fs/cifs/cifsacl.c

/*
 *   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, 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(struct cifs_sid *ctsid, 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 */
}

void get_mode_from_acl(struct inode * inode, const char * path)
{
	
	if (inode == NULL)
		return;

	/* find an open readable handle
	   if handle found
		 lock handle 
	   else open file
	      if no open file can not hurt to check if path is null
	   GetCIFSACL
	   for all ACEs in ACL {
		   if U or G or O
			   inode->i_mode = parse_ace(file_type, UG or O, ace->perms, inode->i_mode)
		   else continue
	   }
	   if handle open close it
	   else unlock handle */

	return;
}


static void parse_ace(struct cifs_ace *pace, char *end_of_acl)
{
	int num_subauth;

	/* validate that we do not go past end of acl */

	/* XXX this if statement can be removed
	if (end_of_acl < (char *)pace + sizeof(struct cifs_ace)) {
		cERROR(1, ("ACL too small to parse ACE"));
		return;
	} */

	num_subauth = pace->num_subauth;
	if (num_subauth) {
#ifdef CONFIG_CIFS_DEBUG2
		int i;
		cFYI(1, ("ACE revision %d num_subauth %d",
			pace->revision, pace->num_subauth));
		for (i = 0; i < num_subauth; ++i) {
			cFYI(1, ("ACE sub_auth[%d]: 0x%x", i,
				le32_to_cpu(pace->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 %d", le32_to_cpu(pace->sub_auth[num_subauth-1])));
#endif
	}

	return;
}

static void parse_ntace(struct cifs_ntace *pntace, char *end_of_acl)
{
	/* validate that we do not go past end of acl */
	if (end_of_acl < (char *)pntace + sizeof(struct cifs_ntace)) {
		cERROR(1, ("ACL too small to parse NT ACE"));
		return;
	}

#ifdef CONFIG_CIFS_DEBUG2
	cFYI(1, ("NTACE type %d flags 0x%x size %d, access Req 0x%x",
		pntace->type, pntace->flags, pntace->size,
		pntace->access_req));
#endif
	return;
}



static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
		       struct cifs_sid *pownersid, struct cifs_sid *pgrpsid)
{
	int i;
	int num_aces = 0;
	int acl_size;
	char *acl_base;
	struct cifs_ntace **ppntace;
	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

	acl_base = (char *)pdacl;
	acl_size = sizeof(struct cifs_acl);

	num_aces = le32_to_cpu(pdacl->num_aces);
	if (num_aces  > 0) {
		ppntace = kmalloc(num_aces * sizeof(struct cifs_ntace *),
				GFP_KERNEL);
		ppace = kmalloc(num_aces * sizeof(struct cifs_ace *),
				GFP_KERNEL);

/*		cifscred->cecount = pdacl->num_aces;
		cifscred->ntaces = kmalloc(num_aces *
			sizeof(struct cifs_ntace *), GFP_KERNEL);
		cifscred->aces = kmalloc(num_aces *
			sizeof(struct cifs_ace *), GFP_KERNEL);*/

		for (i = 0; i < num_aces; ++i) {
			ppntace[i] = (struct cifs_ntace *)
					(acl_base + acl_size);
			ppace[i] = (struct cifs_ace *) ((char *)ppntace[i] +
					sizeof(struct cifs_ntace));

			parse_ntace(ppntace[i], end_of_acl);
			if (end_of_acl < ((char *)ppace[i] +
					(le16_to_cpu(ppntace[i]->size) -
					sizeof(struct cifs_ntace)))) {
				cERROR(1, ("ACL too small to parse ACE"));
				break;
			} else
				parse_ace(ppace[i], end_of_acl);

/*			memcpy((void *)(&(cifscred->ntaces[i])),
				(void *)ppntace[i],
				sizeof(struct cifs_ntace));
			memcpy((void *)(&(cifscred->aces[i])),
				(void *)ppace[i],
				sizeof(struct cifs_ace)); */

			acl_base = (char *)ppntace[i];
			acl_size = le16_to_cpu(ppntace[i]->size);
		}

		kfree(ppace);
		kfree(ppntace);
	}

	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 */
	if (end_of_acl < (char *)psid + sizeof(struct cifs_sid)) {
		cERROR(1, ("ACL too small to parse SID"));
		return -EINVAL;
	}

	if (psid->num_subauth) {
#ifdef CONFIG_CIFS_DEBUG2
		int i;
		cFYI(1, ("SID revision %d num_auth %d First subauth 0x%x",
			psid->revision, psid->num_subauth, psid->sub_auth[0]));

		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 */
int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len)
{
	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;

	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));
	dacl_ptr = (struct cifs_acl *)((char *)pntsd +
				le32_to_cpu(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),
		 le32_to_cpu(pntsd->dacloffset)));
#endif
	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;

	parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr);

/*	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);
}
#endif /* CONFIG_CIFS_EXPERIMENTAL */