[Intel-wired-lan] [PATCH 1/6] [net-next]net: sched: act_mirred: Extend redirect action to accept a traffic class

[Nambiar, Amritha]

On 8/1/2017 4:12 AM, Jiri Pirko wrote:
> Tue, Aug 01, 2017 at 02:37:37AM CEST, amritha.nambiar at intel.com wrote:
>> The Mirred/redirect action is extended to forward to a traffic
>> class on the device. The traffic class index needs to be
>> provided in addition to the device's ifindex.
>>
>> Example:
>> # tc filter add dev eth0 protocol ip parent ffff: prio 1 flower\
>>  dst_ip 192.168.1.1/32 ip_proto udp dst_port 22\
>>  skip_sw indev eth0 action mirred ingress redirect dev eth0 tc 1
> 
> You need to make sure that the current offloaders fill forbid to add
> this rule, not just silently ignore the tc value.

I will fix this in the next version, probably using the 'flags' field
I've defined.

> 
> 
>>
>> Signed-off-by: Amritha Nambiar <amritha.nambiar at intel.com>
>> ---
>> include/net/tc_act/tc_mirred.h        |    7 +++++++
>> include/uapi/linux/tc_act/tc_mirred.h |    5 +++++
>> net/sched/act_mirred.c                |   17 +++++++++++++++++
>> 3 files changed, 29 insertions(+)
>>
>> diff --git a/include/net/tc_act/tc_mirred.h b/include/net/tc_act/tc_mirred.h
>> index 604bc31..60058c4 100644
>> --- a/include/net/tc_act/tc_mirred.h
>> +++ b/include/net/tc_act/tc_mirred.h
>> @@ -9,6 +9,8 @@ struct tcf_mirred {
>> 	int			tcfm_eaction;
>> 	int			tcfm_ifindex;
>> 	bool			tcfm_mac_header_xmit;
>> +	u8			tcfm_tc;
>> +	u32			flags;
>> 	struct net_device __rcu	*tcfm_dev;
>> 	struct list_head	tcfm_list;
>> };
>> @@ -37,4 +39,9 @@ static inline int tcf_mirred_ifindex(const struct tc_action *a)
>> 	return to_mirred(a)->tcfm_ifindex;
>> }
>>
>> +static inline int tcf_mirred_tc(const struct tc_action *a)
>> +{
>> +	return to_mirred(a)->tcfm_tc;
>> +}
>> +
>> #endif /* __NET_TC_MIR_H */
>> diff --git a/include/uapi/linux/tc_act/tc_mirred.h b/include/uapi/linux/tc_act/tc_mirred.h
>> index 3d7a2b3..8ff4d76 100644
>> --- a/include/uapi/linux/tc_act/tc_mirred.h
>> +++ b/include/uapi/linux/tc_act/tc_mirred.h
>> @@ -9,6 +9,10 @@
>> #define TCA_EGRESS_MIRROR 2 /* mirror packet to EGRESS */
>> #define TCA_INGRESS_REDIR 3  /* packet redirect to INGRESS*/
>> #define TCA_INGRESS_MIRROR 4 /* mirror packet to INGRESS */
>> +
>> +#define MIRRED_F_TC_MAP		0x1
>> +#define MIRRED_TC_MAP_MAX	0x10
>> +#define MIRRED_TC_MAP_MASK	0xF
> 
> I'm completely lost. Why do you have these values here? and in fact one
> twice?

I'll fix this to remove the defines for the TC max range and its bitmap
here and reuse the existing ones defined in linux/netdevice.h

> 
> 
>>                                                                                 
>> struct tc_mirred {
>> 	tc_gen;
>> @@ -21,6 +25,7 @@ enum {
>> 	TCA_MIRRED_TM,
>> 	TCA_MIRRED_PARMS,
>> 	TCA_MIRRED_PAD,
>> +	TCA_MIRRED_TC_MAP,
>> 	__TCA_MIRRED_MAX
>> };
>> #define TCA_MIRRED_MAX (__TCA_MIRRED_MAX - 1)
>> diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
>> index 1b5549a..f9801de 100644
>> --- a/net/sched/act_mirred.c
>> +++ b/net/sched/act_mirred.c
>> @@ -67,6 +67,7 @@ static void tcf_mirred_release(struct tc_action *a, int bind)
>>
>> static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
>> 	[TCA_MIRRED_PARMS]	= { .len = sizeof(struct tc_mirred) },
>> +	[TCA_MIRRED_TC_MAP]	= { .type = NLA_U8 },
>> };
>>
>> static unsigned int mirred_net_id;
>> @@ -83,6 +84,8 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla,
>> 	struct tcf_mirred *m;
>> 	struct net_device *dev;
>> 	bool exists = false;
>> +	u8 *tc_map = NULL;
>> +	u32 flags = 0;
>> 	int ret;
>>
>> 	if (nla == NULL)
>> @@ -92,6 +95,14 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla,
>> 		return ret;
>> 	if (tb[TCA_MIRRED_PARMS] == NULL)
>> 		return -EINVAL;
>> +
>> +	if (tb[TCA_MIRRED_TC_MAP]) {
>> +		tc_map = nla_data(tb[TCA_MIRRED_TC_MAP]);
>> +		if (*tc_map >= MIRRED_TC_MAP_MAX)
>> +			return -EINVAL;
>> +		flags |= MIRRED_F_TC_MAP;
>> +	}
>> +
>> 	parm = nla_data(tb[TCA_MIRRED_PARMS]);
>>
>> 	exists = tcf_hash_check(tn, parm->index, a, bind);
>> @@ -139,6 +150,7 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla,
>> 	ASSERT_RTNL();
>> 	m->tcf_action = parm->action;
>> 	m->tcfm_eaction = parm->eaction;
>> +	m->flags = flags;
>> 	if (dev != NULL) {
>> 		m->tcfm_ifindex = parm->ifindex;
>> 		if (ret != ACT_P_CREATED)
>> @@ -146,6 +158,8 @@ static int tcf_mirred_init(struct net *net, struct nlattr *nla,
>> 		dev_hold(dev);
>> 		rcu_assign_pointer(m->tcfm_dev, dev);
>> 		m->tcfm_mac_header_xmit = mac_header_xmit;
>> +		if (flags & MIRRED_F_TC_MAP)
>> +			m->tcfm_tc = *tc_map & MIRRED_TC_MAP_MASK;
>> 	}
>>
>> 	if (ret == ACT_P_CREATED) {
>> @@ -259,6 +273,9 @@ static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
>>
>> 	if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
>> 		goto nla_put_failure;
>> +	if ((m->flags & MIRRED_F_TC_MAP) &&
>> +	    nla_put_u8(skb, TCA_MIRRED_TC_MAP, m->tcfm_tc))
>> +		goto nla_put_failure;
>>
>> 	tcf_tm_dump(&t, &m->tcf_tm);
>> 	if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
>>