libtorrent: Move resolver callback to connection manager (#40)

We need to move the resolver callback up to the connection manager, so it's always accessible by UDNS. Otherwise, we crash.
stickz · Jul 20, 2024 · 5517bef · 5517bef
1 parent 80f01db
commit 5517bef
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Showing 3 changed files with 15 additions and 1 deletion.
diff --git a/libtorrent/src/torrent/connection_manager.cc b/libtorrent/src/torrent/connection_manager.cc
@@ -85,6 +85,12 @@ ConnectionManager::start_udp_announce(uint64_t idx, const sockaddr* sa, int err)
   }
 }
 
+void 
+ConnectionManager::add_resolver_callback(uint64_t idx) {
+  resolver_callback c = std::bind(&ConnectionManager::start_udp_announce, this, idx, std::placeholders::_1, std::placeholders::_2);
+  m_resolver_callback_list.push_back(c);
+}
+
 #define ASYNC_RESOLVER_IMPL UdnsAsyncResolver
 #else
 class StubAsyncResolver : public AsyncResolver {

diff --git a/libtorrent/src/torrent/connection_manager.h b/libtorrent/src/torrent/connection_manager.h
@@ -191,6 +191,9 @@ class LIBTORRENT_EXPORT ConnectionManager {
   void                null_udp_tracker(uint64_t idx)          { m_tracker_udp_list[idx] = NULL; }
   void                add_udp_tracker(TrackerUdp* tracker)    { m_tracker_udp_list.push_back(tracker); }
   uint64_t            get_udp_tracker_count()                 { return m_tracker_udp_list.size(); }
+
+  void                add_resolver_callback(uint64_t idx);
+  resolver_callback*  get_resolver_callback(uint64_t idx)     { return &m_resolver_callback_list[idx]; }
 #endif
 
   // Legacy synchronous resolver interface.
@@ -232,6 +235,7 @@ class LIBTORRENT_EXPORT ConnectionManager {
 
 #ifdef USE_UDNS
   std::vector<TrackerUdp*> m_tracker_udp_list;
+  std::vector<resolver_callback>  m_resolver_callback_list;
 #endif
 
   std::unique_ptr<AsyncResolver> m_async_resolver;

diff --git a/libtorrent/src/tracker/tracker_udp.cc b/libtorrent/src/tracker/tracker_udp.cc
@@ -79,7 +79,7 @@ TrackerUdp::TrackerUdp(TrackerList* parent, rak::udp_tracker_info& info, int fla
 #ifdef USE_UDNS
   manager->connection_manager()->add_udp_tracker(this);
   m_vec_idx = manager->connection_manager()->get_udp_tracker_count() - 1;
-  m_resolver_callback = std::bind(&ConnectionManager::start_udp_announce, manager->connection_manager(), m_vec_idx, std::placeholders::_1, std::placeholders::_2);
+  manager->connection_manager()->add_resolver_callback(m_vec_idx);
 #else
   m_resolver_callback = std::bind(&TrackerUdp::start_announce, this, std::placeholders::_1, std::placeholders::_2);
 #endif
@@ -111,7 +111,11 @@ TrackerUdp::send_state(int state) {
   m_resolver_query = manager->connection_manager()->async_resolver().enqueue(
       m_hostname.c_str(),
       AF_UNSPEC,
+#ifdef USE_UDNS
+      manager->connection_manager()->get_resolver_callback(m_vec_idx)
+#else
       &m_resolver_callback
+#endif
   );
   manager->connection_manager()->async_resolver().flush();
 }