/*
 * 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 2006 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.
 */

/*
 * Boot subsystem client side rpc
 */

#include <sys/errno.h>
#include <rpc/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "socket_inet.h"
#include "ipv4.h"
#include "clnt.h"
#include <rpc/rpc.h>
#include "brpc.h"
#include "pmap.h"
#include <sys/promif.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_sys.h>
#include "auth_inet.h"
#include <rpc/rpc_msg.h>
#include <sys/salib.h>
#include <sys/bootdebug.h>

#define dprintf if (boothowto & RB_DEBUG) printf

/* retries to send RPC message when sendto fails */
#define RPC_UDP_SEND_RETRIES    3

extern int errno;

/*
 * If we create another clnt type this should be
 * moved to a common file
 */
extern struct rpc_createerr rpc_createerr;

static struct clnt_ops *clntbudp_ops();

/*
 * Private data kept per client handle
 */
struct cu_data {
        int                cu_sock;
        bool_t             cu_closeit;
        struct sockaddr_in cu_raddr;
        int                cu_rlen;
        struct timeval     cu_wait;
        struct timeval     cu_total;
        struct rpc_err     cu_error;
        XDR                cu_outxdrs;
        uint_t             cu_xdrpos;
        uint_t             cu_sendsz;
        char               *cu_outbuf;
        uint_t             cu_recvsz;
        char               cu_inbuf[1];
};

/*
 * Create a UDP based client handle.
 * If *sockp<0, *sockp is set to a newly created UPD socket.
 * If raddr->sin_port is 0 a binder on the remote machine
 * is consulted for the correct port number.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is initialized to null authentication.
 *      Caller may wish to set this something more useful.
 *
 * wait is the amount of time used between retransmitting a call if
 * no response has been heard;  retransmition occurs until the actual
 * rpc call times out.
 *
 * sendsz and recvsz are the maximum allowable packet sizes that can be
 * sent and received.
 */
CLIENT *
clntbudp_bufcreate(struct sockaddr_in *raddr, rpcprog_t program,
    rpcvers_t version, struct timeval wait, int *sockp, uint_t sendsz,
    uint_t recvsz)
{
        CLIENT *cl;
        struct cu_data *cu;
        struct rpc_msg call_msg;

        cl = (CLIENT *)bkmem_alloc(sizeof (CLIENT));
        if (cl == NULL) {
                errno = ENOMEM;
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                return ((CLIENT *)NULL);
        }
        sendsz = ((sendsz + 3) / 4) * 4;
        recvsz = ((recvsz + 3) / 4) * 4;
        cu = (struct cu_data *)bkmem_alloc(sizeof (*cu) + sendsz + recvsz);
        if (cu == NULL) {
                errno = ENOMEM;
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                goto fooy;
        }
        cu->cu_outbuf = &cu->cu_inbuf[recvsz];

        if (raddr->sin_port == 0) {
                ushort_t port;
                if ((port = bpmap_getport(program, version,
                    &(rpc_createerr.cf_stat), raddr, NULL)) == 0) {
                        goto fooy;
                }
                raddr->sin_port = htons(port);
        }
        cl->cl_ops = clntbudp_ops();
        cl->cl_private = (caddr_t)cu;
        cu->cu_raddr = *raddr;
        cu->cu_rlen = sizeof (cu->cu_raddr);
        cu->cu_wait = wait;
        cu->cu_total.tv_sec = -1;
        cu->cu_total.tv_usec = -1;
        cu->cu_sendsz = sendsz;
        cu->cu_recvsz = recvsz;
        call_msg.rm_xid = (uint_t)prom_gettime() + 1;
        call_msg.rm_direction = CALL;
        call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
        call_msg.rm_call.cb_prog = program;
        call_msg.rm_call.cb_vers = version;
        xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
            sendsz, XDR_ENCODE);
        if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
                goto fooy;
        }
        cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
        cu->cu_closeit = FALSE;

        if (*sockp < 0) {
                struct sockaddr_in from;

                *sockp = socket(PF_INET, SOCK_DGRAM, 0);
                if (*sockp < 0) {
                        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                        rpc_createerr.cf_error.re_errno = errno;
                        goto fooy;
                }

                if (dontroute) {
                        (void) setsockopt(*sockp, SOL_SOCKET, SO_DONTROUTE,
                            (const void *)&dontroute, sizeof (dontroute));
                }

                /* attempt to bind to priv port */
                from.sin_family = AF_INET;
                ipv4_getipaddr(&from.sin_addr);
                from.sin_addr.s_addr = htonl(from.sin_addr.s_addr);
                from.sin_port = get_source_port(TRUE);

                if (bind(*sockp, (struct sockaddr *)&from, sizeof (from)) < 0) {
                        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                        rpc_createerr.cf_error.re_errno = errno;
                        goto fooy;
                }

                cu->cu_closeit = TRUE;
        }

        cu->cu_sock = *sockp;
        cl->cl_auth = authnone_create();
        return (cl);
fooy:
        if (cu)
                bkmem_free((caddr_t)cu, sizeof (*cu) + sendsz + recvsz);
        if (cl)
                bkmem_free((caddr_t)cl, sizeof (CLIENT));
        return ((CLIENT *)NULL);
}

CLIENT *
clntbudp_create(struct sockaddr_in *raddr, rpcprog_t program,
    rpcvers_t version, struct timeval wait, int *sockp)
{

        return (clntbudp_bufcreate(raddr, program, version, wait, sockp,
            UDPMSGSIZE, UDPMSGSIZE));
}

static enum clnt_stat
clntbudp_call(CLIENT *cl, rpcproc_t proc, xdrproc_t xargs, caddr_t argsp,
    xdrproc_t  xresults, caddr_t resultsp, struct timeval utimeout)
{
        struct cu_data *cu;
        XDR *xdrs;
        int outlen;
        int inlen;
        socklen_t fromlen;
        struct sockaddr_in from;
        struct rpc_msg reply_msg;
        XDR reply_xdrs;
        uint_t xdelay;
        int wait_time;
        bool_t ok;
        int nrefreshes = 2;     /* number of times to refresh cred */
        struct timeval timeout;
        int errors;
        short send_retries = RPC_UDP_SEND_RETRIES;

        cu = (struct cu_data *)cl->cl_private;
        if (cu->cu_total.tv_usec == -1)
                timeout = utimeout;     /* use supplied timeout */
        else
                timeout = cu->cu_total; /* use default timeout */

        /*
         * set a media level timeout
         */
        xdelay = cu->cu_wait.tv_sec + 1000 + cu->cu_wait.tv_usec / 1000;
        (void) setsockopt(cu->cu_sock, SOL_SOCKET, SO_RCVTIMEO,
            (void *)&xdelay, sizeof (xdelay));

        wait_time = (timeout.tv_sec * 1000) + (timeout.tv_usec / 1000);
        if (wait_time == 0)
                wait_time = RPC_RCVWAIT_MSEC;
        wait_time += prom_gettime();

        errors = 0;

call_again:
        xdrs = &(cu->cu_outxdrs);
        xdrs->x_op = XDR_ENCODE;
        (void) XDR_SETPOS(xdrs, cu->cu_xdrpos);
        /*
         * the transaction is the first thing in the out buffer
         */
        (*(ushort_t *)(cu->cu_outbuf))++;
        if ((! XDR_PUTINT32(xdrs, (int32_t *)&proc)) ||
            (! AUTH_MARSHALL(cl->cl_auth, xdrs, NULL)) ||
            (! (*xargs)(xdrs, argsp)))
                return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
        outlen = (int)XDR_GETPOS(xdrs);

send_again:
        if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
            (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen)
            != outlen) {
                if (errno == ETIMEDOUT) {
                        /*
                         * sendto() times out probably because
                         * ARP times out while waiting for reply.
                         * We retry sending RPC message again.
                         */
                        if (send_retries-- > 0) {
                                dprintf("clntbudp_call: timedout, try sending"
                                    "RPC again\n");
                                errno = 0;
                                goto send_again;
                        }
                        cu->cu_error.re_status = RPC_TIMEDOUT;
                } else {
                        cu->cu_error.re_status = RPC_CANTSEND;
                }
                cu->cu_error.re_errno = errno;
                return (cu->cu_error.re_status);
        }

        /*
         * sub-optimal code appears here because we have
         * some clock time to spare while the packets are in flight.
         * (We assume that this is actually only executed once.)
         */
recv_again:
        reply_msg.acpted_rply.ar_verf = _null_auth;
        reply_msg.acpted_rply.ar_results.where = resultsp;
        reply_msg.acpted_rply.ar_results.proc = xresults;

        for (;;) {
                if (errors >= RPC_ALLOWABLE_ERRORS)
                        return (cu->cu_error.re_status);

                if (prom_gettime() >= wait_time) {
                        cu->cu_error.re_errno = ETIMEDOUT;
                        return (cu->cu_error.re_status = RPC_TIMEDOUT);
                }

                /*
                 * Use MSG_DONTWAIT because we have set
                 * a media level timeout above.
                 */
                fromlen = sizeof (struct sockaddr);

                inlen = recvfrom(cu->cu_sock, cu->cu_inbuf,
                    (int)cu->cu_recvsz, MSG_DONTWAIT,
                    (struct sockaddr *)&from, &fromlen);

                if (inlen < 0) {
                        if (errno == EWOULDBLOCK) {
                                /*
                                 * Media level has timedout
                                 * and no more data in buffers.
                                 */
                                goto send_again;
                        }

                        cu->cu_error.re_status = RPC_CANTRECV;
                        if (errno == ETIMEDOUT) {
                                errno = ETIMEDOUT;
                                cu->cu_error.re_status = RPC_TIMEDOUT;
                        }

                        cu->cu_error.re_errno = errno;
                        return (cu->cu_error.re_status);
                }

                if (inlen < sizeof (uint32_t))
                        continue;

                /* see if reply transaction id matches sent id */
                if (*((uint32_t *)(cu->cu_inbuf)) !=
                    *((uint32_t *)(cu->cu_outbuf))) {
                        dprintf("clntbudp_call: xid: 0x%x != 0x%x\n",
                            *(uint32_t *)(cu->cu_inbuf),
                            *(uint32_t *)(cu->cu_outbuf));
                        continue;
                }
                /* we now assume we have the proper reply */
                break;
        }

        /*
         * now decode and validate the response
         */
        xdrmem_create(&reply_xdrs, cu->cu_inbuf, (uint_t)inlen, XDR_DECODE);
        ok = xdr_replymsg(&reply_xdrs, &reply_msg);
        /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
        if (!ok) {
                cu->cu_error.re_status = RPC_CANTDECODERES;
                return (cu->cu_error.re_status);
        }

        _seterr_reply(&reply_msg, &(cu->cu_error));
        if (cu->cu_error.re_status == RPC_SUCCESS) {
                if (! AUTH_VALIDATE(cl->cl_auth,
                    &reply_msg.acpted_rply.ar_verf)) {
                        cu->cu_error.re_status = RPC_AUTHERROR;
                        cu->cu_error.re_why = AUTH_INVALIDRESP;
                        errors++;
                        goto call_again;
                }
                if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
                        xdrs->x_op = XDR_FREE;
                        (void) xdr_opaque_auth(xdrs,
                            &(reply_msg.acpted_rply.ar_verf));
                }
                return (cu->cu_error.re_status);
        }  /* end successful completion */

        if (cu->cu_error.re_status == RPC_AUTHERROR) {
                /* maybe our credentials need to be refreshed ... */
                if (nrefreshes > 0 &&
                    AUTH_REFRESH(cl->cl_auth, NULL, NULL)) {
                        nrefreshes--;
                }
                errors++;
                goto call_again;
        }

        /* Just keep trying till there's no data... */
        errors++;
        dprintf("clntbudp_call: from: %s, error: ",
            inet_ntoa(from.sin_addr));
        rpc_disperr(&cu->cu_error);
        goto recv_again;
}

static void
clntbudp_geterr(CLIENT *cl, struct rpc_err *errp)
{
        struct cu_data *cu = (struct cu_data *)cl->cl_private;

        *errp = cu->cu_error;
}


static bool_t
clntbudp_freeres(CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
{
        struct cu_data *cu = (struct cu_data *)cl->cl_private;
        XDR *xdrs = &(cu->cu_outxdrs);

        xdrs->x_op = XDR_FREE;
        return ((*xdr_res)(xdrs, res_ptr));
}

static void
clntbudp_abort(void)
{
}

/* ARGSUSED */
static bool_t
clntbudp_control(CLIENT *cl, int request, char *info)
{
        /* CLNT_CONTROL is not used in boot */
        return (FALSE);
}

static void
clntbudp_destroy(CLIENT *cl)
{
        struct cu_data *cu = (struct cu_data *)cl->cl_private;

        if (cu->cu_closeit) {
                (void) socket_close(cu->cu_sock);
        }
        XDR_DESTROY(&(cu->cu_outxdrs));
        bkmem_free((caddr_t)cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
        bkmem_free((caddr_t)cl, sizeof (CLIENT));
}

static struct clnt_ops *
clntbudp_ops(void)
{
        static struct clnt_ops ops;

        if (ops.cl_call == NULL) {
                ops.cl_call = clntbudp_call;
                ops.cl_abort = clntbudp_abort;
                ops.cl_geterr = clntbudp_geterr;
                ops.cl_freeres = clntbudp_freeres;
                ops.cl_destroy = clntbudp_destroy;
                ops.cl_control = clntbudp_control;
        }
        return (&ops);
}