/*      $NetBSD: rpc_generic.c,v 1.4 2000/09/28 09:07:04 kleink 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.
 */
/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
 */

#include <sys/cdefs.h>
/*
 * rpc_generic.c, Miscl routines for RPC.
 *
 */

#include "opt_inet6.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/sbuf.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/syslog.h>

#include <net/vnet.h>

#include <rpc/rpc.h>
#include <rpc/nettype.h>
#include <rpc/rpcsec_gss.h>
#include <rpc/rpcsec_tls.h>

#include <rpc/rpc_com.h>
#include <rpc/krpc.h>

#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>

extern  u_long sb_max_adj;      /* not defined in socketvar.h */

/* Provide an entry point hook for the rpcsec_gss module. */
struct rpc_gss_entries  rpc_gss_entries;

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 }
};

struct rpc_createerr rpc_createerr;

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

        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 > sb_max_adj ? (u_int)sb_max_adj : (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

/*
 * Used to ping the NULL procedure for clnt handle.
 * Returns NULL if fails, else a non-NULL pointer.
 */
void *
rpc_nullproc(clnt)
        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);
}

#endif

int
__rpc_socket2sockinfo(struct socket *so, struct __rpc_sockinfo *sip)
{
        int type, proto;
        struct sockaddr_storage ss = { .ss_len = sizeof(ss) };
        sa_family_t family;
        struct sockopt opt;
        int error;

        error = sosockaddr(so, (struct sockaddr *)&ss);
        if (error)
                return 0;

        sip->si_alen = ss.ss_len;
        family = ss.ss_family;

        opt.sopt_dir = SOPT_GET;
        opt.sopt_level = SOL_SOCKET;
        opt.sopt_name = SO_TYPE;
        opt.sopt_val = &type;
        opt.sopt_valsize = sizeof type;
        opt.sopt_td = NULL;
        error = sogetopt(so, &opt);
        if (error)
                return 0;

        /* XXX */
        if (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 = 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)
{
        int i;

        for (i = 0; i < (sizeof na_cvt) / (sizeof (struct netid_af)); i++)
                if (strcmp(na_cvt[i].netid, nconf->nc_netid) == 0 || (
                    strcmp(nconf->nc_netid, "unix") == 0 &&
                    strcmp(na_cvt[i].netid, "local") == 0)) {
                        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;
}

struct socket *
__rpc_nconf2socket(const struct netconfig *nconf)
{
        struct __rpc_sockinfo si;
        struct socket *so;
        int error;

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

        so = NULL;
        error =  socreate(si.si_af, &so, si.si_socktype, si.si_proto,
            curthread->td_ucred, curthread);

        if (error)
                return NULL;
        else
                return so;
}

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

        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;
        
        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 sbuf sb;
        struct sockaddr_in *sin;
        struct sockaddr_un *sun;
        char namebuf[INET_ADDRSTRLEN];
#ifdef INET6
        struct sockaddr_in6 *sin6;
        char namebuf6[INET6_ADDRSTRLEN];
#endif
        uint16_t port;

        sbuf_new(&sb, NULL, 0, SBUF_AUTOEXTEND);

        switch (af) {
        case AF_INET:
                if (nbuf->len < sizeof(*sin))
                        return NULL;
                sin = nbuf->buf;
                if (inet_ntop(af, &sin->sin_addr, namebuf, sizeof namebuf)
                    == NULL)
                        return NULL;
                port = ntohs(sin->sin_port);
                if (sbuf_printf(&sb, "%s.%u.%u", namebuf,
                        ((uint32_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, sizeof namebuf6)
                    == NULL)
                        return NULL;
                port = ntohs(sin6->sin6_port);
                if (sbuf_printf(&sb, "%s.%u.%u", namebuf6,
                        ((uint32_t)port) >> 8,
                        port & 0xff) < 0)
                        return NULL;
                break;
#endif
        case AF_LOCAL:
                sun = nbuf->buf;
                if (sbuf_printf(&sb, "%.*s", (int)(sun->sun_len -
                            offsetof(struct sockaddr_un, sun_path)),
                        sun->sun_path) < 0)
                        return (NULL);
                break;
        default:
                return NULL;
        }

        sbuf_finish(&sb);
        ret = strdup(sbuf_data(&sb), M_RPC);
        sbuf_delete(&sb);

        return ret;
}

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

        port = 0;
        sin = NULL;

        if (uaddr == NULL)
                return NULL;

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

        /*
         * AF_LOCAL addresses are expected to be absolute
         * pathnames, anything else will be AF_INET or AF_INET6.
         */
        if (*addrstr != '/') {
                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                portlo = (unsigned)strtol(p + 1, NULL, 10);
                *p = '\0';

                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                porthi = (unsigned)strtol(p + 1, NULL, 10);
                *p = '\0';
                port = (porthi << 8) | portlo;
        }

        ret = (struct netbuf *)malloc(sizeof *ret, M_RPC, M_WAITOK);
        
        switch (af) {
        case AF_INET:
                sin = (struct sockaddr_in *)malloc(sizeof *sin, M_RPC,
                    M_WAITOK);
                memset(sin, 0, sizeof *sin);
                sin->sin_family = AF_INET;
                sin->sin_port = htons(port);
                if (inet_pton(AF_INET, addrstr, &sin->sin_addr) <= 0) {
                        free(sin, M_RPC);
                        free(ret, M_RPC);
                        ret = NULL;
                        goto out;
                }
                sin->sin_len = ret->maxlen = ret->len = sizeof *sin;
                ret->buf = sin;
                break;
#ifdef INET6
        case AF_INET6:
                sin6 = (struct sockaddr_in6 *)malloc(sizeof *sin6, M_RPC,
                    M_WAITOK);
                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, M_RPC);
                        free(ret, M_RPC);
                        ret = NULL;
                        goto out;
                }
                sin6->sin6_len = ret->maxlen = ret->len = sizeof *sin6;
                ret->buf = sin6;
                break;
#endif
        case AF_LOCAL:
                sun = (struct sockaddr_un *)malloc(sizeof *sun, M_RPC,
                    M_WAITOK);
                memset(sun, 0, sizeof *sun);
                sun->sun_family = AF_LOCAL;
                strncpy(sun->sun_path, addrstr, sizeof(sun->sun_path) - 1);
                ret->len = ret->maxlen = sun->sun_len = SUN_LEN(sun);
                ret->buf = sun;
                break;
        default:
                break;
        }
out:
        free(addrstr, M_RPC);
        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;
}

/*
 * 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()
 */
struct netconfig *
__rpc_getconfip(const char *nettype)
{
        char *netid;
        static char *netid_tcp = (char *) NULL;
        static char *netid_udp = (char *) NULL;
        struct netconfig *dummy;

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

                if (!(confighandle = setnetconfig())) {
                        log(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,
                                            M_RPC);
                                } else
                                if (strcmp(nconf->nc_proto, NC_UDP) == 0) {
                                        netid_udp = strdup(nconf->nc_netid,
                                            M_RPC);
                                }
                        }
                }
                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().
 *
 * For simplicity in the kernel, we don't support the NETPATH
 * environment variable. We behave as userland would then NETPATH is
 * unset, i.e. iterate over all visible entries in netconfig.
 */
void *
__rpc_setconf(const char *nettype)
{
        struct handle *handle;

        handle = (struct handle *) malloc(sizeof (struct handle),
            M_RPC, M_WAITOK);
        switch (handle->nettype = getnettype(nettype)) {
        case _RPC_NETPATH:
        case _RPC_CIRCUIT_N:
        case _RPC_DATAGRAM_N:
                if (!(handle->nhandle = setnetconfig()))
                        goto failed;
                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())) {
                        log(LOG_ERR, "rpc: failed to open " NETCONFIG);
                        goto failed;
                }
                handle->nflag = FALSE;
                break;
        default:
                goto failed;
        }

        return (handle);

failed:
        free(handle, M_RPC);
        return (NULL);
}

/*
 * 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 = getnetconfig(handle->nhandle);
                        if (nconf && !(nconf->nc_flag & NC_VISIBLE))
                                continue;
                } 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;
        }
        endnetconfig(handle->nhandle);
        free(handle, M_RPC);
}

int
__rpc_sockisbound(struct socket *so)
{
        struct sockaddr_storage ss = { .ss_len = sizeof(ss) };
        int error, bound;

        error = sosockaddr(so, (struct sockaddr *)&ss);
        if (error)
                return (0);

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

        return bound;
}

/*
 * Implement XDR-style API for RPC call.
 */
enum clnt_stat
clnt_call_private(
        CLIENT          *cl,            /* client handle */
        struct rpc_callextra *ext,      /* call metadata */
        rpcproc_t       proc,           /* procedure number */
        xdrproc_t       xargs,          /* xdr routine for args */
        void            *argsp,         /* pointer to args */
        xdrproc_t       xresults,       /* xdr routine for results */
        void            *resultsp,      /* pointer to results */
        struct timeval  utimeout)       /* seconds to wait before giving up */
{
        XDR xdrs;
        struct mbuf *mreq;
        struct mbuf *mrep;
        enum clnt_stat stat;

        mreq = m_getcl(M_WAITOK, MT_DATA, 0);

        xdrmbuf_create(&xdrs, mreq, XDR_ENCODE);
        if (!xargs(&xdrs, argsp)) {
                m_freem(mreq);
                return (RPC_CANTENCODEARGS);
        }
        XDR_DESTROY(&xdrs);

        stat = CLNT_CALL_MBUF(cl, ext, proc, mreq, &mrep, utimeout);
        m_freem(mreq);

        if (stat == RPC_SUCCESS) {
                xdrmbuf_create(&xdrs, mrep, XDR_DECODE);
                if (!xresults(&xdrs, resultsp)) {
                        XDR_DESTROY(&xdrs);
                        return (RPC_CANTDECODERES);
                }
                XDR_DESTROY(&xdrs);
        }

        return (stat);
}

/*
 * Bind a socket to a privileged IP port
 */
int
bindresvport(struct socket *so, struct sockaddr *sa)
{
        struct sockaddr_storage ss = { .ss_len = sizeof(ss) };
        int old, error, af;
        struct sockaddr_in *sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
        struct sockopt opt;
        int proto, portrange, portlow;
        uint16_t *portp;
        socklen_t salen;

        if (sa == NULL) {
                sa = (struct sockaddr *)&ss;
                error = sosockaddr(so, sa);
                if (error)
                        return (error);
                af = sa->sa_family;
                salen = sa->sa_len;
                memset(sa, 0, sa->sa_len);
        } else {
                af = sa->sa_family;
                salen = sa->sa_len;
        }

        switch (af) {
        case AF_INET:
                proto = IPPROTO_IP;
                portrange = IP_PORTRANGE;
                portlow = IP_PORTRANGE_LOW;
                sin = (struct sockaddr_in *)sa;
                portp = &sin->sin_port;
                break;
#ifdef INET6
        case AF_INET6:
                proto = IPPROTO_IPV6;
                portrange = IPV6_PORTRANGE;
                portlow = IPV6_PORTRANGE_LOW;
                sin6 = (struct sockaddr_in6 *)sa;
                portp = &sin6->sin6_port;
                break;
#endif
        default:
                return (EPFNOSUPPORT);
        }

        sa->sa_family = af;
        sa->sa_len = salen;

        if (*portp == 0) {
                bzero(&opt, sizeof(opt));
                opt.sopt_dir = SOPT_GET;
                opt.sopt_level = proto;
                opt.sopt_name = portrange;
                opt.sopt_val = &old;
                opt.sopt_valsize = sizeof(old);
                error = sogetopt(so, &opt);
                if (error)
                        return (error);

                opt.sopt_dir = SOPT_SET;
                opt.sopt_val = &portlow;
                error = sosetopt(so, &opt);
                if (error)
                        return (error);
        }

        error = sobind(so, sa, curthread);

        if (*portp == 0) {
                if (error) {
                        opt.sopt_dir = SOPT_SET;
                        opt.sopt_val = &old;
                        sosetopt(so, &opt);
                }
        }

        return (error);
}

/*
 * Make sure an mbuf list is made up entirely of ext_pgs mbufs.
 * This is needed for sosend() when KERN_TLS is being used.
 * (There might also be a performance improvement for certain
 *  network interfaces that handle ext_pgs mbufs efficiently.)
 * It expects at least one non-ext_pgs mbuf followed by zero
 * or more ext_pgs mbufs.  It does not handle the case where
 * non-ext_pgs mbuf(s) follow ext_pgs ones.
 * It also performs sanity checks on the resultant list.
 * The "mp" argument list is consumed.
 * The "maxextsiz" argument is the upper bound on the data
 * size for each mbuf (usually 16K for KERN_TLS).
 */
struct mbuf *
_rpc_copym_into_ext_pgs(struct mbuf *mp, int maxextsiz)
{
        struct mbuf *m, *m2, *m3, *mhead;
        int tlen;

        KASSERT((mp->m_flags & (M_EXT | M_EXTPG)) !=
            (M_EXT | M_EXTPG), ("_rpc_copym_into_ext_pgs:"
            " first mbuf is an ext_pgs"));
        /*
         * Find the last non-ext_pgs mbuf and the total
         * length of the non-ext_pgs mbuf(s).
         * The first mbuf must always be a non-ext_pgs
         * mbuf.
         */
        tlen = mp->m_len;
        m2 = mp;
        for (m = mp->m_next; m != NULL; m = m->m_next) {
                if ((m->m_flags & M_EXTPG) != 0)
                        break;
                tlen += m->m_len;
                m2 = m;
        }

        /*
         * Copy the non-ext_pgs mbuf(s) into an ext_pgs
         * mbuf list.
         */
        m2->m_next = NULL;
        mhead = mb_mapped_to_unmapped(mp, tlen, maxextsiz,
            M_WAITOK, &m2);

        /*
         * Link the ext_pgs list onto the newly copied
         * list and free up the non-ext_pgs mbuf(s).
         */
        m2->m_next = m;
        m_freem(mp);

        /*
         * Sanity check the resultant mbuf list.  Check for and
         * remove any 0 length mbufs in the list, since the
         * KERN_TLS code does not expect any 0 length mbuf(s)
         * in the list.
         */
        m3 = NULL;
        m2 = mhead;
        tlen = 0;
        while (m2 != NULL) {
                KASSERT(m2->m_len >= 0, ("_rpc_copym_into_ext_pgs:"
                    " negative m_len"));
                KASSERT((m2->m_flags & (M_EXT | M_EXTPG)) ==
                    (M_EXT | M_EXTPG), ("_rpc_copym_into_ext_pgs:"
                            " non-nomap mbuf in list"));
                if (m2->m_len == 0) {
                        if (m3 != NULL)
                                m3->m_next = m2->m_next;
                        else
                                m = m2->m_next;
                        m2->m_next = NULL;
                        m_free(m2);
                        if (m3 != NULL)
                                m2 = m3->m_next;
                        else
                                m2 = m;
                } else {
                        MBUF_EXT_PGS_ASSERT_SANITY(m2);
                        m3 = m2;
                        tlen += m2->m_len;
                        m2 = m2->m_next;
                }
        }
        return (mhead);
}

/*
 * Kernel module glue
 */
static int
krpc_modevent(module_t mod, int type, void *data)
{
        int error = 0;

        switch (type) {
        case MOD_LOAD:
                rpcnl_init();
                error = rpctls_init();
                break;
        case MOD_UNLOAD:
                /*
                 * Cannot be unloaded, since the rpctlssd or rpctlscd daemons
                 * might be performing a rpctls syscall.
                 */
                /* FALLTHROUGH */
        default:
                error = EOPNOTSUPP;
        }
        return (error);
}
static moduledata_t krpc_mod = {
        "krpc",
        krpc_modevent,
        NULL,
};
DECLARE_MODULE(krpc, krpc_mod, SI_SUB_VFS, SI_ORDER_FIRST);

/* So that loader and kldload(2) can find us, wherever we are.. */
MODULE_VERSION(krpc, 1);
MODULE_DEPEND(krpc, xdr, 1, 1, 1);