Maurice
58f6a49f32
The 4.3.0 features had no pages, or pages that described an earlier state. Three new pages and a rewrite: - Road-Trip: the addon from enabling it to the phone tab, stays and a stop's End as the time you leave, pinned times and the backward schedule, daily travel times, the three driving limits, search along the route, via points, other ways and what avoiding tolls needs, following a track, the warning layer, MCP tools and troubleshooting. - Document-Sync: switching stores on, binding a trip, what each store asks for and binds, direction and delete rules, conflicts, the mass-delete guard, renames and restores, what needs a look, limits, private addresses, and the MCP tools. - TREK-Places-API: what the index is, where TREK asks it, what leaves the instance, switching it off or pointing it at a copy of your own, and what happens when it is down. - Dawarich: brought up to date with suggestions, the journal fold, recorded routes, Atlas proposals and the wish list. Places and search, documents, the addon and admin overviews, MCP tools, environment variables, internal network access, the sidebar and home link the new pages, and the in-app help picks them up from the sidebar.
6.7 KiB
Internal Network Access
TREK makes outbound HTTP requests when you configure integrations such as Immich or Synology Photos. By default, it blocks requests to private and local IP ranges to prevent server-side request forgery (SSRF) attacks. You need to allow internal network access when those services are hosted on your LAN.
Default behavior
TREK has two SSRF guards, both in ssrfGuard.ts. Which one applies depends on the call site, not on who configured the URL.
The strict guard (safeFetch / safeFetchFollow, built on checkSsrf) covers most outbound traffic: Immich, Synology Photos, AirTrail, Dawarich, the document stores behind Document-Sync (Paperless-ngx, Papra, Nextcloud, OpenCloud and Synology), notification webhooks, ntfy, Unsplash, and place lookups. It resolves the hostname to an IP address before allowing the connection and blocks loopback, link-local and private ranges. Only the private ranges open up, and only with ALLOW_INTERNAL_NETWORK=true. The two tables below describe this guard.
The relaxed guard (safeFetchAdminConfigured, also exported as safeFetchLlm) covers endpoints that are expected to live on your own network: OIDC (discovery, token, userinfo, JWKS), the LLM providers behind the AI Parsing addon (a local Ollama or any OpenAI-compatible endpoint), and plugin OAuth token exchanges. The self-hosted routing engines an admin sets for the Road-Trip addon (Own routing engine, Own Valhalla instance) go through it too when the server asks them itself, which it does for the MCP road trip tools. The planner asks them from the browser, so they must also be reachable from your users' devices. It deliberately permits loopback and LAN targets, so a model server on localhost or an identity provider on your LAN works without ALLOW_INTERNAL_NETWORK. It still resolves every hostname, re-checks every redirect hop, and always blocks link-local and cloud-metadata addresses (169.254.0.0/16, the full fe80::/10, and the AWS and Alibaba metadata addresses).
No guard applies to the addresses an admin sets in the environment for place search: TREK_PLACES_URL, NOMINATIM_URL and OVERPASS_URL. They are configuration rather than user input, so a self-run copy of the TREK Places API, a Nominatim or an Overpass instance on your LAN or in the same Docker network is reached without ALLOW_INTERNAL_NETWORK.
Always blocked (no override possible)
Under the strict guard, these ranges are blocked regardless of any setting:
| Range | Description |
|---|---|
127.0.0.0/8, ::1 |
Loopback |
0.0.0.0/8 |
Unspecified |
169.254.0.0/16, fe80::/16 |
Link-local / cloud metadata endpoints |
::ffff:127.x.x.x, ::ffff:169.254.x.x |
IPv4-mapped loopback and link-local |
The IPv6 link-local rule here matches the fe80: hextet only, which is narrower than the nominal fe80::/10 prefix (fe80: to febf:). In practice that is the same set of addresses, since RFC 4291 link-local addresses are always fe80::/64. The relaxed guard covers the whole /10.
Blocked unless ALLOW_INTERNAL_NETWORK=true
| Range / Hostname | Description |
|---|---|
10.0.0.0/8 |
RFC-1918 private |
172.16.0.0/12 |
RFC-1918 private |
192.168.0.0/16 |
RFC-1918 private |
100.64.0.0/10 |
CGNAT / Tailscale shared address space |
fc00::/7 |
IPv6 ULA |
| IPv4-mapped RFC-1918 variants | e.g. ::ffff:10.x, ::ffff:192.168.x |
*.local, *.internal, localhost hostnames |
mDNS / internal DNS suffixes (e.g. Docker service names, LAN hosts) and the literal localhost |
The hostname localhost is matched at the hostname stage too, but it normally resolves to a loopback address (127.0.0.1 or ::1), which the always-blocked loopback rule catches first, so under the strict guard it is blocked no matter how ALLOW_INTERNAL_NETWORK is set. On a host that maps localhost somewhere else, the hostname rule still applies and it stays blocked unless ALLOW_INTERNAL_NETWORK=true. The relaxed guard allows localhost outright, which is what makes a local Ollama the supported default for AI Parsing.
*.local and *.internal hostnames are permitted when ALLOW_INTERNAL_NETWORK=true: the guard still resolves them to an IP and enforces all IP-level rules, so any such hostname that resolves to a loopback or link-local address remains blocked regardless.
When to enable
Set ALLOW_INTERNAL_NETWORK=true when a service reached through the strict guard (Immich, Synology Photos, AirTrail, Dawarich, a document store bound through Document-Sync, or a notification webhook) is hosted on your local network and you need TREK to reach it. You do not need it for a local or LAN Ollama, an OpenAI-compatible endpoint, an OIDC provider on your LAN, your own OSRM or Valhalla, or plugin OAuth; those go through the relaxed guard and already work. Nor do you need it for your own TREK Places API, Nominatim or Overpass, which are not guarded at all. Leave the flag off if only those need internal access, since turning it on widens the surface for every strict-guard integration at once.
A service in another container on the same Docker network counts as internal too, because its container name resolves to a private address; so do a Tailscale address (100.64.0.0/10) and a .local name. A service on loopback (localhost, 127.0.0.1) is never reached through the strict guard, whatever the flag says: use the host's LAN address or the container name instead.
See Environment-Variables for how to set environment variables.
Admin: Set
ALLOW_INTERNAL_NETWORK=truein Environment-Variables before configuring Immich, Synology Photos, AirTrail, Dawarich or a document store on a LAN.
DNS rebinding protection
Even with ALLOW_INTERNAL_NETWORK=true, TREK pins the DNS resolution to prevent rebinding attacks. When the guard checks a URL, it resolves the hostname once and records the IP. The outbound connection is then made directly to that IP using a pinned dispatcher (via undici), so the hostname cannot re-resolve to a different address between the check and the actual request.
Audit log
When a user saves an Immich URL that resolves to a private IP, TREK records an immich.private_ip_configured entry in the Audit-Log including the URL and the resolved IP address. AirTrail does the same with airtrail.private_ip_configured, and Dawarich with dawarich.private_ip_configured. Synology Photos does not emit an equivalent event, and neither does document sync.