39393479c514f271c42750ffcd0adc6bc1db2e2f p2p: pass strings to NetPermissions::TryParse functions by const ref (Jon Atack)
Pull request description:
instead of by value, as these are "in" params that are not cheap to copy.
Reference: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#f16-for-in-parameters-pass-cheaply-copied-types-by-value-and-others-by-reference-to-const
ACKs for top commit:
MarcoFalke:
cr ACK 39393479c514f271c42750ffcd0adc6bc1db2e2f
Tree-SHA512: 294fe0f2d900293b4447d4e1f0ccc60c1ed27b3bdbd0f5d71d3dbf71de86879638b1b813fadfb44c58b4acff4e7d75b7ed6a4f9cc5fcf627108224e6a21b524c
c5b404e8f1973afe071a07c63ba1038eefe13f0f Add functional tests for flexible whitebind/list (nicolas.dorier)
d541fa391844f658bd7035659b5b16695733dd56 Replace the use of fWhitelisted by permission checks (nicolas.dorier)
ecd5cf7ea4c3644a30092100ffc399e30e193275 Do not disconnect peer for asking mempool if it has NO_BAN permission (nicolas.dorier)
e5b26deaaa6842f7dd7c4537ede000f965ea0189 Make whitebind/whitelist permissions more flexible (nicolas.dorier)
Pull request description:
# Motivation
In 0.19, bloom filter will be disabled by default. I tried to make [a PR](https://github.com/bitcoin/bitcoin/pull/16176) to enable bloom filter for whitelisted peers regardless of `-peerbloomfilters`.
Bloom filter have non existent privacy and server can omit filter's matches. However, both problems are completely irrelevant when you connect to your own node. If you connect to your own node, bloom filters are the most bandwidth efficient way to synchronize your light client without the need of some middleware like Electrum.
It is also a superior alternative to BIP157 as it does not require to maintain an additional index and it would work well on pruned nodes.
When I attempted to allow bloom filters for whitelisted peer, my proposal has been NACKed in favor of [a more flexible approach](https://github.com/bitcoin/bitcoin/pull/16176#issuecomment-500762907) which should allow node operator to set fine grained permissions instead of a global `whitelisted` attribute.
Doing so will also make follow up idea very easy to implement in a backward compatible way.
# Implementation details
The PR propose a new format for `--white{list,bind}`. I added a way to specify permissions granted to inbound connection matching `white{list,bind}`.
The following permissions exists:
* ForceRelay
* Relay
* NoBan
* BloomFilter
* Mempool
Example:
* `-whitelist=bloomfilter@127.0.0.1/32`.
* `-whitebind=bloomfilter,relay,noban@127.0.0.1:10020`.
If no permissions are specified, `NoBan | Mempool` is assumed. (making this PR backward compatible)
When we receive an inbound connection, we calculate the effective permissions for this peer by fetching the permissions granted from `whitelist` and add to it the permissions granted from `whitebind`.
To keep backward compatibility, if no permissions are specified in `white{list,bind}` (e.g. `--whitelist=127.0.0.1`) then parameters `-whitelistforcerelay` and `-whiterelay` will add the permissions `ForceRelay` and `Relay` to the inbound node.
`-whitelistforcerelay` and `-whiterelay` are ignored if the permissions flags are explicitly set in `white{bind,list}`.
# Follow up idea
Based on this PR, other changes become quite easy to code in a trivially review-able, backward compatible way:
* Changing `connect` at rpc and config file level to understand the permissions flags.
* Changing the permissions of a peer at RPC level.
ACKs for top commit:
laanwj:
re-ACK c5b404e8f1973afe071a07c63ba1038eefe13f0f
Tree-SHA512: adfefb373d09e68cae401247c8fc64034e305694cdef104bdcdacb9f1704277bd53b18f52a2427a5cffdbc77bda410d221aed252bc2ece698ffbb9cf1b830577
