Fixed NAT service and modified utils function. We need to investigate if the problem persists for future transparent services

Author: DavideAG

src/libs/polycube/include/polycube/services/utils.h

@@ -28,9 +28,12 @@ namespace polycube {
 namespace service {
 namespace utils {
 
-/* ip (a.b.c.d) to string and viceversa
+/* IP string (a.b.c.d) or IP prefix (a.b.c.d/m) to nbo uint. If (a.b.c.d/m) only IP will be processed
  * Number is in network byte order (nbo), i.e., big endian */
 uint32_t ip_string_to_nbo_uint(const std::string &ip);
+
+/* IP (a.b.c.d) to string 
+ * Number is in network byte order (nbo), i.e., big endian */
 std::string nbo_uint_to_ip_string(uint32_t ip);
 
 /* mac (aa:bb:cc:dd:ee:ff) to string and vicersa
@@ -54,7 +57,7 @@ uint64_t hex_string_to_uint(const std::string &str);
 std::string get_random_mac();
 
 /* Take in ingress a string like 192.168.0.1/24 and return only the ip
- * 192.168.0.1 */
+ * 192.168.0.1 . If no prefix it will return the same input string*/
 std::string get_ip_from_string(const std::string &ipv_net);
 
 /* Take in ingress a string like 192.168.0.1/24 and return only the "prefix

src/libs/polycube/src/utils.cpp

@@ -34,12 +34,15 @@ namespace service {
 namespace utils {
 
 // new set of functions
+
 uint32_t ip_string_to_nbo_uint(const std::string &ip) {
   unsigned char a[4];
   int last = -1;
-  int rc = std::sscanf(ip.c_str(), "%hhu.%hhu.%hhu.%hhu%n", a + 0, a + 1, a + 2,
+  std::string IP_address = get_ip_from_string(ip);
+
+  int rc = std::sscanf(IP_address.c_str(), "%hhu.%hhu.%hhu.%hhu%n", a + 0, a + 1, a + 2,
                        a + 3, &last);
-  if (rc != 4 || ip.size() != last)
+  if (rc != 4 || IP_address.size() != last)
     throw std::runtime_error("Not an ipv4 address " + ip);
 
   return uint32_t(a[3]) << 24 | uint32_t(a[2]) << 16 | uint32_t(a[1]) << 8 |
@@ -230,7 +233,7 @@ uint64_t hex_string_to_uint(const std::string &str) {
 std::string get_ip_from_string(const std::string &ipv_net) {
   size_t pos = ipv_net.find("/");
   if (pos == std::string::npos) {
-    return std::string();  // throw?
+    return ipv_net;
   }
   return ipv_net.substr(0, pos);
 }

src/services/pcn-nat/src/Nat.cpp

@@ -34,8 +34,8 @@ Nat::Nat(const std::string name, const NatJsonObject &conf)
   //addNattingTableList(conf.getNattingTable());
 
   ParameterEventCallback cb = [&](const std::string &parameter, const std::string &value) {
-    logger()->debug("parent IP has been updated to {}", value);
-    external_ip_ = value;
+    external_ip_ = utils::get_ip_from_string(value);
+    logger()->debug("parent IP has been updated to {}", external_ip_);
     if (rule_->getMasquerade()->getEnabled()) {
       rule_->getMasquerade()->inject(utils::ip_string_to_nbo_uint(external_ip_));
     }