diff options
Diffstat (limited to 'node/Packet.hpp')
| -rw-r--r-- | node/Packet.hpp | 66 |
1 files changed, 56 insertions, 10 deletions
diff --git a/node/Packet.hpp b/node/Packet.hpp index 27da6fb5..8e82bd34 100644 --- a/node/Packet.hpp +++ b/node/Packet.hpp @@ -150,7 +150,7 @@ * * In cryptography, a "break" means something different from what it means in * common discussion. If a cipher is 256 bits strong and someone finds a way - * to reduce key search to 254 bits, this constitues a "break" in the academic + * to reduce key search to 254 bits, this constitutes a "break" in the academic * literature. 254 bits is still far beyond what can be leveraged to accomplish * a "break" as most people would understand it -- the actual decryption and * reading of traffic. @@ -249,7 +249,7 @@ */ #define ZT_PROTO_MIN_FRAGMENT_LENGTH ZT_PACKET_FRAGMENT_IDX_PAYLOAD -// Field incides for parsing verbs ------------------------------------------- +// Field indices for parsing verbs ------------------------------------------- // Some verbs have variable-length fields. Those aren't fully defined here // yet-- instead they are parsed using relative indexes in IncomingPacket. @@ -419,7 +419,7 @@ public: template<unsigned int C2> Fragment(const Buffer<C2> &b) : - Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b) + Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b) { } @@ -734,7 +734,7 @@ public: * Credentials can be for any number of networks. * * The use of a zero byte to terminate the COM section is for legacy - * backward compatiblity. Newer fields are prefixed with a length. + * backward compatibility. Newer fields are prefixed with a length. * * OK/ERROR are not generated. */ @@ -751,7 +751,7 @@ public: * This message requests network configuration from a node capable of * providing it. * - * Respones to this are always whole configs intended for the recipient. + * Responses to this are always whole configs intended for the recipient. * For patches and other updates a NETWORK_CONFIG is sent instead. * * It would be valid and correct as of 1.2.0 to use NETWORK_CONFIG always, @@ -884,7 +884,7 @@ public: * <[6] MAC address of multicast group> * <[4] 32-bit ADI for multicast group> * <[1] flags> - * [<[...] network certficate of membership (DEPRECATED)>] + * [<[...] network certificate of membership (DEPRECATED)>] * [<[...] implicit gather results if flag 0x01 is set>] * * OK flags (same bits as request flags): @@ -930,7 +930,53 @@ public: */ VERB_PUSH_DIRECT_PATHS = 0x10, - // 0x11, 0x12 -- deprecated + // 0x11 -- deprecated + + /** + * An acknowledgment of receipt of a series of recent packets from another + * peer. This is used to calculate relative throughput values and to detect + * packet loss. Only VERB_FRAME and VERB_EXT_FRAME packets are counted. + * + * ACK response format: + * <[4] 32-bit number of bytes received since last ACK> + * + * Upon receipt of this packet, the local peer will verify that the correct + * number of bytes were received by the remote peer. If these values do + * not agree that could be an indicator of packet loss. + * + * Additionally, the local peer knows the interval of time that has + * elapsed since the last received ACK. With this information it can compute + * a rough estimate of the current throughput. + * + * This is sent at a maximum rate of once per every ZT_PATH_ACK_INTERVAL + */ + VERB_ACK = 0x12, + + /** + * A packet containing timing measurements useful for estimating path quality. + * Composed of a list of <packet ID:internal sojourn time> pairs for an + * arbitrary set of recent packets. This is used to sample for latency and + * packet delay variance (PDV, "jitter"). + * + * QoS record format: + * + * <[8] 64-bit packet ID of previously-received packet> + * <[1] 8-bit packet sojourn time> + * <...repeat until end of max 1400 byte packet...> + * + * The number of possible records per QoS packet is: (1400 * 8) / 72 = 155 + * This packet should be sent very rarely (every few seconds) as it can be + * somewhat large if the connection is saturated. Future versions might use + * a bloom table to probabilistically determine these values in a vastly + * more space-efficient manner. + * + * Note: The 'internal packet sojourn time' is a slight misnomer as it is a + * measure of the amount of time between when a packet was received and the + * egress time of its tracking QoS packet. + * + * This is sent at a maximum rate of once per every ZT_PATH_QOS_INTERVAL + */ + VERB_QOS_MEASUREMENT = 0x13, /** * A message with arbitrary user-definable content: @@ -954,7 +1000,7 @@ public: * * This message contains a remote trace event. Remote trace events can * be sent to observers configured at the network level for those that - * pertain directly to actiity on a network, or to global observers if + * pertain directly to activity on a network, or to global observers if * locally configured. * * The instance ID is a random 64-bit value generated by each ZeroTier @@ -999,7 +1045,7 @@ public: template<unsigned int C2> Packet(const Buffer<C2> &b) : - Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b) + Buffer<ZT_PROTO_MAX_PACKET_LENGTH>(b) { } @@ -1251,7 +1297,7 @@ public: * Encrypt/decrypt a separately armored portion of a packet * * This is currently only used to mask portions of HELLO as an extra - * security precation since most of that message is sent in the clear. + * security precaution since most of that message is sent in the clear. * * This must NEVER be used more than once in the same packet, as doing * so will result in re-use of the same key stream. |