Try fix get_local_ip_for_gateway for Linux

src/platform/linux/misc.cpp

@@ -245,7 +245,7 @@ namespace platf {
 get_local_ip_for_gateway() {
   int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
   if (fd < 0) {
-      BOOST_LOG(warning) << "Socket creation failed";
+    BOOST_LOG(warning) << "Socket creation failed: " << strerror(errno);
     return "";
   }
 
@@ -263,21 +263,21 @@ namespace platf {
   nlMsg->nlmsg_pid = getpid();
 
   if (send(fd, nlMsg, nlMsg->nlmsg_len, 0) < 0) {
+    BOOST_LOG(warning) << "Send message failed: " << strerror(errno);
     close(fd);
-      BOOST_LOG(warning) << "Send message failed";
-      return "";
-    }
-
-    len = recv(fd, nlMsg, sizeof(buffer), 0);
-    if (len < 0) {
-      close(fd);
-      BOOST_LOG(warning) << "Receive message failed";
     return "";
   }
 
   std::string local_ip;
+  bool found = false;
 
+  while ((len = recv(fd, nlMsg, sizeof(buffer), 0)) > 0) {
     for (; NLMSG_OK(nlMsg, len); nlMsg = NLMSG_NEXT(nlMsg, len)) {
+      if (nlMsg->nlmsg_type == NLMSG_DONE) {
+        found = true;
+        break;
+      }
+
       rtMsg = (struct rtmsg *)NLMSG_DATA(nlMsg);
       if (rtMsg->rtm_family != AF_INET || rtMsg->rtm_table != RT_TABLE_MAIN)
         continue;
@@ -305,10 +305,14 @@ namespace platf {
 
       if (gateway.s_addr != 0 && local.s_addr != 0) {
         local_ip = inet_ntoa(local);
+        found = true;
         break;
       }
     }
 
+    if (found) break;
+  }
+
   close(fd);
 
   if (local_ip.empty()) {