On Mon, Oct 22, 2018 at 11:18 PM Marcelo Ricardo Leitner
[off-list ref] wrote:

On Sun, Oct 21, 2018 at 12:43:36PM +0800, Xin Long wrote:

quoted

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.

quoted

      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