We already have the ability to get peer information from ChanMgr
errors, and therefore from any RetryErrors that contain ChanMgr
errors.

This commit adds optional peer information to tor-proto errors, and
a function to expose whatever peer information is available.

It'll soon more convenient to pass in FallbackDirs as a slice of
references, rather than just a slice of FallbackDirs: I'm going to
be changing how we handle these in tor-dirmgr.

If all guards are down and they won't be retriable for a while, try
waiting that long to get whichever guard _is_ retriable.

Additionally, if we are making multiple circuit plans in parallel,
only report our planning as having failed if we failed at making
_all_ the plans.  Previously we treated any failure as fatal for the
other plans, which could lead to trouble in the case when guards
were all down or pending.

Part of #407.

When all guards are down, we would previously mark them all as up,
and retry aggressively.  But that's far too aggressive: if there's
something wrong with our ability to connect to guards, it makes us
hammer the network over and over, ignoring all the guard retry
timeouts in practice.

Instead,
  * We now allow the `pick_guard()` function to fail without
    automatically retrying.
  * We give different errors in the cases when all our guards are
    down, and when all of the guards selected by our active usage
    are down.
  * Our "guards are down" error includes the time at which a guard
    will next be retriable.

This is part of #407.

C tor used one schedule, and guard-spec specified another.  But in
reality we should probably use a randomized schedule to retry
guards, for the reasons explained in the documentation for
RetrySchedule.

I've chosen the minima to be not too far from our previous minima
for primary and non-primary guards.

This is part of #407.

UdpSocket: remove support for connect().

Closes #410

See merge request tpo/core/arti!424

Combine logging config and implementation in arti lib crate

See merge request tpo/core/arti!421

This was clumsy.  Now it is brought together it can be simplified.

This de-duplicates the code that was in those accessors, and is now in
filt_from_opt_str.

Code motion and direct field access.

There are no longer needed, because the code that uses this
configuration now lives in the same module as the configuration
itself.

Code motion and import fixups.

We are going to move LoggingConfig here.  We should follow the
already-public name IMO.

Code motion and import fixups.

Abolish some accessors in drmgr

See merge request tpo/core/arti!423

Ian Jackson authored 3 years ago and Nick Mathewson committed 3 years ago

This makes this information crate-private.  The crate can reasonably
just access it.

Ian Jackson authored 3 years ago and Nick Mathewson committed 3 years ago

Using accessors for crate-only fields is otiose.

Ian Jackson authored 3 years ago and Nick Mathewson committed 3 years ago

Rename this to be named the same as its accessor, and use the rename
feature of builder and serde.  (The shorter name is nicer in the code
IMO.)

Currently, Arti doesn't need this.  But once it does, it will be
way better to have a separate type for connected sockets, rather
than having to error-check every time somebody gives us a socket.

Part of #410

Actually throw an anyhow

See merge request tpo/core/arti!422

Prompted by a compiler warning which I weirdly can't seem to reproduce?

ClientCirc: add functions to return the circuit's actual path

Closes #415

See merge request tpo/core/arti!419

Use less space in hashtables for microdescriptors

Closes #386

See merge request tpo/core/arti!415

Closes #415

Alternative API for set_isolation_group().

See merge request tpo/core/arti!418

Each channel now remembers an OwnedChanTarget.

Each circuit now remembers a vector of OwnedChanTarget to represent
the path that it was constructed for.

Part of #415.

This will help with #415

Instead of requiring a `Box<dyn Isolation>`, it now takes either a
`Box<dyn Isolation>`, or an arbitrary `T` that implements
`Isolation`.

This API still allows the user to pass in a `Box<dyn Isolation>` if
that's what they have, but it doesn't require them to Box the
isolation on their own.

Part of #414.

new api for isolation

See merge request tpo/core/arti!377

Absolish builders for CircMgrConfig and DirMgrConfig

See merge request tpo/core/arti!417