You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
util-linux/libmount/src/utils.c

898 lines
18 KiB

/*
* Copyright (C) 2008-2009 Karel Zak <kzak@redhat.com>
*
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
*/
/**
* SECTION: utils
* @title: Utils
* @short_description: misc utils.
*/
#include <ctype.h>
#include <fcntl.h>
#include <pwd.h>
#include <grp.h>
#include "strutils.h"
#include "pathnames.h"
#include "mountP.h"
#include "mangle.h"
#include "canonicalize.h"
#include "env.h"
int endswith(const char *s, const char *sx)
{
ssize_t off;
assert(s);
assert(sx);
off = strlen(s);
if (!off)
return 0;
off -= strlen(sx);
if (off < 0)
return 0;
return !strcmp(s + off, sx);
}
int startswith(const char *s, const char *sx)
{
size_t off;
assert(s);
assert(sx);
off = strlen(sx);
if (!off)
return 0;
return !strncmp(s, sx, off);
}
int mnt_parse_offset(const char *str, size_t len, uintmax_t *res)
{
char *p;
int rc = 0;
if (!str && !*str)
return -EINVAL;
p = strndup(str, len);
if (!p)
return -errno;
if (strtosize(p, res))
rc = -EINVAL;
free(p);
return rc;
}
/* returns basename and keeps dirname in the @path, if @path is "/" (root)
* then returns empty string */
static char *stripoff_last_component(char *path)
{
char *p = path ? strrchr(path, '/') : NULL;
if (!p)
return NULL;
*p = '\0';
return p + 1;
}
/*
* Note that the @target has to be absolute path (so at least "/"). The
* @filename returns allocated buffer with last path component, for example:
*
* mnt_chdir_to_parent("/mnt/test", &buf) ==> chdir("/mnt"), buf="test"
*/
int mnt_chdir_to_parent(const char *target, char **filename)
{
char *buf, *parent, *last = NULL;
char cwd[PATH_MAX];
int rc = -EINVAL;
if (!target || *target != '/')
return -EINVAL;
DBG(UTILS, mnt_debug("moving to %s parent", target));
buf = strdup(target);
if (!buf)
return -ENOMEM;
if (*(buf + 1) != '\0') {
last = stripoff_last_component(buf);
if (!last)
goto err;
}
parent = buf && *buf ? buf : "/";
if (chdir(parent) == -1) {
DBG(UTILS, mnt_debug("failed to chdir to %s: %m", parent));
rc = -errno;
goto err;
}
if (!getcwd(cwd, sizeof(cwd))) {
DBG(UTILS, mnt_debug("failed to obtain current directory: %m"));
rc = -errno;
goto err;
}
if (strcmp(cwd, parent) != 0) {
DBG(UTILS, mnt_debug(
"unexpected chdir (expected=%s, cwd=%s)", parent, cwd));
goto err;
}
DBG(CXT, mnt_debug(
"current directory moved to %s [last_component='%s']",
parent, last));
*filename = buf;
if (!last || !*last)
memcpy(*filename, ".", 2);
else
memcpy(*filename, last, strlen(last) + 1);
return 0;
err:
free(buf);
return rc;
}
/**
* mnt_mangle:
* @str: string
*
* Encode @str to be compatible with fstab/mtab
*
* Returns: new allocated string or NULL in case of error.
*/
char *mnt_mangle(const char *str)
{
return mangle(str);
}
/**
* mnt_unmangle:
* @str: string
*
* Decode @str from fstab/mtab
*
* Returns: new allocated string or NULL in case of error.
*/
char *mnt_unmangle(const char *str)
{
return unmangle(str, NULL);
}
/**
* mnt_fstype_is_pseudofs:
* @type: filesystem name
*
* Returns: 1 for filesystems like proc, sysfs, ... or 0.
*/
int mnt_fstype_is_pseudofs(const char *type)
{
if (!type)
return 0;
if (strcmp(type, "none") == 0 ||
strcmp(type, "proc") == 0 ||
strcmp(type, "tmpfs") == 0 ||
strcmp(type, "sysfs") == 0 ||
strcmp(type, "autofs") == 0 ||
strcmp(type, "devpts") == 0||
strcmp(type, "cgroup") == 0 ||
strcmp(type, "devtmpfs") == 0 ||
strcmp(type, "devfs") == 0 ||
strcmp(type, "dlmfs") == 0 ||
strcmp(type, "cpuset") == 0 ||
strcmp(type, "securityfs") == 0 ||
strcmp(type, "hugetlbfs") == 0 ||
strcmp(type, "rpc_pipefs") == 0 ||
strcmp(type, "fusectl") == 0 ||
strcmp(type, "mqueue") == 0 ||
strcmp(type, "binfmt_misc") == 0 ||
strcmp(type, "fuse.gvfs-fuse-daemon") == 0 ||
strcmp(type, "debugfs") == 0 ||
strcmp(type, "spufs") == 0)
return 1;
return 0;
}
/**
* mnt_fstype_is_netfs:
* @type: filesystem name
*
* Returns: 1 for filesystems like cifs, nfs, ... or 0.
*/
int mnt_fstype_is_netfs(const char *type)
{
if (!type)
return 0;
if (strcmp(type, "cifs") == 0 ||
strcmp(type, "smbfs") == 0 ||
strncmp(type,"nfs", 3) == 0 ||
strcmp(type, "afs") == 0 ||
strcmp(type, "ncpfs") == 0 ||
strncmp(type,"9p", 2) == 0)
return 1;
return 0;
}
/**
* mnt_match_fstype:
* @type: filesystem type
* @pattern: filesystem name or comma delimited list of names
*
* The @pattern list of filesystem can be prefixed with a global
* "no" prefix to invert matching of the whole list. The "no" could
* also be used for individual items in the @pattern list. So,
* "nofoo,bar" has the same meaning as "nofoo,nobar".
*
* "bar" : "nofoo,bar" -> False (global "no" prefix)
*
* "bar" : "foo,bar" -> True
*
* "bar" : "foo,nobar" -> False
*
* Returns: 1 if type is matching, else 0. This function also returns
* 0 if @pattern is NULL and @type is non-NULL.
*/
int mnt_match_fstype(const char *type, const char *pattern)
{
return match_fstype(type, pattern);
}
/* Returns 1 if needle found or noneedle not found in haystack
* Otherwise returns 0
*/
static int check_option(const char *haystack, size_t len,
const char *needle, size_t needle_len)
{
const char *p;
int no = 0;
if (needle_len >= 2 && !strncmp(needle, "no", 2)) {
no = 1;
needle += 2;
needle_len -= 2;
}
for (p = haystack; p && p < haystack + len; p++) {
char *sep = strchr(p, ',');
size_t plen = sep ? (size_t) (sep - p) :
len - (p - haystack);
if (plen == needle_len) {
if (!strncmp(p, needle, plen))
return !no; /* foo or nofoo was found */
}
p += plen;
}
return no; /* foo or nofoo was not found */
}
/**
* mnt_match_options:
* @optstr: options string
* @pattern: comma delimited list of options
*
* The "no" could used for individual items in the @options list. The "no"
* prefix does not have a global meaning.
*
* Unlike fs type matching, nonetdev,user and nonetdev,nouser have
* DIFFERENT meanings; each option is matched explicitly as specified.
*
* "xxx,yyy,zzz" : "nozzz" -> False
*
* "xxx,yyy,zzz" : "xxx,noeee" -> True
*
* Returns: 1 if pattern is matching, else 0. This function also returns 0
* if @pattern is NULL and @optstr is non-NULL.
*/
int mnt_match_options(const char *optstr, const char *pattern)
{
const char *p;
size_t len, optstr_len = 0;
if (!pattern && !optstr)
return 1;
if (!pattern)
return 0;
len = strlen(pattern);
if (optstr)
optstr_len = strlen(optstr);
for (p = pattern; p < pattern + len; p++) {
char *sep = strchr(p, ',');
size_t plen = sep ? (size_t) (sep - p) :
len - (p - pattern);
if (!plen)
continue; /* if two ',' appear in a row */
if (!check_option(optstr, optstr_len, p, plen))
return 0; /* any match failure means failure */
p += plen;
}
/* no match failures in list means success */
return 1;
}
void mnt_free_filesystems(char **filesystems)
{
char **p;
if (!filesystems)
return;
for (p = filesystems; *p; p++)
free(*p);
free(filesystems);
}
static int add_filesystem(char ***filesystems, char *name)
{
int n = 0;
assert(filesystems);
assert(name);
if (*filesystems) {
char **p;
for (n = 0, p = *filesystems; *p; p++, n++) {
if (strcmp(*p, name) == 0)
return 0;
}
}
#define MYCHUNK 16
if (n == 0 || !((n + 1) % MYCHUNK)) {
size_t items = ((n + 1 + MYCHUNK) / MYCHUNK) * MYCHUNK;
char **x = realloc(*filesystems, items * sizeof(char *));
if (!x)
goto err;
*filesystems = x;
}
name = strdup(name);
if (!name)
goto err;
(*filesystems)[n] = name;
(*filesystems)[n + 1] = NULL;
return 0;
err:
mnt_free_filesystems(*filesystems);
return -ENOMEM;
}
static int get_filesystems(const char *filename, char ***filesystems, const char *pattern)
{
FILE *f;
char line[128];
f = fopen(filename, "r");
if (!f)
return 0;
while (fgets(line, sizeof(line), f)) {
char name[sizeof(line)];
int rc;
if (*line == '#' || strncmp(line, "nodev", 5) == 0)
continue;
if (sscanf(line, " %128[^\n ]\n", name) != 1)
continue;
if (pattern && !mnt_match_fstype(name, pattern))
continue;
rc = add_filesystem(filesystems, name);
if (rc)
return rc;
}
return 0;
}
int mnt_get_filesystems(char ***filesystems, const char *pattern)
{
int rc;
if (!filesystems)
return -EINVAL;
*filesystems = NULL;
rc = get_filesystems(_PATH_FILESYSTEMS, filesystems, pattern);
if (rc)
return rc;
return get_filesystems(_PATH_PROC_FILESYSTEMS, filesystems, pattern);
}
/*
* Returns allocated string with username or NULL.
*/
char *mnt_get_username(const uid_t uid)
{
struct passwd pwd;
struct passwd *res;
#ifdef _SC_GETPW_R_SIZE_MAX
size_t sz = sysconf(_SC_GETPW_R_SIZE_MAX);
#else
size_t sz = 0;
#endif
char *buf, *username = NULL;
if (sz <= 0)
sz = 16384; /* Should be more than enough */
buf = malloc(sz);
if (!buf)
return NULL;
if (!getpwuid_r(uid, &pwd, buf, sz, &res) && res)
username = strdup(pwd.pw_name);
free(buf);
return username;
}
int mnt_get_uid(const char *username, uid_t *uid)
{
int rc = -1;
struct passwd pwd;
struct passwd *pw;
size_t sz = sysconf(_SC_GETPW_R_SIZE_MAX);
char *buf;
if (!username || !uid)
return -EINVAL;
if (sz <= 0)
sz = 16384; /* Should be more than enough */
buf = malloc(sz);
if (!buf)
return -ENOMEM;
if (!getpwnam_r(username, &pwd, buf, sz, &pw) && pw) {
*uid= pw->pw_uid;
rc = 0;
} else {
DBG(UTILS, mnt_debug(
"cannot convert '%s' username to UID", username));
}
free(buf);
return rc;
}
int mnt_get_gid(const char *groupname, gid_t *gid)
{
int rc = -1;
struct group grp;
struct group *gr;
size_t sz = sysconf(_SC_GETGR_R_SIZE_MAX);
char *buf;
if (!groupname || !gid)
return -EINVAL;
if (sz <= 0)
sz = 16384; /* Should be more than enough */
buf = malloc(sz);
if (!buf)
return -ENOMEM;
if (!getgrnam_r(groupname, &grp, buf, sz, &gr) && gr) {
*gid= gr->gr_gid;
rc = 0;
} else {
DBG(UTILS, mnt_debug(
"cannot convert '%s' groupname to GID", groupname));
}
free(buf);
return rc;
}
int mnt_in_group(gid_t gid)
{
int rc = 0, n, i;
gid_t *grps = NULL;
if (getgid() == gid)
return 1;
n = getgroups(0, NULL);
if (n <= 0)
goto done;
grps = malloc(n * sizeof(*grps));
if (!grps)
goto done;
if (getgroups(n, grps) == n) {
for (i = 0; i < n; i++) {
if (grps[i] == gid) {
rc = 1;
break;
}
}
}
done:
free(grps);
return rc;
}
static int try_write(const char *filename)
{
int fd;
if (!filename)
return -EINVAL;
fd = open(filename, O_RDWR|O_CREAT, S_IWUSR| \
S_IRUSR|S_IRGRP|S_IROTH);
if (fd >= 0) {
close(fd);
return 0;
}
return -errno;
}
/**
* mnt_has_regular_mtab:
* @mtab: returns path to mtab
* @writable: returns 1 if the file is writable
*
* If the file does not exist and @writable argument is not NULL then it will
* try to create the file
*
* Returns: 1 if /etc/mtab is a regular file, and 0 in case of error (check
* errno for more details).
*/
int mnt_has_regular_mtab(const char **mtab, int *writable)
{
struct stat st;
int rc;
const char *filename = mtab && *mtab ? *mtab : mnt_get_mtab_path();
if (writable)
*writable = 0;
if (mtab && !*mtab)
*mtab = filename;
DBG(UTILS, mnt_debug("mtab: %s", filename));
rc = lstat(filename, &st);
if (rc == 0) {
/* file exist */
if (S_ISREG(st.st_mode)) {
if (writable)
*writable = !try_write(filename);
return 1;
}
goto done;
}
/* try to create the file */
if (writable) {
*writable = !try_write(filename);
if (*writable)
return 1;
}
done:
DBG(UTILS, mnt_debug("%s: irregular/non-writable", filename));
return 0;
}
/*
* Don't export this to libmount API -- utab is private library stuff.
*
* If the file does not exist and @writable argument is not NULL then it will
* try to create the directory (e.g. /run/mount) and the file.
*
* Returns: 1 if utab is a regular file, and 0 in case of
* error (check errno for more details).
*/
int mnt_has_regular_utab(const char **utab, int *writable)
{
struct stat st;
int rc;
const char *filename = utab && *utab ? *utab : mnt_get_utab_path();
if (writable)
*writable = 0;
if (utab && !*utab)
*utab = filename;
DBG(UTILS, mnt_debug("utab: %s", filename));
rc = lstat(filename, &st);
if (rc == 0) {
/* file exist */
if (S_ISREG(st.st_mode)) {
if (writable)
*writable = !try_write(filename);
return 1;
}
goto done; /* it's not regular file */
}
if (writable) {
char *dirname = strdup(filename);
if (!dirname)
goto done;
stripoff_last_component(dirname); /* remove filename */
rc = mkdir(dirname, S_IWUSR|
S_IRUSR|S_IRGRP|S_IROTH|
S_IXUSR|S_IXGRP|S_IXOTH);
free(dirname);
if (rc && errno != EEXIST)
goto done; /* probably EACCES */
*writable = !try_write(filename);
if (*writable)
return 1;
}
done:
DBG(UTILS, mnt_debug("%s: irregular/non-writable file", filename));
return 0;
}
/**
* mnt_get_fstab_path:
*
* Returns: path to /etc/fstab or $LIBMOUNT_FSTAB.
*/
const char *mnt_get_fstab_path(void)
{
const char *p = safe_getenv("LIBMOUNT_FSTAB");
return p ? : _PATH_MNTTAB;
}
/**
* mnt_get_mtab_path:
*
* This function returns *default* location of the mtab file. The result does
* not have to be writable. See also mnt_has_regular_mtab().
*
* Returns: path to /etc/mtab or $LIBMOUNT_MTAB.
*/
const char *mnt_get_mtab_path(void)
{
const char *p = safe_getenv("LIBMOUNT_MTAB");
return p ? : _PATH_MOUNTED;
}
/*
* Don't export this to libmount API -- utab is private library stuff.
*
* Returns: path to /run/mount/utab (or /dev/.mount/utab) or $LIBMOUNT_UTAB.
*/
const char *mnt_get_utab_path(void)
{
struct stat st;
const char *p = safe_getenv("LIBMOUNT_UTAB");
if (p)
return p;
if (stat(MNT_RUNTIME_TOPDIR, &st) == 0)
return MNT_PATH_UTAB;
return MNT_PATH_UTAB_OLD;
}
/* returns file descriptor or -errno, @name returns uniques filename
*/
int mnt_open_uniq_filename(const char *filename, char **name)
{
int rc, fd;
char *n;
assert(filename);
if (name)
*name = NULL;
rc = asprintf(&n, "%s.XXXXXX", filename);
if (rc <= 0)
return -errno;
fd = mkstemp(n);
if (fd >= 0 && name)
*name = n;
else
free(n);
return fd < 0 ? -errno : fd;
}
char *mnt_get_mountpoint(const char *path)
{
char *mnt = strdup(path);
struct stat st;
dev_t dir, base;
if (!mnt)
return NULL;
if (*mnt == '/' && *(mnt + 1) == '\0')
goto done;
if (stat(mnt, &st))
goto err;
base = st.st_dev;
do {
char *p = stripoff_last_component(mnt);
if (!p)
break;
if (stat(*mnt ? mnt : "/", &st))
goto err;
dir = st.st_dev;
if (dir != base) {
*(p - 1) = '/';
goto done;
}
base = dir;
} while (mnt && *(mnt + 1) != '\0');
memcpy(mnt, "/", 2);
done:
DBG(UTILS, mnt_debug("%s mountpoint is %s", path, mnt));
return mnt;
err:
free(mnt);
return NULL;
}
char *mnt_get_fs_root(const char *path, const char *mnt)
{
char *m = (char *) mnt, *res;
const char *p;
size_t sz;
if (!m)
m = mnt_get_mountpoint(path);
if (!m)
return NULL;
sz = strlen(m);
p = sz > 1 ? path + sz : path;
if (m != mnt)
free(m);
res = *p ? strdup(p) : strdup("/");
DBG(UTILS, mnt_debug("%s fs-root is %s", path, res));
return res;
}
#ifdef TEST_PROGRAM
int test_match_fstype(struct libmnt_test *ts, int argc, char *argv[])
{
char *type = argv[1];
char *pattern = argv[2];
printf("%s\n", mnt_match_fstype(type, pattern) ? "MATCH" : "NOT-MATCH");
return 0;
}
int test_match_options(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr = argv[1];
char *pattern = argv[2];
printf("%s\n", mnt_match_options(optstr, pattern) ? "MATCH" : "NOT-MATCH");
return 0;
}
int test_startswith(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr = argv[1];
char *pattern = argv[2];
printf("%s\n", startswith(optstr, pattern) ? "YES" : "NOT");
return 0;
}
int test_endswith(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr = argv[1];
char *pattern = argv[2];
printf("%s\n", endswith(optstr, pattern) ? "YES" : "NOT");
return 0;
}
int test_mountpoint(struct libmnt_test *ts, int argc, char *argv[])
{
char *path = canonicalize_path(argv[1]),
*mnt = path ? mnt_get_mountpoint(path) : NULL;
printf("%s: %s\n", argv[1], mnt ? : "unknown");
free(mnt);
free(path);
return 0;
}
int test_fsroot(struct libmnt_test *ts, int argc, char *argv[])
{
char *path = canonicalize_path(argv[1]),
*mnt = path ? mnt_get_fs_root(path, NULL) : NULL;
printf("%s: %s\n", argv[1], mnt ? : "unknown");
free(mnt);
free(path);
return 0;
}
int test_filesystems(struct libmnt_test *ts, int argc, char *argv[])
{
char **filesystems = NULL;
int rc;
rc = mnt_get_filesystems(&filesystems, argc ? argv[1] : NULL);
if (!rc) {
char **p;
for (p = filesystems; *p; p++)
printf("%s\n", *p);
mnt_free_filesystems(filesystems);
}
return rc;
}
int test_chdir(struct libmnt_test *ts, int argc, char *argv[])
{
int rc;
char *path = canonicalize_path(argv[1]),
*last = NULL;
if (!path)
return -errno;
rc = mnt_chdir_to_parent(path, &last);
if (!rc) {
printf("path='%s', abs='%s', last='%s'\n",
argv[1], path, last);
}
free(path);
free(last);
return rc;
}
int main(int argc, char *argv[])
{
struct libmnt_test tss[] = {
{ "--match-fstype", test_match_fstype, "<type> <pattern> FS types matching" },
{ "--match-options", test_match_options, "<options> <pattern> options matching" },
{ "--filesystems", test_filesystems, "[<pattern>] list /{etc,proc}/filesystems" },
{ "--starts-with", test_startswith, "<string> <prefix>" },
{ "--ends-with", test_endswith, "<string> <prefix>" },
{ "--mountpoint", test_mountpoint, "<path>" },
{ "--fs-root", test_fsroot, "<path>" },
{ "--cd-parent", test_chdir, "<path>" },
{ NULL }
};
return mnt_run_test(tss, argc, argv);
}
#endif /* TEST_PROGRAM */