mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-27 16:28:52 +00:00
273 lines
8.2 KiB
C++
273 lines
8.2 KiB
C++
/*
|
|
* ZeroTier One - Network Virtualization Everywhere
|
|
* Copyright (C) 2011-2018 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/>.
|
|
*
|
|
* --
|
|
*
|
|
* You can be released from the requirements of the license by purchasing
|
|
* a commercial license. Buying such a license is mandatory as soon as you
|
|
* develop commercial closed-source software that incorporates or links
|
|
* directly against ZeroTier software without disclosing the source code
|
|
* of your own application.
|
|
*/
|
|
|
|
#include "NeighborDiscovery.hpp"
|
|
#include "OSUtils.hpp"
|
|
|
|
#include "../include/ZeroTierOne.h"
|
|
|
|
#include <assert.h>
|
|
|
|
namespace ZeroTier {
|
|
|
|
uint16_t calc_checksum (uint16_t *addr, int len)
|
|
{
|
|
int count = len;
|
|
uint32_t sum = 0;
|
|
uint16_t answer = 0;
|
|
|
|
// Sum up 2-byte values until none or only one byte left.
|
|
while (count > 1) {
|
|
sum += *(addr++);
|
|
count -= 2;
|
|
}
|
|
|
|
// Add left-over byte, if any.
|
|
if (count > 0) {
|
|
sum += *(uint8_t *) addr;
|
|
}
|
|
|
|
// Fold 32-bit sum into 16 bits; we lose information by doing this,
|
|
// increasing the chances of a collision.
|
|
// sum = (lower 16 bits) + (upper 16 bits shifted right 16 bits)
|
|
while (sum >> 16) {
|
|
sum = (sum & 0xffff) + (sum >> 16);
|
|
}
|
|
|
|
// Checksum is one's compliment of sum.
|
|
answer = ~sum;
|
|
|
|
return (answer);
|
|
}
|
|
|
|
struct _pseudo_header {
|
|
uint8_t sourceAddr[16];
|
|
uint8_t targetAddr[16];
|
|
uint32_t length;
|
|
uint8_t zeros[3];
|
|
uint8_t next; // 58
|
|
};
|
|
|
|
struct _option {
|
|
_option(int optionType)
|
|
: type(optionType)
|
|
, length(8)
|
|
{
|
|
memset(mac, 0, sizeof(mac));
|
|
}
|
|
|
|
uint8_t type;
|
|
uint8_t length;
|
|
uint8_t mac[6];
|
|
};
|
|
|
|
struct _neighbor_solicitation {
|
|
_neighbor_solicitation()
|
|
: type(135)
|
|
, code(0)
|
|
, checksum(0)
|
|
, option(1)
|
|
{
|
|
memset(&reserved, 0, sizeof(reserved));
|
|
memset(target, 0, sizeof(target));
|
|
}
|
|
|
|
void calculateChecksum(const sockaddr_storage &sourceIp, const sockaddr_storage &destIp) {
|
|
_pseudo_header ph;
|
|
memset(&ph, 0, sizeof(_pseudo_header));
|
|
const sockaddr_in6 *src = (const sockaddr_in6*)&sourceIp;
|
|
const sockaddr_in6 *dest = (const sockaddr_in6*)&destIp;
|
|
|
|
memcpy(ph.sourceAddr, &src->sin6_addr, sizeof(struct in6_addr));
|
|
memcpy(ph.targetAddr, &dest->sin6_addr, sizeof(struct in6_addr));
|
|
ph.next = 58;
|
|
ph.length = htonl(sizeof(_neighbor_solicitation));
|
|
|
|
size_t len = sizeof(_pseudo_header) + sizeof(_neighbor_solicitation);
|
|
uint8_t *tmp = (uint8_t*)malloc(len);
|
|
memcpy(tmp, &ph, sizeof(_pseudo_header));
|
|
memcpy(tmp+sizeof(_pseudo_header), this, sizeof(_neighbor_solicitation));
|
|
|
|
checksum = calc_checksum((uint16_t*)tmp, (int)len);
|
|
|
|
free(tmp);
|
|
tmp = NULL;
|
|
}
|
|
|
|
uint8_t type; // 135
|
|
uint8_t code; // 0
|
|
uint16_t checksum;
|
|
uint32_t reserved;
|
|
uint8_t target[16];
|
|
_option option;
|
|
};
|
|
|
|
struct _neighbor_advertisement {
|
|
_neighbor_advertisement()
|
|
: type(136)
|
|
, code(0)
|
|
, checksum(0)
|
|
, rso(0x40)
|
|
, option(2)
|
|
{
|
|
memset(padding, 0, sizeof(padding));
|
|
memset(target, 0, sizeof(target));
|
|
}
|
|
|
|
void calculateChecksum(const sockaddr_storage &sourceIp, const sockaddr_storage &destIp) {
|
|
_pseudo_header ph;
|
|
memset(&ph, 0, sizeof(_pseudo_header));
|
|
const sockaddr_in6 *src = (const sockaddr_in6*)&sourceIp;
|
|
const sockaddr_in6 *dest = (const sockaddr_in6*)&destIp;
|
|
|
|
memcpy(ph.sourceAddr, &src->sin6_addr, sizeof(struct in6_addr));
|
|
memcpy(ph.targetAddr, &dest->sin6_addr, sizeof(struct in6_addr));
|
|
ph.next = 58;
|
|
ph.length = htonl(sizeof(_neighbor_advertisement));
|
|
|
|
size_t len = sizeof(_pseudo_header) + sizeof(_neighbor_advertisement);
|
|
uint8_t *tmp = (uint8_t*)malloc(len);
|
|
memcpy(tmp, &ph, sizeof(_pseudo_header));
|
|
memcpy(tmp+sizeof(_pseudo_header), this, sizeof(_neighbor_advertisement));
|
|
|
|
checksum = calc_checksum((uint16_t*)tmp, (int)len);
|
|
|
|
free(tmp);
|
|
tmp = NULL;
|
|
}
|
|
|
|
uint8_t type; // 136
|
|
uint8_t code; // 0
|
|
uint16_t checksum;
|
|
uint8_t rso;
|
|
uint8_t padding[3];
|
|
uint8_t target[16];
|
|
_option option;
|
|
};
|
|
|
|
NeighborDiscovery::NeighborDiscovery()
|
|
: _cache(256)
|
|
, _lastCleaned(OSUtils::now())
|
|
{}
|
|
|
|
void NeighborDiscovery::addLocal(const sockaddr_storage &address, const MAC &mac)
|
|
{
|
|
_NDEntry &e = _cache[InetAddress(address)];
|
|
e.lastQuerySent = 0;
|
|
e.lastResponseReceived = 0;
|
|
e.mac = mac;
|
|
e.local = true;
|
|
}
|
|
|
|
void NeighborDiscovery::remove(const sockaddr_storage &address)
|
|
{
|
|
_cache.erase(InetAddress(address));
|
|
}
|
|
|
|
sockaddr_storage NeighborDiscovery::processIncomingND(const uint8_t *nd, unsigned int len, const sockaddr_storage &localIp, uint8_t *response, unsigned int &responseLen, MAC &responseDest)
|
|
{
|
|
assert(sizeof(_neighbor_solicitation) == 28);
|
|
assert(sizeof(_neighbor_advertisement) == 32);
|
|
|
|
const uint64_t now = OSUtils::now();
|
|
sockaddr_storage ip = {0};
|
|
|
|
if (len >= sizeof(_neighbor_solicitation) && nd[0] == 0x87) {
|
|
// respond to Neighbor Solicitation request for local address
|
|
_neighbor_solicitation solicitation;
|
|
memcpy(&solicitation, nd, len);
|
|
InetAddress targetAddress(solicitation.target, 16, 0);
|
|
_NDEntry *targetEntry = _cache.get(targetAddress);
|
|
if (targetEntry && targetEntry->local) {
|
|
_neighbor_advertisement adv;
|
|
targetEntry->mac.copyTo(adv.option.mac, 6);
|
|
memcpy(adv.target, solicitation.target, 16);
|
|
adv.calculateChecksum(localIp, targetAddress);
|
|
memcpy(response, &adv, sizeof(_neighbor_advertisement));
|
|
responseLen = sizeof(_neighbor_advertisement);
|
|
responseDest.setTo(solicitation.option.mac, 6);
|
|
}
|
|
} else if (len >= sizeof(_neighbor_advertisement) && nd[0] == 0x88) {
|
|
_neighbor_advertisement adv;
|
|
memcpy(&adv, nd, len);
|
|
InetAddress responseAddress(adv.target, 16, 0);
|
|
_NDEntry *queryEntry = _cache.get(responseAddress);
|
|
if(queryEntry && !queryEntry->local && (now - queryEntry->lastQuerySent <= ZT_ND_QUERY_MAX_TTL)) {
|
|
queryEntry->lastResponseReceived = now;
|
|
queryEntry->mac.setTo(adv.option.mac, 6);
|
|
ip = responseAddress;
|
|
}
|
|
}
|
|
|
|
if ((now - _lastCleaned) >= ZT_ND_EXPIRE) {
|
|
_lastCleaned = now;
|
|
Hashtable<InetAddress, _NDEntry>::Iterator i(_cache);
|
|
InetAddress *k = NULL;
|
|
_NDEntry *v = NULL;
|
|
while (i.next(k, v)) {
|
|
if(!v->local && (now - v->lastResponseReceived) >= ZT_ND_EXPIRE) {
|
|
_cache.erase(*k);
|
|
}
|
|
}
|
|
}
|
|
|
|
return ip;
|
|
}
|
|
|
|
MAC NeighborDiscovery::query(const MAC &localMac, const sockaddr_storage &localIp, const sockaddr_storage &targetIp, uint8_t *query, unsigned int &queryLen, MAC &queryDest)
|
|
{
|
|
const uint64_t now = OSUtils::now();
|
|
|
|
InetAddress localAddress(localIp);
|
|
localAddress.setPort(0);
|
|
InetAddress targetAddress(targetIp);
|
|
targetAddress.setPort(0);
|
|
|
|
_NDEntry &e = _cache[targetAddress];
|
|
|
|
if ( (e.mac && ((now - e.lastResponseReceived) >= (ZT_ND_EXPIRE / 3))) ||
|
|
(!e.mac && ((now - e.lastQuerySent) >= ZT_ND_QUERY_INTERVAL))) {
|
|
e.lastQuerySent = now;
|
|
|
|
_neighbor_solicitation ns;
|
|
memcpy(ns.target, targetAddress.rawIpData(), 16);
|
|
localMac.copyTo(ns.option.mac, 6);
|
|
ns.calculateChecksum(localIp, targetIp);
|
|
if (e.mac) {
|
|
queryDest = e.mac;
|
|
} else {
|
|
queryDest = (uint64_t)0xffffffffffffULL;
|
|
}
|
|
} else {
|
|
queryLen = 0;
|
|
queryDest.zero();
|
|
}
|
|
|
|
return e.mac;
|
|
}
|
|
|
|
}
|