1 /*-------------------------------------------------------------------------
4 * RLS-related utility functions.
6 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * src/backend/utils/misc/rls.c
13 *-------------------------------------------------------------------------
17 #include "access/htup.h"
18 #include "access/htup_details.h"
19 #include "access/transam.h"
20 #include "catalog/namespace.h"
21 #include "catalog/pg_class.h"
22 #include "miscadmin.h"
23 #include "utils/acl.h"
24 #include "utils/builtins.h"
25 #include "utils/elog.h"
26 #include "utils/lsyscache.h"
27 #include "utils/rls.h"
28 #include "utils/syscache.h"
34 * Determine, based on the relation, row_security setting, and current role,
35 * if RLS is applicable to this query. RLS_NONE_ENV indicates that, while
36 * RLS is not to be added for this query, a change in the environment may change
37 * that. RLS_NONE means that RLS is not on the relation at all and therefore
38 * we don't need to worry about it. RLS_ENABLED means RLS should be implemented
39 * for the table and the plan cache needs to be invalidated if the environment
42 * Handle checking as another role via checkAsUser (for views, etc). Pass
43 * InvalidOid to check the current user.
45 * If noError is set to 'true' then we just return RLS_ENABLED instead of doing
46 * an ereport() if the user has attempted to bypass RLS and they are not
47 * allowed to. This allows users to check if RLS is enabled without having to
48 * deal with the actual error case (eg: error cases which are trying to decide
49 * if the user should get data from the relation back as part of the error).
52 check_enable_rls(Oid relid, Oid checkAsUser, bool noError)
54 Oid user_id = checkAsUser ? checkAsUser : GetUserId();
56 Form_pg_class classform;
58 bool relforcerowsecurity;
61 /* Nothing to do for built-in relations */
62 if (relid < (Oid) FirstNormalObjectId)
65 /* Fetch relation's relrowsecurity and relforcerowsecurity flags */
66 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
67 if (!HeapTupleIsValid(tuple))
69 classform = (Form_pg_class) GETSTRUCT(tuple);
71 relrowsecurity = classform->relrowsecurity;
72 relforcerowsecurity = classform->relforcerowsecurity;
74 ReleaseSysCache(tuple);
76 /* Nothing to do if the relation does not have RLS */
81 * BYPASSRLS users always bypass RLS. Note that superusers are always
82 * considered to have BYPASSRLS.
84 * Return RLS_NONE_ENV to indicate that this decision depends on the
85 * environment (in this case, the user_id).
87 if (has_bypassrls_privilege(user_id))
91 * Table owners generally bypass RLS, except if the table has been set (by
92 * an owner) to FORCE ROW SECURITY, and this is not a referential
95 * Return RLS_NONE_ENV to indicate that this decision depends on the
96 * environment (in this case, the user_id).
98 amowner = pg_class_ownercheck(relid, user_id);
102 * If FORCE ROW LEVEL SECURITY has been set on the relation then we
103 * should return RLS_ENABLED to indicate that RLS should be applied.
104 * If not, or if we are in an InNoForceRLSOperation context, we return
107 * InNoForceRLSOperation indicates that we should not apply RLS even
108 * if the table has FORCE RLS set - IF the current user is the owner.
109 * This is specifically to ensure that referential integrity checks
110 * are able to still run correctly.
112 * This is intentionally only done after we have checked that the user
113 * is the table owner, which should always be the case for referential
116 if (!relforcerowsecurity || InNoForceRLSOperation())
121 * We should apply RLS. However, the user may turn off the row_security
122 * GUC to get a forced error instead.
124 if (!row_security && !noError)
126 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
127 errmsg("query would be affected by row-level security policy for table \"%s\"",
128 get_rel_name(relid)),
129 amowner ? errhint("To disable the policy for the table's owner, use ALTER TABLE NO FORCE ROW LEVEL SECURITY.") : 0));
131 /* RLS should be fully enabled for this relation. */
136 * row_security_active
138 * check_enable_rls wrapped as a SQL callable function except
139 * RLS_NONE_ENV and RLS_NONE are the same for this purpose.
142 row_security_active(PG_FUNCTION_ARGS)
145 Oid tableoid = PG_GETARG_OID(0);
148 rls_status = check_enable_rls(tableoid, InvalidOid, true);
149 PG_RETURN_BOOL(rls_status == RLS_ENABLED);
153 row_security_active_name(PG_FUNCTION_ARGS)
155 /* By qualified name */
156 text *tablename = PG_GETARG_TEXT_P(0);
161 /* Look up table name. Can't lock it - we might not have privileges. */
162 tablerel = makeRangeVarFromNameList(textToQualifiedNameList(tablename));
163 tableoid = RangeVarGetRelid(tablerel, NoLock, false);
165 rls_status = check_enable_rls(tableoid, InvalidOid, true);
166 PG_RETURN_BOOL(rls_status == RLS_ENABLED);