/*
* fs/cifs/cifsacl.c
*
* Copyright (C) International Business Machines Corp., 2007
* Author(s): Steve French (sfrench@us.ibm.com)
*
* Contains the routines for mapping CIFS/NTFS ACLs
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsacl.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#ifdef CONFIG_CIFS_EXPERIMENTAL
static struct cifs_wksid wksidarr[NUM_WK_SIDS] = {
{{1, 0, {0, 0, 0, 0, 0, 0}, {0, 0, 0, 0, 0} }, "null user"},
{{1, 1, {0, 0, 0, 0, 0, 1}, {0, 0, 0, 0, 0} }, "nobody"},
{{1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11), 0, 0, 0, 0} }, "net-users"},
{{1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(18), 0, 0, 0, 0} }, "sys"},
{{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(544), 0, 0, 0} }, "root"},
{{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(545), 0, 0, 0} }, "users"},
{{1, 2, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(32), cpu_to_le32(546), 0, 0, 0} }, "guest"} }
;
/* security id for everyone */
static const struct cifs_sid sid_everyone = {
1, 1, {0, 0, 0, 0, 0, 1}, {0} };
/* group users */
static const struct cifs_sid sid_user =
{1, 2 , {0, 0, 0, 0, 0, 5}, {} };
int match_sid(struct cifs_sid *ctsid)
{
int i, j;
int num_subauth, num_sat, num_saw;
struct cifs_sid *cwsid;
if (!ctsid)
return (-1);
for (i = 0; i < NUM_WK_SIDS; ++i) {
cwsid = &(wksidarr[i].cifssid);
/* compare the revision */
if (ctsid->revision != cwsid->revision)
continue;
/* compare all of the six auth values */
for (j = 0; j < 6; ++j) {
if (ctsid->authority[j] != cwsid->authority[j])
break;
}
if (j < 6)
continue; /* all of the auth values did not match */
/* compare all of the subauth values if any */
num_sat = ctsid->num_subauth;
num_saw = cwsid->num_subauth;
num_subauth = num_sat < num_saw ? num_sat : num_saw;
if (num_subauth) {
for (j = 0; j < num_subauth; ++j) {
if (ctsid->sub_auth[j] != cwsid->sub_auth[j])
break;
}
if (j < num_subauth)
continue; /* all sub_auth values do not match */
}
cFYI(1, ("matching sid: %s\n", wksidarr[i].sidname));
return (0); /* sids compare/match */
}
cFYI(1, ("No matching sid"));
return (-1);
}
/* if the two SIDs (roughly equivalent to a UUID for a user or group) are
the same returns 1, if they do not match returns 0 */
int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid)
{
int i;
int num_subauth, num_sat, num_saw;
if ((!ctsid) || (!cwsid))
return (0);
/* compare the revision */
if (ctsid->revision != cwsid->revision)
return (0);
/* compare all of the six auth values */
for (i = 0; i < 6; ++i) {
if (ctsid->authority[i] != cwsid->authority[i])
return (0);
}
/* compare all of the subauth values if any */
num_sat = ctsid->num_subauth;
num_saw = cwsid->num_subauth;
num_subauth = num_sat < num_saw ? num_sat : num_saw;
if (num_subauth) {
for (i = 0; i < num_subauth; ++i) {
if (ctsid->sub_auth[i] != cwsid->sub_auth[i])
return (0);
}
}
return (1); /* sids compare/match */
}
/*
change posix mode to reflect permissions
pmode is the existing mode (we only want to overwrite part of this
bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
*/
static void access_flags_to_mode(__u32 ace_flags, umode_t *pmode,
umode_t bits_to_set)
{
if (ace_flags & GENERIC_ALL) {
*pmode |= (S_IRWXUGO & bits_to_set);
#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("all perms"));
#endif
return;
}
if ((ace_flags & GENERIC_WRITE) ||
((ace_flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
*pmode |= (S_IWUGO & bits_to_set);
if ((ace_flags & GENERIC_READ) ||
((ace_flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
*pmode |= (S_IRUGO & bits_to_set);
if ((ace_flags & GENERIC_EXECUTE) ||
((ace_flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
*pmode |= (S_IXUGO & bits_to_set);
#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("access flags 0x%x mode now 0x%x", ace_flags, *pmode));
#endif
return;
}
#ifdef CONFIG_CIFS_DEBUG2
static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
{
int num_subauth;
/* validate that we do not go past end of acl */
if (le16_to_cpu(pace->size) < 16) {
cERROR(1, ("ACE too small, %d", le16_to_cpu(pace->size)));
return;
}
if (end_of_acl < (char *)pace + le16_to_cpu(pace->size)) {
cERROR(1, ("ACL too small to parse ACE"));
return;
}
num_subauth = pace->sid.num_subauth;
if (num_subauth) {
int i;
cFYI(1, ("ACE revision %d num_auth %d type %d flags %d size %d",
pace->sid.revision, pace->sid.num_subauth, pace->type,
pace->flags, pace->size));
for (i = 0; i < num_subauth; ++i) {
cFYI(1, ("ACE sub_auth[%d]: 0x%x", i,
le32_to_cpu(pace->sid.sub_auth[i])));
}
/* BB add length check to make sure that we do not have huge
num auths and therefore go off the end */
}
return;
}
#endif
static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
struct inode *inode)
{
int i;
int num_aces = 0;
int acl_size;
char *acl_base;
struct cifs_ace **ppace;
/* BB need to add parm so we can store the SID BB */
/* validate that we do not go past end of acl */
if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
cERROR(1, ("ACL too small to parse DACL"));
return;
}
#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("DACL revision %d size %d num aces %d",
le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
le32_to_cpu(pdacl->num_aces)));
#endif
/* reset rwx permissions for user/group/other.
Also, if num_aces is 0 i.e. DACL has no ACEs,
user/group/other have no permissions */
inode->i_mode &= ~(S_IRWXUGO);
if (!pdacl) {
/* no DACL in the security descriptor, set
all the permissions for user/group/other */
inode->i_mode |= S_IRWXUGO;
return;
}
acl_base = (char *)pdacl;
acl_size = sizeof(struct cifs_acl);
num_aces = le32_to_cpu(pdacl->num_aces);
if (num_aces > 0) {
ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
GFP_KERNEL);
/* cifscred->cecount = pdacl->num_aces;
cifscred->aces = kmalloc(num_aces *
sizeof(struct cifs_ace *), GFP_KERNEL);*/
for (i = 0; i < num_aces; ++i) {
ppace[i] = (struct cifs_ace *) (acl_base + acl_size);
#ifdef CONFIG_CIFS_DEBUG2
dump_ace(ppace[i], end_of_acl);
#endif
if (compare_sids(&(ppace[i]->sid), pownersid))
access_flags_to_mode(ppace[i]->access_req,
&(inode->i_mode), S_IRWXU);
if (compare_sids(&(ppace[i]->sid), pgrpsid))
access_flags_to_mode(ppace[i]->access_req,
&(inode->i_mode), S_IRWXG);
if (compare_sids(&(ppace[i]->sid), &sid_everyone))
access_flags_to_mode(ppace[i]->access_req,
&(inode->i_mode), S_IRWXO);
/* memcpy((void *)(&(cifscred->aces[i])),
(void *)ppace[i],
sizeof(struct cifs_ace)); */
acl_base = (char *)ppace[i];
acl_size = le16_to_cpu(ppace[i]->size);
}
kfree(ppace);
}
return;
}
static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
{
/* BB need to add parm so we can store the SID BB */
/* validate that we do not go past end of ACL - sid must be at least 8
bytes long (assuming no sub-auths - e.g. the null SID */
if (end_of_acl < (char *)psid + 8) {
cERROR(1, ("ACL too small to parse SID %p", psid));
return -EINVAL;
}
if (psid->num_subauth) {
#ifdef CONFIG_CIFS_DEBUG2
int i;
cFYI(1, ("SID revision %d num_auth %d",
psid->revision, psid->num_subauth));
for (i = 0; i < psid->num_subauth; i++) {
cFYI(1, ("SID sub_auth[%d]: 0x%x ", i,
le32_to_cpu(psid->sub_auth[i])));
}
/* BB add length check to make sure that we do not have huge
num auths and therefore go off the end */
cFYI(1, ("RID 0x%x",
le32_to_cpu(psid->sub_auth[psid->num_subauth-1])));
#endif
}
return 0;
}
/* Convert CIFS ACL to POSIX form */
static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len,
struct inode *inode)
{
int rc;
struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
struct cifs_acl *dacl_ptr; /* no need for SACL ptr */
char *end_of_acl = ((char *)pntsd) + acl_len;
__u32 dacloffset;
if ((inode == NULL) || (pntsd == NULL))
return -EIO;
owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
le32_to_cpu(pntsd->osidoffset));
group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
le32_to_cpu(pntsd->gsidoffset));
dacloffset = le32_to_cpu(pntsd->dacloffset);
dacl_ptr = (struct cifs_acl *)(char *)pntsd + dacloffset;
#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("revision %d type 0x%x ooffset 0x%x goffset 0x%x "
"sacloffset 0x%x dacloffset 0x%x",
pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
le32_to_cpu(pntsd->gsidoffset),
le32_to_cpu(pntsd->sacloffset), dacloffset));
#endif
/* cifs_dump_mem("owner_sid: ", owner_sid_ptr, 64); */
rc = parse_sid(owner_sid_ptr, end_of_acl);
if (rc)
return rc;
rc = parse_sid(group_sid_ptr, end_of_acl);
if (rc)
return rc;
if (dacloffset)
parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
group_sid_ptr, inode);
else
cFYI(1, ("no ACL")); /* BB grant all or default perms? */
/* cifscred->uid = owner_sid_ptr->rid;
cifscred->gid = group_sid_ptr->rid;
memcpy((void *)(&(cifscred->osid)), (void *)owner_sid_ptr,
sizeof(struct cifs_sid));
memcpy((void *)(&(cifscred->gsid)), (void *)group_sid_ptr,
sizeof(struct cifs_sid)); */
return (0);
}
/* Retrieve an ACL from the server */
static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
const char *path)
{
struct cifsFileInfo *open_file;
int unlock_file = FALSE;
int xid;
int rc = -EIO;
__u16 fid;
struct super_block *sb;
struct cifs_sb_info *cifs_sb;
struct cifs_ntsd *pntsd = NULL;
cFYI(1, ("get mode from ACL for %s", path));
if (inode == NULL)
return NULL;
xid = GetXid();
open_file = find_readable_file(CIFS_I(inode));
sb = inode->i_sb;
if (sb == NULL) {
FreeXid(xid);
return NULL;
}
cifs_sb = CIFS_SB(sb);
if (open_file) {
unlock_file = TRUE;
fid = open_file->netfid;
} else {
int oplock = FALSE;
/* open file */
rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
READ_CONTROL, 0, &fid, &oplock, NULL,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc != 0) {
cERROR(1, ("Unable to open file to get ACL"));
FreeXid(xid);
return NULL;
}
}
rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, &pntsd, pacllen);
cFYI(1, ("GetCIFSACL rc = %d ACL len %d", rc, *pacllen));
if (unlock_file == TRUE)
atomic_dec(&open_file->wrtPending);
else
CIFSSMBClose(xid, cifs_sb->tcon, fid);
FreeXid(xid);
return pntsd;
}
/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
void acl_to_uid_mode(struct inode *inode, const char *path)
{
struct cifs_ntsd *pntsd = NULL;
u32 acllen = 0;
int rc = 0;
#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("converting ACL to mode for %s", path));
#endif
pntsd = get_cifs_acl(&acllen, inode, path);
/* if we can retrieve the ACL, now parse Access Control Entries, ACEs */
if (pntsd)
rc = parse_sec_desc(pntsd, acllen, inode);
if (rc)
cFYI(1, ("parse sec desc failed rc = %d", rc));
kfree(pntsd);
return;
}
/* Convert mode bits to an ACL so we can update the ACL on the server */
int mode_to_acl(struct inode *inode, const char *path)
{
int rc = 0;
__u32 acllen = 0;
struct cifs_ntsd *pntsd = NULL;
cFYI(1, ("set ACL from mode for %s", path));
/* Get the security descriptor */
pntsd = get_cifs_acl(&acllen, inode, path);
/* Add/Modify the three ACEs for owner, group, everyone
while retaining the other ACEs */
/* Set the security descriptor */
kfree(pntsd);
return rc;
}
#endif /* CONFIG_CIFS_EXPERIMENTAL */
