1 files changed, 150 insertions, 89 deletions

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index ccc598079..0d9e9d7bb 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -20,10 +20,12 @@
 #include <linux/wait.h>
 #include <linux/vmalloc.h>
 
+#include <net/addrconf.h>
 #include <net/inet_connection_sock.h>
 #include <net/inet_hashtables.h>
 #include <net/secure_seq.h>
 #include <net/ip.h>
+#include <net/sock_reuseport.h>
 
 static u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 			const __u16 lport, const __be32 faddr,
@@ -205,6 +207,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
 
 struct sock *__inet_lookup_listener(struct net *net,
 				    struct inet_hashinfo *hashinfo,
+				    struct sk_buff *skb, int doff,
 				    const __be32 saddr, __be16 sport,
 				    const __be32 daddr, const unsigned short hnum,
 				    const int dif)
@@ -214,6 +217,7 @@ struct sock *__inet_lookup_listener(struct net *net,
 	unsigned int hash = inet_lhashfn(net, hnum);
 	struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
 	int score, hiscore, matches = 0, reuseport = 0;
+	bool select_ok = true;
 	u32 phash = 0;
 
 	rcu_read_lock();
@@ -229,6 +233,15 @@ begin:
 			if (reuseport) {
 				phash = inet_ehashfn(net, daddr, hnum,
 						     saddr, sport);
+				if (select_ok) {
+					struct sock *sk2;
+					sk2 = reuseport_select_sock(sk, phash,
+								    skb, doff);
+					if (sk2) {
+						result = sk2;
+						goto found;
+					}
+				}
 				matches = 1;
 			}
 		} else if (score == hiscore && reuseport) {
@@ -246,11 +259,13 @@ begin:
 	if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
 		goto begin;
 	if (result) {
+found:
 		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
 			result = NULL;
 		else if (unlikely(compute_score(result, net, hnum, daddr,
 				  dif) < hiscore)) {
 			sock_put(result);
+			select_ok = false;
 			goto begin;
 		}
 	}
@@ -449,32 +464,76 @@ bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
 }
 EXPORT_SYMBOL_GPL(inet_ehash_nolisten);
 
-void __inet_hash(struct sock *sk, struct sock *osk)
+static int inet_reuseport_add_sock(struct sock *sk,
+				   struct inet_listen_hashbucket *ilb,
+				   int (*saddr_same)(const struct sock *sk1,
+						     const struct sock *sk2,
+						     bool match_wildcard))
+{
+	struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
+	struct sock *sk2;
+	struct hlist_nulls_node *node;
+	kuid_t uid = sock_i_uid(sk);
+
+	sk_nulls_for_each_rcu(sk2, node, &ilb->head) {
+		if (sk2 != sk &&
+		    sk2->sk_family == sk->sk_family &&
+		    ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
+		    sk2->sk_bound_dev_if == sk->sk_bound_dev_if &&
+		    inet_csk(sk2)->icsk_bind_hash == tb &&
+		    sk2->sk_reuseport && uid_eq(uid, sock_i_uid(sk2)) &&
+		    saddr_same(sk, sk2, false))
+			return reuseport_add_sock(sk, sk2);
+	}
+
+	/* Initial allocation may have already happened via setsockopt */
+	if (!rcu_access_pointer(sk->sk_reuseport_cb))
+		return reuseport_alloc(sk);
+	return 0;
+}
+
+int __inet_hash(struct sock *sk, struct sock *osk,
+		 int (*saddr_same)(const struct sock *sk1,
+				   const struct sock *sk2,
+				   bool match_wildcard))
 {
 	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
 	struct inet_listen_hashbucket *ilb;
+	int err = 0;
 
 	if (sk->sk_state != TCP_LISTEN) {
 		inet_ehash_nolisten(sk, osk);
-		return;
+		return 0;
 	}
 	WARN_ON(!sk_unhashed(sk));
 	ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
 
 	spin_lock(&ilb->lock);
+	if (sk->sk_reuseport) {
+		err = inet_reuseport_add_sock(sk, ilb, saddr_same);
+		if (err)
+			goto unlock;
+	}
 	__sk_nulls_add_node_rcu(sk, &ilb->head);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+unlock:
 	spin_unlock(&ilb->lock);
+
+	return err;
 }
 EXPORT_SYMBOL(__inet_hash);
 
-void inet_hash(struct sock *sk)
+int inet_hash(struct sock *sk)
 {
+	int err = 0;
+
 	if (sk->sk_state != TCP_CLOSE) {
 		local_bh_disable();
-		__inet_hash(sk, NULL);
+		err = __inet_hash(sk, NULL, ipv4_rcv_saddr_equal);
 		local_bh_enable();
 	}
+
+	return err;
 }
 EXPORT_SYMBOL_GPL(inet_hash);
 
@@ -493,6 +552,8 @@ void inet_unhash(struct sock *sk)
 		lock = inet_ehash_lockp(hashinfo, sk->sk_hash);
 
 	spin_lock_bh(lock);
+	if (rcu_access_pointer(sk->sk_reuseport_cb))
+		reuseport_detach_sock(sk);
 	done = __sk_nulls_del_node_init_rcu(sk);
 	if (done)
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
@@ -506,106 +567,106 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row,
 			struct sock *, __u16, struct inet_timewait_sock **))
 {
 	struct inet_hashinfo *hinfo = death_row->hashinfo;
-	const unsigned short snum = inet_sk(sk)->inet_num;
+	struct inet_timewait_sock *tw = NULL;
 	struct inet_bind_hashbucket *head;
-	struct inet_bind_bucket *tb;
-	int ret;
+	int port = inet_sk(sk)->inet_num;
 	struct net *net = sock_net(sk);
+	struct inet_bind_bucket *tb;
+	u32 remaining, offset;
+	int ret, i, low, high;
+	static u32 hint;
+
+	if (port) {
+		head = &hinfo->bhash[inet_bhashfn(net, port,
+						  hinfo->bhash_size)];
+		tb = inet_csk(sk)->icsk_bind_hash;
+		spin_lock_bh(&head->lock);
+		if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
+			inet_ehash_nolisten(sk, NULL);
+			spin_unlock_bh(&head->lock);
+			return 0;
+		}
+		spin_unlock(&head->lock);
+		/* No definite answer... Walk to established hash table */
+		ret = check_established(death_row, sk, port, NULL);
+		local_bh_enable();
+		return ret;
+	}
 
-	if (!snum) {
-		int i, remaining, low, high, port;
-		static u32 hint;
-		u32 offset = hint + port_offset;
-		struct inet_timewait_sock *tw = NULL;
+	inet_get_local_port_range(net, &low, &high);
+	high++; /* [32768, 60999] -> [32768, 61000[ */
+	remaining = high - low;
+	if (likely(remaining > 1))
+		remaining &= ~1U;
 
-		inet_get_local_port_range(net, &low, &high);
-		remaining = (high - low) + 1;
+	offset = (hint + port_offset) % remaining;
+	/* In first pass we try ports of @low parity.
+	 * inet_csk_get_port() does the opposite choice.
+	 */
+	offset &= ~1U;
+other_parity_scan:
+	port = low + offset;
+	for (i = 0; i < remaining; i += 2, port += 2) {
+		if (unlikely(port >= high))
+			port -= remaining;
+		if (inet_is_local_reserved_port(net, port))
+			continue;
+		head = &hinfo->bhash[inet_bhashfn(net, port,
+						  hinfo->bhash_size)];
+		spin_lock_bh(&head->lock);
 
-		/* By starting with offset being an even number,
-		 * we tend to leave about 50% of ports for other uses,
-		 * like bind(0).
+		/* Does not bother with rcv_saddr checks, because
+		 * the established check is already unique enough.
 		 */
-		offset &= ~1;
-
-		local_bh_disable();
-		for (i = 0; i < remaining; i++) {
-			port = low + (i + offset) % remaining;
-			if (inet_is_local_reserved_port(net, port))
-				continue;
-			head = &hinfo->bhash[inet_bhashfn(net, port,
-					hinfo->bhash_size)];
-			spin_lock(&head->lock);
-
-			/* Does not bother with rcv_saddr checks,
-			 * because the established check is already
-			 * unique enough.
-			 */
-			inet_bind_bucket_for_each(tb, &head->chain) {
-				if (net_eq(ib_net(tb), net) &&
-				    tb->port == port) {
-					if (tb->fastreuse >= 0 ||
-					    tb->fastreuseport >= 0)
-						goto next_port;
-					WARN_ON(hlist_empty(&tb->owners));
-					if (!check_established(death_row, sk,
-								port, &tw))
-						goto ok;
+		inet_bind_bucket_for_each(tb, &head->chain) {
+			if (net_eq(ib_net(tb), net) && tb->port == port) {
+				if (tb->fastreuse >= 0 ||
+				    tb->fastreuseport >= 0)
 					goto next_port;
-				}
+				WARN_ON(hlist_empty(&tb->owners));
+				if (!check_established(death_row, sk,
+						       port, &tw))
+					goto ok;
+				goto next_port;
 			}
-
-			tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
-					net, head, port);
-			if (!tb) {
-				spin_unlock(&head->lock);
-				break;
-			}
-			tb->fastreuse = -1;
-			tb->fastreuseport = -1;
-			goto ok;
-
-		next_port:
-			spin_unlock(&head->lock);
 		}
-		local_bh_enable();
-
-		return -EADDRNOTAVAIL;
 
-ok:
-		hint += (i + 2) & ~1;
-
-		/* Head lock still held and bh's disabled */
-		inet_bind_hash(sk, tb, port);
-		if (sk_unhashed(sk)) {
-			inet_sk(sk)->inet_sport = htons(port);
-			inet_ehash_nolisten(sk, (struct sock *)tw);
+		tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep,
+					     net, head, port);
+		if (!tb) {
+			spin_unlock_bh(&head->lock);
+			return -ENOMEM;
 		}
-		if (tw)
-			inet_twsk_bind_unhash(tw, hinfo);
-		spin_unlock(&head->lock);
+		tb->fastreuse = -1;
+		tb->fastreuseport = -1;
+		goto ok;
+next_port:
+		spin_unlock_bh(&head->lock);
+		cond_resched();
+	}
 
-		if (tw)
-			inet_twsk_deschedule_put(tw);
+	offset++;
+	if ((offset & 1) && remaining > 1)
+		goto other_parity_scan;
 
-		ret = 0;
-		goto out;
-	}
+	return -EADDRNOTAVAIL;
 
-	head = &hinfo->bhash[inet_bhashfn(net, snum, hinfo->bhash_size)];
-	tb  = inet_csk(sk)->icsk_bind_hash;
-	spin_lock_bh(&head->lock);
-	if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
-		inet_ehash_nolisten(sk, NULL);
-		spin_unlock_bh(&head->lock);
-		return 0;
-	} else {
-		spin_unlock(&head->lock);
-		/* No definite answer... Walk to established hash table */
-		ret = check_established(death_row, sk, snum, NULL);
-out:
-		local_bh_enable();
-		return ret;
+ok:
+	hint += i + 2;
+
+	/* Head lock still held and bh's disabled */
+	inet_bind_hash(sk, tb, port);
+	if (sk_unhashed(sk)) {
+		inet_sk(sk)->inet_sport = htons(port);
+		inet_ehash_nolisten(sk, (struct sock *)tw);
 	}
+	if (tw)
+		inet_twsk_bind_unhash(tw, hinfo);
+	spin_unlock(&head->lock);
+	if (tw)
+		inet_twsk_deschedule_put(tw);
+	local_bh_enable();
+	return 0;
 }
 
 /*