From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nirgal =?ISO-8859-1?Q?Vourg=E8re?= Subject: Re: Fwd: Issue migrating "iptables -m socket --transparent" into nftables Date: Tue, 18 Aug 2020 13:08:43 +0200 Message-ID: <32610365.DCq6cjG4UW@deimos> References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="nextPart21026257.Zcmz9MDH7y" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: Sender: netfilter-owner@vger.kernel.org List-ID: To: pablo@netfilter.org, Balazs Scheidler , netfilter@vger.kernel.org This is a multi-part message in MIME format. --nextPart21026257.Zcmz9MDH7y Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" On Tuesday, 18 August 2020 11:18:50 CEST Balazs Scheidler wrote: >> Does any one know the proper equivalent to >> iptables -t mangle -A PREROUTING -m socket --transparent -j MARK --set-mark 1 >> using nft? > > The original iptables "socket" match had an extra check so that it wouldn't > match listener sockets, at least by default (that is if --nowildcard is not > specified). > > I don't see however how "outbound masqueraded connection" could be > impacted. The "socket transparent 1" expression should require that the > socket being matched has IP_TRANSPARENT setsockopt set. Are those > connections also initiated by haproxy? > > In any case, I think the check to ignore wildcard bound listener sockets is > definitely missing, however I am not sure how to properly add it to > nftables. If I added it to the socket match implementation that might break > a few currently well behaving use-cases. @pablo@netfilter.org > can you please advise? This is the check that is in > iptables -m socket: > > wildcard = (!(info->flags & XT_SOCKET_NOWILDCARD) && > sk_fullsock(sk) && > inet_sk(sk)->inet_rcv_saddr == 0); > > And then if --transparent is used, these sockets are not accepted / the > rule does not match. That's it I guess: I tried adding --nowildcard to my working iptables rules and I got the same error, https connections from the lan side are not masqueraded toward the wan, but routed locally to the socket listening to *:443. (thanks tcptraceroute for the info) So basically nft > socket transparent 1 meta mark set 1 may be the equivalent of iptables > -m socket --transparent --nowildcard -j MARK --set-mark 1 while I'm looking for *not* having "--nowildcard". Any idea about how work around this? I was thinking of using the "fib" rules to match the wan side packets since they have a destination ip address that match one of the local address, while the wan bound packets don't. Regarding your question about IP_TRANSPARENT setsockopt, I don't quite know how to look at that easily. Attached is a fragment from my haproxy.cfg file, the key points being "source 0.0.0.0 usesrc clientip" and "bind :443 strict-sni transparent". --nextPart21026257.Zcmz9MDH7y Content-Disposition: inline; filename="haproxy.cfg" Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8"; name="haproxy.cfg" ############################################################################ # DO NOT EDIT THAT FILE # Notice: That file was generated using: # /root/bin/update-virtualhosts /etc/haproxy/virtualhosts.haproxy # See /etc/haproxy/virtualhosts.haproxy/config ############################################################################ global log /dev/log local0 log /dev/log local1 notice chroot /var/lib/haproxy stats socket /run/haproxy/admin.sock mode 660 level admin stats timeout 30s # user haproxy # transparent proxying requires root privileges group haproxy daemon # Default SSL material locations ca-base /etc/ssl/certs crt-base /etc/ssl/private # Default ciphers to use on SSL-enabled listening sockets. # For more information, see ciphers(1SSL). This list is from: # https://hynek.me/articles/hardening-your-web-servers-ssl-ciphers/ # An alternative list with additional directives can be obtained from # https://mozilla.github.io/server-side-tls/ssl-config-generator/?server=haproxy ssl-default-bind-ciphers ECDH+AESGCM:DH+AESGCM:ECDH+AES256:DH+AES256:ECDH+AES128:DH+AES:RSA+AESGCM:RSA+AES:!aNULL:!MD5:!DSS ssl-default-bind-options no-sslv3 defaults source 0.0.0.0 usesrc clientip log global #mode http #option httplog option dontlognull timeout connect 5000 timeout client 50000 timeout server 50000 errorfile 400 /etc/haproxy/errors/400.http errorfile 403 /etc/haproxy/errors/403.http errorfile 408 /etc/haproxy/errors/408.http errorfile 500 /etc/haproxy/errors/500.http errorfile 502 /etc/haproxy/errors/502.http errorfile 503 /etc/haproxy/errors/503.http errorfile 504 /etc/haproxy/errors/504.http frontend https4-in bind :443 strict-sni transparent mode tcp tcp-request inspect-delay 5s tcp-request content accept if { req_ssl_hello_type 1 } default_backend https4-www2.in.nirgal.com backend https4-www2.in.nirgal.com server https4-www2.in.nirgal.com ipv4@192.168.1.99:443 --nextPart21026257.Zcmz9MDH7y--