[Sysadmins] iptables и ftp --- фича или баг?

[Alexey Shabalin]

2008/11/19 Kharitonov A. Dmitry :
> [user на SERVER ~]$ sudo lsmod | egrep "ftp|ipt"
> ipt_MASQUERADE          7808  1
> ipt_REJECT              9472  705
> iptable_mangle          7040  0
> iptable_nat            11652  1
> iptable_filter          7168  1
> ip_tables              17604  3 iptable_mangle,iptable_nat,iptable_filter
> ipt_REDIRECT            6272  0
> ipt_LOG                10496  0
> x_tables               18180  8
> xt_state,xt_tcpudp,ipt_MASQUERADE,ipt_REJECT,iptable_nat,ip_tables,ipt_REDIRECT,ipt_LOG
> ip_nat_ftp              7680  0
> ip_nat                 22060  4
> ipt_MASQUERADE,iptable_nat,ipt_REDIRECT,ip_nat_ftp
> ip_conntrack_ftp       12016  1 ip_nat_ftp
> ip_conntrack           56800  6
> xt_state,ipt_MASQUERADE,iptable_nat,ip_nat_ftp,ip_nat,ip_conntrack_ftp
>
> делаю
> -A INPUT -i wan -p tcp -m tcp --sport 20 ! --tcp-flags FIN,SYN,RST,ACK SYN
> -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A INPUT -i wan -p tcp -m tcp --sport 21 ! --tcp-flags FIN,SYN,RST,ACK SYN
> -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -o wan -p tcp -m tcp --dport 20 -m state --state
> NEW,RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -o wan -p tcp -m tcp --dport 21 -m state --state
> NEW,RELATED,ESTABLISHED -j ACCEPT
>
> запускаю firefox
> ERROR
> The requested URL could not be retrieved
>
> An FTP protocol error occurred while trying to retrieve the URL:
> ftp://ftp.altlinux.org/pub/distributions/
> <ftp://ftp.altlinux.org/pub/distributions/OpenMusic/>
>
> Squid sent the following FTP command:*
> *NLST
> **and then received this reply*
> *Use PORT or PASV first.
> Your cache administrator is webmaster <mailto:webmaster>.
> Generated Wed, 19 Nov 2008 23:35:09 GMT by server.dimahost
> (squid/2.6.STABLE13)
>
> делаю
> -A INPUT -i wan -p tcp -m tcp --sport 20 ! --tcp-flags FIN,SYN,RST,ACK SYN
> -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A INPUT -i wan -p tcp -m tcp --sport 21 ! --tcp-flags FIN,SYN,RST,ACK SYN
> -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A INPUT -i wan -p tcp -m tcp --sport 1024:65535 ! --tcp-flags
> FIN,SYN,RST,ACK SYN -m state --state RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -o wan -p tcp -m tcp --dport 20 -m state --state
> NEW,RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -o wan -p tcp -m tcp --dport 21 -m state --state
> NEW,RELATED,ESTABLISHED -j ACCEPT
> -A OUTPUT -o wan -p tcp -m tcp --dport 1024:65535 -m state --state
> NEW,RELATED,ESTABLISHED -j ACCEPT
>
> запускаю firefox
> Всё нормально.
>
> Я, так понимаю, не работают
> ip_nat_ftp              7680  0
> ip_conntrack_ftp       12016  1 ip_nat_ftp
>
>
> Кто мне разъеснит: это фича или баг?
это пасивный режим работы ftp.

-- 
Alexey Shabalin