From de9409f80dbfc5cc61a28316b271600e9da95cdc Mon Sep 17 00:00:00 2001 From: Christian Grothoff Date: Thu, 20 Jun 2013 08:56:24 +0000 Subject: adding file that was moved here from regex.c and forgotten in earlier commit --- src/tun/regex.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 src/tun/regex.c (limited to 'src') diff --git a/src/tun/regex.c b/src/tun/regex.c new file mode 100644 index 000000000..5ec454637 --- /dev/null +++ b/src/tun/regex.c @@ -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 */ -- cgit v1.2.3