feat: enhance ACK handling for client invites in transaction state

Author: shenjinti

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rsipstack"
-version = "0.2.57"
+version = "0.2.58"
 edition = "2021"
 description = "SIP Stack Rust library for building SIP applications"
 license = "MIT"

src/dialog/dialog.rs

@@ -380,9 +380,6 @@ impl DialogInner {
         body: Option<Vec<u8>>,
     ) -> rsip::Response {
         let mut resp_headers = rsip::Headers::default();
-        self.local_contact
-            .as_ref()
-            .map(|c| resp_headers.push(Contact::from(c.clone()).into()));
 
         for header in request.headers.iter() {
             match header {
@@ -430,11 +427,22 @@ impl DialogInner {
             }
         }
 
+        resp_headers.retain(|h| {
+            !matches!(
+                h,
+                Header::Contact(_) | Header::ContentLength(_) | Header::UserAgent(_)
+            )
+        });
+
+        self.local_contact
+            .as_ref()
+            .map(|c| resp_headers.push(Contact::from(c.clone()).into()));
+
         body.as_ref().map(|b| {
             resp_headers.push(Header::ContentLength((b.len() as u32).into()));
         });
 
-        resp_headers.unique_push(Header::UserAgent(
+        resp_headers.push(Header::UserAgent(
             self.endpoint_inner.user_agent.clone().into(),
         ));
 

src/transaction/endpoint.rs

@@ -369,8 +369,17 @@ impl EndpointInner {
                     match last_message {
                         SipMessage::Request(ref mut last_req) => {
                             if last_req.method() == &rsip::Method::Ack {
-                                if resp.status_code.kind() == rsip::StatusCodeKind::Provisional {
-                                    return Ok(());
+                                match resp.status_code.kind() {
+                                    rsip::StatusCodeKind::Provisional => {
+                                        return Ok(());
+                                    }
+                                    rsip::StatusCodeKind::Successful => {
+                                        if last_req.to_header()?.tag().ok().is_none() {
+                                            // don't ack 2xx response when ack is placeholder
+                                            return Ok(());
+                                        }
+                                    }
+                                    _ => {}
                                 }
                                 if let Ok(Some(tag)) = resp.to_header()?.tag() {
                                     last_req.to_header_mut().and_then(|h| h.mut_tag(tag)).ok();

src/transaction/transaction.rs

@@ -873,7 +873,26 @@ impl Transaction {
 
         let last_message = {
             match self.transaction_type {
-                TransactionType::ClientInvite => self.last_ack.take().map(SipMessage::Request),
+                TransactionType::ClientInvite => {
+                    //
+                    // For client invite, make a placeholder ACK if in proceeding or trying state
+                    if matches!(
+                        self.state,
+                        TransactionState::Proceeding | TransactionState::Trying
+                    ) {
+                        if self.last_ack.is_none() {
+                            if let Some(ref resp) = self.last_response {
+                                if let Ok(ack) = self
+                                    .endpoint_inner
+                                    .make_ack(self.original.uri.clone(), resp)
+                                {
+                                    self.last_ack.replace(ack);
+                                }
+                            }
+                        }
+                    }
+                    self.last_ack.take().map(SipMessage::Request)
+                }
                 TransactionType::ServerNonInvite => {
                     self.last_response.take().map(SipMessage::Response)
                 }