[PATCH net-next 3/5] ipv6: add new arguments to udp_tunnel6_dst_lookup()

Beniamino Galvani
2023-10-20T11:56:02Z

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).

This is similar to what already done for IPv4 in commit 72fc68c6356b
("ipv4: add new arguments to udp_tunnel_dst_lookup()").

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
drivers/net/bareudp.c | 10 +++++++---
include/net/udp_tunnel.h | 7 ++++---
net/ipv6/ip6_udp_tunnel.c | 33 ++++++++++++++++++---------------
3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/drivers/net/bareudp.c b/drivers/net/bareudp.c
index 9eb5e11c09b4..9c11a0d0273b 100644
--- a/drivers/net/bareudp.c
+++ b/drivers/net/bareudp.c
@@ -371,8 +371,10 @@ static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
if (!sock)
return -ESHUTDOWN;

- dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, &saddr, info,
- use_cache);
+ dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, 0, &saddr,
+ key, 0, 0, key->tos,
+ use_cache ?
+ (struct dst_cache *) &info->dst_cache : NULL);
if (IS_ERR(dst))
return PTR_ERR(dst);

@@ -499,7 +501,9 @@ static int bareudp_fill_metadata_dst(struct net_device *dev,
struct socket *sock = rcu_dereference(bareudp->sock);

dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
- &saddr, info, use_cache);
+ 0, &saddr, &info->key,
+ 0, 0, info->key.tos,
+ use_cache ? &info->dst_cache : NULL);
if (IS_ERR(dst))
return PTR_ERR(dst);

diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 583867643bd1..d716214fe03d 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h
@@ -172,10 +172,11 @@ struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
struct net *net,
- struct socket *sock,
+ struct socket *sock, int oif,
struct in6_addr *saddr,
- const struct ip_tunnel_info *info,
- bool use_cache);
+ const struct ip_tunnel_key *key,
+ __be16 sport, __be16 dport, u8 dsfield,
+ 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/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c
index b9c906518ce2..a7bf0327b380 100644
--- a/net/ipv6/ip6_udp_tunnel.c
+++ b/net/ipv6/ip6_udp_tunnel.c
@@ -119,9 +119,13 @@ EXPORT_SYMBOL_GPL(udp_tunnel6_xmit_skb);
* @dev: Tunnel device
* @net: Network namespace of tunnel device
* @sock: Socket which provides route info
+ * @oif: Index of the output interface
* @saddr: Memory to store the src ip address
- * @info: Tunnel information
- * @use_cache: Flag to enable cache usage
+ * @key: Tunnel information
+ * @sport: UDP source port
+ * @dport: UDP destination port
+ * @dsfield: The traffic class field
+ * @dst_cache: The dst cache to use for lookup
* This function performs a route lookup on a UDP tunnel
*
* It returns a valid dst pointer and stores src address to be used in
@@ -132,20 +136,17 @@ struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
struct net *net,
struct socket *sock,
+ int oif,
struct in6_addr *saddr,
- const struct ip_tunnel_info *info,
- bool use_cache)
+ const struct ip_tunnel_key *key,
+ __be16 sport, __be16 dport, u8 dsfield,
+ struct dst_cache *dst_cache)
{
struct dst_entry *dst = NULL;
-#ifdef CONFIG_DST_CACHE
- struct dst_cache *dst_cache;
-#endif
struct flowi6 fl6;
- __u8 prio;

#ifdef CONFIG_DST_CACHE
- dst_cache = (struct dst_cache *)&info->dst_cache;
- if (use_cache) {
+ if (dst_cache) {
dst = dst_cache_get_ip6(dst_cache, saddr);
if (dst)
return dst;
@@ -154,10 +155,12 @@ struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = IPPROTO_UDP;
- fl6.daddr = info->key.u.ipv6.dst;
- fl6.saddr = info->key.u.ipv6.src;
- prio = info->key.tos;
- fl6.flowlabel = ip6_make_flowinfo(prio, info->key.label);
+ fl6.flowi6_oif = oif;
+ fl6.daddr = key->u.ipv6.dst;
+ fl6.saddr = key->u.ipv6.src;
+ fl6.fl6_sport = sport;
+ fl6.fl6_dport = dport;
+ fl6.flowlabel = ip6_make_flowinfo(dsfield, key->label);

dst = ipv6_stub->ipv6_dst_lookup_flow(net, sock->sk, &fl6,
NULL);
@@ -171,7 +174,7 @@ struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
return ERR_PTR(-ELOOP);
}
#ifdef CONFIG_DST_CACHE
- if (use_cache)
+ if (dst_cache)
dst_cache_set_ip6(dst_cache, dst, &fl6.saddr);
#endif
*saddr = fl6.saddr;
--
2.40.1