* [PATCH v2 net-next 0/7] gue: Remote checksum offload
@ 2014-11-04 17:06 Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 1/7] net: Move fou_build_header into fou.c and refactor Tom Herbert
` (7 more replies)
0 siblings, 8 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
This patch set implements remote checksum offload for
GUE, which is a mechanism that provides checksum offload of
encapsulated packets using rudimentary offload capabilities found in
most Network Interface Card (NIC) devices. The outer header checksum
for UDP is enabled in packets and, with some additional meta
information in the GUE header, a receiver is able to deduce the
checksum to be set for an inner encapsulated packet. Effectively this
offloads the computation of the inner checksum. Enabling the outer
checksum in encapsulation has the additional advantage that it covers
more of the packet than the inner checksum including the encapsulation
headers.
Remote checksum offload is described in:
http://tools.ietf.org/html/draft-herbert-remotecsumoffload-01
The GUE transmit and receive paths are modified to support the
remote checksum offload option. The option contains a checksum
offset and checksum start which are directly derived from values
set in stack when doing CHECKSUM_PARTIAL. On receipt of the option, the
operation is to calculate the packet checksum from "start" to end of
the packet (normally derived for checksum complete), and then set
the resultant value at checksum "offset" (the checksum field has
already been primed with the pseudo header). This emulates a NIC
that implements NETIF_F_HW_CSUM.
The primary purpose of this feature is to eliminate cost of performing
checksum calculation over a packet when encpasulating.
In this patch set:
- Move fou_build_header into fou.c and split it into a couple of
functions
- Enable offloading of outer UDP checksum in encapsulation
- Change udp_offload to support remote checksum offload, includes
new GSO type and ensuring encapsulated layers (TCP) doesn't try to
set a checksum covered by RCO
- TX support for RCO with GUE. This is configured through ip_tunnel
and set the option on transmit when packet being encapsulated is
CHECKSUM_PARTIAL
- RX support for RCO with GUE for normal and GRO paths. Includes
resolving the offloaded checksum
v2:
Address comments from davem: Move accounting for private option
field in gue_encap_hlen to patch in which we add the remote checksum
offload option.
Testing:
I ran performance numbers using netperf TCP_STREAM and TCP_RR with 200
streams, comparing GUE with and without remote checksum offload (doing
checksum-unnecessary to complete conversion in both cases). These
were run on mlnx4 and bnx2x. Some mlnx4 results are below.
GRE/GUE
TCP_STREAM
IPv4, with remote checksum offload
9.71% TX CPU utilization
7.42% RX CPU utilization
36380 Mbps
IPv4, without remote checksum offload
12.40% TX CPU utilization
7.36% RX CPU utilization
36591 Mbps
TCP_RR
IPv4, with remote checksum offload
77.79% CPU utilization
91/144/216 90/95/99% latencies
1.95127e+06 tps
IPv4, without remote checksum offload
78.70% CPU utilization
89/152/297 90/95/99% latencies
1.95458e+06 tps
IPIP/GUE
TCP_STREAM
With remote checksum offload
10.30% TX CPU utilization
7.43% RX CPU utilization
36486 Mbps
Without remote checksum offload
12.47% TX CPU utilization
7.49% RX CPU utilization
36694 Mbps
TCP_RR
With remote checksum offload
77.80% CPU utilization
87/153/270 90/95/99% latencies
1.98735e+06 tps
Without remote checksum offload
77.98% CPU utilization
87/150/287 90/95/99% latencies
1.98737e+06 tps
SIT/GUE
TCP_STREAM
With remote checksum offload
9.68% TX CPU utilization
7.36% RX CPU utilization
35971 Mbps
Without remote checksum offload
12.95% TX CPU utilization
8.04% RX CPU utilization
36177 Mbps
TCP_RR
With remote checksum offload
79.32% CPU utilization
94/158/295 90/95/99% latencies
1.88842e+06 tps
Without remote checksum offload
80.23% CPU utilization
94/149/226 90/95/99% latencies
1.90338e+06 tps
VXLAN
TCP_STREAM
35.03% TX CPU utilization
20.85% RX CPU utilization
36230 Mbps
TCP_RR
77.36% CPU utilization
84/146/270 90/95/99% latencies
2.08063e+06 tps
We can also look at CPU time in csum_partial using perf (with bnx2x
setup). For GRE with TCP_STREAM I see:
With remote checksum offload
0.33% TX
1.81% RX
Without remote checksum offload
6.00% TX
0.51% RX
I suspect the fact that time in csum_partial noticably increases
with remote checksum offload for RX is due to taking the cache miss on
the encapsulated header in that function. By similar reasoning, if on
the TX side the packet were not in cache (say we did a splice from a
file whose data was never touched by the CPU) the CPU savings for TX
would probably be more pronounced.
Tom Herbert (7):
net: Move fou_build_header into fou.c and refactor
udp: Offload outer UDP tunnel csum if available
gue: Add infrastructure for flags and options
udp: Changes to udp_offload to support remote checksum offload
gue: Protocol constants for remote checksum offload
gue: TX support for using remote checksum offload option
gue: Receive side of remote checksum offload
include/linux/netdev_features.h | 4 +-
include/linux/netdevice.h | 1 +
include/linux/skbuff.h | 4 +-
include/net/fou.h | 38 ++++
include/net/gue.h | 103 ++++++++++-
include/uapi/linux/if_tunnel.h | 1 +
net/core/skbuff.c | 4 +-
net/ipv4/Kconfig | 9 +
net/ipv4/af_inet.c | 1 +
net/ipv4/fou.c | 388 +++++++++++++++++++++++++++++++++++-----
net/ipv4/ip_tunnel.c | 61 ++-----
net/ipv4/tcp_offload.c | 1 +
net/ipv4/udp_offload.c | 66 +++++--
net/ipv6/ip6_offload.c | 1 +
net/ipv6/udp_offload.c | 1 +
15 files changed, 565 insertions(+), 118 deletions(-)
create mode 100644 include/net/fou.h
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 1/7] net: Move fou_build_header into fou.c and refactor
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 2/7] udp: Offload outer UDP tunnel csum if available Tom Herbert
` (6 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Move fou_build_header out of ip_tunnel.c and into fou.c splitting
it up into fou_build_header, gue_build_header, and fou_build_udp.
This allows for other users for TX of FOU or GUE. Change ip_tunnel_encap
to call fou_build_header or gue_build_header based on the tunnel
encapsulation type. Similarly, added fou_encap_hlen and gue_encap_hlen
functions which are called by ip_encap_hlen. New net/fou.h has
prototypes and defines for this.
Added NET_FOU_IP_TUNNELS configuration. When this is set, IP tunnels
can use FOU/GUE and fou module is also selected.
Signed-off-by: Tom Herbert <therbert@google.com>
---
include/net/fou.h | 26 +++++++++++++++++++
net/ipv4/Kconfig | 9 +++++++
net/ipv4/fou.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++
net/ipv4/ip_tunnel.c | 61 +++++++++----------------------------------
4 files changed, 120 insertions(+), 49 deletions(-)
create mode 100644 include/net/fou.h
diff --git a/include/net/fou.h b/include/net/fou.h
new file mode 100644
index 0000000..cf4ce88
--- /dev/null
+++ b/include/net/fou.h
@@ -0,0 +1,26 @@
+#ifndef __NET_FOU_H
+#define __NET_FOU_H
+
+#include <linux/skbuff.h>
+
+#include <net/flow.h>
+#include <net/gue.h>
+#include <net/ip_tunnels.h>
+#include <net/udp.h>
+
+int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi4 *fl4);
+int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi4 *fl4);
+
+static size_t fou_encap_hlen(struct ip_tunnel_encap *e)
+{
+ return sizeof(struct udphdr);
+}
+
+static size_t gue_encap_hlen(struct ip_tunnel_encap *e)
+{
+ return sizeof(struct udphdr) + sizeof(struct guehdr);
+}
+
+#endif
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index e682b48..bd29016 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -322,6 +322,15 @@ config NET_FOU
network mechanisms and optimizations for UDP (such as ECMP
and RSS) can be leveraged to provide better service.
+config NET_FOU_IP_TUNNELS
+ bool "IP: FOU encapsulation of IP tunnels"
+ depends on NET_IPIP || NET_IPGRE || IPV6_SIT
+ select NET_FOU
+ ---help---
+ Allow configuration of FOU or GUE encapsulation for IP tunnels.
+ When this option is enabled IP tunnels can be configured to use
+ FOU or GUE encapsulation.
+
config GENEVE
tristate "Generic Network Virtualization Encapsulation (Geneve)"
depends on INET
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 32e7892..5446c1c 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -487,6 +487,79 @@ static const struct genl_ops fou_nl_ops[] = {
},
};
+static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ struct flowi4 *fl4, u8 *protocol, __be16 sport)
+{
+ struct udphdr *uh;
+
+ skb_push(skb, sizeof(struct udphdr));
+ skb_reset_transport_header(skb);
+
+ uh = udp_hdr(skb);
+
+ uh->dest = e->dport;
+ uh->source = sport;
+ uh->len = htons(skb->len);
+ uh->check = 0;
+ udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
+ fl4->saddr, fl4->daddr, skb->len);
+
+ *protocol = IPPROTO_UDP;
+}
+
+int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi4 *fl4)
+{
+ bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
+ int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+ __be16 sport;
+
+ skb = iptunnel_handle_offloads(skb, csum, type);
+
+ if (IS_ERR(skb))
+ return PTR_ERR(skb);
+
+ sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
+ skb, 0, 0, false);
+ fou_build_udp(skb, e, fl4, protocol, sport);
+
+ return 0;
+}
+EXPORT_SYMBOL(fou_build_header);
+
+int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi4 *fl4)
+{
+ bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
+ int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+ struct guehdr *guehdr;
+ size_t hdr_len = sizeof(struct guehdr);
+ __be16 sport;
+
+ skb = iptunnel_handle_offloads(skb, csum, type);
+
+ if (IS_ERR(skb))
+ return PTR_ERR(skb);
+
+ /* Get source port (based on flow hash) before skb_push */
+ sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
+ skb, 0, 0, false);
+
+ skb_push(skb, hdr_len);
+
+ guehdr = (struct guehdr *)skb->data;
+
+ guehdr->version = 0;
+ guehdr->hlen = 0;
+ guehdr->flags = 0;
+ guehdr->next_hdr = *protocol;
+
+ fou_build_udp(skb, e, fl4, protocol, sport);
+
+ return 0;
+}
+EXPORT_SYMBOL(gue_build_header);
+
static int __init fou_init(void)
{
int ret;
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 0bb8e14..c3587e1 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -56,7 +56,10 @@
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#include <net/udp.h>
-#include <net/gue.h>
+
+#if IS_ENABLED(CONFIG_NET_FOU)
+#include <net/fou.h>
+#endif
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
@@ -494,10 +497,12 @@ static int ip_encap_hlen(struct ip_tunnel_encap *e)
switch (e->type) {
case TUNNEL_ENCAP_NONE:
return 0;
+#if IS_ENABLED(CONFIG_NET_FOU)
case TUNNEL_ENCAP_FOU:
- return sizeof(struct udphdr);
+ return fou_encap_hlen(e);
case TUNNEL_ENCAP_GUE:
- return sizeof(struct udphdr) + sizeof(struct guehdr);
+ return gue_encap_hlen(e);
+#endif
default:
return -EINVAL;
}
@@ -526,60 +531,18 @@ int ip_tunnel_encap_setup(struct ip_tunnel *t,
}
EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup);
-static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
- size_t hdr_len, u8 *protocol, struct flowi4 *fl4)
-{
- struct udphdr *uh;
- __be16 sport;
- bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
- int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
-
- skb = iptunnel_handle_offloads(skb, csum, type);
-
- if (IS_ERR(skb))
- return PTR_ERR(skb);
-
- /* Get length and hash before making space in skb */
-
- sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
- skb, 0, 0, false);
-
- skb_push(skb, hdr_len);
-
- skb_reset_transport_header(skb);
- uh = udp_hdr(skb);
-
- if (e->type == TUNNEL_ENCAP_GUE) {
- struct guehdr *guehdr = (struct guehdr *)&uh[1];
-
- guehdr->version = 0;
- guehdr->hlen = 0;
- guehdr->flags = 0;
- guehdr->next_hdr = *protocol;
- }
-
- uh->dest = e->dport;
- uh->source = sport;
- uh->len = htons(skb->len);
- uh->check = 0;
- udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
- fl4->saddr, fl4->daddr, skb->len);
-
- *protocol = IPPROTO_UDP;
-
- return 0;
-}
-
int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
u8 *protocol, struct flowi4 *fl4)
{
switch (t->encap.type) {
case TUNNEL_ENCAP_NONE:
return 0;
+#if IS_ENABLED(CONFIG_NET_FOU)
case TUNNEL_ENCAP_FOU:
+ return fou_build_header(skb, &t->encap, protocol, fl4);
case TUNNEL_ENCAP_GUE:
- return fou_build_header(skb, &t->encap, t->encap_hlen,
- protocol, fl4);
+ return gue_build_header(skb, &t->encap, protocol, fl4);
+#endif
default:
return -EINVAL;
}
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 2/7] udp: Offload outer UDP tunnel csum if available
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 1/7] net: Move fou_build_header into fou.c and refactor Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 3/7] gue: Add infrastructure for flags and options Tom Herbert
` (5 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
In __skb_udp_tunnel_segment if outer UDP checksums are enabled and
ip_summed is not already CHECKSUM_PARTIAL, set up checksum offload
if device features allow it.
Signed-off-by: Tom Herbert <therbert@google.com>
---
net/ipv4/udp_offload.c | 52 ++++++++++++++++++++++++++++++++++----------------
1 file changed, 36 insertions(+), 16 deletions(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 6480cea..a774711 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -29,7 +29,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
netdev_features_t features,
struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
netdev_features_t features),
- __be16 new_protocol)
+ __be16 new_protocol, bool is_ipv6)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
u16 mac_offset = skb->mac_header;
@@ -39,7 +39,9 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
netdev_features_t enc_features;
int udp_offset, outer_hlen;
unsigned int oldlen;
- bool need_csum;
+ bool need_csum = !!(skb_shinfo(skb)->gso_type &
+ SKB_GSO_UDP_TUNNEL_CSUM);
+ bool offload_csum = false, dont_encap = need_csum;
oldlen = (u16)~skb->len;
@@ -52,10 +54,12 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
skb_set_network_header(skb, skb_inner_network_offset(skb));
skb->mac_len = skb_inner_network_offset(skb);
skb->protocol = new_protocol;
+ skb->encap_hdr_csum = need_csum;
- need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
- if (need_csum)
- skb->encap_hdr_csum = 1;
+ /* Try to offload checksum if possible */
+ offload_csum = !!(need_csum &&
+ (skb->dev->features &
+ (is_ipv6 ? NETIF_F_V6_CSUM : NETIF_F_V4_CSUM)));
/* segment inner packet. */
enc_features = skb->dev->hw_enc_features & features;
@@ -72,11 +76,21 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
do {
struct udphdr *uh;
int len;
-
- skb_reset_inner_headers(skb);
- skb->encapsulation = 1;
+ __be32 delta;
+
+ if (dont_encap) {
+ skb->encapsulation = 0;
+ skb->ip_summed = CHECKSUM_NONE;
+ } else {
+ /* Only set up inner headers if we might be offloading
+ * inner checksum.
+ */
+ skb_reset_inner_headers(skb);
+ skb->encapsulation = 1;
+ }
skb->mac_len = mac_len;
+ skb->protocol = protocol;
skb_push(skb, outer_hlen);
skb_reset_mac_header(skb);
@@ -86,19 +100,25 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
uh = udp_hdr(skb);
uh->len = htons(len);
- if (need_csum) {
- __be32 delta = htonl(oldlen + len);
+ if (!need_csum)
+ continue;
+
+ delta = htonl(oldlen + len);
+
+ uh->check = ~csum_fold((__force __wsum)
+ ((__force u32)uh->check +
+ (__force u32)delta));
- uh->check = ~csum_fold((__force __wsum)
- ((__force u32)uh->check +
- (__force u32)delta));
+ if (offload_csum) {
+ skb->ip_summed = CHECKSUM_PARTIAL;
+ skb->csum_start = skb_transport_header(skb) - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ } else {
uh->check = gso_make_checksum(skb, ~uh->check);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
}
-
- skb->protocol = protocol;
} while ((skb = skb->next));
out:
return segs;
@@ -134,7 +154,7 @@ struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
}
segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment,
- protocol);
+ protocol, is_ipv6);
out_unlock:
rcu_read_unlock();
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 3/7] gue: Add infrastructure for flags and options
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 1/7] net: Move fou_build_header into fou.c and refactor Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 2/7] udp: Offload outer UDP tunnel csum if available Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 4/7] udp: Changes to udp_offload to support remote checksum offload Tom Herbert
` (4 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Add functions and basic definitions for processing standard flags,
private flags, and control messages. This includes definitions
to compute length of optional fields corresponding to a set of flags.
Flag validation is in validate_gue_flags function. This checks for
unknown flags, and that length of optional fields is <= length
in guehdr hlen.
Signed-off-by: Tom Herbert <therbert@google.com>
---
include/net/gue.h | 100 ++++++++++++++++++++++++++++++++++++--
net/ipv4/fou.c | 142 ++++++++++++++++++++++++++++++++++++------------------
2 files changed, 189 insertions(+), 53 deletions(-)
diff --git a/include/net/gue.h b/include/net/gue.h
index b6c3327..cb68ae8 100644
--- a/include/net/gue.h
+++ b/include/net/gue.h
@@ -1,23 +1,113 @@
#ifndef __NET_GUE_H
#define __NET_GUE_H
+/* Definitions for the GUE header, standard and private flags, lengths
+ * of optional fields are below.
+ *
+ * Diagram of GUE header:
+ *
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * |Ver|C| Hlen | Proto/ctype | Standard flags |P|
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * ~ Fields (optional) ~
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Private flags (optional, P bit is set) |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * ~ Private fields (optional) ~
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * C bit indicates contol message when set, data message when unset.
+ * For a control message, proto/ctype is interpreted as a type of
+ * control message. For data messages, proto/ctype is the IP protocol
+ * of the next header.
+ *
+ * P bit indicates private flags field is present. The private flags
+ * may refer to options placed after this field.
+ */
+
struct guehdr {
union {
struct {
#if defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 hlen:4,
- version:4;
+ __u8 hlen:5,
+ control:1,
+ version:2;
#elif defined (__BIG_ENDIAN_BITFIELD)
- __u8 version:4,
- hlen:4;
+ __u8 version:2,
+ control:1,
+ hlen:5;
#else
#error "Please fix <asm/byteorder.h>"
#endif
- __u8 next_hdr;
+ __u8 proto_ctype;
__u16 flags;
};
__u32 word;
};
};
+/* Standard flags in GUE header */
+
+#define GUE_FLAG_PRIV htons(1<<0) /* Private flags are in options */
+#define GUE_LEN_PRIV 4
+
+#define GUE_FLAGS_ALL (GUE_FLAG_PRIV)
+
+/* Private flags in the private option extension */
+
+#define GUE_PFLAGS_ALL (0)
+
+/* Functions to compute options length corresponding to flags.
+ * If we ever have a lot of flags this can be potentially be
+ * converted to a more optimized algorithm (table lookup
+ * for instance).
+ */
+static inline size_t guehdr_flags_len(__be16 flags)
+{
+ return ((flags & GUE_FLAG_PRIV) ? GUE_LEN_PRIV : 0);
+}
+
+static inline size_t guehdr_priv_flags_len(__be32 flags)
+{
+ return 0;
+}
+
+/* Validate standard and private flags. Returns non-zero (meaning invalid)
+ * if there is an unknown standard or private flags, or the options length for
+ * the flags exceeds the options length specific in hlen of the GUE header.
+ */
+static inline int validate_gue_flags(struct guehdr *guehdr,
+ size_t optlen)
+{
+ size_t len;
+ __be32 flags = guehdr->flags;
+
+ if (flags & ~GUE_FLAGS_ALL)
+ return 1;
+
+ len = guehdr_flags_len(flags);
+ if (len > optlen)
+ return 1;
+
+ if (flags & GUE_FLAG_PRIV) {
+ /* Private flags are last four bytes accounted in
+ * guehdr_flags_len
+ */
+ flags = *(__be32 *)((void *)&guehdr[1] + len - GUE_LEN_PRIV);
+
+ if (flags & ~GUE_PFLAGS_ALL)
+ return 1;
+
+ len += guehdr_priv_flags_len(flags);
+ if (len > optlen)
+ return 1;
+ }
+
+ return 0;
+}
+
#endif
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 5446c1c..a3b8c5b 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -38,21 +38,17 @@ static inline struct fou *fou_from_sock(struct sock *sk)
return sk->sk_user_data;
}
-static int fou_udp_encap_recv_deliver(struct sk_buff *skb,
- u8 protocol, size_t len)
+static void fou_recv_pull(struct sk_buff *skb, size_t len)
{
struct iphdr *iph = ip_hdr(skb);
/* Remove 'len' bytes from the packet (UDP header and
- * FOU header if present), modify the protocol to the one
- * we found, and then call rcv_encap.
+ * FOU header if present).
*/
iph->tot_len = htons(ntohs(iph->tot_len) - len);
__skb_pull(skb, len);
skb_postpull_rcsum(skb, udp_hdr(skb), len);
skb_reset_transport_header(skb);
-
- return -protocol;
}
static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
@@ -62,16 +58,24 @@ static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
if (!fou)
return 1;
- return fou_udp_encap_recv_deliver(skb, fou->protocol,
- sizeof(struct udphdr));
+ fou_recv_pull(skb, sizeof(struct udphdr));
+
+ return -fou->protocol;
+}
+
+static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
+{
+ /* No support yet */
+ kfree_skb(skb);
+ return 0;
}
static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct fou *fou = fou_from_sock(sk);
- size_t len;
+ size_t len, optlen, hdrlen;
struct guehdr *guehdr;
- struct udphdr *uh;
+ void *data;
if (!fou)
return 1;
@@ -80,25 +84,38 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
if (!pskb_may_pull(skb, len))
goto drop;
- uh = udp_hdr(skb);
- guehdr = (struct guehdr *)&uh[1];
+ guehdr = (struct guehdr *)&udp_hdr(skb)[1];
+
+ optlen = guehdr->hlen << 2;
+ len += optlen;
- len += guehdr->hlen << 2;
if (!pskb_may_pull(skb, len))
goto drop;
- uh = udp_hdr(skb);
- guehdr = (struct guehdr *)&uh[1];
+ /* guehdr may change after pull */
+ guehdr = (struct guehdr *)&udp_hdr(skb)[1];
- if (guehdr->version != 0)
- goto drop;
+ hdrlen = sizeof(struct guehdr) + optlen;
- if (guehdr->flags) {
- /* No support yet */
+ if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
goto drop;
+
+ /* Pull UDP and GUE headers */
+ fou_recv_pull(skb, len);
+
+ data = &guehdr[1];
+
+ if (guehdr->flags & GUE_FLAG_PRIV) {
+ data += GUE_LEN_PRIV;
+
+ /* Process private flags */
}
- return fou_udp_encap_recv_deliver(skb, guehdr->next_hdr, len);
+ if (unlikely(guehdr->control))
+ return gue_control_message(skb, guehdr);
+
+ return -guehdr->proto_ctype;
+
drop:
kfree_skb(skb);
return 0;
@@ -154,36 +171,47 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
const struct net_offload *ops;
struct sk_buff **pp = NULL;
struct sk_buff *p;
- u8 proto;
struct guehdr *guehdr;
- unsigned int hlen, guehlen;
- unsigned int off;
+ size_t len, optlen, hdrlen, off;
+ void *data;
int flush = 1;
off = skb_gro_offset(skb);
- hlen = off + sizeof(*guehdr);
+ len = off + sizeof(*guehdr);
+
guehdr = skb_gro_header_fast(skb, off);
- if (skb_gro_header_hard(skb, hlen)) {
- guehdr = skb_gro_header_slow(skb, hlen, off);
+ if (skb_gro_header_hard(skb, len)) {
+ guehdr = skb_gro_header_slow(skb, len, off);
if (unlikely(!guehdr))
goto out;
}
- proto = guehdr->next_hdr;
+ optlen = guehdr->hlen << 2;
+ len += optlen;
- rcu_read_lock();
- offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
- ops = rcu_dereference(offloads[proto]);
- if (WARN_ON(!ops || !ops->callbacks.gro_receive))
- goto out_unlock;
+ if (skb_gro_header_hard(skb, len)) {
+ guehdr = skb_gro_header_slow(skb, len, off);
+ if (unlikely(!guehdr))
+ goto out;
+ }
- guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
+ if (unlikely(guehdr->control) || guehdr->version != 0 ||
+ validate_gue_flags(guehdr, optlen))
+ goto out;
- hlen = off + guehlen;
- if (skb_gro_header_hard(skb, hlen)) {
- guehdr = skb_gro_header_slow(skb, hlen, off);
- if (unlikely(!guehdr))
- goto out_unlock;
+ hdrlen = sizeof(*guehdr) + optlen;
+
+ skb_gro_pull(skb, hdrlen);
+
+ /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
+ skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
+
+ data = &guehdr[1];
+
+ if (guehdr->flags & GUE_FLAG_PRIV) {
+ data += GUE_LEN_PRIV;
+
+ /* Process private flags */
}
flush = 0;
@@ -197,7 +225,7 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
guehdr2 = (struct guehdr *)(p->data + off);
/* Compare base GUE header to be equal (covers
- * hlen, version, next_hdr, and flags.
+ * hlen, version, proto_ctype, and flags.
*/
if (guehdr->word != guehdr2->word) {
NAPI_GRO_CB(p)->same_flow = 0;
@@ -212,10 +240,11 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
}
}
- skb_gro_pull(skb, guehlen);
-
- /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
- skb_gro_postpull_rcsum(skb, guehdr, guehlen);
+ rcu_read_lock();
+ offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
+ ops = rcu_dereference(offloads[guehdr->proto_ctype]);
+ if (WARN_ON(!ops || !ops->callbacks.gro_receive))
+ goto out_unlock;
pp = ops->callbacks.gro_receive(head, skb);
@@ -236,7 +265,7 @@ static int gue_gro_complete(struct sk_buff *skb, int nhoff)
u8 proto;
int err = -ENOENT;
- proto = guehdr->next_hdr;
+ proto = guehdr->proto_ctype;
guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
@@ -533,8 +562,12 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
struct guehdr *guehdr;
- size_t hdr_len = sizeof(struct guehdr);
+ size_t optlen = 0;
__be16 sport;
+ void *data;
+ bool need_priv = false;
+
+ optlen += need_priv ? GUE_LEN_PRIV : 0;
skb = iptunnel_handle_offloads(skb, csum, type);
@@ -545,14 +578,27 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
- skb_push(skb, hdr_len);
+ skb_push(skb, sizeof(struct guehdr) + optlen);
guehdr = (struct guehdr *)skb->data;
+ guehdr->control = 0;
guehdr->version = 0;
- guehdr->hlen = 0;
+ guehdr->hlen = optlen >> 2;
guehdr->flags = 0;
- guehdr->next_hdr = *protocol;
+ guehdr->proto_ctype = *protocol;
+
+ data = &guehdr[1];
+
+ if (need_priv) {
+ __be32 *flags = data;
+
+ guehdr->flags |= GUE_FLAG_PRIV;
+ *flags = 0;
+ data += GUE_LEN_PRIV;
+
+ /* Add private flags */
+ }
fou_build_udp(skb, e, fl4, protocol, sport);
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 4/7] udp: Changes to udp_offload to support remote checksum offload
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
` (2 preceding siblings ...)
2014-11-04 17:06 ` [PATCH v2 net-next 3/7] gue: Add infrastructure for flags and options Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 5/7] gue: Protocol constants for " Tom Herbert
` (3 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Add a new GSO type, SKB_GSO_TUNNEL_REMCSUM, which indicates remote
checksum offload being done (in this case inner checksum must not
be offloaded to the NIC).
Added logic in __skb_udp_tunnel_segment to handle remote checksum
offload case.
Signed-off-by: Tom Herbert <therbert@google.com>
---
include/linux/netdev_features.h | 4 +++-
include/linux/netdevice.h | 1 +
include/linux/skbuff.h | 4 +++-
net/core/skbuff.c | 4 ++--
net/ipv4/af_inet.c | 1 +
net/ipv4/tcp_offload.c | 1 +
net/ipv4/udp_offload.c | 18 ++++++++++++++++--
net/ipv6/ip6_offload.c | 1 +
net/ipv6/udp_offload.c | 1 +
9 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index dcfdecb..8c94b07 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -48,8 +48,9 @@ enum {
NETIF_F_GSO_UDP_TUNNEL_BIT, /* ... UDP TUNNEL with TSO */
NETIF_F_GSO_UDP_TUNNEL_CSUM_BIT,/* ... UDP TUNNEL with TSO & CSUM */
NETIF_F_GSO_MPLS_BIT, /* ... MPLS segmentation */
+ NETIF_F_GSO_TUNNEL_REMCSUM_BIT, /* ... TUNNEL with TSO & REMCSUM */
/**/NETIF_F_GSO_LAST = /* last bit, see GSO_MASK */
- NETIF_F_GSO_MPLS_BIT,
+ NETIF_F_GSO_TUNNEL_REMCSUM_BIT,
NETIF_F_FCOE_CRC_BIT, /* FCoE CRC32 */
NETIF_F_SCTP_CSUM_BIT, /* SCTP checksum offload */
@@ -119,6 +120,7 @@ enum {
#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_GSO_TUNNEL_REMCSUM __NETIF_F(GSO_TUNNEL_REMCSUM)
#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)
#define NETIF_F_HW_VLAN_STAG_TX __NETIF_F(HW_VLAN_STAG_TX)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5ed05bd..4767f54 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3584,6 +3584,7 @@ static inline bool net_gso_ok(netdev_features_t features, int gso_type)
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));
+ BUILD_BUG_ON(SKB_GSO_TUNNEL_REMCSUM != (NETIF_F_GSO_TUNNEL_REMCSUM >> NETIF_F_GSO_SHIFT));
return (features & feature) == feature;
}
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 5ad9675..74ed344 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -373,6 +373,7 @@ enum {
SKB_GSO_MPLS = 1 << 12,
+ SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
};
#if BITS_PER_LONG > 32
@@ -603,7 +604,8 @@ struct sk_buff {
#endif
__u8 ipvs_property:1;
__u8 inner_protocol_type:1;
- /* 4 or 6 bit hole */
+ __u8 remcsum_offload:1;
+ /* 3 or 5 bit hole */
#ifdef CONFIG_NET_SCHED
__u16 tc_index; /* traffic control index */
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e48e5c0..7001896 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3013,7 +3013,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
if (nskb->len == len + doffset)
goto perform_csum_check;
- if (!sg) {
+ if (!sg && !nskb->remcsum_offload) {
nskb->ip_summed = CHECKSUM_NONE;
nskb->csum = skb_copy_and_csum_bits(head_skb, offset,
skb_put(nskb, len),
@@ -3085,7 +3085,7 @@ skip_fraglist:
nskb->truesize += nskb->data_len;
perform_csum_check:
- if (!csum) {
+ if (!csum && !nskb->remcsum_offload) {
nskb->csum = skb_checksum(nskb, doffset,
nskb->len - doffset, 0);
nskb->ip_summed = CHECKSUM_NONE;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8b7fe5b..ed2c672 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1222,6 +1222,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
SKB_GSO_TCPV6 |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
SKB_GSO_MPLS |
0)))
goto out;
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 5b90f2f..a1b2a56 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -97,6 +97,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
SKB_GSO_MPLS |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
0) ||
!(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
goto out;
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index a774711..0a5a70d 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -41,7 +41,8 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
unsigned int oldlen;
bool need_csum = !!(skb_shinfo(skb)->gso_type &
SKB_GSO_UDP_TUNNEL_CSUM);
- bool offload_csum = false, dont_encap = need_csum;
+ bool remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
+ bool offload_csum = false, dont_encap = (need_csum || remcsum);
oldlen = (u16)~skb->len;
@@ -55,6 +56,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
skb->mac_len = skb_inner_network_offset(skb);
skb->protocol = new_protocol;
skb->encap_hdr_csum = need_csum;
+ skb->remcsum_offload = remcsum;
/* Try to offload checksum if possible */
offload_csum = !!(need_csum &&
@@ -108,11 +110,22 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
uh->check = ~csum_fold((__force __wsum)
((__force u32)uh->check +
(__force u32)delta));
-
if (offload_csum) {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
+ } else if (remcsum) {
+ /* Need to calculate checksum from scratch,
+ * inner checksums are never when doing
+ * remote_checksum_offload.
+ */
+
+ skb->csum = skb_checksum(skb, udp_offset,
+ skb->len - udp_offset,
+ 0);
+ uh->check = csum_fold(skb->csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
} else {
uh->check = gso_make_checksum(skb, ~uh->check);
@@ -192,6 +205,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
SKB_GSO_IPIP |
SKB_GSO_GRE | SKB_GSO_GRE_CSUM |
SKB_GSO_MPLS) ||
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index a071563..e976707 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -78,6 +78,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
SKB_GSO_SIT |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
SKB_GSO_MPLS |
SKB_GSO_TCPV6 |
0)))
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 6b8f543..637ba2e 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -42,6 +42,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
SKB_GSO_DODGY |
SKB_GSO_UDP_TUNNEL |
SKB_GSO_UDP_TUNNEL_CSUM |
+ SKB_GSO_TUNNEL_REMCSUM |
SKB_GSO_GRE |
SKB_GSO_GRE_CSUM |
SKB_GSO_IPIP |
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 5/7] gue: Protocol constants for remote checksum offload
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
` (3 preceding siblings ...)
2014-11-04 17:06 ` [PATCH v2 net-next 4/7] udp: Changes to udp_offload to support remote checksum offload Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 6/7] gue: TX support for using remote checksum offload option Tom Herbert
` (2 subsequent siblings)
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Define a private flag for remote checksun offload as well as a length
for the option.
Signed-off-by: Tom Herbert <therbert@google.com>
---
include/net/gue.h | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/net/gue.h b/include/net/gue.h
index cb68ae8..3f28ec7 100644
--- a/include/net/gue.h
+++ b/include/net/gue.h
@@ -59,7 +59,10 @@ struct guehdr {
/* Private flags in the private option extension */
-#define GUE_PFLAGS_ALL (0)
+#define GUE_PFLAG_REMCSUM htonl(1 << 31)
+#define GUE_PLEN_REMCSUM 4
+
+#define GUE_PFLAGS_ALL (GUE_PFLAG_REMCSUM)
/* Functions to compute options length corresponding to flags.
* If we ever have a lot of flags this can be potentially be
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 6/7] gue: TX support for using remote checksum offload option
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
` (4 preceding siblings ...)
2014-11-04 17:06 ` [PATCH v2 net-next 5/7] gue: Protocol constants for " Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 7/7] gue: Receive side of remote checksum offload Tom Herbert
2014-11-05 21:44 ` [PATCH v2 net-next 0/7] gue: Remote " David Miller
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Add if_tunnel flag TUNNEL_ENCAP_FLAG_REMCSUM to configure
remote checksum offload on an IP tunnel. Add logic in gue_build_header
to insert remote checksum offload option.
Signed-off-by: Tom Herbert <therbert@google.com>
---
include/net/fou.h | 14 +++++++++++++-
include/uapi/linux/if_tunnel.h | 1 +
net/ipv4/fou.c | 35 ++++++++++++++++++++++++++++++++---
3 files changed, 46 insertions(+), 4 deletions(-)
diff --git a/include/net/fou.h b/include/net/fou.h
index cf4ce88..25b26ff 100644
--- a/include/net/fou.h
+++ b/include/net/fou.h
@@ -20,7 +20,19 @@ static size_t fou_encap_hlen(struct ip_tunnel_encap *e)
static size_t gue_encap_hlen(struct ip_tunnel_encap *e)
{
- return sizeof(struct udphdr) + sizeof(struct guehdr);
+ size_t len;
+ bool need_priv = false;
+
+ len = sizeof(struct udphdr) + sizeof(struct guehdr);
+
+ if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
+ len += GUE_PLEN_REMCSUM;
+ need_priv = true;
+ }
+
+ len += need_priv ? GUE_LEN_PRIV : 0;
+
+ return len;
}
#endif
diff --git a/include/uapi/linux/if_tunnel.h b/include/uapi/linux/if_tunnel.h
index 280d9e0..bd3cc11 100644
--- a/include/uapi/linux/if_tunnel.h
+++ b/include/uapi/linux/if_tunnel.h
@@ -69,6 +69,7 @@ enum tunnel_encap_types {
#define TUNNEL_ENCAP_FLAG_CSUM (1<<0)
#define TUNNEL_ENCAP_FLAG_CSUM6 (1<<1)
+#define TUNNEL_ENCAP_FLAG_REMCSUM (1<<2)
/* SIT-mode i_flags */
#define SIT_ISATAP 0x0001
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index a3b8c5b..fb0db99 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -562,11 +562,19 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
struct guehdr *guehdr;
- size_t optlen = 0;
+ size_t hdrlen, optlen = 0;
__be16 sport;
void *data;
bool need_priv = false;
+ if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
+ skb->ip_summed == CHECKSUM_PARTIAL) {
+ csum = false;
+ optlen += GUE_PLEN_REMCSUM;
+ type |= SKB_GSO_TUNNEL_REMCSUM;
+ need_priv = true;
+ }
+
optlen += need_priv ? GUE_LEN_PRIV : 0;
skb = iptunnel_handle_offloads(skb, csum, type);
@@ -578,7 +586,9 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
- skb_push(skb, sizeof(struct guehdr) + optlen);
+ hdrlen = sizeof(struct guehdr) + optlen;
+
+ skb_push(skb, hdrlen);
guehdr = (struct guehdr *)skb->data;
@@ -597,7 +607,26 @@ int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
*flags = 0;
data += GUE_LEN_PRIV;
- /* Add private flags */
+ if (type & SKB_GSO_TUNNEL_REMCSUM) {
+ u16 csum_start = skb_checksum_start_offset(skb);
+ __be16 *pd = data;
+
+ if (csum_start < hdrlen)
+ return -EINVAL;
+
+ csum_start -= hdrlen;
+ pd[0] = htons(csum_start);
+ pd[1] = htons(csum_start + skb->csum_offset);
+
+ if (!skb_is_gso(skb)) {
+ skb->ip_summed = CHECKSUM_NONE;
+ skb->encapsulation = 0;
+ }
+
+ *flags |= GUE_PFLAG_REMCSUM;
+ data += GUE_PLEN_REMCSUM;
+ }
+
}
fou_build_udp(skb, e, fl4, protocol, sport);
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v2 net-next 7/7] gue: Receive side of remote checksum offload
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
` (5 preceding siblings ...)
2014-11-04 17:06 ` [PATCH v2 net-next 6/7] gue: TX support for using remote checksum offload option Tom Herbert
@ 2014-11-04 17:06 ` Tom Herbert
2014-11-05 21:44 ` [PATCH v2 net-next 0/7] gue: Remote " David Miller
7 siblings, 0 replies; 9+ messages in thread
From: Tom Herbert @ 2014-11-04 17:06 UTC (permalink / raw
To: davem, netdev
Add processing of the remote checksum offload option in both the normal
path as well as the GRO path. The implements patching the affected
checksum to derive the offloaded checksum.
Signed-off-by: Tom Herbert <therbert@google.com>
---
net/ipv4/fou.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 161 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index fb0db99..740ae09 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -63,6 +63,59 @@ static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
return -fou->protocol;
}
+static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
+ void *data, int hdrlen, u8 ipproto)
+{
+ __be16 *pd = data;
+ u16 start = ntohs(pd[0]);
+ u16 offset = ntohs(pd[1]);
+ u16 poffset = 0;
+ u16 plen;
+ __wsum csum, delta;
+ __sum16 *psum;
+
+ if (skb->remcsum_offload) {
+ /* Already processed in GRO path */
+ skb->remcsum_offload = 0;
+ return guehdr;
+ }
+
+ if (start > skb->len - hdrlen ||
+ offset > skb->len - hdrlen - sizeof(u16))
+ return NULL;
+
+ if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE))
+ __skb_checksum_complete(skb);
+
+ plen = hdrlen + offset + sizeof(u16);
+ if (!pskb_may_pull(skb, plen))
+ return NULL;
+ guehdr = (struct guehdr *)&udp_hdr(skb)[1];
+
+ if (ipproto == IPPROTO_IP && sizeof(struct iphdr) < plen) {
+ struct iphdr *ip = (struct iphdr *)(skb->data + hdrlen);
+
+ /* If next header happens to be IP we can skip that for the
+ * checksum calculation since the IP header checksum is zero
+ * if correct.
+ */
+ poffset = ip->ihl * 4;
+ }
+
+ csum = csum_sub(skb->csum, skb_checksum(skb, poffset + hdrlen,
+ start - poffset - hdrlen, 0));
+
+ /* Set derived checksum in packet */
+ psum = (__sum16 *)(skb->data + hdrlen + offset);
+ delta = csum_sub(csum_fold(csum), *psum);
+ *psum = csum_fold(csum);
+
+ /* Adjust skb->csum since we changed the packet */
+ skb->csum = csum_add(skb->csum, delta);
+
+ return guehdr;
+}
+
static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
{
/* No support yet */
@@ -76,6 +129,7 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
size_t len, optlen, hdrlen;
struct guehdr *guehdr;
void *data;
+ u16 doffset = 0;
if (!fou)
return 1;
@@ -100,20 +154,43 @@ static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
goto drop;
- /* Pull UDP and GUE headers */
- fou_recv_pull(skb, len);
+ hdrlen = sizeof(struct guehdr) + optlen;
+
+ ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
+
+ /* Pull UDP header now, skb->data points to guehdr */
+ __skb_pull(skb, sizeof(struct udphdr));
+
+ /* Pull csum through the guehdr now . This can be used if
+ * there is a remote checksum offload.
+ */
+ skb_postpull_rcsum(skb, udp_hdr(skb), len);
data = &guehdr[1];
if (guehdr->flags & GUE_FLAG_PRIV) {
- data += GUE_LEN_PRIV;
+ __be32 flags = *(__be32 *)(data + doffset);
+
+ doffset += GUE_LEN_PRIV;
- /* Process private flags */
+ if (flags & GUE_PFLAG_REMCSUM) {
+ guehdr = gue_remcsum(skb, guehdr, data + doffset,
+ hdrlen, guehdr->proto_ctype);
+ if (!guehdr)
+ goto drop;
+
+ data = &guehdr[1];
+
+ doffset += GUE_PLEN_REMCSUM;
+ }
}
if (unlikely(guehdr->control))
return gue_control_message(skb, guehdr);
+ __skb_pull(skb, hdrlen);
+ skb_reset_transport_header(skb);
+
return -guehdr->proto_ctype;
drop:
@@ -164,6 +241,66 @@ out_unlock:
return err;
}
+static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
+ struct guehdr *guehdr, void *data,
+ size_t hdrlen, u8 ipproto)
+{
+ __be16 *pd = data;
+ u16 start = ntohs(pd[0]);
+ u16 offset = ntohs(pd[1]);
+ u16 poffset = 0;
+ u16 plen;
+ void *ptr;
+ __wsum csum, delta;
+ __sum16 *psum;
+
+ if (skb->remcsum_offload)
+ return guehdr;
+
+ if (start > skb_gro_len(skb) - hdrlen ||
+ offset > skb_gro_len(skb) - hdrlen - sizeof(u16) ||
+ !NAPI_GRO_CB(skb)->csum_valid || skb->remcsum_offload)
+ return NULL;
+
+ plen = hdrlen + offset + sizeof(u16);
+
+ /* Pull checksum that will be written */
+ if (skb_gro_header_hard(skb, off + plen)) {
+ guehdr = skb_gro_header_slow(skb, off + plen, off);
+ if (!guehdr)
+ return NULL;
+ }
+
+ ptr = (void *)guehdr + hdrlen;
+
+ if (ipproto == IPPROTO_IP &&
+ (hdrlen + sizeof(struct iphdr) < plen)) {
+ struct iphdr *ip = (struct iphdr *)(ptr + hdrlen);
+
+ /* If next header happens to be IP we can skip
+ * that for the checksum calculation since the
+ * IP header checksum is zero if correct.
+ */
+ poffset = ip->ihl * 4;
+ }
+
+ csum = csum_sub(NAPI_GRO_CB(skb)->csum,
+ csum_partial(ptr + poffset, start - poffset, 0));
+
+ /* Set derived checksum in packet */
+ psum = (__sum16 *)(ptr + offset);
+ delta = csum_sub(csum_fold(csum), *psum);
+ *psum = csum_fold(csum);
+
+ /* Adjust skb->csum since we changed the packet */
+ skb->csum = csum_add(skb->csum, delta);
+ NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);
+
+ skb->remcsum_offload = 1;
+
+ return guehdr;
+}
+
static struct sk_buff **gue_gro_receive(struct sk_buff **head,
struct sk_buff *skb)
{
@@ -174,6 +311,7 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
struct guehdr *guehdr;
size_t len, optlen, hdrlen, off;
void *data;
+ u16 doffset = 0;
int flush = 1;
off = skb_gro_offset(skb);
@@ -201,19 +339,33 @@ static struct sk_buff **gue_gro_receive(struct sk_buff **head,
hdrlen = sizeof(*guehdr) + optlen;
- skb_gro_pull(skb, hdrlen);
-
- /* Adjusted NAPI_GRO_CB(skb)->csum after skb_gro_pull()*/
+ /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
+ * this is needed if there is a remote checkcsum offload.
+ */
skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
data = &guehdr[1];
if (guehdr->flags & GUE_FLAG_PRIV) {
- data += GUE_LEN_PRIV;
+ __be32 flags = *(__be32 *)(data + doffset);
- /* Process private flags */
+ doffset += GUE_LEN_PRIV;
+
+ if (flags & GUE_PFLAG_REMCSUM) {
+ guehdr = gue_gro_remcsum(skb, off, guehdr,
+ data + doffset, hdrlen,
+ guehdr->proto_ctype);
+ if (!guehdr)
+ goto out;
+
+ data = &guehdr[1];
+
+ doffset += GUE_PLEN_REMCSUM;
+ }
}
+ skb_gro_pull(skb, hdrlen);
+
flush = 0;
for (p = *head; p; p = p->next) {
--
2.1.0.rc2.206.gedb03e5
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2 net-next 0/7] gue: Remote checksum offload
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
` (6 preceding siblings ...)
2014-11-04 17:06 ` [PATCH v2 net-next 7/7] gue: Receive side of remote checksum offload Tom Herbert
@ 2014-11-05 21:44 ` David Miller
7 siblings, 0 replies; 9+ messages in thread
From: David Miller @ 2014-11-05 21:44 UTC (permalink / raw
To: therbert; +Cc: netdev
From: Tom Herbert <therbert@google.com>
Date: Tue, 4 Nov 2014 09:06:50 -0800
> This patch set implements remote checksum offload for
> GUE, which is a mechanism that provides checksum offload of
> encapsulated packets using rudimentary offload capabilities found in
> most Network Interface Card (NIC) devices.
Series applied, thanks for doing this work Tom.
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2014-11-05 21:44 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-11-04 17:06 [PATCH v2 net-next 0/7] gue: Remote checksum offload Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 1/7] net: Move fou_build_header into fou.c and refactor Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 2/7] udp: Offload outer UDP tunnel csum if available Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 3/7] gue: Add infrastructure for flags and options Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 4/7] udp: Changes to udp_offload to support remote checksum offload Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 5/7] gue: Protocol constants for " Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 6/7] gue: TX support for using remote checksum offload option Tom Herbert
2014-11-04 17:06 ` [PATCH v2 net-next 7/7] gue: Receive side of remote checksum offload Tom Herbert
2014-11-05 21:44 ` [PATCH v2 net-next 0/7] gue: Remote " David Miller
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