diff options
Diffstat (limited to 'contrib/sepgsql/relation.c')
| -rw-r--r-- | contrib/sepgsql/relation.c | 773 |
1 files changed, 773 insertions, 0 deletions
diff --git a/contrib/sepgsql/relation.c b/contrib/sepgsql/relation.c new file mode 100644 index 0000000..31e2ed5 --- /dev/null +++ b/contrib/sepgsql/relation.c @@ -0,0 +1,773 @@ +/* ------------------------------------------------------------------------- + * + * contrib/sepgsql/relation.c + * + * Routines corresponding to relation/attribute objects + * + * Copyright (c) 2010-2021, 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_attribute.h" +#include "catalog/pg_class.h" +#include "catalog/pg_namespace.h" +#include "commands/seclabel.h" +#include "lib/stringinfo.h" +#include "sepgsql.h" +#include "utils/builtins.h" +#include "utils/catcache.h" +#include "utils/fmgroids.h" +#include "utils/lsyscache.h" +#include "utils/rel.h" +#include "utils/snapmgr.h" +#include "utils/syscache.h" + +static void sepgsql_index_modify(Oid indexOid); + +/* + * sepgsql_attribute_post_create + * + * This routine assigns a default security label on a newly defined + * column, using ALTER TABLE ... ADD COLUMN. + * Note that this routine is not invoked in the case of CREATE TABLE, + * although it also defines columns in addition to table. + */ +void +sepgsql_attribute_post_create(Oid relOid, AttrNumber attnum) +{ + Relation rel; + ScanKeyData skey[2]; + SysScanDesc sscan; + HeapTuple tuple; + char *scontext; + char *tcontext; + char *ncontext; + ObjectAddress object; + Form_pg_attribute attForm; + StringInfoData audit_name; + char relkind = get_rel_relkind(relOid); + + /* + * Only attributes within regular relations or partition relations have + * individual security labels. + */ + if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE) + return; + + /* + * Compute a default security label of the new column underlying the + * specified relation, and check permission to create it. + */ + rel = table_open(AttributeRelationId, AccessShareLock); + + ScanKeyInit(&skey[0], + Anum_pg_attribute_attrelid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(relOid)); + ScanKeyInit(&skey[1], + Anum_pg_attribute_attnum, + BTEqualStrategyNumber, F_INT2EQ, + Int16GetDatum(attnum)); + + sscan = systable_beginscan(rel, AttributeRelidNumIndexId, true, + SnapshotSelf, 2, &skey[0]); + + tuple = systable_getnext(sscan); + if (!HeapTupleIsValid(tuple)) + elog(ERROR, "could not find tuple for column %d of relation %u", + attnum, relOid); + + attForm = (Form_pg_attribute) GETSTRUCT(tuple); + + scontext = sepgsql_get_client_label(); + tcontext = sepgsql_get_label(RelationRelationId, relOid, 0); + ncontext = sepgsql_compute_create(scontext, tcontext, + SEPG_CLASS_DB_COLUMN, + NameStr(attForm->attname)); + + /* + * check db_column:{create} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + + initStringInfo(&audit_name); + appendStringInfo(&audit_name, "%s.%s", + getObjectIdentity(&object, false), + quote_identifier(NameStr(attForm->attname))); + sepgsql_avc_check_perms_label(ncontext, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__CREATE, + audit_name.data, + true); + + /* + * Assign the default security label on a new procedure + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attnum; + SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ncontext); + + systable_endscan(sscan); + table_close(rel, AccessShareLock); + + pfree(tcontext); + pfree(ncontext); +} + +/* + * sepgsql_attribute_drop + * + * It checks privileges to drop the supplied column. + */ +void +sepgsql_attribute_drop(Oid relOid, AttrNumber attnum) +{ + ObjectAddress object; + char *audit_name; + char relkind = get_rel_relkind(relOid); + + if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE) + return; + + /* + * check db_column:{drop} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attnum; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__DROP, + audit_name, + true); + pfree(audit_name); +} + +/* + * sepgsql_attribute_relabel + * + * It checks privileges to relabel the supplied column + * by the `seclabel'. + */ +void +sepgsql_attribute_relabel(Oid relOid, AttrNumber attnum, + const char *seclabel) +{ + ObjectAddress object; + char *audit_name; + char relkind = get_rel_relkind(relOid); + + if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("cannot set security label on non-regular columns"))); + + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attnum; + audit_name = getObjectIdentity(&object, false); + + /* + * check db_column:{setattr relabelfrom} permission + */ + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__SETATTR | + SEPG_DB_COLUMN__RELABELFROM, + audit_name, + true); + + /* + * check db_column:{relabelto} permission + */ + sepgsql_avc_check_perms_label(seclabel, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_PROCEDURE__RELABELTO, + audit_name, + true); + pfree(audit_name); +} + +/* + * sepgsql_attribute_setattr + * + * It checks privileges to alter the supplied column. + */ +void +sepgsql_attribute_setattr(Oid relOid, AttrNumber attnum) +{ + ObjectAddress object; + char *audit_name; + char relkind = get_rel_relkind(relOid); + + if (relkind != RELKIND_RELATION && relkind != RELKIND_PARTITIONED_TABLE) + return; + + /* + * check db_column:{setattr} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attnum; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__SETATTR, + audit_name, + true); + pfree(audit_name); +} + +/* + * sepgsql_relation_post_create + * + * The post creation hook of relation/attribute + */ +void +sepgsql_relation_post_create(Oid relOid) +{ + Relation rel; + ScanKeyData skey; + SysScanDesc sscan; + HeapTuple tuple; + Form_pg_class classForm; + ObjectAddress object; + uint16_t tclass; + char *scontext; /* subject */ + char *tcontext; /* schema */ + char *rcontext; /* relation */ + char *ccontext; /* column */ + char *nsp_name; + StringInfoData audit_name; + + /* + * Fetch catalog record of the new relation. Because pg_class entry is not + * visible right now, we need to scan the catalog using SnapshotSelf. + */ + rel = table_open(RelationRelationId, AccessShareLock); + + ScanKeyInit(&skey, + Anum_pg_class_oid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(relOid)); + + sscan = systable_beginscan(rel, ClassOidIndexId, true, + SnapshotSelf, 1, &skey); + + tuple = systable_getnext(sscan); + if (!HeapTupleIsValid(tuple)) + elog(ERROR, "could not find tuple for relation %u", relOid); + + classForm = (Form_pg_class) GETSTRUCT(tuple); + + /* ignore indexes on toast tables */ + if (classForm->relkind == RELKIND_INDEX && + classForm->relnamespace == PG_TOAST_NAMESPACE) + goto out; + + /* + * check db_schema:{add_name} permission of the namespace + */ + object.classId = NamespaceRelationId; + object.objectId = classForm->relnamespace; + object.objectSubId = 0; + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_SCHEMA, + SEPG_DB_SCHEMA__ADD_NAME, + getObjectIdentity(&object, false), + true); + + switch (classForm->relkind) + { + case RELKIND_RELATION: + case RELKIND_PARTITIONED_TABLE: + tclass = SEPG_CLASS_DB_TABLE; + break; + case RELKIND_SEQUENCE: + tclass = SEPG_CLASS_DB_SEQUENCE; + break; + case RELKIND_VIEW: + tclass = SEPG_CLASS_DB_VIEW; + break; + case RELKIND_INDEX: + /* deal with indexes specially; no need for tclass */ + sepgsql_index_modify(relOid); + goto out; + default: + /* ignore other relkinds */ + goto out; + } + + /* + * Compute a default security label when we create a new relation object + * under the specified namespace. + */ + scontext = sepgsql_get_client_label(); + tcontext = sepgsql_get_label(NamespaceRelationId, + classForm->relnamespace, 0); + rcontext = sepgsql_compute_create(scontext, tcontext, tclass, + NameStr(classForm->relname)); + + /* + * check db_xxx:{create} permission + */ + nsp_name = get_namespace_name(classForm->relnamespace); + initStringInfo(&audit_name); + appendStringInfo(&audit_name, "%s.%s", + quote_identifier(nsp_name), + quote_identifier(NameStr(classForm->relname))); + sepgsql_avc_check_perms_label(rcontext, + tclass, + SEPG_DB_DATABASE__CREATE, + audit_name.data, + true); + + /* + * Assign the default security label on the new regular or partitioned + * relation. + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, rcontext); + + /* + * We also assign a default security label on columns of a new table. + */ + if (classForm->relkind == RELKIND_RELATION || + classForm->relkind == RELKIND_PARTITIONED_TABLE) + { + Relation arel; + ScanKeyData akey; + SysScanDesc ascan; + HeapTuple atup; + Form_pg_attribute attForm; + + arel = table_open(AttributeRelationId, AccessShareLock); + + ScanKeyInit(&akey, + Anum_pg_attribute_attrelid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(relOid)); + + ascan = systable_beginscan(arel, AttributeRelidNumIndexId, true, + SnapshotSelf, 1, &akey); + + while (HeapTupleIsValid(atup = systable_getnext(ascan))) + { + attForm = (Form_pg_attribute) GETSTRUCT(atup); + + resetStringInfo(&audit_name); + appendStringInfo(&audit_name, "%s.%s.%s", + quote_identifier(nsp_name), + quote_identifier(NameStr(classForm->relname)), + quote_identifier(NameStr(attForm->attname))); + + ccontext = sepgsql_compute_create(scontext, + rcontext, + SEPG_CLASS_DB_COLUMN, + NameStr(attForm->attname)); + + /* + * check db_column:{create} permission + */ + sepgsql_avc_check_perms_label(ccontext, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__CREATE, + audit_name.data, + true); + + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attForm->attnum; + SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ccontext); + + pfree(ccontext); + } + systable_endscan(ascan); + table_close(arel, AccessShareLock); + } + pfree(rcontext); + +out: + systable_endscan(sscan); + table_close(rel, AccessShareLock); +} + +/* + * sepgsql_relation_drop + * + * It checks privileges to drop the supplied relation. + */ +void +sepgsql_relation_drop(Oid relOid) +{ + ObjectAddress object; + char *audit_name; + uint16_t tclass = 0; + char relkind = get_rel_relkind(relOid); + + switch (relkind) + { + case RELKIND_RELATION: + case RELKIND_PARTITIONED_TABLE: + tclass = SEPG_CLASS_DB_TABLE; + break; + case RELKIND_SEQUENCE: + tclass = SEPG_CLASS_DB_SEQUENCE; + break; + case RELKIND_VIEW: + tclass = SEPG_CLASS_DB_VIEW; + break; + case RELKIND_INDEX: + /* ignore indexes on toast tables */ + if (get_rel_namespace(relOid) == PG_TOAST_NAMESPACE) + return; + /* other indexes are handled specially below; no need for tclass */ + break; + default: + /* ignore other relkinds */ + return; + } + + /* + * check db_schema:{remove_name} permission + */ + object.classId = NamespaceRelationId; + object.objectId = get_rel_namespace(relOid); + object.objectSubId = 0; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_SCHEMA, + SEPG_DB_SCHEMA__REMOVE_NAME, + audit_name, + true); + pfree(audit_name); + + /* deal with indexes specially */ + if (relkind == RELKIND_INDEX) + { + sepgsql_index_modify(relOid); + return; + } + + /* + * check db_table/sequence/view:{drop} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + tclass, + SEPG_DB_TABLE__DROP, + audit_name, + true); + pfree(audit_name); + + /* + * check db_column:{drop} permission + */ + if (relkind == RELKIND_RELATION || relkind == RELKIND_PARTITIONED_TABLE) + { + Form_pg_attribute attForm; + CatCList *attrList; + HeapTuple atttup; + int i; + + attrList = SearchSysCacheList1(ATTNUM, ObjectIdGetDatum(relOid)); + for (i = 0; i < attrList->n_members; i++) + { + atttup = &attrList->members[i]->tuple; + attForm = (Form_pg_attribute) GETSTRUCT(atttup); + + if (attForm->attisdropped) + continue; + + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = attForm->attnum; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + SEPG_CLASS_DB_COLUMN, + SEPG_DB_COLUMN__DROP, + audit_name, + true); + pfree(audit_name); + } + ReleaseCatCacheList(attrList); + } +} + +/* + * sepgsql_relation_truncate + * + * Check privileges to TRUNCATE the supplied relation. + */ +void +sepgsql_relation_truncate(Oid relOid) +{ + ObjectAddress object; + char *audit_name; + uint16_t tclass = 0; + char relkind = get_rel_relkind(relOid); + + switch (relkind) + { + case RELKIND_RELATION: + case RELKIND_PARTITIONED_TABLE: + tclass = SEPG_CLASS_DB_TABLE; + break; + default: + /* ignore other relkinds */ + return; + } + + /* + * check db_table:{truncate} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + tclass, + SEPG_DB_TABLE__TRUNCATE, + audit_name, + true); + pfree(audit_name); +} + +/* + * sepgsql_relation_relabel + * + * It checks privileges to relabel the supplied relation by the `seclabel'. + */ +void +sepgsql_relation_relabel(Oid relOid, const char *seclabel) +{ + ObjectAddress object; + char *audit_name; + char relkind = get_rel_relkind(relOid); + uint16_t tclass = 0; + + if (relkind == RELKIND_RELATION || relkind == RELKIND_PARTITIONED_TABLE) + tclass = SEPG_CLASS_DB_TABLE; + else if (relkind == RELKIND_SEQUENCE) + tclass = SEPG_CLASS_DB_SEQUENCE; + else if (relkind == RELKIND_VIEW) + tclass = SEPG_CLASS_DB_VIEW; + else + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("cannot set security labels on relations except " + "for tables, sequences or views"))); + + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + audit_name = getObjectIdentity(&object, false); + + /* + * check db_xxx:{setattr relabelfrom} permission + */ + sepgsql_avc_check_perms(&object, + tclass, + SEPG_DB_TABLE__SETATTR | + SEPG_DB_TABLE__RELABELFROM, + audit_name, + true); + + /* + * check db_xxx:{relabelto} permission + */ + sepgsql_avc_check_perms_label(seclabel, + tclass, + SEPG_DB_TABLE__RELABELTO, + audit_name, + true); + pfree(audit_name); +} + +/* + * sepgsql_relation_setattr + * + * It checks privileges to set attribute of the supplied relation + */ +void +sepgsql_relation_setattr(Oid relOid) +{ + Relation rel; + ScanKeyData skey; + SysScanDesc sscan; + HeapTuple oldtup; + HeapTuple newtup; + Form_pg_class oldform; + Form_pg_class newform; + ObjectAddress object; + char *audit_name; + uint16_t tclass; + + switch (get_rel_relkind(relOid)) + { + case RELKIND_RELATION: + case RELKIND_PARTITIONED_TABLE: + tclass = SEPG_CLASS_DB_TABLE; + break; + case RELKIND_SEQUENCE: + tclass = SEPG_CLASS_DB_SEQUENCE; + break; + case RELKIND_VIEW: + tclass = SEPG_CLASS_DB_VIEW; + break; + case RELKIND_INDEX: + /* deal with indexes specially */ + sepgsql_index_modify(relOid); + return; + default: + /* other relkinds don't need additional work */ + return; + } + + /* + * Fetch newer catalog + */ + rel = table_open(RelationRelationId, AccessShareLock); + + ScanKeyInit(&skey, + Anum_pg_class_oid, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(relOid)); + + sscan = systable_beginscan(rel, ClassOidIndexId, true, + SnapshotSelf, 1, &skey); + + newtup = systable_getnext(sscan); + if (!HeapTupleIsValid(newtup)) + elog(ERROR, "could not find tuple for relation %u", relOid); + newform = (Form_pg_class) GETSTRUCT(newtup); + + /* + * Fetch older catalog + */ + oldtup = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid)); + if (!HeapTupleIsValid(oldtup)) + elog(ERROR, "cache lookup failed for relation %u", relOid); + oldform = (Form_pg_class) GETSTRUCT(oldtup); + + /* + * Does this ALTER command takes operation to namespace? + */ + if (newform->relnamespace != oldform->relnamespace) + { + sepgsql_schema_remove_name(oldform->relnamespace); + sepgsql_schema_add_name(newform->relnamespace); + } + if (strcmp(NameStr(newform->relname), NameStr(oldform->relname)) != 0) + sepgsql_schema_rename(oldform->relnamespace); + + /* + * XXX - In the future version, db_tuple:{use} of system catalog entry + * shall be checked, if tablespace configuration is changed. + */ + + /* + * check db_xxx:{setattr} permission + */ + object.classId = RelationRelationId; + object.objectId = relOid; + object.objectSubId = 0; + audit_name = getObjectIdentity(&object, false); + + sepgsql_avc_check_perms(&object, + tclass, + SEPG_DB_TABLE__SETATTR, + audit_name, + true); + pfree(audit_name); + + ReleaseSysCache(oldtup); + systable_endscan(sscan); + table_close(rel, AccessShareLock); +} + +/* + * sepgsql_relation_setattr_extra + * + * It checks permission of the relation being referenced by extra attributes, + * such as pg_index entries. Like core PostgreSQL, sepgsql also does not deal + * with such entries as individual "objects", thus, modification of these + * entries shall be considered as setting an attribute of the underlying + * relation. + */ +static void +sepgsql_relation_setattr_extra(Relation catalog, + Oid catindex_id, + Oid extra_oid, + AttrNumber anum_relation_id, + AttrNumber anum_extra_id) +{ + ScanKeyData skey; + SysScanDesc sscan; + HeapTuple tuple; + Datum datum; + bool isnull; + + ScanKeyInit(&skey, anum_extra_id, + BTEqualStrategyNumber, F_OIDEQ, + ObjectIdGetDatum(extra_oid)); + + sscan = systable_beginscan(catalog, catindex_id, true, + SnapshotSelf, 1, &skey); + tuple = systable_getnext(sscan); + if (!HeapTupleIsValid(tuple)) + elog(ERROR, "could not find tuple for object %u in catalog \"%s\"", + extra_oid, RelationGetRelationName(catalog)); + + datum = heap_getattr(tuple, anum_relation_id, + RelationGetDescr(catalog), &isnull); + Assert(!isnull); + + sepgsql_relation_setattr(DatumGetObjectId(datum)); + + systable_endscan(sscan); +} + +/* + * sepgsql_index_modify + * Handle index create, update, drop + * + * Unlike other relation kinds, indexes do not have their own security labels, + * so instead of doing checks directly, treat them as extra attributes of their + * owning tables; so check 'setattr' permissions on the table. + */ +static void +sepgsql_index_modify(Oid indexOid) +{ + Relation catalog = table_open(IndexRelationId, AccessShareLock); + + /* check db_table:{setattr} permission of the table being indexed */ + sepgsql_relation_setattr_extra(catalog, + IndexRelidIndexId, + indexOid, + Anum_pg_index_indrelid, + Anum_pg_index_indexrelid); + table_close(catalog, AccessShareLock); +} |