1 files changed, 43 insertions, 23 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 0819d6001b9a..7876b7d703cb 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -28,9 +28,9 @@
 #include <net/tcp.h>
 #include <net/sock_reuseport.h>
 
-static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
-			const __u16 lport, const __be32 faddr,
-			const __be16 fport)
+u32 inet_ehashfn(const struct net *net, const __be32 laddr,
+		 const __u16 lport, const __be32 faddr,
+		 const __be16 fport)
 {
 	static u32 inet_ehash_secret __read_mostly;
 
@@ -39,6 +39,7 @@ static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 	return __inet_ehashfn(laddr, lport, faddr, fport,
 			      inet_ehash_secret + net_hash_mix(net));
 }
+EXPORT_SYMBOL_GPL(inet_ehashfn);
 
 /* This function handles inet_sock, but also timewait and request sockets
  * for IPv4/IPv6.
@@ -332,20 +333,38 @@ static inline int compute_score(struct sock *sk, struct net *net,
 	return score;
 }
 
-static inline struct sock *lookup_reuseport(struct net *net, struct sock *sk,
-					    struct sk_buff *skb, int doff,
-					    __be32 saddr, __be16 sport,
-					    __be32 daddr, unsigned short hnum)
+/**
+ * inet_lookup_reuseport() - execute reuseport logic on AF_INET socket if necessary.
+ * @net: network namespace.
+ * @sk: AF_INET socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
+ * @skb: context for a potential SK_REUSEPORT program.
+ * @doff: header offset.
+ * @saddr: source address.
+ * @sport: source port.
+ * @daddr: destination address.
+ * @hnum: destination port in host byte order.
+ * @ehashfn: hash function used to generate the fallback hash.
+ *
+ * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
+ *         the selected sock or an error.
+ */
+struct sock *inet_lookup_reuseport(struct net *net, struct sock *sk,
+				   struct sk_buff *skb, int doff,
+				   __be32 saddr, __be16 sport,
+				   __be32 daddr, unsigned short hnum,
+				   inet_ehashfn_t *ehashfn)
 {
 	struct sock *reuse_sk = NULL;
 	u32 phash;
 
 	if (sk->sk_reuseport) {
-		phash = inet_ehashfn(net, daddr, hnum, saddr, sport);
+		phash = INDIRECT_CALL_2(ehashfn, udp_ehashfn, inet_ehashfn,
+					net, daddr, hnum, saddr, sport);
 		reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
 	}
 	return reuse_sk;
 }
+EXPORT_SYMBOL_GPL(inet_lookup_reuseport);
 
 /*
  * Here are some nice properties to exploit here. The BSD API
@@ -369,8 +388,8 @@ static struct sock *inet_lhash2_lookup(struct net *net,
 	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
 		score = compute_score(sk, net, hnum, daddr, dif, sdif);
 		if (score > hiscore) {
-			result = lookup_reuseport(net, sk, skb, doff,
-						  saddr, sport, daddr, hnum);
+			result = inet_lookup_reuseport(net, sk, skb, doff,
+						       saddr, sport, daddr, hnum, inet_ehashfn);
 			if (result)
 				return result;
 
@@ -382,24 +401,23 @@ static struct sock *inet_lhash2_lookup(struct net *net,
 	return result;
 }
 
-static inline struct sock *inet_lookup_run_bpf(struct net *net,
-					       struct inet_hashinfo *hashinfo,
-					       struct sk_buff *skb, int doff,
-					       __be32 saddr, __be16 sport,
-					       __be32 daddr, u16 hnum, const int dif)
+struct sock *inet_lookup_run_sk_lookup(struct net *net,
+				       int protocol,
+				       struct sk_buff *skb, int doff,
+				       __be32 saddr, __be16 sport,
+				       __be32 daddr, u16 hnum, const int dif,
+				       inet_ehashfn_t *ehashfn)
 {
 	struct sock *sk, *reuse_sk;
 	bool no_reuseport;
 
-	if (hashinfo != net->ipv4.tcp_death_row.hashinfo)
-		return NULL; /* only TCP is supported */
-
-	no_reuseport = bpf_sk_lookup_run_v4(net, IPPROTO_TCP, saddr, sport,
+	no_reuseport = bpf_sk_lookup_run_v4(net, protocol, saddr, sport,
 					    daddr, hnum, dif, &sk);
 	if (no_reuseport || IS_ERR_OR_NULL(sk))
 		return sk;
 
-	reuse_sk = lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum);
+	reuse_sk = inet_lookup_reuseport(net, sk, skb, doff, saddr, sport, daddr, hnum,
+					 ehashfn);
 	if (reuse_sk)
 		sk = reuse_sk;
 	return sk;
@@ -417,9 +435,11 @@ struct sock *__inet_lookup_listener(struct net *net,
 	unsigned int hash2;
 
 	/* Lookup redirect from BPF */
-	if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
-		result = inet_lookup_run_bpf(net, hashinfo, skb, doff,
-					     saddr, sport, daddr, hnum, dif);
+	if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
+	    hashinfo == net->ipv4.tcp_death_row.hashinfo) {
+		result = inet_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
+						   saddr, sport, daddr, hnum, dif,
+						   inet_ehashfn);
 		if (result)
 			goto done;
 	}