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#pragma once
#include <MeshCore.h>
namespace mesh {
// Packet::header values
#define PH_ROUTE_MASK 0x03 // 2-bits
#define PH_TYPE_SHIFT 2
#define PH_TYPE_MASK 0x0F // 4-bits
#define PH_VER_SHIFT 6
#define PH_VER_MASK 0x03 // 2-bits
#define ROUTE_TYPE_TRANSPORT_FLOOD 0x00 // flood mode + transport codes
#define ROUTE_TYPE_FLOOD 0x01 // flood mode, needs 'path' to be built up (max 64 bytes)
#define ROUTE_TYPE_DIRECT 0x02 // direct route, 'path' is supplied
#define ROUTE_TYPE_TRANSPORT_DIRECT 0x03 // direct route + transport codes
#define PAYLOAD_TYPE_REQ 0x00 // request (prefixed with dest/src hashes, MAC) (enc data: timestamp, blob)
#define PAYLOAD_TYPE_RESPONSE 0x01 // response to REQ or ANON_REQ (prefixed with dest/src hashes, MAC) (enc data: timestamp, blob)
#define PAYLOAD_TYPE_TXT_MSG 0x02 // a plain text message (prefixed with dest/src hashes, MAC) (enc data: timestamp, text)
#define PAYLOAD_TYPE_ACK 0x03 // a simple ack
#define PAYLOAD_TYPE_ADVERT 0x04 // a node advertising its Identity
#define PAYLOAD_TYPE_GRP_TXT 0x05 // an (unverified) group text message (prefixed with channel hash, MAC) (enc data: timestamp, "name: msg")
#define PAYLOAD_TYPE_GRP_DATA 0x06 // an (unverified) group datagram (prefixed with channel hash, MAC) (enc data: timestamp, blob)
#define PAYLOAD_TYPE_ANON_REQ 0x07 // generic request (prefixed with dest_hash, ephemeral pub_key, MAC) (enc data: ...)
#define PAYLOAD_TYPE_PATH 0x08 // returned path (prefixed with dest/src hashes, MAC) (enc data: path, extra)
#define PAYLOAD_TYPE_TRACE 0x09 // trace a path, collecting SNI for each hop
#define PAYLOAD_TYPE_MULTIPART 0x0A // packet is one of a set of packets
#define PAYLOAD_TYPE_CONTROL 0x0B // a control/discovery packet
//...
#define PAYLOAD_TYPE_RAW_CUSTOM 0x0F // custom packet as raw bytes, for applications with custom encryption, payloads, etc
#define PAYLOAD_VER_1 0x00 // 1-byte src/dest hashes, 2-byte MAC
#define PAYLOAD_VER_2 0x01 // FUTURE (eg. 2-byte hashes, 4-byte MAC ??)
#define PAYLOAD_VER_3 0x02 // FUTURE
#define PAYLOAD_VER_4 0x03 // FUTURE
/**
* \brief The fundamental transmission unit.
*/
class Packet {
public:
Packet();
uint8_t header;
uint16_t payload_len, path_len;
uint16_t transport_codes[2];
uint8_t path[MAX_PATH_SIZE];
uint8_t payload[MAX_PACKET_PAYLOAD];
int8_t _snr;
/**
* \brief calculate the hash of payload + type
* \param dest_hash destination to store the hash (must be MAX_HASH_SIZE bytes)
*/
void calculatePacketHash(uint8_t* dest_hash) const;
/**
* \returns one of ROUTE_ values
*/
uint8_t getRouteType() const { return header & PH_ROUTE_MASK; }
bool isRouteFlood() const { return getRouteType() == ROUTE_TYPE_FLOOD || getRouteType() == ROUTE_TYPE_TRANSPORT_FLOOD; }
bool isRouteDirect() const { return getRouteType() == ROUTE_TYPE_DIRECT || getRouteType() == ROUTE_TYPE_TRANSPORT_DIRECT; }
bool hasTransportCodes() const { return getRouteType() == ROUTE_TYPE_TRANSPORT_FLOOD || getRouteType() == ROUTE_TYPE_TRANSPORT_DIRECT; }
/**
* \returns one of PAYLOAD_TYPE_ values
*/
uint8_t getPayloadType() const { return (header >> PH_TYPE_SHIFT) & PH_TYPE_MASK; }
/**
* \returns one of PAYLOAD_VER_ values
*/
uint8_t getPayloadVer() const { return (header >> PH_VER_SHIFT) & PH_VER_MASK; }
uint8_t getPathHashSize() const { return (path_len >> 6) + 1; }
uint8_t getPathHashCount() const { return path_len & 63; }
uint8_t getPathByteLen() const { return getPathHashCount() * getPathHashSize(); }
void setPathHashCount(uint8_t n) { path_len &= ~63; path_len |= n; }
void setPathHashSizeAndCount(uint8_t sz, uint8_t n) { path_len = ((sz - 1) << 6) | (n & 63); }
static uint8_t copyPath(uint8_t* dest, const uint8_t* src, uint8_t path_len); // returns path_len
static size_t writePath(uint8_t* dest, const uint8_t* src, uint8_t path_len); // returns byte length written
static bool isValidPathLen(uint8_t path_len);
void markDoNotRetransmit() { header = 0xFF; }
bool isMarkedDoNotRetransmit() const { return header == 0xFF; }
float getSNR() const { return ((float)_snr) / 4.0f; }
/**
* \returns the encoded/wire format length of this packet
*/
int getRawLength() const;
/**
* \brief save entire packet as a blob
* \param dest (OUT) destination buffer (assumed to be MAX_MTU_SIZE)
* \returns the packet length
*/
uint8_t writeTo(uint8_t dest[]) const;
/**
* \brief restore this packet from a blob (as created using writeTo())
* \param src (IN) buffer containing blob
* \param len the packet length (as returned by writeTo())
*/
bool readFrom(const uint8_t src[], uint8_t len);
};
}
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