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SubjectRe: [PATCH net-next 1/9] sctp: Make the port hash table use struct net in it's key.
On 08/06/2012 02:39 PM, Eric W. Biederman wrote:
>
> - Add struct net into the port hash table hash calculation
> - Add struct net inot the struct sctp_bind_bucket so there
> is a memory of which network namespace a port is allocated in.
> No need for a ref count because sctp_bind_bucket only exists
> when there are sockets in the hash table and sockets can not
> change their network namspace, and sockets already ref count
> their network namespace.
> - Add struct net into the key comparison when we are testing
> to see if we have found the port hash table entry we are
> looking for.
>
> With these changes lookups in the port hash table becomes
> safe to use in multiple network namespaces.
>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Acked-by: Vlad Yasevich <vyasevich@gmail.com>


> ---
> include/net/sctp/sctp.h | 4 ++--
> include/net/sctp/structs.h | 1 +
> net/sctp/socket.c | 22 +++++++++++++---------
> 3 files changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> index ff49964..7c05040 100644
> --- a/include/net/sctp/sctp.h
> +++ b/include/net/sctp/sctp.h
> @@ -632,9 +632,9 @@ static inline int sctp_sanity_check(void)
>
> /* Warning: The following hash functions assume a power of two 'size'. */
> /* This is the hash function for the SCTP port hash table. */
> -static inline int sctp_phashfn(__u16 lport)
> +static inline int sctp_phashfn(struct net *net, __u16 lport)
> {
> - return lport & (sctp_port_hashsize - 1);
> + return (net_hash_mix(net) + lport) & (sctp_port_hashsize - 1);
> }
>
> /* This is the hash function for the endpoint hash table. */
> diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
> index fc5e600..c089bb1 100644
> --- a/include/net/sctp/structs.h
> +++ b/include/net/sctp/structs.h
> @@ -102,6 +102,7 @@ struct sctp_bind_bucket {
> unsigned short fastreuse;
> struct hlist_node node;
> struct hlist_head owner;
> + struct net *net;
> };
>
> struct sctp_bind_hashbucket {
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 5e25981..4316b0f 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -5769,7 +5769,7 @@ static void sctp_unhash(struct sock *sk)
> * a fastreuse flag (FIXME: NPI ipg).
> */
> static struct sctp_bind_bucket *sctp_bucket_create(
> - struct sctp_bind_hashbucket *head, unsigned short snum);
> + struct sctp_bind_hashbucket *head, struct net *, unsigned short snum);
>
> static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
> {
> @@ -5799,11 +5799,12 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
> rover = low;
> if (inet_is_reserved_local_port(rover))
> continue;
> - index = sctp_phashfn(rover);
> + index = sctp_phashfn(sock_net(sk), rover);
> head = &sctp_port_hashtable[index];
> sctp_spin_lock(&head->lock);
> sctp_for_each_hentry(pp, node, &head->chain)
> - if (pp->port == rover)
> + if ((pp->port == rover) &&
> + net_eq(sock_net(sk), pp->net))
> goto next;
> break;
> next:
> @@ -5827,10 +5828,10 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
> * to the port number (snum) - we detect that with the
> * port iterator, pp being NULL.
> */
> - head = &sctp_port_hashtable[sctp_phashfn(snum)];
> + head = &sctp_port_hashtable[sctp_phashfn(sock_net(sk), snum)];
> sctp_spin_lock(&head->lock);
> sctp_for_each_hentry(pp, node, &head->chain) {
> - if (pp->port == snum)
> + if ((pp->port == snum) && net_eq(pp->net, sock_net(sk)))
> goto pp_found;
> }
> }
> @@ -5881,7 +5882,7 @@ pp_found:
> pp_not_found:
> /* If there was a hash table miss, create a new port. */
> ret = 1;
> - if (!pp && !(pp = sctp_bucket_create(head, snum)))
> + if (!pp && !(pp = sctp_bucket_create(head, sock_net(sk), snum)))
> goto fail_unlock;
>
> /* In either case (hit or miss), make sure fastreuse is 1 only
> @@ -6113,7 +6114,7 @@ unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
> ********************************************************************/
>
> static struct sctp_bind_bucket *sctp_bucket_create(
> - struct sctp_bind_hashbucket *head, unsigned short snum)
> + struct sctp_bind_hashbucket *head, struct net *net, unsigned short snum)
> {
> struct sctp_bind_bucket *pp;
>
> @@ -6123,6 +6124,7 @@ static struct sctp_bind_bucket *sctp_bucket_create(
> pp->port = snum;
> pp->fastreuse = 0;
> INIT_HLIST_HEAD(&pp->owner);
> + pp->net = net;
> hlist_add_head(&pp->node, &head->chain);
> }
> return pp;
> @@ -6142,7 +6144,8 @@ static void sctp_bucket_destroy(struct sctp_bind_bucket *pp)
> static inline void __sctp_put_port(struct sock *sk)
> {
> struct sctp_bind_hashbucket *head =
> - &sctp_port_hashtable[sctp_phashfn(inet_sk(sk)->inet_num)];
> + &sctp_port_hashtable[sctp_phashfn(sock_net(sk),
> + inet_sk(sk)->inet_num)];
> struct sctp_bind_bucket *pp;
>
> sctp_spin_lock(&head->lock);
> @@ -6809,7 +6812,8 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
> newsp->hmac = NULL;
>
> /* Hook this new socket in to the bind_hash list. */
> - head = &sctp_port_hashtable[sctp_phashfn(inet_sk(oldsk)->inet_num)];
> + head = &sctp_port_hashtable[sctp_phashfn(sock_net(oldsk),
> + inet_sk(oldsk)->inet_num)];
> sctp_local_bh_disable();
> sctp_spin_lock(&head->lock);
> pp = sctp_sk(oldsk)->bind_hash;
>



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