X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fnat%2Fgnunet-helper-nat-server.c;h=2978261e4f11e6d96a0d7909fc3ce9ece0fc18e5;hb=cbd60b5e56aac2d6711e299086383f83357794f8;hp=ef8e97482771d0054713251e7f23c35fc028ed0d;hpb=60c6dfd1fe22a01a3f7723e7e2bb18d52895c527;p=oweals%2Fgnunet.git

diff --git a/src/nat/gnunet-helper-nat-server.c b/src/nat/gnunet-helper-nat-server.c
index ef8e97482..2978261e4 100644
--- a/src/nat/gnunet-helper-nat-server.c
+++ b/src/nat/gnunet-helper-nat-server.c
@@ -2,20 +2,15 @@
      This file is part of GNUnet.
      Copyright (C) 2010 GNUnet e.V.
 
-     GNUnet is free software; you can redistribute it and/or modify
-     it under the terms of the GNU General Public License as published
-     by the Free Software Foundation; either version 3, or (at your
-     option) any later version.
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
 
      GNUnet is distributed in the hope that it will be useful, but
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-     General Public License for more details.
-
-     You should have received a copy of the GNU General Public License
-     along with GNUnet; see the file COPYING.  If not, write to the
-     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-     Boston, MA 02110-1301, USA.
+     Affero General Public License for more details.
 */
 
 /**
@@ -70,6 +65,17 @@
 #define ICMP_TIME_EXCEEDED 11
 #endif
 
+/**
+ * Call memcpy() but check for @a n being 0 first. In the latter
+ * case, it is now safe to pass NULL for @a src or @a dst.
+ * Unlike traditional memcpy(), returns nothing.
+ *
+ * @param dst destination of the copy, may be NULL if @a n is zero
+ * @param src source of the copy, may be NULL if @a n is zero
+ * @param n number of bytes to copy
+ */
+#define GNUNET_memcpy(dst,src,n) do { if (0 != n) { (void) memcpy (dst,src,n); } } while (0)
+
 /**
  * Should we print some debug output?
  */
@@ -266,9 +272,9 @@ send_icmp_echo (const struct in_addr *my_ip)
   ip_pkt.checksum =
       htons (calc_checksum ((uint16_t *) & ip_pkt,
 			    sizeof (struct ip_header)));
-  memcpy (&packet[off],
-	  &ip_pkt,
-	  sizeof (struct ip_header));
+  GNUNET_memcpy (&packet[off],
+                 &ip_pkt,
+                 sizeof (struct ip_header));
   off += sizeof (struct ip_header);
 
   icmp_echo.type = ICMP_ECHO;
@@ -279,9 +285,9 @@ send_icmp_echo (const struct in_addr *my_ip)
     htons (calc_checksum
 	   ((uint16_t *) & icmp_echo,
 	    sizeof (struct icmp_echo_header)));
-  memcpy (&packet[off],
-	  &icmp_echo,
-	  sizeof (struct icmp_echo_header));
+  GNUNET_memcpy (&packet[off],
+                 &icmp_echo,
+                 sizeof (struct icmp_echo_header));
   off += sizeof (struct icmp_echo_header);
 
   memset (&dst, 0, sizeof (dst));
@@ -388,9 +394,13 @@ process_icmp_response ()
     return;
   }
   off = 0;
-  memcpy (&ip_pkt, &buf[off], sizeof (struct ip_header));
+  GNUNET_memcpy (&ip_pkt,
+                 &buf[off],
+                 sizeof (struct ip_header));
   off += sizeof (struct ip_header);
-  memcpy (&icmp_ttl, &buf[off], sizeof (struct icmp_ttl_exceeded_header));
+  GNUNET_memcpy (&icmp_ttl,
+                 &buf[off],
+                 sizeof (struct icmp_ttl_exceeded_header));
   off += sizeof (struct icmp_ttl_exceeded_header);
   if ((ICMP_TIME_EXCEEDED != icmp_ttl.type) || (0 != icmp_ttl.code))
   {
@@ -401,7 +411,9 @@ process_icmp_response ()
   source_ip.s_addr = ip_pkt.src_ip;
 
   /* skip 2nd IP header */
-  memcpy (&ip_pkt, &buf[off], sizeof (struct ip_header));
+  GNUNET_memcpy (&ip_pkt,
+                 &buf[off],
+                 sizeof (struct ip_header));
   off += sizeof (struct ip_header);
 
   switch (ip_pkt.proto)
@@ -416,7 +428,9 @@ process_icmp_response ()
       return;
     }
     /* grab ICMP ECHO content */
-    memcpy (&icmp_echo, &buf[off], sizeof (struct icmp_echo_header));
+    GNUNET_memcpy (&icmp_echo,
+                   &buf[off],
+                   sizeof (struct icmp_echo_header));
     port = (uint16_t) ntohl (icmp_echo.reserved);
     break;
   case IPPROTO_UDP:
@@ -428,7 +442,9 @@ process_icmp_response ()
       return;
     }
     /* grab UDP content */
-    memcpy (&udp_pkt, &buf[off], sizeof (struct udp_header));
+    GNUNET_memcpy (&udp_pkt,
+                   &buf[off],
+                   sizeof (struct udp_header));
     port = ntohs (udp_pkt.length);
     break;
   default: