* Any part of the system which is returning records back to the user, or
* which is accepting records from the user to add to a table, needs to
* consider the policies associated with the table (if any). For normal
- * queries, this is handled by calling prepend_row_security_policies() during
- * rewrite, which looks at each RTE and adds the expressions defined by the
- * policies to the securityQuals list for the RTE. For queries which modify
- * the relation, any WITH CHECK policies are added to the list of
- * WithCheckOptions for the Query and checked against each row which is being
+ * queries, this is handled by calling get_row_security_policies() during
+ * rewrite, for each RTE in the query. This returns the expressions defined
+ * by the table's policies as a list that is prepended to the securityQuals
+ * list for the RTE. For queries which modify the table, any WITH CHECK
+ * clauses from the table's policies are also returned and prepended to the
+ * list of WithCheckOptions for the Query to check each row that is being
* added to the table. Other parts of the system (eg: COPY) simply construct
* a normal query and use that, if RLS is to be applied.
*
#include "utils/syscache.h"
#include "tcop/utility.h"
-static List *pull_row_security_policies(CmdType cmd, Relation relation,
- Oid user_id);
-static void process_policies(Query *root, List *policies, int rt_index,
- Expr **final_qual,
- Expr **final_with_check_qual,
- bool *hassublinks,
- BoolExprType boolop);
+static void get_policies_for_relation(Relation relation,
+ CmdType cmd, Oid user_id,
+ List **permissive_policies,
+ List **restrictive_policies);
+
+static List *sort_policies_by_name(List *policies);
+
+static int row_security_policy_cmp(const void *a, const void *b);
+
+static void add_security_quals(int rt_index,
+ List *permissive_policies,
+ List *restrictive_policies,
+ List **securityQuals,
+ bool *hasSubLinks);
+
+static void add_with_check_options(Relation rel,
+ int rt_index,
+ WCOKind kind,
+ List *permissive_policies,
+ List *restrictive_policies,
+ List **withCheckOptions,
+ bool *hasSubLinks);
+
static bool check_role_for_policy(ArrayType *policy_roles, Oid user_id);
/*
*
* row_security_policy_hook_restrictive can be used to add policies which
* are enforced, regardless of other policies (they are "AND"d).
- *
- * See below where the hook is called in prepend_row_security_policies for
- * insight into how to use this hook.
*/
row_security_policy_hook_type row_security_policy_hook_permissive = NULL;
row_security_policy_hook_type row_security_policy_hook_restrictive = NULL;
/*
- * Get any row security quals and check quals that should be applied to the
- * specified RTE.
+ * Get any row security quals and WithCheckOption checks that should be
+ * applied to the specified RTE.
*
* In addition, hasRowSecurity is set to true if row level security is enabled
* (even if this RTE doesn't have any row security quals), and hasSubLinks is
* set to true if any of the quals returned contain sublinks.
*/
void
-get_row_security_policies(Query *root, CmdType commandType, RangeTblEntry *rte,
- int rt_index, List **securityQuals,
- List **withCheckOptions, bool *hasRowSecurity,
- bool *hasSubLinks)
+get_row_security_policies(Query *root, RangeTblEntry *rte, int rt_index,
+ List **securityQuals, List **withCheckOptions,
+ bool *hasRowSecurity, bool *hasSubLinks)
{
- Expr *rowsec_expr = NULL;
- Expr *rowsec_with_check_expr = NULL;
- Expr *hook_expr_restrictive = NULL;
- Expr *hook_with_check_expr_restrictive = NULL;
- Expr *hook_expr_permissive = NULL;
- Expr *hook_with_check_expr_permissive = NULL;
-
- List *rowsec_policies;
- List *hook_policies_restrictive = NIL;
- List *hook_policies_permissive = NIL;
-
- Relation rel;
Oid user_id;
int sec_context;
int rls_status;
- bool defaultDeny = false;
+ Relation rel;
+ CmdType commandType;
+ List *permissive_policies;
+ List *restrictive_policies;
/* Defaults for the return values */
*securityQuals = NIL;
/* Grab the built-in policies which should be applied to this relation. */
rel = heap_open(rte->relid, NoLock);
- rowsec_policies = pull_row_security_policies(commandType, rel,
- user_id);
-
- /*
- * Check if this is only the default-deny policy.
- *
- * Normally, if the table has row security enabled but there are no
- * policies, we use a default-deny policy and not allow anything. However,
- * when an extension uses the hook to add their own policies, we don't
- * want to include the default deny policy or there won't be any way for a
- * user to use an extension exclusively for the policies to be used.
- */
- if (((RowSecurityPolicy *) linitial(rowsec_policies))->policy_id
- == InvalidOid)
- defaultDeny = true;
+ commandType = rt_index == root->resultRelation ?
+ root->commandType : CMD_SELECT;
- /* Now that we have our policies, build the expressions from them. */
- process_policies(root, rowsec_policies, rt_index, &rowsec_expr,
- &rowsec_with_check_expr, hasSubLinks, OR_EXPR);
+ get_policies_for_relation(rel, commandType, user_id, &permissive_policies,
+ &restrictive_policies);
/*
- * Also, allow extensions to add their own policies.
- *
- * extensions can add either permissive or restrictive policies.
+ * For SELECT, UPDATE and DELETE, add security quals to enforce these
+ * policies. These security quals control access to existing table rows.
+ * Restrictive policies are "AND"d together, and permissive policies are
+ * "OR"d together.
*
- * Note that, as with the internal policies, if multiple policies are
- * returned then they will be combined into a single expression with all
- * of them OR'd (for permissive) or AND'd (for restrictive) together.
- *
- * If only a USING policy is returned by the extension then it will be
- * used for WITH CHECK as well, similar to how internal policies are
- * handled.
- *
- * The only caveat to this is that if there are NO internal policies
- * defined, there ARE policies returned by the extension, and RLS is
- * enabled on the table, then we will ignore the internally-generated
- * default-deny policy and use only the policies returned by the
- * extension.
+ * If there are no policy clauses controlling access to the table, this
+ * will add a single always-false clause (a default-deny policy).
*/
- if (row_security_policy_hook_restrictive)
- {
- hook_policies_restrictive = (*row_security_policy_hook_restrictive) (commandType, rel);
-
- /* Build the expression from any policies returned. */
- if (hook_policies_restrictive != NIL)
- process_policies(root, hook_policies_restrictive, rt_index,
- &hook_expr_restrictive,
- &hook_with_check_expr_restrictive,
- hasSubLinks,
- AND_EXPR);
- }
-
- if (row_security_policy_hook_permissive)
- {
- hook_policies_permissive = (*row_security_policy_hook_permissive) (commandType, rel);
-
- /* Build the expression from any policies returned. */
- if (hook_policies_permissive != NIL)
- process_policies(root, hook_policies_permissive, rt_index,
- &hook_expr_permissive,
- &hook_with_check_expr_permissive, hasSubLinks,
- OR_EXPR);
- }
+ if (commandType == CMD_SELECT ||
+ commandType == CMD_UPDATE ||
+ commandType == CMD_DELETE)
+ add_security_quals(rt_index,
+ permissive_policies,
+ restrictive_policies,
+ securityQuals,
+ hasSubLinks);
/*
- * If the only built-in policy is the default-deny one, and permissive hook
- * policies exist, then use the hook policies only and do not apply the
- * default-deny policy. Otherwise, we will apply both sets below.
- *
- * Note that we do not remove the defaultDeny policy if only *restrictive*
- * policies exist as restrictive policies should only ever be reducing what
- * is visible. Therefore, at least one permissive policy must exist which
- * allows records to be seen before restrictive policies can remove rows
- * from that set. A single "true" policy can be created to address this
- * requirement, if necessary.
- */
- if (defaultDeny && hook_policies_permissive != NIL)
- {
- rowsec_expr = NULL;
- rowsec_with_check_expr = NULL;
- }
-
- /*
- * For INSERT or UPDATE, we need to add the WITH CHECK quals to Query's
- * withCheckOptions to verify that any new records pass the WITH CHECK
- * policy (this will be a copy of the USING policy, if no explicit WITH
- * CHECK policy exists).
+ * For INSERT and UPDATE, add withCheckOptions to verify that any new
+ * records added are consistent with the security policies. This will use
+ * each policy's WITH CHECK clause, or its USING clause if no explicit
+ * WITH CHECK clause is defined.
*/
if (commandType == CMD_INSERT || commandType == CMD_UPDATE)
{
- /*
- * WITH CHECK OPTIONS wants a WCO node which wraps each Expr, so
- * create them as necessary.
- */
+ /* This should be the target relation */
+ Assert(rt_index == root->resultRelation);
+
+ add_with_check_options(rel, rt_index,
+ commandType == CMD_INSERT ?
+ WCO_RLS_INSERT_CHECK : WCO_RLS_UPDATE_CHECK,
+ permissive_policies,
+ restrictive_policies,
+ withCheckOptions,
+ hasSubLinks);
/*
- * Handle any restrictive policies first.
- *
- * They can simply be added.
+ * For INSERT ... ON CONFLICT DO UPDATE we need additional policy
+ * checks for the UPDATE which may be applied to the same RTE.
*/
- if (hook_with_check_expr_restrictive)
+ if (commandType == CMD_INSERT &&
+ root->onConflict && root->onConflict->action == ONCONFLICT_UPDATE)
{
- WithCheckOption *wco;
+ List *conflict_permissive_policies;
+ List *conflict_restrictive_policies;
+
+ /* Get the policies that apply to the auxiliary UPDATE */
+ get_policies_for_relation(rel, CMD_UPDATE, user_id,
+ &conflict_permissive_policies,
+ &conflict_restrictive_policies);
- wco = (WithCheckOption *) makeNode(WithCheckOption);
- wco->kind = commandType == CMD_INSERT ? WCO_RLS_INSERT_CHECK :
- WCO_RLS_UPDATE_CHECK;
- wco->relname = pstrdup(RelationGetRelationName(rel));
- wco->qual = (Node *) hook_with_check_expr_restrictive;
- wco->cascaded = false;
- *withCheckOptions = lappend(*withCheckOptions, wco);
+ /*
+ * Enforce the USING clauses of the UPDATE policies using WCOs
+ * rather than security quals. This ensures that an error is
+ * raised if the conflicting row cannot be updated due to RLS,
+ * rather than the change being silently dropped.
+ */
+ add_with_check_options(rel, rt_index,
+ WCO_RLS_CONFLICT_CHECK,
+ conflict_permissive_policies,
+ conflict_restrictive_policies,
+ withCheckOptions,
+ hasSubLinks);
+
+ /* Enforce the WITH CHECK clauses of the UPDATE policies */
+ add_with_check_options(rel, rt_index,
+ WCO_RLS_UPDATE_CHECK,
+ conflict_permissive_policies,
+ conflict_restrictive_policies,
+ withCheckOptions,
+ hasSubLinks);
}
+ }
- /*
- * Handle built-in policies, if there are no permissive policies from
- * the hook.
- */
- if (rowsec_with_check_expr && !hook_with_check_expr_permissive)
- {
- WithCheckOption *wco;
+ heap_close(rel, NoLock);
- wco = (WithCheckOption *) makeNode(WithCheckOption);
- wco->kind = commandType == CMD_INSERT ? WCO_RLS_INSERT_CHECK :
- WCO_RLS_UPDATE_CHECK;
- wco->relname = pstrdup(RelationGetRelationName(rel));
- wco->qual = (Node *) rowsec_with_check_expr;
- wco->cascaded = false;
- *withCheckOptions = lappend(*withCheckOptions, wco);
- }
- /* Handle the hook policies, if there are no built-in ones. */
- else if (!rowsec_with_check_expr && hook_with_check_expr_permissive)
- {
- WithCheckOption *wco;
+ /*
+ * Mark this query as having row security, so plancache can invalidate it
+ * when necessary (eg: role changes)
+ */
+ *hasRowSecurity = true;
- wco = (WithCheckOption *) makeNode(WithCheckOption);
- wco->kind = commandType == CMD_INSERT ? WCO_RLS_INSERT_CHECK :
- WCO_RLS_UPDATE_CHECK;
- wco->relname = pstrdup(RelationGetRelationName(rel));
- wco->qual = (Node *) hook_with_check_expr_permissive;
- wco->cascaded = false;
- *withCheckOptions = lappend(*withCheckOptions, wco);
- }
- /* Handle the case where there are both. */
- else if (rowsec_with_check_expr && hook_with_check_expr_permissive)
- {
- WithCheckOption *wco;
- List *combined_quals = NIL;
- Expr *combined_qual_eval;
+ return;
+}
- combined_quals = lcons(copyObject(rowsec_with_check_expr),
- combined_quals);
+/*
+ * get_policies_for_relation
+ *
+ * Returns lists of permissive and restrictive policies to be applied to the
+ * specified relation, based on the command type and role.
+ *
+ * This includes any policies added by extensions.
+ */
+static void
+get_policies_for_relation(Relation relation, CmdType cmd, Oid user_id,
+ List **permissive_policies,
+ List **restrictive_policies)
+{
+ ListCell *item;
- combined_quals = lcons(copyObject(hook_with_check_expr_permissive),
- combined_quals);
+ *permissive_policies = NIL;
+ *restrictive_policies = NIL;
- combined_qual_eval = makeBoolExpr(OR_EXPR, combined_quals, -1);
+ /*
+ * First find all internal policies for the relation. CREATE POLICY does
+ * not currently support defining restrictive policies, so for now all
+ * internal policies are permissive.
+ */
+ foreach(item, relation->rd_rsdesc->policies)
+ {
+ bool cmd_matches = false;
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
- wco = (WithCheckOption *) makeNode(WithCheckOption);
- wco->kind = commandType == CMD_INSERT ? WCO_RLS_INSERT_CHECK :
- WCO_RLS_UPDATE_CHECK;
- wco->relname = pstrdup(RelationGetRelationName(rel));
- wco->qual = (Node *) combined_qual_eval;
- wco->cascaded = false;
- *withCheckOptions = lappend(*withCheckOptions, wco);
+ /* Always add ALL policies, if they exist. */
+ if (policy->polcmd == '*')
+ cmd_matches = true;
+ else
+ {
+ /* Check whether the policy applies to the specified command type */
+ switch (cmd)
+ {
+ case CMD_SELECT:
+ if (policy->polcmd == ACL_SELECT_CHR)
+ cmd_matches = true;
+ break;
+ case CMD_INSERT:
+ if (policy->polcmd == ACL_INSERT_CHR)
+ cmd_matches = true;
+ break;
+ case CMD_UPDATE:
+ if (policy->polcmd == ACL_UPDATE_CHR)
+ cmd_matches = true;
+ break;
+ case CMD_DELETE:
+ if (policy->polcmd == ACL_DELETE_CHR)
+ cmd_matches = true;
+ break;
+ default:
+ elog(ERROR, "unrecognized policy command type %d",
+ (int) cmd);
+ break;
+ }
}
/*
- * ON CONFLICT DO UPDATE has an RTE that is subject to both INSERT and
- * UPDATE RLS enforcement. Those are enforced (as a special, distinct
- * kind of WCO) on the target tuple.
- *
- * Make a second, recursive pass over the RTE for this, gathering
- * UPDATE-applicable RLS checks/WCOs, and gathering and converting
- * UPDATE-applicable security quals into WCO_RLS_CONFLICT_CHECK RLS
- * checks/WCOs. Finally, these distinct kinds of RLS checks/WCOs are
- * concatenated with our own INSERT-applicable list.
+ * Add this policy to the list of permissive policies if it
+ * applies to the specified role.
*/
- if (root->onConflict && root->onConflict->action == ONCONFLICT_UPDATE &&
- commandType == CMD_INSERT)
- {
- List *conflictSecurityQuals = NIL;
- List *conflictWCOs = NIL;
- ListCell *item;
- bool conflictHasRowSecurity = false;
- bool conflictHasSublinks = false;
-
- /* Assume that RTE is target resultRelation */
- get_row_security_policies(root, CMD_UPDATE, rte, rt_index,
- &conflictSecurityQuals, &conflictWCOs,
- &conflictHasRowSecurity,
- &conflictHasSublinks);
-
- if (conflictHasRowSecurity)
- *hasRowSecurity = true;
- if (conflictHasSublinks)
- *hasSubLinks = true;
+ if (cmd_matches && check_role_for_policy(policy->roles, user_id))
+ *permissive_policies = lappend(*permissive_policies, policy);
+ }
- /*
- * Append WITH CHECK OPTIONs/RLS checks, which should not conflict
- * between this INSERT and the auxiliary UPDATE
- */
- *withCheckOptions = list_concat(*withCheckOptions,
- conflictWCOs);
+ /*
+ * Then add any permissive or restrictive policies defined by extensions.
+ * These are simply appended to the lists of internal policies, if they
+ * apply to the specified role.
+ */
+ if (row_security_policy_hook_restrictive)
+ {
+ List *hook_policies =
+ (*row_security_policy_hook_restrictive) (cmd, relation);
- foreach(item, conflictSecurityQuals)
- {
- Expr *conflict_rowsec_expr = (Expr *) lfirst(item);
- WithCheckOption *wco;
+ /*
+ * We sort restrictive policies by name so that any WCOs they generate
+ * are checked in a well-defined order.
+ */
+ hook_policies = sort_policies_by_name(hook_policies);
- wco = (WithCheckOption *) makeNode(WithCheckOption);
+ foreach(item, hook_policies)
+ {
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
- wco->kind = WCO_RLS_CONFLICT_CHECK;
- wco->relname = pstrdup(RelationGetRelationName(rel));
- wco->qual = (Node *) copyObject(conflict_rowsec_expr);
- wco->cascaded = false;
- *withCheckOptions = lappend(*withCheckOptions, wco);
- }
+ if (check_role_for_policy(policy->roles, user_id))
+ *restrictive_policies = lappend(*restrictive_policies, policy);
}
}
- /* For SELECT, UPDATE, and DELETE, set the security quals */
- if (commandType == CMD_SELECT
- || commandType == CMD_UPDATE
- || commandType == CMD_DELETE)
+ if (row_security_policy_hook_permissive)
{
- /* restrictive policies can simply be added to the list first */
- if (hook_expr_restrictive)
- *securityQuals = lappend(*securityQuals, hook_expr_restrictive);
-
- /* If we only have internal permissive, then just add those */
- if (rowsec_expr && !hook_expr_permissive)
- *securityQuals = lappend(*securityQuals, rowsec_expr);
- /* .. and if we have only permissive policies from the hook */
- else if (!rowsec_expr && hook_expr_permissive)
- *securityQuals = lappend(*securityQuals, hook_expr_permissive);
- /* if we have both, we have to combine them with an OR */
- else if (rowsec_expr && hook_expr_permissive)
+ List *hook_policies =
+ (*row_security_policy_hook_permissive) (cmd, relation);
+
+ foreach(item, hook_policies)
{
- List *combined_quals = NIL;
- Expr *combined_qual_eval;
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
- combined_quals = lcons(copyObject(rowsec_expr), combined_quals);
- combined_quals = lcons(copyObject(hook_expr_permissive),
- combined_quals);
+ if (check_role_for_policy(policy->roles, user_id))
+ *permissive_policies = lappend(*permissive_policies, policy);
+ }
+ }
+}
- combined_qual_eval = makeBoolExpr(OR_EXPR, combined_quals, -1);
+/*
+ * sort_policies_by_name
+ *
+ * This is only used for restrictive policies, ensuring that any
+ * WithCheckOptions they generate are applied in a well-defined order.
+ * This is not necessary for permissive policies, since they are all "OR"d
+ * together into a single WithCheckOption check.
+ */
+static List *
+sort_policies_by_name(List *policies)
+{
+ int npol = list_length(policies);
+ RowSecurityPolicy *pols;
+ ListCell *item;
+ int ii = 0;
- *securityQuals = lappend(*securityQuals, combined_qual_eval);
- }
+ if (npol <= 1)
+ return policies;
+
+ pols = (RowSecurityPolicy *) palloc(sizeof(RowSecurityPolicy) * npol);
+
+ foreach(item, policies)
+ {
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
+ pols[ii++] = *policy;
}
- heap_close(rel, NoLock);
+ qsort(pols, npol, sizeof(RowSecurityPolicy), row_security_policy_cmp);
- /*
- * Mark this query as having row security, so plancache can invalidate it
- * when necessary (eg: role changes)
- */
- *hasRowSecurity = true;
+ policies = NIL;
+ for (ii = 0; ii < npol; ii++)
+ policies = lappend(policies, &pols[ii]);
- return;
+ return policies;
+}
+
+/*
+ * qsort comparator to sort RowSecurityPolicy entries by name
+ */
+static int
+row_security_policy_cmp(const void *a, const void *b)
+{
+ const RowSecurityPolicy *pa = (const RowSecurityPolicy *) a;
+ const RowSecurityPolicy *pb = (const RowSecurityPolicy *) b;
+
+ /* Guard against NULL policy names from extensions */
+ if (pa->policy_name == NULL)
+ return pb->policy_name == NULL ? 0 : 1;
+ if (pb->policy_name == NULL)
+ return -1;
+
+ return strcmp(pa->policy_name, pb->policy_name);
}
/*
- * pull_row_security_policies
+ * add_security_quals
*
- * Returns the list of policies to be added for this relation, based on the
- * type of command and the roles to which it applies, from the relation cache.
+ * Add security quals to enforce the specified RLS policies, restricting
+ * access to existing data in a table. If there are no policies controlling
+ * access to the table, then all access is prohibited --- i.e., an implicit
+ * default-deny policy is used.
*
+ * New security quals are added to securityQuals, and hasSubLinks is set to
+ * true if any of the quals added contain sublink subqueries.
*/
-static List *
-pull_row_security_policies(CmdType cmd, Relation relation, Oid user_id)
+static void
+add_security_quals(int rt_index,
+ List *permissive_policies,
+ List *restrictive_policies,
+ List **securityQuals,
+ bool *hasSubLinks)
{
- List *policies = NIL;
ListCell *item;
+ List *permissive_quals = NIL;
+ Expr *rowsec_expr;
/*
- * Row security is enabled for the relation and the row security GUC is
- * either 'on' or 'force' here, so find the policies to apply to the
- * table. There must always be at least one policy defined (may be the
- * simple 'default-deny' policy, if none are explicitly defined on the
- * table).
+ * First collect up the permissive quals. If we do not find any permissive
+ * policies then no rows are visible (this is handled below).
*/
- foreach(item, relation->rd_rsdesc->policies)
+ foreach(item, permissive_policies)
{
RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
- /* Always add ALL policies, if they exist. */
- if (policy->polcmd == '*' &&
- check_role_for_policy(policy->roles, user_id))
- policies = lcons(policy, policies);
-
- /* Add relevant command-specific policies to the list. */
- switch (cmd)
+ if (policy->qual != NULL)
{
- case CMD_SELECT:
- if (policy->polcmd == ACL_SELECT_CHR
- && check_role_for_policy(policy->roles, user_id))
- policies = lcons(policy, policies);
- break;
- case CMD_INSERT:
- /* If INSERT then only need to add the WITH CHECK qual */
- if (policy->polcmd == ACL_INSERT_CHR
- && check_role_for_policy(policy->roles, user_id))
- policies = lcons(policy, policies);
- break;
- case CMD_UPDATE:
- if (policy->polcmd == ACL_UPDATE_CHR
- && check_role_for_policy(policy->roles, user_id))
- policies = lcons(policy, policies);
- break;
- case CMD_DELETE:
- if (policy->polcmd == ACL_DELETE_CHR
- && check_role_for_policy(policy->roles, user_id))
- policies = lcons(policy, policies);
- break;
- default:
- elog(ERROR, "unrecognized policy command type %d", (int) cmd);
- break;
+ permissive_quals = lappend(permissive_quals,
+ copyObject(policy->qual));
+ *hasSubLinks |= policy->hassublinks;
}
}
/*
- * There should always be a policy applied. If there are none found then
- * create a simply defauly-deny policy (might be that policies exist but
- * that none of them apply to the role which is querying the table).
+ * We must have permissive quals, always, or no rows are visible.
+ *
+ * If we do not, then we simply return a single 'false' qual which results
+ * in no rows being visible.
*/
- if (policies == NIL)
+ if (permissive_quals != NIL)
{
- RowSecurityPolicy *policy = NULL;
- Datum role;
-
- role = ObjectIdGetDatum(ACL_ID_PUBLIC);
-
- policy = palloc0(sizeof(RowSecurityPolicy));
- policy->policy_name = pstrdup("default-deny policy");
- policy->policy_id = InvalidOid;
- policy->polcmd = '*';
- policy->roles = construct_array(&role, 1, OIDOID, sizeof(Oid), true,
- 'i');
- policy->qual = (Expr *) makeConst(BOOLOID, -1, InvalidOid,
- sizeof(bool), BoolGetDatum(false),
- false, true);
- policy->with_check_qual = copyObject(policy->qual);
- policy->hassublinks = false;
-
- policies = list_make1(policy);
- }
+ /*
+ * We now know that permissive policies exist, so we can now add
+ * security quals based on the USING clauses from the restrictive
+ * policies. Since these need to be "AND"d together, we can
+ * just add them one at a time.
+ */
+ foreach(item, restrictive_policies)
+ {
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
+ Expr *qual;
- Assert(policies != NIL);
+ if (policy->qual != NULL)
+ {
+ qual = copyObject(policy->qual);
+ ChangeVarNodes((Node *) qual, 1, rt_index, 0);
- return policies;
+ *securityQuals = lappend(*securityQuals, qual);
+ *hasSubLinks |= policy->hassublinks;
+ }
+ }
+
+ /*
+ * Then add a single security qual "OR"ing together the USING clauses
+ * from all the permissive policies.
+ */
+ if (list_length(permissive_quals) == 1)
+ rowsec_expr = (Expr *) linitial(permissive_quals);
+ else
+ rowsec_expr = makeBoolExpr(OR_EXPR, permissive_quals, -1);
+
+ ChangeVarNodes((Node *) rowsec_expr, 1, rt_index, 0);
+ *securityQuals = lappend(*securityQuals, rowsec_expr);
+ }
+ else
+ /*
+ * A permissive policy must exist for rows to be visible at all.
+ * Therefore, if there were no permissive policies found, return a
+ * single always-false clause.
+ */
+ *securityQuals = lappend(*securityQuals,
+ makeConst(BOOLOID, -1, InvalidOid,
+ sizeof(bool), BoolGetDatum(false),
+ false, true));
}
/*
- * process_policies
+ * add_with_check_options
*
- * This will step through the policies which are passed in (which would come
- * from either the built-in ones created on a table, or from policies provided
- * by an extension through the hook provided), work out how to combine them,
- * rewrite them as necessary, and produce an Expr for the normal security
- * quals and an Expr for the with check quals.
+ * Add WithCheckOptions of the specified kind to check that new records
+ * added by an INSERT or UPDATE are consistent with the specified RLS
+ * policies. Normally new data must satisfy the WITH CHECK clauses from the
+ * policies. If a policy has no explicit WITH CHECK clause, its USING clause
+ * is used instead. In the special case of an UPDATE arising from an
+ * INSERT ... ON CONFLICT DO UPDATE, existing records are first checked using
+ * a WCO_RLS_CONFLICT_CHECK WithCheckOption, which always uses the USING
+ * clauses from RLS policies.
*
- * qual_eval, with_check_eval, and hassublinks are output variables
+ * New WCOs are added to withCheckOptions, and hasSubLinks is set to true if
+ * any of the check clauses added contain sublink subqueries.
*/
static void
-process_policies(Query *root, List *policies, int rt_index, Expr **qual_eval,
- Expr **with_check_eval, bool *hassublinks,
- BoolExprType boolop)
+add_with_check_options(Relation rel,
+ int rt_index,
+ WCOKind kind,
+ List *permissive_policies,
+ List *restrictive_policies,
+ List **withCheckOptions,
+ bool *hasSubLinks)
{
ListCell *item;
- List *quals = NIL;
- List *with_check_quals = NIL;
+ List *permissive_quals = NIL;
+
+#define QUAL_FOR_WCO(policy) \
+ ( kind != WCO_RLS_CONFLICT_CHECK && \
+ (policy)->with_check_qual != NULL ? \
+ (policy)->with_check_qual : (policy)->qual )
/*
- * Extract the USING and WITH CHECK quals from each of the policies and
- * add them to our lists. We only want WITH CHECK quals if this RTE is
- * the query's result relation.
+ * First collect up the permissive policy clauses, similar to
+ * add_security_quals.
*/
- foreach(item, policies)
+ foreach(item, permissive_policies)
{
RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
+ Expr *qual = QUAL_FOR_WCO(policy);
- if (policy->qual != NULL)
- quals = lcons(copyObject(policy->qual), quals);
-
- if (policy->with_check_qual != NULL &&
- rt_index == root->resultRelation)
- with_check_quals = lcons(copyObject(policy->with_check_qual),
- with_check_quals);
+ if (qual != NULL)
+ {
+ permissive_quals = lappend(permissive_quals, copyObject(qual));
+ *hasSubLinks |= policy->hassublinks;
+ }
+ }
+ /*
+ * There must be at least one permissive qual found or no rows are
+ * allowed to be added. This is the same as in add_security_quals.
+ *
+ * If there are no permissive_quals then we fall through and return a single
+ * 'false' WCO, preventing all new rows.
+ */
+ if (permissive_quals != NIL)
+ {
/*
- * For each policy, if there is only a USING clause then copy/use it
- * for the WITH CHECK policy also, if this RTE is the query's result
- * relation.
+ * Add a single WithCheckOption for all the permissive policy clauses
+ * "OR"d together. This check has no policy name, since if the check
+ * fails it means that no policy granted permission to perform the
+ * update, rather than any particular policy being violated.
*/
- if (policy->qual != NULL && policy->with_check_qual == NULL &&
- rt_index == root->resultRelation)
- with_check_quals = lcons(copyObject(policy->qual),
- with_check_quals);
+ WithCheckOption *wco;
+ wco = (WithCheckOption *) makeNode(WithCheckOption);
+ wco->kind = kind;
+ wco->relname = pstrdup(RelationGetRelationName(rel));
+ wco->polname = NULL;
+ wco->cascaded = false;
- if (policy->hassublinks)
- *hassublinks = true;
- }
+ if (list_length(permissive_quals) == 1)
+ wco->qual = (Node *) linitial(permissive_quals);
+ else
+ wco->qual = (Node *) makeBoolExpr(OR_EXPR, permissive_quals, -1);
- /*
- * If we end up without any normal quals (perhaps the only policy matched
- * was for INSERT), then create a single all-false one.
- */
- if (quals == NIL)
- quals = lcons(makeConst(BOOLOID, -1, InvalidOid, sizeof(bool),
- BoolGetDatum(false), false, true), quals);
+ ChangeVarNodes(wco->qual, 1, rt_index, 0);
- /*
- * Row security quals always have the target table as varno 1, as no joins
- * are permitted in row security expressions. We must walk the expression,
- * updating any references to varno 1 to the varno the table has in the
- * outer query.
- *
- * We rewrite the expression in-place.
- *
- * We must have some quals at this point; the default-deny policy, if
- * nothing else. Note that we might not have any WITH CHECK quals- that's
- * fine, as this might not be the resultRelation.
- */
- Assert(quals != NIL);
+ *withCheckOptions = lappend(*withCheckOptions, wco);
- ChangeVarNodes((Node *) quals, 1, rt_index, 0);
+ /*
+ * Now add WithCheckOptions for each of the restrictive policy clauses
+ * (which will be "AND"d together). We use a separate WithCheckOption
+ * for each restrictive policy to allow the policy name to be included
+ * in error reports if the policy is violated.
+ */
+ foreach(item, restrictive_policies)
+ {
+ RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
+ Expr *qual = QUAL_FOR_WCO(policy);
+ WithCheckOption *wco;
- if (with_check_quals != NIL)
- ChangeVarNodes((Node *) with_check_quals, 1, rt_index, 0);
+ if (qual != NULL)
+ {
+ qual = copyObject(qual);
+ ChangeVarNodes((Node *) qual, 1, rt_index, 0);
- /*
- * If more than one security qual is returned, then they need to be
- * combined together.
- */
- if (list_length(quals) > 1)
- *qual_eval = makeBoolExpr(boolop, quals, -1);
- else
- *qual_eval = (Expr *) linitial(quals);
+ wco = (WithCheckOption *) makeNode(WithCheckOption);
+ wco->kind = kind;
+ wco->relname = pstrdup(RelationGetRelationName(rel));
+ wco->polname = pstrdup(policy->policy_name);
+ wco->qual = (Node *) qual;
+ wco->cascaded = false;
- /*
- * Similarly, if more than one WITH CHECK qual is returned, then they need
- * to be combined together.
- *
- * with_check_quals is allowed to be NIL here since this might not be the
- * resultRelation (see above).
- */
- if (list_length(with_check_quals) > 1)
- *with_check_eval = makeBoolExpr(boolop, with_check_quals, -1);
- else if (with_check_quals != NIL)
- *with_check_eval = (Expr *) linitial(with_check_quals);
+ *withCheckOptions = lappend(*withCheckOptions, wco);
+ *hasSubLinks |= policy->hassublinks;
+ }
+ }
+ }
else
- *with_check_eval = NULL;
-
- return;
+ {
+ /*
+ * If there were no policy clauses to check new data, add a single
+ * always-false WCO (a default-deny policy).
+ */
+ WithCheckOption *wco;
+
+ wco = (WithCheckOption *) makeNode(WithCheckOption);
+ wco->kind = kind;
+ wco->relname = pstrdup(RelationGetRelationName(rel));
+ wco->polname = NULL;
+ wco->qual = (Node *) makeConst(BOOLOID, -1, InvalidOid,
+ sizeof(bool), BoolGetDatum(false),
+ false, true);
+ wco->cascaded = false;
+
+ *withCheckOptions = lappend(*withCheckOptions, wco);
+ }
}
/*
projects / postgres-xl.git / commitdiff