Replace maybenot submodule with direct ffi re-export wrapper crate

MULLVAD-CHANGELOG.md

@@ -20,6 +20,8 @@ Line wrap the file at 100 chars.                                              Th
 * **Security**: in case of vulnerabilities.
 
 ## [Unreleased]
+### Changed
+- Change how maybenot-ffi is included and built as a dependency to wireguard-go with DAITA support.
 
 
 ## [0.1.5] - 2024-12-12

Makefile

@@ -27,8 +27,8 @@ install: wireguard-go
 daita: libmaybenot.a
 	go build --tags daita -v -o wireguard-go
 
-libmaybenot.a: $(wildcard maybenot/*)
-	make --directory maybenot/crates/maybenot-ffi/ DESTINATION=$(LIBDEST) TARGET=$(TARGET)
+libmaybenot.a: $(wildcard maybenot-ffi/*)
+	make --directory maybenot-ffi DESTINATION=$(LIBDEST) TARGET=$(TARGET)
 
 test:
 	go test ./...

device/daita.go

@@ -12,7 +12,7 @@ import (
 
 // #include <stdio.h>
 // #include <stdlib.h>
-// #include "../maybenot/crates/maybenot-ffi/maybenot.h"
+// #include "../maybenot-ffi/maybenot.h"
 // #cgo LDFLAGS: -L${SRCDIR}/../ -lmaybenot -lm
 import "C"
 

maybenot-ffi/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "maybenot-ffi"
+license = "MIT OR Apache-2.0"
+edition = "2021"
+
+# We are not setting crate-type = ["staticlib"] here, because
+# we solve that by passing --crate-type=staticlib in the accompanying
+# Makefile instead. We do this because we only want to build it as a
+# staticlib on some platforms. On the other platforms it's included
+# as a normal dependency.
+
+[dependencies]
+# This should be the one single place where we actually specify the
+# maybenot-ffi dependency and its version.
+# If this is bumped, check if `maybenot.h` has to be updated. See README.md
+maybenot-ffi = "2.0.1"

maybenot-ffi/Makefile

@@ -0,0 +1,39 @@
+CARGO ?= cargo
+TARGET ?=
+PROFILE ?= release
+DESTINATION ?= .
+
+CARGO_OUTPUT_DIR := $(CARGO_TARGET_DIR)/$(TARGET)/$(PROFILE)
+CARGOFLAGS += --target-dir $(CARGO_TARGET_DIR)
+
+ifeq ($(PROFILE), release)
+	CARGOFLAGS += --release --locked
+endif
+
+ifneq ($(TARGET),)
+	CARGOFLAGS += --target
+	CARGOFLAGS += $(TARGET)
+endif
+
+.PHONY: clean check-env
+
+
+# copy the library to the final destination, and strip the _ffi part
+$(DESTINATION)/libmaybenot.a: $(CARGO_OUTPUT_DIR)/libmaybenot_ffi.a check-env
+# Copy first prerequisite ($^) to the target ($@)
+	cp $< $@
+
+# build maybenot-ffi as a static library
+$(CARGO_OUTPUT_DIR)/libmaybenot_ffi.a: src/*.rs Cargo.toml check-env
+	RUSTFLAGS="-C metadata=maybenot-ffi" ${CARGO} rustc --crate-type=staticlib $(CARGOFLAGS)
+
+
+# Verify that required environment variables are set.
+check-env:
+ifndef CARGO_TARGET_DIR
+	$(error CARGO_TARGET_DIR is undefined)
+endif
+
+clean:
+	rm -f $(DESTINATION)/libmaybenot.a
+	${CARGO} clean $(CARGOFLAGS)

maybenot-ffi/README.md

@@ -0,0 +1,22 @@
+This is just an empty wrapper around the real `maybenot-ffi` crate. It just depends
+on maybenot-ffi and re-exports the entire API. It also contains the C header
+file, and a Makefile to aid building a static library out of it.
+
+This allows us to include maybenot-ffi in a workspace without it being a direct or
+transitive Rust dependency in the workspace. This is achieved by including this crate in the
+workspace as a member. Doing this allows tracking the checksums and versions of `maybenot-ffi`
+and its dependencies in the workspace lockfile, for simpler version management,
+supply chain security and easier reproducible builds.
+
+# maybenot.h
+
+The C header file is copied here from the real `maybenot-ffi` crate.
+
+To update the header, just copy it from the corresponding `maybenot-ffi` release (the same version
+as the one specified in [`Cargo.toml`](./Cargo.toml)).
+You can use this command, just replace `${VERSION}` with the version you want the header from.
+(You first need to install `cargo download` subcommand with `cargo install cargo-download`):
+```bash
+cargo download maybenot-ffi==${VERSION} | \
+    tar xzvf - --wildcards --strip-components=1 '*/maybenot.h'
+```

maybenot-ffi/maybenot.h

@@ -0,0 +1,229 @@
+/* Generated with cbindgen:0.27.0 */
+
+/* Warning, this file is autogenerated by cbindgen. Don't modify this manually. */
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+enum MaybenotEventType {
+  MaybenotEventType_NormalRecv = 0,
+  MaybenotEventType_PaddingRecv = 1,
+  MaybenotEventType_TunnelRecv = 2,
+  MaybenotEventType_NormalSent = 3,
+  MaybenotEventType_PaddingSent = 4,
+  MaybenotEventType_TunnelSent = 5,
+  MaybenotEventType_BlockingBegin = 6,
+  MaybenotEventType_BlockingEnd = 7,
+  MaybenotEventType_TimerBegin = 8,
+  MaybenotEventType_TimerEnd = 9,
+};
+typedef uint32_t MaybenotEventType;
+
+/**
+ * An FFI friendly result error code type.
+ */
+enum MaybenotResult {
+  /**
+   * Operation completed successfully
+   */
+  MaybenotResult_Ok = 0,
+  /**
+   * The machine string wasn't valid UTF-8
+   */
+  MaybenotResult_MachineStringNotUtf8 = 1,
+  /**
+   * Failed to parse machine string
+   */
+  MaybenotResult_InvalidMachineString = 2,
+  /**
+   * Failed to start framework
+   */
+  MaybenotResult_StartFramework = 3,
+  /**
+   * A null pointer was encountered
+   */
+  MaybenotResult_NullPointer = 4,
+};
+typedef uint32_t MaybenotResult;
+
+/**
+ * The different types of timers used by a [Machine].
+ */
+enum MaybenotTimer {
+  /**
+   * The scheduled timer for actions with a timeout.
+   */
+  MaybenotTimer_Action = 0,
+  /**
+   * The machine's internal timer, updated by the machine using [MaybenotAction::UpdateTimer].
+   */
+  MaybenotTimer_Internal = 1,
+  /**
+   * Apply to all timers.
+   */
+  MaybenotTimer_All = 2,
+};
+typedef uint32_t MaybenotTimer;
+
+/**
+ * A running Maybenot instance.
+ *
+ * - Create it: [maybenot_start].
+ * - Feed it actions: [maybenot_on_events].
+ * - Stop it: [maybenot_stop].
+ */
+typedef struct MaybenotFramework MaybenotFramework;
+
+typedef struct MaybenotEvent {
+  MaybenotEventType event_type;
+  /**
+   * The ID of the machine that triggered the event, if any.
+   */
+  uintptr_t machine;
+} MaybenotEvent;
+
+typedef struct MaybenotDuration {
+  /**
+   * Number of whole seconds
+   */
+  uint64_t secs;
+  /**
+   * A nanosecond fraction of a second.
+   */
+  uint32_t nanos;
+} MaybenotDuration;
+
+/**
+ * The action to be taken by the framework user.
+ */
+enum MaybenotAction_Tag {
+  /**
+   * Cancel the timer for a machine.
+   */
+  MaybenotAction_Cancel = 0,
+  /**
+   * Schedule padding to be injected after the given timeout for a machine.
+   */
+  MaybenotAction_SendPadding = 1,
+  /**
+   * Schedule blocking of outgoing traffic after the given timeout for a machine.
+   */
+  MaybenotAction_BlockOutgoing = 2,
+  /**
+   * Update the timer duration for a machine.
+   */
+  MaybenotAction_UpdateTimer = 3,
+};
+typedef uint32_t MaybenotAction_Tag;
+
+typedef struct MaybenotAction_Cancel_Body {
+  /**
+   * The machine that generated the action.
+   */
+  uintptr_t machine;
+  MaybenotTimer timer;
+} MaybenotAction_Cancel_Body;
+
+typedef struct MaybenotAction_SendPadding_Body {
+  /**
+   * The machine that generated the action.
+   */
+  uintptr_t machine;
+  /**
+   * The time to wait before injecting a padding packet.
+   */
+  struct MaybenotDuration timeout;
+  bool replace;
+  bool bypass;
+} MaybenotAction_SendPadding_Body;
+
+typedef struct MaybenotAction_BlockOutgoing_Body {
+  /**
+   * The machine that generated the action.
+   */
+  uintptr_t machine;
+  /**
+   * The time to wait before blocking.
+   */
+  struct MaybenotDuration timeout;
+  bool replace;
+  bool bypass;
+  /**
+   * How long to block.
+   */
+  struct MaybenotDuration duration;
+} MaybenotAction_BlockOutgoing_Body;
+
+typedef struct MaybenotAction_UpdateTimer_Body {
+  uintptr_t machine;
+  struct MaybenotDuration duration;
+  bool replace;
+} MaybenotAction_UpdateTimer_Body;
+
+typedef struct MaybenotAction {
+  MaybenotAction_Tag tag;
+  union {
+    MaybenotAction_Cancel_Body cancel;
+    MaybenotAction_SendPadding_Body send_padding;
+    MaybenotAction_BlockOutgoing_Body block_outgoing;
+    MaybenotAction_UpdateTimer_Body update_timer;
+  };
+} MaybenotAction;
+
+/**
+ * Get the version of maybenot-ffi as a null terminated UTF-8-string.
+ *
+ * Example: `maybenot-ffi/1.0.1`
+ */
+const char *maybenot_version(void);
+
+/**
+ * Start a new [`MaybenotFramework`] instance.
+ *
+ * # Safety
+ * - `machines_str` must be a null-terminated UTF-8 string, containing LF-separated machines.
+ * - `out` must be a valid pointer to some valid and aligned pointer-sized memory.
+ * - The pointer written to `out` is NOT safe to be used concurrently.
+ */
+MaybenotResult maybenot_start(const char *machines_str,
+                              double max_padding_frac,
+                              double max_blocking_frac,
+                              struct MaybenotFramework **out);
+
+/**
+ * Get the number of machines running in the [`MaybenotFramework`] instance.
+ *
+ * # Safety
+ * - `this` must have been created by [`maybenot_start`].
+ */
+uintptr_t maybenot_num_machines(struct MaybenotFramework *this_);
+
+/**
+ * Stop a running [`MaybenotFramework`] instance. This will free the maybenot pointer.
+ *
+ * # Safety
+ * - `this` MUST have been created by [`maybenot_start`].
+ * - `this` MUST NOT be used after it has been passed to [`maybenot_stop`].
+ */
+void maybenot_stop(struct MaybenotFramework *this_);
+
+/**
+ * Feed events to the [`MaybenotFramework`] instance.
+ *
+ * This may generate [super::MaybenotAction]s that will be written to `actions_out`.
+ * The number of actions will be written to `num_actions_out`.
+ *
+ * # Safety
+ * - `this` MUST have been created by [`maybenot_start`].
+ * - `events` MUST be a valid pointer to an array of size `num_events`.
+ * - `actions_out` MUST have capacity for [`maybenot_num_machines`] items of size
+ *   `sizeof(MaybenotAction)` bytes.
+ * - `num_actions_out` MUST be a valid pointer where a 64bit int can be written.
+ */
+MaybenotResult maybenot_on_events(struct MaybenotFramework *this_,
+                                  const struct MaybenotEvent *events,
+                                  uintptr_t num_events,
+                                  struct MaybenotAction *actions_out,
+                                  uintptr_t *num_actions_out);

maybenot-ffi/src/lib.rs

@@ -0,0 +1 @@
+pub use maybenot_ffi::*;