/*      $NetBSD: rpc_generic.c,v 1.30 2017/05/03 21:39:27 christos Exp $        */

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * 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 the "Oracle America, 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.
 */
/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
 */

/* #pragma ident        "@(#)rpc_generic.c      1.17    94/04/24 SMI" */

/*
 * rpc_generic.c, Miscl routines for RPC.
 *
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: rpc_generic.c,v 1.30 2017/05/03 21:39:27 christos Exp $");
#endif

#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/resource.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <assert.h>
#include <ctype.h>
#include <stdio.h>
#include <netdb.h>
#include <netconfig.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <rpc/nettype.h>

#include "svc_fdset.h"
#include "rpc_internal.h"

#ifdef __weak_alias
__weak_alias(taddr2uaddr,_taddr2uaddr)
__weak_alias(uaddr2taddr,_uaddr2taddr)
#endif

struct handle {
        NCONF_HANDLE *nhandle;
        int nflag;              /* Whether NETPATH or NETCONFIG */
        int nettype;
};

static const struct _rpcnettype {
        const char *name;
        const int type;
} _rpctypelist[] = {
        { "netpath", _RPC_NETPATH },
        { "visible", _RPC_VISIBLE },
        { "circuit_v", _RPC_CIRCUIT_V },
        { "datagram_v", _RPC_DATAGRAM_V },
        { "circuit_n", _RPC_CIRCUIT_N },
        { "datagram_n", _RPC_DATAGRAM_N },
        { "tcp", _RPC_TCP },
        { "udp", _RPC_UDP },
        { 0, _RPC_NONE }
};

struct netid_af {
        const char      *netid;
        int             af;
        int             protocol;
};

static const struct netid_af na_cvt[] = {
        { "udp",  AF_INET,  IPPROTO_UDP },
        { "tcp",  AF_INET,  IPPROTO_TCP },
#ifdef INET6
        { "udp6", AF_INET6, IPPROTO_UDP },
        { "tcp6", AF_INET6, IPPROTO_TCP },
#endif
        { "local", AF_LOCAL, 0 }
};

#if 0
static char *strlocase(char *);
#endif
static int getnettype(const char *);

/*
 * Cache the result of getrlimit(), so we don't have to do an
 * expensive call every time.
 */
int
__rpc_dtbsize(void)
{
        static int tbsize;
        struct rlimit rl;

        if (tbsize) {
                return (tbsize);
        }
        if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
                return (tbsize = (int)rl.rlim_max);
        }
        /*
         * Something wrong.  I'll try to save face by returning a
         * pessimistic number.
         */
        return (32);
}


/*
 * Find the appropriate buffer size
 */
u_int
/*ARGSUSED*/
__rpc_get_t_size(
        int af,
        int proto,
        int size)       /* Size requested */
{
        int maxsize, defsize;

        maxsize = 256 * 1024;   /* XXX */
        switch (proto) {
        case IPPROTO_TCP:
                defsize = 64 * 1024;    /* XXX */
                break;
        case IPPROTO_UDP:
                defsize = UDPMSGSIZE;
                break;
        default:
                defsize = RPC_MAXDATASIZE;
                break;
        }
        if (size == 0)
                return defsize;

        /* Check whether the value is within the upper max limit */
        return (size > maxsize ? (u_int)maxsize : (u_int)size);
}

/*
 * Find the appropriate address buffer size
 */
u_int
__rpc_get_a_size(int af)
{
        switch (af) {
        case AF_INET:
                return sizeof (struct sockaddr_in);
#ifdef INET6
        case AF_INET6:
                return sizeof (struct sockaddr_in6);
#endif
        case AF_LOCAL:
                return sizeof (struct sockaddr_un);
        default:
                break;
        }
        return ((u_int)RPC_MAXADDRSIZE);
}

#if 0
static char *
strlocase(char *p)
{
        char *t = p;

        _DIAGASSERT(p != NULL);

        for (; *p; p++)
                if (isupper(*p))
                        *p = tolower(*p);
        return (t);
}
#endif

/*
 * Returns the type of the network as defined in <rpc/nettype.h>
 * If nettype is NULL, it defaults to NETPATH.
 */
static int
getnettype(const char *nettype)
{
        int i;

        if ((nettype == NULL) || (nettype[0] == 0)) {
                return (_RPC_NETPATH);  /* Default */
        }

#if 0
        nettype = strlocase(nettype);
#endif
        for (i = 0; _rpctypelist[i].name; i++)
                if (strcasecmp(nettype, _rpctypelist[i].name) == 0) {
                        return (_rpctypelist[i].type);
                }
        return (_rpctypelist[i].type);
}

/*
 * For the given nettype (tcp or udp only), return the first structure found.
 * This should be freed by calling freenetconfigent()
 */

#ifdef _REENTRANT
static thread_key_t tcp_key, udp_key;
static once_t __rpc_getconfigp_once = ONCE_INITIALIZER;

static void
__rpc_getconfigp_setup(void)
{

        thr_keycreate(&tcp_key, free);
        thr_keycreate(&udp_key, free);
}
#endif

struct netconfig *
__rpc_getconfip(const char *nettype)
{
        char *netid;
        char *netid_tcp = NULL;
        char *netid_udp = NULL;
        static char *netid_tcp_main;
        static char *netid_udp_main;
        struct netconfig *dummy;
#ifdef _REENTRANT
        if (__isthreaded == 0) {
                netid_udp = netid_udp_main;
                netid_tcp = netid_tcp_main;
        } else {
                thr_once(&__rpc_getconfigp_once, __rpc_getconfigp_setup);
                netid_tcp = thr_getspecific(tcp_key);
                netid_udp = thr_getspecific(udp_key);
        }
#else
        netid_udp = netid_udp_main;
        netid_tcp = netid_tcp_main;
#endif

        _DIAGASSERT(nettype != NULL);

        if (!netid_udp && !netid_tcp) {
                struct netconfig *nconf;
                void *confighandle;

                if (!(confighandle = setnetconfig())) {
                        syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
                        return (NULL);
                }
                while ((nconf = getnetconfig(confighandle)) != NULL) {
                        if (strcmp(nconf->nc_protofmly, NC_INET) == 0) {
                                if (strcmp(nconf->nc_proto, NC_TCP) == 0) {
                                        netid_tcp = strdup(nconf->nc_netid);
                                        if (netid_tcp == NULL)
                                                return NULL;
#ifdef _REENTRANT
                                        if (__isthreaded == 0)
                                                netid_tcp_main = netid_tcp;
                                        else
                                                thr_setspecific(tcp_key,
                                                        (void *) netid_tcp);
#else
                                        netid_tcp_main = netid_tcp;
#endif
                                } else
                                if (strcmp(nconf->nc_proto, NC_UDP) == 0) {
                                        netid_udp = strdup(nconf->nc_netid);
                                        if (netid_udp == NULL)
                                                return NULL;
#ifdef _REENTRANT
                                        if (__isthreaded == 0)
                                                netid_udp_main = netid_udp;
                                        else
                                                thr_setspecific(udp_key,
                                                        (void *) netid_udp);
#else
                                        netid_udp_main = netid_udp;
#endif
                                }
                        }
                }
                endnetconfig(confighandle);
        }
        if (strcmp(nettype, "udp") == 0)
                netid = netid_udp;
        else if (strcmp(nettype, "tcp") == 0)
                netid = netid_tcp;
        else {
                return (NULL);
        }
        if ((netid == NULL) || (netid[0] == 0)) {
                return (NULL);
        }
        dummy = getnetconfigent(netid);
        return (dummy);
}

/*
 * Returns the type of the nettype, which should then be used with
 * __rpc_getconf().
 */
void *
__rpc_setconf(const char *nettype)
{
        struct handle *handle;

        /* nettype may be NULL; getnettype() supports that */

        handle = malloc(sizeof(*handle));
        if (handle == NULL) {
                return (NULL);
        }
        switch (handle->nettype = getnettype(nettype)) {
        case _RPC_NETPATH:
        case _RPC_CIRCUIT_N:
        case _RPC_DATAGRAM_N:
                if (!(handle->nhandle = setnetpath())) {
                        free(handle);
                        return (NULL);
                }
                handle->nflag = TRUE;
                break;
        case _RPC_VISIBLE:
        case _RPC_CIRCUIT_V:
        case _RPC_DATAGRAM_V:
        case _RPC_TCP:
        case _RPC_UDP:
                if (!(handle->nhandle = setnetconfig())) {
                        syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
                        free(handle);
                        return (NULL);
                }
                handle->nflag = FALSE;
                break;
        default:
                free(handle);
                return (NULL);
        }

        return (handle);
}

/*
 * Returns the next netconfig struct for the given "net" type.
 * __rpc_setconf() should have been called previously.
 */
struct netconfig *
__rpc_getconf(void *vhandle)
{
        struct handle *handle;
        struct netconfig *nconf;

        handle = (struct handle *)vhandle;
        if (handle == NULL) {
                return (NULL);
        }
        for (;;) {
                if (handle->nflag)
                        nconf = getnetpath(handle->nhandle);
                else
                        nconf = getnetconfig(handle->nhandle);
                if (nconf == NULL)
                        break;
                if ((nconf->nc_semantics != NC_TPI_CLTS) &&
                        (nconf->nc_semantics != NC_TPI_COTS) &&
                        (nconf->nc_semantics != NC_TPI_COTS_ORD))
                        continue;
                switch (handle->nettype) {
                case _RPC_VISIBLE:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_NETPATH:      /* Be happy */
                        break;
                case _RPC_CIRCUIT_V:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_CIRCUIT_N:
                        if ((nconf->nc_semantics != NC_TPI_COTS) &&
                                (nconf->nc_semantics != NC_TPI_COTS_ORD))
                                continue;
                        break;
                case _RPC_DATAGRAM_V:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_DATAGRAM_N:
                        if (nconf->nc_semantics != NC_TPI_CLTS)
                                continue;
                        break;
                case _RPC_TCP:
                        if (((nconf->nc_semantics != NC_TPI_COTS) &&
                                (nconf->nc_semantics != NC_TPI_COTS_ORD)) ||
                                (strcmp(nconf->nc_protofmly, NC_INET)
#ifdef INET6
                                 && strcmp(nconf->nc_protofmly, NC_INET6))
#else
                                )
#endif
                                ||
                                strcmp(nconf->nc_proto, NC_TCP))
                                continue;
                        break;
                case _RPC_UDP:
                        if ((nconf->nc_semantics != NC_TPI_CLTS) ||
                                (strcmp(nconf->nc_protofmly, NC_INET)
#ifdef INET6
                                && strcmp(nconf->nc_protofmly, NC_INET6))
#else
                                )
#endif
                                ||
                                strcmp(nconf->nc_proto, NC_UDP))
                                continue;
                        break;
                }
                break;
        }
        return (nconf);
}

void
__rpc_endconf(void *vhandle)
{
        struct handle *handle;

        handle = (struct handle *) vhandle;
        if (handle == NULL) {
                return;
        }
        if (handle->nflag) {
                endnetpath(handle->nhandle);
        } else {
                endnetconfig(handle->nhandle);
        }
        free(handle);
}

/*
 * Used to ping the NULL procedure for clnt handle.
 * Returns NULL if fails, else a non-NULL pointer.
 */
void *
rpc_nullproc(CLIENT *clnt)
{
        struct timeval TIMEOUT = {25, 0};

        if (clnt_call(clnt, NULLPROC, (xdrproc_t) xdr_void, NULL,
                (xdrproc_t) xdr_void, NULL, TIMEOUT) != RPC_SUCCESS) {
                return (NULL);
        }
        return ((void *) clnt);
}

/*
 * Try all possible transports until
 * one succeeds in finding the netconf for the given fd.
 */
struct netconfig *
__rpcgettp(int fd)
{
        const char *netid;
        struct __rpc_sockinfo si;

        if (!__rpc_fd2sockinfo(fd, &si))
                return NULL;

        if (!__rpc_sockinfo2netid(&si, &netid))
                return NULL;

        return getnetconfigent(__UNCONST(netid));
}

int
__rpc_fd2sockinfo(int fd, struct __rpc_sockinfo *sip)
{
        socklen_t len;
        int type, proto;
        struct sockaddr_storage ss;

        _DIAGASSERT(sip != NULL);

        len = sizeof ss;
        if (getsockname(fd, (struct sockaddr *)(void *)&ss, &len) < 0)
                return 0;
        sip->si_alen = len;

        len = sizeof type;
        if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &len) < 0)
                return 0;

        /* XXX */
        if (ss.ss_family != AF_LOCAL) {
                if (type == SOCK_STREAM)
                        proto = IPPROTO_TCP;
                else if (type == SOCK_DGRAM)
                        proto = IPPROTO_UDP;
                else
                        return 0;
        } else
                proto = 0;

        sip->si_af = ss.ss_family;
        sip->si_proto = proto;
        sip->si_socktype = type;

        return 1;
}

/*
 * Linear search, but the number of entries is small.
 */
int
__rpc_nconf2sockinfo(const struct netconfig *nconf, struct __rpc_sockinfo *sip)
{
        size_t i;

        _DIAGASSERT(nconf != NULL);
        _DIAGASSERT(sip != NULL);

        for (i = 0; i < (sizeof na_cvt) / (sizeof (struct netid_af)); i++)
                if (!strcmp(na_cvt[i].netid, nconf->nc_netid)) {
                        sip->si_af = na_cvt[i].af;
                        sip->si_proto = na_cvt[i].protocol;
                        sip->si_socktype =
                            __rpc_seman2socktype((int)nconf->nc_semantics);
                        if (sip->si_socktype == -1)
                                return 0;
                        sip->si_alen = __rpc_get_a_size(sip->si_af);
                        return 1;
                }

        return 0;
}

int
__rpc_nconf2fd(const struct netconfig *nconf)
{
        struct __rpc_sockinfo si;

        _DIAGASSERT(nconf != NULL);

        if (!__rpc_nconf2sockinfo(nconf, &si))
                return 0;

        return socket(si.si_af, si.si_socktype, si.si_proto);
}

int
__rpc_sockinfo2netid(struct __rpc_sockinfo *sip, const char **netid)
{
        size_t i;

        _DIAGASSERT(sip != NULL);
        /* netid may be NULL */

        for (i = 0; i < (sizeof na_cvt) / (sizeof (struct netid_af)); i++)
                if (na_cvt[i].af == sip->si_af &&
                    na_cvt[i].protocol == sip->si_proto) {
                        if (netid)
                                *netid = na_cvt[i].netid;
                        return 1;
                }

        return 0;
}

char *
taddr2uaddr(const struct netconfig *nconf, const struct netbuf *nbuf)
{
        struct __rpc_sockinfo si;

        _DIAGASSERT(nconf != NULL);
        _DIAGASSERT(nbuf != NULL);

        if (!__rpc_nconf2sockinfo(nconf, &si))
                return NULL;
        return __rpc_taddr2uaddr_af(si.si_af, nbuf);
}

struct netbuf *
uaddr2taddr(const struct netconfig *nconf, const char *uaddr)
{
        struct __rpc_sockinfo si;

        _DIAGASSERT(nconf != NULL);
        _DIAGASSERT(uaddr != NULL);
        
        if (!__rpc_nconf2sockinfo(nconf, &si))
                return NULL;
        return __rpc_uaddr2taddr_af(si.si_af, uaddr);
}

char *
__rpc_taddr2uaddr_af(int af, const struct netbuf *nbuf)
{
        char *ret;
        struct sockaddr_in *sinp;
        struct sockaddr_un *sun;
        char namebuf[INET_ADDRSTRLEN];
#ifdef INET6
        struct sockaddr_in6 *sin6;
        char namebuf6[INET6_ADDRSTRLEN];
#endif
        u_int16_t port;

        _DIAGASSERT(nbuf != NULL);

        switch (af) {
        case AF_INET:
                if (nbuf->len < sizeof(*sinp)) {
                        return NULL;
                }
                sinp = nbuf->buf;
                if (inet_ntop(af, &sinp->sin_addr, namebuf,
                    (socklen_t)sizeof namebuf) == NULL)
                        return NULL;
                port = ntohs(sinp->sin_port);
                if (asprintf(&ret, "%s.%u.%u", namebuf, ((u_int32_t)port) >> 8,
                    port & 0xff) < 0)
                        return NULL;
                break;
#ifdef INET6
        case AF_INET6:
                if (nbuf->len < sizeof(*sin6)) {
                        return NULL;
                }
                sin6 = nbuf->buf;
                if (inet_ntop(af, &sin6->sin6_addr, namebuf6,
                    (socklen_t)sizeof namebuf6) == NULL)
                        return NULL;
                port = ntohs(sin6->sin6_port);
                if (asprintf(&ret, "%s.%u.%u", namebuf6, ((u_int32_t)port) >> 8,
                    port & 0xff) < 0)
                        return NULL;
                break;
#endif
        case AF_LOCAL:
                sun = nbuf->buf;
                sun->sun_path[sizeof(sun->sun_path) - 1] = '\0'; /* safety */
                ret = strdup(sun->sun_path);
                break;
        default:
                return NULL;
        }

        return ret;
}

struct netbuf *
__rpc_uaddr2taddr_af(int af, const char *uaddr)
{
        struct netbuf *ret = NULL;
        char *addrstr, *p;
        unsigned port, portlo, porthi;
        size_t len;
        struct sockaddr_in *sinp;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
        struct sockaddr_un *sun;

        if (uaddr == NULL)
                return NULL;

        addrstr = strdup(uaddr);
        if (addrstr == NULL)
                return NULL;

        /*
         * AF_LOCAL addresses are expected to be absolute
         * pathnames, anything else will be AF_INET or AF_INET6.
         */
        port = 0;
        if (*addrstr != '/') {
                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                portlo = (unsigned)atoi(p + 1);
                *p = '\0';

                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                porthi = (unsigned)atoi(p + 1);
                *p = '\0';
                port = (porthi << 8) | portlo;
        }

        ret = malloc(sizeof(*ret));
        if (ret == NULL)
                goto out;
        
        switch (af) {
        case AF_INET:
                sinp = malloc(sizeof(*sinp));
                if (sinp == NULL)
                        goto out;
                memset(sinp, 0, sizeof *sinp);
                sinp->sin_family = AF_INET;
                sinp->sin_port = htons(port);
                if (inet_pton(AF_INET, addrstr, &sinp->sin_addr) <= 0) {
                        free(sinp);
                        free(ret);
                        ret = NULL;
                        goto out;
                }
                sinp->sin_len = ret->maxlen = ret->len = sizeof *sinp;
                ret->buf = sinp;
                break;
#ifdef INET6
        case AF_INET6:
                sin6 = malloc(sizeof(*sin6));
                if (sin6 == NULL)
                        goto out;
                memset(sin6, 0, sizeof *sin6);
                sin6->sin6_family = AF_INET6;
                sin6->sin6_port = htons(port);
                if (inet_pton(AF_INET6, addrstr, &sin6->sin6_addr) <= 0) {
                        free(sin6);
                        free(ret);
                        ret = NULL;
                        goto out;
                }
                sin6->sin6_len = ret->maxlen = ret->len = sizeof *sin6;
                ret->buf = sin6;
                break;
#endif
        case AF_LOCAL:
                sun = malloc(sizeof(*sun));
                if (sun == NULL)
                        goto out;
                memset(sun, 0, sizeof *sun);
                sun->sun_family = AF_LOCAL;
                strncpy(sun->sun_path, addrstr, sizeof(sun->sun_path) - 1);
                len = SUN_LEN(sun);
                _DIAGASSERT(__type_fit(uint8_t, len));
                ret->len = ret->maxlen = sun->sun_len = (uint8_t)len;
                ret->buf = sun;
                break;
        default:
                break;
        }
out:
        free(addrstr);
        return ret;
}

int
__rpc_seman2socktype(int semantics)
{
        switch (semantics) {
        case NC_TPI_CLTS:
                return SOCK_DGRAM;
        case NC_TPI_COTS_ORD:
                return SOCK_STREAM;
        case NC_TPI_RAW:
                return SOCK_RAW;
        default:
                break;
        }

        return -1;
}

int
__rpc_socktype2seman(int socktype)
{
        switch (socktype) {
        case SOCK_DGRAM:
                return NC_TPI_CLTS;
        case SOCK_STREAM:
                return NC_TPI_COTS_ORD;
        case SOCK_RAW:
                return NC_TPI_RAW;
        default:
                break;
        }

        return -1;
}

/*
 * XXXX - IPv6 scope IDs can't be handled in universal addresses.
 * Here, we compare the original server address to that of the RPC
 * service we just received back from a call to rpcbind on the remote
 * machine. If they are both "link local" or "site local", copy
 * the scope id of the server address over to the service address.
 */
/* ARGSUSED */
int
__rpc_fixup_addr(struct netbuf *new, const struct netbuf *svc)
{
#ifdef INET6
        struct sockaddr *sa_new, *sa_svc;
        struct sockaddr_in6 *sin6_new, *sin6_svc;

        _DIAGASSERT(new != NULL);
        _DIAGASSERT(svc != NULL);

        sa_svc = (struct sockaddr *)svc->buf;
        sa_new = (struct sockaddr *)new->buf;

        if (sa_new->sa_family == sa_svc->sa_family &&
            sa_new->sa_family == AF_INET6) {
                sin6_new = (struct sockaddr_in6 *)new->buf;
                sin6_svc = (struct sockaddr_in6 *)svc->buf;

                if ((IN6_IS_ADDR_LINKLOCAL(&sin6_new->sin6_addr) &&
                     IN6_IS_ADDR_LINKLOCAL(&sin6_svc->sin6_addr)) ||
                    (IN6_IS_ADDR_SITELOCAL(&sin6_new->sin6_addr) &&
                     IN6_IS_ADDR_SITELOCAL(&sin6_svc->sin6_addr))) {
                        sin6_new->sin6_scope_id = sin6_svc->sin6_scope_id;
                }
        }
#endif
        return 1;
}

int
__rpc_sockisbound(int fd)
{
        struct sockaddr_storage ss;
        socklen_t slen;

        slen = sizeof (struct sockaddr_storage);
        if (getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
                return 0;

        switch (ss.ss_family) {
                case AF_INET:
                        return (((struct sockaddr_in *)
                            (void *)&ss)->sin_port != 0);
#ifdef INET6
                case AF_INET6:
                        return (((struct sockaddr_in6 *)
                            (void *)&ss)->sin6_port != 0);
#endif
                case AF_LOCAL:
                        /* XXX check this */
                        return (((struct sockaddr_un *)
                            (void *)&ss)->sun_path[0] != '\0');
                default:
                        break;
        }

        return 0;
}

/*
 * For TCP transport, Host Requirements RFCs mandate
 * Nagle (RFC-896) processing.  But for RPC, Nagle
 * processing adds adds unwanted latency to the last,
 * partial TCP segment of each RPC message. See:
 *   R. W. Scheifler and J. Gettys, The X Window System,
 *   ACM Transactions on Graphics 16:8 (Aug. 1983), pp. 57-69. 
 * So for TCP transport, disable Nagle via TCP_NODELAY.
 * XXX: moral equivalent for non-TCP protocols?
 */
int
__rpc_setnodelay(int fd, const struct __rpc_sockinfo *si)
{
        int one = 1;
        if (si->si_proto != IPPROTO_TCP)
                return 0;
        return setsockopt(fd, si->si_proto, TCP_NODELAY, &one,
            (socklen_t)sizeof(one));
}