[GNUnet-SVN] r27500 - gnunet/src/tun

[gnunet]

Author: grothoff
Date: 2013-06-20 10:56:24 +0200 (Thu, 20 Jun 2013)
New Revision: 27500

Added:
   gnunet/src/tun/regex.c
Log:
adding file that was moved here from regex.c and forgotten in earlier commit

Added: gnunet/src/tun/regex.c
===================================================================
--- gnunet/src/tun/regex.c                              (rev 0)
+++ gnunet/src/tun/regex.c      2013-06-20 08:56:24 UTC (rev 27500)
@@ -0,0 +1,141 @@
+/*
+     This file is part of GNUnet
+     (C) 2012, 2013 Christian Grothoff (and other contributing authors)
+
+     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 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., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file src/tun/regex.c
+ * @brief functions to convert IP networks to regexes
+ * @author Maximilian Szengel
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_tun_lib.h"
+
+
+/**
+ * Create a string with binary IP notation for the given 'addr' in 'str'.
+ *
+ * @param af address family of the given 'addr'.
+ * @param addr address that should be converted to a string.
+ *             struct in_addr * for IPv4 and struct in6_addr * for IPv6.
+ * @param str string that will contain binary notation of 'addr'. Expected
+ *            to be at least 33 bytes long for IPv4 and 129 bytes long for 
IPv6.
+ */
+static void
+iptobinstr (const int af, const void *addr, char *str)
+{
+  int i;
+  
+  switch (af)
+  {
+    case AF_INET:
+    {
+      uint32_t b = htonl (((struct in_addr *) addr)->s_addr);
+      
+      str[32] = '\0';
+          str += 31;
+          for (i = 31; i >= 0; i--)
+          {
+            *str = (b & 1) + '0';
+            str--;
+            b >>= 1;
+          }
+              break;
+    }
+    case AF_INET6:
+    {
+      struct in6_addr b = *(const struct in6_addr *) addr;
+      
+      str[128] = '\0';
+            str += 127;
+            for (i = 127; i >= 0; i--)
+            {
+              *str = (b.s6_addr[i / 8] & 1) + '0';
+            str--;
+            b.s6_addr[i / 8] >>= 1;
+            }
+                break;
+    }
+  }
+}
+
+
+/**
+ * Get the ipv4 network prefix from the given 'netmask'.
+ *
+ * @param netmask netmask for which to get the prefix len.
+ *
+ * @return length of ipv4 prefix for 'netmask'.
+ */
+static unsigned int
+ipv4netmasktoprefixlen (const char *netmask)
+{
+  struct in_addr a;
+  unsigned int len;
+  uint32_t t;
+  
+  if (1 != inet_pton (AF_INET, netmask, &a))
+    return 0;
+  len = 32;
+  for (t = htonl (~a.s_addr); 0 != t; t >>= 1)
+    len--;
+  return len;
+}
+
+
+/**
+ * Create a regex in 'rxstr' from the given 'ip' and 'netmask'.
+ *
+ * @param ip IPv4 representation.
+ * @param netmask netmask for the ip.
+ * @param rxstr generated regex, must be at least GNUNET_REGEX_IPV4_REGEXLEN
+ *              bytes long.
+ */
+void
+GNUNET_TUN_ipv4toregex (const struct in_addr *ip, const char *netmask,
+                       char *rxstr)
+{
+  unsigned int pfxlen;
+  
+  pfxlen = ipv4netmasktoprefixlen (netmask);
+  iptobinstr (AF_INET, ip, rxstr);
+  rxstr[pfxlen] = '\0';
+            if (pfxlen < 32)
+              strcat (rxstr, "(0|1)+");
+}
+
+
+/**
+ * Create a regex in 'rxstr' from the given 'ipv6' and 'prefixlen'.
+ *
+ * @param ipv6 IPv6 representation.
+ * @param prefixlen length of the ipv6 prefix.
+ * @param rxstr generated regex, must be at least GNUNET_REGEX_IPV6_REGEXLEN
+ *              bytes long.
+ */
+void
+GNUNET_TUN_ipv6toregex (const struct in6_addr *ipv6, unsigned int prefixlen,
+                       char *rxstr)
+{
+  iptobinstr (AF_INET6, ipv6, rxstr);
+  rxstr[prefixlen] = '\0';
+    if (prefixlen < 128)
+      strcat (rxstr, "(0|1)+");
+}
+
+/* end of regex.c */