GSO: Add GSO type for fixed IPv4 ID

This patch adds support for TSO using IPv4 headers with a fixed IP ID
field.  This is meant to allow us to do a lossless GRO in the case of TCP
flows that use a fixed IP ID such as those that convert IPv6 header to IPv4
headers.

In addition I am adding a feature that for now I am referring to TSO with
IP ID mangling.  Basically when this flag is enabled the device has the
option to either output the flow with incrementing IP IDs or with a fixed
IP ID regardless of what the original IP ID ordering was.  This is useful
in cases where the DF bit is set and we do not care if the original IP ID
value is maintained.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index a734bf43d1902b7e7299d98de54da1d9d303cbd7..7cf272a4b5c856e8e0b3a141dd23422b1a896f2f 100644 (file)
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -39,6 +39,7 @@ enum {
        NETIF_F_UFO_BIT,                /* ... UDPv4 fragmentation */
        NETIF_F_GSO_ROBUST_BIT,         /* ... ->SKB_GSO_DODGY */
        NETIF_F_TSO_ECN_BIT,            /* ... TCP ECN support */
+       NETIF_F_TSO_MANGLEID_BIT,       /* ... IPV4 ID mangling allowed */
        NETIF_F_TSO6_BIT,               /* ... TCPv6 segmentation */
        NETIF_F_FSO_BIT,                /* ... FCoE segmentation */
        NETIF_F_GSO_GRE_BIT,            /* ... GRE with TSO */
@@ -120,6 +121,7 @@ enum {
 #define NETIF_F_GSO_SIT                __NETIF_F(GSO_SIT)
 #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_TSO_MANGLEID   __NETIF_F(TSO_MANGLEID)
 #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)
@@ -147,6 +149,7 @@ enum {
 
 /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE   (NETIF_F_TSO | NETIF_F_TSO_ECN | \
+                                NETIF_F_TSO_MANGLEID | \
                                 NETIF_F_TSO6 | NETIF_F_UFO)
 
 /* List of IP checksum features. Note that NETIF_F_ HW_CSUM should not be

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9884fe9a6552a5fa9ea094c9d6ffca6c99c5cdb3..8e372d01b3c196015778310ae3d93108de68cfef 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3992,6 +3992,7 @@ static inline bool net_gso_ok(netdev_features_t features, int gso_type)
        BUILD_BUG_ON(SKB_GSO_UDP     != (NETIF_F_UFO >> NETIF_F_GSO_SHIFT));
        BUILD_BUG_ON(SKB_GSO_DODGY   != (NETIF_F_GSO_ROBUST >> NETIF_F_GSO_SHIFT));
        BUILD_BUG_ON(SKB_GSO_TCP_ECN != (NETIF_F_TSO_ECN >> NETIF_F_GSO_SHIFT));
+       BUILD_BUG_ON(SKB_GSO_TCP_FIXEDID != (NETIF_F_TSO_MANGLEID >> NETIF_F_GSO_SHIFT));
        BUILD_BUG_ON(SKB_GSO_TCPV6   != (NETIF_F_TSO6 >> NETIF_F_GSO_SHIFT));
        BUILD_BUG_ON(SKB_GSO_FCOE    != (NETIF_F_FSO >> NETIF_F_GSO_SHIFT));
        BUILD_BUG_ON(SKB_GSO_GRE     != (NETIF_F_GSO_GRE >> NETIF_F_GSO_SHIFT));

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 007381270ff8d7d92cb05dd31e432983edd4281a..5fba16658f9dd25feb06a93283e1b45317ff3740 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -465,23 +465,25 @@ enum {
        /* This indicates the tcp segment has CWR set. */
        SKB_GSO_TCP_ECN = 1 << 3,
 
-       SKB_GSO_TCPV6 = 1 << 4,
+       SKB_GSO_TCP_FIXEDID = 1 << 4,
 
-       SKB_GSO_FCOE = 1 << 5,
+       SKB_GSO_TCPV6 = 1 << 5,
 
-       SKB_GSO_GRE = 1 << 6,
+       SKB_GSO_FCOE = 1 << 6,
 
-       SKB_GSO_GRE_CSUM = 1 << 7,
+       SKB_GSO_GRE = 1 << 7,
 
-       SKB_GSO_IPIP = 1 << 8,
+       SKB_GSO_GRE_CSUM = 1 << 8,
 
-       SKB_GSO_SIT = 1 << 9,
+       SKB_GSO_IPIP = 1 << 9,
 
-       SKB_GSO_UDP_TUNNEL = 1 << 10,
+       SKB_GSO_SIT = 1 << 10,
 
-       SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
+       SKB_GSO_UDP_TUNNEL = 1 << 11,
 
-       SKB_GSO_TUNNEL_REMCSUM = 1 << 12,
+       SKB_GSO_UDP_TUNNEL_CSUM = 1 << 12,
+
+       SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
 };
 
 #if BITS_PER_LONG > 32

diff --git a/net/core/dev.c b/net/core/dev.c
index 09fb1ace9dc849cf1068bcc6986c7bfeacb13121..e896b1953ab6b2534ba98b6f61b61284045d20cd 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2825,14 +2825,36 @@ static netdev_features_t dflt_features_check(const struct sk_buff *skb,
        return vlan_features_check(skb, features);
 }
 
+static netdev_features_t gso_features_check(const struct sk_buff *skb,
+                                           struct net_device *dev,
+                                           netdev_features_t features)
+{
+       u16 gso_segs = skb_shinfo(skb)->gso_segs;
+
+       if (gso_segs > dev->gso_max_segs)
+               return features & ~NETIF_F_GSO_MASK;
+
+       /* Make sure to clear the IPv4 ID mangling feature if
+        * the IPv4 header has the potential to be fragmented.
+        */
+       if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
+               struct iphdr *iph = skb->encapsulation ?
+                                   inner_ip_hdr(skb) : ip_hdr(skb);
+
+               if (!(iph->frag_off & htons(IP_DF)))
+                       features &= ~NETIF_F_TSO_MANGLEID;
+       }
+
+       return features;
+}
+
 netdev_features_t netif_skb_features(struct sk_buff *skb)
 {
        struct net_device *dev = skb->dev;
        netdev_features_t features = dev->features;
-       u16 gso_segs = skb_shinfo(skb)->gso_segs;
 
-       if (gso_segs > dev->gso_max_segs)
-               features &= ~NETIF_F_GSO_MASK;
+       if (skb_is_gso(skb))
+               features = gso_features_check(skb, dev, features);
 
        /* If encapsulation offload request, verify we are testing
         * hardware encapsulation features instead of standard
@@ -6976,9 +6998,11 @@ int register_netdevice(struct net_device *dev)
        dev->features |= NETIF_F_SOFT_FEATURES;
        dev->wanted_features = dev->features & dev->hw_features;
 
-       if (!(dev->flags & IFF_LOOPBACK)) {
+       if (!(dev->flags & IFF_LOOPBACK))
                dev->hw_features |= NETIF_F_NOCACHE_COPY;
-       }
+
+       if (dev->hw_features & NETIF_F_TSO)
+               dev->hw_features |= NETIF_F_TSO_MANGLEID;
 
        /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
         */

diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 6a7f99661c2fb3e323cd64244cb206fc139da359..9494c41cc77c61ebdddb2e09370a47845687871a 100644 (file)
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -79,6 +79,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
        [NETIF_F_UFO_BIT] =              "tx-udp-fragmentation",
        [NETIF_F_GSO_ROBUST_BIT] =       "tx-gso-robust",
        [NETIF_F_TSO_ECN_BIT] =          "tx-tcp-ecn-segmentation",
+       [NETIF_F_TSO_MANGLEID_BIT] =     "tx-tcp-mangleid-segmentation",
        [NETIF_F_TSO6_BIT] =             "tx-tcp6-segmentation",
        [NETIF_F_FSO_BIT] =              "tx-fcoe-segmentation",
        [NETIF_F_GSO_GRE_BIT] =          "tx-gre-segmentation",

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8217cd22f921d1eef025f2cda12bcb7f4b751384..5bbea9a0ce96f0ae52f51e0cbac8839b12d2f1cd 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1195,10 +1195,10 @@ EXPORT_SYMBOL(inet_sk_rebuild_header);
 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
                                        netdev_features_t features)
 {
+       bool udpfrag = false, fixedid = false, encap;
        struct sk_buff *segs = ERR_PTR(-EINVAL);
        const struct net_offload *ops;
        unsigned int offset = 0;
-       bool udpfrag, encap;
        struct iphdr *iph;
        int proto;
        int nhoff;
@@ -1217,6 +1217,7 @@ 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_TCP_FIXEDID |
                       SKB_GSO_TUNNEL_REMCSUM |
                       0)))
                goto out;
@@ -1248,11 +1249,14 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 
        segs = ERR_PTR(-EPROTONOSUPPORT);
 
-       if (skb->encapsulation &&
-           skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
-               udpfrag = proto == IPPROTO_UDP && encap;
-       else
-               udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
+       if (!skb->encapsulation || encap) {
+               udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
+               fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
+
+               /* fixed ID is invalid if DF bit is not set */
+               if (fixedid && !(iph->frag_off & htons(IP_DF)))
+                       goto out;
+       }
 
        ops = rcu_dereference(inet_offloads[proto]);
        if (likely(ops && ops->callbacks.gso_segment))
@@ -1265,12 +1269,11 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
        do {
                iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
                if (udpfrag) {
-                       iph->id = htons(id);
                        iph->frag_off = htons(offset >> 3);
                        if (skb->next)
                                iph->frag_off |= htons(IP_MF);
                        offset += skb->len - nhoff - ihl;
-               } else {
+               } else if (!fixedid) {
                        iph->id = htons(id++);
                }
                iph->tot_len = htons(skb->len - nhoff);

diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 6a5bd43178666eed954c4ee6f22837059fad470d..6376b0cdf6931661b6e40426106ccd017b4162a6 100644 (file)
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -32,6 +32,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
                                  SKB_GSO_UDP |
                                  SKB_GSO_DODGY |
                                  SKB_GSO_TCP_ECN |
+                                 SKB_GSO_TCP_FIXEDID |
                                  SKB_GSO_GRE |
                                  SKB_GSO_GRE_CSUM |
                                  SKB_GSO_IPIP |

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 773083b7f1e98906f5cdc93f770829f293fea205..08dd25d835af956e2da7cd459375d7e26b3bcf2a 100644 (file)
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -89,6 +89,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
                             ~(SKB_GSO_TCPV4 |
                               SKB_GSO_DODGY |
                               SKB_GSO_TCP_ECN |
+                              SKB_GSO_TCP_FIXEDID |
                               SKB_GSO_TCPV6 |
                               SKB_GSO_GRE |
                               SKB_GSO_GRE_CSUM |
@@ -98,7 +99,8 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
                               SKB_GSO_UDP_TUNNEL_CSUM |
                               SKB_GSO_TUNNEL_REMCSUM |
                               0) ||
-                            !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
+                            !(type & (SKB_GSO_TCPV4 |
+                                      SKB_GSO_TCPV6))))
                        goto out;
 
                skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);

diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 204af221947139c0c308062921a73484df306031..b3a779393d7136fb236a5a429efed65787110cbe 100644 (file)
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -73,6 +73,8 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                       SKB_GSO_UDP |
                       SKB_GSO_DODGY |
                       SKB_GSO_TCP_ECN |
+                      SKB_GSO_TCP_FIXEDID |
+                      SKB_GSO_TCPV6 |
                       SKB_GSO_GRE |
                       SKB_GSO_GRE_CSUM |
                       SKB_GSO_IPIP |
@@ -80,7 +82,6 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                       SKB_GSO_UDP_TUNNEL |
                       SKB_GSO_UDP_TUNNEL_CSUM |
                       SKB_GSO_TUNNEL_REMCSUM |
-                      SKB_GSO_TCPV6 |
                       0)))
                goto out;
 

diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index 0183b32da9427d39aa761e00e080afeff7e4b6d5..bbcf60465e5c439a51b7ef72dcd0d4ddca244ea7 100644 (file)
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -31,6 +31,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
                                  SKB_GSO_TCPV6 |
                                  SKB_GSO_UDP |
                                  SKB_GSO_DODGY |
+                                 SKB_GSO_TCP_FIXEDID |
                                  SKB_GSO_TCP_ECN)))
                goto out;