/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2016 ZeroTier, Inc. https://www.zerotier.com/
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include "Constants.hpp"
#include "Filter.hpp"
#include "InetAddress.hpp"
// Returns true if packet appears valid; pos and proto will be set
static bool _ipv6GetPayload(const uint8_t *frameData,unsigned int frameLen,unsigned int &pos,unsigned int &proto)
{
if (frameLen < 40)
return false;
pos = 40;
proto = frameData[6];
while (pos <= frameLen) {
switch(proto) {
case 0: // hop-by-hop options
case 43: // routing
case 60: // destination options
case 135: // mobility options
if ((pos + 8) > frameLen)
return false; // invalid!
proto = frameData[pos];
pos += ((unsigned int)frameData[pos + 1] * 8) + 8;
break;
//case 44: // fragment -- we currently can't parse these and they are deprecated in IPv6 anyway
//case 50:
//case 51: // IPSec ESP and AH -- we have to stop here since this is encrypted stuff
default:
return true;
}
}
return false; // overflow == invalid
}
namespace ZeroTier {
bool Filter::run(
const uint64_t nwid,
const bool receiving,
const Address &ztSource,
const Address &ztDest,
const MAC &macSource,
const MAC &macDest,
const uint8_t *frameData,
const unsigned int frameLen,
const unsigned int etherType,
const unsigned int vlanId,
const ZT_VirtualNetworkRule *rules,
const unsigned int ruleCount,
const Tag *tags,
const unsigned int tagCount,
Address &sendCopyOfPacketTo)
{
sendCopyOfPacketTo.zero();
// For each set of rules we start by assuming that they match (since no constraints
// yields a 'match all' rule).
uint8_t thisSetMatches = 1;
for(unsigned int rn=0;rn<ruleCount;++rn) {
const ZT_VirtualNetworkRuleType rt = (ZT_VirtualNetworkRuleType)(rules[rn].t & 0x7f);
uint8_t thisRuleMatches = 0;
switch(rt) {
// Actions end a set of ANDed rules
case ZT_NETWORK_RULE_ACTION_DROP:
case ZT_NETWORK_RULE_ACTION_ACCEPT:
case ZT_NETWORK_RULE_ACTION_TEE:
case ZT_NETWORK_RULE_ACTION_REDIRECT:
if (thisSetMatches) {
// This set did match, so perform action!
if (rt != ZT_NETWORK_RULE_ACTION_DROP) {
if ((rt == ZT_NETWORK_RULE_ACTION_TEE)||(rt == ZT_NETWORK_RULE_ACTION_REDIRECT)) {
sendCopyOfPacketTo = rules[rn].v.zt;
/*
// Tee and redirect both want this frame copied to somewhere else.
Packet outp(Address(rules[rn].v.zt),RR->identity.address(),Packet::VERB_EXT_FRAME);
outp.append(nwid);
outp.append((unsigned char)0x00); // TODO: should maybe include COM if needed
macDest.appendTo(outp);
macSource.appendTo(outp);
outp.append((uint16_t)etherType);
outp.append(frameData,frameLen);
outp.compress();
RR->sw->send(outp,true,nwid);
*/
}
// For REDIRECT we will want to DROP at this node. For TEE we ACCEPT at this node but
// also forward it along as we just did.
return (rt != ZT_NETWORK_RULE_ACTION_REDIRECT);
}
return false;
} else {
// Otherwise start a new set, assuming that it will match
//TRACE("[%u] %u previous set did not match, starting next",rn,(unsigned int)rt);
thisSetMatches = 1;
}
continue;
// A rule can consist of one or more MATCH criterion
case ZT_NETWORK_RULE_MATCH_SOURCE_ZEROTIER_ADDRESS:
thisRuleMatches = (uint8_t)(rules[rn].v.zt == ztSource.toInt());
break;
case ZT_NETWORK_RULE_MATCH_DEST_ZEROTIER_ADDRESS:
thisRuleMatches = (uint8_t)(rules[rn].v.zt == ztDest.toInt());
break;
case ZT_NETWORK_RULE_MATCH_VLAN_ID:
thisRuleMatches = (uint8_t)(rules[rn].v.vlanId == (uint16_t)vlanId);
break;
case ZT_NETWORK_RULE_MATCH_VLAN_PCP:
// NOT SUPPORTED YET
thisRuleMatches = (uint8_t)(rules[rn].v.vlanPcp == 0);
break;
case ZT_NETWORK_RULE_MATCH_VLAN_DEI:
// NOT SUPPORTED YET
thisRuleMatches = (uint8_t)(rules[rn].v.vlanDei == 0);
break;
case ZT_NETWORK_RULE_MATCH_ETHERTYPE:
thisRuleMatches = (uint8_t)(rules[rn].v.etherType == (uint16_t)etherType);
break;
case ZT_NETWORK_RULE_MATCH_MAC_SOURCE:
thisRuleMatches = (uint8_t)(MAC(rules[rn].v.mac,6) == macSource);
break;
case ZT_NETWORK_RULE_MATCH_MAC_DEST:
thisRuleMatches = (uint8_t)(MAC(rules[rn].v.mac,6) == macDest);
break;
case ZT_NETWORK_RULE_MATCH_IPV4_SOURCE:
if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
thisRuleMatches = (uint8_t)(InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).containsAddress(InetAddress((const void *)(frameData + 12),4,0)));
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IPV4_DEST:
if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
thisRuleMatches = (uint8_t)(InetAddress((const void *)&(rules[rn].v.ipv4.ip),4,rules[rn].v.ipv4.mask).containsAddress(InetAddress((const void *)(frameData + 16),4,0)));
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IPV6_SOURCE:
if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
thisRuleMatches = (uint8_t)(InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).containsAddress(InetAddress((const void *)(frameData + 8),16,0)));
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IPV6_DEST:
if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
thisRuleMatches = (uint8_t)(InetAddress((const void *)rules[rn].v.ipv6.ip,16,rules[rn].v.ipv6.mask).containsAddress(InetAddress((const void *)(frameData + 24),16,0)));
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IP_TOS:
if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
thisRuleMatches = (uint8_t)(rules[rn].v.ipTos == ((frameData[1] & 0xfc) >> 2));
} else if ((etherType == ZT_ETHERTYPE_IPV6)&&(frameLen >= 40)) {
const uint8_t trafficClass = ((frameData[0] << 4) & 0xf0) | ((frameData[1] >> 4) & 0x0f);
thisRuleMatches = (uint8_t)(rules[rn].v.ipTos == ((trafficClass & 0xfc) >> 2));
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IP_PROTOCOL:
if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
thisRuleMatches = (uint8_t)(rules[rn].v.ipProtocol == frameData[9]);
} else if (etherType == ZT_ETHERTYPE_IPV6) {
unsigned int pos = 0,proto = 0;
if (_ipv6GetPayload(frameData,frameLen,pos,proto)) {
thisRuleMatches = (uint8_t)(rules[rn].v.ipProtocol == (uint8_t)proto);
} else {
thisRuleMatches = 0;
}
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_IP_SOURCE_PORT_RANGE:
case ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE:
if ((etherType == ZT_ETHERTYPE_IPV4)&&(frameLen >= 20)) {
const unsigned int headerLen = 4 * (frameData[0] & 0xf);
int p = -1;
switch(frameData[9]) { // IP protocol number
// All these start with 16-bit source and destination port in that order
case 0x06: // TCP
case 0x11: // UDP
case 0x84: // SCTP
case 0x88: // UDPLite
if (frameLen > (headerLen + 4)) {
unsigned int pos = headerLen + (((unsigned int)(rt == ZT_NETWORK_RULE_MATCH_IP_DEST_PORT_RANGE)) << 1); // headerLen or +2 for destination port
p = (int)frameData[pos++] << 8;
p |= (int)frameData[pos];
}
break;
}
thisRuleMatches = (p > 0) ? (uint8_t)((p >= (int)rules[rn].v.port[0])&&(p <= (int)rules[rn].v.port[1])) : (uint8_t)0;
} else if (etherType == ZT_ETHERTYPE_IPV6) {
unsigned int pos = 0,proto = 0;
if (_ipv6GetPayload(frameData,frameLen,pos,proto)) {
int p = -1;
switch(proto) { // IP protocol number
// All these start with 16-bit source and destination port in that order
case 0x06: // TCP
case 0x11: // UDP
case 0x84: // SCTP
case 0x88: // UDPLite
if (frameLen > (pos + 4)) {
p = (int)frameData[pos++] << 8;
p |= (int)frameData[pos];
}
break;
}
thisRuleMatches = (p > 0) ? (uint8_t)((p >= (int)rules[rn].v.port[0])&&(p <= (int)rules[rn].v.port[1])) : (uint8_t)0;
} else {
thisRuleMatches = 0;
}
} else {
thisRuleMatches = 0;
}
break;
case ZT_NETWORK_RULE_MATCH_CHARACTERISTICS:
// TODO: not supported yet
break;
case ZT_NETWORK_RULE_MATCH_FRAME_SIZE_RANGE:
thisRuleMatches = (uint8_t)((frameLen >= (unsigned int)rules[rn].v.frameSize[0])&&(frameLen <= (unsigned int)rules[rn].v.frameSize[1]));
break;
case ZT_NETWORK_RULE_MATCH_TAG_VALUE_RANGE:
case ZT_NETWORK_RULE_MATCH_TAG_VALUE_BITS_ALL:
case ZT_NETWORK_RULE_MATCH_TAG_VALUE_BITS_ANY:
for(unsigned int i=0;i<tagCount;++i) { // sequential scan is probably fastest since this is going to be <64 entries (usually only one or two)
if (tags[i].id() == rules[rn].v.tag.id) {
if (rt == ZT_NETWORK_RULE_MATCH_TAG_VALUE_RANGE) {
thisRuleMatches = (uint8_t)((tags[i].value() >= rules[rn].v.tag.value[0])&&(tags[i].value() <= rules[rn].v.tag.value[1]));
} else if (rt == ZT_NETWORK_RULE_MATCH_TAG_VALUE_BITS_ALL) {
thisRuleMatches = (uint8_t)((tags[i].value() & rules[rn].v.tag.value[0]) == rules[rn].v.tag.value[0]);
} else if (rt == ZT_NETWORK_RULE_MATCH_TAG_VALUE_BITS_ANY) {
thisRuleMatches = (uint8_t)((tags[i].value() & rules[rn].v.tag.value[0]) != 0);
}
break;
}
}
break;
}
// thisSetMatches remains true if the current rule matched... or does NOT match if not bit (0x80) is 1
thisSetMatches &= (thisRuleMatches ^ ((rules[rn].t & 0x80) >> 7));
//TRACE("[%u] %u result==%u set==%u",rn,(unsigned int)rt,(unsigned int)thisRuleMatches,(unsigned int)thisSetMatches);
}
return false; // no matches, no rules, default action is therefore DROP
}
} // namespace ZeroTier