mountd.c

早期freebsd实现

/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif not lint

#ifndef lint
static char sccsid[] = "@(#)mountd.c	8.8 (Berkeley) 2/20/94";
#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 <sys/syslog.h>
#include <sys/ucred.h>

#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#ifdef ISO
#include <netiso/iso.h>
#endif
#include <nfs/rpcv2.h>
#include <nfs/nfsv2.h>

#include <arpa/inet.h>

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

#ifdef DEBUG
#include <stdarg.h>
#endif

/*
 * 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];
};

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

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

struct netmsk {
	u_long	nt_net;
	u_long	nt_mask;
	char *nt_name;
};

union grouptypes {
	struct hostent *gt_hostent;
	struct netmsk	gt_net;
#ifdef ISO
	struct sockaddr_iso *gt_isoaddr;
#endif
};

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
#define	GT_ISO		0x4

struct hostlist {
	struct grouplist *ht_grp;
	struct hostlist	 *ht_next;
};

/* Global defs */
char	*add_expdir __P((struct dirlist **, char *, int));
void	add_dlist __P((struct dirlist **, struct dirlist *,
				struct grouplist *));
void	add_mlist __P((char *, char *));
int	check_dirpath __P((char *));
int	check_options __P((struct dirlist *));
int	chk_host __P((struct dirlist *, u_long, int *));
void	del_mlist __P((char *, char *));
struct dirlist *dirp_search __P((struct dirlist *, char *));
int	do_mount __P((struct exportlist *, struct grouplist *, int,
				struct ucred *, char *, int, struct statfs *));
int	do_opt __P((char **, char **, struct exportlist *, struct grouplist *,
				int *, int *, struct ucred *));
struct	exportlist *ex_search __P((fsid_t *));
struct	exportlist *get_exp __P((void));
void	free_dir __P((struct dirlist *));
void	free_exp __P((struct exportlist *));
void	free_grp __P((struct grouplist *));
void	free_host __P((struct hostlist *));
void	get_exportlist __P((void));
int	get_host __P((char *, struct grouplist *));
struct hostlist *get_ht __P((void));
int	get_line __P((void));
void	get_mountlist __P((void));
int	get_net __P((char *, struct netmsk *, int));
void	getexp_err __P((struct exportlist *, struct grouplist *));
struct grouplist *get_grp __P((void));
void	hang_dirp __P((struct dirlist *, struct grouplist *,
				struct exportlist *, int));
void	mntsrv __P((struct svc_req *, SVCXPRT *));
void	nextfield __P((char **, char **));
void	out_of_mem __P((void));
void	parsecred __P((char *, struct ucred *));
int	put_exlist __P((struct dirlist *, XDR *, struct dirlist *, int *));
int	scan_tree __P((struct dirlist *, u_long));
void	send_umntall __P((void));
int	umntall_each __P((caddr_t, struct sockaddr_in *));
int	xdr_dir __P((XDR *, char *));
int	xdr_explist __P((XDR *, caddr_t));
int	xdr_fhs __P((XDR *, nfsv2fh_t *));
int	xdr_mlist __P((XDR *, caddr_t));

/* C library */
int	getnetgrent();
void	endnetgrent();
void	setnetgrent();

#ifdef ISO
struct iso_addr *iso_addr();
#endif

struct exportlist *exphead;
struct mountlist *mlhead;
struct grouplist *grphead;
char exname[MAXPATHLEN];
struct ucred def_anon = {
	1,
	(uid_t) -2,
	1,
	{ (gid_t) -2 }
};
int root_only = 1;
int opt_flags;
/* Bits for above */
#define	OP_MAPROOT	0x01
#define	OP_MAPALL	0x02
#define	OP_KERB		0x04
#define	OP_MASK		0x08
#define	OP_NET		0x10
#define	OP_ISO		0x20
#define	OP_ALLDIRS	0x40

#ifdef DEBUG
int debug = 1;
void	SYSLOG __P((int, const char *, ...));
#define syslog SYSLOG
#else
int debug = 0;
#endif

/*
 * 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
 * and "-n" to allow nonroot mount.
 */
int
main(argc, argv)
	int argc;
	char **argv;
{
	SVCXPRT *transp;
	int c;

	while ((c = getopt(argc, argv, "n")) != EOF)
		switch (c) {
		case 'n':
			root_only = 0;
			break;
		default:
			fprintf(stderr, "Usage: mountd [-n] [export_file]\n");
			exit(1);
		};
	argc -= optind;
	argv += optind;
	grphead = (struct grouplist *)NULL;
	exphead = (struct exportlist *)NULL;
	mlhead = (struct mountlist *)NULL;
	if (argc == 1) {
		strncpy(exname, *argv, MAXPATHLEN-1);
		exname[MAXPATHLEN-1] = '\0';
	} else
		strcpy(exname, _PATH_EXPORTS);
	openlog("mountd", LOG_PID, LOG_DAEMON);
	if (debug)
		fprintf(stderr,"Getting export list.\n");
	get_exportlist();
	if (debug)
		fprintf(stderr,"Getting mount list.\n");
	get_mountlist();
	if (debug)
		fprintf(stderr,"Here we go.\n");
	if (debug == 0) {
		daemon(0, 0);
		signal(SIGINT, SIG_IGN);
		signal(SIGQUIT, SIG_IGN);
	}
	signal(SIGHUP, (void (*) __P((int))) get_exportlist);
	signal(SIGTERM, (void (*) __P((int))) send_umntall);
	{ FILE *pidfile = fopen(_PATH_MOUNTDPID, "w");
	  if (pidfile != NULL) {
		fprintf(pidfile, "%d\n", getpid());
		fclose(pidfile);
	  }
	}
	if ((transp = svcudp_create(RPC_ANYSOCK)) == NULL) {
		syslog(LOG_ERR, "Can't create socket");
		exit(1);
	}
	pmap_unset(RPCPROG_MNT, RPCMNT_VER1);
	if (!svc_register(transp, RPCPROG_MNT, RPCMNT_VER1, mntsrv,
	    IPPROTO_UDP)) {
		syslog(LOG_ERR, "Can't register mount");
		exit(1);
	}
	svc_run();
	syslog(LOG_ERR, "Mountd died");
	exit(1);
}

/*
 * The mount rpc service
 */
void
mntsrv(rqstp, transp)
	struct svc_req *rqstp;
	SVCXPRT *transp;
{
	struct exportlist *ep;
	struct dirlist *dp;
	nfsv2fh_t nfh;
	struct authunix_parms *ucr;
	struct stat stb;
	struct statfs fsb;
	struct hostent *hp;
	u_long saddr;
	char rpcpath[RPCMNT_PATHLEN+1], dirpath[MAXPATHLEN];
	int bad = ENOENT, omask, defset;
	uid_t uid = -2;

	/* Get authorization */
	switch (rqstp->rq_cred.oa_flavor) {
	case AUTH_UNIX:
		ucr = (struct authunix_parms *)rqstp->rq_clntcred;
		uid = ucr->aup_uid;
		break;
	case AUTH_NULL:
	default:
		break;
	}

	saddr = transp->xp_raddr.sin_addr.s_addr;
	hp = (struct hostent *)NULL;
	switch (rqstp->rq_proc) {
	case NULLPROC:
		if (!svc_sendreply(transp, xdr_void, (caddr_t)NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case RPCMNT_MOUNT:
		if ((uid != 0 && root_only) || uid == -2) {
			svcerr_weakauth(transp);
			return;
		}
		if (!svc_getargs(transp, xdr_dir, rpcpath)) {
			svcerr_decode(transp);
			return;
		}

		/*
		 * Get the real pathname and make sure it is a directory
		 * that exists.
		 */
		if (realpath(rpcpath, dirpath) == 0 ||
		    stat(dirpath, &stb) < 0 ||
		    (stb.st_mode & S_IFMT) != S_IFDIR ||
		    statfs(dirpath, &fsb) < 0) {
			chdir("/");	/* Just in case realpath doesn't */
			if (debug)
				fprintf(stderr, "stat failed on %s\n", dirpath);
			if (!svc_sendreply(transp, xdr_long, (caddr_t)&bad))
				syslog(LOG_ERR, "Can't send reply");
			return;
		}

		/* Check in the exports list */
		omask = sigblock(sigmask(SIGHUP));
		ep = ex_search(&fsb.f_fsid);
		defset = 0;
		if (ep && (chk_host(ep->ex_defdir, saddr, &defset) ||
		    ((dp = dirp_search(ep->ex_dirl, dirpath)) &&
		     chk_host(dp, saddr, &defset)) ||
		     (defset && scan_tree(ep->ex_defdir, saddr) == 0 &&
		      scan_tree(ep->ex_dirl, saddr) == 0))) {
			/* Get the file handle */
			bzero((caddr_t)&nfh, sizeof(nfh));
			if (getfh(dirpath, (fhandle_t *)&nfh) < 0) {
				bad = errno;
				syslog(LOG_ERR, "Can't get fh for %s", dirpath);
				if (!svc_sendreply(transp, xdr_long,
				    (caddr_t)&bad))
					syslog(LOG_ERR, "Can't send reply");
				sigsetmask(omask);
				return;
			}
			if (!svc_sendreply(transp, xdr_fhs, (caddr_t)&nfh))
				syslog(LOG_ERR, "Can't send reply");
			if (hp == NULL)
				hp = gethostbyaddr((caddr_t)&saddr,
				    sizeof(saddr), AF_INET);
			if (hp)
				add_mlist(hp->h_name, dirpath);
			else
				add_mlist(inet_ntoa(transp->xp_raddr.sin_addr),
					dirpath);
			if (debug)
				fprintf(stderr,"Mount successfull.\n");
		} else {
			bad = EACCES;
			if (!svc_sendreply(transp, xdr_long, (caddr_t)&bad))
				syslog(LOG_ERR, "Can't send reply");
		}
		sigsetmask(omask);
		return;
	case RPCMNT_DUMP:
		if (!svc_sendreply(transp, xdr_mlist, (caddr_t)NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	case RPCMNT_UMOUNT:
		if ((uid != 0 && root_only) || uid == -2) {
			svcerr_weakauth(transp);
			return;
		}
		if (!svc_getargs(transp, xdr_dir, dirpath)) {
			svcerr_decode(transp);
			return;
		}
		if (!svc_sendreply(transp, xdr_void, (caddr_t)NULL))
			syslog(LOG_ERR, "Can't send reply");
		hp = gethostbyaddr((caddr_t)&saddr, sizeof(saddr), AF_INET);
		if (hp)
			del_mlist(hp->h_name, dirpath);
		del_mlist(inet_ntoa(transp->xp_raddr.sin_addr), dirpath);
		return;
	case RPCMNT_UMNTALL:
		if ((uid != 0 && root_only) || uid == -2) {
			svcerr_weakauth(transp);
			return;
		}
		if (!svc_sendreply(transp, xdr_void, (caddr_t)NULL))
			syslog(LOG_ERR, "Can't send reply");
		hp = gethostbyaddr((caddr_t)&saddr, sizeof(saddr), AF_INET);
		if (hp)
			del_mlist(hp->h_name, (char *)NULL);
		del_mlist(inet_ntoa(transp->xp_raddr.sin_addr), (char *)NULL);
		return;
	case RPCMNT_EXPORT:
		if (!svc_sendreply(transp, xdr_explist, (caddr_t)NULL))
			syslog(LOG_ERR, "Can't send reply");
		return;
	default:
		svcerr_noproc(transp);
		return;
	}
}

/*
 * Xdr conversion for a dirpath string
 */
int
xdr_dir(xdrsp, dirp)
	XDR *xdrsp;
	char *dirp;
{
	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
}

/*
 * Xdr routine to generate fhstatus
 */
int
xdr_fhs(xdrsp, nfh)
	XDR *xdrsp;
	nfsv2fh_t *nfh;
{
	int ok = 0;

	if (!xdr_long(xdrsp, &ok))
		return (0);
	return (xdr_opaque(xdrsp, (caddr_t)nfh, NFSX_FH));
}

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

	mlp = mlhead;
	while (mlp) {
		if (!xdr_bool(xdrsp, &true))
			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, &false))
		return (0);
	return (1);
}

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

	omask = sigblock(sigmask(SIGHUP));
	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, (struct dirlist *)NULL,
			&putdef))
			goto errout;
		ep = ep->ex_next;
	}
	sigsetmask(omask);
	if (!xdr_bool(xdrsp, &false))
		return (0);
	return (1);
errout:
	sigsetmask(omask);
	return (0);
}

/*
 * Called from xdr_explist() to traverse the tree and export the
 * directory paths.
 */
int
put_exlist(dp, xdrsp, adp, putdefp)
	struct dirlist *dp;
	XDR *xdrsp;
	struct dirlist *adp;
	int *putdefp;
{
	struct grouplist *grp;
	struct hostlist *hp;
	int true = 1;
	int false = 0;
	int gotalldir = 0;
	char *strp;

	if (dp) {
		if (put_exlist(dp->dp_left, xdrsp, adp, putdefp))
			return (1);
		if (!xdr_bool(xdrsp, &true))
			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, &true))
						return (1);
					strp = grp->gr_ptr.gt_hostent->h_name;
					if (!xdr_string(xdrsp, &strp, 
					    RPCMNT_NAMELEN))
						return (1);
				} else if (grp->gr_type == GT_NET) {
					if (!xdr_bool(xdrsp, &true))
						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 == (struct hostlist *)NULL) {
					hp = adp->dp_hosts;
					gotalldir = 0;
				}
			}
		}
		if (!xdr_bool(xdrsp, &false))
			return (1);
		if (put_exlist(dp->dp_right, xdrsp, adp, putdefp))
			return (1);
	}
	return (0);
}

#define LINESIZ	10240
char line[LINESIZ];
FILE *exp_file;

/*
 * Get the export list
 */
void
get_exportlist()
{
	struct exportlist *ep, *ep2;
	struct grouplist *grp, *tgrp;
	struct exportlist **epp;
	struct dirlist *dirhead;
	struct statfs fsb, *fsp;
	struct hostent *hpe;
	struct ucred anon;
	char *cp, *endcp, *dirp, *hst, *usr, *dom, savedc;
	int len, has_host, exflags, got_nondir, dirplen, num, i, netgrp;

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

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

	/*
	 * And delete exports that are in the kernel for all local
	 * file systems.
	 * XXX: Should know how to handle all local exportable file systems
	 *      instead of just MOUNT_UFS.
	 */
	num = getmntinfo(&fsp, MNT_NOWAIT);
	for (i = 0; i < num; i++) {
		union {
			struct ufs_args ua;
			struct iso_args ia;
			struct mfs_args ma;
		} targs;

		switch (fsp->f_type) {
		case MOUNT_MFS:
		case MOUNT_UFS:
		case MOUNT_CD9660:
			targs.ua.fspec = NULL;
			targs.ua.export.ex_flags = MNT_DELEXPORT;
			if (mount(fsp->f_type, fsp->f_mntonname,
				  fsp->f_flags | MNT_UPDATE,
				  (caddr_t)&targs) < 0)
				syslog(LOG_ERR, "Can't delete exports for %s",
				       fsp->f_mntonname);
		}
		fsp++;
	}

	/*
	 * Read in the exports file and build the list, calling
	 * mount() as we go along to push the export rules into the kernel.
	 */
	if ((exp_file = fopen(exname, "r")) == NULL) {
		syslog(LOG_ERR, "Can't open %s", exname);
		exit(2);
	}
	dirhead = (struct dirlist *)NULL;
	while (get_line()) {
		if (debug)