Added Utils::interface_id.

include/utils.h

@@ -102,6 +102,14 @@ namespace Tins {
          */
         bool interface_hwaddr(const std::string &iface, uint8_t *buffer);
 
+        /** \brief Lookup the interface identifier.
+         * 
+         * If the lookup fails, false will be returned, true otherwise.
+         * \param iface The interface from which to extract the identifier.
+         * \param flag The interface id will be returned in this parameter.
+         */
+        bool interface_id(const std::string &iface, uint32_t &id);
+        
         /** \brief Convert 32 bit integer into network byte order.
          * 
          * \param data The data to convert.

src/utils.cpp

@@ -57,6 +57,21 @@ struct IPv4Collector {
     }
 };
 
+struct InterfaceIDCollector {
+    uint32_t id;
+    bool found;
+    const char *iface;
+    
+    InterfaceIDCollector(const char *interface) : id(0), found(false), iface(interface) { }
+    
+    void operator() (struct ifaddrs *addr) {
+        if(!found && !strcmp(addr->ifa_name, iface)) {
+            id = addr->ifa_flags;
+            found = true;
+        }
+    }
+};
+
 struct HWAddressCollector {
     uint8_t *result;
     bool found;
@@ -173,6 +188,13 @@ bool Tins::Utils::interface_hwaddr(const string &iface, uint8_t *buffer) {
     return collector.found;
 }
 
+bool Tins::Utils::interface_id(const string &iface, uint32_t &id) {
+    InterfaceIDCollector collector(iface.c_str());
+    generic_iface_loop(collector);
+    id = collector.id;
+    return collector.found;
+}
+
 uint32_t Tins::Utils::crc32(uint8_t* data, uint32_t data_size) {
     uint32_t i, crc = 0;
     static uint32_t crc_table[] = {