freebsd-skq/sbin/umount/umount.c
Ian Dowse 38f102c2f6 When mount(8) is invoked with the `-v' flag, display the filesystem
ID for each file system in addition to the normal information.

In umount(8), accept filesystem IDs as well as the usual device and
path names. This makes it possible to unambiguously specify which
file system is to be unmounted even when two or more file systems
share the same device and mountpoint names (e.g. NFS mounts from
the same export into different chroots).

Suggested by:	Dan Nelson <dnelson@allantgroup.com>
2003-07-18 17:43:13 +00:00

752 lines
19 KiB
C

/*-
* 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. 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 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 <netdb.h>
#include <rpc/rpc.h>
#include <nfs/rpcv2.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"
#define ISDOT(x) ((x)[0] == '.' && (x)[1] == '\0')
#define ISDOTDOT(x) ((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0')
typedef enum { MNTON, MNTFROM, MNTFSID, NOTHING } mntwhat;
typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat;
struct addrinfo *nfshost_ai = NULL;
int fflag, vflag;
char *nfshost;
struct statfs *checkmntlist(char *);
int checkvfsname (const char *, char **);
struct statfs *getmntentry(const char *, const char *, mntwhat, dowhat);
char *getrealname(char *, char *resolved_path);
char **makevfslist (const char *);
size_t mntinfo (struct statfs **);
int namematch (struct addrinfo *);
int sacmp (struct sockaddr *, struct sockaddr *);
int umountall (char **);
int checkname (char *, char **);
int umountfs (char *, char *, fsid_t *, char *);
void usage (void);
int xdr_dir (XDR *, char *);
int
main(int argc, char *argv[])
{
int all, errs, ch, mntsize, error;
char **typelist = NULL;
struct statfs *mntbuf, *sfs;
struct addrinfo hints;
/* Start disks transferring immediately. */
sync();
all = errs = 0;
while ((ch = getopt(argc, argv, "AaF:fh:t: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 '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 ((argc == 0 && !all) || (argc != 0 && all))
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 (umountfs(sfs->f_mntfromname, sfs->f_mntonname,
&sfs->f_fsid, sfs->f_fstypename) != 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 (checkname(*argv, typelist) != 0)
errs = 1;
break;
}
(void)getmntentry(NULL, NULL, NOTHING, FREE);
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 and device or hand over
* it to unmount(2) if everything fails.
*/
int
checkname(char *name, char **typelist)
{
size_t len;
int speclen;
char *resolved, realname[MAXPATHLEN];
char *hostp, *delimp, *origname;
struct statfs *sfs;
len = 0;
delimp = hostp = NULL;
sfs = NULL;
/*
* 1. Check if the name exists in the mounttable.
*/
sfs = checkmntlist(name);
/*
* 2. Remove trailing slashes if there are any. After that
* we look up the name in the mounttable again.
*/
if (sfs == NULL) {
speclen = strlen(name);
for (speclen = strlen(name);
speclen > 1 && name[speclen - 1] == '/';
speclen--)
name[speclen - 1] = '\0';
sfs = checkmntlist(name);
resolved = name;
/* Save off original name in origname */
if ((origname = strdup(name)) == NULL)
err(1, "strdup");
/*
* 3. Check if the deprecated nfs-syntax with an '@'
* has been used and translate it to the ':' syntax.
* Look up the name in the mounttable again.
*/
if (sfs == NULL) {
if ((delimp = strrchr(name, '@')) != NULL) {
hostp = delimp + 1;
if (*hostp != '\0') {
/*
* Make both '@' and ':'
* notations equal
*/
char *host = strdup(hostp);
len = strlen(hostp);
if (host == NULL)
err(1, "strdup");
memmove(name + len + 1, name,
(size_t)(delimp - name));
name[len] = ':';
memmove(name, host, len);
free(host);
}
for (speclen = strlen(name);
speclen > 1 && name[speclen - 1] == '/';
speclen--)
name[speclen - 1] = '\0';
name[len + speclen + 1] = '\0';
sfs = checkmntlist(name);
resolved = name;
}
/*
* 4. Check if a relative mountpoint has been
* specified. This should happen as last check,
* the order is important. To prevent possible
* nfs-hangs, we just call realpath(3) on the
* basedir of mountpoint and add the dirname again.
* Check the name in mounttable one last time.
*/
if (sfs == NULL) {
(void)strcpy(name, origname);
if ((getrealname(name, realname)) != NULL) {
sfs = checkmntlist(realname);
resolved = realname;
}
/*
* 5. All tests failed, just hand over the
* mountpoint to the kernel, maybe the statfs
* structure has been truncated or is not
* useful anymore because of a chroot(2).
* Please note that nfs will not be able to
* notify the nfs-server about unmounting.
* These things can change in future when the
* fstat structure get's more reliable,
* but at the moment we cannot thrust it.
*/
if (sfs == NULL) {
(void)strcpy(name, origname);
if (umountfs(NULL, origname, NULL,
"none") == 0) {;
warnx("%s not found in "
"mount table, "
"unmounted it anyway",
origname);
free(origname);
return (0);
} else
free(origname);
return (1);
}
}
}
free(origname);
} else
resolved = name;
if (checkvfsname(sfs->f_fstypename, typelist))
return (1);
/*
* Mark the uppermost mount as unmounted.
*/
(void)getmntentry(sfs->f_mntfromname, sfs->f_mntonname, NOTHING, MARK);
return (umountfs(sfs->f_mntfromname, sfs->f_mntonname, &sfs->f_fsid,
sfs->f_fstypename));
}
/*
* NFS stuff and unmount(2) call
*/
int
umountfs(char *mntfromname, char *mntonname, fsid_t *fsid, char *type)
{
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;
ai = NULL;
do_rpc = 0;
hostp = NULL;
nfsdirname = delimp = orignfsdirname = NULL;
memset(&hints, 0, sizeof hints);
if (strcmp(type, "nfs") == 0) {
if ((nfsdirname = strdup(mntfromname)) == NULL)
err(1, "strdup");
orignfsdirname = nfsdirname;
if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
*delimp = '\0';
hostp = nfsdirname;
getaddrinfo(hostp, NULL, &hints, &ai);
if (ai == NULL) {
warnx("can't get net id for host");
}
nfsdirname = delimp + 1;
}
/*
* 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(mntfromname, NULL, NOTHING, COUNT) != NULL)
do_rpc = 1;
}
if (!namematch(ai))
return (1);
/* First try to unmount using the specified file system ID. */
if (fsid != NULL) {
snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", fsid->val[0],
fsid->val[1]);
if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
warn("unmount of %s failed", mntonname);
if (errno != ENOENT)
return (1);
/* Compatability for old kernels. */
warnx("retrying using path instead of file system ID");
fsid = NULL;
}
}
if (fsid == NULL && unmount(mntonname, fflag) != 0) {
warn("unmount of %s failed", mntonname);
return (1);
}
if (vflag)
(void)printf("%s: unmount from %s\n", mntfromname, mntonname);
/*
* Report to mountd-server which nfsname
* has been unmounted.
*/
if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
if (clp == NULL) {
warnx("%s: %s", hostp,
clnt_spcreateerror("RPCPROG_MNT"));
return (1);
}
clp->cl_auth = authsys_create_default();
try.tv_sec = 20;
try.tv_usec = 0;
clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (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"));
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();
}
free(orignfsdirname);
auth_destroy(clp->cl_auth);
clnt_destroy(clp);
}
return (0);
}
struct statfs *
getmntentry(const char *fromname, const char *onname, mntwhat what, dowhat mark)
{
static struct statfs *mntbuf;
static size_t mntsize = 0;
static char *mntcheck = NULL;
static char *mntcount = NULL;
fsid_t fsid;
char hexbuf[3];
int i, count;
if (mntsize <= 0) {
if ((mntsize = mntinfo(&mntbuf)) <= 0)
return (NULL);
}
if (mntcheck == NULL) {
if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
(mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
err(1, "calloc");
}
/*
* We want to get the file systems in the reverse order
* that they were mounted. Mounted and unmounted file systems
* are marked or unmarked in a table called 'mntcheck'.
* Unmount(const char *dir, int flags) does only take the
* mountpoint as argument, not the destination. If we don't pay
* attention to the order, it can happen that an overlaying
* file system gets unmounted instead of the one the user
* has choosen.
*/
switch (mark) {
case NAME:
/* Return only the specific name */
if (fromname == NULL)
return (NULL);
if (what == MNTFSID) {
/* Convert the hex filesystem ID to a fsid_t. */
if (strlen(fromname) != sizeof(fsid) * 2)
return (NULL);
hexbuf[2] = '\0';
for (i = 0; i < sizeof(fsid); i++) {
hexbuf[0] = fromname[i * 2];
hexbuf[1] = fromname[i * 2 + 1];
if (!isxdigit(hexbuf[0]) ||
!isxdigit(hexbuf[1]))
return (NULL);
((u_char *)&fsid)[i] = strtol(hexbuf, NULL, 16);
}
}
for (i = mntsize - 1; i >= 0; i--) {
switch (what) {
case MNTON:
if (strcmp(mntbuf[i].f_mntonname,
fromname) != 0)
continue;
break;
case MNTFROM:
if (strcmp(mntbuf[i].f_mntfromname,
fromname) != 0)
continue;
case MNTFSID:
if (bcmp(&mntbuf[i].f_fsid, &fsid,
sizeof(fsid)) != 0)
continue;
case NOTHING: /* silence compiler warning */
break;
}
if (mntcheck[i] != 1)
return (&mntbuf[i]);
}
return (NULL);
case MARK:
/* Mark current mount with '1' and return name */
for (i = mntsize - 1; i >= 0; i--) {
if (mntcheck[i] == 0 &&
(strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
(strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
mntcheck[i] = 1;
return (&mntbuf[i]);
}
}
return (NULL);
case UNMARK:
/* Unmark current mount with '0' and return name */
for (i = 0; i < mntsize; i++) {
if (mntcheck[i] == 1 &&
(strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
(strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
mntcheck[i] = 0;
return (&mntbuf[i]);
}
}
return (NULL);
case COUNT:
/* Count the equal mntfromnames */
count = 0;
for (i = mntsize - 1; i >= 0; i--) {
if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
count++;
}
/* Mark the already unmounted mounts and return
* mntfromname if count <= 1. Else return NULL.
*/
for (i = mntsize - 1; i >= 0; i--) {
if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
if (mntcount[i] == 1)
count--;
else {
mntcount[i] = 1;
break;
}
}
}
if (count <= 1)
return (&mntbuf[i]);
else
return (NULL);
case FREE:
free(mntbuf);
free(mntcheck);
free(mntcount);
return (NULL);
default:
return (NULL);
}
}
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);
}
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 *name)
{
struct statfs *sfs;
sfs = getmntentry(name, NULL, MNTFSID, NAME);
if (sfs == NULL)
sfs = getmntentry(name, NULL, MNTON, NAME);
if (sfs == NULL)
sfs = getmntentry(name, NULL, MNTFROM, NAME);
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);
}
char *
getrealname(char *name, char *realname)
{
char *dirname;
int havedir;
size_t baselen;
size_t dirlen;
dirname = '\0';
havedir = 0;
if (*name == '/') {
if (ISDOT(name + 1) || ISDOTDOT(name + 1))
strcpy(realname, "/");
else {
if ((dirname = strrchr(name + 1, '/')) == NULL)
snprintf(realname, MAXPATHLEN, "%s", name);
else
havedir = 1;
}
} else {
if (ISDOT(name) || ISDOTDOT(name))
(void)realpath(name, realname);
else {
if ((dirname = strrchr(name, '/')) == NULL) {
if ((realpath(name, realname)) == NULL)
return (NULL);
} else
havedir = 1;
}
}
if (havedir) {
*dirname++ = '\0';
if (ISDOT(dirname)) {
*dirname = '\0';
if ((realpath(name, realname)) == NULL)
return (NULL);
} else if (ISDOTDOT(dirname)) {
*--dirname = '/';
if ((realpath(name, realname)) == NULL)
return (NULL);
} else {
if ((realpath(name, realname)) == NULL)
return (NULL);
baselen = strlen(realname);
dirlen = strlen(dirname);
if (baselen + dirlen + 1 > MAXPATHLEN)
return (NULL);
if (realname[1] == '\0') {
memmove(realname + 1, dirname, dirlen);
realname[dirlen + 1] = '\0';
} else {
realname[baselen] = '/';
memmove(realname + baselen + 1,
dirname, dirlen);
realname[baselen + dirlen + 1] = '\0';
}
}
}
return (realname);
}
/*
* xdr routines for mount rpc's
*/
int
xdr_dir(XDR *xdrsp, char *dirp)
{
return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
}
void
usage()
{
(void)fprintf(stderr, "%s\n%s\n",
"usage: umount [-fv] special | node",
" umount -a | -A [ -F fstab] [-fv] [-h host] [-t type]");
exit(1);
}