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/*
* Copyright Cedar Contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//! Note on panic safety
//! If any of the panics in this file are triggered, that means that this file has become
//! out-of-date with the decimal extension definition in Core.
//! This is tested by the `extension_schema_correctness()` test
use crate::extension_schema::{ArgumentCheckFn, ExtensionFunctionType, ExtensionSchema};
use crate::types::{self, Type};
use cedar_policy_core::ast::{Expr, ExprKind, Literal, Name};
use cedar_policy_core::extensions::ipaddr;
use itertools::Itertools;
use super::eval_extension_constructor;
// Note on safety:
// This module depends on the Cedar parser only constructing AST with valid extension calls
// If any of the panics in this file are triggered, that means that this file has become
// out-of-date with the ipaddr extension definition in Core.
// PANIC SAFETY see `Note on safety` above
#[allow(clippy::panic)]
fn get_argument_types(fname: &Name, ipaddr_ty: &Type) -> Vec<types::Type> {
if !fname.as_ref().is_unqualified() {
panic!("unexpected ipaddr extension function name: {fname}")
}
match fname.basename().as_ref() {
"ip" => vec![Type::primitive_string()],
"isIpv4" | "isIpv6" | "isLoopback" | "isMulticast" => vec![ipaddr_ty.clone()],
"isInRange" => vec![ipaddr_ty.clone(), ipaddr_ty.clone()],
_ => panic!("unexpected ipaddr extension function name: {fname}"),
}
}
// PANIC SAFETY see `Note on safety` above
#[allow(clippy::panic)]
fn get_return_type(fname: &Name, ipaddr_ty: &Type) -> Type {
if !fname.as_ref().is_unqualified() {
panic!("unexpected ipaddr extension function name: {fname}")
}
match fname.basename().as_ref() {
"ip" => ipaddr_ty.clone(),
"isIpv4" | "isIpv6" | "isLoopback" | "isMulticast" | "isInRange" => {
Type::primitive_boolean()
}
_ => panic!("unexpected ipaddr extension function name: {fname}"),
}
}
// PANIC SAFETY see `Note on safety` above
#[allow(clippy::panic)]
fn get_argument_check(fname: &Name) -> Option<ArgumentCheckFn> {
if !fname.as_ref().is_unqualified() {
panic!("unexpected ipaddr extension function name: {fname}")
}
match fname.basename().as_ref() {
"ip" => {
let fname = fname.clone();
Some(Box::new(move |args| {
validate_ip_string(fname.clone(), args)
}))
}
"isIpv4" | "isIpv6" | "isLoopback" | "isMulticast" | "isInRange" => None,
_ => panic!("unexpected ipaddr extension function name: {fname}"),
}
}
/// Construct the extension schema
pub fn extension_schema() -> ExtensionSchema {
let ipaddr_ext = ipaddr::extension();
let ipaddr_ty = Type::extension(ipaddr_ext.name().clone());
let fun_tys = ipaddr_ext.funcs().map(|f| {
let return_type = get_return_type(f.name(), &ipaddr_ty);
debug_assert!(f
.return_type()
.map(|ty| return_type.is_consistent_with(ty))
.unwrap_or_else(|| return_type == Type::Never));
ExtensionFunctionType::new(
f.name().clone(),
get_argument_types(f.name(), &ipaddr_ty),
return_type,
get_argument_check(f.name()),
)
});
ExtensionSchema::new(ipaddr_ext.name().clone(), fun_tys, std::iter::empty())
}
/// Extra validation step for the `ip` function.
/// Note we already checked that `exprs` contains correct number of arguments,
/// these arguments have the correct types, and that they are all literals.
fn validate_ip_string(ip_constructor_name: Name, exprs: &[Expr]) -> Result<(), String> {
match exprs.iter().exactly_one().map(|a| a.expr_kind()) {
Ok(ExprKind::Lit(lit_arg @ Literal::String(s))) => {
eval_extension_constructor(ip_constructor_name, s.clone())
.map(|_| ())
.map_err(|_| format!("Failed to parse as IP address: `{lit_arg}`"))
}
_ => Ok(()),
}
}
#[cfg(test)]
mod test {
use super::*;
// Ensures that `extension_schema()` does not panic
#[test]
fn extension_schema_correctness() {
let _ = extension_schema();
}
}
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