add on-demand arp responder (#167)

* add arp responder

include/aca_arp_responder.h

@@ -0,0 +1,147 @@
+// Copyright 2019 The Alcor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef ACA_ARP_RESPONDER_H
+#define ACA_ARP_RESPONDER_H
+
+#include <string>
+#include <unordered_map>
+#include "hashmap/HashMap.h"
+#include <mutex>
+
+using namespace std;
+
+namespace aca_arp_responder
+{
+
+#define ARP_ENTRY_DATA_SET(pData,pConfig)                           \
+  do {                                                              \
+    (pData)->ipv4_address = (pConfig)->ipv4_address;                \
+    (pData)->vlan_id = (pConfig)->vlan_id;                          \
+  } while (0)                                                       
+
+#define ARP_TABLE_DATA_SET(pData,pConfig)                           \
+  do {                                                              \
+    (pData)->mac_address = (pConfig)->mac_address;                  \
+  } while (0)  
+
+
+struct arp_config{
+  string mac_address;
+  string ipv4_address;
+  string ipv6_address; 
+  uint16_t vlan_id;
+  string port_host_name;
+};
+
+struct arp_entry_data{
+  string ipv4_address;
+  string ipv6_address; 
+  uint16_t vlan_id;
+  bool operator==(const arp_entry_data &p) const{
+    return ipv4_address==p.ipv4_address && vlan_id==p.vlan_id;
+  }
+
+  bool operator!=(const arp_entry_data &p) const{
+    return ipv4_address!=p.ipv4_address || vlan_id!=p.vlan_id;
+  }
+};
+
+
+struct arp_hash{
+  size_t operator() (const arp_entry_data &p) const{
+    return hash<string>()(p.ipv4_address) ^ (hash<uint16_t>()(p.vlan_id) << 1);
+  }
+};
+
+struct arp_table_data{
+  string mac_address;
+};
+
+struct arp_message{
+  uint16_t hrd;
+  uint16_t pro;
+  uint8_t hln;
+  uint8_t pln;
+  uint16_t op;
+  uint8_t sha[6];
+  uint32_t spa;
+  uint8_t tha[6];
+  uint32_t tpa;
+} __attribute__ ((__packed__));
+
+struct vlan_message{
+  uint16_t vlan_proto; //should always be 0x8100
+  uint16_t vlan_tci;
+};
+
+//ARP Message Type
+#define ARP_MSG_ARPREQUEST (0x1)
+#define ARP_MSG_ARPREPLY (0x2)
+
+//ARP Message Fields
+#define ARP_MSG_HRD_TYPE (0x1)
+#define ARP_MSG_PRO_TYPE (0x0800)
+#define ARP_MSG_HRD_LEN (0x6)
+#define ARP_MSG_PRO_LEN (0x4)
+
+class ACA_ARP_Responder{
+  public:  
+    static ACA_ARP_Responder &get_instance();
+
+    /* Managemet Plane Ops*/
+    int add_arp_entry(arp_config *arp_config_in);
+    int create_or_update_arp_entry(arp_config *arp_config_in);
+    int delete_arp_entry(arp_config *arp_config_in);
+
+    /* Data plane Ops */
+    void arp_recv(uint32_t in_port, void *vlanmsg, void *message);
+    void arp_xmit(uint32_t in_port, void *vlanmsg, void *message, int is_find);
+
+
+  private:
+    ACA_ARP_Responder();
+    ~ACA_ARP_Responder();
+
+    CTSL::HashMap<arp_entry_data,arp_table_data *,arp_hash> _arp_db;
+
+
+
+
+    /*************** Initialization and De-initialization ***********************/
+    void _init_arp_db();
+    void _deinit_arp_db();
+    void _init_arp_ofp();
+    void _deinit_arp_ofp();
+
+    /*************** Management plane operations ***********************/
+    void _validate_mac_address(const char *mac_string);
+    void _validate_ipv4_address(const char *ip_address);
+    void _validate_ipv6_address(const char *ip_address);
+    int _validate_arp_entry(arp_config *arp_cfg_in);
+
+    /**************** Data plane operations *********************/
+    int _validate_arp_message(arp_message *arpmsg);
+    string _get_requested_ip(arp_message *arpmsg);
+
+    void _parse_arp_request(uint32_t in_port, vlan_message *vlanmsg, arp_message *arpmsg);
+
+    arp_message *_pack_arp_reply(arp_message *arpreq, string mac_address);
+
+    string _serialize_arp_message(vlan_message *vlanmsg, arp_message *arpmsg);
+
+};
+} // namespace aca_arp_responder
+#endif // #ifndef ACA_ARP_RESPONDER_H
+

src/CMakeLists.txt

@@ -19,6 +19,7 @@ set(SOURCES
     ./dhcp/aca_dhcp_server.cpp
     ./zeta/aca_zeta_oam_server.cpp
     ./zeta/aca_zeta_programming.cpp  
+    ./ovs/aca_arp_responder.cpp 
 )
 FIND_LIBRARY(RDKAFKA rdkafka /usr/lib/x86_64-linux-gnu NO_DEFAULT_PATH)
 FIND_LIBRARY(CPPKAFKA cppkafka /usr/local/lib NO_DEFAULT_PATH)

src/aca_main.cpp

@@ -18,6 +18,7 @@
 #include "aca_message_pulsar_consumer.h"
 #include "aca_grpc.h"
 #include "aca_ovs_l2_programmer.h"
+#include "aca_ovs_control.h"
 #include "goalstateprovisioner.grpc.pb.h"
 #include <thread>
 #include <unistd.h> /* for getopt */
@@ -41,6 +42,8 @@ using namespace std;
 
 // Global variables
 std::thread *g_grpc_server_thread = NULL;
+std::thread *ovs_monitor_brtun_thread = NULL;
+std::thread *ovs_monitor_brint_thread = NULL;
 GoalStateProvisionerImpl *g_grpc_server = NULL;
 string g_broker_list = EMPTY_STRING;
 string g_pulsar_topic = EMPTY_STRING;
@@ -126,7 +129,7 @@ static void aca_signal_handler(int sig_num)
 int main(int argc, char *argv[])
 {
   int option;
-  int rc;
+  int rc = 0;
 
   ACA_LOG_INIT(ACALOGNAME);
 
@@ -207,11 +210,18 @@ int main(int argc, char *argv[])
 
   aca_ovs_l2_programmer::ACA_OVS_L2_Programmer::get_instance().setup_ovs_bridges_if_need();
 
-  ACA_OVS_Control::get_instance().monitor("br-int", "resume");
+
+  // monitor br-int for dhcp request message
+  ovs_monitor_brint_thread =
+          new thread(bind(&ACA_OVS_Control::monitor,
+                          &ACA_OVS_Control::get_instance(), "br-int", "resume"));
+  ovs_monitor_brint_thread->detach();
+
+  // monitor br-tun for arp request message
+  ACA_OVS_Control::get_instance().monitor("br-tun","resume");
 
   ACA_Message_Pulsar_Consumer network_config_consumer(g_broker_list, g_pulsar_subsription_name);
   rc = network_config_consumer.consumeDispatched(g_pulsar_topic);
-
   aca_cleanup();
   return rc;
 }