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Commit 6fb4bdc4 authored by henry's avatar henry Committed by Pier Angelo Vendrame
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fixup! TB 40597: Implement TorSettings module 

TB 43405: TorSettings handles failures to apply Tor settings.

We update TorSettings.#applySettings to catch TorProvider write errors
and signal this error with "ApplyError".

We also keep track of which group of settings have failed so that we can
restore them on the user's request.
parent 358a0ff0
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1 merge request!1500TB 43415: Rebased onto 134.0a1
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toolkit/modules/TorSettings.sys.mjs
+ 439
− 67
View file @ 6fb4bdc4
......@@ -9,7 +9,6 @@ ChromeUtils.defineESModuleGetters(lazy, {
Lox: "resource://gre/modules/Lox.sys.mjs",
LoxTopics: "resource://gre/modules/Lox.sys.mjs",
TorParsers: "resource://gre/modules/TorParsers.sys.mjs",
TorProviderBuilder: "resource://gre/modules/TorProviderBuilder.sys.mjs",
});
ChromeUtils.defineLazyGetter(lazy, "logger", () => {
......@@ -23,6 +22,7 @@ ChromeUtils.defineLazyGetter(lazy, "logger", () => {
export const TorSettingsTopics = Object.freeze({
Ready: "torsettings:ready",
SettingsChanged: "torsettings:settings-changed",
ApplyError: "torsettings:apply-error",
});
/* Prefs used to store settings in TorBrowser prefs */
......@@ -162,44 +162,74 @@ function arrayShuffle(array) {
return array;
}
/* TorSettings module */
class TorSettingsImpl {
/**
* The underlying settings values.
* @typedef {Object} TorBridgeSettings
*
* Represents the Tor bridge settings.
*
* @type {object}
* @property {boolean} enabled - Whether bridges are enabled.
* @property {integer} source - The source of bridges. One of the values in
* `TorBridgeSource`.
* @property {string} lox_id - The ID of the lox credentials to get bridges for.
* Or "" if not using a `Lox` `source`.
* @property {string} builtin_type - The name of the built-in bridge type. Or ""
* if not using a `BuiltIn` `source`.
* @property {string[]} bridge_strings - The bridge lines to be passed to the
* provider. Should be empty if and only if the `source` is `Invalid`.
*/
#settings = {
bridges: {
/**
* Whether the bridges are enabled or not.
* @typedef {Object} TorProxySettings
*
* @type {boolean}
* Represents the Tor proxy settings.
*
* @property {boolean} enabled - Whether the proxy should be enabled.
* @property {integer} type - The proxy type. One of the values in
* `TorProxyType`.
* @property {string} address - The proxy address, or "" if the proxy is not
* being used.
* @property {integer} port - The proxy port, or 0 if the proxy is not being
* used.
* @property {string} username - The proxy user name, or "" if this is not
* needed.
* @property {string} password - The proxy password, or "" if this is not
* needed.
*/
enabled: false,
source: TorBridgeSource.Invalid,
/**
* The lox id is used with the Lox "source", and remains set with the
* stored value when other sources are used.
* @typedef {Object} TorFirewallSettings
*
* @type {string}
* Represents the Tor firewall settings.
*
* @property {boolean} enabled - Whether the firewall settings should be
* enabled.
* @property {integer[]} allowed_ports - The list of ports that are allowed.
*/
lox_id: "",
/**
* The built-in type to use when using the BuiltIn "source", or empty when
* using any other source.
* @typedef {Object} TorCombinedSettings
*
* @type {string}
* A combination of Tor settings.
*
* @property {TorBridgeSettings} bridges - The bridge settings.
* @property {TorProxySettings} proxy - The proxy settings.
* @property {TorFirewallSettings} firewall - The firewall settings.
*/
builtin_type: "",
/* TorSettings module */
class TorSettingsImpl {
/**
* The current bridge strings.
*
* Can only be non-empty if the "source" is not Invalid.
* The default settings to use.
*
* @type {Array<string>}
* @type {TorCombinedSettings}
*/
#defaultSettings = {
bridges: {
enabled: false,
source: TorBridgeSource.Invalid,
lox_id: "",
builtin_type: "",
bridge_strings: [],
},
proxy: {
......@@ -216,10 +246,71 @@ class TorSettingsImpl {
},
};
/**
* The underlying settings values.
*
* @type {TorCombinedSettings}
*/
#settings = structuredClone(this.#defaultSettings);
/**
* The last successfully applied settings for the current `TorProvider`, if
* any.
*
* NOTE: Should only be written to within `#applySettings`.
*
* @type {{
* bridges: ?TorBridgeSettings,
* proxy: ?TorProxySettings,
* firewall: ?TorFirewallSettings
* }}
*/
#successfulSettings = { bridges: null, proxy: null, firewall: null };
/**
* Whether temporary bridge settings have been applied to the current
* `TorProvider`.
*
* @type {boolean}
*/
#temporaryBridgesApplied = false;
/**
* @typedef {TorSettingsApplyError}
*
* @property {boolean} canUndo - Whether the latest error can be "undone".
* When this is `false`, the TorProvider will be using its default values
* instead.
*/
/**
* A summary of the latest failures to apply our settings, if any.
*
* NOTE: Should only be written to within `#applySettings`.
*
* @type {{
* bridges: ?TorSettingsApplyError,
* proxy: ?TorSettingsApplyError,
* firewall: ?TorSettingsApplyError,
* }}
*/
#applyErrors = { bridges: null, proxy: null, firewall: null };
/**
* Get the latest failure for the given setting, if any.
*
* @param {string} group - The settings to get the error details for.
*
* @returns {?TorSettingsApplyError} - The error details, if any.
*/
getApplyError(group) {
return structuredClone(this.#applyErrors[group]);
}
/**
* Temporary bridge settings to apply instead of #settings.bridges.
*
* @type {?Object}
* @type {?TorBridgeSettings}
*/
#temporaryBridgeSettings = null;
......@@ -351,6 +442,30 @@ class TorSettingsImpl {
return Number.isInteger(val) && val >= 1 && val <= 65535;
}
/**
* Verify that some SOCKS5 credentials are valid.
*
* @param {string} username - The SOCKS5 username.
* @param {string} password - The SOCKS5 password.
* @return {boolean} - Whether the credentials are valid.
*/
validSocks5Credentials(username, password) {
if (!username && !password) {
// Both empty is valid.
return true;
}
for (const val of [username, password]) {
if (typeof val !== "string") {
return false;
}
const byteLen = new TextEncoder().encode(val).length;
if (byteLen < 1 || byteLen > 255) {
return false;
}
}
return true;
}
/**
* Test whether two arrays have equal members and order.
*
......@@ -745,20 +860,222 @@ class TorSettingsImpl {
}
}
/**
* A blocker promise for the #applySettings method.
*
* Ensures only one active caller to protect the #applyErrors and
* #successfulSettings properties.
*
* @type {?Promise}
*/
#applySettingsTask = null;
/**
* Push our settings down to the tor provider.
*
* Even though this introduces a circular depdency, it makes the API nicer for
* frontend consumers.
*
* @param {boolean} flush - Whether to also flush the settings to disk.
* @param {Object} apply - The list of settings to apply.
* @param {boolean} [apply.bridges] - Whether to apply our bridge settings.
* @param {boolean} [apply.proxy] - Whether to apply our proxy settings.
* @param {boolean} [apply.firewall] - Whether to apply our firewall settings.
* @param {boolean} [details] - Optional details.
* @param {boolean} [details.useTemporaryBridges] - Whether the caller wants
* to apply temporary bridges.
* @param {boolean} [details.newProvider] - Whether the caller is initialising
* a new `TorProvider`.
*/
async #applySettings(flush) {
const provider = await lazy.TorProviderBuilder.build();
await provider.writeSettings();
if (flush) {
async #applySettings(apply, details) {
// Grab this provider before awaiting.
// In particular, if the provider is changed we do not want to switch to
// writing to the new instance.
const providerRef = this.#providerRef;
const provider = providerRef?.deref();
if (!provider) {
// Wait until setTorProvider is called.
lazy.logger.info("No TorProvider yet");
return;
}
// We only want one instance of #applySettings to be running at any given
// time, so we await the previous call first.
// Read and replace #applySettingsTask before we do any async operations.
// I.e. this is effectively an atomic read and replace.
const prevTask = this.#applySettingsTask;
let taskComplete;
({ promise: this.#applySettingsTask, resolve: taskComplete } =
Promise.withResolvers());
await prevTask;
try {
let flush = false;
const errors = [];
// Test whether the provider is no longer running or has been replaced.
const providerRunning = () => {
return providerRef === this.#providerRef && provider.isRunning;
};
lazy.logger.debug("Passing on settings to the provider", apply, details);
if (details?.newProvider) {
// If we have a new provider we clear our successful settings.
// In particular, the user may have changed their settings several times
// whilst the tor process was not running. In the event of an
// "ApplyError", we want to correctly show to the user that they are now
// using default settings and we do not want to allow them to "undo"
// since the previous successful settings may be out of date.
// NOTE: We do not do this within `setTorProvider` since some other
// caller's `#applySettingsTask` may still be running and writing to
// these values when `setTorProvider` is called.
this.#successfulSettings.bridges = null;
this.#successfulSettings.proxy = null;
this.#successfulSettings.firewall = null;
this.#applyErrors.bridges = null;
this.#applyErrors.proxy = null;
this.#applyErrors.firewall = null;
// Temporary bridges are not applied to the new provider.
this.#temporaryBridgesApplied = false;
}
for (const group of ["bridges", "proxy", "firewall"]) {
if (!apply[group]) {
continue;
}
if (!providerRunning()) {
lazy.logger.info("The TorProvider is no longer running");
// Bail on this task since the old provider should not accept
// settings. setTorProvider will be called for the new provider and
// will already handle applying the same settings.
return;
}
let usingSettings = true;
if (group === "bridges") {
// Only record successes or failures when using the user settings.
if (this.#temporaryBridgeSettings && !details?.useTemporaryBridges) {
// #temporaryBridgeSettings were written whilst awaiting the
// previous task. Do nothing and allow applyTemporarySettings to
// apply the temporary bridges instead.
lazy.logger.info(
"Not apply bridges since temporary bridges were applied"
);
continue;
}
if (!this.#temporaryBridgeSettings && details?.useTemporaryBridges) {
// #temporaryBridgeSettings were cleared whilst awaiting the
// previous task. Do nothing and allow changeSettings or
// clearTemporaryBridges to apply the non-temporary bridges
// instead.
lazy.logger.info(
"Not apply temporary bridges since they were cleared"
);
continue;
}
usingSettings = !details?.useTemporaryBridges;
}
try {
switch (group) {
case "bridges": {
const bridges = structuredClone(
usingSettings
? this.#settings.bridges
: this.#temporaryBridgeSettings
);
try {
await provider.writeBridgeSettings(bridges);
} catch (e) {
if (
usingSettings &&
this.#temporaryBridgesApplied &&
providerRunning()
) {
lazy.logger.warn(
"Recovering to clear temporary bridges from the provider"
);
// The TorProvider is still using the temporary bridges. As a
// priority we want to try and restore the TorProvider to the
// state it was in prior to the temporary bridges being
// applied.
const prevBridges = structuredClone(
this.#successfulSettings.bridges ??
this.#defaultSettings.bridges
);
try {
await provider.writeBridgeSettings(prevBridges);
this.#temporaryBridgesApplied = false;
} catch (e) {
lazy.logger.error(
"Failed to clear the temporary bridges from the provider",
e
);
}
}
throw e;
}
if (usingSettings) {
this.#successfulSettings.bridges = bridges;
this.#temporaryBridgesApplied = false;
this.#applyErrors.bridges = null;
flush = true;
} else {
this.#temporaryBridgesApplied = true;
// Do not flush the temporary bridge settings until they are
// saved.
}
break;
}
case "proxy": {
const proxy = structuredClone(this.#settings.proxy);
await provider.writeProxySettings(proxy);
this.#successfulSettings.proxy = proxy;
this.#applyErrors.proxy = null;
flush = true;
break;
}
case "firewall": {
const firewall = structuredClone(this.#settings.firewall);
await provider.writeFirewallSettings(firewall);
this.#successfulSettings.firewall = firewall;
this.#applyErrors.firewall = null;
flush = true;
break;
}
}
} catch (e) {
// Store the error and throw later.
errors.push(e);
if (usingSettings && providerRunning()) {
// Record and signal the error.
// NOTE: We do not signal ApplyError when we fail to apply temporary
// bridges.
this.#applyErrors[group] = {
canUndo: Boolean(this.#successfulSettings[group]),
};
lazy.logger.debug(`Signalling new ApplyError for ${group}`);
Services.obs.notifyObservers(
{ group },
TorSettingsTopics.ApplyError
);
}
}
}
if (flush && providerRunning()) {
provider.flushSettings();
}
if (errors.length) {
lazy.logger.error("Failed to apply settings", errors);
throw new Error(`Failed to apply settings. ${errors.join(". ")}.`);
}
} finally {
// Allow the next caller to proceed.
taskComplete();
}
}
/**
......@@ -862,14 +1179,13 @@ class TorSettingsImpl {
proxy.password = "";
break;
case TorProxyType.Socks5:
case TorProxyType.HTTPS:
if (proxy.username && !proxy.password) {
throw new Error("Missing proxy password");
}
if (proxy.password && !proxy.username) {
throw new Error("Missing proxy username");
if (!this.validSocks5Credentials(proxy.username, proxy.password)) {
throw new Error("Invalid SOCKS5 credentials");
}
break;
case TorProxyType.HTTPS:
// username and password are both optional.
break;
}
proxy.address = String(proxy.address);
......@@ -904,6 +1220,72 @@ class TorSettingsImpl {
firewall.allowed_ports = [...new Set(firewall.allowed_ports)];
}
/**
* The current `TorProvider` instance we are using, if any.
*
* @type {?WeakRef<TorProvider>}
*/
#providerRef = null;
/**
* Called whenever we have a new provider to send settings to.
*
* @param {TorProvider} provider - The provider to apply our settings to.
*/
async setTorProvider(provider) {
lazy.logger.debug("Applying settings to new provider");
this.#checkIfInitialized();
// Use a WeakRef to not keep the TorProvider instance alive.
this.#providerRef = new WeakRef(provider);
// NOTE: We need the caller to pass in the TorProvider instance because
// TorProvider's initialisation waits for this method. In particular, we
// cannot await TorProviderBuilder.build since it would hang!
await this.#applySettings(
{ bridges: true, proxy: true, firewall: true },
{ newProvider: true }
);
}
/**
* Undo settings that have failed to be applied by restoring the last
* successfully applied settings instead.
*
* @param {string} group - The group to undo the settings for.
*/
async undoFailedSettings(group) {
if (!this.#applyErrors[group]) {
lazy.logger.warn(
`${group} settings have already been successfully replaced.`
);
return;
}
if (!this.#successfulSettings[group]) {
// Unexpected.
lazy.logger.warn(
`Cannot undo ${group} settings since we have no successful settings.`
);
return;
}
await this.changeSettings({ [group]: this.#successfulSettings[group] });
}
/**
* Clear settings that have failed to be applied by using the default settings
* instead.
*
* @param {string} group - The group to clear the settings for.
*/
async clearFailedSettings(group) {
if (!this.#applyErrors[group]) {
lazy.logger.warn(
`${group} settings have already been successfully replaced.`
);
return;
}
await this.changeSettings({ [group]: this.#defaultSettings[group] });
}
/**
* Change the Tor settings in use.
*
......@@ -915,8 +1297,8 @@ class TorSettingsImpl {
* + proxy settings can be set as a group.
* + firewall settings can be set a group.
*
* @param {object} newValues - The new setting values, a subset of the
* complete settings that should be changed.
* @param {object} newValues - The new setting values that should be changed.
* A subset of the `TorCombinedSettings` object.
*/
async changeSettings(newValues) {
lazy.logger.debug("changeSettings()", newValues);
......@@ -928,6 +1310,7 @@ class TorSettingsImpl {
const completeSettings = structuredClone(this.#settings);
const changes = [];
const apply = {};
/**
* Change the given setting to a new value. Does nothing if the new value
......@@ -946,10 +1329,11 @@ class TorSettingsImpl {
}
completeSettings[group][prop] = value;
changes.push(`${group}.${prop}`);
// Apply these settings.
apply[group] = true;
};
if ("bridges" in newValues) {
const changesLength = changes.length;
if ("source" in newValues.bridges) {
this.#fixupBridgeSettings(newValues.bridges);
changeSetting("bridges", "source", newValues.bridges.source);
......@@ -980,7 +1364,7 @@ class TorSettingsImpl {
changeSetting("bridges", "enabled", newValues.bridges.enabled);
}
if (this.#temporaryBridgeSettings && changes.length !== changesLength) {
if (this.#temporaryBridgeSettings && apply.bridges) {
// A change in the bridges settings.
// We want to clear the temporary bridge settings to ensure that they
// cannot be used to overwrite these user-provided settings.
......@@ -1030,34 +1414,22 @@ class TorSettingsImpl {
lazy.logger.debug("setSettings result", this.#settings, changes);
if (apply.bridges || apply.proxy || apply.firewall) {
// After we have sent out the notifications for the changed settings and
// saved the preferences we send the new settings to TorProvider.
// Some properties are unread by TorProvider. So if only these values change
// there is no need to re-apply the settings.
const unreadProps = ["bridges.builtin_type", "bridges.lox_id"];
const shouldApply = changes.some(prop => !unreadProps.includes(prop));
if (shouldApply) {
await this.#applySettings(true);
await this.#applySettings(apply);
}
}
/**
* Get a copy of all our settings.
*
* @param {boolean} [useTemporary=false] - Whether the returned settings
* should use the temporary bridge settings, if any, instead.
*
* @returns {object} A copy of the settings object
* @returns {TorCombinedSettings} A copy of the current settings.
*/
getSettings(useTemporary = false) {
getSettings() {
lazy.logger.debug("getSettings()");
this.#checkIfInitialized();
const settings = structuredClone(this.#settings);
if (useTemporary && this.#temporaryBridgeSettings) {
// Override the bridge settings with our temporary ones.
settings.bridges = structuredClone(this.#temporaryBridgeSettings);
}
return settings;
return structuredClone(this.#settings);
}
/**
......@@ -1105,8 +1477,8 @@ class TorSettingsImpl {
// After checks are complete, we commit them.
this.#temporaryBridgeSettings = bridgeSettings;
// Do not flush the temporary bridge settings until they are saved.
await this.#applySettings(false);
await this.#applySettings({ bridges: true }, { useTemporaryBridges: true });
}
/**
......@@ -1133,7 +1505,7 @@ class TorSettingsImpl {
return;
}
this.#temporaryBridgeSettings = null;
await this.#applySettings();
await this.#applySettings({ bridges: true });
}
}
......
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