From e7f20ad5f9345d17f7699d2d5ffab2ca5de335c1 Mon Sep 17 00:00:00 2001 From: Adam Ierymenko Date: Mon, 8 Jul 2013 19:52:40 -0400 Subject: [PATCH] More filter development. It builds but is not integrated with the rest of the code. --- node/Filter.cpp | 108 +++++++++++++++++++++++++++++++++++++++++++++++- node/Filter.hpp | 12 +++++- node/Switch.cpp | 9 ++-- objects.mk | 1 + 4 files changed, 123 insertions(+), 7 deletions(-) diff --git a/node/Filter.cpp b/node/Filter.cpp index 8a41b3f91..1f81a360f 100644 --- a/node/Filter.cpp +++ b/node/Filter.cpp @@ -39,11 +39,16 @@ bool Filter::Rule::operator()(unsigned int etype,const void *data,unsigned int l if ((!_etherType)||(_etherType(etype))) { // ethertype is ANY, or matches // Ethertype determines meaning of protocol and port switch(etype) { + default: + if ((!_protocol)&&(!_port)) + return true; // match other ethertypes if protocol and port are ANY, since we don't know what to do with them + break; + case ZT_ETHERTYPE_IPV4: if (len > 20) { if ((!_protocol)||(_protocol(((const uint8_t *)data)[9]))) { // IP protocol if (!_port) - return true; // protocol matches, port is ANY + return true; // protocol matches or is ANY, port is ANY // Don't match on fragments beyond fragment 0. If we've blocked // fragment 0, further fragments will fall on deaf ears anyway. @@ -71,6 +76,52 @@ bool Filter::Rule::operator()(unsigned int etype,const void *data,unsigned int l case ZT_ETHERTYPE_IPV6: if (len > 40) { // see: http://stackoverflow.com/questions/17518951/is-the-ipv6-header-really-this-nutty + int nextHeader = ((const uint8_t *)data)[6]; + unsigned int pos = 40; + while ((pos < len)&&(nextHeader >= 0)&&(nextHeader != 59)) { // 59 == no next header + fprintf(stderr,"[rule] V6: start header parse, header %.2x pos %d\n",nextHeader,pos); + + switch(nextHeader) { + case 0: // hop-by-hop options + case 60: // destination options + case 43: // routing + case 135: // mobility (mobile IPv6 options) + if (_protocol((unsigned int)nextHeader)) + return true; // match if our goal was to match any of these + nextHeader = ((const uint8_t *)data)[pos]; + pos += 8 + (8 * ((const uint8_t *)data)[pos + 1]); + break; + case 44: // fragment + if (_protocol(44)) + return true; // match if our goal was to match fragments + nextHeader = ((const uint8_t *)data)[pos]; + pos += 8; + break; + case ZT_IPPROTO_AH: // AH + return _protocol(ZT_IPPROTO_AH); // true if AH is matched protocol, otherwise false since packet will be IPsec + case ZT_IPPROTO_ESP: // ESP + return _protocol(ZT_IPPROTO_ESP); // true if ESP is matched protocol, otherwise false since packet will be IPsec + case ZT_IPPROTO_ICMPV6: + if (_protocol(ZT_IPPROTO_ICMPV6)) { // only match ICMPv6 if specified + if ((!_port)||(_port(((const uint8_t *)data)[pos]))) + return true; // protocol matches, port is ANY or matches ICMP type + } + break; + case ZT_IPPROTO_TCP: + case ZT_IPPROTO_UDP: + case ZT_IPPROTO_SCTP: + case ZT_IPPROTO_UDPLITE: + // If we encounter any of these, match if protocol matches or is wildcard as + // we'll consider these the "real payload" if present. + if ((!_protocol)||(_protocol(nextHeader))) { + if ((!_port)||(_port(((const uint16_t *)data)[(pos / 2) + 1]))) + return true; // protocol matches or is ANY, port is ANY or matches + } + break; + } + + fprintf(stderr,"[rule] V6: end header parse, next header %.2x, new pos %d\n",nextHeader,pos); + } } break; } @@ -100,6 +151,61 @@ void Filter::add(const Rule &r,const Action &a) _chain.push_back(Entry(r,a)); } +std::string Filter::toString(const char *sep) const +{ + char buf[256]; + + if (!sep) + sep = ","; + + std::string s; + + Mutex::Lock _l(_chain_m); + for(std::vector::const_iterator i(_chain.begin());i!=_chain.end();++i) { + bool first = (i == _chain.begin()); + + s.push_back('['); + + if (i->rule.etherType()) { + sprintf(buf,"%u-%u",i->rule.etherType().start,i->rule.etherType().end); + s.append(buf); + } else s.push_back('*'); + + s.push_back(';'); + + if (i->rule.protocol()) { + sprintf(buf,"%u-%u",i->rule.protocol().start,i->rule.protocol().end); + s.append(buf); + } else s.push_back('*'); + + s.push_back(';'); + + if (i->rule.port()) { + sprintf(buf,"%u-%u",i->rule.port().start,i->rule.port().end); + s.append(buf); + } else s.push_back('*'); + + s.append("]:"); + + switch(i->action) { + case ACTION_DENY: + s.append("DENY"); + break; + case ACTION_ALLOW: + s.append("ALLOW"); + break; + case ACTION_LOG: + s.append("LOG"); + break; + } + + if (!first) + s.append(sep); + } + + return s; +} + const char *Filter::etherTypeName(const unsigned int etherType) throw() { diff --git a/node/Filter.hpp b/node/Filter.hpp index df9f904d8..861603f00 100644 --- a/node/Filter.hpp +++ b/node/Filter.hpp @@ -258,7 +258,7 @@ public: throw() { Mutex::Lock _l(_chain_m); - return _chain.length(); + return _chain.size(); } /** @@ -268,11 +268,19 @@ public: throw() { Mutex::Lock _l(_chain_m); - if (i < _chain.length()) + if (i < _chain.size()) return _chain[i]; return Entry(); } + /** + * Get a string representation of this filter + * + * @param sep Separator between filter rules, or NULL for comma (default) + * @return Human-readable string + */ + std::string toString(const char *sep = (const char *)0) const; + /** * @param etherType Ethernet type ID * @return Name of Ethernet protocol (e.g. ARP, IPV4) diff --git a/node/Switch.cpp b/node/Switch.cpp index 2e8a549ae..6f237a10e 100644 --- a/node/Switch.cpp +++ b/node/Switch.cpp @@ -41,6 +41,7 @@ #include "Peer.hpp" #include "NodeConfig.hpp" #include "Demarc.hpp" +#include "Filter.hpp" #include "../version.h" @@ -233,7 +234,7 @@ Switch_onRemotePacket_complete_packet_handler: void Switch::onLocalEthernet(const SharedPtr &network,const MAC &from,const MAC &to,unsigned int etherType,const Buffer<4096> &data) { if (from != network->tap().mac()) { - LOG("ignored tap: %s -> %s %s (bridging is not supported)",from.toString().c_str(),to.toString().c_str(),Utils::etherTypeName(etherType)); + LOG("ignored tap: %s -> %s %s (bridging is not supported)",from.toString().c_str(),to.toString().c_str(),Filter::etherTypeName(etherType)); return; } @@ -245,7 +246,7 @@ void Switch::onLocalEthernet(const SharedPtr &network,const MAC &from,c } if ((etherType != ZT_ETHERTYPE_ARP)&&(etherType != ZT_ETHERTYPE_IPV4)&&(etherType != ZT_ETHERTYPE_IPV6)) { - LOG("ignored tap: %s -> %s %s (not a supported etherType)",from.toString().c_str(),to.toString().c_str(),Utils::etherTypeName(etherType)); + LOG("ignored tap: %s -> %s %s (not a supported etherType)",from.toString().c_str(),to.toString().c_str(),Filter::etherTypeName(etherType)); return; } @@ -277,10 +278,10 @@ void Switch::onLocalEthernet(const SharedPtr &network,const MAC &from,c outp.compress(); send(outp,true); } else { - TRACE("UNICAST: %s -> %s %s (dropped, destination not a member of closed network %llu)",from.toString().c_str(),to.toString().c_str(),Utils::etherTypeName(etherType),network->id()); + TRACE("UNICAST: %s -> %s %s (dropped, destination not a member of closed network %llu)",from.toString().c_str(),to.toString().c_str(),Filter::etherTypeName(etherType),network->id()); } } else { - TRACE("UNICAST: %s -> %s %s (dropped, destination MAC not ZeroTier)",from.toString().c_str(),to.toString().c_str(),Utils::etherTypeName(etherType)); + TRACE("UNICAST: %s -> %s %s (dropped, destination MAC not ZeroTier)",from.toString().c_str(),to.toString().c_str(),Filter::etherTypeName(etherType)); } } diff --git a/objects.mk b/objects.mk index fcccf1edc..6cc1121ab 100644 --- a/objects.mk +++ b/objects.mk @@ -11,6 +11,7 @@ OBJS=\ node/Demarc.o \ node/EllipticCurveKeyPair.o \ node/EthernetTap.o \ + node/Filter.o \ node/HMAC.o \ node/Http.o \ node/Identity.o \