proper route poking (#1330)

* route poking:

* remove popen() call, replace with reading /proc/net/route for getting default route
* dynamically poke and unpoke routes on runtime

* swap intros and fix rpc endpoint for version to return what the ui expects

* use std::string::find_first_not_of instead of using a lambda

llarp/iwp/iwp.cpp

@@ -13,6 +13,7 @@ namespace llarp
         GetRCFunc getrc,
         LinkMessageHandler h,
         SignBufferFunc sign,
+        BeforeConnectFunc_t before,
         SessionEstablishedHandler est,
         SessionRenegotiateHandler reneg,
         TimeoutHandler timeout,
@@ -21,7 +22,7 @@ namespace llarp
         WorkerFunc_t work)
     {
       return std::make_shared<LinkLayer>(
-          keyManager, getrc, h, sign, est, reneg, timeout, closed, pumpDone, work, true);
+          keyManager, getrc, h, sign, before, est, reneg, timeout, closed, pumpDone, work, true);
     }
 
     LinkLayer_ptr
@@ -30,6 +31,7 @@ namespace llarp
         GetRCFunc getrc,
         LinkMessageHandler h,
         SignBufferFunc sign,
+        BeforeConnectFunc_t before,
         SessionEstablishedHandler est,
         SessionRenegotiateHandler reneg,
         TimeoutHandler timeout,
@@ -38,7 +40,7 @@ namespace llarp
         WorkerFunc_t work)
     {
       return std::make_shared<LinkLayer>(
-          keyManager, getrc, h, sign, est, reneg, timeout, closed, pumpDone, work, false);
+          keyManager, getrc, h, sign, before, est, reneg, timeout, closed, pumpDone, work, false);
     }
   }  // namespace iwp
 }  // namespace llarp

llarp/iwp/iwp.hpp

@@ -14,6 +14,7 @@ namespace llarp::iwp
       GetRCFunc getrc,
       LinkMessageHandler h,
       SignBufferFunc sign,
+      BeforeConnectFunc_t before,
       SessionEstablishedHandler est,
       SessionRenegotiateHandler reneg,
       TimeoutHandler timeout,
@@ -27,6 +28,7 @@ namespace llarp::iwp
       GetRCFunc getrc,
       LinkMessageHandler h,
       SignBufferFunc sign,
+      BeforeConnectFunc_t before,
       SessionEstablishedHandler est,
       SessionRenegotiateHandler reneg,
       TimeoutHandler timeout,

llarp/iwp/linklayer.cpp

@@ -13,6 +13,7 @@ namespace llarp
         GetRCFunc getrc,
         LinkMessageHandler h,
         SignBufferFunc sign,
+        BeforeConnectFunc_t before,
         SessionEstablishedHandler est,
         SessionRenegotiateHandler reneg,
         TimeoutHandler timeout,
@@ -20,7 +21,8 @@ namespace llarp
         PumpDoneHandler pumpDone,
         WorkerFunc_t worker,
         bool allowInbound)
-        : ILinkLayer(keyManager, getrc, h, sign, est, reneg, timeout, closed, pumpDone, worker)
+        : ILinkLayer(
+            keyManager, getrc, h, sign, before, est, reneg, timeout, closed, pumpDone, worker)
         , permitInbound{allowInbound}
     {
     }

llarp/iwp/linklayer.hpp

@@ -21,6 +21,7 @@ namespace llarp
           GetRCFunc getrc,
           LinkMessageHandler h,
           SignBufferFunc sign,
+          BeforeConnectFunc_t before,
           SessionEstablishedHandler est,
           SessionRenegotiateHandler reneg,
           TimeoutHandler timeout,

llarp/link/server.cpp

@@ -18,6 +18,7 @@ namespace llarp
       GetRCFunc getrc,
       LinkMessageHandler handler,
       SignBufferFunc signbuf,
+      BeforeConnectFunc_t before,
       SessionEstablishedHandler establishedSession,
       SessionRenegotiateHandler reneg,
       TimeoutHandler timeout,
@@ -28,6 +29,7 @@ namespace llarp
       , HandleTimeout(std::move(timeout))
       , Sign(std::move(signbuf))
       , GetOurRC(std::move(getrc))
+      , BeforeConnect(std::move(before))
       , SessionEstablished(std::move(establishedSession))
       , SessionClosed(std::move(closed))
       , SessionRenegotiate(std::move(reneg))
@@ -311,6 +313,10 @@ namespace llarp
       }
     }
     std::shared_ptr<ILinkSession> s = NewOutboundSession(rc, to);
+    if (BeforeConnect)
+    {
+      BeforeConnect(std::move(rc));
+    }
     if (PutSession(s))
     {
       s->Start();

llarp/link/server.hpp

@@ -70,6 +70,9 @@ namespace llarp
   /// queue work to worker thread
   using WorkerFunc_t = std::function<void(Work_t)>;
 
+  /// before connection hook, called before we try connecting via outbound link
+  using BeforeConnectFunc_t = std::function<void(llarp::RouterContact)>;
+
   struct ILinkLayer
   {
     ILinkLayer(
@@ -77,6 +80,7 @@ namespace llarp
         GetRCFunc getrc,
         LinkMessageHandler handler,
         SignBufferFunc signFunc,
+        BeforeConnectFunc_t before,
         SessionEstablishedHandler sessionEstablish,
         SessionRenegotiateHandler renegotiate,
         TimeoutHandler timeout,
@@ -195,6 +199,7 @@ namespace llarp
     TimeoutHandler HandleTimeout;
     SignBufferFunc Sign;
     GetRCFunc GetOurRC;
+    BeforeConnectFunc_t BeforeConnect;
     SessionEstablishedHandler SessionEstablished;
     SessionClosedHandler SessionClosed;
     SessionRenegotiateHandler SessionRenegotiate;

llarp/net/route.cpp

@@ -10,6 +10,7 @@
 #include <linux/rtnetlink.h>
 #include <net/net.hpp>
 #include <exception>
+#include <charconv>
 #endif
 #ifdef __APPLE__
 #include <net/net.hpp>
@@ -25,6 +26,7 @@
 
 #include <sstream>
 #include <util/logging/logger.hpp>
+#include <util/str.hpp>
 
 namespace llarp::net
 {
@@ -338,28 +340,22 @@ namespace llarp::net
   {
     std::vector<std::string> gateways;
 #ifdef __linux__
-
-    FILE* p = popen("ip route", "r");
-    if (p == nullptr)
-      return gateways;
-    char* line = nullptr;
-    size_t len = 0;
-    ssize_t read = 0;
-    while ((read = getline(&line, &len, p)) != -1)
+    std::ifstream inf("/proc/net/route");
+    for (std::string line; std::getline(inf, line);)
     {
-      std::string line_str(line, len);
-      std::vector<std::string> words;
-      std::istringstream instr(line_str);
-      for (std::string word; std::getline(instr, word, ' ');)
-      {
-        words.emplace_back(std::move(word));
-      }
-      if (words[0] == "default" and words[1] == "via" and words[3] == "dev" and words[4] != ifname)
+      const auto parts = split(line, '\t');
+      if (parts[1].find_first_not_of('0') == std::string::npos and parts[0] != ifname)
       {
-        gateways.emplace_back(std::move(words[2]));
+        const auto& ip = parts[2];
+        if ((ip.size() == sizeof(uint32_t) * 2) and lokimq::is_hex(ip))
+        {
+          huint32_t x{};
+          lokimq::from_hex(ip.begin(), ip.end(), reinterpret_cast<char*>(&x.h));
+          gateways.emplace_back(x.ToString());
+        }
       }
     }
-    pclose(p);
+
     return gateways;
 #elif _WIN32
 #define MALLOC(x) HeapAlloc(GetProcessHeap(), 0, (x))

llarp/router/router.cpp

@@ -12,6 +12,7 @@
 #include <link/server.hpp>
 #include <messages/link_message.hpp>
 #include <net/net.hpp>
+#include <net/route.hpp>
 #include <stdexcept>
 #include <util/buffer.hpp>
 #include <util/logging/file_logger.hpp>
@@ -332,6 +333,10 @@ namespace llarp
   void
   Router::Close()
   {
+    for (const auto& [ip, gateway] : m_PokedRoutes)
+    {
+      net::DelRoute(ip, gateway);
+    }
     if (_onDown)
       _onDown();
     LogInfo("closing router");
@@ -574,6 +579,7 @@ namespace llarp
           util::memFn(&AbstractRouter::rc, this),
           util::memFn(&AbstractRouter::HandleRecvLinkMessageBuffer, this),
           util::memFn(&AbstractRouter::Sign, this),
+          nullptr,
           util::memFn(&Router::ConnectionEstablished, this),
           util::memFn(&AbstractRouter::CheckRenegotiateValid, this),
           util::memFn(&Router::ConnectionTimedOut, this),
@@ -853,6 +859,12 @@ namespace llarp
     dht()->impl->Nodes()->DelNode(k);
 
     LogInfo("Session to ", remote, " fully closed");
+    if (IsServiceNode())
+      return;
+    RouterContact rc;
+    if (not nodedb()->Get(remote, rc))
+      return;
+    DelRoute(rc.addrs[0].toIpAddress().toHost());
   }
 
   void
@@ -1216,6 +1228,34 @@ namespace llarp
     return true;
   }
 
+  std::string
+  Router::GetDefaultGateway() const
+  {
+    const auto ep = hiddenServiceContext().GetDefault();
+    const auto gateways = net::GetGatewaysNotOnInterface(ep->GetIfName());
+    if (gateways.empty())
+      throw std::runtime_error("no gateways?");
+    return gateways[0];
+  }
+
+  void
+  Router::AddRoute(std::string ip)
+  {
+    const auto gateway = GetDefaultGateway();
+    m_PokedRoutes.emplace(ip, gateway);
+    net::AddRoute(ip, gateway);
+  }
+
+  void
+  Router::DelRoute(std::string ip)
+  {
+    const auto itr = m_PokedRoutes.find(ip);
+    if (itr == m_PokedRoutes.end())
+      return;
+    net::DelRoute(itr->first, itr->second);
+    m_PokedRoutes.erase(itr);
+  }
+
   bool
   Router::InitOutboundLinks()
   {
@@ -1224,6 +1264,11 @@ namespace llarp
         util::memFn(&AbstractRouter::rc, this),
         util::memFn(&AbstractRouter::HandleRecvLinkMessageBuffer, this),
         util::memFn(&AbstractRouter::Sign, this),
+        [&](llarp::RouterContact rc) {
+          if (IsServiceNode())
+            return;
+          AddRoute(rc.addrs[0].toIpAddress().toHost());
+        },
         util::memFn(&Router::ConnectionEstablished, this),
         util::memFn(&AbstractRouter::CheckRenegotiateValid, this),
         util::memFn(&Router::ConnectionTimedOut, this),

llarp/router/router.hpp

@@ -260,6 +260,17 @@ namespace llarp
       */
     }
 
+    std::string
+    GetDefaultGateway() const;
+
+    void
+    AddRoute(std::string ip);
+
+    void
+    DelRoute(std::string ip);
+
+    std::unordered_map<std::string, std::string> m_PokedRoutes;
+
     void
     PumpLL() override;
 

llarp/rpc/rpc_server.cpp

@@ -98,7 +98,11 @@ namespace llarp::rpc
             })
         .add_request_command(
             "version",
-            [](lokimq::Message& msg) { msg.send_reply(CreateJSONResponse(llarp::VERSION_FULL)); })
+            [r = m_Router](lokimq::Message& msg) {
+              util::StatusObject result{{"version", llarp::VERSION_FULL},
+                                        {"uptime", to_json(r->Uptime())}};
+              msg.send_reply(CreateJSONResponse(result));
+            })
         .add_request_command(
             "status",
             [&](lokimq::Message& msg) {

llarp/service/context.cpp

@@ -153,7 +153,7 @@ namespace llarp
     }
 
     Endpoint_ptr
-    Context::GetEndpointByName(const std::string& name)
+    Context::GetEndpointByName(const std::string& name) const
     {
       auto itr = m_Endpoints.find(name);
       if (itr != m_Endpoints.end())

llarp/service/context.hpp

@@ -51,10 +51,10 @@ namespace llarp
       RemoveEndpoint(const std::string& name);
 
       Endpoint_ptr
-      GetEndpointByName(const std::string& name);
+      GetEndpointByName(const std::string& name) const;
 
       Endpoint_ptr
-      GetDefault()
+      GetDefault() const
       {
         return GetEndpointByName("default");
       }

llarp/service/outbound_context.cpp

@@ -110,7 +110,7 @@ namespace llarp
           return true;
         }
         currentIntroSet = *foundIntro;
-        ShiftIntroduction(false);
+        SwapIntros();
       }
       else
       {

test/iwp/test_iwp_session.cpp

@@ -85,6 +85,8 @@ struct IWPLinkContext
           REQUIRE(llarp::CryptoManager::instance()->sign(sig, keyManager->identityKey, buf));
           return true;
         },
+        // before connect
+        nullptr,
         // established handler
         [established](llarp::ILinkSession* s, bool linkIsInbound) {
           REQUIRE(s != nullptr);