#include "postgres.h"
#include "access/table.h"
#include "catalog/pg_class.h"
#include "catalog/pg_type.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/pg_list.h"
#include "parser/parse_relation.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteManip.h"
#include "rewrite/rowsecurity.h"
#include "utils/acl.h"
#include "utils/rel.h"
#include "utils/rls.h"

Include dependency graph for rowsecurity.c:

Macros
#define	QUAL_FOR_WCO(policy)

Functions
static void	get_policies_for_relation (Relation relation, CmdType cmd, Oid user_id, List permissive_policies, List restrictive_policies)

static void	sort_policies_by_name (List *policies)

static int	row_security_policy_cmp (const ListCell a, const ListCell 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, bool force_using)

static bool	check_role_for_policy (ArrayType *policy_roles, Oid user_id)

void	get_row_security_policies (Query root, RangeTblEntry rte, int rt_index, List securityQuals, List withCheckOptions, bool hasRowSecurity, bool hasSubLinks)

Variables
row_security_policy_hook_type	row_security_policy_hook_permissive = NULL

row_security_policy_hook_type	row_security_policy_hook_restrictive = NULL

Macro Definition Documentation

◆ QUAL_FOR_WCO

#define QUAL_FOR_WCO ( policy )

Value:

    ( !force_using && \
      (policy)->with_check_qual != NULL ? \
      (policy)->with_check_qual : (policy)->qual )

Function Documentation

◆ add_security_quals()

static void add_security_quals	(	int	rt_index,
		List *	permissive_policies,
		List *	restrictive_policies,
		List **	securityQuals,
		bool *	hasSubLinks
	)

static

Definition at line 740 of file rowsecurity.c.

{
    ListCell   *item;
    List       *permissive_quals = NIL;
    Expr       *rowsec_expr;
 
    /*
     * 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, permissive_policies)
    {
        RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 
        if (policy->qual != NULL)
        {
            permissive_quals = lappend(permissive_quals,
                                       copyObject(policy->qual));
            *hasSubLinks |= policy->hassublinks;
        }
    }
 
    /*
     * 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 (permissive_quals != NIL)
    {
        /*
         * 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 combined together using AND, we
         * can just add them one at a time.
         */
        foreach(item, restrictive_policies)
        {
            RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
            Expr       *qual;
 
            if (policy->qual != NULL)
            {
                qual = copyObject(policy->qual);
                ChangeVarNodes((Node *) qual, 1, rt_index, 0);
 
                *securityQuals = list_append_unique(*securityQuals, qual);
                *hasSubLinks |= policy->hassublinks;
            }
        }
 
        /*
         * Then add a single security qual combining together the USING
         * clauses from all the permissive policies using OR.
         */
        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 = list_append_unique(*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));
}

References BoolGetDatum(), ChangeVarNodes(), copyObject, fb(), InvalidOid, lappend(), lfirst, linitial, list_append_unique(), list_length(), makeBoolExpr(), makeConst(), NIL, and OR_EXPR.

Referenced by get_row_security_policies().

◆ add_with_check_options()

static void add_with_check_options	(	Relation	rel,
		int	rt_index,
		WCOKind	kind,
		List *	permissive_policies,
		List *	restrictive_policies,
		List **	withCheckOptions,
		bool *	hasSubLinks,
		bool	force_using
	)

static

Definition at line 836 of file rowsecurity.c.

{
    ListCell   *item;
    List       *permissive_quals = NIL;
 
#define QUAL_FOR_WCO(policy) \
    ( !force_using && \
      (policy)->with_check_qual != NULL ? \
      (policy)->with_check_qual : (policy)->qual )
 
    /*
     * First collect up the permissive policy clauses, similar to
     * add_security_quals.
     */
    foreach(item, permissive_policies)
    {
        RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
        Expr       *qual = QUAL_FOR_WCO(policy);
 
        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)
    {
        /*
         * Add a single WithCheckOption for all the permissive policy clauses,
         * combining them together using OR.  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.
         */
        WithCheckOption *wco;
 
        wco = makeNode(WithCheckOption);
        wco->kind = kind;
        wco->relname = pstrdup(RelationGetRelationName(rel));
        wco->polname = NULL;
        wco->cascaded = false;
 
        if (list_length(permissive_quals) == 1)
            wco->qual = (Node *) linitial(permissive_quals);
        else
            wco->qual = (Node *) makeBoolExpr(OR_EXPR, permissive_quals, -1);
 
        ChangeVarNodes(wco->qual, 1, rt_index, 0);
 
        *withCheckOptions = list_append_unique(*withCheckOptions, wco);
 
        /*
         * Now add WithCheckOptions for each of the restrictive policy clauses
         * (which will be combined together using AND).  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);
 
            if (qual != NULL)
            {
                qual = copyObject(qual);
                ChangeVarNodes((Node *) qual, 1, rt_index, 0);
 
                wco = makeNode(WithCheckOption);
                wco->kind = kind;
                wco->relname = pstrdup(RelationGetRelationName(rel));
                wco->polname = pstrdup(policy->policy_name);
                wco->qual = (Node *) qual;
                wco->cascaded = false;
 
                *withCheckOptions = list_append_unique(*withCheckOptions, wco);
                *hasSubLinks |= policy->hassublinks;
            }
        }
    }
    else
    {
        /*
         * If there were no policy clauses to check new data, add a single
         * always-false WCO (a default-deny policy).
         */
        WithCheckOption *wco;
 
        wco = 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);
    }
}

References BoolGetDatum(), ChangeVarNodes(), copyObject, fb(), InvalidOid, lappend(), lfirst, linitial, list_append_unique(), list_length(), makeBoolExpr(), makeConst(), makeNode, NIL, OR_EXPR, pstrdup(), QUAL_FOR_WCO, and RelationGetRelationName.

Referenced by get_row_security_policies().

◆ check_role_for_policy()

static bool check_role_for_policy	(	ArrayType *	policy_roles,
		Oid	user_id
	)

static

Definition at line 956 of file rowsecurity.c.

{
    int         i;
    Oid        *roles = (Oid *) ARR_DATA_PTR(policy_roles);
 
    /* Quick fall-thru for policies applied to all roles */
    if (roles[0] == ACL_ID_PUBLIC)
        return true;
 
    for (i = 0; i < ARR_DIMS(policy_roles)[0]; i++)
    {
        if (has_privs_of_role(user_id, roles[i]))
            return true;
    }
 
    return false;
}

References ACL_ID_PUBLIC, ARR_DATA_PTR, ARR_DIMS, fb(), has_privs_of_role(), and i.

Referenced by get_policies_for_relation().

◆ get_policies_for_relation()

static void get_policies_for_relation	(	Relation	relation,
		CmdType	cmd,
		Oid	user_id,
		List **	permissive_policies,
		List **	restrictive_policies
	)

static

Definition at line 581 of file rowsecurity.c.

{
    ListCell   *item;
 
    *permissive_policies = NIL;
    *restrictive_policies = NIL;
 
    /* First find all internal policies for the relation. */
    foreach(item, relation->rd_rsdesc->policies)
    {
        bool        cmd_matches = false;
        RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 
        /* 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;
                case CMD_MERGE:
 
                    /*
                     * We do not support a separate policy for MERGE command.
                     * Instead it derives from the policies defined for other
                     * commands.
                     */
                    break;
                default:
                    elog(ERROR, "unrecognized policy command type %d",
                         (int) cmd);
                    break;
            }
        }
 
        /*
         * Add this policy to the relevant list of policies if it applies to
         * the specified role.
         */
        if (cmd_matches && check_role_for_policy(policy->roles, user_id))
        {
            if (policy->permissive)
                *permissive_policies = lappend(*permissive_policies, policy);
            else
                *restrictive_policies = lappend(*restrictive_policies, policy);
        }
    }
 
    /*
     * We sort restrictive policies by name so that any WCOs they generate are
     * checked in a well-defined order.
     */
    sort_policies_by_name(*restrictive_policies);
 
    /*
     * 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);
 
        /*
         * As with built-in restrictive policies, we sort any hook-provided
         * restrictive policies by name also.  Note that we also intentionally
         * always check all built-in restrictive policies, in name order,
         * before checking restrictive policies added by hooks, in name order.
         */
        sort_policies_by_name(hook_policies);
 
        foreach(item, hook_policies)
        {
            RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 
            if (check_role_for_policy(policy->roles, user_id))
                *restrictive_policies = lappend(*restrictive_policies, policy);
        }
    }
 
    if (row_security_policy_hook_permissive)
    {
        List       *hook_policies =
            (*row_security_policy_hook_permissive) (cmd, relation);
 
        foreach(item, hook_policies)
        {
            RowSecurityPolicy *policy = (RowSecurityPolicy *) lfirst(item);
 
            if (check_role_for_policy(policy->roles, user_id))
                *permissive_policies = lappend(*permissive_policies, policy);
        }
    }
}

References ACL_DELETE_CHR, ACL_INSERT_CHR, ACL_SELECT_CHR, ACL_UPDATE_CHR, check_role_for_policy(), CMD_DELETE, CMD_INSERT, CMD_MERGE, CMD_SELECT, CMD_UPDATE, elog, ERROR, fb(), lappend(), lfirst, NIL, RowSecurityDesc::policies, RelationData::rd_rsdesc, row_security_policy_hook_permissive, row_security_policy_hook_restrictive, and sort_policies_by_name().

Referenced by get_row_security_policies().

◆ get_row_security_policies()

void get_row_security_policies	(	Query *	root,
		RangeTblEntry *	rte,
		int	rt_index,
		List **	securityQuals,
		List **	withCheckOptions,
		bool *	hasRowSecurity,
		bool *	hasSubLinks
	)

Definition at line 98 of file rowsecurity.c.

{
    Oid         user_id;
    int         rls_status;
    Relation    rel;
    CmdType     commandType;
    List       *permissive_policies;
    List       *restrictive_policies;
    RTEPermissionInfo *perminfo;
 
    /* Defaults for the return values */
    *securityQuals = NIL;
    *withCheckOptions = NIL;
    *hasRowSecurity = false;
    *hasSubLinks = false;
 
    Assert(rte->rtekind == RTE_RELATION);
 
    /* If this is not a normal relation, just return immediately */
    if (rte->relkind != RELKIND_RELATION &&
        rte->relkind != RELKIND_PARTITIONED_TABLE)
        return;
 
    perminfo = getRTEPermissionInfo(root->rteperminfos, rte);
 
    /* Switch to checkAsUser if it's set */
    user_id = OidIsValid(perminfo->checkAsUser) ?
        perminfo->checkAsUser : GetUserId();
 
    /* Determine the state of RLS for this, pass checkAsUser explicitly */
    rls_status = check_enable_rls(rte->relid, perminfo->checkAsUser, false);
 
    /* If there is no RLS on this table at all, nothing to do */
    if (rls_status == RLS_NONE)
        return;
 
    /*
     * RLS_NONE_ENV means we are not doing any RLS now, but that may change
     * with changes to the environment, so we mark it as hasRowSecurity to
     * force a re-plan when the environment changes.
     */
    if (rls_status == RLS_NONE_ENV)
    {
        /*
         * Indicate that this query may involve RLS and must therefore be
         * replanned if the environment changes (GUCs, role), but we are not
         * adding anything here.
         */
        *hasRowSecurity = true;
 
        return;
    }
 
    /*
     * RLS is enabled for this relation.
     *
     * Get the security policies that should be applied, based on the command
     * type.  Note that if this isn't the target relation, we actually want
     * the relation's SELECT policies, regardless of the query command type,
     * for example in UPDATE t1 ... FROM t2 we need to apply t1's UPDATE
     * policies and t2's SELECT policies.
     */
    rel = table_open(rte->relid, NoLock);
 
    commandType = rt_index == root->resultRelation ?
        root->commandType : CMD_SELECT;
 
    /*
     * In some cases, we need to apply USING policies (which control the
     * visibility of records) associated with multiple command types (see
     * specific cases below).
     *
     * When considering the order in which to apply these USING policies, we
     * prefer to apply higher privileged policies, those which allow the user
     * to lock records (UPDATE and DELETE), first, followed by policies which
     * don't (SELECT).
     *
     * Note that the optimizer is free to push down and reorder quals which
     * use leakproof functions.
     *
     * In all cases, if there are no policy clauses allowing access to rows in
     * the table for the specific type of operation, then a single
     * always-false clause (a default-deny policy) will be added (see
     * add_security_quals).
     */
 
    /*
     * For a SELECT, if UPDATE privileges are required (eg: the user has
     * specified FOR [KEY] UPDATE/SHARE), then add the UPDATE USING quals
     * first.
     *
     * This way, we filter out any records from the SELECT FOR SHARE/UPDATE
     * which the user does not have access to via the UPDATE USING policies,
     * similar to how we require normal UPDATE rights for these queries.
     */
    if (commandType == CMD_SELECT && perminfo->requiredPerms & ACL_UPDATE)
    {
        List       *update_permissive_policies;
        List       *update_restrictive_policies;
 
        get_policies_for_relation(rel, CMD_UPDATE, user_id,
                                  &update_permissive_policies,
                                  &update_restrictive_policies);
 
        add_security_quals(rt_index,
                           update_permissive_policies,
                           update_restrictive_policies,
                           securityQuals,
                           hasSubLinks);
    }
 
    /*
     * For SELECT, UPDATE and DELETE, add security quals to enforce the USING
     * policies.  These security quals control access to existing table rows.
     * Restrictive policies are combined together using AND, and permissive
     * policies are combined together using OR.
     */
 
    get_policies_for_relation(rel, commandType, user_id, &permissive_policies,
                              &restrictive_policies);
 
    if (commandType == CMD_SELECT ||
        commandType == CMD_UPDATE ||
        commandType == CMD_DELETE)
        add_security_quals(rt_index,
                           permissive_policies,
                           restrictive_policies,
                           securityQuals,
                           hasSubLinks);
 
    /*
     * Similar to above, during an UPDATE, DELETE, or MERGE, if SELECT rights
     * are also required (eg: when a RETURNING clause exists, or the user has
     * provided a WHERE clause which involves columns from the relation), we
     * collect up CMD_SELECT policies and add them via add_security_quals
     * first.
     *
     * This way, we filter out any records which are not visible through an
     * ALL or SELECT USING policy.
     */
    if ((commandType == CMD_UPDATE || commandType == CMD_DELETE ||
         commandType == CMD_MERGE) &&
        perminfo->requiredPerms & ACL_SELECT)
    {
        List       *select_permissive_policies;
        List       *select_restrictive_policies;
 
        get_policies_for_relation(rel, CMD_SELECT, user_id,
                                  &select_permissive_policies,
                                  &select_restrictive_policies);
 
        add_security_quals(rt_index,
                           select_permissive_policies,
                           select_restrictive_policies,
                           securityQuals,
                           hasSubLinks);
    }
 
    /*
     * 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)
    {
        /* 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,
                               false);
 
        /*
         * Get and add ALL/SELECT policies, if SELECT rights are required for
         * this relation (eg: when RETURNING is used).  These are added as WCO
         * policies rather than security quals to ensure that an error is
         * raised if a policy is violated; otherwise, we might end up silently
         * dropping rows to be added.
         */
        if (perminfo->requiredPerms & ACL_SELECT)
        {
            List       *select_permissive_policies = NIL;
            List       *select_restrictive_policies = NIL;
 
            get_policies_for_relation(rel, CMD_SELECT, user_id,
                                      &select_permissive_policies,
                                      &select_restrictive_policies);
            add_with_check_options(rel, rt_index,
                                   commandType == CMD_INSERT ?
                                   WCO_RLS_INSERT_CHECK : WCO_RLS_UPDATE_CHECK,
                                   select_permissive_policies,
                                   select_restrictive_policies,
                                   withCheckOptions,
                                   hasSubLinks,
                                   true);
        }
 
        /*
         * For INSERT ... ON CONFLICT DO SELECT/UPDATE we need additional
         * policy checks for the SELECT/UPDATE which may be applied to the
         * same RTE.
         */
        if (commandType == CMD_INSERT && root->onConflict &&
            (root->onConflict->action == ONCONFLICT_UPDATE ||
             root->onConflict->action == ONCONFLICT_SELECT))
        {
            List       *conflict_permissive_policies = NIL;
            List       *conflict_restrictive_policies = NIL;
            List       *conflict_select_permissive_policies = NIL;
            List       *conflict_select_restrictive_policies = NIL;
 
            if (perminfo->requiredPerms & ACL_UPDATE)
            {
                /*
                 * Get the policies that apply to the auxiliary UPDATE or
                 * SELECT FOR UPDATE/SHARE.
                 */
                get_policies_for_relation(rel, CMD_UPDATE, user_id,
                                          &conflict_permissive_policies,
                                          &conflict_restrictive_policies);
 
                /*
                 * 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/locked 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,
                                       true);
            }
 
            /*
             * Get and add ALL/SELECT policies, as WCO_RLS_CONFLICT_CHECK WCOs
             * to ensure they are considered when taking the SELECT/UPDATE
             * path of an INSERT .. ON CONFLICT, if SELECT rights are required
             * for this relation, also as WCO policies, again, to avoid
             * silently dropping data.  See above.
             */
            if (perminfo->requiredPerms & ACL_SELECT)
            {
                get_policies_for_relation(rel, CMD_SELECT, user_id,
                                          &conflict_select_permissive_policies,
                                          &conflict_select_restrictive_policies);
                add_with_check_options(rel, rt_index,
                                       WCO_RLS_CONFLICT_CHECK,
                                       conflict_select_permissive_policies,
                                       conflict_select_restrictive_policies,
                                       withCheckOptions,
                                       hasSubLinks,
                                       true);
            }
 
            /*
             * For INSERT .. ON CONFLICT DO UPDATE, add additional policies to
             * be checked when the auxiliary UPDATE is executed.
             */
            if (root->onConflict->action == ONCONFLICT_UPDATE)
            {
                /* 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,
                                       false);
 
                /*
                 * Add ALL/SELECT policies as WCO_RLS_UPDATE_CHECK WCOs, to
                 * ensure that the final updated row is visible when taking
                 * the UPDATE path of an INSERT .. ON CONFLICT, if SELECT
                 * rights are required for this relation.
                 */
                if (perminfo->requiredPerms & ACL_SELECT)
                    add_with_check_options(rel, rt_index,
                                           WCO_RLS_UPDATE_CHECK,
                                           conflict_select_permissive_policies,
                                           conflict_select_restrictive_policies,
                                           withCheckOptions,
                                           hasSubLinks,
                                           true);
            }
        }
    }
 
    /*
     * UPDATE/DELETE FOR PORTION OF may insert leftover rows to preserve the
     * portions of the old row not covered by the target range.  Those hidden
     * inserts go through ExecInsert(), so they need the same INSERT RLS WITH
     * CHECK options as ordinary INSERTs.  SELECT rights are never needed for
     * the leftover rows, because they are not considered by RETURNING.
     */
    if (root->forPortionOf != NULL && rt_index == root->resultRelation &&
        (commandType == CMD_UPDATE || commandType == CMD_DELETE))
    {
        List       *insert_permissive_policies;
        List       *insert_restrictive_policies;
 
        get_policies_for_relation(rel, CMD_INSERT, user_id,
                                  &insert_permissive_policies,
                                  &insert_restrictive_policies);
        add_with_check_options(rel, rt_index,
                               WCO_RLS_INSERT_CHECK,
                               insert_permissive_policies,
                               insert_restrictive_policies,
                               withCheckOptions,
                               hasSubLinks,
                               false);
    }
 
    /*
     * FOR MERGE, we fetch policies for UPDATE, DELETE and INSERT (and ALL)
     * and set them up so that we can enforce the appropriate policy depending
     * on the final action we take.
     *
     * We already fetched the SELECT policies above, to check existing rows,
     * but we must also check that new rows created by INSERT/UPDATE actions
     * are visible, if SELECT rights are required. For INSERT actions, we only
     * do this if RETURNING is specified, to be consistent with a plain INSERT
     * command, which can only require SELECT rights when RETURNING is used.
     *
     * We don't push the UPDATE/DELETE USING quals to the RTE because we don't
     * really want to apply them while scanning the relation since we don't
     * know whether we will be doing an UPDATE or a DELETE at the end. We
     * apply the respective policy once we decide the final action on the
     * target tuple.
     *
     * XXX We are setting up USING quals as WITH CHECK. If RLS prohibits
     * UPDATE/DELETE on the target row, we shall throw an error instead of
     * silently ignoring the row. This is different than how normal
     * UPDATE/DELETE works and more in line with INSERT ON CONFLICT DO
     * SELECT/UPDATE handling.
     */
    if (commandType == CMD_MERGE)
    {
        List       *merge_update_permissive_policies;
        List       *merge_update_restrictive_policies;
        List       *merge_delete_permissive_policies;
        List       *merge_delete_restrictive_policies;
        List       *merge_insert_permissive_policies;
        List       *merge_insert_restrictive_policies;
        List       *merge_select_permissive_policies = NIL;
        List       *merge_select_restrictive_policies = NIL;
 
        /*
         * Fetch the UPDATE policies and set them up to execute on the
         * existing target row before doing UPDATE.
         */
        get_policies_for_relation(rel, CMD_UPDATE, user_id,
                                  &merge_update_permissive_policies,
                                  &merge_update_restrictive_policies);
 
        /*
         * WCO_RLS_MERGE_UPDATE_CHECK is used to check UPDATE USING quals on
         * the existing target row.
         */
        add_with_check_options(rel, rt_index,
                               WCO_RLS_MERGE_UPDATE_CHECK,
                               merge_update_permissive_policies,
                               merge_update_restrictive_policies,
                               withCheckOptions,
                               hasSubLinks,
                               true);
 
        /* Enforce the WITH CHECK clauses of the UPDATE policies */
        add_with_check_options(rel, rt_index,
                               WCO_RLS_UPDATE_CHECK,
                               merge_update_permissive_policies,
                               merge_update_restrictive_policies,
                               withCheckOptions,
                               hasSubLinks,
                               false);
 
        /*
         * Add ALL/SELECT policies as WCO_RLS_UPDATE_CHECK WCOs, to ensure
         * that the updated row is visible when executing an UPDATE action, if
         * SELECT rights are required for this relation.
         */
        if (perminfo->requiredPerms & ACL_SELECT)
        {
            get_policies_for_relation(rel, CMD_SELECT, user_id,
                                      &merge_select_permissive_policies,
                                      &merge_select_restrictive_policies);
            add_with_check_options(rel, rt_index,
                                   WCO_RLS_UPDATE_CHECK,
                                   merge_select_permissive_policies,
                                   merge_select_restrictive_policies,
                                   withCheckOptions,
                                   hasSubLinks,
                                   true);
        }
 
        /*
         * Fetch the DELETE policies and set them up to execute on the
         * existing target row before doing DELETE.
         */
        get_policies_for_relation(rel, CMD_DELETE, user_id,
                                  &merge_delete_permissive_policies,
                                  &merge_delete_restrictive_policies);
 
        /*
         * WCO_RLS_MERGE_DELETE_CHECK is used to check DELETE USING quals on
         * the existing target row.
         */
        add_with_check_options(rel, rt_index,
                               WCO_RLS_MERGE_DELETE_CHECK,
                               merge_delete_permissive_policies,
                               merge_delete_restrictive_policies,
                               withCheckOptions,
                               hasSubLinks,
                               true);
 
        /*
         * No special handling is required for INSERT policies. They will be
         * checked and enforced during ExecInsert(). But we must add them to
         * withCheckOptions.
         */
        get_policies_for_relation(rel, CMD_INSERT, user_id,
                                  &merge_insert_permissive_policies,
                                  &merge_insert_restrictive_policies);
 
        add_with_check_options(rel, rt_index,
                               WCO_RLS_INSERT_CHECK,
                               merge_insert_permissive_policies,
                               merge_insert_restrictive_policies,
                               withCheckOptions,
                               hasSubLinks,
                               false);
 
        /*
         * Add ALL/SELECT policies as WCO_RLS_INSERT_CHECK WCOs, to ensure
         * that the inserted row is visible when executing an INSERT action,
         * if RETURNING is specified and SELECT rights are required for this
         * relation.
         */
        if (perminfo->requiredPerms & ACL_SELECT && root->returningList)
            add_with_check_options(rel, rt_index,
                                   WCO_RLS_INSERT_CHECK,
                                   merge_select_permissive_policies,
                                   merge_select_restrictive_policies,
                                   withCheckOptions,
                                   hasSubLinks,
                                   true);
    }
 
    table_close(rel, NoLock);
 
    /*
     * Copy checkAsUser to the row security quals and WithCheckOption checks,
     * in case they contain any subqueries referring to other relations.
     */
    setRuleCheckAsUser((Node *) *securityQuals, perminfo->checkAsUser);
    setRuleCheckAsUser((Node *) *withCheckOptions, perminfo->checkAsUser);
 
    /*
     * Mark this query as having row security, so plancache can invalidate it
     * when necessary (eg: role changes)
     */
    *hasRowSecurity = true;
}

References ACL_SELECT, ACL_UPDATE, add_security_quals(), add_with_check_options(), Assert, check_enable_rls(), CMD_DELETE, CMD_INSERT, CMD_MERGE, CMD_SELECT, CMD_UPDATE, fb(), get_policies_for_relation(), getRTEPermissionInfo(), GetUserId(), NIL, NoLock, OidIsValid, ONCONFLICT_SELECT, ONCONFLICT_UPDATE, RLS_NONE, RLS_NONE_ENV, root, RTE_RELATION, setRuleCheckAsUser(), table_close(), table_open(), WCO_RLS_CONFLICT_CHECK, WCO_RLS_INSERT_CHECK, WCO_RLS_MERGE_DELETE_CHECK, WCO_RLS_MERGE_UPDATE_CHECK, and WCO_RLS_UPDATE_CHECK.

Referenced by fireRIRrules().

◆ row_security_policy_cmp()

static int row_security_policy_cmp	(	const ListCell *	a,
		const ListCell *	b
	)

static

Definition at line 714 of file rowsecurity.c.

{
    const RowSecurityPolicy *pa = (const RowSecurityPolicy *) lfirst(a);
    const RowSecurityPolicy *pb = (const RowSecurityPolicy *) lfirst(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);
}

References a, b, fb(), lfirst, and RowSecurityPolicy::policy_name.

Referenced by sort_policies_by_name().

◆ sort_policies_by_name()

static void sort_policies_by_name ( List * policies )

static

Definition at line 705 of file rowsecurity.c.

{
    list_sort(policies, row_security_policy_cmp);
}

References list_sort(), and row_security_policy_cmp().

Referenced by get_policies_for_relation().

Variable Documentation

◆ row_security_policy_hook_permissive

row_security_policy_hook_type row_security_policy_hook_permissive = NULL

Definition at line 86 of file rowsecurity.c.

Referenced by _PG_init(), and get_policies_for_relation().

◆ row_security_policy_hook_restrictive

row_security_policy_hook_type row_security_policy_hook_restrictive = NULL

Definition at line 87 of file rowsecurity.c.

Referenced by _PG_init(), and get_policies_for_relation().

Macros

Functions

Variables

Macro Definition Documentation

◆ QUAL_FOR_WCO

Function Documentation

◆ add_security_quals()

◆ add_with_check_options()

◆ check_role_for_policy()

◆ get_policies_for_relation()

◆ get_row_security_policies()

◆ row_security_policy_cmp()

◆ sort_policies_by_name()

Variable Documentation

◆ row_security_policy_hook_permissive

◆ row_security_policy_hook_restrictive