feat(simapp): Wire rate limitting middleware to v2 in simapp

[Eric-Warehime]

Description

Wire rate limitting into v2 transfer stack within simapp.

closes: #XXXX

---

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[greptile-apps]

Greptile Summary

This PR wires the rate-limiting v2 middleware in front of the ICS-20 v2 transfer module within simapp, mirroring the existing v1 middleware stack. A thin v2ToV1Packet adapter bridges v2 payload types to the v1 keeper methods.

• Outgoing sends on native IBC v2 paths (non-aliased client IDs) will be unconditionally blocked: SendRateLimitedPacket calls channelKeeper.GetNextSequenceSend(ctx, port, sourceClient) where sourceClient is a client ID for pure v2 paths — no channel-sequence entry exists for those identifiers, so the function always returns ErrSequenceSendNotFound and the packet is rejected before reaching the transfer module.
• The keeper is passed as a value copy (*app.RateLimitKeeper) rather than as a pointer, diverging from the v1 convention and creating a potential for silent state divergence if SetICS4Wrapper is called after this line in the future.

Confidence Score: 3/5

Not safe to merge as-is; native IBC v2 sends on non-aliased paths are unconditionally blocked by the current keeper implementation.

A P1 defect where any outgoing native IBC v2 transfer (non-aliased client ID) triggers ErrSequenceSendNotFound inside SendRateLimitedPacket and is rejected, plus the pre-existing TODO in v2ToV1Packet flagging the conversion as potentially incorrect.

modules/apps/rate-limiting/v2/ibc_middleware.go — the v2ToV1Packet TODO and the OnSendPacket path that calls SendRateLimitedPacket need review before simapp can safely enable this middleware.

Important Files Changed

Filename	Overview
simapp/app.go	Wires the rate-limiting v2 middleware into the v2 transfer stack; introduces a P1 bug where native (non-aliased) IBC v2 sends are unconditionally blocked by GetNextSequenceSend returning not-found for client IDs, and a P2 value-copy inconsistency vs. the v1 middleware.

Sequence Diagram

sequenceDiagram
    participant Core as IBC Core v2
    participant RL as RateLimiting v2 Middleware
    participant Transfer as Transfer v2 Module
    participant Keeper as RateLimitKeeper

    Note over Core,Transfer: OnSendPacket (v2 path)
    Core->>RL: OnSendPacket(sourceClient, destClient, payload)
    RL->>RL: v2ToV1Packet(payload, sourceClient, destClient)
    RL->>Keeper: SendRateLimitedPacket(sourcePort, sourceClient, ...)
    alt sourceClient is aliased channel-ID
        Keeper->>Keeper: GetNextSequenceSend(port, channelID) ✅
        Keeper->>Keeper: CheckRateLimitAndUpdateFlow
        Keeper-->>RL: nil (allowed)
        RL->>Transfer: OnSendPacket(...)
    else sourceClient is native v2 client-ID
        Keeper->>Keeper: GetNextSequenceSend(port, clientID) ❌ not found
        Keeper-->>RL: ErrSequenceSendNotFound
        RL-->>Core: error (packet blocked)
    end

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_{Reviews (1): Last reviewed commit: "Add changelog" | Re-trigger Greptile}

[greptile-apps]

Native IBC v2 sends blocked for non-aliased client paths

SendRateLimitedPacket begins by calling k.channelKeeper.GetNextSequenceSend(ctx, sourcePort, sourceChannel) where sourceChannel is the sourceClient string from the v2 packet. For native IBC v2 paths that use actual client IDs (e.g. "07-tendermint-0") rather than aliased channel IDs, no channel-sequence entry is stored, so GetNextSequenceSend returns !found and the function immediately returns ErrSequenceSendNotFound — blocking the outgoing transfer entirely, regardless of whether any rate-limit quota is configured for that path.

The existing comment acknowledges this works for aliased v1 channels, but any native v2 client path will be unconditionally rejected by OnSendPacket. The v2 middleware should check whether the identifier corresponds to an aliased channel and skip the GetNextSequenceSend path (or skip the pending-packet tracking entirely) for native v2 client IDs.

[greptile-apps]

Value copy of keeper may drift from the singleton

*app.RateLimitKeeper dereferences the pointer and passes a shallow value copy of the keeper to NewIBCMiddleware. The v2 IBCMiddleware stores this copy by value (keeper keeper.Keeper). Any future call to app.RateLimitKeeper.SetICS4Wrapper(...) — e.g. added during stack-wiring refactors — would update only the original pointer and not the copy inside the v2 middleware. The v1 stack avoids this by passing the pointer directly. Consider accepting *keeper.Keeper in NewIBCMiddleware (mirroring the v1 signature) to keep both stacks consistent and resilient to future wiring changes.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.52%. Comparing base (41bc2d4) to head (e8b38aa).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8919   +/-   ##
=======================================
  Coverage   66.52%   66.52%           
=======================================
  Files         327      327           
  Lines       17143    17143           
=======================================
  Hits        11404    11404           
  Misses       5048     5048           
  Partials      691      691           

Flag	Coverage Δ
08-wasm	65.04% <ø> (ø)
ibc-go	66.57% <ø> (ø)

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[srdtrk]

Can you also wire this in testing/simapp/app.go

[srdtrk]

I think there is a problem in the rate limit v2, this keeper should have taken a pointer rather than a copy. So that we can have:

Suggested change

	transferStackV2 := ratelimitingv2.NewIBCMiddleware(*app.RateLimitKeeper, transferv2.NewIBCModule(app.TransferKeeper))
	transferStackV2 := ratelimitingv2.NewIBCMiddleware(app.RateLimitKeeper, transferv2.NewIBCModule(app.TransferKeeper))

This should be a simple change in ratelimitingv2.