use std::slice;
use dope::Driver;
use dope::runtime::token::Token;
use dope::transport::link::Core;
use dope::wire::{Reclaim, RecvChunk, Vectored, Wire};
use shin::record::MAX_PLAINTEXT_BODY;
use crate::pool::Pooled;
use crate::staging::MAX_TLS_RECORD;
use crate::state::State;
const PENDING_APP_CAP: usize = 1 << 20;
const INGRESS_CAP: usize = 1 << 20;
pub struct ConnState {
pub tls: Option<State>,
pub pending_app: Vec<u8>,
pub close: bool,
}
impl ConnState {
fn empty() -> Self {
Self {
tls: None,
pending_app: Vec::new(),
close: false,
}
}
}
#[derive(Clone, Default)]
pub enum Endpoint {
#[default]
None,
Server(Box<shin::server::Config>),
Client(shin::client::Config),
}
pub struct Tls {
state: ConnState,
ingress: Vec<u8>,
egress: Pooled,
send_inflight: bool,
}
impl Tls {
fn ingress_decrypt(&mut self, wire_in: &[u8]) {
match self.state.tls.as_mut() {
None => {
if self.ingress.len() + wire_in.len() > INGRESS_CAP {
self.state.close = true;
return;
}
self.ingress.extend_from_slice(wire_in);
}
Some(tls) => {
if !tls.try_read_tcp(wire_in) {
self.state.close = true;
return;
}
if tls.is_closed() {
self.state.close = true;
}
}
}
}
fn encrypt(&mut self, plain: &[u8]) -> usize {
if self.state.tls.is_none() {
if self.state.pending_app.len() + plain.len() > PENDING_APP_CAP {
self.state.close = true;
return 0;
}
if !plain.is_empty() {
self.state.pending_app.extend_from_slice(plain);
}
return plain.len();
}
self.drain_to_egress();
if !self.is_established() {
if self.state.pending_app.len() + plain.len() > PENDING_APP_CAP {
self.state.close = true;
return 0;
}
if !plain.is_empty() {
self.state.pending_app.extend_from_slice(plain);
}
return plain.len();
}
self.flush_pending_app();
if !self.state.pending_app.is_empty() {
return 0;
}
let mut consumed = 0;
while consumed < plain.len() && self.egress_has_record_room() {
let end = (consumed + MAX_PLAINTEXT_BODY).min(plain.len());
let n = self.seal_record(&plain[consumed..end]);
if n == 0 {
break;
}
consumed += n;
}
consumed
}
fn is_established(&self) -> bool {
self.state.tls.as_ref().is_some_and(State::is_established)
}
fn egress_has_record_room(&self) -> bool {
self.egress.spare_capacity() >= MAX_TLS_RECORD
}
fn seal_record(&mut self, chunk: &[u8]) -> usize {
let Some(tls) = self.state.tls.as_mut() else {
return 0;
};
let consumed = match tls.write_app(chunk) {
Ok(n) => n,
Err(_) => {
self.state.close = true;
return 0;
}
};
self.drain_to_egress();
consumed
}
fn flush_pending_app(&mut self) {
while !self.state.pending_app.is_empty() && self.egress_has_record_room() {
let end = MAX_PLAINTEXT_BODY.min(self.state.pending_app.len());
let chunk = self.state.pending_app[..end].to_vec();
let n = self.seal_record(&chunk);
if n == 0 {
return;
}
self.state.pending_app.drain(..n);
}
}
fn drain_to_egress(&mut self) {
if self.send_inflight {
return;
}
let spare = self.egress.spare_capacity();
if spare == 0 {
return;
}
if let Some(tls) = self.state.tls.as_mut() {
let pending = tls.pending_send_slice();
let n = pending.len().min(spare);
if n > 0 {
self.egress.push(&pending[..n]);
tls.consume_pending_send(n);
}
}
}
fn submit_wire_buf(&mut self, core: &mut Core, ud: Token, driver: &mut Driver) {
if core.is_send_inflight() {
return;
}
let wire = self.egress.as_slice();
if wire.is_empty() {
return;
}
core.submit_single(ud, wire, driver);
self.send_inflight = true;
}
fn propagate_close(&self, core: &mut Core) {
if self.state.close {
core.set_close_after();
}
}
}
impl Wire for Tls {
type InitConfig = Endpoint;
const RECLAIM: Reclaim = Reclaim::OnSubmit;
fn new(cfg: &Endpoint) -> Self {
let mut s = ConnState::empty();
let tls = match cfg {
Endpoint::Server(c) => Some(State::new_server((**c).clone())),
Endpoint::Client(c) => State::new_client(c.clone()).ok(),
Endpoint::None => None,
};
s.close = tls.is_none();
s.tls = tls;
Self {
state: s,
ingress: Vec::new(),
egress: Pooled::egress(),
send_inflight: false,
}
}
fn process_recv<'a>(&mut self, bytes: &'a [u8]) -> Option<RecvChunk<'a>> {
self.ingress_decrypt(bytes);
if self.is_established() && !self.state.pending_app.is_empty() {
self.flush_pending_app();
}
self.drain_to_egress();
let data = match self.state.tls.as_mut() {
Some(tls) => tls.take_app(),
None => std::mem::take(&mut self.ingress),
};
if data.is_empty() {
return None;
}
Some(RecvChunk::Owned(data))
}
fn submit_send(
&mut self,
core: &mut Core,
plain: &[u8],
ud: Token,
driver: &mut Driver,
) -> usize {
let consumed = self.encrypt(plain);
self.submit_wire_buf(core, ud, driver);
self.propagate_close(core);
consumed
}
fn submit_send_vectored(
&mut self,
core: &mut Core,
vectored: Vectored<'_>,
ud: Token,
driver: &mut Driver,
) -> usize {
let mut consumed = 0;
for iov in vectored.iovs {
if iov.is_empty() {
continue;
}
let plain = unsafe { slice::from_raw_parts(iov.as_ptr(), iov.len()) };
let c = self.encrypt(plain);
consumed += c;
if c < plain.len() {
break;
}
}
self.submit_wire_buf(core, ud, driver);
self.propagate_close(core);
consumed
}
fn after_send_cqe(
&mut self,
core: &mut Core,
n: usize,
ud: Token,
driver: &mut Driver,
) -> bool {
self.send_inflight = false;
self.egress.consume(n);
self.drain_to_egress();
if self.egress.is_empty() {
self.egress.release_if_empty();
self.propagate_close(core);
return false;
}
self.submit_wire_buf(core, ud, driver);
true
}
fn flush_pending(&mut self, core: &mut Core, ud: Token, driver: &mut Driver) {
self.encrypt(&[]);
self.submit_wire_buf(core, ud, driver);
self.propagate_close(core);
}
}
#[cfg(test)]
mod buffer_sizing_tests {
use ring::rand::{SecureRandom, SystemRandom};
use shin::sig::SigningKey;
use super::*;
use crate::staging::TLS_STAGING_CAP;
fn server_endpoint() -> Endpoint {
let mut seed = [0u8; 32];
SystemRandom::new().fill(&mut seed).unwrap();
let signing = SigningKey::from_seed(&seed).unwrap();
Endpoint::Server(Box::new(shin::server::Config {
source: shin::server::CertSource::RawPublicKey {
signing_key: signing,
},
transport_params: Vec::new(),
alpn_protocols: Vec::new(),
ticket_secret: None,
accept_early_data: false,
}))
}
#[test]
fn egress_is_right_sized_to_one_record() {
const {
assert!(
TLS_STAGING_CAP >= MAX_TLS_RECORD,
"egress must fit one full TLS record"
);
assert!(
TLS_STAGING_CAP <= 32 * 1024,
"egress must not be a 32/64 KiB bulk buffer"
);
}
}
#[test]
fn ingress_is_lazy_not_preallocated() {
let tls = Tls::new(&server_endpoint());
assert_eq!(
tls.ingress.capacity(),
0,
"ingress must be lazily allocated, not pre-sized"
);
}
#[test]
fn inline_tls_does_not_embed_staging_array() {
const {
assert!(
core::mem::size_of::<Tls>() < MAX_TLS_RECORD,
"inline Tls must not embed a record-sized staging array"
);
}
}
}