When a peer sends us the routing graph, it may include gossip
messages for our channels, despite it not being a party to them.
This is completely fine, but we currently print a somewhat-scary
looking log messages in these cases, eg:
```
ERROR [lightning::ln::channelmanager:4104] Got a message for a channel from the wrong node!
TRACE [lightning::ln::peer_handler:1267] Handling SendErrorMessage HandleError event in peer_handler for node ... with message Got a message for a channel from the wrong node!
```
Instead, we should simply not consider this an "error" condition
and stay silent.
The only practical way to meet this requirement is to block
disconnect_socket until any pending events are fully processed,
leading to this trivial deadlock:
* Thread 1: select() woken up due to a read event
* Thread 2: Event processing causes a disconnect_socket call to
fire while the PeerManager lock is held.
* Thread 2: disconnect_socket blocks until the read event in
thread 1 completes.
* Thread 1: bytes are read from the socket and
PeerManager::read_event is called, waiting on the lock
still held by thread 2.
There isn't a trivial way to address this deadlock without simply
making the final read_event call return immediately, which we do
here. This also implies that users can freely call event methods
after disconnect_socket, but only so far as the socket descriptor
is different from any later socket descriptor (ie until the file
descriptor is re-used).
`Julian Knutsen <julianknutsen@users.noreply.github.com>` pointed
out in a previous discussion that `read_event` can reenter user
code despite the documentation stating explicitly that it will not.
This was addressed in #456 by simply codifying the reentrancy, but
its somewhat simpler to just drop the `do_attempt_write_data` call.
Ideally we could land most of Julian's work, but its still in need
of substantial git history cleanup to get it in a reviewable state
and this solves the immediate issue.
We can never assume that messages were reliably delivered whether
we placed them in the socket or not, so there isn't a lot of use in
explicitly handling the case that a peer was not connected when we
went to send it a message.
Two TODOs are left for the generation of a `FundingAbandoned` (or
similar) event, though it ultimately belongs in `ChannelManager`.
Previously, poll::Validate was pub(crate) to force external implementors
of Poll to define their implementation in terms of ChainPoller. This was
because ChainPoller::look_up_previous_header checks for consistency
between headers and any errors would be checked at that level rather
than by the caller. Otherwise, if performed by the caller, a Poll
implementation would not be aware if the underlying BlockSource was
providing bad data and therefore couldn't react accordingly.
Widening the visibility to pub relaxes this requirement, although it's
still encourage to use ChainPoller to implement Poll. This permits
either copying or moving lightning-block-sync's test utilities to a
separate crate since they use poll::Validate.
Latest rustc warns that "this URL is not a hyperlink" and notes that
"bare URLs are not automatically turned into clickable links". This
resolves those warnings.
Thanks to Joshua Nelson for pointing out the correct syntax for
this.
Lightning invoices allow for zero or more multi-hop route hints. Update
get_route's interface to accept such hints, although only the last hop
from each is used for the time being.
Moves RouteHint from lightning-invoice crate to lightning crate. Adds a
PrivateRoute wrapper around RouteHint for use in lightning-invoice.
