Cause ALTER OWNER commands to update the object's ACL, replacing references

[postgresql] / src / backend / utils / adt / acl.c

diff --git a/src/backend/utils/adt/acl.c b/src/backend/utils/adt/acl.c
index 4b45ca7c4d479f2345af028de5758b3958e9439a..290c3ed49d2d04335e0531b9706af0af0bda2ca7 100644 (file)
--- a/src/backend/utils/adt/acl.c
+++ b/src/backend/utils/adt/acl.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/acl.c,v 1.107 2004/07/12 20:23:50 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/acl.c,v 1.108 2004/08/01 20:30:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -717,6 +717,109 @@ aclupdate(const Acl *old_acl, const AclItem *mod_aip,
        return new_acl;
 }
 
+/*
+ * Update an ACL array to reflect a change of owner to the parent object
+ *
+ *     old_acl: the input ACL array (must not be NULL)
+ *     oldownerid: AclId of the old object owner
+ *     newownerid: AclId of the new object owner
+ *
+ * The result is a modified copy; the input object is not changed.
+ *
+ * NB: caller is responsible for having detoasted the input ACL, if needed.
+ */
+Acl *
+aclnewowner(const Acl *old_acl, AclId oldownerid, AclId newownerid)
+{
+       Acl                *new_acl;
+       AclItem    *new_aip;
+       AclItem    *old_aip;
+       AclItem    *dst_aip;
+       AclItem    *src_aip;
+       AclItem    *targ_aip;
+       bool            newpresent = false;
+       int                     dst,
+                               src,
+                               targ,
+                               num;
+
+       /*
+        * Make a copy of the given ACL, substituting new owner ID for old
+        * wherever it appears as either grantor or grantee.  Also note if
+        * the new owner ID is already present.
+        */
+       num = ACL_NUM(old_acl);
+       old_aip = ACL_DAT(old_acl);
+       new_acl = allocacl(num);
+       new_aip = ACL_DAT(new_acl);
+       memcpy(new_aip, old_aip, num * sizeof(AclItem));
+       for (dst = 0, dst_aip = new_aip; dst < num; dst++, dst_aip++)
+       {
+               /* grantor is always a UID, but grantee might not be */
+               if (dst_aip->ai_grantor == oldownerid)
+                       dst_aip->ai_grantor = newownerid;
+               else if (dst_aip->ai_grantor == newownerid)
+                       newpresent = true;
+               if (ACLITEM_GET_IDTYPE(*dst_aip) == ACL_IDTYPE_UID)
+               {
+                       if (dst_aip->ai_grantee == oldownerid)
+                               dst_aip->ai_grantee = newownerid;
+                       else if (dst_aip->ai_grantee == newownerid)
+                               newpresent = true;
+               }
+       }
+
+       /*
+        * If the old ACL contained any references to the new owner, then we
+        * may now have generated an ACL containing duplicate entries.  Find
+        * them and merge them so that there are not duplicates.  (This is
+        * relatively expensive since we use a stupid O(N^2) algorithm, but
+        * it's unlikely to be the normal case.)
+        *
+        * To simplify deletion of duplicate entries, we temporarily leave them
+        * in the array but set their privilege masks to zero; when we reach
+        * such an entry it's just skipped.  (Thus, a side effect of this code
+        * will be to remove privilege-free entries, should there be any in the
+        * input.)  dst is the next output slot, targ is the currently considered
+        * input slot (always >= dst), and src scans entries to the right of targ
+        * looking for duplicates.  Once an entry has been emitted to dst it is
+        * known duplicate-free and need not be considered anymore.
+        */
+       if (newpresent)
+       {
+               dst = 0;
+               for (targ = 0, targ_aip = new_aip; targ < num; targ++, targ_aip++)
+               {
+                       /* ignore if deleted in an earlier pass */
+                       if (ACLITEM_GET_RIGHTS(*targ_aip) == ACL_NO_RIGHTS)
+                               continue;
+                       /* find and merge any duplicates */
+                       for (src = targ + 1, src_aip = targ_aip + 1; src < num;
+                                src++, src_aip++)
+                       {
+                               if (ACLITEM_GET_RIGHTS(*src_aip) == ACL_NO_RIGHTS)
+                                       continue;
+                               if (aclitem_match(targ_aip, src_aip))
+                               {
+                                       ACLITEM_SET_RIGHTS(*targ_aip,
+                                                                          ACLITEM_GET_RIGHTS(*targ_aip) |
+                                                                          ACLITEM_GET_RIGHTS(*src_aip));
+                                       /* mark the duplicate deleted */
+                                       ACLITEM_SET_RIGHTS(*src_aip, ACL_NO_RIGHTS);
+                               }
+                       }
+                       /* and emit to output */
+                       new_aip[dst] = *targ_aip;
+                       dst++;
+               }
+               /* Adjust array size to be 'dst' items */
+               ARR_DIMS(new_acl)[0] = dst;
+               ARR_SIZE(new_acl) = ACL_N_SIZE(dst);
+       }
+
+       return new_acl;
+}
+
 
 /*
  * When granting grant options, we must disallow attempts to set up circular
@@ -2373,15 +2476,15 @@ convert_tablespace_name(text *tablespacename)
 {
        char                    *spcname;
        Oid                     oid;
-       
+
        spcname = DatumGetCString(DirectFunctionCall1(textout,
-                                                           PointerGetDatum(tablespacename)));
+                                                                                                 PointerGetDatum(tablespacename)));
        oid = get_tablespace_oid(spcname);
 
-        if (!OidIsValid(oid))
-                ereport(ERROR,
-                                (errcode(ERRCODE_UNDEFINED_OBJECT),
-                                 errmsg("tablespace \"%s\" does not exist", spcname)));
+       if (!OidIsValid(oid))
+               ereport(ERROR,
+                               (errcode(ERRCODE_UNDEFINED_OBJECT),
+                                errmsg("tablespace \"%s\" does not exist", spcname)));
 
        return oid;
 }