From d27cf5c59a12f66425df29cd81f61aa73ef14ac1 Mon Sep 17 00:00:00 2001
From: John Hurley <john.hurley@netronome.com>
Date: Sun, 7 Jul 2019 15:01:56 +0100
Subject: [PATCH] net: core: add MPLS update core helper and use in OvS
Open vSwitch allows the updating of an existing MPLS header on a packet.
In preparation for supporting similar functionality in TC, move this to a
common skb helper function.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/skbuff.h | 1 +
net/core/skbuff.c | 33 +++++++++++++++++++++++++++++++++
net/openvswitch/actions.c | 13 +++----------
3 files changed, 37 insertions(+), 10 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 08d1c8e705405e..9f7e01f2be8317 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3449,6 +3449,7 @@ int skb_vlan_pop(struct sk_buff *skb);
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto);
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto);
+int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
gfp_t gfp);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 8c00be4d891942..93443a01ab39ec 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5531,6 +5531,39 @@ int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto)
}
EXPORT_SYMBOL_GPL(skb_mpls_pop);
+/**
+ * skb_mpls_update_lse() - modify outermost MPLS header and update csum
+ *
+ * @skb: buffer
+ * @mpls_lse: new MPLS label stack entry to update to
+ *
+ * Expects skb->data at mac header.
+ *
+ * Returns 0 on success, -errno otherwise.
+ */
+int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse)
+{
+ int err;
+
+ if (unlikely(!eth_p_mpls(skb->protocol)))
+ return -EINVAL;
+
+ err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
+ if (unlikely(err))
+ return err;
+
+ if (skb->ip_summed == CHECKSUM_COMPLETE) {
+ __be32 diff[] = { ~mpls_hdr(skb)->label_stack_entry, mpls_lse };
+
+ skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum);
+ }
+
+ mpls_hdr(skb)->label_stack_entry = mpls_lse;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(skb_mpls_update_lse);
+
/**
* alloc_skb_with_frags - allocate skb with page frags
*
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 62715bb8d6110b..3572e11b6f21ed 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -193,19 +193,12 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
__be32 lse;
int err;
- err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
- if (unlikely(err))
- return err;
-
stack = mpls_hdr(skb);
lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
- if (skb->ip_summed == CHECKSUM_COMPLETE) {
- __be32 diff[] = { ~(stack->label_stack_entry), lse };
-
- skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum);
- }
+ err = skb_mpls_update_lse(skb, lse);
+ if (err)
+ return err;
- stack->label_stack_entry = lse;
flow_key->mpls.top_lse = lse;
return 0;
}
--
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