Merge branch 'sctp-vrf'

Xin Long says:

====================
sctp: support vrf processing

This patchset adds the VRF processing in SCTP. Simliar to TCP/UDP,
it includes socket bind and socket/association lookup changes.

For socket bind change, it allows sockets to bind to a VRF device
and allows multiple sockets with the same IP and PORT to bind to
different interfaces in patch 1-3.

For socket/association lookup change, it adds dif and sdif check
in both asoc and ep lookup in patch 4 and 5, and when binding to
nodev, users can decide if accept the packets received from one
l3mdev by setup a sysctl option in patch 6.

Note with VRF support, in a netns, an association will be decided
by src ip + src port + dst ip + dst port + bound_dev_if, and it's
possible for ss to have:

  State       Local Address:Port      Peer Address:Port
   ESTAB     192.168.1.2%vrf-s1:1234
   `- ESTAB   192.168.1.2%veth1:1234   192.168.1.1:1234
   ESTAB     192.168.1.2%vrf-s2:1234
   `- ESTAB   192.168.1.2%veth2:1234   192.168.1.1:1234

See the selftest in patch 7 for more usage.

Also, thanks Carlo for testing this patch series on their use.

v1->v2:
  - In Patch 5, move sctp_sk_bound_dev_eq() definition to net/sctp/
    input.c to avoid a build error when IP_SCTP is disabled, as Paolo
    suggested.
  - In Patch 7, avoid one sleep by disabling the IPv6 dad, and remove
    another sleep by using ss to check if the server's ready, and also
    delete two unncessary sleeps in sctp_hello.c, as Paolo suggested.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 49 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 4f43afa8678f..bf70371301ff 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -50,16 +50,19 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
 				      struct sk_buff *skb,
 				      const union sctp_addr *paddr,
 				      const union sctp_addr *laddr,
-				      struct sctp_transport **transportp);
+				      struct sctp_transport **transportp,
+				      int dif, int sdif);
 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);
+					const union sctp_addr *daddr,
+					int dif, int sdif);
 static struct sctp_association *__sctp_lookup_association(
 					struct net *net,
 					const union sctp_addr *local,
 					const union sctp_addr *peer,
-					struct sctp_transport **pt);
+					struct sctp_transport **pt,
+					int dif, int sdif);
 
 static int sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
 
@@ -92,11 +95,11 @@ int sctp_rcv(struct sk_buff *skb)
 	struct sctp_chunk *chunk;
 	union sctp_addr src;
 	union sctp_addr dest;
-	int bound_dev_if;
 	int family;
 	struct sctp_af *af;
 	struct net *net = dev_net(skb->dev);
 	bool is_gso = skb_is_gso(skb) && skb_is_gso_sctp(skb);
+	int dif, sdif;
 
 	if (skb->pkt_type != PACKET_HOST)
 		goto discard_it;
@@ -141,6 +144,8 @@ int sctp_rcv(struct sk_buff *skb)
 	/* Initialize local addresses for lookups. */
 	af->from_skb(&src, skb, 1);
 	af->from_skb(&dest, skb, 0);
+	dif = af->skb_iif(skb);
+	sdif = af->skb_sdif(skb);
 
 	/* If the packet is to or from a non-unicast address,
 	 * silently discard the packet.
@@ -157,36 +162,16 @@ int sctp_rcv(struct sk_buff *skb)
 	    !af->addr_valid(&dest, NULL, skb))
 		goto discard_it;
 
-	asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport);
+	asoc = __sctp_rcv_lookup(net, skb, &src, &dest, &transport, dif, sdif);
 
 	if (!asoc)
-		ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src);
+		ep = __sctp_rcv_lookup_endpoint(net, skb, &dest, &src, dif, sdif);
 
 	/* Retrieve the common input handling substructure. */
 	rcvr = asoc ? &asoc->base : &ep->base;
 	sk = rcvr->sk;
 
 	/*
-	 * If a frame arrives on an interface and the receiving socket is
-	 * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
-	 */
-	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
-	if (bound_dev_if && (bound_dev_if != af->skb_iif(skb))) {
-		if (transport) {
-			sctp_transport_put(transport);
-			asoc = NULL;
-			transport = NULL;
-		} else {
-			sctp_endpoint_put(ep);
-			ep = NULL;
-		}
-		sk = net->sctp.ctl_sock;
-		ep = sctp_sk(sk)->ep;
-		sctp_endpoint_hold(ep);
-		rcvr = &ep->base;
-	}
-
-	/*
 	 * RFC 2960, 8.4 - Handle "Out of the blue" Packets.
 	 * An SCTP packet is called an "out of the blue" (OOTB)
 	 * packet if it is correctly formed, i.e., passed the
@@ -485,6 +470,8 @@ struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb,
 	struct sctp_association *asoc;
 	struct sctp_transport *transport = NULL;
 	__u32 vtag = ntohl(sctphdr->vtag);
+	int sdif = inet_sdif(skb);
+	int dif = inet_iif(skb);
 
 	*app = NULL; *tpp = NULL;
 
@@ -500,7 +487,7 @@ struct sock *sctp_err_lookup(struct net *net, int family, struct sk_buff *skb,
 	/* Look for an association that matches the incoming ICMP error
 	 * packet.
 	 */
-	asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport);
+	asoc = __sctp_lookup_association(net, &saddr, &daddr, &transport, dif, sdif);
 	if (!asoc)
 		return NULL;
 
@@ -850,7 +837,8 @@ static inline __u32 sctp_hashfn(const struct net *net, __be16 lport,
 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)
+					const union sctp_addr *paddr,
+					int dif, int sdif)
 {
 	struct sctp_hashbucket *head;
 	struct sctp_endpoint *ep;
@@ -863,7 +851,7 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(
 	head = &sctp_ep_hashtable[hash];
 	read_lock(&head->lock);
 	sctp_for_each_hentry(ep, &head->chain) {
-		if (sctp_endpoint_is_match(ep, net, laddr))
+		if (sctp_endpoint_is_match(ep, net, laddr, dif, sdif))
 			goto hit;
 	}
 
@@ -990,14 +978,26 @@ void sctp_unhash_transport(struct sctp_transport *t)
 			sctp_hash_params);
 }
 
+bool sctp_sk_bound_dev_eq(struct net *net, int bound_dev_if, int dif, int sdif)
+{
+	bool l3mdev_accept = true;
+
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+	l3mdev_accept = !!READ_ONCE(net->sctp.l3mdev_accept);
+#endif
+	return inet_bound_dev_eq(l3mdev_accept, bound_dev_if, dif, sdif);
+}
+
 /* return a transport with holding it */
 struct sctp_transport *sctp_addrs_lookup_transport(
 				struct net *net,
 				const union sctp_addr *laddr,
-				const union sctp_addr *paddr)
+				const union sctp_addr *paddr,
+				int dif, int sdif)
 {
 	struct rhlist_head *tmp, *list;
 	struct sctp_transport *t;
+	int bound_dev_if;
 	struct sctp_hash_cmp_arg arg = {
 		.paddr = paddr,
 		.net   = net,
@@ -1011,7 +1011,9 @@ struct sctp_transport *sctp_addrs_lookup_transport(
 		if (!sctp_transport_hold(t))
 			continue;
 
-		if (sctp_bind_addr_match(&t->asoc->base.bind_addr,
+		bound_dev_if = READ_ONCE(t->asoc->base.sk->sk_bound_dev_if);
+		if (sctp_sk_bound_dev_eq(net, bound_dev_if, dif, sdif) &&
+		    sctp_bind_addr_match(&t->asoc->base.bind_addr,
 					 laddr, sctp_sk(t->asoc->base.sk)))
 			return t;
 		sctp_transport_put(t);
@@ -1048,12 +1050,13 @@ static struct sctp_association *__sctp_lookup_association(
 					struct net *net,
 					const union sctp_addr *local,
 					const union sctp_addr *peer,
-					struct sctp_transport **pt)
+					struct sctp_transport **pt,
+					int dif, int sdif)
 {
 	struct sctp_transport *t;
 	struct sctp_association *asoc = NULL;
 
-	t = sctp_addrs_lookup_transport(net, local, peer);
+	t = sctp_addrs_lookup_transport(net, local, peer, dif, sdif);
 	if (!t)
 		goto out;
 
@@ -1069,12 +1072,13 @@ static
 struct sctp_association *sctp_lookup_association(struct net *net,
 						 const union sctp_addr *laddr,
 						 const union sctp_addr *paddr,
-						 struct sctp_transport **transportp)
+						 struct sctp_transport **transportp,
+						 int dif, int sdif)
 {
 	struct sctp_association *asoc;
 
 	rcu_read_lock();
-	asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
+	asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif);
 	rcu_read_unlock();
 
 	return asoc;
@@ -1083,11 +1087,12 @@ struct sctp_association *sctp_lookup_association(struct net *net,
 /* Is there an association matching the given local and peer addresses? */
 bool sctp_has_association(struct net *net,
 			  const union sctp_addr *laddr,
-			  const union sctp_addr *paddr)
+			  const union sctp_addr *paddr,
+			  int dif, int sdif)
 {
 	struct sctp_transport *transport;
 
-	if (sctp_lookup_association(net, laddr, paddr, &transport)) {
+	if (sctp_lookup_association(net, laddr, paddr, &transport, dif, sdif)) {
 		sctp_transport_put(transport);
 		return true;
 	}
@@ -1115,7 +1120,8 @@ bool sctp_has_association(struct net *net,
  */
 static struct sctp_association *__sctp_rcv_init_lookup(struct net *net,
 	struct sk_buff *skb,
-	const union sctp_addr *laddr, struct sctp_transport **transportp)
+	const union sctp_addr *laddr, struct sctp_transport **transportp,
+	int dif, int sdif)
 {
 	struct sctp_association *asoc;
 	union sctp_addr addr;
@@ -1154,7 +1160,7 @@ static struct sctp_association *__sctp_rcv_init_lookup(struct net *net,
 		if (!af->from_addr_param(paddr, params.addr, sh->source, 0))
 			continue;
 
-		asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
+		asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif);
 		if (asoc)
 			return asoc;
 	}
@@ -1181,7 +1187,8 @@ static struct sctp_association *__sctp_rcv_asconf_lookup(
 					struct sctp_chunkhdr *ch,
 					const union sctp_addr *laddr,
 					__be16 peer_port,
-					struct sctp_transport **transportp)
+					struct sctp_transport **transportp,
+					int dif, int sdif)
 {
 	struct sctp_addip_chunk *asconf = (struct sctp_addip_chunk *)ch;
 	struct sctp_af *af;
@@ -1201,7 +1208,7 @@ static struct sctp_association *__sctp_rcv_asconf_lookup(
 	if (!af->from_addr_param(&paddr, param, peer_port, 0))
 		return NULL;
 
-	return __sctp_lookup_association(net, laddr, &paddr, transportp);
+	return __sctp_lookup_association(net, laddr, &paddr, transportp, dif, sdif);
 }
 
 
@@ -1217,7 +1224,8 @@ static struct sctp_association *__sctp_rcv_asconf_lookup(
 static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
 				      struct sk_buff *skb,
 				      const union sctp_addr *laddr,
-				      struct sctp_transport **transportp)
+				      struct sctp_transport **transportp,
+				      int dif, int sdif)
 {
 	struct sctp_association *asoc = NULL;
 	struct sctp_chunkhdr *ch;
@@ -1260,7 +1268,7 @@ static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
 				asoc = __sctp_rcv_asconf_lookup(
 						net, ch, laddr,
 						sctp_hdr(skb)->source,
-						transportp);
+						transportp, dif, sdif);
 			break;
 		default:
 			break;
@@ -1285,7 +1293,8 @@ static struct sctp_association *__sctp_rcv_walk_lookup(struct net *net,
 static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net,
 				      struct sk_buff *skb,
 				      const union sctp_addr *laddr,
-				      struct sctp_transport **transportp)
+				      struct sctp_transport **transportp,
+				      int dif, int sdif)
 {
 	struct sctp_chunkhdr *ch;
 
@@ -1309,9 +1318,9 @@ static struct sctp_association *__sctp_rcv_lookup_harder(struct net *net,
 
 	/* If this is INIT/INIT-ACK look inside the chunk too. */
 	if (ch->type == SCTP_CID_INIT || ch->type == SCTP_CID_INIT_ACK)
-		return __sctp_rcv_init_lookup(net, skb, laddr, transportp);
+		return __sctp_rcv_init_lookup(net, skb, laddr, transportp, dif, sdif);
 
-	return __sctp_rcv_walk_lookup(net, skb, laddr, transportp);
+	return __sctp_rcv_walk_lookup(net, skb, laddr, transportp, dif, sdif);
 }
 
 /* Lookup an association for an inbound skb. */
@@ -1319,11 +1328,12 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
 				      struct sk_buff *skb,
 				      const union sctp_addr *paddr,
 				      const union sctp_addr *laddr,
-				      struct sctp_transport **transportp)
+				      struct sctp_transport **transportp,
+				      int dif, int sdif)
 {
 	struct sctp_association *asoc;
 
-	asoc = __sctp_lookup_association(net, laddr, paddr, transportp);
+	asoc = __sctp_lookup_association(net, laddr, paddr, transportp, dif, sdif);
 	if (asoc)
 		goto out;
 
@@ -1331,7 +1341,7 @@ static struct sctp_association *__sctp_rcv_lookup(struct net *net,
 	 * SCTP Implementors Guide, 2.18 Handling of address
 	 * parameters within the INIT or INIT-ACK.
 	 */
-	asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp);
+	asoc = __sctp_rcv_lookup_harder(net, skb, laddr, transportp, dif, sdif);
 	if (asoc)
 		goto out;