From e334f3c37f412b80a23d9d158eff5caa8b3ef04c Mon Sep 17 00:00:00 2001
From: Yat Ho <lagoho7@gmail.com>
Date: Sun, 14 Jul 2024 18:55:37 +0800
Subject: [PATCH] =?UTF-8?q?fix:=20misc=20=C2=B5TP=20trace=20log=20fixes=20?=
 =?UTF-8?q?(#6929)?=
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* fix: FTBFS when `TR_UTP_TRACE` is defined

* refactor: log socket address when processing udp packets

* refactor: log details of unexpected UDP packet

* fix: don't unset utp context userdata during shutdown

It is still needed inside `utp_destroy()` when `UTP_DEBUG_LOGGING` is defined.

* code review: lazy evaluate incoming udp packet display name

* code review: move `from_str` out of loop
---
 libtransmission/tr-udp.cc | 13 +++++++++++--
 libtransmission/tr-utp.cc |  3 +--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/libtransmission/tr-udp.cc b/libtransmission/tr-udp.cc
index 1c5f8b503..0b72d33e2 100644
--- a/libtransmission/tr-udp.cc
+++ b/libtransmission/tr-udp.cc
@@ -95,6 +95,11 @@ void event_callback(evutil_socket_t s, [[maybe_unused]] short type, void* vsessi
     auto* const session = static_cast<tr_session*>(vsession);
     auto got_utp_packet = false;
 
+    auto const from_str = [from_sa]
+    {
+        return tr_socket_address::from_sockaddr(from_sa).value_or(tr_socket_address{}).display_name();
+    };
+
     for (;;)
     {
         auto const n_read = recvfrom(s, reinterpret_cast<char*>(std::data(buf)), std::size(buf) - 1, 0, from_sa, &fromlen);
@@ -128,7 +133,7 @@ void event_callback(evutil_socket_t s, [[maybe_unused]] short type, void* vsessi
         {
             if (!session->announcer_udp_->handle_message(std::data(buf), n_read, from_sa, fromlen))
             {
-                tr_logAddTrace("Couldn't parse UDP tracker packet.");
+                tr_logAddTrace(fmt::format("{} Couldn't parse UDP tracker packet.", from_str()));
             }
         }
         else if (session->allowsUTP() && session->utp_context != nullptr)
@@ -139,7 +144,11 @@ void event_callback(evutil_socket_t s, [[maybe_unused]] short type, void* vsessi
             }
             else
             {
-                tr_logAddTrace("Unexpected UDP packet");
+                tr_logAddTrace(fmt::format(
+                    "{} Unexpected UDP packet... len {} [{}]",
+                    from_str(),
+                    n_read,
+                    tr_base64_encode({ reinterpret_cast<char const*>(std::data(buf)), static_cast<size_t>(n_read) })));
             }
         }
     }
diff --git a/libtransmission/tr-utp.cc b/libtransmission/tr-utp.cc
index fae16e9dc..069ca5f5d 100644
--- a/libtransmission/tr-utp.cc
+++ b/libtransmission/tr-utp.cc
@@ -122,7 +122,7 @@ uint64 utp_callback(utp_callback_arguments* args)
     {
 #ifdef TR_UTP_TRACE
     case UTP_LOG:
-        fmt::print(stderr, "[µTP] {}\n", args->buf);
+        tr_logAddTrace(fmt::format("[µTP] {}", reinterpret_cast<char const*>(args->buf)));
         break;
 #endif
 
@@ -227,7 +227,6 @@ void tr_utp_close(tr_session* session)
 
     if (session->utp_context != nullptr)
     {
-        utp_context_set_userdata(session->utp_context, nullptr);
         utp_destroy(session->utp_context);
         session->utp_context = nullptr;
     }