/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * rpc_prot.c
 * 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/types.h>
#include <sys/t_lock.h>
#include <sys/systm.h>

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

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

/*
 * XDR a DES block
 */
bool_t
xdr_des_block(XDR *xdrs, des_block *blkp)
{
        return (xdr_opaque(xdrs, (caddr_t)blkp, sizeof (des_block)));
}

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

/*
 * XDR the MSG_ACCEPTED part of a reply message union
 */
bool_t
xdr_accepted_reply(XDR *xdrs, struct accepted_reply *ar)
{
        /* personalized union, rather than calling xdr_union */
        if (!xdr_opaque_auth(xdrs, &(ar->ar_verf)))
                return (FALSE);
        if (!xdr_enum(xdrs, (enum_t *)&(ar->ar_stat)))
                return (FALSE);

        switch (ar->ar_stat) {
        case SUCCESS:
                return ((*(ar->ar_results.proc))(xdrs, ar->ar_results.where));

        case PROG_MISMATCH:
                if (!xdr_rpcvers(xdrs, &(ar->ar_vers.low)))
                        return (FALSE);
                return (xdr_rpcvers(xdrs, &(ar->ar_vers.high)));
        }
        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)
{
        /* personalized union, rather than calling xdr_union */
        if (!xdr_enum(xdrs, (enum_t *)&(rr->rj_stat)))
                return (FALSE);
        switch (rr->rj_stat) {

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

        case AUTH_ERROR:
                return (xdr_enum(xdrs, (enum_t *)&(rr->rj_why)));
        }
        return (FALSE);
}

static struct xdr_discrim reply_dscrm[3] = {
        { MSG_ACCEPTED, xdr_accepted_reply },
        { MSG_DENIED, xdr_rejected_reply },
        { __dontcare__, NULL_xdrproc_t }
};

/*
 * XDR a reply message
 */
bool_t
xdr_replymsg(XDR *xdrs, struct rpc_msg *rmsg)
{
        int32_t *buf;
        struct accepted_reply *ar;
        struct opaque_auth *oa;
        uint_t rndup;

        if (xdrs->x_op == XDR_ENCODE &&
            rmsg->rm_reply.rp_stat == MSG_ACCEPTED &&
            rmsg->rm_direction == REPLY &&
            (buf = XDR_INLINE(xdrs, 6 * BYTES_PER_XDR_UNIT + (rndup =
            RNDUP(rmsg->rm_reply.rp_acpt.ar_verf.oa_length)))) != NULL) {
                IXDR_PUT_INT32(buf, rmsg->rm_xid);
                IXDR_PUT_ENUM(buf, rmsg->rm_direction);
                IXDR_PUT_ENUM(buf, rmsg->rm_reply.rp_stat);
                ar = &rmsg->rm_reply.rp_acpt;
                oa = &ar->ar_verf;
                IXDR_PUT_ENUM(buf, oa->oa_flavor);
                IXDR_PUT_INT32(buf, oa->oa_length);
                if (oa->oa_length) {
                        bcopy(oa->oa_base, buf, oa->oa_length);
                        buf = (int32_t *)(((caddr_t)buf) + oa->oa_length);
                        if ((rndup = (rndup - oa->oa_length)) > 0) {
                                bzero(buf, rndup);
                                buf = (int32_t *)(((caddr_t)buf) + rndup);
                        }
                }
                /*
                 * stat and rest of reply, copied from xdr_accepted_reply
                 */
                IXDR_PUT_ENUM(buf, ar->ar_stat);
                switch (ar->ar_stat) {
                case SUCCESS:
                        return ((*(ar->ar_results.proc))(xdrs,
                            ar->ar_results.where));

                case PROG_MISMATCH:
                        if (!xdr_rpcvers(xdrs, &(ar->ar_vers.low)))
                                return (FALSE);
                        return (xdr_rpcvers(xdrs, &(ar->ar_vers.high)));
                }
                return (TRUE);
        }
        if (xdrs->x_op == XDR_DECODE &&
            (buf = XDR_INLINE(xdrs, 3 * BYTES_PER_XDR_UNIT)) != NULL) {
                rmsg->rm_xid = IXDR_GET_INT32(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) {
                        if (rmsg->rm_reply.rp_stat == MSG_DENIED)
                                return (xdr_rejected_reply(xdrs,
                                    &rmsg->rm_reply.rp_rjct));
                        return (FALSE);
                }
                ar = &rmsg->rm_reply.rp_acpt;
                oa = &ar->ar_verf;
                buf = XDR_INLINE(xdrs, 2 * BYTES_PER_XDR_UNIT);
                if (buf != NULL) {
                        oa->oa_flavor = IXDR_GET_ENUM(buf, enum_t);
                        oa->oa_length = IXDR_GET_INT32(buf);
                } else {
                        if (xdr_enum(xdrs, &oa->oa_flavor) == FALSE ||
                            xdr_u_int(xdrs, &oa->oa_length) == FALSE)
                                return (FALSE);
                }
                if (oa->oa_length) {
                        if (oa->oa_length > MAX_AUTH_BYTES)
                                return (FALSE);
                        if (oa->oa_base == NULL) {
                                oa->oa_base = (caddr_t)
                                    mem_alloc(oa->oa_length);
                        }
                        buf = XDR_INLINE(xdrs, RNDUP(oa->oa_length));
                        if (buf == NULL) {
                                if (xdr_opaque(xdrs, oa->oa_base,
                                    oa->oa_length) == FALSE)
                                        return (FALSE);
                        } else {
                                bcopy(buf, oa->oa_base, oa->oa_length);
                        }
                }
                /*
                 * stat and rest of reply, copied from
                 * xdr_accepted_reply
                 */
                if (!xdr_enum(xdrs, (enum_t *)&ar->ar_stat))
                        return (FALSE);
                switch (ar->ar_stat) {
                case SUCCESS:
                        return ((*(ar->ar_results.proc))(xdrs,
                            ar->ar_results.where));

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

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

/*
 * XDR a reply message header (encode only)
 */
bool_t
xdr_replymsg_hdr(XDR *xdrs, struct rpc_msg *rmsg)
{
        int32_t *buf;
        struct accepted_reply *ar;
        struct opaque_auth *oa;
        uint_t rndup;

        if (xdrs->x_op != XDR_ENCODE ||
            rmsg->rm_reply.rp_stat != MSG_ACCEPTED ||
            rmsg->rm_direction != REPLY)
                return (FALSE);

        if ((buf = XDR_INLINE(xdrs, 6 * BYTES_PER_XDR_UNIT + (rndup =
            RNDUP(rmsg->rm_reply.rp_acpt.ar_verf.oa_length)))) != NULL) {
                IXDR_PUT_INT32(buf, rmsg->rm_xid);
                IXDR_PUT_ENUM(buf, rmsg->rm_direction);
                IXDR_PUT_ENUM(buf, rmsg->rm_reply.rp_stat);
                ar = &rmsg->rm_reply.rp_acpt;
                oa = &ar->ar_verf;
                IXDR_PUT_ENUM(buf, oa->oa_flavor);
                IXDR_PUT_INT32(buf, oa->oa_length);
                if (oa->oa_length) {
                        bcopy(oa->oa_base, buf, oa->oa_length);
                        buf = (int32_t *)(((caddr_t)buf) + oa->oa_length);
                        if ((rndup = (rndup - oa->oa_length)) > 0) {
                                bzero(buf, rndup);
                                buf = (int32_t *)(((caddr_t)buf) + rndup);
                        }
                }
                /*
                 * stat and rest of reply, copied from xdr_accepted_reply
                 */
                IXDR_PUT_ENUM(buf, ar->ar_stat);
                return (TRUE);
        }

        if (xdr_u_int(xdrs, &(rmsg->rm_xid)) &&
            xdr_enum(xdrs, (enum_t *)&(rmsg->rm_direction)) &&
            xdr_enum(xdrs, (enum_t *)&(rmsg->rm_reply.rp_stat)) &&
            xdr_opaque_auth(xdrs, &rmsg->rm_reply.rp_acpt.ar_verf) &&
            xdr_enum(xdrs, (enum_t *)&(rmsg->rm_reply.rp_acpt.ar_stat)))
                return (TRUE);
        return (FALSE);
}

/*
 * XDR a reply message body (encode only)
 */
bool_t
xdr_replymsg_body(XDR *xdrs, struct rpc_msg *rmsg)
{
        struct accepted_reply *ar;

        if (xdrs->x_op != XDR_ENCODE)
                return (FALSE);

        ar = &rmsg->rm_reply.rp_acpt;

        if (ar->ar_results.proc == NULL)
                return (TRUE);
        return ((*(ar->ar_results.proc))(xdrs, ar->ar_results.where));
}

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

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

static void
accepted(enum accept_stat acpt_stat, struct rpc_err *error)
{
        switch (acpt_stat) {
        case PROG_UNAVAIL:
                error->re_status = RPC_PROGUNAVAIL;
                return;

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

        case PROC_UNAVAIL:
                error->re_status = RPC_PROCUNAVAIL;
                return;

        case GARBAGE_ARGS:
                error->re_status = RPC_CANTDECODEARGS;
                return;

        case SYSTEM_ERR:
                error->re_status = RPC_SYSTEMERROR;
                return;

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

static void
rejected(enum reject_stat rjct_stat, struct rpc_err *error)
{
        switch (rjct_stat) {
        case RPC_VERSMISMATCH:
                error->re_status = RPC_VERSMISMATCH;
                return;

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

/*
 * given a reply message, fills in the error
 */
void
_seterr_reply(struct rpc_msg *msg, struct rpc_err *error)
{
        /* optimized for normal, SUCCESSful case */
        switch (msg->rm_reply.rp_stat) {
        case MSG_ACCEPTED:
                if (msg->acpted_rply.ar_stat == SUCCESS) {
                        error->re_status = RPC_SUCCESS;
                        return;
                };
                accepted(msg->acpted_rply.ar_stat, error);
                break;

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

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

        switch (error->re_status) {
        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;
        }
}

/*
 * given a reply message, frees the accepted verifier
 */
bool_t
xdr_rpc_free_verifier(XDR *xdrs, struct rpc_msg *msg)
{
        if (msg->rm_direction == REPLY &&
            msg->rm_reply.rp_stat == MSG_ACCEPTED &&
            msg->acpted_rply.ar_verf.oa_base != NULL) {
                xdrs->x_op = XDR_FREE;
                return (xdr_opaque_auth(xdrs, &(msg->acpted_rply.ar_verf)));
        }
        return (TRUE);
}