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authorDavid S. Miller <davem@davemloft.net>2018-08-18 09:59:19 -0700
committerDavid S. Miller <davem@davemloft.net>2018-08-18 09:59:19 -0700
commit3fe49d699a9604eed851eb45e1e0adab0e25688e (patch)
treea9a307f2dc93f8aec686d9a0a9f22a0a54ae53bc /Documentation
parentbfdd19ad80f203f42f05fd32a31c678c9c524ef9 (diff)
parentfeb9f55c33e5114127238a2c87c069b4f30d1f23 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says: ==================== Netfilter/IPVS fixes for net The following patchset contains Netfilter/IPVS fixes for your net tree: 1) Infinite loop in IPVS when net namespace is released, from Tan Hu. 2) Do not show negative timeouts in ip_vs_conn by using the new jiffies_delta_to_msecs(), patches from Matteo Croce. 3) Set F_IFACE flag for linklocal addresses in ip6t_rpfilter, from Florian Westphal. 4) Fix overflow in set size allocation, from Taehee Yoo. 5) Use netlink_dump_start() from ctnetlink to fix memleak from the error path, again from Florian. 6) Register nfnetlink_subsys in last place, otherwise netns init path may lose race and see net->nft uninitialized data. This also reverts previous attempt to fix this by increase netns refcount, patches from Florian. 7) Remove conntrack entries on layer 4 protocol tracker module removal, from Florian. 8) Use GFP_KERNEL_ACCOUNT for xtables blob allocation, from Michal Hocko. 9) Get tproxy documentation in sync with existing codebase, from Mate Eckl. 10) Honor preset layer 3 protocol via ctx->family in the new nft_ct timeout infrastructure, from Harsha Sharma. 11) Let uapi nfnetlink_osf.h compile standalone with no errors, from Dmitry V. Levin. 12) Missing braces compilation warning in nft_tproxy, patch from Mate Eclk. 13) Disregard bogus check to bail out on non-anonymous sets from the dynamic set update extension. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/networking/tproxy.txt34
1 files changed, 27 insertions, 7 deletions
diff --git a/Documentation/networking/tproxy.txt b/Documentation/networking/tproxy.txt
index ec11429e1d42..b9a188823d9f 100644
--- a/Documentation/networking/tproxy.txt
+++ b/Documentation/networking/tproxy.txt
@@ -5,19 +5,28 @@ This feature adds Linux 2.2-like transparent proxy support to current kernels.
To use it, enable the socket match and the TPROXY target in your kernel config.
You will need policy routing too, so be sure to enable that as well.
+From Linux 4.18 transparent proxy support is also available in nf_tables.
1. Making non-local sockets work
================================
The idea is that you identify packets with destination address matching a local
-socket on your box, set the packet mark to a certain value, and then match on that
-value using policy routing to have those packets delivered locally:
+socket on your box, set the packet mark to a certain value:
# iptables -t mangle -N DIVERT
# iptables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
# iptables -t mangle -A DIVERT -j MARK --set-mark 1
# iptables -t mangle -A DIVERT -j ACCEPT
+Alternatively you can do this in nft with the following commands:
+
+# nft add table filter
+# nft add chain filter divert "{ type filter hook prerouting priority -150; }"
+# nft add rule filter divert meta l4proto tcp socket transparent 1 meta mark set 1 accept
+
+And then match on that value using policy routing to have those packets
+delivered locally:
+
# ip rule add fwmark 1 lookup 100
# ip route add local 0.0.0.0/0 dev lo table 100
@@ -57,17 +66,28 @@ add rules like this to the iptables ruleset above:
# iptables -t mangle -A PREROUTING -p tcp --dport 80 -j TPROXY \
--tproxy-mark 0x1/0x1 --on-port 50080
+Or the following rule to nft:
+
+# nft add rule filter divert tcp dport 80 tproxy to :50080 meta mark set 1 accept
+
Note that for this to work you'll have to modify the proxy to enable (SOL_IP,
IP_TRANSPARENT) for the listening socket.
+As an example implementation, tcprdr is available here:
+https://git.breakpoint.cc/cgit/fw/tcprdr.git/
+This tool is written by Florian Westphal and it was used for testing during the
+nf_tables implementation.
-3. Iptables extensions
-======================
+3. Iptables and nf_tables extensions
+====================================
-To use tproxy you'll need to have the 'socket' and 'TPROXY' modules
-compiled for iptables. A patched version of iptables is available
-here: http://git.balabit.hu/?p=bazsi/iptables-tproxy.git
+To use tproxy you'll need to have the following modules compiled for iptables:
+ - NETFILTER_XT_MATCH_SOCKET
+ - NETFILTER_XT_TARGET_TPROXY
+Or the floowing modules for nf_tables:
+ - NFT_SOCKET
+ - NFT_TPROXY
4. Application support
======================