[ovs-dev] [PATCH v2 1/4] net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len

[Daniel Axtens]

If you take a GSO skb, and split it into packets, will the network
length (L3 headers + L4 headers + payload) of those packets be small
enough to fit within a given MTU?

skb_gso_validate_mtu gives you the answer to that question. However,
we're about to add a way to validate the MAC length of a split GSO
skb (L2+L3+L4+payload), and the names get confusing, so rename
skb_gso_validate_mtu to skb_gso_validate_network_len

Signed-off-by: Daniel Axtens <dja at axtens.net>
---
 include/linux/skbuff.h                  | 2 +-
 net/core/skbuff.c                       | 9 +++++----
 net/ipv4/ip_forward.c                   | 2 +-
 net/ipv4/ip_output.c                    | 2 +-
 net/ipv4/netfilter/nf_flow_table_ipv4.c | 2 +-
 net/ipv6/ip6_output.c                   | 2 +-
 net/ipv6/netfilter/nf_flow_table_ipv6.c | 2 +-
 net/mpls/af_mpls.c                      | 2 +-
 net/xfrm/xfrm_device.c                  | 2 +-
 9 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b8e0da6c27d6..b137c79bf88d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3286,7 +3286,7 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
-bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu);
+bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
 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);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 01e8285aea73..a93e5c7aa5b2 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4914,15 +4914,16 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb)
 EXPORT_SYMBOL_GPL(skb_gso_transport_seglen);
 
 /**
- * skb_gso_validate_mtu - Return in case such skb fits a given MTU
+ * skb_gso_validate_network_len - Will a split GSO skb fit into a given MTU?
  *
  * @skb: GSO skb
  * @mtu: MTU to validate against
  *
- * skb_gso_validate_mtu validates if a given skb will fit a wanted MTU
- * once split.
+ * skb_gso_validate_network_len validates if a given skb will fit a
+ * wanted MTU once split. It considers L3 headers, L4 headers, and the
+ * payload.
  */
-bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu)
+bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu)
 {
 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
 	const struct sk_buff *iter;
diff --git a/net/ipv4/ip_forward.c b/net/ipv4/ip_forward.c
index 2dd21c3281a1..b54b948b0596 100644
--- a/net/ipv4/ip_forward.c
+++ b/net/ipv4/ip_forward.c
@@ -55,7 +55,7 @@ static bool ip_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
 	if (skb->ignore_df)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 		return false;
 
 	return true;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index e8e675be60ec..66340ab750e6 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -248,7 +248,7 @@ static int ip_finish_output_gso(struct net *net, struct sock *sk,
 
 	/* common case: seglen is <= mtu
 	 */
-	if (skb_gso_validate_mtu(skb, mtu))
+	if (skb_gso_validate_network_len(skb, mtu))
 		return ip_finish_output2(net, sk, skb);
 
 	/* Slowpath -  GSO segment length exceeds the egress MTU.
diff --git a/net/ipv4/netfilter/nf_flow_table_ipv4.c b/net/ipv4/netfilter/nf_flow_table_ipv4.c
index b2d01eb25f2c..cdf2625dc277 100644
--- a/net/ipv4/netfilter/nf_flow_table_ipv4.c
+++ b/net/ipv4/netfilter/nf_flow_table_ipv4.c
@@ -185,7 +185,7 @@ static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
 	if ((ip_hdr(skb)->frag_off & htons(IP_DF)) == 0)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 		return false;
 
 	return true;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 18547a44bdaf..4e888328d4dd 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -412,7 +412,7 @@ static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 	if (skb->ignore_df)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 		return false;
 
 	return true;
diff --git a/net/ipv6/netfilter/nf_flow_table_ipv6.c b/net/ipv6/netfilter/nf_flow_table_ipv6.c
index 0c3b9d32f64f..f1ab4e03df7d 100644
--- a/net/ipv6/netfilter/nf_flow_table_ipv6.c
+++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
@@ -179,7 +179,7 @@ static bool __nf_flow_exceeds_mtu(const struct sk_buff *skb, unsigned int mtu)
 	if (skb->len <= mtu)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 		return false;
 
 	return true;
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 5dce8336d33f..ec2a62c1d296 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -121,7 +121,7 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
 	if (skb->len <= mtu)
 		return false;
 
-	if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+	if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 		return false;
 
 	return true;
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 75982506617b..a6dd9cb17d1d 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -209,7 +209,7 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
 		if (skb->len <= mtu)
 			goto ok;
 
-		if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
+		if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
 			goto ok;
 	}
 
-- 
2.14.1