fix(network): prevent datagram socket SendTo errors in HDR multiplayer

Changes:
- Add validation in BSD::SendToImpl to check for empty address buffers on
  datagram sockets and return EINVAL instead of passing nullptr to sendto()
- Add null pointer check in ProxySocket::SendTo to prevent dereferencing
  nullptr address parameters
- Improve error logging to help identify socket configuration issues

Fixes: Socket operation errors in HDR multiplayer sessions
Signed-off-by: Zephyron <zephyron@citron-emu.org>

src/core/hle/service/sockets/bsd.cpp

@@ -889,6 +889,14 @@ std::pair<s32, Errno> BSD::SendToImpl(s32 fd, u32 flags, std::span<const u8> mes
         return {-1, Errno::BADF};
     }
 
+    FileDescriptor& descriptor = *file_descriptors[fd];
+
+    // For datagram sockets (UDP), a destination address is required
+    if (!descriptor.is_connection_based && addr.empty()) {
+        LOG_ERROR(Service, "SendTo called on datagram socket without destination address");
+        return {-1, Errno::INVAL};
+    }
+
     Network::SockAddrIn addr_in;
     Network::SockAddrIn* p_addr_in = nullptr;
     if (!addr.empty()) {

src/core/internal_network/socket_proxy.cpp

@@ -205,6 +205,12 @@ std::pair<s32, Errno> ProxySocket::SendTo(u32 flags, std::span<const u8> message
         return {static_cast<s32>(message.size()), Errno::SUCCESS};
     }
 
+    // For datagram sockets, a destination address is required
+    if (!addr) {
+        LOG_ERROR(Network, "SendTo called on ProxySocket without destination address");
+        return {-1, Errno::INVAL};
+    }
+
     if (auto room_member = room_network.GetRoomMember().lock()) {
         if (!room_member->IsConnected()) {
             return {static_cast<s32>(message.size()), Errno::SUCCESS};