/*
 * 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.
 */

/*
 * clnt_raw.c
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * Memory based rpc for simple testing and timing.
 * Interface to create an rpc client and server in the same process.
 * This lets us similate rpc and get round trip overhead, without
 * any interference from the kernel.
 */
#include <config.h>
#include <pthread.h>
#include <reentrant.h>
#include <assert.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>

#include <rpc/rpc.h>
#include <rpc/raw.h>

extern mutex_t clntraw_lock; /* XXXX does it need to be extern? */

#define MCALL_MSG_SIZE 24

/*
 * This is the "network" we will be moving stuff over.
 */
static struct clntraw_private {
	CLIENT client_object;
	XDR xdr_stream;
	char *_raw_buf;
	union {
		struct rpc_msg mashl_rpcmsg;
		char mashl_callmsg[MCALL_MSG_SIZE];
	} u;
	u_int mcnt;
} *clntraw_private;

static enum clnt_stat clnt_raw_call(CLIENT *, AUTH *, rpcproc_t, xdrproc_t,
				    void *, xdrproc_t, void *, struct timeval);
static void clnt_raw_geterr(CLIENT *, struct rpc_err *);
static bool clnt_raw_freeres(CLIENT *, xdrproc_t, void *);
static void clnt_raw_abort(CLIENT *);
static bool clnt_raw_control(CLIENT *, u_int, void *);
static void clnt_raw_destroy(CLIENT *);
static struct clnt_ops *clnt_raw_ops(void);

/*
 * Create a client handle for memory based rpc.
 */
CLIENT *
clnt_raw_ncreate(rpcprog_t prog, rpcvers_t vers)
{
	struct clntraw_private *clp;
	struct rpc_msg call_msg;
	XDR *xdrs;
	CLIENT *client;

	mutex_lock(&clntraw_lock);
	clp = clntraw_private;
	if (clp == NULL) {
		clp = (struct clntraw_private *)calloc(1, sizeof(*clp));
		if (clp == NULL) {
			mutex_unlock(&clntraw_lock);
			return NULL;
		}
		if (__rpc_rawcombuf == NULL)
			__rpc_rawcombuf =
			    (char *)calloc(UDPMSGSIZE, sizeof(char));
		clp->_raw_buf = __rpc_rawcombuf;
		clntraw_private = clp;
	}
	xdrs = &clp->xdr_stream;
	client = &clp->client_object;
	/*
	 * pre-serialize the static part of the call msg and stash it away
	 */
	call_msg.rm_direction = CALL;
	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
	/* XXX: prog and vers have been long historically :-( */
	call_msg.rm_call.cb_prog = (u_int32_t) prog;
	call_msg.rm_call.cb_vers = (u_int32_t) vers;
	xdrmem_create(xdrs, clp->u.mashl_callmsg, MCALL_MSG_SIZE, XDR_ENCODE);
	if (!xdr_callhdr(xdrs, &call_msg))
		__warnx(TIRPC_DEBUG_FLAG_CLNT_RAW,
			"clntraw_create - Fatal header serialization error.");
	clp->mcnt = XDR_GETPOS(xdrs);
	XDR_DESTROY(xdrs);

	/*
	 * Set xdrmem for client/server shared buffer
	 */
	xdrmem_create(xdrs, clp->_raw_buf, UDPMSGSIZE, XDR_FREE);

	/*
	 * create client handle
	 */
	client->cl_ops = clnt_raw_ops();
	mutex_unlock(&clntraw_lock);
	return (client);
}

/* ARGSUSED */
static enum clnt_stat
clnt_raw_call(CLIENT *h, AUTH *auth, rpcproc_t proc,
	      xdrproc_t xargs, void *argsp,
	      xdrproc_t xresults, void *resultsp,
	      struct timeval timeout)
{
	struct clntraw_private *clp = clntraw_private;
	XDR *xdrs = &clp->xdr_stream;
	struct rpc_msg msg;
	enum clnt_stat status;
	struct rpc_err error;

	assert(h != NULL);

	mutex_lock(&clntraw_lock);
	if (clp == NULL) {
		mutex_unlock(&clntraw_lock);
		return (RPC_FAILED);
	}
	mutex_unlock(&clntraw_lock);

 call_again:
	/*
	 * send request
	 */
	xdrs->x_op = XDR_ENCODE;
	XDR_SETPOS(xdrs, 0);
	clp->u.mashl_rpcmsg.rm_xid++;
	if ((!XDR_PUTBYTES(xdrs, clp->u.mashl_callmsg, clp->mcnt))
	    || (!XDR_PUTINT32(xdrs, (int32_t *) &proc))
	    || (!AUTH_MARSHALL(auth, xdrs)) || (!(*xargs) (xdrs, argsp))) {
		return (RPC_CANTENCODEARGS);
	}
	(void)XDR_GETPOS(xdrs);	/* called just to cause overhead */

	/*
	 * We have to call server input routine here because this is
	 * all going on in one process. Yuk.
	 */
	svc_getreq_common(FD_SETSIZE);

	/*
	 * get results
	 */
	xdrs->x_op = XDR_DECODE;
	XDR_SETPOS(xdrs, 0);
	msg.acpted_rply.ar_verf = _null_auth;
	msg.acpted_rply.ar_results.where = resultsp;
	msg.acpted_rply.ar_results.proc = xresults;
	if (!xdr_replymsg(xdrs, &msg)) {
		/*
		 * 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.
		 */
		int op = xdrs->x_op;
		xdrs->x_op = XDR_FREE;
		(void) xdr_replymsg(xdrs, &msg);
		xdrs->x_op = op;
		return (RPC_CANTDECODERES);
	}
	_seterr_reply(&msg, &error);
	status = error.re_status;

	if (status == RPC_SUCCESS) {
		if (!AUTH_VALIDATE(auth, &msg.acpted_rply.ar_verf))
			status = RPC_AUTHERROR;
	} /* end successful completion */
	else {
		if (AUTH_REFRESH(auth, &msg))
			goto call_again;
	}			/* end of unsuccessful completion */

	if (status == RPC_SUCCESS) {
		if (!AUTH_VALIDATE(auth, &msg.acpted_rply.ar_verf))
			status = RPC_AUTHERROR;
		if (msg.acpted_rply.ar_verf.oa_base != NULL) {
			xdrs->x_op = XDR_FREE;
			(void)xdr_opaque_auth(xdrs, &(msg.acpted_rply.ar_verf));
		}
	}

	return (status);
}

 /*ARGSUSED*/
static void clnt_raw_geterr(CLIENT *cl, struct rpc_err *err)
{
}

/* ARGSUSED */
static bool
clnt_raw_freeres(CLIENT *cl, xdrproc_t xdr_res, void *res_ptr)
{
	struct clntraw_private *clp = clntraw_private;
	XDR *xdrs = &clp->xdr_stream;
	bool rval;

	mutex_lock(&clntraw_lock);
	if (clp == NULL) {
		rval = (bool) RPC_FAILED;
		mutex_unlock(&clntraw_lock);
		return (rval);
	}
	mutex_unlock(&clntraw_lock);
	xdrs->x_op = XDR_FREE;
	return ((*xdr_res) (xdrs, res_ptr));
}

/*ARGSUSED*/
static void
clnt_raw_abort(CLIENT *cl)
{
}

/*ARGSUSED*/
static bool
clnt_raw_control(CLIENT *cl, u_int ui, void *str)
{
	return (false);
}

/*ARGSUSED*/
static void clnt_raw_destroy(CLIENT *cl)
{
}

static struct clnt_ops *
clnt_raw_ops(void)
{
	static struct clnt_ops ops;
	extern mutex_t ops_lock; /* XXXX does it need to be extern? */

	/* VARIABLES PROTECTED BY ops_lock: ops */

	mutex_lock(&ops_lock);
	if (ops.cl_call == NULL) {
		ops.cl_call = clnt_raw_call;
		ops.cl_abort = clnt_raw_abort;
		ops.cl_geterr = clnt_raw_geterr;
		ops.cl_freeres = clnt_raw_freeres;
		ops.cl_destroy = clnt_raw_destroy;
		ops.cl_control = clnt_raw_control;
	}
	mutex_unlock(&ops_lock);
	return (&ops);
}