postgresql/contrib/sepgsql/schema.c

236 lines
5.5 KiB
C

/* -------------------------------------------------------------------------
*
* contrib/sepgsql/schema.c
*
* Routines corresponding to schema objects
*
* Copyright (c) 2010-2022, PostgreSQL Global Development Group
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/table.h"
#include "catalog/dependency.h"
#include "catalog/pg_database.h"
#include "catalog/pg_namespace.h"
#include "commands/seclabel.h"
#include "lib/stringinfo.h"
#include "miscadmin.h"
#include "sepgsql.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/lsyscache.h"
#include "utils/snapmgr.h"
/*
* sepgsql_schema_post_create
*
* This routine assigns a default security label on a newly defined
* schema.
*/
void
sepgsql_schema_post_create(Oid namespaceId)
{
Relation rel;
ScanKeyData skey;
SysScanDesc sscan;
HeapTuple tuple;
char *tcontext;
char *ncontext;
const char *nsp_name;
ObjectAddress object;
Form_pg_namespace nspForm;
StringInfoData audit_name;
/*
* Compute a default security label when we create a new schema object
* under the working database.
*
* XXX - upcoming version of libselinux supports to take object name to
* handle special treatment on default security label; such as special
* label on "pg_temp" schema.
*/
rel = table_open(NamespaceRelationId, AccessShareLock);
ScanKeyInit(&skey,
Anum_pg_namespace_oid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(namespaceId));
sscan = systable_beginscan(rel, NamespaceOidIndexId, true,
SnapshotSelf, 1, &skey);
tuple = systable_getnext(sscan);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "could not find tuple for namespace %u", namespaceId);
nspForm = (Form_pg_namespace) GETSTRUCT(tuple);
nsp_name = NameStr(nspForm->nspname);
if (strncmp(nsp_name, "pg_temp_", 8) == 0)
nsp_name = "pg_temp";
else if (strncmp(nsp_name, "pg_toast_temp_", 14) == 0)
nsp_name = "pg_toast_temp";
tcontext = sepgsql_get_label(DatabaseRelationId, MyDatabaseId, 0);
ncontext = sepgsql_compute_create(sepgsql_get_client_label(),
tcontext,
SEPG_CLASS_DB_SCHEMA,
nsp_name);
/*
* check db_schema:{create}
*/
initStringInfo(&audit_name);
appendStringInfo(&audit_name, "%s", quote_identifier(nsp_name));
sepgsql_avc_check_perms_label(ncontext,
SEPG_CLASS_DB_SCHEMA,
SEPG_DB_SCHEMA__CREATE,
audit_name.data,
true);
systable_endscan(sscan);
table_close(rel, AccessShareLock);
/*
* Assign the default security label on a new procedure
*/
object.classId = NamespaceRelationId;
object.objectId = namespaceId;
object.objectSubId = 0;
SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ncontext);
pfree(ncontext);
pfree(tcontext);
}
/*
* sepgsql_schema_drop
*
* It checks privileges to drop the supplied schema object.
*/
void
sepgsql_schema_drop(Oid namespaceId)
{
ObjectAddress object;
char *audit_name;
/*
* check db_schema:{drop} permission
*/
object.classId = NamespaceRelationId;
object.objectId = namespaceId;
object.objectSubId = 0;
audit_name = getObjectIdentity(&object, false);
sepgsql_avc_check_perms(&object,
SEPG_CLASS_DB_SCHEMA,
SEPG_DB_SCHEMA__DROP,
audit_name,
true);
pfree(audit_name);
}
/*
* sepgsql_schema_relabel
*
* It checks privileges to relabel the supplied schema
* by the `seclabel'.
*/
void
sepgsql_schema_relabel(Oid namespaceId, const char *seclabel)
{
ObjectAddress object;
char *audit_name;
object.classId = NamespaceRelationId;
object.objectId = namespaceId;
object.objectSubId = 0;
audit_name = getObjectIdentity(&object, false);
/*
* check db_schema:{setattr relabelfrom} permission
*/
sepgsql_avc_check_perms(&object,
SEPG_CLASS_DB_SCHEMA,
SEPG_DB_SCHEMA__SETATTR |
SEPG_DB_SCHEMA__RELABELFROM,
audit_name,
true);
/*
* check db_schema:{relabelto} permission
*/
sepgsql_avc_check_perms_label(seclabel,
SEPG_CLASS_DB_SCHEMA,
SEPG_DB_SCHEMA__RELABELTO,
audit_name,
true);
pfree(audit_name);
}
/*
* sepgsql_schema_check_perms
*
* utility routine to check db_schema:{xxx} permissions
*/
static bool
check_schema_perms(Oid namespaceId, uint32 required, bool abort_on_violation)
{
ObjectAddress object;
char *audit_name;
bool result;
object.classId = NamespaceRelationId;
object.objectId = namespaceId;
object.objectSubId = 0;
audit_name = getObjectIdentity(&object, false);
result = sepgsql_avc_check_perms(&object,
SEPG_CLASS_DB_SCHEMA,
required,
audit_name,
abort_on_violation);
pfree(audit_name);
return result;
}
/* db_schema:{setattr} permission */
void
sepgsql_schema_setattr(Oid namespaceId)
{
check_schema_perms(namespaceId, SEPG_DB_SCHEMA__SETATTR, true);
}
/* db_schema:{search} permission */
bool
sepgsql_schema_search(Oid namespaceId, bool abort_on_violation)
{
return check_schema_perms(namespaceId,
SEPG_DB_SCHEMA__SEARCH,
abort_on_violation);
}
void
sepgsql_schema_add_name(Oid namespaceId)
{
check_schema_perms(namespaceId, SEPG_DB_SCHEMA__ADD_NAME, true);
}
void
sepgsql_schema_remove_name(Oid namespaceId)
{
check_schema_perms(namespaceId, SEPG_DB_SCHEMA__REMOVE_NAME, true);
}
void
sepgsql_schema_rename(Oid namespaceId)
{
check_schema_perms(namespaceId,
SEPG_DB_SCHEMA__ADD_NAME |
SEPG_DB_SCHEMA__REMOVE_NAME,
true);
}