/* +------------------------------------+ * | Inspire Internet Relay Chat Daemon | * +------------------------------------+ * * InspIRCd: (C) 2002-2009 InspIRCd Development Team * See: http://www.inspircd.org/wiki/index.php/Credits * * This program is free but copyrighted software; see * the file COPYING for details. * * --------------------------------------------------- */ /* $Core */ #include "inspircd.h" /* Used when comparing CIDR masks for the modulus bits left over. * A lot of ircd's seem to do this: * ((-1) << (8 - (mask % 8))) * But imho, it sucks in comparison to a nice neat lookup table. */ const unsigned char inverted_bits[8] = { 0x00, /* 00000000 - 0 bits - never actually used */ 0x80, /* 10000000 - 1 bits */ 0xC0, /* 11000000 - 2 bits */ 0xE0, /* 11100000 - 3 bits */ 0xF0, /* 11110000 - 4 bits */ 0xF8, /* 11111000 - 5 bits */ 0xFC, /* 11111100 - 6 bits */ 0xFE /* 11111110 - 7 bits */ }; /* Match raw bytes using CIDR bit matching, used by higher level MatchCIDR() */ bool irc::sockets::MatchCIDRBits(const unsigned char* address, const unsigned char* mask, unsigned int mask_bits) { unsigned int divisor = mask_bits / 8; /* Number of whole bytes in the mask */ unsigned int modulus = mask_bits % 8; /* Remaining bits in the mask after whole bytes are dealt with */ /* First (this is faster) compare the odd bits with logic ops */ if (modulus) if ((address[divisor] & inverted_bits[modulus]) != (mask[divisor] & inverted_bits[modulus])) /* If they dont match, return false */ return false; /* Secondly (this is slower) compare the whole bytes */ if (memcmp(address, mask, divisor)) return false; /* The address matches the mask, to mask_bits bits of mask */ return true; } /* Match CIDR, but dont attempt to match() against leading *!*@ sections */ bool irc::sockets::MatchCIDR(const std::string &address, const std::string &cidr_mask) { return MatchCIDR(address, cidr_mask, false); } /* Match CIDR strings, e.g. 127.0.0.1 to 127.0.0.0/8 or 3ffe:1:5:6::8 to 3ffe:1::0/32 * If you have a lot of hosts to match, youre probably better off building your mask once * and then using the lower level MatchCIDRBits directly. * * This will also attempt to match any leading usernames or nicknames on the mask, using * match(), when match_with_username is true. */ bool irc::sockets::MatchCIDR(const std::string &address, const std::string &cidr_mask, bool match_with_username) { unsigned char addr_raw[16]; unsigned char mask_raw[16]; unsigned int bits = 0; std::string address_copy; std::string cidr_copy; /* The caller is trying to match ident@/bits. * Chop off the ident@ portion, use match() on it * seperately. */ if (match_with_username) { /* Use strchr not strrchr, because its going to be nearer to the left */ std::string::size_type username_mask_pos = cidr_mask.rfind('@'); std::string::size_type username_addr_pos = address.rfind('@'); /* Both strings have an @ symbol in them */ if (username_mask_pos != std::string::npos && username_addr_pos != std::string::npos) { /* Try and match() the strings before the @ * symbols, and recursively call MatchCIDR without * username matching enabled to match the host part. */ return (InspIRCd::Match(address.substr(0, username_addr_pos), cidr_mask.substr(0, username_mask_pos), ascii_case_insensitive_map) && MatchCIDR(address.substr(username_addr_pos + 1), cidr_mask.substr(username_mask_pos + 1), false)); } else { address_copy = address.substr(username_addr_pos + 1); cidr_copy = cidr_mask.substr(username_mask_pos + 1); } } else { address_copy.assign(address); cidr_copy.assign(cidr_mask); } in_addr address_in4; in_addr mask_in4; std::string::size_type bits_chars = cidr_copy.rfind('/'); if (bits_chars != std::string::npos) { bits = atoi(cidr_copy.substr(bits_chars + 1).c_str()); cidr_copy.erase(bits_chars, cidr_copy.length() - bits_chars); } else { /* No 'number of bits' field! */ return false; } #ifdef SUPPORT_IP6LINKS in6_addr address_in6; in6_addr mask_in6; if (inet_pton(AF_INET6, address_copy.c_str(), &address_in6) > 0) { if (inet_pton(AF_INET6, cidr_copy.c_str(), &mask_in6) > 0) { memcpy(&addr_raw, &address_in6.s6_addr, 16); memcpy(&mask_raw, &mask_in6.s6_addr, 16); if (bits > 128) bits = 128; } else { /* The address was valid ipv6, but the mask * that goes with it wasnt. */ return false; } } else #endif if (inet_pton(AF_INET, address_copy.c_str(), &address_in4) > 0) { if (inet_pton(AF_INET, cidr_copy.c_str(), &mask_in4) > 0) { memcpy(&addr_raw, &address_in4.s_addr, 4); memcpy(&mask_raw, &mask_in4.s_addr, 4); if (bits > 32) bits = 32; } else { /* The address was valid ipv4, * but the mask that went with it wasnt. */ return false; } } else { /* The address was neither ipv4 or ipv6 */ return false; } /* Low-level-match the bits in the raw data */ return MatchCIDRBits(addr_raw, mask_raw, bits); }