Class: BotVerification::Service

Inherits:
Object
  • Object
show all
Includes:
BotPatterns
Defined in:
lib/bot_verification/service.rb

Overview

Core verification service

Performance characteristics:

  1. Rails cache lookup (~1ms) - checks if IP was recently verified
  2. IP range check (~5-10ms) - database lookup with in-memory caching
  3. Reverse DNS (~100-2000ms) - only if IP range check fails, with strict timeout

Constant Summary collapse

MODES = 
i[search_engines search_and_ai all_known].freeze

Constants included from BotPatterns

BotPatterns::AI_BOTS_WITHOUT_VERIFICATION, BotPatterns::AI_BOTS_WITH_IP_RANGES, BotPatterns::AI_BOT_PATTERNS, BotPatterns::AI_BOT_SOURCES, BotPatterns::AI_BOT_TYPES, BotPatterns::ALL_BOTS_WITH_IP_RANGES, BotPatterns::ALL_BOT_PATTERNS, BotPatterns::IP_RANGE_SOURCES, BotPatterns::SEARCH_BOTS_WITH_DNS, BotPatterns::SEARCH_BOTS_WITH_IP_RANGES, BotPatterns::SEARCH_BOT_DNS_SUFFIXES, BotPatterns::SEARCH_BOT_PATTERNS, BotPatterns::SEARCH_BOT_TYPES, BotPatterns::SEARCH_ENGINE_SOURCES, BotPatterns::SOCIAL_BOT_PATTERNS, BotPatterns::VALID_BOT_TYPES

Class Method Summary collapse

Class Method Details

.ai_bot_user_agent?(user_agent) ⇒ Boolean

Check if a user agent is a known AI bot



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# File 'lib/bot_verification/service.rb', line 151

def ai_bot_user_agent?(user_agent)
  return false if user_agent.blank?

  BotPatterns::AI_BOT_PATTERNS.values.any? { |pattern| user_agent.match?(pattern) }
end

.detect_ai_bot_type(user_agent) ⇒ Object

Detect AI bot type specifically



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# File 'lib/bot_verification/service.rb', line 82

def detect_ai_bot_type(user_agent)
  BotPatterns::AI_BOT_PATTERNS.each do |bot_type, pattern|
    return bot_type if user_agent.match?(pattern)
  end
  nil
end

.detect_bot_type(user_agent) ⇒ Object

Detect which bot type based on user agent (all bot types)



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# File 'lib/bot_verification/service.rb', line 72

def detect_bot_type(user_agent)
  return nil if user_agent.blank?

  BotPatterns::ALL_BOT_PATTERNS.each do |bot_type, pattern|
    return bot_type if user_agent.match?(pattern)
  end
  nil
end

.detect_search_bot_type(user_agent) ⇒ Object

Detect search engine bot type specifically



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# File 'lib/bot_verification/service.rb', line 90

def detect_search_bot_type(user_agent)
  BotPatterns::SEARCH_BOT_PATTERNS.each do |bot_type, pattern|
    return bot_type if user_agent.match?(pattern)
  end
  nil
end

.ip_in_known_ranges?(ip, bot_type) ⇒ Boolean

Check if IP is in known IP ranges for the bot type



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# File 'lib/bot_verification/service.rb', line 116

def ip_in_known_ranges?(ip, bot_type)
  return false unless BotPatterns::ALL_BOTS_WITH_IP_RANGES.include?(bot_type)

  BotVerification.ip_range_model.ip_belongs_to_bot?(ip, bot_type)
end

.search_bot_user_agent?(user_agent) ⇒ Boolean

Check if a user agent is a known search engine bot



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# File 'lib/bot_verification/service.rb', line 158

def search_bot_user_agent?(user_agent)
  return false if user_agent.blank?

  BotPatterns::SEARCH_BOT_PATTERNS.values.any? { |pattern| user_agent.match?(pattern) }
end

.session_cache_key(ip, user_agent) ⇒ Object

Generate a cache key for session-based caching



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# File 'lib/bot_verification/service.rb', line 165

def session_cache_key(ip, user_agent)
  fingerprint = Digest::SHA256.hexdigest("#{ip}:#{user_agent}")[0, 16]
  "bot_verify:#{fingerprint}"
end

.verified_ai_bot?(ip, user_agent, strict: true) ⇒ Boolean

Check specifically if request is from a verified AI bot



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# File 'lib/bot_verification/service.rb', line 52

def verified_ai_bot?(ip, user_agent, strict: true)
  return false if ip.blank? || user_agent.blank?

  bot_type = detect_ai_bot_type(user_agent)
  return false unless bot_type

  # AI bots without published IP ranges must be trusted by user agent
  # (there's no other way to verify them)
  if BotPatterns::AI_BOTS_WITHOUT_VERIFICATION.include?(bot_type)
    true
  elsif BotPatterns::AI_BOTS_WITH_IP_RANGES.include?(bot_type)
    verified_bot_ip?(ip, bot_type)
  elsif strict
    false
  else
    true
  end
end

.verified_bot_ip?(ip, bot_type) ⇒ Boolean

Check if IP belongs to a known bot via IP ranges or DNS



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# File 'lib/bot_verification/service.rb', line 98

def verified_bot_ip?(ip, bot_type)
  cache_key = "#{config.cache_key_prefix}:#{bot_type}:#{ip}"

  cached = cache.read(cache_key)
  return cached unless cached.nil?

  result = ip_in_known_ranges?(ip, bot_type)

  # Fall back to DNS verification if IP range check failed and DNS is enabled
  if result == false && !config.skip_dns_verification && BotPatterns::SEARCH_BOTS_WITH_DNS.include?(bot_type)
    result = verify_by_reverse_dns_with_timeout(ip, bot_type)
  end

  cache.write(cache_key, result, expires_in: config.cache_ttl)
  result
end

.verified_good_bot?(ip, user_agent, mode: :search_engines) ⇒ Boolean

Main entry point - checks if request is from a verified good bot

Raises:

  • (ArgumentError) 


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# File 'lib/bot_verification/service.rb', line 26

def verified_good_bot?(ip, user_agent, mode: :search_engines)
  return false if ip.blank? || user_agent.blank?
  raise ArgumentError, "Invalid mode: #{mode}" unless MODES.include?(mode)

  bot_type = detect_bot_type(user_agent)
  return report_verification_result(nil, false, mode, ip, user_agent) unless bot_type

  verified = case mode
  when :search_engines
    verify_search_engine_bot(ip, bot_type)
  when :search_and_ai
    verify_search_engine_bot(ip, bot_type) || verify_ai_bot_internal(ip, bot_type)
  when :all_known
    true
  end

  report_verification_result(bot_type, verified, mode, ip, user_agent)
end

.verify_by_reverse_dns(ip, bot_type) ⇒ Object

Verify bot by reverse DNS lookup



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# File 'lib/bot_verification/service.rb', line 133

def verify_by_reverse_dns(ip, bot_type)
  suffixes = BotPatterns::SEARCH_BOT_DNS_SUFFIXES[bot_type]
  return false unless suffixes

  hostname = reverse_dns_lookup(ip)
  return false unless hostname

  valid_suffix = suffixes.any? { |suffix| hostname.end_with?(suffix) }
  return false unless valid_suffix

  forward_ips = forward_dns_lookup(hostname)
  forward_ips.include?(ip)
rescue StandardError => e
  config.logger.warn("BotVerification: DNS verification failed for #{ip}: #{e.message}")
  false
end

.verify_by_reverse_dns_with_timeout(ip, bot_type) ⇒ Object

Verify bot by reverse DNS lookup with strict timeout



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# File 'lib/bot_verification/service.rb', line 123

def verify_by_reverse_dns_with_timeout(ip, bot_type)
  Timeout.timeout(config.dns_total_timeout) do
    verify_by_reverse_dns(ip, bot_type)
  end
rescue Timeout::Error
  config.logger.warn("BotVerification: DNS verification timed out for #{ip} (#{bot_type})")
  false
end