cmd/ypcmd/yp_b_svc.c

	yp_b_svc.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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 (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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.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();

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);

    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);
}