/*      $NetBSD: rpc_prot.c,v 1.16 2000/06/02 23:11:13 fvdl Exp $       */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * 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.
 */

#include <sys/cdefs.h>
/*
 * rpc_prot.c
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * This set of routines implements the rpc message definition,
 * its serializer and some common rpc utility routines.
 * The routines are meant for various implementations of rpc -
 * they are NOT for the rpc client or rpc service implementations!
 * Because authentication stuff is easy and is part of rpc, the opaque
 * routines are also in this program.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>

#include <rpc/types.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/clnt.h>
#include <rpc/rpc_msg.h>

#define assert(exp)     KASSERT(exp, ("bad arguments"))

static enum clnt_stat accepted(enum accept_stat, struct rpc_err *);
static enum clnt_stat rejected(enum reject_stat, struct rpc_err *);

/* * * * * * * * * * * * * * XDR Authentication * * * * * * * * * * * */

struct opaque_auth _null_auth;

/*
 * XDR an opaque authentication struct
 * (see auth.h)
 */
bool_t
xdr_opaque_auth(XDR *xdrs, struct opaque_auth *ap)
{

        assert(xdrs != NULL);
        assert(ap != NULL);

        if (xdr_enum(xdrs, &(ap->oa_flavor)))
                return (xdr_bytes(xdrs, &ap->oa_base,
                        &ap->oa_length, MAX_AUTH_BYTES));
        return (FALSE);
}

/* * * * * * * * * * * * * * XDR RPC MESSAGE * * * * * * * * * * * * * * * */

/*
 * XDR the MSG_ACCEPTED part of a reply message union
 */
bool_t
xdr_accepted_reply(XDR *xdrs, struct accepted_reply *ar)
{
        enum accept_stat *par_stat;

        assert(xdrs != NULL);
        assert(ar != NULL);

        par_stat = &ar->ar_stat;

        /* personalized union, rather than calling xdr_union */
        if (! xdr_opaque_auth(xdrs, &(ar->ar_verf)))
                return (FALSE);
        if (! xdr_enum(xdrs, (enum_t *) par_stat))
                return (FALSE);
        switch (ar->ar_stat) {

        case SUCCESS:
                if (ar->ar_results.proc != (xdrproc_t) xdr_void)
                        return ((*(ar->ar_results.proc))(xdrs,
                                ar->ar_results.where));
                else
                        return (TRUE);

        case PROG_MISMATCH:
                if (! xdr_uint32_t(xdrs, &(ar->ar_vers.low)))
                        return (FALSE);
                return (xdr_uint32_t(xdrs, &(ar->ar_vers.high)));

        case GARBAGE_ARGS:
        case SYSTEM_ERR:
        case PROC_UNAVAIL:
        case PROG_UNAVAIL:
                break;
        }
        return (TRUE);  /* TRUE => open ended set of problems */
}

/*
 * XDR the MSG_DENIED part of a reply message union
 */
bool_t 
xdr_rejected_reply(XDR *xdrs, struct rejected_reply *rr)
{
        enum reject_stat *prj_stat;
        enum auth_stat *prj_why;

        assert(xdrs != NULL);
        assert(rr != NULL);

        prj_stat = &rr->rj_stat;

        /* personalized union, rather than calling xdr_union */
        if (! xdr_enum(xdrs, (enum_t *) prj_stat))
                return (FALSE);
        switch (rr->rj_stat) {

        case RPC_MISMATCH:
                if (! xdr_uint32_t(xdrs, &(rr->rj_vers.low)))
                        return (FALSE);
                return (xdr_uint32_t(xdrs, &(rr->rj_vers.high)));

        case AUTH_ERROR:
                prj_why = &rr->rj_why;
                return (xdr_enum(xdrs, (enum_t *) prj_why));
        }
        /* NOTREACHED */
        assert(0);
        return (FALSE);
}

static const struct xdr_discrim reply_dscrm[3] = {
        { (int)MSG_ACCEPTED, (xdrproc_t)xdr_accepted_reply },
        { (int)MSG_DENIED, (xdrproc_t)xdr_rejected_reply },
        { __dontcare__, NULL_xdrproc_t } };

/*
 * XDR a reply message
 */
bool_t
xdr_replymsg(XDR *xdrs, struct rpc_msg *rmsg)
{
        int32_t *buf;
        enum msg_type *prm_direction;
        enum reply_stat *prp_stat;

        assert(xdrs != NULL);
        assert(rmsg != NULL);

        if (xdrs->x_op == XDR_DECODE) {
                buf = XDR_INLINE(xdrs, 3 * BYTES_PER_XDR_UNIT);
                if (buf != NULL) {
                        rmsg->rm_xid = IXDR_GET_UINT32(buf);
                        rmsg->rm_direction = IXDR_GET_ENUM(buf, enum msg_type);
                        if (rmsg->rm_direction != REPLY) {
                                return (FALSE);
                        }
                        rmsg->rm_reply.rp_stat =
                                IXDR_GET_ENUM(buf, enum reply_stat);
                        if (rmsg->rm_reply.rp_stat == MSG_ACCEPTED)
                                return (xdr_accepted_reply(xdrs,
                                        &rmsg->acpted_rply));
                        else if (rmsg->rm_reply.rp_stat == MSG_DENIED)
                                return (xdr_rejected_reply(xdrs,
                                        &rmsg->rjcted_rply));
                        else
                                return (FALSE);
                }
        }

        prm_direction = &rmsg->rm_direction;
        prp_stat = &rmsg->rm_reply.rp_stat;

        if (
            xdr_uint32_t(xdrs, &(rmsg->rm_xid)) && 
            xdr_enum(xdrs, (enum_t *) prm_direction) &&
            (rmsg->rm_direction == REPLY) )
                return (xdr_union(xdrs, (enum_t *) prp_stat,
                   (caddr_t)(void *)&(rmsg->rm_reply.ru), reply_dscrm,
                   NULL_xdrproc_t));
        return (FALSE);
}


/*
 * Serializes the "static part" of a call message header.
 * The fields include: rm_xid, rm_direction, rpcvers, prog, and vers.
 * The rm_xid is not really static, but the user can easily munge on the fly.
 */
bool_t
xdr_callhdr(XDR *xdrs, struct rpc_msg *cmsg)
{
        enum msg_type *prm_direction;

        assert(xdrs != NULL);
        assert(cmsg != NULL);

        prm_direction = &cmsg->rm_direction;

        cmsg->rm_direction = CALL;
        cmsg->rm_call.cb_rpcvers = RPC_MSG_VERSION;
        if (
            (xdrs->x_op == XDR_ENCODE) &&
            xdr_uint32_t(xdrs, &(cmsg->rm_xid)) &&
            xdr_enum(xdrs, (enum_t *) prm_direction) &&
            xdr_uint32_t(xdrs, &(cmsg->rm_call.cb_rpcvers)) &&
            xdr_uint32_t(xdrs, &(cmsg->rm_call.cb_prog)) )
                return (xdr_uint32_t(xdrs, &(cmsg->rm_call.cb_vers)));
        return (FALSE);
}

/* ************************** Client utility routine ************* */

static enum clnt_stat
accepted(enum accept_stat acpt_stat, struct rpc_err *error)
{

        assert(error != NULL);

        switch (acpt_stat) {

        case PROG_UNAVAIL:
                error->re_status = RPC_PROGUNAVAIL;
                return (RPC_PROGUNAVAIL);

        case PROG_MISMATCH:
                error->re_status = RPC_PROGVERSMISMATCH;
                return (RPC_PROGVERSMISMATCH);

        case PROC_UNAVAIL:
                return (RPC_PROCUNAVAIL);

        case GARBAGE_ARGS:
                return (RPC_CANTDECODEARGS);

        case SYSTEM_ERR:
                return (RPC_SYSTEMERROR);

        case SUCCESS:
                return (RPC_SUCCESS);
        }
        /* NOTREACHED */
        /* something's wrong, but we don't know what ... */
        error->re_lb.s1 = (int32_t)MSG_ACCEPTED;
        error->re_lb.s2 = (int32_t)acpt_stat;
        return (RPC_FAILED);
}

static enum clnt_stat
rejected(enum reject_stat rjct_stat, struct rpc_err *error)
{

        assert(error != NULL);

        switch (rjct_stat) {
        case RPC_MISMATCH:
                return (RPC_VERSMISMATCH);

        case AUTH_ERROR:
                return (RPC_AUTHERROR);
        }
        /* something's wrong, but we don't know what ... */
        /* NOTREACHED */
        error->re_lb.s1 = (int32_t)MSG_DENIED;
        error->re_lb.s2 = (int32_t)rjct_stat;
        return (RPC_FAILED);
}

/*
 * given a reply message, fills in the error
 */
enum clnt_stat
_seterr_reply(struct rpc_msg *msg, struct rpc_err *error)
{
        enum clnt_stat stat;

        assert(msg != NULL);
        assert(error != NULL);

        /* optimized for normal, SUCCESSful case */
        switch (msg->rm_reply.rp_stat) {

        case MSG_ACCEPTED:
                if (msg->acpted_rply.ar_stat == SUCCESS) {
                        stat = RPC_SUCCESS;
                        return (stat);
                }
                stat = accepted(msg->acpted_rply.ar_stat, error);
                break;

        case MSG_DENIED:
                stat = rejected(msg->rjcted_rply.rj_stat, error);
                break;

        default:
                stat = RPC_FAILED;
                error->re_lb.s1 = (int32_t)(msg->rm_reply.rp_stat);
                break;
        }
        error->re_status = stat;

        switch (stat) {

        case RPC_VERSMISMATCH:
                error->re_vers.low = msg->rjcted_rply.rj_vers.low;
                error->re_vers.high = msg->rjcted_rply.rj_vers.high;
                break;

        case RPC_AUTHERROR:
                error->re_why = msg->rjcted_rply.rj_why;
                break;

        case RPC_PROGVERSMISMATCH:
                error->re_vers.low = msg->acpted_rply.ar_vers.low;
                error->re_vers.high = msg->acpted_rply.ar_vers.high;
                break;

        case RPC_FAILED:
        case RPC_SUCCESS:
        case RPC_PROGNOTREGISTERED:
        case RPC_PMAPFAILURE:
        case RPC_UNKNOWNPROTO:
        case RPC_UNKNOWNHOST:
        case RPC_SYSTEMERROR:
        case RPC_CANTDECODEARGS:
        case RPC_PROCUNAVAIL:
        case RPC_PROGUNAVAIL:
        case RPC_TIMEDOUT:
        case RPC_CANTRECV:
        case RPC_CANTSEND:
        case RPC_CANTDECODERES:
        case RPC_CANTENCODEARGS:
        default:
                break;
        }

        return (stat);
}