diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
index 236e40ba06bf1b115cb5a1aaa00a2e03c24c3337..69b4bcf880c9ec5ece7597964df6e08e912c24e8 100644
--- a/include/net/ip6_tunnel.h
+++ b/include/net/ip6_tunnel.h
@@ -69,6 +69,8 @@ struct ip6_tnl_encap_ops {
size_t (*encap_hlen)(struct ip_tunnel_encap *e);
int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi6 *fl6);
+ int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info);
};
#ifdef CONFIG_INET
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index b0d022ff6ea1702037b84a038f3c81ce56540aa4..db6b2218a2ad2a3c9aa720ea7d36d8c997cb4f50 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -311,6 +311,7 @@ struct ip_tunnel_encap_ops {
size_t (*encap_hlen)(struct ip_tunnel_encap *e);
int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi4 *fl4);
+ int (*err_handler)(struct sk_buff *skb, u32 info);
};
#define MAX_IPTUN_ENCAP_OPS 8
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a505ee5eb92c35b2c0ad3f0a8b22fa1c32de547b..6f8890c5bc7eb50ef48d7a7e7ff268cfdd3b4b35 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -105,6 +105,7 @@
#include <net/net_namespace.h>
#include <net/icmp.h>
#include <net/inet_hashtables.h>
+#include <net/ip_tunnels.h>
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
@@ -590,6 +591,26 @@ void udp_encap_enable(void)
}
EXPORT_SYMBOL(udp_encap_enable);
+/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
+ * through error handlers in encapsulations looking for a match.
+ */
+static int __udp4_lib_err_encap_no_sk(struct sk_buff *skb, u32 info)
+{
+ int i;
+
+ for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
+ int (*handler)(struct sk_buff *skb, u32 info);
+
+ if (!iptun_encaps[i])
+ continue;
+ handler = rcu_dereference(iptun_encaps[i]->err_handler);
+ if (handler && !handler(skb, info))
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
/* Try to match ICMP errors to UDP tunnels by looking up a socket without
* reversing source and destination port: this will match tunnels that force the
* same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
@@ -597,28 +618,25 @@ EXPORT_SYMBOL(udp_encap_enable);
* different destination ports on endpoints, in this case we won't be able to
* trace ICMP messages back to them.
*
+ * If this doesn't match any socket, probe tunnels with arbitrary destination
+ * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
+ * we've sent packets to won't necessarily match the local destination port.
+ *
* Then ask the tunnel implementation to match the error against a valid
* association.
*
- * Return the socket if we have a match.
+ * Return an error if we can't find a match, the socket if we need further
+ * processing, zero otherwise.
*/
static struct sock *__udp4_lib_err_encap(struct net *net,
const struct iphdr *iph,
struct udphdr *uh,
struct udp_table *udptable,
- struct sk_buff *skb)
+ struct sk_buff *skb, u32 info)
{
- int (*lookup)(struct sock *sk, struct sk_buff *skb);
int network_offset, transport_offset;
- struct udp_sock *up;
struct sock *sk;
- sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
- iph->saddr, uh->dest, skb->dev->ifindex, 0,
- udptable, NULL);
- if (!sk)
- return NULL;
-
network_offset = skb_network_offset(skb);
transport_offset = skb_transport_offset(skb);
@@ -628,10 +646,20 @@ static struct sock *__udp4_lib_err_encap(struct net *net,
/* Transport header needs to point to the UDP header */
skb_set_transport_header(skb, iph->ihl << 2);
- up = udp_sk(sk);
- lookup = READ_ONCE(up->encap_err_lookup);
- if (!lookup || lookup(sk, skb))
- sk = NULL;
+ sk = __udp4_lib_lookup(net, iph->daddr, uh->source,
+ iph->saddr, uh->dest, skb->dev->ifindex, 0,
+ udptable, NULL);
+ if (sk) {
+ int (*lookup)(struct sock *sk, struct sk_buff *skb);
+ struct udp_sock *up = udp_sk(sk);
+
+ lookup = READ_ONCE(up->encap_err_lookup);
+ if (!lookup || lookup(sk, skb))
+ sk = NULL;
+ }
+
+ if (!sk)
+ sk = ERR_PTR(__udp4_lib_err_encap_no_sk(skb, info));
skb_set_transport_header(skb, transport_offset);
skb_set_network_header(skb, network_offset);
@@ -668,13 +696,19 @@ int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
inet_sdif(skb), udptable, NULL);
if (!sk) {
/* No socket for error: try tunnels before discarding */
- if (static_branch_unlikely(&udp_encap_needed_key))
- sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb);
+ sk = ERR_PTR(-ENOENT);
+ if (static_branch_unlikely(&udp_encap_needed_key)) {
+ sk = __udp4_lib_err_encap(net, iph, uh, udptable, skb,
+ info);
+ if (!sk)
+ return 0;
+ }
- if (!sk) {
+ if (IS_ERR(sk)) {
__ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
- return -ENOENT;
+ return PTR_ERR(sk);
}
+
tunnel = true;
}
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 61316ec48b51ec16ef590c9a5a1eabbb7d22e60b..0c0cb1611aef27cb5c2536acf6299435298362b2 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -45,6 +45,7 @@
#include <net/raw.h>
#include <net/tcp_states.h>
#include <net/ip6_checksum.h>
+#include <net/ip6_tunnel.h>
#include <net/xfrm.h>
#include <net/inet_hashtables.h>
#include <net/inet6_hashtables.h>
@@ -469,6 +470,29 @@ void udpv6_encap_enable(void)
}
EXPORT_SYMBOL(udpv6_encap_enable);
+/* Handler for tunnels with arbitrary destination ports: no socket lookup, go
+ * through error handlers in encapsulations looking for a match.
+ */
+static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb,
+ struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, u32 info)
+{
+ int i;
+
+ for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) {
+ int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, u32 info);
+
+ if (!ip6tun_encaps[i])
+ continue;
+ handler = rcu_dereference(ip6tun_encaps[i]->err_handler);
+ if (handler && !handler(skb, opt, type, code, offset, info))
+ return 0;
+ }
+
+ return -ENOENT;
+}
+
/* Try to match ICMP errors to UDP tunnels by looking up a socket without
* reversing source and destination port: this will match tunnels that force the
* same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that
@@ -476,28 +500,27 @@ EXPORT_SYMBOL(udpv6_encap_enable);
* different destination ports on endpoints, in this case we won't be able to
* trace ICMP messages back to them.
*
+ * If this doesn't match any socket, probe tunnels with arbitrary destination
+ * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port
+ * we've sent packets to won't necessarily match the local destination port.
+ *
* Then ask the tunnel implementation to match the error against a valid
* association.
*
- * Return the socket if we have a match.
+ * Return an error if we can't find a match, the socket if we need further
+ * processing, zero otherwise.
*/
static struct sock *__udp6_lib_err_encap(struct net *net,
const struct ipv6hdr *hdr, int offset,
struct udphdr *uh,
struct udp_table *udptable,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ struct inet6_skb_parm *opt,
+ u8 type, u8 code, __be32 info)
{
- int (*lookup)(struct sock *sk, struct sk_buff *skb);
int network_offset, transport_offset;
- struct udp_sock *up;
struct sock *sk;
- sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
- &hdr->saddr, uh->dest,
- inet6_iif(skb), 0, udptable, skb);
- if (!sk)
- return NULL;
-
network_offset = skb_network_offset(skb);
transport_offset = skb_transport_offset(skb);
@@ -507,13 +530,26 @@ static struct sock *__udp6_lib_err_encap(struct net *net,
/* Transport header needs to point to the UDP header */
skb_set_transport_header(skb, offset);
- up = udp_sk(sk);
- lookup = READ_ONCE(up->encap_err_lookup);
- if (!lookup || lookup(sk, skb))
- sk = NULL;
+ sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source,
+ &hdr->saddr, uh->dest,
+ inet6_iif(skb), 0, udptable, skb);
+ if (sk) {
+ int (*lookup)(struct sock *sk, struct sk_buff *skb);
+ struct udp_sock *up = udp_sk(sk);
+
+ lookup = READ_ONCE(up->encap_err_lookup);
+ if (!lookup || lookup(sk, skb))
+ sk = NULL;
+ }
+
+ if (!sk) {
+ sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code,
+ offset, info));
+ }
skb_set_transport_header(skb, transport_offset);
skb_set_network_header(skb, network_offset);
+
return sk;
}
@@ -536,16 +572,21 @@ int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
inet6_iif(skb), inet6_sdif(skb), udptable, skb);
if (!sk) {
/* No socket for error: try tunnels before discarding */
+ sk = ERR_PTR(-ENOENT);
if (static_branch_unlikely(&udpv6_encap_needed_key)) {
sk = __udp6_lib_err_encap(net, hdr, offset, uh,
- udptable, skb);
+ udptable, skb,
+ opt, type, code, info);
+ if (!sk)
+ return 0;
}
- if (!sk) {
+ if (IS_ERR(sk)) {
__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
ICMP6_MIB_INERRORS);
- return -ENOENT;
+ return PTR_ERR(sk);
}
+
tunnel = true;
}