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ntfs-3g/libntfs-3g/acls.c
Jean-Pierre André 891b7e97b3 Improved sanity checks on a security descriptor
2010-07-22 14:49:46 +02:00

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/**
* acls.c - General function to process NTFS ACLs
*
* This module is part of ntfs-3g library, but may also be
* integrated in tools running over Linux or Windows
*
* Copyright (c) 2007-2009 Jean-Pierre Andre
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
/*
* integration into ntfs-3g
*/
#include "config.h"
#ifdef HAVE_STDIO_H
#include <stdio.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYSLOG_H
#include <syslog.h>
#endif
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
#include "types.h"
#include "layout.h"
#include "security.h"
#include "acls.h"
#include "misc.h"
#else
/*
* integration into secaudit, check whether Win32,
* may have to be adapted to compiler or something else
*/
#ifndef WIN32
#if defined(__WIN32) | defined(__WIN32__) | defined(WNSC)
#define WIN32 1
#endif
#endif
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <errno.h>
/*
* integration into secaudit/Win32
*/
#ifdef WIN32
#include <fcntl.h>
#include <windows.h>
#define __LITTLE_ENDIAN 1234
#define __BYTE_ORDER __LITTLE_ENDIAN
#else
/*
* integration into secaudit/STSC
*/
#ifdef STSC
#include <stat.h>
#undef __BYTE_ORDER
#define __BYTE_ORDER __BIG_ENDIAN
#else
/*
* integration into secaudit/Linux
*/
#include <sys/stat.h>
#include <endian.h>
#include <unistd.h>
#include <dlfcn.h>
#endif /* STSC */
#endif /* WIN32 */
#include "secaudit.h"
#endif /* HAVE_CONFIG_H */
/*
* A few useful constants
*/
/*
* null SID (S-1-0-0)
*/
static const char nullsidbytes[] = {
1, /* revision */
1, /* auth count */
0, 0, 0, 0, 0, 0, /* base */
0, 0, 0, 0 /* 1st level */
};
static const SID *nullsid = (const SID*)nullsidbytes;
/*
* SID for world (S-1-1-0)
*/
static const char worldsidbytes[] = {
1, /* revision */
1, /* auth count */
0, 0, 0, 0, 0, 1, /* base */
0, 0, 0, 0 /* 1st level */
} ;
const SID *worldsid = (const SID*)worldsidbytes;
/*
* SID for administrator
*/
static const char adminsidbytes[] = {
1, /* revision */
2, /* auth count */
0, 0, 0, 0, 0, 5, /* base */
32, 0, 0, 0, /* 1st level */
32, 2, 0, 0 /* 2nd level */
};
const SID *adminsid = (const SID*)adminsidbytes;
/*
* SID for system
*/
static const char systemsidbytes[] = {
1, /* revision */
1, /* auth count */
0, 0, 0, 0, 0, 5, /* base */
18, 0, 0, 0 /* 1st level */
};
static const SID *systemsid = (const SID*)systemsidbytes;
/*
* SID for generic creator-owner
* S-1-3-0
*/
static const char ownersidbytes[] = {
1, /* revision */
1, /* auth count */
0, 0, 0, 0, 0, 3, /* base */
0, 0, 0, 0 /* 1st level */
} ;
static const SID *ownersid = (const SID*)ownersidbytes;
/*
* SID for generic creator-group
* S-1-3-1
*/
static const char groupsidbytes[] = {
1, /* revision */
1, /* auth count */
0, 0, 0, 0, 0, 3, /* base */
1, 0, 0, 0 /* 1st level */
} ;
static const SID *groupsid = (const SID*)groupsidbytes;
/*
* Determine the size of a SID
*/
int ntfs_sid_size(const SID * sid)
{
return (sid->sub_authority_count * 4 + 8);
}
/*
* Test whether two SID are equal
*/
BOOL ntfs_same_sid(const SID *first, const SID *second)
{
int size;
size = ntfs_sid_size(first);
return ((ntfs_sid_size(second) == size)
&& !memcmp(first, second, size));
}
/*
* Test whether a SID means "world user"
* Local users group also recognized as world
*/
static int is_world_sid(const SID * usid)
{
return (
/* check whether S-1-1-0 : world */
((usid->sub_authority_count == 1)
&& (usid->identifier_authority.high_part == const_cpu_to_be16(0))
&& (usid->identifier_authority.low_part == const_cpu_to_be32(1))
&& (usid->sub_authority[0] == const_cpu_to_le32(0)))
/* check whether S-1-5-32-545 : local user */
|| ((usid->sub_authority_count == 2)
&& (usid->identifier_authority.high_part == const_cpu_to_be16(0))
&& (usid->identifier_authority.low_part == const_cpu_to_be32(5))
&& (usid->sub_authority[0] == const_cpu_to_le32(32))
&& (usid->sub_authority[1] == const_cpu_to_le32(545)))
);
}
/*
* Test whether a SID means "some user (or group)"
* Currently we only check for S-1-5-21... but we should
* probably test for other configurations
*/
BOOL ntfs_is_user_sid(const SID *usid)
{
return ((usid->sub_authority_count == 5)
&& (usid->identifier_authority.high_part == const_cpu_to_be16(0))
&& (usid->identifier_authority.low_part == const_cpu_to_be32(5))
&& (usid->sub_authority[0] == const_cpu_to_le32(21)));
}
/*
* Determine the size of a security attribute
* whatever the order of fields
*/
unsigned int ntfs_attr_size(const char *attr)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pdacl;
const ACL *psacl;
const SID *psid;
unsigned int offdacl;
unsigned int offsacl;
unsigned int offowner;
unsigned int offgroup;
unsigned int endsid;
unsigned int endacl;
unsigned int attrsz;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)attr;
/*
* First check group, which is the last field in all descriptors
* we build, and in most descriptors built by Windows
*/
attrsz = sizeof(SECURITY_DESCRIPTOR_RELATIVE);
offgroup = le32_to_cpu(phead->group);
if (offgroup >= attrsz) {
/* find end of GSID */
psid = (const SID*)&attr[offgroup];
endsid = offgroup + ntfs_sid_size(psid);
if (endsid > attrsz) attrsz = endsid;
}
offowner = le32_to_cpu(phead->owner);
if (offowner >= attrsz) {
/* find end of USID */
psid = (const SID*)&attr[offowner];
endsid = offowner + ntfs_sid_size(psid);
attrsz = endsid;
}
offsacl = le32_to_cpu(phead->sacl);
if (offsacl >= attrsz) {
/* find end of SACL */
psacl = (const ACL*)&attr[offsacl];
endacl = offsacl + le16_to_cpu(psacl->size);
if (endacl > attrsz)
attrsz = endacl;
}
/* find end of DACL */
offdacl = le32_to_cpu(phead->dacl);
if (offdacl >= attrsz) {
pdacl = (const ACL*)&attr[offdacl];
endacl = offdacl + le16_to_cpu(pdacl->size);
if (endacl > attrsz)
attrsz = endacl;
}
return (attrsz);
}
/*
* Do sanity checks on a SID read from storage
* (just check revision and number of authorities)
*/
BOOL ntfs_valid_sid(const SID *sid)
{
return ((sid->revision == SID_REVISION)
&& (sid->sub_authority_count >= 1)
&& (sid->sub_authority_count <= 8));
}
/*
* Check whether a SID is acceptable for an implicit
* mapping pattern.
* It should have been already checked it is a valid user SID.
*
* The last authority reference has to be >= 1000 (Windows usage)
* and <= 0x7fffffff, so that 30 bits from a uid and 30 more bits
* from a gid an be inserted with no overflow.
*/
BOOL ntfs_valid_pattern(const SID *sid)
{
int cnt;
u32 auth;
le32 leauth;
cnt = sid->sub_authority_count;
leauth = sid->sub_authority[cnt-1];
auth = le32_to_cpu(leauth);
return ((auth >= 1000) && (auth <= 0x7fffffff));
}
/*
* Compute the uid or gid associated to a SID
* through an implicit mapping
*
* Returns 0 (root) if it does not match pattern
*/
static u32 findimplicit(const SID *xsid, const SID *pattern, int parity)
{
BIGSID defsid;
SID *psid;
u32 xid; /* uid or gid */
int cnt;
u32 carry;
le32 leauth;
u32 uauth;
u32 xlast;
u32 rlast;
memcpy(&defsid,pattern,ntfs_sid_size(pattern));
psid = (SID*)&defsid;
cnt = psid->sub_authority_count;
xid = 0;
if (xsid->sub_authority_count == cnt) {
psid->sub_authority[cnt-1] = xsid->sub_authority[cnt-1];
leauth = xsid->sub_authority[cnt-1];
xlast = le32_to_cpu(leauth);
leauth = pattern->sub_authority[cnt-1];
rlast = le32_to_cpu(leauth);
if ((xlast > rlast) && !((xlast ^ rlast ^ parity) & 1)) {
/* direct check for basic situation */
if (ntfs_same_sid(psid,xsid))
xid = ((xlast - rlast) >> 1) & 0x3fffffff;
else {
/*
* check whether part of mapping had to be
* recorded in a higher level authority
*/
carry = 1;
do {
leauth = psid->sub_authority[cnt-2];
uauth = le32_to_cpu(leauth) + 1;
psid->sub_authority[cnt-2]
= cpu_to_le32(uauth);
} while (!ntfs_same_sid(psid,xsid)
&& (++carry < 4));
if (carry < 4)
xid = (((xlast - rlast) >> 1)
& 0x3fffffff) | (carry << 30);
}
}
}
return (xid);
}
/*
* Find usid mapped to a Linux user
* Returns NULL if not found
*/
const SID *ntfs_find_usid(const struct MAPPING* usermapping,
uid_t uid, SID *defusid)
{
const struct MAPPING *p;
const SID *sid;
le32 leauth;
u32 uauth;
int cnt;
if (!uid)
sid = adminsid;
else {
p = usermapping;
while (p && p->xid && ((uid_t)p->xid != uid))
p = p->next;
if (p && !p->xid) {
/*
* default pattern has been reached :
* build an implicit SID according to pattern
* (the pattern format was checked while reading
* the mapping file)
*/
memcpy(defusid, p->sid, ntfs_sid_size(p->sid));
cnt = defusid->sub_authority_count;
leauth = defusid->sub_authority[cnt-1];
uauth = le32_to_cpu(leauth) + 2*(uid & 0x3fffffff);
defusid->sub_authority[cnt-1] = cpu_to_le32(uauth);
if (uid & 0xc0000000) {
leauth = defusid->sub_authority[cnt-2];
uauth = le32_to_cpu(leauth) + ((uid >> 30) & 3);
defusid->sub_authority[cnt-2] = cpu_to_le32(uauth);
}
sid = defusid;
} else
sid = (p ? p->sid : (const SID*)NULL);
}
return (sid);
}
/*
* Find Linux group mapped to a gsid
* Returns 0 (root) if not found
*/
const SID *ntfs_find_gsid(const struct MAPPING* groupmapping,
gid_t gid, SID *defgsid)
{
const struct MAPPING *p;
const SID *sid;
le32 leauth;
u32 uauth;
int cnt;
if (!gid)
sid = adminsid;
else {
p = groupmapping;
while (p && p->xid && ((gid_t)p->xid != gid))
p = p->next;
if (p && !p->xid) {
/*
* default pattern has been reached :
* build an implicit SID according to pattern
* (the pattern format was checked while reading
* the mapping file)
*/
memcpy(defgsid, p->sid, ntfs_sid_size(p->sid));
cnt = defgsid->sub_authority_count;
leauth = defgsid->sub_authority[cnt-1];
uauth = le32_to_cpu(leauth) + 2*(gid & 0x3fffffff) + 1;
defgsid->sub_authority[cnt-1] = cpu_to_le32(uauth);
if (gid & 0xc0000000) {
leauth = defgsid->sub_authority[cnt-2];
uauth = le32_to_cpu(leauth) + ((gid >> 30) & 3);
defgsid->sub_authority[cnt-2] = cpu_to_le32(uauth);
}
sid = defgsid;
} else
sid = (p ? p->sid : (const SID*)NULL);
}
return (sid);
}
/*
* Find Linux owner mapped to a usid
* Returns 0 (root) if not found
*/
uid_t ntfs_find_user(const struct MAPPING* usermapping, const SID *usid)
{
uid_t uid;
const struct MAPPING *p;
p = usermapping;
while (p && p->xid && !ntfs_same_sid(usid, p->sid))
p = p->next;
if (p && !p->xid)
/*
* No explicit mapping found, try implicit mapping
*/
uid = findimplicit(usid,p->sid,0);
else
uid = (p ? p->xid : 0);
return (uid);
}
/*
* Find Linux group mapped to a gsid
* Returns 0 (root) if not found
*/
gid_t ntfs_find_group(const struct MAPPING* groupmapping, const SID * gsid)
{
gid_t gid;
const struct MAPPING *p;
int gsidsz;
gsidsz = ntfs_sid_size(gsid);
p = groupmapping;
while (p && p->xid && !ntfs_same_sid(gsid, p->sid))
p = p->next;
if (p && !p->xid)
/*
* No explicit mapping found, try implicit mapping
*/
gid = findimplicit(gsid,p->sid,1);
else
gid = (p ? p->xid : 0);
return (gid);
}
/*
* Check the validity of the ACEs in a DACL or SACL
*/
static BOOL valid_acl(const ACL *pacl, unsigned int end)
{
const ACCESS_ALLOWED_ACE *pace;
unsigned int offace;
unsigned int acecnt;
unsigned int acesz;
unsigned int nace;
BOOL ok;
ok = TRUE;
acecnt = le16_to_cpu(pacl->ace_count);
offace = sizeof(ACL);
for (nace = 0; (nace < acecnt) && ok; nace++) {
/* be sure the beginning is within range */
if ((offace + sizeof(ACCESS_ALLOWED_ACE)) > end)
ok = FALSE;
else {
pace = (const ACCESS_ALLOWED_ACE*)
&((const char*)pacl)[offace];
acesz = le16_to_cpu(pace->size);
if (((offace + acesz) > end)
|| !ntfs_valid_sid(&pace->sid)
|| ((ntfs_sid_size(&pace->sid) + 8) != (int)acesz))
ok = FALSE;
offace += acesz;
}
}
return (ok);
}
/*
* Do sanity checks on security descriptors read from storage
* basically, we make sure that every field holds within
* allocated storage
* Should not be called with a NULL argument
* returns TRUE if considered safe
* if not, error should be logged by caller
*/
BOOL ntfs_valid_descr(const char *securattr, unsigned int attrsz)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pdacl;
const ACL *psacl;
unsigned int offdacl;
unsigned int offsacl;
unsigned int offowner;
unsigned int offgroup;
BOOL ok;
ok = TRUE;
/*
* first check overall size if within allocation range
* and a DACL is present
* and owner and group SID are valid
*/
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
offsacl = le32_to_cpu(phead->sacl);
offowner = le32_to_cpu(phead->owner);
offgroup = le32_to_cpu(phead->group);
pdacl = (const ACL*)&securattr[offdacl];
psacl = (const ACL*)&securattr[offsacl];
/*
* size check occurs before the above pointers are used
*
* "DR Watson" standard directory on WinXP has an
* old revision and no DACL though SE_DACL_PRESENT is set
*/
if ((attrsz >= sizeof(SECURITY_DESCRIPTOR_RELATIVE))
&& (phead->revision == SECURITY_DESCRIPTOR_REVISION)
&& (offowner >= sizeof(SECURITY_DESCRIPTOR_RELATIVE))
&& ((offowner + 2) < attrsz)
&& (offgroup >= sizeof(SECURITY_DESCRIPTOR_RELATIVE))
&& ((offgroup + 2) < attrsz)
&& (!offdacl
|| ((offdacl >= sizeof(SECURITY_DESCRIPTOR_RELATIVE))
&& (offdacl+sizeof(ACL) < attrsz)))
&& (!offsacl
|| ((offsacl >= sizeof(SECURITY_DESCRIPTOR_RELATIVE))
&& (offsacl+sizeof(ACL) < attrsz)))
&& !(phead->owner & const_cpu_to_le32(3))
&& !(phead->group & const_cpu_to_le32(3))
&& !(phead->dacl & const_cpu_to_le32(3))
&& !(phead->sacl & const_cpu_to_le32(3))
&& (ntfs_attr_size(securattr) <= attrsz)
&& ntfs_valid_sid((const SID*)&securattr[offowner])
&& ntfs_valid_sid((const SID*)&securattr[offgroup])
/*
* if there is an ACL, as indicated by offdacl,
* require SE_DACL_PRESENT
* but "Dr Watson" has SE_DACL_PRESENT though no DACL
*/
&& (!offdacl
|| ((phead->control & SE_DACL_PRESENT)
&& ((pdacl->revision == ACL_REVISION)
|| (pdacl->revision == ACL_REVISION_DS))))
/* same for SACL */
&& (!offsacl
|| ((phead->control & SE_SACL_PRESENT)
&& ((psacl->revision == ACL_REVISION)
|| (psacl->revision == ACL_REVISION_DS))))) {
/*
* Check the DACL and SACL if present
*/
if ((offdacl && !valid_acl(pdacl,attrsz - offdacl))
|| (offsacl && !valid_acl(psacl,attrsz - offsacl)))
ok = FALSE;
} else
ok = FALSE;
return (ok);
}
/*
* Copy the inheritable parts of an ACL
*
* Returns the size of the new ACL
* or zero if nothing is inheritable
*/
int ntfs_inherit_acl(const ACL *oldacl, ACL *newacl,
const SID *usid, const SID *gsid, BOOL fordir)
{
unsigned int src;
unsigned int dst;
int oldcnt;
int newcnt;
unsigned int selection;
int nace;
int acesz;
int usidsz;
int gsidsz;
const ACCESS_ALLOWED_ACE *poldace;
ACCESS_ALLOWED_ACE *pnewace;
usidsz = ntfs_sid_size(usid);
gsidsz = ntfs_sid_size(gsid);
/* ACL header */
newacl->revision = ACL_REVISION;
newacl->alignment1 = 0;
newacl->alignment2 = const_cpu_to_le16(0);
src = dst = sizeof(ACL);
selection = (fordir ? CONTAINER_INHERIT_ACE : OBJECT_INHERIT_ACE);
newcnt = 0;
oldcnt = le16_to_cpu(oldacl->ace_count);
for (nace = 0; nace < oldcnt; nace++) {
poldace = (const ACCESS_ALLOWED_ACE*)((const char*)oldacl + src);
acesz = le16_to_cpu(poldace->size);
/* inheritance for access */
if (poldace->flags & selection) {
pnewace = (ACCESS_ALLOWED_ACE*)
((char*)newacl + dst);
memcpy(pnewace,poldace,acesz);
/*
* Replace generic creator-owner and
* creator-group by owner and group
*/
if (ntfs_same_sid(&pnewace->sid, ownersid)) {
memcpy(&pnewace->sid, usid, usidsz);
acesz = usidsz + 8;
pnewace->size = cpu_to_le16(acesz);
}
if (ntfs_same_sid(&pnewace->sid, groupsid)) {
memcpy(&pnewace->sid, gsid, gsidsz);
acesz = gsidsz + 8;
pnewace->size = cpu_to_le16(acesz);
}
if (pnewace->mask & GENERIC_ALL) {
pnewace->mask &= ~GENERIC_ALL;
if (fordir)
pnewace->mask |= OWNER_RIGHTS
| DIR_READ
| DIR_WRITE
| DIR_EXEC;
else
/*
* The last flag is not defined for a file,
* however Windows sets it, so do the same
*/
pnewace->mask |= OWNER_RIGHTS
| FILE_READ
| FILE_WRITE
| FILE_EXEC
| cpu_to_le32(0x40);
}
/* remove inheritance flags */
pnewace->flags &= ~(OBJECT_INHERIT_ACE
| CONTAINER_INHERIT_ACE
| INHERIT_ONLY_ACE);
dst += acesz;
newcnt++;
}
/* inheritance for further inheritance */
if (fordir
&& (poldace->flags
& (CONTAINER_INHERIT_ACE | OBJECT_INHERIT_ACE))) {
pnewace = (ACCESS_ALLOWED_ACE*)
((char*)newacl + dst);
memcpy(pnewace,poldace,acesz);
/*
* Replace generic creator-owner and
* creator-group by owner and group
*/
if (ntfs_same_sid(&pnewace->sid, ownersid)) {
memcpy(&pnewace->sid, usid, usidsz);
acesz = usidsz + 8;
}
if (ntfs_same_sid(&pnewace->sid, groupsid)) {
memcpy(&pnewace->sid, gsid, gsidsz);
acesz = gsidsz + 8;
}
dst += acesz;
newcnt++;
}
src += acesz;
}
/*
* Adjust header if something was inherited
*/
if (dst > sizeof(ACL)) {
newacl->ace_count = cpu_to_le16(newcnt);
newacl->size = cpu_to_le16(dst);
} else
dst = 0;
return (dst);
}
#if POSIXACLS
/*
* Do sanity checks on a Posix descriptor
* Should not be called with a NULL argument
* returns TRUE if considered safe
* if not, error should be logged by caller
*/
BOOL ntfs_valid_posix(const struct POSIX_SECURITY *pxdesc)
{
const struct POSIX_ACL *pacl;
int i;
BOOL ok;
u16 tag;
u32 id;
int perms;
struct {
u16 previous;
u32 previousid;
u16 tagsset;
mode_t mode;
int owners;
int groups;
int others;
} checks[2], *pchk;
for (i=0; i<2; i++) {
checks[i].mode = 0;
checks[i].tagsset = 0;
checks[i].owners = 0;
checks[i].groups = 0;
checks[i].others = 0;
checks[i].previous = 0;
checks[i].previousid = 0;
}
ok = TRUE;
pacl = &pxdesc->acl;
/*
* header (strict for now)
*/
if ((pacl->version != POSIX_VERSION)
|| (pacl->flags != 0)
|| (pacl->filler != 0))
ok = FALSE;
/*
* Reject multiple owner, group or other
* but do not require them to be present
* Also check the ACEs are in correct order
* which implies there is no duplicates
*/
for (i=0; i<pxdesc->acccnt + pxdesc->defcnt; i++) {
if (i >= pxdesc->firstdef)
pchk = &checks[1];
else
pchk = &checks[0];
perms = pacl->ace[i].perms;
tag = pacl->ace[i].tag;
pchk->tagsset |= tag;
id = pacl->ace[i].id;
if (perms & ~7) ok = FALSE;
if ((tag < pchk->previous)
|| ((tag == pchk->previous)
&& (id <= pchk->previousid)))
ok = FALSE;
pchk->previous = tag;
pchk->previousid = id;
switch (tag) {
case POSIX_ACL_USER_OBJ :
if (pchk->owners++)
ok = FALSE;
if (id != (u32)-1)
ok = FALSE;
pchk->mode |= perms << 6;
break;
case POSIX_ACL_GROUP_OBJ :
if (pchk->groups++)
ok = FALSE;
if (id != (u32)-1)
ok = FALSE;
pchk->mode = (pchk->mode & 07707) | (perms << 3);
break;
case POSIX_ACL_OTHER :
if (pchk->others++)
ok = FALSE;
if (id != (u32)-1)
ok = FALSE;
pchk->mode |= perms;
break;
case POSIX_ACL_USER :
case POSIX_ACL_GROUP :
if (id == (u32)-1)
ok = FALSE;
break;
case POSIX_ACL_MASK :
if (id != (u32)-1)
ok = FALSE;
pchk->mode = (pchk->mode & 07707) | (perms << 3);
break;
default :
ok = FALSE;
break;
}
}
if ((pxdesc->acccnt > 0)
&& ((checks[0].owners != 1) || (checks[0].groups != 1)
|| (checks[0].others != 1)))
ok = FALSE;
/* do not check owner, group or other are present in */
/* the default ACL, Windows does not necessarily set them */
/* descriptor */
if (pxdesc->defcnt && (pxdesc->acccnt > pxdesc->firstdef))
ok = FALSE;
if ((pxdesc->acccnt < 0) || (pxdesc->defcnt < 0))
ok = FALSE;
/* check mode, unless null or no tag set */
if (pxdesc->mode
&& checks[0].tagsset
&& (checks[0].mode != (pxdesc->mode & 0777)))
ok = FALSE;
/* check tagsset */
if (pxdesc->tagsset != checks[0].tagsset)
ok = FALSE;
return (ok);
}
/*
* Set standard header data into a Posix ACL
* The mode argument should provide the 3 upper bits of target mode
*/
static mode_t posix_header(struct POSIX_SECURITY *pxdesc, mode_t basemode)
{
mode_t mode;
u16 tagsset;
struct POSIX_ACE *pace;
int i;
mode = basemode & 07000;
tagsset = 0;
for (i=0; i<pxdesc->acccnt; i++) {
pace = &pxdesc->acl.ace[i];
tagsset |= pace->tag;
switch(pace->tag) {
case POSIX_ACL_USER_OBJ :
mode |= (pace->perms & 7) << 6;
break;
case POSIX_ACL_GROUP_OBJ :
case POSIX_ACL_MASK :
mode = (mode & 07707) | ((pace->perms & 7) << 3);
break;
case POSIX_ACL_OTHER :
mode |= pace->perms & 7;
break;
default :
break;
}
}
pxdesc->tagsset = tagsset;
pxdesc->mode = mode;
pxdesc->acl.version = POSIX_VERSION;
pxdesc->acl.flags = 0;
pxdesc->acl.filler = 0;
return (mode);
}
/*
* Sort ACEs in a Posix ACL
* This is useful for always getting reusable converted ACLs,
* it also helps in merging ACEs.
* Repeated tag+id are allowed and not merged here.
*
* Tags should be in ascending sequence and for a repeatable tag
* ids should be in ascending sequence.
*/
void ntfs_sort_posix(struct POSIX_SECURITY *pxdesc)
{
struct POSIX_ACL *pacl;
struct POSIX_ACE ace;
int i;
int offs;
BOOL done;
u16 tag;
u16 previous;
u32 id;
u32 previousid;
/*
* Check sequencing of tag+id in access ACE's
*/
pacl = &pxdesc->acl;
do {
done = TRUE;
previous = pacl->ace[0].tag;
previousid = pacl->ace[0].id;
for (i=1; i<pxdesc->acccnt; i++) {
tag = pacl->ace[i].tag;
id = pacl->ace[i].id;
if ((tag < previous)
|| ((tag == previous) && (id < previousid))) {
done = FALSE;
memcpy(&ace,&pacl->ace[i-1],sizeof(struct POSIX_ACE));
memcpy(&pacl->ace[i-1],&pacl->ace[i],sizeof(struct POSIX_ACE));
memcpy(&pacl->ace[i],&ace,sizeof(struct POSIX_ACE));
} else {
previous = tag;
previousid = id;
}
}
} while (!done);
/*
* Same for default ACEs
*/
do {
done = TRUE;
if ((pxdesc->defcnt) > 1) {
offs = pxdesc->firstdef;
previous = pacl->ace[offs].tag;
previousid = pacl->ace[offs].id;
for (i=offs+1; i<offs+pxdesc->defcnt; i++) {
tag = pacl->ace[i].tag;
id = pacl->ace[i].id;
if ((tag < previous)
|| ((tag == previous) && (id < previousid))) {
done = FALSE;
memcpy(&ace,&pacl->ace[i-1],sizeof(struct POSIX_ACE));
memcpy(&pacl->ace[i-1],&pacl->ace[i],sizeof(struct POSIX_ACE));
memcpy(&pacl->ace[i],&ace,sizeof(struct POSIX_ACE));
} else {
previous = tag;
previousid = id;
}
}
}
} while (!done);
}
/*
* Merge a new mode into a Posix descriptor
* The Posix descriptor is not reallocated, its size is unchanged
*
* returns 0 if ok
*/
int ntfs_merge_mode_posix(struct POSIX_SECURITY *pxdesc, mode_t mode)
{
int i;
BOOL maskfound;
struct POSIX_ACE *pace;
int todo;
maskfound = FALSE;
todo = POSIX_ACL_USER_OBJ | POSIX_ACL_GROUP_OBJ | POSIX_ACL_OTHER;
for (i=pxdesc->acccnt-1; i>=0; i--) {
pace = &pxdesc->acl.ace[i];
switch(pace->tag) {
case POSIX_ACL_USER_OBJ :
pace->perms = (mode >> 6) & 7;
todo &= ~POSIX_ACL_USER_OBJ;
break;
case POSIX_ACL_GROUP_OBJ :
if (!maskfound)
pace->perms = (mode >> 3) & 7;
todo &= ~POSIX_ACL_GROUP_OBJ;
break;
case POSIX_ACL_MASK :
pace->perms = (mode >> 3) & 7;
maskfound = TRUE;
break;
case POSIX_ACL_OTHER :
pace->perms = mode & 7;
todo &= ~POSIX_ACL_OTHER;
break;
default :
break;
}
}
pxdesc->mode = mode;
return (todo ? -1 : 0);
}
/*
* Replace an access or default Posix ACL
* The resulting ACL is checked for validity
*
* Returns a new ACL or NULL if there is a problem
*/
struct POSIX_SECURITY *ntfs_replace_acl(const struct POSIX_SECURITY *oldpxdesc,
const struct POSIX_ACL *newacl, int count, BOOL deflt)
{
struct POSIX_SECURITY *newpxdesc;
size_t newsize;
int offset;
int oldoffset;
int i;
if (deflt)
newsize = sizeof(struct POSIX_SECURITY)
+ (oldpxdesc->acccnt + count)*sizeof(struct POSIX_ACE);
else
newsize = sizeof(struct POSIX_SECURITY)
+ (oldpxdesc->defcnt + count)*sizeof(struct POSIX_ACE);
newpxdesc = (struct POSIX_SECURITY*)malloc(newsize);
if (newpxdesc) {
if (deflt) {
offset = oldpxdesc->acccnt;
newpxdesc->acccnt = oldpxdesc->acccnt;
newpxdesc->defcnt = count;
newpxdesc->firstdef = offset;
/* copy access ACEs */
for (i=0; i<newpxdesc->acccnt; i++)
newpxdesc->acl.ace[i] = oldpxdesc->acl.ace[i];
/* copy default ACEs */
for (i=0; i<count; i++)
newpxdesc->acl.ace[i + offset] = newacl->ace[i];
} else {
offset = count;
newpxdesc->acccnt = count;
newpxdesc->defcnt = oldpxdesc->defcnt;
newpxdesc->firstdef = count;
/* copy access ACEs */
for (i=0; i<count; i++)
newpxdesc->acl.ace[i] = newacl->ace[i];
/* copy default ACEs */
oldoffset = oldpxdesc->firstdef;
for (i=0; i<newpxdesc->defcnt; i++)
newpxdesc->acl.ace[i + offset] = oldpxdesc->acl.ace[i + oldoffset];
}
/* assume special flags unchanged */
posix_header(newpxdesc, oldpxdesc->mode);
if (!ntfs_valid_posix(newpxdesc)) {
/* do not log, this is an application error */
free(newpxdesc);
newpxdesc = (struct POSIX_SECURITY*)NULL;
errno = EINVAL;
}
} else
errno = ENOMEM;
return (newpxdesc);
}
/*
* Build an inherited Posix descriptor from parent
* descriptor (if any) restricted to creation mode
*
* Returns the inherited descriptor or NULL if there is a problem
*/
struct POSIX_SECURITY *ntfs_build_inherited_posix(
const struct POSIX_SECURITY *pxdesc, mode_t mode,
mode_t mask, BOOL isdir)
{
struct POSIX_SECURITY *pydesc;
struct POSIX_ACE *pyace;
int count;
int defcnt;
int size;
int i;
s16 tagsset;
if (pxdesc && pxdesc->defcnt) {
if (isdir)
count = 2*pxdesc->defcnt + 3;
else
count = pxdesc->defcnt + 3;
} else
count = 3;
pydesc = (struct POSIX_SECURITY*)malloc(
sizeof(struct POSIX_SECURITY) + count*sizeof(struct POSIX_ACE));
if (pydesc) {
/*
* Copy inherited tags and adapt perms
* Use requested mode, ignoring umask
* (not possible with older versions of fuse)
*/
tagsset = 0;
defcnt = (pxdesc ? pxdesc->defcnt : 0);
for (i=defcnt-1; i>=0; i--) {
pyace = &pydesc->acl.ace[i];
*pyace = pxdesc->acl.ace[pxdesc->firstdef + i];
switch (pyace->tag) {
case POSIX_ACL_USER_OBJ :
pyace->perms &= (mode >> 6) & 7;
break;
case POSIX_ACL_GROUP_OBJ :
if (!(tagsset & POSIX_ACL_MASK))
pyace->perms &= (mode >> 3) & 7;
break;
case POSIX_ACL_OTHER :
pyace->perms &= mode & 7;
break;
case POSIX_ACL_MASK :
pyace->perms &= (mode >> 3) & 7;
break;
default :
break;
}
tagsset |= pyace->tag;
}
pydesc->acccnt = defcnt;
/*
* If some standard tags were missing, append them from mode
* and sort the list
* Here we have to use the umask'ed mode
*/
if (~tagsset & (POSIX_ACL_USER_OBJ
| POSIX_ACL_GROUP_OBJ | POSIX_ACL_OTHER)) {
i = defcnt;
/* owner was missing */
if (!(tagsset & POSIX_ACL_USER_OBJ)) {
pyace = &pydesc->acl.ace[i];
pyace->tag = POSIX_ACL_USER_OBJ;
pyace->id = -1;
pyace->perms = ((mode & ~mask) >> 6) & 7;
tagsset |= POSIX_ACL_USER_OBJ;
i++;
}
/* owning group was missing */
if (!(tagsset & POSIX_ACL_GROUP_OBJ)) {
pyace = &pydesc->acl.ace[i];
pyace->tag = POSIX_ACL_GROUP_OBJ;
pyace->id = -1;
pyace->perms = ((mode & ~mask) >> 3) & 7;
tagsset |= POSIX_ACL_GROUP_OBJ;
i++;
}
/* other was missing */
if (!(tagsset & POSIX_ACL_OTHER)) {
pyace = &pydesc->acl.ace[i];
pyace->tag = POSIX_ACL_OTHER;
pyace->id = -1;
pyace->perms = mode & ~mask & 7;
tagsset |= POSIX_ACL_OTHER;
i++;
}
pydesc->acccnt = i;
pydesc->firstdef = i;
pydesc->defcnt = 0;
ntfs_sort_posix(pydesc);
}
/*
* append as a default ACL if a directory
*/
pydesc->firstdef = pydesc->acccnt;
if (defcnt && isdir) {
size = sizeof(struct POSIX_ACE)*defcnt;
memcpy(&pydesc->acl.ace[pydesc->firstdef],
&pxdesc->acl.ace[pxdesc->firstdef],size);
pydesc->defcnt = defcnt;
} else {
pydesc->defcnt = 0;
}
/* assume special bits are not inherited */
posix_header(pydesc, mode & 07000);
if (!ntfs_valid_posix(pydesc)) {
ntfs_log_error("Error building an inherited Posix desc\n");
errno = EIO;
free(pydesc);
pydesc = (struct POSIX_SECURITY*)NULL;
}
} else
errno = ENOMEM;
return (pydesc);
}
static int merge_lists_posix(struct POSIX_ACE *targetace,
const struct POSIX_ACE *firstace,
const struct POSIX_ACE *secondace,
int firstcnt, int secondcnt)
{
int k;
k = 0;
/*
* No list is exhausted :
* if same tag+id in both list :
* ignore ACE from second list
* else take the one with smaller tag+id
*/
while ((firstcnt > 0) && (secondcnt > 0))
if ((firstace->tag == secondace->tag)
&& (firstace->id == secondace->id)) {
secondace++;
secondcnt--;
} else
if ((firstace->tag < secondace->tag)
|| ((firstace->tag == secondace->tag)
&& (firstace->id < secondace->id))) {
targetace->tag = firstace->tag;
targetace->id = firstace->id;
targetace->perms = firstace->perms;
firstace++;
targetace++;
firstcnt--;
k++;
} else {
targetace->tag = secondace->tag;
targetace->id = secondace->id;
targetace->perms = secondace->perms;
secondace++;
targetace++;
secondcnt--;
k++;
}
/*
* One list is exhausted, copy the other one
*/
while (firstcnt > 0) {
targetace->tag = firstace->tag;
targetace->id = firstace->id;
targetace->perms = firstace->perms;
firstace++;
targetace++;
firstcnt--;
k++;
}
while (secondcnt > 0) {
targetace->tag = secondace->tag;
targetace->id = secondace->id;
targetace->perms = secondace->perms;
secondace++;
targetace++;
secondcnt--;
k++;
}
return (k);
}
/*
* Merge two Posix ACLs
* The input ACLs have to be adequately sorted
*
* Returns the merged ACL, which is allocated and has to be freed by caller,
* or NULL if failed
*/
struct POSIX_SECURITY *ntfs_merge_descr_posix(const struct POSIX_SECURITY *first,
const struct POSIX_SECURITY *second)
{
struct POSIX_SECURITY *pxdesc;
struct POSIX_ACE *targetace;
const struct POSIX_ACE *firstace;
const struct POSIX_ACE *secondace;
size_t size;
int k;
size = sizeof(struct POSIX_SECURITY)
+ (first->acccnt + first->defcnt
+ second->acccnt + second->defcnt)*sizeof(struct POSIX_ACE);
pxdesc = (struct POSIX_SECURITY*)malloc(size);
if (pxdesc) {
/*
* merge access ACEs
*/
firstace = first->acl.ace;
secondace = second->acl.ace;
targetace = pxdesc->acl.ace;
k = merge_lists_posix(targetace,firstace,secondace,
first->acccnt,second->acccnt);
pxdesc->acccnt = k;
/*
* merge default ACEs
*/
pxdesc->firstdef = k;
firstace = &first->acl.ace[first->firstdef];
secondace = &second->acl.ace[second->firstdef];
targetace = &pxdesc->acl.ace[k];
k = merge_lists_posix(targetace,firstace,secondace,
first->defcnt,second->defcnt);
pxdesc->defcnt = k;
/*
* build header
*/
pxdesc->acl.version = POSIX_VERSION;
pxdesc->acl.flags = 0;
pxdesc->acl.filler = 0;
pxdesc->mode = 0;
pxdesc->tagsset = 0;
} else
errno = ENOMEM;
return (pxdesc);
}
struct BUILD_CONTEXT {
BOOL isdir;
BOOL adminowns;
BOOL groupowns;
u16 selfuserperms;
u16 selfgrpperms;
u16 grpperms;
u16 othperms;
u16 mask;
u16 designates;
u16 withmask;
u16 rootspecial;
} ;
static BOOL build_user_denials(ACL *pacl,
const SID *usid, struct MAPPING* const mapping[],
ACE_FLAGS flags, const struct POSIX_ACE *pxace,
struct BUILD_CONTEXT *pset)
{
BIGSID defsid;
ACCESS_ALLOWED_ACE *pdace;
const SID *sid;
int sidsz;
int pos;
int acecnt;
le32 grants;
le32 denials;
u16 perms;
u16 mixperms;
u16 tag;
BOOL rejected;
BOOL rootuser;
BOOL avoidmask;
rejected = FALSE;
tag = pxace->tag;
perms = pxace->perms;
rootuser = FALSE;
pos = le16_to_cpu(pacl->size);
acecnt = le16_to_cpu(pacl->ace_count);
avoidmask = (pset->mask == (POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X))
&& ((pset->designates && pset->withmask)
|| (!pset->designates && !pset->withmask));
if (tag == POSIX_ACL_USER_OBJ) {
sid = usid;
sidsz = ntfs_sid_size(sid);
grants = OWNER_RIGHTS;
} else {
if (pxace->id) {
sid = NTFS_FIND_USID(mapping[MAPUSERS],
pxace->id, (SID*)&defsid);
grants = WORLD_RIGHTS;
} else {
sid = adminsid;
rootuser = TRUE;
grants = WORLD_RIGHTS & ~ROOT_OWNER_UNMARK;
}
if (sid) {
sidsz = ntfs_sid_size(sid);
/*
* Insert denial of complement of mask for
* each designated user (except root)
* WRITE_OWNER is inserted so that
* the mask can be identified
*/
if (!avoidmask && !rootuser) {
denials = WRITE_OWNER;
pdace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
if (pset->isdir) {
if (!(pset->mask & POSIX_PERM_X))
denials |= DIR_EXEC;
if (!(pset->mask & POSIX_PERM_W))
denials |= DIR_WRITE;
if (!(pset->mask & POSIX_PERM_R))
denials |= DIR_READ;
} else {
if (!(pset->mask & POSIX_PERM_X))
denials |= FILE_EXEC;
if (!(pset->mask & POSIX_PERM_W))
denials |= FILE_WRITE;
if (!(pset->mask & POSIX_PERM_R))
denials |= FILE_READ;
}
if (rootuser)
grants &= ~ROOT_OWNER_UNMARK;
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = flags;
pdace->size = cpu_to_le16(sidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt++;
}
} else
rejected = TRUE;
}
if (!rejected) {
if (pset->isdir) {
if (perms & POSIX_PERM_X)
grants |= DIR_EXEC;
if (perms & POSIX_PERM_W)
grants |= DIR_WRITE;
if (perms & POSIX_PERM_R)
grants |= DIR_READ;
} else {
if (perms & POSIX_PERM_X)
grants |= FILE_EXEC;
if (perms & POSIX_PERM_W)
grants |= FILE_WRITE;
if (perms & POSIX_PERM_R)
grants |= FILE_READ;
}
/* a possible ACE to deny owner what he/she would */
/* induely get from administrator, group or world */
/* unless owner is administrator or group */
denials = const_cpu_to_le32(0);
pdace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
if (!pset->adminowns && !rootuser) {
if (!pset->groupowns) {
mixperms = pset->grpperms | pset->othperms;
if (tag == POSIX_ACL_USER_OBJ)
mixperms |= pset->selfuserperms;
if (pset->isdir) {
if (mixperms & POSIX_PERM_X)
denials |= DIR_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= DIR_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= DIR_READ;
} else {
if (mixperms & POSIX_PERM_X)
denials |= FILE_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= FILE_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= FILE_READ;
}
} else {
mixperms = ~pset->grpperms & pset->othperms;
if (tag == POSIX_ACL_USER_OBJ)
mixperms |= pset->selfuserperms;
if (pset->isdir) {
if (mixperms & POSIX_PERM_X)
denials |= DIR_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= DIR_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= DIR_READ;
} else {
if (mixperms & POSIX_PERM_X)
denials |= FILE_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= FILE_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= FILE_READ;
}
}
denials &= ~grants;
if (denials) {
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = flags;
pdace->size = cpu_to_le16(sidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt++;
}
}
}
pacl->size = cpu_to_le16(pos);
pacl->ace_count = cpu_to_le16(acecnt);
return (!rejected);
}
static BOOL build_user_grants(ACL *pacl,
const SID *usid, struct MAPPING* const mapping[],
ACE_FLAGS flags, const struct POSIX_ACE *pxace,
struct BUILD_CONTEXT *pset)
{
BIGSID defsid;
ACCESS_ALLOWED_ACE *pgace;
const SID *sid;
int sidsz;
int pos;
int acecnt;
le32 grants;
u16 perms;
u16 tag;
BOOL rejected;
BOOL rootuser;
rejected = FALSE;
tag = pxace->tag;
perms = pxace->perms;
rootuser = FALSE;
pos = le16_to_cpu(pacl->size);
acecnt = le16_to_cpu(pacl->ace_count);
if (tag == POSIX_ACL_USER_OBJ) {
sid = usid;
sidsz = ntfs_sid_size(sid);
grants = OWNER_RIGHTS;
} else {
if (pxace->id) {
sid = NTFS_FIND_USID(mapping[MAPUSERS],
pxace->id, (SID*)&defsid);
if (sid)
sidsz = ntfs_sid_size(sid);
else
rejected = TRUE;
grants = WORLD_RIGHTS;
} else {
sid = adminsid;
sidsz = ntfs_sid_size(sid);
rootuser = TRUE;
grants = WORLD_RIGHTS & ~ROOT_OWNER_UNMARK;
}
}
if (!rejected) {
if (pset->isdir) {
if (perms & POSIX_PERM_X)
grants |= DIR_EXEC;
if (perms & POSIX_PERM_W)
grants |= DIR_WRITE;
if (perms & POSIX_PERM_R)
grants |= DIR_READ;
} else {
if (perms & POSIX_PERM_X)
grants |= FILE_EXEC;
if (perms & POSIX_PERM_W)
grants |= FILE_WRITE;
if (perms & POSIX_PERM_R)
grants |= FILE_READ;
}
if (rootuser)
grants &= ~ROOT_OWNER_UNMARK;
pgace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->size = cpu_to_le16(sidsz + 8);
pgace->flags = flags;
pgace->mask = grants;
memcpy((char*)&pgace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt = le16_to_cpu(pacl->ace_count) + 1;
pacl->ace_count = cpu_to_le16(acecnt);
pacl->size = cpu_to_le16(pos);
}
return (!rejected);
}
/* a grant ACE for group */
/* unless group-obj has the same rights as world */
/* but present if group is owner or owner is administrator */
/* this ACE will be inserted after denials for group */
static BOOL build_group_denials_grant(ACL *pacl,
const SID *gsid, struct MAPPING* const mapping[],
ACE_FLAGS flags, const struct POSIX_ACE *pxace,
struct BUILD_CONTEXT *pset)
{
BIGSID defsid;
ACCESS_ALLOWED_ACE *pdace;
ACCESS_ALLOWED_ACE *pgace;
const SID *sid;
int sidsz;
int pos;
int acecnt;
le32 grants;
le32 denials;
u16 perms;
u16 mixperms;
u16 tag;
BOOL avoidmask;
BOOL rootgroup;
BOOL rejected;
rejected = FALSE;
tag = pxace->tag;
perms = pxace->perms;
pos = le16_to_cpu(pacl->size);
acecnt = le16_to_cpu(pacl->ace_count);
rootgroup = FALSE;
avoidmask = (pset->mask == (POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X))
&& ((pset->designates && pset->withmask)
|| (!pset->designates && !pset->withmask));
if (tag == POSIX_ACL_GROUP_OBJ)
sid = gsid;
else
if (pxace->id)
sid = NTFS_FIND_GSID(mapping[MAPGROUPS],
pxace->id, (SID*)&defsid);
else {
sid = adminsid;
rootgroup = TRUE;
}
if (sid) {
sidsz = ntfs_sid_size(sid);
/*
* Insert denial of complement of mask for
* each group
* WRITE_OWNER is inserted so that
* the mask can be identified
* Note : this mask may lead on Windows to
* deny rights to administrators belonging
* to some user group
*/
if ((!avoidmask && !rootgroup)
|| (pset->rootspecial
&& (tag == POSIX_ACL_GROUP_OBJ))) {
denials = WRITE_OWNER;
pdace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
if (pset->isdir) {
if (!(pset->mask & POSIX_PERM_X))
denials |= DIR_EXEC;
if (!(pset->mask & POSIX_PERM_W))
denials |= DIR_WRITE;
if (!(pset->mask & POSIX_PERM_R))
denials |= DIR_READ;
} else {
if (!(pset->mask & POSIX_PERM_X))
denials |= FILE_EXEC;
if (!(pset->mask & POSIX_PERM_W))
denials |= FILE_WRITE;
if (!(pset->mask & POSIX_PERM_R))
denials |= FILE_READ;
}
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = flags;
pdace->size = cpu_to_le16(sidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt++;
}
} else
rejected = TRUE;
if (!rejected
&& (pset->adminowns
|| pset->groupowns
|| avoidmask
|| rootgroup
|| (perms != pset->othperms))) {
grants = WORLD_RIGHTS;
if (rootgroup)
grants &= ~ROOT_GROUP_UNMARK;
if (pset->isdir) {
if (perms & POSIX_PERM_X)
grants |= DIR_EXEC;
if (perms & POSIX_PERM_W)
grants |= DIR_WRITE;
if (perms & POSIX_PERM_R)
grants |= DIR_READ;
} else {
if (perms & POSIX_PERM_X)
grants |= FILE_EXEC;
if (perms & POSIX_PERM_W)
grants |= FILE_WRITE;
if (perms & POSIX_PERM_R)
grants |= FILE_READ;
}
/* a possible ACE to deny group what it would get from world */
/* or administrator, unless owner is administrator or group */
denials = const_cpu_to_le32(0);
pdace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
if (!pset->adminowns
&& !pset->groupowns
&& !rootgroup) {
mixperms = pset->othperms;
if (tag == POSIX_ACL_GROUP_OBJ)
mixperms |= pset->selfgrpperms;
if (pset->isdir) {
if (mixperms & POSIX_PERM_X)
denials |= DIR_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= DIR_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= DIR_READ;
} else {
if (mixperms & POSIX_PERM_X)
denials |= FILE_EXEC;
if (mixperms & POSIX_PERM_W)
denials |= FILE_WRITE;
if (mixperms & POSIX_PERM_R)
denials |= FILE_READ;
}
denials &= ~(grants | OWNER_RIGHTS);
if (denials) {
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = flags;
pdace->size = cpu_to_le16(sidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt++;
}
}
/* now insert grants to group if more than world */
if (pset->adminowns
|| pset->groupowns
|| (avoidmask && (pset->designates || pset->withmask))
|| (perms & ~pset->othperms)
|| (pset->rootspecial
&& (tag == POSIX_ACL_GROUP_OBJ))
|| (tag == POSIX_ACL_GROUP)) {
if (rootgroup)
grants &= ~ROOT_GROUP_UNMARK;
pgace = (ACCESS_DENIED_ACE*)&((char*)pacl)[pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = flags;
pgace->size = cpu_to_le16(sidsz + 8);
pgace->mask = grants;
memcpy((char*)&pgace->sid, sid, sidsz);
pos += sidsz + 8;
acecnt++;
}
}
pacl->size = cpu_to_le16(pos);
pacl->ace_count = cpu_to_le16(acecnt);
return (!rejected);
}
/*
* Build an ACL composed of several ACE's
* returns size of ACL or zero if failed
*
* Three schemes are defined :
*
* 1) if root is neither owner nor group up to 7 ACE's are set up :
* - denials to owner (preventing grants to world or group to apply)
* + mask denials to designated user (unless mask allows all)
* + denials to designated user
* - grants to owner (always present - first grant)
* + grants to designated user
* + mask denial to group (unless mask allows all)
* - denials to group (preventing grants to world to apply)
* - grants to group (unless group has no more than world rights)
* + mask denials to designated group (unless mask allows all)
* + grants to designated group
* + denials to designated group
* - grants to world (unless none)
* - full privileges to administrator, always present
* - full privileges to system, always present
*
* The same scheme is applied for Posix ACLs, with the mask represented
* as denials prepended to grants for designated users and groups
*
* This is inspired by an Internet Draft from Marius Aamodt Eriksen
* for mapping NFSv4 ACLs to Posix ACLs (draft-ietf-nfsv4-acl-mapping-00.txt)
* More recent versions of the draft (draft-ietf-nfsv4-acl-mapping-05.txt)
* are not followed, as they ignore the Posix mask and lead to
* loss of compatibility with Linux implementations on other fs.
*
* Note that denials to group are located after grants to owner.
* This only occurs in the unfrequent situation where world
* has more rights than group and cannot be avoided if owner and other
* have some common right which is denied to group (eg for mode 745
* executing has to be denied to group, but not to owner or world).
* This rare situation is processed by Windows correctly, but
* Windows utilities may want to change the order, with a
* consequence of applying the group denials to the Windows owner.
* The interpretation on Linux is not affected by the order change.
*
* 2) if root is either owner or group, two problems arise :
* - granting full rights to administrator (as needed to transpose
* to Windows rights bypassing granting to root) would imply
* Linux permissions to always be seen as rwx, no matter the chmod
* - there is no different SID to separate an administrator owner
* from an administrator group. Hence Linux permissions for owner
* would always be similar to permissions to group.
*
* as a work-around, up to 5 ACE's are set up if owner or group :
* - grants to owner, always present at first position
* - grants to group, always present
* - grants to world, unless none
* - full privileges to administrator, always present
* - full privileges to system, always present
*
* On Windows, these ACE's are processed normally, though they
* are redundant (owner, group and administrator are the same,
* as a consequence any denials would damage administrator rights)
* but on Linux, privileges to administrator are ignored (they
* are not needed as root has always full privileges), and
* neither grants to group are applied to owner, nor grants to
* world are applied to owner or group.
*
* 3) finally a similar situation arises when group is owner (they
* have the same SID), but is not root.
* In this situation up to 6 ACE's are set up :
*
* - denials to owner (preventing grants to world to apply)
* - grants to owner (always present)
* - grants to group (unless groups has same rights as world)
* - grants to world (unless none)
* - full privileges to administrator, always present
* - full privileges to system, always present
*
* On Windows, these ACE's are processed normally, though they
* are redundant (as owner and group are the same), but this has
* no impact on administrator rights
*
* Special flags (S_ISVTX, S_ISGID, S_ISUID) :
* an extra null ACE is inserted to hold these flags, using
* the same conventions as cygwin.
*
*/
static int buildacls_posix(struct MAPPING* const mapping[],
char *secattr, int offs, const struct POSIX_SECURITY *pxdesc,
int isdir, const SID *usid, const SID *gsid)
{
struct BUILD_CONTEXT aceset[2], *pset;
BOOL adminowns;
BOOL groupowns;
ACL *pacl;
ACCESS_ALLOWED_ACE *pgace;
ACCESS_ALLOWED_ACE *pdace;
const struct POSIX_ACE *pxace;
BOOL ok;
mode_t mode;
u16 tag;
u16 perms;
ACE_FLAGS flags;
int pos;
int i;
int k;
BIGSID defsid;
const SID *sid;
int acecnt;
int usidsz;
int gsidsz;
int wsidsz;
int asidsz;
int ssidsz;
int nsidsz;
le32 grants;
usidsz = ntfs_sid_size(usid);
gsidsz = ntfs_sid_size(gsid);
wsidsz = ntfs_sid_size(worldsid);
asidsz = ntfs_sid_size(adminsid);
ssidsz = ntfs_sid_size(systemsid);
mode = pxdesc->mode;
/* adminowns and groupowns are used for both lists */
adminowns = ntfs_same_sid(usid, adminsid)
|| ntfs_same_sid(gsid, adminsid);
groupowns = !adminowns && ntfs_same_sid(usid, gsid);
ok = TRUE;
/* ACL header */
pacl = (ACL*)&secattr[offs];
pacl->revision = ACL_REVISION;
pacl->alignment1 = 0;
pacl->size = cpu_to_le16(sizeof(ACL) + usidsz + 8);
pacl->ace_count = const_cpu_to_le16(0);
pacl->alignment2 = const_cpu_to_le16(0);
/*
* Determine what is allowed to some group or world
* to prevent designated users or other groups to get
* rights from groups or world
* Do the same if owner and group appear as designated
* user or group
* Also get global mask
*/
for (k=0; k<2; k++) {
pset = &aceset[k];
pset->selfuserperms = 0;
pset->selfgrpperms = 0;
pset->grpperms = 0;
pset->othperms = 0;
pset->mask = (POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X);
pset->designates = 0;
pset->withmask = 0;
pset->rootspecial = 0;
pset->adminowns = adminowns;
pset->groupowns = groupowns;
pset->isdir = isdir;
}
for (i=pxdesc->acccnt+pxdesc->defcnt-1; i>=0; i--) {
if (i >= pxdesc->acccnt) {
pset = &aceset[1];
pxace = &pxdesc->acl.ace[i + pxdesc->firstdef - pxdesc->acccnt];
} else {
pset = &aceset[0];
pxace = &pxdesc->acl.ace[i];
}
switch (pxace->tag) {
case POSIX_ACL_USER :
pset->designates++;
if (pxace->id) {
sid = NTFS_FIND_USID(mapping[MAPUSERS],
pxace->id, (SID*)&defsid);
if (sid && ntfs_same_sid(sid,usid))
pset->selfuserperms |= pxace->perms;
} else
/* root as designated user is processed apart */
pset->rootspecial = TRUE;
break;
case POSIX_ACL_GROUP :
pset->designates++;
if (pxace->id) {
sid = NTFS_FIND_GSID(mapping[MAPUSERS],
pxace->id, (SID*)&defsid);
if (sid && ntfs_same_sid(sid,gsid))
pset->selfgrpperms |= pxace->perms;
} else
/* root as designated group is processed apart */
pset->rootspecial = TRUE;
/* fall through */
case POSIX_ACL_GROUP_OBJ :
pset->grpperms |= pxace->perms;
break;
case POSIX_ACL_OTHER :
pset->othperms = pxace->perms;
break;
case POSIX_ACL_MASK :
pset->withmask++;
pset->mask = pxace->perms;
default :
break;
}
}
if (pxdesc->defcnt && (pxdesc->firstdef != pxdesc->acccnt)) {
ntfs_log_error("** error : access and default not consecutive\n");
return (0);
}
/*
* First insert all denials for owner and each
* designated user (with mask if needed)
*/
pacl->ace_count = const_cpu_to_le16(0);
pacl->size = const_cpu_to_le16(sizeof(ACL));
for (i=0; (i<(pxdesc->acccnt + pxdesc->defcnt)) && ok; i++) {
if (i >= pxdesc->acccnt) {
flags = INHERIT_ONLY_ACE
| OBJECT_INHERIT_ACE | CONTAINER_INHERIT_ACE;
pset = &aceset[1];
pxace = &pxdesc->acl.ace[i + pxdesc->firstdef - pxdesc->acccnt];
} else {
if (pxdesc->defcnt)
flags = NO_PROPAGATE_INHERIT_ACE;
else
flags = (isdir ? DIR_INHERITANCE
: FILE_INHERITANCE);
pset = &aceset[0];
pxace = &pxdesc->acl.ace[i];
}
tag = pxace->tag;
perms = pxace->perms;
switch (tag) {
/* insert denial ACEs for each owner or allowed user */
case POSIX_ACL_USER :
case POSIX_ACL_USER_OBJ :
ok = build_user_denials(pacl,
usid, mapping, flags, pxace, pset);
break;
default :
break;
}
}
/*
* for directories, insert a world execution denial
* inherited to plain files.
* This is to prevent Windows from granting execution
* of files through inheritance from parent directory
*/
if (isdir && ok) {
pos = le16_to_cpu(pacl->size);
pdace = (ACCESS_DENIED_ACE*) &secattr[offs + pos];
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = INHERIT_ONLY_ACE | OBJECT_INHERIT_ACE;
pdace->size = cpu_to_le16(wsidsz + 8);
pdace->mask = FILE_EXEC;
memcpy((char*)&pdace->sid, worldsid, wsidsz);
pos += wsidsz + 8;
acecnt = le16_to_cpu(pacl->ace_count) + 1;
pacl->ace_count = cpu_to_le16(acecnt);
pacl->size = cpu_to_le16(pos);
}
/*
* now insert (if needed)
* - grants to owner and designated users
* - mask and denials for all groups
* - grants to other
*/
for (i=0; (i<(pxdesc->acccnt + pxdesc->defcnt)) && ok; i++) {
if (i >= pxdesc->acccnt) {
flags = INHERIT_ONLY_ACE
| OBJECT_INHERIT_ACE | CONTAINER_INHERIT_ACE;
pset = &aceset[1];
pxace = &pxdesc->acl.ace[i + pxdesc->firstdef - pxdesc->acccnt];
} else {
if (pxdesc->defcnt)
flags = NO_PROPAGATE_INHERIT_ACE;
else
flags = (isdir ? DIR_INHERITANCE
: FILE_INHERITANCE);
pset = &aceset[0];
pxace = &pxdesc->acl.ace[i];
}
tag = pxace->tag;
perms = pxace->perms;
switch (tag) {
/* ACE for each owner or allowed user */
case POSIX_ACL_USER :
case POSIX_ACL_USER_OBJ :
ok = build_user_grants(pacl,usid,
mapping,flags,pxace,pset);
break;
case POSIX_ACL_GROUP :
case POSIX_ACL_GROUP_OBJ :
/* denials and grants for groups */
ok = build_group_denials_grant(pacl,gsid,
mapping,flags,pxace,pset);
break;
case POSIX_ACL_OTHER :
/* grants for other users */
pos = le16_to_cpu(pacl->size);
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
grants = WORLD_RIGHTS;
if (isdir) {
if (perms & POSIX_PERM_X)
grants |= DIR_EXEC;
if (perms & POSIX_PERM_W)
grants |= DIR_WRITE;
if (perms & POSIX_PERM_R)
grants |= DIR_READ;
} else {
if (perms & POSIX_PERM_X)
grants |= FILE_EXEC;
if (perms & POSIX_PERM_W)
grants |= FILE_WRITE;
if (perms & POSIX_PERM_R)
grants |= FILE_READ;
}
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = flags;
pgace->size = cpu_to_le16(wsidsz + 8);
pgace->mask = grants;
memcpy((char*)&pgace->sid, worldsid, wsidsz);
pos += wsidsz + 8;
acecnt = le16_to_cpu(pacl->ace_count) + 1;
pacl->ace_count = cpu_to_le16(acecnt);
pacl->size = cpu_to_le16(pos);
break;
}
}
if (!ok) {
errno = EINVAL;
pos = 0;
} else {
/* an ACE for administrators */
/* always full access */
pos = le16_to_cpu(pacl->size);
acecnt = le16_to_cpu(pacl->ace_count);
if (isdir)
flags = OBJECT_INHERIT_ACE
| CONTAINER_INHERIT_ACE;
else
flags = NO_PROPAGATE_INHERIT_ACE;
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = flags;
pgace->size = cpu_to_le16(asidsz + 8);
grants = OWNER_RIGHTS | FILE_READ | FILE_WRITE | FILE_EXEC;
pgace->mask = grants;
memcpy((char*)&pgace->sid, adminsid, asidsz);
pos += asidsz + 8;
acecnt++;
/* an ACE for system (needed ?) */
/* always full access */
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = flags;
pgace->size = cpu_to_le16(ssidsz + 8);
grants = OWNER_RIGHTS | FILE_READ | FILE_WRITE | FILE_EXEC;
pgace->mask = grants;
memcpy((char*)&pgace->sid, systemsid, ssidsz);
pos += ssidsz + 8;
acecnt++;
/* a null ACE to hold special flags */
/* using the same representation as cygwin */
if (mode & (S_ISVTX | S_ISGID | S_ISUID)) {
nsidsz = ntfs_sid_size(nullsid);
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = NO_PROPAGATE_INHERIT_ACE;
pgace->size = cpu_to_le16(nsidsz + 8);
grants = const_cpu_to_le32(0);
if (mode & S_ISUID)
grants |= FILE_APPEND_DATA;
if (mode & S_ISGID)
grants |= FILE_WRITE_DATA;
if (mode & S_ISVTX)
grants |= FILE_READ_DATA;
pgace->mask = grants;
memcpy((char*)&pgace->sid, nullsid, nsidsz);
pos += nsidsz + 8;
acecnt++;
}
/* fix ACL header */
pacl->size = cpu_to_le16(pos);
pacl->ace_count = cpu_to_le16(acecnt);
}
return (ok ? pos : 0);
}
#endif /* POSIXACLS */
static int buildacls(char *secattr, int offs, mode_t mode, int isdir,
const SID * usid, const SID * gsid)
{
ACL *pacl;
ACCESS_ALLOWED_ACE *pgace;
ACCESS_ALLOWED_ACE *pdace;
BOOL adminowns;
BOOL groupowns;
ACE_FLAGS gflags;
int pos;
int acecnt;
int usidsz;
int gsidsz;
int wsidsz;
int asidsz;
int ssidsz;
int nsidsz;
le32 grants;
le32 denials;
usidsz = ntfs_sid_size(usid);
gsidsz = ntfs_sid_size(gsid);
wsidsz = ntfs_sid_size(worldsid);
asidsz = ntfs_sid_size(adminsid);
ssidsz = ntfs_sid_size(systemsid);
adminowns = ntfs_same_sid(usid, adminsid)
|| ntfs_same_sid(gsid, adminsid);
groupowns = !adminowns && ntfs_same_sid(usid, gsid);
/* ACL header */
pacl = (ACL*)&secattr[offs];
pacl->revision = ACL_REVISION;
pacl->alignment1 = 0;
pacl->size = cpu_to_le16(sizeof(ACL) + usidsz + 8);
pacl->ace_count = const_cpu_to_le16(1);
pacl->alignment2 = const_cpu_to_le16(0);
pos = sizeof(ACL);
acecnt = 0;
/* compute a grant ACE for owner */
/* this ACE will be inserted after denial for owner */
grants = OWNER_RIGHTS;
if (isdir) {
gflags = DIR_INHERITANCE;
if (mode & S_IXUSR)
grants |= DIR_EXEC;
if (mode & S_IWUSR)
grants |= DIR_WRITE;
if (mode & S_IRUSR)
grants |= DIR_READ;
} else {
gflags = FILE_INHERITANCE;
if (mode & S_IXUSR)
grants |= FILE_EXEC;
if (mode & S_IWUSR)
grants |= FILE_WRITE;
if (mode & S_IRUSR)
grants |= FILE_READ;
}
/* a possible ACE to deny owner what he/she would */
/* induely get from administrator, group or world */
/* unless owner is administrator or group */
denials = const_cpu_to_le32(0);
pdace = (ACCESS_DENIED_ACE*) &secattr[offs + pos];
if (!adminowns) {
if (!groupowns) {
if (isdir) {
pdace->flags = DIR_INHERITANCE;
if (mode & (S_IXGRP | S_IXOTH))
denials |= DIR_EXEC;
if (mode & (S_IWGRP | S_IWOTH))
denials |= DIR_WRITE;
if (mode & (S_IRGRP | S_IROTH))
denials |= DIR_READ;
} else {
pdace->flags = FILE_INHERITANCE;
if (mode & (S_IXGRP | S_IXOTH))
denials |= FILE_EXEC;
if (mode & (S_IWGRP | S_IWOTH))
denials |= FILE_WRITE;
if (mode & (S_IRGRP | S_IROTH))
denials |= FILE_READ;
}
} else {
if (isdir) {
pdace->flags = DIR_INHERITANCE;
if ((mode & S_IXOTH) && !(mode & S_IXGRP))
denials |= DIR_EXEC;
if ((mode & S_IWOTH) && !(mode & S_IWGRP))
denials |= DIR_WRITE;
if ((mode & S_IROTH) && !(mode & S_IRGRP))
denials |= DIR_READ;
} else {
pdace->flags = FILE_INHERITANCE;
if ((mode & S_IXOTH) && !(mode & S_IXGRP))
denials |= FILE_EXEC;
if ((mode & S_IWOTH) && !(mode & S_IWGRP))
denials |= FILE_WRITE;
if ((mode & S_IROTH) && !(mode & S_IRGRP))
denials |= FILE_READ;
}
}
denials &= ~grants;
if (denials) {
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->size = cpu_to_le16(usidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, usid, usidsz);
pos += usidsz + 8;
acecnt++;
}
}
/*
* for directories, a world execution denial
* inherited to plain files
*/
if (isdir) {
pdace = (ACCESS_DENIED_ACE*) &secattr[offs + pos];
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->flags = INHERIT_ONLY_ACE | OBJECT_INHERIT_ACE;
pdace->size = cpu_to_le16(wsidsz + 8);
pdace->mask = FILE_EXEC;
memcpy((char*)&pdace->sid, worldsid, wsidsz);
pos += wsidsz + 8;
acecnt++;
}
/* now insert grants to owner */
pgace = (ACCESS_ALLOWED_ACE*) &secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->size = cpu_to_le16(usidsz + 8);
pgace->flags = gflags;
pgace->mask = grants;
memcpy((char*)&pgace->sid, usid, usidsz);
pos += usidsz + 8;
acecnt++;
/* a grant ACE for group */
/* unless group has the same rights as world */
/* but present if group is owner or owner is administrator */
/* this ACE will be inserted after denials for group */
if (adminowns
|| groupowns
|| (((mode >> 3) ^ mode) & 7)) {
grants = WORLD_RIGHTS;
if (isdir) {
gflags = DIR_INHERITANCE;
if (mode & S_IXGRP)
grants |= DIR_EXEC;
if (mode & S_IWGRP)
grants |= DIR_WRITE;
if (mode & S_IRGRP)
grants |= DIR_READ;
} else {
gflags = FILE_INHERITANCE;
if (mode & S_IXGRP)
grants |= FILE_EXEC;
if (mode & S_IWGRP)
grants |= FILE_WRITE;
if (mode & S_IRGRP)
grants |= FILE_READ;
}
/* a possible ACE to deny group what it would get from world */
/* or administrator, unless owner is administrator or group */
denials = const_cpu_to_le32(0);
pdace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
if (!adminowns && !groupowns) {
if (isdir) {
pdace->flags = DIR_INHERITANCE;
if (mode & S_IXOTH)
denials |= DIR_EXEC;
if (mode & S_IWOTH)
denials |= DIR_WRITE;
if (mode & S_IROTH)
denials |= DIR_READ;
} else {
pdace->flags = FILE_INHERITANCE;
if (mode & S_IXOTH)
denials |= FILE_EXEC;
if (mode & S_IWOTH)
denials |= FILE_WRITE;
if (mode & S_IROTH)
denials |= FILE_READ;
}
denials &= ~(grants | OWNER_RIGHTS);
if (denials) {
pdace->type = ACCESS_DENIED_ACE_TYPE;
pdace->size = cpu_to_le16(gsidsz + 8);
pdace->mask = denials;
memcpy((char*)&pdace->sid, gsid, gsidsz);
pos += gsidsz + 8;
acecnt++;
}
}
if (adminowns
|| groupowns
|| ((mode >> 3) & ~mode & 7)) {
/* now insert grants to group */
/* if more rights than other */
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = gflags;
pgace->size = cpu_to_le16(gsidsz + 8);
pgace->mask = grants;
memcpy((char*)&pgace->sid, gsid, gsidsz);
pos += gsidsz + 8;
acecnt++;
}
}
/* an ACE for world users */
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
grants = WORLD_RIGHTS;
if (isdir) {
pgace->flags = DIR_INHERITANCE;
if (mode & S_IXOTH)
grants |= DIR_EXEC;
if (mode & S_IWOTH)
grants |= DIR_WRITE;
if (mode & S_IROTH)
grants |= DIR_READ;
} else {
pgace->flags = FILE_INHERITANCE;
if (mode & S_IXOTH)
grants |= FILE_EXEC;
if (mode & S_IWOTH)
grants |= FILE_WRITE;
if (mode & S_IROTH)
grants |= FILE_READ;
}
pgace->size = cpu_to_le16(wsidsz + 8);
pgace->mask = grants;
memcpy((char*)&pgace->sid, worldsid, wsidsz);
pos += wsidsz + 8;
acecnt++;
/* an ACE for administrators */
/* always full access */
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
if (isdir)
pgace->flags = DIR_INHERITANCE;
else
pgace->flags = FILE_INHERITANCE;
pgace->size = cpu_to_le16(asidsz + 8);
grants = OWNER_RIGHTS | FILE_READ | FILE_WRITE | FILE_EXEC;
pgace->mask = grants;
memcpy((char*)&pgace->sid, adminsid, asidsz);
pos += asidsz + 8;
acecnt++;
/* an ACE for system (needed ?) */
/* always full access */
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
if (isdir)
pgace->flags = DIR_INHERITANCE;
else
pgace->flags = FILE_INHERITANCE;
pgace->size = cpu_to_le16(ssidsz + 8);
grants = OWNER_RIGHTS | FILE_READ | FILE_WRITE | FILE_EXEC;
pgace->mask = grants;
memcpy((char*)&pgace->sid, systemsid, ssidsz);
pos += ssidsz + 8;
acecnt++;
/* a null ACE to hold special flags */
/* using the same representation as cygwin */
if (mode & (S_ISVTX | S_ISGID | S_ISUID)) {
nsidsz = ntfs_sid_size(nullsid);
pgace = (ACCESS_ALLOWED_ACE*)&secattr[offs + pos];
pgace->type = ACCESS_ALLOWED_ACE_TYPE;
pgace->flags = NO_PROPAGATE_INHERIT_ACE;
pgace->size = cpu_to_le16(nsidsz + 8);
grants = const_cpu_to_le32(0);
if (mode & S_ISUID)
grants |= FILE_APPEND_DATA;
if (mode & S_ISGID)
grants |= FILE_WRITE_DATA;
if (mode & S_ISVTX)
grants |= FILE_READ_DATA;
pgace->mask = grants;
memcpy((char*)&pgace->sid, nullsid, nsidsz);
pos += nsidsz + 8;
acecnt++;
}
/* fix ACL header */
pacl->size = cpu_to_le16(pos);
pacl->ace_count = cpu_to_le16(acecnt);
return (pos);
}
#if POSIXACLS
/*
* Build a full security descriptor from a Posix ACL
* returns descriptor in allocated memory, must free() after use
*/
char *ntfs_build_descr_posix(struct MAPPING* const mapping[],
struct POSIX_SECURITY *pxdesc,
int isdir, const SID *usid, const SID *gsid)
{
int newattrsz;
SECURITY_DESCRIPTOR_RELATIVE *pnhead;
char *newattr;
int aclsz;
int usidsz;
int gsidsz;
int wsidsz;
int asidsz;
int ssidsz;
int k;
usidsz = ntfs_sid_size(usid);
gsidsz = ntfs_sid_size(gsid);
wsidsz = ntfs_sid_size(worldsid);
asidsz = ntfs_sid_size(adminsid);
ssidsz = ntfs_sid_size(systemsid);
/* allocate enough space for the new security attribute */
newattrsz = sizeof(SECURITY_DESCRIPTOR_RELATIVE) /* header */
+ usidsz + gsidsz /* usid and gsid */
+ sizeof(ACL) /* acl header */
+ 2*(8 + usidsz) /* two possible ACE for user */
+ 3*(8 + gsidsz) /* three possible ACE for group and mask */
+ 8 + wsidsz /* one ACE for world */
+ 8 + asidsz /* one ACE for admin */
+ 8 + ssidsz; /* one ACE for system */
if (isdir) /* a world denial for directories */
newattrsz += 8 + wsidsz;
if (pxdesc->mode & 07000) /* a NULL ACE for special modes */
newattrsz += 8 + ntfs_sid_size(nullsid);
/* account for non-owning users and groups */
for (k=0; k<pxdesc->acccnt; k++) {
if ((pxdesc->acl.ace[k].tag == POSIX_ACL_USER)
|| (pxdesc->acl.ace[k].tag == POSIX_ACL_GROUP))
newattrsz += 3*40; /* fixme : maximum size */
}
/* account for default ACE's */
newattrsz += 2*40*pxdesc->defcnt; /* fixme : maximum size */
newattr = (char*)ntfs_malloc(newattrsz);
if (newattr) {
/* build the main header part */
pnhead = (SECURITY_DESCRIPTOR_RELATIVE*)newattr;
pnhead->revision = SECURITY_DESCRIPTOR_REVISION;
pnhead->alignment = 0;
/*
* The flag SE_DACL_PROTECTED prevents the ACL
* to be changed in an inheritance after creation
*/
pnhead->control = SE_DACL_PRESENT | SE_DACL_PROTECTED
| SE_SELF_RELATIVE;
/*
* Windows prefers ACL first, do the same to
* get the same hash value and avoid duplication
*/
/* build permissions */
aclsz = buildacls_posix(mapping,newattr,
sizeof(SECURITY_DESCRIPTOR_RELATIVE),
pxdesc, isdir, usid, gsid);
if (aclsz && ((int)(sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz + gsidsz) <= newattrsz)) {
/* append usid and gsid */
memcpy(&newattr[sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz], usid, usidsz);
memcpy(&newattr[sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz], gsid, gsidsz);
/* positions of ACL, USID and GSID into header */
pnhead->owner =
cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz);
pnhead->group =
cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz);
pnhead->sacl = const_cpu_to_le32(0);
pnhead->dacl =
const_cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE));
} else {
/* ACL failure (errno set) or overflow */
free(newattr);
newattr = (char*)NULL;
if (aclsz) {
/* hope error was detected before overflowing */
ntfs_log_error("Security descriptor is longer than expected\n");
errno = EIO;
}
}
} else
errno = ENOMEM;
return (newattr);
}
#endif /* POSIXACLS */
/*
* Build a full security descriptor
* returns descriptor in allocated memory, must free() after use
*/
char *ntfs_build_descr(mode_t mode,
int isdir, const SID * usid, const SID * gsid)
{
int newattrsz;
SECURITY_DESCRIPTOR_RELATIVE *pnhead;
char *newattr;
int aclsz;
int usidsz;
int gsidsz;
int wsidsz;
int asidsz;
int ssidsz;
usidsz = ntfs_sid_size(usid);
gsidsz = ntfs_sid_size(gsid);
wsidsz = ntfs_sid_size(worldsid);
asidsz = ntfs_sid_size(adminsid);
ssidsz = ntfs_sid_size(systemsid);
/* allocate enough space for the new security attribute */
newattrsz = sizeof(SECURITY_DESCRIPTOR_RELATIVE) /* header */
+ usidsz + gsidsz /* usid and gsid */
+ sizeof(ACL) /* acl header */
+ 2*(8 + usidsz) /* two possible ACE for user */
+ 2*(8 + gsidsz) /* two possible ACE for group */
+ 8 + wsidsz /* one ACE for world */
+ 8 + asidsz /* one ACE for admin */
+ 8 + ssidsz; /* one ACE for system */
if (isdir) /* a world denial for directories */
newattrsz += 8 + wsidsz;
if (mode & 07000) /* a NULL ACE for special modes */
newattrsz += 8 + ntfs_sid_size(nullsid);
newattr = (char*)ntfs_malloc(newattrsz);
if (newattr) {
/* build the main header part */
pnhead = (SECURITY_DESCRIPTOR_RELATIVE*) newattr;
pnhead->revision = SECURITY_DESCRIPTOR_REVISION;
pnhead->alignment = 0;
/*
* The flag SE_DACL_PROTECTED prevents the ACL
* to be changed in an inheritance after creation
*/
pnhead->control = SE_DACL_PRESENT | SE_DACL_PROTECTED
| SE_SELF_RELATIVE;
/*
* Windows prefers ACL first, do the same to
* get the same hash value and avoid duplication
*/
/* build permissions */
aclsz = buildacls(newattr,
sizeof(SECURITY_DESCRIPTOR_RELATIVE),
mode, isdir, usid, gsid);
if (((int)sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz + gsidsz) <= newattrsz) {
/* append usid and gsid */
memcpy(&newattr[sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz], usid, usidsz);
memcpy(&newattr[sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz], gsid, gsidsz);
/* positions of ACL, USID and GSID into header */
pnhead->owner =
cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz);
pnhead->group =
cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE)
+ aclsz + usidsz);
pnhead->sacl = const_cpu_to_le32(0);
pnhead->dacl =
const_cpu_to_le32(sizeof(SECURITY_DESCRIPTOR_RELATIVE));
} else {
/* hope error was detected before overflowing */
free(newattr);
newattr = (char*)NULL;
ntfs_log_error("Security descriptor is longer than expected\n");
errno = EIO;
}
} else
errno = ENOMEM;
return (newattr);
}
/*
* Create a mode_t permission set
* from owner, group and world grants as represented in ACEs
*/
static int merge_permissions(BOOL isdir,
le32 owner, le32 group, le32 world, le32 special)
{
int perm;
perm = 0;
/* build owner permission */
if (owner) {
if (isdir) {
/* exec if any of list, traverse */
if (owner & DIR_GEXEC)
perm |= S_IXUSR;
/* write if any of addfile, adddir, delchild */
if (owner & DIR_GWRITE)
perm |= S_IWUSR;
/* read if any of list */
if (owner & DIR_GREAD)
perm |= S_IRUSR;
} else {
/* exec if execute or generic execute */
if (owner & FILE_GEXEC)
perm |= S_IXUSR;
/* write if any of writedata or generic write */
if (owner & FILE_GWRITE)
perm |= S_IWUSR;
/* read if any of readdata or generic read */
if (owner & FILE_GREAD)
perm |= S_IRUSR;
}
}
/* build group permission */
if (group) {
if (isdir) {
/* exec if any of list, traverse */
if (group & DIR_GEXEC)
perm |= S_IXGRP;
/* write if any of addfile, adddir, delchild */
if (group & DIR_GWRITE)
perm |= S_IWGRP;
/* read if any of list */
if (group & DIR_GREAD)
perm |= S_IRGRP;
} else {
/* exec if execute */
if (group & FILE_GEXEC)
perm |= S_IXGRP;
/* write if any of writedata, appenddata */
if (group & FILE_GWRITE)
perm |= S_IWGRP;
/* read if any of readdata */
if (group & FILE_GREAD)
perm |= S_IRGRP;
}
}
/* build world permission */
if (world) {
if (isdir) {
/* exec if any of list, traverse */
if (world & DIR_GEXEC)
perm |= S_IXOTH;
/* write if any of addfile, adddir, delchild */
if (world & DIR_GWRITE)
perm |= S_IWOTH;
/* read if any of list */
if (world & DIR_GREAD)
perm |= S_IROTH;
} else {
/* exec if execute */
if (world & FILE_GEXEC)
perm |= S_IXOTH;
/* write if any of writedata, appenddata */
if (world & FILE_GWRITE)
perm |= S_IWOTH;
/* read if any of readdata */
if (world & FILE_GREAD)
perm |= S_IROTH;
}
}
/* build special permission flags */
if (special) {
if (special & FILE_APPEND_DATA)
perm |= S_ISUID;
if (special & FILE_WRITE_DATA)
perm |= S_ISGID;
if (special & FILE_READ_DATA)
perm |= S_ISVTX;
}
return (perm);
}
#if POSIXACLS
/*
* Normalize a Posix ACL either from a sorted raw set of
* access ACEs or default ACEs
* (standard case : different owner, group and administrator)
*/
static int norm_std_permissions_posix(struct POSIX_SECURITY *posix_desc,
BOOL groupowns, int start, int count, int target)
{
int j,k;
s32 id;
u16 tag;
u16 tagsset;
struct POSIX_ACE *pxace;
mode_t grantgrps;
mode_t grantwrld;
mode_t denywrld;
mode_t allow;
mode_t deny;
mode_t perms;
mode_t mode;
mode = 0;
tagsset = 0;
/*
* Determine what is granted to some group or world
* Also get denials to world which are meant to prevent
* execution flags to be inherited by plain files
*/
pxace = posix_desc->acl.ace;
grantgrps = 0;
grantwrld = 0;
denywrld = 0;
for (j=start; j<(start + count); j++) {
if (pxace[j].perms & POSIX_PERM_DENIAL) {
/* deny world exec unless for default */
if ((pxace[j].tag == POSIX_ACL_OTHER)
&& !start)
denywrld = pxace[j].perms;
} else {
switch (pxace[j].tag) {
case POSIX_ACL_GROUP_OBJ :
grantgrps |= pxace[j].perms;
break;
case POSIX_ACL_GROUP :
if (pxace[j].id)
grantgrps |= pxace[j].perms;
break;
case POSIX_ACL_OTHER :
grantwrld = pxace[j].perms;
break;
default :
break;
}
}
}
/*
* Collect groups of ACEs related to the same id
* and determine what is granted and what is denied.
* It is important the ACEs have been sorted
*/
j = start;
k = target;
while (j < (start + count)) {
tag = pxace[j].tag;
id = pxace[j].id;
if (pxace[j].perms & POSIX_PERM_DENIAL) {
deny = pxace[j].perms | denywrld;
allow = 0;
} else {
deny = denywrld;
allow = pxace[j].perms;
}
j++;
while ((j < (start + count))
&& (pxace[j].tag == tag)
&& (pxace[j].id == id)) {
if (pxace[j].perms & POSIX_PERM_DENIAL)
deny |= pxace[j].perms;
else
allow |= pxace[j].perms;
j++;
}
/*
* Build the permissions equivalent to grants and denials
*/
if (groupowns) {
if (tag == POSIX_ACL_MASK)
perms = ~deny;
else
perms = allow & ~deny;
} else
switch (tag) {
case POSIX_ACL_USER_OBJ :
perms = (allow | grantgrps | grantwrld) & ~deny;
break;
case POSIX_ACL_USER :
if (id)
perms = (allow | grantgrps | grantwrld)
& ~deny;
else
perms = allow;
break;
case POSIX_ACL_GROUP_OBJ :
perms = (allow | grantwrld) & ~deny;
break;
case POSIX_ACL_GROUP :
if (id)
perms = (allow | grantwrld) & ~deny;
else
perms = allow;
break;
case POSIX_ACL_MASK :
perms = ~deny;
break;
default :
perms = allow & ~deny;
break;
}
/*
* Store into a Posix ACE
*/
if (tag != POSIX_ACL_SPECIAL) {
pxace[k].tag = tag;
pxace[k].id = id;
pxace[k].perms = perms
& (POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X);
tagsset |= tag;
k++;
}
switch (tag) {
case POSIX_ACL_USER_OBJ :
mode |= ((perms & 7) << 6);
break;
case POSIX_ACL_GROUP_OBJ :
case POSIX_ACL_MASK :
mode = (mode & 07707) | ((perms & 7) << 3);
break;
case POSIX_ACL_OTHER :
mode |= perms & 7;
break;
case POSIX_ACL_SPECIAL :
mode |= (perms & (S_ISVTX | S_ISUID | S_ISGID));
break;
default :
break;
}
}
if (!start) { /* not satisfactory */
posix_desc->mode = mode;
posix_desc->tagsset = tagsset;
}
return (k - target);
}
#endif /* POSIXACLS */
/*
* Interpret an ACL and extract meaningful grants
* (standard case : different owner, group and administrator)
*/
static int build_std_permissions(const char *securattr,
const SID *usid, const SID *gsid, BOOL isdir)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
int offdacl;
int offace;
int acecnt;
int nace;
BOOL noown;
le32 special;
le32 allowown, allowgrp, allowall;
le32 denyown, denygrp, denyall;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
pacl = (const ACL*)&securattr[offdacl];
special = const_cpu_to_le32(0);
allowown = allowgrp = allowall = const_cpu_to_le32(0);
denyown = denygrp = denyall = const_cpu_to_le32(0);
noown = TRUE;
if (offdacl) {
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
} else {
acecnt = 0;
offace = 0;
}
for (nace = 0; nace < acecnt; nace++) {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if (!(pace->flags & INHERIT_ONLY_ACE)) {
if (ntfs_same_sid(usid, &pace->sid)
|| ntfs_same_sid(ownersid, &pace->sid)) {
noown = FALSE;
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowown |= pace->mask;
else if (pace->type == ACCESS_DENIED_ACE_TYPE)
denyown |= pace->mask;
} else
if (ntfs_same_sid(gsid, &pace->sid)
&& !(pace->mask & WRITE_OWNER)) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowgrp |= pace->mask;
else if (pace->type == ACCESS_DENIED_ACE_TYPE)
denygrp |= pace->mask;
} else
if (is_world_sid((const SID*)&pace->sid)) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowall |= pace->mask;
else
if (pace->type == ACCESS_DENIED_ACE_TYPE)
denyall |= pace->mask;
} else
if ((ntfs_same_sid((const SID*)&pace->sid,nullsid))
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE))
special |= pace->mask;
}
offace += le16_to_cpu(pace->size);
}
/*
* No indication about owner's rights : grant basic rights
* This happens for files created by Windows in directories
* created by Linux and owned by root, because Windows
* merges the admin ACEs
*/
if (noown)
allowown = (FILE_READ_DATA | FILE_WRITE_DATA | FILE_EXECUTE);
/*
* Add to owner rights granted to group or world
* unless denied personaly, and add to group rights
* granted to world unless denied specifically
*/
allowown |= (allowgrp | allowall);
allowgrp |= allowall;
return (merge_permissions(isdir,
allowown & ~(denyown | denyall),
allowgrp & ~(denygrp | denyall),
allowall & ~denyall,
special));
}
/*
* Interpret an ACL and extract meaningful grants
* (special case : owner and group are the same,
* and not administrator)
*/
static int build_owngrp_permissions(const char *securattr,
const SID *usid, BOOL isdir)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
int offdacl;
int offace;
int acecnt;
int nace;
le32 special;
BOOL grppresent;
le32 allowown, allowgrp, allowall;
le32 denyown, denygrp, denyall;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
pacl = (const ACL*)&securattr[offdacl];
special = const_cpu_to_le32(0);
allowown = allowgrp = allowall = const_cpu_to_le32(0);
denyown = denygrp = denyall = const_cpu_to_le32(0);
grppresent = FALSE;
if (offdacl) {
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
} else
acecnt = 0;
for (nace = 0; nace < acecnt; nace++) {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if (!(pace->flags & INHERIT_ONLY_ACE)) {
if ((ntfs_same_sid(usid, &pace->sid)
|| ntfs_same_sid(ownersid, &pace->sid))
&& (pace->mask & WRITE_OWNER)) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowown |= pace->mask;
} else
if (ntfs_same_sid(usid, &pace->sid)
&& (!(pace->mask & WRITE_OWNER))) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE) {
allowgrp |= pace->mask;
grppresent = TRUE;
}
} else
if (is_world_sid((const SID*)&pace->sid)) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowall |= pace->mask;
else
if (pace->type == ACCESS_DENIED_ACE_TYPE)
denyall |= pace->mask;
} else
if ((ntfs_same_sid((const SID*)&pace->sid,nullsid))
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE))
special |= pace->mask;
}
offace += le16_to_cpu(pace->size);
}
if (!grppresent)
allowgrp = allowall;
return (merge_permissions(isdir,
allowown & ~(denyown | denyall),
allowgrp & ~(denygrp | denyall),
allowall & ~denyall,
special));
}
#if POSIXACLS
/*
* Normalize a Posix ACL either from a sorted raw set of
* access ACEs or default ACEs
* (special case : owner or/and group is administrator)
*/
static int norm_ownadmin_permissions_posix(struct POSIX_SECURITY *posix_desc,
int start, int count, int target)
{
int j,k;
s32 id;
u16 tag;
u16 tagsset;
struct POSIX_ACE *pxace;
int acccnt;
mode_t denywrld;
mode_t allow;
mode_t deny;
mode_t perms;
mode_t mode;
mode = 0;
pxace = posix_desc->acl.ace;
acccnt = posix_desc->acccnt;
tagsset = 0;
denywrld = 0;
/*
* Get denials to world which are meant to prevent
* execution flags to be inherited by plain files
*/
for (j=start; j<(start + count); j++) {
if (pxace[j].perms & POSIX_PERM_DENIAL) {
/* deny world exec not for default */
if ((pxace[j].tag == POSIX_ACL_OTHER)
&& !start)
denywrld = pxace[j].perms;
}
}
/*
* Collect groups of ACEs related to the same id
* and determine what is granted (denials are ignored)
* It is important the ACEs have been sorted
*/
j = start;
k = target;
deny = 0;
while (j < (start + count)) {
allow = 0;
tag = pxace[j].tag;
id = pxace[j].id;
if (tag == POSIX_ACL_MASK) {
deny = pxace[j].perms;
j++;
while ((j < (start + count))
&& (pxace[j].tag == POSIX_ACL_MASK))
j++;
} else {
if (!(pxace[j].perms & POSIX_PERM_DENIAL))
allow = pxace[j].perms;
j++;
while ((j < (start + count))
&& (pxace[j].tag == tag)
&& (pxace[j].id == id)) {
if (!(pxace[j].perms & POSIX_PERM_DENIAL))
allow |= pxace[j].perms;
j++;
}
}
/*
* Store the grants into a Posix ACE
*/
if (tag == POSIX_ACL_MASK)
perms = ~deny;
else
perms = allow & ~denywrld;
if (tag != POSIX_ACL_SPECIAL) {
pxace[k].tag = tag;
pxace[k].id = id;
pxace[k].perms = perms
& (POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X);
tagsset |= tag;
k++;
}
switch (tag) {
case POSIX_ACL_USER_OBJ :
mode |= ((perms & 7) << 6);
break;
case POSIX_ACL_GROUP_OBJ :
case POSIX_ACL_MASK :
mode = (mode & 07707) | ((perms & 7) << 3);
break;
case POSIX_ACL_OTHER :
mode |= perms & 7;
break;
case POSIX_ACL_SPECIAL :
mode |= perms & (S_ISVTX | S_ISUID | S_ISGID);
break;
default :
break;
}
}
if (!start) { /* not satisfactory */
posix_desc->mode = mode;
posix_desc->tagsset = tagsset;
}
return (k - target);
}
#endif /* POSIXACLS */
/*
* Interpret an ACL and extract meaningful grants
* (special case : owner or/and group is administrator)
*/
static int build_ownadmin_permissions(const char *securattr,
const SID *usid, const SID *gsid, BOOL isdir)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
int offdacl;
int offace;
int acecnt;
int nace;
BOOL firstapply;
int isforeign;
le32 special;
le32 allowown, allowgrp, allowall;
le32 denyown, denygrp, denyall;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
pacl = (const ACL*)&securattr[offdacl];
special = const_cpu_to_le32(0);
allowown = allowgrp = allowall = const_cpu_to_le32(0);
denyown = denygrp = denyall = const_cpu_to_le32(0);
if (offdacl) {
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
} else {
acecnt = 0;
offace = 0;
}
firstapply = TRUE;
isforeign = 3;
for (nace = 0; nace < acecnt; nace++) {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if (!(pace->flags & INHERIT_ONLY_ACE)
&& !(~pace->mask & (ROOT_OWNER_UNMARK | ROOT_GROUP_UNMARK))) {
if ((ntfs_same_sid(usid, &pace->sid)
|| ntfs_same_sid(ownersid, &pace->sid))
&& (((pace->mask & WRITE_OWNER) && firstapply))) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE) {
allowown |= pace->mask;
isforeign &= ~1;
} else
if (pace->type == ACCESS_DENIED_ACE_TYPE)
denyown |= pace->mask;
} else
if (ntfs_same_sid(gsid, &pace->sid)
&& (!(pace->mask & WRITE_OWNER))) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE) {
allowgrp |= pace->mask;
isforeign &= ~2;
} else
if (pace->type == ACCESS_DENIED_ACE_TYPE)
denygrp |= pace->mask;
} else if (is_world_sid((const SID*)&pace->sid)) {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
allowall |= pace->mask;
else
if (pace->type == ACCESS_DENIED_ACE_TYPE)
denyall |= pace->mask;
}
firstapply = FALSE;
} else
if (!(pace->flags & INHERIT_ONLY_ACE))
if ((ntfs_same_sid((const SID*)&pace->sid,nullsid))
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE))
special |= pace->mask;
offace += le16_to_cpu(pace->size);
}
if (isforeign) {
allowown |= (allowgrp | allowall);
allowgrp |= allowall;
}
return (merge_permissions(isdir,
allowown & ~(denyown | denyall),
allowgrp & ~(denygrp | denyall),
allowall & ~denyall,
special));
}
#if OWNERFROMACL
/*
* Define the owner of a file as the first user allowed
* to change the owner, instead of the user defined as owner.
*
* This produces better approximations for files written by a
* Windows user in an inheritable directory owned by another user,
* as the access rights are inheritable but the ownership is not.
*
* An important case is the directories "Documents and Settings/user"
* which the users must have access to, though Windows considers them
* as owned by administrator.
*/
const SID *ntfs_acl_owner(const char *securattr)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const SID *usid;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
int offdacl;
int offace;
int acecnt;
int nace;
BOOL found;
found = FALSE;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
if (offdacl) {
pacl = (const ACL*)&securattr[offdacl];
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
nace = 0;
do {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if ((pace->mask & WRITE_OWNER)
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE)
&& ntfs_is_user_sid(&pace->sid))
found = TRUE;
offace += le16_to_cpu(pace->size);
} while (!found && (++nace < acecnt));
}
if (found)
usid = &pace->sid;
else
usid = (const SID*)&securattr[le32_to_cpu(phead->owner)];
return (usid);
}
#else
/*
* Special case for files owned by administrator with full
* access granted to a mapped user : consider this user as the tenant
* of the file.
*
* This situation cannot be represented with Linux concepts and can
* only be found for files or directories created by Windows.
* Typical situation : directory "Documents and Settings/user" which
* is on the path to user's files and must be given access to user
* only.
*
* Check file is owned by administrator and no user has rights before
* calling.
* Returns the uid of tenant or zero if none
*/
static uid_t find_tenant(struct MAPPING *const mapping[],
const char *securattr)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
int offdacl;
int offace;
int acecnt;
int nace;
uid_t tid;
uid_t xid;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
pacl = (const ACL*)&securattr[offdacl];
tid = 0;
if (offdacl) {
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
} else
acecnt = 0;
for (nace = 0; nace < acecnt; nace++) {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if ((pace->type == ACCESS_ALLOWED_ACE_TYPE)
&& (pace->mask & DIR_WRITE)) {
xid = NTFS_FIND_USER(mapping[MAPUSERS], &pace->sid);
if (xid) tid = xid;
}
offace += le16_to_cpu(pace->size);
}
return (tid);
}
#endif /* OWNERFROMACL */
#if POSIXACLS
/*
* Build Posix permissions from an ACL
* returns a pointer to the requested permissions
* or a null pointer (with errno set) if there is a problem
*
* If the NTFS ACL was created according to our rules, the retrieved
* Posix ACL should be the exact ACL which was set. However if
* the NTFS ACL was built by a different tool, the result could
* be a a poor approximation of what was expected
*/
struct POSIX_SECURITY *ntfs_build_permissions_posix(
struct MAPPING *const mapping[],
const char *securattr,
const SID *usid, const SID *gsid, BOOL isdir)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
struct POSIX_SECURITY *pxdesc;
const ACL *pacl;
const ACCESS_ALLOWED_ACE *pace;
struct POSIX_ACE *pxace;
struct {
uid_t prevuid;
gid_t prevgid;
int groupmasks;
s16 tagsset;
BOOL gotowner;
BOOL gotownermask;
BOOL gotgroup;
mode_t permswrld;
} ctx[2], *pctx;
int offdacl;
int offace;
int alloccnt;
int acecnt;
uid_t uid;
gid_t gid;
int i,j;
int k,l;
BOOL ignore;
BOOL adminowns;
BOOL groupowns;
BOOL firstinh;
BOOL genericinh;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
offdacl = le32_to_cpu(phead->dacl);
if (offdacl) {
pacl = (const ACL*)&securattr[offdacl];
acecnt = le16_to_cpu(pacl->ace_count);
offace = offdacl + sizeof(ACL);
} else {
acecnt = 0;
offace = 0;
}
adminowns = FALSE;
groupowns = ntfs_same_sid(gsid,usid);
firstinh = FALSE;
genericinh = FALSE;
/*
* Build a raw posix security descriptor
* by just translating permissions and ids
* Add 2 to the count of ACE to be able to insert
* a group ACE later in access and default ACLs
* and add 2 more to be able to insert ACEs for owner
* and 2 more for other
*/
alloccnt = acecnt + 6;
pxdesc = (struct POSIX_SECURITY*)malloc(
sizeof(struct POSIX_SECURITY)
+ alloccnt*sizeof(struct POSIX_ACE));
k = 0;
l = alloccnt;
for (i=0; i<2; i++) {
pctx = &ctx[i];
pctx->permswrld = 0;
pctx->prevuid = -1;
pctx->prevgid = -1;
pctx->groupmasks = 0;
pctx->tagsset = 0;
pctx->gotowner = FALSE;
pctx->gotgroup = FALSE;
pctx->gotownermask = FALSE;
}
for (j=0; j<acecnt; j++) {
pace = (const ACCESS_ALLOWED_ACE*)&securattr[offace];
if (pace->flags & INHERIT_ONLY_ACE) {
pxace = &pxdesc->acl.ace[l - 1];
pctx = &ctx[1];
} else {
pxace = &pxdesc->acl.ace[k];
pctx = &ctx[0];
}
ignore = FALSE;
/*
* grants for root as a designated user or group
*/
if ((~pace->mask & (ROOT_OWNER_UNMARK | ROOT_GROUP_UNMARK))
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE)
&& ntfs_same_sid(&pace->sid, adminsid)) {
pxace->tag = (pace->mask & ROOT_OWNER_UNMARK ? POSIX_ACL_GROUP : POSIX_ACL_USER);
pxace->id = 0;
if ((pace->mask & (GENERIC_ALL | WRITE_OWNER))
&& (pace->flags & INHERIT_ONLY_ACE))
ignore = genericinh = TRUE;
} else
if (ntfs_same_sid(usid, &pace->sid)) {
pxace->id = -1;
/*
* Owner has no write-owner right :
* a group was defined same as owner
* or admin was owner or group :
* denials are meant to owner
* and grants are meant to group
*/
if (!(pace->mask & (WRITE_OWNER | GENERIC_ALL))
&& (pace->type == ACCESS_ALLOWED_ACE_TYPE)) {
if (ntfs_same_sid(gsid,usid)) {
pxace->tag = POSIX_ACL_GROUP_OBJ;
pxace->id = -1;
} else {
if (ntfs_same_sid(&pace->sid,usid))
groupowns = TRUE;
gid = NTFS_FIND_GROUP(mapping[MAPGROUPS],&pace->sid);
if (gid) {
pxace->tag = POSIX_ACL_GROUP;
pxace->id = gid;
pctx->prevgid = gid;
} else {
uid = NTFS_FIND_USER(mapping[MAPUSERS],&pace->sid);
if (uid) {
pxace->tag = POSIX_ACL_USER;
pxace->id = uid;
} else
ignore = TRUE;
}
}
} else {
/*
* when group owns, late denials for owner
* mean group mask
*/
if ((pace->type == ACCESS_DENIED_ACE_TYPE)
&& (pace->mask & WRITE_OWNER)) {
pxace->tag = POSIX_ACL_MASK;
pctx->gotownermask = TRUE;
if (pctx->gotowner)
pctx->groupmasks++;
} else {
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
pctx->gotowner = TRUE;
if (pctx->gotownermask && !pctx->gotowner) {
uid = NTFS_FIND_USER(mapping[MAPUSERS],&pace->sid);
pxace->id = uid;
pxace->tag = POSIX_ACL_USER;
} else
pxace->tag = POSIX_ACL_USER_OBJ;
/* system ignored, and admin */
/* ignored at first position */
if (pace->flags & INHERIT_ONLY_ACE) {
if ((firstinh && ntfs_same_sid(&pace->sid,adminsid))
|| ntfs_same_sid(&pace->sid,systemsid))
ignore = TRUE;
if (!firstinh) {
firstinh = TRUE;
}
} else {
if ((adminowns && ntfs_same_sid(&pace->sid,adminsid))
|| ntfs_same_sid(&pace->sid,systemsid))
ignore = TRUE;
if (ntfs_same_sid(usid,adminsid))
adminowns = TRUE;
}
}
}
} else if (ntfs_same_sid(gsid, &pace->sid)) {
if ((pace->type == ACCESS_DENIED_ACE_TYPE)
&& (pace->mask & WRITE_OWNER)) {
pxace->tag = POSIX_ACL_MASK;
pxace->id = -1;
if (pctx->gotowner)
pctx->groupmasks++;
} else {
if (pctx->gotgroup || (pctx->groupmasks > 1)) {
gid = NTFS_FIND_GROUP(mapping[MAPGROUPS],&pace->sid);
if (gid) {
pxace->id = gid;
pxace->tag = POSIX_ACL_GROUP;
pctx->prevgid = gid;
} else
ignore = TRUE;
} else {
pxace->id = -1;
pxace->tag = POSIX_ACL_GROUP_OBJ;
if (pace->type == ACCESS_ALLOWED_ACE_TYPE)
pctx->gotgroup = TRUE;
}
if (ntfs_same_sid(gsid,adminsid)
|| ntfs_same_sid(gsid,systemsid)) {
if (pace->mask & (WRITE_OWNER | GENERIC_ALL))
ignore = TRUE;
if (ntfs_same_sid(gsid,adminsid))
adminowns = TRUE;
else
genericinh = ignore;
}
}
} else if (is_world_sid((const SID*)&pace->sid)) {
pxace->id = -1;
pxace->tag = POSIX_ACL_OTHER;
if ((pace->type == ACCESS_DENIED_ACE_TYPE)
&& (pace->flags & INHERIT_ONLY_ACE))
ignore = TRUE;
} else if (ntfs_same_sid((const SID*)&pace->sid,nullsid)) {
pxace->id = -1;
pxace->tag = POSIX_ACL_SPECIAL;
} else {
uid = NTFS_FIND_USER(mapping[MAPUSERS],&pace->sid);
if (uid) {
if ((pace->type == ACCESS_DENIED_ACE_TYPE)
&& (pace->mask & WRITE_OWNER)
&& (pctx->prevuid != uid)) {
pxace->id = -1;
pxace->tag = POSIX_ACL_MASK;
} else {
pxace->id = uid;
pxace->tag = POSIX_ACL_USER;
}
pctx->prevuid = uid;
} else {
gid = NTFS_FIND_GROUP(mapping[MAPGROUPS],&pace->sid);
if (gid) {
if ((pace->type == ACCESS_DENIED_ACE_TYPE)
&& (pace->mask & WRITE_OWNER)
&& (pctx->prevgid != gid)) {
pxace->tag = POSIX_ACL_MASK;
pctx->groupmasks++;
} else {
pxace->tag = POSIX_ACL_GROUP;
}
pxace->id = gid;
pctx->prevgid = gid;
} else {
/*
* do not grant rights to unknown
* people and do not define root as a
* designated user or group
*/
ignore = TRUE;
}
}
}
if (!ignore) {
pxace->perms = 0;
/* specific decoding for vtx/uid/gid */
if (pxace->tag == POSIX_ACL_SPECIAL) {
if (pace->mask & FILE_APPEND_DATA)
pxace->perms |= S_ISUID;
if (pace->mask & FILE_WRITE_DATA)
pxace->perms |= S_ISGID;
if (pace->mask & FILE_READ_DATA)
pxace->perms |= S_ISVTX;
} else
if (isdir) {
if (pace->mask & DIR_GEXEC)
pxace->perms |= POSIX_PERM_X;
if (pace->mask & DIR_GWRITE)
pxace->perms |= POSIX_PERM_W;
if (pace->mask & DIR_GREAD)
pxace->perms |= POSIX_PERM_R;
if ((pace->mask & GENERIC_ALL)
&& (pace->flags & INHERIT_ONLY_ACE))
pxace->perms |= POSIX_PERM_X
| POSIX_PERM_W
| POSIX_PERM_R;
} else {
if (pace->mask & FILE_GEXEC)
pxace->perms |= POSIX_PERM_X;
if (pace->mask & FILE_GWRITE)
pxace->perms |= POSIX_PERM_W;
if (pace->mask & FILE_GREAD)
pxace->perms |= POSIX_PERM_R;
}
if (pace->type != ACCESS_ALLOWED_ACE_TYPE)
pxace->perms |= POSIX_PERM_DENIAL;
else
if (pxace->tag == POSIX_ACL_OTHER)
pctx->permswrld = pxace->perms;
pctx->tagsset |= pxace->tag;
if (pace->flags & INHERIT_ONLY_ACE) {
l--;
} else {
k++;
}
}
offace += le16_to_cpu(pace->size);
}
/*
* Create world perms if none (both lists)
*/
for (i=0; i<2; i++)
if ((genericinh || !i)
&& !(ctx[i].tagsset & POSIX_ACL_OTHER)) {
if (i)
pxace = &pxdesc->acl.ace[--l];
else
pxace = &pxdesc->acl.ace[k++];
pxace->tag = POSIX_ACL_OTHER;
pxace->id = -1;
pxace->perms = 0;
ctx[i].tagsset |= POSIX_ACL_OTHER;
ctx[i].permswrld = 0;
}
/*
* Set basic owner perms if none (both lists)
* This happens for files created by Windows in directories
* created by Linux and owned by root, because Windows
* merges the admin ACEs
*/
for (i=0; i<2; i++)
if (!(ctx[i].tagsset & POSIX_ACL_USER_OBJ)
&& (ctx[i].tagsset & POSIX_ACL_OTHER)) {
if (i)
pxace = &pxdesc->acl.ace[--l];
else
pxace = &pxdesc->acl.ace[k++];
pxace->tag = POSIX_ACL_USER_OBJ;
pxace->id = -1;
pxace->perms = POSIX_PERM_R | POSIX_PERM_W | POSIX_PERM_X;
ctx[i].tagsset |= POSIX_ACL_USER_OBJ;
}
/*
* Duplicate world perms as group_obj perms if none
*/
for (i=0; i<2; i++)
if ((ctx[i].tagsset & POSIX_ACL_OTHER)
&& !(ctx[i].tagsset & POSIX_ACL_GROUP_OBJ)) {
if (i)
pxace = &pxdesc->acl.ace[--l];
else
pxace = &pxdesc->acl.ace[k++];
pxace->tag = POSIX_ACL_GROUP_OBJ;
pxace->id = -1;
pxace->perms = ctx[i].permswrld;
ctx[i].tagsset |= POSIX_ACL_GROUP_OBJ;
}
/*
* Also duplicate world perms as group perms if they
* were converted to mask and not followed by a group entry
*/
if (ctx[0].groupmasks) {
for (j=k-2; j>=0; j--) {
if ((pxdesc->acl.ace[j].tag == POSIX_ACL_MASK)
&& (pxdesc->acl.ace[j].id != -1)
&& ((pxdesc->acl.ace[j+1].tag != POSIX_ACL_GROUP)
|| (pxdesc->acl.ace[j+1].id
!= pxdesc->acl.ace[j].id))) {
pxace = &pxdesc->acl.ace[k];
pxace->tag = POSIX_ACL_GROUP;
pxace->id = pxdesc->acl.ace[j].id;
pxace->perms = ctx[0].permswrld;
ctx[0].tagsset |= POSIX_ACL_GROUP;
k++;
}
if (pxdesc->acl.ace[j].tag == POSIX_ACL_MASK)
pxdesc->acl.ace[j].id = -1;
}
}
if (ctx[1].groupmasks) {
for (j=l; j<(alloccnt-1); j++) {
if ((pxdesc->acl.ace[j].tag == POSIX_ACL_MASK)
&& (pxdesc->acl.ace[j].id != -1)
&& ((pxdesc->acl.ace[j+1].tag != POSIX_ACL_GROUP)
|| (pxdesc->acl.ace[j+1].id
!= pxdesc->acl.ace[j].id))) {
pxace = &pxdesc->acl.ace[l - 1];
pxace->tag = POSIX_ACL_GROUP;
pxace->id = pxdesc->acl.ace[j].id;
pxace->perms = ctx[1].permswrld;
ctx[1].tagsset |= POSIX_ACL_GROUP;
l--;
}
if (pxdesc->acl.ace[j].tag == POSIX_ACL_MASK)
pxdesc->acl.ace[j].id = -1;
}
}
/*
* Insert default mask if none present and
* there are designated users or groups
* (the space for it has not beed used)
*/
for (i=0; i<2; i++)
if ((ctx[i].tagsset & (POSIX_ACL_USER | POSIX_ACL_GROUP))
&& !(ctx[i].tagsset & POSIX_ACL_MASK)) {
if (i)
pxace = &pxdesc->acl.ace[--l];
else
pxace = &pxdesc->acl.ace[k++];
pxace->tag = POSIX_ACL_MASK;
pxace->id = -1;
pxace->perms = POSIX_PERM_DENIAL;
ctx[i].tagsset |= POSIX_ACL_MASK;
}
if (k > l) {
ntfs_log_error("Posix descriptor is longer than expected\n");
errno = EIO;
free(pxdesc);
pxdesc = (struct POSIX_SECURITY*)NULL;
} else {
pxdesc->acccnt = k;
pxdesc->defcnt = alloccnt - l;
pxdesc->firstdef = l;
pxdesc->tagsset = ctx[0].tagsset;
pxdesc->acl.version = POSIX_VERSION;
pxdesc->acl.flags = 0;
pxdesc->acl.filler = 0;
ntfs_sort_posix(pxdesc);
if (adminowns) {
k = norm_ownadmin_permissions_posix(pxdesc,
0, pxdesc->acccnt, 0);
pxdesc->acccnt = k;
l = norm_ownadmin_permissions_posix(pxdesc,
pxdesc->firstdef, pxdesc->defcnt, k);
pxdesc->firstdef = k;
pxdesc->defcnt = l;
} else {
k = norm_std_permissions_posix(pxdesc,groupowns,
0, pxdesc->acccnt, 0);
pxdesc->acccnt = k;
l = norm_std_permissions_posix(pxdesc,groupowns,
pxdesc->firstdef, pxdesc->defcnt, k);
pxdesc->firstdef = k;
pxdesc->defcnt = l;
}
}
if (pxdesc && !ntfs_valid_posix(pxdesc)) {
ntfs_log_error("Invalid Posix descriptor built\n");
errno = EIO;
free(pxdesc);
pxdesc = (struct POSIX_SECURITY*)NULL;
}
return (pxdesc);
}
#endif /* POSIXACLS */
/*
* Build unix-style (mode_t) permissions from an ACL
* returns the requested permissions
* or a negative result (with errno set) if there is a problem
*/
int ntfs_build_permissions(const char *securattr,
const SID *usid, const SID *gsid, BOOL isdir)
{
const SECURITY_DESCRIPTOR_RELATIVE *phead;
int perm;
BOOL adminowns;
BOOL groupowns;
phead = (const SECURITY_DESCRIPTOR_RELATIVE*)securattr;
adminowns = ntfs_same_sid(usid,adminsid)
|| ntfs_same_sid(gsid,adminsid);
groupowns = !adminowns && ntfs_same_sid(gsid,usid);
if (adminowns)
perm = build_ownadmin_permissions(securattr, usid, gsid, isdir);
else
if (groupowns)
perm = build_owngrp_permissions(securattr, usid, isdir);
else
perm = build_std_permissions(securattr, usid, gsid, isdir);
return (perm);
}
/*
* The following must be in some library...
*/
static unsigned long atoul(const char *p)
{ /* must be somewhere ! */
unsigned long v;
v = 0;
while ((*p >= '0') && (*p <= '9'))
v = v * 10 + (*p++) - '0';
return (v);
}
/*
* Build an internal representation of a SID
* Returns a copy in allocated memory if it succeeds
* The SID is checked to be a valid user one.
*/
static SID *encodesid(const char *sidstr)
{
SID *sid;
int cnt;
BIGSID bigsid;
SID *bsid;
u32 auth;
const char *p;
sid = (SID*) NULL;
if (!strncmp(sidstr, "S-1-", 4)) {
bsid = (SID*)&bigsid;
bsid->revision = SID_REVISION;
p = &sidstr[4];
auth = atoul(p);
bsid->identifier_authority.high_part = const_cpu_to_be16(0);
bsid->identifier_authority.low_part = cpu_to_be32(auth);
cnt = 0;
p = strchr(p, '-');
while (p && (cnt < 8)) {
p++;
auth = atoul(p);
bsid->sub_authority[cnt] = cpu_to_le32(auth);
p = strchr(p, '-');
cnt++;
}
bsid->sub_authority_count = cnt;
if ((cnt > 0) && ntfs_valid_sid(bsid) && ntfs_is_user_sid(bsid)) {
sid = (SID*) ntfs_malloc(4 * cnt + 8);
if (sid)
memcpy(sid, bsid, 4 * cnt + 8);
}
}
return (sid);
}
/*
* Early logging before the logs are redirected
*
* (not quite satisfactory : this appears before the ntfs-g banner,
* and with a different pid)
*/
static void log_early_error(const char *format, ...)
__attribute__((format(printf, 1, 2)));
static void log_early_error(const char *format, ...)
{
va_list args;
va_start(args, format);
#ifdef HAVE_SYSLOG_H
openlog("ntfs-3g", LOG_PID, LOG_USER);
ntfs_log_handler_syslog(NULL, NULL, 0,
NTFS_LOG_LEVEL_ERROR, NULL,
format, args);
#else
vfprintf(stderr,format,args);
#endif
va_end(args);
}
/*
* Get a single mapping item from buffer
*
* Always reads a full line, truncating long lines
* Refills buffer when exhausted
* Returns pointer to item, or NULL when there is no more
*/
static struct MAPLIST *getmappingitem(FILEREADER reader, void *fileid,
off_t *poffs, char *buf, int *psrc, s64 *psize)
{
int src;
int dst;
char *p;
char *q;
char *pu;
char *pg;
int gotend;
struct MAPLIST *item;
src = *psrc;
dst = 0;
/* allocate and get a full line */
item = (struct MAPLIST*)ntfs_malloc(sizeof(struct MAPLIST));
if (item) {
do {
gotend = 0;
while ((src < *psize)
&& (buf[src] != '\n')) {
if (dst < LINESZ)
item->maptext[dst++] = buf[src];
src++;
}
if (src >= *psize) {
*poffs += *psize;
*psize = reader(fileid, buf, (size_t)BUFSZ, *poffs);
src = 0;
} else {
gotend = 1;
src++;
item->maptext[dst] = '\0';
dst = 0;
}
} while (*psize && ((item->maptext[0] == '#') || !gotend));
if (gotend) {
pu = pg = (char*)NULL;
/* decompose into uid, gid and sid */
p = item->maptext;
item->uidstr = item->maptext;
item->gidstr = strchr(item->uidstr, ':');
if (item->gidstr) {
pu = item->gidstr++;
item->sidstr = strchr(item->gidstr, ':');
if (item->sidstr) {
pg = item->sidstr++;
q = strchr(item->sidstr, ':');
if (q) *q = 0;
}
}
if (pu && pg)
*pu = *pg = '\0';
else {
log_early_error("Bad mapping item \"%s\"\n",
item->maptext);
free(item);
item = (struct MAPLIST*)NULL;
}
} else {
free(item); /* free unused item */
item = (struct MAPLIST*)NULL;
}
}
*psrc = src;
return (item);
}
/*
* Read user mapping file and split into their attribute.
* Parameters are kept as text in a chained list until logins
* are converted to uid.
* Returns the head of list, if any
*
* If an absolute path is provided, the mapping file is assumed
* to be located in another mounted file system, and plain read()
* are used to get its contents.
* If a relative path is provided, the mapping file is assumed
* to be located on the current file system, and internal IO
* have to be used since we are still mounting and we have not
* entered the fuse loop yet.
*/
struct MAPLIST *ntfs_read_mapping(FILEREADER reader, void *fileid)
{
char buf[BUFSZ];
struct MAPLIST *item;
struct MAPLIST *firstitem;
struct MAPLIST *lastitem;
int src;
off_t offs;
s64 size;
firstitem = (struct MAPLIST*)NULL;
lastitem = (struct MAPLIST*)NULL;
offs = 0;
size = reader(fileid, buf, (size_t)BUFSZ, (off_t)0);
if (size > 0) {
src = 0;
do {
item = getmappingitem(reader, fileid, &offs,
buf, &src, &size);
if (item) {
item->next = (struct MAPLIST*)NULL;
if (lastitem)
lastitem->next = item;
else
firstitem = item;
lastitem = item;
}
} while (item);
}
return (firstitem);
}
/*
* Free memory used to store the user mapping
* The only purpose is to facilitate the detection of memory leaks
*/
void ntfs_free_mapping(struct MAPPING *mapping[])
{
struct MAPPING *user;
struct MAPPING *group;
/* free user mappings */
while (mapping[MAPUSERS]) {
user = mapping[MAPUSERS];
/* do not free SIDs used for group mappings */
group = mapping[MAPGROUPS];
while (group && (group->sid != user->sid))
group = group->next;
if (!group)
free(user->sid);
/* free group list if any */
if (user->grcnt)
free(user->groups);
/* unchain item and free */
mapping[MAPUSERS] = user->next;
free(user);
}
/* free group mappings */
while (mapping[MAPGROUPS]) {
group = mapping[MAPGROUPS];
free(group->sid);
/* unchain item and free */
mapping[MAPGROUPS] = group->next;
free(group);
}
}
/*
* Build the user mapping list
* user identification may be given in symbolic or numeric format
*
* ! Note ! : does getpwnam() read /etc/passwd or some other file ?
* if so there is a possible recursion into fuse if this
* file is on NTFS, and fuse is not recursion safe.
*/
struct MAPPING *ntfs_do_user_mapping(struct MAPLIST *firstitem)
{
struct MAPLIST *item;
struct MAPPING *firstmapping;
struct MAPPING *lastmapping;
struct MAPPING *mapping;
struct passwd *pwd;
SID *sid;
int uid;
firstmapping = (struct MAPPING*)NULL;
lastmapping = (struct MAPPING*)NULL;
for (item = firstitem; item; item = item->next) {
if ((item->uidstr[0] >= '0') && (item->uidstr[0] <= '9'))
uid = atoi(item->uidstr);
else {
uid = 0;
if (item->uidstr[0]) {
pwd = getpwnam(item->uidstr);
if (pwd)
uid = pwd->pw_uid;
else
log_early_error("Invalid user \"%s\"\n",
item->uidstr);
}
}
/*
* Records with no uid and no gid are inserted
* to define the implicit mapping pattern
*/
if (uid
|| (!item->uidstr[0] && !item->gidstr[0])) {
sid = encodesid(item->sidstr);
if (sid && !item->uidstr[0] && !item->gidstr[0]
&& !ntfs_valid_pattern(sid)) {
ntfs_log_error("Bad implicit SID pattern %s\n",
item->sidstr);
sid = (SID*)NULL;
}
if (sid) {
mapping =
(struct MAPPING*)
ntfs_malloc(sizeof(struct MAPPING));
if (mapping) {
mapping->sid = sid;
mapping->xid = uid;
mapping->grcnt = 0;
mapping->next = (struct MAPPING*)NULL;
if (lastmapping)
lastmapping->next = mapping;
else
firstmapping = mapping;
lastmapping = mapping;
}
}
}
}
return (firstmapping);
}
/*
* Build the group mapping list
* group identification may be given in symbolic or numeric format
*
* gid not associated to a uid are processed first in order
* to favour real groups
*
* ! Note ! : does getgrnam() read /etc/group or some other file ?
* if so there is a possible recursion into fuse if this
* file is on NTFS, and fuse is not recursion safe.
*/
struct MAPPING *ntfs_do_group_mapping(struct MAPLIST *firstitem)
{
struct MAPLIST *item;
struct MAPPING *firstmapping;
struct MAPPING *lastmapping;
struct MAPPING *mapping;
struct group *grp;
BOOL secondstep;
BOOL ok;
int step;
SID *sid;
int gid;
firstmapping = (struct MAPPING*)NULL;
lastmapping = (struct MAPPING*)NULL;
for (step=1; step<=2; step++) {
for (item = firstitem; item; item = item->next) {
secondstep = (item->uidstr[0] != '\0')
|| !item->gidstr[0];
ok = (step == 1 ? !secondstep : secondstep);
if ((item->gidstr[0] >= '0')
&& (item->gidstr[0] <= '9'))
gid = atoi(item->gidstr);
else {
gid = 0;
if (item->gidstr[0]) {
grp = getgrnam(item->gidstr);
if (grp)
gid = grp->gr_gid;
else
log_early_error("Invalid group \"%s\"\n",
item->gidstr);
}
}
/*
* Records with no uid and no gid are inserted in the
* second step to define the implicit mapping pattern
*/
if (ok
&& (gid
|| (!item->uidstr[0] && !item->gidstr[0]))) {
sid = encodesid(item->sidstr);
if (sid && !item->uidstr[0] && !item->gidstr[0]
&& !ntfs_valid_pattern(sid)) {
/* error already logged */
sid = (SID*)NULL;
}
if (sid) {
mapping = (struct MAPPING*)
ntfs_malloc(sizeof(struct MAPPING));
if (mapping) {
mapping->sid = sid;
mapping->xid = gid;
mapping->grcnt = 0;
mapping->next = (struct MAPPING*)NULL;
if (lastmapping)
lastmapping->next = mapping;
else
firstmapping = mapping;
lastmapping = mapping;
}
}
}
}
}
return (firstmapping);
}
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