[PATCH net-next v2 0/3] geneve: Add support for Remote Checksum Offload

[PATCH net-next v2 0/3] geneve: Add support for Remote Checksum Offload

[Tom Herbert]

This patch set adds UDP checksum configuration via netlink and
Remote Checksum Offload for Geneve,

v2:
  - Fix issue of taking sizeof a pointer instead of the actual object
  - Fix type in commi log

Testing (10Gbps mlx4):

Single connection TCP_STREAM in netperf

  - No UDP checksums, no RCO
     4371.9 Mbpos

  - UDP checksums enabled, no RCO
     7263.4 Mbps
   
  - UDP checksums enabled, RCO enabled
     7607.6 Mbps

200 TCP_RR streams

  - No UDP checksums, no RCO
    55.05% CPU utilization
    879284.9 tps
    184/231/742 50/90/99% latencies

  - UDP checksums enabled, no RCO
    55.46% CPU utilization
    901785 tps
    176/222/738 50/90/99% latencies

  - UDP checksums enabled, RCO enabled
    52.36% CPU utilization
    910582 tps
    174/218/706 50/90/99% latencies


Tom Herbert (3):
  rco: Clean up casting errors
  geneve: UDP checksum configuration via netlink
  geneve: Remote Checksum Offload support

 drivers/net/geneve.c         | 249 ++++++++++++++++++++++++++++++++++++++-----
 include/net/checksum.h       |   3 +-
 include/net/geneve.h         |  22 +++-
 include/uapi/linux/if_link.h |   6 ++
 4 files changed, 246 insertions(+), 34 deletions(-)

-- 
2.4.6

[PATCH net-next v2 1/3] rco: Clean up casting errors

[Tom Herbert]

Fixe a couple of cast errors found by sparse.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 include/net/checksum.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/net/checksum.h b/include/net/checksum.h
index 9fcaedf..10a16b5 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -165,7 +165,8 @@ static inline __wsum remcsum_adjust(void *ptr, __wsum csum,
 	csum = csum_sub(csum, csum_partial(ptr, start, 0));
 
 	/* Set derived checksum in packet */
-	delta = csum_sub(csum_fold(csum), *psum);
+	delta = csum_sub((__force __wsum)csum_fold(csum),
+			 (__force __wsum)*psum);
 	*psum = csum_fold(csum);
 
 	return delta;
-- 
2.4.6

[PATCH net-next v2 2/3] geneve: UDP checksum configuration via netlink

[Tom Herbert]

Add support to enable and disable UDP checksums via netlink. This is
similar to how VXLAN and GUE allow this. This includes support for
enabling the UDP zero checksum (for both TX and RX).

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 drivers/net/geneve.c         | 93 +++++++++++++++++++++++++++++++++-----------
 include/uapi/linux/if_link.h |  3 ++
 2 files changed, 73 insertions(+), 23 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index de5c30c..0750d7a 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -71,8 +71,14 @@ struct geneve_dev {
 	__be16		   dst_port;
 	bool		   collect_md;
 	struct gro_cells   gro_cells;
+	u32		   flags;
 };
 
+/* Geneve device flags */
+#define GENEVE_F_UDP_CSUM		BIT(0)
+#define GENEVE_F_UDP_ZERO_CSUM6_TX	BIT(1)
+#define GENEVE_F_UDP_ZERO_CSUM6_RX	BIT(2)
+
 struct geneve_sock {
 	bool			collect_md;
 	struct list_head	list;
@@ -81,6 +87,7 @@ struct geneve_sock {
 	int			refcnt;
 	struct udp_offload	udp_offloads;
 	struct hlist_head	vni_list[VNI_HASH_SIZE];
+	u32			flags;
 };
 
 static inline __u32 geneve_net_vni_hash(u8 vni[3])
@@ -343,7 +350,7 @@ error:
 }
 
 static struct socket *geneve_create_sock(struct net *net, bool ipv6,
-					 __be16 port)
+					 __be16 port, u32 flags)
 {
 	struct socket *sock;
 	struct udp_port_cfg udp_conf;
@@ -354,6 +361,8 @@ static struct socket *geneve_create_sock(struct net *net, bool ipv6,
 	if (ipv6) {
 		udp_conf.family = AF_INET6;
 		udp_conf.ipv6_v6only = 1;
+		udp_conf.use_udp6_rx_checksums =
+		    !(flags & GENEVE_F_UDP_ZERO_CSUM6_RX);
 	} else {
 		udp_conf.family = AF_INET;
 		udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
@@ -480,7 +489,7 @@ static int geneve_gro_complete(struct sk_buff *skb, int nhoff,
 
 /* Create new listen socket if needed */
 static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
-						bool ipv6)
+						bool ipv6, u32 flags)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_sock *gs;
@@ -492,7 +501,7 @@ static struct geneve_sock *geneve_socket_create(struct net *net, __be16 port,
 	if (!gs)
 		return ERR_PTR(-ENOMEM);
 
-	sock = geneve_create_sock(net, ipv6, port);
+	sock = geneve_create_sock(net, ipv6, port, flags);
 	if (IS_ERR(sock)) {
 		kfree(gs);
 		return ERR_CAST(sock);
@@ -575,12 +584,13 @@ static int geneve_sock_add(struct geneve_dev *geneve, bool ipv6)
 		goto out;
 	}
 
-	gs = geneve_socket_create(net, geneve->dst_port, ipv6);
+	gs = geneve_socket_create(net, geneve->dst_port, ipv6, geneve->flags);
 	if (IS_ERR(gs))
 		return PTR_ERR(gs);
 
 out:
 	gs->collect_md = geneve->collect_md;
+	gs->flags = geneve->flags;
 #if IS_ENABLED(CONFIG_IPV6)
 	if (ipv6)
 		geneve->sock6 = gs;
@@ -642,11 +652,12 @@ static void geneve_build_header(struct genevehdr *geneveh,
 
 static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 			    __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
-			    bool csum, bool xnet)
+			    u32 flags, bool xnet)
 {
 	struct genevehdr *gnvh;
 	int min_headroom;
 	int err;
+	bool udp_sum = !!(flags & GENEVE_F_UDP_CSUM);
 
 	skb_scrub_packet(skb, xnet);
 
@@ -658,7 +669,7 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 		goto free_rt;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, csum);
+	skb = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		goto free_rt;
@@ -678,11 +689,12 @@ free_rt:
 #if IS_ENABLED(CONFIG_IPV6)
 static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 			     __be16 tun_flags, u8 vni[3], u8 opt_len, u8 *opt,
-			     bool csum, bool xnet)
+			     u32 flags, bool xnet)
 {
 	struct genevehdr *gnvh;
 	int min_headroom;
 	int err;
+	bool udp_sum = !(flags & GENEVE_F_UDP_ZERO_CSUM6_TX);
 
 	skb_scrub_packet(skb, xnet);
 
@@ -694,7 +706,7 @@ static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 		goto free_dst;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, csum);
+	skb = udp_tunnel_handle_offloads(skb, udp_sum);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		goto free_dst;
@@ -824,9 +836,9 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	struct flowi4 fl4;
 	__u8 tos, ttl;
 	__be16 sport;
-	bool udp_csum;
 	__be16 df;
 	bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
+	u32 flags = geneve->flags;
 
 	if (geneve->collect_md) {
 		if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
@@ -857,9 +869,13 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 		if (key->tun_flags & TUNNEL_GENEVE_OPT)
 			opts = ip_tunnel_info_opts(info);
 
-		udp_csum = !!(key->tun_flags & TUNNEL_CSUM);
+		if (key->tun_flags & TUNNEL_CSUM)
+			flags |= GENEVE_F_UDP_CSUM;
+		else
+			flags &= ~GENEVE_F_UDP_CSUM;
+
 		err = geneve_build_skb(rt, skb, key->tun_flags, vni,
-				       info->options_len, opts, udp_csum, xnet);
+				       info->options_len, opts, flags, xnet);
 		if (unlikely(err))
 			goto err;
 
@@ -867,9 +883,8 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 		ttl = key->ttl;
 		df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
 	} else {
-		udp_csum = false;
 		err = geneve_build_skb(rt, skb, 0, geneve->vni,
-				       0, NULL, udp_csum, xnet);
+				       0, NULL, flags, xnet);
 		if (unlikely(err))
 			goto err;
 
@@ -883,7 +898,7 @@ static netdev_tx_t geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	err = udp_tunnel_xmit_skb(rt, gs4->sock->sk, skb, fl4.saddr, fl4.daddr,
 				  tos, ttl, df, sport, geneve->dst_port,
 				  !net_eq(geneve->net, dev_net(geneve->dev)),
-				  !udp_csum);
+				  !(flags & GENEVE_F_UDP_CSUM));
 
 	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 	return NETDEV_TX_OK;
@@ -912,8 +927,8 @@ static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	struct flowi6 fl6;
 	__u8 prio, ttl;
 	__be16 sport;
-	bool udp_csum;
 	bool xnet = !net_eq(geneve->net, dev_net(geneve->dev));
+	u32 flags = geneve->flags;
 
 	if (geneve->collect_md) {
 		if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
@@ -942,19 +957,22 @@ static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 		if (key->tun_flags & TUNNEL_GENEVE_OPT)
 			opts = ip_tunnel_info_opts(info);
 
-		udp_csum = !!(key->tun_flags & TUNNEL_CSUM);
+		if (key->tun_flags & TUNNEL_CSUM)
+			flags |= GENEVE_F_UDP_CSUM;
+		else
+			flags &= ~GENEVE_F_UDP_CSUM;
+
 		err = geneve6_build_skb(dst, skb, key->tun_flags, vni,
 					info->options_len, opts,
-					udp_csum, xnet);
+					flags, xnet);
 		if (unlikely(err))
 			goto err;
 
 		prio = ip_tunnel_ecn_encap(key->tos, iip, skb);
 		ttl = key->ttl;
 	} else {
-		udp_csum = false;
 		err = geneve6_build_skb(dst, skb, 0, geneve->vni,
-					0, NULL, udp_csum, xnet);
+					0, NULL, flags, xnet);
 		if (unlikely(err))
 			goto err;
 
@@ -966,7 +984,8 @@ static netdev_tx_t geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	}
 	err = udp_tunnel6_xmit_skb(dst, gs6->sock->sk, skb, dev,
 				   &fl6.saddr, &fl6.daddr, prio, ttl,
-				   sport, geneve->dst_port, !udp_csum);
+				   sport, geneve->dst_port,
+				   !!(flags & GENEVE_F_UDP_ZERO_CSUM6_TX));
 
 	iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 	return NETDEV_TX_OK;
@@ -1099,6 +1118,9 @@ static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
 	[IFLA_GENEVE_TOS]		= { .type = NLA_U8 },
 	[IFLA_GENEVE_PORT]		= { .type = NLA_U16 },
 	[IFLA_GENEVE_COLLECT_METADATA]	= { .type = NLA_FLAG },
+	[IFLA_GENEVE_UDP_CSUM]		= { .type = NLA_U8 },
+	[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]	= { .type = NLA_U8 },
+	[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]	= { .type = NLA_U8 },
 };
 
 static int geneve_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1152,7 +1174,7 @@ static struct geneve_dev *geneve_find_dev(struct geneve_net *gn,
 static int geneve_configure(struct net *net, struct net_device *dev,
 			    union geneve_addr *remote,
 			    __u32 vni, __u8 ttl, __u8 tos, __be16 dst_port,
-			    bool metadata)
+			    bool metadata, u32 flags)
 {
 	struct geneve_net *gn = net_generic(net, geneve_net_id);
 	struct geneve_dev *t, *geneve = netdev_priv(dev);
@@ -1183,6 +1205,7 @@ static int geneve_configure(struct net *net, struct net_device *dev,
 	geneve->tos = tos;
 	geneve->dst_port = dst_port;
 	geneve->collect_md = metadata;
+	geneve->flags = flags;
 
 	t = geneve_find_dev(gn, dst_port, remote, geneve->vni,
 			    &tun_on_same_port, &tun_collect_md);
@@ -1213,6 +1236,7 @@ static int geneve_newlink(struct net *net, struct net_device *dev,
 	bool metadata = false;
 	union geneve_addr remote = geneve_remote_unspec;
 	__u32 vni = 0;
+	u32 flags = 0;
 
 	if (data[IFLA_GENEVE_REMOTE] && data[IFLA_GENEVE_REMOTE6])
 		return -EINVAL;
@@ -1253,8 +1277,20 @@ static int geneve_newlink(struct net *net, struct net_device *dev,
 	if (data[IFLA_GENEVE_COLLECT_METADATA])
 		metadata = true;
 
+	if (data[IFLA_GENEVE_UDP_CSUM] &&
+	    nla_get_u8(data[IFLA_GENEVE_UDP_CSUM]))
+		flags |= GENEVE_F_UDP_CSUM;
+
+	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX] &&
+	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]))
+		flags |= GENEVE_F_UDP_ZERO_CSUM6_TX;
+
+	if (data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX] &&
+	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))
+		flags |= GENEVE_F_UDP_ZERO_CSUM6_RX;
+
 	return geneve_configure(net, dev, &remote, vni, ttl, tos, dst_port,
-				metadata);
+				metadata, flags);
 }
 
 static void geneve_dellink(struct net_device *dev, struct list_head *head)
@@ -1273,6 +1309,9 @@ static size_t geneve_get_size(const struct net_device *dev)
 		nla_total_size(sizeof(__u8)) +  /* IFLA_GENEVE_TOS */
 		nla_total_size(sizeof(__be16)) +  /* IFLA_GENEVE_PORT */
 		nla_total_size(0) +	 /* IFLA_GENEVE_COLLECT_METADATA */
+		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_CSUM */
+		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_TX */
+		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_RX */
 		0;
 }
 
@@ -1309,6 +1348,14 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
 			goto nla_put_failure;
 	}
 
+	if (nla_put_u8(skb, IFLA_GENEVE_UDP_CSUM,
+		       !!(geneve->flags & GENEVE_F_UDP_CSUM)) ||
+	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
+		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_TX)) ||
+	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
+		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_RX)))
+		goto nla_put_failure;
+
 	return 0;
 
 nla_put_failure:
@@ -1342,7 +1389,7 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 		return dev;
 
 	err = geneve_configure(net, dev, &geneve_remote_unspec,
-			       0, 0, 0, htons(dst_port), true);
+			       0, 0, 0, htons(dst_port), true, 0);
 	if (err) {
 		free_netdev(dev);
 		return ERR_PTR(err);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 5ad5737..2be1dd5 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -462,6 +462,9 @@ enum {
 	IFLA_GENEVE_PORT,	/* destination port */
 	IFLA_GENEVE_COLLECT_METADATA,
 	IFLA_GENEVE_REMOTE6,
+	IFLA_GENEVE_UDP_CSUM,
+	IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
+	IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
 	__IFLA_GENEVE_MAX
 };
 #define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
-- 
2.4.6

[PATCH net-next v2 3/3] geneve: Remote Checksum Offload support

[Tom Herbert]

Add support for remote checksum offload in both the normal and GRO
paths. netlinks command are used to enable sending of the Remote
Checksum Data, and allow processing of it on receive.

Signed-off-by: Tom Herbert <tom@herbertland.com>
---
 drivers/net/geneve.c         | 162 ++++++++++++++++++++++++++++++++++++++++---
 include/net/geneve.h         |  22 ++++--
 include/uapi/linux/if_link.h |   3 +
 3 files changed, 174 insertions(+), 13 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 0750d7a..68945a4 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -78,6 +78,9 @@ struct geneve_dev {
 #define GENEVE_F_UDP_CSUM		BIT(0)
 #define GENEVE_F_UDP_ZERO_CSUM6_TX	BIT(1)
 #define GENEVE_F_UDP_ZERO_CSUM6_RX	BIT(2)
+#define GENEVE_F_REMCSUM_TX		BIT(3)
+#define GENEVE_F_REMCSUM_RX		BIT(4)
+#define GENEVE_F_REMCSUM_NOPARTIAL	BIT(5)
 
 struct geneve_sock {
 	bool			collect_md;
@@ -308,6 +311,33 @@ static void geneve_uninit(struct net_device *dev)
 	free_percpu(dev->tstats);
 }
 
+static struct genevehdr *geneve_remcsum(struct sk_buff *skb,
+					struct genevehdr *gh,
+					size_t hdrlen, bool nopartial)
+{
+	size_t start, offset, plen;
+
+	if (skb->remcsum_offload)
+		return gh;
+
+	start = gh->rco_start << GENEVE_RCO_SHIFT;
+	offset = start + (gh->udp_rco ?
+			  offsetof(struct udphdr, check) :
+			  offsetof(struct tcphdr, check));
+
+	plen = hdrlen + offset + sizeof(u16);
+
+	if (!pskb_may_pull(skb, plen))
+		return NULL;
+
+	gh = (struct genevehdr *)(udp_hdr(skb) + 1);
+
+	skb_remcsum_process(skb, (void *)gh + hdrlen, start, offset,
+			    nopartial);
+
+	return gh;
+}
+
 /* Callback from net/ipv4/udp.c to receive packets */
 static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 {
@@ -336,6 +366,15 @@ static int geneve_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	if (!gs)
 		goto drop;
 
+	if (geneveh->rco && (gs->flags & GENEVE_F_REMCSUM_RX)) {
+		geneveh = geneve_remcsum(skb, geneveh,
+					 sizeof(geneveh) + opts_len,
+					 !!(gs->flags &
+					    GENEVE_F_REMCSUM_NOPARTIAL));
+		if (unlikely(!geneveh))
+			goto drop;
+	}
+
 	geneve_rx(gs, skb);
 	return 0;
 
@@ -397,6 +436,32 @@ static int geneve_hlen(struct genevehdr *gh)
 	return sizeof(*gh) + gh->opt_len * 4;
 }
 
+static struct genevehdr *geneve_gro_remcsum(struct sk_buff *skb,
+					    unsigned int off,
+					    struct genevehdr *gh, size_t hdrlen,
+					    struct gro_remcsum *grc,
+					    bool nopartial)
+{
+	size_t start, offset;
+
+	if (skb->remcsum_offload)
+		return gh;
+
+	if (!NAPI_GRO_CB(skb)->csum_valid)
+		return NULL;
+
+	start = gh->rco_start << GENEVE_RCO_SHIFT;
+	offset = start + (gh->udp_rco ?
+			  offsetof(struct udphdr, check) :
+			  offsetof(struct tcphdr, check));
+
+	gh = skb_gro_remcsum_process(skb, (void *)gh, off, hdrlen,
+				     start, offset, grc, nopartial);
+
+	skb->remcsum_offload = 1;
+
+	return gh;
+}
 static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 					   struct sk_buff *skb,
 					   struct udp_offload *uoff)
@@ -407,6 +472,11 @@ static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 	const struct packet_offload *ptype;
 	__be16 type;
 	int flush = 1;
+	struct gro_remcsum grc;
+	struct geneve_sock *gs = container_of(uoff, struct geneve_sock,
+					      udp_offloads);
+
+	skb_gro_remcsum_init(&grc);
 
 	off_gnv = skb_gro_offset(skb);
 	hlen = off_gnv + sizeof(*gh);
@@ -421,6 +491,16 @@ static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 		goto out;
 	gh_len = geneve_hlen(gh);
 
+	skb_gro_postpull_rcsum(skb, gh, gh_len);
+
+	if (gh->rco && (gs->flags & GENEVE_F_REMCSUM_RX)) {
+		gh = geneve_gro_remcsum(skb, off_gnv, gh, gh_len, &grc,
+					!!(gs->flags &
+					  GENEVE_F_REMCSUM_NOPARTIAL));
+		if (unlikely(!gh))
+			goto out;
+	}
+
 	hlen = off_gnv + gh_len;
 	if (skb_gro_header_hard(skb, hlen)) {
 		gh = skb_gro_header_slow(skb, hlen, off_gnv);
@@ -452,7 +532,6 @@ static struct sk_buff **geneve_gro_receive(struct sk_buff **head,
 	}
 
 	skb_gro_pull(skb, gh_len);
-	skb_gro_postpull_rcsum(skb, gh, gh_len);
 	pp = ptype->callbacks.gro_receive(head, skb);
 
 out_unlock:
@@ -636,7 +715,8 @@ static int geneve_stop(struct net_device *dev)
 
 static void geneve_build_header(struct genevehdr *geneveh,
 				__be16 tun_flags, u8 vni[3],
-				u8 options_len, u8 *options)
+				u8 options_len, u8 *options,
+				int type, struct sk_buff *skb)
 {
 	geneveh->ver = GENEVE_VER;
 	geneveh->opt_len = options_len / 4;
@@ -645,7 +725,25 @@ static void geneve_build_header(struct genevehdr *geneveh,
 	geneveh->rsvd1 = 0;
 	memcpy(geneveh->vni, vni, 3);
 	geneveh->proto_type = htons(ETH_P_TEB);
-	geneveh->rsvd2 = 0;
+
+	if (type & SKB_GSO_TUNNEL_REMCSUM) {
+		size_t hdrlen = sizeof(*geneveh) + options_len;
+
+		geneveh->rco = 1;
+		geneveh->rco_start = (skb_checksum_start_offset(skb) -
+				      hdrlen) >> GENEVE_RCO_SHIFT;
+
+		if (skb->csum_offset == offsetof(struct udphdr, check))
+			geneveh->udp_rco = 1;
+
+		if (!skb_is_gso(skb)) {
+			skb->ip_summed = CHECKSUM_NONE;
+			skb->encapsulation = 0;
+		}
+	} else {
+		geneveh->udp_rco = 0;
+		geneveh->rco_start = 0;
+	}
 
 	memcpy(geneveh->options, options, options_len);
 }
@@ -658,6 +756,20 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 	int min_headroom;
 	int err;
 	bool udp_sum = !!(flags & GENEVE_F_UDP_CSUM);
+	int type = udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+
+	if ((flags & GENEVE_F_REMCSUM_TX) &&
+	    skb->ip_summed == CHECKSUM_PARTIAL) {
+		int csum_start = skb_checksum_start_offset(skb);
+
+		if (csum_start <= GENEVE_MAX_REMCSUM_START &&
+		    !(csum_start & GENEVE_RCO_SHIFT_MASK) &&
+		    (skb->csum_offset == offsetof(struct udphdr, check) ||
+		     skb->csum_offset == offsetof(struct tcphdr, check))) {
+			udp_sum = false;
+			type |= SKB_GSO_TUNNEL_REMCSUM;
+		}
+	}
 
 	skb_scrub_packet(skb, xnet);
 
@@ -669,14 +781,14 @@ static int geneve_build_skb(struct rtable *rt, struct sk_buff *skb,
 		goto free_rt;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, udp_sum);
+	skb = iptunnel_handle_offloads(skb, udp_sum, type);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		goto free_rt;
 	}
 
 	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
-	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);
+	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt, type, skb);
 
 	skb_set_inner_protocol(skb, htons(ETH_P_TEB));
 	return 0;
@@ -695,6 +807,20 @@ static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 	int min_headroom;
 	int err;
 	bool udp_sum = !(flags & GENEVE_F_UDP_ZERO_CSUM6_TX);
+	int type = udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+
+	 if ((flags & GENEVE_F_REMCSUM_TX) &&
+	     skb->ip_summed == CHECKSUM_PARTIAL) {
+		int csum_start = skb_checksum_start_offset(skb);
+
+		if (csum_start <= GENEVE_MAX_REMCSUM_START &&
+		    !(csum_start & GENEVE_RCO_SHIFT_MASK) &&
+		    (skb->csum_offset == offsetof(struct udphdr, check) ||
+		     skb->csum_offset == offsetof(struct tcphdr, check))) {
+			udp_sum = false;
+			type |= SKB_GSO_TUNNEL_REMCSUM;
+		}
+	}
 
 	skb_scrub_packet(skb, xnet);
 
@@ -706,14 +832,14 @@ static int geneve6_build_skb(struct dst_entry *dst, struct sk_buff *skb,
 		goto free_dst;
 	}
 
-	skb = udp_tunnel_handle_offloads(skb, udp_sum);
+	skb = iptunnel_handle_offloads(skb, udp_sum, type);
 	if (IS_ERR(skb)) {
 		err = PTR_ERR(skb);
 		goto free_dst;
 	}
 
 	gnvh = (struct genevehdr *)__skb_push(skb, sizeof(*gnvh) + opt_len);
-	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt);
+	geneve_build_header(gnvh, tun_flags, vni, opt_len, opt, type, skb);
 
 	skb_set_inner_protocol(skb, htons(ETH_P_TEB));
 	return 0;
@@ -1121,6 +1247,9 @@ static const struct nla_policy geneve_policy[IFLA_GENEVE_MAX + 1] = {
 	[IFLA_GENEVE_UDP_CSUM]		= { .type = NLA_U8 },
 	[IFLA_GENEVE_UDP_ZERO_CSUM6_TX]	= { .type = NLA_U8 },
 	[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]	= { .type = NLA_U8 },
+	[IFLA_GENEVE_REMCSUM_TX]	= { .type = NLA_U8 },
+	[IFLA_GENEVE_REMCSUM_RX]	= { .type = NLA_U8 },
+	[IFLA_GENEVE_REMCSUM_NOPARTIAL]	= { .type = NLA_FLAG },
 };
 
 static int geneve_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1289,6 +1418,17 @@ static int geneve_newlink(struct net *net, struct net_device *dev,
 	    nla_get_u8(data[IFLA_GENEVE_UDP_ZERO_CSUM6_RX]))
 		flags |= GENEVE_F_UDP_ZERO_CSUM6_RX;
 
+	if (data[IFLA_GENEVE_REMCSUM_TX] &&
+	    nla_get_u8(data[IFLA_GENEVE_REMCSUM_TX]))
+		flags |= GENEVE_F_REMCSUM_TX;
+
+	if (data[IFLA_GENEVE_REMCSUM_RX] &&
+	    nla_get_u8(data[IFLA_GENEVE_REMCSUM_RX]))
+		flags |= GENEVE_F_REMCSUM_RX;
+
+	if (data[IFLA_GENEVE_REMCSUM_NOPARTIAL])
+		flags |= GENEVE_F_REMCSUM_NOPARTIAL;
+
 	return geneve_configure(net, dev, &remote, vni, ttl, tos, dst_port,
 				metadata, flags);
 }
@@ -1312,6 +1452,8 @@ static size_t geneve_get_size(const struct net_device *dev)
 		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_CSUM */
 		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_TX */
 		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_UDP_ZERO_CSUM6_RX */
+		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_REMCSUM_TX */
+		nla_total_size(sizeof(__u8)) + /* IFLA_GENEVE_REMCSUM_RX */
 		0;
 }
 
@@ -1353,7 +1495,11 @@ static int geneve_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
 		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_TX)) ||
 	    nla_put_u8(skb, IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
-		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_RX)))
+		       !!(geneve->flags & GENEVE_F_UDP_ZERO_CSUM6_RX)) ||
+	    nla_put_u8(skb, IFLA_GENEVE_REMCSUM_TX,
+		       !!(geneve->flags & GENEVE_F_REMCSUM_TX)) ||
+	    nla_put_u8(skb, IFLA_GENEVE_REMCSUM_RX,
+		       !!(geneve->flags & GENEVE_F_REMCSUM_RX)))
 		goto nla_put_failure;
 
 	return 0;
diff --git a/include/net/geneve.h b/include/net/geneve.h
index 3106ed6..b59ad0a 100644
--- a/include/net/geneve.h
+++ b/include/net/geneve.h
@@ -8,9 +8,9 @@
 
 /* Geneve Header:
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |Ver|  Opt Len  |O|C|    Rsvd.  |          Protocol Type        |
+ *  |Ver|  Opt Len  |O|C|X|  Rsvd.  |          Protocol Type        |
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *  |        Virtual Network Identifier (VNI)       |    Reserved   |
+ *  |        Virtual Network Identifier (VNI)       |U| Csum start  |
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *  |                    Variable Length Options                    |
  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
@@ -46,7 +46,8 @@ struct genevehdr {
 #ifdef __LITTLE_ENDIAN_BITFIELD
 	u8 opt_len:6;
 	u8 ver:2;
-	u8 rsvd1:6;
+	u8 rsvd1:5;
+	u8 rco:1;
 	u8 critical:1;
 	u8 oam:1;
 #else
@@ -54,14 +55,25 @@ struct genevehdr {
 	u8 opt_len:6;
 	u8 oam:1;
 	u8 critical:1;
-	u8 rsvd1:6;
+	u8 rco:1;
+	u8 rsvd1:5;
 #endif
 	__be16 proto_type;
 	u8 vni[3];
-	u8 rsvd2;
+#ifdef __LITTLE_ENDIAN_BITFIELD
+	u8 rco_start : 7;
+	u8 udp_rco : 1;
+#else
+	u8 udp_rco : 1;
+	u8 rco_start : 7;
+#endif
 	struct geneve_opt options[];
 };
 
+#define GENEVE_RCO_SHIFT 1	/* Left shift of start */
+#define GENEVE_RCO_SHIFT_MASK ((1 << GENEVE_RCO_SHIFT) - 1)
+#define GENEVE_MAX_REMCSUM_START (0x7f << GENEVE_RCO_SHIFT)
+
 #ifdef CONFIG_INET
 struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
 					u8 name_assign_type, u16 dst_port);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 2be1dd5..998eff0 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -465,6 +465,9 @@ enum {
 	IFLA_GENEVE_UDP_CSUM,
 	IFLA_GENEVE_UDP_ZERO_CSUM6_TX,
 	IFLA_GENEVE_UDP_ZERO_CSUM6_RX,
+	IFLA_GENEVE_REMCSUM_RX,
+	IFLA_GENEVE_REMCSUM_TX,
+	IFLA_GENEVE_REMCSUM_NOPARTIAL,
 	__IFLA_GENEVE_MAX
 };
 #define IFLA_GENEVE_MAX	(__IFLA_GENEVE_MAX - 1)
-- 
2.4.6

Re: [PATCH net-next v2 0/3] geneve: Add support for Remote Checksum Offload

[David Miller]

From: Tom Herbert <tom@herbertland.com>
Date: Thu, 10 Dec 2015 12:34:30 -0800

> This patch set adds UDP checksum configuration via netlink and
> Remote Checksum Offload for Geneve,
> 
> v2:
>   - Fix issue of taking sizeof a pointer instead of the actual object
>   - Fix type in commi log

Applied patches #1 and #2 only.

Patch #3 deferred as per Jesse's request.