[PATCH 4.9 077/109] gtp: clear DF bit on GTP packet tx

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andreas Schultz <aschultz@xxxxxxxx>


[ Upstream commit c6ce1d08eede4c2968ed08aafa3165e8e183c5a1 ]

3GPP TS 29.281 and 3GPP TS 29.060 imply that GTP-U packets should be
sent with the DF bit cleared. For example 3GPP TS 29.060, Release 8,
Section 13.2.2:

> Backbone router: Any router in the backbone may fragment the GTP
> packet if needed, according to IPv4.

Signed-off-by: Andreas Schultz <aschultz@xxxxxxxx>
Acked-by: Harald Welte <laforge@xxxxxxxxxxxxx>
Acked-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/gtp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -612,7 +612,7 @@ static netdev_tx_t gtp_dev_xmit(struct s
 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
 				    pktinfo.iph->tos,
 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
-				    htons(IP_DF),
+				    0,
 				    pktinfo.gtph_port, pktinfo.gtph_port,
 				    true, false);
 		break;