polycubed: move logic to detect deleted interface to service controller

When an interface that is connected to a cube's port is deleted, it is needed
to remove the peer from that port.

This commit creates a listener function in the service controller class that is
on charge of removing the peer of a port when the interface is deleted,
this also removes any possible attach to transparent services.

This commit also solves a bug when transparent services where connected to a
interface and that was deleted without detaching first:

create veth1
polycubectl anytransparentservice add t0
polycubectl attach t0 veth1
// traffic is received by t0
polycubetl del t0
delete veth1

create veth1
polycubectl anytransparentservice add t0
polycubectl attach t0 veth1
// at this point t0 does not receives the packets

Signed-off-by: Mauricio Vasquez B <mauriciovasquezbernal@gmail.com>

Author: mauriciovasquezbernal

src/polycubed/src/polycubed.cpp

@@ -28,6 +28,7 @@
 
 #include "config.h"
 #include "polycube/services/json.hpp"
+#include "netlink.h"
 #include "rest_server.h"
 #include "utils.h"
 #include "version.h"
@@ -53,6 +54,7 @@ std::shared_ptr<spdlog::logger> logger;
 // create core instance
 PolycubedCore *core;
 RestServer *restserver;
+int netlink_nofitication_id = -1;
 
 void shutdown() {
   static bool done = false;
@@ -67,6 +69,12 @@ void shutdown() {
     delete core;
     delete restserver;
   }
+
+  if (netlink_nofitication_id != -1) {
+    Netlink::getInstance().unregisterObserver(Netlink::Event::LINK_DELETED,
+                                              netlink_nofitication_id);
+  }
+
   logger->info("polycubed is shutting down. Bye!");
   done = true;
 }
@@ -246,6 +254,12 @@ int main(int argc, char *argv[]) {
   auto base_model = new BaseModel();
   core = new PolycubedCore(base_model);
 
+  // register handler to detect interfaces that are deleted
+  netlink_nofitication_id = Netlink::getInstance().registerObserver(
+    Netlink::Event::LINK_DELETED,
+    std::bind(&ServiceController::netlink_notification, std::placeholders::_1,
+              std::placeholders::_2));
+
   // setup rest server
   int thr = 4;
   Address addr(config.getServerIP(), Pistache::Port(config.getServerPort()));

src/polycubed/src/port.cpp

@@ -17,8 +17,6 @@
 #include "port.h"
 #include "controller.h"
 #include "extiface.h"
-#include "netlink.h"
-
 #include "service_controller.h"
 
 // workaround for now
@@ -37,17 +35,9 @@ Port::Port(CubeIface &parent, const std::string &name, uint16_t index,
       index_(index),
       uuid_(GuidGenerator().newGuid()),
       peer_port_(nullptr),
-      logger(spdlog::get("polycubed")) {
-  netlink_notification_index = Netlink::getInstance().registerObserver(
-      Netlink::Event::LINK_DELETED,
-      std::bind(&Port::netlink_notification, this, std::placeholders::_1,
-                std::placeholders::_2));
-}
+      logger(spdlog::get("polycubed")) {}
 
-Port::~Port() {
-  Netlink::getInstance().unregisterObserver(Netlink::Event::LINK_DELETED,
-                                            netlink_notification_index);
-}
+Port::~Port() {}
 
 uint16_t Port::get_port_id() const {
   return index_;  // TODO: rename this variable
@@ -141,12 +131,6 @@ bool Port::operator==(const PortIface &rhs) const {
     return false;
 }
 
-void Port::netlink_notification(int ifindex, const std::string &ifname) {
-  if (peer_ == ifname) {
-    set_peer("");
-  }
-}
-
 void Port::set_peer(const std::string &peer) {
   {
     std::lock_guard<std::mutex> guard(port_mutex_);

src/polycubed/src/port.h

@@ -76,8 +76,6 @@ class Port : public polycube::service::PortIface, public PeerIface {
   virtual void set_conf(const nlohmann::json &conf);
   virtual nlohmann::json to_json() const;
 
-  void netlink_notification(int ifindex, const std::string &ifname);
-
   static void connect(PeerIface &p1, PeerIface &p2);
   static void unconnect(PeerIface &p1, PeerIface &p2);
 
@@ -93,7 +91,6 @@ class Port : public polycube::service::PortIface, public PeerIface {
   uint16_t index_;
   Guid uuid_;
   std::string peer_;
-  int netlink_notification_index;
 
   // TODO: I know, a better name is needed
   PeerIface *peer_port_;

src/polycubed/src/service_controller.cpp

@@ -284,5 +284,26 @@ bool ServiceController::parse_peer_name(const std::string &peer,
   return true;
 }
 
+void ServiceController::netlink_notification(int ifindex,
+                                             const std::string &ifname) {
+  std::lock_guard<std::mutex> guard(service_ctrl_mutex_);
+  if (ports_to_ifaces.count(ifname) == 0) {
+    return; // nothing to do here
+  }
+
+  auto iface = ports_to_ifaces.at(ifname);
+
+  auto peer = iface->get_peer_iface();
+  if (peer) {
+    auto port = dynamic_cast<Port*>(peer);
+    if (port) {
+      port->set_peer("");
+    }
+  }
+
+  // try to remove it if existed
+  ports_to_ifaces.erase(ifname);
+}
+
 }  // namespace polycubed
 }  // namespace polycube

src/polycubed/src/service_controller.h

@@ -88,6 +88,8 @@ class ServiceController {
   static std::unordered_map<std::string, std::shared_ptr<ExtIface>>
       ports_to_ifaces;
 
+  static void netlink_notification(int ifindex, const std::string &ifname);
+
  private:
   std::shared_ptr<spdlog::logger> l;
   std::shared_ptr<ManagementInterface> management_interface_;