2.6.24

 fs

 cifs

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
new file mode 100644
index 0000000..c312adc
--- /dev/null
+++ b/fs/cifs/cifsacl.c
@@ -0,0 +1,533 @@
+/*
+ *   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(__le32 ace_flags, int type, umode_t *pmode,
+             umode_t *pbits_to_set)
+{
+   __u32 flags = le32_to_cpu(ace_flags);
+   /* the order of ACEs is important.  The canonical order is to begin with
+      DENY entries followed by ALLOW, otherwise an allow entry could be
+      encountered first, making the subsequent deny entry like "dead code"
+      which would be superflous since Windows stops when a match is made
+      for the operation you are trying to perform for your user */
+
+   /* For deny ACEs we change the mask so that subsequent allow access
+      control entries do not turn on the bits we are denying */
+   if (type == ACCESS_DENIED) {
+      if (flags & GENERIC_ALL) {
+         *pbits_to_set &= ~S_IRWXUGO;
+      }
+      if ((flags & GENERIC_WRITE) ||
+         ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
+         *pbits_to_set &= ~S_IWUGO;
+      if ((flags & GENERIC_READ) ||
+         ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
+         *pbits_to_set &= ~S_IRUGO;
+      if ((flags & GENERIC_EXECUTE) ||
+         ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
+         *pbits_to_set &= ~S_IXUGO;
+      return;
+   } else if (type != ACCESS_ALLOWED) {
+      cERROR(1, ("unknown access control type %d", type));
+      return;
+   }
+   /* else ACCESS_ALLOWED type */
+
+   if (flags & GENERIC_ALL) {
+      *pmode |= (S_IRWXUGO & (*pbits_to_set));
+#ifdef CONFIG_CIFS_DEBUG2
+      cFYI(1, ("all perms"));
+#endif
+      return;
+   }
+   if ((flags & GENERIC_WRITE) ||
+         ((flags & FILE_WRITE_RIGHTS) == FILE_WRITE_RIGHTS))
+      *pmode |= (S_IWUGO & (*pbits_to_set));
+   if ((flags & GENERIC_READ) ||
+         ((flags & FILE_READ_RIGHTS) == FILE_READ_RIGHTS))
+      *pmode |= (S_IRUGO & (*pbits_to_set));
+   if ((flags & GENERIC_EXECUTE) ||
+         ((flags & FILE_EXEC_RIGHTS) == FILE_EXEC_RIGHTS))
+      *pmode |= (S_IXUGO & (*pbits_to_set));
+
+#ifdef CONFIG_CIFS_DEBUG2
+   cFYI(1, ("access flags 0x%x mode now 0x%x", flags, *pmode));
+#endif
+   return;
+}
+
+/*
+   Generate access flags to reflect permissions mode is the existing mode.
+   This function is called for every ACE in the DACL whose SID matches
+   with either owner or group or everyone.
+*/
+
+static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
+            __u32 *pace_flags)
+{
+   /* reset access mask */
+   *pace_flags = 0x0;
+
+   /* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
+   mode &= bits_to_use;
+
+   /* check for R/W/X UGO since we do not know whose flags
+      is this but we have cleared all the bits sans RWX for
+      either user or group or other as per bits_to_use */
+   if (mode & S_IRUGO)
+      *pace_flags |= SET_FILE_READ_RIGHTS;
+   if (mode & S_IWUGO)
+      *pace_flags |= SET_FILE_WRITE_RIGHTS;
+   if (mode & S_IXUGO)
+      *pace_flags |= SET_FILE_EXEC_RIGHTS;
+
+#ifdef CONFIG_CIFS_DEBUG2
+   cFYI(1, ("mode: 0x%x, access flags now 0x%x", mode, *pace_flags));
+#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 */
+
+   if (!pdacl) {
+      /* no DACL in the security descriptor, set
+         all the permissions for user/group/other */
+      inode->i_mode |= S_IRWXUGO;
+      return;
+   }
+
+   /* 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);
+
+   acl_base = (char *)pdacl;
+   acl_size = sizeof(struct cifs_acl);
+
+   num_aces = le32_to_cpu(pdacl->num_aces);
+   if (num_aces  > 0) {
+      umode_t user_mask = S_IRWXU;
+      umode_t group_mask = S_IRWXG;
+      umode_t other_mask = S_IRWXO;
+
+      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,
+                       ppace[i]->type,
+                       &(inode->i_mode),
+                       &user_mask);
+         if (compare_sids(&(ppace[i]->sid), pgrpsid))
+            access_flags_to_mode(ppace[i]->access_req,
+                       ppace[i]->type,
+                       &(inode->i_mode),
+                       &group_mask);
+         if (compare_sids(&(ppace[i]->sid), &sid_everyone))
+            access_flags_to_mode(ppace[i]->access_req,
+                       ppace[i]->type,
+                       &(inode->i_mode),
+                       &other_mask);
+
+/*         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 */