From 4b28252cada3d0521ab59751f4240ecdfb9bba18 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sat, 14 Jun 2014 23:23:52 -0700 Subject: net: Fix GSO constants to match NETIF flags Joseph Gasparakis reported that VXLAN GSO offload stopped working with i40e device after recent UDP changes. The problem is that the SKB_GSO_* bits are out of sync with the corresponding NETIF flags. This patch fixes that. Also, we add BUILD_BUG_ONs in net_gso_ok for several GSO constants that were missing to avoid the problem in the future. Reported-by: Joseph Gasparakis Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/netdev_features.h | 1 + include/linux/netdevice.h | 7 +++++++ include/linux/skbuff.h | 11 ++++++----- 3 files changed, 14 insertions(+), 5 deletions(-) diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h index e5a5894..d99800c 100644 --- a/include/linux/netdev_features.h +++ b/include/linux/netdev_features.h @@ -117,6 +117,7 @@ enum { #define NETIF_F_GSO_IPIP __NETIF_F(GSO_IPIP) #define NETIF_F_GSO_SIT __NETIF_F(GSO_SIT) #define NETIF_F_GSO_UDP_TUNNEL __NETIF_F(GSO_UDP_TUNNEL) +#define NETIF_F_GSO_UDP_TUNNEL_CSUM __NETIF_F(GSO_UDP_TUNNEL_CSUM) #define NETIF_F_GSO_MPLS __NETIF_F(GSO_MPLS) #define NETIF_F_HW_VLAN_STAG_FILTER __NETIF_F(HW_VLAN_STAG_FILTER) #define NETIF_F_HW_VLAN_STAG_RX __NETIF_F(HW_VLAN_STAG_RX) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index abe3de1..66f9a04 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3305,6 +3305,13 @@ static inline bool net_gso_ok(netdev_features_t features, int gso_type) BUILD_BUG_ON(SKB_GSO_TCP_ECN != (NETIF_F_TSO_ECN >> NETIF_F_GSO_SHIFT)); BUILD_BUG_ON(SKB_GSO_TCPV6 != (NETIF_F_TSO6 >> NETIF_F_GSO_SHIFT)); BUILD_BUG_ON(SKB_GSO_FCOE != (NETIF_F_FSO >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_GRE != (NETIF_F_GSO_GRE >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_GRE_CSUM != (NETIF_F_GSO_GRE_CSUM >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_IPIP != (NETIF_F_GSO_IPIP >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_SIT != (NETIF_F_GSO_SIT >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_UDP_TUNNEL != (NETIF_F_GSO_UDP_TUNNEL >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_UDP_TUNNEL_CSUM != (NETIF_F_GSO_UDP_TUNNEL_CSUM >> NETIF_F_GSO_SHIFT)); + BUILD_BUG_ON(SKB_GSO_MPLS != (NETIF_F_GSO_MPLS >> NETIF_F_GSO_SHIFT)); return (features & feature) == feature; } diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5b5cd31..e13ed90 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -338,17 +338,18 @@ enum { SKB_GSO_GRE = 1 << 6, - SKB_GSO_IPIP = 1 << 7, + SKB_GSO_GRE_CSUM = 1 << 7, - SKB_GSO_SIT = 1 << 8, + SKB_GSO_IPIP = 1 << 8, - SKB_GSO_UDP_TUNNEL = 1 << 9, + SKB_GSO_SIT = 1 << 9, - SKB_GSO_MPLS = 1 << 10, + SKB_GSO_UDP_TUNNEL = 1 << 10, SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11, - SKB_GSO_GRE_CSUM = 1 << 12, + SKB_GSO_MPLS = 1 << 12, + }; #if BITS_PER_LONG > 32 -- cgit v1.1 From 46fb51eb96cafb2c148b7b5119adb5e31a2bf3c4 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sat, 14 Jun 2014 23:24:03 -0700 Subject: net: Fix save software checksum complete Geert reported issues regarding checksum complete and UDP. The logic introduced in commit 7e3cead5172927732f51fde ("net: Save software checksum complete") is not correct. This patch: 1) Restores code in __skb_checksum_complete_header except for setting CHECKSUM_UNNECESSARY. This function may be calculating checksum on something less than skb->len. 2) Adds saving checksum to __skb_checksum_complete. The full packet checksum 0..skb->len is calculated without adding in pseudo header. This value is saved in skb->csum and then the pseudo header is added to that to derive the checksum for validation. 3) In both __skb_checksum_complete_header and __skb_checksum_complete, set skb->csum_valid to whether checksum of zero was computed. This allows skb_csum_unnecessary to return true without changing to CHECKSUM_UNNECESSARY which was done previously. 4) Copy new csum related bits in __copy_skb_header. Reported-by: Geert Uytterhoeven Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/core/datagram.c | 36 ++++++++++++++++++++++++++---------- net/core/skbuff.c | 3 +++ 2 files changed, 29 insertions(+), 10 deletions(-) diff --git a/net/core/datagram.c b/net/core/datagram.c index 6b1c04c..488dd1a 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -739,22 +739,38 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) __sum16 sum; sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); - if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && !sum && - !skb->csum_complete_sw) - netdev_rx_csum_fault(skb->dev); - - /* Save checksum complete for later use */ - skb->csum = sum; - skb->ip_summed = CHECKSUM_COMPLETE; - skb->csum_complete_sw = 1; - + if (likely(!sum)) { + if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && + !skb->csum_complete_sw) + netdev_rx_csum_fault(skb->dev); + } + skb->csum_valid = !sum; return sum; } EXPORT_SYMBOL(__skb_checksum_complete_head); __sum16 __skb_checksum_complete(struct sk_buff *skb) { - return __skb_checksum_complete_head(skb, skb->len); + __wsum csum; + __sum16 sum; + + csum = skb_checksum(skb, 0, skb->len, 0); + + /* skb->csum holds pseudo checksum */ + sum = csum_fold(csum_add(skb->csum, csum)); + if (likely(!sum)) { + if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && + !skb->csum_complete_sw) + netdev_rx_csum_fault(skb->dev); + } + + /* Save full packet checksum */ + skb->csum = csum; + skb->ip_summed = CHECKSUM_COMPLETE; + skb->csum_complete_sw = 1; + skb->csum_valid = !sum; + + return sum; } EXPORT_SYMBOL(__skb_checksum_complete); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index bf92824..9cd5344 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -689,6 +689,9 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) new->ooo_okay = old->ooo_okay; new->no_fcs = old->no_fcs; new->encapsulation = old->encapsulation; + new->encap_hdr_csum = old->encap_hdr_csum; + new->csum_valid = old->csum_valid; + new->csum_complete_sw = old->csum_complete_sw; #ifdef CONFIG_XFRM new->sp = secpath_get(old->sp); #endif -- cgit v1.1 From bbdff225ede6527f91184b2a7903df8aad803ace Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sat, 14 Jun 2014 23:24:20 -0700 Subject: udp: call __skb_checksum_complete when doing full checksum In __udp_lib_checksum_complete check if checksum is being done over all the data (len is equal to skb->len) and if it is call __skb_checksum_complete instead of __skb_checksum_complete_head. This allows checksum to be saved in checksum complete. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/net/udp.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/net/udp.h b/include/net/udp.h index 2ecfc6e1..68a1fef 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -111,7 +111,9 @@ struct sk_buff; */ static inline __sum16 __udp_lib_checksum_complete(struct sk_buff *skb) { - return __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov); + return (UDP_SKB_CB(skb)->cscov == skb->len ? + __skb_checksum_complete(skb) : + __skb_checksum_complete_head(skb, UDP_SKB_CB(skb)->cscov)); } static inline int udp_lib_checksum_complete(struct sk_buff *skb) -- cgit v1.1 From e5eb4e30a51236079fb22bb9f75fcd31915b03c6 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sat, 14 Jun 2014 23:24:28 -0700 Subject: net: add skb_pop_rcv_encapsulation This function is used by UDP encapsulation protocols in RX when crossing encapsulation boundary. If ip_summed is set to CHECKSUM_UNNECESSARY and encapsulation is not set, change to CHECKSUM_NONE since the checksum has not been validated within the encapsulation. Clears csum_valid by the same rationale. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- include/linux/skbuff.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index e13ed90..ec89301 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1854,6 +1854,18 @@ static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) return pskb_may_pull(skb, skb_network_offset(skb) + len); } +static inline void skb_pop_rcv_encapsulation(struct sk_buff *skb) +{ + /* Only continue with checksum unnecessary if device indicated + * it is valid across encapsulation (skb->encapsulation was set). + */ + if (skb->ip_summed == CHECKSUM_UNNECESSARY && !skb->encapsulation) + skb->ip_summed = CHECKSUM_NONE; + + skb->encapsulation = 0; + skb->csum_valid = 0; +} + /* * CPUs often take a performance hit when accessing unaligned memory * locations. The actual performance hit varies, it can be small if the -- cgit v1.1 From f79b064c15068176e3f6f67715aafd7fe183120c Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sat, 14 Jun 2014 23:24:36 -0700 Subject: vxlan: Checksum fixes Call skb_pop_rcv_encapsulation and postpull_rcsum for the Ethernet header to work properly with checksum complete. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index e0995ff..ade33ef 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1156,15 +1156,7 @@ static int vxlan_udp_encap_recv(struct sock *sk, struct sk_buff *skb) if (!vs) goto drop; - /* If the NIC driver gave us an encapsulated packet - * with the encapsulation mark, the device checksummed it - * for us. Otherwise force the upper layers to verify it. - */ - if ((skb->ip_summed != CHECKSUM_UNNECESSARY && skb->ip_summed != CHECKSUM_PARTIAL) || - !skb->encapsulation) - skb->ip_summed = CHECKSUM_NONE; - - skb->encapsulation = 0; + skb_pop_rcv_encapsulation(skb); vs->rcv(vs, skb, vxh->vx_vni); return 0; @@ -1201,6 +1193,7 @@ static void vxlan_rcv(struct vxlan_sock *vs, skb_reset_mac_header(skb); skb_scrub_packet(skb, !net_eq(vxlan->net, dev_net(vxlan->dev))); skb->protocol = eth_type_trans(skb, vxlan->dev); + skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); /* Ignore packet loops (and multicast echo) */ if (ether_addr_equal(eth_hdr(skb)->h_source, vxlan->dev->dev_addr)) -- cgit v1.1