Encourage adoption of regions and multi-byte hashes

[ZjMNZHgG5jMXw]

This patch defines two new settings for repeaters.

• repeat.unrestricted.hops (default 64) defines the number of hops for which the repeater will not apply any restrictions to packets.
• repeat.restrict.path.hash.size (default 1) defines the minimum path hash size which the repeater will require for repeating packets with restrictions applying.

How

The repeater will first look whether restrictions should apply to incoming packets by evaluating their path length and comparing them with repeat.unrestricted.hops. If the path length is exceeding this maximum and restrictions apply, packets without transport codes (aka scope or region) will be discarded. Packets with transport codes will be considered for repeating if their path hash size is at least matching the minimum repeat.restrict.path.hash.size. All other mainstream repeater restrictions (flood.max, flood.max.unscoped, flood.max.advert, scope/region logic, etc.) apply after these new checks.

The default values make sure that the new settings won't affect the repeater until explicitly set.

Why

The recommended settings will create a safe zone of three hops which newbies can use to get in contact with others no matter whether they have regions or hash sizes set to modern values. Other mesh users in this hop proximity can instruct these newbies how to adjust their settings for achieving a wider message distribution range, for instance by using regions and avoiding ID/path collisions by using multi-byte hash sizes.

Recommended settings

set repeat.unrestricted.hops 2       // the repeater will add itself as hop 3
set repeat.restrict.path.hash.size 2 // deny 1-byte, allow 2 and 3-byte hashes
region allowf *                      // reset to default
set flood.max 64                     // reset to no-op/default
set flood.max.unscoped 64            // reset to no-op/default
set flood.max.advert 8               // reset to default