULL
			    && pl->p_outproc != (xdrproc_t) xdr_void) {
				/* there was an error */
				xdr_free(pl->p_inproc, xdrbuf);
				mutex_unlock(&proglst_lock);
				return;
			}

			req->rq_msg.RPCM_ack.ar_results.where = outdata;
			req->rq_msg.RPCM_ack.ar_results.proc = pl->p_outproc;
			if (svc_sendreply(req) >= XPRT_DIED) {
				__warnx(TIRPC_DEBUG_FLAG_ERROR,
					"rpc: svc_sendreply failed prog %u vers %u",
					(unsigned)prog, (unsigned)vers);
			}
			/* free the decoded arguments */
			xdr_free(pl->p_inproc, xdrbuf);
			mutex_unlock(&proglst_lock);
			return;
		}
	mutex_unlock(&proglst_lock);
	/* This should never happen */
	__warnx(TIRPC_DEBUG_FLAG_ERROR,
		"rpc: rpc_reg: never registered prog %u vers %u",
		(unsigned)prog, (unsigned)vers);
	return;
}