*
* contrib/sepgsql/hooks.c
*
* Entrypoints of the hooks in openGauss, and dispatches the callbacks.
*
* Copyright (c) 2010-2012, PostgreSQL Global Development Group
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "catalog/dependency.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_class.h"
#include "catalog/pg_database.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_proc.h"
#include "commands/seclabel.h"
#include "executor/executor.h"
#include "fmgr.h"
#include "miscadmin.h"
#include "tcop/utility.h"
#include "utils/guc.h"
#include "sepgsql.h"
PG_MODULE_MAGIC;
* Declarations
*/
void _PG_init(void);
* Saved hook entries (if stacked)
*/
static object_access_hook_type next_object_access_hook = NULL;
static ExecutorCheckPerms_hook_type next_exec_check_perms_hook = NULL;
static ProcessUtility_hook_type next_ProcessUtility_hook = NULL;
static ExecutorStart_hook_type next_ExecutorStart_hook = NULL;
* Contextual information on DDL commands
*/
typedef struct {
NodeTag cmdtype;
* Name of the template database given by users on CREATE DATABASE
* command. Elsewhere (including the case of default) NULL.
*/
const char* createdb_dtemplate;
} sepgsql_context_info_t;
static sepgsql_context_info_t sepgsql_context_info;
* GUC: sepgsql.permissive = (on|off)
*/
static bool sepgsql_permissive;
bool sepgsql_get_permissive(void)
{
return sepgsql_permissive;
}
* GUC: sepgsql.debug_audit = (on|off)
*/
static bool sepgsql_debug_audit;
bool sepgsql_get_debug_audit(void)
{
return sepgsql_debug_audit;
}
* sepgsql_object_access
*
* Entrypoint of the object_access_hook. This routine performs as
* a dispatcher of invocation based on access type and object classes.
*/
static void sepgsql_object_access(ObjectAccessType access, Oid classId, Oid objectId, int subId, void* arg)
{
if (next_object_access_hook)
(*next_object_access_hook)(access, classId, objectId, subId, arg);
switch (access) {
case OAT_POST_CREATE:
switch (classId) {
case DatabaseRelationId:
sepgsql_database_post_create(objectId, sepgsql_context_info.createdb_dtemplate);
break;
case NamespaceRelationId:
sepgsql_schema_post_create(objectId);
break;
case RelationRelationId:
if (subId == 0) {
* All cases we want to apply permission checks on
* creation of a new relation are invocation of the
* heap_create_with_catalog via DefineRelation or
* OpenIntoRel. Elsewhere, we need neither assignment
* of security label nor permission checks.
*/
switch (sepgsql_context_info.cmdtype) {
case T_CreateStmt:
case T_ViewStmt:
case T_CreateSeqStmt:
case T_CompositeTypeStmt:
case T_CreateForeignTableStmt:
case T_SelectStmt:
sepgsql_relation_post_create(objectId);
break;
default:
break;
}
} else
sepgsql_attribute_post_create(objectId, subId);
break;
case ProcedureRelationId:
sepgsql_proc_post_create(objectId);
break;
default:
break;
}
break;
case OAT_DROP: {
ObjectAccessDrop* drop_arg = (ObjectAccessDrop*)arg;
* No need to apply permission checks on object deletion due
* to internal cleanups; such as removal of temporary database
* object on session closed.
*/
if ((drop_arg->dropflags & PERFORM_DELETION_INTERNAL) != 0)
break;
switch (classId) {
case DatabaseRelationId:
sepgsql_database_drop(objectId);
break;
case NamespaceRelationId:
sepgsql_schema_drop(objectId);
break;
case RelationRelationId:
if (subId == 0)
sepgsql_relation_drop(objectId);
else
sepgsql_attribute_drop(objectId, subId);
break;
case ProcedureRelationId:
sepgsql_proc_drop(objectId);
break;
default:
break;
}
} break;
default:
elog(ERROR, "unexpected object access type: %d", (int)access);
break;
}
}
* sepgsql_exec_check_perms
*
* Entrypoint of DML permissions
*/
static bool sepgsql_exec_check_perms(List* rangeTabls, bool abort)
{
* If security provider is stacking and one of them replied 'false' at
* least, we don't need to check any more.
*/
if (next_exec_check_perms_hook && !(*next_exec_check_perms_hook)(rangeTabls, abort))
return false;
if (!sepgsql_dml_privileges(rangeTabls, abort))
return false;
return true;
}
* sepgsql_executor_start
*
* It saves contextual information during ExecutorStart to distinguish
* a case with/without permission checks later.
*/
static void sepgsql_executor_start(QueryDesc* queryDesc, int eflags)
{
sepgsql_context_info_t saved_context_info = sepgsql_context_info;
PG_TRY();
{
if (queryDesc->operation == CMD_SELECT)
sepgsql_context_info.cmdtype = T_SelectStmt;
else if (queryDesc->operation == CMD_INSERT)
sepgsql_context_info.cmdtype = T_InsertStmt;
else if (queryDesc->operation == CMD_DELETE)
sepgsql_context_info.cmdtype = T_DeleteStmt;
else if (queryDesc->operation == CMD_UPDATE)
sepgsql_context_info.cmdtype = T_UpdateStmt;
* XXX - If queryDesc->operation is not above four cases, an error
* shall be raised on the following executor stage soon.
*/
if (next_ExecutorStart_hook)
(*next_ExecutorStart_hook)(queryDesc, eflags);
else
standard_ExecutorStart(queryDesc, eflags);
}
PG_CATCH();
{
sepgsql_context_info = saved_context_info;
PG_RE_THROW();
}
PG_END_TRY();
sepgsql_context_info = saved_context_info;
}
* sepgsql_utility_command
*
* It tries to rough-grained control on utility commands; some of them can
* break whole of the things if nefarious user would use.
*/
static void sepgsql_utility_command(processutility_context* processutility_cxt,
DestReceiver* dest,
#ifdef PGXC
bool sentToRemote,
#endif
char* completionTag)
{
sepgsql_context_info_t saved_context_info = sepgsql_context_info;
ListCell* cell = NULL;
Node* parsetree = processutility_cxt->parse_tree;
PG_TRY();
{
* Check command tag to avoid nefarious operations, and save the
* current contextual information to determine whether we should apply
* permission checks here, or not.
*/
sepgsql_context_info.cmdtype = nodeTag(parsetree);
switch (nodeTag(parsetree)) {
case T_CreatedbStmt:
* We hope to reference name of the source database, but it
* does not appear in system catalog. So, we save it here.
*/
foreach (cell, ((CreatedbStmt*)parsetree)->options) {
DefElem* defel = (DefElem*)lfirst(cell);
if (strcmp(defel->defname, "template") == 0) {
sepgsql_context_info.createdb_dtemplate = strVal(defel->arg);
break;
}
}
break;
case T_LoadStmt:
* We reject LOAD command across the board on enforcing mode,
* because a binary module can arbitrarily override hooks.
*/
if (sepgsql_getenforce()) {
ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("SELinux: LOAD is not permitted")));
}
break;
default:
* Right now we don't check any other utility commands,
* because it needs more detailed information to make access
* control decision here, but we don't want to have two parse
* and analyze routines individually.
*/
break;
}
if (next_ProcessUtility_hook)
(*next_ProcessUtility_hook)(processutility_cxt,
dest,
#ifdef PGXC
sentToRemote,
#endif
completionTag);
else
standard_ProcessUtility(processutility_cxt,
dest,
#ifdef PGXC
sentToRemote,
#endif
completionTag);
}
PG_CATCH();
{
sepgsql_context_info = saved_context_info;
PG_RE_THROW();
}
PG_END_TRY();
sepgsql_context_info = saved_context_info;
}
* Module load/unload callback
*/
void _PG_init(void)
{
* We allow to load the SE-PostgreSQL module on single-user-mode or
* shared_preload_libraries settings only.
*/
if (IsUnderPostmaster)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("sepgsql must be loaded via shared_preload_libraries")));
* Check availability of SELinux on the platform. If disabled, we cannot
* activate any SE-PostgreSQL features, and we have to skip rest of
* initialization.
*/
if (is_selinux_enabled() < 1) {
sepgsql_set_mode(SEPGSQL_MODE_DISABLED);
return;
}
* sepgsql.permissive = (on|off)
*
* This variable controls performing mode of SE-PostgreSQL on user's
* session.
*/
DefineCustomBoolVariable("sepgsql.permissive",
"Turn on/off permissive mode in SE-PostgreSQL",
NULL,
&sepgsql_permissive,
false,
PGC_SIGHUP,
GUC_NOT_IN_SAMPLE,
NULL,
NULL,
NULL);
* sepgsql.debug_audit = (on|off)
*
* This variable allows users to turn on/off audit logs on access control
* decisions, independent from auditallow/auditdeny setting in the
* security policy. We intend to use this option for debugging purpose.
*/
DefineCustomBoolVariable("sepgsql.debug_audit",
"Turn on/off debug audit messages",
NULL,
&sepgsql_debug_audit,
false,
PGC_USERSET,
GUC_NOT_IN_SAMPLE,
NULL,
NULL,
NULL);
sepgsql_avc_init();
sepgsql_init_client_label();
register_label_provider(SEPGSQL_LABEL_TAG, sepgsql_object_relabel);
next_object_access_hook = object_access_hook;
object_access_hook = sepgsql_object_access;
next_exec_check_perms_hook = ExecutorCheckPerms_hook;
ExecutorCheckPerms_hook = sepgsql_exec_check_perms;
next_ProcessUtility_hook = ProcessUtility_hook;
ProcessUtility_hook = sepgsql_utility_command;
next_ExecutorStart_hook = ExecutorStart_hook;
ExecutorStart_hook = sepgsql_executor_start;
memset(&sepgsql_context_info, 0, sizeof(sepgsql_context_info));
}