[PATCH net-next] net:sched: add action inheritdsfield to skbmod

[PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Fu, Qiaobin]

net/sched: add action inheritdsfield to skbmod

The new action inheritdsfield copies the field DS of
IPv4 and IPv6 packets into skb->prioriry. This enables
later classification of packets based on the DS field.

Original idea by Jamal Hadi Salim <jhs@mojatatu.com>

Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
Reviewed-by: Michel Machado <michel@digirati.com.br>
---

Note that the motivation for this patch is found in the following discussion:
https://www.spinics.net/lists/netdev/msg501061.html
---

diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
index 38c072f..0718b48 100644
--- a/include/uapi/linux/tc_act/tc_skbmod.h
+++ b/include/uapi/linux/tc_act/tc_skbmod.h
@@ -19,6 +19,7 @@
 #define SKBMOD_F_SMAC	0x2
 #define SKBMOD_F_ETYPE	0x4
 #define SKBMOD_F_SWAPMAC 0x8
+#define SKBMOD_F_INHERITDSFIELD 0x10
 
 struct tc_skbmod {
 	tc_gen;
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index ad050d7..21d5bec 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -16,6 +16,9 @@
 #include <linux/rtnetlink.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/dsfield.h>
 
 #include <linux/tc_act/tc_skbmod.h>
 #include <net/tc_act/tc_skbmod.h>
@@ -72,6 +75,25 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
 		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
 	}
 
+	if (flags & SKBMOD_F_INHERITDSFIELD) {
+		int wlen = skb_network_offset(skb);
+		switch (tc_skb_protocol(skb)) {
+		case htons(ETH_P_IP):
+			wlen += sizeof(struct iphdr);
+			if (!pskb_may_pull(skb, wlen))
+				return TC_ACT_SHOT;
+			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
+			break;
+
+		case htons(ETH_P_IPV6):
+			wlen += sizeof(struct ipv6hdr);
+			if (!pskb_may_pull(skb, wlen))
+				return TC_ACT_SHOT;
+			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
+			break;
+		}
+	}
+
 	return action;
 }
 
@@ -127,6 +149,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 	if (parm->flags & SKBMOD_F_SWAPMAC)
 		lflags = SKBMOD_F_SWAPMAC;
 
+	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
+		lflags |= SKBMOD_F_INHERITDSFIELD;
+
 	exists = tcf_idr_check(tn, parm->index, a, bind);
 	if (exists && bind)
 		return 0;

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Jamal Hadi Salim]

On 17/05/18 03:33 PM, Fu, Qiaobin wrote:
> net/sched: add action inheritdsfield to skbmod
> 
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->prioriry. This enables
> later classification of packets based on the DS field.
> 
> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
> 
> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> Reviewed-by: Michel Machado <michel@digirati.com.br>

LGTM. Thanks for putting the effort.
As a tradition we also require that you post the iproute2
patch and make sure this works. Can you please do that?
Also: If you can add at least a test on tdc it would help
immensely. Other than that:

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>

cheers,
jamal

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Jamal Hadi Salim]

On 21/05/18 10:42 AM, Fu, Qiaobin wrote:
> Hi Jamal,
> 
> I've tested my patch before publishing it here, and Nishanth is going to test it further with version 2 of the GKprio. I'm going to push a patch to the repository iproute2 to add support for "inheritdsfield”.
> 

Thanks. I already acked the kernel patch. It looks good on its own.

Would you consider adding one or more tdc tests as well?

cheers,
jamal

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Marcelo Ricardo Leitner]

Hi,

Some style fixes:

On Thu, May 17, 2018 at 07:33:08PM +0000, Fu, Qiaobin wrote:
> net/sched: add action inheritdsfield to skbmod

This extra line above should not be here.

> 
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->prioriry. This enables
                              typo -----^

> later classification of packets based on the DS field.
> 
> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
> 
> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> Reviewed-by: Michel Machado <michel@digirati.com.br>
> ---
> 
> Note that the motivation for this patch is found in the following discussion:
> https://www.spinics.net/lists/netdev/msg501061.html
> ---
> 
> diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
> index 38c072f..0718b48 100644
> --- a/include/uapi/linux/tc_act/tc_skbmod.h
> +++ b/include/uapi/linux/tc_act/tc_skbmod.h
> @@ -19,6 +19,7 @@
>  #define SKBMOD_F_SMAC	0x2
>  #define SKBMOD_F_ETYPE	0x4
>  #define SKBMOD_F_SWAPMAC 0x8
> +#define SKBMOD_F_INHERITDSFIELD 0x10
>  
>  struct tc_skbmod {
>  	tc_gen;
> diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
> index ad050d7..21d5bec 100644
> --- a/net/sched/act_skbmod.c
> +++ b/net/sched/act_skbmod.c
> @@ -16,6 +16,9 @@
>  #include <linux/rtnetlink.h>
>  #include <net/netlink.h>
>  #include <net/pkt_sched.h>
> +#include <net/ip.h>
> +#include <net/ipv6.h>
> +#include <net/dsfield.h>
>  
>  #include <linux/tc_act/tc_skbmod.h>
>  #include <net/tc_act/tc_skbmod.h>
> @@ -72,6 +75,25 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
>  		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
>  	}
>  
> +	if (flags & SKBMOD_F_INHERITDSFIELD) {
> +		int wlen = skb_network_offset(skb);

You need a blank line here, between var declaration and the rest.

> +		switch (tc_skb_protocol(skb)) {
> +		case htons(ETH_P_IP):
> +			wlen += sizeof(struct iphdr);
> +			if (!pskb_may_pull(skb, wlen))
> +				return TC_ACT_SHOT;
> +			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
> +			break;
> +
> +		case htons(ETH_P_IPV6):
> +			wlen += sizeof(struct ipv6hdr);
> +			if (!pskb_may_pull(skb, wlen))
> +				return TC_ACT_SHOT;
> +			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
> +			break;
> +		}
> +	}
> +
>  	return action;
>  }
>  
> @@ -127,6 +149,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
>  	if (parm->flags & SKBMOD_F_SWAPMAC)
>  		lflags = SKBMOD_F_SWAPMAC;
>  
> +	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
> +		lflags |= SKBMOD_F_INHERITDSFIELD;
> +
>  	exists = tcf_idr_check(tn, parm->index, a, bind);
>  	if (exists && bind)
>  		return 0;

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Cong Wang]

On Thu, May 17, 2018 at 12:33 PM, Fu, Qiaobin <qiaobinf@bu.edu> wrote:
> net/sched: add action inheritdsfield to skbmod
>
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->prioriry. This enables
> later classification of packets based on the DS field.
>
> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
>
> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> Reviewed-by: Michel Machado <michel@digirati.com.br>

Hmm, but skbedit seems better than skbmod for this job,
given:

1) It already modifies skb->priority, although with a given value

2) skbmod doesn't change skb metadata, it only changes payload

I am _not_ saying there is strict rule for what skbmod can or can't
change, it calls itself "data modifier", so I am saying we probably
need to follow this existing practice.

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Jamal Hadi Salim]

On 23/05/18 07:01 PM, Cong Wang wrote:
> On Thu, May 17, 2018 at 12:33 PM, Fu, Qiaobin <qiaobinf@bu.edu> wrote:

> Hmm, but skbedit seems better than skbmod for this job,
> given:
> 
> 1) It already modifies skb->priority, although with a given value
> 
> 2) skbmod doesn't change skb metadata, it only changes payload
> 
> I am _not_ saying there is strict rule for what skbmod can or can't
> change, it calls itself "data modifier", so I am saying we probably
> need to follow this existing practice.
> 

I am indifferent - you can move it to skbedit.
Note: I have patches which i will send out at some point when
I get the chance on pedit for implementing the concept of
"copy data to metadata" and  "copy metadata to data"
for pedit it made a lot of sense to add the feature there.
In this case skbedit makes more sense.

cheers,
jamal

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Fu, Qiaobin]

Hi Marcelo,

Thanks for pointing out these style issues. Below is the updated version:

---
The new action inheritdsfield copies the field DS of
IPv4 and IPv6 packets into skb->priority. This enables
later classification of packets based on the DS field.

Original idea by Jamal Hadi Salim <jhs@mojatatu.com>

Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
Reviewed-by: Michel Machado <michel@digirati.com.br>
---

Note that the motivation for this patch is found in the following discussion:
https://www.spinics.net/lists/netdev/msg501061.html
---

diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
index 38c072f..0718b48 100644
--- a/include/uapi/linux/tc_act/tc_skbmod.h
+++ b/include/uapi/linux/tc_act/tc_skbmod.h
@@ -19,6 +19,7 @@
 #define SKBMOD_F_SMAC	0x2
 #define SKBMOD_F_ETYPE	0x4
 #define SKBMOD_F_SWAPMAC 0x8
+#define SKBMOD_F_INHERITDSFIELD 0x10
 
 struct tc_skbmod {
 	tc_gen;
diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
index ad050d7..e2082f6 100644
--- a/net/sched/act_skbmod.c
+++ b/net/sched/act_skbmod.c
@@ -16,6 +16,9 @@
 #include <linux/rtnetlink.h>
 #include <net/netlink.h>
 #include <net/pkt_sched.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/dsfield.h>
 
 #include <linux/tc_act/tc_skbmod.h>
 #include <net/tc_act/tc_skbmod.h>
@@ -72,6 +75,26 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
 		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
 	}
 
+	if (flags & SKBMOD_F_INHERITDSFIELD) {
+		int wlen = skb_network_offset(skb);
+
+		switch (tc_skb_protocol(skb)) {
+		case htons(ETH_P_IP):
+			wlen += sizeof(struct iphdr);
+			if (!pskb_may_pull(skb, wlen))
+				return TC_ACT_SHOT;
+			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
+			break;
+
+		case htons(ETH_P_IPV6):
+			wlen += sizeof(struct ipv6hdr);
+			if (!pskb_may_pull(skb, wlen))
+				return TC_ACT_SHOT;
+			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
+			break;
+		}
+	}
+
 	return action;
 }
 
@@ -127,6 +150,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 	if (parm->flags & SKBMOD_F_SWAPMAC)
 		lflags = SKBMOD_F_SWAPMAC;
 
+	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
+		lflags |= SKBMOD_F_INHERITDSFIELD;
+
 	exists = tcf_idr_check(tn, parm->index, a, bind);
 	if (exists && bind)
 		return 0;

> On May 23, 2018, at 2:06 PM, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> wrote:
> 
> Hi,
> 
> Some style fixes:
> 
> On Thu, May 17, 2018 at 07:33:08PM +0000, Fu, Qiaobin wrote:
>> net/sched: add action inheritdsfield to skbmod
> 
> This extra line above should not be here.
> 
>> 
>> The new action inheritdsfield copies the field DS of
>> IPv4 and IPv6 packets into skb->prioriry. This enables
>                              typo -----^
> 
>> later classification of packets based on the DS field.
>> 
>> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
>> 
>> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
>> Reviewed-by: Michel Machado <michel@digirati.com.br>
>> ---
>> 
>> Note that the motivation for this patch is found in the following discussion:
>> https://www.spinics.net/lists/netdev/msg501061.html
>> ---
>> 
>> diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
>> index 38c072f..0718b48 100644
>> --- a/include/uapi/linux/tc_act/tc_skbmod.h
>> +++ b/include/uapi/linux/tc_act/tc_skbmod.h
>> @@ -19,6 +19,7 @@
>> #define SKBMOD_F_SMAC	0x2
>> #define SKBMOD_F_ETYPE	0x4
>> #define SKBMOD_F_SWAPMAC 0x8
>> +#define SKBMOD_F_INHERITDSFIELD 0x10
>> 
>> struct tc_skbmod {
>> 	tc_gen;
>> diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
>> index ad050d7..21d5bec 100644
>> --- a/net/sched/act_skbmod.c
>> +++ b/net/sched/act_skbmod.c
>> @@ -16,6 +16,9 @@
>> #include <linux/rtnetlink.h>
>> #include <net/netlink.h>
>> #include <net/pkt_sched.h>
>> +#include <net/ip.h>
>> +#include <net/ipv6.h>
>> +#include <net/dsfield.h>
>> 
>> #include <linux/tc_act/tc_skbmod.h>
>> #include <net/tc_act/tc_skbmod.h>
>> @@ -72,6 +75,25 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
>> 		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
>> 	}
>> 
>> +	if (flags & SKBMOD_F_INHERITDSFIELD) {
>> +		int wlen = skb_network_offset(skb);
> 
> You need a blank line here, between var declaration and the rest.
> 
>> +		switch (tc_skb_protocol(skb)) {
>> +		case htons(ETH_P_IP):
>> +			wlen += sizeof(struct iphdr);
>> +			if (!pskb_may_pull(skb, wlen))
>> +				return TC_ACT_SHOT;
>> +			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
>> +			break;
>> +
>> +		case htons(ETH_P_IPV6):
>> +			wlen += sizeof(struct ipv6hdr);
>> +			if (!pskb_may_pull(skb, wlen))
>> +				return TC_ACT_SHOT;
>> +			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
>> +			break;
>> +		}
>> +	}
>> +
>> 	return action;
>> }
>> 
>> @@ -127,6 +149,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
>> 	if (parm->flags & SKBMOD_F_SWAPMAC)
>> 		lflags = SKBMOD_F_SWAPMAC;
>> 
>> +	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
>> +		lflags |= SKBMOD_F_INHERITDSFIELD;
>> +
>> 	exists = tcf_idr_check(tn, parm->index, a, bind);
>> 	if (exists && bind)
>> 		return 0;

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Marcelo Ricardo Leitner]

On Fri, May 25, 2018 at 05:45:03AM +0000, Fu, Qiaobin wrote:
> Hi Marcelo,
> 
> Thanks for pointing out these style issues. Below is the updated version:

Hi Qiaobin,

Looks good to me. Now you have to submit it like you submitted the
original patch, but add the version tag to the summary. Like '[PATCH
v2 net-next] ....'
And without the text before the changelog.

Thanks.

> 
> ---
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->priority. This enables
> later classification of packets based on the DS field.
> 
> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
> 
> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> Reviewed-by: Michel Machado <michel@digirati.com.br>
> ---
> 
> Note that the motivation for this patch is found in the following discussion:
> https://www.spinics.net/lists/netdev/msg501061.html
> ---
> 
> diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
> index 38c072f..0718b48 100644
> --- a/include/uapi/linux/tc_act/tc_skbmod.h
> +++ b/include/uapi/linux/tc_act/tc_skbmod.h
> @@ -19,6 +19,7 @@
>  #define SKBMOD_F_SMAC	0x2
>  #define SKBMOD_F_ETYPE	0x4
>  #define SKBMOD_F_SWAPMAC 0x8
> +#define SKBMOD_F_INHERITDSFIELD 0x10
>  
>  struct tc_skbmod {
>  	tc_gen;
> diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
> index ad050d7..e2082f6 100644
> --- a/net/sched/act_skbmod.c
> +++ b/net/sched/act_skbmod.c
> @@ -16,6 +16,9 @@
>  #include <linux/rtnetlink.h>
>  #include <net/netlink.h>
>  #include <net/pkt_sched.h>
> +#include <net/ip.h>
> +#include <net/ipv6.h>
> +#include <net/dsfield.h>
>  
>  #include <linux/tc_act/tc_skbmod.h>
>  #include <net/tc_act/tc_skbmod.h>
> @@ -72,6 +75,26 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
>  		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
>  	}
>  
> +	if (flags & SKBMOD_F_INHERITDSFIELD) {
> +		int wlen = skb_network_offset(skb);
> +
> +		switch (tc_skb_protocol(skb)) {
> +		case htons(ETH_P_IP):
> +			wlen += sizeof(struct iphdr);
> +			if (!pskb_may_pull(skb, wlen))
> +				return TC_ACT_SHOT;
> +			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
> +			break;
> +
> +		case htons(ETH_P_IPV6):
> +			wlen += sizeof(struct ipv6hdr);
> +			if (!pskb_may_pull(skb, wlen))
> +				return TC_ACT_SHOT;
> +			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
> +			break;
> +		}
> +	}
> +
>  	return action;
>  }
>  
> @@ -127,6 +150,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
>  	if (parm->flags & SKBMOD_F_SWAPMAC)
>  		lflags = SKBMOD_F_SWAPMAC;
>  
> +	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
> +		lflags |= SKBMOD_F_INHERITDSFIELD;
> +
>  	exists = tcf_idr_check(tn, parm->index, a, bind);
>  	if (exists && bind)
>  		return 0;
> 
> > On May 23, 2018, at 2:06 PM, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> wrote:
> > 
> > Hi,
> > 
> > Some style fixes:
> > 
> > On Thu, May 17, 2018 at 07:33:08PM +0000, Fu, Qiaobin wrote:
> >> net/sched: add action inheritdsfield to skbmod
> > 
> > This extra line above should not be here.
> > 
> >> 
> >> The new action inheritdsfield copies the field DS of
> >> IPv4 and IPv6 packets into skb->prioriry. This enables
> >                              typo -----^
> > 
> >> later classification of packets based on the DS field.
> >> 
> >> Original idea by Jamal Hadi Salim <jhs@mojatatu.com>
> >> 
> >> Signed-off-by: Qiaobin Fu <qiaobinf@bu.edu>
> >> Reviewed-by: Michel Machado <michel@digirati.com.br>
> >> ---
> >> 
> >> Note that the motivation for this patch is found in the following discussion:
> >> https://www.spinics.net/lists/netdev/msg501061.html
> >> ---
> >> 
> >> diff --git a/include/uapi/linux/tc_act/tc_skbmod.h b/include/uapi/linux/tc_act/tc_skbmod.h
> >> index 38c072f..0718b48 100644
> >> --- a/include/uapi/linux/tc_act/tc_skbmod.h
> >> +++ b/include/uapi/linux/tc_act/tc_skbmod.h
> >> @@ -19,6 +19,7 @@
> >> #define SKBMOD_F_SMAC	0x2
> >> #define SKBMOD_F_ETYPE	0x4
> >> #define SKBMOD_F_SWAPMAC 0x8
> >> +#define SKBMOD_F_INHERITDSFIELD 0x10
> >> 
> >> struct tc_skbmod {
> >> 	tc_gen;
> >> diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c
> >> index ad050d7..21d5bec 100644
> >> --- a/net/sched/act_skbmod.c
> >> +++ b/net/sched/act_skbmod.c
> >> @@ -16,6 +16,9 @@
> >> #include <linux/rtnetlink.h>
> >> #include <net/netlink.h>
> >> #include <net/pkt_sched.h>
> >> +#include <net/ip.h>
> >> +#include <net/ipv6.h>
> >> +#include <net/dsfield.h>
> >> 
> >> #include <linux/tc_act/tc_skbmod.h>
> >> #include <net/tc_act/tc_skbmod.h>
> >> @@ -72,6 +75,25 @@ static int tcf_skbmod_run(struct sk_buff *skb, const struct tc_action *a,
> >> 		ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
> >> 	}
> >> 
> >> +	if (flags & SKBMOD_F_INHERITDSFIELD) {
> >> +		int wlen = skb_network_offset(skb);
> > 
> > You need a blank line here, between var declaration and the rest.
> > 
> >> +		switch (tc_skb_protocol(skb)) {
> >> +		case htons(ETH_P_IP):
> >> +			wlen += sizeof(struct iphdr);
> >> +			if (!pskb_may_pull(skb, wlen))
> >> +				return TC_ACT_SHOT;
> >> +			skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
> >> +			break;
> >> +
> >> +		case htons(ETH_P_IPV6):
> >> +			wlen += sizeof(struct ipv6hdr);
> >> +			if (!pskb_may_pull(skb, wlen))
> >> +				return TC_ACT_SHOT;
> >> +			skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
> >> +			break;
> >> +		}
> >> +	}
> >> +
> >> 	return action;
> >> }
> >> 
> >> @@ -127,6 +149,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
> >> 	if (parm->flags & SKBMOD_F_SWAPMAC)
> >> 		lflags = SKBMOD_F_SWAPMAC;
> >> 
> >> +	if (parm->flags & SKBMOD_F_INHERITDSFIELD)
> >> +		lflags |= SKBMOD_F_INHERITDSFIELD;
> >> +
> >> 	exists = tcf_idr_check(tn, parm->index, a, bind);
> >> 	if (exists && bind)
> >> 		return 0;
> 

Re: [PATCH net-next] net:sched: add action inheritdsfield to skbmod

[Cong Wang]

On Thu, May 24, 2018 at 10:45 PM, Fu, Qiaobin <qiaobinf@bu.edu> wrote:
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->priority. This enables
> later classification of packets based on the DS field.

Please move it to skbedit.