From d8c55d2a072433e16ae5c84b7b7c676587f6f2d9 Mon Sep 17 00:00:00 2001 From: Your Name Date: Mon, 18 May 2026 15:33:12 +0530 Subject: docs: add tollgate_core component architecture design plan Design document for extracting core TollGate modules (cashu, dns, firewall, session) into a reusable ESP-IDF component consumed by esp-miner via the IDF Component Manager. Includes platform interface specification, wallet integration design, dependency analysis, and phased implementation checklist. Refs: feature/tollgate-core-component --- docs/TOLLGATE_CORE_DESIGN.md | 380 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 380 insertions(+) create mode 100644 docs/TOLLGATE_CORE_DESIGN.md (limited to 'docs/TOLLGATE_CORE_DESIGN.md') diff --git a/docs/TOLLGATE_CORE_DESIGN.md b/docs/TOLLGATE_CORE_DESIGN.md new file mode 100644 index 0000000..fe31c91 --- /dev/null +++ b/docs/TOLLGATE_CORE_DESIGN.md @@ -0,0 +1,380 @@ +# TollGate Core Component: Architecture Design + +## Goal + +Maintain all TollGate business logic in `esp32-tollgate` as a reusable ESP-IDF +component (`tollgate_core`), and consume it in `esp-miner` (BitAxe) via the +**IDF Component Manager**. No code duplication, no manual sync. + +## Current State (Pre-Refactoring) + +All TollGate modules live flat in `esp32-tollgate/main/`: + +``` +esp32-tollgate/main/ + cashu.c / cashu.h + dns_server.c / dns_server.h + firewall.c / firewall.h + session.c / session.h + tollgate_api.c / tollgate_api.h + tollgate_client.c / tollgate_client.h + config.c / config.h + ... +``` + +The ESP-Miner port (`esp-miner/main/tollgate_*.c`) is a manual copy with edits: +stripped prefixes (`cashu_` → `tollgate_cashu_`), NVS config instead of +`config.h` singleton, removed wallet integration, moved cross-module wiring. + +### Shared Code by Module + +| Module | Shared % | Key Differences | +|--------|----------|-----------------| +| cashu | 73% | Config access, mint check parameterized | +| dns_server | 74% | Minor logic reorder, logging stripped | +| firewall | 94% | Cross-module DNS notification moved | +| session | 79% | Bytes metric stripped, DNS notification added | +| tollgate_api vs tollgate.c | 13% | Full rewrite (HTTP server vs library API) | +| tollgate_client | 0% | No ESP-Miner equivalent | + +## Target Architecture + +### Directory Layout (in `esp32-tollgate`) + +``` +esp32-tollgate/ + components/ + tollgate_core/ ← shared ESP-IDF component + CMakeLists.txt + idf_component.yml ← component metadata for IDF Component Manager + include/ + tollgate_core.h ← public API + tollgate_platform.h ← platform interface (config/state callbacks) + src/ + tollgate_core_cashu.c ← from main/cashu.c + tollgate_core_cashu.h + tollgate_core_dns.c ← from main/dns_server.c + tollgate_core_dns.h + tollgate_core_firewall.c ← from main/firewall.c + tollgate_core_firewall.h + tollgate_core_session.c ← from main/session.c + tollgate_core_session.h + nucula_lib/ ← stays as-is (git submodule + wrapper) + CMakeLists.txt + nucula_wallet.cpp / .h + main/ + tollgate_platform.c ← standalone impl of tollgate_platform.h + tollgate_api.c / .h ← standalone HTTP server (unchanged) + tollgate_client.c / .h ← standalone client mode (unchanged) + config.c / config.h ← standalone config (unchanged) + ... +``` + +### How ESP-Miner Consumes It + +In `esp-miner/main/idf_component.yml`: + +```yaml +dependencies: + tollgate/core: + git: https://github.com//esp32-tollgate.git + path: components/tollgate_core +``` + +ESP-Miner provides only: + +``` +esp-miner/main/ + tollgate_platform.c ← implements tollgate_platform.h (NVS config) + tollgate.c / .h ← ESP-Miner orchestrator (owner detection, WiFi events) + tollgate_page.html ← captive portal payment UI + lwip_tollgate_hooks.h ← LWIP hook (stays in esp-miner) + http_server.c ← modified to call tollgate_core API +``` + +### Why IDF Component Manager (not submodule) + +| Aspect | IDF Component Manager | Git Submodule | +|--------|----------------------|---------------| +| What's downloaded | Only `components/tollgate_core/` | Entire `esp32-tollgate` repo | +| Update mechanism | Modify version in yml, rebuild | Manual `git submodule update` | +| Transitive deps | Automatic (nucula_lib resolved) | Must manage manually | +| CI/CD | Automatic on `idf.py build` | Needs `--recursive` clone | +| Offline after first build | Yes (cached in managed_components) | Yes | +| Contributor friction | Low (automatic) | Moderate (forgot --recursive) | + +ESP-Miner never reaches into tollgate_core's source tree. It calls a clean API +and provides a platform implementation. This is exactly the "packaged API +consumption" pattern the Component Manager is designed for. + +### Why Git Submodule for nucula (not Component Manager) + +nucula is consumed differently — it's a **raw source integration**: + +```cmake +# nucula_lib/CMakeLists.txt reaches INTO the submodule and cherry-picks files: +set(NUCULA_SRC ${CMAKE_CURRENT_SOURCE_DIR}/../../nucula_src/main) +idf_component_register( + SRCS "nucula_wallet.cpp" + "${NUCULA_SRC}/crypto.c" # cherry-picked + "${NUCULA_SRC}/wallet.cpp" # cherry-picked + "${NUCULA_SRC}/cashu_json.cpp" # cherry-picked (6 of ~20 files) + "${NUCULA_SRC}/nut10.cpp" + "${NUCULA_SRC}/hex.c" + "${NUCULA_SRC}/http.c" + ... +) +``` + +The Component Manager downloads packaged components — you get everything or +nothing. You can't say "give me this component but only compile these 6 files +from it." A git submodule gives you the raw source tree on disk, which is what +cherry-picking requires. + +**Principle:** Need to reach into source tree and pick files? → Submodule. +Only need a clean API? → Component Manager. + +### The Platform Interface + +```c +// components/tollgate_core/include/tollgate_platform.h + +#ifndef TOLLGATE_PLATFORM_H +#define TOLLGATE_PLATFORM_H + +#include +#include + +typedef struct { + // Config access (each project implements its own storage) + uint16_t (*get_price_sats)(void); + int32_t (*get_step_ms)(void); + const char * (*get_mint_url)(void); + const char * (*get_metric)(void); // "milliseconds" or "bytes" + int32_t (*get_step_bytes)(void); + + // Time source + int64_t (*get_time_ms)(void); + + // Wallet integration: called after proofs verified, before session create + // Return true to proceed, false to reject payment + // Can be NULL (accepts payment without spending proofs — double-spend risk) + bool (*spend_proofs)(const char *raw_token_json); +} tollgate_platform_t; + +#endif +``` + +**Standalone implementation** (`main/tollgate_platform.c`): +- Reads from `tollgate_config_get()` singleton (SPIFFS-backed) +- `spend_proofs` calls `nucula_wallet_receive()` to swap proofs at the mint + +**ESP-Miner implementation** (`main/tollgate_platform.c`): +- Reads from `nvs_config_get_*()` (NVS flash) +- `spend_proofs` is initially NULL (Phase 1: accept without spending) +- Later: calls nucula_wallet_receive when wallet component is integrated + +### Wallet Integration: The Double-Spend Problem + +The `spend_proofs` hook exists because of a real security gap: + +``` +Client sends Cashu token + │ + ▼ +cashu_decode_token() ← extract proofs + │ + ▼ +cashu_check_proof_states() ← HTTP POST to mint /v1/checkstate: "unspent?" + │ + ▼ +spend_proofs() ← THE CRITICAL STEP + │ standalone: nucula_wallet_receive() → swap at mint + │ esp-miner: NULL → skipped (double-spend window) + ▼ +session_create() ← grant client access +``` + +Without `spend_proofs`, a client can replay the same token on multiple devices. +Both check "unspent?" → both say yes → both grant access. The swap step marks +proofs as spent at the mint, closing the window. + +ESP-Miner accepts this risk initially. When `spend_proofs` is NULL, the +component logs a warning. Phase 2 of ESP-Miner integration adds nucula and +implements the hook. + +### Cross-Module Wiring (Internal to tollgate_core) + +The `session → firewall → dns_server` notification chain stays internal: + +``` +tollgate_core_session_create() + → tollgate_core_firewall_grant(ip) + → tollgate_core_dns_set_authenticated(ip, true) + +tollgate_core_session_revoke() + → tollgate_core_firewall_revoke(ip) + → tollgate_core_dns_set_authenticated(ip, false) +``` + +Consumers never see this. They call `tollgate_core_process_payment()` and +`tollgate_core_tick()`. The internal wiring is an implementation detail. + +### Full Dependency Graph + +``` +esp-miner + └── IDF Component Manager → tollgate_core (API-level boundary) + ├── CMakeLists.txt REQUIRES: nucula_lib + └── Platform: esp-miner provides tollgate_platform_t (NVS-backed) + +esp32-tollgate (standalone) + └── tollgate_core (local component, same repo) + ├── CMakeLists.txt REQUIRES: nucula_lib + └── Platform: main/tollgate_platform.c (config singleton-backed) + +nucula_lib (local component in esp32-tollgate) + └── cherry-picks source files from nucula_src/ (git submodule → zeugmaster/nucula) +``` + +### Dependency Chain for IDF Component Manager + +When `esp-miner` declares: + +```yaml +dependencies: + tollgate/core: + git: https://github.com//esp32-tollgate.git + path: components/tollgate_core +``` + +The Component Manager: +1. Clones `esp32-tollgate` (or fetches the component archive) +2. Reads `tollgate_core/idf_component.yml` → finds dependency on `nucula_lib` +3. Since `nucula_lib` is a sibling component in the same repo, resolves it + from the same clone +4. Downloads into `managed_components/` +5. `nucula_lib` depends on `secp256k1` (local component) and `nucula_src` + (submodule) — these must be available within the cloned repo + +**Note:** The git submodule within `nucula_src` needs verification. The IDF +Component Manager may or may not initialize submodules within a git-sourced +dependency. This needs testing. If it doesn't, `nucula_lib` may need to bundle +the required nucula source files directly instead of referencing a submodule. + +## Blocking Dependencies + +This refactoring **must not proceed** until these branches land on master: + +| Branch | Blocking Files | Status | +|--------|---------------|--------| +| `feature/multi-mint-support` | `cashu.c`, `tollgate_api.c`, `main/CMakeLists.txt`, `nucula_wallet.cpp/h`, `captive_portal.c`, `mint_health.c/h`, `config.c/h` | **In progress** | +| `feature/price-discovery` | `tollgate_api.c`, `tollgate_client.c`, `main/CMakeLists.txt`, `config.c/h`, `beacon_price.c/h`, `market.c/h` | **In progress** | +| `feature/cvm-integration` | Same commit as master — no new changes | **Merged already** | + +**Specific conflicts if we refactor now:** +- Moving `cashu.c` → `tollgate_core_cashu.c` while multi-mint modifies `cashu.c` +- Moving `dns_server.c` while price-discovery may touch it +- Modifying `main/CMakeLists.txt` (remove SRCS) while all branches modify it +- Modifying `tollgate_api.c` call sites while multi-mint and price-discovery modify it + +## Refactoring Plan (After Blocking PRs Merge) + +### Phase 0: Prerequisites + +- [ ] All blocking PRs merged to master +- [ ] This branch rebased onto latest master +- [ ] Full build passes on master + +### Phase 1: Create Component Skeleton + +- [ ] Create `components/tollgate_core/` directory structure +- [ ] Create `components/tollgate_core/include/tollgate_core.h` (public API) +- [ ] Create `components/tollgate_core/include/tollgate_platform.h` (platform interface) +- [ ] Create `components/tollgate_core/idf_component.yml` (component metadata) +- [ ] Create `components/tollgate_core/CMakeLists.txt` (register component, REQUIRES nucula_lib) +- [ ] Verify empty component builds without errors + +### Phase 2: Move Core Modules (one at a time, build after each) + +- [ ] Copy `main/cashu.c/h` → `components/tollgate_core/src/tollgate_core_cashu.c/h` + - [ ] Rename functions: `cashu_*` → `tollgate_core_cashu_*` + - [ ] Replace `tollgate_config_get()` calls with platform callbacks + - [ ] Remove direct `config.h` include + - [ ] Build and verify +- [ ] Copy `main/dns_server.c/h` → `components/tollgate_core/src/tollgate_core_dns.c/h` + - [ ] Rename functions: `dns_server_*` → `tollgate_core_dns_*` + - [ ] No platform dependencies (pure LWIP) — should be clean copy + - [ ] Build and verify +- [ ] Copy `main/firewall.c/h` → `components/tollgate_core/src/tollgate_core_firewall.c/h` + - [ ] Rename functions: `firewall_*` → `tollgate_core_firewall_*` + - [ ] Internalize `dns_set_authenticated` calls (keep within component) + - [ ] Remove `dns_server.h` external dependency + - [ ] Build and verify +- [ ] Copy `main/session.c/h` → `components/tollgate_core/src/tollgate_core_session.c/h` + - [ ] Rename functions: `session_*` → `tollgate_core_session_*` + - [ ] Replace `config.h` calls with platform callbacks for metric check + - [ ] Internalize firewall notification (already calls firewall directly) + - [ ] Support both time and bytes metrics (portable, not stripped) + - [ ] Build and verify + +### Phase 3: Wire Component API + +- [ ] Implement `tollgate_core_init(const tollgate_platform_t *platform)` — stores platform, inits all sub-modules +- [ ] Implement `tollgate_core_process_payment(ip, token)` — decode → verify → spend → create session +- [ ] Implement `tollgate_core_client_connected(mac, ip)` — owner detection + firewall check +- [ ] Implement `tollgate_core_client_disconnected(mac)` — session cleanup + owner reassign +- [ ] Implement `tollgate_core_tick()` — session expiry check +- [ ] Implement `tollgate_core_get_status_json()` — JSON status +- [ ] Implement `tollgate_core_get_config_json()` — JSON config (via platform) +- [ ] Build and verify standalone + +### Phase 4: Standalone Platform Implementation + +- [ ] Create `main/tollgate_platform.c` implementing `tollgate_platform_t` + - [ ] `get_price_sats` → `tollgate_config_get()->price_per_step` + - [ ] `get_step_ms` → `tollgate_config_get()->step_size` + - [ ] `get_mint_url` → `tollgate_config_get()->mint_url` + - [ ] `get_metric` → `tollgate_config_get()->metric` + - [ ] `get_step_bytes` → `tollgate_config_get()->step_bytes` + - [ ] `get_time_ms` → `xTaskGetTickCount() * portTICK_PERIOD_MS` + - [ ] `spend_proofs` → `nucula_wallet_receive()` +- [ ] Update `main/tollgate_api.c` to call `tollgate_core_*` instead of direct module calls +- [ ] Update `main/tollgate_main.c` init sequence +- [ ] Remove old `main/cashu.c`, `main/dns_server.c`, `main/firewall.c`, `main/session.c` +- [ ] Update `main/CMakeLists.txt` (remove old SRCS, add `tollgate_platform.c`) +- [ ] Full standalone build + test + +### Phase 5: ESP-Miner Integration + +- [ ] Update `esp-miner/main/idf_component.yml` to add tollgate_core dependency +- [ ] Create `esp-miner/main/tollgate_platform.c` implementing `tollgate_platform_t` + - [ ] Config reads from NVS (`nvs_config_get_*`) + - [ ] `spend_proofs` = NULL initially (Phase 1: accept without spending) +- [ ] Update `esp-miner/main/tollgate.c` to call `tollgate_core_*` API +- [ ] Remove `esp-miner/main/tollgate_cashu.c`, `tollgate_dns.c`, `tollgate_firewall.c`, `tollgate_session.c` +- [ ] Update `esp-miner/main/CMakeLists.txt` (remove old SRCS) +- [ ] Full ESP-Miner build + test + +### Phase 6: Verify Component Manager Flow + +- [ ] Remove local `managed_components/` if present +- [ ] Run `idf.py reconfigure` in esp-miner — verify Component Manager downloads tollgate_core +- [ ] Run `idf.py build` — verify transitive dependency resolution (nucula_lib + nucula_src) +- [ ] Test that submodule within nucula_src is properly initialized by Component Manager +- [ ] If submodule init fails: bundle nucula source files directly in nucula_lib instead + +### Phase 7: Documentation and Cleanup + +- [ ] Update `esp-miner/main/idf_component.yml` with correct git URL +- [ ] Update `esp-miner/TOLLGATE_PR_PLAN.md` to reflect component-based architecture +- [ ] Add `docs/` to `tollgate_core` with integration guide for new consumers +- [ ] Update `esp-miner/TOLLGATE_CHECKLIST.md` +- [ ] Verify both projects build clean from scratch + +## Open Questions + +- [ ] Does the IDF Component Manager initialize git submodules within git-sourced dependencies? +- [ ] Should tollgate_core publish to the ESP Component Registry (public) or stay git-only? +- [ ] What versioning scheme for tollgate_core? (semver tags in esp32-tollgate?) +- [ ] Should `tollgate_client.c` (client mode) eventually move into tollgate_core? -- cgit v1.2.3