From: David Woodhouse <dwmw2@infradead.org>
To: netdev@vger.kernel.org
Cc: "Jason Wang" <jasowang@redhat.com>,
"Eugenio Pérez" <eperezma@redhat.com>
Subject: [PATCH v2 1/4] net: tun: fix tun_xdp_one() for IFF_TUN mode
Date: Tue, 22 Jun 2021 17:15:30 +0100 [thread overview]
Message-ID: <20210622161533.1214662-1-dwmw2@infradead.org> (raw)
In-Reply-To: <03ee62602dd7b7101f78e0802249a6e2e4c10b7f.camel@infradead.org>
From: David Woodhouse <dwmw@amazon.co.uk>
In tun_get_user(), skb->protocol is either taken from the tun_pi header
or inferred from the first byte of the packet in IFF_TUN mode, while
eth_type_trans() is called only in the IFF_TAP mode where the payload
is expected to be an Ethernet frame.
The alternative path in tun_xdp_one() was unconditionally using
eth_type_trans(), which corrupts packets in IFF_TUN mode. Fix it to
do the correct thing for IFF_TUN mode, as tun_get_user() does.
Fixes: 043d222f93ab ("tuntap: accept an array of XDP buffs through sendmsg()")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
drivers/net/tun.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 43 insertions(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 4cf38be26dc9..f812dcdc640e 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2394,8 +2394,50 @@ static int tun_xdp_one(struct tun_struct *tun,
err = -EINVAL;
goto out;
}
+ switch (tun->flags & TUN_TYPE_MASK) {
+ case IFF_TUN:
+ if (tun->flags & IFF_NO_PI) {
+ u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
+
+ switch (ip_version) {
+ case 4:
+ skb->protocol = htons(ETH_P_IP);
+ break;
+ case 6:
+ skb->protocol = htons(ETH_P_IPV6);
+ break;
+ default:
+ atomic_long_inc(&tun->dev->rx_dropped);
+ kfree_skb(skb);
+ err = -EINVAL;
+ goto out;
+ }
+ } else {
+ struct tun_pi *pi = (struct tun_pi *)skb->data;
+ if (!pskb_may_pull(skb, sizeof(*pi))) {
+ atomic_long_inc(&tun->dev->rx_dropped);
+ kfree_skb(skb);
+ err = -ENOMEM;
+ goto out;
+ }
+ skb_pull_inline(skb, sizeof(*pi));
+ skb->protocol = pi->proto;
+ }
+
+ skb_reset_mac_header(skb);
+ skb->dev = tun->dev;
+ break;
+ case IFF_TAP:
+ if (!pskb_may_pull(skb, ETH_HLEN)) {
+ atomic_long_inc(&tun->dev->rx_dropped);
+ kfree_skb(skb);
+ err = -ENOMEM;
+ goto out;
+ }
+ skb->protocol = eth_type_trans(skb, tun->dev);
+ break;
+ }
- skb->protocol = eth_type_trans(skb, tun->dev);
skb_reset_network_header(skb);
skb_probe_transport_header(skb);
skb_record_rx_queue(skb, tfile->queue_index);
--
2.31.1
next prev parent reply other threads:[~2021-06-22 16:16 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-19 13:33 [PATCH] net: tun: fix tun_xdp_one() for IFF_TUN mode David Woodhouse
2021-06-21 7:00 ` Jason Wang
2021-06-21 10:52 ` David Woodhouse
2021-06-21 14:50 ` David Woodhouse
2021-06-21 20:43 ` David Woodhouse
2021-06-22 4:52 ` Jason Wang
2021-06-22 7:24 ` David Woodhouse
2021-06-22 7:51 ` Jason Wang
2021-06-22 8:10 ` David Woodhouse
2021-06-22 11:36 ` David Woodhouse
2021-06-22 4:34 ` Jason Wang
2021-06-22 4:34 ` Jason Wang
2021-06-22 7:28 ` David Woodhouse
2021-06-22 8:00 ` Jason Wang
2021-06-22 8:29 ` David Woodhouse
2021-06-23 3:39 ` Jason Wang
2021-06-24 12:39 ` David Woodhouse
2021-06-22 16:15 ` David Woodhouse [this message]
2021-06-22 16:15 ` [PATCH v2 2/4] net: tun: don't assume IFF_VNET_HDR in tun_xdp_one() tx path David Woodhouse
2021-06-23 3:46 ` Jason Wang
2021-06-22 16:15 ` [PATCH v2 3/4] vhost_net: validate virtio_net_hdr only if it exists David Woodhouse
2021-06-23 3:48 ` Jason Wang
2021-06-22 16:15 ` [PATCH v2 4/4] vhost_net: Add self test with tun device David Woodhouse
2021-06-23 4:02 ` Jason Wang
2021-06-23 16:12 ` David Woodhouse
2021-06-24 6:12 ` Jason Wang
2021-06-24 10:42 ` David Woodhouse
2021-06-25 2:55 ` Jason Wang
2021-06-25 7:54 ` David Woodhouse
2021-06-23 3:45 ` [PATCH v2 1/4] net: tun: fix tun_xdp_one() for IFF_TUN mode Jason Wang
2021-06-23 8:30 ` David Woodhouse
2021-06-23 13:52 ` David Woodhouse
2021-06-23 17:31 ` David Woodhouse
2021-06-23 22:52 ` David Woodhouse
2021-06-24 6:37 ` Jason Wang
2021-06-24 7:23 ` David Woodhouse
2021-06-24 6:18 ` Jason Wang
2021-06-24 7:05 ` David Woodhouse
2021-06-24 12:30 ` [PATCH v3 1/5] net: add header len parameter to tun_get_socket(), tap_get_socket() David Woodhouse
2021-06-24 12:30 ` [PATCH v3 2/5] net: tun: don't assume IFF_VNET_HDR in tun_xdp_one() tx path David Woodhouse
2021-06-25 6:58 ` Jason Wang
2021-06-24 12:30 ` [PATCH v3 3/5] vhost_net: remove virtio_net_hdr validation, let tun/tap do it themselves David Woodhouse
2021-06-25 7:33 ` Jason Wang
2021-06-25 8:37 ` David Woodhouse
2021-06-28 4:23 ` Jason Wang
2021-06-28 11:23 ` David Woodhouse
2021-06-28 23:29 ` David Woodhouse
2021-06-29 3:43 ` Jason Wang
2021-06-29 6:59 ` David Woodhouse
2021-06-29 10:49 ` David Woodhouse
2021-06-29 13:15 ` David Woodhouse
2021-06-30 4:39 ` Jason Wang
2021-06-30 10:02 ` David Woodhouse
2021-07-01 4:13 ` Jason Wang
2021-07-01 17:39 ` David Woodhouse
2021-07-02 3:13 ` Jason Wang
2021-07-02 8:08 ` David Woodhouse
2021-07-02 8:50 ` Jason Wang
2021-07-09 15:04 ` Eugenio Perez Martin
2021-06-29 3:21 ` Jason Wang
2021-06-24 12:30 ` [PATCH v3 4/5] net: tun: fix tun_xdp_one() for IFF_TUN mode David Woodhouse
2021-06-25 7:41 ` Jason Wang
2021-06-25 8:51 ` David Woodhouse
2021-06-28 4:27 ` Jason Wang
2021-06-28 10:43 ` David Woodhouse
2021-06-25 18:43 ` Willem de Bruijn
2021-06-25 19:00 ` David Woodhouse
2021-06-24 12:30 ` [PATCH v3 5/5] vhost_net: Add self test with tun device David Woodhouse
2021-06-25 5:00 ` [PATCH v3 1/5] net: add header len parameter to tun_get_socket(), tap_get_socket() Jason Wang
2021-06-25 8:23 ` David Woodhouse
2021-06-28 4:22 ` Jason Wang
2021-06-25 18:13 ` Willem de Bruijn
2021-06-25 18:55 ` David Woodhouse
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