Paul Durrant
2013-Nov-26 16:41 UTC
[PATCH net-next v3] xen-netfront: Add support for IPv6 offloads
This patch adds support for IPv6 checksum offload and GSO when those
features are available in the backend.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Annie Li <annie.li@oracle.com>
---
v3:
- Addressed comments raised by Annie Li
v2:
- Addressed comments raised by Ian Campbell
drivers/net/xen-netfront.c | 239 ++++++++++++++++++++++++++++++++++++++++----
include/linux/ipv6.h | 2 +
2 files changed, 224 insertions(+), 17 deletions(-)
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index dd1011e..fe747e4 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -616,7 +616,9 @@ static int xennet_start_xmit(struct sk_buff *skb, struct
net_device *dev)
tx->flags |= XEN_NETTXF_extra_info;
gso->u.gso.size = skb_shinfo(skb)->gso_size;
- gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
+ gso->u.gso.type = (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) ?
+ XEN_NETIF_GSO_TYPE_TCPV6 :
+ XEN_NETIF_GSO_TYPE_TCPV4;
gso->u.gso.pad = 0;
gso->u.gso.features = 0;
@@ -808,15 +810,18 @@ static int xennet_set_skb_gso(struct sk_buff *skb,
return -EINVAL;
}
- /* Currently only TCPv4 S.O. is supported. */
- if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4) {
+ if (gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV4 &&
+ gso->u.gso.type != XEN_NETIF_GSO_TYPE_TCPV6) {
if (net_ratelimit())
pr_warn("Bad GSO type %d\n", gso->u.gso.type);
return -EINVAL;
}
skb_shinfo(skb)->gso_size = gso->u.gso.size;
- skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+ skb_shinfo(skb)->gso_type + (gso->u.gso.type ==
XEN_NETIF_GSO_TYPE_TCPV4) ?
+ SKB_GSO_TCPV4 :
+ SKB_GSO_TCPV6;
/* Header must be checked, and gso_segs computed. */
skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
@@ -856,11 +861,42 @@ static RING_IDX xennet_fill_frags(struct netfront_info
*np,
return cons;
}
-static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
+static inline bool maybe_pull_tail(struct sk_buff *skb, unsigned int min,
+ unsigned int max)
{
- struct iphdr *iph;
- int err = -EPROTO;
+ int target;
+
+ BUG_ON(max < min);
+
+ if (!skb_is_nonlinear(skb) || skb_headlen(skb) >= min)
+ return true;
+
+ /* If we need to pullup then pullup to max, so we hopefully
+ * won''t need to do it again.
+ */
+ target = min_t(int, skb->len, max);
+ __pskb_pull_tail(skb, target - skb_headlen(skb));
+
+ if (skb_headlen(skb) < min) {
+ net_err_ratelimited("Failed to pullup packet header\n");
+ return false;
+ }
+
+ return true;
+}
+
+/* This value should be large enough to cover a tagged ethernet header plus
+ * maximally sized IP and TCP or UDP headers.
+ */
+#define MAX_IP_HEADER 128
+
+static int checksum_setup_ip(struct net_device *dev, struct sk_buff *skb)
+{
+ struct iphdr *iph = (void *)skb->data;
+ unsigned int header_size;
+ unsigned int off;
int recalculate_partial_csum = 0;
+ int err = -EPROTO;
/*
* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy
@@ -879,40 +915,158 @@ static int checksum_setup(struct net_device *dev, struct
sk_buff *skb)
if (skb->ip_summed != CHECKSUM_PARTIAL)
return 0;
- if (skb->protocol != htons(ETH_P_IP))
+ off = sizeof(struct iphdr);
+
+ header_size = skb->network_header + off;
+ if (!maybe_pull_tail(skb, header_size, MAX_IP_HEADER))
goto out;
- iph = (void *)skb->data;
+ off = iph->ihl * 4;
switch (iph->protocol) {
case IPPROTO_TCP:
- if (!skb_partial_csum_set(skb, 4 * iph->ihl,
+ if (!skb_partial_csum_set(skb, off,
offsetof(struct tcphdr, check)))
goto out;
if (recalculate_partial_csum) {
struct tcphdr *tcph = tcp_hdr(skb);
+
+ header_size = skb->network_header +
+ off +
+ sizeof(struct tcphdr);
+ if (!maybe_pull_tail(skb, header_size, MAX_IP_HEADER))
+ goto out;
+
tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
- skb->len - iph->ihl*4,
+ skb->len - off,
IPPROTO_TCP, 0);
}
break;
case IPPROTO_UDP:
- if (!skb_partial_csum_set(skb, 4 * iph->ihl,
+ if (!skb_partial_csum_set(skb, off,
offsetof(struct udphdr, check)))
goto out;
if (recalculate_partial_csum) {
struct udphdr *udph = udp_hdr(skb);
+
+ header_size = skb->network_header +
+ off +
+ sizeof(struct udphdr);
+ if (!maybe_pull_tail(skb, header_size, MAX_IP_HEADER))
+ goto out;
+
udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr,
- skb->len - iph->ihl*4,
+ skb->len - off,
IPPROTO_UDP, 0);
}
break;
default:
- if (net_ratelimit())
- pr_err("Attempting to checksum a non-TCP/UDP packet, dropping a
protocol %d packet\n",
- iph->protocol);
+ net_err_ratelimited("Attempting to checksum a non-TCP/UDP packet,
dropping a protocol %d packet\n",
+ iph->protocol);
+ goto out;
+ }
+
+ err = 0;
+
+out:
+ return err;
+}
+
+/* This value should be large enough to cover a tagged ethernet header plus
+ * an IPv6 header, all options, and a maximal TCP or UDP header.
+ */
+#define MAX_IPV6_HEADER 256
+
+static int checksum_setup_ipv6(struct net_device *dev, struct sk_buff *skb)
+{
+ struct ipv6hdr *ipv6h = (void *)skb->data;
+ u8 nexthdr;
+ unsigned int header_size;
+ unsigned int off;
+ bool fragment;
+ bool done;
+ int err = -EPROTO;
+
+ done = false;
+
+ /* A non-CHECKSUM_PARTIAL SKB does not require setup. */
+ if (skb->ip_summed != CHECKSUM_PARTIAL)
+ return 0;
+
+ off = sizeof(struct ipv6hdr);
+
+ header_size = skb->network_header + off;
+ if (!maybe_pull_tail(skb, header_size, MAX_IPV6_HEADER))
+ goto out;
+
+ nexthdr = ipv6h->nexthdr;
+
+ while ((off <= sizeof(struct ipv6hdr) + ntohs(ipv6h->payload_len))
&&
+ !done) {
+ switch (nexthdr) {
+ case IPPROTO_DSTOPTS:
+ case IPPROTO_HOPOPTS:
+ case IPPROTO_ROUTING: {
+ struct ipv6_opt_hdr *hp = (void *)(skb->data + off);
+
+ header_size = skb->network_header +
+ off +
+ sizeof(struct ipv6_opt_hdr);
+ if (!maybe_pull_tail(skb, header_size, MAX_IPV6_HEADER))
+ goto out;
+
+ nexthdr = hp->nexthdr;
+ off += ipv6_optlen(hp);
+ break;
+ }
+ case IPPROTO_AH: {
+ struct ip_auth_hdr *hp = (void *)(skb->data + off);
+
+ header_size = skb->network_header +
+ off +
+ sizeof(struct ip_auth_hdr);
+ if (!maybe_pull_tail(skb, header_size, MAX_IPV6_HEADER))
+ goto out;
+
+ nexthdr = hp->nexthdr;
+ off += ipv6_ahlen(hp);
+ break;
+ }
+ case IPPROTO_FRAGMENT:
+ fragment = true;
+ /* fall through */
+ default:
+ done = true;
+ break;
+ }
+ }
+
+ if (!done) {
+ net_err_ratelimited("Failed to parse packet header\n");
+ goto out;
+ }
+
+ if (fragment) {
+ net_err_ratelimited("Packet is a fragment!\n");
+ goto out;
+ }
+
+ switch (nexthdr) {
+ case IPPROTO_TCP:
+ if (!skb_partial_csum_set(skb, off,
+ offsetof(struct tcphdr, check)))
+ goto out;
+ break;
+ case IPPROTO_UDP:
+ if (!skb_partial_csum_set(skb, off,
+ offsetof(struct udphdr, check)))
+ goto out;
+ break;
+ default:
+ net_err_ratelimited("Attempting to checksum a non-TCP/UDP packet,
dropping a protocol %d packet\n",
+ nexthdr);
goto out;
}
@@ -922,6 +1076,25 @@ out:
return err;
}
+static int checksum_setup(struct net_device *dev, struct sk_buff *skb)
+{
+ int err;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ err = checksum_setup_ip(dev, skb);
+ break;
+ case htons(ETH_P_IPV6):
+ err = checksum_setup_ipv6(dev, skb);
+ break;
+ default:
+ err = -EPROTO;
+ break;
+ }
+
+ return err;
+}
+
static int handle_incoming_queue(struct net_device *dev,
struct sk_buff_head *rxq)
{
@@ -1232,6 +1405,15 @@ static netdev_features_t xennet_fix_features(struct
net_device *dev,
features &= ~NETIF_F_SG;
}
+ if (features & NETIF_F_IPV6_CSUM) {
+ if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
+ "feature-ipv6-csum-offload", "%d", &val) < 0)
+ val = 0;
+
+ if (!val)
+ features &= ~NETIF_F_IPV6_CSUM;
+ }
+
if (features & NETIF_F_TSO) {
if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
"feature-gso-tcpv4", "%d", &val) < 0)
@@ -1241,6 +1423,15 @@ static netdev_features_t xennet_fix_features(struct
net_device *dev,
features &= ~NETIF_F_TSO;
}
+ if (features & NETIF_F_TSO6) {
+ if (xenbus_scanf(XBT_NIL, np->xbdev->otherend,
+ "feature-gso-tcpv6", "%d", &val) < 0)
+ val = 0;
+
+ if (!val)
+ features &= ~NETIF_F_TSO6;
+ }
+
return features;
}
@@ -1373,7 +1564,9 @@ static struct net_device *xennet_create_dev(struct
xenbus_device *dev)
netif_napi_add(netdev, &np->napi, xennet_poll, 64);
netdev->features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
NETIF_F_GSO_ROBUST;
- netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO;
+ netdev->hw_features = NETIF_F_SG |
+ NETIF_F_IPV6_CSUM |
+ NETIF_F_TSO | NETIF_F_TSO6;
/*
* Assume that all hw features are available for now. This set
@@ -1751,6 +1944,18 @@ again:
goto abort_transaction;
}
+ err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
"%d", 1);
+ if (err) {
+ message = "writing feature-gso-tcpv6";
+ goto abort_transaction;
+ }
+
+ err = xenbus_printf(xbt, dev->nodename,
"feature-ipv6-csum-offload", "%d", 1);
+ if (err) {
+ message = "writing feature-ipv6-csum-offload";
+ goto abort_transaction;
+ }
+
err = xenbus_transaction_end(xbt, 0);
if (err) {
if (err == -EAGAIN)
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 5d89d1b..10f1b03 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -4,6 +4,8 @@
#include <uapi/linux/ipv6.h>
#define ipv6_optlen(p) (((p)->hdrlen+1) << 3)
+#define ipv6_ahlen(p) (((p)->hdrlen+2) << 2);
+
/*
* This structure contains configuration options per IPv6 link.
*/
--
1.7.10.4
David Miller
2013-Nov-28 23:50 UTC
Re: [PATCH net-next v3] xen-netfront: Add support for IPv6 offloads
From: Paul Durrant <paul.durrant@citrix.com> Date: Tue, 26 Nov 2013 16:41:52 +0000> This patch adds support for IPv6 checksum offload and GSO when those > features are available in the backend. > > Signed-off-by: Paul Durrant <paul.durrant@citrix.com>Please resubmit this when the net-next tree opens back up, thank you.