From a98fe452040f9571d51d6fb713ac2c4e38a828a2 Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Sun, 6 Dec 2020 13:26:55 +0000
Subject: [PATCH] Streaming: Add Retry-After header to throttle response
---
.../streaming/impl/ConnectionManager.java | 89 ++++++++++++-------
1 file changed, 58 insertions(+), 31 deletions(-)
diff --git a/apps/streaming/java/src/net/i2p/client/streaming/impl/ConnectionManager.java b/apps/streaming/java/src/net/i2p/client/streaming/impl/ConnectionManager.java
index 11d63f5463..bb479e0bf4 100644
--- a/apps/streaming/java/src/net/i2p/client/streaming/impl/ConnectionManager.java
+++ b/apps/streaming/java/src/net/i2p/client/streaming/impl/ConnectionManager.java
@@ -67,13 +67,15 @@ class ConnectionManager {
/** once over throttle limits, respond this many times before just dropping */
private static final int DROP_OVER_LIMIT = 3;
- // TODO https://stackoverflow.com/questions/16022624/examples-of-http-api-rate-limiting-http-response-headers
+ // https://stackoverflow.com/questions/16022624/examples-of-http-api-rate-limiting-http-response-headers
+ // RFC 6585
private static final String LIMIT_HTTP_RESPONSE =
"HTTP/1.1 429 Denied\r\n"+
"Content-Type: text/html; charset=iso-8859-1\r\n"+
"Cache-Control: no-cache\r\n"+
"Connection: close\r\n"+
"Proxy-Connection: close\r\n"+
+ "Retry-After: 900\r\n"+
"\r\n"+
"<html><head><title>429 Denied</title></head>"+
"<body><h3>429 Denied</h3>" +
@@ -236,20 +238,23 @@ class ConnectionManager {
*/
public Connection receiveConnection(Packet synPacket) {
boolean reject = false;
+ int retryAfter = 0;
if (locked_tooManyStreams()) {
if ((!_defaultOptions.getDisableRejectLogging()) || _log.shouldLog(Log.WARN))
_log.logAlways(Log.WARN, "Refusing connection since we have exceeded our max of "
+ _defaultOptions.getMaxConns() + " connections");
reject = true;
+ retryAfter = 120;
} else {
// this may not be right if more than one is enabled
- String why = shouldRejectConnection(synPacket);
+ Reason why = shouldRejectConnection(synPacket);
if (why != null) {
if ((!_defaultOptions.getDisableRejectLogging()) || _log.shouldLog(Log.WARN))
_log.logAlways(Log.WARN, "Refusing connection since peer is " + why +
(synPacket.getOptionalFrom() == null ? "" : ": " + synPacket.getOptionalFrom().toBase32()));
reject = true;
+ retryAfter = why.getSeconds();
}
}
@@ -265,9 +270,7 @@ class ConnectionManager {
return null;
}
Hash h = from.calculateHash();
- if (_globalBlacklist.contains(h) ||
- (_defaultOptions.isAccessListEnabled() && !_defaultOptions.getAccessList().contains(h)) ||
- (_defaultOptions.isBlacklistEnabled() && _defaultOptions.getBlacklist().contains(h))) {
+ if (retryAfter >= MAX_TIME) {
// always drop these regardless of setting
return null;
}
@@ -290,7 +293,10 @@ class ConnectionManager {
boolean custom = !(reset || http);
String sendResponse;
if (http) {
- sendResponse = LIMIT_HTTP_RESPONSE;
+ if (retryAfter > 0)
+ sendResponse = LIMIT_HTTP_RESPONSE.replace("900", Integer.toString(retryAfter));
+ else
+ sendResponse = LIMIT_HTTP_RESPONSE.replace("Retry-After: 900\r\n", "");
} else if (custom) {
sendResponse = resp.replace("\\r", "\r").replace("\\n", "\n");
} else {
@@ -391,7 +397,7 @@ class ConnectionManager {
return false;
if (con == null) {
// Use the same throttling as for connections
- String why = shouldRejectConnection(ping);
+ Reason why = shouldRejectConnection(ping);
if (why != null) {
if ((!_defaultOptions.getDisableRejectLogging()) || _log.shouldLog(Log.WARN))
_log.logAlways(Log.WARN, "Dropping ping since peer is " + why + ": " + dest.calculateHash());
@@ -591,14 +597,35 @@ class ConnectionManager {
}
/**
+ * @since 0.9.49
+ */
+ private static class Reason {
+ private final String txt;
+ private final int seconds;
+
+ public Reason(String text, int secs) {
+ txt = text; seconds = secs;
+ }
+
+ @Override
+ public String toString() { return txt; }
+
+ public int getSeconds() { return seconds; }
+ }
+
+ private static final int MAX_TIME = 9999999;
+
+
+ /**
+ * Reason time is in seconds for Retry-After header; MAX_TIME for drop, 0 if unknown
* @return reason string or null if not rejected
*/
- private String shouldRejectConnection(Packet syn) {
+ private Reason shouldRejectConnection(Packet syn) {
// unfortunately we don't have access to the router client manager here,
// so we can't whitelist local access
Destination from = syn.getOptionalFrom();
if (from == null)
- return "null";
+ return new Reason("null", MAX_TIME);
Hash h = from.calculateHash();
// As of 0.9.9, run the blacklist checks BEFORE the port counters,
@@ -631,61 +658,61 @@ class ConnectionManager {
}
}
if (hashes.length() > 0 && _globalBlacklist.contains(h))
- return "blacklisted globally";
+ return new Reason("blacklisted globally", MAX_TIME);
if (_defaultOptions.isAccessListEnabled() &&
!_defaultOptions.getAccessList().contains(h))
- return "not whitelisted";
+ return new Reason("not whitelisted", MAX_TIME);
if (_defaultOptions.isBlacklistEnabled() &&
_defaultOptions.getBlacklist().contains(h))
- return "blacklisted";
+ return new Reason("blacklisted", MAX_TIME);
if (_dayThrottler != null && _dayThrottler.shouldThrottle(h)) {
_context.statManager().addRateData("stream.con.throttledDay", 1);
if (_defaultOptions.getMaxConnsPerDay() <= 0)
- return "throttled by" +
+ return new Reason("throttled by" +
" total limit of " + _defaultOptions.getMaxTotalConnsPerDay() +
- " per day";
+ " per day", 86400);
else if (_defaultOptions.getMaxTotalConnsPerDay() <= 0)
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerDay() +
- " per day";
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerDay() +
+ " per day", 86400);
else
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerDay() +
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerDay() +
" or total limit of " + _defaultOptions.getMaxTotalConnsPerDay() +
- " per day";
+ " per day", 86400);
}
if (_hourThrottler != null && _hourThrottler.shouldThrottle(h)) {
_context.statManager().addRateData("stream.con.throttledHour", 1);
if (_defaultOptions.getMaxConnsPerHour() <= 0)
- return "throttled by" +
+ return new Reason("throttled by" +
" total limit of " + _defaultOptions.getMaxTotalConnsPerHour() +
- " per hour";
+ " per hour", 3600);
else if (_defaultOptions.getMaxTotalConnsPerHour() <= 0)
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerHour() +
- " per hour";
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerHour() +
+ " per hour", 3600);
else
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerHour() +
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerHour() +
" or total limit of " + _defaultOptions.getMaxTotalConnsPerHour() +
- " per hour";
+ " per hour", 3600);
}
if (_minuteThrottler != null && _minuteThrottler.shouldThrottle(h)) {
_context.statManager().addRateData("stream.con.throttledMinute", 1);
if (_defaultOptions.getMaxConnsPerMinute() <= 0)
- return "throttled by" +
+ return new Reason("throttled by" +
" total limit of " + _defaultOptions.getMaxTotalConnsPerMinute() +
- " per minute";
+ " per minute", 60);
else if (_defaultOptions.getMaxTotalConnsPerMinute() <= 0)
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerMinute() +
- " per minute";
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerMinute() +
+ " per minute", 60);
else
- return "throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerMinute() +
+ return new Reason("throttled by per-peer limit of " + _defaultOptions.getMaxConnsPerMinute() +
" or total limit of " + _defaultOptions.getMaxTotalConnsPerMinute() +
- " per minute";
+ " per minute", 60);
}
if (!_connectionFilter.allowDestination(from)) {
- return "not allowed by filter";
+ return new Reason("not allowed by filter", 0);
}
return null;
--
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