[PATCH net-next v2 3/7] ipv4: add new arguments to udp_tunnel_dst_lookup()

Beniamino Galvani
2023-10-16T07:15:54Z

We want to make the function more generic so that it can be used by
other UDP tunnel implementations such as geneve and vxlan. To do that,
add the following arguments:

- source and destination UDP port;
- ifindex of the output interface, needed by vxlan;
- the tos, because in some cases it is not taken from struct
ip_tunnel_info (for example, when it's inherited from the inner
packet);
- the dst cache, because not all tunnel types (e.g. vxlan) want to
use the one from struct ip_tunnel_info.

With these parameters, the function no longer needs the full struct
ip_tunnel_info as argument and we can pass only the relevant part of
it (struct ip_tunnel_key).

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
---
drivers/net/bareudp.c | 11 +++++++----
include/net/udp_tunnel.h | 8 +++++---
net/ipv4/udp_tunnel_core.c | 26 +++++++++++++-------------
3 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index 6af67cac6bde..47a9c2a5583c 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -306,8 +306,10 @@ static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
if (!sock)
return -ESHUTDOWN;

- rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, &saddr, info,
- use_cache);
+ rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
+ 0, 0, key->tos,
+ use_cache ?
+ (struct dst_cache *)&info->dst_cache : NULL);

if (IS_ERR(rt))
return PTR_ERR(rt);
@@ -483,8 +485,9 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
struct rtable *rt;
__be32 saddr;

- rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, &saddr,
- info, use_cache);
+ rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
+ &info->key, 0, 0, info->key.tos,
+ use_cache ? &info->dst_cache : NULL);
if (IS_ERR(rt))
return PTR_ERR(rt);

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 8f110dbd3784..4d0578fab01a 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -164,9 +164,11 @@ void udp_tunnel_sock_release(struct socket *sock);

struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
- struct net *net, __be32 *saddr,
- const struct ip_tunnel_info *info,
- bool use_cache);
+ struct net *net, int oif,
+ __be32 *saddr,
+ const struct ip_tunnel_key *key,
+ __be16 sport, __be16 dport, u8 tos,
+ struct dst_cache *dst_cache);

struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
__be16 flags, __be64 tunnel_id,
diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
index 9b0cfd72d5fd..494685e82856 100644
--- a/net/ipv4/udp_tunnel_core.c
+++ b/net/ipv4/udp_tunnel_core.c
@@ -206,31 +206,31 @@ EXPORT_SYMBOL_GPL(udp_tun_rx_dst);

struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
- struct net *net, __be32 *saddr,
- const struct ip_tunnel_info *info,
- bool use_cache)
+ struct net *net, int oif,
+ __be32 *saddr,
+ const struct ip_tunnel_key *key,
+ __be16 sport, __be16 dport, u8 tos,
+ struct dst_cache *dst_cache)
{
-#ifdef CONFIG_DST_CACHE
- struct dst_cache *dst_cache;
-#endif
struct rtable *rt = NULL;
struct flowi4 fl4;
- __u8 tos;

#ifdef CONFIG_DST_CACHE
- dst_cache = (struct dst_cache *)&info->dst_cache;
- if (use_cache) {
+ if (dst_cache) {
rt = dst_cache_get_ip4(dst_cache, saddr);
if (rt)
return rt;
}
#endif
+
memset(&fl4, 0, sizeof(fl4));
fl4.flowi4_mark = skb->mark;
fl4.flowi4_proto = IPPROTO_UDP;
- fl4.daddr = info->key.u.ipv4.dst;
- fl4.saddr = info->key.u.ipv4.src;
- tos = info->key.tos;
+ fl4.flowi4_oif = oif;
+ fl4.daddr = key->u.ipv4.dst;
+ fl4.saddr = key->u.ipv4.src;
+ fl4.fl4_dport = dport;
+ fl4.fl4_sport = sport;
fl4.flowi4_tos = RT_TOS(tos);

rt = ip_route_output_key(net, &fl4);
@@ -244,7 +244,7 @@ struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
return ERR_PTR(-ELOOP);
}
#ifdef CONFIG_DST_CACHE
- if (use_cache)
+ if (dst_cache)
dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
#endif
*saddr = fl4.saddr;
--
2.40.1