postgresql/src/backend/commands/seclabel.c

580 lines
16 KiB
C

/* -------------------------------------------------------------------------
*
* seclabel.c
* routines to support security label feature.
*
* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/relation.h"
#include "access/table.h"
#include "catalog/catalog.h"
#include "catalog/indexing.h"
#include "catalog/pg_seclabel.h"
#include "catalog/pg_shseclabel.h"
#include "commands/seclabel.h"
#include "miscadmin.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/memutils.h"
#include "utils/rel.h"
typedef struct
{
const char *provider_name;
check_object_relabel_type hook;
} LabelProvider;
static List *label_provider_list = NIL;
static bool
SecLabelSupportsObjectType(ObjectType objtype)
{
switch (objtype)
{
case OBJECT_AGGREGATE:
case OBJECT_COLUMN:
case OBJECT_DATABASE:
case OBJECT_DOMAIN:
case OBJECT_EVENT_TRIGGER:
case OBJECT_FOREIGN_TABLE:
case OBJECT_FUNCTION:
case OBJECT_LANGUAGE:
case OBJECT_LARGEOBJECT:
case OBJECT_MATVIEW:
case OBJECT_PROCEDURE:
case OBJECT_PUBLICATION:
case OBJECT_ROLE:
case OBJECT_ROUTINE:
case OBJECT_SCHEMA:
case OBJECT_SEQUENCE:
case OBJECT_SUBSCRIPTION:
case OBJECT_TABLE:
case OBJECT_TABLESPACE:
case OBJECT_TYPE:
case OBJECT_VIEW:
return true;
case OBJECT_ACCESS_METHOD:
case OBJECT_AMOP:
case OBJECT_AMPROC:
case OBJECT_ATTRIBUTE:
case OBJECT_CAST:
case OBJECT_COLLATION:
case OBJECT_CONVERSION:
case OBJECT_DEFAULT:
case OBJECT_DEFACL:
case OBJECT_DOMCONSTRAINT:
case OBJECT_EXTENSION:
case OBJECT_FDW:
case OBJECT_FOREIGN_SERVER:
case OBJECT_INDEX:
case OBJECT_OPCLASS:
case OBJECT_OPERATOR:
case OBJECT_OPFAMILY:
case OBJECT_POLICY:
case OBJECT_PUBLICATION_REL:
case OBJECT_RULE:
case OBJECT_STATISTIC_EXT:
case OBJECT_TABCONSTRAINT:
case OBJECT_TRANSFORM:
case OBJECT_TRIGGER:
case OBJECT_TSCONFIGURATION:
case OBJECT_TSDICTIONARY:
case OBJECT_TSPARSER:
case OBJECT_TSTEMPLATE:
case OBJECT_USER_MAPPING:
return false;
/*
* There's intentionally no default: case here; we want the
* compiler to warn if a new ObjectType hasn't been handled above.
*/
}
/* Shouldn't get here, but if we do, say "no support" */
return false;
}
/*
* ExecSecLabelStmt --
*
* Apply a security label to a database object.
*
* Returns the ObjectAddress of the object to which the policy was applied.
*/
ObjectAddress
ExecSecLabelStmt(SecLabelStmt *stmt)
{
LabelProvider *provider = NULL;
ObjectAddress address;
Relation relation;
ListCell *lc;
/*
* Find the named label provider, or if none specified, check whether
* there's exactly one, and if so use it.
*/
if (stmt->provider == NULL)
{
if (label_provider_list == NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("no security label providers have been loaded")));
if (list_length(label_provider_list) != 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("must specify provider when multiple security label providers have been loaded")));
provider = (LabelProvider *) linitial(label_provider_list);
}
else
{
foreach(lc, label_provider_list)
{
LabelProvider *lp = lfirst(lc);
if (strcmp(stmt->provider, lp->provider_name) == 0)
{
provider = lp;
break;
}
}
if (provider == NULL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("security label provider \"%s\" is not loaded",
stmt->provider)));
}
if (!SecLabelSupportsObjectType(stmt->objtype))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("security labels are not supported for this type of object")));
/*
* Translate the parser representation which identifies this object into
* an ObjectAddress. get_object_address() will throw an error if the
* object does not exist, and will also acquire a lock on the target to
* guard against concurrent modifications.
*/
address = get_object_address(stmt->objtype, stmt->object,
&relation, ShareUpdateExclusiveLock, false);
/* Require ownership of the target object. */
check_object_ownership(GetUserId(), stmt->objtype, address,
stmt->object, relation);
/* Perform other integrity checks as needed. */
switch (stmt->objtype)
{
case OBJECT_COLUMN:
/*
* Allow security labels only on columns of tables, views,
* materialized views, composite types, and foreign tables (which
* are the only relkinds for which pg_dump will dump labels).
*/
if (relation->rd_rel->relkind != RELKIND_RELATION &&
relation->rd_rel->relkind != RELKIND_VIEW &&
relation->rd_rel->relkind != RELKIND_MATVIEW &&
relation->rd_rel->relkind != RELKIND_COMPOSITE_TYPE &&
relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot set security label on relation \"%s\"",
RelationGetRelationName(relation)),
errdetail_relkind_not_supported(relation->rd_rel->relkind)));
break;
default:
break;
}
/* Provider gets control here, may throw ERROR to veto new label. */
provider->hook(&address, stmt->label);
/* Apply new label. */
SetSecurityLabel(&address, provider->provider_name, stmt->label);
/*
* If get_object_address() opened the relation for us, we close it to keep
* the reference count correct - but we retain any locks acquired by
* get_object_address() until commit time, to guard against concurrent
* activity.
*/
if (relation != NULL)
relation_close(relation, NoLock);
return address;
}
/*
* GetSharedSecurityLabel returns the security label for a shared object for
* a given provider, or NULL if there is no such label.
*/
static char *
GetSharedSecurityLabel(const ObjectAddress *object, const char *provider)
{
Relation pg_shseclabel;
ScanKeyData keys[3];
SysScanDesc scan;
HeapTuple tuple;
Datum datum;
bool isnull;
char *seclabel = NULL;
ScanKeyInit(&keys[0],
Anum_pg_shseclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
ScanKeyInit(&keys[1],
Anum_pg_shseclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&keys[2],
Anum_pg_shseclabel_provider,
BTEqualStrategyNumber, F_TEXTEQ,
CStringGetTextDatum(provider));
pg_shseclabel = table_open(SharedSecLabelRelationId, AccessShareLock);
scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true,
NULL, 3, keys);
tuple = systable_getnext(scan);
if (HeapTupleIsValid(tuple))
{
datum = heap_getattr(tuple, Anum_pg_shseclabel_label,
RelationGetDescr(pg_shseclabel), &isnull);
if (!isnull)
seclabel = TextDatumGetCString(datum);
}
systable_endscan(scan);
table_close(pg_shseclabel, AccessShareLock);
return seclabel;
}
/*
* GetSecurityLabel returns the security label for a shared or database object
* for a given provider, or NULL if there is no such label.
*/
char *
GetSecurityLabel(const ObjectAddress *object, const char *provider)
{
Relation pg_seclabel;
ScanKeyData keys[4];
SysScanDesc scan;
HeapTuple tuple;
Datum datum;
bool isnull;
char *seclabel = NULL;
/* Shared objects have their own security label catalog. */
if (IsSharedRelation(object->classId))
return GetSharedSecurityLabel(object, provider);
/* Must be an unshared object, so examine pg_seclabel. */
ScanKeyInit(&keys[0],
Anum_pg_seclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
ScanKeyInit(&keys[1],
Anum_pg_seclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&keys[2],
Anum_pg_seclabel_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(object->objectSubId));
ScanKeyInit(&keys[3],
Anum_pg_seclabel_provider,
BTEqualStrategyNumber, F_TEXTEQ,
CStringGetTextDatum(provider));
pg_seclabel = table_open(SecLabelRelationId, AccessShareLock);
scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true,
NULL, 4, keys);
tuple = systable_getnext(scan);
if (HeapTupleIsValid(tuple))
{
datum = heap_getattr(tuple, Anum_pg_seclabel_label,
RelationGetDescr(pg_seclabel), &isnull);
if (!isnull)
seclabel = TextDatumGetCString(datum);
}
systable_endscan(scan);
table_close(pg_seclabel, AccessShareLock);
return seclabel;
}
/*
* SetSharedSecurityLabel is a helper function of SetSecurityLabel to
* handle shared database objects.
*/
static void
SetSharedSecurityLabel(const ObjectAddress *object,
const char *provider, const char *label)
{
Relation pg_shseclabel;
ScanKeyData keys[4];
SysScanDesc scan;
HeapTuple oldtup;
HeapTuple newtup = NULL;
Datum values[Natts_pg_shseclabel];
bool nulls[Natts_pg_shseclabel];
bool replaces[Natts_pg_shseclabel];
/* Prepare to form or update a tuple, if necessary. */
memset(nulls, false, sizeof(nulls));
memset(replaces, false, sizeof(replaces));
values[Anum_pg_shseclabel_objoid - 1] = ObjectIdGetDatum(object->objectId);
values[Anum_pg_shseclabel_classoid - 1] = ObjectIdGetDatum(object->classId);
values[Anum_pg_shseclabel_provider - 1] = CStringGetTextDatum(provider);
if (label != NULL)
values[Anum_pg_shseclabel_label - 1] = CStringGetTextDatum(label);
/* Use the index to search for a matching old tuple */
ScanKeyInit(&keys[0],
Anum_pg_shseclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
ScanKeyInit(&keys[1],
Anum_pg_shseclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&keys[2],
Anum_pg_shseclabel_provider,
BTEqualStrategyNumber, F_TEXTEQ,
CStringGetTextDatum(provider));
pg_shseclabel = table_open(SharedSecLabelRelationId, RowExclusiveLock);
scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true,
NULL, 3, keys);
oldtup = systable_getnext(scan);
if (HeapTupleIsValid(oldtup))
{
if (label == NULL)
CatalogTupleDelete(pg_shseclabel, &oldtup->t_self);
else
{
replaces[Anum_pg_shseclabel_label - 1] = true;
newtup = heap_modify_tuple(oldtup, RelationGetDescr(pg_shseclabel),
values, nulls, replaces);
CatalogTupleUpdate(pg_shseclabel, &oldtup->t_self, newtup);
}
}
systable_endscan(scan);
/* If we didn't find an old tuple, insert a new one */
if (newtup == NULL && label != NULL)
{
newtup = heap_form_tuple(RelationGetDescr(pg_shseclabel),
values, nulls);
CatalogTupleInsert(pg_shseclabel, newtup);
}
if (newtup != NULL)
heap_freetuple(newtup);
table_close(pg_shseclabel, RowExclusiveLock);
}
/*
* SetSecurityLabel attempts to set the security label for the specified
* provider on the specified object to the given value. NULL means that any
* existing label should be deleted.
*/
void
SetSecurityLabel(const ObjectAddress *object,
const char *provider, const char *label)
{
Relation pg_seclabel;
ScanKeyData keys[4];
SysScanDesc scan;
HeapTuple oldtup;
HeapTuple newtup = NULL;
Datum values[Natts_pg_seclabel];
bool nulls[Natts_pg_seclabel];
bool replaces[Natts_pg_seclabel];
/* Shared objects have their own security label catalog. */
if (IsSharedRelation(object->classId))
{
SetSharedSecurityLabel(object, provider, label);
return;
}
/* Prepare to form or update a tuple, if necessary. */
memset(nulls, false, sizeof(nulls));
memset(replaces, false, sizeof(replaces));
values[Anum_pg_seclabel_objoid - 1] = ObjectIdGetDatum(object->objectId);
values[Anum_pg_seclabel_classoid - 1] = ObjectIdGetDatum(object->classId);
values[Anum_pg_seclabel_objsubid - 1] = Int32GetDatum(object->objectSubId);
values[Anum_pg_seclabel_provider - 1] = CStringGetTextDatum(provider);
if (label != NULL)
values[Anum_pg_seclabel_label - 1] = CStringGetTextDatum(label);
/* Use the index to search for a matching old tuple */
ScanKeyInit(&keys[0],
Anum_pg_seclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
ScanKeyInit(&keys[1],
Anum_pg_seclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
ScanKeyInit(&keys[2],
Anum_pg_seclabel_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(object->objectSubId));
ScanKeyInit(&keys[3],
Anum_pg_seclabel_provider,
BTEqualStrategyNumber, F_TEXTEQ,
CStringGetTextDatum(provider));
pg_seclabel = table_open(SecLabelRelationId, RowExclusiveLock);
scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true,
NULL, 4, keys);
oldtup = systable_getnext(scan);
if (HeapTupleIsValid(oldtup))
{
if (label == NULL)
CatalogTupleDelete(pg_seclabel, &oldtup->t_self);
else
{
replaces[Anum_pg_seclabel_label - 1] = true;
newtup = heap_modify_tuple(oldtup, RelationGetDescr(pg_seclabel),
values, nulls, replaces);
CatalogTupleUpdate(pg_seclabel, &oldtup->t_self, newtup);
}
}
systable_endscan(scan);
/* If we didn't find an old tuple, insert a new one */
if (newtup == NULL && label != NULL)
{
newtup = heap_form_tuple(RelationGetDescr(pg_seclabel),
values, nulls);
CatalogTupleInsert(pg_seclabel, newtup);
}
/* Update indexes, if necessary */
if (newtup != NULL)
heap_freetuple(newtup);
table_close(pg_seclabel, RowExclusiveLock);
}
/*
* DeleteSharedSecurityLabel is a helper function of DeleteSecurityLabel
* to handle shared database objects.
*/
void
DeleteSharedSecurityLabel(Oid objectId, Oid classId)
{
Relation pg_shseclabel;
ScanKeyData skey[2];
SysScanDesc scan;
HeapTuple oldtup;
ScanKeyInit(&skey[0],
Anum_pg_shseclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(objectId));
ScanKeyInit(&skey[1],
Anum_pg_shseclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(classId));
pg_shseclabel = table_open(SharedSecLabelRelationId, RowExclusiveLock);
scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true,
NULL, 2, skey);
while (HeapTupleIsValid(oldtup = systable_getnext(scan)))
CatalogTupleDelete(pg_shseclabel, &oldtup->t_self);
systable_endscan(scan);
table_close(pg_shseclabel, RowExclusiveLock);
}
/*
* DeleteSecurityLabel removes all security labels for an object (and any
* sub-objects, if applicable).
*/
void
DeleteSecurityLabel(const ObjectAddress *object)
{
Relation pg_seclabel;
ScanKeyData skey[3];
SysScanDesc scan;
HeapTuple oldtup;
int nkeys;
/* Shared objects have their own security label catalog. */
if (IsSharedRelation(object->classId))
{
Assert(object->objectSubId == 0);
DeleteSharedSecurityLabel(object->objectId, object->classId);
return;
}
ScanKeyInit(&skey[0],
Anum_pg_seclabel_objoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->objectId));
ScanKeyInit(&skey[1],
Anum_pg_seclabel_classoid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(object->classId));
if (object->objectSubId != 0)
{
ScanKeyInit(&skey[2],
Anum_pg_seclabel_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(object->objectSubId));
nkeys = 3;
}
else
nkeys = 2;
pg_seclabel = table_open(SecLabelRelationId, RowExclusiveLock);
scan = systable_beginscan(pg_seclabel, SecLabelObjectIndexId, true,
NULL, nkeys, skey);
while (HeapTupleIsValid(oldtup = systable_getnext(scan)))
CatalogTupleDelete(pg_seclabel, &oldtup->t_self);
systable_endscan(scan);
table_close(pg_seclabel, RowExclusiveLock);
}
void
register_label_provider(const char *provider_name, check_object_relabel_type hook)
{
LabelProvider *provider;
MemoryContext oldcxt;
oldcxt = MemoryContextSwitchTo(TopMemoryContext);
provider = palloc(sizeof(LabelProvider));
provider->provider_name = pstrdup(provider_name);
provider->hook = hook;
label_provider_list = lappend(label_provider_list, provider);
MemoryContextSwitchTo(oldcxt);
}