Merge pull request #1961 from majestrate/rc-expiration-reeanble-07-18-2022

re enable rc expiration

llarp/nodedb.cpp

@@ -110,6 +110,7 @@ namespace llarp
   {
     if (m_Root.empty())
       return;
+    std::set<fs::path> purge;
 
     for (const char& ch : skiplist_subdirs)
     {
@@ -120,15 +121,50 @@ namespace llarp
       fs::path sub = m_Root / p;
 
       llarp::util::IterDir(sub, [&](const fs::path& f) -> bool {
-        if (fs::is_regular_file(f) and f.extension() == RC_FILE_EXT)
+        // skip files that are not suffixed with .signed
+        if (not(fs::is_regular_file(f) and f.extension() == RC_FILE_EXT))
+          return true;
+
+        RouterContact rc{};
+
+        if (not rc.Read(f))
+        {
+          // try loading it, purge it if it is junk
+          purge.emplace(f);
+          return true;
+        }
+
+        if (not rc.FromOurNetwork())
+        {
+          // skip entries that are not from our network
+          return true;
+        }
+
+        if (rc.IsExpired(time_now_ms()))
         {
-          RouterContact rc{};
-          if (rc.Read(f) and rc.Verify(time_now_ms()))
-            m_Entries.emplace(rc.pubkey, rc);
+          // rc expired dont load it and purge it later
+          purge.emplace(f);
+          return true;
         }
+
+        // validate signature and purge entries with invalid signatures
+        // load ones with valid signatures
+        if (rc.VerifySignature())
+          m_Entries.emplace(rc.pubkey, rc);
+        else
+          purge.emplace(f);
+
         return true;
       });
     }
+
+    if (not purge.empty())
+    {
+      LogWarn("removing {} invalid RC from disk", purge.size());
+
+      for (const auto& fpath : purge)
+        fs::remove(fpath);
+    }
   }
 
   void

llarp/router/router.cpp

@@ -45,6 +45,8 @@ static constexpr std::chrono::milliseconds ROUTER_TICK_INTERVAL = 250ms;
 
 namespace llarp
 {
+  static auto logcat = log::Cat("router");
+
   Router::Router(EventLoop_ptr loop, std::shared_ptr<vpn::Platform> vpnPlatform)
       : ready(false)
       , m_lmq(std::make_shared<oxenmq::OxenMQ>())
@@ -935,25 +937,49 @@ namespace llarp
     nodedb()->RemoveIf([&](const RouterContact& rc) -> bool {
       // don't purge bootstrap nodes from nodedb
       if (IsBootstrapNode(rc.pubkey))
+      {
+        log::debug(logcat, "Not removing {}: is bootstrap node", rc.pubkey);
         return false;
+      }
       // if for some reason we stored an RC that isn't a valid router
       // purge this entry
       if (not rc.IsPublicRouter())
+      {
+        log::debug(logcat, "Removing {}: not a valid router", rc.pubkey);
         return true;
-      // clients have a notion of a whilelist
+      }
+      /// clear out a fully expired RC
+      if (rc.IsExpired(now))
+      {
+        log::debug(logcat, "Removing {}: RC is expired", rc.pubkey);
+        return true;
+      }
+      // clients have no notion of a whilelist
       // we short circuit logic here so we dont remove
       // routers that are not whitelisted for first hops
       if (not isSvcNode)
+      {
+        log::trace(logcat, "Not removing {}: we are a client and it looks fine", rc.pubkey);
         return false;
+      }
+
       // if we have a whitelist enabled and we don't
       // have the whitelist yet don't remove the entry
       if (whitelistRouters and not gotWhitelist)
+      {
+        log::debug(logcat, "Skipping check on {}: don't have whitelist yet", rc.pubkey);
         return false;
+      }
       // if we have no whitelist enabled or we have
       // the whitelist enabled and we got the whitelist
       // check against the whitelist and remove if it's not
       // in the whitelist OR if there is no whitelist don't remove
-      return not _rcLookupHandler.SessionIsAllowed(rc.pubkey);
+      if (_rcLookupHandler.SessionIsAllowed(rc.pubkey))
+      {
+        log::debug(logcat, "Removing {}: not a valid router", rc.pubkey);
+        return true;
+      }
+      return false;
     });
 
     // find all deregistered relays

llarp/router_contact.cpp

@@ -25,17 +25,23 @@ namespace llarp
 
   bool RouterContact::BlockBogons = true;
 
-#ifdef TESTNET
-  // 1 minute for testnet
-  llarp_time_t RouterContact::Lifetime = 1min;
-#else
-  /// 1 day for real network
-  llarp_time_t RouterContact::Lifetime = 24h;
-#endif
+  /// 1 day rc lifespan
+  constexpr auto rc_lifetime = 24h;
   /// an RC inserted long enough ago (4 hrs) is considered stale and is removed
-  llarp_time_t RouterContact::StaleInsertionAge = 4h;
+  constexpr auto rc_stale_age = 4h;
+  /// window of time in which a router wil try to update their RC before it is marked stale
+  constexpr auto rc_update_window = 5min;
   /// update RCs shortly before they are about to expire
-  llarp_time_t RouterContact::UpdateInterval = RouterContact::StaleInsertionAge - 5min;
+  constexpr auto rc_update_interval = rc_stale_age - rc_update_window;
+
+  llarp_time_t RouterContact::Lifetime = rc_lifetime;
+  llarp_time_t RouterContact::StaleInsertionAge = rc_stale_age;
+  llarp_time_t RouterContact::UpdateInterval = rc_update_interval;
+
+  /// how many rc lifetime intervals should we wait until purging an rc
+  constexpr auto expiration_lifetime_generations = 10;
+  /// the max age of an rc before we want to expire it
+  constexpr auto rc_expire_age = rc_lifetime * expiration_lifetime_generations;
 
   NetID::NetID(const byte_t* val)
   {
@@ -116,6 +122,12 @@ namespace llarp
     return result;
   }
 
+  bool
+  RouterContact::FromOurNetwork() const
+  {
+    return netID == NetID::DefaultValue();
+  }
+
   bool
   RouterContact::BEncodeSignedSection(llarp_buffer_t* buf) const
   {
@@ -405,9 +417,7 @@ namespace llarp
   bool
   RouterContact::IsExpired(llarp_time_t now) const
   {
-    (void)now;
-    return false;
-    // return Age(now) >= Lifetime;
+    return Age(now) >= rc_expire_age;
   }
 
   llarp_time_t
@@ -471,15 +481,10 @@ namespace llarp
           "netid mismatch: '", netID, "' (theirs) != '", NetID::DefaultValue(), "' (ours)");
       return false;
     }
-    if (IsExpired(now))
-    {
-      if (!allowExpired)
-      {
-        llarp::LogError("RC is expired");
-        return false;
-      }
-      llarp::LogWarn("RC is expired");
-    }
+
+    if (IsExpired(now) and not allowExpired)
+      return false;
+
     for (const auto& a : addrs)
     {
       if (IsBogon(a.ip) && BlockBogons)

llarp/router_contact.hpp

@@ -201,6 +201,10 @@ namespace llarp
     bool
     VerifySignature() const;
 
+    /// return true if the netid in this rc is for the network id we are using
+    bool
+    FromOurNetwork() const;
+
    private:
     bool
     DecodeVersion_0(llarp_buffer_t* buf);