Subject: Re: [PATCH net-next v4] net: sched: Introduce act_ctinfo action

From: Toke Høiland-Jørgensen <[email-masked]>
Date: Fri, 24 May 2019 12:30:10 +0200

Hi Kevin

I couldn't get 'git am' to accept your email. Not sure if it's because
it's base64 encoded, or because it doesn't apply cleanly to current
net-next.

However, I could get it to apply by manually copying over the diff to a
.patch file, so here are some comments:

> ctinfo is a new tc filter action module.  It is designed to restore
> information contained in conntrack marks to other places.  At present it
> can restore DSCP values to IPv4/6 diffserv fields and also copy
> conntrack marks to skb marks.  As such the 2nd function effectively
> replaces the existing act_connmark module
>
> 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
> CAKE to shape inbound packets according to policies that are easier to
> indicate 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.
>
> ctinfo understands the following parameters:
>
> dscp dscpmask[/statemask]

The slash-separated syntax is usually used for "<value> / <mask applied
to value>", so it is a bit confusing that you are using the syntax for
two masks here.

> 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.
>
> statemask - a 32 bit mask of (usually) 1 bit length, outside the area
> specified by dscpmask.  This represents a conditional operation flag
> whereby the DSCP is only restored if the flag is set.  This is useful to
> implement a 'one shot' iptables based classification where the
> 'complicated' iptables rules are only run once to classify the
> connection on initial (egress) packet and subsequent packets are all
> marked/restored with the same DSCP.  A mask of zero disables the
> 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)
>
> mark [mask]

Also, it took me a second reading to realise that the 'dscpmask' and
'statemask' refer back to the two parameter already mentioned above, and
that 'mark [mask]' were the beginning of two new ones. Maybe just lose
the syntax here and just describe the parameter values?

> mark - enables copying the conntrack connmark value to the skb mark

Maybe make it explicit that this is the bit that is equivalent to the
existing act_connmark? Also, maybe rename this to 'markskb' or
something, to make it explicit that it operates on the skb (there are an
awful lot of 'marks' and 'masks' in this description ;)).

> mask - a 32 bit mask applied to the mark to mask out bit unwanted for
> restoration.  The CAKE qdisc for example understands both DSCP and 'tin'
> classification stored the mark, thus act_ctinfo may be used to restore
> both aspects of classification for CAKE in one action.  A default mask
> of 0xffffffff is applied if not specified.

Not sure I understand this description. What exactly is the use case
here?

> zone - conntrack zone
>
> control - action related control (reclassify | pipe | drop | continue |
> ok | goto chain <CHAIN_INDEX>)
>
> e.g. dscp 0xfc000000/0x01000000
>
> |----0xFC----conntrack mark----000000---|
> | Bits 31-26 | bit 25 | bit24 |~~~ Bit 0|
> | DSCP       | unused | flag  |unused   |
> |-----------------------0x01---000000---|
>       |                   |
>       |                   |
>       ---|             Conditional flag
>          v             only restore if set
> |-ip diffserv-|
> | 6 bits      |
> |-------------|
>
> e.g. mark 0x00ffffff
>
> |----0x00----conntrack mark----ffffff---|
> | Bits 31-24 |                          |
> | DSCP & flag|                          |
> |---------------------------------------|
> 			|
> 			|
> 			v
> |------------skb mark-------------------|
> |                                       |
> |                                       |
> |---------------------------------------|
>
> Signed-off-by: Kevin Darbyshire-Bryant <[email-masked]>
> ---
> v2 - add equivalent connmark functionality with an enhancement
>      to accept a mask
>      pass statistics for each sub-function as individual netlink
>      attributes and stop (ab)using overlimits, drops
>      update the testing config correctly
> v3 - fix a licensing silly & tidy up GPL boilerplate
> v4 - drop stray copy paste inline
>      reverse christmas tree local vars
>
>  include/net/tc_act/tc_ctinfo.h            |  28 ++
>  include/uapi/linux/pkt_cls.h              |   1 +
>  include/uapi/linux/tc_act/tc_ctinfo.h     |  43 +++
>  net/sched/Kconfig                         |  17 +
>  net/sched/Makefile                        |   1 +
>  net/sched/act_ctinfo.c                    | 402 ++++++++++++++++++++++
>  tools/testing/selftests/tc-testing/config |   1 +
>  7 files changed, 493 insertions(+)
>  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
>
> diff --git a/include/net/tc_act/tc_ctinfo.h b/include/net/tc_act/tc_ctinfo.h
> new file mode 100644
> index 000000000000..87334120dcb6
> --- /dev/null
> +++ b/include/net/tc_act/tc_ctinfo.h
> @@ -0,0 +1,28 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __NET_TC_CTINFO_H
> +#define __NET_TC_CTINFO_H
> +
> +#include <net/act_api.h>
> +
> +struct tcf_ctinfo_params {
> +	struct net *net;
> +	u32 dscpmask;
> +	u32 dscpstatemask;
> +	u32 markmask;
> +	u16 zone;
> +	u8 mode;
> +	u8 dscpmaskshift;
> +	struct rcu_head rcu;
> +};
> +
> +struct tcf_ctinfo {
> +	struct tc_action common;
> +	struct tcf_ctinfo_params __rcu *params;
> +	u64 stats_dscp_set;
> +	u64 stats_dscp_error;
> +	u64 stats_mark_set;
> +};
> +
> +#define to_ctinfo(a) ((struct tcf_ctinfo *)a)
> +
> +#endif /* __NET_TC_CTINFO_H */
> diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
> index 51a0496f78ea..a93680fc4bfa 100644
> --- a/include/uapi/linux/pkt_cls.h
> +++ b/include/uapi/linux/pkt_cls.h
> @@ -105,6 +105,7 @@ enum tca_id {
>  	TCA_ID_IFE = TCA_ACT_IFE,
>  	TCA_ID_SAMPLE = TCA_ACT_SAMPLE,
>  	/* other actions go here */
> +	TCA_ID_CTINFO,
>  	__TCA_ID_MAX = 255
>  };
>  
> diff --git a/include/uapi/linux/tc_act/tc_ctinfo.h b/include/uapi/linux/tc_act/tc_ctinfo.h
> new file mode 100644
> index 000000000000..8d254b82151c
> --- /dev/null
> +++ b/include/uapi/linux/tc_act/tc_ctinfo.h
> @@ -0,0 +1,43 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef __UAPI_TC_CTINFO_H
> +#define __UAPI_TC_CTINFO_H
> +
> +#include <linux/types.h>
> +#include <linux/pkt_cls.h>
> +
> +struct tc_ctinfo {
> +	tc_gen;
> +};
> +
> +struct tc_ctinfo_dscp {
> +	__u32 mask;
> +	__u32 statemask;
> +};
>
> +struct tc_ctinfo_stats_dscp {
> +	__u64 set;
> +	__u64 error;
> +};

Why these two structs, when everything else gets their own netlink TLVs?

> +
> +enum {
> +	TCA_CTINFO_UNSPEC,
> +	TCA_CTINFO_ACT,
> +	TCA_CTINFO_ZONE,
> +	TCA_CTINFO_DSCP_PARMS,
> +	TCA_CTINFO_MARK_MASK,
> +	TCA_CTINFO_MODE_DSCP,
> +	TCA_CTINFO_MODE_MARK,
> +	TCA_CTINFO_STATS_DSCP,
> +	TCA_CTINFO_STATS_MARK,
> +	TCA_CTINFO_TM,
> +	TCA_CTINFO_PAD,
> +	__TCA_CTINFO_MAX
> +};
> +#define TCA_CTINFO_MAX (__TCA_CTINFO_MAX - 1)
> +
> +enum {
> +	CTINFO_MODE_SETDSCP	= BIT(0),
> +	CTINFO_MODE_SETMARK	= BIT(1)
> +};
> +
> +#endif
> diff --git a/net/sched/Kconfig b/net/sched/Kconfig
> index 5c02ad97ef23..f5773effcfdc 100644
> --- a/net/sched/Kconfig
> +++ b/net/sched/Kconfig
> @@ -876,6 +876,23 @@ config NET_ACT_CONNMARK
>  	  To compile this code as a module, choose M here: the
>  	  module will be called act_connmark.
>  
> +config NET_ACT_CTINFO
> +        tristate "Netfilter Connection Mark Actions"
> +        depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
> +        depends on NF_CONNTRACK && NF_CONNTRACK_MARK
> +        help
> +	  Say Y here to allow transfer of a connmark stored information.
> +	  Current actions transfer connmark stored DSCP into
> +	  ipv4/v6 diffserv and/or to transfer connmark to packet
> +	  mark.  Both are useful for restoring egress based marks
> +	  back onto ingress connections for qdisc priority mapping
> +	  purposes.
> +
> +	  If unsure, say N.
> +
> +	  To compile this code as a module, choose M here: the
> +	  module will be called act_ctinfo.
> +
>  config NET_ACT_SKBMOD
>          tristate "skb data modification action"
>          depends on NET_CLS_ACT
> diff --git a/net/sched/Makefile b/net/sched/Makefile
> index 8a40431d7b5c..d54bfcbd7981 100644
> --- a/net/sched/Makefile
> +++ b/net/sched/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_NET_ACT_CSUM)	+= act_csum.o
>  obj-$(CONFIG_NET_ACT_VLAN)	+= act_vlan.o
>  obj-$(CONFIG_NET_ACT_BPF)	+= act_bpf.o
>  obj-$(CONFIG_NET_ACT_CONNMARK)	+= act_connmark.o
> +obj-$(CONFIG_NET_ACT_CTINFO)	+= act_ctinfo.o
>  obj-$(CONFIG_NET_ACT_SKBMOD)	+= act_skbmod.o
>  obj-$(CONFIG_NET_ACT_IFE)	+= act_ife.o
>  obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
> diff --git a/net/sched/act_ctinfo.c b/net/sched/act_ctinfo.c
> new file mode 100644
> index 000000000000..93f98d62a962
> --- /dev/null
> +++ b/net/sched/act_ctinfo.c
> @@ -0,0 +1,402 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/* net/sched/act_ctinfo.c  netfilter ctinfo connmark actions
> + *
> + * Copyright (c) 2019 Kevin Darbyshire-Bryant <[email-masked]>
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/skbuff.h>
> +#include <linux/rtnetlink.h>
> +#include <linux/pkt_cls.h>
> +#include <linux/ip.h>
> +#include <linux/ipv6.h>
> +#include <net/netlink.h>
> +#include <net/pkt_sched.h>
> +#include <net/act_api.h>
> +#include <net/pkt_cls.h>
> +#include <uapi/linux/tc_act/tc_ctinfo.h>
> +#include <net/tc_act/tc_ctinfo.h>
> +
> +#include <net/netfilter/nf_conntrack.h>
> +#include <net/netfilter/nf_conntrack_core.h>
> +#include <net/netfilter/nf_conntrack_ecache.h>
> +#include <net/netfilter/nf_conntrack_zones.h>
> +
> +static unsigned int ctinfo_net_id;
> +static struct tc_action_ops act_ctinfo_ops;
> +
> +static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
> +				struct tcf_ctinfo_params *cp,
> +				struct sk_buff *skb, int wlen, int proto)
> +{
> +	u8 dscp, newdscp;
> +
> +	newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) &
> +		     ~INET_ECN_MASK;
> +
> +	switch (proto) {
> +	case NFPROTO_IPV4:
> +		dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK;
> +		if (dscp != newdscp) {
> +			if (likely(!skb_try_make_writable(skb, wlen))) {
> +				ipv4_change_dsfield(ip_hdr(skb),
> +						    INET_ECN_MASK,
> +						    newdscp);
> +				ca->stats_dscp_set++;
> +			} else {
> +				ca->stats_dscp_error++;
> +			}
> +		}
> +		break;
> +	case NFPROTO_IPV6:
> +		dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK;
> +		if (dscp != newdscp) {
> +			if (likely(!skb_try_make_writable(skb, wlen))) {
> +				ipv6_change_dsfield(ipv6_hdr(skb),
> +						    INET_ECN_MASK,
> +						    newdscp);
> +				ca->stats_dscp_set++;
> +			} else {
> +				ca->stats_dscp_error++;
> +			}
> +		}
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +static void tcf_ctinfo_mark_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
> +				struct tcf_ctinfo_params *cp,
> +				struct sk_buff *skb)
> +{
> +	ca->stats_mark_set++;
> +	skb->mark = ct->mark & cp->markmask;
> +}
> +
> +static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a,
> +			  struct tcf_result *res)
> +{
> +	const struct nf_conntrack_tuple_hash *thash = NULL;
> +	struct tcf_ctinfo *ca = to_ctinfo(a);
> +	struct nf_conntrack_tuple tuple;
> +	struct nf_conntrack_zone zone;
> +	enum ip_conntrack_info ctinfo;
> +	struct tcf_ctinfo_params *cp;
> +	struct nf_conn *ct;
> +	int proto, wlen;
> +	int action;
> +
> +	cp = rcu_dereference_bh(ca->params);
> +
> +	tcf_lastuse_update(&ca->tcf_tm);
> +	bstats_update(&ca->tcf_bstats, skb);
> +	action = READ_ONCE(ca->tcf_action);
> +
> +	wlen = skb_network_offset(skb);
> +	if (tc_skb_protocol(skb) == htons(ETH_P_IP)) {
> +		wlen += sizeof(struct iphdr);
> +		if (!pskb_may_pull(skb, wlen))
> +			goto out;
> +
> +		proto = NFPROTO_IPV4;
> +	} else if (tc_skb_protocol(skb) == htons(ETH_P_IPV6)) {
> +		wlen += sizeof(struct ipv6hdr);
> +		if (!pskb_may_pull(skb, wlen))
> +			goto out;
> +
> +		proto = NFPROTO_IPV6;
> +	} else {
> +		goto out;
> +	}
> +
> +	ct = nf_ct_get(skb, &ctinfo);
> +	if (!ct) { /* look harder, usually ingress */
> +		if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
> +				       proto, cp->net, &tuple))
> +			goto out;
> +		zone.id = cp->zone;
> +		zone.dir = NF_CT_DEFAULT_ZONE_DIR;
> +
> +		thash = nf_conntrack_find_get(cp->net, &zone, &tuple);
> +		if (!thash)
> +			goto out;
> +
> +		ct = nf_ct_tuplehash_to_ctrack(thash);
> +	}
> +
> +	if (cp->mode & CTINFO_MODE_SETDSCP)
> +		if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask))
> +			tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto);
> +
> +	if (cp->mode & CTINFO_MODE_SETMARK)
> +		tcf_ctinfo_mark_set(ct, ca, cp, skb);
> +
> +	if (thash)
> +		nf_ct_put(ct);
> +out:
> +	return action;
> +}
> +
> +static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = {
> +	[TCA_CTINFO_ACT] = { .len = sizeof(struct tc_ctinfo) },
> +	[TCA_CTINFO_ZONE] = { .type = NLA_U16 },
> +	[TCA_CTINFO_MODE_DSCP] = { .type = NLA_FLAG },
> +	[TCA_CTINFO_MODE_MARK] = { .type = NLA_FLAG },
> +	[TCA_CTINFO_DSCP_PARMS] = { .len = sizeof(struct tc_ctinfo_dscp)
> },

Think you're missing some parameters here? At least
TCA_CTINFO_MARK_MASK.

> +};
> +
> +static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
> +			   struct nlattr *est, struct tc_action **a,
> +			   int ovr, int bind, bool rtnl_held,
> +			   struct tcf_proto *tp,
> +			   struct netlink_ext_ack *extack)
> +{
> +	struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
> +	struct nlattr *tb[TCA_CTINFO_MAX + 1];
> +	struct tcf_ctinfo_params *cp_new;
> +	struct tcf_chain *goto_ch = NULL;
> +	struct tc_ctinfo_dscp *dscpparm;
> +	struct tcf_ctinfo *ci;
> +	struct tc_ctinfo *actparm;
> +	int ret = 0, err, i;
> +
> +	if (!nla)
> +		return -EINVAL;
> +
> +	err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, NULL);
> +	if (err < 0)
> +		return err;
> +
> +	if (!tb[TCA_CTINFO_ACT])
> +		return -EINVAL;
> +
> +	if (tb[TCA_CTINFO_MODE_DSCP] && !tb[TCA_CTINFO_DSCP_PARMS])
> +		return -EINVAL;
> +
> +	actparm = nla_data(tb[TCA_CTINFO_ACT]);
> +	dscpparm = nla_data(tb[TCA_CTINFO_DSCP_PARMS]);
> +
> +	if (dscpparm) {
> +		/* need at least contiguous 6 bit mask */
> +		i = dscpparm->mask ? __ffs(dscpparm->mask) : 0;
> +		if ((0x3f & (dscpparm->mask >> i)) != 0x3f)
> +			return -EINVAL;

Should this be enforced to be exactly 6 bits? Anything above that is
going to be discarded anyway...

> +		/* mask & statemask must not overlap */
> +		if (dscpparm->mask & dscpparm->statemask)
> +			return -EINVAL;
> +	}
> +
> +	/* done the validation:now to the actual action allocation */
> +	err = tcf_idr_check_alloc(tn, &actparm->index, a, bind);
> +	if (!err) {
> +		ret = tcf_idr_create(tn, actparm->index, est, a,
> +				     &act_ctinfo_ops, bind, false);
> +		if (ret) {
> +			tcf_idr_cleanup(tn, actparm->index);
> +			return ret;
> +		}
> +	} else if (err > 0) {
> +		if (bind) /* don't override defaults */
> +			return 0;
> +		if (!ovr) {
> +			tcf_idr_release(*a, bind);
> +			return -EEXIST;
> +		}
> +	} else {
> +		return err;
> +	}
> +
> +	err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack);
> +	if (err < 0)
> +		goto release_idr;
> +
> +	ci = to_ctinfo(*a);
> +
> +	cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL);
> +	if (unlikely(!cp_new)) {
> +		err = -ENOMEM;
> +		goto put_chain;
> +	}
> +
> +	cp_new->net = net;
> +	cp_new->zone = tb[TCA_CTINFO_ZONE] ?
> +			nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0;
> +	if (dscpparm) {
> +		cp_new->dscpmask = dscpparm->mask;
> +		cp_new->dscpmaskshift = cp_new->dscpmask ?
> +				__ffs(cp_new->dscpmask) : 0;
> +		cp_new->dscpstatemask = dscpparm->statemask;
> +	}
> +	cp_new->markmask = tb[TCA_CTINFO_MARK_MASK] ?
> +			nla_get_u32(tb[TCA_CTINFO_MARK_MASK]) : ~0;
> +
> +	if (tb[TCA_CTINFO_MODE_DSCP])
> +		cp_new->mode |= CTINFO_MODE_SETDSCP;
> +	else
> +		cp_new->mode &= ~CTINFO_MODE_SETDSCP;
> +
> +	if (tb[TCA_CTINFO_MODE_MARK])
> +		cp_new->mode |= CTINFO_MODE_SETMARK;
> +	else
> +		cp_new->mode &= ~CTINFO_MODE_SETMARK;
> +
> +	spin_lock_bh(&ci->tcf_lock);
> +	goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch);
> +	rcu_swap_protected(ci->params, cp_new,
> +			   lockdep_is_held(&ci->tcf_lock));
> +	spin_unlock_bh(&ci->tcf_lock);
> +
> +	if (goto_ch)
> +		tcf_chain_put_by_act(goto_ch);
> +	if (cp_new)
> +		kfree_rcu(cp_new, rcu);
> +
> +	if (ret == ACT_P_CREATED)
> +		tcf_idr_insert(tn, *a);
> +
> +	return ret;
> +
> +put_chain:
> +	if (goto_ch)
> +		tcf_chain_put_by_act(goto_ch);
> +release_idr:
> +	tcf_idr_release(*a, bind);
> +	return err;
> +}
> +
> +static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a,
> +			   int bind, int ref)
> +{
> +	struct tcf_ctinfo *ci = to_ctinfo(a);
> +	struct tc_ctinfo opt = {
> +		.refcnt  = refcount_read(&ci->tcf_refcnt) - ref,
> +		.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
> +		.index   = ci->tcf_index,
> +	};
> +	unsigned char *b = skb_tail_pointer(skb);
> +	struct tc_ctinfo_stats_dscp dscpstats;
> +	struct tc_ctinfo_dscp dscpparm;
> +	struct tcf_ctinfo_params *cp;
> +	struct tcf_t t;
> +
> +	spin_lock_bh(&ci->tcf_lock);
> +	cp = rcu_dereference_protected(ci->params,
> +				       lockdep_is_held(&ci->tcf_lock));
> +	opt.action = ci->tcf_action;
> +
> +	if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt))
> +		goto nla_put_failure;
> +
> +	if (cp->mode & CTINFO_MODE_SETDSCP) {
> +		dscpparm.mask = cp->dscpmask;
> +		dscpparm.statemask = cp->dscpstatemask;
> +		if (nla_put(skb, TCA_CTINFO_DSCP_PARMS, sizeof(dscpparm),
> +			    &dscpparm))
> +			goto nla_put_failure;
> +
> +		if (nla_put_flag(skb, TCA_CTINFO_MODE_DSCP))
> +			goto nla_put_failure;
> +
> +		dscpstats.set = ci->stats_dscp_set;
> +		dscpstats.error = ci->stats_dscp_error;
> +		if (nla_put(skb, TCA_CTINFO_STATS_DSCP, sizeof(dscpstats),
> +			    &dscpstats))
> +			goto nla_put_failure;
> +	}
> +
> +	if (cp->mode & CTINFO_MODE_SETMARK) {
> +		if (nla_put_u32(skb, TCA_CTINFO_MARK_MASK, cp->markmask))
> +			goto nla_put_failure;
> +
> +		if (nla_put_flag(skb, TCA_CTINFO_MODE_MARK))
> +			goto nla_put_failure;
> +
> +		if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_MARK,
> +				      ci->stats_mark_set, TCA_CTINFO_PAD))
> +			goto nla_put_failure;
> +	}
> +
> +	if (cp->zone) {
> +		if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone))
> +			goto nla_put_failure;
> +	}
> +
> +	tcf_tm_dump(&t, &ci->tcf_tm);
> +	if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD))
> +		goto nla_put_failure;
> +
> +	spin_unlock_bh(&ci->tcf_lock);
> +	return skb->len;
> +
> +nla_put_failure:
> +	spin_unlock_bh(&ci->tcf_lock);
> +	nlmsg_trim(skb, b);
> +	return -1;
> +}
> +
> +static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb,
> +			     struct netlink_callback *cb, int type,
> +			     const struct tc_action_ops *ops,
> +			     struct netlink_ext_ack *extack)
> +{
> +	struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
> +
> +	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
> +}
> +
> +static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index)
> +{
> +	struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
> +
> +	return tcf_idr_search(tn, a, index);
> +}
> +
> +static struct tc_action_ops act_ctinfo_ops = {
> +	.kind		=	"ctinfo",
> +	.id		=	TCA_ID_CTINFO,
> +	.owner		=	THIS_MODULE,
> +	.act		=	tcf_ctinfo_act,
> +	.dump		=	tcf_ctinfo_dump,
> +	.init		=	tcf_ctinfo_init,
> +	.walk		=	tcf_ctinfo_walker,
> +	.lookup		=	tcf_ctinfo_search,

After applying the patch, the = doesn't align for this line for me...

> +	.size		=	sizeof(struct tcf_ctinfo),
> +};
> +
> +static __net_init int ctinfo_init_net(struct net *net)
> +{
> +	struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
> +
> +	return tc_action_net_init(tn, &act_ctinfo_ops);
> +}
> +
> +static void __net_exit ctinfo_exit_net(struct list_head *net_list)
> +{
> +	tc_action_net_exit(net_list, ctinfo_net_id);
> +}
> +
> +static struct pernet_operations ctinfo_net_ops = {
> +	.init = ctinfo_init_net,
> +	.exit_batch = ctinfo_exit_net,
> +	.id   = &ctinfo_net_id,
> +	.size = sizeof(struct tc_action_net),
> +};
> +
> +static int __init ctinfo_init_module(void)
> +{
> +	return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops);
> +}
> +
> +static void __exit ctinfo_cleanup_module(void)
> +{
> +	tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops);
> +}
> +
> +module_init(ctinfo_init_module);
> +module_exit(ctinfo_cleanup_module);
> +MODULE_AUTHOR("Kevin Darbyshire-Bryant <[email-masked]>");
> +MODULE_DESCRIPTION("Connection tracking mark actions");
> +MODULE_LICENSE("GPL");
> diff --git a/tools/testing/selftests/tc-testing/config b/tools/testing/selftests/tc-testing/config
> index 203302065458..b235efd55367 100644
> --- a/tools/testing/selftests/tc-testing/config
> +++ b/tools/testing/selftests/tc-testing/config
> @@ -38,6 +38,7 @@ CONFIG_NET_ACT_CSUM=m
>  CONFIG_NET_ACT_VLAN=m
>  CONFIG_NET_ACT_BPF=m
>  CONFIG_NET_ACT_CONNMARK=m
> +CONFIG_NET_ACT_CTINFO=m
>  CONFIG_NET_ACT_SKBMOD=m
>  CONFIG_NET_ACT_IFE=m
>  CONFIG_NET_ACT_TUNNEL_KEY=m
> -- 
> 2.20.1 (Apple Git-117)