On Linux, SO_REUSEADDR is used so that a socket in TIME-WAIT state can
be rebound after a listening process is restarted. It does not allow two
processes to listen on the exact same (addr, port) combination. However,
on Windows, it does, and SO_EXCLUSIVEADDRUSE is required to reproduce
the Linux behavior.
Reticulum relies on an error being returned by bind() that reuses
the same (addr, port) combination as another process to detect whether
there is a shared instance already running. Setting SO_EXCLUSIVEADDRUSE
makes this detection process work on Windows as well.
- StreamDataMessage now packed by struct rather than umsgpack for a more predictable size
- Added protected variable on LocalInterface to allow tests to simulate a low bandwidth connection
- Retry timer now has exponential backoff and a more sane starting value
- Link proves packet _before_ sending contents to Channel; this should help prevent spurious retries especially on half-duplex links
- Prevent Transport packet filter from filtering out duplicate packets for Channel; handle duplicates in Channel to ensure the packet is reproven (in case the original proof packet was lost)
- Fix up other tests broken by these changes