mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-22 06:17:48 +00:00
242 lines
7.1 KiB
C++
242 lines
7.1 KiB
C++
/*
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* ZeroTier One - Global Peer to Peer Ethernet
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* Copyright (C) 2012-2013 ZeroTier Networks LLC
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* --
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*
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* ZeroTier may be used and distributed under the terms of the GPLv3, which
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* are available at: http://www.gnu.org/licenses/gpl-3.0.html
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*
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* If you would like to embed ZeroTier into a commercial application or
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* redistribute it in a modified binary form, please contact ZeroTier Networks
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* LLC. Start here: http://www.zerotier.com/
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*/
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#include <stdint.h>
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#include "RuntimeEnvironment.hpp"
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#include "Logger.hpp"
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#include "Filter.hpp"
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#include "Utils.hpp"
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namespace ZeroTier {
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bool Filter::Rule::operator()(unsigned int etype,const void *data,unsigned int len) const
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{
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if ((!_etherType)||(_etherType(etype))) { // ethertype is ANY, or matches
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// Ethertype determines meaning of protocol and port
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switch(etype) {
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default:
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if ((!_protocol)&&(!_port))
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return true; // match other ethertypes if protocol and port are ANY, since we don't know what to do with them
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break;
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case ZT_ETHERTYPE_IPV4:
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if (len > 20) {
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if ((!_protocol)||(_protocol(((const uint8_t *)data)[9]))) { // IP protocol
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if (!_port)
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return true; // protocol matches or is ANY, port is ANY
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// Don't match on fragments beyond fragment 0. If we've blocked
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// fragment 0, further fragments will fall on deaf ears anyway.
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if ((Utils::ntoh(((const uint16_t *)data)[3]) & 0x1fff))
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return false;
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// Internet header length determines where data begins, in multiples of 32 bits
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unsigned int ihl = 4 * (((const uint8_t *)data)[0] & 0x0f);
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switch(((const uint8_t *)data)[9]) { // port's meaning depends on IP protocol
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case ZT_IPPROTO_ICMP:
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return _port(((const uint8_t *)data)[ihl]); // port = ICMP type
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case ZT_IPPROTO_TCP:
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case ZT_IPPROTO_UDP:
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case ZT_IPPROTO_SCTP:
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case ZT_IPPROTO_UDPLITE:
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return _port(((const uint16_t *)data)[(ihl / 2) + 1]); // destination port
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}
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return false; // no match on port
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}
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}
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break;
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case ZT_ETHERTYPE_IPV6:
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if (len > 40) {
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// see: http://stackoverflow.com/questions/17518951/is-the-ipv6-header-really-this-nutty
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int nextHeader = ((const uint8_t *)data)[6];
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unsigned int pos = 40;
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while ((pos < len)&&(nextHeader >= 0)&&(nextHeader != 59)) { // 59 == no next header
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fprintf(stderr,"[rule] V6: start header parse, header %.2x pos %d\n",nextHeader,pos);
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switch(nextHeader) {
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case 0: // hop-by-hop options
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case 60: // destination options
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case 43: // routing
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case 135: // mobility (mobile IPv6 options)
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if (_protocol((unsigned int)nextHeader))
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return true; // match if our goal was to match any of these
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nextHeader = ((const uint8_t *)data)[pos];
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pos += 8 + (8 * ((const uint8_t *)data)[pos + 1]);
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break;
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case 44: // fragment
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if (_protocol(44))
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return true; // match if our goal was to match fragments
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nextHeader = ((const uint8_t *)data)[pos];
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pos += 8;
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break;
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case ZT_IPPROTO_AH: // AH
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return _protocol(ZT_IPPROTO_AH); // true if AH is matched protocol, otherwise false since packet will be IPsec
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case ZT_IPPROTO_ESP: // ESP
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return _protocol(ZT_IPPROTO_ESP); // true if ESP is matched protocol, otherwise false since packet will be IPsec
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case ZT_IPPROTO_ICMPV6:
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if (_protocol(ZT_IPPROTO_ICMPV6)) { // only match ICMPv6 if specified
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if ((!_port)||(_port(((const uint8_t *)data)[pos])))
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return true; // protocol matches, port is ANY or matches ICMP type
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}
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break;
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case ZT_IPPROTO_TCP:
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case ZT_IPPROTO_UDP:
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case ZT_IPPROTO_SCTP:
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case ZT_IPPROTO_UDPLITE:
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// If we encounter any of these, match if protocol matches or is wildcard as
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// we'll consider these the "real payload" if present.
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if ((!_protocol)||(_protocol(nextHeader))) {
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if ((!_port)||(_port(((const uint16_t *)data)[(pos / 2) + 1])))
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return true; // protocol matches or is ANY, port is ANY or matches
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}
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break;
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}
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fprintf(stderr,"[rule] V6: end header parse, next header %.2x, new pos %d\n",nextHeader,pos);
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}
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}
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break;
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}
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}
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return false;
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}
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Filter::Filter(const RuntimeEnvironment *renv) :
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_r(renv)
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{
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}
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Filter::~Filter()
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{
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}
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void Filter::add(const Rule &r,const Action &a)
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{
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Mutex::Lock _l(_chain_m);
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for(std::vector<Entry>::iterator i(_chain.begin());i!=_chain.end();++i) {
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if (i->rule == r) {
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_chain.erase(i);
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break;
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}
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}
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_chain.push_back(Entry(r,a));
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}
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std::string Filter::toString(const char *sep) const
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{
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char buf[256];
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if (!sep)
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sep = ",";
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std::string s;
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Mutex::Lock _l(_chain_m);
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for(std::vector<Entry>::const_iterator i(_chain.begin());i!=_chain.end();++i) {
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bool first = (i == _chain.begin());
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s.push_back('[');
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if (i->rule.etherType()) {
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if (i->rule.etherType().magnitude() > 1)
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sprintf(buf,"%u-%u",i->rule.etherType().start,i->rule.etherType().end);
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else sprintf(buf,"%u",i->rule.etherType().start);
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s.append(buf);
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} else s.push_back('*');
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s.push_back(';');
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if (i->rule.protocol()) {
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if (i->rule.protocol().magnitude() > 1)
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sprintf(buf,"%u-%u",i->rule.protocol().start,i->rule.protocol().end);
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else sprintf(buf,"%u",i->rule.protocol().start);
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s.append(buf);
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} else s.push_back('*');
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s.push_back(';');
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if (i->rule.port()) {
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if (i->rule.port().magnitude() > 1)
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sprintf(buf,"%u-%u",i->rule.port().start,i->rule.port().end);
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else sprintf(buf,"%u",i->rule.port().start);
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s.append(buf);
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} else s.push_back('*');
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s.append("]:");
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switch(i->action) {
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case ACTION_DENY:
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s.append("DENY");
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break;
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case ACTION_ALLOW:
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s.append("ALLOW");
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break;
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case ACTION_LOG:
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s.append("LOG");
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break;
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}
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if (!first)
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s.append(sep);
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}
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return s;
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}
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const char *Filter::etherTypeName(const unsigned int etherType)
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throw()
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{
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static char tmp[6];
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switch(etherType) {
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case ZT_ETHERTYPE_IPV4:
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return "IPV4";
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case ZT_ETHERTYPE_ARP:
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return "ARP";
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case ZT_ETHERTYPE_RARP:
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return "RARP";
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case ZT_ETHERTYPE_ATALK:
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return "ATALK";
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case ZT_ETHERTYPE_AARP:
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return "AARP";
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case ZT_ETHERTYPE_IPX_A:
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return "IPX_A";
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case ZT_ETHERTYPE_IPX_B:
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return "IPX_B";
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case ZT_ETHERTYPE_IPV6:
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return "IPV6";
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}
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sprintf(tmp,"%.4x",etherType);
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return tmp; // technically not thread safe, but we're only going to see this in debugging if ever
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}
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} // namespace ZeroTier
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