* fix(artwork): block private and loopback addresses in remote image fetches
fromURL fetched any URL with a plain HTTP client, and two untrusted inputs reach it. A playlist
can set #EXTALBUMARTURL to an http(s) URL, which the artwork worker later fetches when
EnableM3UExternalAlbumArt is on, so any user who can import a playlist controls the target.
Metadata agents, including WASM plugins without the http permission, return image URLs that the
core fetches too. Either path could make the server request loopback, LAN or link-local
addresses and store the response as artwork that is served back.
Add httpclient.NewExternal, which dials through a net.Dialer Control hook that rejects private,
loopback, link-local and unspecified addresses. The check runs at dial time on the resolved IP,
so DNS names, redirects and DNS rebinding are covered. fromURL now uses one shared client built
with it and treats a refused address as a definitive miss, so the item settles absent instead of
retrying and tripping the agent's circuit breaker. httpclient.New is unchanged for the other callers.
The IP classification moves from plugins to the new utils/netguard package, shared by the plugin
host client and the new constructor. The artwork test suite swaps in a client that allows
loopback so existing specs can keep using httptest servers; the fromURL specs use the production
client to assert the refusal.
* fix(httpclient): keep dialing a configured proxy in the guarded client
The guard runs on the resolved address, and with HTTP_PROXY set that address is the proxy, not
the image host. A proxy on a private address would have had every remote artwork fetch refused,
and a refusal settles the item as absent, so covers would silently disappear for those setups.
Dial the configured proxy endpoint directly and keep the guard for every other dial. A proxy
relays the request itself, so it is the operator's egress policy, the same one every other
httpclient.New caller already goes through.
* fix(httpclient): exempt only the hop that actually goes through the proxy
The exemption matched any dial to a configured proxy's address, but net/http never proxies
loopback targets, so a URL aimed at a loopback proxy was dialed directly and skipped the guard.
That let an image URL reach that one address.
Tag each request with the proxy it resolves to and exempt a dial only when it is that hop.
Redirects re-enter the RoundTripper, so every hop is tagged on its own.
* fix(plugins): align the Python HTTP example with the repo's host-call pattern
Bind http_send with raw memory offsets like nowplaying-py does, drop
guards for fields the host always sends, and document how plugins
without a PDK call host services and which built-in HTTP APIs are
disabled.
* docs(plugins): document the private-address rules for HTTP requiredHosts
Explain in the README and manifest schema that named hosts can't reach
private addresses while IP/CIDR entries and a bare "*" can.
* docs(plugins): document the private-address rules for requiredHosts
Explain in the README and manifest schema that named hosts can't reach
private addresses while IP/CIDR entries and a bare "*" can, for both
HTTP and WebSocket. Inline the single-use HTTP isHostAllowed wrapper.
* feat(plugins): derive Default for Rust host service structs
The ndpgen client.rs template now adds Default to the derive list of host
service structs, as the capability and shared types templates already do.
Plugin authors can now set only the fields they need, for example
HTTPRequest { method, url, ..Default::default() }. The webhook-rs and
discord-rich-presence-rs examples use this form now. The golden files and
the generated nd-pdk-host crate are updated to match.
* feat(plugins): deprecate pdk.NewHTTPRequest in the Go PDK
Navidrome no longer enables extism's http_request host function, so a
request built with pdk.NewHTTPRequest always fails. ndpgen now reads a small
deprecation table and writes a Deprecated: paragraph for the listed extism
functions, in both the WASM wrapper and the native stub. Linters and IDEs
now point plugin authors to host.HTTPSend. The PDK example tests used to
teach NewHTTPRequest. They now use host.HTTPSend and host.HTTPMock.
* docs(plugins): correct requiredHosts rules for websocket and private addresses
Two statements in the plugin docs did not match the code.
The WebSocket section claimed requiredHosts behaves like HTTP. It does not:
host_httpclient.go only consults the allowlist when the list is non-empty and
otherwise falls back to allowing public addresses, while host_websocket.go
always calls isHostInAllowlist, so an absent list blocks every connection.
The HTTP section claimed a named host can never reach a private address.
checkPrivateDial scans the whole requiredHosts list, so a named host does
reach a private address when the same list also holds a covering IP or CIDR.
Reworded both, plus the matching requiredHosts descriptions in
manifest-schema.json, and regenerated manifest_gen.go.
* fix(plugins): apply the private-address dial guard to WebSocket connections
The WebSocket host service only matched the host string against
requiredHosts, so an allowlisted name resolving (or rebinding) to a
private address was dialed. Share the HTTP client's resolved-IP check
and allowlist matching, so WebSocket follows the same rules: named hosts
can't reach private addresses, literal IP/CIDR entries and a bare "*"
can.
* refactor(plugins): drop redundant WebSocket dial timeout and tidy guard tests
