/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley
 * under license from the Regents of the University of
 * California.
 */

#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <signal.h>
#include <rpc/rpc.h>
#include <memory.h>
#include <netconfig.h>
#include <syslog.h>
#include <rpcsvc/yp_prot.h>
#include "yp_b.h"
#include <sys/resource.h>
#include <sys/stropts.h>
#include <unistd.h>
#include <rpc/nettype.h>
#include <string.h>
#include <tiuser.h>


#ifdef DEBUG
#define RPC_SVC_FG
#endif

#define _RPCSVC_CLOSEDOWN 120
#define YPBIND_ERR_ERR 1                /* Internal error */
#define YPBIND_ERR_NOSERV 2             /* No bound server for passed domain */
#define YPBIND_ERR_RESC 3               /* System resource allocation failure */
#define YPBIND_ERR_NODOMAIN 4           /* Domain doesn't exist */

static  int _rpcpmstart;        /* Started by a port monitor ? */
static  int _rpcsvcdirty;       /* Still serving ? */
int     setok = YPSETNONE;      /* who is allowed to ypset */
int     broadcast = 0;
int     cache_okay = 0;         /* if set, then bindings are cached in files */

extern int sigcld_event;
extern void broadcast_proc_exit();
extern int __rpc_negotiate_uid();
extern bool_t __rpcbind_is_up();
extern void ypbind_init_default();
static void set_signal_handlers();
static void clear_bindings();
static void unregister(int);
static int void_close(void *, int);
void closedown();
void ypbindprog_3();
void ypbindprog_2();
void msgout();
extern void cache_transport();
extern void clean_cache();

int
main(argc, argv)
        int argc;
        char **argv;
{
        pid_t pid;
        int pfd[2];
        char domain[256], servers[300];
        char **Argv = argv;
        struct netconfig *nconf;
        void *nc_handle;
        int loopback_found = 0, udp_found = 0;
        int pipe_closed = 0;
        struct rlimit rl;
        int connmaxrec = RPC_MAXDATASIZE;
        uint32_t inet_tpts = 0, inet6_tpts = 0;
        uint32_t inet_desired_tpts = 0, inet6_desired_tpts = 0;
        bool_t exclbind = TRUE;

        if (geteuid() != 0) {
                (void) fprintf(stderr, "must be root to run %s\n", argv[0]);
                exit(1);
        }

        argc--;
        argv++;

        while (argc > 0) {
                if (strcmp(*argv, "-ypset") == 0) {
                        setok = YPSETALL;
                } else if (strcmp(*argv, "-ypsetme") == 0) {
                        setok = YPSETLOCAL;
                } else if (strcmp(*argv, "-broadcast") == 0) {
                        broadcast = TRUE;
                } else {
                        fprintf(stderr,
                "usage: ypbind [-broadcast] [-ypset] [-ypsetme]\n");
                        exit(1);
                }
                argc--,
                argv++;
        }

        if (setok == YPSETALL) {
                fprintf(stderr,
        "ypbind -ypset: allowing ypset! (this is REALLY insecure)\n");
        }
        if (setok == YPSETLOCAL) {
                fprintf(stderr,
        "ypbind -ypsetme: allowing local ypset! (this is insecure)\n");
        }
        if (broadcast == TRUE) {
                fprintf(stderr,
                        "ypbind -broadcast: allowing broadcast! \
(insecure and transport dependent)\n");
        }

        if (getdomainname(domain, sizeof (domain)) == 0) {
                sprintf(servers, "%s/%s/ypservers", BINDING, domain);
                if (!broadcast && access(servers, R_OK) != 0) {
                        (void) fprintf(stderr,
                "%s: no info on servers - run ypinit -c\n", Argv[0]);
                        exit(1);
                }
        } else {
                (void) fprintf(stderr, "%s: domainname not set - exiting\n",
                        Argv[0]);
                exit(1);
        }

        getrlimit(RLIMIT_NOFILE, &rl);
        rl.rlim_cur = rl.rlim_max;
        setrlimit(RLIMIT_NOFILE, &rl);

        (void) enable_extended_FILE_stdio(-1, -1);

        openlog("ypbind", LOG_PID, LOG_DAEMON);

        /*
         * If stdin looks like a TLI endpoint, we assume
         * that we were started by a port monitor. If
         * t_getstate fails with TBADF, this is not a
         * TLI endpoint.
         */
        _rpcpmstart = (t_getstate(0) != -1 || t_errno != TBADF);

        if (!__rpcbind_is_up()) {
                msgout("terminating: rpcbind is not running");
                exit(1);
        }

        if (_rpcpmstart) {
                /*
                 * We were invoked by ypbind with the request on stdin.
                 *
                 * XXX - This is not the normal way ypbind is used
                 * and has never been tested.
                 */
                char *netid;
                struct netconfig *nconf = NULL;
                SVCXPRT *transp;
                int pmclose;
                extern char *getenv();

                /*
                 * Set non-blocking mode and maximum record size for
                 * connection oriented RPC transports.
                 */
                if (!rpc_control(RPC_SVC_CONNMAXREC_SET, &connmaxrec)) {
                        msgout("unable to set maximum RPC record size");
                }

                clear_bindings();
                if ((netid = getenv("NLSPROVIDER")) == NULL) {
#ifdef DEBUG
                        msgout("cannot get transport name");
#endif
                } else if ((nconf = getnetconfigent(netid)) == NULL) {
#ifdef DEBUG
                        msgout("cannot get transport info");
#endif
                }

                pmclose = (t_getstate(0) != T_DATAXFER);
                if ((transp = svc_tli_create(0, nconf, NULL, 0, 0)) == NULL) {
                        msgout("cannot create server handle");
                        exit(1);
                }

                if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
                        if ((setok != YPSETNONE) &&
                                __rpc_negotiate_uid(transp->xp_fd)) {
                                        syslog(LOG_ERR,
                                "could not negotiate with loopback tranport %s",
                                nconf->nc_netid);
                        }
                }
                if (nconf)
                        freenetconfigent(nconf);
                if (!svc_reg(transp, YPBINDPROG, YPBINDVERS, ypbindprog_3, 0)) {
                        msgout("unable to register (YPBINDPROG, YPBINDVERS).");
                        exit(1);
                }
                if (!svc_reg(transp, YPBINDPROG, YPBINDVERS_2,
                    ypbindprog_2, 0)) {
                        msgout(
                            "unable to register (YPBINDPROG, YPBINDVERS_2).");
                        exit(1);
                }
                /* version 2 and version 1 are the same as far as we care */
                if (!svc_reg(transp, YPBINDPROG, YPBINDVERS_1,
                    ypbindprog_2, 0)) {
                        msgout(
                            "unable to register (YPBINDPROG, YPBINDVERS_1).");
                        exit(1);
                }
                set_signal_handlers();
                if (pmclose) {
                        (void) signal(SIGALRM, closedown);
                        (void) alarm(_RPCSVC_CLOSEDOWN);
                }
#ifdef INIT_DEFAULT
        ypbind_init_default();
#endif
                svc_run();
                msgout("svc_run returned");
                exit(1);
                /* NOTREACHED */
        }
#ifndef RPC_SVC_FG
        /*
         *  In normal operation, ypbind forks a child to do all the work
         *  so that it can run in background.  But, if the parent exits
         *  too soon during system startup, clients will start trying to
         *  talk to the child ypbind before it is ready.  This can cause
         *  spurious client errors.
         *
         *  To prevent these problems, the parent process creates a pipe,
         *  which is inherited by the child, and waits for the child to
         *  close its end.  This happens explicitly before the child goes
         *  into svc_run(), or as a side-effect of exiting.
         */
        if (pipe(pfd) == -1) {
                perror("pipe");
                exit(1);
        }
        pid = fork();
        if (pid < 0) {
                perror("cannot fork");
                exit(1);
        }
        if (pid) {
                /*
                 *  The parent waits for the child to close its end of
                 *  the pipe (to indicate that it is ready to process
                 *  requests).  The read blocks until the child does
                 *  a close (the "domain" array is just a handy buffer).
                 */
                close(pfd[1]);
                read(pfd[0], domain, sizeof (domain));
                exit(0);
        }
        /* close all files except pfd[1] */
        (void) fdwalk(void_close, &pfd[1]);
        (void) open("/dev/null", O_RDONLY);
        (void) open("/dev/null", O_WRONLY);
        (void) dup(1);
        setsid();
#endif
        clean_cache();    /* make sure there are no left-over files */
        cache_okay = cache_check();
        cache_pid();

        /*
         * Set non-blocking mode and maximum record size for
         * connection oriented RPC transports.
         */
        if (!rpc_control(RPC_SVC_CONNMAXREC_SET, &connmaxrec)) {
                msgout("unable to set maximum RPC record size");
        }

        /*
         * Prevent our non-priv udp and tcp ports bound w/wildcard addr
         * from being hijacked by a bind to a more specific addr.
         */
        if (!rpc_control(__RPC_SVC_EXCLBIND_SET, &exclbind)) {
                msgout("warning: unable to set udp/tcp EXCLBIND");
        }

#ifdef INIT_DEFAULT
        ypbind_init_default();
#endif

        nc_handle = __rpc_setconf("netpath");   /* open netconfig file */
        if (nc_handle == NULL) {
                syslog(LOG_ERR, "could not read /etc/netconfig, exiting..");
                exit(1);
        }

        /*
         *  The parent waits for the child to close its end of
         *  the pipe (to indicate that it is ready to process
         *  requests). Now the non-diskless client will wait because the
         *  cache file is valid.
         */
        if (cache_okay) {
                close(pfd[1]);
                pipe_closed = 1;
        }

        clear_bindings();

        while (nconf = __rpc_getconf(nc_handle)) {
                SVCXPRT *xprt;

                if (!__rpcbind_is_up()) {
                        msgout("terminating: rpcbind is not running");
                        exit(1);
                }
                if ((xprt = svc_tp_create(ypbindprog_3,
                        YPBINDPROG, YPBINDVERS, nconf)) == NULL) {
                        msgout("terminating: cannot create rpcbind handle");
                        exit(1);
                }

                cache_transport(nconf, xprt, YPBINDVERS);

                /* support ypbind V2 and V1, but only on udp/tcp transports */
                if (((strcmp(nconf->nc_protofmly, NC_INET) == 0) ||
                        (strcmp(nconf->nc_protofmly, NC_INET6))) &&
                        ((nconf->nc_semantics == NC_TPI_CLTS) ||
                                (nconf->nc_semantics == NC_TPI_COTS_ORD))) {

                        if (strcmp(nconf->nc_protofmly, NC_INET)) {
                                inet_desired_tpts |= 1 >> nconf->nc_semantics;
                        } else {
                                inet6_desired_tpts |= 1 >> nconf->nc_semantics;
                        }

                        (void) rpcb_unset(YPBINDPROG, YPBINDVERS_2, nconf);
                        if (!svc_reg(xprt, YPBINDPROG, YPBINDVERS_2,
                            ypbindprog_2, nconf)) {
                                syslog(LOG_INFO,
                    "unable to register (YPBINDPROG, YPBINDVERS_2) [%s]",
                                nconf->nc_netid);
                                continue;
                        }

                        cache_transport(nconf, xprt, YPBINDVERS_2);

                        /* For NC_INET, register v1 as well; error is fatal */
                        if (strcmp(nconf->nc_protofmly, NC_INET) == 0) {
                                (void) rpcb_unset(YPBINDPROG, YPBINDVERS_1,
                                                nconf);
                                if (!svc_reg(xprt, YPBINDPROG, YPBINDVERS_1,
                                                ypbindprog_2, nconf)) {
                                        syslog(LOG_ERR,
                            "unable to register (YPBINDPROG, YPBINDVERS_1).");
                                        exit(1);
                                }
                        }

                        cache_transport(nconf, xprt, YPBINDVERS_1);

                        if (nconf->nc_semantics == NC_TPI_CLTS)
                                udp_found++;

                        if (strcmp(nconf->nc_protofmly, NC_INET)) {
                                inet_tpts |= 1 >> nconf->nc_semantics;
                        } else {
                                inet6_tpts |= 1 >> nconf->nc_semantics;
                        }
                }
                if (strcmp(nconf->nc_protofmly, NC_LOOPBACK) == 0) {
                        loopback_found++;
                        if ((setok != YPSETNONE) &&
                                __rpc_negotiate_uid(xprt->xp_fd)) {
                                        syslog(LOG_ERR,
                                "could not negotiate with loopback tranport %s",
                                nconf->nc_netid);
                        }
                        /*
                         *  On a diskless client:
                         *  The parent waits for the child to close its end of
                         *  the pipe (to indicate that it is ready to process
                         *  requests). Now the diskless client will wait
                         *  only if ypbind is registered on the loopback.
                         */
                        if ((!pipe_closed) &&
                                ((nconf->nc_semantics == NC_TPI_COTS) ||
                                (nconf->nc_semantics == NC_TPI_COTS_ORD))) {
                                close(pfd[1]);
                                pipe_closed = 1;
                        }
                }
        }

        /* Did we manage to register all IPv4 or all IPv6 transports ? */
        if (inet_tpts != 0 && inet_tpts != inet_desired_tpts) {
                syslog(LOG_ERR,
                        "unable to register all %s transports, exiting..",
                        NC_INET);
                exit(1);
        } else if (inet6_tpts != 0 && inet6_tpts != inet6_desired_tpts) {
                syslog(LOG_ERR,
                        "unable to register all %s transports, exiting..",
                        NC_INET6);
                exit(1);
        }

        if (!pipe_closed) {
                close(pfd[1]);
                pipe_closed = 1;
        }
        __rpc_endconf(nc_handle);
        if (!loopback_found) {
                syslog(LOG_ERR,
                        "could not find loopback transports, exiting..");
                exit(1);
        }
        if (!udp_found) {
                syslog(LOG_ERR,
                        "could not find inet-clts (udp) transport, exiting..");
                exit(1);
        }
        set_signal_handlers();
        svc_run();
        syslog(LOG_ERR, "svc_run returned, exiting..");
        exit(1);
        /* NOTREACHED */
}

/*
 * Callback function for fdwalk() to close all files.
 */
static int
void_close(void *pfdp, int fd)
{
        if (fd != *(int *)pfdp)
                (void) close(fd);
        return (0);
}

void
ypbindprog_3(rqstp, transp)
        struct svc_req *rqstp;
        register SVCXPRT *transp;
{
        union {
                ypbind_domain ypbindproc_domain_3_arg;
                ypbind_setdom ypbindproc_setdom_3_arg;
        } argument;
        char *result;
        bool_t (*xdr_argument)(), (*xdr_result)();
        char *(*local)();

        if (sigcld_event)
                broadcast_proc_exit();

        _rpcsvcdirty = 1;
        switch (rqstp->rq_proc) {
        case YPBINDPROC_NULL:
                xdr_argument = xdr_void;
                xdr_result = xdr_void;
                local = (char *(*)()) ypbindproc_null_3;
                break;

        case YPBINDPROC_DOMAIN:
                xdr_argument = xdr_ypbind_domain;
                xdr_result = xdr_ypbind_resp;
                local = (char *(*)()) ypbindproc_domain_3;
                break;

        case YPBINDPROC_SETDOM:
                xdr_argument = xdr_ypbind_setdom;
                xdr_result = xdr_void;
                local = (char *(*)()) ypbindproc_setdom_3;
                break;

        default:
                svcerr_noproc(transp);
                _rpcsvcdirty = 0;
                return;
        }
        (void) memset((char *)&argument, 0, sizeof (argument));
        if (!svc_getargs(transp, (xdrproc_t)xdr_argument, (char *)&argument)) {
                svcerr_decode(transp);
                _rpcsvcdirty = 0;
                return;
        }
        if (rqstp->rq_proc == YPBINDPROC_SETDOM)
                result = (*local)(&argument, rqstp, transp);
        else
                result = (*local)(&argument, rqstp);
        if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
                svcerr_systemerr(transp);
        }
        if (!svc_freeargs(transp, (xdrproc_t)xdr_argument, (char *)&argument)) {
                syslog(LOG_ERR, "unable to free arguments");
                exit(1);
        }
        _rpcsvcdirty = 0;
}

void
ypbindprog_2(rqstp, transp)
        struct svc_req *rqstp;
        register SVCXPRT *transp;
{
        union {
                domainname_2 ypbindproc_domain_2_arg;
                ypbind_setdom_2 ypbindproc_setdom_2_arg;
        } argument;
        char *result;
        bool_t (*xdr_argument)(), (*xdr_result)();
        char *(*local)();

        if (sigcld_event)
                broadcast_proc_exit();

        _rpcsvcdirty = 1;
        switch (rqstp->rq_proc) {
        case YPBINDPROC_NULL:
                xdr_argument = xdr_void;
                xdr_result = xdr_void;
                /* XXX - don't need two null procedures */
                local = (char *(*)()) ypbindproc_null_3;
                break;

        case YPBINDPROC_DOMAIN:
                xdr_argument = (bool_t (*)())xdr_ypdomain_wrap_string;
                xdr_result = xdr_ypbind_resp_2;
                local = (char *(*)()) ypbindproc_domain_2;
                break;

        case YPBINDPROC_SETDOM: /* not supported, fall through to error */
        default:
                svcerr_noproc(transp);
                _rpcsvcdirty = 0;
                return;
        }
        (void) memset((char *)&argument, 0, sizeof (argument));
        if (!svc_getargs(transp, (xdrproc_t)xdr_argument, (char *)&argument)) {
                svcerr_decode(transp);
                _rpcsvcdirty = 0;
                return;
        }
        result = (*local)(&argument, rqstp);
        if (result != NULL && !svc_sendreply(transp, xdr_result, result)) {
                svcerr_systemerr(transp);
        }
        if (!svc_freeargs(transp, (xdrproc_t)xdr_argument, (char *)&argument)) {
                syslog(LOG_ERR, "unable to free arguments");
                exit(1);
        }
        _rpcsvcdirty = 0;
}

/*
 *  We clear out any old bindings that might have been
 *  left behind.  If there is already a ypbind running,
 *  it will no longer get requests.  We are in control
 *  now.  We ignore the error from rpcb_unset() because
 *  this is just a "best effort".  If the rpcb_unset()
 *  does fail, we will get an error in svc_reg().  By
 *  using 0 for the last argument we are telling the
 *  portmapper to remove the bindings for all transports.
 */
static
void
clear_bindings()
{
        rpcb_unset(YPBINDPROG, YPBINDVERS, 0);
        rpcb_unset(YPBINDPROG, YPBINDVERS_2, 0);
        rpcb_unset(YPBINDPROG, YPBINDVERS_1, 0);
}

/*
 *  This routine is called when we are killed (by most signals).
 *  It first tries to unregister with the portmapper.  Then it
 *  resets the signal handler to the default so that if we get
 *  the same signal, we will just go away.  We clean up our
 *  children by doing a hold in SIGTERM and then killing the
 *  process group (-getpid()) with SIGTERM.  Finally, we redeliver
 *  the signal to ourselves (the handler was reset to the default)
 *  so that we will do the normal handling (e.g., coredump).
 *  If we can't kill ourselves, we get drastic and just exit
 *  after sleeping for a couple of seconds.
 *
 *  This code was taken from the SunOS version of ypbind.
 */
static
void
unregister(int code)
{
        clear_bindings();
        clean_cache();
        signal(code, SIG_DFL);    /* to prevent recursive calls to unregister */
        fprintf(stderr, "ypbind: goind down on signal %d\n", code);
        sighold(SIGCHLD);
        sighold(SIGTERM);
        kill(-getpid(), SIGTERM); /* kill process group (i.e., children) */
        sigrelse(SIGTERM);
        kill(getpid(), code);     /* throw signal again */
        sleep(2);
        exit(-1);
}

static
void
set_signal_handlers()
{
        int i;

        for (i = 1; i <= SIGTERM; i++) {
                if (i == SIGCHLD)
                        continue;
                else if (i == SIGHUP)
                        signal(i, SIG_IGN);
                else
                        signal(i, unregister);
        }
}

void
msgout(msg)
        char *msg;
{
#ifdef RPC_SVC_FG
        if (_rpcpmstart)
                syslog(LOG_ERR, msg);
        else
                (void) fprintf(stderr, "%s\n", msg);
#else
        syslog(LOG_ERR, msg);
#endif
}

void
closedown()
{
        if (_rpcsvcdirty == 0) {
                int i, openfd;
                struct t_info tinfo;

                if (t_getinfo(0, &tinfo) || (tinfo.servtype == T_CLTS))
                        exit(0);

                for (i = 0, openfd = 0; i < svc_max_pollfd && openfd < 2; i++)
                        if (svc_pollfd[i].fd >= 0)
                                openfd++;

                if (openfd <= 1)
                        exit(0);
        }
        (void) alarm(_RPCSVC_CLOSEDOWN);
}