dmake: do not set MAKEFLAGS=k

[unleashed/tickless.git] / usr / src / cmd / fs.d / nfs / mountd / mountd.c

/*
 * 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 2015 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 */

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

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <string.h>
#include <syslog.h>
#include <sys/param.h>
#include <rpc/rpc.h>
#include <sys/stat.h>
#include <netconfig.h>
#include <netdir.h>
#include <sys/file.h>
#include <sys/time.h>
#include <sys/errno.h>
#include <rpcsvc/mount.h>
#include <sys/pathconf.h>
#include <sys/systeminfo.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <sys/resource.h>
#include <signal.h>
#include <locale.h>
#include <unistd.h>
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <thread.h>
#include <assert.h>
#include <priv_utils.h>
#include <nfs/auth.h>
#include <nfs/nfssys.h>
#include <nfs/nfs.h>
#include <nfs/nfs_sec.h>
#include <rpcsvc/daemon_utils.h>
#include <deflt.h>
#include "../../fslib.h"
#include <sharefs/share.h>
#include <sharefs/sharetab.h>
#include "../lib/sharetab.h"
#include "mountd.h"
#include <sys/sdt.h>
#include <libscf.h>
#include <limits.h>
#include <sys/nvpair.h>
#include <attr.h>
#include "smfcfg.h"
#include <pwd.h>
#include <grp.h>
#include <alloca.h>

extern int daemonize_init(void);
extern void daemonize_fini(int);

extern int _nfssys(int, void *);

struct sh_list *share_list;

rwlock_t sharetab_lock;         /* lock to protect the cached sharetab */
static mutex_t mnttab_lock;     /* prevent concurrent mnttab readers */

static mutex_t logging_queue_lock;
static cond_t logging_queue_cv;

static share_t *find_lofsentry(char *, int *);
static int getclientsflavors_old(share_t *, struct cln *, int *);
static int getclientsflavors_new(share_t *, struct cln *, int *);
static int check_client_old(share_t *, struct cln *, int, uid_t, gid_t, uint_t,
    gid_t *, uid_t *, gid_t *, uint_t *, gid_t **);
static int check_client_new(share_t *, struct cln *, int, uid_t, gid_t, uint_t,
    gid_t *, uid_t *, gid_t *i, uint_t *, gid_t **);
static void mnt(struct svc_req *, SVCXPRT *);
static void mnt_pathconf(struct svc_req *);
static int mount(struct svc_req *r);
static void sh_free(struct sh_list *);
static void umount(struct svc_req *);
static void umountall(struct svc_req *);
static int newopts(char *);

static int verbose;
static int rejecting;
static int mount_vers_min = MOUNTVERS;
static int mount_vers_max = MOUNTVERS3;

extern void nfscmd_func(void *, char *, size_t, door_desc_t *, uint_t);

thread_t        nfsauth_thread;
thread_t        cmd_thread;
thread_t        logging_thread;

typedef struct logging_data {
        char                    *ld_host;
        char                    *ld_path;
        char                    *ld_rpath;
        int                     ld_status;
        char                    *ld_netid;
        struct netbuf           *ld_nb;
        struct logging_data     *ld_next;
} logging_data;

static logging_data *logging_head = NULL;
static logging_data *logging_tail = NULL;

/*
 * Our copy of some system variables obtained using sysconf(3c)
 */
static long ngroups_max;        /* _SC_NGROUPS_MAX */
static long pw_size;            /* _SC_GETPW_R_SIZE_MAX */

/* ARGSUSED */
static void *
nfsauth_svc(void *arg)
{
        int     doorfd = -1;
        uint_t  darg;
#ifdef DEBUG
        int     dfd;
#endif

        if ((doorfd = door_create(nfsauth_func, NULL,
            DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) {
                syslog(LOG_ERR, "Unable to create door: %m\n");
                exit(10);
        }

#ifdef DEBUG
        /*
         * Create a file system path for the door
         */
        if ((dfd = open(MOUNTD_DOOR, O_RDWR|O_CREAT|O_TRUNC,
            S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) == -1) {
                syslog(LOG_ERR, "Unable to open %s: %m\n", MOUNTD_DOOR);
                (void) close(doorfd);
                exit(11);
        }

        /*
         * Clean up any stale namespace associations
         */
        (void) fdetach(MOUNTD_DOOR);

        /*
         * Register in namespace to pass to the kernel to door_ki_open
         */
        if (fattach(doorfd, MOUNTD_DOOR) == -1) {
                syslog(LOG_ERR, "Unable to fattach door: %m\n");
                (void) close(dfd);
                (void) close(doorfd);
                exit(12);
        }
        (void) close(dfd);
#endif

        /*
         * Must pass the doorfd down to the kernel.
         */
        darg = doorfd;
        (void) _nfssys(MOUNTD_ARGS, &darg);

        /*
         * Wait for incoming calls
         */
        /*CONSTCOND*/
        for (;;)
                (void) pause();

        /*NOTREACHED*/
        syslog(LOG_ERR, gettext("Door server exited"));
        return (NULL);
}

/*
 * NFS command service thread code for setup and handling of the
 * nfs_cmd requests for character set conversion and other future
 * events.
 */

static void *
cmd_svc(void *arg)
{
        int     doorfd = -1;
        uint_t  darg;

        if ((doorfd = door_create(nfscmd_func, NULL,
            DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) {
                syslog(LOG_ERR, "Unable to create cmd door: %m\n");
                exit(10);
        }

        /*
         * Must pass the doorfd down to the kernel.
         */
        darg = doorfd;
        (void) _nfssys(NFSCMD_ARGS, &darg);

        /*
         * Wait for incoming calls
         */
        /*CONSTCOND*/
        for (;;)
                (void) pause();

        /*NOTREACHED*/
        syslog(LOG_ERR, gettext("Cmd door server exited"));
        return (NULL);
}

static void
free_logging_data(logging_data *lq)
{
        if (lq != NULL) {
                free(lq->ld_host);
                free(lq->ld_netid);

                if (lq->ld_nb != NULL) {
                        free(lq->ld_nb->buf);
                        free(lq->ld_nb);
                }

                free(lq->ld_path);
                free(lq->ld_rpath);

                free(lq);
        }
}

static logging_data *
remove_head_of_queue(void)
{
        logging_data    *lq;

        /*
         * Pull it off the queue.
         */
        lq = logging_head;
        if (lq) {
                logging_head = lq->ld_next;

                /*
                 * Drained it.
                 */
                if (logging_head == NULL) {
                        logging_tail = NULL;
                }
        }

        return (lq);
}

static void
do_logging_queue(logging_data *lq)
{
        int             cleared = 0;
        char            *host;

        while (lq) {
                struct cln cln;

                if (lq->ld_host == NULL) {
                        DTRACE_PROBE(mountd, name_by_lazy);
                        cln_init_lazy(&cln, lq->ld_netid, lq->ld_nb);
                        host = cln_gethost(&cln);
                } else
                        host = lq->ld_host;

                audit_mountd_mount(host, lq->ld_path, lq->ld_status); /* BSM */

                /* add entry to mount list */
                if (lq->ld_rpath)
                        mntlist_new(host, lq->ld_rpath);

                if (lq->ld_host == NULL)
                        cln_fini(&cln);

                free_logging_data(lq);
                cleared++;

                (void) mutex_lock(&logging_queue_lock);
                lq = remove_head_of_queue();
                (void) mutex_unlock(&logging_queue_lock);
        }

        DTRACE_PROBE1(mountd, logging_cleared, cleared);
}

static void *
logging_svc(void *arg)
{
        logging_data    *lq;

        for (;;) {
                (void) mutex_lock(&logging_queue_lock);
                while (logging_head == NULL) {
                        (void) cond_wait(&logging_queue_cv,
                            &logging_queue_lock);
                }

                lq = remove_head_of_queue();
                (void) mutex_unlock(&logging_queue_lock);

                do_logging_queue(lq);
        }

        /*NOTREACHED*/
        syslog(LOG_ERR, gettext("Logging server exited"));
        return (NULL);
}

static int
convert_int(int *val, char *str)
{
        long lval;

        if (str == NULL || !isdigit(*str))
                return (-1);

        lval = strtol(str, &str, 10);
        if (*str != '\0' || lval > INT_MAX)
                return (-2);

        *val = (int)lval;
        return (0);
}

int
main(int argc, char *argv[])
{
        int     pid;
        int     c;
        int     rpc_svc_fdunlim = 1;
        int     rpc_svc_mode = RPC_SVC_MT_AUTO;
        int     maxrecsz = RPC_MAXDATASIZE;
        bool_t  exclbind = TRUE;
        long    thr_flags = (THR_NEW_LWP|THR_DAEMON);
        char defval[4];
        int defvers, ret, bufsz;
        struct rlimit rl;
        int listen_backlog = 0;
        int max_threads = 0;
        int tmp;

        int     pipe_fd = -1;

        /*
         * Mountd requires uid 0 for:
         *      /etc/rmtab updates (we could chown it to daemon)
         *      /etc/dfs/dfstab reading (it wants to lock out share which
         *              doesn't do any locking before first truncate;
         *              NFS share does; should use fcntl locking instead)
         *      Needed privileges:
         *              auditing
         *              nfs syscall
         *              file dac search (so it can stat all files)
         */
        if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET, -1, -1,
            PRIV_SYS_NFS, PRIV_PROC_AUDIT, PRIV_FILE_DAC_SEARCH, NULL) == -1) {
                (void) fprintf(stderr,
                    "%s: must be run with sufficient privileges\n",
                    argv[0]);
                exit(1);
        }

        if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
                syslog(LOG_ERR, "getrlimit failed");
        } else {
                rl.rlim_cur = rl.rlim_max;
                if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
                        syslog(LOG_ERR, "setrlimit failed");
        }

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

        ret = nfs_smf_get_iprop("mountd_max_threads", &max_threads,
            DEFAULT_INSTANCE, SCF_TYPE_INTEGER, NFSD);
        if (ret != SA_OK) {
                syslog(LOG_ERR, "Reading of mountd_max_threads from SMF "
                    "failed, using default value");
        }

        while ((c = getopt(argc, argv, "vrm:")) != EOF) {
                switch (c) {
                case 'v':
                        verbose++;
                        break;
                case 'r':
                        rejecting = 1;
                        break;
                case 'm':
                        if (convert_int(&tmp, optarg) != 0 || tmp < 1) {
                                (void) fprintf(stderr, "%s: invalid "
                                    "max_threads option, using defaults\n",
                                    argv[0]);
                                break;
                        }
                        max_threads = tmp;
                        break;
                default:
                        fprintf(stderr, "usage: mountd [-v] [-r]\n");
                        exit(1);
                }
        }

        /*
         * Read in the NFS version values from config file.
         */
        bufsz = 4;
        ret = nfs_smf_get_prop("server_versmin", defval, DEFAULT_INSTANCE,
            SCF_TYPE_INTEGER, NFSD, &bufsz);
        if (ret == SA_OK) {
                errno = 0;
                defvers = strtol(defval, (char **)NULL, 10);
                if (errno == 0) {
                        mount_vers_min = defvers;
                        /*
                         * special because NFSv2 is
                         * supported by mount v1 & v2
                         */
                        if (defvers == NFS_VERSION)
                                mount_vers_min = MOUNTVERS;
                }
        }

        bufsz = 4;
        ret = nfs_smf_get_prop("server_versmax", defval, DEFAULT_INSTANCE,
            SCF_TYPE_INTEGER, NFSD, &bufsz);
        if (ret == SA_OK) {
                errno = 0;
                defvers = strtol(defval, (char **)NULL, 10);
                if (errno == 0) {
                        mount_vers_max = defvers;
                }
        }

        ret = nfs_smf_get_iprop("mountd_listen_backlog", &listen_backlog,
            DEFAULT_INSTANCE, SCF_TYPE_INTEGER, NFSD);
        if (ret != SA_OK) {
                syslog(LOG_ERR, "Reading of mountd_listen_backlog from SMF "
                    "failed, using default value");
        }

        /*
         * Sanity check versions,
         * even though we may get versions > MOUNTVERS3, we still need
         * to start nfsauth service, so continue on regardless of values.
         */
        if (mount_vers_min > mount_vers_max) {
                fprintf(stderr, "server_versmin > server_versmax\n");
                mount_vers_max = mount_vers_min;
        }
        (void) setlocale(LC_ALL, "");
        (void) rwlock_init(&sharetab_lock, USYNC_THREAD, NULL);
        (void) mutex_init(&mnttab_lock, USYNC_THREAD, NULL);
        (void) mutex_init(&logging_queue_lock, USYNC_THREAD, NULL);
        (void) cond_init(&logging_queue_cv, USYNC_THREAD, NULL);

        netgroup_init();

#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
        (void) textdomain(TEXT_DOMAIN);

        /* Don't drop core if the NFS module isn't loaded. */
        (void) signal(SIGSYS, SIG_IGN);

        pipe_fd = daemonize_init();

        /*
         * If we coredump it'll be in /core
         */
        if (chdir("/") < 0)
                fprintf(stderr, "chdir /: %s\n", strerror(errno));

        openlog("mountd", LOG_PID, LOG_DAEMON);

        /*
         * establish our lock on the lock file and write our pid to it.
         * exit if some other process holds the lock, or if there's any
         * error in writing/locking the file.
         */
        pid = _enter_daemon_lock(MOUNTD);
        switch (pid) {
        case 0:
                break;
        case -1:
                fprintf(stderr, "error locking for %s: %s\n", MOUNTD,
                    strerror(errno));
                exit(2);
        default:
                /* daemon was already running */
                exit(0);
        }

        audit_mountd_setup();   /* BSM */

        /*
         * Get required system variables
         */
        if ((ngroups_max = sysconf(_SC_NGROUPS_MAX)) == -1) {
                syslog(LOG_ERR, "Unable to get _SC_NGROUPS_MAX");
                exit(1);
        }
        if ((pw_size = sysconf(_SC_GETPW_R_SIZE_MAX)) == -1) {
                syslog(LOG_ERR, "Unable to get _SC_GETPW_R_SIZE_MAX");
                exit(1);
        }

        /*
         * Set number of file descriptors to unlimited
         */
        if (!rpc_control(RPC_SVC_USE_POLLFD, &rpc_svc_fdunlim)) {
                syslog(LOG_INFO, "unable to set number of FDs to unlimited");
        }

        /*
         * Tell RPC that we want automatic thread mode.
         * A new thread will be spawned for each request.
         */
        if (!rpc_control(RPC_SVC_MTMODE_SET, &rpc_svc_mode)) {
                fprintf(stderr, "unable to set automatic MT mode\n");
                exit(1);
        }

        /*
         * Enable non-blocking mode and maximum record size checks for
         * connection oriented transports.
         */
        if (!rpc_control(RPC_SVC_CONNMAXREC_SET, &maxrecsz)) {
                fprintf(stderr, "unable to set RPC max record size\n");
        }

        /*
         * 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)) {
                fprintf(stderr, "warning: unable to set udp/tcp EXCLBIND\n");
        }

        /*
         * Set the maximum number of outstanding connection
         * indications (listen backlog) to the value specified.
         */
        if (listen_backlog > 0 && !rpc_control(__RPC_SVC_LSTNBKLOG_SET,
            &listen_backlog)) {
                fprintf(stderr, "unable to set listen backlog\n");
                exit(1);
        }

        /*
         * If max_threads was specified, then set the
         * maximum number of threads to the value specified.
         */
        if (max_threads > 0 && !rpc_control(RPC_SVC_THRMAX_SET, &max_threads)) {
                fprintf(stderr, "unable to set max_threads\n");
                exit(1);
        }

        /*
         * Make sure to unregister any previous versions in case the
         * user is reconfiguring the server in interesting ways.
         */
        svc_unreg(MOUNTPROG, MOUNTVERS);
        svc_unreg(MOUNTPROG, MOUNTVERS_POSIX);
        svc_unreg(MOUNTPROG, MOUNTVERS3);

        /*
         * Create the nfsauth thread with same signal disposition
         * as the main thread. We need to create a separate thread
         * since mountd() will be both an RPC server (for remote
         * traffic) _and_ a doors server (for kernel upcalls).
         */
        if (thr_create(NULL, 0, nfsauth_svc, 0, thr_flags, &nfsauth_thread)) {
                fprintf(stderr,
                    gettext("Failed to create NFSAUTH svc thread\n"));
                exit(2);
        }

        /*
         * Create the cmd service thread with same signal disposition
         * as the main thread. We need to create a separate thread
         * since mountd() will be both an RPC server (for remote
         * traffic) _and_ a doors server (for kernel upcalls).
         */
        if (thr_create(NULL, 0, cmd_svc, 0, thr_flags, &cmd_thread)) {
                syslog(LOG_ERR, gettext("Failed to create CMD svc thread"));
                exit(2);
        }

        /*
         * Create an additional thread to service the rmtab and
         * audit_mountd_mount logging for mount requests. Use the same
         * signal disposition as the main thread. We create
         * a separate thread to allow the mount request threads to
         * clear as soon as possible.
         */
        if (thr_create(NULL, 0, logging_svc, 0, thr_flags, &logging_thread)) {
                syslog(LOG_ERR, gettext("Failed to create LOGGING svc thread"));
                exit(2);
        }

        /*
         * Create datagram and connection oriented services
         */
        if (mount_vers_max >= MOUNTVERS) {
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS, "datagram_v") == 0) {
                        fprintf(stderr,
                            "couldn't register datagram_v MOUNTVERS\n");
                        exit(1);
                }
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS, "circuit_v") == 0) {
                        fprintf(stderr,
                            "couldn't register circuit_v MOUNTVERS\n");
                        exit(1);
                }
        }

        if (mount_vers_max >= MOUNTVERS_POSIX) {
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS_POSIX,
                    "datagram_v") == 0) {
                        fprintf(stderr,
                            "couldn't register datagram_v MOUNTVERS_POSIX\n");
                        exit(1);
                }
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS_POSIX,
                    "circuit_v") == 0) {
                        fprintf(stderr,
                            "couldn't register circuit_v MOUNTVERS_POSIX\n");
                        exit(1);
                }
        }

        if (mount_vers_max >= MOUNTVERS3) {
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS3, "datagram_v") == 0) {
                        fprintf(stderr,
                            "couldn't register datagram_v MOUNTVERS3\n");
                        exit(1);
                }
                if (svc_create(mnt, MOUNTPROG, MOUNTVERS3, "circuit_v") == 0) {
                        fprintf(stderr,
                            "couldn't register circuit_v MOUNTVERS3\n");
                        exit(1);
                }
        }

        /*
         * Start serving
         */
        rmtab_load();

        daemonize_fini(pipe_fd);

        /* Get rid of the most dangerous basic privileges. */
        __fini_daemon_priv(PRIV_PROC_EXEC, PRIV_PROC_INFO, PRIV_PROC_SESSION,
            NULL);

        svc_run();
        syslog(LOG_ERR, "Error: svc_run shouldn't have returned");
        abort();

        /* NOTREACHED */
        return (0);
}

/*
 * Server procedure switch routine
 */
void
mnt(struct svc_req *rqstp, SVCXPRT *transp)
{
        switch (rqstp->rq_proc) {
        case NULLPROC:
                errno = 0;
                if (!svc_sendreply(transp, xdr_void, (char *)0))
                        log_cant_reply(transp);
                return;

        case MOUNTPROC_MNT:
                (void) mount(rqstp);
                return;

        case MOUNTPROC_DUMP:
                mntlist_send(transp);
                return;

        case MOUNTPROC_UMNT:
                umount(rqstp);
                return;

        case MOUNTPROC_UMNTALL:
                umountall(rqstp);
                return;

        case MOUNTPROC_EXPORT:
        case MOUNTPROC_EXPORTALL:
                export(rqstp);
                return;

        case MOUNTPROC_PATHCONF:
                if (rqstp->rq_vers == MOUNTVERS_POSIX)
                        mnt_pathconf(rqstp);
                else
                        svcerr_noproc(transp);
                return;

        default:
                svcerr_noproc(transp);
                return;
        }
}

void
log_cant_reply_cln(struct cln *cln)
{
        int saverrno;
        char *host;

        saverrno = errno;       /* save error code */

        host = cln_gethost(cln);
        if (host == NULL)
                return;

        errno = saverrno;
        if (errno == 0)
                syslog(LOG_ERR, "couldn't send reply to %s", host);
        else
                syslog(LOG_ERR, "couldn't send reply to %s: %m", host);
}

void
log_cant_reply(SVCXPRT *transp)
{
        int saverrno;
        struct cln cln;

        saverrno = errno;       /* save error code */
        cln_init(&cln, transp);
        errno = saverrno;

        log_cant_reply_cln(&cln);

        cln_fini(&cln);
}

/*
 * Answer pathconf questions for the mount point fs
 */
static void
mnt_pathconf(struct svc_req *rqstp)
{
        SVCXPRT *transp;
        struct pathcnf p;
        char *path, rpath[MAXPATHLEN];
        struct stat st;

        transp = rqstp->rq_xprt;
        path = NULL;
        (void) memset((caddr_t)&p, 0, sizeof (p));

        if (!svc_getargs(transp, xdr_dirpath, (caddr_t)&path)) {
                svcerr_decode(transp);
                return;
        }
        if (lstat(path, &st) < 0) {
                _PC_SET(_PC_ERROR, p.pc_mask);
                goto done;
        }
        /*
         * Get a path without symbolic links.
         */
        if (realpath(path, rpath) == NULL) {
                syslog(LOG_DEBUG,
                    "mount request: realpath failed on %s: %m",
                    path);
                _PC_SET(_PC_ERROR, p.pc_mask);
                goto done;
        }
        (void) memset((caddr_t)&p, 0, sizeof (p));
        /*
         * can't ask about devices over NFS
         */
        _PC_SET(_PC_MAX_CANON, p.pc_mask);
        _PC_SET(_PC_MAX_INPUT, p.pc_mask);
        _PC_SET(_PC_PIPE_BUF, p.pc_mask);
        _PC_SET(_PC_VDISABLE, p.pc_mask);

        errno = 0;
        p.pc_link_max = pathconf(rpath, _PC_LINK_MAX);
        if (errno)
                _PC_SET(_PC_LINK_MAX, p.pc_mask);
        p.pc_name_max = pathconf(rpath, _PC_NAME_MAX);
        if (errno)
                _PC_SET(_PC_NAME_MAX, p.pc_mask);
        p.pc_path_max = pathconf(rpath, _PC_PATH_MAX);
        if (errno)
                _PC_SET(_PC_PATH_MAX, p.pc_mask);
        if (pathconf(rpath, _PC_NO_TRUNC) == 1)
                _PC_SET(_PC_NO_TRUNC, p.pc_mask);
        if (pathconf(rpath, _PC_CHOWN_RESTRICTED) == 1)
                _PC_SET(_PC_CHOWN_RESTRICTED, p.pc_mask);

done:
        errno = 0;
        if (!svc_sendreply(transp, xdr_ppathcnf, (char *)&p))
                log_cant_reply(transp);
        if (path != NULL)
                svc_freeargs(transp, xdr_dirpath, (caddr_t)&path);
}

/*
 * If the rootmount (export) option is specified, the all mount requests for
 * subdirectories return EACCES.
 */
static int
checkrootmount(share_t *sh, char *rpath)
{
        char *val;

        if ((val = getshareopt(sh->sh_opts, SHOPT_NOSUB)) != NULL) {
                free(val);
                if (strcmp(sh->sh_path, rpath) != 0)
                        return (0);
                else
                        return (1);
        } else
                return (1);
}

#define MAX_FLAVORS     128

/*
 * Return only EACCES if client does not have access
 *  to this directory.
 * "If the server exports only /a/b, an attempt to
 *  mount a/b/c will fail with ENOENT if the directory
 *  does not exist"... However, if the client
 *  does not have access to /a/b, an attacker can
 *  determine whether the directory exists.
 * This routine checks either existence of the file or
 * existence of the file name entry in the mount table.
 * If the file exists and there is no file name entry,
 * the error returned should be EACCES.
 * If the file does not exist, it must be determined
 * whether the client has access to a parent
 * directory.  If the client has access to a parent
 * directory, the error returned should be ENOENT,
 * otherwise EACCES.
 */
static int
mount_enoent_error(struct cln *cln, char *path, char *rpath, int *flavor_list)
{
        char *checkpath, *dp;
        share_t *sh = NULL;
        int realpath_error = ENOENT, reply_error = EACCES, lofs_tried = 0;
        int flavor_count;

        checkpath = strdup(path);
        if (checkpath == NULL) {
                syslog(LOG_ERR, "mount_enoent: no memory");
                return (EACCES);
        }

        /* CONSTCOND */
        while (1) {
                if (sh) {
                        sharefree(sh);
                        sh = NULL;
                }

                if ((sh = findentry(rpath)) == NULL &&
                    (sh = find_lofsentry(rpath, &lofs_tried)) == NULL) {
                        /*
                         * There is no file name entry.
                         * If the file (with symbolic links resolved) exists,
                         * the error returned should be EACCES.
                         */
                        if (realpath_error == 0)
                                break;
                } else if (checkrootmount(sh, rpath) == 0) {
                        /*
                         * This is a "nosub" only export, in which case,
                         * mounting subdirectories isn't allowed.
                         * If the file (with symbolic links resolved) exists,
                         * the error returned should be EACCES.
                         */
                        if (realpath_error == 0)
                                break;
                } else {
                        /*
                         * Check permissions in mount table.
                         */
                        if (newopts(sh->sh_opts))
                                flavor_count = getclientsflavors_new(sh, cln,
                                    flavor_list);
                        else
                                flavor_count = getclientsflavors_old(sh, cln,
                                    flavor_list);
                        if (flavor_count != 0) {
                                /*
                                 * Found entry in table and
                                 * client has correct permissions.
                                 */
                                reply_error = ENOENT;
                                break;
                        }
                }

                /*
                 * Check all parent directories.
                 */
                dp = strrchr(checkpath, '/');
                if (dp == NULL)
                        break;
                *dp = '\0';
                if (strlen(checkpath) == 0)
                        break;
                /*
                 * Get the real path (no symbolic links in it)
                 */
                if (realpath(checkpath, rpath) == NULL) {
                        if (errno != ENOENT)
                                break;
                } else {
                        realpath_error = 0;
                }
        }

        if (sh)
                sharefree(sh);
        free(checkpath);
        return (reply_error);
}

/*
 * We need to inform the caller whether or not we were
 * able to add a node to the queue. If we are not, then
 * it is up to the caller to go ahead and log the data.
 */
static int
enqueue_logging_data(char *host, SVCXPRT *transp, char *path,
    char *rpath, int status, int error)
{
        logging_data    *lq;
        struct netbuf   *nb;

        lq = (logging_data *)calloc(1, sizeof (logging_data));
        if (lq == NULL)
                goto cleanup;

        /*
         * We might not yet have the host...
         */
        if (host) {
                DTRACE_PROBE1(mountd, log_host, host);
                lq->ld_host = strdup(host);
                if (lq->ld_host == NULL)
                        goto cleanup;
        } else {
                DTRACE_PROBE(mountd, log_no_host);

                lq->ld_netid = strdup(transp->xp_netid);
                if (lq->ld_netid == NULL)
                        goto cleanup;

                lq->ld_nb = calloc(1, sizeof (struct netbuf));
                if (lq->ld_nb == NULL)
                        goto cleanup;

                nb = svc_getrpccaller(transp);
                if (nb == NULL) {
                        DTRACE_PROBE(mountd, e__nb__enqueue);
                        goto cleanup;
                }

                DTRACE_PROBE(mountd, nb_set_enqueue);

                lq->ld_nb->maxlen = nb->maxlen;
                lq->ld_nb->len = nb->len;

                lq->ld_nb->buf = malloc(lq->ld_nb->len);
                if (lq->ld_nb->buf == NULL)
                        goto cleanup;

                bcopy(nb->buf, lq->ld_nb->buf, lq->ld_nb->len);
        }

        lq->ld_path = strdup(path);
        if (lq->ld_path == NULL)
                goto cleanup;

        if (!error) {
                lq->ld_rpath = strdup(rpath);
                if (lq->ld_rpath == NULL)
                        goto cleanup;
        }

        lq->ld_status = status;

        /*
         * Add to the tail of the logging queue.
         */
        (void) mutex_lock(&logging_queue_lock);
        if (logging_tail == NULL) {
                logging_tail = logging_head = lq;
        } else {
                logging_tail->ld_next = lq;
                logging_tail = lq;
        }
        (void) cond_signal(&logging_queue_cv);
        (void) mutex_unlock(&logging_queue_lock);

        return (TRUE);

cleanup:

        free_logging_data(lq);

        return (FALSE);
}


#define CLN_CLNAMES     (1 << 0)
#define CLN_HOST        (1 << 1)

static void
cln_init_common(struct cln *cln, SVCXPRT *transp, char *netid,
    struct netbuf *nbuf)
{
        if ((cln->transp = transp) != NULL) {
                assert(netid == NULL && nbuf == NULL);
                cln->netid = transp->xp_netid;
                cln->nbuf = svc_getrpccaller(transp);
        } else {
                cln->netid = netid;
                cln->nbuf = nbuf;
        }

        cln->nconf = NULL;
        cln->clnames = NULL;
        cln->host = NULL;

        cln->flags = 0;
}

void
cln_init(struct cln *cln, SVCXPRT *transp)
{
        cln_init_common(cln, transp, NULL, NULL);
}

void
cln_init_lazy(struct cln *cln, char *netid, struct netbuf *nbuf)
{
        cln_init_common(cln, NULL, netid, nbuf);
}

void
cln_fini(struct cln *cln)
{
        if (cln->nconf != NULL)
                freenetconfigent(cln->nconf);

        if (cln->clnames != NULL)
                netdir_free(cln->clnames, ND_HOSTSERVLIST);

        free(cln->host);
}

struct netbuf *
cln_getnbuf(struct cln *cln)
{
        return (cln->nbuf);
}

struct nd_hostservlist *
cln_getclientsnames(struct cln *cln)
{
        if ((cln->flags & CLN_CLNAMES) == 0) {
                /*
                 * nconf is not needed if we do not have nbuf (see
                 * cln_gethost() too), so we check for nbuf and in a case it is
                 * NULL we do not try to get nconf.
                 */
                if (cln->netid != NULL && cln->nbuf != NULL) {
                        cln->nconf = getnetconfigent(cln->netid);
                        if (cln->nconf == NULL)
                                syslog(LOG_ERR, "%s: getnetconfigent failed",
                                    cln->netid);
                }

                if (cln->nconf != NULL && cln->nbuf != NULL)
                        (void) __netdir_getbyaddr_nosrv(cln->nconf,
                            &cln->clnames, cln->nbuf);

                cln->flags |= CLN_CLNAMES;
        }

        return (cln->clnames);
}

/*
 * Return B_TRUE if the host is already available at no cost
 */
boolean_t
cln_havehost(struct cln *cln)
{
        return ((cln->flags & (CLN_CLNAMES | CLN_HOST)) != 0);
}

char *
cln_gethost(struct cln *cln)
{
        if (cln_getclientsnames(cln) != NULL)
                return (cln->clnames->h_hostservs[0].h_host);

        if ((cln->flags & CLN_HOST) == 0) {
                if (cln->nconf == NULL || cln->nbuf == NULL) {
                        cln->host = strdup("(anon)");
                } else {
                        char host[MAXIPADDRLEN];

                        if (strcmp(cln->nconf->nc_protofmly, NC_INET) == 0) {
                                struct sockaddr_in *sa;

                                /* LINTED pointer alignment */
                                sa = (struct sockaddr_in *)(cln->nbuf->buf);
                                (void) inet_ntoa_r(sa->sin_addr, host);

                                cln->host = strdup(host);
                        } else if (strcmp(cln->nconf->nc_protofmly,
                            NC_INET6) == 0) {
                                struct sockaddr_in6 *sa;

                                /* LINTED pointer alignment */
                                sa = (struct sockaddr_in6 *)(cln->nbuf->buf);
                                (void) inet_ntop(AF_INET6,
                                    sa->sin6_addr.s6_addr,
                                    host, INET6_ADDRSTRLEN);

                                cln->host = strdup(host);
                        } else {
                                syslog(LOG_ERR, gettext("Client's address is "
                                    "neither IPv4 nor IPv6"));

                                cln->host = strdup("(anon)");
                        }
                }

                cln->flags |= CLN_HOST;
        }

        return (cln->host);
}

/*
 * Check mount requests, add to mounted list if ok
 */
static int
mount(struct svc_req *rqstp)
{
        SVCXPRT *transp;
        int version, vers;
        struct fhstatus fhs;
        struct mountres3 mountres3;
        char fh[FHSIZE3];
        int len = FHSIZE3;
        char *path, rpath[MAXPATHLEN];
        share_t *sh = NULL;
        struct cln cln;
        char *host = NULL;
        int error = 0, lofs_tried = 0, enqueued;
        int flavor_list[MAX_FLAVORS];
        int flavor_count;
        ucred_t *uc = NULL;

        int audit_status;

        transp = rqstp->rq_xprt;
        version = rqstp->rq_vers;
        path = NULL;

        if (!svc_getargs(transp, xdr_dirpath, (caddr_t)&path)) {
                svcerr_decode(transp);
                return (EACCES);
        }

        cln_init(&cln, transp);

        /*
         * Put off getting the name for the client until we
         * need it. This is a performance gain. If we are logging,
         * then we don't care about performance and might as well
         * get the host name now in case we need to spit out an
         * error message.
         */
        if (verbose) {
                DTRACE_PROBE(mountd, name_by_verbose);
                if ((host = cln_gethost(&cln)) == NULL) {
                        /*
                         * We failed to get a name for the client, even
                         * 'anon', probably because we ran out of memory.
                         * In this situation it doesn't make sense to
                         * allow the mount to succeed.
                         */
                        error = EACCES;
                        goto reply;
                }
        }

        /*
         * If the version being used is less than the minimum version,
         * the filehandle translation should not be provided to the
         * client.
         */
        if (rejecting || version < mount_vers_min) {
                if (verbose)
                        syslog(LOG_NOTICE, "Rejected mount: %s for %s",
                            host, path);
                error = EACCES;
                goto reply;
        }

        /*
         * Get the real path (no symbolic links in it)
         */
        if (realpath(path, rpath) == NULL) {
                error = errno;
                if (verbose)
                        syslog(LOG_ERR,
                            "mount request: realpath: %s: %m", path);
                if (error == ENOENT)
                        error = mount_enoent_error(&cln, path, rpath,
                            flavor_list);
                goto reply;
        }

        if ((sh = findentry(rpath)) == NULL &&
            (sh = find_lofsentry(rpath, &lofs_tried)) == NULL) {
                error = EACCES;
                goto reply;
        }

        /*
         * Check if this is a "nosub" only export, in which case, mounting
         * subdirectories isn't allowed. Bug 1184573.
         */
        if (checkrootmount(sh, rpath) == 0) {
                error = EACCES;
                goto reply;
        }

        if (newopts(sh->sh_opts))
                flavor_count = getclientsflavors_new(sh, &cln, flavor_list);
        else
                flavor_count = getclientsflavors_old(sh, &cln, flavor_list);

        if (flavor_count == 0) {
                error = EACCES;
                goto reply;
        }

        /*
         * Now get the filehandle.
         *
         * NFS V2 clients get a 32 byte filehandle.
         * NFS V3 clients get a 32 or 64 byte filehandle, depending on
         * the embedded FIDs.
         */
        vers = (version == MOUNTVERS3) ? NFS_V3 : NFS_VERSION;

        /* LINTED pointer alignment */
        while (nfs_getfh(rpath, vers, &len, fh) < 0) {
                if (errno == EINVAL &&
                    (sh = find_lofsentry(rpath, &lofs_tried)) != NULL) {
                        errno = 0;
                        continue;
                }
                error = errno == EINVAL ? EACCES : errno;
                syslog(LOG_DEBUG, "mount request: getfh failed on %s: %m",
                    path);
                break;
        }

        if (version == MOUNTVERS3) {
                mountres3.mountres3_u.mountinfo.fhandle.fhandle3_len = len;
                mountres3.mountres3_u.mountinfo.fhandle.fhandle3_val = fh;
        } else {
                bcopy(fh, &fhs.fhstatus_u.fhs_fhandle, NFS_FHSIZE);
        }

reply:
        if (uc != NULL)
                ucred_free(uc);

        switch (version) {
        case MOUNTVERS:
        case MOUNTVERS_POSIX:
                if (error == EINVAL)
                        fhs.fhs_status = NFSERR_ACCES;
                else if (error == EREMOTE)
                        fhs.fhs_status = NFSERR_REMOTE;
                else
                        fhs.fhs_status = error;

                if (!svc_sendreply(transp, xdr_fhstatus, (char *)&fhs))
                        log_cant_reply_cln(&cln);

                audit_status = fhs.fhs_status;
                break;

        case MOUNTVERS3:
                if (!error) {
                mountres3.mountres3_u.mountinfo.auth_flavors.auth_flavors_val =
                    flavor_list;
                mountres3.mountres3_u.mountinfo.auth_flavors.auth_flavors_len =
                    flavor_count;

                } else if (error == ENAMETOOLONG)
                        error = MNT3ERR_NAMETOOLONG;

                mountres3.fhs_status = error;
                if (!svc_sendreply(transp, xdr_mountres3, (char *)&mountres3))
                        log_cant_reply_cln(&cln);

                audit_status = mountres3.fhs_status;
                break;
        }

        if (cln_havehost(&cln))
                host = cln_gethost(&cln);

        if (verbose)
                syslog(LOG_NOTICE, "MOUNT: %s %s %s",
                    (host == NULL) ? "unknown host" : host,
                    error ? "denied" : "mounted", path);

        /*
         * If we can not create a queue entry, go ahead and do it
         * in the context of this thread.
         */
        enqueued = enqueue_logging_data(host, transp, path, rpath,
            audit_status, error);
        if (enqueued == FALSE) {
                if (host == NULL) {
                        DTRACE_PROBE(mountd, name_by_in_thread);
                        host = cln_gethost(&cln);
                }

                DTRACE_PROBE(mountd, logged_in_thread);
                audit_mountd_mount(host, path, audit_status); /* BSM */
                if (!error)
                        mntlist_new(host, rpath); /* add entry to mount list */
        }

        if (path != NULL)
                svc_freeargs(transp, xdr_dirpath, (caddr_t)&path);

        if (sh)
                sharefree(sh);

        cln_fini(&cln);

        return (error);
}

/*
 * Determine whether two paths are within the same file system.
 * Returns nonzero (true) if paths are the same, zero (false) if
 * they are different.  If an error occurs, return false.
 *
 * Use the actual FSID if it's available (via getattrat()); otherwise,
 * fall back on st_dev.
 *
 * With ZFS snapshots, st_dev differs from the regular file system
 * versus the snapshot.  But the fsid is the same throughout.  Thus
 * the fsid is a better test.
 */
static int
same_file_system(const char *path1, const char *path2)
{
        uint64_t fsid1, fsid2;
        struct stat64 st1, st2;
        nvlist_t *nvl1 = NULL;
        nvlist_t *nvl2 = NULL;

        if ((getattrat(AT_FDCWD, XATTR_VIEW_READONLY, path1, &nvl1) == 0) &&
            (getattrat(AT_FDCWD, XATTR_VIEW_READONLY, path2, &nvl2) == 0) &&
            (nvlist_lookup_uint64(nvl1, A_FSID, &fsid1) == 0) &&
            (nvlist_lookup_uint64(nvl2, A_FSID, &fsid2) == 0)) {
                nvlist_free(nvl1);
                nvlist_free(nvl2);
                /*
                 * We have found fsid's for both paths.
                 */

                if (fsid1 == fsid2)
                        return (B_TRUE);

                return (B_FALSE);
        }

        nvlist_free(nvl1);
        nvlist_free(nvl2);

        /*
         * We were unable to find fsid's for at least one of the paths.
         * fall back on st_dev.
         */

        if (stat64(path1, &st1) < 0) {
                syslog(LOG_NOTICE, "%s: %m", path1);
                return (B_FALSE);
        }
        if (stat64(path2, &st2) < 0) {
                syslog(LOG_NOTICE, "%s: %m", path2);
                return (B_FALSE);
        }

        if (st1.st_dev == st2.st_dev)
                return (B_TRUE);

        return (B_FALSE);
}

share_t *
findentry(char *path)
{
        share_t *sh = NULL;
        struct sh_list *shp;
        char *p1, *p2;

        check_sharetab();

        (void) rw_rdlock(&sharetab_lock);

        for (shp = share_list; shp; shp = shp->shl_next) {
                sh = shp->shl_sh;
                for (p1 = sh->sh_path, p2 = path; *p1 == *p2; p1++, p2++)
                        if (*p1 == '\0')
                                goto done;      /* exact match */

                /*
                 * Now compare the pathnames for three cases:
                 *
                 * Parent: /export/foo          (no trailing slash on parent)
                 * Child:  /export/foo/bar
                 *
                 * Parent: /export/foo/         (trailing slash on parent)
                 * Child:  /export/foo/bar
                 *
                 * Parent: /export/foo/         (no trailing slash on child)
                 * Child:  /export/foo
                 */
                if ((*p1 == '\0' && *p2 == '/') ||
                    (*p1 == '\0' && *(p1-1) == '/') ||
                    (*p2 == '\0' && *p1 == '/' && *(p1+1) == '\0')) {
                        /*
                         * We have a subdirectory.  Test whether the
                         * subdirectory is in the same file system.
                         */
                        if (same_file_system(path, sh->sh_path))
                                goto done;
                }
        }
done:
        sh = shp ? sharedup(sh) : NULL;

        (void) rw_unlock(&sharetab_lock);

        return (sh);
}


static int
is_substring(char **mntp, char **path)
{
        char *p1 = *mntp, *p2 = *path;

        if (*p1 == '\0' && *p2 == '\0') /* exact match */
                return (1);
        else if (*p1 == '\0' && *p2 == '/')
                return (1);
        else if (*p1 == '\0' && *(p1-1) == '/') {
                *path = --p2; /* we need the slash in p2 */
                return (1);
        } else if (*p2 == '\0') {
                while (*p1 == '/')
                        p1++;
                if (*p1 == '\0') /* exact match */
                        return (1);
        }
        return (0);
}

/*
 * find_lofsentry() searches for the real path which this requested LOFS path
 * (rpath) shadows. If found, it will return the sharetab entry of
 * the real path that corresponds to the LOFS path.
 * We first search mnttab to see if the requested path is an automounted
 * path. If it is an automounted path, it will trigger the mount by stat()ing
 * the requested path. Note that it is important to check that this path is
 * actually an automounted path, otherwise we would stat() a path which may
 * turn out to be NFS and block indefinitely on a dead server. The automounter
 * times-out if the server is dead, so there's no risk of hanging this
 * thread waiting for stat().
 * After the mount has been triggered (if necessary), we look for a
 * mountpoint of type LOFS (by searching /etc/mnttab again) which
 * is a substring of the rpath. If found, we construct a new path by
 * concatenating the mnt_special and the remaining of rpath, call findentry()
 * to make sure the 'real path' is shared.
 */
static share_t *
find_lofsentry(char *rpath, int *done_flag)
{
        struct stat r_stbuf;
        mntlist_t *ml, *mntl, *mntpnt = NULL;
        share_t *retcode = NULL;
        char tmp_path[MAXPATHLEN];
        int mntpnt_len = 0, tmp;
        char *p1, *p2;

        if ((*done_flag)++)
                return (retcode);

        /*
         * While fsgetmntlist() uses lockf() to
         * lock the mnttab before reading it in,
         * the lock ignores threads in the same process.
         * Read in the mnttab with the protection of a mutex.
         */
        (void) mutex_lock(&mnttab_lock);
        mntl = fsgetmntlist();
        (void) mutex_unlock(&mnttab_lock);

        /*
         * Obtain the mountpoint for the requested path.
         */
        for (ml = mntl; ml; ml = ml->mntl_next) {
                for (p1 = ml->mntl_mnt->mnt_mountp, p2 = rpath;
                    *p1 == *p2 && *p1; p1++, p2++)
                        ;
                if (is_substring(&p1, &p2) &&
                    (tmp = strlen(ml->mntl_mnt->mnt_mountp)) >= mntpnt_len) {
                        mntpnt = ml;
                        mntpnt_len = tmp;
                }
        }

        /*
         * If the path needs to be autoFS mounted, trigger the mount by
         * stat()ing it. This is determined by checking whether the
         * mountpoint we just found is of type autofs.
         */
        if (mntpnt != NULL &&
            strcmp(mntpnt->mntl_mnt->mnt_fstype, "autofs") == 0) {
                /*
                 * The requested path is a substring of an autoFS filesystem.
                 * Trigger the mount.
                 */
                if (stat(rpath, &r_stbuf) < 0) {
                        if (verbose)
                                syslog(LOG_NOTICE, "%s: %m", rpath);
                        goto done;
                }
                if ((r_stbuf.st_mode & S_IFMT) == S_IFDIR) {
                        /*
                         * The requested path is a directory, stat(2) it
                         * again with a trailing '.' to force the autoFS
                         * module to trigger the mount of indirect
                         * automount entries, such as /net/jurassic/.
                         */
                        if (strlen(rpath) + 2 > MAXPATHLEN) {
                                if (verbose) {
                                        syslog(LOG_NOTICE,
                                            "%s/.: exceeds MAXPATHLEN %d",
                                            rpath, MAXPATHLEN);
                                }
                                goto done;
                        }
                        (void) strcpy(tmp_path, rpath);
                        (void) strcat(tmp_path, "/.");

                        if (stat(tmp_path, &r_stbuf) < 0) {
                                if (verbose)
                                        syslog(LOG_NOTICE, "%s: %m", tmp_path);
                                goto done;
                        }
                }

                /*
                 * The mount has been triggered, re-read mnttab to pick up
                 * the changes made by autoFS.
                 */
                fsfreemntlist(mntl);
                (void) mutex_lock(&mnttab_lock);
                mntl = fsgetmntlist();
                (void) mutex_unlock(&mnttab_lock);
        }

        /*
         * The autoFS mountpoint has been triggered if necessary,
         * now search mnttab again to determine if the requested path
         * is an LOFS mount of a shared path.
         */
        mntpnt_len = 0;
        for (ml = mntl; ml; ml = ml->mntl_next) {
                if (strcmp(ml->mntl_mnt->mnt_fstype, "lofs"))
                        continue;

                for (p1 = ml->mntl_mnt->mnt_mountp, p2 = rpath;
                    *p1 == *p2 && *p1; p1++, p2++)
                        ;

                if (is_substring(&p1, &p2) &&
                    ((tmp = strlen(ml->mntl_mnt->mnt_mountp)) >= mntpnt_len)) {
                        mntpnt_len = tmp;

                        if ((strlen(ml->mntl_mnt->mnt_special) + strlen(p2)) >
                            MAXPATHLEN) {
                                if (verbose) {
                                        syslog(LOG_NOTICE, "%s%s: exceeds %d",
                                            ml->mntl_mnt->mnt_special, p2,
                                            MAXPATHLEN);
                                }
                                if (retcode)
                                        sharefree(retcode);
                                retcode = NULL;
                                goto done;
                        }

                        (void) strcpy(tmp_path, ml->mntl_mnt->mnt_special);
                        (void) strcat(tmp_path, p2);
                        if (retcode)
                                sharefree(retcode);
                        retcode = findentry(tmp_path);
                }
        }

        if (retcode) {
                assert(strlen(tmp_path) > 0);
                (void) strcpy(rpath, tmp_path);
        }

done:
        fsfreemntlist(mntl);
        return (retcode);
}

/*
 * Determine whether an access list grants rights to a particular host.
 * We match on aliases of the hostname as well as on the canonical name.
 * Names in the access list may be either hosts or netgroups;  they're
 * not distinguished syntactically.  We check for hosts first because
 * it's cheaper, then try netgroups.
 *
 * Return values:
 *  1 - access is granted
 *  0 - access is denied
 * -1 - an error occured
 */
int
in_access_list(struct cln *cln,
    char *access_list)  /* N.B. we clobber this "input" parameter */
{
        char addr[INET_ADDRSTRLEN];
        char buff[256];
        int nentries = 0;
        char *cstr = access_list;
        char *gr = access_list;
        int i;
        int response;
        int ret;
        struct netbuf *pnb;
        struct nd_hostservlist *clnames = NULL;

        /* If no access list - then it's unrestricted */
        if (access_list == NULL || *access_list == '\0')
                return (1);

        if ((pnb = cln_getnbuf(cln)) == NULL)
                return (-1);

        for (;;) {
                if ((cstr = strpbrk(cstr, "[:")) != NULL) {
                        if (*cstr == ':') {
                                *cstr = '\0';
                        } else {
                                assert(*cstr == '[');
                                cstr = strchr(cstr + 1, ']');
                                if (cstr == NULL)
                                        return (-1);
                                cstr++;
                                continue;
                        }
                }

                /*
                 * If the list name has a '-' prepended then a match of
                 * the following name implies failure instead of success.
                 */
                if (*gr == '-') {
                        response = 0;
                        gr++;
                } else {
                        response = 1;
                }

                /*
                 * First check if we have '@' entry, as it doesn't
                 * require client hostname.
                 */
                if (*gr == '@') {
                        gr++;

                        /* Netname support */
                        if (!isdigit(*gr) && *gr != '[') {
                                struct netent n, *np;

                                if ((np = getnetbyname_r(gr, &n, buff,
                                    sizeof (buff))) != NULL &&
                                    np->n_net != 0) {
                                        while ((np->n_net & 0xFF000000u) == 0)
                                                np->n_net <<= 8;
                                        np->n_net = htonl(np->n_net);
                                        if (inet_ntop(AF_INET, &np->n_net, addr,
                                            INET_ADDRSTRLEN) == NULL)
                                                break;
                                        ret = inet_matchaddr(pnb->buf, addr);
                                        if (ret == -1) {
                                                if (errno == EINVAL) {
                                                        syslog(LOG_WARNING,
                                                            "invalid access "
                                                            "list entry: %s",
                                                            addr);
                                                }
                                                return (-1);
                                        } else if (ret == 1) {
                                                return (response);
                                        }
                                }
                        } else {
                                ret = inet_matchaddr(pnb->buf, gr);
                                if (ret == -1) {
                                        if (errno == EINVAL) {
                                                syslog(LOG_WARNING,
                                                    "invalid access list "
                                                    "entry: %s", gr);
                                        }
                                        return (-1);
                                } else if (ret == 1) {
                                        return (response);
                                }
                        }

                        goto next;
                }

                /*
                 * No other checks can be performed if client address
                 * can't be resolved.
                 */
                if ((clnames = cln_getclientsnames(cln)) == NULL)
                        goto next;

                /* Otherwise loop through all client hostname aliases */
                for (i = 0; i < clnames->h_cnt; i++) {
                        char *host = clnames->h_hostservs[i].h_host;

                        /*
                         * If the list name begins with a dot then
                         * do a domain name suffix comparison.
                         * A single dot matches any name with no
                         * suffix.
                         */
                        if (*gr == '.') {
                                if (*(gr + 1) == '\0') {  /* single dot */
                                        if (strchr(host, '.') == NULL)
                                                return (response);
                                } else {
                                        int off = strlen(host) - strlen(gr);
                                        if (off > 0 &&
                                            strcasecmp(host + off, gr) == 0) {
                                                return (response);
                                        }
                                }
                        } else {
                                /* Just do a hostname match */
                                if (strcasecmp(gr, host) == 0)
                                        return (response);
                        }
                }

                nentries++;

next:
                if (cstr == NULL)
                        break;

                gr = ++cstr;
        }

        if (clnames == NULL)
                return (0);

        return (netgroup_check(clnames, access_list, nentries));
}


static char *optlist[] = {
#define OPT_RO          0
        SHOPT_RO,
#define OPT_RW          1
        SHOPT_RW,
#define OPT_ROOT        2
        SHOPT_ROOT,
#define OPT_SECURE      3
        SHOPT_SECURE,
#define OPT_ANON        4
        SHOPT_ANON,
#define OPT_WINDOW      5
        SHOPT_WINDOW,
#define OPT_NOSUID      6
        SHOPT_NOSUID,
#define OPT_ACLOK       7
        SHOPT_ACLOK,
#define OPT_SEC         8
        SHOPT_SEC,
#define OPT_NONE        9
        SHOPT_NONE,
#define OPT_UIDMAP      10
        SHOPT_UIDMAP,
#define OPT_GIDMAP      11
        SHOPT_GIDMAP,
        NULL
};

static int
map_flavor(char *str)
{
        seconfig_t sec;

        if (nfs_getseconfig_byname(str, &sec))
                return (-1);

        return (sec.sc_nfsnum);
}

/*
 * If the option string contains a "sec="
 * option, then use new option syntax.
 */
static int
newopts(char *opts)
{
        char *head, *p, *val;

        if (!opts || *opts == '\0')
                return (0);

        head = strdup(opts);
        if (head == NULL) {
                syslog(LOG_ERR, "opts: no memory");
                return (0);
        }

        p = head;
        while (*p) {
                if (getsubopt(&p, optlist, &val) == OPT_SEC) {
                        free(head);
                        return (1);
                }
        }

        free(head);
        return (0);
}

/*
 * Given an export and the clients hostname(s)
 * determine the security flavors that this
 * client is permitted to use.
 *
 * This routine is called only for "old" syntax, i.e.
 * only one security flavor is allowed.  So we need
 * to determine two things: the particular flavor,
 * and whether the client is allowed to use this
 * flavor, i.e. is in the access list.
 *
 * Note that if there is no access list, then the
 * default is that access is granted.
 */
static int
getclientsflavors_old(share_t *sh, struct cln *cln, int *flavors)
{
        char *opts, *p, *val;
        boolean_t ok = B_FALSE;
        int defaultaccess = 1;
        boolean_t reject = B_FALSE;

        opts = strdup(sh->sh_opts);
        if (opts == NULL) {
                syslog(LOG_ERR, "getclientsflavors: no memory");
                return (0);
        }

        flavors[0] = AUTH_SYS;
        p = opts;

        while (*p) {

                switch (getsubopt(&p, optlist, &val)) {
                case OPT_SECURE:
                        flavors[0] = AUTH_DES;
                        break;

                case OPT_RO:
                case OPT_RW:
                        defaultaccess = 0;
                        if (in_access_list(cln, val) > 0)
                                ok = B_TRUE;
                        break;

                case OPT_NONE:
                        defaultaccess = 0;
                        if (in_access_list(cln, val) > 0)
                                reject = B_TRUE;
                }
        }

        free(opts);

        /* none takes precedence over everything else */
        if (reject)
                ok = B_FALSE;

        return (defaultaccess || ok);
}

/*
 * Given an export and the clients hostname(s)
 * determine the security flavors that this
 * client is permitted to use.
 *
 * This is somewhat more complicated than the "old"
 * routine because the options may contain multiple
 * security flavors (sec=) each with its own access
 * lists.  So a client could be granted access based
 * on a number of security flavors.  Note that the
 * type of access might not always be the same, the
 * client may get readonly access with one flavor
 * and readwrite with another, however the client
 * is not told this detail, it gets only the list
 * of flavors, and only if the client is using
 * version 3 of the mount protocol.
 */
static int
getclientsflavors_new(share_t *sh, struct cln *cln, int *flavors)
{
        char *opts, *p, *val;
        char *lasts;
        char *f;
        boolean_t defaultaccess = B_TRUE;       /* default access is rw */
        boolean_t access_ok = B_FALSE;
        int count, c;
        boolean_t reject = B_FALSE;

        opts = strdup(sh->sh_opts);
        if (opts == NULL) {
                syslog(LOG_ERR, "getclientsflavors: no memory");
                return (0);
        }

        p = opts;
        count = c = 0;

        while (*p) {
                switch (getsubopt(&p, optlist, &val)) {
                case OPT_SEC:
                        if (reject)
                                access_ok = B_FALSE;

                        /*
                         * Before a new sec=xxx option, check if we need
                         * to move the c index back to the previous count.
                         */
                        if (!defaultaccess && !access_ok) {
                                c = count;
                        }

                        /* get all the sec=f1[:f2] flavors */
                        while ((f = strtok_r(val, ":", &lasts)) != NULL) {
                                flavors[c++] = map_flavor(f);
                                val = NULL;
                        }

                        /* for a new sec=xxx option, default is rw access */
                        defaultaccess = B_TRUE;
                        access_ok = B_FALSE;
                        reject = B_FALSE;
                        break;

                case OPT_RO:
                case OPT_RW:
                        defaultaccess = B_FALSE;
                        if (in_access_list(cln, val) > 0)
                                access_ok = B_TRUE;
                        break;

                case OPT_NONE:
                        defaultaccess = B_FALSE;
                        if (in_access_list(cln, val) > 0)
                                reject = B_TRUE; /* none overides rw/ro */
                        break;
                }
        }

        if (reject)
                access_ok = B_FALSE;

        if (!defaultaccess && !access_ok)
                c = count;

        free(opts);

        return (c);
}

/*
 * This is a tricky piece of code that parses the
 * share options looking for a match on the auth
 * flavor that the client is using. If it finds
 * a match, then the client is given ro, rw, or
 * no access depending whether it is in the access
 * list.  There is a special case for "secure"
 * flavor.  Other flavors are values of the new "sec=" option.
 */
int
check_client(share_t *sh, struct cln *cln, int flavor, uid_t clnt_uid,
    gid_t clnt_gid, uint_t clnt_ngids, gid_t *clnt_gids, uid_t *srv_uid,
    gid_t *srv_gid, uint_t *srv_ngids, gid_t **srv_gids)
{
        if (newopts(sh->sh_opts))
                return (check_client_new(sh, cln, flavor, clnt_uid, clnt_gid,
                    clnt_ngids, clnt_gids, srv_uid, srv_gid, srv_ngids,
                    srv_gids));
        else
                return (check_client_old(sh, cln, flavor, clnt_uid, clnt_gid,
                    clnt_ngids, clnt_gids, srv_uid, srv_gid, srv_ngids,
                    srv_gids));
}

extern int _getgroupsbymember(const char *, gid_t[], int, int);

/*
 * Get supplemental groups for uid
 */
static int
getusergroups(uid_t uid, uint_t *ngrps, gid_t **grps)
{
        struct passwd pwd;
        char *pwbuf = alloca(pw_size);
        gid_t *tmpgrps = alloca(ngroups_max * sizeof (gid_t));
        int tmpngrps;
        struct passwd *result;

        getpwuid_r(uid, &pwd, pwbuf, pw_size, &result);
        if (!result)
                return (-1);

        tmpgrps[0] = pwd.pw_gid;

        tmpngrps = _getgroupsbymember(pwd.pw_name, tmpgrps, ngroups_max, 1);
        if (tmpngrps <= 0) {
                syslog(LOG_WARNING,
                    "getusergroups(): Unable to get groups for user %s",
                    pwd.pw_name);

                return (-1);
        }

        *grps = malloc(tmpngrps * sizeof (gid_t));
        if (*grps == NULL) {
                syslog(LOG_ERR,
                    "getusergroups(): Memory allocation failed: %m");

                return (-1);
        }

        *ngrps = tmpngrps;
        (void) memcpy(*grps, tmpgrps, tmpngrps * sizeof (gid_t));

        return (0);
}

/*
 * is_a_number(number)
 *
 * is the string a number in one of the forms we want to use?
 */

static int
is_a_number(char *number)
{
        int ret = 1;
        int hex = 0;

        if (strncmp(number, "0x", 2) == 0) {
                number += 2;
                hex = 1;
        } else if (*number == '-') {
                number++; /* skip the minus */
        }
        while (ret == 1 && *number != '\0') {
                if (hex) {
                        ret = isxdigit(*number++);
                } else {
                        ret = isdigit(*number++);
                }
        }
        return (ret);
}

static boolean_t
get_uid(char *value, uid_t *uid)
{
        if (!is_a_number(value)) {
                struct passwd *pw;
                /*
                 * in this case it would have to be a
                 * user name
                 */
                pw = getpwnam(value);
                if (pw == NULL)
                        return (B_FALSE);
                *uid = pw->pw_uid;
                endpwent();
        } else {
                uint64_t intval;
                intval = strtoull(value, NULL, 0);
                if (intval > UID_MAX && intval != -1)
                        return (B_FALSE);
                *uid = (uid_t)intval;
        }

        return (B_TRUE);
}

static boolean_t
get_gid(char *value, gid_t *gid)
{
        if (!is_a_number(value)) {
                struct group *gr;
                /*
                 * in this case it would have to be a
                 * group name
                 */
                gr = getgrnam(value);
                if (gr == NULL)
                        return (B_FALSE);
                *gid = gr->gr_gid;
                endgrent();
        } else {
                uint64_t intval;
                intval = strtoull(value, NULL, 0);
                if (intval > UID_MAX && intval != -1)
                        return (B_FALSE);
                *gid = (gid_t)intval;
        }

        return (B_TRUE);
}

static int
check_client_old(share_t *sh, struct cln *cln, int flavor, uid_t clnt_uid,
    gid_t clnt_gid, uint_t clnt_ngids, gid_t *clnt_gids, uid_t *srv_uid,
    gid_t *srv_gid, uint_t *srv_ngids, gid_t **srv_gids)
{
        char *opts, *p, *val;
        int match;      /* Set when a flavor is matched */
        int perm = 0;   /* Set when "ro", "rw" or "root" is matched */
        int list = 0;   /* Set when "ro", "rw" is found */
        int ro_val = 0; /* Set if ro option is 'ro=' */
        int rw_val = 0; /* Set if rw option is 'rw=' */

        boolean_t map_deny = B_FALSE;

        opts = strdup(sh->sh_opts);
        if (opts == NULL) {
                syslog(LOG_ERR, "check_client: no memory");
                return (0);
        }

        /*
         * If client provided 16 supplemental groups with AUTH_SYS, lookup
         * locally for all of them
         */
        if (flavor == AUTH_SYS && clnt_ngids == NGRPS && ngroups_max > NGRPS)
                if (getusergroups(clnt_uid, srv_ngids, srv_gids) == 0)
                        perm |= NFSAUTH_GROUPS;

        p = opts;
        match = AUTH_UNIX;

        while (*p) {
                switch (getsubopt(&p, optlist, &val)) {

                case OPT_SECURE:
                        match = AUTH_DES;

                        if (perm & NFSAUTH_GROUPS) {
                                free(*srv_gids);
                                *srv_ngids = 0;
                                *srv_gids = NULL;
                                perm &= ~NFSAUTH_GROUPS;
                        }

                        break;

                case OPT_RO:
                        list++;
                        if (val != NULL)
                                ro_val++;
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_RO;
                        break;

                case OPT_RW:
                        list++;
                        if (val != NULL)
                                rw_val++;
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_RW;
                        break;

                case OPT_ROOT:
                        /*
                         * Check if the client is in
                         * the root list. Only valid
                         * for AUTH_SYS.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (val == NULL || *val == '\0')
                                break;

                        if (clnt_uid != 0)
                                break;

                        if (in_access_list(cln, val) > 0) {
                                perm |= NFSAUTH_ROOT;
                                perm |= NFSAUTH_UIDMAP | NFSAUTH_GIDMAP;
                                map_deny = B_FALSE;

                                if (perm & NFSAUTH_GROUPS) {
                                        free(*srv_gids);
                                        *srv_ngids = 0;
                                        *srv_gids = NULL;
                                        perm &= ~NFSAUTH_GROUPS;
                                }
                        }
                        break;

                case OPT_NONE:
                        /*
                         * Check if the client should have no access
                         * to this share at all. This option behaves
                         * more like "root" than either "rw" or "ro".
                         */
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_DENIED;
                        break;

                case OPT_UIDMAP: {
                        char *c;
                        char *n;

                        /*
                         * The uidmap is supported for AUTH_SYS only.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (perm & NFSAUTH_UIDMAP || map_deny)
                                break;

                        for (c = val; c != NULL; c = n) {
                                char *s;
                                char *al;
                                uid_t srv;

                                n = strchr(c, '~');
                                if (n != NULL)
                                        *n++ = '\0';

                                s = strchr(c, ':');
                                if (s != NULL) {
                                        *s++ = '\0';
                                        al = strchr(s, ':');
                                        if (al != NULL)
                                                *al++ = '\0';
                                }

                                if (s == NULL || al == NULL)
                                        continue;

                                if (*c == '\0') {
                                        if (clnt_uid != (uid_t)-1)
                                                continue;
                                } else if (strcmp(c, "*") != 0) {
                                        uid_t clnt;

                                        if (!get_uid(c, &clnt))
                                                continue;

                                        if (clnt_uid != clnt)
                                                continue;
                                }

                                if (*s == '\0')
                                        srv = UID_NOBODY;
                                else if (!get_uid(s, &srv))
                                        continue;
                                else if (srv == (uid_t)-1) {
                                        map_deny = B_TRUE;
                                        break;
                                }

                                if (in_access_list(cln, al) > 0) {
                                        *srv_uid = srv;
                                        perm |= NFSAUTH_UIDMAP;

                                        if (perm & NFSAUTH_GROUPS) {
                                                free(*srv_gids);
                                                *srv_ngids = 0;
                                                *srv_gids = NULL;
                                                perm &= ~NFSAUTH_GROUPS;
                                        }

                                        break;
                                }
                        }

                        break;
                }

                case OPT_GIDMAP: {
                        char *c;
                        char *n;

                        /*
                         * The gidmap is supported for AUTH_SYS only.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (perm & NFSAUTH_GIDMAP || map_deny)
                                break;

                        for (c = val; c != NULL; c = n) {
                                char *s;
                                char *al;
                                gid_t srv;

                                n = strchr(c, '~');
                                if (n != NULL)
                                        *n++ = '\0';

                                s = strchr(c, ':');
                                if (s != NULL) {
                                        *s++ = '\0';
                                        al = strchr(s, ':');
                                        if (al != NULL)
                                                *al++ = '\0';
                                }

                                if (s == NULL || al == NULL)
                                        break;

                                if (*c == '\0') {
                                        if (clnt_gid != (gid_t)-1)
                                                continue;
                                } else if (strcmp(c, "*") != 0) {
                                        gid_t clnt;

                                        if (!get_gid(c, &clnt))
                                                continue;

                                        if (clnt_gid != clnt)
                                                continue;
                                }

                                if (*s == '\0')
                                        srv = UID_NOBODY;
                                else if (!get_gid(s, &srv))
                                        continue;
                                else if (srv == (gid_t)-1) {
                                        map_deny = B_TRUE;
                                        break;
                                }

                                if (in_access_list(cln, al) > 0) {
                                        *srv_gid = srv;
                                        perm |= NFSAUTH_GIDMAP;

                                        if (perm & NFSAUTH_GROUPS) {
                                                free(*srv_gids);
                                                *srv_ngids = 0;
                                                *srv_gids = NULL;
                                                perm &= ~NFSAUTH_GROUPS;
                                        }

                                        break;
                                }
                        }

                        break;
                }

                default:
                        break;
                }
        }

        free(opts);

        if (perm & NFSAUTH_ROOT) {
                *srv_uid = 0;
                *srv_gid = 0;
        }

        if (map_deny)
                perm |= NFSAUTH_DENIED;

        if (!(perm & NFSAUTH_UIDMAP))
                *srv_uid = clnt_uid;
        if (!(perm & NFSAUTH_GIDMAP))
                *srv_gid = clnt_gid;

        if (flavor != match || perm & NFSAUTH_DENIED)
                return (NFSAUTH_DENIED);

        if (list) {
                /*
                 * If the client doesn't match an "ro" or "rw"
                 * list then set no access.
                 */
                if ((perm & (NFSAUTH_RO | NFSAUTH_RW)) == 0)
                        perm |= NFSAUTH_DENIED;
        } else {
                /*
                 * The client matched a flavor entry that
                 * has no explicit "rw" or "ro" determination.
                 * Default it to "rw".
                 */
                perm |= NFSAUTH_RW;
        }

        /*
         * The client may show up in both ro= and rw=
         * lists.  If so, then turn off the RO access
         * bit leaving RW access.
         */
        if (perm & NFSAUTH_RO && perm & NFSAUTH_RW) {
                /*
                 * Logically cover all permutations of rw=,ro=.
                 * In the case where, rw,ro=<host> we would like
                 * to remove RW access for the host.  In all other cases
                 * RW wins the precedence battle.
                 */
                if (!rw_val && ro_val) {
                        perm &= ~(NFSAUTH_RW);
                } else {
                        perm &= ~(NFSAUTH_RO);
                }
        }

        return (perm);
}

/*
 * Check if the client has access by using a flavor different from
 * the given "flavor". If "flavor" is not in the flavor list,
 * return TRUE to indicate that this "flavor" is a wrong sec.
 */
static bool_t
is_wrongsec(share_t *sh, struct cln *cln, int flavor)
{
        int flavor_list[MAX_FLAVORS];
        int flavor_count, i;

        /* get the flavor list that the client has access with */
        flavor_count = getclientsflavors_new(sh, cln, flavor_list);

        if (flavor_count == 0)
                return (FALSE);

        /*
         * Check if the given "flavor" is in the flavor_list.
         */
        for (i = 0; i < flavor_count; i++) {
                if (flavor == flavor_list[i])
                        return (FALSE);
        }

        /*
         * If "flavor" is not in the flavor_list, return TRUE to indicate
         * that the client should have access by using a security flavor
         * different from this "flavor".
         */
        return (TRUE);
}

/*
 * Given an export and the client's hostname, we
 * check the security options to see whether the
 * client is allowed to use the given security flavor.
 *
 * The strategy is to proceed through the options looking
 * for a flavor match, then pay attention to the ro, rw,
 * and root options.
 *
 * Note that an entry may list several flavors in a
 * single entry, e.g.
 *
 *   sec=krb5,rw=clnt1:clnt2,ro,sec=sys,ro
 *
 */

static int
check_client_new(share_t *sh, struct cln *cln, int flavor, uid_t clnt_uid,
    gid_t clnt_gid, uint_t clnt_ngids, gid_t *clnt_gids, uid_t *srv_uid,
    gid_t *srv_gid, uint_t *srv_ngids, gid_t **srv_gids)
{
        char *opts, *p, *val;
        char *lasts;
        char *f;
        int match = 0;  /* Set when a flavor is matched */
        int perm = 0;   /* Set when "ro", "rw" or "root" is matched */
        int list = 0;   /* Set when "ro", "rw" is found */
        int ro_val = 0; /* Set if ro option is 'ro=' */
        int rw_val = 0; /* Set if rw option is 'rw=' */

        boolean_t map_deny = B_FALSE;

        opts = strdup(sh->sh_opts);
        if (opts == NULL) {
                syslog(LOG_ERR, "check_client: no memory");
                return (0);
        }

        /*
         * If client provided 16 supplemental groups with AUTH_SYS, lookup
         * locally for all of them
         */
        if (flavor == AUTH_SYS && clnt_ngids == NGRPS && ngroups_max > NGRPS)
                if (getusergroups(clnt_uid, srv_ngids, srv_gids) == 0)
                        perm |= NFSAUTH_GROUPS;

        p = opts;

        while (*p) {
                switch (getsubopt(&p, optlist, &val)) {

                case OPT_SEC:
                        if (match)
                                goto done;

                        while ((f = strtok_r(val, ":", &lasts))
                            != NULL) {
                                if (flavor == map_flavor(f)) {
                                        match = 1;
                                        break;
                                }
                                val = NULL;
                        }
                        break;

                case OPT_RO:
                        if (!match)
                                break;

                        list++;
                        if (val != NULL)
                                ro_val++;
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_RO;
                        break;

                case OPT_RW:
                        if (!match)
                                break;

                        list++;
                        if (val != NULL)
                                rw_val++;
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_RW;
                        break;

                case OPT_ROOT:
                        /*
                         * Check if the client is in
                         * the root list. Only valid
                         * for AUTH_SYS.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (!match)
                                break;

                        if (val == NULL || *val == '\0')
                                break;

                        if (clnt_uid != 0)
                                break;

                        if (in_access_list(cln, val) > 0) {
                                perm |= NFSAUTH_ROOT;
                                perm |= NFSAUTH_UIDMAP | NFSAUTH_GIDMAP;
                                map_deny = B_FALSE;

                                if (perm & NFSAUTH_GROUPS) {
                                        free(*srv_gids);
                                        *srv_gids = NULL;
                                        *srv_ngids = 0;
                                        perm &= ~NFSAUTH_GROUPS;
                                }
                        }
                        break;

                case OPT_NONE:
                        /*
                         * Check if the client should have no access
                         * to this share at all. This option behaves
                         * more like "root" than either "rw" or "ro".
                         */
                        if (in_access_list(cln, val) > 0)
                                perm |= NFSAUTH_DENIED;
                        break;

                case OPT_UIDMAP: {
                        char *c;
                        char *n;

                        /*
                         * The uidmap is supported for AUTH_SYS only.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (!match || perm & NFSAUTH_UIDMAP || map_deny)
                                break;

                        for (c = val; c != NULL; c = n) {
                                char *s;
                                char *al;
                                uid_t srv;

                                n = strchr(c, '~');
                                if (n != NULL)
                                        *n++ = '\0';

                                s = strchr(c, ':');
                                if (s != NULL) {
                                        *s++ = '\0';
                                        al = strchr(s, ':');
                                        if (al != NULL)
                                                *al++ = '\0';
                                }

                                if (s == NULL || al == NULL)
                                        continue;

                                if (*c == '\0') {
                                        if (clnt_uid != (uid_t)-1)
                                                continue;
                                } else if (strcmp(c, "*") != 0) {
                                        uid_t clnt;

                                        if (!get_uid(c, &clnt))
                                                continue;

                                        if (clnt_uid != clnt)
                                                continue;
                                }

                                if (*s == '\0')
                                        srv = UID_NOBODY;
                                else if (!get_uid(s, &srv))
                                        continue;
                                else if (srv == (uid_t)-1) {
                                        map_deny = B_TRUE;
                                        break;
                                }

                                if (in_access_list(cln, al) > 0) {
                                        *srv_uid = srv;
                                        perm |= NFSAUTH_UIDMAP;

                                        if (perm & NFSAUTH_GROUPS) {
                                                free(*srv_gids);
                                                *srv_gids = NULL;
                                                *srv_ngids = 0;
                                                perm &= ~NFSAUTH_GROUPS;
                                        }

                                        break;
                                }
                        }

                        break;
                }

                case OPT_GIDMAP: {
                        char *c;
                        char *n;

                        /*
                         * The gidmap is supported for AUTH_SYS only.
                         */
                        if (flavor != AUTH_SYS)
                                break;

                        if (!match || perm & NFSAUTH_GIDMAP || map_deny)
                                break;

                        for (c = val; c != NULL; c = n) {
                                char *s;
                                char *al;
                                gid_t srv;

                                n = strchr(c, '~');
                                if (n != NULL)
                                        *n++ = '\0';

                                s = strchr(c, ':');
                                if (s != NULL) {
                                        *s++ = '\0';
                                        al = strchr(s, ':');
                                        if (al != NULL)
                                                *al++ = '\0';
                                }

                                if (s == NULL || al == NULL)
                                        break;

                                if (*c == '\0') {
                                        if (clnt_gid != (gid_t)-1)
                                                continue;
                                } else if (strcmp(c, "*") != 0) {
                                        gid_t clnt;

                                        if (!get_gid(c, &clnt))
                                                continue;

                                        if (clnt_gid != clnt)
                                                continue;
                                }

                                if (*s == '\0')
                                        srv = UID_NOBODY;
                                else if (!get_gid(s, &srv))
                                        continue;
                                else if (srv == (gid_t)-1) {
                                        map_deny = B_TRUE;
                                        break;
                                }

                                if (in_access_list(cln, al) > 0) {
                                        *srv_gid = srv;
                                        perm |= NFSAUTH_GIDMAP;

                                        if (perm & NFSAUTH_GROUPS) {
                                                free(*srv_gids);
                                                *srv_gids = NULL;
                                                *srv_ngids = 0;
                                                perm &= ~NFSAUTH_GROUPS;
                                        }

                                        break;
                                }
                        }

                        break;
                }

                default:
                        break;
                }
        }

done:
        if (perm & NFSAUTH_ROOT) {
                *srv_uid = 0;
                *srv_gid = 0;
        }

        if (map_deny)
                perm |= NFSAUTH_DENIED;

        if (!(perm & NFSAUTH_UIDMAP))
                *srv_uid = clnt_uid;
        if (!(perm & NFSAUTH_GIDMAP))
                *srv_gid = clnt_gid;

        /*
         * If no match then set the perm accordingly
         */
        if (!match || perm & NFSAUTH_DENIED) {
                free(opts);
                return (NFSAUTH_DENIED);
        }

        if (list) {
                /*
                 * If the client doesn't match an "ro" or "rw" list then
                 * check if it may have access by using a different flavor.
                 * If so, return NFSAUTH_WRONGSEC.
                 * If not, return NFSAUTH_DENIED.
                 */
                if ((perm & (NFSAUTH_RO | NFSAUTH_RW)) == 0) {
                        if (is_wrongsec(sh, cln, flavor))
                                perm |= NFSAUTH_WRONGSEC;
                        else
                                perm |= NFSAUTH_DENIED;
                }
        } else {
                /*
                 * The client matched a flavor entry that
                 * has no explicit "rw" or "ro" determination.
                 * Make sure it defaults to "rw".
                 */
                perm |= NFSAUTH_RW;
        }

        /*
         * The client may show up in both ro= and rw=
         * lists.  If so, then turn off the RO access
         * bit leaving RW access.
         */
        if (perm & NFSAUTH_RO && perm & NFSAUTH_RW) {
                /*
                 * Logically cover all permutations of rw=,ro=.
                 * In the case where, rw,ro=<host> we would like
                 * to remove RW access for the host.  In all other cases
                 * RW wins the precedence battle.
                 */
                if (!rw_val && ro_val) {
                        perm &= ~(NFSAUTH_RW);
                } else {
                        perm &= ~(NFSAUTH_RO);
                }
        }

        free(opts);

        return (perm);
}

void
check_sharetab()
{
        FILE *f;
        struct stat st;
        static timestruc_t last_sharetab_time;
        timestruc_t prev_sharetab_time;
        share_t *sh;
        struct sh_list *shp, *shp_prev;
        int res, c = 0;

        /*
         *  read in /etc/dfs/sharetab if it has changed
         */
        if (stat(SHARETAB, &st) != 0) {
                syslog(LOG_ERR, "Cannot stat %s: %m", SHARETAB);
                return;
        }

        if (st.st_mtim.tv_sec == last_sharetab_time.tv_sec &&
            st.st_mtim.tv_nsec == last_sharetab_time.tv_nsec) {
                /*
                 * No change.
                 */
                return;
        }

        /*
         * Remember the mod time, then after getting the
         * write lock check again.  If another thread
         * already did the update, then there's no
         * work to do.
         */
        prev_sharetab_time = last_sharetab_time;

        (void) rw_wrlock(&sharetab_lock);

        if (prev_sharetab_time.tv_sec != last_sharetab_time.tv_sec ||
            prev_sharetab_time.tv_nsec != last_sharetab_time.tv_nsec) {
                (void) rw_unlock(&sharetab_lock);
                return;
        }

        /*
         * Note that since the sharetab is now in memory
         * and a snapshot is taken, we no longer have to
         * lock the file.
         */
        f = fopen(SHARETAB, "r");
        if (f == NULL) {
                syslog(LOG_ERR, "Cannot open %s: %m", SHARETAB);
                (void) rw_unlock(&sharetab_lock);
                return;
        }

        /*
         * Once we are sure /etc/dfs/sharetab has been
         * modified, flush netgroup cache entries.
         */
        netgrp_cache_flush();

        sh_free(share_list);                    /* free old list */
        share_list = NULL;

        while ((res = getshare(f, &sh)) > 0) {
                c++;
                if (strcmp(sh->sh_fstype, "nfs") != 0)
                        continue;

                shp = malloc(sizeof (*shp));
                if (shp == NULL)
                        goto alloc_failed;
                if (share_list == NULL)
                        share_list = shp;
                else
                        /* LINTED not used before set */
                        shp_prev->shl_next = shp;
                shp_prev = shp;
                shp->shl_next = NULL;
                shp->shl_sh = sharedup(sh);
                if (shp->shl_sh == NULL)
                        goto alloc_failed;
        }

        if (res < 0)
                syslog(LOG_ERR, "%s: invalid at line %d\n",
                    SHARETAB, c + 1);

        if (stat(SHARETAB, &st) != 0) {
                syslog(LOG_ERR, "Cannot stat %s: %m", SHARETAB);
                (void) fclose(f);
                (void) rw_unlock(&sharetab_lock);
                return;
        }

        last_sharetab_time = st.st_mtim;
        (void) fclose(f);
        (void) rw_unlock(&sharetab_lock);

        return;

alloc_failed:

        syslog(LOG_ERR, "check_sharetab: no memory");
        sh_free(share_list);
        share_list = NULL;
        (void) fclose(f);
        (void) rw_unlock(&sharetab_lock);
}

static void
sh_free(struct sh_list *shp)
{
        struct sh_list *next;

        while (shp) {
                sharefree(shp->shl_sh);
                next = shp->shl_next;
                free(shp);
                shp = next;
        }
}


/*
 * Remove an entry from mounted list
 */
static void
umount(struct svc_req *rqstp)
{
        char *host, *path, *remove_path;
        char rpath[MAXPATHLEN];
        SVCXPRT *transp;
        struct cln cln;

        transp = rqstp->rq_xprt;
        path = NULL;
        if (!svc_getargs(transp, xdr_dirpath, (caddr_t)&path)) {
                svcerr_decode(transp);
                return;
        }

        cln_init(&cln, transp);

        errno = 0;
        if (!svc_sendreply(transp, xdr_void, NULL))
                log_cant_reply_cln(&cln);

        host = cln_gethost(&cln);
        if (host == NULL) {
                /*
                 * Without the hostname we can't do audit or delete
                 * this host from the mount entries.
                 */
                svc_freeargs(transp, xdr_dirpath, (caddr_t)&path);
                return;
        }

        if (verbose)
                syslog(LOG_NOTICE, "UNMOUNT: %s unmounted %s", host, path);

        audit_mountd_umount(host, path);

        remove_path = rpath;    /* assume we will use the cannonical path */
        if (realpath(path, rpath) == NULL) {
                if (verbose)
                        syslog(LOG_WARNING, "UNMOUNT: realpath: %s: %m ", path);
                remove_path = path;     /* use path provided instead */
        }

        mntlist_delete(host, remove_path);      /* remove from mount list */

        cln_fini(&cln);

        svc_freeargs(transp, xdr_dirpath, (caddr_t)&path);
}

/*
 * Remove all entries for one machine from mounted list
 */
static void
umountall(struct svc_req *rqstp)
{
        SVCXPRT *transp;
        char *host;
        struct cln cln;

        transp = rqstp->rq_xprt;
        if (!svc_getargs(transp, xdr_void, NULL)) {
                svcerr_decode(transp);
                return;
        }
        /*
         * We assume that this call is asynchronous and made via rpcbind
         * callit routine.  Therefore return control immediately. The error
         * causes rpcbind to remain silent, as opposed to every machine
         * on the net blasting the requester with a response.
         */
        svcerr_systemerr(transp);

        cln_init(&cln, transp);

        host = cln_gethost(&cln);
        if (host == NULL) {
                /* Can't do anything without the name of the client */
                return;
        }

        /*
         * Remove all hosts entries from mount list
         */
        mntlist_delete_all(host);

        if (verbose)
                syslog(LOG_NOTICE, "UNMOUNTALL: from %s", host);

        cln_fini(&cln);
}

void *
exmalloc(size_t size)
{
        void *ret;

        if ((ret = malloc(size)) == NULL) {
                syslog(LOG_ERR, "Out of memory");
                exit(1);
        }
        return (ret);
}