1 files changed, 179 insertions, 62 deletions

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index d2d97d07ef27..09cba4cfe31f 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>
@@ -117,6 +118,7 @@ static int compute_score(struct sock *sk, struct net *net,
 {
 	int score;
 	struct inet_sock *inet;
+	bool dev_match;
 
 	if (!net_eq(sock_net(sk), net) ||
 	    udp_sk(sk)->udp_port_hash != hnum ||
@@ -144,15 +146,10 @@ static int compute_score(struct sock *sk, struct net *net,
 		score++;
 	}
 
-	if (sk->sk_bound_dev_if || exact_dif) {
-		bool dev_match = (sk->sk_bound_dev_if == dif ||
-				  sk->sk_bound_dev_if == sdif);
-
-		if (!dev_match)
-			return -1;
-		if (sk->sk_bound_dev_if)
-			score++;
-	}
+	dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
+	if (!dev_match)
+		return -1;
+	score++;
 
 	if (sk->sk_incoming_cpu == raw_smp_processor_id())
 		score++;
@@ -329,6 +326,7 @@ int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 	int err;
 	int is_udplite = IS_UDPLITE(sk);
 	bool checksum_valid = false;
+	struct udp_mib *mib;
 	int is_udp4;
 
 	if (flags & MSG_ERRQUEUE)
@@ -352,6 +350,7 @@ try_again:
 		msg->msg_flags |= MSG_TRUNC;
 
 	is_udp4 = (skb->protocol == htons(ETH_P_IP));
+	mib = __UDPX_MIB(sk, is_udp4);
 
 	/*
 	 * If checksum is needed at all, try to do it while copying the
@@ -380,24 +379,13 @@ try_again:
 	if (unlikely(err)) {
 		if (!peeked) {
 			atomic_inc(&sk->sk_drops);
-			if (is_udp4)
-				UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
-					      is_udplite);
-			else
-				UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS,
-					       is_udplite);
+			SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 		}
 		kfree_skb(skb);
 		return err;
 	}
-	if (!peeked) {
-		if (is_udp4)
-			UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
-				      is_udplite);
-		else
-			UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS,
-				       is_udplite);
-	}
+	if (!peeked)
+		SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS);
 
 	sock_recv_ts_and_drops(msg, sk, skb);
 
@@ -421,6 +409,9 @@ try_again:
 		*addr_len = sizeof(*sin6);
 	}
 
+	if (udp_sk(sk)->gro_enabled)
+		udp_cmsg_recv(msg, sk, skb);
+
 	if (np->rxopt.all)
 		ip6_datagram_recv_common_ctl(sk, msg, skb);
 
@@ -443,17 +434,8 @@ try_again:
 csum_copy_err:
 	if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags,
 				 udp_skb_destructor)) {
-		if (is_udp4) {
-			UDP_INC_STATS(sock_net(sk),
-				      UDP_MIB_CSUMERRORS, is_udplite);
-			UDP_INC_STATS(sock_net(sk),
-				      UDP_MIB_INERRORS, is_udplite);
-		} else {
-			UDP6_INC_STATS(sock_net(sk),
-				       UDP_MIB_CSUMERRORS, is_udplite);
-			UDP6_INC_STATS(sock_net(sk),
-				       UDP_MIB_INERRORS, is_udplite);
-		}
+		SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS);
+		SNMP_INC_STATS(mib, UDP_MIB_INERRORS);
 	}
 	kfree_skb(skb);
 
@@ -463,15 +445,106 @@ csum_copy_err:
 	goto try_again;
 }
 
-void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
-		    u8 type, u8 code, int offset, __be32 info,
-		    struct udp_table *udptable)
+DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
+void udpv6_encap_enable(void)
+{
+	static_branch_inc(&udpv6_encap_needed_key);
+}
+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
+ * lwtunnels might actually break this assumption by being configured with
+ * 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 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 inet6_skb_parm *opt,
+					 u8 type, u8 code, __be32 info)
+{
+	int network_offset, transport_offset;
+	struct sock *sk;
+
+	network_offset = skb_network_offset(skb);
+	transport_offset = skb_transport_offset(skb);
+
+	/* Network header needs to point to the outer IPv6 header inside ICMP */
+	skb_reset_network_header(skb);
+
+	/* Transport header needs to point to the UDP header */
+	skb_set_transport_header(skb, offset);
+
+	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;
+}
+
+int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+		   u8 type, u8 code, int offset, __be32 info,
+		   struct udp_table *udptable)
 {
 	struct ipv6_pinfo *np;
 	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 	const struct in6_addr *saddr = &hdr->saddr;
 	const struct in6_addr *daddr = &hdr->daddr;
 	struct udphdr *uh = (struct udphdr *)(skb->data+offset);
+	bool tunnel = false;
 	struct sock *sk;
 	int harderr;
 	int err;
@@ -480,9 +553,23 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source,
 			       inet6_iif(skb), inet6_sdif(skb), udptable, skb);
 	if (!sk) {
-		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
-				  ICMP6_MIB_INERRORS);
-		return;
+		/* 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,
+						  opt, type, code, info);
+			if (!sk)
+				return 0;
+		}
+
+		if (IS_ERR(sk)) {
+			__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
+					  ICMP6_MIB_INERRORS);
+			return PTR_ERR(sk);
+		}
+
+		tunnel = true;
 	}
 
 	harderr = icmpv6_err_convert(type, code, &err);
@@ -496,10 +583,19 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 			harderr = 1;
 	}
 	if (type == NDISC_REDIRECT) {
-		ip6_sk_redirect(skb, sk);
+		if (tunnel) {
+			ip6_redirect(skb, sock_net(sk), inet6_iif(skb),
+				     sk->sk_mark, sk->sk_uid);
+		} else {
+			ip6_sk_redirect(skb, sk);
+		}
 		goto out;
 	}
 
+	/* Tunnels don't have an application socket: don't pass errors back */
+	if (tunnel)
+		goto out;
+
 	if (!np->recverr) {
 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 			goto out;
@@ -510,7 +606,7 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	sk->sk_err = err;
 	sk->sk_error_report(sk);
 out:
-	return;
+	return 0;
 }
 
 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
@@ -541,21 +637,14 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	return 0;
 }
 
-static __inline__ void udpv6_err(struct sk_buff *skb,
-				 struct inet6_skb_parm *opt, u8 type,
-				 u8 code, int offset, __be32 info)
+static __inline__ int udpv6_err(struct sk_buff *skb,
+				struct inet6_skb_parm *opt, u8 type,
+				u8 code, int offset, __be32 info)
 {
-	__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
+	return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
 }
 
-DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key);
-void udpv6_encap_enable(void)
-{
-	static_branch_enable(&udpv6_encap_needed_key);
-}
-EXPORT_SYMBOL(udpv6_encap_enable);
-
-static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int is_udplite = IS_UDPLITE(sk);
@@ -638,10 +727,32 @@ drop:
 	return -1;
 }
 
+static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *next, *segs;
+	int ret;
+
+	if (likely(!udp_unexpected_gso(sk, skb)))
+		return udpv6_queue_rcv_one_skb(sk, skb);
+
+	__skb_push(skb, -skb_mac_offset(skb));
+	segs = udp_rcv_segment(sk, skb, false);
+	for (skb = segs; skb; skb = next) {
+		next = skb->next;
+		__skb_pull(skb, skb_transport_offset(skb));
+
+		ret = udpv6_queue_rcv_one_skb(sk, skb);
+		if (ret > 0)
+			ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret,
+						 true);
+	}
+	return 0;
+}
+
 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 				   __be16 loc_port, const struct in6_addr *loc_addr,
 				   __be16 rmt_port, const struct in6_addr *rmt_addr,
-				   int dif, unsigned short hnum)
+				   int dif, int sdif, unsigned short hnum)
 {
 	struct inet_sock *inet = inet_sk(sk);
 
@@ -653,7 +764,7 @@ static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
 	    (inet->inet_dport && inet->inet_dport != rmt_port) ||
 	    (!ipv6_addr_any(&sk->sk_v6_daddr) &&
 		    !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) ||
-	    (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) ||
+	    !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) ||
 	    (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
 		    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr)))
 		return false;
@@ -687,6 +798,7 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
 	unsigned int offset = offsetof(typeof(*sk), sk_node);
 	unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
 	int dif = inet6_iif(skb);
+	int sdif = inet6_sdif(skb);
 	struct hlist_node *node;
 	struct sk_buff *nskb;
 
@@ -701,7 +813,8 @@ start_lookup:
 
 	sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
 		if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
-					    uh->source, saddr, dif, hnum))
+					    uh->source, saddr, dif, sdif,
+					    hnum))
 			continue;
 		/* If zero checksum and no_check is not on for
 		 * the socket then skip it.
@@ -1458,11 +1571,15 @@ void udpv6_destroy_sock(struct sock *sk)
 	udp_v6_flush_pending_frames(sk);
 	release_sock(sk);
 
-	if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) {
-		void (*encap_destroy)(struct sock *sk);
-		encap_destroy = READ_ONCE(up->encap_destroy);
-		if (encap_destroy)
-			encap_destroy(sk);
+	if (static_branch_unlikely(&udpv6_encap_needed_key)) {
+		if (up->encap_type) {
+			void (*encap_destroy)(struct sock *sk);
+			encap_destroy = READ_ONCE(up->encap_destroy);
+			if (encap_destroy)
+				encap_destroy(sk);
+		}
+		if (up->encap_enabled)
+			static_branch_dec(&udpv6_encap_needed_key);
 	}
 
 	inet6_destroy_sock(sk);