Permissioned markets

[armaniferrante]

Summary

Changes that provide the ability to host "permissioned markets" on the orderbook.

A permissioned market is a regular Serum market with an additional authority, which must sign every transaction to create an open orders account. In practice, what this means is that one can create a program that acts as this authority and that marks its own PDAs as the owner of all created open orders accounts, making the program the sole arbiter over who can trade on a given market and what trades can be made.

An example can be found here, where all trades that execute on the markets authorized by the program are required to both provide an identity token and set the referral to a hard coded address.

Accounts

Adds an authority and prune_authority field to the MarketState. To do this in a way that is not breaking, this PR

• Creates a MarketStateV2 account layout that adds the new fields.
• Creates a frontend Market enum that acts as a a unified interface for accessing the different market state versions.
• When creating a market, if the authority doesn't exist, then creates a v1 market state account. Otherwise creates a v2 market state account.
• When reading a market, check the data length. If it's equal to the v1 market state account, interpret as v1. Otherwise, interpret as v2.

Instructions

• Adds a Prune instruction that removes all orders from the order book. This instruction must be authorized by the prune authority (optional).
• Otherwise, no instruction data is changed.
• Accounts list changes are made to InitializeMarket and InitOpenOrders instructions, where an optional account--the market authority and prune authority (for InitailizeMarket)--is_ added to each instruction.

Related Changes

• examples: Permissioned markets otter-sec/anchor#483
• examples: Permissioned markets 2 otter-sec/anchor#519
• serum: Permissioned markets serum-ts#136

Individual PRs.

For easier review, I've broken these changes into three PRs.

• Dynamic sysvars: Dynamic sysvars #155
• Open orders creation authority: Add market authority for creating open orders accounts #156
• Orderbook pruning: Prune orders instruction #157
• Fuzz tests: Permissioned authority fuzz tests #158

Breaking Changes

Although the program can be upgraded in a way such that existing accounts and composing programs on-chain will not break, there are some breaking changes made to the serum_dex crate.

• MarketState::load method is removed. Programs and clients should switch to using Market::load.
• instruction::init_open_orders has a new Option<&Pubkey> parameter added for the market authority.
• instruction::initialize_market has a new Option<&Pubkey> parameter added for the market authority.

[armaniferrante]

This change is required so that an open orders PDA can be the authority of itself. On CPI, solana_program::program::invoke will try to borrow the refcell, and so this borrow must be dropped prior to CPI.

[armaniferrante]

Maybe we should add padding so that we can add additional fields in the future.

[armaniferrante]

I've broken this PR into three components that can be reviewed separately.

• Dynamic sysvars Dynamic sysvars #155
• Open orders creation authority Add market authority for creating open orders accounts #156
• Prune authority + prune instruction Prune orders instruction #157

[armaniferrante]

Closing. See the description above for subsequent changes.