协议len字段实现有问题？

[jerrysearch]

实现了一个udp server，通过LoggingHandler想看下kcp协议头，客户端使用EchoClient，发现长度好像不对

+-------------------------------------------------+
| 0 1 2 3 4 5 6 7 8 9 a b c d e f |
+--------+-------------------------------------------------+----------------+
|00000000| 0a 00 00 00 51 00 20 00 79 75 be 5a 00 00 00 00 |....Q. .yu.Z....|
|00000010| 00 00 00 00 00 01 00 00 00 01 02 03 04 05 06 07 |................|
|00000020| 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 |................|
|00000030| 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 |........ !"#$%&'|
|00000040| 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 36 37 |()*+,-./01234567|
|00000050| 38 39 3a 3b 3c 3d 3e 3f 40 41 42 43 44 45 46 47 |89:;<=>?@ABCDEFG|
|00000060| 48 49 4a 4b 4c 4d 4e 4f 50 51 52 53 54 55 56 57 |HIJKLMNOPQRSTUVW|
|00000070| 58 59 5a 5b 5c 5d 5e 5f 60 61 62 63 64 65 66 67 |XYZ[]^_`abcdefg|
|00000080| 68 69 6a 6b 6c 6d 6e 6f 70 71 72 73 74 75 76 77 |hijklmnopqrstuvw|
|00000090| 78 79 7a 7b 7c 7d 7e 7f 80 81 82 83 84 85 86 87 |xyz{|}~.........|
|000000a0| 88 89 8a 8b 8c 8d 8e 8f 90 91 92 93 94 95 96 97 |................|
|000000b0| 98 99 9a 9b 9c 9d 9e 9f a0 a1 a2 a3 a4 a5 a6 a7 |................|
|000000c0| a8 a9 aa ab ac ad ae af b0 b1 b2 b3 b4 b5 b6 b7 |................|
|000000d0| b8 b9 ba bb bc bd be bf c0 c1 c2 c3 c4 c5 c6 c7 |................|
|000000e0| c8 c9 ca cb cc cd ce cf d0 d1 d2 d3 d4 d5 d6 d7 |................|
|000000f0| d8 d9 da db dc dd de df e0 e1 e2 e3 e4 e5 e6 e7 |................|
|00000100| e8 e9 ea eb ec ed ee ef f0 f1 f2 f3 f4 f5 f6 f7 |................|
|00000110| f8 f9 fa fb fc fd fe ff |........ |
+--------+-------------------------------------------------+----------------+