secubox-openwrt/CLAUDE.md

Claude Instructions for SecuBox OpenWrt

OpenWrt Shell Scripting Guidelines

Process Detection

• Use pgrep crowdsec instead of pgrep -x crowdsec
  • The -x flag requires an exact process name match which doesn't work reliably on OpenWrt/BusyBox
  • Same applies to other daemons: use pgrep <name> without -x

Command Availability

• timeout command is NOT available on OpenWrt by default - use alternatives or check with command -v timeout
• ss command may not be available - use netstat or /proc/net/tcp as fallbacks
• sqlite3 may not be installed - provide fallback methods (e.g., delete database file instead of running SQL)

JSON Parsing

• Use jsonfilter instead of jq - jsonfilter is native to OpenWrt (part of libubox), jq is often not installed
• Syntax examples:

  # Get a field value
  jsonfilter -i /path/to/file.json -e '@.field_name'
  
  # Get nested field
  jsonfilter -i /path/to/file.json -e '@.parent.child'
  
  # Get array length (count elements)
  jsonfilter -i /path/to/file.json -e '@[*]' | wc -l
  
  # Get array element
  jsonfilter -i /path/to/file.json -e '@[0]'
  

• Always check for empty results: [ -z "$result" ] && result=0

Port Detection

When checking if a port is listening, use this order of fallbacks:

1. /proc/net/tcp (always available) - ports are in hex (e.g., 8080 = 1F90)
2. netstat -tln (usually available)
3. ss -tln (may not be available)

Logging

• OpenWrt uses logread instead of traditional log files
• Use logread -l N to get last N lines
• CrowdSec writes to /var/log/crowdsec.log

Build & Sync Workflow

CRITICAL: Sync Local Feed Before Building

• ALWAYS sync the local-feed before building packages from edited source trees
• The build system uses secubox-tools/local-feed/ NOT package/secubox/ directly
• If you edit files in package/secubox/<pkg>/, those changes won't be built unless synced

Before building after edits:

# Option 1: Sync specific package to local-feed
rsync -av --delete package/secubox/<package-name>/ secubox-tools/local-feed/<package-name>/

# Option 2: Sync all SecuBox packages
for pkg in package/secubox/*/; do
  name=$(basename "$pkg")
  rsync -av --delete "$pkg" "secubox-tools/local-feed/$name/"
done

# Then build
./secubox-tools/local-build.sh build <package-name>

Quick deploy without rebuild (for RPCD/shell scripts):

# Copy script directly to router for testing
scp package/secubox/<pkg>/root/usr/libexec/rpcd/<script> root@192.168.255.1:/usr/libexec/rpcd/
ssh root@192.168.255.1 '/etc/init.d/rpcd restart'

Local Feeds Hygiene

• Clean and resync local feeds before build iterations when dependency drift is suspected
• Prefer the repo helpers; avoid ad-hoc rm unless explicitly needed

Local Build Flow

• Use ./secubox-tools/local-build.sh build <module> for cached SDK builds
• If CI parity is required, use make package/<module>/compile V=s

Sync Build Artifacts

• After building, synchronize results into the build output folder used by local-build.sh
• Use the repo sync helper scripts where available to avoid missing root/ vs htdocs/ payloads

Toolchain Usage

• CRITICAL: Non-LuCI SecuBox apps MUST be built with the full OpenWrt toolchain, NOT the SDK

  • Go packages (crowdsec, crowdsec-firewall-bouncer) require the full toolchain due to CGO and ARM64 compatibility
  • Native C/C++ binaries (netifyd, nodogsplash) require the full toolchain
  • The SDK produces binaries with LSE atomic instructions that crash on some ARM64 CPUs (like MochaBin's Cortex-A72)

• Packages requiring full toolchain build (in secubox-tools/openwrt):

  • crowdsec - Go binary with CGO
  • crowdsec-firewall-bouncer - Go binary with CGO
  • netifyd - C++ native binary
  • nodogsplash - C native binary

• To build with full toolchain:

  cd secubox-tools/openwrt
  make package/<package-name>/compile V=s
  

• LuCI apps and pure shell/Lua packages can use the SDK:

  cd secubox-tools/sdk
  make package/<package-name>/compile V=s
  # Or use local-build.sh for LuCI apps
  

• If unsure, check OPENWRT_ONLY_PACKAGES in secubox-tools/local-build.sh

RPCD Backend Scripting (Shell-based RPC handlers)

jshn Argument Size Limits

• json_add_string cannot handle large values (e.g., base64-encoded images/SVGs)
• jshn passes values as shell arguments, which hit BusyBox's argument size limit ("Argument list too long")
• Workaround: Build JSON output manually via file I/O instead of jshn:

  local tmpfile="/tmp/wg_output_$$.json"
  printf '{"field":"' > "$tmpfile"
  # Stream large data via pipe/redirect (never as argument)
  some_command | base64 -w 0 >> "$tmpfile"
  printf '"}\n' >> "$tmpfile"
  cat "$tmpfile"
  rm -f "$tmpfile"
  

• This applies to any RPCD method that returns large blobs (QR codes, certificates, etc.)

UCI Private Data Storage

• Use underscore-prefixed option names for internal/hidden data: uci set network.section._private_field="value"
• These are not shown in standard LuCI forms but are accessible via uci -q get
• Useful for storing client private keys, internal state, etc.

LuCI JavaScript Frontend

RPC expect Field Behavior

• rpc.declare({ expect: { field: '' } }) unwraps the response — it returns ONLY the value of field, not the full object
• If the backend returns {"config": "...", "error": "..."} and expect is { config: '' }, the result is just the config string — result.error is undefined
• Use expect: { } (empty object) when you need the full response including error fields
• Use expect: { field: default } only when you always want just that one field and don't need error handling

Module Caching

• LuCI's JS module loader caches parsed modules in memory — Ctrl+Shift+R does NOT clear this
• Clearing browser cache, rm /tmp/luci-indexcache*, and rm /tmp/luci-modulecache/* may not be enough
• Reliable fix: Force full page navigation with cache-busting query param:

  window.location.href = window.location.pathname + '?' + Date.now();
  

• For development, set uci set uhttpd.main.no_cache=1 && uci commit uhttpd && /etc/init.d/uhttpd restart

Quick Deploy for LuCI JS/RPCD Changes

• LuCI JS views and shared resources can be deployed directly to the router without rebuilding:

  # Deploy JS views
  scp htdocs/luci-static/resources/view/<app>/*.js root@192.168.255.1:/www/luci-static/resources/view/<app>/
  
  # Deploy shared JS libraries
  scp htdocs/luci-static/resources/<app>/*.js root@192.168.255.1:/www/luci-static/resources/<app>/
  
  # Deploy RPCD handler and restart
  scp root/usr/libexec/rpcd/<handler> root@192.168.255.1:/usr/libexec/rpcd/
  ssh root@192.168.255.1 '/etc/init.d/rpcd restart'
  
  # Clear LuCI caches on router
  ssh root@192.168.255.1 'rm -f /tmp/luci-indexcache* /tmp/luci-modulecache/*'
  

Common Pitfalls

• RPC params order matters: The params array in rpc.declare() must match the positional arguments in addPeer(arg1, arg2, ...) calls — adding a new param means updating ALL callers
• sessionStorage is volatile: Data stored in sessionStorage is lost on tab close/refresh — don't rely on it for persistent data; use UCI backend storage instead
• Interface name conflicts: When creating WireGuard interfaces, always check for existing names (wg0, wg1, etc.) and auto-increment to the next available name