Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[firefly-linux-kernel-4.4.55.git] / net / l2tp / l2tp_core.c
index d36875f3427e82b7795012bebe8281318f983d22..6984c3a353cd003bc91150485faeecefa078c763 100644 (file)
@@ -114,7 +114,6 @@ struct l2tp_net {
 
 static void l2tp_session_set_header_len(struct l2tp_session *session, int version);
 static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
-static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
 
 static inline struct l2tp_net *l2tp_pernet(struct net *net)
 {
@@ -192,6 +191,7 @@ struct sock *l2tp_tunnel_sock_lookup(struct l2tp_tunnel *tunnel)
        } else {
                /* Socket is owned by kernelspace */
                sk = tunnel->sock;
+               sock_hold(sk);
        }
 
 out:
@@ -210,6 +210,7 @@ void l2tp_tunnel_sock_put(struct sock *sk)
                }
                sock_put(sk);
        }
+       sock_put(sk);
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_sock_put);
 
@@ -373,10 +374,8 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk
        struct sk_buff *skbp;
        struct sk_buff *tmp;
        u32 ns = L2TP_SKB_CB(skb)->ns;
-       struct l2tp_stats *sstats;
 
        spin_lock_bh(&session->reorder_q.lock);
-       sstats = &session->stats;
        skb_queue_walk_safe(&session->reorder_q, skbp, tmp) {
                if (L2TP_SKB_CB(skbp)->ns > ns) {
                        __skb_queue_before(&session->reorder_q, skbp, skb);
@@ -384,9 +383,7 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk
                                 "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n",
                                 session->name, ns, L2TP_SKB_CB(skbp)->ns,
                                 skb_queue_len(&session->reorder_q));
-                       u64_stats_update_begin(&sstats->syncp);
-                       sstats->rx_oos_packets++;
-                       u64_stats_update_end(&sstats->syncp);
+                       atomic_long_inc(&session->stats.rx_oos_packets);
                        goto out;
                }
        }
@@ -403,23 +400,16 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff *
 {
        struct l2tp_tunnel *tunnel = session->tunnel;
        int length = L2TP_SKB_CB(skb)->length;
-       struct l2tp_stats *tstats, *sstats;
 
        /* We're about to requeue the skb, so return resources
         * to its current owner (a socket receive buffer).
         */
        skb_orphan(skb);
 
-       tstats = &tunnel->stats;
-       u64_stats_update_begin(&tstats->syncp);
-       sstats = &session->stats;
-       u64_stats_update_begin(&sstats->syncp);
-       tstats->rx_packets++;
-       tstats->rx_bytes += length;
-       sstats->rx_packets++;
-       sstats->rx_bytes += length;
-       u64_stats_update_end(&tstats->syncp);
-       u64_stats_update_end(&sstats->syncp);
+       atomic_long_inc(&tunnel->stats.rx_packets);
+       atomic_long_add(length, &tunnel->stats.rx_bytes);
+       atomic_long_inc(&session->stats.rx_packets);
+       atomic_long_add(length, &session->stats.rx_bytes);
 
        if (L2TP_SKB_CB(skb)->has_seq) {
                /* Bump our Nr */
@@ -450,7 +440,6 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
 {
        struct sk_buff *skb;
        struct sk_buff *tmp;
-       struct l2tp_stats *sstats;
 
        /* If the pkt at the head of the queue has the nr that we
         * expect to send up next, dequeue it and any other
@@ -458,13 +447,10 @@ static void l2tp_recv_dequeue(struct l2tp_session *session)
         */
 start:
        spin_lock_bh(&session->reorder_q.lock);
-       sstats = &session->stats;
        skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
                if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) {
-                       u64_stats_update_begin(&sstats->syncp);
-                       sstats->rx_seq_discards++;
-                       sstats->rx_errors++;
-                       u64_stats_update_end(&sstats->syncp);
+                       atomic_long_inc(&session->stats.rx_seq_discards);
+                       atomic_long_inc(&session->stats.rx_errors);
                        l2tp_dbg(session, L2TP_MSG_SEQ,
                                 "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n",
                                 session->name, L2TP_SKB_CB(skb)->ns,
@@ -623,7 +609,6 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
        struct l2tp_tunnel *tunnel = session->tunnel;
        int offset;
        u32 ns, nr;
-       struct l2tp_stats *sstats = &session->stats;
 
        /* The ref count is increased since we now hold a pointer to
         * the session. Take care to decrement the refcnt when exiting
@@ -640,9 +625,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
                                  "%s: cookie mismatch (%u/%u). Discarding.\n",
                                  tunnel->name, tunnel->tunnel_id,
                                  session->session_id);
-                       u64_stats_update_begin(&sstats->syncp);
-                       sstats->rx_cookie_discards++;
-                       u64_stats_update_end(&sstats->syncp);
+                       atomic_long_inc(&session->stats.rx_cookie_discards);
                        goto discard;
                }
                ptr += session->peer_cookie_len;
@@ -711,9 +694,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
                        l2tp_warn(session, L2TP_MSG_SEQ,
                                  "%s: recv data has no seq numbers when required. Discarding.\n",
                                  session->name);
-                       u64_stats_update_begin(&sstats->syncp);
-                       sstats->rx_seq_discards++;
-                       u64_stats_update_end(&sstats->syncp);
+                       atomic_long_inc(&session->stats.rx_seq_discards);
                        goto discard;
                }
 
@@ -732,9 +713,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
                        l2tp_warn(session, L2TP_MSG_SEQ,
                                  "%s: recv data has no seq numbers when required. Discarding.\n",
                                  session->name);
-                       u64_stats_update_begin(&sstats->syncp);
-                       sstats->rx_seq_discards++;
-                       u64_stats_update_end(&sstats->syncp);
+                       atomic_long_inc(&session->stats.rx_seq_discards);
                        goto discard;
                }
        }
@@ -788,9 +767,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
                         * packets
                         */
                        if (L2TP_SKB_CB(skb)->ns != session->nr) {
-                               u64_stats_update_begin(&sstats->syncp);
-                               sstats->rx_seq_discards++;
-                               u64_stats_update_end(&sstats->syncp);
+                               atomic_long_inc(&session->stats.rx_seq_discards);
                                l2tp_dbg(session, L2TP_MSG_SEQ,
                                         "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n",
                                         session->name, L2TP_SKB_CB(skb)->ns,
@@ -816,9 +793,7 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb,
        return;
 
 discard:
-       u64_stats_update_begin(&sstats->syncp);
-       sstats->rx_errors++;
-       u64_stats_update_end(&sstats->syncp);
+       atomic_long_inc(&session->stats.rx_errors);
        kfree_skb(skb);
 
        if (session->deref)
@@ -828,6 +803,23 @@ discard:
 }
 EXPORT_SYMBOL(l2tp_recv_common);
 
+/* Drop skbs from the session's reorder_q
+ */
+int l2tp_session_queue_purge(struct l2tp_session *session)
+{
+       struct sk_buff *skb = NULL;
+       BUG_ON(!session);
+       BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+       while ((skb = skb_dequeue(&session->reorder_q))) {
+               atomic_long_inc(&session->stats.rx_errors);
+               kfree_skb(skb);
+               if (session->deref)
+                       (*session->deref)(session);
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(l2tp_session_queue_purge);
+
 /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame
  * here. The skb is not on a list when we get here.
  * Returns 0 if the packet was a data packet and was successfully passed on.
@@ -843,7 +835,6 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
        u32 tunnel_id, session_id;
        u16 version;
        int length;
-       struct l2tp_stats *tstats;
 
        if (tunnel->sock && l2tp_verify_udp_checksum(tunnel->sock, skb))
                goto discard_bad_csum;
@@ -932,10 +923,7 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb,
 discard_bad_csum:
        LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name);
        UDP_INC_STATS_USER(tunnel->l2tp_net, UDP_MIB_INERRORS, 0);
-       tstats = &tunnel->stats;
-       u64_stats_update_begin(&tstats->syncp);
-       tstats->rx_errors++;
-       u64_stats_update_end(&tstats->syncp);
+       atomic_long_inc(&tunnel->stats.rx_errors);
        kfree_skb(skb);
 
        return 0;
@@ -1062,7 +1050,6 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
        struct l2tp_tunnel *tunnel = session->tunnel;
        unsigned int len = skb->len;
        int error;
-       struct l2tp_stats *tstats, *sstats;
 
        /* Debug */
        if (session->send_seq)
@@ -1091,21 +1078,15 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb,
                error = ip_queue_xmit(skb, fl);
 
        /* Update stats */
-       tstats = &tunnel->stats;
-       u64_stats_update_begin(&tstats->syncp);
-       sstats = &session->stats;
-       u64_stats_update_begin(&sstats->syncp);
        if (error >= 0) {
-               tstats->tx_packets++;
-               tstats->tx_bytes += len;
-               sstats->tx_packets++;
-               sstats->tx_bytes += len;
+               atomic_long_inc(&tunnel->stats.tx_packets);
+               atomic_long_add(len, &tunnel->stats.tx_bytes);
+               atomic_long_inc(&session->stats.tx_packets);
+               atomic_long_add(len, &session->stats.tx_bytes);
        } else {
-               tstats->tx_errors++;
-               sstats->tx_errors++;
+               atomic_long_inc(&tunnel->stats.tx_errors);
+               atomic_long_inc(&session->stats.tx_errors);
        }
-       u64_stats_update_end(&tstats->syncp);
-       u64_stats_update_end(&sstats->syncp);
 
        return 0;
 }
@@ -1282,6 +1263,7 @@ static void l2tp_tunnel_destruct(struct sock *sk)
                /* No longer an encapsulation socket. See net/ipv4/udp.c */
                (udp_sk(sk))->encap_type = 0;
                (udp_sk(sk))->encap_rcv = NULL;
+               (udp_sk(sk))->encap_destroy = NULL;
                break;
        case L2TP_ENCAPTYPE_IP:
                break;
@@ -1311,7 +1293,7 @@ end:
 
 /* When the tunnel is closed, all the attached sessions need to go too.
  */
-static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
+void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel)
 {
        int hash;
        struct hlist_node *walk;
@@ -1334,25 +1316,13 @@ again:
 
                        hlist_del_init(&session->hlist);
 
-                       /* Since we should hold the sock lock while
-                        * doing any unbinding, we need to release the
-                        * lock we're holding before taking that lock.
-                        * Hold a reference to the sock so it doesn't
-                        * disappear as we're jumping between locks.
-                        */
                        if (session->ref != NULL)
                                (*session->ref)(session);
 
                        write_unlock_bh(&tunnel->hlist_lock);
 
-                       if (tunnel->version != L2TP_HDR_VER_2) {
-                               struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
-
-                               spin_lock_bh(&pn->l2tp_session_hlist_lock);
-                               hlist_del_init_rcu(&session->global_hlist);
-                               spin_unlock_bh(&pn->l2tp_session_hlist_lock);
-                               synchronize_rcu();
-                       }
+                       __l2tp_session_unhash(session);
+                       l2tp_session_queue_purge(session);
 
                        if (session->session_close != NULL)
                                (*session->session_close)(session);
@@ -1360,6 +1330,8 @@ again:
                        if (session->deref != NULL)
                                (*session->deref)(session);
 
+                       l2tp_session_dec_refcount(session);
+
                        write_lock_bh(&tunnel->hlist_lock);
 
                        /* Now restart from the beginning of this hash
@@ -1372,6 +1344,17 @@ again:
        }
        write_unlock_bh(&tunnel->hlist_lock);
 }
+EXPORT_SYMBOL_GPL(l2tp_tunnel_closeall);
+
+/* Tunnel socket destroy hook for UDP encapsulation */
+static void l2tp_udp_encap_destroy(struct sock *sk)
+{
+       struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
+       if (tunnel) {
+               l2tp_tunnel_closeall(tunnel);
+               sock_put(sk);
+       }
+}
 
 /* Really kill the tunnel.
  * Come here only when all sessions have been cleared from the tunnel.
@@ -1397,19 +1380,21 @@ static void l2tp_tunnel_del_work(struct work_struct *work)
                return;
 
        sock = sk->sk_socket;
-       BUG_ON(!sock);
 
-       /* If the tunnel socket was created directly by the kernel, use the
-        * sk_* API to release the socket now.  Otherwise go through the
-        * inet_* layer to shut the socket down, and let userspace close it.
+       /* If the tunnel socket was created by userspace, then go through the
+        * inet layer to shut the socket down, and let userspace close it.
+        * Otherwise, if we created the socket directly within the kernel, use
+        * the sk API to release it here.
         * In either case the tunnel resources are freed in the socket
         * destructor when the tunnel socket goes away.
         */
-       if (sock->file == NULL) {
-               kernel_sock_shutdown(sock, SHUT_RDWR);
-               sk_release_kernel(sk);
+       if (tunnel->fd >= 0) {
+               if (sock)
+                       inet_shutdown(sock, 2);
        } else {
-               inet_shutdown(sock, 2);
+               if (sock)
+                       kernel_sock_shutdown(sock, SHUT_RDWR);
+               sk_release_kernel(sk);
        }
 
        l2tp_tunnel_sock_put(sk);
@@ -1668,6 +1653,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32
                /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */
                udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP;
                udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv;
+               udp_sk(sk)->encap_destroy = l2tp_udp_encap_destroy;
 #if IS_ENABLED(CONFIG_IPV6)
                if (sk->sk_family == PF_INET6)
                        udpv6_encap_enable();
@@ -1723,6 +1709,7 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_create);
  */
 int l2tp_tunnel_delete(struct l2tp_tunnel *tunnel)
 {
+       l2tp_tunnel_closeall(tunnel);
        return (false == queue_work(l2tp_wq, &tunnel->del_work));
 }
 EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
@@ -1731,62 +1718,71 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_delete);
  */
 void l2tp_session_free(struct l2tp_session *session)
 {
-       struct l2tp_tunnel *tunnel;
+       struct l2tp_tunnel *tunnel = session->tunnel;
 
        BUG_ON(atomic_read(&session->ref_count) != 0);
 
-       tunnel = session->tunnel;
-       if (tunnel != NULL) {
+       if (tunnel) {
                BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
+               if (session->session_id != 0)
+                       atomic_dec(&l2tp_session_count);
+               sock_put(tunnel->sock);
+               session->tunnel = NULL;
+               l2tp_tunnel_dec_refcount(tunnel);
+       }
+
+       kfree(session);
 
-               /* Delete the session from the hash */
+       return;
+}
+EXPORT_SYMBOL_GPL(l2tp_session_free);
+
+/* Remove an l2tp session from l2tp_core's hash lists.
+ * Provides a tidyup interface for pseudowire code which can't just route all
+ * shutdown via. l2tp_session_delete and a pseudowire-specific session_close
+ * callback.
+ */
+void __l2tp_session_unhash(struct l2tp_session *session)
+{
+       struct l2tp_tunnel *tunnel = session->tunnel;
+
+       /* Remove the session from core hashes */
+       if (tunnel) {
+               /* Remove from the per-tunnel hash */
                write_lock_bh(&tunnel->hlist_lock);
                hlist_del_init(&session->hlist);
                write_unlock_bh(&tunnel->hlist_lock);
 
-               /* Unlink from the global hash if not L2TPv2 */
+               /* For L2TPv3 we have a per-net hash: remove from there, too */
                if (tunnel->version != L2TP_HDR_VER_2) {
                        struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net);
-
                        spin_lock_bh(&pn->l2tp_session_hlist_lock);
                        hlist_del_init_rcu(&session->global_hlist);
                        spin_unlock_bh(&pn->l2tp_session_hlist_lock);
                        synchronize_rcu();
                }
-
-               if (session->session_id != 0)
-                       atomic_dec(&l2tp_session_count);
-
-               sock_put(tunnel->sock);
-
-               /* This will delete the tunnel context if this
-                * is the last session on the tunnel.
-                */
-               session->tunnel = NULL;
-               l2tp_tunnel_dec_refcount(tunnel);
        }
-
-       kfree(session);
-
-       return;
 }
-EXPORT_SYMBOL_GPL(l2tp_session_free);
+EXPORT_SYMBOL_GPL(__l2tp_session_unhash);
 
 /* This function is used by the netlink SESSION_DELETE command and by
    pseudowire modules.
  */
 int l2tp_session_delete(struct l2tp_session *session)
 {
+       if (session->ref)
+               (*session->ref)(session);
+       __l2tp_session_unhash(session);
+       l2tp_session_queue_purge(session);
        if (session->session_close != NULL)
                (*session->session_close)(session);
-
+       if (session->deref)
+               (*session->deref)(session);
        l2tp_session_dec_refcount(session);
-
        return 0;
 }
 EXPORT_SYMBOL_GPL(l2tp_session_delete);
 
-
 /* We come here whenever a session's send_seq, cookie_len or
  * l2specific_len parameters are set.
  */