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