Merge changes I015a5024,I00d0cdf4,Iec91284f,Ib4a2eb50,Ib5c1ed8f

* changes:
  Log the timestamp each part file is created too
  Actually populate boot_uuids in the header
  Move reboot and header responsibility into DataWriter
  Make LogNamer copy a template header rather than modify an input
  Wrap DetachedBufferWriter in an object for logging
diff --git a/aos/aos_cli_utils.cc b/aos/aos_cli_utils.cc
index e36c3d2..84ba1e4 100644
--- a/aos/aos_cli_utils.cc
+++ b/aos/aos_cli_utils.cc
@@ -32,7 +32,8 @@
 
 bool CliUtilInfo::Initialize(
     int *argc, char ***argv,
-    std::function<bool(const aos::Channel *)> channel_filter) {
+    std::function<bool(const aos::Channel *)> channel_filter,
+    bool expect_args) {
   // Don't generate failure output if the config doesn't exist while attempting
   // to autocomplete.
   if (struct stat file_stat;
@@ -44,66 +45,76 @@
     return true;
   }
 
-  std::string channel_name;
-  std::string message_type;
-  if (*argc > 1) {
-    channel_name = (*argv)[1];
-    ShiftArgs(argc, argv);
-  }
-  if (*argc > 1) {
-    message_type = (*argv)[1];
-    ShiftArgs(argc, argv);
-  }
-
   config.emplace(aos::configuration::ReadConfig(FLAGS_config));
   event_loop.emplace(&config->message());
   event_loop->SkipTimingReport();
   event_loop->SkipAosLog();
 
-  if (FLAGS__bash_autocomplete) {
-    Autocomplete(channel_name, message_type, channel_filter);
-    return true;
-  }
-
-  const flatbuffers::Vector<flatbuffers::Offset<aos::Channel>> *const channels =
+  const flatbuffers::Vector<flatbuffers::Offset<aos::Channel>> *channels =
       event_loop->configuration()->channels();
-  if (channel_name.empty() && message_type.empty()) {
-    std::cout << "Channels:\n";
+
+  do {
+    std::string channel_name;
+    std::string message_type;
+    if (*argc > 1) {
+      channel_name = (*argv)[1];
+      ShiftArgs(argc, argv);
+    }
+    if (*argc > 1) {
+      message_type = (*argv)[1];
+      ShiftArgs(argc, argv);
+    }
+
+    if (FLAGS__bash_autocomplete) {
+      Autocomplete(channel_name, message_type, channel_filter);
+      return true;
+    }
+
+    if (channel_name.empty() && message_type.empty()) {
+      std::cout << "Channels:\n";
+      for (const aos::Channel *channel : *channels) {
+        if (FLAGS_all || channel_filter(channel)) {
+          std::cout << channel->name()->c_str() << ' '
+                    << channel->type()->c_str() << '\n';
+        }
+      }
+      return true;
+    }
+
+    std::vector<const aos::Channel *> found_channels_now;
+    bool found_exact = false;
     for (const aos::Channel *channel : *channels) {
-      if (FLAGS_all || channel_filter(channel)) {
-        std::cout << channel->name()->c_str() << ' ' << channel->type()->c_str()
-                  << '\n';
+      if (!FLAGS_all && !channel_filter(channel)) {
+        continue;
       }
-    }
-    return true;
-  }
-
-  bool found_exact = false;
-  for (const aos::Channel *channel : *channels) {
-    if (!FLAGS_all && !channel_filter(channel)) {
-      continue;
-    }
-    if (channel->name()->c_str() != channel_name) {
-      continue;
-    }
-    if (channel->type()->string_view() == message_type) {
-      if (!found_exact) {
-        found_channels.clear();
-        found_exact = true;
+      if (channel->name()->c_str() != channel_name) {
+        continue;
       }
-    } else if (!found_exact && channel->type()->string_view().find(
-                                   message_type) != std::string_view::npos) {
-    } else {
-      continue;
+      if (channel->type()->string_view() == message_type) {
+        if (!found_exact) {
+          found_channels_now.clear();
+          found_exact = true;
+        }
+      } else if (!found_exact && channel->type()->string_view().find(
+                                     message_type) != std::string_view::npos) {
+      } else {
+        continue;
+      }
+      found_channels_now.push_back(channel);
     }
-    found_channels.push_back(channel);
-  }
 
-  if (found_channels.empty()) {
-    LOG(FATAL) << "Could not find any channels with the given name and type.";
-  } else if (found_channels.size() > 1 && !message_type.empty()) {
-    LOG(FATAL) << "Multiple channels found with same type";
-  }
+    if (found_channels_now.empty()) {
+      LOG(FATAL)
+          << "Could not find any channels with the given name and type for "
+          << channel_name << " " << message_type;
+    } else if (found_channels_now.size() > 1 && !message_type.empty()) {
+      LOG(FATAL) << "Multiple channels found with same type for "
+                 << channel_name << " " << message_type;
+    }
+    for (const aos::Channel *channel : found_channels_now) {
+      found_channels.push_back(channel);
+    }
+  } while (expect_args && *argc > 1);
 
   return false;
 }
diff --git a/aos/aos_cli_utils.h b/aos/aos_cli_utils.h
index e158737..962e0a0 100644
--- a/aos/aos_cli_utils.h
+++ b/aos/aos_cli_utils.h
@@ -13,7 +13,8 @@
   // If this returns false, the other fields will be filled out appropriately.
   // event_loop will be filled out before channel_filter is called.
   bool Initialize(int *argc, char ***argv,
-                  std::function<bool(const aos::Channel *)> channel_filter);
+                  std::function<bool(const aos::Channel *)> channel_filter,
+                  bool expect_args);
 
   std::optional<aos::FlatbufferDetachedBuffer<aos::Configuration>> config;
   std::optional<aos::ShmEventLoop> event_loop;
diff --git a/aos/aos_dump.cc b/aos/aos_dump.cc
index e2467b3..477b6fb 100644
--- a/aos/aos_dump.cc
+++ b/aos/aos_dump.cc
@@ -70,11 +70,13 @@
   aos::InitGoogle(&argc, &argv);
 
   aos::CliUtilInfo cli_info;
-  if (cli_info.Initialize(&argc, &argv,
-                          [&cli_info](const aos::Channel *channel) {
-                            return aos::configuration::ChannelIsReadableOnNode(
-                                channel, cli_info.event_loop->node());
-                          })) {
+  if (cli_info.Initialize(
+          &argc, &argv,
+          [&cli_info](const aos::Channel *channel) {
+            return aos::configuration::ChannelIsReadableOnNode(
+                channel, cli_info.event_loop->node());
+          },
+          true)) {
     return 0;
   }
 
diff --git a/aos/aos_send.cc b/aos/aos_send.cc
index d94418a..91ffb1c 100644
--- a/aos/aos_send.cc
+++ b/aos/aos_send.cc
@@ -19,11 +19,13 @@
   aos::InitGoogle(&argc, &argv);
 
   aos::CliUtilInfo cli_info;
-  if (cli_info.Initialize(&argc, &argv,
-                          [&cli_info](const aos::Channel *channel) {
-                            return aos::configuration::ChannelIsSendableOnNode(
-                                channel, cli_info.event_loop->node());
-                          })) {
+  if (cli_info.Initialize(
+          &argc, &argv,
+          [&cli_info](const aos::Channel *channel) {
+            return aos::configuration::ChannelIsSendableOnNode(
+                channel, cli_info.event_loop->node());
+          },
+          false)) {
     return 0;
   }
   if (cli_info.found_channels.size() > 1) {
diff --git a/aos/events/logging/buffer_encoder.cc b/aos/events/logging/buffer_encoder.cc
index 10a7ed1..6ef61d4 100644
--- a/aos/events/logging/buffer_encoder.cc
+++ b/aos/events/logging/buffer_encoder.cc
@@ -39,7 +39,7 @@
 }
 
 DummyDecoder::DummyDecoder(std::string_view filename)
-    : fd_(open(std::string(filename).c_str(), O_RDONLY | O_CLOEXEC)) {
+    : filename_(filename), fd_(open(filename_.c_str(), O_RDONLY | O_CLOEXEC)) {
   PCHECK(fd_ != -1) << ": Failed to open " << filename;
 }
 
diff --git a/aos/events/logging/buffer_encoder.h b/aos/events/logging/buffer_encoder.h
index 1eddd00..235a49c 100644
--- a/aos/events/logging/buffer_encoder.h
+++ b/aos/events/logging/buffer_encoder.h
@@ -2,9 +2,8 @@
 #define AOS_EVENTS_LOGGING_BUFFER_ENCODER_H_
 
 #include "absl/types/span.h"
-#include "flatbuffers/flatbuffers.h"
-
 #include "aos/events/logging/logger_generated.h"
+#include "flatbuffers/flatbuffers.h"
 
 namespace aos::logger {
 
@@ -89,6 +88,9 @@
   // Returns less than end-begin if all bytes have been read. Otherwise, this
   // will always fill the whole range.
   virtual size_t Read(uint8_t *begin, uint8_t *end) = 0;
+
+  // Returns the underlying filename, for debugging purposes.
+  virtual std::string_view filename() const = 0;
 };
 
 // Simply reads the contents of the file into the target buffer.
@@ -102,8 +104,11 @@
   ~DummyDecoder() override;
 
   size_t Read(uint8_t *begin, uint8_t *end) final;
+  std::string_view filename() const final { return filename_; }
 
  private:
+  const std::string filename_;
+
   // File descriptor for the log file.
   int fd_;
 
diff --git a/aos/events/logging/log_cat.cc b/aos/events/logging/log_cat.cc
index 342a491..a26eb49 100644
--- a/aos/events/logging/log_cat.cc
+++ b/aos/events/logging/log_cat.cc
@@ -37,6 +37,10 @@
 DEFINE_bool(print, true,
             "If true, actually print the messages.  If false, discard them, "
             "confirming they can be parsed.");
+DEFINE_uint64(
+    count, 0,
+    "If >0, log_cat will exit after printing this many messages.  This "
+    "includes messages from before the start of the log if --fetch is set.");
 DEFINE_bool(print_parts_only, false,
             "If true, only print out the results of logfile sorting.");
 DEFINE_bool(channels, false,
@@ -247,6 +251,8 @@
 
   bool found_channel = false;
 
+  uint64_t message_print_counter = 0;
+
   for (const aos::Node *node :
        aos::configuration::GetNodes(event_loop_factory.configuration())) {
     std::unique_ptr<aos::EventLoop> printer_event_loop =
@@ -309,10 +315,15 @@
         }
 
         printer_event_loop->MakeRawWatcher(
-            channel, [channel, node_name, &builder](const aos::Context &context,
-                                                    const void * /*message*/) {
+            channel, [channel, node_name, &builder, &event_loop_factory,
+                      &message_print_counter](const aos::Context &context,
+                                               const void * /*message*/) {
               if (FLAGS_print) {
                 PrintMessage(node_name, channel, context, &builder);
+                ++message_print_counter;
+                if (FLAGS_count > 0 && message_print_counter >= FLAGS_count) {
+                  event_loop_factory.Exit();
+                }
               }
             });
         found_channel = true;
@@ -325,6 +336,12 @@
       if (FLAGS_print) {
         PrintMessage(message.node_name, message.fetcher->channel(),
                      message.fetcher->context(), &builder);
+        ++message_print_counter;
+        if (FLAGS_count > 0 && message_print_counter >= FLAGS_count) {
+          // We are done.  Clean up and exit.
+          reader.Deregister();
+          return 0;
+        }
       }
     }
     printer_event_loops.emplace_back(std::move(printer_event_loop));
diff --git a/aos/events/logging/logfile_utils.cc b/aos/events/logging/logfile_utils.cc
index cd2ceb8..4c19867 100644
--- a/aos/events/logging/logfile_utils.cc
+++ b/aos/events/logging/logfile_utils.cc
@@ -17,9 +17,9 @@
 #include "glog/logging.h"
 
 #if defined(__x86_64__)
-#define ENABLE_LZMA 1
+#define ENABLE_LZMA (!__has_feature(memory_sanitizer))
 #elif defined(__aarch64__)
-#define ENABLE_LZMA 1
+#define ENABLE_LZMA (!__has_feature(memory_sanitizer))
 #else
 #define ENABLE_LZMA 0
 #endif
@@ -317,15 +317,15 @@
 }
 
 SpanReader::SpanReader(std::string_view filename) : filename_(filename) {
-  static const std::string_view kXz = ".xz";
+  decoder_ = std::make_unique<DummyDecoder>(filename);
+
+  static constexpr std::string_view kXz = ".xz";
   if (filename.substr(filename.size() - kXz.size()) == kXz) {
 #if ENABLE_LZMA
-    decoder_ = std::make_unique<ThreadedLzmaDecoder>(filename);
+    decoder_ = std::make_unique<ThreadedLzmaDecoder>(std::move(decoder_));
 #else
     LOG(FATAL) << "Reading xz-compressed files not supported on this platform";
 #endif
-  } else {
-    decoder_ = std::make_unique<DummyDecoder>(filename);
   }
 }
 
diff --git a/aos/events/logging/lzma_encoder.cc b/aos/events/logging/lzma_encoder.cc
index 60a203e..1024b91 100644
--- a/aos/events/logging/lzma_encoder.cc
+++ b/aos/events/logging/lzma_encoder.cc
@@ -149,8 +149,9 @@
   total_bytes_ += last_avail_out - stream_.avail_out;
 }
 
-LzmaDecoder::LzmaDecoder(std::string_view filename)
-    : dummy_decoder_(filename), stream_(LZMA_STREAM_INIT), filename_(filename) {
+LzmaDecoder::LzmaDecoder(std::unique_ptr<DataDecoder> underlying_decoder)
+    : underlying_decoder_(std::move(underlying_decoder)),
+      stream_(LZMA_STREAM_INIT) {
   compressed_data_.resize(kBufSize);
 
   lzma_ret status =
@@ -174,8 +175,8 @@
   while (stream_.avail_out > 0) {
     if (action_ == LZMA_RUN && stream_.avail_in == 0) {
       // Read more bytes from the file if we're all out.
-      const size_t count =
-          dummy_decoder_.Read(compressed_data_.begin(), compressed_data_.end());
+      const size_t count = underlying_decoder_->Read(compressed_data_.begin(),
+                                                     compressed_data_.end());
       if (count == 0) {
         // No more data to read in the file, begin the finishing operation.
         action_ = LZMA_FINISH;
@@ -196,17 +197,18 @@
 
     // If we fail to decompress, give up.  Return everything that has been
     // produced so far.
-    if (!LzmaCodeIsOk(status, filename_)) {
+    if (!LzmaCodeIsOk(status, filename())) {
       finished_ = true;
-      LOG(WARNING) << filename_ << " is truncated or corrupted.";
+      LOG(WARNING) << filename() << " is truncated or corrupted.";
       return (end - begin) - stream_.avail_out;
     }
   }
   return end - begin;
 }
 
-ThreadedLzmaDecoder::ThreadedLzmaDecoder(std::string_view filename)
-    : decoder_(filename), decode_thread_([this] {
+ThreadedLzmaDecoder::ThreadedLzmaDecoder(
+    std::unique_ptr<DataDecoder> underlying_decoder)
+    : decoder_(std::move(underlying_decoder)), decode_thread_([this] {
         std::unique_lock lock(decode_mutex_);
         while (true) {
           // Wake if the queue is too small or we are finished.
diff --git a/aos/events/logging/lzma_encoder.h b/aos/events/logging/lzma_encoder.h
index 972ed6c..6696200 100644
--- a/aos/events/logging/lzma_encoder.h
+++ b/aos/events/logging/lzma_encoder.h
@@ -1,6 +1,7 @@
 #ifndef AOS_EVENTS_LOGGING_LZMA_ENCODER_H_
 #define AOS_EVENTS_LOGGING_LZMA_ENCODER_H_
 
+#include <string_view>
 #include <condition_variable>
 #include <mutex>
 #include <thread>
@@ -51,7 +52,9 @@
 // Decompresses data with liblzma.
 class LzmaDecoder final : public DataDecoder {
  public:
-  explicit LzmaDecoder(std::string_view filename);
+  explicit LzmaDecoder(std::unique_ptr<DataDecoder> underlying_decoder);
+  explicit LzmaDecoder(std::string_view filename)
+      : LzmaDecoder(std::make_unique<DummyDecoder>(filename)) {}
   LzmaDecoder(const LzmaDecoder &) = delete;
   LzmaDecoder(LzmaDecoder &&other) = delete;
   LzmaDecoder &operator=(const LzmaDecoder &) = delete;
@@ -59,6 +62,9 @@
   ~LzmaDecoder();
 
   size_t Read(uint8_t *begin, uint8_t *end) final;
+  std::string_view filename() const final {
+    return underlying_decoder_->filename();
+  }
 
  private:
   // Size of temporary buffer to use.
@@ -67,7 +73,7 @@
   // Temporary buffer for storing compressed data.
   ResizeableBuffer compressed_data_;
   // Used for reading data from the file.
-  DummyDecoder dummy_decoder_;
+  std::unique_ptr<DataDecoder> underlying_decoder_;
   // Stream for decompression.
   lzma_stream stream_;
   // The current action. This is LZMA_RUN until we've run out of data to read
@@ -76,9 +82,6 @@
   // Flag that represents whether or not all the data from the file has been
   // successfully decoded.
   bool finished_ = false;
-
-  // Filename we are decompressing.
-  std::string filename_;
 };
 
 // Decompresses data with liblzma in a new thread, up to a maximum queue
@@ -86,7 +89,9 @@
 // or block until more data is queued or the stream finishes.
 class ThreadedLzmaDecoder : public DataDecoder {
  public:
-  explicit ThreadedLzmaDecoder(std::string_view filename);
+  explicit ThreadedLzmaDecoder(std::string_view filename)
+      : ThreadedLzmaDecoder(std::make_unique<DummyDecoder>(filename)) {}
+  explicit ThreadedLzmaDecoder(std::unique_ptr<DataDecoder> underlying_decoder);
   ThreadedLzmaDecoder(const ThreadedLzmaDecoder &) = delete;
   ThreadedLzmaDecoder &operator=(const ThreadedLzmaDecoder &) = delete;
 
@@ -94,6 +99,8 @@
 
   size_t Read(uint8_t *begin, uint8_t *end) final;
 
+  std::string_view filename() const final { return decoder_.filename(); }
+
  private:
   static constexpr size_t kBufSize{256 * 1024};
   static constexpr size_t kQueueSize{8};
diff --git a/aos/logging/log_namer.cc b/aos/logging/log_namer.cc
index 707fd08..dfebe44 100644
--- a/aos/logging/log_namer.cc
+++ b/aos/logging/log_namer.cc
@@ -69,11 +69,9 @@
   if (asprintf(filename, "%s/%s-%03d", directory, basename, fileindex) == -1) {
     PLOG(FATAL) << "couldn't create final name";
   }
-  LOG(INFO) << "Created log file (" << basename << "-" << fileindex
-            << ") in directory (" << directory
-            << "). Previous file "
-               "was ("
-            << previous << ").";
+  // Fix basename formatting.
+  LOG(INFO) << "Created log file (" << filename << "). Previous file was ("
+            << directory << "/" << previous << ").";
 }
 
 bool FoundThumbDrive(const char *path) {
diff --git a/aos/network/message_bridge_client_lib.cc b/aos/network/message_bridge_client_lib.cc
index 1044b2f..80a41d9 100644
--- a/aos/network/message_bridge_client_lib.cc
+++ b/aos/network/message_bridge_client_lib.cc
@@ -90,7 +90,6 @@
   return fbb.Release();
 }
 
-
 }  // namespace
 
 SctpClientConnection::SctpClientConnection(
@@ -150,6 +149,9 @@
 void SctpClientConnection::MessageReceived() {
   // Dispatch the message to the correct receiver.
   aos::unique_c_ptr<Message> message = client_.Read();
+  if (!message) {
+    return;
+  }
 
   if (message->message_type == Message::kNotification) {
     const union sctp_notification *snp =
@@ -228,9 +230,14 @@
   VLOG(1) << "Got a message of size " << message->size;
   CHECK_EQ(message->size, flatbuffers::GetPrefixedSize(message->data()) +
                               sizeof(flatbuffers::uoffset_t));
+  {
+    flatbuffers::Verifier verifier(message->data(), message->size);
+    CHECK(remote_data->Verify(verifier));
+  }
 
   const int stream = message->header.rcvinfo.rcv_sid - kControlStreams();
-  SctpClientChannelState *channel_state = &((*channels_)[stream_to_channel_[stream]]);
+  SctpClientChannelState *channel_state =
+      &((*channels_)[stream_to_channel_[stream]]);
 
   if (remote_data->queue_index() == channel_state->last_queue_index &&
       monotonic_clock::time_point(
diff --git a/aos/network/message_bridge_server_lib.cc b/aos/network/message_bridge_server_lib.cc
index c929e31..da925f5 100644
--- a/aos/network/message_bridge_server_lib.cc
+++ b/aos/network/message_bridge_server_lib.cc
@@ -90,10 +90,10 @@
 
   if (logged_remotely) {
     if (sent_count == 0) {
-      VLOG(1) << "No clients, rejecting";
-      HandleFailure(fbb.Release());
+      VLOG(1)
+          << "No clients, rejecting. TODO(austin): do backup logging to disk";
     } else {
-      sent_messages_.emplace_back(fbb.Release());
+      VLOG(1) << "TODO(austin): backup log to disk if this fails eventually";
     }
   } else {
     VLOG(1) << "Not bothering to track this message since nobody cares.";
@@ -165,40 +165,8 @@
     }
   }
 
-  while (sent_messages_.size() > 0u) {
-    if (sent_messages_.begin()->message().monotonic_sent_time() ==
-            message_header->monotonic_sent_time() &&
-        sent_messages_.begin()->message().queue_index() ==
-            message_header->queue_index()) {
-      sent_messages_.pop_front();
-      continue;
-    }
-
-    if (sent_messages_.begin()->message().monotonic_sent_time() <
-        message_header->monotonic_sent_time()) {
-      VLOG(1) << "Delivery looks wrong, rejecting";
-      HandleFailure(std::move(sent_messages_.front()));
-      sent_messages_.pop_front();
-      continue;
-    }
-
-    break;
-  }
-}
-
-void ChannelState::HandleFailure(
-    SizePrefixedFlatbufferDetachedBuffer<RemoteData> &&message) {
-  // TODO(austin): Put it in the log queue.
-  if (VLOG_IS_ON(2)) {
-    LOG(INFO) << "Failed to send " << FlatbufferToJson(message);
-  } else if (VLOG_IS_ON(1)) {
-    message.mutable_message()->clear_data();
-    LOG(INFO) << "Failed to send " << FlatbufferToJson(message);
-  }
-
-  // Note: this may be really out of order when we avoid the queue...  We
-  // have the ones we know didn't make it immediately, and the ones which
-  // time out eventually.  Need to sort that out.
+  // TODO(austin): record success of preceding messages, and log to disk if we
+  // don't find this in the list.
 }
 
 void ChannelState::AddPeer(const Connection *connection, int node_index,
@@ -329,7 +297,6 @@
 
     if (configuration::ChannelIsSendableOnNode(channel, event_loop_->node()) &&
         channel->has_destination_nodes()) {
-
       bool any_reliable = false;
       for (const Connection *connection : *channel->destination_nodes()) {
         if (connection->time_to_live() == 0) {
@@ -432,6 +399,9 @@
 
 void MessageBridgeServer::MessageReceived() {
   aos::unique_c_ptr<Message> message = server_.Read();
+  if (!message) {
+    return;
+  }
 
   if (message->message_type == Message::kNotification) {
     const union sctp_notification *snp =
@@ -472,6 +442,10 @@
   if (message->header.rcvinfo.rcv_sid == kConnectStream()) {
     // Control channel!
     const Connect *connect = flatbuffers::GetRoot<Connect>(message->data());
+    {
+      flatbuffers::Verifier verifier(message->data(), message->size);
+      CHECK(connect->Verify(verifier));
+    }
     VLOG(1) << FlatbufferToJson(connect);
 
     // Account for the control channel and delivery times channel.
@@ -516,6 +490,10 @@
     // Message delivery
     const logger::MessageHeader *message_header =
         flatbuffers::GetRoot<logger::MessageHeader>(message->data());
+    {
+      flatbuffers::Verifier verifier(message->data(), message->size);
+      CHECK(message_header->Verify(verifier));
+    }
 
     CHECK_LT(message_header->channel_index(), channels_.size());
     CHECK_NOTNULL(channels_[message_header->channel_index()])
diff --git a/aos/network/message_bridge_server_lib.h b/aos/network/message_bridge_server_lib.h
index 7ff4e3a..db6e6d9 100644
--- a/aos/network/message_bridge_server_lib.h
+++ b/aos/network/message_bridge_server_lib.h
@@ -88,18 +88,12 @@
                       uint32_t partial_deliveries,
                       MessageBridgeServerStatus *server_status);
 
-  // Handles (by consuming) failure to deliver a message.
-  void HandleFailure(
-      SizePrefixedFlatbufferDetachedBuffer<RemoteData> &&message);
-
  private:
   const int channel_index_;
   const Channel *const channel_;
 
   std::vector<Peer> peers_;
 
-  std::deque<SizePrefixedFlatbufferDetachedBuffer<RemoteData>> sent_messages_;
-
   // A fetcher to use to send the last message when a node connects and is
   // reliable.
   std::unique_ptr<aos::RawFetcher> last_message_fetcher_;
diff --git a/aos/network/message_bridge_test.cc b/aos/network/message_bridge_test.cc
index 8222760..74d22c2 100644
--- a/aos/network/message_bridge_test.cc
+++ b/aos/network/message_bridge_test.cc
@@ -679,10 +679,12 @@
 
   // Make sure the offset in one direction is less than a second.
   EXPECT_GT(
-      client_statistics_fetcher->connections()->Get(0)->monotonic_offset(), 0);
+      client_statistics_fetcher->connections()->Get(0)->monotonic_offset(), 0)
+      << aos::FlatbufferToJson(client_statistics_fetcher.get());
   EXPECT_LT(
       client_statistics_fetcher->connections()->Get(0)->monotonic_offset(),
-      1000000000);
+      1000000000)
+      << aos::FlatbufferToJson(client_statistics_fetcher.get());
 
   EXPECT_GE(pi1_server_statistics_count, 2);
   EXPECT_GE(pi2_server_statistics_count, 2);
diff --git a/aos/network/sctp_client.cc b/aos/network/sctp_client.cc
index 9e77a84..33115be 100644
--- a/aos/network/sctp_client.cc
+++ b/aos/network/sctp_client.cc
@@ -19,115 +19,30 @@
 SctpClient::SctpClient(std::string_view remote_host, int remote_port,
                        int streams, std::string_view local_host, int local_port)
     : sockaddr_remote_(ResolveSocket(remote_host, remote_port)),
-      sockaddr_local_(ResolveSocket(local_host, local_port)),
-      fd_(socket(sockaddr_local_.ss_family, SOCK_SEQPACKET, IPPROTO_SCTP)) {
-  LOG(INFO) << "socket(" << Family(sockaddr_local_)
-            << ", SOCK_SEQPACKET, IPPROTOSCTP) = " << fd_;
-  PCHECK(fd_ != -1);
-
-  {
-    // Per https://tools.ietf.org/html/rfc6458
-    // Setting this to !0 allows event notifications to be interleaved
-    // with data if enabled, and would have to be handled in the code.
-    // Enabling interleaving would only matter during congestion, which
-    // typically only happens during application startup.
-    int interleaving = 0;
-    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_FRAGMENT_INTERLEAVE,
-                      &interleaving, sizeof(interleaving)) == 0);
-  }
+      sockaddr_local_(ResolveSocket(local_host, local_port)) {
+  sctp_.OpenSocket(sockaddr_local_);
 
   {
     struct sctp_initmsg initmsg;
     memset(&initmsg, 0, sizeof(struct sctp_initmsg));
     initmsg.sinit_num_ostreams = streams;
     initmsg.sinit_max_instreams = streams;
-    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_INITMSG, &initmsg,
+    PCHECK(setsockopt(fd(), IPPROTO_SCTP, SCTP_INITMSG, &initmsg,
                       sizeof(struct sctp_initmsg)) == 0);
   }
 
   {
-    int on = 1;
-    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_RECVRCVINFO, &on, sizeof(int)) ==
-           0);
-  }
-  {
     // Servers send promptly.  Clients don't.
     // TODO(austin): Revisit this assumption when we have time sync.
     int on = 0;
-    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_NODELAY, &on, sizeof(int)) == 0);
+    PCHECK(setsockopt(fd(), IPPROTO_SCTP, SCTP_NODELAY, &on, sizeof(int)) == 0);
   }
 
-  {
-    // TODO(austin): This is the old style registration...  But, the sctp
-    // stack out in the wild for linux is old and primitive.
-    struct sctp_event_subscribe subscribe;
-    memset(&subscribe, 0, sizeof(subscribe));
-    subscribe.sctp_association_event = 1;
-    subscribe.sctp_stream_change_event = 1;
-    PCHECK(setsockopt(fd_, SOL_SCTP, SCTP_EVENTS, (char *)&subscribe,
-                      sizeof(subscribe)) == 0);
-  }
-
-  PCHECK(bind(fd_, (struct sockaddr *)&sockaddr_local_,
+  PCHECK(bind(fd(), (struct sockaddr *)&sockaddr_local_,
               sockaddr_local_.ss_family == AF_INET6
                   ? sizeof(struct sockaddr_in6)
                   : sizeof(struct sockaddr_in)) == 0);
-  VLOG(1) << "bind(" << fd_ << ", " << Address(sockaddr_local_) << ")";
-}
-
-aos::unique_c_ptr<Message> SctpClient::Read() {
-  return ReadSctpMessage(fd_, max_size_);
-}
-
-bool SctpClient::Send(int stream, std::string_view data, int time_to_live) {
-  struct iovec iov;
-  iov.iov_base = const_cast<char *>(data.data());
-  iov.iov_len = data.size();
-
-  struct msghdr outmsg;
-  // Target to send to.
-  outmsg.msg_name = &sockaddr_remote_;
-  outmsg.msg_namelen = sizeof(struct sockaddr_storage);
-  VLOG(1) << "Sending to " << Address(sockaddr_remote_);
-
-  // Data to send.
-  outmsg.msg_iov = &iov;
-  outmsg.msg_iovlen = 1;
-
-  // Build up the sndinfo message.
-  char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
-  outmsg.msg_control = outcmsg;
-  outmsg.msg_controllen = sizeof(outcmsg);
-  outmsg.msg_flags = 0;
-
-  struct cmsghdr *cmsg = CMSG_FIRSTHDR(&outmsg);
-  cmsg->cmsg_level = IPPROTO_SCTP;
-  cmsg->cmsg_type = SCTP_SNDRCV;
-  cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
-
-  outmsg.msg_controllen = cmsg->cmsg_len;
-  struct sctp_sndrcvinfo *sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
-  memset(sinfo, 0, sizeof(struct sctp_sndrcvinfo));
-  sinfo->sinfo_ppid = rand();
-  sinfo->sinfo_stream = stream;
-  sinfo->sinfo_context = 19;
-  sinfo->sinfo_flags = 0;
-  sinfo->sinfo_timetolive = time_to_live;
-
-  // And send.
-  const ssize_t size = sendmsg(fd_, &outmsg, MSG_NOSIGNAL | MSG_DONTWAIT);
-  if (size == -1) {
-    if (errno != EPIPE && errno != EAGAIN && errno != ESHUTDOWN) {
-      PCHECK(size == static_cast<ssize_t>(data.size()));
-    } else {
-      return false;
-    }
-  } else {
-    CHECK_EQ(static_cast<ssize_t>(data.size()), size);
-  }
-
-  VLOG(1) << "Sent " << data.size();
-  return true;
+  VLOG(1) << "bind(" << fd() << ", " << Address(sockaddr_local_) << ")";
 }
 
 void SctpClient::LogSctpStatus(sctp_assoc_t assoc_id) {
diff --git a/aos/network/sctp_client.h b/aos/network/sctp_client.h
index 806026c..9356612 100644
--- a/aos/network/sctp_client.h
+++ b/aos/network/sctp_client.h
@@ -18,18 +18,18 @@
   SctpClient(std::string_view remote_host, int remote_port, int streams,
              std::string_view local_host = "0.0.0.0", int local_port = 9971);
 
-  ~SctpClient() {
-    LOG(INFO) << "close(" << fd_ << ")";
-    PCHECK(close(fd_) == 0);
-  }
+  ~SctpClient() {}
 
   // Receives the next packet from the remote.
-  aos::unique_c_ptr<Message> Read();
+  aos::unique_c_ptr<Message> Read() { return sctp_.ReadMessage(); }
 
   // Sends a block of data on a stream with a TTL.
-  bool Send(int stream, std::string_view data, int time_to_live);
+  // TODO(austin): time_to_live should be a chrono::duration
+  bool Send(int stream, std::string_view data, int time_to_live) {
+    return sctp_.SendMessage(stream, data, time_to_live, sockaddr_remote_, 0);
+  }
 
-  int fd() { return fd_; }
+  int fd() { return sctp_.fd(); }
 
   // Enables the priority scheduler.  This is a SCTP feature which lets us
   // configure the priority per stream so that higher priority packets don't get
@@ -43,26 +43,12 @@
 
   void LogSctpStatus(sctp_assoc_t assoc_id);
 
-  void SetMaxSize(size_t max_size) {
-    max_size_ = max_size;
-    // Have the kernel give us a factor of 10 more.  This lets us have more than
-    // one full sized packet in flight.
-    max_size = max_size * 10;
-
-    CHECK_GE(ReadRMemMax(), max_size);
-    CHECK_GE(ReadWMemMax(), max_size);
-    PCHECK(setsockopt(fd_, SOL_SOCKET, SO_RCVBUF, &max_size,
-                      sizeof(max_size)) == 0);
-    PCHECK(setsockopt(fd_, SOL_SOCKET, SO_SNDBUF, &max_size,
-                      sizeof(max_size)) == 0);
-  }
+  void SetMaxSize(size_t max_size) { sctp_.SetMaxSize(max_size); }
 
  private:
   struct sockaddr_storage sockaddr_remote_;
   struct sockaddr_storage sockaddr_local_;
-  int fd_;
-
-  size_t max_size_ = 1000;
+  SctpReadWrite sctp_;
 };
 
 }  // namespace message_bridge
diff --git a/aos/network/sctp_lib.cc b/aos/network/sctp_lib.cc
index b522851..4651d82 100644
--- a/aos/network/sctp_lib.cc
+++ b/aos/network/sctp_lib.cc
@@ -8,6 +8,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <algorithm>
 #include <string_view>
 
 #include "aos/util/file.h"
@@ -165,8 +166,13 @@
   status.sstat_assoc_id = assoc_id;
 
   socklen_t size = sizeof(status);
-  PCHECK(getsockopt(fd, SOL_SCTP, SCTP_STATUS,
-                    reinterpret_cast<void *>(&status), &size) == 0);
+  const int result = getsockopt(fd, SOL_SCTP, SCTP_STATUS,
+                                reinterpret_cast<void *>(&status), &size);
+  if (result == -1 && errno == EINVAL) {
+    LOG(INFO) << "sctp_status) not associated";
+    return;
+  }
+  PCHECK(result == 0);
 
   LOG(INFO) << "sctp_status) sstat_assoc_id:" << status.sstat_assoc_id
             << " sstat_state:" << status.sstat_state
@@ -180,86 +186,320 @@
             << " sstat_primary.spinfo_rto:" << status.sstat_primary.spinfo_rto;
 }
 
-aos::unique_c_ptr<Message> ReadSctpMessage(int fd, size_t max_size) {
-  char incmsg[CMSG_SPACE(sizeof(_sctp_cmsg_data_t))];
+void SctpReadWrite::OpenSocket(const struct sockaddr_storage &sockaddr_local) {
+  fd_ = socket(sockaddr_local.ss_family, SOCK_SEQPACKET, IPPROTO_SCTP);
+  PCHECK(fd_ != -1);
+  LOG(INFO) << "socket(" << Family(sockaddr_local)
+            << ", SOCK_SEQPACKET, IPPROTOSCTP) = " << fd_;
+  {
+    // Per https://tools.ietf.org/html/rfc6458
+    // Setting this to !0 allows event notifications to be interleaved
+    // with data if enabled. This typically only matters during congestion.
+    // However, Linux seems to interleave under memory pressure regardless of
+    // this being enabled, so we have to handle it in the code anyways, so might
+    // as well turn it on all the time.
+    // TODO(Brian): Change this to 2 once we have kernels that support it, and
+    // also address the TODO in ProcessNotification to match on all the
+    // necessary fields.
+    int interleaving = 1;
+    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_FRAGMENT_INTERLEAVE,
+                      &interleaving, sizeof(interleaving)) == 0);
+  }
+  {
+    // Enable recvinfo when a packet arrives.
+    int on = 1;
+    PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_RECVRCVINFO, &on, sizeof(int)) ==
+           0);
+  }
+
+  {
+    // TODO(austin): This is the old style registration...  But, the sctp
+    // stack out in the wild for linux is old and primitive.
+    struct sctp_event_subscribe subscribe;
+    memset(&subscribe, 0, sizeof(subscribe));
+    subscribe.sctp_association_event = 1;
+    subscribe.sctp_stream_change_event = 1;
+    subscribe.sctp_partial_delivery_event = 1;
+    PCHECK(setsockopt(fd(), SOL_SCTP, SCTP_EVENTS, (char *)&subscribe,
+                      sizeof(subscribe)) == 0);
+  }
+
+  DoSetMaxSize();
+}
+
+bool SctpReadWrite::SendMessage(
+    int stream, std::string_view data, int time_to_live,
+    std::optional<struct sockaddr_storage> sockaddr_remote,
+    sctp_assoc_t snd_assoc_id) {
+  CHECK(fd_ != -1);
   struct iovec iov;
-  struct msghdr inmessage;
+  iov.iov_base = const_cast<char *>(data.data());
+  iov.iov_len = data.size();
 
-  aos::unique_c_ptr<Message> result(
-      reinterpret_cast<Message *>(malloc(sizeof(Message) + max_size + 1)));
-  result->size = 0;
+  // Use the assoc_id for the destination instead of the msg_name.
+  struct msghdr outmsg;
+  if (sockaddr_remote) {
+    outmsg.msg_name = &*sockaddr_remote;
+    outmsg.msg_namelen = sizeof(*sockaddr_remote);
+    VLOG(1) << "Sending to " << Address(*sockaddr_remote);
+  } else {
+    outmsg.msg_namelen = 0;
+  }
 
-  int count = 0;
-  int last_flags = 0;
-  for (count = 0; !(last_flags & MSG_EOR); count++) {
+  // Data to send.
+  outmsg.msg_iov = &iov;
+  outmsg.msg_iovlen = 1;
+
+  // Build up the sndinfo message.
+  char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+  outmsg.msg_control = outcmsg;
+  outmsg.msg_controllen = sizeof(outcmsg);
+  outmsg.msg_flags = 0;
+
+  struct cmsghdr *cmsg = CMSG_FIRSTHDR(&outmsg);
+  cmsg->cmsg_level = IPPROTO_SCTP;
+  cmsg->cmsg_type = SCTP_SNDRCV;
+  cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+
+  struct sctp_sndrcvinfo *sinfo =
+      reinterpret_cast<struct sctp_sndrcvinfo *>(CMSG_DATA(cmsg));
+  memset(sinfo, 0, sizeof(struct sctp_sndrcvinfo));
+  sinfo->sinfo_ppid = ++send_ppid_;
+  sinfo->sinfo_stream = stream;
+  sinfo->sinfo_flags = 0;
+  sinfo->sinfo_assoc_id = snd_assoc_id;
+  sinfo->sinfo_timetolive = time_to_live;
+
+  // And send.
+  const ssize_t size = sendmsg(fd_, &outmsg, MSG_NOSIGNAL | MSG_DONTWAIT);
+  if (size == -1) {
+    if (errno == EPIPE || errno == EAGAIN || errno == ESHUTDOWN ||
+        errno == EINTR) {
+      return false;
+    }
+    PLOG(FATAL) << "sendmsg on sctp socket failed";
+    return false;
+  }
+  CHECK_EQ(static_cast<ssize_t>(data.size()), size);
+  VLOG(1) << "Sent " << data.size();
+  return true;
+}
+
+// We read each fragment into a fresh Message, because most of them won't be
+// fragmented. If we do end up with a fragment, then we copy the data out of it.
+aos::unique_c_ptr<Message> SctpReadWrite::ReadMessage() {
+  CHECK(fd_ != -1);
+
+  while (true) {
+    aos::unique_c_ptr<Message> result(
+        reinterpret_cast<Message *>(malloc(sizeof(Message) + max_size_ + 1)));
+
+    struct msghdr inmessage;
     memset(&inmessage, 0, sizeof(struct msghdr));
 
-    iov.iov_len = max_size + 1 - result->size;
-    iov.iov_base = result->mutable_data() + result->size;
+    struct iovec iov;
+    iov.iov_len = max_size_ + 1;
+    iov.iov_base = result->mutable_data();
 
     inmessage.msg_iov = &iov;
     inmessage.msg_iovlen = 1;
 
+    char incmsg[CMSG_SPACE(sizeof(_sctp_cmsg_data_t))];
     inmessage.msg_control = incmsg;
     inmessage.msg_controllen = sizeof(incmsg);
 
     inmessage.msg_namelen = sizeof(struct sockaddr_storage);
     inmessage.msg_name = &result->sin;
 
-    ssize_t size;
-    PCHECK((size = recvmsg(fd, &inmessage, 0)) > 0);
-
-    if (count > 0) {
-      VLOG(1) << "Count: " << count;
-      VLOG(1) << "Last msg_flags: " << last_flags;
-      VLOG(1) << "msg_flags: " << inmessage.msg_flags;
-      VLOG(1) << "Current size: " << result->size;
-      VLOG(1) << "Received size: " << size;
-      CHECK_EQ(MSG_NOTIFICATION & inmessage.msg_flags, MSG_NOTIFICATION & last_flags);
-    }
-
-    result->size += size;
-    last_flags = inmessage.msg_flags;
-
-    for (struct cmsghdr *scmsg = CMSG_FIRSTHDR(&inmessage); scmsg != NULL;
-         scmsg = CMSG_NXTHDR(&inmessage, scmsg)) {
-      switch (scmsg->cmsg_type) {
-        case SCTP_RCVINFO: {
-          struct sctp_rcvinfo *data = reinterpret_cast<struct sctp_rcvinfo *>(CMSG_DATA(scmsg));
-          if (count > 0) {
-            VLOG(1) << "Got sctp_rcvinfo on continued packet";
-            CHECK_EQ(result->header.rcvinfo.rcv_sid, data->rcv_sid);
-            CHECK_EQ(result->header.rcvinfo.rcv_ssn, data->rcv_ssn);
-            CHECK_EQ(result->header.rcvinfo.rcv_ppid, data->rcv_ppid);
-            CHECK_EQ(result->header.rcvinfo.rcv_assoc_id, data->rcv_assoc_id);
-          }
-          result->header.rcvinfo = *data;
-        } break;
-        default:
-          LOG(INFO) << "\tUnknown type: " << scmsg->cmsg_type;
-          break;
+    const ssize_t size = recvmsg(fd_, &inmessage, MSG_DONTWAIT);
+    if (size == -1) {
+      if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) {
+        // These are all non-fatal failures indicating we should retry later.
+        return nullptr;
       }
+      PLOG(FATAL) << "recvmsg on sctp socket " << fd_ << " failed";
     }
 
-    CHECK_NE(inmessage.msg_flags & MSG_CTRUNC, MSG_CTRUNC)
+    CHECK(!(inmessage.msg_flags & MSG_CTRUNC))
         << ": Control message truncated.";
 
-    CHECK_LE(result->size, max_size) << ": Message overflowed buffer on stream "
-                                     << result->header.rcvinfo.rcv_sid << ".";
-  }
+    CHECK_LE(size, static_cast<ssize_t>(max_size_))
+        << ": Message overflowed buffer on stream "
+        << result->header.rcvinfo.rcv_sid << ".";
 
-  result->partial_deliveries = count - 1;
-  if (count > 1) {
-    VLOG(1) << "Final count: " << count;
-    VLOG(1) << "Final size: " << result->size;
-  }
+    result->size = size;
+    if (MSG_NOTIFICATION & inmessage.msg_flags) {
+      result->message_type = Message::kNotification;
+    } else {
+      result->message_type = Message::kMessage;
+    }
+    result->partial_deliveries = 0;
 
-  if ((MSG_NOTIFICATION & inmessage.msg_flags)) {
-    result->message_type = Message::kNotification;
-  } else {
-    result->message_type = Message::kMessage;
+    {
+      bool found_rcvinfo = false;
+      for (struct cmsghdr *scmsg = CMSG_FIRSTHDR(&inmessage); scmsg != NULL;
+           scmsg = CMSG_NXTHDR(&inmessage, scmsg)) {
+        switch (scmsg->cmsg_type) {
+          case SCTP_RCVINFO: {
+            CHECK(!found_rcvinfo);
+            found_rcvinfo = true;
+            result->header.rcvinfo =
+                *reinterpret_cast<struct sctp_rcvinfo *>(CMSG_DATA(scmsg));
+          } break;
+          default:
+            LOG(INFO) << "\tUnknown type: " << scmsg->cmsg_type;
+            break;
+        }
+      }
+      CHECK_EQ(found_rcvinfo, result->message_type == Message::kMessage)
+          << ": Failed to find a SCTP_RCVINFO cmsghdr. flags: "
+          << inmessage.msg_flags;
+    }
+    if (result->message_type == Message::kNotification) {
+      // Notifications are never fragmented, just return it now.
+      CHECK(inmessage.msg_flags & MSG_EOR)
+          << ": Notifications should never be big enough to fragment";
+      if (ProcessNotification(result.get())) {
+        // We handled this notification internally, so don't pass it on.
+        return nullptr;
+      }
+      return result;
+    }
+
+    auto partial_message_iterator =
+        std::find_if(partial_messages_.begin(), partial_messages_.end(),
+                     [&result](const aos::unique_c_ptr<Message> &candidate) {
+                       return result->header.rcvinfo.rcv_sid ==
+                                  candidate->header.rcvinfo.rcv_sid &&
+                              result->header.rcvinfo.rcv_ssn ==
+                                  candidate->header.rcvinfo.rcv_ssn &&
+                              result->header.rcvinfo.rcv_assoc_id ==
+                                  candidate->header.rcvinfo.rcv_assoc_id;
+                     });
+    if (partial_message_iterator != partial_messages_.end()) {
+      const aos::unique_c_ptr<Message> &partial_message =
+          *partial_message_iterator;
+      // Verify it's really part of the same message.
+      CHECK_EQ(partial_message->message_type, result->message_type)
+          << ": for " << result->header.rcvinfo.rcv_sid << ","
+          << result->header.rcvinfo.rcv_ssn << ","
+          << result->header.rcvinfo.rcv_assoc_id;
+      CHECK_EQ(partial_message->header.rcvinfo.rcv_ppid,
+               result->header.rcvinfo.rcv_ppid)
+          << ": for " << result->header.rcvinfo.rcv_sid << ","
+          << result->header.rcvinfo.rcv_ssn << ","
+          << result->header.rcvinfo.rcv_assoc_id;
+
+      // Now copy the data over and update the size.
+      CHECK_LE(partial_message->size + result->size, max_size_)
+          << ": Assembled fragments overflowed buffer on stream "
+          << result->header.rcvinfo.rcv_sid << ".";
+      memcpy(partial_message->mutable_data() + partial_message->size,
+             result->data(), result->size);
+      ++partial_message->partial_deliveries;
+      VLOG(1) << "Merged fragment of " << result->size << " after "
+              << partial_message->size << ", had "
+              << partial_message->partial_deliveries
+              << ", for: " << result->header.rcvinfo.rcv_sid << ","
+              << result->header.rcvinfo.rcv_ssn << ","
+              << result->header.rcvinfo.rcv_assoc_id;
+      partial_message->size += result->size;
+      result.reset();
+    }
+
+    if (inmessage.msg_flags & MSG_EOR) {
+      // This is the last fragment, so we have something to return.
+      if (partial_message_iterator != partial_messages_.end()) {
+        // It was already merged into the message in the list, so now we pull
+        // that out of the list and return it.
+        CHECK(!result);
+        result = std::move(*partial_message_iterator);
+        partial_messages_.erase(partial_message_iterator);
+        VLOG(1) << "Final count: " << (result->partial_deliveries + 1)
+                << ", size: " << result->size
+                << ", for: " << result->header.rcvinfo.rcv_sid << ","
+                << result->header.rcvinfo.rcv_ssn << ","
+                << result->header.rcvinfo.rcv_assoc_id;
+      }
+      CHECK(result);
+      return result;
+    }
+    if (partial_message_iterator == partial_messages_.end()) {
+      VLOG(1) << "Starting fragment for: " << result->header.rcvinfo.rcv_sid
+              << "," << result->header.rcvinfo.rcv_ssn << ","
+              << result->header.rcvinfo.rcv_assoc_id;
+      // Need to record this as the first fragment.
+      partial_messages_.emplace_back(std::move(result));
+    }
   }
-  return result;
+}
+
+void SctpReadWrite::CloseSocket() {
+  if (fd_ == -1) {
+    return;
+  }
+  LOG(INFO) << "close(" << fd_ << ")";
+  PCHECK(close(fd_) == 0);
+  fd_ = -1;
+}
+
+void SctpReadWrite::DoSetMaxSize() {
+  // Have the kernel give us a factor of 10 more.  This lets us have more than
+  // one full sized packet in flight.
+  size_t max_size = max_size_ * 10;
+
+  CHECK_GE(ReadRMemMax(), max_size)
+      << "rmem_max is too low. To increase rmem_max temporarily, do sysctl "
+         "-w net.core.rmem_max="
+      << max_size;
+  CHECK_GE(ReadWMemMax(), max_size)
+      << "wmem_max is too low. To increase wmem_max temporarily, do sysctl "
+         "-w net.core.wmem_max="
+      << max_size;
+  PCHECK(setsockopt(fd(), SOL_SOCKET, SO_RCVBUF, &max_size, sizeof(max_size)) ==
+         0);
+  PCHECK(setsockopt(fd(), SOL_SOCKET, SO_SNDBUF, &max_size, sizeof(max_size)) ==
+         0);
+}
+
+bool SctpReadWrite::ProcessNotification(const Message *message) {
+  const union sctp_notification *const snp =
+      reinterpret_cast<const union sctp_notification *>(message->data());
+  switch (snp->sn_header.sn_type) {
+    case SCTP_PARTIAL_DELIVERY_EVENT: {
+      const struct sctp_pdapi_event *const partial_delivery =
+          &snp->sn_pdapi_event;
+      CHECK_EQ(partial_delivery->pdapi_length, sizeof(*partial_delivery))
+          << ": Kernel's SCTP code is not a version we support";
+      switch (partial_delivery->pdapi_indication) {
+        case SCTP_PARTIAL_DELIVERY_ABORTED: {
+          const auto iterator = std::find_if(
+              partial_messages_.begin(), partial_messages_.end(),
+              [partial_delivery](const aos::unique_c_ptr<Message> &candidate) {
+                // TODO(Brian): Once we have new enough userpace headers, for
+                // kernels that support level-2 interleaving, we'll need to add
+                // this:
+                //   candidate->header.rcvinfo.rcv_sid ==
+                //     partial_delivery->pdapi_stream &&
+                //   candidate->header.rcvinfo.rcv_ssn ==
+                //     partial_delivery->pdapi_seq &&
+                return candidate->header.rcvinfo.rcv_assoc_id ==
+                       partial_delivery->pdapi_assoc_id;
+              });
+          CHECK(iterator != partial_messages_.end())
+              << ": Got out of sync with the kernel for "
+              << partial_delivery->pdapi_assoc_id;
+          VLOG(1) << "Pruning partial delivery for "
+                  << iterator->get()->header.rcvinfo.rcv_sid << ","
+                  << iterator->get()->header.rcvinfo.rcv_ssn << ","
+                  << iterator->get()->header.rcvinfo.rcv_assoc_id;
+          partial_messages_.erase(iterator);
+        }
+          return true;
+      }
+    } break;
+  }
+  return false;
 }
 
 void Message::LogRcvInfo() const {
diff --git a/aos/network/sctp_lib.h b/aos/network/sctp_lib.h
index 265d1f5..6b40600 100644
--- a/aos/network/sctp_lib.h
+++ b/aos/network/sctp_lib.h
@@ -5,8 +5,10 @@
 #include <netinet/sctp.h>
 
 #include <memory>
+#include <optional>
 #include <string>
 #include <string_view>
+#include <vector>
 
 #include "aos/unique_malloc_ptr.h"
 #include "gflags/gflags.h"
@@ -71,8 +73,54 @@
 // Gets and logs the contents of the sctp_status message.
 void LogSctpStatus(int fd, sctp_assoc_t assoc_id);
 
-// Read and allocate a message.
-aos::unique_c_ptr<Message> ReadSctpMessage(int fd, size_t max_size);
+// Manages reading and writing SCTP messages.
+class SctpReadWrite {
+ public:
+  SctpReadWrite() = default;
+  ~SctpReadWrite() { CloseSocket(); }
+
+  // Opens a new socket.
+  void OpenSocket(const struct sockaddr_storage &sockaddr_local);
+
+  // Sends a message to the kernel.
+  // Returns true for success. Will not send a partial message on failure.
+  bool SendMessage(int stream, std::string_view data, int time_to_live,
+                   std::optional<struct sockaddr_storage> sockaddr_remote,
+                   sctp_assoc_t snd_assoc_id);
+
+  // Reads from the kernel until a complete message is received or it blocks.
+  // Returns nullptr if the kernel blocks before returning a complete message.
+  aos::unique_c_ptr<Message> ReadMessage();
+
+  int fd() const { return fd_; }
+
+  void SetMaxSize(size_t max_size) {
+    CHECK(partial_messages_.empty())
+        << ": May not update size with queued fragments because we do not "
+           "track individual message sizes";
+    max_size_ = max_size;
+    if (fd_ != -1) {
+      DoSetMaxSize();
+    }
+  }
+
+ private:
+  void CloseSocket();
+  void DoSetMaxSize();
+
+  // Examines a notification message for ones we handle here.
+  // Returns true if the notification was handled by this class.
+  bool ProcessNotification(const Message *message);
+
+  int fd_ = -1;
+
+  // We use this as a unique identifier that just increments for each message.
+  uint32_t send_ppid_ = 0;
+
+  size_t max_size_ = 1000;
+
+  std::vector<aos::unique_c_ptr<Message>> partial_messages_;
+};
 
 // Returns the max network buffer available for reading for a socket.
 size_t ReadRMemMax();
diff --git a/aos/network/sctp_server.cc b/aos/network/sctp_server.cc
index 47a5719..894a1f1 100644
--- a/aos/network/sctp_server.cc
+++ b/aos/network/sctp_server.cc
@@ -23,72 +23,41 @@
 SctpServer::SctpServer(std::string_view local_host, int local_port)
     : sockaddr_local_(ResolveSocket(local_host, local_port)) {
   while (true) {
-    fd_ = socket(sockaddr_local_.ss_family, SOCK_SEQPACKET, IPPROTO_SCTP);
-    LOG(INFO) << "socket(" << Family(sockaddr_local_)
-              << ", SOCK_SEQPACKET, IPPROTOSCTP) = " << fd_;
-    PCHECK(fd_ != -1);
+    sctp_.OpenSocket(sockaddr_local_);
 
     {
-      struct sctp_event_subscribe subscribe;
-      memset(&subscribe, 0, sizeof(subscribe));
-      subscribe.sctp_association_event = 1;
-      subscribe.sctp_send_failure_event = 1;
-      subscribe.sctp_partial_delivery_event = 1;
-
-      PCHECK(setsockopt(fd_, SOL_SCTP, SCTP_EVENTS, (char *)&subscribe,
-                        sizeof(subscribe)) == 0);
-    }
-    {
-      // Enable recvinfo when a packet arrives.
-      int on = 1;
-      PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_RECVRCVINFO, &on,
-                        sizeof(int)) == 0);
-    }
-    {
-      // Per https://tools.ietf.org/html/rfc6458
-      // Setting this to !0 allows event notifications to be interleaved
-      // with data if enabled, and would have to be handled in the code.
-      // Enabling interleaving would only matter during congestion, which
-      // typically only happens during application startup.
-      int interleaving = 0;
-      PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_FRAGMENT_INTERLEAVE,
-                        &interleaving, sizeof(interleaving)) == 0);
-    }
-    {
       // Turn off the NAGLE algorithm.
       int on = 1;
-      PCHECK(setsockopt(fd_, IPPROTO_SCTP, SCTP_NODELAY, &on, sizeof(int)) ==
+      PCHECK(setsockopt(fd(), IPPROTO_SCTP, SCTP_NODELAY, &on, sizeof(int)) ==
              0);
     }
 
     {
       int on = 1;
-      PCHECK(setsockopt(fd_, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int)) == 0);
+      LOG(INFO) << "setsockopt(" << fd()
+                << ", SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int)";
+      PCHECK(setsockopt(fd(), SOL_SOCKET, SO_REUSEADDR, &on, sizeof(int)) == 0);
     }
 
     // And go!
-    if (bind(fd_, (struct sockaddr *)&sockaddr_local_,
+    if (bind(fd(), (struct sockaddr *)&sockaddr_local_,
              sockaddr_local_.ss_family == AF_INET6
                  ? sizeof(struct sockaddr_in6)
                  : sizeof(struct sockaddr_in)) != 0) {
       PLOG(ERROR) << "Failed to bind, retrying";
-      close(fd_);
+      close(fd());
       std::this_thread::sleep_for(std::chrono::seconds(5));
       continue;
     }
-    LOG(INFO) << "bind(" << fd_ << ", " << Address(sockaddr_local_) << ")";
+    LOG(INFO) << "bind(" << fd() << ", " << Address(sockaddr_local_) << ")";
 
-    PCHECK(listen(fd_, 100) == 0);
+    PCHECK(listen(fd(), 100) == 0);
 
     SetMaxSize(1000);
     break;
   }
 }
 
-aos::unique_c_ptr<Message> SctpServer::Read() {
-  return ReadSctpMessage(fd_, max_size_);
-}
-
 bool SctpServer::Abort(sctp_assoc_t snd_assoc_id) {
   // Use the assoc_id for the destination instead of the msg_name.
   struct msghdr outmsg;
@@ -109,13 +78,12 @@
 
   struct sctp_sndrcvinfo *sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
   memset(sinfo, 0, sizeof(struct sctp_sndrcvinfo));
-  sinfo->sinfo_ppid = ++ppid_;
   sinfo->sinfo_stream = 0;
   sinfo->sinfo_flags = SCTP_ABORT;
   sinfo->sinfo_assoc_id = snd_assoc_id;
 
   // And send.
-  const ssize_t size = sendmsg(fd_, &outmsg, MSG_NOSIGNAL | MSG_DONTWAIT);
+  const ssize_t size = sendmsg(fd(), &outmsg, MSG_NOSIGNAL | MSG_DONTWAIT);
   if (size == -1) {
     if (errno == EPIPE || errno == EAGAIN || errno == ESHUTDOWN) {
       return false;
@@ -127,53 +95,6 @@
   }
 }
 
-bool SctpServer::Send(std::string_view data, sctp_assoc_t snd_assoc_id,
-                      int stream, int timetolive) {
-  struct iovec iov;
-  iov.iov_base = const_cast<char *>(data.data());
-  iov.iov_len = data.size();
-
-  // Use the assoc_id for the destination instead of the msg_name.
-  struct msghdr outmsg;
-  outmsg.msg_namelen = 0;
-
-  // Data to send.
-  outmsg.msg_iov = &iov;
-  outmsg.msg_iovlen = 1;
-
-  // Build up the sndinfo message.
-  char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
-  outmsg.msg_control = outcmsg;
-  outmsg.msg_controllen = CMSG_SPACE(sizeof(struct sctp_sndrcvinfo));
-  outmsg.msg_flags = 0;
-
-  struct cmsghdr *cmsg = CMSG_FIRSTHDR(&outmsg);
-  cmsg->cmsg_level = IPPROTO_SCTP;
-  cmsg->cmsg_type = SCTP_SNDRCV;
-  cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
-
-  struct sctp_sndrcvinfo *sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
-  memset(sinfo, 0, sizeof(struct sctp_sndrcvinfo));
-  sinfo->sinfo_ppid = ++ppid_;
-  sinfo->sinfo_stream = stream;
-  sinfo->sinfo_flags = 0;
-  sinfo->sinfo_assoc_id = snd_assoc_id;
-  sinfo->sinfo_timetolive = timetolive;
-
-  // And send.
-  const ssize_t size = sendmsg(fd_, &outmsg, MSG_NOSIGNAL | MSG_DONTWAIT);
-  if (size == -1) {
-    if (errno == EPIPE || errno == EAGAIN || errno == ESHUTDOWN) {
-      return false;
-    }
-    PCHECK(size == static_cast<ssize_t>(data.size()));
-    return false;
-  } else {
-    CHECK_EQ(static_cast<ssize_t>(data.size()), size);
-    return true;
-  }
-}
-
 void SctpServer::SetPriorityScheduler(sctp_assoc_t assoc_id) {
   struct sctp_assoc_value scheduler;
   memset(&scheduler, 0, sizeof(scheduler));
diff --git a/aos/network/sctp_server.h b/aos/network/sctp_server.h
index d995c55..c6737d6 100644
--- a/aos/network/sctp_server.h
+++ b/aos/network/sctp_server.h
@@ -24,23 +24,23 @@
  public:
   SctpServer(std::string_view local_host = "0.0.0.0", int local_port = 9971);
 
-  ~SctpServer() {
-    LOG(INFO) << "close(" << fd_ << ")";
-    PCHECK(close(fd_) == 0);
-  }
+  ~SctpServer() {}
 
   // Receives the next packet from the remote.
-  aos::unique_c_ptr<Message> Read();
+  aos::unique_c_ptr<Message> Read() { return sctp_.ReadMessage(); }
 
   // Sends a block of data to a client on a stream with a TTL.  Returns true on
   // success.
   bool Send(std::string_view data, sctp_assoc_t snd_assoc_id, int stream,
-            int timetolive);
+            int time_to_live) {
+    return sctp_.SendMessage(stream, data, time_to_live, std::nullopt,
+                             snd_assoc_id);
+  }
 
   // Aborts a connection.  Returns true on success.
   bool Abort(sctp_assoc_t snd_assoc_id);
 
-  int fd() { return fd_; }
+  int fd() { return sctp_.fd(); }
 
   // Enables the priority scheduler.  This is a SCTP feature which lets us
   // configure the priority per stream so that higher priority packets don't get
@@ -51,27 +51,11 @@
   void SetStreamPriority(sctp_assoc_t assoc_id, int stream_id,
                          uint16_t priority);
 
-  void SetMaxSize(size_t max_size) {
-    max_size_ = max_size;
-    // Have the kernel give us a factor of 10 more.  This lets us have more than
-    // one full sized packet in flight.
-    max_size = max_size * 10;
-
-    CHECK_GE(ReadRMemMax(), max_size);
-    CHECK_GE(ReadWMemMax(), max_size);
-    PCHECK(setsockopt(fd_, SOL_SOCKET, SO_RCVBUF, &max_size,
-                      sizeof(max_size)) == 0);
-    PCHECK(setsockopt(fd_, SOL_SOCKET, SO_SNDBUF, &max_size,
-                      sizeof(max_size)) == 0);
-  }
+  void SetMaxSize(size_t max_size) { sctp_.SetMaxSize(max_size); }
 
  private:
   struct sockaddr_storage sockaddr_local_;
-  int fd_;
-
-  size_t max_size_ = 1000;
-
-  int ppid_ = 1;
+  SctpReadWrite sctp_;
 };
 
 }  // namespace message_bridge
diff --git a/aos/realtime.cc b/aos/realtime.cc
index cd9ea43..dc53a37 100644
--- a/aos/realtime.cc
+++ b/aos/realtime.cc
@@ -36,6 +36,12 @@
 int MallocHook_AddDeleteHook(MallocHook_DeleteHook hook) __attribute__((weak));
 int MallocHook_RemoveDeleteHook(MallocHook_DeleteHook hook)
     __attribute__((weak));
+
+// Declare tc_malloc weak so we can check if it exists.
+void *tc_malloc(size_t size) __attribute__((weak));
+
+void *__libc_malloc(size_t size);
+void __libc_free(void *ptr);
 }  // extern "C"
 
 namespace FLAG__namespace_do_not_use_directly_use_DECLARE_double_instead {
@@ -251,17 +257,57 @@
   }
 }
 
+extern "C" {
+
+// malloc hooks for libc. Tcmalloc will replace everything it finds (malloc,
+// __libc_malloc, etc.), so we need its specific hook above as well.
+void *aos_malloc_hook(size_t size) {
+  if (FLAGS_die_on_malloc && aos::is_realtime) {
+    aos::is_realtime = false;
+    RAW_LOG(FATAL, "Malloced %zu bytes", size);
+    return nullptr;
+  } else {
+    return __libc_malloc(size);
+  }
+}
+
+void aos_free_hook(void *ptr) {
+  if (FLAGS_die_on_malloc && aos::is_realtime && ptr != nullptr) {
+    aos::is_realtime = false;
+    RAW_LOG(FATAL, "Deleted %p", ptr);
+  } else {
+    __libc_free(ptr);
+  }
+}
+
+void *malloc(size_t size) __attribute__((weak, alias("aos_malloc_hook")));
+void free(void *ptr) __attribute__((weak, alias("aos_free_hook")));
+
+}
+
 void RegisterMallocHook() {
   if (FLAGS_die_on_malloc) {
-    if (&MallocHook_AddNewHook != nullptr) {
-      CHECK(MallocHook_AddNewHook(&NewHook));
+    // tcmalloc redefines __libc_malloc, so use this as a feature test.
+    if (&__libc_malloc == &tc_malloc) {
+      RAW_LOG(INFO, "Hooking tcmalloc for die_on_malloc");
+      if (&MallocHook_AddNewHook != nullptr) {
+        CHECK(MallocHook_AddNewHook(&NewHook));
+      } else {
+        has_malloc_hook = false;
+      }
+      if (&MallocHook_AddDeleteHook != nullptr) {
+        CHECK(MallocHook_AddDeleteHook(&DeleteHook));
+      } else {
+        has_malloc_hook = false;
+      }
     } else {
-      has_malloc_hook = false;
-    }
-    if (&MallocHook_AddDeleteHook != nullptr) {
-      CHECK(MallocHook_AddDeleteHook(&DeleteHook));
-    } else {
-      has_malloc_hook = false;
+      RAW_LOG(INFO, "Replacing glibc malloc");
+      if (&malloc != &aos_malloc_hook) {
+        has_malloc_hook = false;
+      }
+      if (&free != &aos_free_hook) {
+        has_malloc_hook = false;
+      }
     }
   }
 }
diff --git a/frc971/control_loops/drivetrain/drivetrain_test_lib.cc b/frc971/control_loops/drivetrain/drivetrain_test_lib.cc
index 7680688..3fa138c 100644
--- a/frc971/control_loops/drivetrain/drivetrain_test_lib.cc
+++ b/frc971/control_loops/drivetrain/drivetrain_test_lib.cc
@@ -41,7 +41,7 @@
     coefs.emplace_back(new StateFeedbackPlantCoefficients<4, 2, 2, double>(
         dt_config.make_drivetrain_loop().plant().coefficients(ii)));
   }
-  return StateFeedbackPlant<4, 2, 2, double>(&coefs);
+  return StateFeedbackPlant<4, 2, 2, double>(std::move(coefs));
 }
 
 }  // namespace
diff --git a/frc971/control_loops/hybrid_state_feedback_loop.h b/frc971/control_loops/hybrid_state_feedback_loop.h
index 6285024..23a3d21 100644
--- a/frc971/control_loops/hybrid_state_feedback_loop.h
+++ b/frc971/control_loops/hybrid_state_feedback_loop.h
@@ -63,8 +63,8 @@
   StateFeedbackHybridPlant(
       ::std::vector<::std::unique_ptr<StateFeedbackHybridPlantCoefficients<
           number_of_states, number_of_inputs, number_of_outputs>>>
-          *coefficients)
-      : coefficients_(::std::move(*coefficients)), index_(0) {
+          &&coefficients)
+      : coefficients_(::std::move(coefficients)), index_(0) {
     Reset();
   }
 
@@ -106,14 +106,14 @@
   Scalar U_max(int i, int j) const { return U_max()(i, j); }
 
   const Eigen::Matrix<Scalar, number_of_states, 1> &X() const { return X_; }
-  Scalar X(int i, int j) const { return X()(i, j); }
+  Scalar X(int i) const { return X()(i); }
   const Eigen::Matrix<Scalar, number_of_outputs, 1> &Y() const { return Y_; }
-  Scalar Y(int i, int j) const { return Y()(i, j); }
+  Scalar Y(int i) const { return Y()(i); }
 
   Eigen::Matrix<Scalar, number_of_states, 1> &mutable_X() { return X_; }
-  Scalar &mutable_X(int i, int j) { return mutable_X()(i, j); }
+  Scalar &mutable_X(int i) { return mutable_X()(i); }
   Eigen::Matrix<Scalar, number_of_outputs, 1> &mutable_Y() { return Y_; }
-  Scalar &mutable_Y(int i, int j) { return mutable_Y()(i, j); }
+  Scalar &mutable_Y(int i) { return mutable_Y()(i); }
 
   const StateFeedbackHybridPlantCoefficients<number_of_states, number_of_inputs,
                                              number_of_outputs, Scalar>
@@ -247,8 +247,12 @@
   explicit HybridKalman(
       ::std::vector<::std::unique_ptr<HybridKalmanCoefficients<
           number_of_states, number_of_inputs, number_of_outputs, Scalar>>>
-          *observers)
-      : coefficients_(::std::move(*observers)) {}
+          &&observers)
+      : coefficients_(::std::move(observers)) {
+    R_.setZero();
+    X_hat_.setZero();
+    P_ = coefficients().P_steady_state;
+  }
 
   HybridKalman(HybridKalman &&other) : index_(other.index_) {
     ::std::swap(coefficients_, other.coefficients_);
@@ -281,22 +285,37 @@
     return X_hat_;
   }
   Eigen::Matrix<Scalar, number_of_states, 1> &mutable_X_hat() { return X_hat_; }
+  Scalar &mutable_X_hat(int i) { return mutable_X_hat()(i); }
+  Scalar X_hat(int i) const { return X_hat_(i); }
 
   void Reset(StateFeedbackHybridPlant<number_of_states, number_of_inputs,
                                       number_of_outputs> *plant) {
     X_hat_.setZero();
     P_ = coefficients().P_steady_state;
-    UpdateQR(plant, ::std::chrono::milliseconds(5));
+    UpdateQR(plant, coefficients().Q_continuous, coefficients().R_continuous,
+             ::std::chrono::milliseconds(5));
   }
 
   void Predict(StateFeedbackHybridPlant<number_of_states, number_of_inputs,
                                         number_of_outputs, Scalar> *plant,
                const Eigen::Matrix<Scalar, number_of_inputs, 1> &new_u,
                ::std::chrono::nanoseconds dt) {
+    Predict(plant, new_u, dt, coefficients().Q_continuous,
+            coefficients().R_continuous);
+  }
+
+  void Predict(
+      StateFeedbackHybridPlant<number_of_states, number_of_inputs,
+                               number_of_outputs, Scalar> *plant,
+      const Eigen::Matrix<Scalar, number_of_inputs, 1> &new_u,
+      ::std::chrono::nanoseconds dt,
+      Eigen::Matrix<Scalar, number_of_states, number_of_states> Q_continuous,
+      Eigen::Matrix<Scalar, number_of_outputs, number_of_outputs>
+          R_continuous) {
     // Trigger the predict step.  This will update A() and B() in the plant.
     mutable_X_hat() = plant->Update(X_hat(), new_u, dt);
 
-    UpdateQR(plant, dt);
+    UpdateQR(plant, Q_continuous, R_continuous, dt);
     P_ = plant->A() * P_ * plant->A().transpose() + Q_;
   }
 
@@ -305,18 +324,29 @@
                                      number_of_outputs, Scalar> &plant,
       const Eigen::Matrix<Scalar, number_of_inputs, 1> &U,
       const Eigen::Matrix<Scalar, number_of_outputs, 1> &Y) {
+    DynamicCorrect(plant.C(), plant.D(), U, Y, R_);
+  }
+
+  // Corrects based on the sensor information available.
+  template <int number_of_measurements>
+  void DynamicCorrect(
+      const Eigen::Matrix<Scalar, number_of_measurements, number_of_states> &C,
+      const Eigen::Matrix<Scalar, number_of_measurements, number_of_inputs> &D,
+      const Eigen::Matrix<Scalar, number_of_inputs, 1> &U,
+      const Eigen::Matrix<Scalar, number_of_outputs, 1> &Y,
+      const Eigen::Matrix<Scalar, number_of_outputs, number_of_outputs> &R) {
     Eigen::Matrix<Scalar, number_of_outputs, 1> Y_bar =
-        Y - (plant.C() * X_hat_ + plant.D() * U);
+        Y - (C * X_hat_ + D * U);
     Eigen::Matrix<Scalar, number_of_outputs, number_of_outputs> S =
-        plant.C() * P_ * plant.C().transpose() + R_;
+        C * P_ * C.transpose() + R;
     Eigen::Matrix<Scalar, number_of_states, number_of_outputs> KalmanGain;
-    KalmanGain =
-        (S.transpose().ldlt().solve((P() * plant.C().transpose()).transpose()))
-            .transpose();
+    KalmanGain = (S.transpose().ldlt().solve((P() * C.transpose()).transpose()))
+                     .transpose();
     X_hat_ = X_hat_ + KalmanGain * Y_bar;
-    P_ = (plant.coefficients().A_continuous.Identity() -
-          KalmanGain * plant.C()) *
-         P();
+    P_ =
+        (Eigen::Matrix<Scalar, number_of_states, number_of_states>::Identity() -
+         KalmanGain * C) *
+        P();
   }
 
   // Sets the current controller to be index, clamped to be within range.
@@ -345,17 +375,17 @@
   }
 
  private:
-  void UpdateQR(StateFeedbackHybridPlant<number_of_states, number_of_inputs,
-                                         number_of_outputs> *plant,
-                ::std::chrono::nanoseconds dt) {
-    ::frc971::controls::DiscretizeQ(coefficients().Q_continuous,
-                                    plant->coefficients().A_continuous, dt,
-                                    &Q_);
+  void UpdateQR(
+      StateFeedbackHybridPlant<number_of_states, number_of_inputs,
+                               number_of_outputs> *plant,
+      Eigen::Matrix<Scalar, number_of_states, number_of_states> Q_continuous,
+      Eigen::Matrix<Scalar, number_of_outputs, number_of_outputs> R_continuous,
+      ::std::chrono::nanoseconds dt) {
+    frc971::controls::DiscretizeQ(Q_continuous,
+                                  plant->coefficients().A_continuous, dt, &Q_);
 
     Eigen::Matrix<Scalar, number_of_outputs, number_of_outputs> Rtemp =
-        (coefficients().R_continuous +
-         coefficients().R_continuous.transpose()) /
-        static_cast<Scalar>(2.0);
+        (R_continuous + R_continuous.transpose()) / static_cast<Scalar>(2.0);
 
     R_ = Rtemp / ::aos::time::TypedDurationInSeconds<Scalar>(dt);
   }
diff --git a/frc971/control_loops/hybrid_state_feedback_loop_test.cc b/frc971/control_loops/hybrid_state_feedback_loop_test.cc
index 13f74fa..c5b0771 100644
--- a/frc971/control_loops/hybrid_state_feedback_loop_test.cc
+++ b/frc971/control_loops/hybrid_state_feedback_loop_test.cc
@@ -84,7 +84,7 @@
   plants[0] = ::std::unique_ptr<StateFeedbackHybridPlantCoefficients<3, 1, 1>>(
       new StateFeedbackHybridPlantCoefficients<3, 1, 1>(
           MakeIntegralShooterPlantCoefficients()));
-  return StateFeedbackHybridPlant<3, 1, 1>(&plants);
+  return StateFeedbackHybridPlant<3, 1, 1>(std::move(plants));
 }
 
 StateFeedbackController<3, 1, 1> MakeIntegralShooterController() {
@@ -94,7 +94,7 @@
       ::std::unique_ptr<StateFeedbackControllerCoefficients<3, 1, 1>>(
           new StateFeedbackControllerCoefficients<3, 1, 1>(
               MakeIntegralShooterControllerCoefficients()));
-  return StateFeedbackController<3, 1, 1>(&controllers);
+  return StateFeedbackController<3, 1, 1>(std::move(controllers));
 }
 
 HybridKalman<3, 1, 1> MakeIntegralShooterObserver() {
@@ -103,7 +103,7 @@
   observers[0] = ::std::unique_ptr<HybridKalmanCoefficients<3, 1, 1>>(
       new HybridKalmanCoefficients<3, 1, 1>(
           MakeIntegralShooterObserverCoefficients()));
-  return HybridKalman<3, 1, 1>(&observers);
+  return HybridKalman<3, 1, 1>(std::move(observers));
 }
 
 StateFeedbackLoop<3, 1, 1, double, StateFeedbackHybridPlant<3, 1, 1>,
@@ -134,7 +134,7 @@
       v_plant;
   v_plant.emplace_back(
       new StateFeedbackPlantCoefficients<2, 4, 7>(coefficients));
-  StateFeedbackPlant<2, 4, 7> plant(&v_plant);
+  StateFeedbackPlant<2, 4, 7> plant(std::move(v_plant));
   plant.Update(Eigen::Matrix<double, 4, 1>::Zero());
   plant.Reset();
   plant.CheckU(Eigen::Matrix<double, 4, 1>::Zero());
@@ -145,7 +145,7 @@
   v_controller.emplace_back(new StateFeedbackControllerCoefficients<2, 4, 7>(
       Eigen::Matrix<double, 4, 2>::Identity(),
       Eigen::Matrix<double, 4, 2>::Identity()));
-  StateFeedbackController<2, 4, 7> controller(&v_controller);
+  StateFeedbackController<2, 4, 7> controller(std::move(v_controller));
 
   ::std::vector<::std::unique_ptr<StateFeedbackObserverCoefficients<2, 4, 7>>>
       v_observer;
@@ -153,7 +153,7 @@
       Eigen::Matrix<double, 2, 7>::Identity(),
       Eigen::Matrix<double, 2, 2>::Identity(),
       Eigen::Matrix<double, 7, 7>::Identity()));
-  StateFeedbackObserver<2, 4, 7> observer(&v_observer);
+  StateFeedbackObserver<2, 4, 7> observer(std::move(v_observer));
 
   StateFeedbackLoop<2, 4, 7> test_loop(
       ::std::move(plant), ::std::move(controller), ::std::move(observer));
diff --git a/frc971/control_loops/python/control_loop.py b/frc971/control_loops/python/control_loop.py
index 74141c1..cea1fdd 100644
--- a/frc971/control_loops/python/control_loop.py
+++ b/frc971/control_loops/python/control_loop.py
@@ -216,7 +216,7 @@
                 fd.write('  plants[%d] = ::std::unique_ptr<%s>(new %s(%s));\n'
                          % (index, self._PlantCoeffType(),
                             self._PlantCoeffType(), loop.PlantFunction()))
-            fd.write('  return %s(&plants);\n' % self._PlantType())
+            fd.write('  return %s(std::move(plants));\n' % self._PlantType())
             fd.write('}\n\n')
 
             fd.write('%s Make%sController() {\n' % (self._ControllerType(),
@@ -229,7 +229,8 @@
                     '  controllers[%d] = ::std::unique_ptr<%s>(new %s(%s));\n'
                     % (index, self._ControllerCoeffType(),
                        self._ControllerCoeffType(), loop.ControllerFunction()))
-            fd.write('  return %s(&controllers);\n' % self._ControllerType())
+            fd.write('  return %s(std::move(controllers));\n' %
+                     self._ControllerType())
             fd.write('}\n\n')
 
             fd.write('%s Make%sObserver() {\n' % (self._ObserverType(),
@@ -241,7 +242,8 @@
                     '  observers[%d] = ::std::unique_ptr<%s>(new %s(%s));\n'
                     % (index, self._ObserverCoeffType(),
                        self._ObserverCoeffType(), loop.ObserverFunction()))
-            fd.write('  return %s(&observers);\n' % self._ObserverType())
+            fd.write(
+                '  return %s(std::move(observers));\n' % self._ObserverType())
             fd.write('}\n\n')
 
             fd.write('%s Make%sLoop() {\n' % (self._LoopType(),
diff --git a/frc971/control_loops/python/drawing_constants.py b/frc971/control_loops/python/drawing_constants.py
index 8d64e0b..644e449 100644
--- a/frc971/control_loops/python/drawing_constants.py
+++ b/frc971/control_loops/python/drawing_constants.py
@@ -1,6 +1,5 @@
 import cairo
 from color import Color, palette
-from constants import *
 import numpy as np
 
 
@@ -59,467 +58,6 @@
     cr.show_text(text)
     cr.scale(widthb, -heightb)
 
-
-def draw_at_home_grid(cr):
-    field = np.zeros(shape=(5, 11), dtype=bool)
-    # field[row from bottom][column from left]
-
-    if GALACTIC_SEARCH in FIELD.tags:
-        # Galactic search start zone
-        field[1][0] = True
-        field[3][0] = True
-
-        # Galactic search end zone
-        field[1][10] = True
-        field[3][10] = True
-
-        if ARED in FIELD.tags:
-            field[4][5] = True
-            field[2][2] = True
-            field[1][4] = True
-        elif ABLUE in FIELD.tags:
-            field[0][5] = True
-            field[3][6] = True
-            field[2][8] = True
-        elif BRED in FIELD.tags:
-            field[3][2] = True
-            field[1][4] = True
-            field[3][6] = True
-        elif BBLUE in FIELD.tags:
-            field[1][5] = True
-            field[3][7] = True
-            field[1][9] = True
-    elif AUTONAV in FIELD.tags:
-        # start/end zone
-        field[1][0] = True
-        field[1][1] = True
-        field[3][0] = True
-        field[3][1] = True
-
-        if BARREL in FIELD.tags:
-            # barrels
-            field[1][4] = True
-            field[3][7] = True
-            field[1][9] = True
-        if SLALOM in FIELD.tags:
-            field[1][3:8] = True  # 3 to 7 inclusive
-            field[1][9] = True
-        if BOUNCE in FIELD.tags:
-            # turn on two rows
-            field[1][:11] = True
-            field[3][:11] = True
-
-            # turn off parts of rows
-            field[3][2] = False
-            field[3][5] = False
-            field[3][8] = False
-
-            field[1][3] = False
-            field[1][5] = False
-            field[1][8] = False
-
-            # markers to hit
-            field[4][2] = True
-            field[4][5] = True
-            field[4][8] = True
-
-    # Move origin to bottom left
-    xorigin = -mToPx(FIELD.width) / 2.0
-    yorigin = -mToPx(FIELD.length) / 2.0
-
-    color = palette["BLACK"]
-    # markers are at least 6.35 x 6.35 cm
-    marker_length = mToPx(0.0635)
-
-    for row, row_array in enumerate(field):
-        for column, has_marker in enumerate(row_array):
-            one_indexed_row = row + 1
-            one_indexed_column = column + 1
-
-            # 76.2 cm increments
-            pos_y = one_indexed_row * mToPx(0.762)
-            pos_x = one_indexed_column * mToPx(0.762)
-
-            if has_marker:
-                draw_px_x(cr, xorigin + pos_x, yorigin + pos_y, marker_length,
-                          color)
-
-
-def markers(cr):
-    SHOW_MARKERS = False
-    if SHOW_MARKERS:
-        # Shield Generator Reference
-        color = palette["BLUE"]
-        yorigin = 0 - SCREEN_SIZE / 2  # Move origin to bottom left
-        # Top Left
-        draw_circle(cr, mToPx(inToM(206.625)),
-                    yorigin + mToPx(inToM(212.097), True), 10, color)
-        # Top Right
-        draw_circle(cr, mToPx(inToM(373.616)),
-                    yorigin + mToPx(inToM(281.26), True), 10, color)
-        # Bottom Right
-        draw_circle(cr, mToPx(inToM(422.625)),
-                    yorigin + mToPx(inToM(124.67), True), 10, color)
-        # Bottom Left
-        draw_circle(cr, mToPx(inToM(255.634)),
-                    yorigin + mToPx(inToM(55.5), True), 10, color)
-
-        # Trench Run Reference
-        color = palette["GREEN"]
-        # Bottom Trench Run
-        # Bottom Right
-        draw_circle(cr, mToPx(inToM(206.625)), yorigin, 10, color)
-        # Top Right
-        draw_circle(cr, mToPx(inToM(206.625)),
-                    yorigin + mToPx(inToM(55.5), True), 10, color)
-        # Top Left
-        draw_circle(cr, mToPx(inToM(422.625)),
-                    yorigin + mToPx(inToM(55.5), True), 10, color)
-        # Bottom Left
-        draw_circle(cr, mToPx(inToM(422.625)), yorigin, 10, color)
-
-        # Top Trench Run
-        # Top Right
-        draw_circle(cr, mToPx(inToM(206.625)),
-                    yorigin + mToPx(inToM(323.25), True), 10, color)
-        # Bottom Right
-        draw_circle(cr, mToPx(inToM(206.625)),
-                    yorigin + mToPx(inToM(281.26), True), 10, color)
-        # Top Left
-        draw_circle(cr, mToPx(inToM(422.625)),
-                    yorigin + mToPx(inToM(281.26), True), 10, color)
-        # Bottom Left
-        draw_circle(cr, mToPx(inToM(422.625)),
-                    yorigin + mToPx(inToM(323.25), True), 10, color)
-        cr.stroke()
-
-
-def draw_init_lines(cr):
-    set_color(cr, palette["RED"])
-    init_line_x = FIELD.width / 2.0 - inToM(120)
-    init_start_y = -FIELD.length / 2.0
-    init_end_y = FIELD.length / 2.0
-    cr.move_to(mToPx(init_line_x), mToPx(init_start_y))
-    cr.line_to(mToPx(init_line_x), mToPx(init_end_y))
-
-    cr.move_to(mToPx(-init_line_x), mToPx(init_start_y))
-    cr.line_to(mToPx(-init_line_x), mToPx(init_end_y))
-
-    cr.stroke()
-
-
-def draw_trench_run(cr):
-    edge_of_field_y = FIELD.length / 2.0
-    edge_of_trench_y = edge_of_field_y - inToM(55.5)
-    trench_start_x = inToM(-108.0)
-    trench_length_x = inToM(216.0)
-    ball_line_y = edge_of_field_y - inToM(27.75)
-    ball_one_x = -inToM(72)
-    ball_two_x = -inToM(36)
-    ball_three_x = 0.0
-    # The fourth/fifth balls are referenced off of the init line...
-    ball_fourfive_x = FIELD.width / 2.0 - inToM(120.0 + 130.36)
-
-    for sign in [1.0, -1.0]:
-        set_color(cr, palette["GREEN"])
-        cr.rectangle(
-            mToPx(sign * trench_start_x), mToPx(sign * edge_of_field_y),
-            mToPx(sign * trench_length_x),
-            mToPx(sign * (edge_of_trench_y - edge_of_field_y)))
-        cr.stroke()
-        draw_circle(cr, mToPx(sign * ball_one_x), mToPx(sign * ball_line_y),
-                    mToPx(0.1), palette["YELLOW"])
-        draw_circle(cr, mToPx(sign * ball_two_x), mToPx(sign * ball_line_y),
-                    mToPx(0.1), palette["YELLOW"])
-        draw_circle(cr, mToPx(sign * ball_three_x), mToPx(sign * ball_line_y),
-                    mToPx(0.1), palette["YELLOW"])
-
-    cr.stroke()
-
-
-def draw_shield_generator(cr):
-    set_color(cr, palette["BLUE"])
-    cr.save()
-    cr.rotate(22.5 * np.pi / 180.)
-    generator_width = mToPx(inToM(14 * 12 + 0.75))
-    generator_height = mToPx(inToM(13 * 12 + 1.5))
-    cr.rectangle(-generator_width / 2.0, -generator_height / 2.0,
-                 generator_width, generator_height)
-    cr.restore()
-
-    cr.stroke()
-
-
-def draw_control_panel(cr):  # Base plates are not included
-    set_color(cr, palette["LIGHT_GREY"])
-    edge_of_field_y = FIELD.length / 2.0
-    edge_of_trench_y = edge_of_field_y - inToM(55.5)
-    high_x = inToM(374.59) - FIELD.width / 2.0
-    low_x = high_x - inToM(30)
-    for sign in [1.0, -1.0]:
-        # Bottom Control Panel
-        # Top Line
-        cr.rectangle(sign * mToPx(high_x), sign * mToPx(edge_of_field_y),
-                     -sign * mToPx(inToM(30)), -sign * mToPx(inToM(55.5)))
-
-    cr.stroke()
-
-
-def draw_HAB(cr):
-    # BASE Constants
-    X_BASE = 0
-    Y_BASE = 0
-    R = 0.381 - .1
-    BACKWALL_X = X_BASE
-    LOADING_Y = mToPx(4.129151) - mToPx(0.696976)
-    # HAB Levels 2 and 3 called in variables backhab
-    # draw loading stations
-    cr.move_to(0, LOADING_Y)
-    cr.line_to(mToPx(0.6), LOADING_Y)
-    cr.move_to(mToPx(R), LOADING_Y)
-    cr.arc(mToPx(R), LOADING_Y, 5, 0, np.pi * 2.0)
-    cr.move_to(0, -1.0 * LOADING_Y)
-    cr.line_to(mToPx(0.6), -1.0 * LOADING_Y)
-    cr.move_to(mToPx(R), -1.0 * LOADING_Y)
-    cr.arc(mToPx(R), -1.0 * LOADING_Y, 5, 0, np.pi * 2.0)
-
-    # HAB Levels 2 and 3 called in variables backhab
-    WIDTH_BACKHAB = mToPx(1.2192)
-
-    Y_TOP_BACKHAB_BOX = Y_BASE + mToPx(0.6096)
-    BACKHAB_LV2_LENGTH = mToPx(1.016)
-
-    BACKHAB_LV3_LENGTH = mToPx(1.2192)
-    Y_LV3_BOX = Y_TOP_BACKHAB_BOX - BACKHAB_LV3_LENGTH
-
-    Y_BOTTOM_BACKHAB_BOX = Y_LV3_BOX - BACKHAB_LV2_LENGTH
-
-    # HAB LEVEL 1
-    X_LV1_BOX = BACKWALL_X + WIDTH_BACKHAB
-
-    WIDTH_LV1_BOX = mToPx(0.90805)
-    LENGTH_LV1_BOX = mToPx(1.6256)
-
-    Y_BOTTOM_LV1_BOX = Y_BASE - LENGTH_LV1_BOX
-
-    # Ramp off Level 1
-    X_RAMP = X_LV1_BOX
-
-    Y_TOP_RAMP = Y_BASE + LENGTH_LV1_BOX
-    WIDTH_TOP_RAMP = mToPx(1.20015)
-    LENGTH_TOP_RAMP = Y_BASE + mToPx(0.28306)
-
-    X_MIDDLE_RAMP = X_RAMP + WIDTH_LV1_BOX
-    Y_MIDDLE_RAMP = Y_BOTTOM_LV1_BOX
-    LENGTH_MIDDLE_RAMP = 2 * LENGTH_LV1_BOX
-    WIDTH_MIDDLE_RAMP = WIDTH_TOP_RAMP - WIDTH_LV1_BOX
-
-    Y_BOTTOM_RAMP = Y_BASE - LENGTH_LV1_BOX - LENGTH_TOP_RAMP
-
-    # Side Bars to Hold in balls
-    X_BARS = BACKWALL_X
-    WIDTH_BARS = WIDTH_BACKHAB
-    LENGTH_BARS = mToPx(0.574675)
-
-    Y_TOP_BAR = Y_TOP_BACKHAB_BOX + BACKHAB_LV2_LENGTH
-
-    Y_BOTTOM_BAR = Y_BOTTOM_BACKHAB_BOX - LENGTH_BARS
-
-    set_color(cr, palette["BLACK"])
-    cr.rectangle(BACKWALL_X, Y_TOP_BACKHAB_BOX, WIDTH_BACKHAB,
-                 BACKHAB_LV2_LENGTH)
-    cr.rectangle(BACKWALL_X, Y_LV3_BOX, WIDTH_BACKHAB, BACKHAB_LV3_LENGTH)
-    cr.rectangle(BACKWALL_X, Y_BOTTOM_BACKHAB_BOX, WIDTH_BACKHAB,
-                 BACKHAB_LV2_LENGTH)
-    cr.rectangle(X_LV1_BOX, Y_BASE, WIDTH_LV1_BOX, LENGTH_LV1_BOX)
-    cr.rectangle(X_LV1_BOX, Y_BOTTOM_LV1_BOX, WIDTH_LV1_BOX, LENGTH_LV1_BOX)
-    cr.rectangle(X_RAMP, Y_TOP_RAMP, WIDTH_TOP_RAMP, LENGTH_TOP_RAMP)
-    cr.rectangle(X_MIDDLE_RAMP, Y_MIDDLE_RAMP, WIDTH_MIDDLE_RAMP,
-                 LENGTH_MIDDLE_RAMP)
-    cr.rectangle(X_RAMP, Y_BOTTOM_RAMP, WIDTH_TOP_RAMP, LENGTH_TOP_RAMP)
-    cr.rectangle(X_BARS, Y_TOP_BAR, WIDTH_BARS, LENGTH_BARS)
-    cr.rectangle(X_BARS, Y_BOTTOM_BAR, WIDTH_BARS, LENGTH_BARS)
-    cr.stroke()
-
-    cr.set_line_join(cairo.LINE_JOIN_ROUND)
-
-    cr.stroke()
-
-    #draw 0, 0
-    set_color(cr, palette["BLACK"])
-    cr.move_to(0, 0)
-    cr.line_to(0, 0 + mToPx(8.2296 / 2.0))
-    cr.move_to(0, 0)
-    cr.line_to(0, 0 + mToPx(-8.2296 / 2.0))
-    cr.move_to(0, 0)
-    cr.line_to(0 + mToPx(8.2296), 0)
-
-    cr.stroke()
-
-
-def draw_rockets(cr):
-    # BASE Constants
-    X_BASE = mToPx(2.41568)
-    Y_BASE = 0
-    # Robot longitudinal radius
-    R = 0.381
-    near_side_rocket_center = [
-        X_BASE + mToPx((2.89973 + 3.15642) / 2.0), Y_BASE + mToPx(
-            (3.86305 + 3.39548) / 2.0)
-    ]
-    middle_rocket_center = [
-        X_BASE + mToPx((3.15642 + 3.6347) / 2.0), Y_BASE + mToPx(
-            (3.39548 + 3.392380) / 2.0)
-    ]
-    far_side_rocket_center = [
-        X_BASE + mToPx((3.63473 + 3.89984) / 2.0), Y_BASE + mToPx(
-            (3.39238 + 3.86305) / 2.0)
-    ]
-
-    cr.move_to(near_side_rocket_center[0], near_side_rocket_center[1])
-    cr.line_to(near_side_rocket_center[0] - 0.8 * mToPx(0.866),
-               near_side_rocket_center[1] - 0.8 * mToPx(0.5))
-    cr.move_to(near_side_rocket_center[0] - R * mToPx(0.866),
-               near_side_rocket_center[1] - R * mToPx(0.5))
-    cr.arc(near_side_rocket_center[0] - R * mToPx(0.866),
-           near_side_rocket_center[1] - R * mToPx(0.5), 5, 0, np.pi * 2.0)
-
-    cr.move_to(middle_rocket_center[0], middle_rocket_center[1])
-    cr.line_to(middle_rocket_center[0], middle_rocket_center[1] - mToPx(0.8))
-    cr.move_to(middle_rocket_center[0], middle_rocket_center[1] - mToPx(R))
-    cr.arc(middle_rocket_center[0], middle_rocket_center[1] - mToPx(R), 5, 0,
-           np.pi * 2.0)
-
-    cr.move_to(far_side_rocket_center[0], far_side_rocket_center[1])
-    cr.line_to(far_side_rocket_center[0] + 0.8 * mToPx(0.866),
-               far_side_rocket_center[1] - 0.8 * mToPx(0.5))
-    cr.move_to(far_side_rocket_center[0] + R * mToPx(0.866),
-               far_side_rocket_center[1] - R * mToPx(0.5))
-    cr.arc(far_side_rocket_center[0] + R * mToPx(0.866),
-           far_side_rocket_center[1] - R * mToPx(0.5), 5, 0, np.pi * 2.0)
-
-    #print(far_side_rocket_center)
-    near_side_rocket_center = [
-        X_BASE + mToPx((2.89973 + 3.15642) / 2.0), Y_BASE - mToPx(
-            (3.86305 + 3.39548) / 2.0)
-    ]
-    middle_rocket_center = [
-        X_BASE + mToPx((3.15642 + 3.6347) / 2.0), Y_BASE - mToPx(
-            (3.39548 + 3.392380) / 2.0)
-    ]
-    far_side_rocket_center = [
-        X_BASE + mToPx((3.63473 + 3.89984) / 2.0), Y_BASE - mToPx(
-            (3.39238 + 3.86305) / 2.0)
-    ]
-
-    cr.move_to(near_side_rocket_center[0], near_side_rocket_center[1])
-    cr.line_to(near_side_rocket_center[0] - 0.8 * mToPx(0.866),
-               near_side_rocket_center[1] + 0.8 * mToPx(0.5))
-
-    cr.move_to(middle_rocket_center[0], middle_rocket_center[1])
-    cr.line_to(middle_rocket_center[0], middle_rocket_center[1] + mToPx(0.8))
-
-    cr.move_to(far_side_rocket_center[0], far_side_rocket_center[1])
-    cr.line_to(far_side_rocket_center[0] + 0.8 * mToPx(0.866),
-               far_side_rocket_center[1] + 0.8 * mToPx(0.5))
-
-    # Leftmost Line
-    cr.move_to(X_BASE + mToPx(2.89973), Y_BASE + mToPx(3.86305))
-    cr.line_to(X_BASE + mToPx(3.15642), Y_BASE + mToPx(3.39548))
-
-    # Top Line
-    cr.move_to(X_BASE + mToPx(3.15642), Y_BASE + mToPx(3.39548))
-    cr.line_to(X_BASE + mToPx(3.63473), Y_BASE + mToPx(3.39238))
-
-    #Rightmost Line
-    cr.move_to(X_BASE + mToPx(3.63473), Y_BASE + mToPx(3.39238))
-    cr.line_to(X_BASE + mToPx(3.89984), Y_BASE + mToPx(3.86305))
-
-    #Back Line
-    cr.move_to(X_BASE + mToPx(2.89973), Y_BASE + mToPx(3.86305))
-    cr.line_to(X_BASE + mToPx(3.89984), Y_BASE + mToPx(3.86305))
-
-    # Bottom Rocket
-    # Leftmost Line
-    cr.move_to(X_BASE + mToPx(2.89973), Y_BASE - mToPx(3.86305))
-    cr.line_to(X_BASE + mToPx(3.15642), Y_BASE - mToPx(3.39548))
-
-    # Top Line
-    cr.move_to(X_BASE + mToPx(3.15642), Y_BASE - mToPx(3.39548))
-    cr.line_to(X_BASE + mToPx(3.63473), Y_BASE - mToPx(3.39238))
-
-    #Rightmost Line
-    cr.move_to(X_BASE + mToPx(3.63473), Y_BASE - mToPx(3.39238))
-    cr.line_to(X_BASE + mToPx(3.89984), Y_BASE - mToPx(3.86305))
-
-    #Back Line
-    cr.move_to(X_BASE + mToPx(2.89973), Y_BASE - mToPx(3.86305))
-    cr.line_to(X_BASE + mToPx(3.89984), Y_BASE - mToPx(3.86305))
-
-    cr.stroke()
-
-
-def draw_cargo_ship(cr):
-    # BASE Constants
-    X_BASE = 0 + mToPx(5.59435)
-    Y_BASE = 0 + 0  #mToPx(4.129151)
-    R = 0.381 - 0.1
-
-    FRONT_PEG_DELTA_Y = mToPx(0.276352)
-    cr.move_to(X_BASE, Y_BASE + FRONT_PEG_DELTA_Y)
-    cr.line_to(X_BASE - mToPx(0.8), Y_BASE + FRONT_PEG_DELTA_Y)
-
-    cr.move_to(X_BASE, Y_BASE + FRONT_PEG_DELTA_Y)
-    cr.arc(X_BASE - mToPx(R), Y_BASE + FRONT_PEG_DELTA_Y, 5, 0, np.pi * 2.0)
-
-    cr.move_to(X_BASE, Y_BASE - FRONT_PEG_DELTA_Y)
-    cr.line_to(X_BASE - mToPx(0.8), Y_BASE - FRONT_PEG_DELTA_Y)
-
-    cr.move_to(X_BASE, Y_BASE - FRONT_PEG_DELTA_Y)
-    cr.arc(X_BASE - mToPx(R), Y_BASE - FRONT_PEG_DELTA_Y, 5, 0, np.pi * 2.0)
-
-    SIDE_PEG_Y = mToPx(1.41605 / 2.0)
-    SIDE_PEG_X = X_BASE + mToPx(1.148842)
-    SIDE_PEG_DX = mToPx(0.55245)
-
-    cr.move_to(SIDE_PEG_X, SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X, SIDE_PEG_Y + mToPx(0.8))
-    cr.move_to(SIDE_PEG_X, SIDE_PEG_Y + mToPx(R))
-    cr.arc(SIDE_PEG_X, SIDE_PEG_Y + mToPx(R), 5, 0, np.pi * 2.0)
-
-    cr.move_to(SIDE_PEG_X + SIDE_PEG_DX, SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X + SIDE_PEG_DX, SIDE_PEG_Y + mToPx(0.8))
-    cr.move_to(SIDE_PEG_X + SIDE_PEG_DX, SIDE_PEG_Y + mToPx(R))
-    cr.arc(SIDE_PEG_X + SIDE_PEG_DX, SIDE_PEG_Y + mToPx(R), 5, 0, np.pi * 2.0)
-
-    cr.move_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, SIDE_PEG_Y + mToPx(0.8))
-    cr.move_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, SIDE_PEG_Y + mToPx(R))
-    cr.arc(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, SIDE_PEG_Y + mToPx(R), 5, 0,
-           np.pi * 2.0)
-
-    cr.move_to(SIDE_PEG_X, -1.0 * SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X, -1.0 * SIDE_PEG_Y - mToPx(0.8))
-    cr.move_to(SIDE_PEG_X, -1.0 * SIDE_PEG_Y - mToPx(R))
-    cr.arc(SIDE_PEG_X, -1.0 * SIDE_PEG_Y - mToPx(R), 5, 0, np.pi * 2.0)
-
-    cr.move_to(SIDE_PEG_X + SIDE_PEG_DX, -1.0 * SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X + SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(0.8))
-    cr.move_to(SIDE_PEG_X + SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(R))
-    cr.arc(SIDE_PEG_X + SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(R), 5, 0,
-           np.pi * 2.0)
-
-    cr.move_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, -1.0 * SIDE_PEG_Y)
-    cr.line_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(0.8))
-    cr.move_to(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(R))
-    cr.arc(SIDE_PEG_X + 2.0 * SIDE_PEG_DX, -1.0 * SIDE_PEG_Y - mToPx(R), 5, 0,
-           np.pi * 2.0)
-
-    cr.rectangle(X_BASE, Y_BASE - mToPx(1.41605 / 2.0), mToPx(2.43205),
-                 mToPx(1.41605))
-    cr.stroke()
-
-
 def draw_points(cr, p, size):
     for i in range(0, len(p)):
         draw_px_cross(cr, p[i][0], p[i][1], size, Color(
diff --git a/frc971/control_loops/python/path_edit.py b/frc971/control_loops/python/path_edit.py
index d402593..3386bc6 100755
--- a/frc971/control_loops/python/path_edit.py
+++ b/frc971/control_loops/python/path_edit.py
@@ -52,8 +52,6 @@
         self.held_x = 0
         self.spline_edit = -1
 
-        self.curves = []
-
         try:
             self.field_png = cairo.ImageSurface.create_from_png(
                 "frc971/control_loops/python/field_images/" + FIELD.field_id +
@@ -185,30 +183,22 @@
 
         if self.mode == Mode.kPlacing or self.mode == Mode.kViewing:
             set_color(cr, palette["BLACK"])
-            plotPoints = self.points.getPoints()
-            if plotPoints:
-                for i, point in enumerate(plotPoints):
-                    draw_px_x(cr, mToPx(point[0]), mToPx(point[1]), 10)
-                    cr.move_to(mToPx(point[0]), mToPx(point[1]) - 15)
-                    display_text(cr, str(i), 0.5, 0.5, 2, 2)
+            for i, point in enumerate(self.points.getPoints()):
+                draw_px_x(cr, mToPx(point[0]), mToPx(point[1]), 10)
             set_color(cr, palette["WHITE"])
-
         elif self.mode == Mode.kEditing:
             set_color(cr, palette["BLACK"])
-            cr.move_to(-SCREEN_SIZE, 170)
-            display_text(cr, "EDITING", 1, 1, 1, 1)
             if self.points.getSplines():
                 self.draw_splines(cr)
                 for i, points in enumerate(self.points.getSplines()):
 
-                    p0 = np.array([mToPx(points[0][0]), mToPx(points[0][1])])
-                    p1 = np.array([mToPx(points[1][0]), mToPx(points[1][1])])
-                    p2 = np.array([mToPx(points[2][0]), mToPx(points[2][1])])
-                    p3 = np.array([mToPx(points[3][0]), mToPx(points[3][1])])
-                    p4 = np.array([mToPx(points[4][0]), mToPx(points[4][1])])
-                    p5 = np.array([mToPx(points[5][0]), mToPx(points[5][1])])
+                    points = [
+                        np.array([mToPx(x), mToPx(y)])
+                        for (x, y) in points
+                    ]
+                    draw_control_points(cr, points)
 
-                    draw_control_points(cr, [p0, p1, p2, p3, p4, p5])
+                    p0, p1, p2, p3, p4, p5 = points
                     first_tangent = p0 + 2.0 * (p1 - p0)
                     second_tangent = p5 + 2.0 * (p4 - p5)
                     cr.set_source_rgb(0, 0.5, 0)
@@ -239,7 +229,6 @@
         print("spent {:.2f} ms drawing the field widget".format(1000 * (time.perf_counter() - start_time)))
 
     def draw_splines(self, cr):
-        holder_spline = []
         for i, points in enumerate(self.points.getSplines()):
             array = np.zeros(shape=(6, 2), dtype=float)
             for j, point in enumerate(points):
@@ -253,15 +242,9 @@
                 cr.line_to(
                     mToPx(spline.Point(k)[0]), mToPx(spline.Point(k)[1]))
                 cr.stroke()
-                holding = [
-                    spline.Point(k - 0.01)[0],
-                    spline.Point(k - 0.01)[1]
-                ]
-                holder_spline.append(holding)
             if i == 0:
                 self.draw_robot_at_point(cr, 0.00, 0.01, spline)
             self.draw_robot_at_point(cr, 1, 0.01, spline)
-        self.curves.append(holder_spline)
 
     def mouse_move(self, event):
         old_x = self.mousex
@@ -274,8 +257,9 @@
 
         if self.mode == Mode.kEditing:
             self.points.updates_for_mouse_move(self.index_of_edit,
-                                               self.spline_edit, self.mousex,
-                                               self.mousey, difs)
+                                               self.spline_edit,
+                                               pxToM(self.mousex),
+                                               pxToM(self.mousey), difs)
 
     def export_json(self, file_name):
         self.path_to_export = os.path.join(
@@ -347,7 +331,8 @@
         self.mousey = event.y
 
         if self.mode == Mode.kPlacing:
-            if self.points.add_point(self.mousex, self.mousey):
+            if self.points.add_point(
+                    pxToM(self.mousex), pxToM(self.mousey)):
                 self.mode = Mode.kEditing
         elif self.mode == Mode.kEditing:
             # Now after index_of_edit is not -1, the point is selected, so
diff --git a/frc971/control_loops/python/points.py b/frc971/control_loops/python/points.py
index c22582e..d874306 100644
--- a/frc971/control_loops/python/points.py
+++ b/frc971/control_loops/python/points.py
@@ -70,7 +70,7 @@
 
     def updates_for_mouse_move(self, index_of_edit, spline_edit, x, y, difs):
         if index_of_edit > -1:
-            self.splines[spline_edit][index_of_edit] = [pxToM(x), pxToM(y)]
+            self.splines[spline_edit][index_of_edit] = [x, y]
 
             if index_of_edit == 5:
                 self.splines[spline_edit][
@@ -150,7 +150,7 @@
 
     def add_point(self, x, y):
         if (len(self.points) < 6):
-            self.points.append([pxToM(x), pxToM(y)])
+            self.points.append([x, y])
         if (len(self.points) == 6):
             self.splines.append(np.array(self.points))
             self.points = []
diff --git a/frc971/control_loops/python/spline_graph.py b/frc971/control_loops/python/spline_graph.py
index ad3ae96..1378e8f 100755
--- a/frc971/control_loops/python/spline_graph.py
+++ b/frc971/control_loops/python/spline_graph.py
@@ -12,6 +12,7 @@
 import basic_window
 import os
 
+
 class GridWindow(Gtk.Window):
     def method_connect(self, event, cb):
         def handler(obj, *args):
diff --git a/frc971/control_loops/state_feedback_loop.h b/frc971/control_loops/state_feedback_loop.h
index 4250df2..f591847 100644
--- a/frc971/control_loops/state_feedback_loop.h
+++ b/frc971/control_loops/state_feedback_loop.h
@@ -69,8 +69,8 @@
   StateFeedbackPlant(
       ::std::vector<::std::unique_ptr<StateFeedbackPlantCoefficients<
           number_of_states, number_of_inputs, number_of_outputs, Scalar>>>
-          *coefficients)
-      : coefficients_(::std::move(*coefficients)), index_(0) {
+          &&coefficients)
+      : coefficients_(::std::move(coefficients)), index_(0) {
     Reset();
   }
 
@@ -222,8 +222,8 @@
   explicit StateFeedbackController(
       ::std::vector<::std::unique_ptr<StateFeedbackControllerCoefficients<
           number_of_states, number_of_inputs, number_of_outputs, Scalar>>>
-          *controllers)
-      : coefficients_(::std::move(*controllers)) {}
+          &&controllers)
+      : coefficients_(::std::move(controllers)) {}
 
   StateFeedbackController(StateFeedbackController &&other)
       : index_(other.index_) {
@@ -300,8 +300,8 @@
   explicit StateFeedbackObserver(
       ::std::vector<::std::unique_ptr<StateFeedbackObserverCoefficients<
           number_of_states, number_of_inputs, number_of_outputs, Scalar>>>
-          *observers)
-      : coefficients_(::std::move(*observers)) {}
+          &&observers)
+      : coefficients_(::std::move(observers)) {}
 
   StateFeedbackObserver(StateFeedbackObserver &&other)
       : X_hat_(other.X_hat_), index_(other.index_) {
diff --git a/y2020/vision/viewer_replay.cc b/y2020/vision/viewer_replay.cc
index 234c445..93e531d 100644
--- a/y2020/vision/viewer_replay.cc
+++ b/y2020/vision/viewer_replay.cc
@@ -8,8 +8,6 @@
 #include "aos/init.h"
 #include "y2020/vision/vision_generated.h"
 
-DEFINE_string(config, "y2020/config.json", "Path to the config file to use.");
-DEFINE_string(logfile, "", "Path to the log file to use.");
 DEFINE_string(node, "pi1", "Node name to replay.");
 DEFINE_string(image_save_prefix, "/tmp/img",
               "Prefix to use for saving images from the logfile.");
@@ -18,13 +16,12 @@
 namespace vision {
 namespace {
 
-void ViewerMain() {
-  CHECK(!FLAGS_logfile.empty()) << "You forgot to specify a logfile.";
+void ViewerMain(int argc, char *argv[]) {
+  std::vector<std::string> unsorted_logfiles =
+      aos::logger::FindLogs(argc, argv);
 
-  aos::FlatbufferDetachedBuffer<aos::Configuration> config =
-      aos::configuration::ReadConfig(FLAGS_config);
-
-  aos::logger::LogReader reader(FLAGS_logfile, &config.message());
+  // open logfiles
+  aos::logger::LogReader reader(aos::logger::SortParts(unsorted_logfiles));
   reader.Register();
   const aos::Node *node = nullptr;
   if (aos::configuration::MultiNode(reader.configuration())) {
@@ -61,5 +58,5 @@
 // Quick and lightweight grayscale viewer for images
 int main(int argc, char **argv) {
   aos::InitGoogle(&argc, &argv);
-  frc971::vision::ViewerMain();
+  frc971::vision::ViewerMain(argc, argv);
 }