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 recently added 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 <d...@axtens.net>
---
include/linux/skbuff.h | 2 +-
net/core/skbuff.c | 11 ++++++-----
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, 14 insertions(+), 13 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c1e66bdcf583..a057dd1a75c7 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);
bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 09bd89c90a71..b63767008824 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -4955,19 +4955,20 @@ static inline bool skb_gso_size_check(const struct
sk_buff *skb,
}
/**
- * 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)
{
return skb_gso_size_check(skb, skb_gso_network_seglen(skb), mtu);
}
-EXPORT_SYMBOL_GPL(skb_gso_validate_mtu);
+EXPORT_SYMBOL_GPL(skb_gso_validate_network_len);
/**
* skb_gso_validate_mac_len - Will a split GSO skb fit in a given length?
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 25d2975da156..2447077d163d 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 997c7f19ad62..a8a919520090 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 d346705d6ee6..207cb35569b1 100644
--- a/net/ipv6/netfilter/nf_flow_table_ipv6.c
+++ b/net/ipv6/netfilter/nf_flow_table_ipv6.c
@@ -178,7 +178,7 @@ 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 e545a3c9365f..7a4de6d618b1 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -122,7 +122,7 @@ 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 8e70291e586a..e87d6c4dd5b6 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -217,7 +217,7 @@ 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
