[PATCH net-next v2 7/7] vxlan: use generic function for tunnel IPv4 route lookup

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

The route lookup can be done now via generic function
udp_tunnel_dst_lookup() to replace the custom implementations in
vxlan_get_route().

Note that this patch only touches IPv4, while IPv6 still uses
vxlan6_get_route(). After IPv6 route lookup gets converted as well,
vxlan_xmit_one() can be simplified by removing local variables that
will be passed via "struct ip_tunnel_key", such as remote_ip,
local_ip, flow_flags, label.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
drivers/net/vxlan/vxlan_core.c | 114 ++++++++++++---------------------
1 file changed, 41 insertions(+), 73 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index ece377b1b6bd..6f7d45e3cfa2 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2215,57 +2215,6 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
return 0;
}

-static struct rtable *vxlan_get_route(struct vxlan_dev *vxlan, struct net_device *dev,
- struct vxlan_sock *sock4,
- struct sk_buff *skb, int oif, u8 tos,
- __be32 daddr, __be32 *saddr, __be16 dport, __be16 sport,
- __u8 flow_flags, struct dst_cache *dst_cache,
- const struct ip_tunnel_info *info)
-{
- bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
- struct rtable *rt = NULL;
- struct flowi4 fl4;
-
- if (!sock4)
- return ERR_PTR(-EIO);
-
- if (tos && !info)
- use_cache = false;
- if (use_cache) {
- rt = dst_cache_get_ip4(dst_cache, saddr);
- if (rt)
- return rt;
- }
-
- memset(&fl4, 0, sizeof(fl4));
- fl4.flowi4_oif = oif;
- fl4.flowi4_tos = RT_TOS(tos);
- fl4.flowi4_mark = skb->mark;
- fl4.flowi4_proto = IPPROTO_UDP;
- fl4.daddr = daddr;
- fl4.saddr = *saddr;
- fl4.fl4_dport = dport;
- fl4.fl4_sport = sport;
- fl4.flowi4_flags = flow_flags;
-
- rt = ip_route_output_key(vxlan->net, &fl4);
- if (!IS_ERR(rt)) {
- if (rt->dst.dev == dev) {
- netdev_dbg(dev, "circular route to %pI4\n", &daddr);
- ip_rt_put(rt);
- return ERR_PTR(-ELOOP);
- }
-
- *saddr = fl4.saddr;
- if (use_cache)
- dst_cache_set_ip4(dst_cache, &rt->dst, fl4.saddr);
- } else {
- netdev_dbg(dev, "no route to %pI4\n", &daddr);
- return ERR_PTR(-ENETUNREACH);
- }
- return rt;
-}
-
#if IS_ENABLED(CONFIG_IPV6)
static struct dst_entry *vxlan6_get_route(struct vxlan_dev *vxlan,
struct net_device *dev,
@@ -2418,30 +2367,38 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
{
struct dst_cache *dst_cache;
struct ip_tunnel_info *info;
+ struct ip_tunnel_key *pkey;
+ struct ip_tunnel_key key;
struct vxlan_dev *vxlan = netdev_priv(dev);
const struct iphdr *old_iph = ip_hdr(skb);
union vxlan_addr *dst;
- union vxlan_addr remote_ip, local_ip;
+ union vxlan_addr remote_ip;
struct vxlan_metadata _md;
struct vxlan_metadata *md = &_md;
unsigned int pkt_len = skb->len;
__be16 src_port = 0, dst_port;
struct dst_entry *ndst = NULL;
- __u8 tos, ttl, flow_flags = 0;
+ __u8 tos, ttl;
int ifindex;
int err;
u32 flags = vxlan->cfg.flags;
+ bool use_cache;
bool udp_sum = false;
bool xnet = !net_eq(vxlan->net, dev_net(vxlan->dev));
__be32 vni = 0;
#if IS_ENABLED(CONFIG_IPV6)
+ union vxlan_addr local_ip;
__be32 label;
#endif

info = skb_tunnel_info(skb);
+ use_cache = ip_tunnel_dst_cache_usable(skb, info);

if (rdst) {
dst = &rdst->remote_ip;
+ memset(&key, 0, sizeof(key));
+ pkey = &key;
+
if (vxlan_addr_any(dst)) {
if (did_rsc) {
/* short-circuited back to local bridge */
@@ -2455,7 +2412,15 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
dst_port = rdst->remote_port ? rdst->remote_port : vxlan->cfg.dst_port;
vni = (rdst->remote_vni) ? : default_vni;
ifindex = rdst->remote_ifindex;
- local_ip = vxlan->cfg.saddr;
+
+ if (dst->sa.sa_family == AF_INET) {
+ key.u.ipv4.src = vxlan->cfg.saddr.sin.sin_addr.s_addr;
+ key.u.ipv4.dst = rdst->remote_ip.sin.sin_addr.s_addr;
+ } else {
+ key.u.ipv6.src = vxlan->cfg.saddr.sin6.sin6_addr;
+ key.u.ipv6.dst = rdst->remote_ip.sin6.sin6_addr;
+ }
+
dst_cache = &rdst->dst_cache;
md->gbp = skb->mark;
if (flags & VXLAN_F_TTL_INHERIT) {
@@ -2469,12 +2434,15 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
tos = vxlan->cfg.tos;
if (tos == 1)
tos = ip_tunnel_get_dsfield(old_iph, skb);
+ if (tos && !info)
+ use_cache = false;

if (dst->sa.sa_family == AF_INET)
udp_sum = !(flags & VXLAN_F_UDP_ZERO_CSUM_TX);
else
udp_sum = !(flags & VXLAN_F_UDP_ZERO_CSUM6_TX);
#if IS_ENABLED(CONFIG_IPV6)
+ local_ip = vxlan->cfg.saddr;
label = vxlan->cfg.label;
#endif
} else {
@@ -2486,14 +2454,15 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
remote_ip.sa.sa_family = ip_tunnel_info_af(info);
if (remote_ip.sa.sa_family == AF_INET) {
remote_ip.sin.sin_addr.s_addr = info->key.u.ipv4.dst;
- local_ip.sin.sin_addr.s_addr = info->key.u.ipv4.src;
} else {
remote_ip.sin6.sin6_addr = info->key.u.ipv6.dst;
+#if IS_ENABLED(CONFIG_IPV6)
local_ip.sin6.sin6_addr = info->key.u.ipv6.src;
+#endif
}
dst = &remote_ip;
+ pkey = &info->key;
dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port;
- flow_flags = info->key.flow_flags;
vni = tunnel_id_to_key32(info->key.tun_id);
ifindex = 0;
dst_cache = &info->dst_cache;
@@ -2517,15 +2486,14 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
struct vxlan_sock *sock4 = rcu_dereference(vxlan->vn4_sock);
struct rtable *rt;
__be16 df = 0;
+ __be32 saddr;

if (!ifindex)
ifindex = sock4->sock->sk->sk_bound_dev_if;

- rt = vxlan_get_route(vxlan, dev, sock4, skb, ifindex, tos,
- dst->sin.sin_addr.s_addr,
- &local_ip.sin.sin_addr.s_addr,
- dst_port, src_port, flow_flags,
- dst_cache, info);
+ rt = udp_tunnel_dst_lookup(skb, dev, vxlan->net, ifindex,
+ &saddr, pkey, src_port, dst_port,
+ tos, use_cache ? dst_cache : NULL);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
goto tx_error;
@@ -2561,16 +2529,13 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
} else if (err) {
if (info) {
struct ip_tunnel_info *unclone;
- struct in_addr src, dst;

unclone = skb_tunnel_info_unclone(skb);
if (unlikely(!unclone))
goto tx_error;

- src = remote_ip.sin.sin_addr;
- dst = local_ip.sin.sin_addr;
- unclone->key.u.ipv4.src = src.s_addr;
- unclone->key.u.ipv4.dst = dst.s_addr;
+ unclone->key.u.ipv4.src = pkey->u.ipv4.dst;
+ unclone->key.u.ipv4.dst = saddr;
}
vxlan_encap_bypass(skb, vxlan, vxlan, vni, false);
dst_release(ndst);
@@ -2584,8 +2549,8 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
if (err < 0)
goto tx_error;

- udp_tunnel_xmit_skb(rt, sock4->sock->sk, skb, local_ip.sin.sin_addr.s_addr,
- dst->sin.sin_addr.s_addr, tos, ttl, df,
+ udp_tunnel_xmit_skb(rt, sock4->sock->sk, skb, saddr,
+ pkey->u.ipv4.dst, tos, ttl, df,
src_port, dst_port, xnet, !udp_sum);
#if IS_ENABLED(CONFIG_IPV6)
} else {
@@ -3286,11 +3251,14 @@ static int vxlan_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
struct vxlan_sock *sock4 = rcu_dereference(vxlan->vn4_sock);
struct rtable *rt;

- rt = vxlan_get_route(vxlan, dev, sock4, skb, 0, info->key.tos,
- info->key.u.ipv4.dst,
- &info->key.u.ipv4.src, dport, sport,
- info->key.flow_flags, &info->dst_cache,
- info);
+ if (!sock4)
+ return -EIO;
+
+ rt = udp_tunnel_dst_lookup(skb, dev, vxlan->net, 0,
+ &info->key.u.ipv4.src,
+ &info->key,
+ sport, dport, info->key.tos,
+ &info->dst_cache);
if (IS_ERR(rt))
return PTR_ERR(rt);
ip_rt_put(rt);
--
2.40.1