blob: 49fc9cc40e6d9fddf72f7f99511760bd22893bd9 [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* This file is part of libmount from util-linux project.
*
* Copyright (C) 2009-2018 Karel Zak <kzak@redhat.com>
*
* libmount is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*/
/**
* SECTION: optstr
* @title: Options string
* @short_description: low-level API for working with mount options
*
* This is a simple and low-level API to working with mount options that are stored
* in a string.
*/
#include <ctype.h>
#ifdef HAVE_LIBSELINUX
#include <selinux/selinux.h>
#include <selinux/context.h>
#endif
#include "strutils.h"
#include "mountP.h"
/*
* Option location
*/
struct libmnt_optloc {
char *begin;
char *end;
char *value;
size_t valsz;
size_t namesz;
};
#define mnt_init_optloc(_ol) (memset((_ol), 0, sizeof(struct libmnt_optloc)))
#define mnt_optmap_entry_novalue(e) \
(e && (e)->name && !strchr((e)->name, '=') && !((e)->mask & MNT_PREFIX))
/*
* Parses the first option from @optstr. The @optstr pointer is set to the beginning
* of the next option.
*
* Returns -EINVAL on parse error, 1 at the end of optstr and 0 on success.
*/
static int mnt_optstr_parse_next(char **optstr, char **name, size_t *namesz,
char **value, size_t *valsz)
{
int open_quote = 0;
char *start = NULL, *stop = NULL, *p, *sep = NULL;
char *optstr0;
assert(optstr);
assert(*optstr);
optstr0 = *optstr;
if (name)
*name = NULL;
if (namesz)
*namesz = 0;
if (value)
*value = NULL;
if (valsz)
*valsz = 0;
/* trim leading commas as to not invalidate option
* strings with multiple consecutive commas */
while (optstr0 && *optstr0 == ',')
optstr0++;
for (p = optstr0; p && *p; p++) {
if (!start)
start = p; /* beginning of the option item */
if (*p == '"')
open_quote ^= 1; /* reverse the status */
if (open_quote)
continue; /* still in quoted block */
if (!sep && p > start && *p == '=')
sep = p; /* name and value separator */
if (*p == ',')
stop = p; /* terminate the option item */
else if (*(p + 1) == '\0')
stop = p + 1; /* end of optstr */
if (!start || !stop)
continue;
if (stop <= start)
goto error;
if (name)
*name = start;
if (namesz)
*namesz = sep ? sep - start : stop - start;
*optstr = *stop ? stop + 1 : stop;
if (sep) {
if (value)
*value = sep + 1;
if (valsz)
*valsz = stop - sep - 1;
}
return 0;
}
return 1; /* end of optstr */
error:
DBG(OPTIONS, ul_debug("parse error: \"%s\"", optstr0));
return -EINVAL;
}
/*
* Locates the first option that matches @name. The @end is set to the
* char behind the option (it means ',' or \0).
*
* Returns negative number on parse error, 1 when not found and 0 on success.
*/
static int mnt_optstr_locate_option(char *optstr, const char *name,
struct libmnt_optloc *ol)
{
char *n;
size_t namesz, nsz;
int rc;
if (!optstr)
return 1;
assert(name);
namesz = strlen(name);
do {
rc = mnt_optstr_parse_next(&optstr, &n, &nsz,
&ol->value, &ol->valsz);
if (rc)
break;
if (namesz == nsz && strncmp(n, name, nsz) == 0) {
ol->begin = n;
ol->end = *(optstr - 1) == ',' ? optstr - 1 : optstr;
ol->namesz = nsz;
return 0;
}
} while(1);
return rc;
}
/**
* mnt_optstr_next_option:
* @optstr: option string, returns the position of the next option
* @name: returns the option name
* @namesz: returns the option name length
* @value: returns the option value or NULL
* @valuesz: returns the option value length or zero
*
* Parses the first option in @optstr.
*
* Returns: 0 on success, 1 at the end of @optstr or negative number in case of
* error.
*/
int mnt_optstr_next_option(char **optstr, char **name, size_t *namesz,
char **value, size_t *valuesz)
{
if (!optstr || !*optstr)
return -EINVAL;
return mnt_optstr_parse_next(optstr, name, namesz, value, valuesz);
}
static int __mnt_optstr_append_option(char **optstr,
const char *name, size_t nsz,
const char *value, size_t vsz)
{
char *p;
size_t sz, osz;
assert(name);
assert(*name);
assert(nsz);
assert(optstr);
osz = *optstr ? strlen(*optstr) : 0;
sz = osz + nsz + 1; /* 1: '\0' */
if (osz)
sz++; /* ',' options separator */
if (value)
sz += vsz + 1; /* 1: '=' */
p = realloc(*optstr, sz);
if (!p)
return -ENOMEM;
*optstr = p;
if (osz) {
p += osz;
*p++ = ',';
}
memcpy(p, name, nsz);
p += nsz;
if (value) {
*p++ = '=';
memcpy(p, value, vsz);
p += vsz;
}
*p = '\0';
return 0;
}
/**
* mnt_optstr_append_option:
* @optstr: option string or NULL, returns a reallocated string
* @name: value name
* @value: value
*
* Returns: 0 on success or <0 in case of error. After an error the @optstr should
* be unmodified.
*/
int mnt_optstr_append_option(char **optstr, const char *name, const char *value)
{
size_t vsz, nsz;
if (!optstr)
return -EINVAL;
if (!name || !*name)
return 0;
nsz = strlen(name);
vsz = value ? strlen(value) : 0;
return __mnt_optstr_append_option(optstr, name, nsz, value, vsz);
}
/**
* mnt_optstr_prepend_option:
* @optstr: option string or NULL, returns a reallocated string
* @name: value name
* @value: value
*
* Returns: 0 on success or <0 in case of error. After an error the @optstr should
* be unmodified.
*/
int mnt_optstr_prepend_option(char **optstr, const char *name, const char *value)
{
int rc = 0;
char *tmp;
if (!optstr)
return -EINVAL;
if (!name || !*name)
return 0;
tmp = *optstr;
*optstr = NULL;
rc = mnt_optstr_append_option(optstr, name, value);
if (!rc && tmp && *tmp)
rc = mnt_optstr_append_option(optstr, tmp, NULL);
if (!rc) {
free(tmp);
return 0;
}
free(*optstr);
*optstr = tmp;
DBG(OPTIONS, ul_debug("failed to prepend '%s[=%s]' to '%s'",
name, value, *optstr));
return rc;
}
/**
* mnt_optstr_get_option:
* @optstr: string with a comma separated list of options
* @name: requested option name
* @value: returns a pointer to the beginning of the value (e.g. name=VALUE) or NULL
* @valsz: returns size of the value or 0
*
* Returns: 0 on success, 1 when not found the @name or negative number in case
* of error.
*/
int mnt_optstr_get_option(const char *optstr, const char *name,
char **value, size_t *valsz)
{
struct libmnt_optloc ol;
int rc;
if (!optstr || !name)
return -EINVAL;
mnt_init_optloc(&ol);
rc = mnt_optstr_locate_option((char *) optstr, name, &ol);
if (!rc) {
if (value)
*value = ol.value;
if (valsz)
*valsz = ol.valsz;
}
return rc;
}
/**
* mnt_optstr_deduplicate_option:
* @optstr: string with a comma separated list of options
* @name: requested option name
*
* Removes all instances of @name except the last one.
*
* Returns: 0 on success, 1 when not found the @name or negative number in case
* of error.
*/
int mnt_optstr_deduplicate_option(char **optstr, const char *name)
{
int rc;
char *begin = NULL, *end = NULL, *opt;
if (!optstr || !name)
return -EINVAL;
opt = *optstr;
do {
struct libmnt_optloc ol;
mnt_init_optloc(&ol);
rc = mnt_optstr_locate_option(opt, name, &ol);
if (!rc) {
if (begin) {
/* remove the previous instance */
size_t shift = strlen(*optstr);
mnt_optstr_remove_option_at(optstr, begin, end);
/* now all the offsets are not valid anymore - recount */
shift -= strlen(*optstr);
ol.begin -= shift;
ol.end -= shift;
}
begin = ol.begin;
end = ol.end;
opt = end && *end ? end + 1 : NULL;
}
if (opt == NULL)
break;
} while (rc == 0 && *opt);
return rc < 0 ? rc : begin ? 0 : 1;
}
/*
* The result never starts or ends with a comma or contains two commas
* (e.g. ",aaa,bbb" or "aaa,,bbb" or "aaa,")
*/
int mnt_optstr_remove_option_at(char **optstr, char *begin, char *end)
{
size_t sz;
if (!optstr || !begin || !end)
return -EINVAL;
if ((begin == *optstr || *(begin - 1) == ',') && *end == ',')
end++;
sz = strlen(end);
memmove(begin, end, sz + 1);
if (!*begin && (begin > *optstr) && *(begin - 1) == ',')
*(begin - 1) = '\0';
return 0;
}
/* insert 'substr' or '=substr' to @str on position @pos */
static int __attribute__((nonnull(1,2,3)))
insert_value(char **str, char *pos, const char *substr, char **next)
{
size_t subsz = strlen(substr); /* substring size */
size_t strsz = strlen(*str);
size_t possz = strlen(pos);
size_t posoff;
char *p;
int sep;
/* is it necessary to prepend '=' before the substring ? */
sep = !(pos > *str && *(pos - 1) == '=');
/* save an offset of the place where we need to add substr */
posoff = pos - *str;
p = realloc(*str, strsz + sep + subsz + 1);
if (!p)
return -ENOMEM;
/* zeroize the newly allocated memory -- valgrind loves us... */
memset(p + strsz, 0, sep + subsz + 1);
/* set pointers to the reallocated string */
*str = p;
pos = p + posoff;
if (possz)
/* create a room for the new substring */
memmove(pos + subsz + sep, pos, possz + 1);
if (sep)
*pos++ = '=';
memcpy(pos, substr, subsz);
if (next) {
/* set pointer to the next option */
*next = pos + subsz;
if (**next == ',')
(*next)++;
}
return 0;
}
/**
* mnt_optstr_set_option:
* @optstr: string with a comma separated list of options
* @name: requested option
* @value: new value or NULL
*
* Set or unset the option @value.
*
* Returns: 0 on success, 1 when not found the @name or negative number in case
* of error.
*/
int mnt_optstr_set_option(char **optstr, const char *name, const char *value)
{
struct libmnt_optloc ol;
char *nameend;
int rc = 1;
if (!optstr || !name)
return -EINVAL;
mnt_init_optloc(&ol);
if (*optstr)
rc = mnt_optstr_locate_option(*optstr, name, &ol);
if (rc < 0)
return rc; /* parse error */
if (rc == 1)
return mnt_optstr_append_option(optstr, name, value); /* not found */
nameend = ol.begin + ol.namesz;
if (value == NULL && ol.value && ol.valsz)
/* remove unwanted "=value" */
mnt_optstr_remove_option_at(optstr, nameend, ol.end);
else if (value && ol.value == NULL)
/* insert "=value" */
rc = insert_value(optstr, nameend, value, NULL);
else if (value && ol.value && strlen(value) == ol.valsz)
/* simply replace =value */
memcpy(ol.value, value, ol.valsz);
else if (value && ol.value) {
mnt_optstr_remove_option_at(optstr, nameend, ol.end);
rc = insert_value(optstr, nameend, value, NULL);
}
return rc;
}
/**
* mnt_optstr_remove_option:
* @optstr: string with a comma separated list of options
* @name: requested option name
*
* Returns: 0 on success, 1 when not found the @name or negative number in case
* of error.
*/
int mnt_optstr_remove_option(char **optstr, const char *name)
{
struct libmnt_optloc ol;
int rc;
if (!optstr || !name)
return -EINVAL;
mnt_init_optloc(&ol);
rc = mnt_optstr_locate_option(*optstr, name, &ol);
if (rc != 0)
return rc;
mnt_optstr_remove_option_at(optstr, ol.begin, ol.end);
return 0;
}
/**
* mnt_split_optstr:
* @optstr: string with comma separated list of options
* @user: returns newly allocated string with userspace options
* @vfs: returns newly allocated string with VFS options
* @fs: returns newly allocated string with FS options
* @ignore_user: option mask for options that should be ignored
* @ignore_vfs: option mask for options that should be ignored
*
* For example:
*
* mnt_split_optstr(optstr, &u, NULL, NULL, MNT_NOMTAB, 0);
*
* returns all userspace options, the options that do not belong to
* mtab are ignored.
*
* Note that FS options are all options that are undefined in MNT_USERSPACE_MAP
* or MNT_LINUX_MAP.
*
* Returns: 0 on success, or a negative number in case of error.
*/
int mnt_split_optstr(const char *optstr, char **user, char **vfs,
char **fs, int ignore_user, int ignore_vfs)
{
char *name, *val, *str = (char *) optstr;
size_t namesz, valsz;
struct libmnt_optmap const *maps[2];
if (!optstr)
return -EINVAL;
maps[0] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
maps[1] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
if (vfs)
*vfs = NULL;
if (fs)
*fs = NULL;
if (user)
*user = NULL;
while (!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
int rc = 0;
const struct libmnt_optmap *ent = NULL;
const struct libmnt_optmap *m =
mnt_optmap_get_entry(maps, 2, name, namesz, &ent);
if (ent && !ent->id)
continue; /* ignore undefined options (comments) */
/* ignore name=<value> if options map expects <name> only */
if (valsz && mnt_optmap_entry_novalue(ent))
m = NULL;
if (ent && m && m == maps[0] && vfs) {
if (ignore_vfs && (ent->mask & ignore_vfs))
continue;
rc = __mnt_optstr_append_option(vfs, name, namesz,
val, valsz);
} else if (ent && m && m == maps[1] && user) {
if (ignore_user && (ent->mask & ignore_user))
continue;
rc = __mnt_optstr_append_option(user, name, namesz,
val, valsz);
} else if (!m && fs)
rc = __mnt_optstr_append_option(fs, name, namesz,
val, valsz);
if (rc) {
if (vfs) {
free(*vfs);
*vfs = NULL;
}
if (fs) {
free(*fs);
*fs = NULL;
}
if (user) {
free(*user);
*user = NULL;
}
return rc;
}
}
return 0;
}
/**
* mnt_optstr_get_options
* @optstr: string with a comma separated list of options
* @subset: returns newly allocated string with options
* @map: options map
* @ignore: mask of the options that should be ignored
*
* Extracts options from @optstr that belong to the @map, for example:
*
* mnt_optstr_get_options(optstr, &p,
* mnt_get_builtin_optmap(MNT_LINUX_MAP),
* MNT_NOMTAB);
*
* the 'p' returns all VFS options, the options that do not belong to mtab
* are ignored.
*
* Returns: 0 on success, or a negative number in case of error.
*/
int mnt_optstr_get_options(const char *optstr, char **subset,
const struct libmnt_optmap *map, int ignore)
{
struct libmnt_optmap const *maps[1];
char *name, *val, *str = (char *) optstr;
size_t namesz, valsz;
if (!optstr || !subset)
return -EINVAL;
maps[0] = map;
*subset = NULL;
while(!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
int rc = 0;
const struct libmnt_optmap *ent;
mnt_optmap_get_entry(maps, 1, name, namesz, &ent);
if (!ent || !ent->id)
continue; /* ignore undefined options (comments) */
if (ignore && (ent->mask & ignore))
continue;
/* ignore name=<value> if options map expects <name> only */
if (valsz && mnt_optmap_entry_novalue(ent))
continue;
rc = __mnt_optstr_append_option(subset, name, namesz, val, valsz);
if (rc) {
free(*subset);
return rc;
}
}
return 0;
}
/**
* mnt_optstr_get_flags:
* @optstr: string with comma separated list of options
* @flags: returns mount flags
* @map: options map
*
* Returns in @flags IDs of options from @optstr as defined in the @map.
*
* For example:
*
* "bind,exec,foo,bar" --returns-> MS_BIND
*
* "bind,noexec,foo,bar" --returns-> MS_BIND|MS_NOEXEC
*
* Note that @flags are not zeroized by this function! This function sets/unsets
* bits in the @flags only.
*
* Returns: 0 on success or negative number in case of error
*/
int mnt_optstr_get_flags(const char *optstr, unsigned long *flags,
const struct libmnt_optmap *map)
{
struct libmnt_optmap const *maps[2];
char *name, *str = (char *) optstr;
size_t namesz = 0, valsz = 0;
int nmaps = 0;
if (!optstr || !flags || !map)
return -EINVAL;
maps[nmaps++] = map;
if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP))
/*
* Add userspace map -- the "user" is interpreted as
* MS_NO{EXEC,SUID,DEV}.
*/
maps[nmaps++] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
while(!mnt_optstr_next_option(&str, &name, &namesz, NULL, &valsz)) {
const struct libmnt_optmap *ent;
const struct libmnt_optmap *m;
m = mnt_optmap_get_entry(maps, nmaps, name, namesz, &ent);
if (!m || !ent || !ent->id)
continue;
/* ignore name=<value> if options map expects <name> only */
if (valsz && mnt_optmap_entry_novalue(ent))
continue;
if (m == map) { /* requested map */
if (ent->mask & MNT_INVERT)
*flags &= ~ent->id;
else
*flags |= ent->id;
} else if (nmaps == 2 && m == maps[1] && valsz == 0) {
/*
* Special case -- translate "user" (but no user=) to
* MS_ options
*/
if (ent->mask & MNT_INVERT)
continue;
if (ent->id & (MNT_MS_OWNER | MNT_MS_GROUP))
*flags |= MS_OWNERSECURE;
else if (ent->id & (MNT_MS_USER | MNT_MS_USERS))
*flags |= MS_SECURE;
}
}
return 0;
}
/**
* mnt_optstr_apply_flags:
* @optstr: string with comma separated list of options
* @flags: returns mount flags
* @map: options map
*
* Removes/adds options to the @optstr according to flags. For example:
*
* MS_NOATIME and "foo,bar,noexec" --returns-> "foo,bar,noatime"
*
* Returns: 0 on success or negative number in case of error.
*/
int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
const struct libmnt_optmap *map)
{
struct libmnt_optmap const *maps[1];
char *name, *next, *val;
size_t namesz = 0, valsz = 0;
unsigned long fl;
int rc = 0;
if (!optstr || !map)
return -EINVAL;
DBG(CXT, ul_debug("applying 0x%08lu flags to '%s'", flags, *optstr));
maps[0] = map;
next = *optstr;
fl = flags;
/*
* There is a convention that 'rw/ro' flags are always at the beginning of
* the string (although the 'rw' is unnecessary).
*/
if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP)) {
const char *o = (fl & MS_RDONLY) ? "ro" : "rw";
if (next &&
(!strncmp(next, "rw", 2) || !strncmp(next, "ro", 2)) &&
(*(next + 2) == '\0' || *(next + 2) == ',')) {
/* already set, be paranoid and fix it */
memcpy(next, o, 2);
} else {
rc = mnt_optstr_prepend_option(optstr, o, NULL);
if (rc)
goto err;
next = *optstr; /* because realloc() */
}
fl &= ~MS_RDONLY;
next += 2;
if (*next == ',')
next++;
}
if (next && *next) {
/*
* scan @optstr and remove options that are missing in
* @flags
*/
while(!mnt_optstr_next_option(&next, &name, &namesz,
&val, &valsz)) {
const struct libmnt_optmap *ent;
if (mnt_optmap_get_entry(maps, 1, name, namesz, &ent)) {
/*
* remove unwanted option (rw/ro is already set)
*/
if (!ent || !ent->id)
continue;
/* ignore name=<value> if options map expects <name> only */
if (valsz && mnt_optmap_entry_novalue(ent))
continue;
if (ent->id == MS_RDONLY ||
(ent->mask & MNT_INVERT) ||
(fl & ent->id) != (unsigned long) ent->id) {
char *end = val ? val + valsz :
name + namesz;
next = name;
rc = mnt_optstr_remove_option_at(
optstr, name, end);
if (rc)
goto err;
}
if (!(ent->mask & MNT_INVERT)) {
fl &= ~ent->id;
if (ent->id & MS_REC)
fl |= MS_REC;
}
}
}
}
/* add missing options (but ignore fl if contains MS_REC only) */
if (fl && fl != MS_REC) {
const struct libmnt_optmap *ent;
char *p;
for (ent = map; ent && ent->name; ent++) {
if ((ent->mask & MNT_INVERT)
|| ent->id == 0
|| (fl & ent->id) != (unsigned long) ent->id)
continue;
/* don't add options which require values (e.g. offset=%d) */
p = strchr(ent->name, '=');
if (p) {
if (p > ent->name && *(p - 1) == '[')
p--; /* name[=] */
else
continue; /* name= */
p = strndup(ent->name, p - ent->name);
if (!p) {
rc = -ENOMEM;
goto err;
}
mnt_optstr_append_option(optstr, p, NULL);
free(p);
} else
mnt_optstr_append_option(optstr, ent->name, NULL);
}
}
DBG(CXT, ul_debug("new optstr '%s'", *optstr));
return rc;
err:
DBG(CXT, ul_debug("failed to apply flags [rc=%d]", rc));
return rc;
}
/*
* @optstr: string with comma separated list of options
* @value: pointer to the begin of the context value
* @valsz: size of the value
* @next: returns pointer to the next option (optional argument)
*
* Translates SELinux context from human to raw format. The function does not
* modify @optstr and returns zero if libmount is compiled without SELinux
* support.
*
* Returns: 0 on success, a negative number in case of error.
*/
#ifndef HAVE_LIBSELINUX
int mnt_optstr_fix_secontext(char **optstr __attribute__ ((__unused__)),
char *value __attribute__ ((__unused__)),
size_t valsz __attribute__ ((__unused__)),
char **next __attribute__ ((__unused__)))
{
return 0;
}
#else
int mnt_optstr_fix_secontext(char **optstr,
char *value,
size_t valsz,
char **next)
{
int rc = 0;
security_context_t raw = NULL;
char *p, *val, *begin, *end;
size_t sz;
if (!optstr || !*optstr || !value || !valsz)
return -EINVAL;
DBG(CXT, ul_debug("fixing SELinux context"));
begin = value;
end = value + valsz;
/* the selinux contexts are quoted */
if (*value == '"') {
if (valsz <= 2 || *(value + valsz - 1) != '"')
return -EINVAL; /* improperly quoted option string */
value++;
valsz -= 2;
}
p = strndup(value, valsz);
if (!p)
return -ENOMEM;
/* translate the context */
rc = selinux_trans_to_raw_context((security_context_t) p, &raw);
DBG(CXT, ul_debug("SELinux context '%s' translated to '%s'",
p, rc == -1 ? "FAILED" : (char *) raw));
free(p);
if (rc == -1 || !raw)
return -EINVAL;
/* create a quoted string from the raw context */
sz = strlen((char *) raw);
if (!sz)
return -EINVAL;
p = val = malloc(valsz + 3);
if (!val)
return -ENOMEM;
*p++ = '"';
memcpy(p, raw, sz);
p += sz;
*p++ = '"';
*p = '\0';
freecon(raw);
/* set new context */
mnt_optstr_remove_option_at(optstr, begin, end);
rc = insert_value(optstr, begin, val, next);
free(val);
return rc;
}
#endif
static int set_uint_value(char **optstr, unsigned int num,
char *begin, char *end, char **next)
{
char buf[40];
snprintf(buf, sizeof(buf), "%u", num);
mnt_optstr_remove_option_at(optstr, begin, end);
return insert_value(optstr, begin, buf, next);
}
/*
* @optstr: string with a comma separated list of options
* @value: pointer to the beginning of the uid value
* @valsz: size of the value
* @next: returns pointer to the next option (optional argument)
* Translates "username" or "useruid" to the real UID.
*
* For example:
* if (!mnt_optstr_get_option(optstr, "uid", &val, &valsz))
* mnt_optstr_fix_uid(&optstr, val, valsz, NULL);
*
* Returns: 0 on success, a negative number in case of error.
*/
int mnt_optstr_fix_uid(char **optstr, char *value, size_t valsz, char **next)
{
char *end;
if (!optstr || !*optstr || !value || !valsz)
return -EINVAL;
DBG(CXT, ul_debug("fixing uid"));
end = value + valsz;
if (valsz == 7 && !strncmp(value, "useruid", 7) &&
(*(value + 7) == ',' || !*(value + 7)))
return set_uint_value(optstr, getuid(), value, end, next);
else if (!isdigit(*value)) {
uid_t id;
int rc;
char *p = strndup(value, valsz);
if (!p)
return -ENOMEM;
rc = mnt_get_uid(p, &id);
free(p);
if (!rc)
return set_uint_value(optstr, id, value, end, next);
}
if (next) {
/* no change, let's keep the original value */
*next = value + valsz;
if (**next == ',')
(*next)++;
}
return 0;
}
/*
* @optstr: string with a comma separated list of options
* @value: pointer to the beginning of the uid value
* @valsz: size of the value
* @next: returns pointer to the next option (optional argument)
* Translates "groupname" or "usergid" to the real GID.
*
* Returns: 0 on success, a negative number in case of error.
*/
int mnt_optstr_fix_gid(char **optstr, char *value, size_t valsz, char **next)
{
char *end;
if (!optstr || !*optstr || !value || !valsz)
return -EINVAL;
DBG(CXT, ul_debug("fixing gid"));
end = value + valsz;
if (valsz == 7 && !strncmp(value, "usergid", 7) &&
(*(value + 7) == ',' || !*(value + 7)))
return set_uint_value(optstr, getgid(), value, end, next);
else if (!isdigit(*value)) {
int rc;
gid_t id;
char *p = strndup(value, valsz);
if (!p)
return -ENOMEM;
rc = mnt_get_gid(p, &id);
free(p);
if (!rc)
return set_uint_value(optstr, id, value, end, next);
}
if (next) {
/* nothing */
*next = value + valsz;
if (**next == ',')
(*next)++;
}
return 0;
}
/*
* Converts "user" to "user=<username>".
*
* Returns: 0 on success, negative number in case of error.
*/
int mnt_optstr_fix_user(char **optstr)
{
char *username;
struct libmnt_optloc ol;
int rc = 0;
DBG(CXT, ul_debug("fixing user"));
mnt_init_optloc(&ol);
rc = mnt_optstr_locate_option(*optstr, "user", &ol);
if (rc)
return rc == 1 ? 0 : rc; /* 1: user= not found */
username = mnt_get_username(getuid());
if (!username)
return -ENOMEM;
if (!ol.valsz || (ol.value && strncmp(ol.value, username, ol.valsz))) {
if (ol.valsz)
/* remove old value */
mnt_optstr_remove_option_at(optstr, ol.value, ol.end);
rc = insert_value(optstr, ol.value ? ol.value : ol.end,
username, NULL);
}
free(username);
return rc;
}
/**
* mnt_match_options:
* @optstr: options string
* @pattern: comma delimited list of options
*
* The "no" could be 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.
*
* The "no" prefix interpretation could be disabled by the "+" prefix, for example
* "+noauto" matches if @optstr literally contains the "noauto" string.
*
* "xxx,yyy,zzz" : "nozzz" -> False
*
* "xxx,yyy,zzz" : "xxx,noeee" -> True
*
* "bar,zzz" : "nofoo" -> True (does not contain "foo")
*
* "nofoo,bar" : "nofoo" -> True (does not contain "foo")
*
* "nofoo,bar" : "+nofoo" -> True (contains "nofoo")
*
* "bar,zzz" : "+nofoo" -> False (does not contain "nofoo")
*
*
* 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)
{
char *name, *pat = (char *) pattern;
char *buf, *patval;
size_t namesz = 0, patvalsz = 0;
int match = 1;
if (!pattern && !optstr)
return 1;
if (!pattern)
return 0;
buf = malloc(strlen(pattern) + 1);
if (!buf)
return 0;
/* walk on pattern string
*/
while (match && !mnt_optstr_next_option(&pat, &name, &namesz,
&patval, &patvalsz)) {
char *val;
size_t sz;
int no = 0, rc;
if (*name == '+')
name++, namesz--;
else if ((no = (startswith(name, "no") != NULL)))
name += 2, namesz -= 2;
xstrncpy(buf, name, namesz + 1);
rc = mnt_optstr_get_option(optstr, buf, &val, &sz);
/* check also value (if the pattern is "foo=value") */
if (rc == 0 && patvalsz > 0 &&
(patvalsz != sz || strncmp(patval, val, sz) != 0))
rc = 1;
switch (rc) {
case 0: /* found */
match = no == 0 ? 1 : 0;
break;
case 1: /* not found */
match = no == 1 ? 1 : 0;
break;
default: /* parse error */
match = 0;
break;
}
}
free(buf);
return match;
}
#ifdef TEST_PROGRAM
static int test_append(struct libmnt_test *ts, int argc, char *argv[])
{
const char *value = NULL, *name;
char *optstr;
int rc;
if (argc < 3)
return -EINVAL;
optstr = strdup(argv[1]);
name = argv[2];
if (argc == 4)
value = argv[3];
rc = mnt_optstr_append_option(&optstr, name, value);
if (!rc)
printf("result: >%s<\n", optstr);
free(optstr);
return rc;
}
static int test_prepend(struct libmnt_test *ts, int argc, char *argv[])
{
const char *value = NULL, *name;
char *optstr;
int rc;
if (argc < 3)
return -EINVAL;
optstr = strdup(argv[1]);
name = argv[2];
if (argc == 4)
value = argv[3];
rc = mnt_optstr_prepend_option(&optstr, name, value);
if (!rc)
printf("result: >%s<\n", optstr);
free(optstr);
return rc;
}
static int test_split(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr, *user = NULL, *fs = NULL, *vfs = NULL;
int rc;
if (argc < 2)
return -EINVAL;
optstr = strdup(argv[1]);
rc = mnt_split_optstr(optstr, &user, &vfs, &fs, 0, 0);
if (!rc) {
printf("user : %s\n", user);
printf("vfs : %s\n", vfs);
printf("fs : %s\n", fs);
}
free(user);
free(vfs);
free(fs);
free(optstr);
return rc;
}
static int test_flags(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr;
int rc;
unsigned long fl = 0;
if (argc < 2)
return -EINVAL;
optstr = strdup(argv[1]);
rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_LINUX_MAP));
if (rc)
return rc;
printf("mountflags: 0x%08lx\n", fl);
fl = 0;
rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
if (rc)
return rc;
printf("userspace-mountflags: 0x%08lx\n", fl);
free(optstr);
return rc;
}
static int test_apply(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr;
int rc, map;
unsigned long flags;
if (argc < 4)
return -EINVAL;
if (!strcmp(argv[1], "--user"))
map = MNT_USERSPACE_MAP;
else if (!strcmp(argv[1], "--linux"))
map = MNT_LINUX_MAP;
else {
fprintf(stderr, "unknown option '%s'\n", argv[1]);
return -EINVAL;
}
optstr = strdup(argv[2]);
flags = strtoul(argv[3], NULL, 16);
printf("flags: 0x%08lx\n", flags);
rc = mnt_optstr_apply_flags(&optstr, flags, mnt_get_builtin_optmap(map));
printf("optstr: %s\n", optstr);
free(optstr);
return rc;
}
static int test_set(struct libmnt_test *ts, int argc, char *argv[])
{
const char *value = NULL, *name;
char *optstr;
int rc;
if (argc < 3)
return -EINVAL;
optstr = strdup(argv[1]);
name = argv[2];
if (argc == 4)
value = argv[3];
rc = mnt_optstr_set_option(&optstr, name, value);
if (!rc)
printf("result: >%s<\n", optstr);
free(optstr);
return rc;
}
static int test_get(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr;
const char *name;
char *val = NULL;
size_t sz = 0;
int rc;
if (argc < 2)
return -EINVAL;
optstr = argv[1];
name = argv[2];
rc = mnt_optstr_get_option(optstr, name, &val, &sz);
if (rc == 0) {
printf("found; name: %s", name);
if (sz) {
printf(", argument: size=%zd data=", sz);
if (fwrite(val, 1, sz, stdout) != sz)
return -1;
}
printf("\n");
} else if (rc == 1)
printf("%s: not found\n", name);
else
printf("parse error: %s\n", optstr);
return rc;
}
static int test_remove(struct libmnt_test *ts, int argc, char *argv[])
{
const char *name;
char *optstr;
int rc;
if (argc < 3)
return -EINVAL;
optstr = strdup(argv[1]);
name = argv[2];
rc = mnt_optstr_remove_option(&optstr, name);
if (!rc)
printf("result: >%s<\n", optstr);
free(optstr);
return rc;
}
static int test_dedup(struct libmnt_test *ts, int argc, char *argv[])
{
const char *name;
char *optstr;
int rc;
if (argc < 3)
return -EINVAL;
optstr = strdup(argv[1]);
name = argv[2];
rc = mnt_optstr_deduplicate_option(&optstr, name);
if (!rc)
printf("result: >%s<\n", optstr);
free(optstr);
return rc;
}
static int test_fix(struct libmnt_test *ts, int argc, char *argv[])
{
char *optstr;
int rc = 0;
char *name, *val, *next;
size_t valsz, namesz;
if (argc < 2)
return -EINVAL;
next = optstr = strdup(argv[1]);
printf("optstr: %s\n", optstr);
while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
if (!strncmp(name, "uid", 3))
rc = mnt_optstr_fix_uid(&optstr, val, valsz, &next);
else if (!strncmp(name, "gid", 3))
rc = mnt_optstr_fix_gid(&optstr, val, valsz, &next);
else if (!strncmp(name, "context", 7))
rc = mnt_optstr_fix_secontext(&optstr, val, valsz, &next);
if (rc)
break;
}
if (rc)
rc = mnt_optstr_fix_user(&optstr);
printf("fixed: %s\n", optstr);
free(optstr);
return rc;
}
int main(int argc, char *argv[])
{
struct libmnt_test tss[] = {
{ "--append", test_append, "<optstr> <name> [<value>] append value to optstr" },
{ "--prepend",test_prepend,"<optstr> <name> [<value>] prepend value to optstr" },
{ "--set", test_set, "<optstr> <name> [<value>] (un)set value" },
{ "--get", test_get, "<optstr> <name> search name in optstr" },
{ "--remove", test_remove, "<optstr> <name> remove name in optstr" },
{ "--dedup", test_dedup, "<optstr> <name> deduplicate name in optstr" },
{ "--split", test_split, "<optstr> split into FS, VFS and userspace" },
{ "--flags", test_flags, "<optstr> convert options to MS_* flags" },
{ "--apply", test_apply, "--{linux,user} <optstr> <mask> apply mask to optstr" },
{ "--fix", test_fix, "<optstr> fix uid=, gid=, user, and context=" },
{ NULL }
};
return mnt_run_test(tss, argc, argv);
}
#endif /* TEST_PROGRAM */