奇怪的广播
起因是抓IPTV，移动光猫 接 交换机8口，本机电脑 接 交换机7口，本机开wireshark，捕获过滤器用mac过滤掉移动光猫、本机和交换机的所有报文：
1 | !ether host 00:D8:61:xx:xx:xx && !ether host CC:ED:21:xx:xx:xx && !ether host 58:41:20:xx:xx:xx |
发现怎么还有东西一直在广播，mac是00:00:00:00:00:12。wireshark每隔约5s抓到一个broadcast：
| No. | Source | Destination | Protocal | Length | Info |
|---|---|---|---|---|---|
| 1 | 00:00:00_00:00:12 | Broadcast | 0xfffa | 72 | Ethernet II |
| 2 | 00:00:00_00:00:12 | Broadcast | 0xfffa | 72 | Ethernet II |
| 3 | 00:00:00_00:00:12 | Broadcast | 0xfffa | 72 | Ethernet II |
| …… | …… | …… | …… | …… | …… |
看一个完整报文：
1 | 0000 ff ff ff ff ff ff 00 00 00 00 00 12 ff fa 00 00 ................ |
其中广播带有58个bytes的data：
1 | ......!...In the gap a new tooth grew,.................... |
我抓了100个之后在wireshark存为unknown_broadcast.txt，用sed提取出data的文本内容并拼接起来：
1 | sed -n '/^00[012]0[ ]*/p' unknown_broadcast.txt | sed -n 's/^.*\(.\{17\}$\)/\1/p'| sed 's/^\(\.*!\.*\)*\([^.]*\)\(\.*\)*/\2/'| sed ':a;N;s/\r\n//;t a' |
(ps：sed的正则怎么用不了非贪婪)
(ps：sed的正则怎么匹配不了行尾$)
1 | In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth tooThe day I lost my very first tooth, |
手动去掉重复片段整理：
1 | The day I lost my very first tooth,Was halfway through grade four,I'd run my tongue along the gap,Where my tooth had been before,I remember I went home crying,And showed it to my mum,She told me that a brand new tooth,Would grow up in my gum,In a while the gap would stop feeling I wouldn't notice the tooth was gone,The only reason I missed it now,Was because it was there for so long,Then slowly but surely over the weeks,In the gap a new tooth grew,And now it makes me wonder,If people are like teeth too. |
拿上面这小作文一搜，发现是首诗。。。。。换下行：
1 | The day I lost my very first tooth, |
怎么我抓出来的跟搜出来的差一个词，In a while the gap would stop feeling strange这句，我的怎么没有strange，手动去翻了一下unknown_broadcast.txt，发现是有strange的，检查发现是sed写错了，改为：
1 | sed -n 's/^00[0123]0[ ]\{2,\}.*[ ]\{2,\}\([\.]*\)/\1/p' unknown_broadcast.txt | sed 's/^\(\.*!\.*\)*\([^.]*\)\(\.*\)*/\2/' | sed '/^[ ]\{3,\}/d' | sed ':a;N;s/\r\n//;t a' |
谷歌翻译下这首诗：
在我失去第一颗牙齿的那天，
四年级上到一半，
我会沿着缝隙伸出舌头，
我以前的牙齿在哪里，
我记得我哭着回家，
并把它展示给我妈妈，
她告诉我，一颗崭新的牙齿，
会在我的口香糖里长大，
过一会儿，差距就不再奇怪了，
我不会注意到牙齿掉了，
我现在错过的唯一原因，
是因为它存在了那么久，
然后在几周内缓慢但肯定地，
缝隙里长出了一颗新牙，
现在它让我想知道，
如果人也像牙齿