[PATCH 5.15 098/244] geneve: fix TOS inheriting for ipv4

Greg Kroah-Hartman
2022-08-23T10:03:07Z

From: Matthias May <matthias.may@westermo.com>

commit b4ab94d6adaa5cf842b68bd28f4b50bc774496bd upstream.

The current code retrieves the TOS field after the lookup
on the ipv4 routing table. The routing process currently
only allows routing based on the original 3 TOS bits, and
not on the full 6 DSCP bits.
As a result the retrieved TOS is cut to the 3 bits.
However for inheriting purposes the full 6 bits should be used.

Extract the full 6 bits before the route lookup and use
that instead of the cut off 3 TOS bits.

Fixes: e305ac6cf5a1 ("geneve: Add support to collect tunnel metadata.")
Signed-off-by: Matthias May <matthias.may@westermo.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/20220805190006.8078-1-matthias.may@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/geneve.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -774,7 +774,8 @@ static struct rtable *geneve_get_v4_rt(s
struct geneve_sock *gs4,
struct flowi4 *fl4,
const struct ip_tunnel_info *info,
- __be16 dport, __be16 sport)
+ __be16 dport, __be16 sport,
+ __u8 *full_tos)
{
bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
struct geneve_dev *geneve = netdev_priv(dev);
@@ -799,6 +800,8 @@ static struct rtable *geneve_get_v4_rt(s
use_cache = false;
}
fl4->flowi4_tos = RT_TOS(tos);
+ if (full_tos)
+ *full_tos = tos;

dst_cache = (struct dst_cache *)&info->dst_cache;
if (use_cache) {
@@ -886,6 +889,7 @@ static int geneve_xmit_skb(struct sk_buf
const struct ip_tunnel_key *key = &info->key;
struct rtable *rt;
struct flowi4 fl4;
+ __u8 full_tos;
__u8 tos, ttl;
__be16 df = 0;
__be16 sport;
@@ -896,7 +900,7 @@ static int geneve_xmit_skb(struct sk_buf

sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info,
- geneve->cfg.info.key.tp_dst, sport);
+ geneve->cfg.info.key.tp_dst, sport, &full_tos);
if (IS_ERR(rt))
return PTR_ERR(rt);

@@ -940,7 +944,7 @@ static int geneve_xmit_skb(struct sk_buf

df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
} else {
- tos = ip_tunnel_ecn_encap(fl4.flowi4_tos, ip_hdr(skb), skb);
+ tos = ip_tunnel_ecn_encap(full_tos, ip_hdr(skb), skb);
if (geneve->cfg.ttl_inherit)
ttl = ip_tunnel_get_ttl(ip_hdr(skb), skb);
else
@@ -1122,7 +1126,7 @@ static int geneve_fill_metadata_dst(stru
1, USHRT_MAX, true);

rt = geneve_get_v4_rt(skb, dev, gs4, &fl4, info,
- geneve->cfg.info.key.tp_dst, sport);
+ geneve->cfg.info.key.tp_dst, sport, NULL);
if (IS_ERR(rt))
return PTR_ERR(rt);