933 lines
35 KiB
Rust
933 lines
35 KiB
Rust
use std::{
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io,
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net::{SocketAddr, UdpSocket},
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time::{Duration, Instant},
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};
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#[cfg(test)]
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use std::cell::Cell;
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#[cfg(test)]
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use irtt_proto::{flags, Params, TimestampFields, PROTOCOL_VERSION};
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use crate::{
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config::{ClientConfig, RecvBudget},
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error::ClientError,
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event::{ClientEvent, OpenOutcome},
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receive::{drain_tx_timestamps, recv_datagram, try_enable_tx_timestamping, ReceivedDatagram},
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session::machine::{
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recv_buffer_size, OpenDatagramDisposition, PreparedOpenAcceptance, ProbeSent,
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SessionMachine, MAX_OPEN_PACKET_SIZE,
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},
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socket::{connect_udp_socket, resolve_remote, validate_open_timeouts},
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socket_options::{apply_traffic_class_to_socket, clear_dscp_on_socket},
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timing::ClientTimestamp,
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};
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pub(crate) mod schedule;
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use schedule::{instant_abs_diff, ProbeSchedule};
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#[derive(Debug, Clone, Copy)]
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enum ProbeScheduleMode {
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CallerPaced,
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#[cfg(test)]
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Managed {
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scheduled_at: Instant,
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},
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}
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#[derive(Debug)]
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struct PreparedClientOpen {
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machine: PreparedOpenAcceptance,
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schedule: Option<ProbeSchedule>,
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recv_buffer_len: Option<usize>,
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negotiated_traffic_class: Option<u8>,
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previous_traffic_class: Option<u8>,
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post_open_recv_timeout: Option<Duration>,
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}
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#[derive(Debug)]
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struct PreparedClientOpenFailure {
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primary: ClientError,
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machine: PreparedOpenAcceptance,
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}
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#[cfg(test)]
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#[derive(Debug, Default)]
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struct ClientTestHooks {
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fail_open_dscp: Cell<bool>,
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fail_open_timeout_restore: Cell<bool>,
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fail_close_event_reserve: Cell<bool>,
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fail_close_dscp_clear: Cell<bool>,
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fail_close_send: Cell<bool>,
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close_reported_len: Cell<Option<usize>>,
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close_send_attempts: Cell<usize>,
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close_sent_at: Cell<Option<ClientTimestamp>>,
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fail_cleanup_send: Cell<bool>,
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recv_buffer_len_override: Cell<Option<usize>>,
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fail_dscp_restore: Cell<bool>,
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last_restored_read_timeout: Cell<Option<Duration>>,
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prepared_active_session_before_dscp: Cell<bool>,
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/// Number of subsequent receive attempts that should report
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/// `io::ErrorKind::Interrupted` before a real receive is attempted.
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/// Decremented on every injected receive; `0` means inject nothing.
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inject_recv_interrupted: Cell<usize>,
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}
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#[cfg(test)]
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#[derive(Debug, Clone, Copy)]
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pub(crate) struct ProbeSendTimestamps {
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pub(crate) permission_at: Instant,
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/// Private pre-send anchor: timeout deadline / kernel TX lower bound.
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pub(crate) send_anchor: ClientTimestamp,
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pub(crate) send_call_start: Instant,
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pub(crate) send_finished_at: Instant,
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/// Public post-send measurement: RTT / OWD fallback / timer_error.
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pub(crate) sent_at: ClientTimestamp,
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}
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#[cfg(test)]
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use crate::{
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session::machine::{
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compute_one_way, compute_rtt, params_from_config, sequence_is_after, sequence_is_before,
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unix_epoch_ns_i64, update_highest_received,
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},
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session::negotiate_params,
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NegotiatedParams, RunMode, SignedDuration, WarningKind, MAX_UDP_PAYLOAD_LENGTH,
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};
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/// Low-level synchronous IRTT client.
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///
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/// `Client` exposes the protocol steps directly: connect a UDP socket, open a
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/// session, send probes, receive replies, poll timeouts, and close. Callers
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/// that do not need to own this loop can use the unified managed API in
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/// [`crate::managed`] when the `tokio` feature is enabled.
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#[derive(Debug)]
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pub struct Client {
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runtime: SessionMachine,
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schedule: Option<ProbeSchedule>,
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socket: UdpSocket,
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remote: SocketAddr,
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recv_buffer: Vec<u8>,
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applied_traffic_class: Option<u8>,
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/// Whether the socket's `SO_TIMESTAMPING` flags carry `TX_SOFTWARE` +
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/// `OPT_ID` + `OPT_TSONLY`. Always `false` off Linux, without the
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/// `ancillary` feature, or before the best-effort post-Open upgrade;
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/// tracked here (adapter-owned capability, not protocol state) so
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/// unnecessary error-queue drains are skipped once it is known there is
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/// nothing to drain.
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tx_timestamping_enabled: bool,
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#[cfg(test)]
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test_hooks: ClientTestHooks,
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#[cfg(test)]
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probe_reported_len: Option<usize>,
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#[cfg(test)]
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probe_send_error: bool,
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#[cfg(test)]
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probe_send_timestamps: Option<ProbeSendTimestamps>,
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}
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impl Client {
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/// Resolve the configured server and create a connected UDP socket.
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///
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/// This validates local configuration and prepares the open request, but it
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/// does not contact the server. Call [`open`](Self::open) to perform the
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/// IRTT open exchange.
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pub fn connect(config: ClientConfig) -> Result<Self, ClientError> {
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validate_open_timeouts(&config.open_timeouts)?;
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let remote = resolve_remote(&config)?;
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let runtime = SessionMachine::new(config.clone(), remote)?;
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let socket = connect_udp_socket(&config.socket_config, remote)?;
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Ok(Self {
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runtime,
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schedule: None,
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socket,
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remote,
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recv_buffer: vec![0_u8; recv_buffer_size(false, None)?],
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applied_traffic_class: None,
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tx_timestamping_enabled: false,
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#[cfg(test)]
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test_hooks: ClientTestHooks::default(),
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#[cfg(test)]
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probe_reported_len: None,
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#[cfg(test)]
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probe_send_error: false,
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#[cfg(test)]
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probe_send_timestamps: None,
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})
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}
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/// Perform the IRTT open exchange.
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///
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/// On success, returns the negotiated open outcome and transitions the
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/// client into either an open probe session or completed no-test state.
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/// Open attempts use [`ClientConfig::open_timeouts`]. Malformed or
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/// unrelated datagrams are ignored until the current attempt's absolute
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/// deadline, so one attempt may consume several datagrams without
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/// retransmitting. Silence or ignored traffic eventually produces
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/// [`ClientError::OpenTimeout`]. A structurally recognizable malformed or
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/// incompatible Open reply from the connected peer is terminal; when HMAC
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/// is configured, that recognition additionally requires authentication.
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///
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/// When a trusted reply allocates a token but later negotiation or socket
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/// preparation fails, the client sends a best-effort cleanup close and
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/// preserves the original failure. Failed opening never leaves the session
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/// machine open.
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pub fn open(&mut self) -> Result<OpenOutcome, ClientError> {
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let result = self.open_transaction();
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if result.is_err() {
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let _ =
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self.restore_open_read_timeout(self.runtime.config().socket_config.recv_timeout);
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}
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result
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}
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/// Send a close request and emit a [`ClientEvent::SessionClosed`] event.
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///
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/// The close event means the client has sent its close packet and stopped
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/// tracking the session locally; it is not a server acknowledgement. If the
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/// send fails, the negotiated DSCP is restored best-effort and the session
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/// and probe schedule remain open.
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pub fn close(&mut self) -> Result<Vec<ClientEvent>, ClientError> {
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let prepared = self.runtime.prepare_close()?;
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let mut events = Vec::new();
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#[cfg(test)]
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if self.test_hooks.fail_close_event_reserve.replace(false) {
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events
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.try_reserve(usize::MAX)
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.map_err(|source| ClientError::AllocationFailed {
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operation: "close event result",
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source,
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})?;
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}
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events
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.try_reserve(1)
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.map_err(|source| ClientError::AllocationFailed {
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operation: "close event result",
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source,
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})?;
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let previous_traffic_class = self.applied_traffic_class;
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let expected_bytes = prepared.bytes.len();
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self.clear_close_dscp()?;
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let bytes = match self.send_close_datagram(prepared.bytes) {
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Ok(bytes) => bytes,
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Err(err) => {
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self.restore_dscp_best_effort(previous_traffic_class);
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return Err(ClientError::Socket(err));
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}
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};
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#[cfg(not(test))]
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let sent_at = ClientTimestamp::now();
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#[cfg(test)]
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let sent_at = self
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.test_hooks
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.close_sent_at
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.take()
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.unwrap_or_else(ClientTimestamp::now);
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let event = self.runtime.commit_local_close(prepared.commit, sent_at);
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self.schedule = None;
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self.applied_traffic_class = None;
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validate_datagram_length(expected_bytes, bytes)?;
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events.push(event);
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Ok(events)
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}
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/// Return the monotonic deadline for the next probe send, if another probe
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/// is scheduled.
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pub fn next_send_deadline(&self) -> Option<Instant> {
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if !self.runtime.is_open() {
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return None;
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}
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self.schedule.as_ref()?.next_send_deadline()
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}
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/// Return the local timeout used to classify pending probes as lost.
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pub fn probe_timeout(&self) -> Duration {
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self.runtime.probe_timeout()
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}
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/// Send one echo probe if the negotiated run is still active.
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///
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/// Returns an `EchoSent` event when a probe is sent. Returns an empty event
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/// list when the run duration has elapsed and no further probe should be
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/// sent.
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pub fn send_probe(&mut self) -> Result<Vec<ClientEvent>, ClientError> {
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self.send_probe_transaction(ProbeScheduleMode::CallerPaced)
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}
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/// Receive and classify at most one datagram from the socket.
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///
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/// Returns an empty event list when the socket read would block or times
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/// out. Malformed or unrelated datagrams are reported as warning events.
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pub fn recv_once(&mut self) -> Result<Vec<ClientEvent>, ClientError> {
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self.socket
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.set_read_timeout(self.runtime.config().socket_config.recv_timeout)?;
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self.recv_once_inner()
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}
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/// Receive one datagram into `self.recv_buffer`. In test builds, a
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/// pending `inject_recv_interrupted` count reports
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/// `io::ErrorKind::Interrupted` instead of performing a real receive,
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/// deterministically exercising interrupted-syscall retry behavior.
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fn recv_datagram_once(&mut self) -> Result<ReceivedDatagram, io::Error> {
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#[cfg(test)]
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{
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let remaining = self.test_hooks.inject_recv_interrupted.get();
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if remaining > 0 {
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self.test_hooks.inject_recv_interrupted.set(remaining - 1);
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return Err(io::Error::from(io::ErrorKind::Interrupted));
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}
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}
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recv_datagram(&self.socket, &mut self.recv_buffer)
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}
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/// Same as [`Self::recv_datagram_once`], receiving into a caller-supplied
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/// buffer instead of `self.recv_buffer` (used before the negotiated
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/// receive buffer size is known, i.e. during Open).
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fn recv_datagram_once_into(&self, buf: &mut [u8]) -> Result<ReceivedDatagram, io::Error> {
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#[cfg(test)]
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{
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let remaining = self.test_hooks.inject_recv_interrupted.get();
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if remaining > 0 {
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self.test_hooks.inject_recv_interrupted.set(remaining - 1);
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return Err(io::Error::from(io::ErrorKind::Interrupted));
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}
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}
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recv_datagram(&self.socket, buf)
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}
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fn recv_once_inner(&mut self) -> Result<Vec<ClientEvent>, ClientError> {
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let Some(datagram) = self.recv_datagram_retrying_interrupted()? else {
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return Ok(vec![]);
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};
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// One final bounded drain before processing the reply, so a TX
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// timestamp that raced the reply is still associated with its probe
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// before that probe is looked up and possibly removed below.
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self.drain_tx_timestamps()?;
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let events = self.runtime.process_received_echo_packet(
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&self.recv_buffer[..datagram.len],
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datagram.received_at,
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datagram.meta,
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)?;
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if self.runtime.is_peer_closed() {
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self.schedule = None;
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if self.clear_close_dscp().is_ok() {
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self.applied_traffic_class = None;
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}
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}
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Ok(events)
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}
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/// Receive one datagram, transparently retrying an interrupted syscall
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/// (`io::ErrorKind::Interrupted`, e.g. `EINTR`) without treating it as a
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/// genuine socket error, timeout, or empty receive.
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///
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/// One logical receive keeps one timeout budget: when a receive timeout
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/// is configured, an absolute deadline is computed once here and each
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/// retry after an interruption restores the socket's remaining time
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/// against that same deadline, so repeated interruptions cannot extend
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/// this receive past its configured timeout. An unconfigured timeout
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/// (`None`) keeps blocking indefinitely after an interruption, matching
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/// its no-timeout contract. The socket's read timeout is restored to the
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/// caller-configured value before returning, so a later call in the same
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/// `recv_available` budget is unaffected by an earlier interruption here.
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fn recv_datagram_retrying_interrupted(
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&mut self,
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) -> Result<Option<ReceivedDatagram>, ClientError> {
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let configured_timeout = self.runtime.config().socket_config.recv_timeout;
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let deadline = match configured_timeout {
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Some(timeout) => Some(
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Instant::now()
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.checked_add(timeout)
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.ok_or(ClientError::DurationOverflow)?,
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),
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None => None,
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};
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let mut timeout_narrowed = false;
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let result = loop {
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match self.recv_datagram_once() {
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Ok(datagram) => break Ok(Some(datagram)),
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Err(err)
|
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if matches!(
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err.kind(),
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io::ErrorKind::WouldBlock | io::ErrorKind::TimedOut
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) =>
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{
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break Ok(None);
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}
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Err(err) if err.kind() == io::ErrorKind::Interrupted => {
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if let Some(deadline) = deadline {
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let Some(remaining) = deadline.checked_duration_since(Instant::now())
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else {
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break Ok(None);
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};
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if remaining.is_zero() {
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break Ok(None);
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}
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if let Err(err) = self.socket.set_read_timeout(Some(remaining)) {
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break Err(ClientError::Socket(err));
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}
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timeout_narrowed = true;
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}
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}
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Err(err) => break Err(ClientError::Socket(err)),
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}
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};
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|
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if timeout_narrowed {
|
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if let Err(err) = self.socket.set_read_timeout(configured_timeout) {
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return Err(ClientError::Socket(err));
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}
|
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}
|
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result
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}
|
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|
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/// Receive and classify datagrams until a receive produces no events or the
|
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/// receive budget is exhausted.
|
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pub fn recv_available(&mut self, budget: RecvBudget) -> Result<Vec<ClientEvent>, ClientError> {
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self.socket
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.set_read_timeout(self.runtime.config().socket_config.recv_timeout)?;
|
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let mut all_events = Vec::new();
|
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for _ in 0..budget.max_packets {
|
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let events = self.recv_once_inner()?;
|
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if events.is_empty() {
|
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break;
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}
|
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all_events.extend(events);
|
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if self.is_peer_closed() {
|
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break;
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}
|
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}
|
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Ok(all_events)
|
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}
|
|
|
|
/// Polls for probes that have timed out as of the current monotonic time.
|
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pub fn poll_timeouts(&mut self) -> Result<Vec<ClientEvent>, ClientError> {
|
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self.poll_timeouts_at(Instant::now())
|
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}
|
|
|
|
/// Polls for probes that have timed out as of `now`.
|
|
///
|
|
/// This is useful for callers that drive `Client` from their own event loop and
|
|
/// want timeout decisions to use the same sampled `Instant` as their scheduling
|
|
/// logic.
|
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///
|
|
/// `now` is monotonic time only; wall-clock time is not used for timeout expiry.
|
|
pub fn poll_timeouts_at(&mut self, now: Instant) -> Result<Vec<ClientEvent>, ClientError> {
|
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self.drain_tx_timestamps()?;
|
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self.runtime.poll_timeouts_at(now)
|
|
}
|
|
|
|
/// Return whether the current run has completed.
|
|
///
|
|
/// A normal run is complete once no more probes will be sent and all
|
|
/// pending probes have either replied or timed out. No-test and closed
|
|
/// sessions are also considered complete.
|
|
pub fn is_run_complete(&self) -> bool {
|
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self.runtime.is_terminal()
|
|
|| self
|
|
.schedule
|
|
.as_ref()
|
|
.is_some_and(|schedule| schedule.is_finished() && self.runtime.pending_is_empty())
|
|
}
|
|
|
|
/// Return whether the session was closed by a peer close-flagged reply.
|
|
///
|
|
/// Direct operations on a closed client still return
|
|
/// [`ClientError::AlreadyClosed`]. This method lets higher-level run loops
|
|
/// avoid treating a successfully observed peer close as a local cleanup
|
|
/// failure.
|
|
pub fn is_peer_closed(&self) -> bool {
|
|
self.runtime.is_peer_closed()
|
|
}
|
|
|
|
#[cfg(test)]
|
|
pub(crate) fn send_managed_probe(
|
|
&mut self,
|
|
scheduled_at: Instant,
|
|
) -> Result<Vec<ClientEvent>, ClientError> {
|
|
self.send_probe_transaction(ProbeScheduleMode::Managed { scheduled_at })
|
|
}
|
|
|
|
fn send_probe_transaction(
|
|
&mut self,
|
|
mode: ProbeScheduleMode,
|
|
) -> Result<Vec<ClientEvent>, ClientError> {
|
|
self.runtime.ensure_open()?;
|
|
#[cfg(test)]
|
|
let test_timestamps = self.probe_send_timestamps.take();
|
|
#[cfg(test)]
|
|
let fail_send = std::mem::take(&mut self.probe_send_error);
|
|
let remote = self.remote;
|
|
let (runtime, schedule, socket) = (&mut self.runtime, &mut self.schedule, &self.socket);
|
|
let schedule = schedule
|
|
.as_mut()
|
|
.expect("open sessions always have a probe schedule");
|
|
#[cfg(not(test))]
|
|
let permission_at = Instant::now();
|
|
#[cfg(test)]
|
|
let permission_at = test_timestamps
|
|
.map(|timestamps| timestamps.permission_at)
|
|
.unwrap_or_else(Instant::now);
|
|
if !schedule.permit_probe_at(permission_at) {
|
|
return Ok(Vec::new());
|
|
}
|
|
|
|
let Some(prepared) = runtime.prepare_probe()? else {
|
|
return Ok(Vec::new());
|
|
};
|
|
let machine_preflight = runtime.preflight_probe_commit(&prepared)?;
|
|
let schedule_commit = match mode {
|
|
ProbeScheduleMode::CallerPaced => {
|
|
schedule.preflight_caller_commit(machine_preflight.next_packets_sent)?
|
|
}
|
|
#[cfg(test)]
|
|
ProbeScheduleMode::Managed { scheduled_at } => {
|
|
schedule.preflight_managed_commit(scheduled_at, permission_at)?
|
|
}
|
|
};
|
|
let mut events = Vec::new();
|
|
events
|
|
.try_reserve(1)
|
|
.map_err(|source| ClientError::AllocationFailed {
|
|
operation: "probe event result",
|
|
source,
|
|
})?;
|
|
|
|
let expected_bytes = prepared.bytes.len();
|
|
let scheduled_at = schedule_commit.scheduled_at;
|
|
#[cfg(test)]
|
|
let reported_bytes = self.probe_reported_len.take();
|
|
// All fallible probe-commit preflight (timeout deadline arithmetic,
|
|
// capacity/collision checks already done above) is finalized from
|
|
// this PRIVATE pre-send anchor, before the socket send. It is not
|
|
// the public measurement `sent_at` captured further below.
|
|
#[cfg(not(test))]
|
|
let send_anchor = ClientTimestamp::now();
|
|
#[cfg(test)]
|
|
let send_anchor = test_timestamps
|
|
.map(|timestamps| timestamps.send_anchor)
|
|
.unwrap_or_else(ClientTimestamp::now);
|
|
let machine_commit = runtime.finalize_probe_commit(machine_preflight, send_anchor)?;
|
|
#[cfg(not(test))]
|
|
let send_call_start = Instant::now();
|
|
#[cfg(test)]
|
|
let send_call_start = test_timestamps
|
|
.map(|timestamps| timestamps.send_call_start)
|
|
.unwrap_or_else(Instant::now);
|
|
#[cfg(test)]
|
|
if fail_send {
|
|
runtime.invalidate_kernel_tx_correlation();
|
|
return Err(ClientError::Socket(io::Error::other(
|
|
"injected probe send failure",
|
|
)));
|
|
}
|
|
let bytes = match socket.send(&prepared.bytes) {
|
|
Ok(bytes) => bytes,
|
|
Err(error) => {
|
|
runtime.invalidate_kernel_tx_correlation();
|
|
return Err(ClientError::Socket(error));
|
|
}
|
|
};
|
|
#[cfg(not(test))]
|
|
let send_finished_at = Instant::now();
|
|
#[cfg(test)]
|
|
let send_finished_at = test_timestamps
|
|
.map(|timestamps| timestamps.send_finished_at)
|
|
.unwrap_or_else(Instant::now);
|
|
// The public measurement timestamp: paired wall/monotonic sample
|
|
// captured immediately after the successful socket send completed.
|
|
// This, not `send_anchor` above, is the RTT/OWD-fallback/timer_error
|
|
// endpoint. The infallible machine/schedule commit below never fails.
|
|
#[cfg(not(test))]
|
|
let sent_at = ClientTimestamp::now();
|
|
#[cfg(test)]
|
|
let sent_at = test_timestamps
|
|
.map(|timestamps| timestamps.sent_at)
|
|
.unwrap_or_else(ClientTimestamp::now);
|
|
let sent = runtime.commit_probe_sent(machine_commit, sent_at, bytes);
|
|
schedule.commit(schedule_commit);
|
|
|
|
let send_call = send_finished_at.saturating_duration_since(send_call_start);
|
|
let timer_error = instant_abs_diff(sent_at.mono, scheduled_at);
|
|
#[cfg(test)]
|
|
let bytes = reported_bytes.unwrap_or(bytes);
|
|
validate_datagram_length(expected_bytes, bytes)?;
|
|
self.drain_tx_timestamps()?;
|
|
|
|
events.push(echo_sent_event(
|
|
remote,
|
|
sent,
|
|
send_call,
|
|
scheduled_at,
|
|
timer_error,
|
|
));
|
|
Ok(events)
|
|
}
|
|
|
|
fn open_transaction(&mut self) -> Result<OpenOutcome, ClientError> {
|
|
let request = self.runtime.prepare_open_request()?;
|
|
let mut buf = [0_u8; MAX_OPEN_PACKET_SIZE];
|
|
let attempt_count = self.runtime.config().open_timeouts.len();
|
|
|
|
for attempt in 0..attempt_count {
|
|
let timeout = self.runtime.config().open_timeouts[attempt];
|
|
let deadline = Instant::now()
|
|
.checked_add(timeout)
|
|
.ok_or(ClientError::DurationOverflow)?;
|
|
self.socket.set_read_timeout(Some(timeout))?;
|
|
self.socket.send(&request.bytes)?;
|
|
|
|
loop {
|
|
let now = Instant::now();
|
|
let Some(remaining) = deadline.checked_duration_since(now) else {
|
|
break;
|
|
};
|
|
if remaining.is_zero() {
|
|
break;
|
|
}
|
|
self.socket.set_read_timeout(Some(remaining))?;
|
|
|
|
let datagram = match self.recv_datagram_once_into(&mut buf) {
|
|
Ok(datagram) => datagram,
|
|
// WouldBlock/TimedOut mean the attempt's own deadline
|
|
// elapsed; Interrupted (EINTR) means the syscall was
|
|
// merely interrupted and carries no timing information of
|
|
// its own. Both retry through the same loop, which
|
|
// recomputes `remaining` and re-applies it as the read
|
|
// timeout on every iteration — so an interruption resumes
|
|
// within this same absolute deadline rather than
|
|
// resetting or extending it.
|
|
Err(err)
|
|
if matches!(
|
|
err.kind(),
|
|
io::ErrorKind::WouldBlock
|
|
| io::ErrorKind::TimedOut
|
|
| io::ErrorKind::Interrupted
|
|
) =>
|
|
{
|
|
if Instant::now() >= deadline {
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
Err(err) => return Err(ClientError::Socket(err)),
|
|
};
|
|
if datagram.received_at.mono > deadline {
|
|
break;
|
|
}
|
|
|
|
let reply = match self.runtime.inspect_open_datagram(&buf[..datagram.len])? {
|
|
OpenDatagramDisposition::Ignore => continue,
|
|
OpenDatagramDisposition::Trusted(reply) => reply,
|
|
};
|
|
let machine = match self
|
|
.runtime
|
|
.prepare_open_acceptance(reply, datagram.received_at)
|
|
{
|
|
Ok(machine) => machine,
|
|
Err(failure) => {
|
|
self.send_cleanup_close_best_effort(failure.cleanup_close.as_deref());
|
|
return Err(failure.primary);
|
|
}
|
|
};
|
|
let prepared = match self.prepare_client_open(machine, datagram.received_at) {
|
|
Ok(prepared) => prepared,
|
|
Err(failure) => {
|
|
self.send_cleanup_close_best_effort(failure.machine.cleanup_close_packet());
|
|
return Err(failure.primary);
|
|
}
|
|
};
|
|
return self.apply_prepared_open(prepared);
|
|
}
|
|
}
|
|
|
|
Err(ClientError::OpenTimeout)
|
|
}
|
|
|
|
fn prepare_client_open(
|
|
&self,
|
|
machine: PreparedOpenAcceptance,
|
|
opened_at: ClientTimestamp,
|
|
) -> Result<PreparedClientOpen, Box<PreparedClientOpenFailure>> {
|
|
let Some(negotiated) = machine.normal_negotiated() else {
|
|
return Ok(PreparedClientOpen {
|
|
machine,
|
|
schedule: None,
|
|
recv_buffer_len: None,
|
|
negotiated_traffic_class: None,
|
|
previous_traffic_class: self.applied_traffic_class,
|
|
post_open_recv_timeout: self.runtime.config().socket_config.recv_timeout,
|
|
});
|
|
};
|
|
let schedule = match ProbeSchedule::new(opened_at.mono, negotiated) {
|
|
Ok(schedule) => schedule,
|
|
Err(primary) => return Err(Box::new(PreparedClientOpenFailure { primary, machine })),
|
|
};
|
|
let recv_buffer_len = match recv_buffer_size(self.runtime.has_hmac(), Some(negotiated)) {
|
|
Ok(size) => size,
|
|
Err(primary) => return Err(Box::new(PreparedClientOpenFailure { primary, machine })),
|
|
};
|
|
#[cfg(test)]
|
|
let recv_buffer_len = self
|
|
.test_hooks
|
|
.recv_buffer_len_override
|
|
.get()
|
|
.unwrap_or(recv_buffer_len);
|
|
let negotiated_traffic_class = match u8::try_from(negotiated.params.dscp) {
|
|
Ok(traffic_class) => traffic_class,
|
|
Err(_) => {
|
|
return Err(Box::new(PreparedClientOpenFailure {
|
|
primary: ClientError::InvalidConfig {
|
|
reason: "negotiated dscp must be in range 0..=255".to_owned(),
|
|
},
|
|
machine,
|
|
}));
|
|
}
|
|
};
|
|
|
|
Ok(PreparedClientOpen {
|
|
machine,
|
|
schedule: Some(schedule),
|
|
recv_buffer_len: Some(recv_buffer_len),
|
|
negotiated_traffic_class: Some(negotiated_traffic_class),
|
|
previous_traffic_class: self.applied_traffic_class,
|
|
post_open_recv_timeout: self.runtime.config().socket_config.recv_timeout,
|
|
})
|
|
}
|
|
|
|
fn apply_prepared_open(
|
|
&mut self,
|
|
prepared: PreparedClientOpen,
|
|
) -> Result<OpenOutcome, ClientError> {
|
|
let PreparedClientOpen {
|
|
machine,
|
|
schedule,
|
|
recv_buffer_len,
|
|
negotiated_traffic_class,
|
|
previous_traffic_class,
|
|
post_open_recv_timeout,
|
|
} = prepared;
|
|
|
|
if let (Some(recv_buffer_len), Some(negotiated_traffic_class)) =
|
|
(recv_buffer_len, negotiated_traffic_class)
|
|
{
|
|
let previous_len = self.recv_buffer.len();
|
|
let additional = recv_buffer_len.saturating_sub(previous_len);
|
|
if let Err(source) = self.recv_buffer.try_reserve(additional) {
|
|
self.send_cleanup_close_best_effort(machine.cleanup_close_packet());
|
|
return Err(ClientError::AllocationFailed {
|
|
operation: "negotiated receive buffer",
|
|
source,
|
|
});
|
|
}
|
|
self.recv_buffer.resize(recv_buffer_len, 0);
|
|
|
|
#[cfg(test)]
|
|
self.test_hooks
|
|
.prepared_active_session_before_dscp
|
|
.set(machine.has_prepared_active_session());
|
|
if let Err(primary) = self.apply_open_dscp(negotiated_traffic_class) {
|
|
self.recv_buffer.truncate(previous_len);
|
|
self.restore_dscp_best_effort(previous_traffic_class);
|
|
self.send_cleanup_close_best_effort(machine.cleanup_close_packet());
|
|
return Err(primary);
|
|
}
|
|
if let Err(source) = self.restore_open_read_timeout(post_open_recv_timeout) {
|
|
let primary = ClientError::ReadTimeoutRestore { source };
|
|
self.recv_buffer.truncate(previous_len);
|
|
self.restore_dscp_best_effort(previous_traffic_class);
|
|
self.send_cleanup_close_best_effort(machine.cleanup_close_packet());
|
|
return Err(primary);
|
|
}
|
|
|
|
let outcome = self.runtime.commit_open(machine);
|
|
self.schedule = schedule;
|
|
self.applied_traffic_class = Some(negotiated_traffic_class);
|
|
self.tx_timestamping_enabled = try_enable_tx_timestamping(&self.socket);
|
|
Ok(outcome)
|
|
} else {
|
|
debug_assert!(schedule.is_none());
|
|
if let Err(source) = self.restore_open_read_timeout(post_open_recv_timeout) {
|
|
return Err(ClientError::ReadTimeoutRestore { source });
|
|
}
|
|
let outcome = self.runtime.commit_open(machine);
|
|
self.schedule = None;
|
|
self.applied_traffic_class = None;
|
|
self.tx_timestamping_enabled = try_enable_tx_timestamping(&self.socket);
|
|
Ok(outcome)
|
|
}
|
|
}
|
|
|
|
/// Best-effort, bounded, nonblocking drain of the socket's
|
|
/// `MSG_ERRQUEUE`. A no-op unless [`Self::apply_prepared_open`]
|
|
/// successfully upgraded the socket to TX timestamping. Any TX
|
|
/// timestamp found is handed to the session machine to attach to its
|
|
/// matching probe; a genuine socket/network error found on the queue is
|
|
/// surfaced through the normal socket-error path.
|
|
fn drain_tx_timestamps(&mut self) -> Result<(), ClientError> {
|
|
if !self.tx_timestamping_enabled {
|
|
return Ok(());
|
|
}
|
|
let runtime = &mut self.runtime;
|
|
drain_tx_timestamps(&self.socket, |id, timestamp| {
|
|
runtime.record_kernel_tx_timestamp(id, timestamp);
|
|
})
|
|
.map_err(ClientError::Socket)
|
|
}
|
|
|
|
fn restore_dscp_best_effort(&self, previous_traffic_class: Option<u8>) {
|
|
#[cfg(test)]
|
|
if self.test_hooks.fail_dscp_restore.replace(false) {
|
|
return;
|
|
}
|
|
let _ = match previous_traffic_class {
|
|
Some(traffic_class) => {
|
|
apply_traffic_class_to_socket(&self.socket, self.remote, traffic_class)
|
|
}
|
|
None => clear_dscp_on_socket(&self.socket, self.remote),
|
|
};
|
|
}
|
|
|
|
fn clear_close_dscp(&self) -> Result<(), ClientError> {
|
|
#[cfg(test)]
|
|
if self.test_hooks.fail_close_dscp_clear.replace(false) {
|
|
return Err(ClientError::SocketOption {
|
|
operation: "clear negotiated DSCP",
|
|
remote: self.remote,
|
|
source: io::Error::other("injected negotiated DSCP clear failure"),
|
|
});
|
|
}
|
|
clear_dscp_on_socket(&self.socket, self.remote)
|
|
}
|
|
|
|
fn send_cleanup_close_best_effort(&self, packet: Option<&[u8]>) {
|
|
if let Some(packet) = packet {
|
|
#[cfg(test)]
|
|
if self.test_hooks.fail_cleanup_send.replace(false) {
|
|
return;
|
|
}
|
|
let _ = self.socket.send(packet);
|
|
}
|
|
}
|
|
|
|
fn apply_open_dscp(&self, traffic_class: u8) -> Result<(), ClientError> {
|
|
#[cfg(test)]
|
|
if self.test_hooks.fail_open_dscp.replace(false) {
|
|
return Err(ClientError::SocketOption {
|
|
operation: "set negotiated DSCP",
|
|
remote: self.remote,
|
|
source: io::Error::other("injected negotiated DSCP failure"),
|
|
});
|
|
}
|
|
apply_traffic_class_to_socket(&self.socket, self.remote, traffic_class)
|
|
}
|
|
|
|
fn restore_open_read_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
|
|
#[cfg(test)]
|
|
self.test_hooks.last_restored_read_timeout.set(timeout);
|
|
#[cfg(test)]
|
|
if self.test_hooks.fail_open_timeout_restore.replace(false) {
|
|
return Err(io::Error::other(
|
|
"injected configured read timeout restoration failure",
|
|
));
|
|
}
|
|
self.socket.set_read_timeout(timeout)
|
|
}
|
|
|
|
fn send_close_datagram(&self, packet: &[u8]) -> io::Result<usize> {
|
|
#[cfg(test)]
|
|
{
|
|
self.test_hooks
|
|
.close_send_attempts
|
|
.set(self.test_hooks.close_send_attempts.get() + 1);
|
|
if self.test_hooks.fail_close_send.replace(false) {
|
|
return Err(io::Error::other("injected close send failure"));
|
|
}
|
|
}
|
|
let bytes = self.socket.send(packet)?;
|
|
#[cfg(test)]
|
|
if let Some(reported) = self.test_hooks.close_reported_len.take() {
|
|
return Ok(reported);
|
|
}
|
|
Ok(bytes)
|
|
}
|
|
}
|
|
|
|
pub(crate) fn echo_sent_event(
|
|
remote: SocketAddr,
|
|
sent: ProbeSent,
|
|
send_call: Duration,
|
|
scheduled_at: Instant,
|
|
timer_error: Duration,
|
|
) -> ClientEvent {
|
|
ClientEvent::EchoSent {
|
|
seq: sent.seq,
|
|
remote,
|
|
scheduled_at,
|
|
sent_at: sent.sent_at,
|
|
bytes: sent.bytes,
|
|
send_call,
|
|
timer_error,
|
|
}
|
|
}
|
|
|
|
pub(crate) fn validate_datagram_length(expected: usize, actual: usize) -> Result<(), ClientError> {
|
|
if actual == expected {
|
|
Ok(())
|
|
} else {
|
|
Err(ClientError::DatagramLengthMismatch { expected, actual })
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
impl Client {
|
|
fn send_probe_at(
|
|
&mut self,
|
|
timestamps: ProbeSendTimestamps,
|
|
) -> Result<Vec<ClientEvent>, ClientError> {
|
|
self.probe_send_timestamps = Some(timestamps);
|
|
self.send_probe()
|
|
}
|
|
|
|
fn send_managed_probe_at(
|
|
&mut self,
|
|
scheduled_at: Instant,
|
|
timestamps: ProbeSendTimestamps,
|
|
) -> Result<Vec<ClientEvent>, ClientError> {
|
|
self.probe_send_timestamps = Some(timestamps);
|
|
self.send_managed_probe(scheduled_at)
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
fn bounded_receive_timeout(
|
|
deadline: Option<Instant>,
|
|
configured_timeout: Option<Duration>,
|
|
max_wait: Duration,
|
|
now: Instant,
|
|
) -> Option<Duration> {
|
|
if max_wait.is_zero() {
|
|
return None;
|
|
}
|
|
let mut timeout = configured_timeout.unwrap_or(max_wait).min(max_wait);
|
|
if let Some(deadline) = deadline {
|
|
let remaining = deadline.checked_duration_since(now)?;
|
|
if remaining.is_zero() {
|
|
return None;
|
|
}
|
|
timeout = timeout.min(remaining);
|
|
}
|
|
(!timeout.is_zero()).then_some(timeout)
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests;
|