MiniDLNA update: 1.0.19.1 to 1.0.20

[tomato.git] / release / src / router / portmap / portmap.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1990 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

/*
@(#)portmap.c   2.3 88/08/11 4.0 RPCSRC
static char sccsid[] = "@(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
*/

/*
 * portmap.c, Implements the program,version to port number mapping for
 * rpc.
 */

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 * 
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 * 
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 * 
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 * 
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <stdio.h>
#include <unistd.h>
#include <syslog.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/signal.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/types.h>
#ifdef SYSV40
#include <netinet/in.h>
#endif
#include <arpa/inet.h>

#include <stdlib.h>
#include <pwd.h>

#ifndef LOG_PERROR
#define LOG_PERROR 0
#endif

#ifndef LOG_DAEMON
#define LOG_DAEMON 0
#endif

/* Older SYSV. */
#if !defined(SIGCHLD) && defined(SIGCLD)
#define SIGCHLD      SIGCLD
#endif

#ifndef svc_getcaller           /* SYSV4 */
#  define svc_getcaller svc_getrpccaller
#endif

static void reg_service(struct svc_req *rqstp, SVCXPRT *xprt);
#ifndef IGNORE_SIGCHLD                  /* Lionel Cons <cons@dxcern.cern.ch> */
static void reap(int);
#endif
static void callit(struct svc_req *rqstp, SVCXPRT *xprt);
struct pmaplist *pmaplist;
int debugging = 0;
int store_fd = -1;
static void dump_table(void);
static void load_table(void);

#include "pmap_check.h"

 /*
  * How desperate can one be. It is possible to prevent an attacker from
  * manipulating your portmapper tables from outside with requests that
  * contain spoofed source address information. The countermeasure is to
  * force all rpc servers to register and unregister with the portmapper via
  * the loopback network interface, instead of via the primary network
  * interface that every host can talk to. For this countermeasure to work it
  * is necessary to #define LOOPBACK_SETUNSET, to disable source routing in
  * the kernel, and to modify libc so that get_myaddress() chooses the
  * loopback interface address.
  */

#ifdef LOOPBACK_SETUNSET
static SVCXPRT *ludpxprt, *ltcpxprt;
static int on = 1;
#ifndef INADDR_LOOPBACK
#define INADDR_LOOPBACK ntohl(inet_addr("127.0.0.1"))
#endif
#endif

#ifdef DAEMON_UID
int daemon_uid = DAEMON_UID;
int daemon_gid = DAEMON_GID;
#else
int daemon_uid = 1;
int daemon_gid = 1;
#endif

/*
 * We record with each registration a flag telling whether it was
 * registered with a privilege port or not.
 * If it was, it can only be unregistered with a privileged port.
 * So that we can still use standard pmap xdr routines, we store
 * this flag in a structure wrapped around a pmaplist.
 */
struct flagged_pml {
        struct pmaplist pml;
        int priv;
};

int
main(int argc, char **argv)
{
        SVCXPRT *xprt;
        int sock, c;
        struct sockaddr_in addr;
        int len = sizeof(struct sockaddr_in);
        struct pmaplist *pml;
        struct flagged_pml *fpml;
        char *chroot_path = NULL;
        struct in_addr bindaddr;
        int have_bindaddr = 0;
        int foreground = 0;
        int have_uid = 0;

        while ((c = getopt(argc, argv, "Vdflt:vi:u:g:")) != EOF) {
                switch (c) {

                case 'V':
                        printf("portmap version 6.0 - 2007-May-11\n");
                        exit(1);

                case 'u':
                        daemon_uid = atoi(optarg);
                        if (daemon_uid <= 0) {
                                fprintf(stderr,
                                        "portmap: illegal uid: %s\n", optarg);
                                exit(1);
                        }
                        have_uid = 1;
                        break;
                case 'g':
                        daemon_gid = atoi(optarg);
                        if (daemon_gid <= 0) {
                                fprintf(stderr,
                                        "portmap: illegal gid: %s\n", optarg);
                                exit(1);
                        }
                        have_uid = 1;
                        break;
                case 'd':
                        debugging = 1;
                case 'f':
                        foreground = 1;
                        break;

                case 't':
                        chroot_path = optarg;
                        break;

                case 'v':
                        verboselog = 1;
                        break;

                case 'l':
                        optarg = "127.0.0.1";
                        /* FALL THROUGH */
                case 'i':
                        have_bindaddr = inet_aton(optarg, &bindaddr);
                        break;
                default:
                        fprintf(stderr,
                                "usage: %s [-dflv] [-t dir] [-i address] "
                                "[-u uid] [-g gid]\n",
                                argv[0]);
                        fprintf(stderr, "-d: debugging mode\n");
                        fprintf(stderr,
                                "-f: don't daemonize, log to standard error\n");
                        fprintf(stderr, "-t dir: chroot into dir\n");
                        fprintf(stderr, "-v: verbose logging\n");
                        fprintf(stderr, "-i address: bind to address\n");
                        fprintf(stderr, "-l: same as -i 127.0.0.1\n");
                        fprintf(stderr, "-u uid : setuid to this uid\n");
                        fprintf(stderr, "-g uid : setgid to this gid\n");
                        exit(1);
                }
        }

        if (!foreground && daemon(0, 0)) {
                (void) fprintf(stderr, "portmap: fork: %s", strerror(errno));
                exit(1);
        }

#ifdef LOG_DAEMON
        openlog("portmap", LOG_PID|LOG_NDELAY | ( foreground ? LOG_PERROR : 0),
            FACILITY);
#else
        openlog("portmap", LOG_PID|LOG_NDELAY | ( foreground ? LOG_PERROR : 0));
#endif

#ifdef RPCUSER
        if (!have_uid) {
                struct passwd *pwent;
                pwent = getpwnam(RPCUSER);
                if (pwent) {
                        daemon_uid = pwent->pw_uid;
                        daemon_gid = pwent->pw_gid;
                } else
                        syslog(LOG_WARNING, "user '" RPCUSER
                               "' not found, reverting to default uid");
        }
#endif

        if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
                syslog(LOG_ERR, "cannot create udp socket: %m");
                exit(1);
        }
#ifdef LOOPBACK_SETUNSET
        setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
#endif

        memset((char *) &addr, 0, sizeof(addr));
        addr.sin_addr.s_addr = 0;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(PMAPPORT);
        if (have_bindaddr)
                memcpy(&addr.sin_addr, &bindaddr, sizeof(bindaddr));

        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                syslog(LOG_ERR, "cannot bind udp: %m");
                exit(1);
        }

        if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
                syslog(LOG_ERR, "couldn't do udp_create");
                exit(1);
        }
        /* make an entry for ourself */
        fpml = malloc(sizeof(struct flagged_pml));
        pml = &fpml->pml;
        fpml->priv = 1;
        pml->pml_next = NULL;
        pml->pml_map.pm_prog = PMAPPROG;
        pml->pml_map.pm_vers = PMAPVERS;
        pml->pml_map.pm_prot = IPPROTO_UDP;
        pml->pml_map.pm_port = PMAPPORT;
        pmaplist = pml;

        if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
                syslog(LOG_ERR, "cannot create tcp socket: %m");
                exit(1);
        }
#ifdef LOOPBACK_SETUNSET
        setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
#endif
        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                syslog(LOG_ERR, "cannot bind tcp: %m");
                exit(1);
        }
        if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
            == (SVCXPRT *)NULL) {
                syslog(LOG_ERR, "couldn't do tcp_create");
                exit(1);
        }
        /* make an entry for ourself */
        fpml = malloc(sizeof(struct flagged_pml));
        pml = &fpml->pml;
        fpml->priv = 1;
        pml->pml_map.pm_prog = PMAPPROG;
        pml->pml_map.pm_vers = PMAPVERS;
        pml->pml_map.pm_prot = IPPROTO_TCP;
        pml->pml_map.pm_port = PMAPPORT;
        pml->pml_next = pmaplist;
        pmaplist = pml;

#ifdef LOOPBACK_SETUNSET
        if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
                syslog(LOG_ERR, "cannot create udp socket: %m");
                exit(1);
        }
        setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);

        addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                syslog(LOG_ERR, "cannot bind udp: %m");
                exit(1);
        }

        if ((ludpxprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
                syslog(LOG_ERR, "couldn't do udp_create");
                exit(1);
        }
        if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
                syslog(LOG_ERR, "cannot create tcp socket: %m");
                exit(1);
        }
        setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof on);
        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                syslog(LOG_ERR, "cannot bind tcp: %m");
                exit(1);
        }
        if ((ltcpxprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
            == (SVCXPRT *)NULL) {
                syslog(LOG_ERR, "couldn't do tcp_create");
                exit(1);
        }
#endif

        (void)svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE);

        store_fd = open("/var/run/portmap_mapping", O_RDWR|O_CREAT, 0600);
        load_table();

        /* additional initializations */
        if (chroot_path) {
                if (chroot(chroot_path) < 0) {
                        syslog(LOG_ERR, "couldn't do chroot");
                        exit(1);
                }
        }
        check_startup();
#ifdef IGNORE_SIGCHLD                   /* Lionel Cons <cons@dxcern.cern.ch> */
        (void)signal(SIGCHLD, SIG_IGN);
#else
        (void)signal(SIGCHLD, reap);
#endif
        (void)signal(SIGPIPE, SIG_IGN);
        svc_run();
        syslog(LOG_ERR, "run_svc returned unexpectedly");
        abort();
}

/* need to override perror calls in rpc library */
void perror(const char *what)
{

        syslog(LOG_ERR, "%s: %m", what);
}

static struct pmaplist *
find_service(u_long prog, u_long vers, u_long prot)
{
        struct pmaplist *hit = NULL;
        struct pmaplist *pml;

        for (pml = pmaplist; 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);
}

/* 
 * 1 OK, 0 not
 */
static void reg_service(struct svc_req *rqstp, SVCXPRT *xprt)
{
        struct pmap reg;
        struct pmaplist *pml, *prevpml, *fnd;
        struct flagged_pml *fpml;
        int ans, port;
        caddr_t t;
        
        /*
         * Later wrappers change the logging severity on the fly. Reset to
         * defaults before handling the next request.
         */
        allow_severity = LOG_INFO;
        deny_severity = LOG_WARNING;

        if (debugging)
                (void) fprintf(stderr, "server: about do a switch\n");
        switch (rqstp->rq_proc) {

        case PMAPPROC_NULL:
                /*
                 * Null proc call
                 */
                /* remote host authorization check */
                check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
                if (!svc_sendreply(xprt, (xdrproc_t) xdr_void, (caddr_t)0)
                    && debugging) {
                        abort();
                }
                break;

        case PMAPPROC_SET:
                /*
                 * Set a program,version to port mapping
                 */
                if (!svc_getargs(xprt, (xdrproc_t) xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        /* reject non-local requests, protect priv. ports */
                        if (!CHECK_SETUNSET(xprt, ludpxprt, ltcpxprt,
                            rqstp->rq_proc, reg.pm_prog, reg.pm_port)) {
                                ans = 0;
                                goto done;
                        } 
                        /*
                         * check to see if already used
                         * find_service returns a hit even if
                         * the versions don't match, so check for it
                         */
                        fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
                        if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
                                if (fnd->pml_map.pm_port == reg.pm_port) {
                                        ans = 1;
                                        goto done;
                                }
                                else {
                                        ans = 0;
                                        goto done;
                                }
                        } else {
                                /* 
                                 * add to END of list
                                 */
                                fpml = (struct flagged_pml *)
                                    malloc((u_int)sizeof(struct flagged_pml));
                                pml = &fpml->pml;
                                fpml->priv =
                                        (ntohs(svc_getcaller(xprt)->sin_port)
                                         < IPPORT_RESERVED);
                                pml->pml_map = reg;
                                pml->pml_next = 0;

                                if (pmaplist == 0) {
                                        pmaplist = pml;
                                } else {
                                        for (fnd= pmaplist; fnd->pml_next != 0;
                                            fnd = fnd->pml_next);
                                        fnd->pml_next = pml;
                                }
                                ans = 1;
                                dump_table();
                        }
                done:
                        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_int,
                                            (caddr_t)&ans)) &&
                            debugging) {
                                (void) fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_UNSET:
                /*
                 * Remove a program,version to port mapping.
                 */
                if (!svc_getargs(xprt, (xdrproc_t)xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        ans = 0;
                        /* reject non-local requests */
                        if (!CHECK_SETUNSET(xprt, ludpxprt, ltcpxprt,
                            rqstp->rq_proc, reg.pm_prog, (u_long) 0))
                                goto done;
                        for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
                                if ((pml->pml_map.pm_prog != reg.pm_prog) ||
                                        (pml->pml_map.pm_vers != reg.pm_vers)) {
                                        /* both pml & prevpml move forwards */
                                        prevpml = pml;
                                        pml = pml->pml_next;
                                        continue;
                                }
                                /* found it; pml moves forward, prevpml stays */
                                /* privileged port check */
                                if (!check_privileged_port(svc_getcaller(xprt), 
                                    rqstp->rq_proc, 
                                    reg.pm_prog, 
                                    pml->pml_map.pm_port)) {
                                        ans = 0;
                                        break;
                                }
                                fpml = (struct flagged_pml*)pml;
                                if (fpml->priv &&
                                    (ntohs(svc_getcaller(xprt)->sin_port)
                                     >= IPPORT_RESERVED)) {
                                        ans = 0;
                                        break;
                                }

                                ans = 1;
                                t = (caddr_t)pml;
                                pml = pml->pml_next;
                                if (prevpml == NULL)
                                        pmaplist = pml;
                                else
                                        prevpml->pml_next = pml;
                                free(t);
                                dump_table();
                        }
                        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_int,
                                            (caddr_t)&ans)) &&
                            debugging) {
                                (void) fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_GETPORT:
                /*
                 * Lookup the mapping for a program,version and return its port
                 */
                if (!svc_getargs(xprt, (xdrproc_t)xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        /* remote host authorization check */
                        if (!check_default(svc_getcaller(xprt), 
                            rqstp->rq_proc, 
                            reg.pm_prog)) {
                                ans = 0;
                                goto done;
                        }
                        fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
                        if (fnd)
                                port = fnd->pml_map.pm_port;
                        else
                                port = 0;
                        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_int,
                                            (caddr_t)&port)) &&
                            debugging) {
                                (void) fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_DUMP:
                /*
                 * Return the current set of mapped program,version
                 */
                if (!svc_getargs(xprt, (xdrproc_t)xdr_void, NULL))
                        svcerr_decode(xprt);
                else {
                        /* remote host authorization check */
                        struct pmaplist *p;
                        if (!check_default(svc_getcaller(xprt), 
                            rqstp->rq_proc, (u_long) 0)) {
                                p = 0;  /* send empty list */
                        } else {
                                p = pmaplist;
                        }
                        if ((!svc_sendreply(xprt, (xdrproc_t)xdr_pmaplist,
                            (caddr_t)&p)) && debugging) {
                                (void) fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                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.
                 */
                callit(rqstp, xprt);
                break;

        default:
                /* remote host authorization check */
                check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
                svcerr_noproc(xprt);
                break;
        }
}


/*
 * Stuff for the rmtcall service
 */
#define ARGSIZE 9000

struct encap_parms {
        u_int arglen;
        char *args;
};

static bool_t
xdr_encap_parms(XDR *xdrs, struct encap_parms *epp)
{

        return (xdr_bytes(xdrs, &(epp->args), &(epp->arglen), ARGSIZE));
}

struct rmtcallargs {
        u_long  rmt_prog;
        u_long  rmt_vers;
        u_long  rmt_port;
        u_long  rmt_proc;
        struct encap_parms rmt_args;
};

static bool_t
xdr_rmtcall_args(XDR *xdrs, struct rmtcallargs *cap)
{

        /* does not get a port number */
        if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
            xdr_u_long(xdrs, &(cap->rmt_vers)) &&
            xdr_u_long(xdrs, &(cap->rmt_proc))) {
                return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
        }
        return (FALSE);
}

static bool_t
xdr_rmtcall_result(XDR *xdrs, struct rmtcallargs *cap)
{
        if (xdr_u_long(xdrs, &(cap->rmt_port)))
                return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
        return (FALSE);
}

/*
 * only worries about the struct encap_parms part of struct rmtcallargs.
 * The arglen must already be set!!
 */
static bool_t
xdr_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
{

        return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
}

/*
 * This routine finds and sets the length of incoming opaque paraters
 * and then calls xdr_opaque_parms.
 */
static bool_t
xdr_len_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
{
        u_int beginpos, lowpos, highpos, currpos, pos;

        beginpos = lowpos = pos = xdr_getpos(xdrs);
        highpos = lowpos + ARGSIZE;
        while ((int)(highpos - lowpos) >= 0) {
                currpos = (lowpos + highpos) / 2;
                if (xdr_setpos(xdrs, currpos)) {
                        pos = currpos;
                        lowpos = currpos + 1;
                } else {
                        highpos = currpos - 1;
                }
        }
        xdr_setpos(xdrs, beginpos);
        cap->rmt_args.arglen = pos - beginpos;
        return (xdr_opaque_parms(xdrs, cap));
}

/*
 * Call a remote procedure service
 * This procedure is very quiet when things go wrong.
 * The proc is written to support broadcast rpc.  In the broadcast case,
 * a machine should shut-up instead of complain, less the requestor be
 * overrun with complaints at the expense of not hearing a valid reply ...
 *
 * This now forks so that the program & process that it calls can call 
 * back to the portmapper.
 */
static void callit(struct svc_req *rqstp, SVCXPRT *xprt)
{
        struct rmtcallargs a;
        struct pmaplist *pml;
        u_short port;
        struct sockaddr_in me;
        int pid, so = -1;
        CLIENT *client;
        struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
        struct timeval timeout;
        char buf[ARGSIZE];

        timeout.tv_sec = 5;
        timeout.tv_usec = 0;
        a.rmt_args.args = buf;
        if (!svc_getargs(xprt, (xdrproc_t)xdr_rmtcall_args, (caddr_t)&a))
                return;
        /* host and service access control */
        if (!check_callit(svc_getcaller(xprt), 
            rqstp->rq_proc, a.rmt_prog, a.rmt_proc))
                return;
        if ((pml = find_service(a.rmt_prog, a.rmt_vers,
            (u_long)IPPROTO_UDP)) == NULL)
                return;
        /*
         * fork a child to do the work.  Parent immediately returns.
         * Child exits upon completion.
         */
        if ((pid = fork()) != 0) {
                if (pid < 0)
                        syslog(LOG_ERR, "CALLIT (prog %lu): fork: %m",
                            a.rmt_prog);
                return;
        }
        port = pml->pml_map.pm_port;
        get_myaddress(&me);
        me.sin_port = htons(port);
        client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &so);
        if (client != (CLIENT *)NULL) {
                if (rqstp->rq_cred.oa_flavor == AUTH_UNIX) {
                        client->cl_auth = authunix_create(au->aup_machname,
                           au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
                }
                a.rmt_port = (u_long)port;
                if (clnt_call(client, a.rmt_proc, (xdrproc_t)xdr_opaque_parms,
                              (caddr_t)&a, (xdrproc_t)xdr_len_opaque_parms,
                              (caddr_t)&a, timeout) == RPC_SUCCESS) {
                        svc_sendreply(xprt, (xdrproc_t)xdr_rmtcall_result,
                                      (caddr_t)&a);
                }
                AUTH_DESTROY(client->cl_auth);
                clnt_destroy(client);
        }
        (void)close(so);
        exit(0);
}

#ifndef IGNORE_SIGCHLD                  /* Lionel Cons <cons@dxcern.cern.ch> */
static void reap(int ignore)
{
        int save_errno = errno;
        while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
        errno = save_errno;
}
#endif

/* Dump and restore mapping table so that we can survive kill/restart.
 * To cope with chroot, an fd is opened early and we just write to that.
 * If we are killed while writing the file, we lose, but that isn't
 * very likely...
 */

static void dump_table(void)
{
        FILE *f;
        struct pmaplist *pml;

        if (store_fd < 0)
                return;
        ftruncate(store_fd, 0);
        lseek(store_fd, 0, 0);
        f = fdopen(dup(store_fd), "w");
        if (!f)
                return;

        for (pml = pmaplist ; pml ; pml = pml->pml_next) {
                struct flagged_pml *fpml = (struct flagged_pml*)pml;

                fprintf(f, "%lu %lu %lu %lu %d\n",
                        pml->pml_map.pm_prog,
                        pml->pml_map.pm_vers,
                        pml->pml_map.pm_prot,
                        pml->pml_map.pm_port,
                        fpml->priv);
        }
        fclose(f);
}

static void load_table(void)
{
        FILE *f;
        struct pmaplist **ep;
        struct flagged_pml fpml, *fpmlp;

        ep = &pmaplist;
        while ((*ep)->pml_next)
                ep = & (*ep)->pml_next;

        if (store_fd < 0)
                return;
        lseek(store_fd, 0, 0);
        f = fdopen(dup(store_fd), "r");
        if (f == NULL)
                return;

        while (fscanf(f, "%lu %lu %lu %lu %d\n",
                      &fpml.pml.pml_map.pm_prog,
                      &fpml.pml.pml_map.pm_vers,
                      &fpml.pml.pml_map.pm_prot,
                      &fpml.pml.pml_map.pm_port,
                      &fpml.priv) == 5) {
                if (fpml.pml.pml_map.pm_port == PMAPPORT)
                        continue;
                fpmlp = malloc(sizeof(struct flagged_pml));
                if (!fpmlp)
                        break;
                *fpmlp = fpml;
                *ep = &fpmlp->pml;
                ep = &fpmlp->pml.pml_next;
                *ep = NULL;
        }
        fclose(f);
}