Add PFM Support to Agoric (Pegasus)

[schnetzlerjoe]

Description

This PR adds a PFM contract into Pegasus to add Packet Forward Middleware support for Agoric. This is crucial for EVM call support for Calypso and Squid Router.

What this does is allow for IBC transfers to append either a forward transfer message to an IBC transfer or a contract call to the IBC transfer.

Security Considerations

This follows typical ocap security principals. The contract uses the namesByAddress lookup to find a publicFacet that was publically exposed to run functions on the facet. Thus you MUST purposely expose your instance facet to be called by PFM. If you can't access it, you can't run it.

The only other thing is, that this means on IBC transfer, all assets forwarded with the PFM message will be pushed into that message. Meaning, that if the forward is an IBC transfer, it forwards ALL of those assets to the next chain. If it's a contract call it sends ALL of the payment from the IBC transfer into the contract call. On failure, the assets just live in the users (the receivers address on the original IBC transfers) account.

Scaling Considerations

No

Testing Considerations

I added tests for the additions. They should be fine but let me know if we need more!

Upgrade Considerations

I would imagine Pegasus in some capacity would need to be upgraded? In order to add support to mainnet/testnet live Pegasus contract?

[michaelfig]

Okay, I've finally gotten a handle on what it is you're doing here. I agree that PFM support is important at this time, but I want to factor it differently.

I think we can leverage Agoric's modularity to follow Strangelove's PFM middleware architecture more closely. I would suggest that PFM can be implemented by wrapping Pegasus's Connection handler object then supplying that wrapper to the Network API to control the IBC channel instead of the original handler. That wrapper can intercept the Connection's callbacks, and use them to drive all the PFM logic without modifying Pegasus directly.

I'll reach out offline so we can discuss more about this.

[michaelfig]

setTimeout doesn't exist on chain, instead we need to use the TimerService.

[turadg]

I think this one is obsolete. If work resumes feel free to re-open.