freebsd-nq/sbin/umount/umount.c
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00

663 lines
16 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1980, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)umount.c 8.8 (Berkeley) 5/8/95";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netdb.h>
#include <rpc/rpc.h>
#include <rpcsvc/mount.h>
#include <nfs/nfssvc.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fstab.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "mounttab.h"
typedef enum { FIND, REMOVE, CHECKUNIQUE } dowhat;
static struct addrinfo *nfshost_ai = NULL;
static int fflag, vflag;
static char *nfshost;
struct statfs *checkmntlist(char *);
int checkvfsname (const char *, char **);
struct statfs *getmntentry(const char *fromname, const char *onname,
fsid_t *fsid, dowhat what);
char **makevfslist (const char *);
size_t mntinfo (struct statfs **);
int namematch (struct addrinfo *);
int parsehexfsid(const char *hex, fsid_t *fsid);
int sacmp (void *, void *);
int umountall (char **);
int checkname (char *, char **);
int umountfs(struct statfs *sfs);
void usage (void);
int xdr_dir (XDR *, char *);
int
main(int argc, char *argv[])
{
int all, errs, ch, mntsize, error, nfsforce, ret;
char **typelist = NULL;
struct statfs *mntbuf, *sfs;
struct addrinfo hints;
nfsforce = all = errs = 0;
while ((ch = getopt(argc, argv, "AaF:fh:Nnt:v")) != -1)
switch (ch) {
case 'A':
all = 2;
break;
case 'a':
all = 1;
break;
case 'F':
setfstab(optarg);
break;
case 'f':
fflag |= MNT_FORCE;
break;
case 'h': /* -h implies -A. */
all = 2;
nfshost = optarg;
break;
case 'N':
nfsforce = 1;
break;
case 'n':
fflag |= MNT_NONBUSY;
break;
case 't':
if (typelist != NULL)
err(1, "only one -t option may be specified");
typelist = makevfslist(optarg);
break;
case 'v':
vflag = 1;
break;
default:
usage();
/* NOTREACHED */
}
argc -= optind;
argv += optind;
if ((fflag & MNT_FORCE) != 0 && (fflag & MNT_NONBUSY) != 0)
err(1, "-f and -n are mutually exclusive");
/* Start disks transferring immediately. */
if ((fflag & (MNT_FORCE | MNT_NONBUSY)) == 0 && nfsforce == 0)
sync();
if ((argc == 0 && !all) || (argc != 0 && all))
usage();
if (nfsforce != 0 && (argc == 0 || nfshost != NULL || typelist != NULL))
usage();
/* -h implies "-t nfs" if no -t flag. */
if ((nfshost != NULL) && (typelist == NULL))
typelist = makevfslist("nfs");
if (nfshost != NULL) {
memset(&hints, 0, sizeof hints);
error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
if (error)
errx(1, "%s: %s", nfshost, gai_strerror(error));
}
switch (all) {
case 2:
if ((mntsize = mntinfo(&mntbuf)) <= 0)
break;
/*
* We unmount the nfs-mounts in the reverse order
* that they were mounted.
*/
for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
sfs = &mntbuf[mntsize];
if (checkvfsname(sfs->f_fstypename, typelist))
continue;
if (strcmp(sfs->f_mntonname, "/dev") == 0)
continue;
if (umountfs(sfs) != 0)
errs = 1;
}
free(mntbuf);
break;
case 1:
if (setfsent() == 0)
err(1, "%s", getfstab());
errs = umountall(typelist);
break;
case 0:
for (errs = 0; *argv != NULL; ++argv)
if (nfsforce != 0) {
/*
* First do the nfssvc() syscall to shut down
* the mount point and then do the forced
* dismount.
*/
ret = nfssvc(NFSSVC_FORCEDISM, *argv);
if (ret >= 0)
ret = unmount(*argv, MNT_FORCE);
if (ret < 0) {
warn("%s", *argv);
errs = 1;
}
} else if (checkname(*argv, typelist) != 0)
errs = 1;
break;
}
exit(errs);
}
int
umountall(char **typelist)
{
struct xvfsconf vfc;
struct fstab *fs;
int rval;
char *cp;
static int firstcall = 1;
if ((fs = getfsent()) != NULL)
firstcall = 0;
else if (firstcall)
errx(1, "fstab reading failure");
else
return (0);
do {
/* Ignore the root. */
if (strcmp(fs->fs_file, "/") == 0)
continue;
/*
* !!!
* Historic practice: ignore unknown FSTAB_* fields.
*/
if (strcmp(fs->fs_type, FSTAB_RW) &&
strcmp(fs->fs_type, FSTAB_RO) &&
strcmp(fs->fs_type, FSTAB_RQ))
continue;
/* Ignore unknown file system types. */
if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
continue;
if (checkvfsname(fs->fs_vfstype, typelist))
continue;
/*
* We want to unmount the file systems in the reverse order
* that they were mounted. So, we save off the file name
* in some allocated memory, and then call recursively.
*/
if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
err(1, "malloc failed");
(void)strcpy(cp, fs->fs_file);
rval = umountall(typelist);
rval = checkname(cp, typelist) || rval;
free(cp);
return (rval);
} while ((fs = getfsent()) != NULL);
return (0);
}
/*
* Do magic checks on mountpoint/device/fsid, and then call unmount(2).
*/
int
checkname(char *mntname, char **typelist)
{
char buf[MAXPATHLEN];
struct statfs sfsbuf;
struct stat sb;
struct statfs *sfs;
char *delimp;
dev_t dev;
int len;
/*
* 1. Check if the name exists in the mounttable.
*/
sfs = checkmntlist(mntname);
/*
* 2. Remove trailing slashes if there are any. After that
* we look up the name in the mounttable again.
*/
if (sfs == NULL) {
len = strlen(mntname);
while (len > 1 && mntname[len - 1] == '/')
mntname[--len] = '\0';
sfs = checkmntlist(mntname);
}
/*
* 3. Check if the deprecated NFS syntax with an '@' has been used
* and translate it to the ':' syntax. Look up the name in the
* mount table again.
*/
if (sfs == NULL && (delimp = strrchr(mntname, '@')) != NULL) {
snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1,
(int)(delimp - mntname), mntname);
len = strlen(buf);
while (len > 1 && buf[len - 1] == '/')
buf[--len] = '\0';
sfs = checkmntlist(buf);
}
/*
* 4. Resort to a statfs(2) call. This is the last check so that
* hung NFS filesystems for example can be unmounted without
* potentially blocking forever in statfs() as long as the
* filesystem is specified unambiguously. This covers all the
* hard cases such as symlinks and mismatches between the
* mount list and reality.
* We also do this if an ambiguous mount point was specified.
*/
if (sfs == NULL || (getmntentry(NULL, mntname, NULL, FIND) != NULL &&
getmntentry(NULL, mntname, NULL, CHECKUNIQUE) == NULL)) {
if (statfs(mntname, &sfsbuf) != 0) {
warn("%s: statfs", mntname);
} else if (stat(mntname, &sb) != 0) {
warn("%s: stat", mntname);
} else if (S_ISDIR(sb.st_mode)) {
/* Check that `mntname' is the root directory. */
dev = sb.st_dev;
snprintf(buf, sizeof(buf), "%s/..", mntname);
if (stat(buf, &sb) != 0) {
warn("%s: stat", buf);
} else if (sb.st_dev == dev) {
warnx("%s: not a file system root directory",
mntname);
return (1);
} else
sfs = &sfsbuf;
}
}
if (sfs == NULL) {
warnx("%s: unknown file system", mntname);
return (1);
}
if (checkvfsname(sfs->f_fstypename, typelist))
return (1);
return (umountfs(sfs));
}
/*
* NFS stuff and unmount(2) call
*/
int
umountfs(struct statfs *sfs)
{
char fsidbuf[64];
enum clnt_stat clnt_stat;
struct timeval try;
struct addrinfo *ai, hints;
int do_rpc;
CLIENT *clp;
char *nfsdirname, *orignfsdirname;
char *hostp, *delimp;
char buf[1024];
struct nfscl_dumpmntopts dumpmntopts;
const char *proto_ptr = NULL;
ai = NULL;
do_rpc = 0;
hostp = NULL;
nfsdirname = delimp = orignfsdirname = NULL;
memset(&hints, 0, sizeof hints);
if (strcmp(sfs->f_fstypename, "nfs") == 0) {
if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
err(1, "strdup");
orignfsdirname = nfsdirname;
if (*nfsdirname == '[' &&
(delimp = strchr(nfsdirname + 1, ']')) != NULL &&
*(delimp + 1) == ':') {
hostp = nfsdirname + 1;
nfsdirname = delimp + 2;
} else if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
hostp = nfsdirname;
nfsdirname = delimp + 1;
}
if (hostp != NULL) {
*delimp = '\0';
getaddrinfo(hostp, NULL, &hints, &ai);
if (ai == NULL) {
warnx("can't get net id for host");
}
}
/*
* Check if we have to start the rpc-call later.
* If there are still identical nfs-names mounted,
* we skip the rpc-call. Obviously this has to
* happen before unmount(2), but it should happen
* after the previous namecheck.
* A non-NULL return means that this is the last
* mount from mntfromname that is still mounted.
*/
if (getmntentry(sfs->f_mntfromname, NULL, NULL,
CHECKUNIQUE) != NULL) {
do_rpc = 1;
proto_ptr = "udp";
/*
* Try and find out whether this NFS mount is NFSv4 and
* what protocol is being used. If this fails, the
* default is NFSv2,3 and use UDP for the Unmount RPC.
*/
dumpmntopts.ndmnt_fname = sfs->f_mntonname;
dumpmntopts.ndmnt_buf = buf;
dumpmntopts.ndmnt_blen = sizeof(buf);
if (nfssvc(NFSSVC_DUMPMNTOPTS, &dumpmntopts) >= 0) {
if (strstr(buf, "nfsv4,") != NULL)
do_rpc = 0;
else if (strstr(buf, ",tcp,") != NULL)
proto_ptr = "tcp";
}
}
}
if (!namematch(ai)) {
free(orignfsdirname);
return (1);
}
/* First try to unmount using the file system ID. */
snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
sfs->f_fsid.val[1]);
if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
/* XXX, non-root users get a zero fsid, so don't warn. */
if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
sfs->f_fsid.val[1] != 0)
warn("unmount of %s failed", sfs->f_mntonname);
if (errno != ENOENT) {
free(orignfsdirname);
return (1);
}
/* Compatibility for old kernels. */
if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
warnx("retrying using path instead of file system ID");
if (unmount(sfs->f_mntonname, fflag) != 0) {
warn("unmount of %s failed", sfs->f_mntonname);
free(orignfsdirname);
return (1);
}
}
/* Mark this this file system as unmounted. */
getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
if (vflag)
(void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
sfs->f_mntonname);
/*
* Report to mountd-server which nfsname
* has been unmounted.
*/
if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
clp = clnt_create(hostp, MOUNTPROG, MOUNTVERS3, proto_ptr);
if (clp == NULL) {
warnx("%s: %s", hostp,
clnt_spcreateerror("MOUNTPROG"));
free(orignfsdirname);
return (1);
}
clp->cl_auth = authsys_create_default();
try.tv_sec = 20;
try.tv_usec = 0;
clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir,
nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
if (clnt_stat != RPC_SUCCESS) {
warnx("%s: %s", hostp,
clnt_sperror(clp, "RPCMNT_UMOUNT"));
free(orignfsdirname);
return (1);
}
/*
* Remove the unmounted entry from /var/db/mounttab.
*/
if (read_mtab()) {
clean_mtab(hostp, nfsdirname, vflag);
if(!write_mtab(vflag))
warnx("cannot remove mounttab entry %s:%s",
hostp, nfsdirname);
free_mtab();
}
auth_destroy(clp->cl_auth);
clnt_destroy(clp);
}
free(orignfsdirname);
return (0);
}
struct statfs *
getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
{
static struct statfs *mntbuf;
static size_t mntsize = 0;
static int *mntcheck = NULL;
struct statfs *sfs, *foundsfs;
int i, count;
if (mntsize <= 0) {
if ((mntsize = mntinfo(&mntbuf)) <= 0)
return (NULL);
}
if (mntcheck == NULL) {
if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
err(1, "calloc");
}
/*
* We want to get the file systems in the reverse order
* that they were mounted. Unmounted file systems are marked
* in a table called 'mntcheck'.
*/
count = 0;
foundsfs = NULL;
for (i = mntsize - 1; i >= 0; i--) {
if (mntcheck[i])
continue;
sfs = &mntbuf[i];
if (fromname != NULL && strcmp(sfs->f_mntfromname,
fromname) != 0)
continue;
if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
continue;
if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
sizeof(*fsid)) != 0)
continue;
switch (what) {
case CHECKUNIQUE:
foundsfs = sfs;
count++;
continue;
case REMOVE:
mntcheck[i] = 1;
break;
default:
break;
}
return (sfs);
}
if (what == CHECKUNIQUE && count == 1)
return (foundsfs);
return (NULL);
}
int
sacmp(void *sa1, void *sa2)
{
void *p1, *p2;
int len;
if (((struct sockaddr *)sa1)->sa_family !=
((struct sockaddr *)sa2)->sa_family)
return (1);
switch (((struct sockaddr *)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);
}
int
namematch(struct addrinfo *ai)
{
struct addrinfo *aip;
if (nfshost == NULL || nfshost_ai == NULL)
return (1);
while (ai != NULL) {
aip = nfshost_ai;
while (aip != NULL) {
if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
return (1);
aip = aip->ai_next;
}
ai = ai->ai_next;
}
return (0);
}
struct statfs *
checkmntlist(char *mntname)
{
struct statfs *sfs;
fsid_t fsid;
sfs = NULL;
if (parsehexfsid(mntname, &fsid) == 0)
sfs = getmntentry(NULL, NULL, &fsid, FIND);
if (sfs == NULL)
sfs = getmntentry(NULL, mntname, NULL, FIND);
if (sfs == NULL)
sfs = getmntentry(mntname, NULL, NULL, FIND);
return (sfs);
}
size_t
mntinfo(struct statfs **mntbuf)
{
static struct statfs *origbuf;
size_t bufsize;
int mntsize;
mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
if (mntsize <= 0)
return (0);
bufsize = (mntsize + 1) * sizeof(struct statfs);
if ((origbuf = malloc(bufsize)) == NULL)
err(1, "malloc");
mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
*mntbuf = origbuf;
return (mntsize);
}
/*
* Convert a hexadecimal filesystem ID to an fsid_t.
* Returns 0 on success.
*/
int
parsehexfsid(const char *hex, fsid_t *fsid)
{
char hexbuf[3];
int i;
if (strlen(hex) != sizeof(*fsid) * 2)
return (-1);
hexbuf[2] = '\0';
for (i = 0; i < (int)sizeof(*fsid); i++) {
hexbuf[0] = hex[i * 2];
hexbuf[1] = hex[i * 2 + 1];
if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
return (-1);
((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
}
return (0);
}
/*
* xdr routines for mount rpc's
*/
int
xdr_dir(XDR *xdrsp, char *dirp)
{
return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
}
void
usage(void)
{
(void)fprintf(stderr, "%s\n%s\n",
"usage: umount [-fNnv] special ... | node ... | fsid ...",
" umount -a | -A [-F fstab] [-fnv] [-h host] [-t type]");
exit(1);
}