xref: /src/usr.sbin/mountd/mountd.c

/* 	$NetBSD: mountd.c,v 1.137 2021/06/05 08:26:34 hannken Exp $	 */

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Herb Hasler and Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif				/* not lint */

#ifndef lint
#if 0
static char     sccsid[] = "@(#)mountd.c  8.15 (Berkeley) 5/1/95";
#else
__RCSID("$NetBSD: mountd.c,v 1.137 2021/06/05 08:26:34 hannken Exp $");
#endif
#endif				/* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <syslog.h>
#include <sys/ucred.h>

#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#include <rpcsvc/mount.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfs/nfs.h>
#include <nfs/nfsmount.h>

#ifdef MOUNTD_RUMP
#include <rump/rump.h>
#include <rump/rump_syscallshotgun.h>
#include <rump/rump_syscalls.h>
#include <pthread.h>
#include <semaphore.h>
#endif

#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <grp.h>
#include <netdb.h>
#include <pwd.h>
#include <netgroup.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include <util.h>
#include "pathnames.h"

#ifdef IPSEC
#include <netipsec/ipsec.h>
#ifndef IPSEC_POLICY_IPSEC	/* no ipsec support on old ipsec */
#undef IPSEC
#endif
#include "ipsec.h"
#endif

#include <stdarg.h>

#ifdef MOUNTD_RUMP
#include "svc_fdset.h"
#define DEBUGGING 1
#else
#define DEBUGGING 0
#endif

#include "mountd.h"

/*
 * Structures for keeping the mount list and export list
 */
struct mountlist {
	struct mountlist *ml_next;
	char ml_host[RPCMNT_NAMELEN + 1];
	char ml_dirp[RPCMNT_PATHLEN + 1];
	int ml_flag;/* XXX more flags (same as dp_flag) */
};

struct dirlist {
	struct dirlist *dp_left;
	struct dirlist *dp_right;
	int dp_flag;
	struct hostlist *dp_hosts;	/* List of hosts this dir exported to */
	char dp_dirp[1];		/* Actually malloc'd to size of dir */
};
/* dp_flag bits */
#define	DP_DEFSET	0x1
#define DP_HOSTSET	0x2
#define DP_KERB		0x4
#define DP_NORESMNT	0x8

struct exportlist {
	struct exportlist *ex_next;
	struct dirlist *ex_dirl;
	struct dirlist *ex_defdir;
	int             ex_flag;
	fsid_t          ex_fs;
	char           *ex_fsdir;
	char           *ex_indexfile;
};
/* ex_flag bits */
#define	EX_LINKED	0x1

union grouptypes {
	struct addrinfo *gt_addrinfo;
	struct netmsk   gt_net;
};

struct grouplist {
	int             gr_type;
	union grouptypes gr_ptr;
	struct grouplist *gr_next;
};
/* Group types */
#define	GT_NULL		0x0
#define	GT_HOST		0x1
#define	GT_NET		0x2

struct hostlist {
	int             ht_flag;/* Uses DP_xx bits */
	struct grouplist *ht_grp;
	struct hostlist *ht_next;
};

struct fhreturn {
	int             fhr_flag;
	int             fhr_vers;
	size_t		fhr_fhsize;
	union {
		uint8_t v2[NFSX_V2FH];
		uint8_t v3[NFSX_V3FHMAX];
	} fhr_fh;
};

/* Global defs */
static char    *add_expdir(struct dirlist **, char *, int);
static void add_dlist(struct dirlist **, struct dirlist *,
    struct grouplist *, int);
static void add_mlist(char *, char *, int);
static int check_dirpath(const char *, size_t, char *);
static int check_options(const char *, size_t, struct dirlist *);
static int chk_host(struct dirlist *, struct sockaddr *, int *, int *);
static int del_mlist(char *, char *, struct sockaddr *);
static struct dirlist *dirp_search(struct dirlist *, char *);
static int do_nfssvc(const char *, size_t, struct exportlist *,
    struct grouplist *, int, struct uucred *, char *, int, struct statvfs *);
static int do_opt(const char *, size_t, char **, char **,
    struct exportlist *, struct grouplist *, int *, int *, struct uucred *);
static struct exportlist *ex_search(fsid_t *);
static int parse_directory(const char *, size_t, struct grouplist *,
    int, char *, struct exportlist **, struct statvfs *);
static int parse_host_netgroup(const char *, size_t, struct exportlist *,
    struct grouplist *, char *, int *, struct grouplist **);
static struct exportlist *get_exp(void);
static void free_dir(struct dirlist *);
static void free_exp(struct exportlist *);
static void free_grp(struct grouplist *);
static void free_host(struct hostlist *);
static void get_exportlist(int);
static int get_host(const char *, size_t, const char *,
    struct grouplist *);
static struct hostlist *get_ht(void);
static void get_mountlist(void);
static void free_exp_grp(struct exportlist *, struct grouplist *);
static struct grouplist *get_grp(void);
static void hang_dirp(struct dirlist *, struct grouplist *,
    struct exportlist *, int);
static void mntsrv(struct svc_req *, SVCXPRT *);
static void nextfield(char **, char **);
static void parsecred(char *, struct uucred *);
static int put_exlist(struct dirlist *, XDR *, struct dirlist *, int *);
static int scan_tree(struct dirlist *, struct sockaddr *);
__dead static void send_umntall(int);
static int xdr_dir(XDR *, char *);
static int xdr_explist(XDR *, caddr_t);
static int xdr_fhs(XDR *, caddr_t);
static int xdr_mlist(XDR *, caddr_t);
static int bitcmp(void *, void *, int);
static int netpartcmp(struct sockaddr *, struct sockaddr *, int);
static int sacmp(struct sockaddr *, struct sockaddr *);
static int allones(struct sockaddr_storage *, int);
static void bind_resv_port(int, sa_family_t, in_port_t);
__dead static void no_nfs(int);
static struct exportlist *exphead;
static struct mountlist *mlhead;
static struct grouplist *grphead;
static char *const exnames_default[] = { __UNCONST(_PATH_EXPORTS), NULL };
static char *const *exnames;
static struct uucred def_anon = {
	1,
	(uid_t) -2,
	(gid_t) -2,
	0,
	{ 0 }
};
static struct mountd_exports_list *mel_tab;
static int mel_tab_len;

int      opt_flags;
static int	have_v6 = 1;
const int ninumeric = NI_NUMERICHOST;

int      mountd_debug = DEBUGGING;
#if 0
static void SYSLOG(int, const char *,...);
#endif

/*
 * If this is non-zero, -noresvport and -noresvmnt are implied for
 * each export.
 */
static int noprivports;

#ifdef MOUNTD_RUMP
#define C2FD(_c_) ((int)(uintptr_t)(_c_))
static int
rumpread(void *cookie, char *buf, int count)
{

	return rump_sys_read(C2FD(cookie), buf, count);
}

static int
rumpwrite(void *cookie, const char *buf, int count)
{

	return rump_sys_write(C2FD(cookie), buf, count);
}

static off_t
rumpseek(void *cookie, off_t off, int whence)
{

	return rump_sys_lseek(C2FD(cookie), off, whence);
}

static int
rumpclose(void *cookie)
{

	return rump_sys_close(C2FD(cookie));
}

int __sflags(const char *, int *); /* XXX */
static FILE *
rumpfopen(const char *path, const char *opts)
{
	int fd, oflags;

	__sflags(opts, &oflags);
	fd = rump_sys_open(path, oflags, 0777);
	if (fd == -1)
		return NULL;

	return funopen((void *)(uintptr_t)fd,
	    rumpread, rumpwrite, rumpseek, rumpclose);
}

/*
 * Make sure mountd signal handler is executed from a thread context
 * instead of the signal handler.  This avoids the signal handler
 * ruining our kernel context.
 */
static sem_t exportsem;
static void
signal_get_exportlist(int sig)
{

	sem_post(&exportsem);
}

static void *
exportlist_thread(void *arg)
{

	for (;;) {
		sem_wait(&exportsem);
		get_exportlist(0);
	}

	return NULL;
}
#define statvfs1(a, b, c) rump_sys_statvfs1((a), (b), (c))
#define getfh(a, b, c) rump_sys_getfh((a), (b), (c))
#define nfssvc(a, b) rump_sys_nfssvc((a), (b))
#define fopen(a, b) rumpfopen((a), (b))
#define lstat(a, b) rump_sys_lstat((a), (b))
#define stat(a, b) rump_sys_stat((a), (b))

/*
 * Mountd server for NFS mount protocol as described in:
 * NFS: Network File System Protocol Specification, RFC1094, Appendix A
 * The optional arguments are the exports file name
 * default: _PATH_EXPORTS
 * "-d" to enable debugging
 * and "-n" to allow nonroot mount.
 */
void *mountd_main(void *);
void *
mountd_main(void *arg)
#else
int
main(int argc, char **argv)
#endif
{
	SVCXPRT *udptransp, *tcptransp, *udp6transp, *tcp6transp;
	struct netconfig *udpconf, *tcpconf, *udp6conf, *tcp6conf;
	int udpsock, tcpsock, udp6sock, tcp6sock;
	int xcreated = 0;
	int one = 1;
	int maxrec = RPC_MAXDATASIZE;
	in_port_t forcedport = 0;
#ifdef IPSEC
	char *policy = NULL;
#define ADDOPTS "P:"
#else
#define ADDOPTS
#endif
#ifndef MOUNTD_RUMP
	int s, c;
	while ((c = getopt(argc, argv, "dNnrp:" ADDOPTS)) != -1)
		switch (c) {
#ifdef IPSEC
		case 'P':
			if (ipsecsetup_test(policy = optarg))
				errx(1, "Invalid ipsec policy `%s'", policy);
			break;
#endif
		case 'p':
			/* A forced port "0" will dynamically allocate a port */
			forcedport = atoi(optarg);
			break;
		case 'd':
			mountd_debug = 1;
			break;
		case 'N':
			noprivports = 1;
			break;
			/* Compatibility */
		case 'n':
		case 'r':
			break;
		default:
			fprintf(stderr, "Usage: %s [-dN]"
#ifdef IPSEC
			    " [-P policy]"
#endif
			    " [-p port] [exportsfile ...]\n", getprogname());
			exit(1);
		};
	argc -= optind;
	argv += optind;
	if (argc > 0)
		exnames = argv;
	else
		exnames = exnames_default;

	s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
	if (s < 0)
		have_v6 = 0;
	else
		close(s);
	(void)signal(SIGHUP, get_exportlist);
#else
	extern sem_t gensem;
	pthread_t ptdummy;

	svc_fdset_init(SVC_FDSET_MT);

	sem_init(&exportsem, 0, 0);
	pthread_create(&ptdummy, NULL, exportlist_thread, NULL);
	exnames = exnames_default;
	have_v6 = 0;
	(void)signal(SIGHUP, signal_get_exportlist);
#endif
	grphead = NULL;
	exphead = NULL;
	mlhead = NULL;
	openlog("mountd", LOG_PID | (mountd_debug ? LOG_PERROR : 0), LOG_DAEMON);
	(void)signal(SIGSYS, no_nfs);

	if (mountd_debug)
		(void)fprintf(stderr, "Getting export list.\n");
	get_exportlist(0);
	if (mountd_debug)
		(void)fprintf(stderr, "Getting mount list.\n");
	get_mountlist();
	if (mountd_debug)
		(void)fprintf(stderr, "Here we go.\n");
	(void)signal(SIGTERM, send_umntall);

	rpcb_unset(RPCPROG_MNT, RPCMNT_VER1, NULL);
	rpcb_unset(RPCPROG_MNT, RPCMNT_VER3, NULL);

	udpsock  = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
	tcpsock  = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	udp6sock = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
	tcp6sock = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);

	/*
	 * We're doing host-based access checks here, so don't allow
	 * v4-in-v6 to confuse things. The kernel will disable it
	 * by default on NFS sockets too.
	 */
	if (udp6sock != -1 && setsockopt(udp6sock, IPPROTO_IPV6,
	    IPV6_V6ONLY, &one, sizeof one) < 0){
		syslog(LOG_ERR, "can't disable v4-in-v6 on UDP socket");
		exit(1);
	}
	if (tcp6sock != -1 && setsockopt(tcp6sock, IPPROTO_IPV6,
	    IPV6_V6ONLY, &one, sizeof one) < 0){
		syslog(LOG_ERR, "can't disable v4-in-v6 on UDP socket");
		exit(1);
	}

	udpconf  = getnetconfigent("udp");
	tcpconf  = getnetconfigent("tcp");
	udp6conf = getnetconfigent("udp6");
	tcp6conf = getnetconfigent("tcp6");

	rpc_control(RPC_SVC_CONNMAXREC_SET, &maxrec);

	if (udpsock != -1 && udpconf != NULL) {
		bind_resv_port(udpsock, AF_INET, forcedport);
#ifdef IPSEC
		if (policy)
			ipsecsetup(AF_INET, udpsock, policy);
#endif
		udptransp = svc_dg_create(udpsock, 0, 0);
		if (udptransp != NULL) {
			if (!svc_reg(udptransp, RPCPROG_MNT, RPCMNT_VER1,
				mntsrv, udpconf) ||
			    !svc_reg(udptransp, RPCPROG_MNT, RPCMNT_VER3,
				mntsrv, udpconf))
				syslog(LOG_WARNING, "can't register UDP service");
			else
				xcreated++;
		} else
			syslog(LOG_WARNING, "can't create UDP service");

	}

	if (tcpsock != -1 && tcpconf != NULL) {
		bind_resv_port(tcpsock, AF_INET, forcedport);
#ifdef IPSEC
		if (policy)
			ipsecsetup(AF_INET, tcpsock, policy);
#endif
		listen(tcpsock, SOMAXCONN);
		tcptransp = svc_vc_create(tcpsock, RPC_MAXDATASIZE,
		    RPC_MAXDATASIZE);
		if (tcptransp != NULL) {
			if (!svc_reg(tcptransp, RPCPROG_MNT, RPCMNT_VER1,
				mntsrv, tcpconf) ||
			    !svc_reg(tcptransp, RPCPROG_MNT, RPCMNT_VER3,
				mntsrv, tcpconf))
				syslog(LOG_WARNING, "can't register TCP service");
			else
				xcreated++;
		} else
			syslog(LOG_WARNING, "can't create TCP service");

	}

	if (udp6sock != -1 && udp6conf != NULL) {
		bind_resv_port(udp6sock, AF_INET6, forcedport);
#ifdef IPSEC
		if (policy)
			ipsecsetup(AF_INET6, tcpsock, policy);
#endif
		udp6transp = svc_dg_create(udp6sock, 0, 0);
		if (udp6transp != NULL) {
			if (!svc_reg(udp6transp, RPCPROG_MNT, RPCMNT_VER1,
				mntsrv, udp6conf) ||
			    !svc_reg(udp6transp, RPCPROG_MNT, RPCMNT_VER3,
				mntsrv, udp6conf))
				syslog(LOG_WARNING, "can't register UDP6 service");
			else
				xcreated++;
		} else
			syslog(LOG_WARNING, "can't create UDP6 service");

	}

	if (tcp6sock != -1 && tcp6conf != NULL) {
		bind_resv_port(tcp6sock, AF_INET6, forcedport);
#ifdef IPSEC
		if (policy)
			ipsecsetup(AF_INET6, tcpsock, policy);
#endif
		listen(tcp6sock, SOMAXCONN);
		tcp6transp = svc_vc_create(tcp6sock, RPC_MAXDATASIZE,
		    RPC_MAXDATASIZE);
		if (tcp6transp != NULL) {
			if (!svc_reg(tcp6transp, RPCPROG_MNT, RPCMNT_VER1,
				mntsrv, tcp6conf) ||
			    !svc_reg(tcp6transp, RPCPROG_MNT, RPCMNT_VER3,
				mntsrv, tcp6conf))
				syslog(LOG_WARNING, "can't register TCP6 service");
			else
				xcreated++;
		} else
			syslog(LOG_WARNING, "can't create TCP6 service");

	}

	if (xcreated == 0) {
		syslog(LOG_ERR, "could not create any services");
		exit(1);
	}

	if (mountd_debug == 0) {
		daemon(0, 0);
		(void)signal(SIGINT, SIG_IGN);
		(void)signal(SIGQUIT, SIG_IGN);
	}
	pidfile(NULL);
#ifdef MOUNTD_RUMP
	sem_post(&gensem);
#endif
	svc_run();
	syslog(LOG_ERR, "Mountd died");
	exit(1);
}

/*
 * The mount rpc service
 */
void
mntsrv(struct svc_req *rqstp, SVCXPRT *transp)
{
	struct exportlist *ep;
	struct dirlist *dp;
	struct fhreturn fhr;
	struct stat     stb;
	struct statvfs   fsb;
	char host[NI_MAXHOST], numerichost[NI_MAXHOST];
	int lookup_failed = 1;
	struct sockaddr *saddr;
	u_short         sport;
	char            rpcpath[RPCMNT_PATHLEN + 1], rdirpath[MAXPATHLEN];
	long            bad = EACCES;
	int             defset, hostset, ret;
	sigset_t        sighup_mask;
	struct sockaddr_in6 *sin6;
	struct sockaddr_in *sin;
	size_t fh_size;

	(void)sigemptyset(&sighup_mask);
	(void)sigaddset(&sighup_mask, SIGHUP);
	saddr = svc_getrpccaller(transp)->buf;
	switch (saddr->sa_family) {
	case AF_INET6:
		sin6 = (struct sockaddr_in6 *)saddr;
		sport = ntohs(sin6->sin6_port);
		break;
	case AF_INET:
		sin = (struct sockaddr_in *)saddr;
		sport = ntohs(sin->sin_port);
		break;
	default:
		syslog(LOG_ERR, "request from unknown address family");
		return;
	}
	lookup_failed = getnameinfo(saddr, saddr->sa_len, host, sizeof host,
	    NULL, 0, 0);
	if (getnameinfo(saddr, saddr->sa_len, numerichost,
	    sizeof numerichost, NULL, 0, ninumeric) != 0)
		strlcpy(numerichost, "?", sizeof(numerichost));
	ret = 0;
	switch (rqstp->rq_proc) {
	case NULLPROC:
		if (!svc_sendreply(transp, (xdrproc_t)xdr_void, NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case MOUNTPROC_MNT:
		if (mountd_debug)
			fprintf(stderr,
			    "got mount request from %s\n", numerichost);
		if (!svc_getargs(transp, xdr_dir, rpcpath)) {
			if (mountd_debug)
				fprintf(stderr, "-> garbage args\n");
			svcerr_decode(transp);
			return;
		}
		if (mountd_debug)
			fprintf(stderr,
			    "-> rpcpath: %s\n", rpcpath);
		/*
		 * Get the real pathname and make sure it is a file or
		 * directory that exists.
		 */
		if (
#ifndef MOUNTD_RUMP
		realpath(rpcpath, rdirpath) == NULL ||
#else
		strcpy(rdirpath, rpcpath) == NULL ||
#endif
		    stat(rdirpath, &stb) < 0 ||
		    (!S_ISDIR(stb.st_mode) && !S_ISREG(stb.st_mode)) ||
		    statvfs1(rdirpath, &fsb, ST_WAIT) < 0) {
			(void)chdir("/"); /* Just in case realpath doesn't */
			if (mountd_debug)
				(void)fprintf(stderr, "-> stat failed on %s\n",
				    rdirpath);
			if (!svc_sendreply(transp, (xdrproc_t)xdr_long, (caddr_t) &bad))
				syslog(LOG_ERR, "Can't send reply");
			return;
		}
		if (mountd_debug)
			fprintf(stderr,
			    "-> dirpath: %s\n", rdirpath);
		/* Check in the exports list */
		(void)sigprocmask(SIG_BLOCK, &sighup_mask, NULL);
		ep = ex_search(&fsb.f_fsidx);
		hostset = defset = 0;
		if (ep && (chk_host(ep->ex_defdir, saddr, &defset,
		   &hostset) || ((dp = dirp_search(ep->ex_dirl, rdirpath)) &&
		   chk_host(dp, saddr, &defset, &hostset)) ||
		   (defset && scan_tree(ep->ex_defdir, saddr) == 0 &&
		   scan_tree(ep->ex_dirl, saddr) == 0))) {
			if ((hostset & DP_HOSTSET) == 0) {
				hostset = defset;
			}
			if (sport >= IPPORT_RESERVED &&
			    !(hostset & DP_NORESMNT)) {
				syslog(LOG_NOTICE,
				    "Refused mount RPC from host %s port %d",
				    numerichost, sport);
				svcerr_weakauth(transp);
				goto out;
			}
			fhr.fhr_flag = hostset;
			fhr.fhr_vers = rqstp->rq_vers;
			/* Get the file handle */
			memset(&fhr.fhr_fh, 0, sizeof(fhr.fhr_fh)); /* for v2 */
			fh_size = sizeof(fhr.fhr_fh);
			if (getfh(rdirpath, &fhr.fhr_fh, &fh_size) < 0) {
				bad = errno;
				syslog(LOG_ERR, "Can't get fh for %s", rdirpath);
				if (!svc_sendreply(transp, (xdrproc_t)xdr_long,
				    (char *)&bad))
					syslog(LOG_ERR, "Can't send reply");
				goto out;
			}
			if ((fhr.fhr_vers == 1 && fh_size > NFSX_V2FH) ||
			    fh_size > NFSX_V3FHMAX) {
				bad = EINVAL; /* XXX */
				if (!svc_sendreply(transp, (xdrproc_t)xdr_long,
				    (char *)&bad))
					syslog(LOG_ERR, "Can't send reply");
				goto out;
			}
			fhr.fhr_fhsize = fh_size;
			if (!svc_sendreply(transp, (xdrproc_t)xdr_fhs, (char *) &fhr))
				syslog(LOG_ERR, "Can't send reply");
			if (!lookup_failed)
				add_mlist(host, rdirpath, hostset);
			else
				add_mlist(numerichost, rdirpath, hostset);
			if (mountd_debug)
				(void)fprintf(stderr, "Mount successful.\n");
		} else {
			if (!svc_sendreply(transp, (xdrproc_t)xdr_long, (caddr_t) &bad))
				syslog(LOG_ERR, "Can't send reply");
		}
out:
		(void)sigprocmask(SIG_UNBLOCK, &sighup_mask, NULL);
		return;
	case MOUNTPROC_DUMP:
		if (!svc_sendreply(transp, (xdrproc_t)xdr_mlist, NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case MOUNTPROC_UMNT:
		if (!svc_getargs(transp, xdr_dir, rdirpath)) {
			svcerr_decode(transp);
			return;
		}
		if (!lookup_failed)
			ret = del_mlist(host, rdirpath, saddr);
		ret |= del_mlist(numerichost, rdirpath, saddr);
		if (ret) {
			svcerr_weakauth(transp);
			return;
		}
		if (!svc_sendreply(transp, (xdrproc_t)xdr_void, NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case MOUNTPROC_UMNTALL:
		if (!lookup_failed)
			ret = del_mlist(host, NULL, saddr);
		ret |= del_mlist(numerichost, NULL, saddr);
		if (ret) {
			svcerr_weakauth(transp);
			return;
		}
		if (!svc_sendreply(transp, (xdrproc_t)xdr_void, NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case MOUNTPROC_EXPORT:
	case MOUNTPROC_EXPORTALL:
		if (!svc_sendreply(transp, (xdrproc_t)xdr_explist, NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;


	default:
		svcerr_noproc(transp);
		return;
	}
}

/*
 * Xdr conversion for a dirpath string
 */
static int
xdr_dir(XDR *xdrsp, char *dirp)
{

	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
}

/*
 * Xdr routine to generate file handle reply
 */
static int
xdr_fhs(XDR *xdrsp, caddr_t cp)
{
	struct fhreturn *fhrp = (struct fhreturn *) cp;
	long ok = 0, len, auth;

	if (!xdr_long(xdrsp, &ok))
		return (0);
	switch (fhrp->fhr_vers) {
	case 1:
		return (xdr_opaque(xdrsp, (caddr_t)&fhrp->fhr_fh, NFSX_V2FH));
	case 3:
		len = fhrp->fhr_fhsize;
		if (!xdr_long(xdrsp, &len))
			return (0);
		if (!xdr_opaque(xdrsp, (caddr_t)&fhrp->fhr_fh, len))
			return (0);
		if (fhrp->fhr_flag & DP_KERB)
			auth = RPCAUTH_KERB4;
		else
			auth = RPCAUTH_UNIX;
		len = 1;
		if (!xdr_long(xdrsp, &len))
			return (0);
		return (xdr_long(xdrsp, &auth));
	};
	return (0);
}

int
xdr_mlist(XDR *xdrsp, caddr_t cp)
{
	struct mountlist *mlp;
	int trueval = 1;
	int falseval = 0;
	char *strp;

	mlp = mlhead;
	while (mlp) {
		if (!xdr_bool(xdrsp, &trueval))
			return (0);
		strp = &mlp->ml_host[0];
		if (!xdr_string(xdrsp, &strp, RPCMNT_NAMELEN))
			return (0);
		strp = &mlp->ml_dirp[0];
		if (!xdr_string(xdrsp, &strp, RPCMNT_PATHLEN))
			return (0);
		mlp = mlp->ml_next;
	}
	if (!xdr_bool(xdrsp, &falseval))
		return (0);
	return (1);
}

/*
 * Xdr conversion for export list
 */
int
xdr_explist(XDR *xdrsp, caddr_t cp)
{
	struct exportlist *ep;
	int falseval = 0;
	int putdef;
	sigset_t sighup_mask;

	(void)sigemptyset(&sighup_mask);
	(void)sigaddset(&sighup_mask, SIGHUP);
	(void)sigprocmask(SIG_BLOCK, &sighup_mask, NULL);
	ep = exphead;
	while (ep) {
		putdef = 0;
		if (put_exlist(ep->ex_dirl, xdrsp, ep->ex_defdir, &putdef))
			goto errout;
		if (ep->ex_defdir && putdef == 0 &&
		    put_exlist(ep->ex_defdir, xdrsp, NULL, &putdef))
			goto errout;
		ep = ep->ex_next;
	}
	(void)sigprocmask(SIG_UNBLOCK, &sighup_mask, NULL);
	if (!xdr_bool(xdrsp, &falseval))
		return (0);
	return (1);
errout:
	(void)sigprocmask(SIG_UNBLOCK, &sighup_mask, NULL);
	return (0);
}

/*
 * Called from xdr_explist() to traverse the tree and export the
 * directory paths.  Assumes SIGHUP has already been masked.
 */
int
put_exlist(struct dirlist *dp, XDR *xdrsp, struct dirlist *adp, int *putdefp)
{
	struct grouplist *grp;
	struct hostlist *hp;
	int trueval = 1;
	int falseval = 0;
	int gotalldir = 0;
	char *strp;

	if (dp) {
		if (put_exlist(dp->dp_left, xdrsp, adp, putdefp))
			return (1);
		if (!xdr_bool(xdrsp, &trueval))
			return (1);
		strp = dp->dp_dirp;
		if (!xdr_string(xdrsp, &strp, RPCMNT_PATHLEN))
			return (1);
		if (adp && !strcmp(dp->dp_dirp, adp->dp_dirp)) {
			gotalldir = 1;
			*putdefp = 1;
		}
		if ((dp->dp_flag & DP_DEFSET) == 0 &&
		    (gotalldir == 0 || (adp->dp_flag & DP_DEFSET) == 0)) {
			hp = dp->dp_hosts;
			while (hp) {
				grp = hp->ht_grp;
				if (grp->gr_type == GT_HOST) {
					if (!xdr_bool(xdrsp, &trueval))
						return (1);
					strp =
					  grp->gr_ptr.gt_addrinfo->ai_canonname;
					if (!xdr_string(xdrsp, &strp,
							RPCMNT_NAMELEN))
						return (1);
				} else if (grp->gr_type == GT_NET) {
					if (!xdr_bool(xdrsp, &trueval))
						return (1);
					strp = grp->gr_ptr.gt_net.nt_name;
					if (!xdr_string(xdrsp, &strp,
							RPCMNT_NAMELEN))
						return (1);
				}
				hp = hp->ht_next;
				if (gotalldir && hp == NULL) {
					hp = adp->dp_hosts;
					gotalldir = 0;
				}
			}
		}
		if (!xdr_bool(xdrsp, &falseval))
			return (1);
		if (put_exlist(dp->dp_right, xdrsp, adp, putdefp))
			return (1);
	}
	return (0);
}

static int
parse_host_netgroup(const char *line, size_t lineno, struct exportlist *ep,
    struct grouplist *tgrp, char *cp, int *has_host, struct grouplist **grp)
{
	const char *hst, *usr, *dom;
	int netgrp;

	if (ep == NULL) {
		syslog(LOG_ERR, "\"%s\", line %ld: No current export",
		    line, (unsigned long)lineno);
		return 0;
	}
	setnetgrent(cp);
	netgrp = getnetgrent(&hst, &usr, &dom);
	do {
		if (*has_host) {
			(*grp)->gr_next = get_grp();
			*grp = (*grp)->gr_next;
		}
		if (netgrp) {
			if (hst == NULL) {
				syslog(LOG_ERR,
				    "\"%s\", line %ld: No host in netgroup %s",
				    line, (unsigned long)lineno, cp);
				goto bad;
			}
			if (get_host(line, lineno, hst, *grp))
				goto bad;
		} else if (get_host(line, lineno, cp, *grp))
			goto bad;
		*has_host = TRUE;
	} while (netgrp && getnetgrent(&hst, &usr, &dom));

	endnetgrent();
	return 1;
bad:
	endnetgrent();
	return 0;

}

static int
parse_directory(const char *line, size_t lineno, struct grouplist *tgrp,
    int got_nondir, char *cp, struct exportlist **ep, struct statvfs *fsp)
{
	if (!check_dirpath(line, lineno, cp))
		return 0;

	if (statvfs1(cp, fsp, ST_WAIT) == -1) {
		syslog(LOG_ERR, "\"%s\", line %ld: statvfs for `%s' failed: %m",
		    line, (unsigned long)lineno, cp);
		return 0;
	}

	if ((fsp->f_flag & MNT_AUTOMOUNTED) != 0)
		syslog(LOG_ERR, "\"%s\", line %ld: Warning: exporting of "
		    "automounted fs %s not supported",
		    line, (unsigned long)lineno, cp);
	if (got_nondir) {
		syslog(LOG_ERR,
		    "\"%s\", line %ld: Directories must precede files",
		    line, (unsigned long)lineno);
		return 0;
	}
	if (*ep) {
		if ((*ep)->ex_fs.__fsid_val[0] != fsp->f_fsidx.__fsid_val[0] ||
		    (*ep)->ex_fs.__fsid_val[1] != fsp->f_fsidx.__fsid_val[1]) {
			syslog(LOG_ERR,
			    "\"%s\", line %ld: filesystem ids disagree",
			    line, (unsigned long)lineno);
			return 0;
		}
	} else {
		/*
		 * See if this directory is already
		 * in the list.
		 */
		*ep = ex_search(&fsp->f_fsidx);
		if (*ep == NULL) {
			*ep = get_exp();
			(*ep)->ex_fs = fsp->f_fsidx;
			(*ep)->ex_fsdir = estrdup(fsp->f_mntonname);
			if (mountd_debug)
				(void)fprintf(stderr,
				    "Making new ep fs=0x%x,0x%x\n",
				    fsp->f_fsidx.__fsid_val[0], fsp->f_fsidx.__fsid_val[1]);
		} else {
			if (mountd_debug)
				(void)fprintf(stderr,
				    "Found ep fs=0x%x,0x%x\n",
				    fsp->f_fsidx.__fsid_val[0], fsp->f_fsidx.__fsid_val[1]);
		}
	}

	return 1;
}


static void
get_exportlist_one(FILE *exp_file)
{
	struct exportlist *ep, *ep2;
	struct grouplist *grp, *tgrp;
	struct exportlist **epp;
	struct dirlist *dirhead;
	struct statvfs fsb;
	struct addrinfo *ai;
	struct uucred anon;
	char *cp, *endcp, *dirp, savedc;
	int has_host, exflags, got_nondir, dirplen;
	char *line;
	size_t lineno = 0, len;

	dirp = NULL;
	dirhead = NULL;
	while ((line = fparseln(exp_file, &len, &lineno, NULL, 0)) != NULL) {
		if (mountd_debug)
			(void)fprintf(stderr, "Got line %s\n", line);
		cp = line;
		nextfield(&cp, &endcp);
		if (cp == endcp)
			goto nextline;	/* skip empty line */
		/*
		 * Set defaults.
		 */
		has_host = FALSE;
		anon = def_anon;
		exflags = MNT_EXPORTED;
		got_nondir = 0;
		opt_flags = 0;
		ep = NULL;

		if (noprivports) {
			opt_flags |= OP_NORESMNT | OP_NORESPORT;
			exflags |= MNT_EXNORESPORT;
		}

		/*
		 * Create new exports list entry
		 */
		len = endcp - cp;
		tgrp = grp = get_grp();
		while (len > 0) {
			if (len > RPCMNT_NAMELEN) {
				*endcp = '\0';
				syslog(LOG_ERR,
				    "\"%s\", line %ld: name `%s' is too long",
				    line, (unsigned long)lineno, cp);
				goto badline;
			}
			switch (*cp) {
			case '-':
				/*
				 * Option
				 */
				if (ep == NULL) {
					syslog(LOG_ERR,
				"\"%s\", line %ld: No current export list",
					    line, (unsigned long)lineno);
					goto badline;
				}
				if (mountd_debug)
					(void)fprintf(stderr, "doing opt %s\n",
					    cp);
				got_nondir = 1;
				if (do_opt(line, lineno, &cp, &endcp, ep, grp,
				    &has_host, &exflags, &anon))
					goto badline;
				break;

			case '/':
				/*
				 * Directory
				 */
				savedc = *endcp;
				*endcp = '\0';

				if (!parse_directory(line, lineno, tgrp,
				    got_nondir, cp, &ep, &fsb))
					goto badline;
				/*
				 * Add dirpath to export mount point.
				 */
				dirp = add_expdir(&dirhead, cp, len);
				dirplen = len;

				*endcp = savedc;
				break;

			default:
				/*
				 * Host or netgroup.
				 */
				savedc = *endcp;
				*endcp = '\0';

				if (!parse_host_netgroup(line, lineno, ep,
				    tgrp, cp, &has_host, &grp))
					goto badline;

				got_nondir = 1;

				*endcp = savedc;
				break;
			}

			cp = endcp;
			nextfield(&cp, &endcp);
			len = endcp - cp;
		}
		if (check_options(line, lineno, dirhead))
			goto badline;

		if (!has_host) {
			grp->gr_type = GT_HOST;
			if (mountd_debug)
				(void)fprintf(stderr,
				    "Adding a default entry\n");
			/* add a default group and make the grp list NULL */
			ai = emalloc(sizeof(struct addrinfo));
			ai->ai_flags = 0;
			ai->ai_family = AF_INET;	/* XXXX */
			ai->ai_socktype = SOCK_DGRAM;
			/* setting the length to 0 will match anything */
			ai->ai_addrlen = 0;
			ai->ai_flags = AI_CANONNAME;
			ai->ai_canonname = estrdup("Default");
			ai->ai_addr = NULL;
			ai->ai_next = NULL;
			grp->gr_ptr.gt_addrinfo = ai;

		} else if ((opt_flags & OP_NET) && tgrp->gr_next) {
			/*
			 * Don't allow a network export coincide with a list of
			 * host(s) on the same line.
			 */
			syslog(LOG_ERR,
			    "\"%s\", line %ld: Mixed exporting of networks and hosts is disallowed",
			    line, (unsigned long)lineno);
			goto badline;
		}
		/*
		 * Loop through hosts, pushing the exports into the kernel.
		 * After loop, tgrp points to the start of the list and
		 * grp points to the last entry in the list.
		 */
		grp = tgrp;
		do {
			if (do_nfssvc(line, lineno, ep, grp, exflags, &anon,
			    dirp, dirplen, &fsb))
				goto badline;
		} while (grp->gr_next && (grp = grp->gr_next));

		/*
		 * Success. Update the data structures.
		 */
		if (has_host) {
			hang_dirp(dirhead, tgrp, ep, opt_flags);
			grp->gr_next = grphead;
			grphead = tgrp;
		} else {
			hang_dirp(dirhead, NULL, ep, opt_flags);
			free_grp(tgrp);
		}
		tgrp = NULL;
		dirhead = NULL;
		if ((ep->ex_flag & EX_LINKED) == 0) {
			ep2 = exphead;
			epp = &exphead;

			/*
			 * Insert in the list in alphabetical order.
			 */
			while (ep2 && strcmp(ep2->ex_fsdir, ep->ex_fsdir) < 0) {
				epp = &ep2->ex_next;
				ep2 = ep2->ex_next;
			}
			if (ep2)
				ep->ex_next = ep2;
			*epp = ep;
			ep->ex_flag |= EX_LINKED;
		}
		goto nextline;
badline:
		free_exp_grp(ep, grp);
nextline:
		if (dirhead) {
			free_dir(dirhead);
			dirhead = NULL;
		}
		free(line);
	}
}

/*
 * Compare two export lists by path.
 */
static int
mel_compare(const void *a, const void *b)
{
	const struct mountd_exports_list *mela = a;
	const struct mountd_exports_list *melb = b;

	return strcmp(mela->mel_path, melb->mel_path);
}

/*
 * Get the export list
 */
/* ARGSUSED */
void
get_exportlist(int n)
{
	struct exportlist *ep, *ep2;
	struct grouplist *grp, *tgrp;
	struct statvfs *fsp;
	int i, j;
	FILE *exp_file;


	/*
	 * First, get rid of the old list
	 */
	ep = exphead;
	while (ep) {
		ep2 = ep;
		ep = ep->ex_next;
		free_exp(ep2);
	}
	exphead = NULL;

	grp = grphead;
	while (grp) {
		tgrp = grp;
		grp = grp->gr_next;
		free_grp(tgrp);
	}
	grphead = NULL;

	/*
	 * And delete exports that are in the kernel for all local
	 * file systems.
	 */
	mel_tab_len = getmntinfo(&fsp, MNT_NOWAIT);
	mel_tab = ecalloc(mel_tab_len, sizeof(*mel_tab));
	for (i = 0; i < mel_tab_len; i++) {
		mel_tab[i].mel_path = estrdup(fsp[i].f_mntonname);
		mel_tab[i].mel_nexports = 0;
		mel_tab[i].mel_exports = NULL;
	}
	qsort(mel_tab, mel_tab_len, sizeof(mel_tab[0]), mel_compare);

	/*
	 * Read in the exports file and build the list, calling
	 * mount() as we go along to push the export rules into the kernel.
	 */
	for (i = 0; exnames[i] != NULL; i++) {
		if ((exp_file = fopen(exnames[i], "r")) == NULL) {
			/*
			 * Don't exit here; we can still reload the config
			 * after a SIGHUP.
			 */
			if (mountd_debug)
				(void)fprintf(stderr, "Can't open %s: %s\n",
				    exnames[i], strerror(errno));
			continue;
		}

		get_exportlist_one(exp_file);

		(void)fclose(exp_file);
	}

	for (i = 0; i < mel_tab_len; i++) {
		struct mountd_exports_list *mel = &mel_tab[i];

		if (nfssvc(NFSSVC_REPLACEEXPORTSLIST, mel) == -1 &&
		    (mel->mel_nexports > 0 || errno != EOPNOTSUPP))
			syslog(LOG_ERR, "Can't update exports for %s (%m)",
			    mel_tab[i].mel_path);
		for (j = 0; j < (int)mel->mel_nexports; j++) {
			struct export_args *export = &mel->mel_exports[j];

			if (export->ex_indexfile)
				free(export->ex_indexfile);
			if (export->ex_addr)
				free(export->ex_addr);
			if (export->ex_mask)
				free(export->ex_mask);
		}
		if (mel->mel_nexports > 0)
			free(mel->mel_exports);
		free(__UNCONST(mel->mel_path));
	}
	free(mel_tab);
	mel_tab_len = 0;
}

/*
 * Allocate an export list element
 */
static struct exportlist *
get_exp(void)
{
	struct exportlist *ep;

	ep = emalloc(sizeof(struct exportlist));
	(void)memset(ep, 0, sizeof(struct exportlist));
	return (ep);
}

/*
 * Allocate a group list element
 */
static struct grouplist *
get_grp(void)
{
	struct grouplist *gp;

	gp = emalloc(sizeof(struct grouplist));
	(void)memset(gp, 0, sizeof(struct grouplist));
	return (gp);
}

/*
 * Clean up upon an error in get_exportlist().
 */
static void
free_exp_grp(struct exportlist *ep, struct grouplist *grp)
{
	struct grouplist *tgrp;

	if (ep && (ep->ex_flag & EX_LINKED) == 0)
		free_exp(ep);
	while (grp) {
		tgrp = grp;
		grp = grp->gr_next;
		free_grp(tgrp);
	}
}

/*
 * Search the export list for a matching fs.
 */
static struct exportlist *
ex_search(fsid_t *fsid)
{
#ifdef MOUNTD_RUMP
	return exphead;
#else
	struct exportlist *ep;

	ep = exphead;
	while (ep) {
		if (ep->ex_fs.__fsid_val[0] == fsid->__fsid_val[0] &&
		    ep->ex_fs.__fsid_val[1] == fsid->__fsid_val[1])
			return (ep);
		ep = ep->ex_next;
	}
	return (ep);
#endif
}

/*
 * Add a directory path to the list.
 */
static char *
add_expdir(struct dirlist **dpp, char *cp, int len)
{
	struct dirlist *dp;

	dp = emalloc(sizeof(struct dirlist) + len);
	dp->dp_left = *dpp;
	dp->dp_right = NULL;
	dp->dp_flag = 0;
	dp->dp_hosts = NULL;
	(void)strcpy(dp->dp_dirp, cp);
	*dpp = dp;
	return (dp->dp_dirp);
}

/*
 * Hang the dir list element off the dirpath binary tree as required
 * and update the entry for host.
 */
void
hang_dirp(struct dirlist *dp, struct grouplist *grp, struct exportlist *ep,
    int flags)
{
	struct hostlist *hp;
	struct dirlist *dp2;

	if (flags & OP_ALLDIRS) {
		if (ep->ex_defdir)
			free(dp);
		else
			ep->ex_defdir = dp;
		if (grp == NULL) {
			ep->ex_defdir->dp_flag |= DP_DEFSET;
			if (flags & OP_KERB)
				ep->ex_defdir->dp_flag |= DP_KERB;
			if (flags & OP_NORESMNT)
				ep->ex_defdir->dp_flag |= DP_NORESMNT;
		} else
			while (grp) {
				hp = get_ht();
				if (flags & OP_KERB)
					hp->ht_flag |= DP_KERB;
				if (flags & OP_NORESMNT)
					hp->ht_flag |= DP_NORESMNT;
				hp->ht_grp = grp;
				hp->ht_next = ep->ex_defdir->dp_hosts;
				ep->ex_defdir->dp_hosts = hp;
				grp = grp->gr_next;
			}
	} else {

		/*
		 * Loop through the directories adding them to the tree.
		 */
		while (dp) {
			dp2 = dp->dp_left;
			add_dlist(&ep->ex_dirl, dp, grp, flags);
			dp = dp2;
		}
	}
}

/*
 * Traverse the binary tree either updating a node that is already there
 * for the new directory or adding the new node.
 */
static void
add_dlist(struct dirlist **dpp, struct dirlist *newdp, struct grouplist *grp,
    int flags)
{
	struct dirlist *dp;
	struct hostlist *hp;
	int cmp;

	dp = *dpp;
	if (dp) {
		cmp = strcmp(dp->dp_dirp, newdp->dp_dirp);
		if (cmp > 0) {
			add_dlist(&dp->dp_left, newdp, grp, flags);
			return;
		} else if (cmp < 0) {
			add_dlist(&dp->dp_right, newdp, grp, flags);
			return;
		} else
			free(newdp);
	} else {
		dp = newdp;
		dp->dp_left = NULL;
		*dpp = dp;
	}
	if (grp) {

		/*
		 * Hang all of the host(s) off of the directory point.
		 */
		do {
			hp = get_ht();
			if (flags & OP_KERB)
				hp->ht_flag |= DP_KERB;
			if (flags & OP_NORESMNT)
				hp->ht_flag |= DP_NORESMNT;
			hp->ht_grp = grp;
			hp->ht_next = dp->dp_hosts;
			dp->dp_hosts = hp;
			grp = grp->gr_next;
		} while (grp);
	} else {
		dp->dp_flag |= DP_DEFSET;
		if (flags & OP_KERB)
			dp->dp_flag |= DP_KERB;
		if (flags & OP_NORESMNT)
			dp->dp_flag |= DP_NORESMNT;
	}
}

/*
 * Search for a dirpath on the export point.
 */
static struct dirlist *
dirp_search(struct dirlist *dp, char *dirp)
{
	int cmp;

	if (dp) {
		cmp = strcmp(dp->dp_dirp, dirp);
		if (cmp > 0)
			return (dirp_search(dp->dp_left, dirp));
		else if (cmp < 0)
			return (dirp_search(dp->dp_right, dirp));
		else
			return (dp);
	}
	return (dp);
}

/*
 * Some helper functions for netmasks. They all assume masks in network
 * order (big endian).
 */
static int
bitcmp(void *dst, void *src, int bitlen)
{
	int i;
	u_int8_t *p1 = dst, *p2 = src;
	u_int8_t bitmask;
	int bytelen, bitsleft;

	bytelen = bitlen / 8;
	bitsleft = bitlen % 8;

	if (mountd_debug) {
		printf("comparing:\n");
		for (i = 0; i < (bitsleft ? bytelen + 1 : bytelen); i++)
			printf("%02x", p1[i]);
		printf("\n");
		for (i = 0; i < (bitsleft ? bytelen + 1 : bytelen); i++)
			printf("%02x", p2[i]);
		printf("\n");
	}

	for (i = 0; i < bytelen; i++) {
		if (*p1 != *p2)
			return 1;
		p1++;
		p2++;
	}

	for (i = 0; i < bitsleft; i++) {
		bitmask = 1 << (7 - i);
		if ((*p1 & bitmask) != (*p2 & bitmask))
			return 1;
	}

	return 0;
}

static int
netpartcmp(struct sockaddr *s1, struct sockaddr *s2, int bitlen)
{
	void *src, *dst;

	if (s1->sa_family != s2->sa_family)
		return 1;

	switch (s1->sa_family) {
	case AF_INET:
		src = &((struct sockaddr_in *)s1)->sin_addr;
		dst = &((struct sockaddr_in *)s2)->sin_addr;
		if (bitlen > (int)sizeof(((struct sockaddr_in *)s1)->sin_addr) * 8)
			return 1;
		break;
	case AF_INET6:
		src = &((struct sockaddr_in6 *)s1)->sin6_addr;
		dst = &((struct sockaddr_in6 *)s2)->sin6_addr;
		if (((struct sockaddr_in6 *)s1)->sin6_scope_id !=
		    ((struct sockaddr_in6 *)s2)->sin6_scope_id)
			return 1;
		if (bitlen > (int)sizeof(((struct sockaddr_in6 *)s1)->sin6_addr) * 8)
			return 1;
		break;
	default:
		return 1;
	}

	return bitcmp(src, dst, bitlen);
}

static int
allones(struct sockaddr_storage *ssp, int bitlen)
{
	u_int8_t *p;
	int bytelen, bitsleft, i;
	int zerolen;

	switch (ssp->ss_family) {
	case AF_INET:
		p = (u_int8_t *)&((struct sockaddr_in *)ssp)->sin_addr;
		zerolen = sizeof (((struct sockaddr_in *)ssp)->sin_addr);
		break;
	case AF_INET6:
		p = (u_int8_t *)&((struct sockaddr_in6 *)ssp)->sin6_addr;
		zerolen = sizeof (((struct sockaddr_in6 *)ssp)->sin6_addr);
		break;
	default:
		return -1;
	}

	memset(p, 0, zerolen);

	bytelen = bitlen / 8;
	bitsleft = bitlen % 8;

	if (bytelen > zerolen)
		return -1;

	for (i = 0; i < bytelen; i++)
		*p++ = 0xff;

	for (i = 0; i < bitsleft; i++)
		*p |= 1 << (7 - i);

	return 0;
}

static int
sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
{
	void *p1, *p2;
	int len;

	if (sa1->sa_family != sa2->sa_family)
		return 1;

	switch (sa1->sa_family) {
	case AF_INET:
		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
		len = 4;
		break;
	case AF_INET6:
		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
		len = 16;
		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
			return 1;
		break;
	default:
		return 1;
	}

	return memcmp(p1, p2, len);
}

/*
 * Scan for a host match in a directory tree.
 */
static int
chk_host(struct dirlist *dp, struct sockaddr *saddr, int *defsetp,
    int *hostsetp)
{
	struct hostlist *hp;
	struct grouplist *grp;
	struct addrinfo *ai;

	if (dp) {
		if (dp->dp_flag & DP_DEFSET)
			*defsetp = dp->dp_flag;
		hp = dp->dp_hosts;
		while (hp) {
			grp = hp->ht_grp;
			switch (grp->gr_type) {
			case GT_HOST:
				ai = grp->gr_ptr.gt_addrinfo;
				for (; ai; ai = ai->ai_next) {
					if (!sacmp(ai->ai_addr, saddr)) {
						*hostsetp =
						    (hp->ht_flag | DP_HOSTSET);
						return (1);
					}
				}
				break;
			case GT_NET:
				if (!netpartcmp(saddr,
				    (struct sockaddr *)
					&grp->gr_ptr.gt_net.nt_net,
				    grp->gr_ptr.gt_net.nt_len)) {
					*hostsetp = (hp->ht_flag | DP_HOSTSET);
					return (1);
				}
				break;
			};
			hp = hp->ht_next;
		}
	}
	return (0);
}

/*
 * Scan tree for a host that matches the address.
 */
static int
scan_tree(struct dirlist *dp, struct sockaddr *saddr)
{
	int defset, hostset;

	if (dp) {
		if (scan_tree(dp->dp_left, saddr))
			return (1);
		if (chk_host(dp, saddr, &defset, &hostset))
			return (1);
		if (scan_tree(dp->dp_right, saddr))
			return (1);
	}
	return (0);
}

/*
 * Traverse the dirlist tree and free it up.
 */
static void
free_dir(struct dirlist *dp)
{

	if (dp) {
		free_dir(dp->dp_left);
		free_dir(dp->dp_right);
		free_host(dp->dp_hosts);
		free(dp);
	}
}

/*
 * Parse the option string and update fields.
 * Option arguments may either be -<option>=<value> or
 * -<option> <value>
 */
static int
do_opt(const char *line, size_t lineno, char **cpp, char **endcpp,
    struct exportlist *ep, struct grouplist *grp, int *has_hostp,
    int *exflagsp, struct uucred *cr)
{
	char *cpoptarg, *cpoptend;
	char *cp, *cpopt, savedc, savedc2;
	char *endcp = NULL;	/* XXX: GCC */
	int allflag, usedarg;

	cpopt = *cpp;
	cpopt++;
	cp = *endcpp;
	savedc = *cp;
	*cp = '\0';
	while (cpopt && *cpopt) {
		allflag = 1;
		usedarg = -2;
		savedc2 = '\0';
		if ((cpoptend = strchr(cpopt, ',')) != NULL) {
			*cpoptend++ = '\0';
			if ((cpoptarg = strchr(cpopt, '=')) != NULL)
				*cpoptarg++ = '\0';
		} else {
			if ((cpoptarg = strchr(cpopt, '=')) != NULL)
				*cpoptarg++ = '\0';
			else {
				*cp = savedc;
				nextfield(&cp, &endcp);
				**endcpp = '\0';
				if (endcp > cp && *cp != '-') {
					cpoptarg = cp;
					savedc2 = *endcp;
					*endcp = '\0';
					usedarg = 0;
				}
			}
		}
		if (!strcmp(cpopt, "ro") || !strcmp(cpopt, "o")) {
			*exflagsp |= MNT_EXRDONLY;
		} else if (cpoptarg && (!strcmp(cpopt, "maproot") ||
		    !(allflag = strcmp(cpopt, "mapall")) ||
		    !strcmp(cpopt, "root") || !strcmp(cpopt, "r"))) {
			usedarg++;
			parsecred(cpoptarg, cr);
			if (allflag == 0) {
				*exflagsp |= MNT_EXPORTANON;
				opt_flags |= OP_MAPALL;
			} else
				opt_flags |= OP_MAPROOT;
		} else if (!strcmp(cpopt, "kerb") || !strcmp(cpopt, "k")) {
			*exflagsp |= MNT_EXKERB;
			opt_flags |= OP_KERB;
		} else if (cpoptarg && (!strcmp(cpopt, "mask") ||
		    !strcmp(cpopt, "m"))) {
			if (get_net(cpoptarg, &grp->gr_ptr.gt_net, 1)) {
				syslog(LOG_ERR,
				    "\"%s\", line %ld: Bad mask: %s",
				    line, (unsigned long)lineno, cpoptarg);
				return (1);
			}
			usedarg++;
			opt_flags |= OP_MASK;
		} else if (cpoptarg && (!strcmp(cpopt, "network") ||
		    !strcmp(cpopt, "n"))) {
			if (strchr(cpoptarg, '/') != NULL) {
				if (mountd_debug)
					fprintf(stderr, "setting OP_MASKLEN\n");
				opt_flags |= OP_MASKLEN;
			}
			if (grp->gr_type != GT_NULL) {
				syslog(LOG_ERR,
				    "\"%s\", line %ld: Network/host conflict",
				    line, (unsigned long)lineno);
				return (1);
			} else if (get_net(cpoptarg, &grp->gr_ptr.gt_net, 0)) {
				syslog(LOG_ERR,
				    "\"%s\", line %ld: Bad net: %s",
				    line, (unsigned long)lineno, cpoptarg);
				return (1);
			}
			grp->gr_type = GT_NET;
			*has_hostp = 1;
			usedarg++;
			opt_flags |= OP_NET;
		} else if (!strcmp(cpopt, "alldirs")) {
			opt_flags |= OP_ALLDIRS;
		} else if (!strcmp(cpopt, "noresvmnt")) {
			opt_flags |= OP_NORESMNT;
		} else if (!strcmp(cpopt, "noresvport")) {
			opt_flags |= OP_NORESPORT;
			*exflagsp |= MNT_EXNORESPORT;
		} else if (!strcmp(cpopt, "public")) {
			*exflagsp |= (MNT_EXNORESPORT | MNT_EXPUBLIC);
			opt_flags |= OP_NORESPORT;
		} else if (!strcmp(cpopt, "webnfs")) {
			*exflagsp |= (MNT_EXNORESPORT | MNT_EXPUBLIC |
			    MNT_EXRDONLY | MNT_EXPORTANON);
			opt_flags |= (OP_MAPALL | OP_NORESPORT);
		} else if (cpoptarg && !strcmp(cpopt, "index")) {
			ep->ex_indexfile = strdup(cpoptarg);
		} else {
			syslog(LOG_ERR,
			    "\"%s\", line %ld: Bad opt %s",
			    line, (unsigned long)lineno, cpopt);
			return (1);
		}
		if (usedarg >= 0) {
			*endcp = savedc2;
			**endcpp = savedc;
			if (usedarg > 0) {
				*cpp = cp;
				*endcpp = endcp;
			}
			return (0);
		}
		cpopt = cpoptend;
	}
	**endcpp = savedc;
	return (0);
}

/*
 * Translate a character string to the corresponding list of network
 * addresses for a hostname.
 */
static int
get_host(const char *line, size_t lineno, const char *cp,
    struct grouplist *grp)
{
	struct addrinfo *ai, hints;
	int ecode;
	char host[NI_MAXHOST];

	if (grp->gr_type != GT_NULL) {
		syslog(LOG_ERR,
		    "\"%s\", line %ld: Bad netgroup type for ip host %s",
		    line, (unsigned long)lineno, cp);
		return (1);
	}
	memset(&hints, 0, sizeof hints);
	hints.ai_flags = AI_CANONNAME;
	hints.ai_protocol = IPPROTO_UDP;
	ecode = getaddrinfo(cp, NULL, &hints, &ai);
	if (ecode != 0) {
		syslog(LOG_ERR, "\"%s\", line %ld: can't get address info for "
				"host %s",
		    line, (long)lineno, cp);
		return 1;
	}
	grp->gr_type = GT_HOST;
	grp->gr_ptr.gt_addrinfo = ai;
	while (ai != NULL) {
		if (ai->ai_canonname == NULL) {
			if (getnameinfo(ai->ai_addr, ai->ai_addrlen, host,
			    sizeof host, NULL, 0, ninumeric) != 0)
				strlcpy(host, "?", sizeof(host));
			ai->ai_canonname = estrdup(host);
			ai->ai_flags |= AI_CANONNAME;
		} else
			ai->ai_flags &= ~AI_CANONNAME;
		if (mountd_debug)
			(void)fprintf(stderr, "got host %s\n", ai->ai_canonname);
		ai = ai->ai_next;
	}
	return (0);
}

/*
 * Free up an exports list component
 */
static void
free_exp(struct exportlist *ep)
{

	if (ep->ex_defdir) {
		free_host(ep->ex_defdir->dp_hosts);
		free(ep->ex_defdir);
	}
	if (ep->ex_fsdir)
		free(ep->ex_fsdir);
	if (ep->ex_indexfile)
		free(ep->ex_indexfile);
	free_dir(ep->ex_dirl);
	free(ep);
}

/*
 * Free hosts.
 */
static void
free_host(struct hostlist *hp)
{
	struct hostlist *hp2;

	while (hp) {
		hp2 = hp;
		hp = hp->ht_next;
		free(hp2);
	}
}

static struct hostlist *
get_ht(void)
{
	struct hostlist *hp;

	hp = emalloc(sizeof(struct hostlist));
	hp->ht_next = NULL;
	hp->ht_flag = 0;
	return (hp);
}

static int
add_export_arg(const char *path, int exflags, struct uucred *anoncrp,
    struct sockaddr *addrp, int addrlen, struct sockaddr *maskp, int masklen,
    char *indexfile)
{
	const struct mountd_exports_list mel_key = { .mel_path = path };
	struct mountd_exports_list *mel;
	struct export_args *export;

	if (addrp != NULL && addrp->sa_family == AF_INET6 && have_v6 == 0)
		return 0;

	mel = bsearch(&mel_key, mel_tab, mel_tab_len, sizeof(mel_tab[0]),
	    mel_compare);
	if (mel == NULL) {
		syslog(LOG_ERR, "Can't change attributes for %s: not found",
		    path);
		return 1;
	}
	ereallocarr(&mel->mel_exports, mel->mel_nexports + 1,
	    sizeof(*mel->mel_exports));
	export = &mel->mel_exports[mel->mel_nexports++];
	memset(export, 0, sizeof(*export));

	export->ex_flags = exflags;
	export->ex_anon = *anoncrp;
	if (indexfile)
		export->ex_indexfile = estrdup(indexfile);
	if (addrlen > 0) {
		export->ex_addr = emalloc(addrlen);
		export->ex_addrlen = addrlen;
		memcpy(export->ex_addr, addrp, addrlen);
	}
	if (masklen > 0) {
		export->ex_mask = emalloc(masklen);
		export->ex_masklen = masklen;
		memcpy(export->ex_mask, maskp, masklen);
	}

	return 0;
}

/*
 * Do the nfssvc syscall to push the export info into the kernel.
 */
static int
do_nfssvc(const char *line, size_t lineno, struct exportlist *ep,
    struct grouplist *grp, int exflags, struct uucred *anoncrp,
    char *dirp, int dirplen, struct statvfs *fsb)
{
	struct sockaddr *addrp;
	struct sockaddr_storage ss;
	struct addrinfo *ai;
	int addrlen;

	if (grp->gr_type == GT_HOST) {
		for (ai = grp->gr_ptr.gt_addrinfo; ai; ai = ai->ai_next) {
			addrp = ai->ai_addr;
			addrlen = ai->ai_addrlen;
			if (add_export_arg(fsb->f_mntonname, exflags, anoncrp,
			    addrp, addrlen, NULL, 0, ep->ex_indexfile) != 0)
				return 1;
		}
	} else if (grp->gr_type == GT_NET) {
		addrp = (struct sockaddr *)&grp->gr_ptr.gt_net.nt_net;
		addrlen = addrp->sa_len;
		memset(&ss, 0, sizeof ss);
		ss.ss_family = addrp->sa_family;
		ss.ss_len = addrp->sa_len;
		if (allones(&ss, grp->gr_ptr.gt_net.nt_len) != 0) {
			syslog(LOG_ERR, "\"%s\", line %ld: Bad network flag",
			    line, (unsigned long)lineno);
			return 1;
		}
		if (add_export_arg(fsb->f_mntonname, exflags, anoncrp,
		    addrp, addrlen, (struct sockaddr *)&ss, ss.ss_len,
		    ep->ex_indexfile) != 0)
			return 1;
	} else {
		syslog(LOG_ERR, "\"%s\", line %ld: Bad netgroup type",
		    line, (unsigned long)lineno);
		return 1;
	}

	return 0;
}

/*
 * Parse out the next white space separated field
 */
static void
nextfield(char **cp, char **endcp)
{
	char *p;

	p = *cp;
	while (*p == ' ' || *p == '\t')
		p++;
	if (*p == '\n' || *p == '\0')
		*cp = *endcp = p;
	else {
		*cp = p++;
		while (*p != ' ' && *p != '\t' && *p != '\n' && *p != '\0')
			p++;
		*endcp = p;
	}
}

/*
 * Parse a description of a credential.
 */
static void
parsecred(char *namelist, struct uucred *cr)
{
	char *username;
	int cnt;
	char *names;
	struct passwd *pw;
	struct group *gr;
	int ngroups;
	gid_t usergroups[NGROUPS + 1];

	/*
	 * Set up the unprivileged user.
	 */
	*cr = def_anon;
	/*
	 * Get the user's password table entry.
	 */
	names = strsep(&namelist, " \t\n");
	username = strsep(&names, ":");
	if (isdigit((unsigned char)*username) || *username == '-')
		pw = getpwuid(atoi(username));
	else
		pw = getpwnam(username);
	/*
	 * Credentials specified as those of a user.
	 */
	if (names == NULL) {
		if (pw == NULL) {
			syslog(LOG_ERR, "Unknown user: %s", username);
			return;
		}
		cr->cr_uid = pw->pw_uid;
		ngroups = NGROUPS + 1;
		if (getgrouplist(pw->pw_name, pw->pw_gid, usergroups, &ngroups))
			syslog(LOG_ERR, "Too many groups for user %s", username);
		/*
		 * Convert from int's to gid_t's and compress out duplicate
		 */
		cr->cr_ngroups = ngroups - 1;
		cr->cr_gid = usergroups[0];
		for (cnt = 1; cnt < ngroups; cnt++)
			cr->cr_groups[cnt - 1] = usergroups[cnt];
		return;
	}
	/*
	 * Explicit credential specified as a colon separated list:
	 *	uid:gid:gid:...
	 */
	if (pw != NULL)
		cr->cr_uid = pw->pw_uid;
	else if (isdigit((unsigned char)*username) || *username == '-')
		cr->cr_uid = atoi(username);
	else {
		syslog(LOG_ERR, "Unknown user: %s", username);
		return;
	}
	cr->cr_ngroups = 0;
	while (names != NULL && *names != '\0' && cr->cr_ngroups < NGROUPS) {
		username = strsep(&names, ":");
		if (isdigit((unsigned char)*username) || *username == '-') {
			cr->cr_groups[cr->cr_ngroups++] = atoi(username);
		} else {
			if ((gr = getgrnam(username)) == NULL) {
				syslog(LOG_ERR, "Unknown group: %s", username);
				continue;
			}
			cr->cr_groups[cr->cr_ngroups++] = gr->gr_gid;
		}
	}
	if (names != NULL && *names != '\0' && cr->cr_ngroups == NGROUPS)
		syslog(LOG_ERR, "Too many groups");
}

#define	STRSIZ	(RPCMNT_NAMELEN+RPCMNT_PATHLEN+50)
/*
 * Routines that maintain the remote mounttab
 */
static void
get_mountlist(void)
{
	struct mountlist *mlp, **mlpp;
	char *host, *dirp, *cp;
	char str[STRSIZ];
	FILE *mlfile;

	if ((mlfile = fopen(_PATH_RMOUNTLIST, "r")) == NULL) {
		syslog(LOG_ERR, "Can't open %s: %m", _PATH_RMOUNTLIST);
		return;
	}
	mlpp = &mlhead;
	while (fgets(str, STRSIZ, mlfile) != NULL) {
		cp = str;
		host = strsep(&cp, " \t\n");
		dirp = strsep(&cp, " \t\n");
		if (host == NULL || dirp == NULL)
			continue;
		mlp = emalloc(sizeof(*mlp));
		(void)strncpy(mlp->ml_host, host, RPCMNT_NAMELEN);
		mlp->ml_host[RPCMNT_NAMELEN] = '\0';
		(void)strncpy(mlp->ml_dirp, dirp, RPCMNT_PATHLEN);
		mlp->ml_dirp[RPCMNT_PATHLEN] = '\0';
		mlp->ml_next = NULL;
		*mlpp = mlp;
		mlpp = &mlp->ml_next;
	}
	(void)fclose(mlfile);
}

static int
del_mlist(char *hostp, char *dirp, struct sockaddr *saddr)
{
	struct mountlist *mlp, **mlpp;
	struct mountlist *mlp2;
	u_short sport;
	FILE *mlfile;
	int fnd = 0, ret = 0;
	char host[NI_MAXHOST];

	switch (saddr->sa_family) {
	case AF_INET6:
		sport = ntohs(((struct sockaddr_in6 *)saddr)->sin6_port);
		break;
	case AF_INET:
		sport = ntohs(((struct sockaddr_in *)saddr)->sin_port);
		break;
	default:
		return -1;
	}
	mlpp = &mlhead;
	mlp = mlhead;
	while (mlp) {
		if (!strcmp(mlp->ml_host, hostp) &&
		    (!dirp || !strcmp(mlp->ml_dirp, dirp))) {
			if (!(mlp->ml_flag & DP_NORESMNT) &&
			    sport >= IPPORT_RESERVED) {
				if (getnameinfo(saddr, saddr->sa_len, host,
				    sizeof host, NULL, 0, ninumeric) != 0)
					strlcpy(host, "?", sizeof(host));
				syslog(LOG_NOTICE,
				"Umount request for %s:%s from %s refused\n",
				    mlp->ml_host, mlp->ml_dirp, host);
				ret = -1;
				goto cont;
			}
			fnd = 1;
			mlp2 = mlp;
			*mlpp = mlp = mlp->ml_next;
			free(mlp2);
		} else {
cont:
			mlpp = &mlp->ml_next;
			mlp = mlp->ml_next;
		}
	}
	if (fnd) {
		if ((mlfile = fopen(_PATH_RMOUNTLIST, "w")) == NULL) {
			syslog(LOG_ERR, "Can't update %s: %m",
			    _PATH_RMOUNTLIST);
			return ret;
		}
		mlp = mlhead;
		while (mlp) {
			(void)fprintf(mlfile, "%s %s\n", mlp->ml_host,
		            mlp->ml_dirp);
			mlp = mlp->ml_next;
		}
		(void)fclose(mlfile);
	}
	return ret;
}

static void
add_mlist(char *hostp, char *dirp, int flags)
{
	struct mountlist *mlp, **mlpp;
	FILE *mlfile;

	mlpp = &mlhead;
	mlp = mlhead;
	while (mlp) {
		if (!strcmp(mlp->ml_host, hostp) && !strcmp(mlp->ml_dirp, dirp))
			return;
		mlpp = &mlp->ml_next;
		mlp = mlp->ml_next;
	}
	mlp = emalloc(sizeof(*mlp));
	strncpy(mlp->ml_host, hostp, RPCMNT_NAMELEN);
	mlp->ml_host[RPCMNT_NAMELEN] = '\0';
	strncpy(mlp->ml_dirp, dirp, RPCMNT_PATHLEN);
	mlp->ml_dirp[RPCMNT_PATHLEN] = '\0';
	mlp->ml_flag = flags;
	mlp->ml_next = NULL;
	*mlpp = mlp;
	if ((mlfile = fopen(_PATH_RMOUNTLIST, "a")) == NULL) {
		syslog(LOG_ERR, "Can't update %s: %m", _PATH_RMOUNTLIST);
		return;
	}
	(void)fprintf(mlfile, "%s %s\n", mlp->ml_host, mlp->ml_dirp);
	(void)fclose(mlfile);
}

#ifndef MOUNTD_RUMP
static int
umntall_each(caddr_t resultsp, struct sockaddr_in *raddr)
{
	return (1);
}
#endif

/*
 * This function is called via. SIGTERM when the system is going down.
 * It sends a broadcast RPCMNT_UMNTALL.
 */
/* ARGSUSED */
static void
send_umntall(int n)
{
#ifndef MOUNTD_RUMP
	(void)clnt_broadcast(RPCPROG_MNT, RPCMNT_VER1, RPCMNT_UMNTALL,
	    (xdrproc_t)xdr_void, NULL, (xdrproc_t)xdr_void, NULL,
	    (resultproc_t)umntall_each);
#endif
	exit(0);
}


/*
 * Free up a group list.
 */
static void
free_grp(struct grouplist *grp)
{

	if (grp->gr_type == GT_HOST) {
		if (grp->gr_ptr.gt_addrinfo != NULL)
			freeaddrinfo(grp->gr_ptr.gt_addrinfo);
	} else if (grp->gr_type == GT_NET) {
		if (grp->gr_ptr.gt_net.nt_name)
			free(grp->gr_ptr.gt_net.nt_name);
	}
	free(grp);
}

#if 0
static void
SYSLOG(int pri, const char *fmt,...)
{
	va_list ap;

	va_start(ap, fmt);

	if (mountd_debug)
		vfprintf(stderr, fmt, ap);
	else
		vsyslog(pri, fmt, ap);

	va_end(ap);
}
#endif

/*
 * Check options for consistency.
 */
static int
check_options(const char *line, size_t lineno, struct dirlist *dp)
{

	if (dp == NULL) {
		syslog(LOG_ERR,
		    "\"%s\", line %ld: missing directory list",
		    line, (unsigned long)lineno);
		return (1);
	}
	if ((opt_flags & (OP_MAPROOT|OP_MAPALL)) == (OP_MAPROOT|OP_MAPALL) ||
	    (opt_flags & (OP_MAPROOT|OP_KERB)) == (OP_MAPROOT|OP_KERB) ||
	    (opt_flags & (OP_MAPALL|OP_KERB)) == (OP_MAPALL|OP_KERB)) {
		syslog(LOG_ERR,
		    "\"%s\", line %ld: -mapall, -maproot and -kerb mutually exclusive",
		    line, (unsigned long)lineno);
		return (1);
	}
	if ((opt_flags & OP_MASK) && (opt_flags & OP_NET) == 0) {
		syslog(LOG_ERR, "\"%s\", line %ld: -mask requires -net",
		    line, (unsigned long)lineno);
		return (1);
	}
	if ((opt_flags & OP_MASK) && (opt_flags & OP_MASKLEN) != 0) {
		syslog(LOG_ERR, "\"%s\", line %ld: /pref and -mask mutually"
		    " exclusive",
		    line, (unsigned long)lineno);
		return (1);
	}
	if ((opt_flags & OP_ALLDIRS) && dp->dp_left) {
		syslog(LOG_ERR,
		    "\"%s\", line %ld: -alldirs has multiple directories",
		    line, (unsigned long)lineno);
		return (1);
	}
	return (0);
}

/*
 * Check an absolute directory path for any symbolic links. Return true
 * if no symbolic links are found.
 */
static int
check_dirpath(const char *line, size_t lineno, char *dirp)
{
	char *cp;
	struct stat sb;
	const char *file = "";

	for (cp = dirp + 1; *cp; cp++) {
		if (*cp == '/') {
			*cp = '\0';
			if (lstat(dirp, &sb) == -1)
				goto bad;
			if (!S_ISDIR(sb.st_mode))
				goto bad1;
			*cp = '/';
		}
	}

	cp = NULL;
	if (lstat(dirp, &sb) == -1)
		goto bad;

	if (!S_ISDIR(sb.st_mode) && !S_ISREG(sb.st_mode)) {
		file = " file or a";
		goto bad1;
	}

	return 1;

bad:
	syslog(LOG_ERR,
	    "\"%s\", line %ld: lstat for `%s' failed: %m",
	    line, (unsigned long)lineno, dirp);
	if (cp)
		*cp = '/';
	return 0;

bad1:
	syslog(LOG_ERR,
	    "\"%s\", line %ld: `%s' is not a%s directory",
	    line, (unsigned long)lineno, dirp, file);
	if (cp)
		*cp = '/';
	return 0;
}

static void
bind_resv_port(int sock, sa_family_t family, in_port_t port)
{
	struct sockaddr *sa;
	struct sockaddr_in sasin;
	struct sockaddr_in6 sasin6;

	switch (family) {
	case AF_INET:
		(void)memset(&sasin, 0, sizeof(sasin));
		sasin.sin_len = sizeof(sasin);
		sasin.sin_family = family;
		sasin.sin_port = htons(port);
		sa = (struct sockaddr *)(void *)&sasin;
		break;
	case AF_INET6:
		(void)memset(&sasin6, 0, sizeof(sasin6));
		sasin6.sin6_len = sizeof(sasin6);
		sasin6.sin6_family = family;
		sasin6.sin6_port = htons(port);
		sa = (struct sockaddr *)(void *)&sasin6;
		break;
	default:
		syslog(LOG_ERR, "Unsupported address family %d", family);
		return;
	}
	if (bindresvport_sa(sock, sa) == -1)
		syslog(LOG_ERR, "Cannot bind to reserved port %d (%m)", port);
}

/* ARGSUSED */
static void
no_nfs(int sig)
{
	syslog(LOG_ERR, "kernel NFS support not present; exiting");
	exit(1);
}