MT#57437 Upstream: Support looking up aliased interface names

Backport from the upstream to support looking up aliased
interface names.

Upstream commit: a84509091031331159abb199e21701cb6d7e79b1

Change-Id: I557dee742351268737fe69df8991aede531bb57b

core/AmConfig.cpp

@@ -67,7 +67,8 @@ vector<AmConfig::RTP_interface> AmConfig::RTP_Ifs;
 map<string,unsigned short>      AmConfig::SIP_If_names;
 map<string,unsigned short>      AmConfig::RTP_If_names;
 map<string,unsigned short>      AmConfig::LocalSIPIP2If;
-vector<AmConfig::SysIntf>         AmConfig::SysIfs;
+vector<AmConfig::SysIntf>       AmConfig::SysIfs;
+map<string, string>             AmConfig::IfName2IP;
 
 #ifndef DISABLE_DAEMON_MODE
 bool         AmConfig::DaemonMode              = DEFAULT_DAEMON_MODE;
@@ -1026,6 +1027,7 @@ static bool fillSysIntfList()
 
     DBG("iface='%s';ip='%s';flags=0x%x\n",p_if->ifa_name,host,p_if->ifa_flags);
     intf_it->addrs.push_back(AmConfig::IPAddr(host,p_if->ifa_addr->sa_family));
+    AmConfig::IfName2IP[p_if->ifa_name] = host;
   }
 
   freeifaddrs(ifap);
@@ -1077,20 +1079,10 @@ string fixIface2IP(const string& dev_name, bool v6_for_sip)
       return dev_name;
   }
 
-  for(vector<AmConfig::SysIntf>::iterator intf_it = AmConfig::SysIfs.begin();
-      intf_it != AmConfig::SysIfs.end(); ++intf_it) {
-      
-    if(intf_it->name != dev_name)
-      continue;
-
-    if(intf_it->addrs.empty()){
-      ERROR("No IP address for interface '%s'\n",intf_it->name.c_str());
-      return "";
-    }
-      
-    DBG("dev_name = '%s'\n",dev_name.c_str());
-    return intf_it->addrs.front().addr;
-  }    
+  if (!AmConfig::IfName2IP[dev_name].empty()) {
+    DBG("dev_name = '%s, ip=%s'\n", dev_name.c_str(), AmConfig::IfName2IP[dev_name].c_str());
+    return AmConfig::IfName2IP[dev_name];
+  }
 
   return "";
 }

core/AmConfig.h

@@ -160,6 +160,7 @@ struct AmConfig
     unsigned int mtu;
   };
 
+  static map<string, string> IfName2IP;
   static vector<SysIntf> SysIfs;
 
   static int insert_SIP_interface(const SIP_interface& intf);