@ -1,29 +1,41 @@
From c17877e414155b9b97d10416ff62b102d25019a1 Mon Sep 17 00:00:00 2001
From 6d8071bbbdcd9d3a2fbb49e55b51617906e3b816 Mon Sep 17 00:00:00 2001
From: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Date: Wed, 13 Mar 2019 20:54:49 +0000
Subject: [PATCH] net: sched: Introduce act_ctinfo action
Subject: [PATCH] net: sched: Backport Introduce act_ctinfo action
MIME-Version: 1.0
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ctinfo is a new tc filter action module. It is designed to restore DSCPs
stored in conntrack marks into the ipv4/v6 diffserv field.
ctinfo is a new tc filter action module. It is designed to restore
information contained in firewall conntrack marks to other packet fields
and is typically used on packet ingress paths. At present it has two
independent sub-functions or operating modes, DSCP restoration mode &
skb mark restoration mode.
The feature is intended for use and has been found useful for restoring
ingress classifications based on egress classifications across links
that bleach or otherwise change DSCP, typically home ISP Internet links.
Restoring DSCP on ingress on the WAN link allows qdiscs such as CAKE to
shape inbound packets according to policies that are easier to indicate
on egress.
The DSCP restore mode:
This mode copies DSCP values that have been placed in the firewall
conntrack mark back into the IPv4/v6 diffserv fields of relevant
packets.
The DSCP restoration is intended for use and has been found useful for
restoring ingress classifications based on egress classifications across
links that bleach or otherwise change DSCP, typically home ISP Internet
links. Restoring DSCP on ingress on the WAN link allows qdiscs such as
but by no means limited to CAKE to shape inbound packets according to
policies that are easier to set & mark on egress.
Ingress classification is traditionally a challenging task since
iptables rules haven't yet run and tc filter/eBPF programs are pre-NAT
lookups, hence are unable to see internal IPv4 addresses as used on the
typical home masquerading gateway.
typical home masquerading gateway. Thus marking the connection in some
manner on egress for later restoration of classification on ingress is
easier to implement.
ctinfo understands the following parameters:
Parameters related to DSCP restore mode :
dscp dscpmask[/statemask]
dscpmask - a 32 bit mask of at least 6 contiguous bits and indicates
where ctinfo will find the DSCP bits stored in the conntrack mark.
dscpmask - a 32 bit mask of 6 contiguous bits and indicate bits of the
conntrack mark field contain the DSCP value to be restored.
statemask - a 32 bit mask of (usually) 1 bit length, outside the area
specified by dscpmask. This represents a conditional operation flag
@ -36,14 +48,7 @@ conditional behaviour ie. the conntrack mark DSCP bits are always
restored to the ip diffserv field (assuming the conntrack entry is found
& the skb is an ipv4/ipv6 type)
optional parameters:
zone - conntrack zone
control - action related control (reclassify | pipe | drop | continue |
ok | goto chain <CHAIN_INDEX>)
e.g. dscp 0xfc000000/0x01000000
e.g. dscpmask 0xfc000000 statemask 0x01000000
|----0xFC----conntrack mark----000000---|
| Bits 31-26 | bit 25 | bit24 |~~~ Bit 0|
@ -57,6 +62,49 @@ e.g. dscp 0xfc000000/0x01000000
| 6 bits |
|-------------|
The skb mark restore mode (cpmark):
This mode copies the firewall conntrack mark to the skb's mark field.
It is completely the functional equivalent of the existing act_connmark
action with the additional feature of being able to apply a mask to the
restored value.
Parameters related to skb mark restore mode:
mask - a 32 bit mask applied to the firewall conntrack mark to mask out
bits unwanted for restoration. This can be useful where the conntrack
mark is being used for different purposes by different applications. If
not specified and by default the whole mark field is copied (i.e.
default mask of 0xffffffff)
e.g. mask 0x00ffffff to mask out the top 8 bits being used by the
aforementioned DSCP restore mode.
|----0x00----conntrack mark----ffffff---|
| Bits 31-24 | |
| DSCP & flag| some value here |
|---------------------------------------|
|
|
v
|------------skb mark-------------------|
| | |
| zeroed | |
|---------------------------------------|
Overall parameters:
zone - conntrack zone
control - action related control (reclassify | pipe | drop | continue |
ok | goto chain <CHAIN_INDEX>)
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Backport
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
---
include/net/tc_act/tc_ctinfo.h | 33 ++
@ -64,9 +112,9 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
include/uapi/linux/tc_act/tc_ctinfo.h | 29 ++
net/sched/Kconfig | 17 +
net/sched/Makefile | 1 +
net/sched/act_ctinfo.c | 395 ++++++++++++++++++++++
net/sched/act_ctinfo.c | 409 ++++++++++++++++++++++
tools/testing/selftests/tc-testing/config | 1 +
7 files changed, 478 insertions(+), 1 deletion(-)
7 files changed, 492 insertions(+), 1 deletion(-)
create mode 100644 include/net/tc_act/tc_ctinfo.h
create mode 100644 include/uapi/linux/tc_act/tc_ctinfo.h
create mode 100644 net/sched/act_ctinfo.c
@ -189,7 +237,7 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
obj-$(CONFIG_NET_IFE_SKBMARK) += act_meta_mark.o
--- /dev/null
+++ b/net/sched/act_ctinfo.c
@@ -0,0 +1, 395 @@
@@ -0,0 +1, 409 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* net/sched/act_ctinfo.c netfilter ctinfo connmark actions
+ *
@ -347,24 +395,29 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
+ u32 dscpmask = 0, dscpstatemask, index;
+ struct nlattr *tb[TCA_CTINFO_MAX + 1];
+ struct tcf_ctinfo_params *cp_new;
+/* struct tcf_chain *goto_ch = NULL; */
+ u32 dscpmask = 0, dscpstatemask;
+ struct tc_ctinfo *actparm;
+ struct tcf_ctinfo *ci;
+ u8 dscpmaskshift;
+ int ret = 0, err;
+
+ if (!nla)
+ if (!nla) {
+ NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed");
+ return -EINVAL;
+ }
+
+ err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, NULL );
+ err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack );
+ if (err < 0)
+ return err;
+
+ if (!tb[TCA_CTINFO_ACT])
+ if (!tb[TCA_CTINFO_ACT]) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Missing required TCA_CTINFO_ACT attribute");
+ return -EINVAL;
+ }
+ actparm = nla_data(tb[TCA_CTINFO_ACT]);
+
+ /* do some basic validation here before dynamically allocating things */
@ -373,22 +426,31 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+ dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]);
+ /* need contiguous 6 bit mask */
+ dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0;
+ if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f)
+ if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) {
+ NL_SET_ERR_MSG_ATTR(extack,
+ tb[TCA_CTINFO_PARMS_DSCP_MASK],
+ "dscp mask must be 6 contiguous bits");
+ return -EINVAL;
+ }
+ dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ?
+ nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0;
+ /* mask & statemask must not overlap */
+ if (dscpmask & dscpstatemask)
+ if (dscpmask & dscpstatemask) {
+ NL_SET_ERR_MSG_ATTR(extack,
+ tb[TCA_CTINFO_PARMS_DSCP_STATEMASK],
+ "dscp statemask must not overlap dscp mask");
+ return -EINVAL;
+ }
+ }
+
+ /* done the validation:now to the actual action allocation */
+ err = tcf_idr_check_alloc(tn, &actparm->index, a, bind);
+ index = actparm->index;
+ err = tcf_idr_check_alloc(tn, &index, a, bind);
+ if (!err) {
+ ret = tcf_idr_create(tn, actparm-> index, est, a,
+ ret = tcf_idr_create(tn, index, est, a,
+ &act_ctinfo_ops, bind, false);
+ if (ret) {
+ tcf_idr_cleanup(tn, actparm-> index);
+ tcf_idr_cleanup(tn, index);
+ return ret;
+ }
+ ret = ACT_P_CREATED;
@ -587,11 +649,11 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+MODULE_LICENSE("GPL");
--- a/tools/testing/selftests/tc-testing/config
+++ b/tools/testing/selftests/tc-testing/config
@@ -37,6 +37,7 @@ CONFIG_NET_ACT_SKBEDIT=m
CONFIG_NET_ACT_CSUM=m
@@ -38,6 +38,7 @@ CONFIG_NET_ACT_CSUM=m
CONFIG_NET_ACT_VLAN=m
CONFIG_NET_ACT_BPF=m
+CONFIG_NET_ACT_CONNDSCP=m
CONFIG_NET_ACT_CONNMARK=m
+CONFIG_NET_ACT_CONNCTINFO=m
CONFIG_NET_ACT_SKBMOD=m
CONFIG_NET_ACT_IFE=m
CONFIG_NET_ACT_TUNNEL_KEY=m
Kevin Darbyshire-Bryant
5 years ago