net: add gso_ipv4_max_size and gro_ipv4_max_size per device

This patch introduces gso_ipv4_max_size and gro_ipv4_max_size
per device and adds netlink attributes for them, so that IPV4
BIG TCP can be guarded by a separate tunable in the next patch.

To not break the old application using "gso/gro_max_size" for
IPv4 GSO packets, this patch updates "gso/gro_ipv4_max_size"
in netif_set_gso/gro_max_size() if the new size isn't greater
than GSO_LEGACY_MAX_SIZE, so that nothing will change even if
userspace doesn't realize the new netlink attributes.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 2466afa..d5ef4c1 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1964,6 +1964,8 @@ enum netdev_ml_priv_type {
  *     @gso_max_segs:  Maximum number of segments that can be passed to the
  *                     NIC for GSO
  *     @tso_max_segs:  Device (as in HW) limit on the max TSO segment count
+ *     @gso_ipv4_max_size:     Maximum size of generic segmentation offload,
+ *                             for IPv4.
  *
  *     @dcbnl_ops:     Data Center Bridging netlink ops
  *     @num_tc:        Number of traffic classes in the net device
@@ -2004,6 +2006,8 @@ enum netdev_ml_priv_type {
  *                     keep a list of interfaces to be deleted.
  *     @gro_max_size:  Maximum size of aggregated packet in generic
  *                     receive offload (GRO)
+ *     @gro_ipv4_max_size:     Maximum size of aggregated packet in generic
+ *                             receive offload (GRO), for IPv4.
  *
  *     @dev_addr_shadow:       Copy of @dev_addr to catch direct writes.
  *     @linkwatch_dev_tracker: refcount tracker used by linkwatch.
@@ -2207,6 +2211,7 @@ struct net_device {
  */
 #define GRO_MAX_SIZE           (8 * 65535u)
        unsigned int            gro_max_size;
+       unsigned int            gro_ipv4_max_size;
        rx_handler_func_t __rcu *rx_handler;
        void __rcu              *rx_handler_data;
 
@@ -2330,6 +2335,7 @@ struct net_device {
        u16                     gso_max_segs;
 #define TSO_MAX_SEGS           U16_MAX
        u16                     tso_max_segs;
+       unsigned int            gso_ipv4_max_size;
 
 #ifdef CONFIG_DCB
        const struct dcbnl_rtnl_ops *dcbnl_ops;

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 1021a7e..02b87e4 100644 (file)
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -374,6 +374,9 @@ enum {
 
        IFLA_DEVLINK_PORT,
 
+       IFLA_GSO_IPV4_MAX_SIZE,
+       IFLA_GRO_IPV4_MAX_SIZE,
+
        __IFLA_MAX
 };
 

diff --git a/net/core/dev.c b/net/core/dev.c
index f72f5c4..bb42150 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3001,6 +3001,8 @@ void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
        dev->tso_max_size = min(GSO_MAX_SIZE, size);
        if (size < READ_ONCE(dev->gso_max_size))
                netif_set_gso_max_size(dev, size);
+       if (size < READ_ONCE(dev->gso_ipv4_max_size))
+               netif_set_gso_ipv4_max_size(dev, size);
 }
 EXPORT_SYMBOL(netif_set_tso_max_size);
 
@@ -10614,6 +10616,8 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
        dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
        dev->gso_max_segs = GSO_MAX_SEGS;
        dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
+       dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
+       dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
        dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
        dev->tso_max_segs = TSO_MAX_SEGS;
        dev->upper_level = 1;

diff --git a/net/core/dev.h b/net/core/dev.h
index 814ed5b..a065b75 100644 (file)
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -100,6 +100,8 @@ static inline void netif_set_gso_max_size(struct net_device *dev,
 {
        /* dev->gso_max_size is read locklessly from sk_setup_caps() */
        WRITE_ONCE(dev->gso_max_size, size);
+       if (size <= GSO_LEGACY_MAX_SIZE)
+               WRITE_ONCE(dev->gso_ipv4_max_size, size);
 }
 
 static inline void netif_set_gso_max_segs(struct net_device *dev,
@@ -114,6 +116,22 @@ static inline void netif_set_gro_max_size(struct net_device *dev,
 {
        /* This pairs with the READ_ONCE() in skb_gro_receive() */
        WRITE_ONCE(dev->gro_max_size, size);
+       if (size <= GRO_LEGACY_MAX_SIZE)
+               WRITE_ONCE(dev->gro_ipv4_max_size, size);
+}
+
+static inline void netif_set_gso_ipv4_max_size(struct net_device *dev,
+                                              unsigned int size)
+{
+       /* dev->gso_ipv4_max_size is read locklessly from sk_setup_caps() */
+       WRITE_ONCE(dev->gso_ipv4_max_size, size);
+}
+
+static inline void netif_set_gro_ipv4_max_size(struct net_device *dev,
+                                              unsigned int size)
+{
+       /* This pairs with the READ_ONCE() in skb_gro_receive() */
+       WRITE_ONCE(dev->gro_ipv4_max_size, size);
 }
 
 #endif

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 64289bc..b9f5849 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1074,6 +1074,8 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
               + nla_total_size(4) /* IFLA_GSO_MAX_SEGS */
               + nla_total_size(4) /* IFLA_GSO_MAX_SIZE */
               + nla_total_size(4) /* IFLA_GRO_MAX_SIZE */
+              + nla_total_size(4) /* IFLA_GSO_IPV4_MAX_SIZE */
+              + nla_total_size(4) /* IFLA_GRO_IPV4_MAX_SIZE */
               + nla_total_size(4) /* IFLA_TSO_MAX_SIZE */
               + nla_total_size(4) /* IFLA_TSO_MAX_SEGS */
               + nla_total_size(1) /* IFLA_OPERSTATE */
@@ -1807,6 +1809,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
            nla_put_u32(skb, IFLA_GSO_MAX_SEGS, dev->gso_max_segs) ||
            nla_put_u32(skb, IFLA_GSO_MAX_SIZE, dev->gso_max_size) ||
            nla_put_u32(skb, IFLA_GRO_MAX_SIZE, dev->gro_max_size) ||
+           nla_put_u32(skb, IFLA_GSO_IPV4_MAX_SIZE, dev->gso_ipv4_max_size) ||
+           nla_put_u32(skb, IFLA_GRO_IPV4_MAX_SIZE, dev->gro_ipv4_max_size) ||
            nla_put_u32(skb, IFLA_TSO_MAX_SIZE, dev->tso_max_size) ||
            nla_put_u32(skb, IFLA_TSO_MAX_SEGS, dev->tso_max_segs) ||
 #ifdef CONFIG_RPS
@@ -1968,6 +1972,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
        [IFLA_TSO_MAX_SIZE]     = { .type = NLA_REJECT },
        [IFLA_TSO_MAX_SEGS]     = { .type = NLA_REJECT },
        [IFLA_ALLMULTI]         = { .type = NLA_REJECT },
+       [IFLA_GSO_IPV4_MAX_SIZE]        = { .type = NLA_U32 },
+       [IFLA_GRO_IPV4_MAX_SIZE]        = { .type = NLA_U32 },
 };
 
 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
@@ -2883,6 +2889,29 @@ static int do_setlink(const struct sk_buff *skb,
                }
        }
 
+       if (tb[IFLA_GSO_IPV4_MAX_SIZE]) {
+               u32 max_size = nla_get_u32(tb[IFLA_GSO_IPV4_MAX_SIZE]);
+
+               if (max_size > dev->tso_max_size) {
+                       err = -EINVAL;
+                       goto errout;
+               }
+
+               if (dev->gso_ipv4_max_size ^ max_size) {
+                       netif_set_gso_ipv4_max_size(dev, max_size);
+                       status |= DO_SETLINK_MODIFIED;
+               }
+       }
+
+       if (tb[IFLA_GRO_IPV4_MAX_SIZE]) {
+               u32 gro_max_size = nla_get_u32(tb[IFLA_GRO_IPV4_MAX_SIZE]);
+
+               if (dev->gro_ipv4_max_size ^ gro_max_size) {
+                       netif_set_gro_ipv4_max_size(dev, gro_max_size);
+                       status |= DO_SETLINK_MODIFIED;
+               }
+       }
+
        if (tb[IFLA_OPERSTATE])
                set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
 
@@ -3325,6 +3354,10 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname,
                netif_set_gso_max_segs(dev, nla_get_u32(tb[IFLA_GSO_MAX_SEGS]));
        if (tb[IFLA_GRO_MAX_SIZE])
                netif_set_gro_max_size(dev, nla_get_u32(tb[IFLA_GRO_MAX_SIZE]));
+       if (tb[IFLA_GSO_IPV4_MAX_SIZE])
+               netif_set_gso_ipv4_max_size(dev, nla_get_u32(tb[IFLA_GSO_IPV4_MAX_SIZE]));
+       if (tb[IFLA_GRO_IPV4_MAX_SIZE])
+               netif_set_gro_ipv4_max_size(dev, nla_get_u32(tb[IFLA_GRO_IPV4_MAX_SIZE]));
 
        return dev;
 }