This software monitors a set of directories (the "upload directories") for new files and uploads them to a server using a persistent HTTP connection.

How to use:

1. Build a copy of bismark-data-transmit. See bismark-packages for the companion OpenWRT package Makefile.
2. Install bismark-data-transmit on your BISmark router.
3. Create the UPLOAD_ROOT directory. By default, this is /tmp/bismark-uploads but you can change it using the package Makefile.
4. Create subdirectories of UPLOAD_ROOT. bismark-data-transmit will monitor these for new files to upload. Each subdirectory should represent a certain type of data to be processed on the server side. For example, I created /tmp/bismark-uploads/passive for bismark-passive log files and /tmp/bismark-uploads/passive-frequent for bismark-passive's frequent uCap-specific updates. Data from these directories will be processed by different entities on the server side. Alternatively, you can place directory names in /etc/config/bismark-data-transmit and they will be automatically created before starting.
5. Restart bismark-data-transmit for it to rescan UPLOAD_ROOT and begin accepting uploads from the new directories.
6. To upload files, move files into the subdirectories of UPLOAD_ROOT. Do not create new files directly inside subdirectories of UPLOAD_ROOT. They will not get uploaded in a timely fashion. Instead, create files somewhere else and mv them into the desired subdirectory.
7. Collect your files on the server side. Files are not guaranteed to arrive in any particular order, since files that fail to upload are retried after a delay (3 minutes by default).
8. There is a limited buffer for storing uploads. If more than 5 MB of pending uploads accumulate, bismark-data-transmit will start deleting the oldest uploads. It counts the number of files it's deleted and writes the counters to /tmp/bismark-data-transmit-failures.log.

Point 6 deserves repetition: Do not create new files directly inside /tmp/bismark-uploads. Instead, create the files elsewhere and mv them into /tmp/bismark-uploads/.