net: add IFLA_TSO_{MAX_SIZE|SEGS} attributes

New netlink attributes IFLA_TSO_MAX_SIZE and IFLA_TSO_MAX_SEGS
are used to report to user-space the device TSO limits.

ip -d link sh dev eth1
...
   tso_max_size 65536 tso_max_segs 65535
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NAlexander Duyck <alexanderduyck@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/if_link.h

@@ -368,6 +368,8 @@ enum {
 	IFLA_PARENT_DEV_NAME,
 	IFLA_PARENT_DEV_BUS_NAME,
 	IFLA_GRO_MAX_SIZE,
+	IFLA_TSO_MAX_SIZE,
+	IFLA_TSO_MAX_SEGS,
 
 	__IFLA_MAX
 };

net/core/rtnetlink.c

@@ -1064,6 +1064,8 @@ 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_TSO_MAX_SIZE */
+	       + nla_total_size(4) /* IFLA_TSO_MAX_SEGS */
 	       + nla_total_size(1) /* IFLA_OPERSTATE */
 	       + nla_total_size(1) /* IFLA_LINKMODE */
 	       + nla_total_size(4) /* IFLA_CARRIER_CHANGES */
@@ -1769,6 +1771,8 @@ 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_TSO_MAX_SIZE, dev->tso_max_size) ||
+	    nla_put_u32(skb, IFLA_TSO_MAX_SEGS, dev->tso_max_segs) ||
 #ifdef CONFIG_RPS
 	    nla_put_u32(skb, IFLA_NUM_RX_QUEUES, dev->num_rx_queues) ||
 #endif
@@ -1922,6 +1926,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_NEW_IFINDEX]	= NLA_POLICY_MIN(NLA_S32, 1),
 	[IFLA_PARENT_DEV_NAME]	= { .type = NLA_NUL_STRING },
 	[IFLA_GRO_MAX_SIZE]	= { .type = NLA_U32 },
+	[IFLA_TSO_MAX_SIZE]	= { .type = NLA_REJECT },
+	[IFLA_TSO_MAX_SEGS]	= { .type = NLA_REJECT },
 };
 
 static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {

tools/include/uapi/linux/if_link.h

@@ -348,6 +348,8 @@ enum {
 	IFLA_PARENT_DEV_NAME,
 	IFLA_PARENT_DEV_BUS_NAME,
 	IFLA_GRO_MAX_SIZE,
+	IFLA_TSO_MAX_SIZE,
+	IFLA_TSO_MAX_SEGS,
 
 	__IFLA_MAX
 };