Files
2026-06-14 19:56:20 +08:00

268 lines
8.0 KiB
Go
Raw Permalink Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
package mqtpp
import (
"fmt"
"strconv"
"strings"
"unicode/utf8"
"google.golang.org/protobuf/encoding/protowire"
)
const NodeNumBroadcast uint32 = 0xffffffff
type PacketBuildOptions struct {
FromNodeNum uint32
ToNodeNum uint32
PacketID uint32
ChannelID string
GatewayID string
PSK []byte
Encrypt bool
ViaMQTT bool
}
type TextMessageBuildOptions struct {
PacketBuildOptions
Text string
}
type NodeInfoBuildOptions struct {
PacketBuildOptions
NodeID string
LongName string
ShortName string
HWModel uint32
Role uint32
IsLicensed bool
PublicKey []byte
}
// AckBuildOptions 描述构造一个 Routing-NONE ACKPSK 频道路径)所需字段。
// RequestID 是被 ACK 原始包的 packet_id(写入 Data.request_id, tag 6)。
type AckBuildOptions struct {
PacketBuildOptions
RequestID uint32
}
func BuildTextMessageServiceEnvelope(opts TextMessageBuildOptions) ([]byte, error) {
if opts.FromNodeNum == 0 {
return nil, fmt.Errorf("from node number is required")
}
if opts.PacketID == 0 {
return nil, fmt.Errorf("packet id is required")
}
if opts.ChannelID == "" {
return nil, fmt.Errorf("channel id is required")
}
if strings.TrimSpace(opts.GatewayID) == "" {
opts.GatewayID = NodeNumToID(opts.FromNodeNum)
}
if opts.Text == "" {
return nil, fmt.Errorf("text is required")
}
if !utf8.ValidString(opts.Text) {
return nil, fmt.Errorf("text must be valid utf-8")
}
data := buildDataPacket(textMessageApp, []byte(opts.Text))
packet, err := buildMeshPacket(opts.PacketBuildOptions, data)
if err != nil {
return nil, err
}
return buildServiceEnvelope(packet, opts.ChannelID, opts.GatewayID), nil
}
func BuildNodeInfoServiceEnvelope(opts NodeInfoBuildOptions) ([]byte, error) {
if opts.NodeID == "" {
opts.NodeID = NodeNumToID(opts.FromNodeNum)
}
opts.NodeID = truncateUTF8Bytes(opts.NodeID, 16)
opts.LongName = truncateUTF8Bytes(strings.TrimSpace(opts.LongName), 40)
opts.ShortName = truncateUTF8Bytes(strings.TrimSpace(opts.ShortName), 5)
if opts.LongName == "" {
return nil, fmt.Errorf("long name is required")
}
if opts.ShortName == "" {
return nil, fmt.Errorf("short name is required")
}
if len(opts.PublicKey) > 32 {
opts.PublicKey = opts.PublicKey[:32]
}
user := buildUserPacket(opts)
data := buildDataPacket(nodeInfoApp, user)
packet, err := buildMeshPacket(opts.PacketBuildOptions, data)
if err != nil {
return nil, err
}
return buildServiceEnvelope(packet, opts.ChannelID, opts.GatewayID), nil
}
// BuildAckServiceEnvelope 构造一个 PSK 频道上的 Routing ACKerror_reason=NONE)。
// 与固件 MeshModule::allocAckNak/Router::sendAckNak 行为对齐:
// - portnum = ROUTING_APP(5)
// - Data.request_id = 原始包 ID
// - Routing.which_variant = error_reasonerror_reason = NONE(0)
//
// 用 PacketBuildOptions 中 ChannelID + PSK 加密;调用方负责把 ToNodeNum 设为原 from。
func BuildAckServiceEnvelope(opts AckBuildOptions) ([]byte, error) {
if opts.RequestID == 0 {
return nil, fmt.Errorf("ack request_id is required")
}
if opts.ChannelID == "" {
return nil, fmt.Errorf("channel id is required")
}
data := buildAckDataPacket(opts.RequestID)
packet, err := buildMeshPacket(opts.PacketBuildOptions, data)
if err != nil {
return nil, err
}
if strings.TrimSpace(opts.GatewayID) == "" {
opts.GatewayID = NodeNumToID(opts.FromNodeNum)
}
return buildServiceEnvelope(packet, opts.ChannelID, opts.GatewayID), nil
}
// buildAckDataPacket 构造 Data { portnum=ROUTING_APP, payload=Routing{error_reason=NONE}, request_id=req }。
func buildAckDataPacket(requestID uint32) []byte {
// Routing payload: oneof variant=error_reason(tag 3), value=NONE(0) → 0x18 0x00
routing := protowire.AppendTag(nil, 3, protowire.VarintType)
routing = protowire.AppendVarint(routing, 0)
var out []byte
out = protowire.AppendTag(out, 1, protowire.VarintType)
out = protowire.AppendVarint(out, uint64(routingApp))
out = protowire.AppendTag(out, 2, protowire.BytesType)
out = protowire.AppendBytes(out, routing)
out = protowire.AppendTag(out, 6, protowire.Fixed32Type)
out = protowire.AppendFixed32(out, requestID)
return out
}
func NodeNumToID(nodeNum uint32) string {
return nodeNumToID(nodeNum)
}
func truncateUTF8Bytes(value string, maxBytes int) string {
if maxBytes <= 0 || len(value) <= maxBytes {
return value
}
out := make([]byte, 0, maxBytes)
for _, r := range value {
part := string(r)
if len(out)+len(part) > maxBytes {
break
}
out = append(out, part...)
}
return string(out)
}
func ParseNodeID(nodeID string) (uint32, error) {
value := strings.TrimSpace(nodeID)
if value == "" {
return 0, fmt.Errorf("node id is required")
}
value = strings.TrimPrefix(value, "!")
if len(value) != 8 {
return 0, fmt.Errorf("node id must be !xxxxxxxx")
}
num, err := strconv.ParseUint(value, 16, 32)
if err != nil {
return 0, fmt.Errorf("invalid node id: %w", err)
}
return uint32(num), nil
}
func buildDataPacket(portnum uint32, payload []byte) []byte {
var out []byte
out = protowire.AppendTag(out, 1, protowire.VarintType)
out = protowire.AppendVarint(out, uint64(portnum))
out = protowire.AppendTag(out, 2, protowire.BytesType)
out = protowire.AppendBytes(out, payload)
return out
}
func buildUserPacket(opts NodeInfoBuildOptions) []byte {
var out []byte
out = protowire.AppendTag(out, 1, protowire.BytesType)
out = protowire.AppendBytes(out, []byte(opts.NodeID))
out = protowire.AppendTag(out, 2, protowire.BytesType)
out = protowire.AppendBytes(out, []byte(opts.LongName))
out = protowire.AppendTag(out, 3, protowire.BytesType)
out = protowire.AppendBytes(out, []byte(opts.ShortName))
if opts.HWModel != 0 {
out = protowire.AppendTag(out, 5, protowire.VarintType)
out = protowire.AppendVarint(out, uint64(opts.HWModel))
}
out = protowire.AppendTag(out, 6, protowire.VarintType)
if opts.IsLicensed {
out = protowire.AppendVarint(out, 1)
} else {
out = protowire.AppendVarint(out, 0)
}
out = protowire.AppendTag(out, 7, protowire.VarintType)
out = protowire.AppendVarint(out, uint64(opts.Role))
if len(opts.PublicKey) > 0 {
out = protowire.AppendTag(out, 8, protowire.BytesType)
out = protowire.AppendBytes(out, opts.PublicKey)
}
return out
}
func buildMeshPacket(opts PacketBuildOptions, data []byte) ([]byte, error) {
if opts.FromNodeNum == 0 {
return nil, fmt.Errorf("from node number is required")
}
if opts.PacketID == 0 {
return nil, fmt.Errorf("packet id is required")
}
if opts.ChannelID == "" {
return nil, fmt.Errorf("channel id is required")
}
if strings.TrimSpace(opts.GatewayID) == "" {
opts.GatewayID = NodeNumToID(opts.FromNodeNum)
}
var out []byte
out = protowire.AppendTag(out, 1, protowire.Fixed32Type)
out = protowire.AppendFixed32(out, opts.FromNodeNum)
out = protowire.AppendTag(out, 2, protowire.Fixed32Type)
out = protowire.AppendFixed32(out, opts.ToNodeNum)
if opts.Encrypt {
if len(opts.PSK) == 0 {
return nil, fmt.Errorf("psk is required for encrypted packet")
}
ciphertext, err := cryptAESCTR(opts.PSK, opts.FromNodeNum, opts.PacketID, data)
if err != nil {
return nil, err
}
out = protowire.AppendTag(out, 3, protowire.VarintType)
out = protowire.AppendVarint(out, uint64(channelHash(opts.ChannelID, opts.PSK)))
out = protowire.AppendTag(out, 5, protowire.BytesType)
out = protowire.AppendBytes(out, ciphertext)
} else {
out = protowire.AppendTag(out, 4, protowire.BytesType)
out = protowire.AppendBytes(out, data)
}
out = protowire.AppendTag(out, 6, protowire.Fixed32Type)
out = protowire.AppendFixed32(out, opts.PacketID)
if opts.ViaMQTT {
out = protowire.AppendTag(out, 14, protowire.VarintType)
out = protowire.AppendVarint(out, 1)
}
return out, nil
}
func buildServiceEnvelope(packet []byte, channelID string, gatewayID string) []byte {
var out []byte
out = protowire.AppendTag(out, 1, protowire.BytesType)
out = protowire.AppendBytes(out, packet)
out = protowire.AppendTag(out, 2, protowire.BytesType)
out = protowire.AppendBytes(out, []byte(channelID))
out = protowire.AppendTag(out, 3, protowire.BytesType)
out = protowire.AppendBytes(out, []byte(gatewayID))
return out
}