From 9b6051380f6902616abdfb2e21d158aee4a32cc6 Mon Sep 17 00:00:00 2001
From: Will Greenberg <willg@eff.org>
Date: Wed, 30 Jul 2025 15:57:54 -0700
Subject: [PATCH] lib: write ltemac packets as gsmtap

---
 lib/src/gsmtap_parser.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/src/gsmtap_parser.rs b/lib/src/gsmtap_parser.rs
index 4a7ea58..e1c512b 100644
--- a/lib/src/gsmtap_parser.rs
+++ b/lib/src/gsmtap_parser.rs
@@ -1,6 +1,7 @@
 use crate::diag::*;
 use crate::gsmtap::*;
 
+use deku::DekuContainerWrite;
 use log::error;
 use thiserror::Error;
 
@@ -148,7 +149,16 @@ fn log_to_gsmtap(value: LogBody) -> Result<Option<GsmtapMessage>, GsmtapParserEr
                 header,
                 payload: msg,
             }))
-        }
+        },
+        LogBody::LteMacDl { subpackets, .. } => {
+            let mut header = GsmtapHeader::new(GsmtapType::LteMac);
+            header.uplink = false;
+            let mut payload = Vec::new();
+            for packet in subpackets {
+                payload.extend(packet.to_bytes().unwrap());
+            }
+            Ok(Some(GsmtapMessage { header, payload }))
+        },
         _ => {
             error!("gsmtap_sink: ignoring unhandled log type: {value:?}");
             Ok(None)