Copilot commented on code in PR #13586: URL: https://github.com/apache/trafficserver/pull/13586#discussion_r3905731250
########## plugins/experimental/abuse_shield/stats.h: ########## @@ -0,0 +1,61 @@ +/** @file + + Abuse Shield plugin statistics. + + @section license License + + Licensed to the Apache Software Foundation (ASF) under one or more contributor license + agreements. See the NOTICE file distributed with this work for additional information regarding + copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with the License. You may obtain + a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software distributed under the License + is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express + or implied. See the License for the specific language governing permissions and limitations under + the License. +*/ + +#pragma once + +namespace abuse_shield +{ + +/** Per-tracker statistics/metrics. */ +struct TrackerStats { + int events{-1}; ///< Total events tracked + int events_untracked{-1}; ///< Events lost in an ordinary contest or bounded scan + int scan_exhausted{-1}; ///< Events not tracked because the protected-slot scan hit its bound + int slots_used{-1}; ///< Current slots in use (gauge) + int contests{-1}; ///< Total contest attempts + int contests_won{-1}; ///< Contests won by new IP + int evictions{-1}; ///< IPs evicted (score reached 0) + Review Comment: TrackerStats::evictions is documented as “score reached 0”, but UdiTable increments its eviction counter whenever an occupied slot is replaced by a contest winner (which can happen even when the incumbent score is > 0). This comment should match the actual metric semantics to avoid misleading operators. ########## plugins/experimental/abuse_shield/abuse_shield.cc: ########## @@ -0,0 +1,1288 @@ +/** @file + + Abuse Shield Plugin - HTTP/2 error tracking and IP-based abuse detection. + + Uses the Udi "King of the Hill" algorithm for efficient, bounded-memory IP tracking. + + @section license License + + Licensed to the Apache Software Foundation (ASF) under one or more contributor license + agreements. See the NOTICE file distributed with this work for additional information regarding + copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with the License. You may obtain + a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software distributed under the License + is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express + or implied. See the License for the specific language governing permissions and limitations under + the License. +*/ + +#include <algorithm> +#include <chrono> +#include <cinttypes> +#include <cstring> +#include <ctime> +#include <exception> +#include <iomanip> +#include <memory> +#include <mutex> +#include <shared_mutex> +#include <sstream> +#include <string> +#include <type_traits> +#include <unordered_map> + +#include <sys/socket.h> + +#include "ts/ts.h" +#include "swoc/IPRange.h" +#include "swoc/BufferWriter.h" +#include "swoc/bwf_ip.h" + +#include "config.h" +#include "fingerprint.h" +#include "fingerprint_registry.h" +#include "ip_data.h" +#include "stats.h" +#include "logging.h" + +namespace +{ +using abuse_shield::dbg_ctl; +using abuse_shield::PLUGIN_NAME; + +// Optional log file for LOG action output. +TSTextLogObject g_log_object = nullptr; + +// Global action stats. +abuse_shield::ActionStats g_action_stats; + +// Named JAx VConn user-arg selected by global.fingerprint_registry. +int g_fingerprint_registry_index = -1; + +// Per-tracker stats. +abuse_shield::TrackerStats g_txn_stats; +abuse_shield::TrackerStats g_conn_stats; +abuse_shield::TrackerStats g_h2_stats; + +// Helper to convert IPAddr to string. +std::string +ip_to_string(const swoc::IPAddr &ip) +{ + swoc::LocalBufferWriter<64> writer; + writer.print("{}", ip); + return std::string(writer.view()); +} + +std::string +format_local_time(std::time_t time, const char *format) +{ + struct tm time_parts; + + if (localtime_r(&time, &time_parts) == nullptr) { + return "-"; + } + + std::ostringstream oss; + oss << std::put_time(&time_parts, format); + return oss.str(); +} + +// Helper to get current wall clock time as string. +std::string +current_time_str() +{ + auto now = std::chrono::system_clock::now(); + auto now_t = std::chrono::system_clock::to_time_t(now); + return format_local_time(now_t, "%Y-%m-%dT%H:%M:%S"); +} + +// ============================================================================ +// Global state +// ============================================================================ + +// Separate UDI tables for different event types, each with its own data type. +std::unique_ptr<abuse_shield::TxnTable> g_txn_tracker; ///< Transaction/request rate tracking +std::unique_ptr<abuse_shield::ConnTable> g_conn_tracker; ///< Connection rate tracking +std::unique_ptr<abuse_shield::H2Table> g_h2_tracker; ///< HTTP/2 error tracking + +/** Bounded block state which never evicts an unexpired block. */ +class BlockedIpTable +{ +public: + explicit BlockedIpTable(size_t capacity) : capacity_(capacity) { blocked_.reserve(capacity); } + + bool + block(const swoc::IPAddr &ip, uint64_t until_ms) + { + std::lock_guard lock(mutex_); + auto spot = blocked_.find(ip); + if (spot != blocked_.end()) { + spot->second = std::max(spot->second, until_ms); + return true; + } + + if (blocked_.size() >= capacity_) { + uint64_t now = abuse_shield::now_ms(); + std::erase_if(blocked_, [now](auto const &item) { return item.second <= now; }); + } + if (blocked_.size() >= capacity_) { + return false; + } + + blocked_.emplace(ip, until_ms); + return true; + } + + bool + is_blocked(const swoc::IPAddr &ip) + { + std::lock_guard lock(mutex_); + auto spot = blocked_.find(ip); + if (spot == blocked_.end()) { + return false; + } + if (spot->second <= abuse_shield::now_ms()) { + blocked_.erase(spot); + return false; + } + return true; + } + +private: + size_t capacity_; + std::mutex mutex_; + std::unordered_map<swoc::IPAddr, uint64_t> blocked_; +}; + +std::unique_ptr<BlockedIpTable> g_blocked_ips; + +std::shared_ptr<abuse_shield::Config> g_config; +std::shared_mutex g_config_mutex; // Protects g_config pointer swaps + +// Sync the metrics from a single Udi table to its stats. +void +sync_tracker_stats(abuse_shield::TxnTable *tracker, abuse_shield::TrackerStats &stats) +{ + if (tracker) { + TSStatIntSet(stats.slots_used, static_cast<int64_t>(tracker->slots_used())); + TSStatIntSet(stats.contests, static_cast<int64_t>(tracker->contests())); + TSStatIntSet(stats.contests_won, static_cast<int64_t>(tracker->contests_won())); + TSStatIntSet(stats.evictions, static_cast<int64_t>(tracker->evictions())); + } +} + +void +sync_tracker_stats(abuse_shield::ConnTable *tracker, abuse_shield::TrackerStats &stats) +{ + if (tracker) { + TSStatIntSet(stats.slots_used, static_cast<int64_t>(tracker->slots_used())); + TSStatIntSet(stats.contests, static_cast<int64_t>(tracker->contests())); + TSStatIntSet(stats.contests_won, static_cast<int64_t>(tracker->contests_won())); + TSStatIntSet(stats.evictions, static_cast<int64_t>(tracker->evictions())); + } +} + +void +sync_tracker_stats(abuse_shield::H2Table *tracker, abuse_shield::TrackerStats &stats) +{ + if (tracker) { + TSStatIntSet(stats.slots_used, static_cast<int64_t>(tracker->slots_used())); + TSStatIntSet(stats.contests, static_cast<int64_t>(tracker->contests())); + TSStatIntSet(stats.contests_won, static_cast<int64_t>(tracker->contests_won())); + TSStatIntSet(stats.evictions, static_cast<int64_t>(tracker->evictions())); + } +} + +// Sync the metrics from all Udi tables. +void +sync_all_tracker_stats() +{ + sync_tracker_stats(g_txn_tracker.get(), g_txn_stats); + sync_tracker_stats(g_conn_tracker.get(), g_conn_stats); + sync_tracker_stats(g_h2_tracker.get(), g_h2_stats); +} + +template <typename Table> +void +reset_tracker_stats(Table *tracker, abuse_shield::TrackerStats &stats) +{ + if (tracker) { + tracker->reset_metrics(); + } + TSStatIntSet(stats.events, 0); + TSStatIntSet(stats.events_untracked, 0); + TSStatIntSet(stats.scan_exhausted, 0); + sync_tracker_stats(tracker, stats); +} + +// ============================================================================ +// Rule evaluation +// ============================================================================ + +int +metric_rate(const abuse_shield::RuleFilter &filter, abuse_shield::RateMetric metric) +{ + switch (metric) { + case abuse_shield::RateMetric::REQUEST: + return filter.max_req_rate; + case abuse_shield::RateMetric::CONNECTION: + return filter.max_conn_rate; + case abuse_shield::RateMetric::H2_ERROR: + return filter.max_h2_error_rate; + } + return 0; +} + +double +metric_burst_multiplier(const abuse_shield::RuleFilter &filter, abuse_shield::RateMetric metric) +{ + switch (metric) { + case abuse_shield::RateMetric::REQUEST: + return filter.req_burst_multiplier; + case abuse_shield::RateMetric::CONNECTION: + return filter.conn_burst_multiplier; + case abuse_shield::RateMetric::H2_ERROR: + return filter.h2_burst_multiplier; + } + return 1.0; +} + +template <typename Table> +bool +rate_exceeded(Table *tracker, const abuse_shield::Rule &rule, const swoc::IPAddr &ip) +{ + auto slot = tracker ? tracker->find(ip) : nullptr; + return slot && slot->buckets.exceeded(rule.name); +} + +template <typename Table> +void +consume_rule_buckets(Table *tracker, const swoc::IPAddr &ip, const abuse_shield::Config &config, abuse_shield::RateMetric metric, + abuse_shield::TrackerStats &stats, uint64_t error_code = 0) +{ + typename Table::data_ptr slot; + bool consumed = false; + + for (const auto &rule : config.rules()) { + int rate = metric_rate(rule.filter, metric); + if (rate <= 0 || !config.rule_applies_to_ip(rule, ip)) { + continue; + } + + if (!slot) { + typename Table::ProcessStatus status; + slot = tracker->process_event(ip, 1, &status); + if (!slot) { + TSStatIntIncrement(stats.events_untracked, 1); + if (status == Table::ProcessStatus::NO_CANDIDATE) { + TSStatIntIncrement(stats.scan_exhausted, 1); + } + return; + } + } + + int burst = static_cast<int>(static_cast<double>(rate) * metric_burst_multiplier(rule.filter, metric)); + if constexpr (std::is_same_v<typename Table::data_type, abuse_shield::H2Data>) { + slot->consume(rule.name, rate, burst, error_code); + } else { + slot->consume(rule.name, rate, burst); + } + consumed = true; + } + + if (consumed) { + TSStatIntIncrement(stats.events, 1); + } +} + +/** Check if a rule's filter criteria match for the given IP. + * + * A rule matches only if ALL enabled filter criteria are satisfied (AND logic). + * Each filter uses token bucket rate limiting - a rate is exceeded when tokens < 0. + * Fingerprint values and methods use OR logic with one another. The resulting + * fingerprint criterion is ANDed with any enabled rate criteria. + * + * @param[in] rule The rule containing filter criteria to check. + * @param[in] ip The IP address to evaluate. + * @return True if all enabled filter criteria are satisfied, false otherwise. + */ +bool +rule_matches(const abuse_shield::Rule &rule, const swoc::IPAddr &ip, const abuse_shield::Config &config, + const abuse_shield::FingerprintResults *fingerprints, std::string_view &matched_method, + std::string_view &matched_fingerprint) +{ + const auto &f = rule.filter; + + if (!config.rule_applies_to_ip(rule, ip)) { + return false; + } + + if (f.max_req_rate == 0 && f.max_conn_rate == 0 && f.max_h2_error_rate == 0 && !f.has_fingerprints()) { + return false; + } + + if (f.has_fingerprints()) { + if (!fingerprints) { + return false; + } + + bool fingerprint_matched = false; + for (const auto &[method, configured_values] : f.fingerprints) { + auto computed = fingerprints->find(method); + if (computed != fingerprints->end() && configured_values.contains(computed->second)) { + matched_method = computed->first; + matched_fingerprint = computed->second; + fingerprint_matched = true; + break; + } + } + if (!fingerprint_matched) { + return false; + } + } + + if (f.max_req_rate > 0 && !rate_exceeded(g_txn_tracker.get(), rule, ip)) { + return false; + } + if (f.max_conn_rate > 0 && !rate_exceeded(g_conn_tracker.get(), rule, ip)) { + return false; + } + if (f.max_h2_error_rate > 0 && !rate_exceeded(g_h2_tracker.get(), rule, ip)) { + return false; + } + + return true; // All enabled filters matched +} + +abuse_shield::RuleMatch +evaluate_rate_rules(const swoc::IPAddr &ip, const abuse_shield::Config &config) +{ + for (const auto &rule : config.rules()) { + if (rule.filter.has_fingerprints()) { + continue; + } + + std::string_view matched_method; + std::string_view matched_fingerprint; + if (rule_matches(rule, ip, config, nullptr, matched_method, matched_fingerprint)) { + Dbg(dbg_ctl, "Rule matched: %s", rule.name.c_str()); + return abuse_shield::RuleMatch{&rule, rule.actions, {}, {}}; + } + } + return abuse_shield::RuleMatch{}; +} + +abuse_shield::RuleMatch +evaluate_fingerprint_rules(const swoc::IPAddr &ip, const abuse_shield::Config &config, + const abuse_shield::FingerprintResults &fingerprints) +{ + for (const auto &rule : config.rules()) { + if (!rule.filter.has_fingerprints()) { + continue; + } + + std::string_view matched_method; + std::string_view matched_fingerprint; + if (rule_matches(rule, ip, config, &fingerprints, matched_method, matched_fingerprint)) { + Dbg(dbg_ctl, "Fingerprint rule matched: %s", rule.name.c_str()); + return abuse_shield::RuleMatch{&rule, rule.actions, matched_method, matched_fingerprint}; + } + } + return abuse_shield::RuleMatch{}; +} + +// ============================================================================ +// Action execution +// ============================================================================ + +/** Store block state independently from the evictable rate tables. */ +bool +block_ip(const swoc::IPAddr &ip, uint64_t until_ms) +{ + return g_blocked_ips && g_blocked_ips->block(ip, until_ms); +} + +/** Execute the log action while respecting the log rate limit. + * + * @param[in] match The rule match result. + * @param[in] ip The client IP address. + * @param[in] config The current configuration. + */ +void +execute_log_action(const abuse_shield::RuleMatch &match, const swoc::IPAddr &ip, const abuse_shield::Config &config) +{ + uint64_t log_interval_ms = static_cast<uint64_t>(config.log_interval_sec()) * 1000; + uint64_t now = abuse_shield::now_ms(); + + // Find the most recent log time across all trackers for this IP. + uint64_t most_recent_log = 0; + auto txn_slot = g_txn_tracker ? g_txn_tracker->find(ip) : nullptr; + auto conn_slot = g_conn_tracker ? g_conn_tracker->find(ip) : nullptr; + auto h2_slot = g_h2_tracker ? g_h2_tracker->find(ip) : nullptr; + + // Fingerprint-only rules do not otherwise need a rate-tracking slot. Use the + // bounded connection table to retain their per-IP log interval state. + if (!txn_slot && !conn_slot && !h2_slot && g_conn_tracker) { + conn_slot = g_conn_tracker->process_event(ip, 1); + } + + if (txn_slot) { + most_recent_log = std::max(most_recent_log, txn_slot->last_logged.load(std::memory_order_relaxed)); + } + if (conn_slot) { + most_recent_log = std::max(most_recent_log, conn_slot->last_logged.load(std::memory_order_relaxed)); + } + if (h2_slot) { + most_recent_log = std::max(most_recent_log, h2_slot->last_logged.load(std::memory_order_relaxed)); + } + + // Only log if enough time has passed since the last log for this IP. + if (now - most_recent_log < log_interval_ms) { + return; + } + + // Try to claim the log opportunity atomically using the first available slot. + bool claimed = false; + uint64_t expected = 0; + + if (txn_slot) { + expected = txn_slot->last_logged.load(std::memory_order_relaxed); + if (now - expected >= log_interval_ms) { + claimed = txn_slot->last_logged.compare_exchange_weak(expected, now, std::memory_order_relaxed); + } + } else if (conn_slot) { + expected = conn_slot->last_logged.load(std::memory_order_relaxed); + if (now - expected >= log_interval_ms) { + claimed = conn_slot->last_logged.compare_exchange_weak(expected, now, std::memory_order_relaxed); + } + } else if (h2_slot) { + expected = h2_slot->last_logged.load(std::memory_order_relaxed); + if (now - expected >= log_interval_ms) { + claimed = h2_slot->last_logged.compare_exchange_weak(expected, now, std::memory_order_relaxed); + } + } Review Comment: execute_log_action() treats last_logged==0 as a real timestamp, so if now_ms() is less than log_interval_ms (e.g., soon after boot / steady_clock epoch), the first log for an IP can be suppressed until the interval elapses. last_logged==0 should mean “never logged” and allow the first log immediately. -- This is an automated message from the Apache Git Service. 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