Constants

The ERRORS constants for the IP Protection feature are defined in toolkit/components/ipprotection/IPPProxyManager.sys.mjs, and the IPPMode constants in toolkit/components/ipprotection/IPPChannelFilter.sys.mjs.

Error Codes

The ERRORS object collects all error string constants used across the feature. Each value is a stable identifier that travels as a rejection reason or a state payload through the proxy activation pipeline and into the UI layer.

ERRORS.GENERIC: Catch-all fallback used when no more-specific code is available. The UI surfaces a generic error message.
ERRORS.NETWORK: The device is offline at activation time. The UI renders a dedicated network error message distinct from the generic one.
ERRORS.TIMEOUT: Activation exceeded the 30-second deadline. The activation is aborted and the proxy moves to the ERROR state.
ERRORS.PASS_UNAVAILABLE: The server did not return a valid proxy pass during activation.
ERRORS.SERVER_NOT_FOUND: No proxy server is available for the default location.
ERRORS.MISSING_PROMISE: Internal consistency guard: the activation promise was unexpectedly absent while the proxy was in the ACTIVATING state. Should never occur in normal operation.
ERRORS.MISSING_ABORT: Internal consistency guard: the abort controller was unexpectedly absent while stopping an in-progress activation. Should never occur in normal operation.
ERRORS.CANCELED: The activation was canceled by calling stop() while the proxy was still in the ACTIVATING state. The UI suppresses the error message in this case.
ERRORS.VPN_UNAVAILABLE: VPN service is unavailable in the given region.
ERRORS.CATASTROPHIC: The service failed in a way it cannot recover from.
ERRORS.NOT_READY: Activation was requested while the proxy was not in the READY state.
ERRORS.QUOTA_EXHAUSTED: The bandwidth limit has been reached, so the proxy is PAUSED rather than activating.
ERRORS.CONNECTION_FAILED: The connection never became active, even though a pass and a server were available.
ERRORS.SERVERLIST_UNAVAILABLE: The list of proxy servers could not be fetched.
ERRORS.MISSING_PASS: Internal consistency guard: a pass rotation completed without returning either a pass or an error. Should never occur in normal operation.

Error propagation

Errors thrown inside IPPProxyManager.start() are reported back to the caller; the panel uses the error code to determine which message to show. A failed user activation reverts the proxy to its previous state (typically READY). A failed system activation moves it to IPPProxyStates.ERROR instead, keeping the channel filter until stop(); ERRORS.NOT_READY and ERRORS.CANCELED still revert.

Errors that occur while the proxy is already ACTIVE (such as a pass rotation failure) move the state machine to IPPProxyStates.ERROR and are recorded as its errorType.

ERRORS.MISSING_PROMISE and ERRORS.MISSING_ABORT are thrown directly from start() or stop() as Error objects and bypass the activation promise; they represent internal consistency violations and do not affect proxy state.

Proxy Modes

IPPMode are the routing behaviors a connection can run in, applied to requests that no IPPSiteRuleManager rule matched. IPPMode.from() maps any other value onto MODE_FULL, and IPPMode.getDefault() reads the mode new connections start in from browser.ipProtection.mode.

IPPMode.MODE_FULL (0): Route every request. The default.
IPPMode.MODE_PB (1): Route only requests made from a private browsing window.
IPPMode.MODE_TRACKER (2): Route only requests classified as third-party tracking.
IPPMode.MODE_INCLUSION (3): Route nothing unless a site rule includes it.