l2tp: define l2tp_tunnel_dst_mtu()
Consolidate retrieval of tunnel's socket mtu in order to simplify
l2tp_eth and l2tp_ppp a bit.
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
index 5c366ec..cfca5e6 100644
--- a/net/l2tp/l2tp_eth.c
+++ b/net/l2tp/l2tp_eth.c
@@ -226,8 +226,8 @@ static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
struct net_device *dev)
{
unsigned int overhead = 0;
- struct dst_entry *dst;
u32 l3_overhead = 0;
+ u32 mtu;
/* if the encap is UDP, account for UDP header size */
if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
@@ -256,15 +256,9 @@ static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
overhead += session->hdr_len + ETH_HLEN + l3_overhead;
/* If PMTU discovery was enabled, use discovered MTU on L2TP device */
- dst = sk_dst_get(tunnel->sock);
- if (dst) {
- /* dst_mtu will use PMTU if found, else fallback to intf MTU */
- u32 pmtu = dst_mtu(dst);
-
- if (pmtu != 0)
- dev->mtu = pmtu;
- dst_release(dst);
- }
+ mtu = l2tp_tunnel_dst_mtu(tunnel);
+ if (mtu)
+ dev->mtu = mtu;
session->mtu = dev->mtu - overhead;
dev->mtu = session->mtu;
dev->needed_headroom += session->hdr_len;