Allow limiting logging in users from too many different IPs.

1 files changed, 70 insertions, 0 deletions

diff --git a/lib/gitlab/auth/unique_ips_limiter.rb b/lib/gitlab/auth/unique_ips_limiter.rb
new file mode 100644
index 00000000000..21307eb35e4
--- /dev/null
+++ b/lib/gitlab/auth/unique_ips_limiter.rb
@@ -0,0 +1,70 @@
+module Gitlab
+  module Auth
+    class TooManyIps < StandardError
+      attr_reader :user_id, :ip, :unique_ips_count
+
+      def initialize(user_id, ip, unique_ips_count)
+        @user_id = user_id
+        @ip = ip
+        @unique_ips_count = unique_ips_count
+      end
+
+      def message
+        "User #{user_id} from IP: #{ip} tried logging from too many ips: #{unique_ips_count}"
+      end
+    end
+
+    class UniqueIpsLimiter
+      USER_UNIQUE_IPS_PREFIX = 'user_unique_ips'
+
+      class << self
+        def limit_user_id!(user_id)
+          if config.unique_ips_limit_enabled
+            ip = RequestContext.client_ip
+            unique_ips = count_unique_ips(user_id, ip)
+            raise TooManyIps.new(user_id, ip, unique_ips) if unique_ips > config.unique_ips_limit_per_user
+          end
+        end
+
+        def limit_user!(user = nil)
+          user = yield if user.nil?
+          limit_user_id!(user.id) unless user.nil?
+          user
+        end
+
+        def config
+          Gitlab::CurrentSettings.current_application_settings
+        end
+
+        def count_unique_ips(user_id, ip)
+          time = Time.now.to_i
+          key = "#{USER_UNIQUE_IPS_PREFIX}:#{user_id}"
+
+          Gitlab::Redis.with do |redis|
+            unique_ips_count = nil
+            redis.multi do |r|
+              r.zadd(key, time, ip)
+              r.zremrangebyscore(key, 0, time - config.unique_ips_limit_time_window)
+              unique_ips_count = r.zcard(key)
+            end
+            unique_ips_count.value
+          end
+        end
+      end
+
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        begin
+          @app.call(env)
+        rescue TooManyIps => ex
+
+          Rails.logger.info ex.message
+          [429, {'Content-Type' => 'text/plain', 'Retry-After' => UniqueIpsLimiter.config.unique_ips_limit_time_window }, ["Retry later\n"]]
+        end
+      end
+    end
+  end
+end