/*
 * 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 2014 Gary Mills
 * Copyright 2009 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.
 */

/*
 * svc_dg.c, Server side for connectionless RPC.
 *
 * Does some caching in the hopes of achieving execute-at-most-once semantics.
 */

#include "mt.h"
#include "rpc_mt.h"
#include <stdio.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#include <rpc/rpc.h>
#include <rpcsvc/svc_dg_priv.h>
#include <errno.h>
#include <syslog.h>
#include <stdlib.h>
#include <string.h>
#include <ucred.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#ifdef RPC_CACHE_DEBUG
#include <netconfig.h>
#include <netdir.h>
#endif

#ifndef MAX
#define MAX(a, b)       (((a) > (b)) ? (a) : (b))
#endif

static struct xp_ops *svc_dg_ops();
static void cache_set();
static int cache_get();

#define rpc_buffer(xprt) ((xprt)->xp_p1)

/*
 * Usage:
 *      xprt = svc_dg_create(sock, sendsize, recvsize);
 * Does other connectionless specific initializations.
 * Once *xprt is initialized, it is registered.
 * see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
 * system defaults are chosen.
 * The routines returns NULL if a problem occurred.
 */
static const char svc_dg_str[] = "svc_dg_create: %s";
static const char svc_dg_err1[] = "could not get transport information";
static const char svc_dg_err2[] = " transport does not support data transfer";
static const char svc_dg_err3[] =
                "fd > FD_SETSIZE; Use rpc_control(RPC_SVC_USE_POLLFD,...);";
static const char __no_mem_str[] = "out of memory";

/* Structure used to initialize SVC_XP_AUTH(xprt).svc_ah_ops. */
extern struct svc_auth_ops svc_auth_any_ops;
extern int __rpc_get_ltaddr(struct netbuf *, struct netbuf *);

void
svc_dg_xprtfree(SVCXPRT *xprt)
{
/* LINTED pointer alignment */
        SVCXPRT_EXT             *xt = xprt ? SVCEXT(xprt) : NULL;
/* LINTED pointer alignment */
        struct svc_dg_data      *su = xprt ? get_svc_dg_data(xprt) : NULL;

        if (xprt == NULL)
                return;
        if (xprt->xp_netid)
                free(xprt->xp_netid);
        if (xprt->xp_tp)
                free(xprt->xp_tp);
        if (xt->parent == NULL)
                if (xprt->xp_ltaddr.buf)
                        free(xprt->xp_ltaddr.buf);
        if (xprt->xp_rtaddr.buf)
                free(xprt->xp_rtaddr.buf);
        if (su != NULL) {
                XDR_DESTROY(&(su->su_xdrs));
                free(su);
        }
        if (rpc_buffer(xprt))
                free(rpc_buffer(xprt));
        svc_xprt_free(xprt);
}

SVCXPRT *
svc_dg_create_private(int fd, uint_t sendsize, uint_t recvsize)
{
        SVCXPRT *xprt;
        struct svc_dg_data *su = NULL;
        struct t_info tinfo;
        size_t ucred_sz = ucred_size();

        if (RPC_FD_NOTIN_FDSET(fd)) {
                errno = EBADF;
                t_errno = TBADF;
                syslog(LOG_ERR, svc_dg_str, svc_dg_err3);
                return (NULL);
        }

        if (t_getinfo(fd, &tinfo) == -1) {
                syslog(LOG_ERR, svc_dg_str, svc_dg_err1);
                return (NULL);
        }
        /*
         * Find the receive and the send size
         */
        sendsize = __rpc_get_t_size((int)sendsize, tinfo.tsdu);
        recvsize = __rpc_get_t_size((int)recvsize, tinfo.tsdu);
        if ((sendsize == 0) || (recvsize == 0)) {
                syslog(LOG_ERR, svc_dg_str, svc_dg_err2);
                return (NULL);
        }

        if ((xprt = svc_xprt_alloc()) == NULL)
                goto freedata;
/* LINTED pointer alignment */
        svc_flags(xprt) |= SVC_DGRAM;

        su = malloc(sizeof (*su) + ucred_sz);
        if (su == NULL)
                goto freedata;
        su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
        if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL)
                goto freedata;
        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
            XDR_DECODE);
        su->su_cache = NULL;
        xprt->xp_fd = fd;
        xprt->xp_p2 = (caddr_t)su;
        xprt->xp_verf.oa_base = su->su_verfbody;
        xprt->xp_ops = svc_dg_ops();

        su->su_tudata.addr.maxlen =  0; /* Fill in later */

        su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
        su->su_tudata.opt.buf = (char *)su->opts;
        su->su_tudata.udata.maxlen = su->su_iosz;
        su->su_tudata.opt.maxlen = MAX_OPT_WORDS * sizeof (int) + ucred_sz;
/* LINTED pointer alignment */
        SVC_XP_AUTH(xprt).svc_ah_ops = svc_auth_any_ops;
/* LINTED pointer alignment */
        SVC_XP_AUTH(xprt).svc_ah_private = NULL;
        return (xprt);
freedata:
        (void) syslog(LOG_ERR, svc_dg_str, __no_mem_str);
        if (xprt)
                svc_dg_xprtfree(xprt);
        return (NULL);
}

SVCXPRT *
svc_dg_create(const int fd, const uint_t sendsize, const uint_t recvsize)
{
        SVCXPRT *xprt;

        if ((xprt = svc_dg_create_private(fd, sendsize, recvsize)) != NULL)
                xprt_register(xprt);
        return (xprt);
}

SVCXPRT *
svc_dg_xprtcopy(SVCXPRT *parent)
{
        SVCXPRT                 *xprt;
        struct svc_dg_data      *su;
        size_t                  ucred_sz = ucred_size();

        if ((xprt = svc_xprt_alloc()) == NULL)
                return (NULL);

/* LINTED pointer alignment */
        SVCEXT(xprt)->parent = parent;
/* LINTED pointer alignment */
        SVCEXT(xprt)->flags = SVCEXT(parent)->flags;

        xprt->xp_fd = parent->xp_fd;
        xprt->xp_port = parent->xp_port;
        xprt->xp_ops = svc_dg_ops();
        if (parent->xp_tp) {
                xprt->xp_tp = (char *)strdup(parent->xp_tp);
                if (xprt->xp_tp == NULL) {
                        syslog(LOG_ERR, "svc_dg_xprtcopy: strdup failed");
                        svc_dg_xprtfree(xprt);
                        return (NULL);
                }
        }
        if (parent->xp_netid) {
                xprt->xp_netid = (char *)strdup(parent->xp_netid);
                if (xprt->xp_netid == NULL) {
                        syslog(LOG_ERR, "svc_dg_xprtcopy: strdup failed");
                        if (parent->xp_tp)
                                free(parent->xp_tp);
                        svc_dg_xprtfree(xprt);
                        return (NULL);
                }
        }
        xprt->xp_ltaddr = parent->xp_ltaddr;    /* shared with parent */

        xprt->xp_rtaddr = parent->xp_rtaddr;
        xprt->xp_rtaddr.buf = malloc(xprt->xp_rtaddr.maxlen);
        if (xprt->xp_rtaddr.buf == NULL) {
                svc_dg_xprtfree(xprt);
                return (NULL);
        }
        (void) memcpy(xprt->xp_rtaddr.buf, parent->xp_rtaddr.buf,
            xprt->xp_rtaddr.maxlen);
        xprt->xp_type = parent->xp_type;

        if ((su = malloc(sizeof (struct svc_dg_data) + ucred_sz)) == NULL) {
                svc_dg_xprtfree(xprt);
                return (NULL);
        }
/* LINTED pointer alignment */
        su->su_iosz = get_svc_dg_data(parent)->su_iosz;
        if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL) {
                svc_dg_xprtfree(xprt);
                free(su);
                return (NULL);
        }
        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
            XDR_DECODE);
        su->su_cache = NULL;
        su->su_tudata.addr.maxlen =  0; /* Fill in later */
        su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
        su->su_tudata.opt.buf = (char *)su->opts;
        su->su_tudata.udata.maxlen = su->su_iosz;
        su->su_tudata.opt.maxlen = MAX_OPT_WORDS * sizeof (int) + ucred_sz;
        xprt->xp_p2 = (caddr_t)su;      /* get_svc_dg_data(xprt) = su */
        xprt->xp_verf.oa_base = su->su_verfbody;

        return (xprt);
}

/*ARGSUSED*/
static enum xprt_stat
svc_dg_stat(SVCXPRT *xprt)
{
        return (XPRT_IDLE);
}

/*
 * Find the SCM_UCRED in src and place a pointer to that option alone in dest.
 * Note that these two 'netbuf' structures might be the same one, so the code
 * has to be careful about referring to src after changing dest.
 */
static void
extract_cred(const struct netbuf *src, struct netbuf *dest)
{
        char *cp = src->buf;
        unsigned int len = src->len;
        const struct T_opthdr *opt;
        unsigned int olen;

        while (len >= sizeof (*opt)) {
                /* LINTED: pointer alignment */
                opt = (const struct T_opthdr *)cp;
                olen = opt->len;
                if (olen > len || olen < sizeof (*opt) ||
                    !IS_P2ALIGNED(olen, sizeof (t_uscalar_t)))
                        break;
                if (opt->level == SOL_SOCKET && opt->name == SCM_UCRED) {
                        dest->buf = cp;
                        dest->len = olen;
                        return;
                }
                cp += olen;
                len -= olen;
        }
        dest->len = 0;
}

/*
 * This routine extracts the destination IP address of the inbound RPC packet
 * and sets that as source IP address for the outbound response.
 */
static void
set_src_addr(SVCXPRT *xprt, struct netbuf *opt)
{
        struct netbuf *nbufp, *ltaddr;
        struct T_opthdr *opthdr;
        in_pktinfo_t *pktinfo;
        struct sockaddr_in *sock = (struct sockaddr_in *)NULL;

        /* extract dest IP of inbound packet */
        /* LINTED pointer alignment */
        nbufp = (struct netbuf *)xprt->xp_p2;
        ltaddr = &xprt->xp_ltaddr;
        if (__rpc_get_ltaddr(nbufp, ltaddr) != 0)
                return;

        /* do nothing for non-IPv4 packet */
        /* LINTED pointer alignment */
        sock = (struct sockaddr_in *)ltaddr->buf;
        if (sock->sin_family != AF_INET)
                return;

        /* set desired option header */
        opthdr = (struct T_opthdr *)memalign(sizeof (int),
            sizeof (struct T_opthdr) + sizeof (in_pktinfo_t));
        if (opthdr == NULL)
                return;
        opthdr->len = sizeof (struct T_opthdr) + sizeof (in_pktinfo_t);
        opthdr->level = IPPROTO_IP;
        opthdr->name = IP_PKTINFO;

        /*
         * 1. set source IP of outbound packet
         * 2. value '0' for index means IP layer uses this as source address
         */
        pktinfo = (in_pktinfo_t *)(opthdr + 1);
        (void) memset(pktinfo, 0, sizeof (in_pktinfo_t));
        pktinfo->ipi_spec_dst.s_addr = sock->sin_addr.s_addr;
        pktinfo->ipi_ifindex = 0;

        /* copy data into ancillary buffer */
        if (opthdr->len + opt->len <= opt->maxlen) {
                (void) memcpy((void *)(opt->buf+opt->len), (const void *)opthdr,
                    opthdr->len);
                opt->len += opthdr->len;
        }
        free(opthdr);
}

static bool_t
svc_dg_recv(SVCXPRT *xprt, struct rpc_msg *msg)
{
/* LINTED pointer alignment */
        struct svc_dg_data *su = get_svc_dg_data(xprt);
        XDR *xdrs = &(su->su_xdrs);
        struct t_unitdata *tu_data = &(su->su_tudata);
        int moreflag;
        struct netbuf *nbufp;
        struct netconfig *nconf;

        /* XXX: tudata should have been made a part of the server handle */
        if (tu_data->addr.maxlen == 0)
                tu_data->addr = xprt->xp_rtaddr;
again:
        tu_data->addr.len = 0;
        tu_data->opt.len  = 0;
        tu_data->udata.len  = 0;

        moreflag = 0;
        if (t_rcvudata(xprt->xp_fd, tu_data, &moreflag) == -1) {
#ifdef RPC_DEBUG
                syslog(LOG_ERR, "svc_dg_recv: t_rcvudata t_errno=%d errno=%d\n",
                    t_errno, errno);
#endif
                if (t_errno == TLOOK) {
                        int lookres;

                        lookres = t_look(xprt->xp_fd);
                        if ((lookres == T_UDERR) &&
                            (t_rcvuderr(xprt->xp_fd,
                                    (struct t_uderr *)0) < 0)) {
                                /*EMPTY*/
#ifdef RPC_DEBUG
                                syslog(LOG_ERR,
                                "svc_dg_recv: t_rcvuderr t_errno = %d\n",
                                        t_errno);
#endif
                        }
                        if (lookres == T_DATA)
                                goto again;
                } else if ((errno == EINTR) && (t_errno == TSYSERR))
                        goto again;
                else {
                        return (FALSE);
                }
        }

        if ((moreflag) ||
            (tu_data->udata.len < 4 * (uint_t)sizeof (uint32_t))) {
                /*
                 * If moreflag is set, drop that data packet. Something wrong
                 */
                return (FALSE);
        }
        su->optbuf = tu_data->opt;
        xprt->xp_rtaddr.len = tu_data->addr.len;
        xdrs->x_op = XDR_DECODE;
        XDR_SETPOS(xdrs, 0);
        if (!xdr_callmsg(xdrs, msg))
                return (FALSE);
        su->su_xid = msg->rm_xid;
        if (su->su_cache != NULL) {
                char *reply;
                uint32_t replylen;

                if (cache_get(xprt, msg, &reply, &replylen)) {
                        /* tu_data.addr is already set */
                        tu_data->udata.buf = reply;
                        tu_data->udata.len = (uint_t)replylen;
                        extract_cred(&tu_data->opt, &tu_data->opt);
                        set_src_addr(xprt, &tu_data->opt);
                        (void) t_sndudata(xprt->xp_fd, tu_data);
                        tu_data->udata.buf = (char *)rpc_buffer(xprt);
                        tu_data->opt.buf = (char *)su->opts;
                        return (FALSE);
                }
        }

        /*
         * get local ip address
         */

        if ((nconf = getnetconfigent(xprt->xp_netid)) != NULL) {
                if (strcmp(nconf->nc_protofmly, NC_INET) == 0 ||
                    strcmp(nconf->nc_protofmly, NC_INET6) == 0) {
                        if (nconf->nc_semantics == NC_TPI_CLTS) {
                                /* LINTED pointer cast */
                                nbufp = (struct netbuf *)(xprt->xp_p2);
                                if (__rpc_get_ltaddr(nbufp,
                                    &xprt->xp_ltaddr) < 0) {
                                        if (strcmp(nconf->nc_protofmly,
                                            NC_INET) == 0) {
                                                syslog(LOG_ERR,
                                                    "svc_dg_recv: ip(udp), "
                                                    "t_errno=%d, errno=%d",
                                                    t_errno, errno);
                                        }
                                        if (strcmp(nconf->nc_protofmly,
                                            NC_INET6) == 0) {
                                                syslog(LOG_ERR,
                                                    "svc_dg_recv: ip (udp6), "
                                                    "t_errno=%d, errno=%d",
                                                    t_errno, errno);
                                        }
                                        freenetconfigent(nconf);
                                        return (FALSE);
                                }
                        }
                }
                freenetconfigent(nconf);
        }
        return (TRUE);
}

static bool_t
svc_dg_reply(SVCXPRT *xprt, struct rpc_msg *msg)
{
/* LINTED pointer alignment */
        struct svc_dg_data *su = get_svc_dg_data(xprt);
        XDR *xdrs = &(su->su_xdrs);
        bool_t stat = FALSE;
        xdrproc_t xdr_results;
        caddr_t xdr_location;
        bool_t has_args;

        if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
            msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
                has_args = TRUE;
                xdr_results = msg->acpted_rply.ar_results.proc;
                xdr_location = msg->acpted_rply.ar_results.where;
                msg->acpted_rply.ar_results.proc = xdr_void;
                msg->acpted_rply.ar_results.where = NULL;
        } else
                has_args = FALSE;

        xdrs->x_op = XDR_ENCODE;
        XDR_SETPOS(xdrs, 0);
        msg->rm_xid = su->su_xid;
        if (xdr_replymsg(xdrs, msg) && (!has_args ||
/* LINTED pointer alignment */
            SVCAUTH_WRAP(&SVC_XP_AUTH(xprt), xdrs, xdr_results,
            xdr_location))) {
                int slen;
                struct t_unitdata *tu_data = &(su->su_tudata);

                slen = (int)XDR_GETPOS(xdrs);
                tu_data->udata.len = slen;
                extract_cred(&su->optbuf, &tu_data->opt);
                set_src_addr(xprt, &tu_data->opt);
try_again:
                if (t_sndudata(xprt->xp_fd, tu_data) == 0) {
                        stat = TRUE;
                        if (su->su_cache && slen >= 0) {
                                cache_set(xprt, (uint32_t)slen);
                        }
                } else {
                        if (errno == EINTR)
                                goto try_again;

                        syslog(LOG_ERR,
                            "svc_dg_reply: t_sndudata error t_errno=%d ",
                            "errno=%d\n", t_errno, errno);
                }
                tu_data->opt.buf = (char *)su->opts;
        }
        return (stat);
}

static bool_t
svc_dg_getargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
{
        if (svc_mt_mode != RPC_SVC_MT_NONE)
                svc_args_done(xprt);
/* LINTED pointer alignment */
        return (SVCAUTH_UNWRAP(&SVC_XP_AUTH(xprt),
            &(get_svc_dg_data(xprt)->su_xdrs), xdr_args, args_ptr));
}

static bool_t
svc_dg_freeargs(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
{
/* LINTED pointer alignment */
        XDR *xdrs = &(get_svc_dg_data(xprt)->su_xdrs);

        xdrs->x_op = XDR_FREE;
        return ((*xdr_args)(xdrs, args_ptr));
}

static void
svc_dg_destroy(SVCXPRT *xprt)
{
        (void) mutex_lock(&svc_mutex);
        _svc_dg_destroy_private(xprt);
        (void) mutex_unlock(&svc_mutex);
}

void
_svc_dg_destroy_private(SVCXPRT *xprt)
{
        if (svc_mt_mode != RPC_SVC_MT_NONE) {
/* LINTED pointer alignment */
                if (SVCEXT(xprt)->parent)
/* LINTED pointer alignment */
                        xprt = SVCEXT(xprt)->parent;
/* LINTED pointer alignment */
                svc_flags(xprt) |= SVC_DEFUNCT;
/* LINTED pointer alignment */
                if (SVCEXT(xprt)->refcnt > 0)
                        return;
        }

        xprt_unregister(xprt);
        (void) t_close(xprt->xp_fd);

        if (svc_mt_mode != RPC_SVC_MT_NONE)
                svc_xprt_destroy(xprt);
        else
                svc_dg_xprtfree(xprt);
}

/*ARGSUSED*/
static bool_t
svc_dg_control(SVCXPRT *xprt, const uint_t rq, void *in)
{
        switch (rq) {
        case SVCGET_XID:
                if (xprt->xp_p2 == NULL)
                        return (FALSE);
                /* LINTED pointer alignment */
                *(uint32_t *)in = ((struct svc_dg_data *)(xprt->xp_p2))->su_xid;
                return (TRUE);
        default:
                return (FALSE);
        }
}

static struct xp_ops *
svc_dg_ops(void)
{
        static struct xp_ops ops;
        extern mutex_t ops_lock;

/* VARIABLES PROTECTED BY ops_lock: ops */

        (void) mutex_lock(&ops_lock);
        if (ops.xp_recv == NULL) {
                ops.xp_recv = svc_dg_recv;
                ops.xp_stat = svc_dg_stat;
                ops.xp_getargs = svc_dg_getargs;
                ops.xp_reply = svc_dg_reply;
                ops.xp_freeargs = svc_dg_freeargs;
                ops.xp_destroy = svc_dg_destroy;
                ops.xp_control = svc_dg_control;
        }
        (void) mutex_unlock(&ops_lock);
        return (&ops);
}

/*  The CACHING COMPONENT */

/*
 * Could have been a separate file, but some part of it depends upon the
 * private structure of the client handle.
 *
 * Fifo cache for cl server
 * Copies pointers to reply buffers into fifo cache
 * Buffers are sent again if retransmissions are detected.
 */

#define SPARSENESS 4    /* 75% sparse */

/*
 * An entry in the cache
 */
typedef struct cache_node *cache_ptr;
struct cache_node {
        /*
         * Index into cache is xid, proc, vers, prog and address
         */
        uint32_t cache_xid;
        rpcproc_t cache_proc;
        rpcvers_t cache_vers;
        rpcprog_t cache_prog;
        struct netbuf cache_addr;
        /*
         * The cached reply and length
         */
        char *cache_reply;
        uint32_t cache_replylen;
        /*
         * Next node on the list, if there is a collision
         */
        cache_ptr cache_next;
};

/*
 * The entire cache
 */
struct cl_cache {
        uint32_t uc_size;               /* size of cache */
        cache_ptr *uc_entries;  /* hash table of entries in cache */
        cache_ptr *uc_fifo;     /* fifo list of entries in cache */
        uint32_t uc_nextvictim; /* points to next victim in fifo list */
        rpcprog_t uc_prog;      /* saved program number */
        rpcvers_t uc_vers;      /* saved version number */
        rpcproc_t uc_proc;      /* saved procedure number */
};


/*
 * the hashing function
 */
#define CACHE_LOC(transp, xid)  \
        (xid % (SPARSENESS * ((struct cl_cache *) \
                get_svc_dg_data(transp)->su_cache)->uc_size))

extern mutex_t  dupreq_lock;

/*
 * Enable use of the cache. Returns 1 on success, 0 on failure.
 * Note: there is no disable.
 */
static const char cache_enable_str[] = "svc_enablecache: %s %s";
static const char alloc_err[] = "could not allocate cache ";
static const char enable_err[] = "cache already enabled";

int
svc_dg_enablecache(SVCXPRT *xprt, const uint_t size)
{
        SVCXPRT *transp;
        struct svc_dg_data *su;
        struct cl_cache *uc;

/* LINTED pointer alignment */
        if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
/* LINTED pointer alignment */
                transp = SVCEXT(xprt)->parent;
        else
                transp = xprt;
/* LINTED pointer alignment */
        su = get_svc_dg_data(transp);

        (void) mutex_lock(&dupreq_lock);
        if (su->su_cache != NULL) {
                (void) syslog(LOG_ERR, cache_enable_str,
                    enable_err, " ");
                (void) mutex_unlock(&dupreq_lock);
                return (0);
        }
        uc = malloc(sizeof (struct cl_cache));
        if (uc == NULL) {
                (void) syslog(LOG_ERR, cache_enable_str,
                    alloc_err, " ");
                (void) mutex_unlock(&dupreq_lock);
                return (0);
        }
        uc->uc_size = size;
        uc->uc_nextvictim = 0;
        uc->uc_entries = calloc(size * SPARSENESS, sizeof (cache_ptr));
        if (uc->uc_entries == NULL) {
                (void) syslog(LOG_ERR, cache_enable_str, alloc_err, "data");
                free(uc);
                (void) mutex_unlock(&dupreq_lock);
                return (0);
        }
        uc->uc_fifo = calloc(size, sizeof (cache_ptr));
        if (uc->uc_fifo == NULL) {
                (void) syslog(LOG_ERR, cache_enable_str, alloc_err, "fifo");
                free(uc->uc_entries);
                free(uc);
                (void) mutex_unlock(&dupreq_lock);
                return (0);
        }
        su->su_cache = (char *)uc;
        (void) mutex_unlock(&dupreq_lock);
        return (1);
}

/*
 * Set an entry in the cache.  It assumes that the uc entry is set from
 * the earlier call to cache_get() for the same procedure.  This will always
 * happen because cache_get() is calle by svc_dg_recv and cache_set() is called
 * by svc_dg_reply().  All this hoopla because the right RPC parameters are
 * not available at svc_dg_reply time.
 */

static const char cache_set_str[] = "cache_set: %s";
static const char cache_set_err1[] = "victim not found";
static const char cache_set_err2[] = "victim alloc failed";
static const char cache_set_err3[] = "could not allocate new rpc buffer";

static void
cache_set(SVCXPRT *xprt, uint32_t replylen)
{
        SVCXPRT *parent;
        cache_ptr victim;
        cache_ptr *vicp;
        struct svc_dg_data *su;
        struct cl_cache *uc;
        uint_t loc;
        char *newbuf, *newbuf2;
        int my_mallocs = 0;
#ifdef RPC_CACHE_DEBUG
        struct netconfig *nconf;
        char *uaddr;
#endif

/* LINTED pointer alignment */
        if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
/* LINTED pointer alignment */
                parent = SVCEXT(xprt)->parent;
        else
                parent = xprt;
/* LINTED pointer alignment */
        su = get_svc_dg_data(xprt);
/* LINTED pointer alignment */
        uc = (struct cl_cache *)get_svc_dg_data(parent)->su_cache;

        (void) mutex_lock(&dupreq_lock);
        /*
         * Find space for the new entry, either by
         * reusing an old entry, or by mallocing a new one
         */
        victim = uc->uc_fifo[uc->uc_nextvictim];
        if (victim != NULL) {
/* LINTED pointer alignment */
                loc = CACHE_LOC(parent, victim->cache_xid);
                for (vicp = &uc->uc_entries[loc];
                    *vicp != NULL && *vicp != victim;
                    vicp = &(*vicp)->cache_next)
                        ;
                if (*vicp == NULL) {
                        (void) syslog(LOG_ERR, cache_set_str, cache_set_err1);
                        (void) mutex_unlock(&dupreq_lock);
                        return;
                }
                *vicp = victim->cache_next;     /* remove from cache */
                newbuf = victim->cache_reply;
        } else {
                victim = malloc(sizeof (struct cache_node));
                if (victim == NULL) {
                        (void) syslog(LOG_ERR, cache_set_str, cache_set_err2);
                        (void) mutex_unlock(&dupreq_lock);
                        return;
                }
                newbuf = malloc(su->su_iosz);
                if (newbuf == NULL) {
                        (void) syslog(LOG_ERR, cache_set_str, cache_set_err3);
                        free(victim);
                        (void) mutex_unlock(&dupreq_lock);
                        return;
                }
                my_mallocs = 1;
        }

        /*
         * Store it away
         */
#ifdef RPC_CACHE_DEBUG
        if (nconf = getnetconfigent(xprt->xp_netid)) {
                uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
                freenetconfigent(nconf);
                printf(
        "cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
                    su->su_xid, uc->uc_prog, uc->uc_vers, uc->uc_proc, uaddr);
                free(uaddr);
        }
#endif
        newbuf2 = malloc(sizeof (char) * xprt->xp_rtaddr.len);
        if (newbuf2 == NULL) {
                syslog(LOG_ERR, "cache_set : out of memory");
                if (my_mallocs) {
                        free(victim);
                        free(newbuf);
                }
                (void) mutex_unlock(&dupreq_lock);
                return;
        }
        victim->cache_replylen = replylen;
        victim->cache_reply = rpc_buffer(xprt);
        rpc_buffer(xprt) = newbuf;
        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
            XDR_ENCODE);
        su->su_tudata.udata.buf = (char *)rpc_buffer(xprt);
        victim->cache_xid = su->su_xid;
        victim->cache_proc = uc->uc_proc;
        victim->cache_vers = uc->uc_vers;
        victim->cache_prog = uc->uc_prog;
        victim->cache_addr = xprt->xp_rtaddr;
        victim->cache_addr.buf = newbuf2;
        (void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
            (int)xprt->xp_rtaddr.len);
/* LINTED pointer alignment */
        loc = CACHE_LOC(parent, victim->cache_xid);
        victim->cache_next = uc->uc_entries[loc];
        uc->uc_entries[loc] = victim;
        uc->uc_fifo[uc->uc_nextvictim++] = victim;
        uc->uc_nextvictim %= uc->uc_size;
        (void) mutex_unlock(&dupreq_lock);
}

/*
 * Try to get an entry from the cache
 * return 1 if found, 0 if not found and set the stage for cache_set()
 */
static int
cache_get(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp,
                                                        uint32_t *replylenp)
{
        SVCXPRT *parent;
        uint_t loc;
        cache_ptr ent;
        struct svc_dg_data *su;
        struct cl_cache *uc;
#ifdef RPC_CACHE_DEBUG
        struct netconfig *nconf;
        char *uaddr;
#endif

/* LINTED pointer alignment */
        if (svc_mt_mode != RPC_SVC_MT_NONE && SVCEXT(xprt)->parent != NULL)
/* LINTED pointer alignment */
                parent = SVCEXT(xprt)->parent;
        else
                parent = xprt;
/* LINTED pointer alignment */
        su = get_svc_dg_data(xprt);
/* LINTED pointer alignment */
        uc = (struct cl_cache *)get_svc_dg_data(parent)->su_cache;

        (void) mutex_lock(&dupreq_lock);
/* LINTED pointer alignment */
        loc = CACHE_LOC(parent, su->su_xid);
        for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {
                if (ent->cache_xid == su->su_xid &&
                    ent->cache_proc == msg->rm_call.cb_proc &&
                    ent->cache_vers == msg->rm_call.cb_vers &&
                    ent->cache_prog == msg->rm_call.cb_prog &&
                    ent->cache_addr.len == xprt->xp_rtaddr.len &&
                    (memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
                    xprt->xp_rtaddr.len) == 0)) {
#ifdef RPC_CACHE_DEBUG
                        if (nconf = getnetconfigent(xprt->xp_netid)) {
                                uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
                                freenetconfigent(nconf);
                                printf(
        "cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
                                    su->su_xid, msg->rm_call.cb_prog,
                                    msg->rm_call.cb_vers,
                                    msg->rm_call.cb_proc, uaddr);
                                free(uaddr);
                        }
#endif
                        *replyp = ent->cache_reply;
                        *replylenp = ent->cache_replylen;
                        (void) mutex_unlock(&dupreq_lock);
                        return (1);
                }
        }
        /*
         * Failed to find entry
         * Remember a few things so we can do a set later
         */
        uc->uc_proc = msg->rm_call.cb_proc;
        uc->uc_vers = msg->rm_call.cb_vers;
        uc->uc_prog = msg->rm_call.cb_prog;
        (void) mutex_unlock(&dupreq_lock);
        return (0);
}