rtnetlink: allow GSO maximums to be set on device creation

Netlink device already allows changing GSO sizes with
ip set command. The part that is missing is allowing overriding
GSO settings on device creation.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/rtnetlink.c

@@ -1637,6 +1637,8 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_PROMISCUITY]	= { .type = NLA_U32 },
 	[IFLA_NUM_TX_QUEUES]	= { .type = NLA_U32 },
 	[IFLA_NUM_RX_QUEUES]	= { .type = NLA_U32 },
+	[IFLA_GSO_MAX_SEGS]	= { .type = NLA_U32 },
+	[IFLA_GSO_MAX_SIZE]	= { .type = NLA_U32 },
 	[IFLA_PHYS_PORT_ID]	= { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
 	[IFLA_CARRIER_CHANGES]	= { .type = NLA_U32 },  /* ignored */
 	[IFLA_PHYS_SWITCH_ID]	= { .type = NLA_BINARY, .len = MAX_PHYS_ITEM_ID_LEN },
@@ -2287,6 +2289,34 @@ static int do_setlink(const struct sk_buff *skb,
 		}
 	}
 
+	if (tb[IFLA_GSO_MAX_SIZE]) {
+		u32 max_size = nla_get_u32(tb[IFLA_GSO_MAX_SIZE]);
+
+		if (max_size > GSO_MAX_SIZE) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		if (dev->gso_max_size ^ max_size) {
+			netif_set_gso_max_size(dev, max_size);
+			status |= DO_SETLINK_MODIFIED;
+		}
+	}
+
+	if (tb[IFLA_GSO_MAX_SEGS]) {
+		u32 max_segs = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]);
+
+		if (max_segs > GSO_MAX_SEGS) {
+			err = -EINVAL;
+			goto errout;
+		}
+
+		if (dev->gso_max_segs ^ max_segs) {
+			dev->gso_max_segs = max_segs;
+			status |= DO_SETLINK_MODIFIED;
+		}
+	}
+
 	if (tb[IFLA_OPERSTATE])
 		set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
 
@@ -2651,6 +2681,10 @@ struct net_device *rtnl_create_link(struct net *net,
 		dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
 	if (tb[IFLA_GROUP])
 		dev_set_group(dev, nla_get_u32(tb[IFLA_GROUP]));
+	if (tb[IFLA_GSO_MAX_SIZE])
+		netif_set_gso_max_size(dev, nla_get_u32(tb[IFLA_GSO_MAX_SIZE]));
+	if (tb[IFLA_GSO_MAX_SEGS])
+		dev->gso_max_size = nla_get_u32(tb[IFLA_GSO_MAX_SEGS]);
 
 	return dev;
 }