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@xxxxxxxxx>
> ---
> 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
>
