Commit b9815eb1 authored Jun 29, 2020 by Jason A. Donenfeld Committed by David S. Miller Jun 30, 2020

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>

parent 1a574074

drivers/net/tun.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;

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