tun: implement header_ops->parse_protocol for AF_PACKET

The tun driver passes up skb->protocol to userspace in the form of PI headers.
For AF_PACKET injection, we need to support its call chain of:

    packet_sendmsg -> packet_snd -> packet_parse_headers ->
      dev_parse_header_protocol -> parse_protocol

Without a valid parse_protocol, this returns zero, and the tun driver
then gives userspace bogus values that it can't deal with.

Note that this isn't the case with tap, because tap already benefits
from the shared infrastructure for ethernet headers. But with tun,
there's nothing.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 858b012074bd1e733ccaf6255dd733a6eef432b1..7adeb91bd368dceab1357c4ec007572a7784a091 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -62,6 +62,7 @@
 #include <net/rtnetlink.h>
 #include <net/sock.h>
 #include <net/xdp.h>
+#include <net/ip_tunnels.h>
 #include <linux/seq_file.h>
 #include <linux/uio.h>
 #include <linux/skb_array.h>
@@ -1351,6 +1352,7 @@ static void tun_net_init(struct net_device *dev)
        switch (tun->flags & TUN_TYPE_MASK) {
        case IFF_TUN:
                dev->netdev_ops = &tun_netdev_ops;
+               dev->header_ops = &ip_tunnel_header_ops;
 
                /* Point-to-Point TUN Device */
                dev->hard_header_len = 0;