zebra/zebra-network
teor 4d22a0bae9
Security: Limit reconnection rate to individual peers (#2275)
* Security: Limit reconnection rate to individual peers

Reconnection Rate

Limit the reconnection rate to each individual peer by applying the
liveness cutoff to the attempt, responded, and failure time fields.
If any field is recent, the peer is skipped.

The new liveness cutoff skips any peers that have recently been attempted
or failed. (Previously, the liveness check was only applied if the peer
was in the `Responded` state, which could lead to repeated retries of
`Failed` peers, particularly in small address books.)

Reconnection Order

Zebra prefers more useful peer states, then the earliest attempted,
failed, and responded times, then the most recent gossiped last seen
times.

Before this change, Zebra took the most recent time in all the peer time
fields, and used that time for liveness and ordering. This led to
confusion between trusted and untrusted data, and success and failure
times.

Unlike the previous order, the new order:
- tries all peers in each state, before re-trying any peer in that state,
  and
- only checks the the gossiped untrusted last seen time
  if all other times are equal.

* Preserve the later time if changes arrive out of order

* Update CandidateSet::next documentation

* Update CandidateSet state diagram

* Fix variant names in comments

* Explain why timestamps can be left out of MetaAddrChanges

* Add a simple test for the individual peer retry limit

* Only generate valid Arbitrary PeerServices values

* Add an individual peer retry limit AddressBook and CandidateSet test

* Stop deleting recently live addresses from the address book

If we delete recently live addresses from the address book, we can get a
new entry for them, and reconnect too rapidly.

* Rename functions to match similar tokio API

* Fix docs for service sorting

* Clarify a comment

* Cleanup a variable and comments

* Remove blank lines in the CandidateSet state diagram

* Add a multi-peer proptest that checks outbound attempt fairness

* Fix a comment typo

Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>

* Simplify time maths in MetaAddr

* Create a Duration32 type to simplify calculations and comparisons

* Rename variables for clarity

* Split a string constant into multiple lines

* Make constants match rustdoc order

Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
2021-06-18 09:30:44 -03:00
..
proptest-regressions Security: only apply the outbound connection rate-limit to actual connections (#2278) 2021-06-15 08:29:17 +10:00
src Security: Limit reconnection rate to individual peers (#2275) 2021-06-18 09:30:44 -03:00
Cargo.toml Update versions for zebra v1.0.0-alpha.11 release (#2334) 2021-06-18 10:37:58 +01:00