add fake peer injection mechanism

config/dev.exs

@@ -49,6 +49,7 @@ config :extracker,
   reverse_proxy_address: "",
   http_request_timeout: 60_000,
   integration: "none",
+  fake_peers_in_responses: 0,
   debug: true
 
 config :logger,

config/prod.exs

@@ -49,6 +49,7 @@ config :extracker,
   reverse_proxy_address: "",
   http_request_timeout: 60_000,
   integration: "none",
+  fake_peers_in_responses: 0,
   debug: false
 
 config :logger,

config/runtime.exs

@@ -52,6 +52,7 @@ if config_env() in [:prod] do
     reverse_proxy_address: "", # specify the address of a reverse proxy if present (caddy, nginx, apache, etc)
     http_request_timeout: 60_000, # time before *outgoing* http requests timeout (mainly for integrations)
     integration: "none", # select which integration (if any) to be enabled (current options: "arcadia", "none")
+    fake_peers_in_responses: 0, # amount of fake peers to inject in the responses (prevent mass scraping of torrent peer lists), a recommended value is 3
     debug: false # enable extra debug logs and checks
 
   config :logger, level: :notice # log minimum level. info and debug may get spammy

config/test.exs

@@ -49,6 +49,7 @@ config :extracker,
   reverse_proxy_address: "",
   http_request_timeout: 60_000,
   integration: "none",
+  fake_peers_in_responses: 0,
   debug: false
 
 config :logger,

docker-compose.yml

@@ -61,6 +61,7 @@ services:
 #      - EXTRACKER_REVERSE_PROXY_ADDRESS=
 #      - EXTRACKER_HTTP_REQUEST_TIMEOUT=
 #      - EXTRACKER_INTEGRATION=
+#      - EXTRACKER_FAKE_PEERS_IN_RESPONSES=
 #      - EXTRACKER_DEBUG=false
 #      - EXTRACKER_ARCADIA_API_BIND_ADDRESS=
 #      - EXTRACKER_ARCADIA_API_PORT=

lib/ex_tracker/swarm.ex

@@ -245,18 +245,49 @@ defmodule ExTracker.Swarm do
       # convert the IDs back to the normal type
       case include_data do
         false ->
-          Enum.map(result, &PeerID.from_storage/1)
+          result
+          |> Enum.map(&PeerID.from_storage/1)
+          |> add_fake_peers(family, include_data)
         true ->
           Enum.map(result, fn {sid, data} -> {PeerID.from_storage(sid), data} end)
       end
-
+      
     rescue
       # the swarm table may be gone while the query reaches this point
       e in ArgumentError ->
         Logger.debug("get_peers/5: #{Exception.message(e)}")
         []
     end
   end
+
+  def add_fake_peers(peers, :inet, false) do
+    case Application.get_env(:extracker, :fake_peers_in_responses, 0) do
+      amount when amount > 0 ->
+      fake_peers = for _ <- 1..amount do
+        {a, b, c, d} = {:rand.uniform(255), :rand.uniform(255), :rand.uniform(255), :rand.uniform(255)}
+        port = :rand.uniform(65535)
+        PeerID.new({a, b, c, d}, port)
+      end
+      peers ++ fake_peers
+      _ -> peers
+    end
+  end
+
+  def add_fake_peers(peers, :inet6, false) do
+    case Application.get_env(:extracker, :fake_peers_in_responses, 0) do
+      amount when amount > 0 ->
+      fake_peers = for _ <- 1..amount do
+        ip = {:rand.uniform(65535), :rand.uniform(65535), :rand.uniform(65535), :rand.uniform(65535),
+              :rand.uniform(65535), :rand.uniform(65535), :rand.uniform(65535), :rand.uniform(65535)}
+        port = :rand.uniform(65535)
+        PeerID.new(ip, port)
+      end
+      peers ++ fake_peers
+      _ -> peers
+    end
+  end
+
+  def add_fake_peers(peers, :all, _), do: peers
 
   def get_all_peers(swarm, include_data) do
     get_peers(swarm, :all, :all, :all, include_data)