[patch net-next v2 1/4] openvswitch: actions: use skb_postpull_rcsum when possible

[patch net-next v2 1/4] openvswitch: actions: use skb_postpull_rcsum when possible

[Jiri Pirko]

Replace duplicated code by calling skb_postpull_rcsum

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 net/openvswitch/actions.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 394efa6..749a301 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -175,10 +175,7 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 	if (unlikely(err))
 		return err;
 
-	if (skb->ip_summed == CHECKSUM_COMPLETE)
-		skb->csum = csum_sub(skb->csum,
-				     csum_partial(skb_mpls_header(skb),
-						  MPLS_HLEN, 0));
+	skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);
 
 	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
 		skb->mac_len);
@@ -230,9 +227,7 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
 	if (unlikely(err))
 		return err;
 
-	if (skb->ip_summed == CHECKSUM_COMPLETE)
-		skb->csum = csum_sub(skb->csum, csum_partial(skb->data
-					+ (2 * ETH_ALEN), VLAN_HLEN, 0));
+	skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
 
 	vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
 	*current_tci = vhdr->h_vlan_TCI;
-- 
1.9.3

[patch net-next v2 2/4] net: move make_writable helper into common code

[Jiri Pirko]

note that skb_make_writable already exists in net/netfilter/core.c
but does something slightly different.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---
 include/linux/skbuff.h    |  1 +
 net/core/skbuff.c         | 12 ++++++++++++
 net/openvswitch/actions.c | 39 ++++++++++++++-------------------------
 3 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 73c370e..e045516 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2678,6 +2678,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet);
 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
+int skb_ensure_writable(struct sk_buff *skb, int write_len);
 
 struct skb_checksum_ops {
 	__wsum (*update)(const void *mem, int len, __wsum wsum);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 7001896..d11bbe0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4151,6 +4151,18 @@ err_free:
 }
 EXPORT_SYMBOL(skb_vlan_untag);
 
+int skb_ensure_writable(struct sk_buff *skb, int write_len)
+{
+	if (!pskb_may_pull(skb, write_len))
+		return -ENOMEM;
+
+	if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
+		return 0;
+
+	return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
+}
+EXPORT_SYMBOL(skb_ensure_writable);
+
 /**
  * alloc_skb_with_frags - allocate skb with page frags
  *
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 749a301..04c9680 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -119,17 +119,6 @@ static bool is_flow_key_valid(const struct sw_flow_key *key)
 	return !!key->eth.type;
 }
 
-static int make_writable(struct sk_buff *skb, int write_len)
-{
-	if (!pskb_may_pull(skb, write_len))
-		return -ENOMEM;
-
-	if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
-		return 0;
-
-	return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
-}
-
 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 		     const struct ovs_action_push_mpls *mpls)
 {
@@ -171,7 +160,7 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 	struct ethhdr *hdr;
 	int err;
 
-	err = make_writable(skb, skb->mac_len + MPLS_HLEN);
+	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 	if (unlikely(err))
 		return err;
 
@@ -201,7 +190,7 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 	__be32 *stack;
 	int err;
 
-	err = make_writable(skb, skb->mac_len + MPLS_HLEN);
+	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
 	if (unlikely(err))
 		return err;
 
@@ -223,7 +212,7 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
 	struct vlan_hdr *vhdr;
 	int err;
 
-	err = make_writable(skb, VLAN_ETH_HLEN);
+	err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
 	if (unlikely(err))
 		return err;
 
@@ -308,7 +297,7 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
 			const struct ovs_key_ethernet *eth_key)
 {
 	int err;
-	err = make_writable(skb, ETH_HLEN);
+	err = skb_ensure_writable(skb, ETH_HLEN);
 	if (unlikely(err))
 		return err;
 
@@ -410,8 +399,8 @@ static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key,
 	struct iphdr *nh;
 	int err;
 
-	err = make_writable(skb, skb_network_offset(skb) +
-				 sizeof(struct iphdr));
+	err = skb_ensure_writable(skb, skb_network_offset(skb) +
+				  sizeof(struct iphdr));
 	if (unlikely(err))
 		return err;
 
@@ -448,8 +437,8 @@ static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
 	__be32 *saddr;
 	__be32 *daddr;
 
-	err = make_writable(skb, skb_network_offset(skb) +
-			    sizeof(struct ipv6hdr));
+	err = skb_ensure_writable(skb, skb_network_offset(skb) +
+				  sizeof(struct ipv6hdr));
 	if (unlikely(err))
 		return err;
 
@@ -491,7 +480,7 @@ static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
 	return 0;
 }
 
-/* Must follow make_writable() since that can move the skb data. */
+/* Must follow skb_ensure_writable() since that can move the skb data. */
 static void set_tp_port(struct sk_buff *skb, __be16 *port,
 			 __be16 new_port, __sum16 *check)
 {
@@ -521,8 +510,8 @@ static int set_udp(struct sk_buff *skb, struct sw_flow_key *key,
 	struct udphdr *uh;
 	int err;
 
-	err = make_writable(skb, skb_transport_offset(skb) +
-				 sizeof(struct udphdr));
+	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
+				  sizeof(struct udphdr));
 	if (unlikely(err))
 		return err;
 
@@ -546,8 +535,8 @@ static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key,
 	struct tcphdr *th;
 	int err;
 
-	err = make_writable(skb, skb_transport_offset(skb) +
-				 sizeof(struct tcphdr));
+	err = skb_ensure_writable(skb, skb_transport_offset(skb) +
+				  sizeof(struct tcphdr));
 	if (unlikely(err))
 		return err;
 
@@ -572,7 +561,7 @@ static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key,
 	int err;
 	unsigned int sctphoff = skb_transport_offset(skb);
 
-	err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
+	err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
 	if (unlikely(err))
 		return err;
 
-- 
1.9.3

[patch net-next v2 3/4] net: move vlan pop/push functions into common code

[Jiri Pirko]

So it can be used from out of openvswitch code.
Did couple of cosmetic changes on the way, namely variable naming and
adding support for 8021AD proto.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
---

v1->v2:
- adjusted to fix recent ovs changes
- included change to use make_writable suggested by Eric

 include/linux/skbuff.h    |  2 ++
 net/core/skbuff.c         | 78 +++++++++++++++++++++++++++++++++++++++++++++
 net/openvswitch/actions.c | 81 +++++------------------------------------------
 3 files changed, 88 insertions(+), 73 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index e045516..78c299f 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2679,6 +2679,8 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
 int skb_ensure_writable(struct sk_buff *skb, int write_len);
+int skb_vlan_pop(struct sk_buff *skb);
+int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
 
 struct skb_checksum_ops {
 	__wsum (*update)(const void *mem, int len, __wsum wsum);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d11bbe0..c7d3000 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4163,6 +4163,84 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len)
 }
 EXPORT_SYMBOL(skb_ensure_writable);
 
+/* remove VLAN header from packet and update csum accordingly. */
+static int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci)
+{
+	struct vlan_hdr *vhdr;
+	int err;
+
+	err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
+	if (unlikely(err))
+		return err;
+
+	skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
+
+	vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
+	*vlan_tci = ntohs(vhdr->h_vlan_TCI);
+
+	memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
+	__skb_pull(skb, VLAN_HLEN);
+
+	vlan_set_encap_proto(skb, vhdr);
+	skb->mac_header += VLAN_HLEN;
+	if (skb_network_offset(skb) < ETH_HLEN)
+		skb_set_network_header(skb, ETH_HLEN);
+	skb_reset_mac_len(skb);
+
+	return 0;
+}
+
+int skb_vlan_pop(struct sk_buff *skb)
+{
+	u16 vlan_tci;
+	__be16 vlan_proto;
+	int err;
+
+	if (likely(vlan_tx_tag_present(skb))) {
+		skb->vlan_tci = 0;
+	} else {
+		if (unlikely((skb->protocol != htons(ETH_P_8021Q) &&
+			      skb->protocol != htons(ETH_P_8021AD)) ||
+			     skb->len < VLAN_ETH_HLEN))
+			return 0;
+
+		err = __skb_vlan_pop(skb, &vlan_tci);
+		if (err)
+			return err;
+	}
+	/* move next vlan tag to hw accel tag */
+	if (likely((skb->protocol != htons(ETH_P_8021Q) &&
+		    skb->protocol != htons(ETH_P_8021AD)) ||
+		   skb->len < VLAN_ETH_HLEN))
+		return 0;
+
+	vlan_proto = skb->protocol;
+	err = __skb_vlan_pop(skb, &vlan_tci);
+	if (unlikely(err))
+		return err;
+
+	__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
+	return 0;
+}
+EXPORT_SYMBOL(skb_vlan_pop);
+
+int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
+{
+	if (vlan_tx_tag_present(skb)) {
+		/* push down current VLAN tag */
+		if (!__vlan_put_tag(skb, skb->vlan_proto,
+				    vlan_tx_tag_get(skb)))
+			return -ENOMEM;
+
+		if (skb->ip_summed == CHECKSUM_COMPLETE)
+			skb->csum = csum_add(skb->csum, csum_partial(skb->data
+					+ (2 * ETH_ALEN), VLAN_HLEN, 0));
+	}
+	__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
+	return 0;
+}
+EXPORT_SYMBOL(skb_vlan_push);
+
 /**
  * alloc_skb_with_frags - allocate skb with page frags
  *
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 04c9680..e1a5182 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -206,91 +206,26 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
 	return 0;
 }
 
-/* remove VLAN header from packet and update csum accordingly. */
-static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
-{
-	struct vlan_hdr *vhdr;
-	int err;
-
-	err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
-	if (unlikely(err))
-		return err;
-
-	skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
-
-	vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
-	*current_tci = vhdr->h_vlan_TCI;
-
-	memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
-	__skb_pull(skb, VLAN_HLEN);
-
-	vlan_set_encap_proto(skb, vhdr);
-	skb->mac_header += VLAN_HLEN;
-
-	if (skb_network_offset(skb) < ETH_HLEN)
-		skb_set_network_header(skb, ETH_HLEN);
-
-	/* Update mac_len for subsequent MPLS actions */
-	skb_reset_mac_len(skb);
-	return 0;
-}
-
 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
 {
-	__be16 tci;
 	int err;
 
-	if (likely(vlan_tx_tag_present(skb))) {
-		skb->vlan_tci = 0;
-	} else {
-		if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
-			     skb->len < VLAN_ETH_HLEN))
-			return 0;
-
-		err = __pop_vlan_tci(skb, &tci);
-		if (err)
-			return err;
-	}
-	/* move next vlan tag to hw accel tag */
-	if (likely(skb->protocol != htons(ETH_P_8021Q) ||
-		   skb->len < VLAN_ETH_HLEN)) {
+	err = skb_vlan_pop(skb);
+	if (vlan_tx_tag_present(skb))
+		invalidate_flow_key(key);
+	else
 		key->eth.tci = 0;
-		return 0;
-	}
-
-	invalidate_flow_key(key);
-	err = __pop_vlan_tci(skb, &tci);
-	if (unlikely(err))
-		return err;
-
-	__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
-	return 0;
+	return err;
 }
 
 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
 		     const struct ovs_action_push_vlan *vlan)
 {
-	if (unlikely(vlan_tx_tag_present(skb))) {
-		u16 current_tag;
-
-		/* push down current VLAN tag */
-		current_tag = vlan_tx_tag_get(skb);
-
-		if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
-			return -ENOMEM;
-		/* Update mac_len for subsequent MPLS actions */
-		skb->mac_len += VLAN_HLEN;
-
-		if (skb->ip_summed == CHECKSUM_COMPLETE)
-			skb->csum = csum_add(skb->csum, csum_partial(skb->data
-					+ (2 * ETH_ALEN), VLAN_HLEN, 0));
-
+	if (vlan_tx_tag_present(skb))
 		invalidate_flow_key(key);
-	} else {
+	else
 		key->eth.tci = vlan->vlan_tci;
-	}
-	__vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
-	return 0;
+	return skb_vlan_push(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
 }
 
 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
-- 
1.9.3

[patch net-next v2 4/4] sched: introduce vlan action

[Jiri Pirko]

This tc action allows to work with vlan tagged skbs. Two supported
sub-actions are header pop and header push.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---

v1->v2:
- fixed protocol dumping in tcf_vlan_dump

 include/net/tc_act/tc_vlan.h        |  27 +++++
 include/uapi/linux/tc_act/tc_vlan.h |  35 ++++++
 net/sched/Kconfig                   |  11 ++
 net/sched/Makefile                  |   1 +
 net/sched/act_vlan.c                | 207 ++++++++++++++++++++++++++++++++++++
 5 files changed, 281 insertions(+)
 create mode 100644 include/net/tc_act/tc_vlan.h
 create mode 100644 include/uapi/linux/tc_act/tc_vlan.h
 create mode 100644 net/sched/act_vlan.c

diff --git a/include/net/tc_act/tc_vlan.h b/include/net/tc_act/tc_vlan.h
new file mode 100644
index 0000000..c809c1d
--- /dev/null
+++ b/include/net/tc_act/tc_vlan.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __NET_TC_VLAN_H
+#define __NET_TC_VLAN_H
+
+#include <net/act_api.h>
+
+#define VLAN_F_POP		0x1
+#define VLAN_F_PUSH		0x2
+
+struct tcf_vlan {
+	struct tcf_common	common;
+	int			tcfv_action;
+	__be16			tcfv_push_vid;
+	__be16			tcfv_push_proto;
+};
+#define to_vlan(a) \
+	container_of(a->priv, struct tcf_vlan, common)
+
+#endif /* __NET_TC_VLAN_H */
diff --git a/include/uapi/linux/tc_act/tc_vlan.h b/include/uapi/linux/tc_act/tc_vlan.h
new file mode 100644
index 0000000..f7b8d44
--- /dev/null
+++ b/include/uapi/linux/tc_act/tc_vlan.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_TC_VLAN_H
+#define __LINUX_TC_VLAN_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_ACT_VLAN 12
+
+#define TCA_VLAN_ACT_POP	1
+#define TCA_VLAN_ACT_PUSH	2
+
+struct tc_vlan {
+	tc_gen;
+	int v_action;
+};
+
+enum {
+	TCA_VLAN_UNSPEC,
+	TCA_VLAN_TM,
+	TCA_VLAN_PARMS,
+	TCA_VLAN_PUSH_VLAN_ID,
+	TCA_VLAN_PUSH_VLAN_PROTOCOL,
+	__TCA_VLAN_MAX,
+};
+#define TCA_VLAN_MAX (__TCA_VLAN_MAX - 1)
+
+#endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index a1a8e29..88618f8 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -686,6 +686,17 @@ config NET_ACT_CSUM
 	  To compile this code as a module, choose M here: the
 	  module will be called act_csum.
 
+config NET_ACT_VLAN
+        tristate "Vlan manipulation"
+        depends on NET_CLS_ACT
+        ---help---
+	  Say Y here to push or pop vlan headers.
+
+	  If unsure, say N.
+
+	  To compile this code as a module, choose M here: the
+	  module will be called act_vlan.
+
 config NET_CLS_IND
 	bool "Incoming device classification"
 	depends on NET_CLS_U32 || NET_CLS_FW
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 0a869a1..679f24a 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_NET_ACT_PEDIT)	+= act_pedit.o
 obj-$(CONFIG_NET_ACT_SIMP)	+= act_simple.o
 obj-$(CONFIG_NET_ACT_SKBEDIT)	+= act_skbedit.o
 obj-$(CONFIG_NET_ACT_CSUM)	+= act_csum.o
+obj-$(CONFIG_NET_ACT_VLAN)	+= act_vlan.o
 obj-$(CONFIG_NET_SCH_FIFO)	+= sch_fifo.o
 obj-$(CONFIG_NET_SCH_CBQ)	+= sch_cbq.o
 obj-$(CONFIG_NET_SCH_HTB)	+= sch_htb.o
diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c
new file mode 100644
index 0000000..d735ecf
--- /dev/null
+++ b/net/sched/act_vlan.c
@@ -0,0 +1,207 @@
+/*
+ * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/if_vlan.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+
+#include <linux/tc_act/tc_vlan.h>
+#include <net/tc_act/tc_vlan.h>
+
+#define VLAN_TAB_MASK     15
+
+static int tcf_vlan(struct sk_buff *skb, const struct tc_action *a,
+		    struct tcf_result *res)
+{
+	struct tcf_vlan *v = a->priv;
+	int action;
+	int err;
+
+	spin_lock(&v->tcf_lock);
+	v->tcf_tm.lastuse = jiffies;
+	bstats_update(&v->tcf_bstats, skb);
+	action = v->tcf_action;
+
+	switch (v->tcfv_action) {
+	case TCA_VLAN_ACT_POP:
+		err = skb_vlan_pop(skb);
+		if (err)
+			goto drop;
+		break;
+	case TCA_VLAN_ACT_PUSH:
+		err = skb_vlan_push(skb, v->tcfv_push_proto, v->tcfv_push_vid);
+		if (err)
+			goto drop;
+		break;
+	default:
+		BUG();
+	}
+
+	goto unlock;
+
+drop:
+	action = TC_ACT_SHOT;
+	v->tcf_qstats.drops++;
+unlock:
+	spin_unlock(&v->tcf_lock);
+	return action;
+}
+
+static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
+	[TCA_VLAN_PARMS]		= { .len = sizeof(struct tc_vlan) },
+	[TCA_VLAN_PUSH_VLAN_ID]		= { .type = NLA_U16 },
+	[TCA_VLAN_PUSH_VLAN_PROTOCOL]	= { .type = NLA_U16 },
+};
+
+static int tcf_vlan_init(struct net *net, struct nlattr *nla,
+			 struct nlattr *est, struct tc_action *a,
+			 int ovr, int bind)
+{
+	struct nlattr *tb[TCA_VLAN_MAX + 1];
+	struct tc_vlan *parm;
+	struct tcf_vlan *v;
+	int action;
+	__be16 push_vid = 0;
+	__be16 push_proto = 0;
+	int ret = 0;
+	int err;
+
+	if (!nla)
+		return -EINVAL;
+
+	err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy);
+	if (err < 0)
+		return err;
+
+	if (!tb[TCA_VLAN_PARMS])
+		return -EINVAL;
+	parm = nla_data(tb[TCA_VLAN_PARMS]);
+	switch (parm->v_action) {
+	case TCA_VLAN_ACT_POP:
+		break;
+	case TCA_VLAN_ACT_PUSH:
+		if (!tb[TCA_VLAN_PUSH_VLAN_ID])
+			return -EINVAL;
+		push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
+		if (push_vid >= VLAN_VID_MASK)
+			return -ERANGE;
+
+		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
+			push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
+			switch (push_proto) {
+			case htons(ETH_P_8021Q):
+			case htons(ETH_P_8021AD):
+				break;
+			default:
+				return -EPROTONOSUPPORT;
+			}
+		} else {
+			push_proto = htons(ETH_P_8021Q);
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+	action = parm->v_action;
+
+	if (!tcf_hash_check(parm->index, a, bind)) {
+		ret = tcf_hash_create(parm->index, est, a, sizeof(*v), bind);
+		if (ret)
+			return ret;
+
+		ret = ACT_P_CREATED;
+	} else {
+		if (bind)
+			return 0;
+		tcf_hash_release(a, bind);
+		if (!ovr)
+			return -EEXIST;
+	}
+
+	v = to_vlan(a);
+
+	spin_lock_bh(&v->tcf_lock);
+
+	v->tcfv_action = action;
+	v->tcfv_push_vid = push_vid;
+	v->tcfv_push_proto = push_proto;
+
+	v->tcf_action = parm->action;
+
+	spin_unlock_bh(&v->tcf_lock);
+
+	if (ret == ACT_P_CREATED)
+		tcf_hash_insert(a);
+	return ret;
+}
+
+static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
+			 int bind, int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_vlan *v = a->priv;
+	struct tc_vlan opt = {
+		.index    = v->tcf_index,
+		.refcnt   = v->tcf_refcnt - ref,
+		.bindcnt  = v->tcf_bindcnt - bind,
+		.action   = v->tcf_action,
+		.v_action = v->tcfv_action,
+	};
+	struct tcf_t t;
+
+	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+
+	if (v->tcfv_action == TCA_VLAN_ACT_PUSH &&
+	    (nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, v->tcfv_push_vid) ||
+	     nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL, v->tcfv_push_proto)))
+		goto nla_put_failure;
+
+	t.install = jiffies_to_clock_t(jiffies - v->tcf_tm.install);
+	t.lastuse = jiffies_to_clock_t(jiffies - v->tcf_tm.lastuse);
+	t.expires = jiffies_to_clock_t(v->tcf_tm.expires);
+	if (nla_put(skb, TCA_VLAN_TM, sizeof(t), &t))
+		goto nla_put_failure;
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static struct tc_action_ops act_vlan_ops = {
+	.kind		=	"vlan",
+	.type		=	TCA_ACT_VLAN,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_vlan,
+	.dump		=	tcf_vlan_dump,
+	.init		=	tcf_vlan_init,
+};
+
+static int __init vlan_init_module(void)
+{
+	return tcf_register_action(&act_vlan_ops, VLAN_TAB_MASK);
+}
+
+static void __exit vlan_cleanup_module(void)
+{
+	tcf_unregister_action(&act_vlan_ops);
+}
+
+module_init(vlan_init_module);
+module_exit(vlan_cleanup_module);
+
+MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
+MODULE_DESCRIPTION("vlan manipulation actions");
+MODULE_LICENSE("GPL v2");
-- 
1.9.3

[patch iproute2] tc: add support for vlan tc action

[Jiri Pirko]

Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v1->v2:
- included changes suggested by Jamal

---
 include/linux/tc_act/tc_vlan.h |  35 +++++++
 tc/Makefile                    |   1 +
 tc/m_vlan.c                    | 221 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 257 insertions(+)
 create mode 100644 include/linux/tc_act/tc_vlan.h
 create mode 100644 tc/m_vlan.c

diff --git a/include/linux/tc_act/tc_vlan.h b/include/linux/tc_act/tc_vlan.h
new file mode 100644
index 0000000..f7b8d44
--- /dev/null
+++ b/include/linux/tc_act/tc_vlan.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_TC_VLAN_H
+#define __LINUX_TC_VLAN_H
+
+#include <linux/pkt_cls.h>
+
+#define TCA_ACT_VLAN 12
+
+#define TCA_VLAN_ACT_POP	1
+#define TCA_VLAN_ACT_PUSH	2
+
+struct tc_vlan {
+	tc_gen;
+	int v_action;
+};
+
+enum {
+	TCA_VLAN_UNSPEC,
+	TCA_VLAN_TM,
+	TCA_VLAN_PARMS,
+	TCA_VLAN_PUSH_VLAN_ID,
+	TCA_VLAN_PUSH_VLAN_PROTOCOL,
+	__TCA_VLAN_MAX,
+};
+#define TCA_VLAN_MAX (__TCA_VLAN_MAX - 1)
+
+#endif
diff --git a/tc/Makefile b/tc/Makefile
index 1ab36c6..830c97d 100644
--- a/tc/Makefile
+++ b/tc/Makefile
@@ -40,6 +40,7 @@ TCMODULES += m_pedit.o
 TCMODULES += m_skbedit.o
 TCMODULES += m_csum.o
 TCMODULES += m_simple.o
+TCMODULES += m_vlan.o
 TCMODULES += p_ip.o
 TCMODULES += p_icmp.o
 TCMODULES += p_tcp.o
diff --git a/tc/m_vlan.c b/tc/m_vlan.c
new file mode 100644
index 0000000..872bf72
--- /dev/null
+++ b/tc/m_vlan.c
@@ -0,0 +1,221 @@
+/*
+ * m_vlan.c		vlan manipulation module
+ *
+ *              This program is free software; you can redistribute it and/or
+ *              modify it under the terms of the GNU General Public License
+ *              as published by the Free Software Foundation; either version
+ *              2 of the License, or (at your option) any later version.
+ *
+ * Authors:     Jiri Pirko <jiri@resnulli.us>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <linux/if_ether.h>
+#include "utils.h"
+#include "rt_names.h"
+#include "tc_util.h"
+#include <linux/tc_act/tc_vlan.h>
+
+static void explain(void)
+{
+	fprintf(stderr, "Usage: vlan pop\n");
+	fprintf(stderr, "       vlan push [ protocol VLANPROTO ] id VLANID\n");
+	fprintf(stderr, "       VLANPROTO is one of 802.1Q or 802.1AD\n");
+	fprintf(stderr, "            with default: 802.1Q\n");
+}
+
+static void usage(void)
+{
+	explain();
+	exit(-1);
+}
+
+static int parse_vlan(struct action_util *a, int *argc_p, char ***argv_p,
+		      int tca_id, struct nlmsghdr *n)
+{
+	int argc = *argc_p;
+	char **argv = *argv_p;
+	struct rtattr *tail;
+	int action = 0;
+	__u16 id;
+	int id_set = 0;
+	__u16 proto;
+	int proto_set = 0;
+	struct tc_vlan parm = { 0 };
+
+	if (matches(*argv, "vlan") != 0)
+		return -1;
+
+	NEXT_ARG();
+
+	while (argc > 0) {
+		if (matches(*argv, "pop") == 0) {
+			if (action) {
+				fprintf(stderr, "unexpexted \"%s\" - action already specified\n",
+					*argv);
+				explain();
+				return -1;
+			}
+			action = TCA_VLAN_ACT_POP;
+		} else if (matches(*argv, "push") == 0) {
+			if (action) {
+				fprintf(stderr, "unexpexted \"%s\" - action already specified\n",
+					*argv);
+				explain();
+				return -1;
+			}
+			action = TCA_VLAN_ACT_PUSH;
+		} else if (matches(*argv, "id") == 0) {
+			if (action != TCA_VLAN_ACT_PUSH) {
+				fprintf(stderr, "\"%s\" is only valid for push\n",
+					*argv);
+				explain();
+				return -1;
+			}
+			NEXT_ARG();
+			if (get_u16(&id, *argv, 0))
+				invarg("id is invalid", *argv);
+			id_set = 1;
+		} else if (matches(*argv, "protocol") == 0) {
+			if (action != TCA_VLAN_ACT_PUSH) {
+				fprintf(stderr, "\"%s\" is only valid for push\n",
+					*argv);
+				explain();
+				return -1;
+			}
+			NEXT_ARG();
+			if (ll_proto_a2n(&proto, *argv))
+				invarg("protocol is invalid", *argv);
+			proto_set = 1;
+		} else if (matches(*argv, "help") == 0) {
+			usage();
+		} else {
+			break;
+		}
+		argc--;
+		argv++;
+	}
+
+	parm.action = TC_ACT_PIPE;
+	if (argc) {
+		if (matches(*argv, "reclassify") == 0) {
+			parm.action = TC_ACT_RECLASSIFY;
+			NEXT_ARG();
+		} else if (matches(*argv, "pipe") == 0) {
+			parm.action = TC_ACT_PIPE;
+			NEXT_ARG();
+		} else if (matches(*argv, "drop") == 0 ||
+			   matches(*argv, "shot") == 0) {
+			parm.action = TC_ACT_SHOT;
+			NEXT_ARG();
+		} else if (matches(*argv, "continue") == 0) {
+			parm.action = TC_ACT_UNSPEC;
+			NEXT_ARG();
+		} else if (matches(*argv, "pass") == 0) {
+			parm.action = TC_ACT_OK;
+			NEXT_ARG();
+		}
+	}
+
+	if (argc) {
+		if (matches(*argv, "index") == 0) {
+			NEXT_ARG();
+			if (get_u32(&parm.index, *argv, 10)) {
+				fprintf(stderr, "vlan: Illegal \"index\"\n");
+				return -1;
+			}
+			argc--;
+			argv++;
+		}
+	}
+
+	if (action == TCA_VLAN_ACT_PUSH && !id_set) {
+		fprintf(stderr, "id needs to be set for push\n");
+		explain();
+		return -1;
+	}
+
+	parm.v_action = action;
+	tail = NLMSG_TAIL(n);
+	addattr_l(n, MAX_MSG, tca_id, NULL, 0);
+	addattr_l(n, MAX_MSG, TCA_VLAN_PARMS, &parm, sizeof(parm));
+	if (id_set)
+		addattr_l(n, MAX_MSG, TCA_VLAN_PUSH_VLAN_ID, &id, 2);
+	if (proto_set) {
+		if (proto != htons(ETH_P_8021Q) &&
+		    proto != htons(ETH_P_8021AD)) {
+			fprintf(stderr, "protocol not supported\n");
+			explain();
+			return -1;
+		}
+
+		addattr_l(n, MAX_MSG, TCA_VLAN_PUSH_VLAN_PROTOCOL, &proto, 2);
+	}
+	tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
+
+	*argc_p = argc;
+	*argv_p = argv;
+	return 0;
+}
+
+static int print_vlan(struct action_util *au, FILE *f, struct rtattr *arg)
+{
+	SPRINT_BUF(b1);
+	struct rtattr *tb[TCA_VLAN_MAX + 1];
+	__u16 val;
+	struct tc_vlan *parm;
+
+	if (arg == NULL)
+		return -1;
+
+	parse_rtattr_nested(tb, TCA_VLAN_MAX, arg);
+
+	if (!tb[TCA_VLAN_PARMS]) {
+		fprintf(f, "[NULL vlan parameters]");
+		return -1;
+	}
+	parm = RTA_DATA(tb[TCA_VLAN_PARMS]);
+
+	fprintf(f, " vlan");
+
+	switch(parm->v_action) {
+	case TCA_VLAN_ACT_POP:
+		fprintf(f, " pop");
+		break;
+	case TCA_VLAN_ACT_PUSH:
+		fprintf(f, " push");
+		if (tb[TCA_VLAN_PUSH_VLAN_ID]) {
+			val = rta_getattr_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
+			fprintf(f, " id %u", val);
+		}
+		if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
+			fprintf(f, " protocol %s",
+				ll_proto_n2a(rta_getattr_u16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]),
+					     b1, sizeof(b1)));
+		}
+		break;
+	}
+
+	fprintf(f, "\n\t index %d ref %d bind %d", parm->index, parm->refcnt,
+		parm->bindcnt);
+
+	if (show_stats) {
+		if (tb[TCA_VLAN_TM]) {
+			struct tcf_t *tm = RTA_DATA(tb[TCA_VLAN_TM]);
+			print_tm(f, tm);
+		}
+	}
+
+	fprintf(f, "\n ");
+
+	return 0;
+}
+
+struct action_util vlan_action_util = {
+	.id = "vlan",
+	.parse_aopt = parse_vlan,
+	.print_aopt = print_vlan,
+};
-- 
1.9.3

Re: [patch net-next v2 1/4] openvswitch: actions: use skb_postpull_rcsum when possible

[Pravin Shelar]

On Wed, Nov 12, 2014 at 6:52 AM, Jiri Pirko <jiri@resnulli.us> wrote:
> Replace duplicated code by calling skb_postpull_rcsum
>
> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>

Looks good.
Acked-by: Pravin B Shelar <pshelar@nicira.com>

> ---
>  net/openvswitch/actions.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
>
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 394efa6..749a301 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -175,10 +175,7 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>         if (unlikely(err))
>                 return err;
>
> -       if (skb->ip_summed == CHECKSUM_COMPLETE)
> -               skb->csum = csum_sub(skb->csum,
> -                                    csum_partial(skb_mpls_header(skb),
> -                                                 MPLS_HLEN, 0));
> +       skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN);
>
>         memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
>                 skb->mac_len);
> @@ -230,9 +227,7 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
>         if (unlikely(err))
>                 return err;
>
> -       if (skb->ip_summed == CHECKSUM_COMPLETE)
> -               skb->csum = csum_sub(skb->csum, csum_partial(skb->data
> -                                       + (2 * ETH_ALEN), VLAN_HLEN, 0));
> +       skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
>
>         vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
>         *current_tci = vhdr->h_vlan_TCI;
> --
> 1.9.3
>

Re: [patch net-next v2 2/4] net: move make_writable helper into common code

[Pravin Shelar]

On Wed, Nov 12, 2014 at 6:52 AM, Jiri Pirko <jiri@resnulli.us> wrote:
> note that skb_make_writable already exists in net/netfilter/core.c
> but does something slightly different.
>
> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>

Looks good.
Acked-by: Pravin B Shelar <pshelar@nicira.com>

> ---
>  include/linux/skbuff.h    |  1 +
>  net/core/skbuff.c         | 12 ++++++++++++
>  net/openvswitch/actions.c | 39 ++++++++++++++-------------------------
>  3 files changed, 27 insertions(+), 25 deletions(-)
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index 73c370e..e045516 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -2678,6 +2678,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet);
>  unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
>  struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
>  struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
> +int skb_ensure_writable(struct sk_buff *skb, int write_len);
>
>  struct skb_checksum_ops {
>         __wsum (*update)(const void *mem, int len, __wsum wsum);
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 7001896..d11bbe0 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -4151,6 +4151,18 @@ err_free:
>  }
>  EXPORT_SYMBOL(skb_vlan_untag);
>
> +int skb_ensure_writable(struct sk_buff *skb, int write_len)
> +{
> +       if (!pskb_may_pull(skb, write_len))
> +               return -ENOMEM;
> +
> +       if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
> +               return 0;
> +
> +       return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
> +}
> +EXPORT_SYMBOL(skb_ensure_writable);
> +
>  /**
>   * alloc_skb_with_frags - allocate skb with page frags
>   *
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 749a301..04c9680 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -119,17 +119,6 @@ static bool is_flow_key_valid(const struct sw_flow_key *key)
>         return !!key->eth.type;
>  }
>
> -static int make_writable(struct sk_buff *skb, int write_len)
> -{
> -       if (!pskb_may_pull(skb, write_len))
> -               return -ENOMEM;
> -
> -       if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
> -               return 0;
> -
> -       return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
> -}
> -
>  static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>                      const struct ovs_action_push_mpls *mpls)
>  {
> @@ -171,7 +160,7 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>         struct ethhdr *hdr;
>         int err;
>
> -       err = make_writable(skb, skb->mac_len + MPLS_HLEN);
> +       err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
>         if (unlikely(err))
>                 return err;
>
> @@ -201,7 +190,7 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>         __be32 *stack;
>         int err;
>
> -       err = make_writable(skb, skb->mac_len + MPLS_HLEN);
> +       err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
>         if (unlikely(err))
>                 return err;
>
> @@ -223,7 +212,7 @@ static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
>         struct vlan_hdr *vhdr;
>         int err;
>
> -       err = make_writable(skb, VLAN_ETH_HLEN);
> +       err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
>         if (unlikely(err))
>                 return err;
>
> @@ -308,7 +297,7 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
>                         const struct ovs_key_ethernet *eth_key)
>  {
>         int err;
> -       err = make_writable(skb, ETH_HLEN);
> +       err = skb_ensure_writable(skb, ETH_HLEN);
>         if (unlikely(err))
>                 return err;
>
> @@ -410,8 +399,8 @@ static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *key,
>         struct iphdr *nh;
>         int err;
>
> -       err = make_writable(skb, skb_network_offset(skb) +
> -                                sizeof(struct iphdr));
> +       err = skb_ensure_writable(skb, skb_network_offset(skb) +
> +                                 sizeof(struct iphdr));
>         if (unlikely(err))
>                 return err;
>
> @@ -448,8 +437,8 @@ static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
>         __be32 *saddr;
>         __be32 *daddr;
>
> -       err = make_writable(skb, skb_network_offset(skb) +
> -                           sizeof(struct ipv6hdr));
> +       err = skb_ensure_writable(skb, skb_network_offset(skb) +
> +                                 sizeof(struct ipv6hdr));
>         if (unlikely(err))
>                 return err;
>
> @@ -491,7 +480,7 @@ static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *key,
>         return 0;
>  }
>
> -/* Must follow make_writable() since that can move the skb data. */
> +/* Must follow skb_ensure_writable() since that can move the skb data. */
>  static void set_tp_port(struct sk_buff *skb, __be16 *port,
>                          __be16 new_port, __sum16 *check)
>  {
> @@ -521,8 +510,8 @@ static int set_udp(struct sk_buff *skb, struct sw_flow_key *key,
>         struct udphdr *uh;
>         int err;
>
> -       err = make_writable(skb, skb_transport_offset(skb) +
> -                                sizeof(struct udphdr));
> +       err = skb_ensure_writable(skb, skb_transport_offset(skb) +
> +                                 sizeof(struct udphdr));
>         if (unlikely(err))
>                 return err;
>
> @@ -546,8 +535,8 @@ static int set_tcp(struct sk_buff *skb, struct sw_flow_key *key,
>         struct tcphdr *th;
>         int err;
>
> -       err = make_writable(skb, skb_transport_offset(skb) +
> -                                sizeof(struct tcphdr));
> +       err = skb_ensure_writable(skb, skb_transport_offset(skb) +
> +                                 sizeof(struct tcphdr));
>         if (unlikely(err))
>                 return err;
>
> @@ -572,7 +561,7 @@ static int set_sctp(struct sk_buff *skb, struct sw_flow_key *key,
>         int err;
>         unsigned int sctphoff = skb_transport_offset(skb);
>
> -       err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
> +       err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
>         if (unlikely(err))
>                 return err;
>
> --
> 1.9.3
>

Re: [patch net-next v2 3/4] net: move vlan pop/push functions into common code

[Pravin Shelar]

On Wed, Nov 12, 2014 at 6:52 AM, Jiri Pirko <jiri@resnulli.us> wrote:
> So it can be used from out of openvswitch code.
> Did couple of cosmetic changes on the way, namely variable naming and
> adding support for 8021AD proto.
>
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
> ---
>
> v1->v2:
> - adjusted to fix recent ovs changes
> - included change to use make_writable suggested by Eric
>
>  include/linux/skbuff.h    |  2 ++
>  net/core/skbuff.c         | 78 +++++++++++++++++++++++++++++++++++++++++++++
>  net/openvswitch/actions.c | 81 +++++------------------------------------------
>  3 files changed, 88 insertions(+), 73 deletions(-)
>
> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> index e045516..78c299f 100644
> --- a/include/linux/skbuff.h
> +++ b/include/linux/skbuff.h
> @@ -2679,6 +2679,8 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
>  struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
>  struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
>  int skb_ensure_writable(struct sk_buff *skb, int write_len);
> +int skb_vlan_pop(struct sk_buff *skb);
> +int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
>
>  struct skb_checksum_ops {
>         __wsum (*update)(const void *mem, int len, __wsum wsum);
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index d11bbe0..c7d3000 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -4163,6 +4163,84 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len)
>  }
>  EXPORT_SYMBOL(skb_ensure_writable);
>
> +/* remove VLAN header from packet and update csum accordingly. */
> +static int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci)
> +{
> +       struct vlan_hdr *vhdr;
> +       int err;
> +
> +       err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
> +       if (unlikely(err))
> +               return err;
> +
> +       skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
> +
> +       vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
> +       *vlan_tci = ntohs(vhdr->h_vlan_TCI);
> +
> +       memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
> +       __skb_pull(skb, VLAN_HLEN);
> +
> +       vlan_set_encap_proto(skb, vhdr);
> +       skb->mac_header += VLAN_HLEN;
> +       if (skb_network_offset(skb) < ETH_HLEN)
> +               skb_set_network_header(skb, ETH_HLEN);
> +       skb_reset_mac_len(skb);
> +
> +       return 0;
> +}
> +
> +int skb_vlan_pop(struct sk_buff *skb)
> +{
> +       u16 vlan_tci;
> +       __be16 vlan_proto;
> +       int err;
> +
> +       if (likely(vlan_tx_tag_present(skb))) {
> +               skb->vlan_tci = 0;
> +       } else {
> +               if (unlikely((skb->protocol != htons(ETH_P_8021Q) &&
> +                             skb->protocol != htons(ETH_P_8021AD)) ||
> +                            skb->len < VLAN_ETH_HLEN))
> +                       return 0;
> +
> +               err = __skb_vlan_pop(skb, &vlan_tci);
> +               if (err)
> +                       return err;
> +       }
> +       /* move next vlan tag to hw accel tag */
> +       if (likely((skb->protocol != htons(ETH_P_8021Q) &&
> +                   skb->protocol != htons(ETH_P_8021AD)) ||
> +                  skb->len < VLAN_ETH_HLEN))
> +               return 0;
> +
> +       vlan_proto = skb->protocol;
> +       err = __skb_vlan_pop(skb, &vlan_tci);
> +       if (unlikely(err))
> +               return err;
> +
> +       __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
> +       return 0;
> +}
> +EXPORT_SYMBOL(skb_vlan_pop);
> +
> +int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
> +{
> +       if (vlan_tx_tag_present(skb)) {
> +               /* push down current VLAN tag */
> +               if (!__vlan_put_tag(skb, skb->vlan_proto,
> +                                   vlan_tx_tag_get(skb)))
> +                       return -ENOMEM;
> +
> +               if (skb->ip_summed == CHECKSUM_COMPLETE)
> +                       skb->csum = csum_add(skb->csum, csum_partial(skb->data
> +                                       + (2 * ETH_ALEN), VLAN_HLEN, 0));
> +       }

Needs to update skb->mac_len.


> +       __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
> +       return 0;
> +}
> +EXPORT_SYMBOL(skb_vlan_push);
> +
>  /**
>   * alloc_skb_with_frags - allocate skb with page frags
>   *
> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
> index 04c9680..e1a5182 100644
> --- a/net/openvswitch/actions.c
> +++ b/net/openvswitch/actions.c
> @@ -206,91 +206,26 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key,
>         return 0;
>  }
>
> -/* remove VLAN header from packet and update csum accordingly. */
> -static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
> -{
> -       struct vlan_hdr *vhdr;
> -       int err;
> -
> -       err = skb_ensure_writable(skb, VLAN_ETH_HLEN);
> -       if (unlikely(err))
> -               return err;
> -
> -       skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
> -
> -       vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
> -       *current_tci = vhdr->h_vlan_TCI;
> -
> -       memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
> -       __skb_pull(skb, VLAN_HLEN);
> -
> -       vlan_set_encap_proto(skb, vhdr);
> -       skb->mac_header += VLAN_HLEN;
> -
> -       if (skb_network_offset(skb) < ETH_HLEN)
> -               skb_set_network_header(skb, ETH_HLEN);
> -
> -       /* Update mac_len for subsequent MPLS actions */
> -       skb_reset_mac_len(skb);
> -       return 0;
> -}
> -
>  static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
>  {
> -       __be16 tci;
>         int err;
>
> -       if (likely(vlan_tx_tag_present(skb))) {
> -               skb->vlan_tci = 0;
> -       } else {
> -               if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
> -                            skb->len < VLAN_ETH_HLEN))
> -                       return 0;
> -
> -               err = __pop_vlan_tci(skb, &tci);
> -               if (err)
> -                       return err;
> -       }
> -       /* move next vlan tag to hw accel tag */
> -       if (likely(skb->protocol != htons(ETH_P_8021Q) ||
> -                  skb->len < VLAN_ETH_HLEN)) {
> +       err = skb_vlan_pop(skb);
> +       if (vlan_tx_tag_present(skb))
> +               invalidate_flow_key(key);
> +       else
>                 key->eth.tci = 0;
> -               return 0;
> -       }
> -
> -       invalidate_flow_key(key);
> -       err = __pop_vlan_tci(skb, &tci);
> -       if (unlikely(err))
> -               return err;
> -
> -       __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
> -       return 0;
> +       return err;
>  }
>
>  static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
>                      const struct ovs_action_push_vlan *vlan)
>  {
> -       if (unlikely(vlan_tx_tag_present(skb))) {
> -               u16 current_tag;
> -
> -               /* push down current VLAN tag */
> -               current_tag = vlan_tx_tag_get(skb);
> -
> -               if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
> -                       return -ENOMEM;
> -               /* Update mac_len for subsequent MPLS actions */
> -               skb->mac_len += VLAN_HLEN;
> -
> -               if (skb->ip_summed == CHECKSUM_COMPLETE)
> -                       skb->csum = csum_add(skb->csum, csum_partial(skb->data
> -                                       + (2 * ETH_ALEN), VLAN_HLEN, 0));
> -
> +       if (vlan_tx_tag_present(skb))
>                 invalidate_flow_key(key);
> -       } else {
> +       else
>                 key->eth.tci = vlan->vlan_tci;
> -       }
> -       __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
> -       return 0;
> +       return skb_vlan_push(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
>  }
>
>  static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key,
> --
> 1.9.3
>

Re: [patch net-next v2 4/4] sched: introduce vlan action

[Cong Wang]

On Wed, Nov 12, 2014 at 6:52 AM, Jiri Pirko <jiri@resnulli.us> wrote:
> This tc action allows to work with vlan tagged skbs. Two supported
> sub-actions are header pop and header push.
>
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>

Reviewed-by: Cong Wang <cwang@twopensource.com>

Re: [patch iproute2] tc: add support for vlan tc action

[Jamal Hadi Salim]

On 11/12/14 09:55, Jiri Pirko wrote:
> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
> Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>

Latest patches work great. If you want you can
include these notes in the iproute2 commit log.

There is only one small doubt when i add two vlan
tags(Q followed by QandQ). Look at the very end
of the text i have below...

cheers,
jamal

---
export TC=/media/MT1/other-gits/iproute2-jiri/tc/tc
export ETH=eth0
#index supplied by kernel
sudo $TC actions add action vlan pop
#explicit add with our index
sudo $TC actions add action vlan pop index 10
sudo $TC actions add action vlan push id 123
sudo $TC actions add action vlan push id 456 protocol 802.1Q
sudo $TC actions add action vlan push id 789 protocol 802.1ad

sudo $TC actions ls action vlan
------ expect something like ----
         action order 0:  vlan pop
          index 1 ref 1 bind 0

         action order 1:  vlan push id 123 protocol 802.1Q
          index 2 ref 1 bind 0

         action order 2:  vlan push id 456 protocol 802.1Q
          index 3 ref 1 bind 0

         action order 3:  vlan push id 789 protocol 802.1ad
          index 4 ref 1 bind 0

         action order 4:  vlan pop
          index 10 ref 1 bind 0
-------
#show stats
sudo $TC -s actions ls action vlan

-------
         action order 0:  vlan pop
          index 1 ref 1 bind 0 installed 78 sec used 78 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 1:  vlan push id 123 protocol 802.1Q
          index 2 ref 1 bind 0 installed 44 sec used 44 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 2:  vlan push id 456 protocol 802.1Q
          index 3 ref 1 bind 0 installed 42 sec used 42 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 3:  vlan push id 789 protocol 802.1ad
          index 4 ref 1 bind 0 installed 39 sec used 39 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 4:  vlan pop
          index 10 ref 1 bind 0 installed 47 sec used 47 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
-----

sudo $TC actions flush action vlan
#expect all actions to be gone..
sudo $TC actions ls action vlan

#lets bind actions to filters...
sudo ip li add dev dummy0 type dummy
sudo ifconfig dummy0 up
#
sudo tc qdisc del dev $ETH ingress
sudo tc qdisc add dev $ETH ingress
#
sudo $TC filter add dev $ETH parent ffff: pref 11 protocol ip \
u32 match ip src 10.0.0.1 flowid 1:1 \
action  vlan  push id 123 \
action mirred egress redirect dev dummy0

window 1> sudo tcpdump -n -i dummy0 -e -X
window 2> ping -c 1 10.0.0.1

Expect something like:
52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q (0x8100), length 
102: vlan 123, p 0, ethertype IPv4, ...
#now look at the stats..
sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
#
sudo $TC filter add dev $ETH parent ffff: pref 12 protocol ip \
u32 match ip src 10.0.0.2 flowid 1:2 \
action vlan push id 456 protocol 802.1Q \
action mirred egress redirect dev dummy0

sudo tcpdump -n -i dummy0 -X -e
ping -c 1 10.0.0.2
#look at the stats..
sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
#
sudo $TC filter add dev $ETH parent ffff: pref 13 protocol ip \
u32 match ip src 10.0.0.13 flowid 1:13 \
action vlan push id 789 protocol 802.1ad \
action mirred egress redirect dev dummy0
ping -c 1 10.0.0.2

sudo tcpdump -n -i dummy0 -X -e
Expect ...
52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q-QinQ (0x88a8), 
length 102: vlan 789, p 0, ethertype IPv4,,,
#
sudo $TC -s filter ls dev $ETH parent 1: protocol ip
#
# Speaking in New Brunswickian:
#             For shits and giggles lets add two vlans ...
# match all pings this time...
#
sudo $TC filter add dev $ETH parent ffff: pref 11 protocol ip u32 \
match ip protocol 1 0xff flowid 1:1 \
action  vlan  push id 123 \
action vlan push id 789 protocol 802.1ad \
action mirred egress redirect dev dummy0

sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
------
filter pref 11 u32
filter pref 11 u32 fh 800: ht divisor 1
filter pref 11 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 
(rule hit 2 success 0)
   match 00010000/00ff0000 at 8 (success 0 )
         action order 1:  vlan push id 123 protocol 802.1Q
          index 13 ref 1 bind 1 installed 6 sec used 6 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 2:  vlan push id 789 protocol 802.1ad
          index 14 ref 1 bind 1 installed 6 sec used 6 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 3: mirred (Egress Redirect to device dummy0) stolen
         index 9 ref 1 bind 1 installed 6 sec used 6 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
----

Send 10 pings to 192.168.100.1
ping 192.168.100.1 -c 10

sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
------
filter pref 11 u32
filter pref 11 u32 fh 800: ht divisor 1
filter pref 11 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 
(rule hit 24 success 10)
   match 00010000/00ff0000 at 8 (success 10 )
         action order 1:  vlan push id 123 protocol 802.1Q
          index 13 ref 1 bind 1 installed 143 sec used 60 sec
         Action statistics:
         Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 2:  vlan push id 789 protocol 802.1ad
          index 14 ref 1 bind 1 installed 143 sec used 60 sec
         Action statistics:
         Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0

         action order 3: mirred (Egress Redirect to device dummy0) stolen
         index 9 ref 1 bind 1 installed 143 sec used 60 sec
         Action statistics:
         Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
--------

As can be seen, the two vlan tags were supposedly added. I am
not sure how well it worked. I see 4 more bytes added. tcpdump doesnt do
a good job telling me if it worked...

17:58:31.636816 00:22:01:01:52:54 > 00:00:00:00:02:00, ethertype 
802.1Q-QinQ (0x88a8), length 106: vlan 789, p 0, LLC, dsap Unknown 
(0x44) Group, ssap Null (0x00) Command, ctrl 0x5400: Information, send 
seq 0, rcv seq 42, Flags [Command], length 88
         0x0000:  0000 0000 0200 0022 0101 5254 88a8 0315
         0x0010:  00c3 4500 0054 c06b 0000 4001 704c 8100
         0x0020:  007b c0a8 6401 c0a8 649f 0000 24b8 027c
         0x0030:  000a c7e5 6854 0000 0000 e0b4 0900 0000
         0x0040:  0000 1011 1213 1415 1617 1819 1a1b 1c1d
         0x0050:  1e1f 2021 2223 2425 2627 2829 2a2b 2c2d
         0x0060:  2e2f 3031 3233 3435 3637

Here it is with just 802.1q tag...
17:53:38.198323 52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q 
(0x8100), length 102: vlan 456, p 0, ethertype IPv4, 192.168.100.1 > 
192.168.100.159: ICMP echo reply, id 620, seq 1, length 64
         0x0000:  0200 0022 0101 5254 00c3 4bc5 8100 01c8
         0x0010:  0800 4500 0054 c052 0000 4001 7065 c0a8
         0x0020:  6401 c0a8 649f 0000 6482 026c 0001 a2e4
         0x0030:  6854 0000 0000 cc04 0300 0000 0000 1011
         0x0040:  1213 1415 1617 1819 1a1b 1c1d 1e1f 2021
         0x0050:  2223 2425 2627 2829 2a2b 2c2d 2e2f 3031
         0x0060:  3233 3435 3637

------------

Re: [patch iproute2] tc: add support for vlan tc action

[Jiri Pirko]

Sun, Nov 16, 2014 at 09:19:34PM CET, jhs@mojatatu.com wrote:
>On 11/12/14 09:55, Jiri Pirko wrote:
>>Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
>>Signed-off-by: Jiri Pirko <jiri@resnulli.us>
>>
>
>Latest patches work great. If you want you can
>include these notes in the iproute2 commit log.
>
>There is only one small doubt when i add two vlan
>tags(Q followed by QandQ). Look at the very end
>of the text i have below...

I fixed that. Trouble was that tc action finds skb->data in different
state so I have to push and pull. Sending v3 shortly.

>
>cheers,
>jamal
>
>---
>export TC=/media/MT1/other-gits/iproute2-jiri/tc/tc
>export ETH=eth0
>#index supplied by kernel
>sudo $TC actions add action vlan pop
>#explicit add with our index
>sudo $TC actions add action vlan pop index 10
>sudo $TC actions add action vlan push id 123
>sudo $TC actions add action vlan push id 456 protocol 802.1Q
>sudo $TC actions add action vlan push id 789 protocol 802.1ad
>
>sudo $TC actions ls action vlan
>------ expect something like ----
>        action order 0:  vlan pop
>         index 1 ref 1 bind 0
>
>        action order 1:  vlan push id 123 protocol 802.1Q
>         index 2 ref 1 bind 0
>
>        action order 2:  vlan push id 456 protocol 802.1Q
>         index 3 ref 1 bind 0
>
>        action order 3:  vlan push id 789 protocol 802.1ad
>         index 4 ref 1 bind 0
>
>        action order 4:  vlan pop
>         index 10 ref 1 bind 0
>-------
>#show stats
>sudo $TC -s actions ls action vlan
>
>-------
>        action order 0:  vlan pop
>         index 1 ref 1 bind 0 installed 78 sec used 78 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 1:  vlan push id 123 protocol 802.1Q
>         index 2 ref 1 bind 0 installed 44 sec used 44 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 2:  vlan push id 456 protocol 802.1Q
>         index 3 ref 1 bind 0 installed 42 sec used 42 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 3:  vlan push id 789 protocol 802.1ad
>         index 4 ref 1 bind 0 installed 39 sec used 39 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 4:  vlan pop
>         index 10 ref 1 bind 0 installed 47 sec used 47 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>-----
>
>sudo $TC actions flush action vlan
>#expect all actions to be gone..
>sudo $TC actions ls action vlan
>
>#lets bind actions to filters...
>sudo ip li add dev dummy0 type dummy
>sudo ifconfig dummy0 up
>#
>sudo tc qdisc del dev $ETH ingress
>sudo tc qdisc add dev $ETH ingress
>#
>sudo $TC filter add dev $ETH parent ffff: pref 11 protocol ip \
>u32 match ip src 10.0.0.1 flowid 1:1 \
>action  vlan  push id 123 \
>action mirred egress redirect dev dummy0
>
>window 1> sudo tcpdump -n -i dummy0 -e -X
>window 2> ping -c 1 10.0.0.1
>
>Expect something like:
>52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q (0x8100), length 102:
>vlan 123, p 0, ethertype IPv4, ...
>#now look at the stats..
>sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
>#
>sudo $TC filter add dev $ETH parent ffff: pref 12 protocol ip \
>u32 match ip src 10.0.0.2 flowid 1:2 \
>action vlan push id 456 protocol 802.1Q \
>action mirred egress redirect dev dummy0
>
>sudo tcpdump -n -i dummy0 -X -e
>ping -c 1 10.0.0.2
>#look at the stats..
>sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
>#
>sudo $TC filter add dev $ETH parent ffff: pref 13 protocol ip \
>u32 match ip src 10.0.0.13 flowid 1:13 \
>action vlan push id 789 protocol 802.1ad \
>action mirred egress redirect dev dummy0
>ping -c 1 10.0.0.2
>
>sudo tcpdump -n -i dummy0 -X -e
>Expect ...
>52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q-QinQ (0x88a8), length
>102: vlan 789, p 0, ethertype IPv4,,,
>#
>sudo $TC -s filter ls dev $ETH parent 1: protocol ip
>#
># Speaking in New Brunswickian:
>#             For shits and giggles lets add two vlans ...
># match all pings this time...
>#
>sudo $TC filter add dev $ETH parent ffff: pref 11 protocol ip u32 \
>match ip protocol 1 0xff flowid 1:1 \
>action  vlan  push id 123 \
>action vlan push id 789 protocol 802.1ad \
>action mirred egress redirect dev dummy0
>
>sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
>------
>filter pref 11 u32
>filter pref 11 u32 fh 800: ht divisor 1
>filter pref 11 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 (rule
>hit 2 success 0)
>  match 00010000/00ff0000 at 8 (success 0 )
>        action order 1:  vlan push id 123 protocol 802.1Q
>         index 13 ref 1 bind 1 installed 6 sec used 6 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 2:  vlan push id 789 protocol 802.1ad
>         index 14 ref 1 bind 1 installed 6 sec used 6 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 3: mirred (Egress Redirect to device dummy0) stolen
>        index 9 ref 1 bind 1 installed 6 sec used 6 sec
>        Action statistics:
>        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>----
>
>Send 10 pings to 192.168.100.1
>ping 192.168.100.1 -c 10
>
>sudo $TC -s filter ls dev $ETH parent ffff: protocol ip
>------
>filter pref 11 u32
>filter pref 11 u32 fh 800: ht divisor 1
>filter pref 11 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1 (rule
>hit 24 success 10)
>  match 00010000/00ff0000 at 8 (success 10 )
>        action order 1:  vlan push id 123 protocol 802.1Q
>         index 13 ref 1 bind 1 installed 143 sec used 60 sec
>        Action statistics:
>        Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 2:  vlan push id 789 protocol 802.1ad
>         index 14 ref 1 bind 1 installed 143 sec used 60 sec
>        Action statistics:
>        Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>
>        action order 3: mirred (Egress Redirect to device dummy0) stolen
>        index 9 ref 1 bind 1 installed 143 sec used 60 sec
>        Action statistics:
>        Sent 840 bytes 10 pkt (dropped 0, overlimits 0 requeues 0)
>        backlog 0b 0p requeues 0
>--------
>
>As can be seen, the two vlan tags were supposedly added. I am
>not sure how well it worked. I see 4 more bytes added. tcpdump doesnt do
>a good job telling me if it worked...
>
>17:58:31.636816 00:22:01:01:52:54 > 00:00:00:00:02:00, ethertype 802.1Q-QinQ
>(0x88a8), length 106: vlan 789, p 0, LLC, dsap Unknown (0x44) Group, ssap
>Null (0x00) Command, ctrl 0x5400: Information, send seq 0, rcv seq 42, Flags
>[Command], length 88
>        0x0000:  0000 0000 0200 0022 0101 5254 88a8 0315
>        0x0010:  00c3 4500 0054 c06b 0000 4001 704c 8100
>        0x0020:  007b c0a8 6401 c0a8 649f 0000 24b8 027c
>        0x0030:  000a c7e5 6854 0000 0000 e0b4 0900 0000
>        0x0040:  0000 1011 1213 1415 1617 1819 1a1b 1c1d
>        0x0050:  1e1f 2021 2223 2425 2627 2829 2a2b 2c2d
>        0x0060:  2e2f 3031 3233 3435 3637
>
>Here it is with just 802.1q tag...
>17:53:38.198323 52:54:00:c3:4b:c5 > 02:00:00:22:01:01, ethertype 802.1Q
>(0x8100), length 102: vlan 456, p 0, ethertype IPv4, 192.168.100.1 >
>192.168.100.159: ICMP echo reply, id 620, seq 1, length 64
>        0x0000:  0200 0022 0101 5254 00c3 4bc5 8100 01c8
>        0x0010:  0800 4500 0054 c052 0000 4001 7065 c0a8
>        0x0020:  6401 c0a8 649f 0000 6482 026c 0001 a2e4
>        0x0030:  6854 0000 0000 cc04 0300 0000 0000 1011
>        0x0040:  1213 1415 1617 1819 1a1b 1c1d 1e1f 2021
>        0x0050:  2223 2425 2627 2829 2a2b 2c2d 2e2f 3031
>        0x0060:  3233 3435 3637
>
>------------
>
>