Add: Add function to get the local mac address (#922)

* Add function to get the local mac address associated to the local ip

* Extend the function for ipv6 support

* Fix ipv6 support

Use ntop also for ipv4. Improve code

misc/pcap.c

@@ -1274,3 +1274,56 @@ routethrough (struct in_addr *dest, struct in_addr *source)
     return myroutes[best_match].dev->name;
   return NULL;
 }
+
+/** @brief Given an IP address, determines which interface belongs to.
+ *
+ * @param local_ip IP address.
+ *
+ * @return Iface name if found, Null otherwise.
+ */
+char *
+get_iface_from_ip (const char *local_ip)
+{
+  char errbuf[PCAP_ERRBUF_SIZE];
+  pcap_if_t *alldevsp1 = NULL, *devs_aux = NULL;
+  char *if_name = NULL;
+
+  if (pcap_findalldevs (&alldevsp1, errbuf) == -1)
+    g_debug ("Error for pcap_findalldevs(): %s", errbuf);
+
+  devs_aux = alldevsp1;
+  while (devs_aux)
+    {
+      pcap_addr_t *addr_aux = NULL;
+
+      addr_aux = devs_aux->addresses;
+      while (addr_aux)
+        {
+          char buffer[INET6_ADDRSTRLEN];
+
+          if (((struct sockaddr *) addr_aux->addr)->sa_family == AF_INET)
+            inet_ntop (AF_INET,
+                       &(((struct sockaddr_in *) addr_aux->addr)->sin_addr),
+                       buffer, INET_ADDRSTRLEN);
+          else if (((struct sockaddr *) addr_aux->addr)->sa_family == AF_INET6)
+            inet_ntop (AF_INET6,
+                       &(((struct sockaddr_in6 *) addr_aux->addr)->sin6_addr),
+                       buffer, INET6_ADDRSTRLEN);
+
+          if (!g_strcmp0 (buffer, local_ip))
+            {
+              if_name = g_strdup (devs_aux->name);
+              break;
+            }
+          addr_aux = addr_aux->next;
+        }
+
+      if (if_name)
+        break;
+      devs_aux = devs_aux->next;
+    }
+  pcap_freealldevs (alldevsp1);
+  g_debug ("returning %s as device", if_name);
+
+  return if_name;
+}

misc/pcap_openvas.h

@@ -54,4 +54,7 @@ v6_routethrough (struct in6_addr *, struct in6_addr *);
 int
 v6_getsourceip (struct in6_addr *, struct in6_addr *);
 
+char *
+get_iface_from_ip (const char *);
+
 #endif

nasl/nasl_host.c

@@ -41,10 +41,13 @@
 #include <arpa/inet.h> /* for inet_aton */
 #include <gvm/base/networking.h>
 #include <gvm/util/kb.h>
+#include <net/if.h>
+#include <net/if_arp.h>
 #include <netdb.h>      /* for gethostbyaddr */
 #include <netinet/in.h> /* for in_addr */
 #include <string.h>     /* for strlen */
-#include <unistd.h>     /* for gethostname */
+#include <sys/ioctl.h>
+#include <unistd.h> /* for gethostname */
 
 tree_cell *
 get_hostnames (lex_ctxt *lexic)
@@ -577,3 +580,59 @@ nasl_target_is_ipv6 (lex_ctxt *lexic)
 
   return retc;
 }
+
+/**
+ * @brief Get the MAC address of host
+ *
+ * @param[in] lexic   Lexical context of NASL interpreter.
+ * @param[in] ip_address    Local IP address
+ *
+ * @return The MAC address of the host. NULL otherwise
+ */
+tree_cell *
+nasl_get_local_mac_address_from_ip (lex_ctxt *lexic)
+{
+  tree_cell *retc;
+  struct ifreq ifr;
+  int sock;
+  char *if_name = NULL, *buffer = NULL;
+  const unsigned char *mac;
+
+  char *ip_address = get_str_var_by_num (lexic, 0);
+
+  if_name = get_iface_from_ip (ip_address);
+  if (!if_name)
+    {
+      nasl_perror (lexic, "Missing interface name\n");
+      return NULL;
+    }
+
+  strncpy (ifr.ifr_name, if_name, sizeof (ifr.ifr_name) - 1);
+  g_free (if_name);
+  ifr.ifr_name[sizeof (ifr.ifr_name) - 1] = '\0';
+
+  sock = socket (PF_INET, SOCK_STREAM, 0);
+  if (-1 == sock)
+    {
+      perror ("socket() ");
+      return NULL;
+    }
+
+  if (-1 == ioctl (sock, SIOCGIFHWADDR, &ifr))
+    {
+      perror ("ioctl(SIOCGIFHWADDR) ");
+      return NULL;
+    }
+
+  mac = (unsigned char *) ifr.ifr_hwaddr.sa_data;
+  buffer = g_strdup_printf ("%02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1],
+                            mac[2], mac[3], mac[4], mac[5]);
+
+  close (sock);
+
+  retc = alloc_typed_cell (CONST_DATA);
+  retc->x.str_val = buffer;
+  retc->size = 17;
+
+  return retc;
+}

nasl/nasl_host.h

@@ -73,4 +73,7 @@ nasl_same_host (lex_ctxt *);
 tree_cell *
 nasl_target_is_ipv6 (lex_ctxt *lexic);
 
+tree_cell *
+nasl_get_local_mac_address_from_ip (lex_ctxt *);
+
 #endif

nasl/nasl_init.c

@@ -137,6 +137,7 @@ static init_func libfuncs[] = {
   {"resolve_host_name", resolve_hostname},
   {"resolve_hostname_to_multiple_ips", resolve_hostname_to_multiple_ips},
   {"get_host_ip", get_host_ip},
+  {"get_local_mac_address_from_ip", nasl_get_local_mac_address_from_ip},
   {"same_host", nasl_same_host},
   {"TARGET_IS_IPV6", nasl_target_is_ipv6},
   {"get_host_open_port", get_host_open_port},