| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 18 Mar 2016 16:25:22 -0700
From: Alexander Duyck <aduyck@...antis.com>
To: ecree@...arflare.com, netdev@...r.kernel.org, davem@...emloft.net,
alexander.duyck@...il.com, tom@...bertland.com
Subject: [RFC PATCH 7/9] GSO: Support partial segmentation offload
This patch adds support for something I am referring to as GSO partial.
The basic idea is that we can support a broader range of devices for
segmentation if we use fixed outer headers and have the hardware only
really deal with segmenting the inner header. The idea behind the naming
is due to the fact that everything before csum_start will be fixed headers,
and everything after will be the region that is handled by hardware.
With the current implementation it allows us to add support for the
following GSO types with an inner TSO or TSO6 offload:
NETIF_F_GSO_GRE
NETIF_F_GSO_GRE_CSUM
NETIF_F_UDP_TUNNEL
NETIF_F_UDP_TUNNEL_CSUM
Signed-off-by: Alexander Duyck <aduyck@...antis.com>
---
include/linux/netdev_features.h | 7 ++++++-
include/linux/netdevice.h | 2 ++
include/linux/skbuff.h | 7 ++++++-
net/core/dev.c | 31 ++++++++++++++++++++++++++++++-
net/core/ethtool.c | 1 +
net/core/skbuff.c | 21 ++++++++++++++++++++-
net/ipv4/af_inet.c | 12 ++++++++++--
net/ipv4/gre_offload.c | 23 +++++++++++++++++++----
net/ipv4/tcp_offload.c | 10 ++++++++--
net/ipv4/udp_offload.c | 20 ++++++++++++++++----
net/ipv6/ip6_offload.c | 9 ++++++++-
11 files changed, 126 insertions(+), 17 deletions(-)
diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index a734bf43d190..8df3c5553af0 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -48,8 +48,12 @@ 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_TUNNEL_REMCSUM_BIT, /* ... TUNNEL with TSO & REMCSUM */
+ NETIF_F_GSO_PARTIAL_BIT, /* ... Only segment inner-most L4
+ * in hardware and all other
+ * headers in software.
+ */
/**/NETIF_F_GSO_LAST = /* last bit, see GSO_MASK */
- NETIF_F_GSO_TUNNEL_REMCSUM_BIT,
+ NETIF_F_GSO_PARTIAL_BIT,
NETIF_F_FCOE_CRC_BIT, /* FCoE CRC32 */
NETIF_F_SCTP_CRC_BIT, /* SCTP checksum offload */
@@ -121,6 +125,7 @@ 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_TUNNEL_REMCSUM __NETIF_F(GSO_TUNNEL_REMCSUM)
+#define NETIF_F_GSO_PARTIAL __NETIF_F(GSO_PARTIAL)
#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 31474d9d8a96..427d748ad8f9 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1647,6 +1647,7 @@ struct net_device {
netdev_features_t vlan_features;
netdev_features_t hw_enc_features;
netdev_features_t mpls_features;
+ netdev_features_t gso_partial_features;
int ifindex;
int group;
@@ -4014,6 +4015,7 @@ 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_TUNNEL_REMCSUM != (NETIF_F_GSO_TUNNEL_REMCSUM >> NETIF_F_GSO_SHIFT));
+ BUILD_BUG_ON(SKB_GSO_PARTIAL != (NETIF_F_GSO_PARTIAL >> NETIF_F_GSO_SHIFT));
return (features & feature) == feature;
}
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 15d0df943466..c291a282f8b6 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -482,6 +482,8 @@ enum {
SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
SKB_GSO_TUNNEL_REMCSUM = 1 << 12,
+
+ SKB_GSO_PARTIAL = 1 << 13,
};
#if BITS_PER_LONG > 32
@@ -3584,7 +3586,10 @@ static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
* Keeps track of level of encapsulation of network headers.
*/
struct skb_gso_cb {
- int mac_offset;
+ union {
+ int mac_offset;
+ int data_offset;
+ };
int encap_level;
__wsum csum;
__u16 csum_start;
diff --git a/net/core/dev.c b/net/core/dev.c
index edb7179bc051..666cf427898b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2711,6 +2711,19 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
return ERR_PTR(err);
}
+ /* Only report GSO partial support if it will enable us to
+ * support segmentation on this frame without needing additional
+ * work.
+ */
+ if (features & NETIF_F_GSO_PARTIAL) {
+ netdev_features_t partial_features;
+ struct net_device *dev = skb->dev;
+
+ partial_features = dev->features & dev->gso_partial_features;
+ if (!skb_gso_ok(skb, features | partial_features))
+ features &= ~NETIF_F_GSO_PARTIAL;
+ }
+
BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
@@ -2841,6 +2854,14 @@ netdev_features_t netif_skb_features(struct sk_buff *skb)
if (skb->encapsulation)
features &= dev->hw_enc_features;
+ /* Support for GSO partial features requires software intervention
+ * before we can actually process the packets so we need to strip
+ * support for any partial features now and we can pull them back
+ * in after we have partially segmented the frame.
+ */
+ if (skb_is_gso(skb) && !(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
+ features &= ~dev->gso_partial_features;
+
if (skb_vlan_tagged(skb))
features = netdev_intersect_features(features,
dev->vlan_features |
@@ -6702,6 +6723,14 @@ static netdev_features_t netdev_fix_features(struct net_device *dev,
}
}
+ /* GSO partial features require GSO partial be set */
+ if ((features & dev->gso_partial_features) &&
+ !(features & NETIF_F_GSO_PARTIAL)) {
+ netdev_dbg(dev,
+ "Dropping partially supported GSO features since no GSO partial.\n");
+ features &= ~dev->gso_partial_features;
+ }
+
#ifdef CONFIG_NET_RX_BUSY_POLL
if (dev->netdev_ops->ndo_busy_poll)
features |= NETIF_F_BUSY_POLL;
@@ -6982,7 +7011,7 @@ int register_netdevice(struct net_device *dev)
/* Make NETIF_F_SG inheritable to tunnel devices.
*/
- dev->hw_enc_features |= NETIF_F_SG;
+ dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
/* Make NETIF_F_SG inheritable to MPLS.
*/
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index b3c39d531469..d1b278c6c29f 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -88,6 +88,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
[NETIF_F_GSO_UDP_TUNNEL_BIT] = "tx-udp_tnl-segmentation",
[NETIF_F_GSO_UDP_TUNNEL_CSUM_BIT] = "tx-udp_tnl-csum-segmentation",
[NETIF_F_GSO_TUNNEL_REMCSUM_BIT] = "tx-remcsum-segmentation",
+ [NETIF_F_GSO_PARTIAL_BIT] = "tx-gso-partial",
[NETIF_F_FCOE_CRC_BIT] = "tx-checksum-fcoe-crc",
[NETIF_F_SCTP_CRC_BIT] = "tx-checksum-sctp",
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f044f970f1a6..bdcba77e164c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3076,8 +3076,9 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
struct sk_buff *frag_skb = head_skb;
unsigned int offset = doffset;
unsigned int tnl_hlen = skb_tnl_header_len(head_skb);
+ unsigned int partial_segs = 0;
unsigned int headroom;
- unsigned int len;
+ unsigned int len = head_skb->len;
__be16 proto;
bool csum;
int sg = !!(features & NETIF_F_SG);
@@ -3094,6 +3095,15 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
csum = !!can_checksum_protocol(features, proto);
+ /* GSO partial only requires that we trim off any excess that
+ * doesn't fit into an MSS sized block, so take care of that
+ * now.
+ */
+ if (features & NETIF_F_GSO_PARTIAL) {
+ partial_segs = len / mss;
+ mss *= partial_segs;
+ }
+
headroom = skb_headroom(head_skb);
pos = skb_headlen(head_skb);
@@ -3281,6 +3291,15 @@ perform_csum_check:
*/
segs->prev = tail;
+ /* Update GSO info on first skb in partial sequence. */
+ if (partial_segs) {
+ skb_shinfo(segs)->gso_size = mss / partial_segs;
+ skb_shinfo(segs)->gso_segs = partial_segs;
+ skb_shinfo(segs)->gso_type = skb_shinfo(head_skb)->gso_type |
+ SKB_GSO_PARTIAL;
+ SKB_GSO_CB(segs)->data_offset = skb_headroom(segs) + doffset;
+ }
+
/* Following permits correct backpressure, for protocols
* using skb_set_owner_w().
* Idea is to tranfert ownership from head_skb to last segment.
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5e3885672907..d091f91fa25d 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1199,7 +1199,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
unsigned int offset = 0;
bool udpfrag, encap;
struct iphdr *iph;
- int proto;
+ int proto, tot_len;
int nhoff;
int ihl;
int id;
@@ -1269,10 +1269,18 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
if (skb->next)
iph->frag_off |= htons(IP_MF);
offset += skb->len - nhoff - ihl;
+ tot_len = skb->len - nhoff;
+ } else if (skb_is_gso(skb)) {
+ iph->id = htons(id);
+ id += skb_shinfo(skb)->gso_segs;
+ tot_len = skb_shinfo(skb)->gso_size +
+ SKB_GSO_CB(skb)->data_offset +
+ skb->head - (unsigned char *)iph;
} else {
iph->id = htons(id++);
+ tot_len = skb->len - nhoff;
}
- iph->tot_len = htons(skb->len - nhoff);
+ iph->tot_len = htons(tot_len);
ip_send_check(iph);
if (encap)
skb_reset_inner_headers(skb);
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 7ea14ced9222..dea0390d65bb 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -85,7 +85,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
skb = segs;
do {
struct gre_base_hdr *greh;
- __be32 *pcsum;
+ __sum16 *pcsum;
/* Set up inner headers if we are offloading inner checksum */
if (skb->ip_summed == CHECKSUM_PARTIAL) {
@@ -105,10 +105,25 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
continue;
greh = (struct gre_base_hdr *)skb_transport_header(skb);
- pcsum = (__be32 *)(greh + 1);
+ pcsum = (__sum16 *)(greh + 1);
+
+ if (skb_is_gso(skb)) {
+ unsigned int partial_adj;
+
+ /* Adjust checksum to account for the fact that
+ * the partial checksum is based on actual size
+ * whereas headers should be based on MSS size.
+ */
+ partial_adj = skb->len + skb_headroom(skb) -
+ SKB_GSO_CB(skb)->data_offset -
+ skb_shinfo(skb)->gso_size;
+ *pcsum = ~csum_fold((__force __wsum)htonl(partial_adj));
+ } else {
+ *pcsum = 0;
+ }
- *pcsum = 0;
- *(__sum16 *)pcsum = gso_make_checksum(skb, 0);
+ *(pcsum + 1) = 0;
+ *pcsum = gso_make_checksum(skb, 0);
} while ((skb = skb->next));
out:
return segs;
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 1a2e9957c177..4e9b8f011473 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -107,6 +107,12 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
goto out;
}
+ /* GSO partial only requires splitting the frame into an MSS
+ * multiple and possibly a remainder. So update the mss now.
+ */
+ if (features & NETIF_F_GSO_PARTIAL)
+ mss = skb->len - (skb->len % mss);
+
copy_destructor = gso_skb->destructor == tcp_wfree;
ooo_okay = gso_skb->ooo_okay;
/* All segments but the first should have ooo_okay cleared */
@@ -131,7 +137,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
newcheck = ~csum_fold((__force __wsum)((__force u32)th->check +
(__force u32)delta));
- do {
+ while (skb->next) {
th->fin = th->psh = 0;
th->check = newcheck;
@@ -151,7 +157,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
th->seq = htonl(seq);
th->cwr = 0;
- } while (skb->next);
+ }
/* Following permits TCP Small Queues to work well with GSO :
* The callback to TCP stack will be called at the time last frag
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 8a3405a80260..5fcb93269afb 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -100,7 +100,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
udp_offset = outer_hlen - tnl_hlen;
skb = segs;
do {
- __be16 len;
+ unsigned int len;
if (remcsum)
skb->ip_summed = CHECKSUM_NONE;
@@ -118,14 +118,26 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
skb_reset_mac_header(skb);
skb_set_network_header(skb, mac_len);
skb_set_transport_header(skb, udp_offset);
- len = htons(skb->len - udp_offset);
+ len = skb->len - udp_offset;
uh = udp_hdr(skb);
- uh->len = len;
+
+ /* If we are only performing partial GSO the inner header
+ * will be using a length value equal to only one MSS sized
+ * segment instead of the entire frame.
+ */
+ if (skb_is_gso(skb)) {
+ uh->len = htons(skb_shinfo(skb)->gso_size +
+ SKB_GSO_CB(skb)->data_offset +
+ skb->head - (unsigned char *)uh);
+ } else {
+ uh->len = htons(len);
+ }
if (!need_csum)
continue;
- uh->check = ~csum_fold(csum_add(partial, (__force __wsum)len));
+ uh->check = ~csum_fold(csum_add(partial,
+ (__force __wsum)htonl(len)));
if (skb->encapsulation || !offload_csum) {
uh->check = gso_make_checksum(skb, ~uh->check);
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index eeca943f12dc..d467053c226a 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -63,6 +63,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
int proto;
struct frag_hdr *fptr;
unsigned int unfrag_ip6hlen;
+ unsigned int payload_len;
u8 *prevhdr;
int offset = 0;
bool encap, udpfrag;
@@ -117,7 +118,13 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
for (skb = segs; skb; skb = skb->next) {
ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);
- ipv6h->payload_len = htons(skb->len - nhoff - sizeof(*ipv6h));
+ if (skb_is_gso(skb))
+ payload_len = skb_shinfo(skb)->gso_size +
+ SKB_GSO_CB(skb)->data_offset +
+ skb->head - (unsigned char *)(ipv6h + 1);
+ else
+ payload_len = skb->len - nhoff - sizeof(*ipv6h);
+ ipv6h->payload_len = htons(payload_len);
skb->network_header = (u8 *)ipv6h - skb->head;
if (udpfrag) {
Powered by blists - more mailing lists