Given the scenario of 3 peers, A, B, and C each having a project R. If
peer A has B's fork, but C does not, then when peer A attempts to
fetch from C the fetch will be rejected since Git will fail when a
refspec that is asked for does not exist on the remote side.
To avoid this, the fetch logic is changed so that the client first calls
ls-remote to the remote side, which results in the references that the
remote has which the client is interested in. The follow-up fetch then
uses these refs as the refspecs -- which should succeed unless there
was a race for a deletion on the remote side.
The rest of the verification logic stays the same, so the storage
should still be in a working state before transferring from the staged
repository to the production repository.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
Ensure that non-existent tracking relationships do not affect
fetching.
This is tested by first performing a clone, by `bob` from `alice`,
after `bob` tracks a remote that does not exist. `alice` creates an
issue which is then fetched by `bob` -- to ensure the fetching
scenario is also tested.
Signed-off-by: Fintan Halpenny <fintan.halpenny@gmail.com>
X-Clacks-Overhead: GNU Terry Pratchett
We were allowing remotes to be constructed via a function that didn't
check its inputs.
This is now fixed by moving the public key into the `SignedRefs` struct.
It's currently possible for a channel to be blocked forever while
waiting for data, if the remote peer keeps the connection alive.
This can occupy a worker indefinitely.
With these timeouts, we ensure that workers exit if there is no
activity after a certain amount of time.
This command announces refs to peers and waits for them to be
in sync.
Adds a subscribe method to `Handle` so that we can get the events
from the seed to allow us to confirm that the configured seeds fetched
from us.
By having the keep-alive delta be the same as the ping timeout,
we essentially disconnected peers right after we sent them our
first ping.
This fixes that issue by setting the ping timeout to double the
keep-alive delta.
Instead of returning the namespaces that we fetched with,
we return the remotes that were actually fetched from.
This can differ if some trusted peers were not available
on the remote node.
Previously, if that was the case, it would cause errors
since the remotes were looked up and that lookup failed.
With this change, we not only verify the signed refs before
the repository "transfer", but also validate that all refs in the
repo are signed and there is no discrepancy with the signed refs
file.
If `git-fetch` returns a non-zero code on exit, we keep going in the
case of an existing repository.
The reason is that `git-fetch` will return an error code if any ref
is rejected during the fetch. But this can happen if someone
pushes conflicting `rad/sigrefs` branches for example, and the node
already has a copy of that branch.
Instead of parsing the worker requests and responses, which was causing issues
around packfile transmission, we use threads and pass the bytes
transparently.
Previously we were announcing inventories all the time, due to
relying on the timestamp changing on insertion.
We change this to only announce our inventory when it actually changes.
Previously, during the "transfer" stage of a fetch, we used `force:
false`, which didn't allow refs to be force-updated.
This change makes it possible to fetch force-updated refs, but ensures
that the sigrefs branch is never force-updated.
To improve the reliability and flexibility of the protocol, we introduce
multiplexing over peer connections. This involves a new `Frame` type
that carries a stream-id and payload.
Three stream types are made available:
1. Control
2. Gossip
3. Git
This change brings the following improvements:
* Removed need to queue fetch requests
* Removed need to queue gossip messages
* Removed need for `Fetch` and `FetchOk` messages
* Service doesn't need to know about inbound fetches
* Removed one round-trip for fetch negotiation
* Removed special `done` git packet
* Removed session logic and state around Git/Fetch protocols
* Removed code around upgrading/downgrading transport
* Worker in responder mode is able to process any number of fetches
* Connections support any number of concurrent fetches
We had to introduce a few extra things however to make it all work:
* A `VarInt` type for variable-length integers, since we want the frames
to be lightweight.
* A custom "tunnel" implementation, since we couldn't use the existing
one anymore.
Overall the change removes more complexity than it adds, while improving
the protocol along the way.
Fintan Halpenny
xphoniex
Alexis Sellier