[PATCH net-next 0/3] sctp: add support for sk_reuseport

[PATCH net-next 0/3] sctp: add support for sk_reuseport

[Xin Long]

sctp sk_reuseport allows multiple socks to listen on the same port and
addresses, as long as these socks have the same uid. This works pretty
much as TCP/UDP does, the only difference is that sctp is multi-homing
and all the bind_addrs in these socks will have to completely matched,
otherwise listen() will return err.

The below is when 5 sockets are listening on 172.16.254.254:6400 on a
server, 26 sockets on a client connect to 172.16.254.254:6400 and each
may be processed by a different socket on the server which is selected
by hash(lport, pport, paddr) in reuseport_select_sock():

 # ss --sctp -nn
   State      Recv-Q Send-Q        Local Address:Port     Peer Address:Port
   LISTEN     0      10           172.16.254.254:6400                *:*
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.1:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.4:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.3:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.4:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.2:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.3:1234
   LISTEN     0      10           172.16.254.254:6400                *:*
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.3:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.4:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.2:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.1:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.2:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.3:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.4:1234
   LISTEN     0      10           172.16.254.254:6400                *:*
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.2:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.5:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.5:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400   172.16.253.253:1234
   LISTEN     0      10           172.16.254.254:6400                *:*
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.2:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.3:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.4:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.5:1234
   LISTEN     0      10           172.16.254.254:6400                *:*
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.1:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.5:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.5:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.1:1234
   `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.1:1234

Xin Long (3):
  sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint
  sctp: add sock_reuseport for the sock in __sctp_hash_endpoint
  sctp: process sk_reuseport in sctp_get_port_local

 include/net/sctp/sctp.h    |   2 +-
 include/net/sctp/structs.h |   6 ++-
 net/core/sock_reuseport.c  |   1 +
 net/sctp/bind_addr.c       |  28 ++++++++++
 net/sctp/input.c           | 129 ++++++++++++++++++++++++++++++++-------------
 net/sctp/socket.c          |  49 +++++++++++------
 6 files changed, 162 insertions(+), 53 deletions(-)

-- 
2.1.0

[PATCH net-next 1/3] sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint

[Xin Long]

This is a part of sk_reuseport support for sctp, and it selects a
sock by the hashkey of lport, paddr and dport by default. It will
work until sk_reuseport support is added in sctp_get_port_local()
in the next patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/input.c | 69 +++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 41 insertions(+), 28 deletions(-)

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 5c36a99..60ede89 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -57,6 +57,7 @@
 #include <net/sctp/checksum.h>
 #include <net/net_namespace.h>
 #include <linux/rhashtable.h>
+#include <net/sock_reuseport.h>
 
 /* Forward declarations for internal helpers. */
 static int sctp_rcv_ootb(struct sk_buff *);
@@ -65,8 +66,10 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
 				      const union sctp_addr *paddr,
 				      const union sctp_addr *laddr,
 				      struct sctp_transport **transportp);
-static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
-						const union sctp_addr *laddr);
+static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
+					struct net *net, struct sk_buff *skb,
+					const union sctp_addr *laddr,
+					const union sctp_addr *daddr);
 static struct sctp_association *__sctp_lookup_association(
 					struct net *net,
 					const union sctp_addr *local,
@@ -171,7 +174,7 @@ int sctp_rcv(struct sk_buff *skb)
 	asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);
 
 	if (!asoc)
-		ep = __sctp_rcv_lookup_endpoint(net, &dest);
+		ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src);
 
 	/* Retrieve the common input handling substructure. */
 	rcvr = asoc ? &asoc->base : &ep->base;
@@ -770,16 +773,35 @@ void sctp_unhash_endpoint(struct sctp_endpoint *ep)
 	local_bh_enable();
 }
 
+static inline __u32 sctp_hashfn(const struct net *net, __be16 lport,
+				const union sctp_addr *paddr, __u32 seed)
+{
+	__u32 addr;
+
+	if (paddr->sa.sa_family == AF_INET6)
+		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
+	else
+		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
+
+	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
+			     (__force __u32)lport, net_hash_mix(net), seed);
+}
+
 /* Look up an endpoint. */
-static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
-						const union sctp_addr *laddr)
+static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
+					struct net *net, struct sk_buff *skb,
+					const union sctp_addr *laddr,
+					const union sctp_addr *paddr)
 {
 	struct sctp_hashbucket *head;
 	struct sctp_ep_common *epb;
 	struct sctp_endpoint *ep;
+	struct sock *sk;
+	__be32 lport;
 	int hash;
 
-	hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port));
+	lport = laddr->v4.sin_port;
+	hash = sctp_ep_hashfn(net, ntohs(lport));
 	head = &sctp_ep_hashtable[hash];
 	read_lock(&head->lock);
 	sctp_for_each_hentry(epb, &head->chain) {
@@ -791,6 +813,15 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
 	ep = sctp_sk(net->sctp.ctl_sock)->ep;
 
 hit:
+	sk = ep->base.sk;
+	if (sk->sk_reuseport) {
+		__u32 phash = sctp_hashfn(net, lport, paddr, 0);
+
+		sk = reuseport_select_sock(sk, phash, skb,
+					   sizeof(struct sctphdr));
+		if (sk)
+			ep = sctp_sk(sk)->ep;
+	}
 	sctp_endpoint_hold(ep);
 	read_unlock(&head->lock);
 	return ep;
@@ -829,35 +860,17 @@ static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg,
 static inline __u32 sctp_hash_obj(const void *data, u32 len, u32 seed)
 {
 	const struct sctp_transport *t = data;
-	const union sctp_addr *paddr = &t->ipaddr;
-	const struct net *net = sock_net(t->asoc->base.sk);
-	__be16 lport = htons(t->asoc->base.bind_addr.port);
-	__u32 addr;
-
-	if (paddr->sa.sa_family == AF_INET6)
-		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
-	else
-		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
 
-	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
-			     (__force __u32)lport, net_hash_mix(net), seed);
+	return sctp_hashfn(sock_net(t->asoc->base.sk),
+			   htons(t->asoc->base.bind_addr.port),
+			   &t->ipaddr, seed);
 }
 
 static inline __u32 sctp_hash_key(const void *data, u32 len, u32 seed)
 {
 	const struct sctp_hash_cmp_arg *x = data;
-	const union sctp_addr *paddr = x->paddr;
-	const struct net *net = x->net;
-	__be16 lport = x->lport;
-	__u32 addr;
-
-	if (paddr->sa.sa_family == AF_INET6)
-		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
-	else
-		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
 
-	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
-			     (__force __u32)lport, net_hash_mix(net), seed);
+	return sctp_hashfn(x->net, x->lport, x->paddr, seed);
 }
 
 static const struct rhashtable_params sctp_hash_params = {
-- 
2.1.0

[PATCH net-next 2/3] sctp: add sock_reuseport for the sock in __sctp_hash_endpoint

[Xin Long]

This is a part of sk_reuseport support for sctp. It defines a helper
sctp_bind_addrs_check() to check if the bind_addrs in two socks are
matched. It will add sock_reuseport if they are completely matched,
and return err if they are partly matched, and alloc sock_reuseport
if all socks are not matched at all.

It will work until sk_reuseport support is added in
sctp_get_port_local() in the next patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/sctp/sctp.h    |  2 +-
 include/net/sctp/structs.h |  2 ++
 net/core/sock_reuseport.c  |  1 +
 net/sctp/bind_addr.c       | 28 ++++++++++++++++++++++
 net/sctp/input.c           | 60 +++++++++++++++++++++++++++++++++++++++-------
 net/sctp/socket.c          |  3 +--
 6 files changed, 85 insertions(+), 11 deletions(-)

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 8c2caa3..b8cd58d 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -152,7 +152,7 @@ int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
  */
 int sctp_rcv(struct sk_buff *skb);
 void sctp_v4_err(struct sk_buff *skb, u32 info);
-void sctp_hash_endpoint(struct sctp_endpoint *);
+int sctp_hash_endpoint(struct sctp_endpoint *ep);
 void sctp_unhash_endpoint(struct sctp_endpoint *);
 struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
 			     struct sctphdr *, struct sctp_association **,
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index a11f937..15d017f 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1190,6 +1190,8 @@ int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
 			 struct sctp_sock *, struct sctp_sock *);
 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
 			 const union sctp_addr *addr);
+int sctp_bind_addrs_check(struct sctp_sock *sp,
+			  struct sctp_sock *sp2, int cnt2);
 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
 					const union sctp_addr	*addrs,
 					int			addrcnt,
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index ba5cba5..d8fe3e5 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -187,6 +187,7 @@ int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany)
 		call_rcu(&old_reuse->rcu, reuseport_free_rcu);
 	return 0;
 }
+EXPORT_SYMBOL(reuseport_add_sock);
 
 void reuseport_detach_sock(struct sock *sk)
 {
diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
index 7df3704..78d0d93 100644
--- a/net/sctp/bind_addr.c
+++ b/net/sctp/bind_addr.c
@@ -337,6 +337,34 @@ int sctp_bind_addr_match(struct sctp_bind_addr *bp,
 	return match;
 }
 
+int sctp_bind_addrs_check(struct sctp_sock *sp,
+			  struct sctp_sock *sp2, int cnt2)
+{
+	struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
+	struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
+	struct sctp_sockaddr_entry *laddr, *laddr2;
+	bool exist = false;
+	int cnt = 0;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
+		list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
+			if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
+			    laddr->valid == laddr2->valid) {
+				exist = true;
+				goto next;
+			}
+		}
+		cnt = 0;
+		break;
+next:
+		cnt++;
+	}
+	rcu_read_unlock();
+
+	return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
+}
+
 /* Does the address 'addr' conflict with any addresses in
  * the bp.
  */
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 60ede89..6bfeb10 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -723,43 +723,87 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
 }
 
 /* Insert endpoint into the hash table.  */
-static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
+static int __sctp_hash_endpoint(struct sctp_endpoint *ep)
 {
-	struct net *net = sock_net(ep->base.sk);
-	struct sctp_ep_common *epb;
+	struct sock *sk = ep->base.sk;
+	struct net *net = sock_net(sk);
 	struct sctp_hashbucket *head;
+	struct sctp_ep_common *epb;
 
 	epb = &ep->base;
-
 	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
 	head = &sctp_ep_hashtable[epb->hashent];
 
+	if (sk->sk_reuseport) {
+		bool any = sctp_is_ep_boundall(sk);
+		struct sctp_ep_common *epb2;
+		struct list_head *list;
+		int cnt = 0, err = 1;
+
+		list_for_each(list, &ep->base.bind_addr.address_list)
+			cnt++;
+
+		sctp_for_each_hentry(epb2, &head->chain) {
+			struct sock *sk2 = epb2->sk;
+
+			if (!net_eq(sock_net(sk2), net) || sk2 == sk ||
+			    !uid_eq(sock_i_uid(sk2), sock_i_uid(sk)) ||
+			    !sk2->sk_reuseport)
+				continue;
+
+			err = sctp_bind_addrs_check(sctp_sk(sk2),
+						    sctp_sk(sk), cnt);
+			if (!err) {
+				err = reuseport_add_sock(sk, sk2, any);
+				if (err)
+					return err;
+				break;
+			} else if (err < 0) {
+				return err;
+			}
+		}
+
+		if (err) {
+			err = reuseport_alloc(sk, any);
+			if (err)
+				return err;
+		}
+	}
+
 	write_lock(&head->lock);
 	hlist_add_head(&epb->node, &head->chain);
 	write_unlock(&head->lock);
+	return 0;
 }
 
 /* Add an endpoint to the hash. Local BH-safe. */
-void sctp_hash_endpoint(struct sctp_endpoint *ep)
+int sctp_hash_endpoint(struct sctp_endpoint *ep)
 {
+	int err;
+
 	local_bh_disable();
-	__sctp_hash_endpoint(ep);
+	err = __sctp_hash_endpoint(ep);
 	local_bh_enable();
+
+	return err;
 }
 
 /* Remove endpoint from the hash table.  */
 static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
 {
-	struct net *net = sock_net(ep->base.sk);
+	struct sock *sk = ep->base.sk;
 	struct sctp_hashbucket *head;
 	struct sctp_ep_common *epb;
 
 	epb = &ep->base;
 
-	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
+	epb->hashent = sctp_ep_hashfn(sock_net(sk), epb->bind_addr.port);
 
 	head = &sctp_ep_hashtable[epb->hashent];
 
+	if (rcu_access_pointer(sk->sk_reuseport_cb))
+		reuseport_detach_sock(sk);
+
 	write_lock(&head->lock);
 	hlist_del_init(&epb->node);
 	write_unlock(&head->lock);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index fc0386e..44e7d8c 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7850,8 +7850,7 @@ static int sctp_listen_start(struct sock *sk, int backlog)
 	}
 
 	sk->sk_max_ack_backlog = backlog;
-	sctp_hash_endpoint(ep);
-	return 0;
+	return sctp_hash_endpoint(ep);
 }
 
 /*
-- 
2.1.0

[PATCH net-next 3/3] sctp: process sk_reuseport in sctp_get_port_local

[Xin Long]

When socks' sk_reuseport is set, the same port and address are allowed
to be bound into these socks who have the same uid.

Note that the difference from sk_reuse is that it allows multiple socks
to listen on the same port and address.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/sctp/structs.h |  4 +++-
 net/sctp/socket.c          | 46 +++++++++++++++++++++++++++++++++-------------
 2 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 15d017f..af9d494 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -96,7 +96,9 @@ struct sctp_stream;
 
 struct sctp_bind_bucket {
 	unsigned short	port;
-	unsigned short	fastreuse;
+	signed char	fastreuse;
+	signed char	fastreuseport;
+	kuid_t		fastuid;
 	struct hlist_node	node;
 	struct hlist_head	owner;
 	struct net	*net;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 44e7d8c..8605705 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7642,8 +7642,10 @@ static struct sctp_bind_bucket *sctp_bucket_create(
 
 static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 {
-	bool reuse = (sk->sk_reuse || sctp_sk(sk)->reuse);
+	struct sctp_sock *sp = sctp_sk(sk);
+	bool reuse = (sk->sk_reuse || sp->reuse);
 	struct sctp_bind_hashbucket *head; /* hash list */
+	kuid_t uid = sock_i_uid(sk);
 	struct sctp_bind_bucket *pp;
 	unsigned short snum;
 	int ret;
@@ -7719,7 +7721,10 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 
 		pr_debug("%s: found a possible match\n", __func__);
 
-		if (pp->fastreuse && reuse && sk->sk_state != SCTP_SS_LISTENING)
+		if ((pp->fastreuse && reuse &&
+		     sk->sk_state != SCTP_SS_LISTENING) ||
+		    (pp->fastreuseport && sk->sk_reuseport &&
+		     uid_eq(pp->fastuid, uid)))
 			goto success;
 
 		/* Run through the list of sockets bound to the port
@@ -7733,16 +7738,18 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 		 * in an endpoint.
 		 */
 		sk_for_each_bound(sk2, &pp->owner) {
-			struct sctp_endpoint *ep2;
-			ep2 = sctp_sk(sk2)->ep;
+			struct sctp_sock *sp2 = sctp_sk(sk2);
+			struct sctp_endpoint *ep2 = sp2->ep;
 
 			if (sk == sk2 ||
-			    (reuse && (sk2->sk_reuse || sctp_sk(sk2)->reuse) &&
-			     sk2->sk_state != SCTP_SS_LISTENING))
+			    (reuse && (sk2->sk_reuse || sp2->reuse) &&
+			     sk2->sk_state != SCTP_SS_LISTENING) ||
+			    (sk->sk_reuseport && sk2->sk_reuseport &&
+			     uid_eq(uid, sock_i_uid(sk2))))
 				continue;
 
-			if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr,
-						 sctp_sk(sk2), sctp_sk(sk))) {
+			if (sctp_bind_addr_conflict(&ep2->base.bind_addr,
+						    addr, sp2, sp)) {
 				ret = (long)sk2;
 				goto fail_unlock;
 			}
@@ -7765,19 +7772,32 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 			pp->fastreuse = 1;
 		else
 			pp->fastreuse = 0;
-	} else if (pp->fastreuse &&
-		   (!reuse || sk->sk_state == SCTP_SS_LISTENING))
-		pp->fastreuse = 0;
+
+		if (sk->sk_reuseport) {
+			pp->fastreuseport = 1;
+			pp->fastuid = uid;
+		} else {
+			pp->fastreuseport = 0;
+		}
+	} else {
+		if (pp->fastreuse &&
+		    (!reuse || sk->sk_state == SCTP_SS_LISTENING))
+			pp->fastreuse = 0;
+
+		if (pp->fastreuseport &&
+		    (!sk->sk_reuseport || !uid_eq(pp->fastuid, uid)))
+			pp->fastreuseport = 0;
+	}
 
 	/* We are set, so fill up all the data in the hash table
 	 * entry, tie the socket list information with the rest of the
 	 * sockets FIXME: Blurry, NPI (ipg).
 	 */
 success:
-	if (!sctp_sk(sk)->bind_hash) {
+	if (!sp->bind_hash) {
 		inet_sk(sk)->inet_num = snum;
 		sk_add_bind_node(sk, &pp->owner);
-		sctp_sk(sk)->bind_hash = pp;
+		sp->bind_hash = pp;
 	}
 	ret = 0;
 
-- 
2.1.0

Re: [PATCH net-next 0/3] sctp: add support for sk_reuseport

[Xin Long]

[-- Attachment #1: Type: text/plain, Size: 3812 bytes --]

On Sun, Oct 21, 2018 at 1:43 PM Xin Long <lucien.xin@gmail.com> wrote:
>
> sctp sk_reuseport allows multiple socks to listen on the same port and
> addresses, as long as these socks have the same uid. This works pretty
> much as TCP/UDP does, the only difference is that sctp is multi-homing
> and all the bind_addrs in these socks will have to completely matched,
> otherwise listen() will return err.
>
> The below is when 5 sockets are listening on 172.16.254.254:6400 on a
> server, 26 sockets on a client connect to 172.16.254.254:6400 and each
> may be processed by a different socket on the server which is selected
> by hash(lport, pport, paddr) in reuseport_select_sock():
>
>  # ss --sctp -nn
>    State      Recv-Q Send-Q        Local Address:Port     Peer Address:Port
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.3:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.4:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400   172.16.253.253:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.5:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.1:1234
Attached is the testcase based on sctp-tests.git.

>
> Xin Long (3):
>   sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint
>   sctp: add sock_reuseport for the sock in __sctp_hash_endpoint
>   sctp: process sk_reuseport in sctp_get_port_local
>
>  include/net/sctp/sctp.h    |   2 +-
>  include/net/sctp/structs.h |   6 ++-
>  net/core/sock_reuseport.c  |   1 +
>  net/sctp/bind_addr.c       |  28 ++++++++++
>  net/sctp/input.c           | 129 ++++++++++++++++++++++++++++++++-------------
>  net/sctp/socket.c          |  49 +++++++++++------
>  6 files changed, 162 insertions(+), 53 deletions(-)
>
> --
> 2.1.0
>

[-- Attachment #2: reuseport.tar.gz --]
[-- Type: application/x-gzip, Size: 2501 bytes --]

Re: [PATCH net-next 0/3] sctp: add support for sk_reuseport

[Neil Horman]

On Sun, Oct 21, 2018 at 12:43:35PM +0800, Xin Long wrote:
> sctp sk_reuseport allows multiple socks to listen on the same port and
> addresses, as long as these socks have the same uid. This works pretty
> much as TCP/UDP does, the only difference is that sctp is multi-homing
> and all the bind_addrs in these socks will have to completely matched,
> otherwise listen() will return err.
> 
> The below is when 5 sockets are listening on 172.16.254.254:6400 on a
> server, 26 sockets on a client connect to 172.16.254.254:6400 and each
> may be processed by a different socket on the server which is selected
> by hash(lport, pport, paddr) in reuseport_select_sock():
> 
>  # ss --sctp -nn
>    State      Recv-Q Send-Q        Local Address:Port     Peer Address:Port
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.3:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.4:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.4.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400   172.16.253.253:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.2:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.3:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.4:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.5:1234
>    LISTEN     0      10           172.16.254.254:6400                *:*
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.1.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.2.5:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.3.1:1234
>    `- ESTAB   0      0       172.16.254.254%eth1:6400       172.16.5.1:1234
> 
> Xin Long (3):
>   sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint
>   sctp: add sock_reuseport for the sock in __sctp_hash_endpoint
>   sctp: process sk_reuseport in sctp_get_port_local
> 
>  include/net/sctp/sctp.h    |   2 +-
>  include/net/sctp/structs.h |   6 ++-
>  net/core/sock_reuseport.c  |   1 +
>  net/sctp/bind_addr.c       |  28 ++++++++++
>  net/sctp/input.c           | 129 ++++++++++++++++++++++++++++++++-------------
>  net/sctp/socket.c          |  49 +++++++++++------
>  6 files changed, 162 insertions(+), 53 deletions(-)
> 
> -- 
> 2.1.0
> 
> 
Series
Acked-by: Neil Horman <nhorman@tuxdriver.com>

Re: [PATCH net-next 2/3] sctp: add sock_reuseport for the sock in __sctp_hash_endpoint

[Marcelo Ricardo Leitner]

On Sun, Oct 21, 2018 at 12:43:37PM +0800, Xin Long wrote:
> This is a part of sk_reuseport support for sctp. It defines a helper
> sctp_bind_addrs_check() to check if the bind_addrs in two socks are
> matched. It will add sock_reuseport if they are completely matched,
> and return err if they are partly matched, and alloc sock_reuseport
> if all socks are not matched at all.
> 
> It will work until sk_reuseport support is added in
> sctp_get_port_local() in the next patch.
> 
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
>  include/net/sctp/sctp.h    |  2 +-
>  include/net/sctp/structs.h |  2 ++
>  net/core/sock_reuseport.c  |  1 +
>  net/sctp/bind_addr.c       | 28 ++++++++++++++++++++++
>  net/sctp/input.c           | 60 +++++++++++++++++++++++++++++++++++++++-------
>  net/sctp/socket.c          |  3 +--
>  6 files changed, 85 insertions(+), 11 deletions(-)
> 
> diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> index 8c2caa3..b8cd58d 100644
> --- a/include/net/sctp/sctp.h
> +++ b/include/net/sctp/sctp.h
> @@ -152,7 +152,7 @@ int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
>   */
>  int sctp_rcv(struct sk_buff *skb);
>  void sctp_v4_err(struct sk_buff *skb, u32 info);
> -void sctp_hash_endpoint(struct sctp_endpoint *);
> +int sctp_hash_endpoint(struct sctp_endpoint *ep);
>  void sctp_unhash_endpoint(struct sctp_endpoint *);
>  struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
>  			     struct sctphdr *, struct sctp_association **,
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index a11f937..15d017f 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -1190,6 +1190,8 @@ int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
>  			 struct sctp_sock *, struct sctp_sock *);
>  int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
>  			 const union sctp_addr *addr);
> +int sctp_bind_addrs_check(struct sctp_sock *sp,
> +			  struct sctp_sock *sp2, int cnt2);
>  union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr	*bp,
>  					const union sctp_addr	*addrs,
>  					int			addrcnt,
> diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
> index ba5cba5..d8fe3e5 100644
> --- a/net/core/sock_reuseport.c
> +++ b/net/core/sock_reuseport.c
> @@ -187,6 +187,7 @@ int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany)
>  		call_rcu(&old_reuse->rcu, reuseport_free_rcu);
>  	return 0;
>  }
> +EXPORT_SYMBOL(reuseport_add_sock);
>  
>  void reuseport_detach_sock(struct sock *sk)
>  {
> diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
> index 7df3704..78d0d93 100644
> --- a/net/sctp/bind_addr.c
> +++ b/net/sctp/bind_addr.c
> @@ -337,6 +337,34 @@ int sctp_bind_addr_match(struct sctp_bind_addr *bp,
>  	return match;
>  }
>  
> +int sctp_bind_addrs_check(struct sctp_sock *sp,
> +			  struct sctp_sock *sp2, int cnt2)
> +{
> +	struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
> +	struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
> +	struct sctp_sockaddr_entry *laddr, *laddr2;
> +	bool exist = false;
> +	int cnt = 0;
> +
> +	rcu_read_lock();
> +	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
> +		list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
> +			if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
> +			    laddr->valid == laddr2->valid) {

I think by here in the normal run laddr2->valid will always be true,
but as is it gives the impression that it accepts 0 == 0 too, which
would be bad.  May be on a fast BINDX_REM/BINDX_ADD it could trigger
laddr2->valid = 0 in there, not sure.

Anyway, may be '... laddr->valid && laddr2->valid' instead or you
really want to allow the 0 == 0 case?

> +				exist = true;
> +				goto next;
> +			}
> +		}
> +		cnt = 0;
> +		break;
> +next:
> +		cnt++;
> +	}
> +	rcu_read_unlock();
> +
> +	return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
> +}
> +
>  /* Does the address 'addr' conflict with any addresses in
>   * the bp.
>   */
> diff --git a/net/sctp/input.c b/net/sctp/input.c
> index 60ede89..6bfeb10 100644
> --- a/net/sctp/input.c
> +++ b/net/sctp/input.c
> @@ -723,43 +723,87 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
>  }
>  
>  /* Insert endpoint into the hash table.  */
> -static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
> +static int __sctp_hash_endpoint(struct sctp_endpoint *ep)
>  {
> -	struct net *net = sock_net(ep->base.sk);
> -	struct sctp_ep_common *epb;
> +	struct sock *sk = ep->base.sk;
> +	struct net *net = sock_net(sk);
>  	struct sctp_hashbucket *head;
> +	struct sctp_ep_common *epb;
>  
>  	epb = &ep->base;
> -
>  	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
>  	head = &sctp_ep_hashtable[epb->hashent];
>  
> +	if (sk->sk_reuseport) {
> +		bool any = sctp_is_ep_boundall(sk);
> +		struct sctp_ep_common *epb2;
> +		struct list_head *list;
> +		int cnt = 0, err = 1;
> +
> +		list_for_each(list, &ep->base.bind_addr.address_list)
> +			cnt++;
> +
> +		sctp_for_each_hentry(epb2, &head->chain) {
> +			struct sock *sk2 = epb2->sk;
> +
> +			if (!net_eq(sock_net(sk2), net) || sk2 == sk ||
> +			    !uid_eq(sock_i_uid(sk2), sock_i_uid(sk)) ||
> +			    !sk2->sk_reuseport)
> +				continue;
> +
> +			err = sctp_bind_addrs_check(sctp_sk(sk2),
> +						    sctp_sk(sk), cnt);
> +			if (!err) {
> +				err = reuseport_add_sock(sk, sk2, any);
> +				if (err)
> +					return err;
> +				break;
> +			} else if (err < 0) {
> +				return err;
> +			}
> +		}
> +
> +		if (err) {
> +			err = reuseport_alloc(sk, any);
> +			if (err)
> +				return err;
> +		}
> +	}
> +
>  	write_lock(&head->lock);
>  	hlist_add_head(&epb->node, &head->chain);
>  	write_unlock(&head->lock);
> +	return 0;
>  }
>  
>  /* Add an endpoint to the hash. Local BH-safe. */
> -void sctp_hash_endpoint(struct sctp_endpoint *ep)
> +int sctp_hash_endpoint(struct sctp_endpoint *ep)
>  {
> +	int err;
> +
>  	local_bh_disable();
> -	__sctp_hash_endpoint(ep);
> +	err = __sctp_hash_endpoint(ep);
>  	local_bh_enable();
> +
> +	return err;
>  }
>  
>  /* Remove endpoint from the hash table.  */
>  static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
>  {
> -	struct net *net = sock_net(ep->base.sk);
> +	struct sock *sk = ep->base.sk;
>  	struct sctp_hashbucket *head;
>  	struct sctp_ep_common *epb;
>  
>  	epb = &ep->base;
>  
> -	epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
> +	epb->hashent = sctp_ep_hashfn(sock_net(sk), epb->bind_addr.port);
>  
>  	head = &sctp_ep_hashtable[epb->hashent];
>  
> +	if (rcu_access_pointer(sk->sk_reuseport_cb))
> +		reuseport_detach_sock(sk);
> +
>  	write_lock(&head->lock);
>  	hlist_del_init(&epb->node);
>  	write_unlock(&head->lock);
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index fc0386e..44e7d8c 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -7850,8 +7850,7 @@ static int sctp_listen_start(struct sock *sk, int backlog)
>  	}
>  
>  	sk->sk_max_ack_backlog = backlog;
> -	sctp_hash_endpoint(ep);
> -	return 0;
> +	return sctp_hash_endpoint(ep);
>  }
>  
>  /*
> -- 
> 2.1.0
> 

Re: [PATCH net-next 1/3] sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint

[Marcelo Ricardo Leitner]

On Sun, Oct 21, 2018 at 12:43:36PM +0800, Xin Long wrote:
> This is a part of sk_reuseport support for sctp, and it selects a
> sock by the hashkey of lport, paddr and dport by default. It will
> work until sk_reuseport support is added in sctp_get_port_local()
> in the next patch.
> 
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---
>  net/sctp/input.c | 69 +++++++++++++++++++++++++++++++++-----------------------
>  1 file changed, 41 insertions(+), 28 deletions(-)
> 
> diff --git a/net/sctp/input.c b/net/sctp/input.c
> index 5c36a99..60ede89 100644
> --- a/net/sctp/input.c
> +++ b/net/sctp/input.c
> @@ -57,6 +57,7 @@
>  #include <net/sctp/checksum.h>
>  #include <net/net_namespace.h>
>  #include <linux/rhashtable.h>
> +#include <net/sock_reuseport.h>
>  
>  /* Forward declarations for internal helpers. */
>  static int sctp_rcv_ootb(struct sk_buff *);
> @@ -65,8 +66,10 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
>  				      const union sctp_addr *paddr,
>  				      const union sctp_addr *laddr,
>  				      struct sctp_transport **transportp);
> -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
> -						const union sctp_addr *laddr);
> +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
> +					struct net *net, struct sk_buff *skb,
> +					const union sctp_addr *laddr,
> +					const union sctp_addr *daddr);
>  static struct sctp_association *__sctp_lookup_association(
>  					struct net *net,
>  					const union sctp_addr *local,
> @@ -171,7 +174,7 @@ int sctp_rcv(struct sk_buff *skb)
>  	asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);
>  
>  	if (!asoc)
> -		ep = __sctp_rcv_lookup_endpoint(net, &dest);
> +		ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src);
>  
>  	/* Retrieve the common input handling substructure. */
>  	rcvr = asoc ? &asoc->base : &ep->base;
> @@ -770,16 +773,35 @@ void sctp_unhash_endpoint(struct sctp_endpoint *ep)
>  	local_bh_enable();
>  }
>  
> +static inline __u32 sctp_hashfn(const struct net *net, __be16 lport,
> +				const union sctp_addr *paddr, __u32 seed)
> +{
> +	__u32 addr;
> +
> +	if (paddr->sa.sa_family == AF_INET6)
> +		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> +	else
> +		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
> +
> +	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> +			     (__force __u32)lport, net_hash_mix(net), seed);
> +}
> +
>  /* Look up an endpoint. */
> -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
> -						const union sctp_addr *laddr)
> +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
> +					struct net *net, struct sk_buff *skb,
> +					const union sctp_addr *laddr,
> +					const union sctp_addr *paddr)
>  {
>  	struct sctp_hashbucket *head;
>  	struct sctp_ep_common *epb;
>  	struct sctp_endpoint *ep;
> +	struct sock *sk;
> +	__be32 lport;

This could be a __be16 one.

>  	int hash;
>  
> -	hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port));
> +	lport = laddr->v4.sin_port;
> +	hash = sctp_ep_hashfn(net, ntohs(lport));
>  	head = &sctp_ep_hashtable[hash];
>  	read_lock(&head->lock);
>  	sctp_for_each_hentry(epb, &head->chain) {
> @@ -791,6 +813,15 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
>  	ep = sctp_sk(net->sctp.ctl_sock)->ep;
>  
>  hit:
> +	sk = ep->base.sk;
> +	if (sk->sk_reuseport) {
> +		__u32 phash = sctp_hashfn(net, lport, paddr, 0);
> +
> +		sk = reuseport_select_sock(sk, phash, skb,
> +					   sizeof(struct sctphdr));
> +		if (sk)
> +			ep = sctp_sk(sk)->ep;
> +	}
>  	sctp_endpoint_hold(ep);
>  	read_unlock(&head->lock);
>  	return ep;
> @@ -829,35 +860,17 @@ static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg,
>  static inline __u32 sctp_hash_obj(const void *data, u32 len, u32 seed)
>  {
>  	const struct sctp_transport *t = data;
> -	const union sctp_addr *paddr = &t->ipaddr;
> -	const struct net *net = sock_net(t->asoc->base.sk);
> -	__be16 lport = htons(t->asoc->base.bind_addr.port);
> -	__u32 addr;
> -
> -	if (paddr->sa.sa_family == AF_INET6)
> -		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> -	else
> -		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
>  
> -	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> -			     (__force __u32)lport, net_hash_mix(net), seed);
> +	return sctp_hashfn(sock_net(t->asoc->base.sk),
> +			   htons(t->asoc->base.bind_addr.port),
> +			   &t->ipaddr, seed);
>  }
>  
>  static inline __u32 sctp_hash_key(const void *data, u32 len, u32 seed)
>  {
>  	const struct sctp_hash_cmp_arg *x = data;
> -	const union sctp_addr *paddr = x->paddr;
> -	const struct net *net = x->net;
> -	__be16 lport = x->lport;
> -	__u32 addr;
> -
> -	if (paddr->sa.sa_family == AF_INET6)
> -		addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> -	else
> -		addr = (__force __u32)paddr->v4.sin_addr.s_addr;
>  
> -	return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> -			     (__force __u32)lport, net_hash_mix(net), seed);
> +	return sctp_hashfn(x->net, x->lport, x->paddr, seed);
>  }
>  
>  static const struct rhashtable_params sctp_hash_params = {
> -- 
> 2.1.0
> 

Re: [PATCH net-next 0/3] sctp: add support for sk_reuseport

[Marcelo Ricardo Leitner]

On Sun, Oct 21, 2018 at 12:43:35PM +0800, Xin Long wrote:
> sctp sk_reuseport allows multiple socks to listen on the same port and
> addresses, as long as these socks have the same uid. This works pretty
> much as TCP/UDP does, the only difference is that sctp is multi-homing
> and all the bind_addrs in these socks will have to completely matched,
> otherwise listen() will return err.
> 

FWIW, I won't be able to review this patchset thoroughly. The 2 small
comments that I sent are all I have.

Thanks,
Marcelo

Re: [PATCH net-next 1/3] sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint

[Xin Long]

On Mon, Oct 22, 2018 at 11:18 PM Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
>
> On Sun, Oct 21, 2018 at 12:43:36PM +0800, Xin Long wrote:
> > This is a part of sk_reuseport support for sctp, and it selects a
> > sock by the hashkey of lport, paddr and dport by default. It will
> > work until sk_reuseport support is added in sctp_get_port_local()
> > in the next patch.
> >
> > Signed-off-by: Xin Long <lucien.xin@gmail.com>
> > ---
> >  net/sctp/input.c | 69 +++++++++++++++++++++++++++++++++-----------------------
> >  1 file changed, 41 insertions(+), 28 deletions(-)
> >
> > diff --git a/net/sctp/input.c b/net/sctp/input.c
> > index 5c36a99..60ede89 100644
> > --- a/net/sctp/input.c
> > +++ b/net/sctp/input.c
> > @@ -57,6 +57,7 @@
> >  #include <net/sctp/checksum.h>
> >  #include <net/net_namespace.h>
> >  #include <linux/rhashtable.h>
> > +#include <net/sock_reuseport.h>
> >
> >  /* Forward declarations for internal helpers. */
> >  static int sctp_rcv_ootb(struct sk_buff *);
> > @@ -65,8 +66,10 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
> >                                     const union sctp_addr *paddr,
> >                                     const union sctp_addr *laddr,
> >                                     struct sctp_transport **transportp);
> > -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
> > -                                             const union sctp_addr *laddr);
> > +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
> > +                                     struct net *net, struct sk_buff *skb,
> > +                                     const union sctp_addr *laddr,
> > +                                     const union sctp_addr *daddr);
> >  static struct sctp_association *__sctp_lookup_association(
> >                                       struct net *net,
> >                                       const union sctp_addr *local,
> > @@ -171,7 +174,7 @@ int sctp_rcv(struct sk_buff *skb)
> >       asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);
> >
> >       if (!asoc)
> > -             ep = __sctp_rcv_lookup_endpoint(net, &dest);
> > +             ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src);
> >
> >       /* Retrieve the common input handling substructure. */
> >       rcvr = asoc ? &asoc->base : &ep->base;
> > @@ -770,16 +773,35 @@ void sctp_unhash_endpoint(struct sctp_endpoint *ep)
> >       local_bh_enable();
> >  }
> >
> > +static inline __u32 sctp_hashfn(const struct net *net, __be16 lport,
> > +                             const union sctp_addr *paddr, __u32 seed)
> > +{
> > +     __u32 addr;
> > +
> > +     if (paddr->sa.sa_family == AF_INET6)
> > +             addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> > +     else
> > +             addr = (__force __u32)paddr->v4.sin_addr.s_addr;
> > +
> > +     return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> > +                          (__force __u32)lport, net_hash_mix(net), seed);
> > +}
> > +
> >  /* Look up an endpoint. */
> > -static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
> > -                                             const union sctp_addr *laddr)
> > +static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
> > +                                     struct net *net, struct sk_buff *skb,
> > +                                     const union sctp_addr *laddr,
> > +                                     const union sctp_addr *paddr)
> >  {
> >       struct sctp_hashbucket *head;
> >       struct sctp_ep_common *epb;
> >       struct sctp_endpoint *ep;
> > +     struct sock *sk;
> > +     __be32 lport;
>
> This could be a __be16 one.
right, will correct it in v2.

>
> >       int hash;
> >
> > -     hash = sctp_ep_hashfn(net, ntohs(laddr->v4.sin_port));
> > +     lport = laddr->v4.sin_port;
> > +     hash = sctp_ep_hashfn(net, ntohs(lport));
> >       head = &sctp_ep_hashtable[hash];
> >       read_lock(&head->lock);
> >       sctp_for_each_hentry(epb, &head->chain) {
> > @@ -791,6 +813,15 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(struct net *net,
> >       ep = sctp_sk(net->sctp.ctl_sock)->ep;
> >
> >  hit:
> > +     sk = ep->base.sk;
> > +     if (sk->sk_reuseport) {
> > +             __u32 phash = sctp_hashfn(net, lport, paddr, 0);
> > +
> > +             sk = reuseport_select_sock(sk, phash, skb,
> > +                                        sizeof(struct sctphdr));
> > +             if (sk)
> > +                     ep = sctp_sk(sk)->ep;
> > +     }
> >       sctp_endpoint_hold(ep);
> >       read_unlock(&head->lock);
> >       return ep;
> > @@ -829,35 +860,17 @@ static inline int sctp_hash_cmp(struct rhashtable_compare_arg *arg,
> >  static inline __u32 sctp_hash_obj(const void *data, u32 len, u32 seed)
> >  {
> >       const struct sctp_transport *t = data;
> > -     const union sctp_addr *paddr = &t->ipaddr;
> > -     const struct net *net = sock_net(t->asoc->base.sk);
> > -     __be16 lport = htons(t->asoc->base.bind_addr.port);
> > -     __u32 addr;
> > -
> > -     if (paddr->sa.sa_family == AF_INET6)
> > -             addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> > -     else
> > -             addr = (__force __u32)paddr->v4.sin_addr.s_addr;
> >
> > -     return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> > -                          (__force __u32)lport, net_hash_mix(net), seed);
> > +     return sctp_hashfn(sock_net(t->asoc->base.sk),
> > +                        htons(t->asoc->base.bind_addr.port),
> > +                        &t->ipaddr, seed);
> >  }
> >
> >  static inline __u32 sctp_hash_key(const void *data, u32 len, u32 seed)
> >  {
> >       const struct sctp_hash_cmp_arg *x = data;
> > -     const union sctp_addr *paddr = x->paddr;
> > -     const struct net *net = x->net;
> > -     __be16 lport = x->lport;
> > -     __u32 addr;
> > -
> > -     if (paddr->sa.sa_family == AF_INET6)
> > -             addr = jhash(&paddr->v6.sin6_addr, 16, seed);
> > -     else
> > -             addr = (__force __u32)paddr->v4.sin_addr.s_addr;
> >
> > -     return  jhash_3words(addr, ((__force __u32)paddr->v4.sin_port) << 16 |
> > -                          (__force __u32)lport, net_hash_mix(net), seed);
> > +     return sctp_hashfn(x->net, x->lport, x->paddr, seed);
> >  }
> >
> >  static const struct rhashtable_params sctp_hash_params = {
> > --
> > 2.1.0
> >

Re: [PATCH net-next 2/3] sctp: add sock_reuseport for the sock in __sctp_hash_endpoint

[Xin Long]

On Mon, Oct 22, 2018 at 11:15 PM Marcelo Ricardo Leitner
<marcelo.leitner@gmail.com> wrote:
>
> On Sun, Oct 21, 2018 at 12:43:37PM +0800, Xin Long wrote:
> > This is a part of sk_reuseport support for sctp. It defines a helper
> > sctp_bind_addrs_check() to check if the bind_addrs in two socks are
> > matched. It will add sock_reuseport if they are completely matched,
> > and return err if they are partly matched, and alloc sock_reuseport
> > if all socks are not matched at all.
> >
> > It will work until sk_reuseport support is added in
> > sctp_get_port_local() in the next patch.
> >
> > Signed-off-by: Xin Long <lucien.xin@gmail.com>
> > ---
> >  include/net/sctp/sctp.h    |  2 +-
> >  include/net/sctp/structs.h |  2 ++
> >  net/core/sock_reuseport.c  |  1 +
> >  net/sctp/bind_addr.c       | 28 ++++++++++++++++++++++
> >  net/sctp/input.c           | 60 +++++++++++++++++++++++++++++++++++++++-------
> >  net/sctp/socket.c          |  3 +--
> >  6 files changed, 85 insertions(+), 11 deletions(-)
> >
> > diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> > index 8c2caa3..b8cd58d 100644
> > --- a/include/net/sctp/sctp.h
> > +++ b/include/net/sctp/sctp.h
> > @@ -152,7 +152,7 @@ int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
> >   */
> >  int sctp_rcv(struct sk_buff *skb);
> >  void sctp_v4_err(struct sk_buff *skb, u32 info);
> > -void sctp_hash_endpoint(struct sctp_endpoint *);
> > +int sctp_hash_endpoint(struct sctp_endpoint *ep);
> >  void sctp_unhash_endpoint(struct sctp_endpoint *);
> >  struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *,
> >                            struct sctphdr *, struct sctp_association **,
> > diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> > index a11f937..15d017f 100644
> > --- a/include/net/sctp/structs.h
> > +++ b/include/net/sctp/structs.h
> > @@ -1190,6 +1190,8 @@ int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
> >                        struct sctp_sock *, struct sctp_sock *);
> >  int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
> >                        const union sctp_addr *addr);
> > +int sctp_bind_addrs_check(struct sctp_sock *sp,
> > +                       struct sctp_sock *sp2, int cnt2);
> >  union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr        *bp,
> >                                       const union sctp_addr   *addrs,
> >                                       int                     addrcnt,
> > diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
> > index ba5cba5..d8fe3e5 100644
> > --- a/net/core/sock_reuseport.c
> > +++ b/net/core/sock_reuseport.c
> > @@ -187,6 +187,7 @@ int reuseport_add_sock(struct sock *sk, struct sock *sk2, bool bind_inany)
> >               call_rcu(&old_reuse->rcu, reuseport_free_rcu);
> >       return 0;
> >  }
> > +EXPORT_SYMBOL(reuseport_add_sock);
> >
> >  void reuseport_detach_sock(struct sock *sk)
> >  {
> > diff --git a/net/sctp/bind_addr.c b/net/sctp/bind_addr.c
> > index 7df3704..78d0d93 100644
> > --- a/net/sctp/bind_addr.c
> > +++ b/net/sctp/bind_addr.c
> > @@ -337,6 +337,34 @@ int sctp_bind_addr_match(struct sctp_bind_addr *bp,
> >       return match;
> >  }
> >
> > +int sctp_bind_addrs_check(struct sctp_sock *sp,
> > +                       struct sctp_sock *sp2, int cnt2)
> > +{
> > +     struct sctp_bind_addr *bp2 = &sp2->ep->base.bind_addr;
> > +     struct sctp_bind_addr *bp = &sp->ep->base.bind_addr;
> > +     struct sctp_sockaddr_entry *laddr, *laddr2;
> > +     bool exist = false;
> > +     int cnt = 0;
> > +
> > +     rcu_read_lock();
> > +     list_for_each_entry_rcu(laddr, &bp->address_list, list) {
> > +             list_for_each_entry_rcu(laddr2, &bp2->address_list, list) {
> > +                     if (sp->pf->af->cmp_addr(&laddr->a, &laddr2->a) &&
> > +                         laddr->valid == laddr2->valid) {
>
> I think by here in the normal run laddr2->valid will always be true,
> but as is it gives the impression that it accepts 0 == 0 too, which
> would be bad.  May be on a fast BINDX_REM/BINDX_ADD it could trigger
> laddr2->valid = 0 in there, not sure.
>
> Anyway, may be '... laddr->valid && laddr2->valid' instead or you
> really want to allow the 0 == 0 case?
>
will improve it in v2. thanks.

> > +                             exist = true;
> > +                             goto next;
> > +                     }
> > +             }
> > +             cnt = 0;
> > +             break;
> > +next:
> > +             cnt++;
> > +     }
> > +     rcu_read_unlock();
> > +
> > +     return (cnt == cnt2) ? 0 : (exist ? -EEXIST : 1);
> > +}
> > +
> >  /* Does the address 'addr' conflict with any addresses in
> >   * the bp.
> >   */
> > diff --git a/net/sctp/input.c b/net/sctp/input.c
> > index 60ede89..6bfeb10 100644
> > --- a/net/sctp/input.c
> > +++ b/net/sctp/input.c
> > @@ -723,43 +723,87 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
> >  }
> >
> >  /* Insert endpoint into the hash table.  */
> > -static void __sctp_hash_endpoint(struct sctp_endpoint *ep)
> > +static int __sctp_hash_endpoint(struct sctp_endpoint *ep)
> >  {
> > -     struct net *net = sock_net(ep->base.sk);
> > -     struct sctp_ep_common *epb;
> > +     struct sock *sk = ep->base.sk;
> > +     struct net *net = sock_net(sk);
> >       struct sctp_hashbucket *head;
> > +     struct sctp_ep_common *epb;
> >
> >       epb = &ep->base;
> > -
> >       epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
> >       head = &sctp_ep_hashtable[epb->hashent];
> >
> > +     if (sk->sk_reuseport) {
> > +             bool any = sctp_is_ep_boundall(sk);
> > +             struct sctp_ep_common *epb2;
> > +             struct list_head *list;
> > +             int cnt = 0, err = 1;
> > +
> > +             list_for_each(list, &ep->base.bind_addr.address_list)
> > +                     cnt++;
> > +
> > +             sctp_for_each_hentry(epb2, &head->chain) {
> > +                     struct sock *sk2 = epb2->sk;
> > +
> > +                     if (!net_eq(sock_net(sk2), net) || sk2 == sk ||
> > +                         !uid_eq(sock_i_uid(sk2), sock_i_uid(sk)) ||
> > +                         !sk2->sk_reuseport)
> > +                             continue;
> > +
> > +                     err = sctp_bind_addrs_check(sctp_sk(sk2),
> > +                                                 sctp_sk(sk), cnt);
> > +                     if (!err) {
> > +                             err = reuseport_add_sock(sk, sk2, any);
> > +                             if (err)
> > +                                     return err;
> > +                             break;
> > +                     } else if (err < 0) {
> > +                             return err;
> > +                     }
> > +             }
> > +
> > +             if (err) {
> > +                     err = reuseport_alloc(sk, any);
> > +                     if (err)
> > +                             return err;
> > +             }
> > +     }
> > +
> >       write_lock(&head->lock);
> >       hlist_add_head(&epb->node, &head->chain);
> >       write_unlock(&head->lock);
> > +     return 0;
> >  }
> >
> >  /* Add an endpoint to the hash. Local BH-safe. */
> > -void sctp_hash_endpoint(struct sctp_endpoint *ep)
> > +int sctp_hash_endpoint(struct sctp_endpoint *ep)
> >  {
> > +     int err;
> > +
> >       local_bh_disable();
> > -     __sctp_hash_endpoint(ep);
> > +     err = __sctp_hash_endpoint(ep);
> >       local_bh_enable();
> > +
> > +     return err;
> >  }
> >
> >  /* Remove endpoint from the hash table.  */
> >  static void __sctp_unhash_endpoint(struct sctp_endpoint *ep)
> >  {
> > -     struct net *net = sock_net(ep->base.sk);
> > +     struct sock *sk = ep->base.sk;
> >       struct sctp_hashbucket *head;
> >       struct sctp_ep_common *epb;
> >
> >       epb = &ep->base;
> >
> > -     epb->hashent = sctp_ep_hashfn(net, epb->bind_addr.port);
> > +     epb->hashent = sctp_ep_hashfn(sock_net(sk), epb->bind_addr.port);
> >
> >       head = &sctp_ep_hashtable[epb->hashent];
> >
> > +     if (rcu_access_pointer(sk->sk_reuseport_cb))
> > +             reuseport_detach_sock(sk);
> > +
> >       write_lock(&head->lock);
> >       hlist_del_init(&epb->node);
> >       write_unlock(&head->lock);
> > diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> > index fc0386e..44e7d8c 100644
> > --- a/net/sctp/socket.c
> > +++ b/net/sctp/socket.c
> > @@ -7850,8 +7850,7 @@ static int sctp_listen_start(struct sock *sk, int backlog)
> >       }
> >
> >       sk->sk_max_ack_backlog = backlog;
> > -     sctp_hash_endpoint(ep);
> > -     return 0;
> > +     return sctp_hash_endpoint(ep);
> >  }
> >
> >  /*
> > --
> > 2.1.0
> >