[NET]: IPV6 checksum offloading in network devices

The existing model for checksum offload does not correctly handle
devices that can offload IPV4 and IPV6 only. The NETIF_F_HW_CSUM flag
implies device can do any arbitrary protocol.

This patch:
 * adds NETIF_F_IPV6_CSUM for those devices
 * fixes bnx2 and tg3 devices that need it
 * add NETIF_F_IPV6_CSUM to ipv6 output (incl GSO)
 * fixes assumptions about NETIF_F_ALL_CSUM in nat
 * adjusts bridge union of checksumming computation

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index ce3ed67..0f4f76f 100644 (file)
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -6490,10 +6490,10 @@ bnx2_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        memcpy(dev->perm_addr, bp->mac_addr, 6);
        bp->name = board_info[ent->driver_data].name;
 
+       dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
        if (CHIP_NUM(bp) == CHIP_NUM_5709)
-               dev->features |= NETIF_F_HW_CSUM | NETIF_F_SG;
-       else
-               dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
+               dev->features |= NETIF_F_IPV6_CSUM;
+
 #ifdef BCM_VLAN
        dev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
 #endif

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 2f31841..3a43426 100644 (file)
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -11944,12 +11944,11 @@ static int __devinit tg3_init_one(struct pci_dev *pdev,
         * checksumming.
         */
        if ((tp->tg3_flags & TG3_FLAG_BROKEN_CHECKSUMS) == 0) {
+               dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
                if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5755 ||
                    GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5787)
-                       dev->features |= NETIF_F_HW_CSUM;
-               else
-                       dev->features |= NETIF_F_IP_CSUM;
-               dev->features |= NETIF_F_SG;
+                       dev->features |= NETIF_F_IPV6_CSUM;
+
                tp->tg3_flags |= TG3_FLAG_RX_CHECKSUMS;
        } else
                tp->tg3_flags &= ~TG3_FLAG_RX_CHECKSUMS;

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e7913ee..7a8f22f 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -314,9 +314,10 @@ struct net_device
        /* Net device features */
        unsigned long           features;
 #define NETIF_F_SG             1       /* Scatter/gather IO. */
-#define NETIF_F_IP_CSUM                2       /* Can checksum only TCP/UDP over IPv4. */
+#define NETIF_F_IP_CSUM                2       /* Can checksum TCP/UDP over IPv4. */
 #define NETIF_F_NO_CSUM                4       /* Does not require checksum. F.e. loopack. */
 #define NETIF_F_HW_CSUM                8       /* Can checksum all the packets. */
+#define NETIF_F_IPV6_CSUM      16      /* Can checksum TCP/UDP over IPV6 */
 #define NETIF_F_HIGHDMA                32      /* Can DMA to high memory. */
 #define NETIF_F_FRAGLIST       64      /* Scatter/gather IO. */
 #define NETIF_F_HW_VLAN_TX     128     /* Transmit VLAN hw acceleration */
@@ -338,8 +339,11 @@ struct net_device
        /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE   (NETIF_F_TSO | NETIF_F_TSO_ECN | NETIF_F_TSO6)
 
+
 #define NETIF_F_GEN_CSUM       (NETIF_F_NO_CSUM | NETIF_F_HW_CSUM)
-#define NETIF_F_ALL_CSUM       (NETIF_F_IP_CSUM | NETIF_F_GEN_CSUM)
+#define NETIF_F_V4_CSUM                (NETIF_F_GEN_CSUM | NETIF_F_IP_CSUM)
+#define NETIF_F_V6_CSUM                (NETIF_F_GEN_CSUM | NETIF_F_IPV6_CSUM)
+#define NETIF_F_ALL_CSUM       (NETIF_F_V4_CSUM | NETIF_F_V6_CSUM)
 
        struct net_device       *next_sched;
 

diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index 849deaf..7b4ce91 100644 (file)
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -368,10 +368,18 @@ void br_features_recompute(struct net_bridge *br)
        list_for_each_entry(p, &br->port_list, list) {
                unsigned long feature = p->dev->features;
 
+               /* if device needs checksumming, downgrade to hw checksumming */
                if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
                        checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
+
+               /* if device can't do all checksum, downgrade to ipv4/ipv6 */
                if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
-                       checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
+                       checksum ^= NETIF_F_HW_CSUM
+                               | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+
+               if (checksum & NETIF_F_IPV6_CSUM && !(feature & NETIF_F_IPV6_CSUM))
+                       checksum &= ~NETIF_F_IPV6_CSUM;
+
                if (!(feature & NETIF_F_IP_CSUM))
                        checksum = 0;
 

diff --git a/net/core/dev.c b/net/core/dev.c
index ee051bb..a0a46e7 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1509,9 +1509,11 @@ int dev_queue_xmit(struct sk_buff *skb)
                skb_set_transport_header(skb, skb->csum_start -
                                              skb_headroom(skb));
 
-               if (!(dev->features & NETIF_F_GEN_CSUM) &&
-                   (!(dev->features & NETIF_F_IP_CSUM) ||
-                    skb->protocol != htons(ETH_P_IP)))
+               if (!(dev->features & NETIF_F_GEN_CSUM)
+                   || ((dev->features & NETIF_F_IP_CSUM)
+                       && skb->protocol == htons(ETH_P_IP))
+                   || ((dev->features & NETIF_F_IPV6_CSUM)
+                       && skb->protocol == htons(ETH_P_IPV6)))
                        if (skb_checksum_help(skb))
                                goto out_kfree_skb;
        }
@@ -3107,6 +3109,22 @@ int register_netdevice(struct net_device *dev)
                }
        }
 
+       /* Fix illegal checksum combinations */
+       if ((dev->features & NETIF_F_HW_CSUM) &&
+           (dev->features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
+               printk(KERN_NOTICE "%s: mixed HW and IP checksum settings.\n",
+                      dev->name);
+               dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
+       }
+
+       if ((dev->features & NETIF_F_NO_CSUM) &&
+           (dev->features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
+               printk(KERN_NOTICE "%s: mixed no checksumming and other settings.\n",
+                      dev->name);
+               dev->features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
+       }
+
+
        /* Fix illegal SG+CSUM combinations. */
        if ((dev->features & NETIF_F_SG) &&
            !(dev->features & NETIF_F_ALL_CSUM)) {

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 041fba3..06c08e5 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1170,6 +1170,9 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
        int ihl;
        int id;
 
+       if (!(features & NETIF_F_V4_CSUM))
+               features &= ~NETIF_F_SG;
+
        if (unlikely(skb_shinfo(skb)->gso_type &
                     ~(SKB_GSO_TCPV4 |
                       SKB_GSO_UDP |

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 34ea454..a7dd343 100644 (file)
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -837,7 +837,7 @@ int ip_append_data(struct sock *sk,
         */
        if (transhdrlen &&
            length + fragheaderlen <= mtu &&
-           rt->u.dst.dev->features & NETIF_F_ALL_CSUM &&
+           rt->u.dst.dev->features & NETIF_F_V4_CSUM &&
            !exthdrlen)
                csummode = CHECKSUM_PARTIAL;
 

diff --git a/net/ipv4/netfilter/nf_nat_helper.c b/net/ipv4/netfilter/nf_nat_helper.c
index 15b6e5c..b1aa598 100644 (file)
--- a/net/ipv4/netfilter/nf_nat_helper.c
+++ b/net/ipv4/netfilter/nf_nat_helper.c
@@ -178,7 +178,7 @@ nf_nat_mangle_tcp_packet(struct sk_buff **pskb,
        datalen = (*pskb)->len - iph->ihl*4;
        if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
                if (!(rt->rt_flags & RTCF_LOCAL) &&
-                   (*pskb)->dev->features & NETIF_F_ALL_CSUM) {
+                   (*pskb)->dev->features & NETIF_F_V4_CSUM) {
                        (*pskb)->ip_summed = CHECKSUM_PARTIAL;
                        (*pskb)->csum_start = skb_headroom(*pskb) +
                                              skb_network_offset(*pskb) +
@@ -265,7 +265,7 @@ nf_nat_mangle_udp_packet(struct sk_buff **pskb,
 
        if ((*pskb)->ip_summed != CHECKSUM_PARTIAL) {
                if (!(rt->rt_flags & RTCF_LOCAL) &&
-                   (*pskb)->dev->features & NETIF_F_ALL_CSUM) {
+                   (*pskb)->dev->features & NETIF_F_V4_CSUM) {
                        (*pskb)->ip_summed = CHECKSUM_PARTIAL;
                        (*pskb)->csum_start = skb_headroom(*pskb) +
                                              skb_network_offset(*pskb) +

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index b636c38..1c35066 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -123,7 +123,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, int features)
        struct ipv6hdr *ipv6h;
        struct inet6_protocol *ops;
 
-       if (!(features & NETIF_F_HW_CSUM))
+       if (!(features & NETIF_F_V6_CSUM))
                features &= ~NETIF_F_SG;
 
        if (unlikely(skb_shinfo(skb)->gso_type &