/*
* Copyright (C) 2009 Karel Zak <kzak@redhat.com>
*
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
*/
#include <ctype.h>
#include <limits.h>
#include <dirent.h>
#include <fcntl.h>
#include "at.h"
#include "mangle.h"
#include "mountP.h"
#include "pathnames.h"
static inline char *skip_spaces(char *s)
{
assert(s);
while (*s == ' ' || *s == '\t')
s++;
return s;
}
static int next_number(char **s, int *num)
{
char *end = NULL;
assert(num);
assert(s);
*s = skip_spaces(*s);
if (!**s)
return -1;
*num = strtol(*s, &end, 10);
if (end == NULL || *s == end)
return -1;
*s = end;
/* valid end of number is space or terminator */
if (*end == ' ' || *end == '\t' || *end == '\0')
return 0;
return -1;
}
/*
* Parses one line from {fs,m}tab
*/
static int mnt_parse_table_line(struct libmnt_fs *fs, char *s)
{
int rc, n = 0;
char *src, *fstype, *optstr;
rc = sscanf(s, "%ms " /* (1) source */
"%ms " /* (2) target */
"%ms " /* (3) FS type */
"%ms " /* (4) options */
"%n", /* byte count */
&src,
&fs->target,
&fstype,
&optstr,
&n);
if (rc == 4) {
unmangle_string(src);
unmangle_string(fs->target);
unmangle_string(fstype);
unmangle_string(optstr);
rc = __mnt_fs_set_source_ptr(fs, src);
if (!rc)
rc = __mnt_fs_set_fstype_ptr(fs, fstype);
if (!rc)
rc = mnt_fs_set_options(fs, optstr);
free(optstr);
} else {
DBG(TAB, mnt_debug("tab parse error: [sscanf rc=%d]: '%s'", rc, s));
rc = -EINVAL;
}
if (rc)
return rc; /* error */
fs->passno = fs->freq = 0;
s = skip_spaces(s + n);
if (*s) {
if (next_number(&s, &fs->freq) != 0) {
if (*s) {
DBG(TAB, mnt_debug("tab parse error: [freq]"));
rc = -EINVAL;
}
} else if (next_number(&s, &fs->passno) != 0 && *s) {
DBG(TAB, mnt_debug("tab parse error: [passno]"));
rc = -EINVAL;
}
}
return rc;
}
/*
* Parses one line from mountinfo file
*/
static int mnt_parse_mountinfo_line(struct libmnt_fs *fs, char *s)
{
int rc, end = 0;
unsigned int maj, min;
char *fstype, *src, *p;
rc = sscanf(s, "%u " /* (1) id */
"%u " /* (2) parent */
"%u:%u " /* (3) maj:min */
"%ms " /* (4) mountroot */
"%ms " /* (5) target */
"%ms" /* (6) vfs options (fs-independent) */
"%n", /* number of read bytes */
&fs->id,
&fs->parent,
&maj, &min,
&fs->root,
&fs->target,
&fs->vfs_optstr,
&end);
if (rc >= 7 && end > 0)
s += end;
/* (7) optional fields, terminated by " - " */
p = strstr(s, " - ");
if (!p) {
DBG(TAB, mnt_debug("mountinfo parse error: not found separator"));
return -EINVAL;
}
s = p + 3;
rc += sscanf(s, "%ms " /* (8) FS type */
"%ms " /* (9) source */
"%ms", /* (10) fs options (fs specific) */
&fstype,
&src,
&fs->fs_optstr);
if (rc >= 10) {
fs->flags |= MNT_FS_KERNEL;
fs->devno = makedev(maj, min);
unmangle_string(fs->root);
unmangle_string(fs->target);
unmangle_string(fs->vfs_optstr);
unmangle_string(fstype);
unmangle_string(src);
if (!strcmp(fs->fs_optstr, "none")) {
free(fs->fs_optstr);
fs->fs_optstr = NULL;
} else
unmangle_string(fs->fs_optstr);
rc = __mnt_fs_set_fstype_ptr(fs, fstype);
if (!rc)
rc = __mnt_fs_set_source_ptr(fs, src);
/* merge VFS and FS options to the one string */
fs->optstr = mnt_fs_strdup_options(fs);
if (!fs->optstr)
rc = -ENOMEM;
} else {
DBG(TAB, mnt_debug(
"mountinfo parse error [sscanf rc=%d]: '%s'", rc, s));
rc = -EINVAL;
}
return rc;
}
/*
* Parses one line from utab file
*/
static int mnt_parse_utab_line(struct libmnt_fs *fs, const char *s)
{
const char *p = s;
assert(fs);
assert(s);
assert(!fs->source);
assert(!fs->target);
while (p && *p) {
char *end = NULL;
while (*p == ' ') p++;
if (!*p)
break;
if (!fs->source && !strncmp(p, "SRC=", 4)) {
char *v = unmangle(p + 4, &end);
if (!v)
goto enomem;
__mnt_fs_set_source_ptr(fs, v);
} else if (!fs->target && !strncmp(p, "TARGET=", 7)) {
fs->target = unmangle(p + 7, &end);
if (!fs->target)
goto enomem;
} else if (!fs->root && !strncmp(p, "ROOT=", 5)) {
fs->root = unmangle(p + 5, &end);
if (!fs->root)
goto enomem;
} else if (!fs->bindsrc && !strncmp(p, "BINDSRC=", 8)) {
fs->bindsrc = unmangle(p + 8, &end);
if (!fs->bindsrc)
goto enomem;
} else if (!fs->user_optstr && !strncmp(p, "OPTS=", 5)) {
fs->user_optstr = unmangle(p + 5, &end);
if (!fs->user_optstr)
goto enomem;
} else if (!fs->attrs && !strncmp(p, "ATTRS=", 6)) {
fs->attrs = unmangle(p + 6, &end);
if (!fs->attrs)
goto enomem;
} else {
/* unknown variable */
while (*p && *p != ' ') p++;
}
if (end)
p = end;
}
return 0;
enomem:
DBG(TAB, mnt_debug("utab parse error: ENOMEM"));
return -ENOMEM;
}
/*
* Returns {m,fs}tab or mountinfo file format (MNT_FMT_*)
*
* Note that we aren't trying to guess utab file format, because this file has
* to be always parsed by private libmount routines with explicitly defined
* format.
*
* mountinfo: "<number> <number> ... "
*/
static int guess_table_format(char *line)
{
unsigned int a, b;
if (sscanf(line, "%u %u", &a, &b) == 2)
return MNT_FMT_MOUNTINFO;
return MNT_FMT_FSTAB; /* fstab, mtab or /proc/mounts */
}
/*
* Read and parse the next line from {fs,m}tab or mountinfo
*/
static int mnt_table_parse_next(struct libmnt_table *tb, FILE *f, struct libmnt_fs *fs,
const char *filename, int *nlines)
{
char buf[BUFSIZ];
char *s;
assert(tb);
assert(f);
assert(fs);
/* read the next non-blank non-comment line */
do {
if (fgets(buf, sizeof(buf), f) == NULL)
return -EINVAL;
++*nlines;
s = index (buf, '\n');
if (!s) {
/* Missing final newline? Otherwise extremely */
/* long line - assume file was corrupted */
if (feof(f)) {
DBG(TAB, mnt_debug_h(tb,
"%s: no final newline", filename));
s = index (buf, '\0');
} else {
DBG(TAB, mnt_debug_h(tb,
"%s:%d: missing newline at line",
filename, *nlines));
goto err;
}
}
*s = '\0';
if (--s >= buf && *s == '\r')
*s = '\0';
s = skip_spaces(buf);
} while (*s == '\0' || *s == '#');
if (tb->fmt == MNT_FMT_GUESS)
tb->fmt = guess_table_format(s);
if (tb->fmt == MNT_FMT_FSTAB) {
if (mnt_parse_table_line(fs, s) != 0)
goto err;
} else if (tb->fmt == MNT_FMT_MOUNTINFO) {
if (mnt_parse_mountinfo_line(fs, s) != 0)
goto err;
} else if (tb->fmt == MNT_FMT_UTAB) {
if (mnt_parse_utab_line(fs, s) != 0)
goto err;
}
/*DBG(TAB, mnt_fs_print_debug(fs, stderr));*/
return 0;
err:
DBG(TAB, mnt_debug_h(tb, "%s:%d: %s parse error", filename, *nlines,
tb->fmt == MNT_FMT_MOUNTINFO ? "mountinfo" :
tb->fmt == MNT_FMT_FSTAB ? "tab" : "utab"));
/* by default all errors are recoverable, otherwise behavior depends on
* errcb() function. See mnt_table_set_parser_errcb().
*/
return tb->errcb ? tb->errcb(tb, filename, *nlines) : 1;
}
/**
* mnt_table_parse_stream:
* @tb: tab pointer
* @f: file stream
* @filename: filename used for debug and error messages
*
* Returns: 0 on success, negative number in case of error.
*/
int mnt_table_parse_stream(struct libmnt_table *tb, FILE *f, const char *filename)
{
int nlines = 0;
int rc = -1;
int flags = 0;
assert(tb);
assert(f);
assert(filename);
DBG(TAB, mnt_debug_h(tb, "%s: start parsing (%d entries)",
filename, mnt_table_get_nents(tb)));
/* necessary for /proc/mounts only, the /proc/self/mountinfo
* parser sets the flag properly
*/
if (filename && strcmp(filename, _PATH_PROC_MOUNTS) == 0)
flags = MNT_FS_KERNEL;
while (!feof(f)) {
struct libmnt_fs *fs = mnt_new_fs();
if (!fs)
goto err;
rc = mnt_table_parse_next(tb, f, fs, filename, &nlines);
if (!rc) {
rc = mnt_table_add_fs(tb, fs);
fs->flags |= flags;
}
if (rc) {
mnt_free_fs(fs);
if (rc == 1)
continue; /* recoverable error */
if (feof(f))
break;
goto err; /* fatal error */
}
}
DBG(TAB, mnt_debug_h(tb, "%s: stop parsing (%d entries)",
filename, mnt_table_get_nents(tb)));
return 0;
err:
DBG(TAB, mnt_debug_h(tb, "%s: parse error (rc=%d)", filename, rc));
return rc;
}
/**
* mnt_table_parse_file:
* @tb: tab pointer
* @filename: file
*
* Parses whole table (e.g. /etc/mtab) and appends new records to the @tab.
*
* The libmount parser ignores broken (syntax error) lines, these lines are
* reported to caller by errcb() function (see mnt_table_set_parser_errcb()).
*
* Returns: 0 on success, negative number in case of error.
*/
int mnt_table_parse_file(struct libmnt_table *tb, const char *filename)
{
FILE *f;
int rc;
assert(tb);
assert(filename);
if (!filename || !tb)
return -EINVAL;
f = fopen(filename, "r");
if (f) {
rc = mnt_table_parse_stream(tb, f, filename);
fclose(f);
} else
return -errno;
return rc;
}
static int mnt_table_parse_dir(struct libmnt_table *tb, const char *dirname)
{
int n = 0, i;
DIR *dir = NULL;
struct dirent **namelist = NULL;
/* TODO: it would be nice to have a scandir() implementation that
* is able to use already opened directory */
n = scandir(dirname, &namelist, NULL, versionsort);
if (n <= 0)
return 0;
/* let use "at" functions rather than play crazy games with paths... */
dir = opendir(dirname);
if (!dir)
return -errno;
for (i = 0; i < n; i++) {
struct dirent *d = namelist[i];
struct stat st;
size_t namesz;
FILE *f;
#ifdef _DIRENT_HAVE_D_TYPE
if (d->d_type != DT_UNKNOWN && d->d_type != DT_REG &&
d->d_type != DT_LNK)
continue;
#endif
if (*d->d_name == '.')
continue;
#define MNT_MNTTABDIR_EXTSIZ (sizeof(MNT_MNTTABDIR_EXT) - 1)
namesz = strlen(d->d_name);
if (!namesz || namesz < MNT_MNTTABDIR_EXTSIZ + 1 ||
strcmp(d->d_name + (namesz - MNT_MNTTABDIR_EXTSIZ),
MNT_MNTTABDIR_EXT))
continue;
if (fstat_at(dirfd(dir), _PATH_MNTTAB_DIR, d->d_name, &st, 0) ||
!S_ISREG(st.st_mode))
continue;
f = fopen_at(dirfd(dir), _PATH_MNTTAB_DIR,
d->d_name, O_RDONLY, "r");
if (f) {
mnt_table_parse_stream(tb, f, d->d_name);
fclose(f);
}
}
for (i = 0; i < n; i++)
free(namelist[i]);
free(namelist);
if (dir)
closedir(dir);
return 0;
}
struct libmnt_table *__mnt_new_table_from_file(const char *filename, int fmt)
{
struct libmnt_table *tb;
struct stat st;
assert(filename);
if (!filename)
return NULL;
if (stat(filename, &st))
return NULL;
tb = mnt_new_table();
if (tb) {
tb->fmt = fmt;
if (mnt_table_parse_file(tb, filename) != 0) {
mnt_free_table(tb);
tb = NULL;
}
}
return tb;
}
/**
* mnt_new_table_from_file:
* @filename: /etc/{m,fs}tab or /proc/self/mountinfo path
*
* Same as mnt_new_table() + mnt_table_parse_file(). Use this function for private
* files only. This function does not allow to use error callback, so you
* cannot provide any feedback to end-users about broken records in files (e.g.
* fstab).
*
* Returns: newly allocated tab on success and NULL in case of error.
*/
struct libmnt_table *mnt_new_table_from_file(const char *filename)
{
return __mnt_new_table_from_file(filename, MNT_FMT_GUESS);
}
/**
* mnt_new_table_from_dir
* @dirname: for example /etc/fstab.d
*
* Returns: newly allocated tab on success and NULL in case of error.
*/
struct libmnt_table *mnt_new_table_from_dir(const char *dirname)
{
struct libmnt_table *tb;
assert(dirname);
if (!dirname)
return NULL;
tb = mnt_new_table();
if (tb && mnt_table_parse_dir(tb, dirname) != 0) {
mnt_free_table(tb);
tb = NULL;
}
return tb;
}
/**
* mnt_table_set_parser_errcb:
* @tb: pointer to table
* @cb: pointer to callback function
*
* The error callback function is called by table parser (mnt_table_parse_file())
* in case of syntax error. The callback function could be used for errors
* evaluation, libmount will continue/stop parsing according to callback return
* codes:
*
* <0 : fatal error (abort parsing)
* 0 : success (parsing continue)
* >0 : recoverable error (the line is ignored, parsing continue).
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_set_parser_errcb(struct libmnt_table *tb,
int (*cb)(struct libmnt_table *tb, const char *filename, int line))
{
assert(tb);
tb->errcb = cb;
return 0;
}
/**
* mnt_table_parse_fstab:
* @tb: table
* @filename: overwrites default (/etc/fstab or $LIBMOUNT_FSTAB) or NULL
*
* This function parses /etc/fstab or /etc/fstab.d and appends new lines to the
* @tab. If the system contains classic fstab file and also fstab.d directory
* then the fstab file is parsed before the fstab.d directory.
*
* The fstab.d directory:
* - files are sorted by strverscmp(3)
* - files that starts with "." are ignored (e.g. ".10foo.fstab")
* - files without the ".fstab" extension are ignored
*
* See also mnt_table_set_parser_errcb().
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_parse_fstab(struct libmnt_table *tb, const char *filename)
{
FILE *f;
assert(tb);
if (!tb)
return -EINVAL;
if (!filename)
filename = mnt_get_fstab_path();
tb->fmt = MNT_FMT_FSTAB;
f = fopen(filename, "r");
if (f) {
int rc = mnt_table_parse_stream(tb, f, filename);
fclose(f);
if (rc)
return rc;
if (strcmp(filename, _PATH_MNTTAB))
/* /etc/fstab.d sould be used together with /etc/fstab only */
return 0;
}
if (!access(_PATH_MNTTAB_DIR, R_OK))
return mnt_table_parse_dir(tb, _PATH_MNTTAB_DIR);
return 0;
}
/*
* This function uses @uf to found corresponding record in @tb, then the record
* from @tb is updated (user specific mount options are added).
*
* Note that @uf must contain only user specific mount options instead of
* VFS options (note that FS options are ignored).
*
* Returns modified filesystem (from @tb) or NULL.
*/
static struct libmnt_fs *mnt_table_merge_user_fs(struct libmnt_table *tb, struct libmnt_fs *uf)
{
struct libmnt_fs *fs;
struct libmnt_iter itr;
const char *optstr, *src, *target, *root, *attrs;
assert(tb);
assert(uf);
if (!tb || !uf)
return NULL;
DBG(TAB, mnt_debug_h(tb, "merging user fs"));
src = mnt_fs_get_srcpath(uf);
target = mnt_fs_get_target(uf);
optstr = mnt_fs_get_user_options(uf);
attrs = mnt_fs_get_attributes(uf);
root = mnt_fs_get_root(uf);
if (!src || !target || !root || (!attrs && !optstr))
return NULL;
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
while(mnt_table_next_fs(tb, &itr, &fs) == 0) {
const char *s = mnt_fs_get_srcpath(fs),
*t = mnt_fs_get_target(fs),
*r = mnt_fs_get_root(fs);
if (fs->flags & MNT_FS_MERGED)
continue;
if (s && t && r && !strcmp(t, target) &&
!strcmp(s, src) && !strcmp(r, root))
break;
}
if (fs) {
DBG(TAB, mnt_debug_h(tb, "found fs -- appending user optstr"));
mnt_fs_append_options(fs, optstr);
mnt_fs_append_attributes(fs, attrs);
mnt_fs_set_bindsrc(fs, mnt_fs_get_bindsrc(uf));
fs->flags |= MNT_FS_MERGED;
DBG(TAB, mnt_debug_h(tb, "found fs:"));
DBG(TAB, mnt_fs_print_debug(fs, stderr));
}
return fs;
}
/**
* mnt_table_parse_mtab:
* @tb: table
* @filename: overwrites default (/etc/mtab or $LIBMOUNT_MTAB) or NULL
*
* This function parses /etc/mtab or /proc/self/mountinfo +
* /run/mount/utabs or /proc/mounts.
*
* See also mnt_table_set_parser_errcb().
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_table_parse_mtab(struct libmnt_table *tb, const char *filename)
{
int rc;
const char *utab = NULL;
if (mnt_has_regular_mtab(&filename, NULL)) {
DBG(TAB, mnt_debug_h(tb, "force %s usage", filename));
rc = mnt_table_parse_file(tb, filename);
if (!rc)
return 0;
filename = NULL; /* failed */
}
/*
* useless /etc/mtab
* -- read kernel information from /proc/self/mountinfo
*/
tb->fmt = MNT_FMT_MOUNTINFO;
rc = mnt_table_parse_file(tb, _PATH_PROC_MOUNTINFO);
if (rc) {
/* hmm, old kernel? ...try /proc/mounts */
tb->fmt = MNT_FMT_MTAB;
return mnt_table_parse_file(tb, _PATH_PROC_MOUNTS);
}
/*
* try to read user specific information from /run/mount/utabs
*/
utab = mnt_get_utab_path();
if (utab) {
struct libmnt_table *u_tb = __mnt_new_table_from_file(utab, MNT_FMT_UTAB);
if (u_tb) {
struct libmnt_fs *u_fs;
struct libmnt_iter itr;
mnt_reset_iter(&itr, MNT_ITER_BACKWARD);
/* merge user options into mountinfo from kernel */
while(mnt_table_next_fs(u_tb, &itr, &u_fs) == 0)
mnt_table_merge_user_fs(tb, u_fs);
mnt_free_table(u_tb);
}
}
return 0;
}