rust/ffi: use ThreadVars wrapper in flow callbacks

Update the flow init, update and finish callback registrations to pass the
safe ThreadVars wrapper instead of a raw pointer.

Ticket: OISF#8598

Author: jasonish

doc/userguide/devguide/extending/flow-lifecycle-callbacks.rst

@@ -104,18 +104,19 @@ The Rust wrappers register closures or function items and return
 
 .. code-block:: rust
 
-   use suricata_ffi::flow::{self, Flow, Packet, ThreadVars};
+   use suricata_ffi::flow::{self, Flow, Packet};
+   use suricata_ffi::thread::ThreadVars;
    use suricata_ffi::SCLogNotice;
 
-   fn flow_init(_tv: *mut ThreadVars, f: *mut Flow, _p: *const Packet) {
+   fn flow_init(_tv: &ThreadVars, f: *mut Flow, _p: *const Packet) {
        SCLogNotice!("flow initialized: {:p}", f);
    }
 
-   fn flow_update(_tv: *mut ThreadVars, f: *mut Flow, p: *mut Packet) {
+   fn flow_update(_tv: &ThreadVars, f: *mut Flow, p: *mut Packet) {
        SCLogNotice!("flow updated: {:p} packet: {:p}", f, p);
    }
 
-   fn flow_finish(_tv: *mut ThreadVars, f: *mut Flow) {
+   fn flow_finish(_tv: &ThreadVars, f: *mut Flow) {
        SCLogNotice!("flow finished: {:p}", f);
    }
 

examples/plugins/rust/src/mod.rs

@@ -73,19 +73,19 @@ fn on_thread_init(tv: &ThreadVars) {
     );
 }
 
-fn log_flow_init(_tv: *mut sys::ThreadVars, _f: *mut Flow, _p: *const Packet) {
+fn log_flow_init(_tv: &ThreadVars, _f: *mut Flow, _p: *const Packet) {
     SCLogNotice!("rust example flow init callback: flow={:p}", _f);
 }
 
-fn log_flow_update(_tv: *mut sys::ThreadVars, _f: *mut Flow, _p: *mut Packet) {
+fn log_flow_update(_tv: &ThreadVars, _f: *mut Flow, _p: *mut Packet) {
     SCLogNotice!(
         "rust example flow update callback: flow={:p}, packet={:p}",
         _f,
         _p
     );
 }
 
-fn log_flow_finish(_tv: *mut sys::ThreadVars, _f: *mut Flow) {
+fn log_flow_finish(_tv: &ThreadVars, _f: *mut Flow) {
     SCLogNotice!("rust example flow finish callback: flow={:p}", _f);
 }
 

rust/ffi/src/flow.rs

@@ -17,11 +17,13 @@
 
 use std::os::raw::c_void;
 
-use suricata_sys::sys::{Flow, Packet, ThreadVars};
 use suricata_sys::sys::{
-    SCFlowRegisterFinishCallback, SCFlowRegisterInitCallback, SCFlowRegisterUpdateCallback,
+    self, Flow, Packet, SCFlowRegisterFinishCallback, SCFlowRegisterInitCallback,
+    SCFlowRegisterUpdateCallback,
 };
 
+use crate::thread::ThreadVars;
+
 /// Register a flow initialization callback.
 ///
 /// The callback is invoked whenever Suricata initializes a flow. It receives:
@@ -37,7 +39,7 @@ use suricata_sys::sys::{
 /// The callback must not panic.
 pub fn register_init_callback<F>(callback: F) -> Result<(), &'static str>
 where
-    F: Fn(*mut ThreadVars, *mut Flow, *const Packet) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow, *const Packet) + Send + Sync + 'static,
 {
     let user = Box::into_raw(Box::new(callback)) as *mut c_void;
     if unsafe { SCFlowRegisterInitCallback(Some(init_callback_wrapper::<F>), user) } {
@@ -66,7 +68,7 @@ where
 /// The callback must not panic.
 pub fn register_update_callback<F>(callback: F) -> Result<(), &'static str>
 where
-    F: Fn(*mut ThreadVars, *mut Flow, *mut Packet) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow, *mut Packet) + Send + Sync + 'static,
 {
     let user = Box::into_raw(Box::new(callback)) as *mut c_void;
     if unsafe { SCFlowRegisterUpdateCallback(Some(update_callback_wrapper::<F>), user) } {
@@ -93,7 +95,7 @@ where
 /// The callback must not panic.
 pub fn register_finish_callback<F>(callback: F) -> Result<(), &'static str>
 where
-    F: Fn(*mut ThreadVars, *mut Flow) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow) + Send + Sync + 'static,
 {
     let user = Box::into_raw(Box::new(callback)) as *mut c_void;
     if unsafe { SCFlowRegisterFinishCallback(Some(finish_callback_wrapper::<F>), user) } {
@@ -107,28 +109,31 @@ where
 }
 
 unsafe extern "C" fn init_callback_wrapper<F>(
-    tv: *mut ThreadVars, f: *mut Flow, p: *const Packet, user: *mut c_void,
+    tv: *mut sys::ThreadVars, f: *mut Flow, p: *const Packet, user: *mut c_void,
 ) where
-    F: Fn(*mut ThreadVars, *mut Flow, *const Packet) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow, *const Packet) + Send + Sync + 'static,
 {
     let callback = &*(user as *const F);
-    callback(tv, f, p);
+    let tv = ThreadVars::from_ptr(tv);
+    callback(&tv, f, p);
 }
 
 unsafe extern "C" fn update_callback_wrapper<F>(
-    tv: *mut ThreadVars, f: *mut Flow, p: *mut Packet, user: *mut c_void,
+    tv: *mut sys::ThreadVars, f: *mut Flow, p: *mut Packet, user: *mut c_void,
 ) where
-    F: Fn(*mut ThreadVars, *mut Flow, *mut Packet) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow, *mut Packet) + Send + Sync + 'static,
 {
     let callback = &*(user as *const F);
-    callback(tv, f, p);
+    let tv = ThreadVars::from_ptr(tv);
+    callback(&tv, f, p);
 }
 
 unsafe extern "C" fn finish_callback_wrapper<F>(
-    tv: *mut ThreadVars, f: *mut Flow, user: *mut c_void,
+    tv: *mut sys::ThreadVars, f: *mut Flow, user: *mut c_void,
 ) where
-    F: Fn(*mut ThreadVars, *mut Flow) + Send + Sync + 'static,
+    F: Fn(&ThreadVars, *mut Flow) + Send + Sync + 'static,
 {
     let callback = &*(user as *const F);
-    callback(tv, f);
+    let tv = ThreadVars::from_ptr(tv);
+    callback(&tv, f);
 }