mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-19 13:07:55 +00:00
933 lines
31 KiB
C++
933 lines
31 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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#ifndef _ZT_N_PACKET_HPP
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#define _ZT_N_PACKET_HPP
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#include <stdint.h>
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#include <string.h>
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#include <stdio.h>
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#include <string>
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#include <iostream>
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#include "Address.hpp"
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#include "Poly1305.hpp"
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#include "Salsa20.hpp"
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#include "Utils.hpp"
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#include "Constants.hpp"
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#include "Buffer.hpp"
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#include "../ext/lz4/lz4.h"
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/**
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* Protocol version
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*
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* 1 - 0.2.0 ... 0.2.5
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* 2 - 0.3.0 ...
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* * Added signature and originating peer to multicast frame
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* * Double size of multicast frame bloom filter
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*/
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#define ZT_PROTO_VERSION 2
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/**
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* Maximum hop count allowed by packet structure (3 bits, 0-7)
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*
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* This is not necessarily the maximum hop counter after which
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* relaying is no longer performed.
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*/
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#define ZT_PROTO_MAX_HOPS 7
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/**
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* Header flag indicating that a packet is encrypted with Salsa20
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*
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* If this is not set, then the packet's payload is in the clear and the
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* MAC is over this (since there is no ciphertext). Otherwise the MAC is
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* of the ciphertext after encryption.
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*/
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#define ZT_PROTO_FLAG_ENCRYPTED 0x80
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/**
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* Header flag indicating that a packet is fragmented
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*
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* If this flag is set, the receiver knows to expect more than one fragment.
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* See Packet::Fragment for details.
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*/
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#define ZT_PROTO_FLAG_FRAGMENTED 0x40
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/**
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* Verb flag indicating payload is compressed with LZ4
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*/
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#define ZT_PROTO_VERB_FLAG_COMPRESSED 0x80
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// Indices of fields in normal packet header -- do not change as this
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// might require both code rework and will break compatibility.
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#define ZT_PACKET_IDX_IV 0
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#define ZT_PACKET_IDX_DEST 8
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#define ZT_PACKET_IDX_SOURCE 13
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#define ZT_PACKET_IDX_FLAGS 18
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#define ZT_PACKET_IDX_MAC 19
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#define ZT_PACKET_IDX_VERB 27
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#define ZT_PACKET_IDX_PAYLOAD 28
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/**
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* ZeroTier packet buffer size
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*
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* This can be changed. This provides enough room for MTU-size packet
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* payloads plus some overhead. The subtraction of sizeof(unsigned int)
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* makes it an even multiple of 1024 (see Buffer), which might reduce
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* memory use a little.
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*/
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#define ZT_PROTO_MAX_PACKET_LENGTH (3072 - sizeof(unsigned int))
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/**
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* Minimum viable packet length (also length of header)
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*/
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#define ZT_PROTO_MIN_PACKET_LENGTH ZT_PACKET_IDX_PAYLOAD
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// Indexes of fields in fragment header -- also can't be changed without
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// breaking compatibility.
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#define ZT_PACKET_FRAGMENT_IDX_PACKET_ID 0
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#define ZT_PACKET_FRAGMENT_IDX_DEST 8
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#define ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR 13
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#define ZT_PACKET_FRAGMENT_IDX_FRAGMENT_NO 14
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#define ZT_PACKET_FRAGMENT_IDX_HOPS 15
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#define ZT_PACKET_FRAGMENT_IDX_PAYLOAD 16
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/**
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* Value found at ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR in fragments
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*/
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#define ZT_PACKET_FRAGMENT_INDICATOR ZT_ADDRESS_RESERVED_PREFIX
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/**
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* Minimum viable fragment length
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*/
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#define ZT_PROTO_MIN_FRAGMENT_LENGTH ZT_PACKET_FRAGMENT_IDX_PAYLOAD
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// Size of bloom filter used in multicast propagation graph exploration
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#define ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE_BITS 512
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#define ZT_PROTO_VERB_MULTICAST_FRAME_BLOOM_FILTER_SIZE_BYTES 64
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// Field incides for parsing verbs -------------------------------------------
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#define ZT_PROTO_VERB_HELLO_IDX_PROTOCOL_VERSION (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_HELLO_IDX_MAJOR_VERSION (ZT_PROTO_VERB_HELLO_IDX_PROTOCOL_VERSION + 1)
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#define ZT_PROTO_VERB_HELLO_IDX_MINOR_VERSION (ZT_PROTO_VERB_HELLO_IDX_MAJOR_VERSION + 1)
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#define ZT_PROTO_VERB_HELLO_IDX_REVISION (ZT_PROTO_VERB_HELLO_IDX_MINOR_VERSION + 1)
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#define ZT_PROTO_VERB_HELLO_IDX_TIMESTAMP (ZT_PROTO_VERB_HELLO_IDX_REVISION + 2)
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#define ZT_PROTO_VERB_HELLO_IDX_IDENTITY (ZT_PROTO_VERB_HELLO_IDX_TIMESTAMP + 8)
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#define ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_ERROR_IDX_IN_RE_PACKET_ID (ZT_PROTO_VERB_ERROR_IDX_IN_RE_VERB + 1)
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#define ZT_PROTO_VERB_ERROR_IDX_ERROR_CODE (ZT_PROTO_VERB_ERROR_IDX_IN_RE_PACKET_ID + 8)
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#define ZT_PROTO_VERB_ERROR_IDX_PAYLOAD (ZT_PROTO_VERB_ERROR_IDX_ERROR_CODE + 1)
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#define ZT_PROTO_VERB_OK_IDX_IN_RE_VERB (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_OK_IDX_IN_RE_PACKET_ID (ZT_PROTO_VERB_OK_IDX_IN_RE_VERB + 1)
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#define ZT_PROTO_VERB_OK_IDX_PAYLOAD (ZT_PROTO_VERB_OK_IDX_IN_RE_PACKET_ID + 8)
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#define ZT_PROTO_VERB_WHOIS_IDX_ZTADDRESS (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT (ZT_PROTO_VERB_RENDEZVOUS_IDX_ZTADDRESS + 5)
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#define ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRLEN (ZT_PROTO_VERB_RENDEZVOUS_IDX_PORT + 2)
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#define ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRESS (ZT_PROTO_VERB_RENDEZVOUS_IDX_ADDRLEN + 1)
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#define ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE (ZT_PROTO_VERB_FRAME_IDX_NETWORK_ID + 8)
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#define ZT_PROTO_VERB_FRAME_IDX_PAYLOAD (ZT_PROTO_VERB_FRAME_IDX_ETHERTYPE + 2)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FLAGS (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_FLAGS + 1)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SUBMITTER_ADDRESS (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_NETWORK_ID + 8)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SOURCE_MAC (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SUBMITTER_ADDRESS + 5)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DESTINATION_MAC (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SOURCE_MAC + 6)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ADI (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_DESTINATION_MAC + 6)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_BLOOM_FILTER (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ADI + 4)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_HOP_COUNT (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_BLOOM_FILTER + 64)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_HOP_COUNT + 1)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD_LENGTH (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_ETHERTYPE + 2)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SIGNATURE_LENGTH (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD_LENGTH + 2)
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#define ZT_PROTO_VERB_MULTICAST_FRAME_IDX_PAYLOAD (ZT_PROTO_VERB_MULTICAST_FRAME_IDX_SIGNATURE_LENGTH + 2)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_NETWORK_ID (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_DICT_LEN (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_NETWORK_ID + 8)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_DICT (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST_IDX_DICT_LEN + 2)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REFRESH_IDX_NETWORK_ID (ZT_PACKET_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_HELLO__OK__IDX_TIMESTAMP (ZT_PROTO_VERB_OK_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_WHOIS__OK__IDX_IDENTITY (ZT_PROTO_VERB_OK_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_WHOIS__ERROR__IDX_ZTADDRESS (ZT_PROTO_VERB_ERROR_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_NETWORK_ID (ZT_PROTO_VERB_OK_IDX_PAYLOAD)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT_LEN (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_NETWORK_ID + 8)
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#define ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT (ZT_PROTO_VERB_NETWORK_CONFIG_REQUEST__OK__IDX_DICT_LEN + 2)
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// ---------------------------------------------------------------------------
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namespace ZeroTier {
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/**
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* ZeroTier packet
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*
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* Packet format:
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* <[8] random initialization vector (doubles as 64-bit packet ID)>
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* <[5] destination ZT address>
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* <[5] source ZT address>
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* <[1] flags (LS 5 bits) and ZT hop count (MS 3 bits)>
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* <[8] 8-bit MAC (currently first 8 bytes of poly1305 tag)>
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* [... -- begin encryption envelope -- ...]
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* <[1] encrypted flags (MS 3 bits) and verb (LS 5 bits)>
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* [... verb-specific payload ...]
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*
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* Packets smaller than 28 bytes are invalid and silently discarded.
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*
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* MAC is computed on ciphertext *after* encryption. See also:
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*
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* http://tonyarcieri.com/all-the-crypto-code-youve-ever-written-is-probably-broken
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*
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* For unencrypted packets, MAC is computed on plaintext. Only HELLO is ever
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* sent in the clear, as it's the "here is my public key" message.
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*/
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class Packet : public Buffer<ZT_PROTO_MAX_PACKET_LENGTH>
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{
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public:
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/**
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* A packet fragment
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*
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* Fragments are sent if a packet is larger than UDP MTU. The first fragment
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* is sent with its normal header with the fragmented flag set. Remaining
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* fragments are sent this way.
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*
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* The fragmented bit indicates that there is at least one fragment. Fragments
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* themselves contain the total, so the receiver must "learn" this from the
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* first fragment it receives.
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*
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* Fragments are sent with the following format:
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* <[8] packet ID of packet whose fragment this belongs to>
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* <[5] destination ZT address>
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* <[1] 0xff, a reserved address, signals that this isn't a normal packet>
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* <[1] total fragments (most significant 4 bits), fragment no (LS 4 bits)>
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* <[1] ZT hop count>
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* <[...] fragment data>
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*
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* The protocol supports a maximum of 16 fragments. If a fragment is received
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* before its main packet header, it should be cached for a brief period of
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* time to see if its parent arrives. Loss of any fragment constitutes packet
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* loss; there is no retransmission mechanism. The receiver must wait for full
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* receipt to authenticate and decrypt; there is no per-fragment MAC. (But if
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* fragments are corrupt, the MAC will fail for the whole assembled packet.)
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*/
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class Fragment : public Buffer<ZT_PROTO_MAX_PACKET_LENGTH>
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{
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public:
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Fragment() :
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Buffer<ZT_PROTO_MAX_PACKET_LENGTH>()
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{
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}
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template<unsigned int C2>
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Fragment(const Buffer<C2> &b)
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throw(std::out_of_range) :
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Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b)
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{
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}
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/**
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* Initialize from a packet
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*
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* @param p Original assembled packet
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* @param fragStart Start of fragment (raw index in packet data)
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* @param fragLen Length of fragment in bytes
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* @param fragNo Which fragment (>= 1, since 0 is Packet with end chopped off)
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* @param fragTotal Total number of fragments (including 0)
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* @throws std::out_of_range Packet size would exceed buffer
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*/
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Fragment(const Packet &p,unsigned int fragStart,unsigned int fragLen,unsigned int fragNo,unsigned int fragTotal)
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throw(std::out_of_range)
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{
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init(p,fragStart,fragLen,fragNo,fragTotal);
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}
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/**
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* Initialize from a packet
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*
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* @param p Original assembled packet
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* @param fragStart Start of fragment (raw index in packet data)
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* @param fragLen Length of fragment in bytes
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* @param fragNo Which fragment (>= 1, since 0 is Packet with end chopped off)
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* @param fragTotal Total number of fragments (including 0)
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* @throws std::out_of_range Packet size would exceed buffer
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*/
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inline void init(const Packet &p,unsigned int fragStart,unsigned int fragLen,unsigned int fragNo,unsigned int fragTotal)
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throw(std::out_of_range)
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{
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if ((fragStart + fragLen) > p.size())
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throw std::out_of_range("Packet::Fragment: tried to construct fragment of packet past its length");
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setSize(fragLen + ZT_PROTO_MIN_FRAGMENT_LENGTH);
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// NOTE: this copies both the IV/packet ID and the destination address.
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memcpy(field(ZT_PACKET_FRAGMENT_IDX_PACKET_ID,13),p.data() + ZT_PACKET_IDX_IV,13);
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(*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_INDICATOR] = ZT_PACKET_FRAGMENT_INDICATOR;
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(*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_NO] = (char)(((fragTotal & 0xf) << 4) | (fragNo & 0xf));
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(*this)[ZT_PACKET_FRAGMENT_IDX_HOPS] = 0;
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memcpy(field(ZT_PACKET_FRAGMENT_IDX_PAYLOAD,fragLen),p.data() + fragStart,fragLen);
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}
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/**
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* Get this fragment's destination
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*
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* @return Destination ZT address
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*/
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inline Address destination() const { return Address(field(ZT_PACKET_FRAGMENT_IDX_DEST,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); }
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/**
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* @return True if fragment is of a valid length
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*/
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inline bool lengthValid() const { return (size() >= ZT_PACKET_FRAGMENT_IDX_PAYLOAD); }
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/**
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* @return ID of packet this is a fragment of
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*/
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inline uint64_t packetId() const { return at<uint64_t>(ZT_PACKET_FRAGMENT_IDX_PACKET_ID); }
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/**
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* @return Total number of fragments in packet
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*/
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inline unsigned int totalFragments() const { return (((unsigned int)((*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_NO]) >> 4) & 0xf); }
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/**
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* @return Fragment number of this fragment
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*/
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inline unsigned int fragmentNumber() const { return ((unsigned int)((*this)[ZT_PACKET_FRAGMENT_IDX_FRAGMENT_NO]) & 0xf); }
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/**
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* @return Fragment ZT hop count
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*/
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inline unsigned int hops() const { return (unsigned int)((*this)[ZT_PACKET_FRAGMENT_IDX_HOPS]); }
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/**
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* Increment this packet's hop count
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*/
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inline void incrementHops()
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{
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(*this)[ZT_PACKET_FRAGMENT_IDX_HOPS] = (((*this)[ZT_PACKET_FRAGMENT_IDX_HOPS]) + 1) & ZT_PROTO_MAX_HOPS;
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}
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/**
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* @return Length of payload in bytes
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*/
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inline unsigned int payloadLength() const { return ((size() > ZT_PACKET_FRAGMENT_IDX_PAYLOAD) ? (size() - ZT_PACKET_FRAGMENT_IDX_PAYLOAD) : 0); }
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/**
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* @return Raw packet payload
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*/
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inline const unsigned char *payload() const
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{
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return field(ZT_PACKET_FRAGMENT_IDX_PAYLOAD,size() - ZT_PACKET_FRAGMENT_IDX_PAYLOAD);
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}
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};
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/**
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* ZeroTier protocol verbs
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*/
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enum Verb /* Max value: 32 (5 bits) */
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{
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/* No operation, payload ignored, no reply */
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VERB_NOP = 0,
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/* Announcement of a node's existence:
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* <[1] protocol version>
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* <[1] software major version>
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* <[1] software minor version>
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* <[2] software revision>
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* <[8] timestamp (ms since epoch)>
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* <[...] binary serialized identity (see Identity)>
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*
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* OK payload:
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* <[8] timestamp (echoed from original HELLO)>
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* <[1] protocol version (of responder)>
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* <[1] software major version (of responder)>
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* <[1] software minor version (of responder)>
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* <[2] software revision (of responder)>
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*
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* ERROR has no payload.
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*/
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VERB_HELLO = 1,
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/* Error response:
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* <[1] in-re verb>
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* <[8] in-re packet ID>
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* <[1] error code>
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* <[...] error-dependent payload>
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*/
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VERB_ERROR = 2,
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/* Success response:
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* <[1] in-re verb>
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* <[8] in-re packet ID>
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* <[...] request-specific payload>
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*/
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VERB_OK = 3,
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/* Query an identity by address:
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* <[5] address to look up>
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*
|
|
* OK response payload:
|
|
* <[...] binary serialized identity>
|
|
*
|
|
* Error payload will be address queried.
|
|
*/
|
|
VERB_WHOIS = 4,
|
|
|
|
/* Meet another node at a given protocol address:
|
|
* <[5] ZeroTier address of peer that might be found at this address>
|
|
* <[2] 16-bit protocol address port>
|
|
* <[1] protocol address length (4 for IPv4, 16 for IPv6)>
|
|
* <[...] protocol address (network byte order)>
|
|
*
|
|
* This is sent by a relaying node to initiate NAT traversal between two
|
|
* peers that are communicating by way of indirect relay. The relay will
|
|
* send this to both peers at the same time on a periodic basis, telling
|
|
* each where it might find the other on the network.
|
|
*
|
|
* Upon receipt, a peer sends a message such as NOP or HELLO to the other
|
|
* peer. Peers only "learn" one anothers' direct addresses when they
|
|
* successfully *receive* a message and authenticate it. Optionally, peers
|
|
* will usually preface these messages with one or more firewall openers
|
|
* to clear the path.
|
|
*
|
|
* Nodes should implement rate control, limiting the rate at which they
|
|
* respond to these packets to prevent their use in DDOS attacks. Nodes
|
|
* may also ignore these messages if a peer is not known or is not being
|
|
* actively communicated with.
|
|
*
|
|
* No OK or ERROR is generated.
|
|
*/
|
|
VERB_RENDEZVOUS = 5,
|
|
|
|
/* A ZT-to-ZT unicast ethernet frame:
|
|
* <[8] 64-bit network ID>
|
|
* <[2] 16-bit ethertype>
|
|
* <[...] ethernet payload>
|
|
*
|
|
* MAC addresses are derived from the packet's source and destination
|
|
* ZeroTier addresses. ZeroTier does not support VLANs or other extensions
|
|
* beyond core Ethernet.
|
|
*
|
|
* No OK or ERROR is generated.
|
|
*/
|
|
VERB_FRAME = 6,
|
|
|
|
/* 7 - old VERB_MULTICAST_FRAME, might be reused once all old 0.2
|
|
* clients are off the net. */
|
|
|
|
/* Announce interest in multicast group(s):
|
|
* <[8] 64-bit network ID>
|
|
* <[6] multicast Ethernet address>
|
|
* <[4] multicast additional distinguishing information (ADI)>
|
|
* [... additional tuples of network/address/adi ...]
|
|
*
|
|
* OK is generated on successful receipt.
|
|
*/
|
|
VERB_MULTICAST_LIKE = 8,
|
|
|
|
/* A multicast frame:
|
|
* <[1] flags, currently unused and must be 0>
|
|
* <[8] 64-bit network ID>
|
|
* <[5] ZeroTier address of original submitter of this multicast>
|
|
* <[6] source MAC address>
|
|
* <[6] destination multicast Ethernet address>
|
|
* <[4] multicast additional distinguishing information (ADI)>
|
|
* <[64] multicast propagation bloom filter>
|
|
* <[1] 8-bit propagation hop count>
|
|
* <[2] 16-bit ethertype>
|
|
* <[2] 16-bit length of payload>
|
|
* <[2] 16-bit length of signature>
|
|
* <[...] ethernet payload>
|
|
* <[...] ECDSA signature of SHA-256 hash (see below)>
|
|
*
|
|
* The signature is made using the key of the original submitter, and
|
|
* can be used to authenticate the submitter for security and rate
|
|
* control purposes. Fields in the signature are: network ID, source
|
|
* MAC, destination MAC, multicast ADI, ethertype, and payload. All
|
|
* integers are hashed in big-endian byte order. A zero byte is added
|
|
* to the hash between each field.
|
|
*
|
|
* In the future flags could indicate additional fields appended to the
|
|
* end or a different signature algorithm.
|
|
*
|
|
* No OK or ERROR is generated.
|
|
*/
|
|
VERB_MULTICAST_FRAME = 9,
|
|
|
|
/* Network member certificate for sending peer:
|
|
* <[8] 64-bit network ID>
|
|
* <[2] 16-bit length of certificate>
|
|
* <[2] 16-bit length of signature>
|
|
* <[...] string-serialized certificate dictionary>
|
|
* <[...] ECDSA signature of certificate>
|
|
*
|
|
* OK is generated on acceptance. ERROR is returned on failure. In both
|
|
* cases the payload is the network ID.
|
|
*/
|
|
VERB_NETWORK_MEMBERSHIP_CERTIFICATE = 10,
|
|
|
|
/* Network configuration request:
|
|
* <[8] 64-bit network ID>
|
|
* <[2] 16-bit length of request meta-data dictionary>
|
|
* <[...] string-serialized request meta-data>
|
|
*
|
|
* This message requests network configuration from a node capable of
|
|
* providing it. Such nodes run the netconf service, which must be
|
|
* installed into the ZeroTier home directory.
|
|
*
|
|
* OK response payload:
|
|
* <[8] 64-bit network ID>
|
|
* <[2] 16-bit length of network configuration dictionary>
|
|
* <[...] network configuration dictionary>
|
|
*
|
|
* OK returns a Dictionary (string serialized) containing the network's
|
|
* configuration and IP address assignment information for the querying
|
|
* node. It also contains a membership certificate that the querying
|
|
* node can push to other peers to demonstrate its right to speak on
|
|
* a given network.
|
|
*
|
|
* ERROR may be NOT_FOUND if no such network is known, or
|
|
* UNSUPPORTED_OPERATION if the netconf service isn't available. The
|
|
* payload will be the network ID.
|
|
*/
|
|
VERB_NETWORK_CONFIG_REQUEST = 11,
|
|
|
|
/* Network configuration refresh request:
|
|
* <[8] 64-bit network ID>
|
|
*
|
|
* This message can be sent by the network configuration master node
|
|
* to request that nodes refresh their network configuration. It can
|
|
* thus be used to "push" updates.
|
|
*
|
|
* It does not generate an OK or ERROR message, and is treated only as
|
|
* a hint to refresh now.
|
|
*/
|
|
VERB_NETWORK_CONFIG_REFRESH = 12
|
|
};
|
|
|
|
/**
|
|
* Error codes for VERB_ERROR
|
|
*/
|
|
enum ErrorCode
|
|
{
|
|
/* No error, not actually used in transit */
|
|
ERROR_NONE = 0,
|
|
|
|
/* Invalid request */
|
|
ERROR_INVALID_REQUEST = 1,
|
|
|
|
/* Bad/unsupported protocol version */
|
|
ERROR_BAD_PROTOCOL_VERSION = 2,
|
|
|
|
/* Unknown object queried (e.g. with WHOIS) */
|
|
ERROR_OBJ_NOT_FOUND = 3,
|
|
|
|
/* HELLO pushed an identity whose address is already claimed */
|
|
ERROR_IDENTITY_COLLISION = 4,
|
|
|
|
/* Identity was not valid */
|
|
ERROR_IDENTITY_INVALID = 5,
|
|
|
|
/* Verb or use case not supported/enabled by this node */
|
|
ERROR_UNSUPPORTED_OPERATION = 6,
|
|
|
|
/* Message to private network rejected -- no unexpired certificate on file */
|
|
ERROR_NO_MEMBER_CERTIFICATE = 7
|
|
};
|
|
|
|
/**
|
|
* @param v Verb
|
|
* @return String representation (e.g. HELLO, OK)
|
|
*/
|
|
static const char *verbString(Verb v)
|
|
throw();
|
|
|
|
/**
|
|
* @param e Error code
|
|
* @return String error name
|
|
*/
|
|
static const char *errorString(ErrorCode e)
|
|
throw();
|
|
|
|
template<unsigned int C2>
|
|
Packet(const Buffer<C2> &b)
|
|
throw(std::out_of_range) :
|
|
Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Construct a new empty packet with a unique random packet ID
|
|
*
|
|
* Flags and hops will be zero. Other fields and data region are undefined.
|
|
* Use the header access methods (setDestination() and friends) to fill out
|
|
* the header. Payload should be appended; initial size is header size.
|
|
*/
|
|
Packet() :
|
|
Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(ZT_PROTO_MIN_PACKET_LENGTH)
|
|
{
|
|
Utils::getSecureRandom(field(ZT_PACKET_IDX_IV,8),8);
|
|
(*this)[ZT_PACKET_IDX_FLAGS] = 0; // zero flags and hops
|
|
}
|
|
|
|
/**
|
|
* Construct a new empty packet with a unique random packet ID
|
|
*
|
|
* @param dest Destination ZT address
|
|
* @param source Source ZT address
|
|
* @param v Verb
|
|
*/
|
|
Packet(const Address &dest,const Address &source,const Verb v) :
|
|
Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(ZT_PROTO_MIN_PACKET_LENGTH)
|
|
{
|
|
Utils::getSecureRandom(field(ZT_PACKET_IDX_IV,8),8);
|
|
setDestination(dest);
|
|
setSource(source);
|
|
(*this)[ZT_PACKET_IDX_FLAGS] = 0; // zero flags and hops
|
|
setVerb(v);
|
|
}
|
|
|
|
/**
|
|
* Reset this packet structure for reuse in place
|
|
*
|
|
* @param dest Destination ZT address
|
|
* @param source Source ZT address
|
|
* @param v Verb
|
|
*/
|
|
inline void reset(const Address &dest,const Address &source,const Verb v)
|
|
{
|
|
setSize(ZT_PROTO_MIN_PACKET_LENGTH);
|
|
Utils::getSecureRandom(field(ZT_PACKET_IDX_IV,8),8);
|
|
setDestination(dest);
|
|
setSource(source);
|
|
(*this)[ZT_PACKET_IDX_FLAGS] = 0; // zero flags and hops
|
|
setVerb(v);
|
|
}
|
|
|
|
/**
|
|
* Generate a new IV / packet ID in place
|
|
*
|
|
* This can be used to re-use a packet buffer multiple times to send
|
|
* technically different but otherwise identical copies of the same
|
|
* packet.
|
|
*/
|
|
inline void newInitializationVector()
|
|
{
|
|
Utils::getSecureRandom(field(ZT_PACKET_IDX_IV,8),8);
|
|
}
|
|
|
|
/**
|
|
* Set this packet's destination
|
|
*
|
|
* @param dest ZeroTier address of destination
|
|
*/
|
|
inline void setDestination(const Address &dest)
|
|
{
|
|
unsigned char *d = field(ZT_PACKET_IDX_DEST,ZT_ADDRESS_LENGTH);
|
|
for(unsigned int i=0;i<ZT_ADDRESS_LENGTH;++i)
|
|
d[i] = dest[i];
|
|
}
|
|
|
|
/**
|
|
* Set this packet's source
|
|
*
|
|
* @param source ZeroTier address of source
|
|
*/
|
|
inline void setSource(const Address &source)
|
|
{
|
|
unsigned char *s = field(ZT_PACKET_IDX_SOURCE,ZT_ADDRESS_LENGTH);
|
|
for(unsigned int i=0;i<ZT_ADDRESS_LENGTH;++i)
|
|
s[i] = source[i];
|
|
}
|
|
|
|
/**
|
|
* Get this packet's destination
|
|
*
|
|
* @return Destination ZT address
|
|
*/
|
|
inline Address destination() const { return Address(field(ZT_PACKET_IDX_DEST,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); }
|
|
|
|
/**
|
|
* Get this packet's source
|
|
*
|
|
* @return Source ZT address
|
|
*/
|
|
inline Address source() const { return Address(field(ZT_PACKET_IDX_SOURCE,ZT_ADDRESS_LENGTH),ZT_ADDRESS_LENGTH); }
|
|
|
|
/**
|
|
* @return True if packet is of valid length
|
|
*/
|
|
inline bool lengthValid() const { return (size() >= ZT_PROTO_MIN_PACKET_LENGTH); }
|
|
|
|
/**
|
|
* @return True if packet is encrypted
|
|
*/
|
|
inline bool encrypted() const { return (((unsigned char)(*this)[ZT_PACKET_IDX_FLAGS] & ZT_PROTO_FLAG_ENCRYPTED) != 0); }
|
|
|
|
/**
|
|
* @return True if packet is fragmented (expect fragments)
|
|
*/
|
|
inline bool fragmented() const { return (((unsigned char)(*this)[ZT_PACKET_IDX_FLAGS] & ZT_PROTO_FLAG_FRAGMENTED) != 0); }
|
|
|
|
/**
|
|
* Set this packet's fragmented flag
|
|
*
|
|
* @param f Fragmented flag value
|
|
*/
|
|
inline void setFragmented(bool f)
|
|
{
|
|
if (f)
|
|
(*this)[ZT_PACKET_IDX_FLAGS] |= (char)ZT_PROTO_FLAG_FRAGMENTED;
|
|
else (*this)[ZT_PACKET_IDX_FLAGS] &= (char)(~ZT_PROTO_FLAG_FRAGMENTED);
|
|
}
|
|
|
|
/**
|
|
* @return True if compressed (result only valid if unencrypted)
|
|
*/
|
|
inline bool compressed() const { return (((unsigned char)(*this)[ZT_PACKET_IDX_VERB] & ZT_PROTO_VERB_FLAG_COMPRESSED) != 0); }
|
|
|
|
/**
|
|
* @return ZeroTier forwarding hops (0 to 7)
|
|
*/
|
|
inline unsigned int hops() const { return ((unsigned int)(*this)[ZT_PACKET_IDX_FLAGS] & 0x07); }
|
|
|
|
/**
|
|
* Increment this packet's hop count
|
|
*/
|
|
inline void incrementHops()
|
|
{
|
|
(*this)[ZT_PACKET_IDX_FLAGS] = (char)((unsigned char)(*this)[ZT_PACKET_IDX_FLAGS] & 0xf8) | (((unsigned char)(*this)[ZT_PACKET_IDX_FLAGS] + 1) & 0x07);
|
|
}
|
|
|
|
/**
|
|
* Get this packet's unique ID (the IV field interpreted as uint64_t)
|
|
*
|
|
* @return Packet ID
|
|
*/
|
|
inline uint64_t packetId() const { return at<uint64_t>(ZT_PACKET_IDX_IV); }
|
|
|
|
/**
|
|
* Set packet verb
|
|
*
|
|
* This also has the side-effect of clearing any verb flags, such as
|
|
* compressed, and so must only be done during packet composition.
|
|
*
|
|
* @param v New packet verb
|
|
*/
|
|
inline void setVerb(Verb v) { (*this)[ZT_PACKET_IDX_VERB] = (char)v; }
|
|
|
|
/**
|
|
* @return Packet verb (not including flag bits)
|
|
*/
|
|
inline Verb verb() const { return (Verb)((*this)[ZT_PACKET_IDX_VERB] & 0x1f); }
|
|
|
|
/**
|
|
* @return Length of packet payload
|
|
*/
|
|
inline unsigned int payloadLength() const { return ((size() < ZT_PROTO_MIN_PACKET_LENGTH) ? 0 : (size() - ZT_PROTO_MIN_PACKET_LENGTH)); }
|
|
|
|
/**
|
|
* @return Raw packet payload
|
|
*/
|
|
inline const unsigned char *payload() const
|
|
{
|
|
return field(ZT_PACKET_IDX_PAYLOAD,size() - ZT_PACKET_IDX_PAYLOAD);
|
|
}
|
|
|
|
/**
|
|
* Generate a message authenticationc code and set MAC field of packet
|
|
*
|
|
* For encrypted packets, this must be called after encryption.
|
|
*
|
|
* @param key 256-bit (32 byte) key
|
|
*/
|
|
inline void macSet(const void *key)
|
|
{
|
|
unsigned char mac[16];
|
|
unsigned char key2[32];
|
|
_mangleKey((const unsigned char *)key,key2);
|
|
unsigned int macLen = (size() >= ZT_PACKET_IDX_VERB) ? (size() - ZT_PACKET_IDX_VERB) : 0;
|
|
Poly1305::compute(mac,field(ZT_PACKET_IDX_VERB,macLen),macLen,key2);
|
|
memcpy(field(ZT_PACKET_IDX_MAC,8),mac,8);
|
|
}
|
|
|
|
/**
|
|
* Check the MAC of this packet's payload
|
|
*
|
|
* For encrypted packets, this must be checked before decryption.
|
|
*
|
|
* @param key 256-bit (32 byte) key
|
|
*/
|
|
inline bool macVerify(const void *key) const
|
|
{
|
|
unsigned char mac[16];
|
|
unsigned char key2[32];
|
|
if (size() < ZT_PACKET_IDX_VERB)
|
|
return false; // incomplete packets fail
|
|
_mangleKey((const unsigned char *)key,key2);
|
|
unsigned int macLen = size() - ZT_PACKET_IDX_VERB;
|
|
Poly1305::compute(mac,field(ZT_PACKET_IDX_VERB,macLen),macLen,key2);
|
|
return Utils::secureEq(mac,field(ZT_PACKET_IDX_MAC,8),8);
|
|
}
|
|
|
|
/**
|
|
* Encrypt this packet
|
|
*
|
|
* @param key 256-bit (32 byte) key
|
|
*/
|
|
inline void encrypt(const void *key)
|
|
{
|
|
(*this)[ZT_PACKET_IDX_FLAGS] |= ZT_PROTO_FLAG_ENCRYPTED;
|
|
unsigned char key2[32];
|
|
if (size() >= ZT_PACKET_IDX_VERB) {
|
|
_mangleKey((const unsigned char *)key,key2);
|
|
Salsa20 s20(key2,256,field(ZT_PACKET_IDX_IV,8));
|
|
unsigned int encLen = size() - ZT_PACKET_IDX_VERB;
|
|
unsigned char *const encBuf = field(ZT_PACKET_IDX_VERB,encLen);
|
|
s20.encrypt(encBuf,encBuf,encLen);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Decrypt this packet
|
|
*
|
|
* @param key 256-bit (32 byte) key
|
|
*/
|
|
inline void decrypt(const void *key)
|
|
{
|
|
unsigned char key2[32];
|
|
if (size() >= ZT_PACKET_IDX_VERB) {
|
|
_mangleKey((const unsigned char *)key,key2);
|
|
Salsa20 s20(key2,256,field(ZT_PACKET_IDX_IV,8));
|
|
unsigned int decLen = size() - ZT_PACKET_IDX_VERB;
|
|
unsigned char *const decBuf = field(ZT_PACKET_IDX_VERB,decLen);
|
|
s20.decrypt(decBuf,decBuf,decLen);
|
|
}
|
|
(*this)[ZT_PACKET_IDX_FLAGS] &= (char)(~ZT_PROTO_FLAG_ENCRYPTED);
|
|
}
|
|
|
|
/**
|
|
* Attempt to compress payload if not already (must be unencrypted)
|
|
*
|
|
* This requires that the payload at least contain the verb byte already
|
|
* set. The compressed flag in the verb is set if compression successfully
|
|
* results in a size reduction. If no size reduction occurs, compression
|
|
* is not done and the flag is left cleared.
|
|
*
|
|
* @return True if compression occurred
|
|
*/
|
|
inline bool compress()
|
|
{
|
|
unsigned char buf[ZT_PROTO_MAX_PACKET_LENGTH * 2];
|
|
if ((!compressed())&&(size() > (ZT_PACKET_IDX_PAYLOAD + 32))) {
|
|
int pl = (int)(size() - ZT_PACKET_IDX_PAYLOAD);
|
|
int cl = LZ4_compress((const char *)field(ZT_PACKET_IDX_PAYLOAD,(unsigned int)pl),(char *)buf,pl);
|
|
if ((cl > 0)&&(cl < pl)) {
|
|
(*this)[ZT_PACKET_IDX_VERB] |= (char)ZT_PROTO_VERB_FLAG_COMPRESSED;
|
|
setSize((unsigned int)cl + ZT_PACKET_IDX_PAYLOAD);
|
|
memcpy(field(ZT_PACKET_IDX_PAYLOAD,(unsigned int)cl),buf,cl);
|
|
return true;
|
|
}
|
|
}
|
|
(*this)[ZT_PACKET_IDX_VERB] &= (char)(~ZT_PROTO_VERB_FLAG_COMPRESSED);
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Attempt to decompress payload if it is compressed (must be unencrypted)
|
|
*
|
|
* If payload is compressed, it is decompressed and the compressed verb
|
|
* flag is cleared. Otherwise nothing is done and true is returned.
|
|
*
|
|
* @return True if data is now decompressed and valid, false on error
|
|
*/
|
|
inline bool uncompress()
|
|
{
|
|
unsigned char buf[ZT_PROTO_MAX_PACKET_LENGTH];
|
|
if ((compressed())&&(size() >= ZT_PROTO_MIN_PACKET_LENGTH)) {
|
|
if (size() > ZT_PACKET_IDX_PAYLOAD) {
|
|
unsigned int compLen = size() - ZT_PACKET_IDX_PAYLOAD;
|
|
int ucl = LZ4_uncompress_unknownOutputSize((const char *)field(ZT_PACKET_IDX_PAYLOAD,compLen),(char *)buf,compLen,sizeof(buf));
|
|
if ((ucl > 0)&&(ucl <= (int)(capacity() - ZT_PACKET_IDX_PAYLOAD))) {
|
|
setSize((unsigned int)ucl + ZT_PACKET_IDX_PAYLOAD);
|
|
memcpy(field(ZT_PACKET_IDX_PAYLOAD,(unsigned int)ucl),buf,ucl);
|
|
} else return false;
|
|
}
|
|
(*this)[ZT_PACKET_IDX_VERB] &= ~ZT_PROTO_VERB_FLAG_COMPRESSED;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
/**
|
|
* Deterministically mangle a 256-bit crypto key based on packet
|
|
*
|
|
* @param in Input key (32 bytes)
|
|
* @param out Output buffer (32 bytes)
|
|
*/
|
|
inline void _mangleKey(const unsigned char *in,unsigned char *out) const
|
|
{
|
|
// IV and source/destination addresses. Salsa uses the IV natively
|
|
// so this is redundant there, but not harmful. But Poly1305 depends
|
|
// on the key being mangled with the IV. Using the source and
|
|
// destination addresses bifurcates the key space into a different
|
|
// key space for each direction of the conversation.
|
|
for(unsigned int i=0;i<18;++i) // 8 + (ZT_ADDRESS_LENGTH * 2) == 18
|
|
out[i] = in[i] ^ (unsigned char)(*this)[i];
|
|
|
|
// Flags, but with hop count masked off. Hop count is altered by forwarding
|
|
// nodes. It's one of the only parts of a packet modifiable by people
|
|
// without the key.
|
|
out[18] = in[18] ^ ((unsigned char)(*this)[ZT_PACKET_IDX_FLAGS] & 0xf8);
|
|
|
|
// Raw packet size in bytes -- thus each packet size defines a new
|
|
// key space.
|
|
out[19] = in[19] ^ (unsigned char)(size() & 0xff);
|
|
out[20] = in[20] ^ (unsigned char)((size() >> 8) & 0xff); // little endian
|
|
|
|
// Rest of raw key is used unchanged
|
|
for(unsigned int i=21;i<32;++i)
|
|
out[i] = in[i];
|
|
}
|
|
};
|
|
|
|
} // namespace ZeroTier
|
|
|
|
#endif
|