[PATCH 5.19 015/155] ip_tunnel: Respect tunnel keys "flow_flags" in IP tunnels

Greg Kroah-Hartman
2022-09-06T14:00:16Z

From: Eyal Birger <eyal.birger@gmail.com>

[ Upstream commit 7ec9fce4b31604f8415136a4c07f7dc8ad431aec ]

Commit 451ef36bd229 ("ip_tunnels: Add new flow flags field to ip_tunnel_key")
added a "flow_flags" member to struct ip_tunnel_key which was later used by
the commit in the fixes tag to avoid dropping packets with sources that
aren't locally configured when set in bpf_set_tunnel_key().

VXLAN and GENEVE were made to respect this flag, ip tunnels like IPIP and GRE
were not.

This commit fixes this omission by making ip_tunnel_init_flow() receive
the flow flags from the tunnel key in the relevant collect_md paths.

Fixes: b8fff748521c ("bpf: Set flow flag to allow any source IP in bpf_tunnel_key")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Paul Chaignon <paul@isovalent.com>
Link: https://lore.kernel.org/bpf/20220818074118.726639-1-eyal.birger@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c | 3 ++-
include/net/ip_tunnels.h | 4 +++-
net/ipv4/ip_gre.c | 2 +-
net/ipv4/ip_tunnel.c | 7 ++++---
4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
index fe663b0ab7086..68d87e61bdc05 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c
@@ -423,7 +423,8 @@ mlxsw_sp_span_gretap4_route(const struct net_device *to_dev,

parms = mlxsw_sp_ipip_netdev_parms4(to_dev);
ip_tunnel_init_flow(&fl4, parms.iph.protocol, *daddrp, *saddrp,
- 0, 0, dev_net(to_dev), parms.link, tun->fwmark, 0);
+ 0, 0, dev_net(to_dev), parms.link, tun->fwmark, 0,
+ 0);

rt = ip_route_output_key(tun->net, &fl4);
if (IS_ERR(rt))
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 20f60d9da7418..cf1f22c01ed3d 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -246,7 +246,8 @@ static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
__be32 daddr, __be32 saddr,
__be32 key, __u8 tos,
struct net *net, int oif,
- __u32 mark, __u32 tun_inner_hash)
+ __u32 mark, __u32 tun_inner_hash,
+ __u8 flow_flags)
{
memset(fl4, 0, sizeof(*fl4));

@@ -263,6 +264,7 @@ static inline void ip_tunnel_init_flow(struct flowi4 *fl4,
fl4->fl4_gre_key = key;
fl4->flowi4_mark = mark;
fl4->flowi4_multipath_hash = tun_inner_hash;
+ fl4->flowi4_flags = flow_flags;
}

int ip_tunnel_init(struct net_device *dev);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 5c58e21f724e9..f866d6282b2b3 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -609,7 +609,7 @@ static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
tunnel_id_to_key32(key->tun_id),
key->tos & ~INET_ECN_MASK, dev_net(dev), 0,
- skb->mark, skb_get_hash(skb));
+ skb->mark, skb_get_hash(skb), key->flow_flags);
rt = ip_route_output_key(dev_net(dev), &fl4);
if (IS_ERR(rt))
return PTR_ERR(rt);
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 94017a8c39945..1ad8809fc2e3b 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -295,7 +295,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev)
ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr,
iph->saddr, tunnel->parms.o_key,
RT_TOS(iph->tos), dev_net(dev),
- tunnel->parms.link, tunnel->fwmark, 0);
+ tunnel->parms.link, tunnel->fwmark, 0, 0);
rt = ip_route_output_key(tunnel->net, &fl4);

if (!IS_ERR(rt)) {
@@ -570,7 +570,8 @@ void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
}
ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src,
tunnel_id_to_key32(key->tun_id), RT_TOS(tos),
- dev_net(dev), 0, skb->mark, skb_get_hash(skb));
+ dev_net(dev), 0, skb->mark, skb_get_hash(skb),
+ key->flow_flags);
if (tunnel->encap.type != TUNNEL_ENCAP_NONE)
goto tx_error;

@@ -728,7 +729,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr,
tunnel->parms.o_key, RT_TOS(tos),
dev_net(dev), tunnel->parms.link,
- tunnel->fwmark, skb_get_hash(skb));
+ tunnel->fwmark, skb_get_hash(skb), 0);

if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
goto tx_error;
--
2.35.1