geneve: expose gso partial features for tunnel offload

GSO partial features for tunnels do not require any kind of support from
the underlying device: we can safely add them to the geneve UDP tunnel.

The only point of attention is the skb required features propagation in
the device xmit op: partial features must be stripped, except for
UDP_TUNNEL*.

Keep partial features disabled by default.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/d851ca8e928cf05d68310bcbaeaa5e9e0b01e058.1769011015.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 77b0c3d52041405eaaa1fbd25fa14d2bbe5a123d..64ea4b9703767b39b14e35ef97ee456b87582e38 100644 (file)
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -774,6 +774,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
        bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
        struct genevehdr *gnvh;
        __be16 inner_proto;
+       bool double_encap;
        int min_headroom;
        int err;
 
@@ -786,6 +787,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
        if (unlikely(err))
                goto free_dst;
 
+       double_encap = udp_tunnel_handle_partial(skb);
        err = udp_tunnel_handle_offloads(skb, udp_sum);
        if (err)
                goto free_dst;
@@ -793,7 +795,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb,
        gnvh = __skb_push(skb, sizeof(*gnvh) + info->options_len);
        inner_proto = inner_proto_inherit ? skb->protocol : htons(ETH_P_TEB);
        geneve_build_header(gnvh, info, inner_proto);
-       skb_set_inner_protocol(skb, inner_proto);
+       udp_tunnel_set_inner_protocol(skb, double_encap, inner_proto);
        return 0;
 
 free_dst:
@@ -1211,9 +1213,16 @@ static void geneve_setup(struct net_device *dev)
        dev->features    |= NETIF_F_RXCSUM;
        dev->features    |= NETIF_F_GSO_SOFTWARE;
 
+       /* Partial features are disabled by default. */
        dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
        dev->hw_features |= NETIF_F_RXCSUM;
        dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+       dev->hw_features |= UDP_TUNNEL_PARTIAL_FEATURES;
+       dev->hw_features |= NETIF_F_GSO_PARTIAL;
+
+       dev->hw_enc_features = dev->hw_features;
+       dev->gso_partial_features = UDP_TUNNEL_PARTIAL_FEATURES;
+       dev->mangleid_features = NETIF_F_GSO_PARTIAL;
 
        dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
        /* MTU range: 68 - (something less than 65535) */

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 9acef2fbd2fdcf6000ee292752dd122b7a20dae3..d9c6d04bb3b587d50397e83df087b39963ba5121 100644 (file)
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -10,6 +10,11 @@
 #include <net/ipv6_stubs.h>
 #endif
 
+#define UDP_TUNNEL_PARTIAL_FEATURES    NETIF_F_GSO_ENCAP_ALL
+#define UDP_TUNNEL_STRIPPED_GSO_TYPES  ((UDP_TUNNEL_PARTIAL_FEATURES | \
+                                         NETIF_F_GSO_PARTIAL) >>       \
+                                        NETIF_F_GSO_SHIFT)
+
 struct udp_port_cfg {
        u8                      family;
 
@@ -145,6 +150,33 @@ void udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
                          __be16 src_port, __be16 dst_port, bool nocheck,
                          u16 ip6cb_flags);
 
+static inline bool udp_tunnel_handle_partial(struct sk_buff *skb)
+{
+       bool double_encap = !!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL);
+
+       /*
+        * If the skb went through partial segmentation, lower devices
+        * will not need to offload the related features - except for
+        * UDP_TUNNEL, that will be re-added by the later
+        * udp_tunnel_handle_offloads().
+        */
+       if (double_encap)
+               skb_shinfo(skb)->gso_type &= ~UDP_TUNNEL_STRIPPED_GSO_TYPES;
+       return double_encap;
+}
+
+static inline void udp_tunnel_set_inner_protocol(struct sk_buff *skb,
+                                                bool double_encap,
+                                                __be16 inner_proto)
+{
+       /*
+        * The inner protocol has been set by the nested tunnel, don't
+        * overraid it.
+        */
+       if (!double_encap)
+               skb_set_inner_protocol(skb, inner_proto);
+}
+
 void udp_tunnel_sock_release(struct socket *sock);
 
 struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,