DNS compression pointer mutation

$LD_PRELOAD=$PWD/sendmsg.so dig twitter.com @8.8.8.8 ;; Warning: Message parser reports malformed message packet. <-- malformed 因为把压缩指针当作域名一部分了 ;; Question section mismatch: got twitter.com/RESERVED0/CLASS256

; <<>> DiG 9.9.5-3-Ubuntu <<>> twitter.com @8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44722 ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;twitter.com. IN A

;; ANSWER SECTION: twitter.com. 12 IN A 199.59.150.7 twitter.com. 12 IN A 199.59.148.82 twitter.com. 12 IN A 199.59.149.198 twitter.com. 12 IN A 199.59.149.230

;; Query time: 400 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Sat Nov 15 -------- CST 2014 ;; MSG SIZE rcvd: 104

$LD_PRELOAD=$PWD/sendmsg.so host twitter.com 8.8.8.8 Using domain server: Name: 8.8.8.8 Address: 8.8.8.8#53 Aliases:

twitter.com has address 199.59.148.82 twitter.com has address 199.59.149.230 twitter.com has address 199.59.149.198 twitter.com has address 199.59.148.10 twitter.com mail is handled by 30 ASPMX2.GOOGLEMAIL.com. twitter.com mail is handled by 10 aspmx.l.google.com. twitter.com mail is handled by 20 alt2.aspmx.l.google.com. twitter.com mail is handled by 20 alt1.aspmx.l.google.com. twitter.com mail is handled by 30 ASPMX3.GOOGLEMAIL.com. $ host twitter.com 8.8.8.8 Using domain server: Name: 8.8.8.8 Address: 8.8.8.8#53 Aliases:

twitter.com has address 59.24.3.173 twitter.com has address 59.24.3.173 twitter.com has address 37.61.54.158