/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
 */
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * pmap_svc.c
 * The server procedure for the version 2 portmaper.
 * All the portmapper related interface from the portmap side.
 */

#include <rpc/rpc.h>
#include <tcpd.h>

#include "rpcbind.h"

#ifdef PORTMAP
#include <stdio.h>
#include <alloca.h>
#include <ucred.h>
#include <rpc/pmap_prot.h>
#include <rpc/rpcb_prot.h>
#include <assert.h>

static bool_t pmapproc_change(struct svc_req *, SVCXPRT *, unsigned long);
static bool_t pmapproc_getport(struct svc_req *, SVCXPRT *);
static bool_t pmapproc_dump(struct svc_req *, SVCXPRT *);

/*
 * Called for all the version 2 inquiries.
 */
void
pmap_service(struct svc_req *rqstp, SVCXPRT *xprt)
{
        rpcbs_procinfo(RPCBVERS_2_STAT, rqstp->rq_proc);

        switch (rqstp->rq_proc) {
        case PMAPPROC_NULL:
                /*
                 * Null proc call
                 */
                PMAP_CHECK(xprt, rqstp->rq_proc);

                if ((!svc_sendreply(xprt, (xdrproc_t)xdr_void, NULL)) &&
                    debugging) {
                        if (doabort) {
                                rpcbind_abort();
                        }
                }
                break;

        case PMAPPROC_SET:
                /*
                 * Set a program, version to port mapping
                 */
                pmapproc_change(rqstp, xprt, rqstp->rq_proc);
                break;

        case PMAPPROC_UNSET:
                /*
                 * Remove a program, version to port mapping.
                 */
                pmapproc_change(rqstp, xprt, rqstp->rq_proc);
                break;

        case PMAPPROC_GETPORT:
                /*
                 * Lookup the mapping for a program, version and return its
                 * port number.
                 */
                pmapproc_getport(rqstp, xprt);
                break;

        case PMAPPROC_DUMP:
                /*
                 * Return the current set of mapped program, version
                 */
                PMAP_CHECK(xprt, rqstp->rq_proc);
                pmapproc_dump(rqstp, xprt);
                break;

        case PMAPPROC_CALLIT:
                /*
                 * Calls a procedure on the local machine. If the requested
                 * procedure is not registered this procedure does not return
                 * error information!!
                 * This procedure is only supported on rpc/udp and calls via
                 * rpc/udp. It passes null authentication parameters.
                 */
                rpcbproc_callit_com(rqstp, xprt, PMAPPROC_CALLIT, PMAPVERS);
                break;

        default:
                PMAP_CHECK(xprt, rqstp->rq_proc);
                svcerr_noproc(xprt);
                break;
        }
}

/*
 * returns the item with the given program, version number. If that version
 * number is not found, it returns the item with that program number, so that
 * the port number is now returned to the caller. The caller when makes a
 * call to this program, version number, the call will fail and it will
 * return with PROGVERS_MISMATCH. The user can then determine the highest
 * and the lowest version number for this program using clnt_geterr() and
 * use those program version numbers.
 */
static PMAPLIST *
find_service_pmap(rpcprog_t prog, rpcvers_t vers, rpcprot_t prot)
{
        PMAPLIST *hit = NULL;
        PMAPLIST *pml;

        assert(RW_LOCK_HELD(&list_pml_lock));

        for (pml = list_pml; pml != NULL; pml = pml->pml_next) {
                if ((pml->pml_map.pm_prog != prog) ||
                    (pml->pml_map.pm_prot != prot))
                        continue;
                hit = pml;
                if (pml->pml_map.pm_vers == vers)
                        break;
        }

        return (hit);
}

/* ARGSUSED */
static bool_t
pmapproc_change(struct svc_req *rqstp, SVCXPRT *xprt, unsigned long op)
{
        PMAP reg;
        RPCB rpcbreg;
        int ans;
        struct sockaddr_in *who;
        char owner[64];

        if (!svc_getargs(xprt, (xdrproc_t)xdr_pmap, (char *)&reg)) {
                svcerr_decode(xprt);
                return (FALSE);
        }
        who = (struct sockaddr_in *)svc_getrpccaller(xprt)->buf;

        /* Don't allow unset/set from remote. */
        if (!localxprt(xprt, B_TRUE)) {
                ans = FALSE;
                goto done_change;
        }

        rpcbreg.r_owner = getowner(xprt, owner);

        if ((op == PMAPPROC_SET) && (reg.pm_port < IPPORT_RESERVED) &&
            (ntohs(who->sin_port) >= IPPORT_RESERVED)) {
                ans = FALSE;
                goto done_change;
        }
        rpcbreg.r_prog = reg.pm_prog;
        rpcbreg.r_vers = reg.pm_vers;

        if (op == PMAPPROC_SET) {
                char buf[32];

                sprintf(buf, "0.0.0.0.%d.%d", (reg.pm_port >> 8) & 0xff,
                    reg.pm_port & 0xff);
                rpcbreg.r_addr = buf;
                if (reg.pm_prot == IPPROTO_UDP) {
                        rpcbreg.r_netid = udptrans;
                } else if (reg.pm_prot == IPPROTO_TCP) {
                        rpcbreg.r_netid = tcptrans;
                } else {
                        ans = FALSE;
                        goto done_change;
                }
                ans = map_set(&rpcbreg, rpcbreg.r_owner);
        } else if (op == PMAPPROC_UNSET) {
                bool_t ans1, ans2;

                rpcbreg.r_addr = NULL;
                rpcbreg.r_netid = tcptrans;
                ans1 = map_unset(&rpcbreg, rpcbreg.r_owner);
                rpcbreg.r_netid = udptrans;
                ans2 = map_unset(&rpcbreg, rpcbreg.r_owner);
                ans = ans1 || ans2;
        } else {
                ans = FALSE;
        }
done_change:
        PMAP_LOG(ans, xprt, op, reg.pm_prog);

        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_long, (caddr_t)&ans)) &&
            debugging) {
                fprintf(stderr, "portmap: svc_sendreply\n");
                if (doabort) {
                        rpcbind_abort();
                }
        }
        if (op == PMAPPROC_SET)
                rpcbs_set(RPCBVERS_2_STAT, ans);
        else
                rpcbs_unset(RPCBVERS_2_STAT, ans);
        return (TRUE);
}

/* ARGSUSED */
static bool_t
pmapproc_getport(struct svc_req *rqstp, SVCXPRT *xprt)
{
        PMAP reg;
        int port = 0;
        PMAPLIST *fnd;
        bool_t rbl_locked = FALSE;

        if (!svc_getargs(xprt, (xdrproc_t)xdr_pmap, (char *)&reg)) {
                svcerr_decode(xprt);
                return (FALSE);
        }
        PMAP_CHECK_RET(xprt, rqstp->rq_proc, FALSE);

        (void) rw_rdlock(&list_pml_lock);
retry:
        fnd = find_service_pmap(reg.pm_prog, reg.pm_vers, reg.pm_prot);
        if (fnd) {
                char serveuaddr[32], *ua;
                int h1, h2, h3, h4, p1, p2;
                char *netid;

                if (reg.pm_prot == IPPROTO_UDP) {
                        ua = udp_uaddr;
                        netid = udptrans;
                } else {
                        ua = tcp_uaddr; /* To get the len */
                        netid = tcptrans;
                }
                if (ua == NULL) {
                        (void) rw_unlock(&list_pml_lock);
                        if (rbl_locked)
                                (void) rw_unlock(&list_rbl_lock);
                        goto sendreply;
                }
                if (sscanf(ua, "%d.%d.%d.%d.%d.%d", &h1, &h2, &h3,
                    &h4, &p1, &p2) == 6) {
                        p1 = (fnd->pml_map.pm_port >> 8) & 0xff;
                        p2 = (fnd->pml_map.pm_port) & 0xff;
                        sprintf(serveuaddr, "%d.%d.%d.%d.%d.%d",
                            h1, h2, h3, h4, p1, p2);
                        if (is_bound(netid, serveuaddr)) {
                                port = fnd->pml_map.pm_port;
                        } else { /* this service is dead; delete it */
                                if (!rbl_locked) {
                                        (void) rw_unlock(&list_pml_lock);
                                        (void) rw_wrlock(&list_rbl_lock);
                                        (void) rw_wrlock(&list_pml_lock);
                                        rbl_locked = TRUE;
                                        goto retry;
                                }
                                delete_prog(reg.pm_prog);
                        }
                }
        }
        (void) rw_unlock(&list_pml_lock);
        if (rbl_locked)
                (void) rw_unlock(&list_rbl_lock);

sendreply:
        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_long, (caddr_t)&port)) &&
            debugging) {
                (void) fprintf(stderr, "portmap: svc_sendreply\n");
                if (doabort) {
                        rpcbind_abort();
                }
        }
        rpcbs_getaddr(RPCBVERS_2_STAT, reg.pm_prog, reg.pm_vers,
            reg.pm_prot == IPPROTO_UDP ? udptrans : tcptrans,
            port ? udptrans : "");

        return (TRUE);
}

/* ARGSUSED */
static bool_t
pmapproc_dump(struct svc_req *rqstp, SVCXPRT *xprt)
{
        if (!svc_getargs(xprt, (xdrproc_t)xdr_void, NULL)) {
                svcerr_decode(xprt);
                return (FALSE);
        }

        (void) rw_rdlock(&list_pml_lock);
        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_pmaplist_ptr,
            (caddr_t)&list_pml)) && debugging) {
                (void) rw_unlock(&list_pml_lock);
                (void) fprintf(stderr, "portmap: svc_sendreply\n");
                if (doabort) {
                        rpcbind_abort();
                }
        } else {
                (void) rw_unlock(&list_pml_lock);
        }

        return (TRUE);
}
#endif /* PORTMAP */

/*
 * Is the transport local?  The original rpcbind code tried to
 * figure out all the network interfaces but there can be a nearly
 * infinite number of network interfaces.  And the number of interfaces can
 * vary over time.
 *
 * Note that when we get here, we've already establised that we're
 * dealing with a TCP/IP endpoint.
 */
boolean_t
localxprt(SVCXPRT *transp, boolean_t forceipv4)
{
        struct sockaddr_gen *sgen = svc_getgencaller(transp);

        switch (SGFAM(sgen)) {
        case AF_INET:
                break;
        case AF_INET6:
                if (forceipv4)
                        return (B_FALSE);
                break;
        default:
                return (B_FALSE);
        }

        /*
         * Get the peer's uid; if it is known it is sufficiently
         * authenticated and considered local.  The magic behind this
         * call is all in libnsl.
         */
        return (rpcb_caller_uid(transp) != -1);
}