git.r.bdr.sh - rbdr/mobius/blob - hotline/transaction.go

   1 package hotline
   2
   3 import (
   4         "encoding/binary"
   5         "errors"
   6         "fmt"
   7         "github.com/jhalter/mobius/concat"
   8         "math/rand"
   9 )
  10
  11 const (
  12         tranError          = 0
  13         tranGetMsgs        = 101
  14         tranNewMsg         = 102
  15         tranOldPostNews    = 103
  16         tranServerMsg      = 104
  17         tranChatSend       = 105
  18         tranChatMsg        = 106
  19         tranLogin          = 107
  20         tranSendInstantMsg = 108
  21         tranShowAgreement  = 109
  22         tranDisconnectUser = 110
  23         // tranDisconnectMsg        = 111 TODO: implement friendly disconnect
  24         tranInviteNewChat        = 112
  25         tranInviteToChat         = 113
  26         tranRejectChatInvite     = 114
  27         tranJoinChat             = 115
  28         tranLeaveChat            = 116
  29         tranNotifyChatChangeUser = 117
  30         tranNotifyChatDeleteUser = 118
  31         tranNotifyChatSubject    = 119
  32         tranSetChatSubject       = 120
  33         tranAgreed               = 121
  34         tranServerBanner         = 122
  35         tranGetFileNameList      = 200
  36         tranDownloadFile         = 202
  37         tranUploadFile           = 203
  38         tranNewFolder            = 205
  39         tranDeleteFile           = 204
  40         tranGetFileInfo          = 206
  41         tranSetFileInfo          = 207
  42         tranMoveFile             = 208
  43         tranMakeFileAlias        = 209
  44         tranDownloadFldr         = 210
  45         // tranDownloadInfo         = 211 TODO: implement file transfer queue
  46         tranDownloadBanner     = 212
  47         tranUploadFldr         = 213
  48         tranGetUserNameList    = 300
  49         tranNotifyChangeUser   = 301
  50         tranNotifyDeleteUser   = 302
  51         tranGetClientInfoText  = 303
  52         tranSetClientUserInfo  = 304
  53         tranListUsers          = 348
  54         tranUpdateUser         = 349
  55         tranNewUser            = 350
  56         tranDeleteUser         = 351
  57         tranGetUser            = 352
  58         tranSetUser            = 353
  59         tranUserAccess         = 354
  60         tranUserBroadcast      = 355
  61         tranGetNewsCatNameList = 370
  62         tranGetNewsArtNameList = 371
  63         tranDelNewsItem        = 380
  64         tranNewNewsFldr        = 381
  65         tranNewNewsCat         = 382
  66         tranGetNewsArtData     = 400
  67         tranPostNewsArt        = 410
  68         tranDelNewsArt         = 411
  69         tranKeepAlive          = 500
  70 )
  71
  72 type Transaction struct {
  73         clientID *[]byte
  74
  75         Flags      byte   // Reserved (should be 0)
  76         IsReply    byte   // Request (0) or reply (1)
  77         Type       []byte // Requested operation (user defined)
  78         ID         []byte // Unique transaction ID (must be != 0)
  79         ErrorCode  []byte // Used in the reply (user defined, 0 = no error)
  80         TotalSize  []byte // Total data size for the transaction (all parts)
  81         DataSize   []byte // Size of data in this transaction part. This allows splitting large transactions into smaller parts.
  82         ParamCount []byte // Number of the parameters for this transaction
  83         Fields     []Field
  84 }
  85
  86 func NewTransaction(t int, clientID *[]byte, fields ...Field) *Transaction {
  87         typeSlice := make([]byte, 2)
  88         binary.BigEndian.PutUint16(typeSlice, uint16(t))
  89
  90         idSlice := make([]byte, 4)
  91         binary.BigEndian.PutUint32(idSlice, rand.Uint32())
  92
  93         return &Transaction{
  94                 clientID:  clientID,
  95                 Flags:     0x00,
  96                 IsReply:   0x00,
  97                 Type:      typeSlice,
  98                 ID:        idSlice,
  99                 ErrorCode: []byte{0, 0, 0, 0},
 100                 Fields:    fields,
 101         }
 102 }
 103
 104 // ReadTransaction parses a byte slice into a struct.  The input slice may be shorter or longer
 105 // that the transaction size depending on what was read from the network connection.
 106 func ReadTransaction(buf []byte) (*Transaction, int, error) {
 107         totalSize := binary.BigEndian.Uint32(buf[12:16])
 108
 109         // the buf may include extra bytes that are not part of the transaction
 110         // tranLen represents the length of bytes that are part of the transaction
 111         tranLen := int(20 + totalSize)
 112
 113         if tranLen > len(buf) {
 114                 return nil, 0, errors.New("buflen too small for tranLen")
 115         }
 116         fields, err := ReadFields(buf[20:22], buf[22:tranLen])
 117         if err != nil {
 118                 return nil, 0, err
 119         }
 120
 121         return &Transaction{
 122                 Flags:      buf[0],
 123                 IsReply:    buf[1],
 124                 Type:       buf[2:4],
 125                 ID:         buf[4:8],
 126                 ErrorCode:  buf[8:12],
 127                 TotalSize:  buf[12:16],
 128                 DataSize:   buf[16:20],
 129                 ParamCount: buf[20:22],
 130                 Fields:     fields,
 131         }, tranLen, nil
 132 }
 133
 134 func readTransactions(buf []byte) ([]Transaction, int, error) {
 135         var transactions []Transaction
 136
 137         bufLen := len(buf)
 138
 139         var bytesRead = 0
 140         for bytesRead < bufLen {
 141                 t, tReadLen, err := ReadTransaction(buf[bytesRead:])
 142                 if err != nil {
 143                         return transactions, bytesRead, err
 144                 }
 145                 bytesRead += tReadLen
 146
 147                 transactions = append(transactions, *t)
 148         }
 149
 150         return transactions, bytesRead, nil
 151 }
 152
 153 const minFieldLen = 4
 154
 155 func ReadFields(paramCount []byte, buf []byte) ([]Field, error) {
 156         paramCountInt := int(binary.BigEndian.Uint16(paramCount))
 157         if paramCountInt > 0 && len(buf) < minFieldLen {
 158                 return []Field{}, fmt.Errorf("invalid field length %v", len(buf))
 159         }
 160
 161         // A Field consists of:
 162         // ID: 2 bytes
 163         // Size: 2 bytes
 164         // Data: FieldSize number of bytes
 165         var fields []Field
 166         for i := 0; i < paramCountInt; i++ {
 167                 if len(buf) < minFieldLen {
 168                         return []Field{}, fmt.Errorf("invalid field length %v", len(buf))
 169                 }
 170                 fieldID := buf[0:2]
 171                 fieldSize := buf[2:4]
 172                 fieldSizeInt := int(binary.BigEndian.Uint16(buf[2:4]))
 173                 expectedLen := minFieldLen + fieldSizeInt
 174                 if len(buf) < expectedLen {
 175                         return []Field{}, fmt.Errorf("field length too short")
 176                 }
 177
 178                 fields = append(fields, Field{
 179                         ID:        fieldID,
 180                         FieldSize: fieldSize,
 181                         Data:      buf[4 : 4+fieldSizeInt],
 182                 })
 183
 184                 buf = buf[fieldSizeInt+4:]
 185         }
 186
 187         if len(buf) != 0 {
 188                 return []Field{}, fmt.Errorf("extra field bytes")
 189         }
 190
 191         return fields, nil
 192 }
 193
 194 func (t *Transaction) MarshalBinary() (data []byte, err error) {
 195         payloadSize := t.Size()
 196
 197         fieldCount := make([]byte, 2)
 198         binary.BigEndian.PutUint16(fieldCount, uint16(len(t.Fields)))
 199
 200         var fieldPayload []byte
 201         for _, field := range t.Fields {
 202                 fieldPayload = append(fieldPayload, field.Payload()...)
 203         }
 204
 205         return concat.Slices(
 206                 []byte{t.Flags, t.IsReply},
 207                 t.Type,
 208                 t.ID,
 209                 t.ErrorCode,
 210                 payloadSize,
 211                 payloadSize, // this is the dataSize field, but seeming the same as totalSize
 212                 fieldCount,
 213                 fieldPayload,
 214         ), err
 215 }
 216
 217 // Size returns the total size of the transaction payload
 218 func (t *Transaction) Size() []byte {
 219         bs := make([]byte, 4)
 220
 221         fieldSize := 0
 222         for _, field := range t.Fields {
 223                 fieldSize += len(field.Data) + 4
 224         }
 225
 226         binary.BigEndian.PutUint32(bs, uint32(fieldSize+2))
 227
 228         return bs
 229 }
 230
 231 func (t *Transaction) GetField(id int) Field {
 232         for _, field := range t.Fields {
 233                 if id == int(binary.BigEndian.Uint16(field.ID)) {
 234                         return field
 235                 }
 236         }
 237
 238         return Field{}
 239 }