aboutsummaryrefslogtreecommitdiffstats
path: root/net/rxrpc/ar-local.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/rxrpc/ar-local.c')
-rw-r--r--net/rxrpc/ar-local.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/net/rxrpc/ar-local.c b/net/rxrpc/ar-local.c
new file mode 100644
index 000000000000..a20a2c0fe105
--- /dev/null
+++ b/net/rxrpc/ar-local.c
@@ -0,0 +1,309 @@
+/* AF_RXRPC local endpoint management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static LIST_HEAD(rxrpc_locals);
+DEFINE_RWLOCK(rxrpc_local_lock);
+static DECLARE_RWSEM(rxrpc_local_sem);
+static DECLARE_WAIT_QUEUE_HEAD(rxrpc_local_wq);
+
+static void rxrpc_destroy_local(struct work_struct *work);
+
+/*
+ * allocate a new local
+ */
+static
+struct rxrpc_local *rxrpc_alloc_local(struct sockaddr_rxrpc *srx)
+{
+ struct rxrpc_local *local;
+
+ local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
+ if (local) {
+ INIT_WORK(&local->destroyer, &rxrpc_destroy_local);
+ INIT_WORK(&local->acceptor, &rxrpc_accept_incoming_calls);
+ INIT_WORK(&local->rejecter, &rxrpc_reject_packets);
+ INIT_LIST_HEAD(&local->services);
+ INIT_LIST_HEAD(&local->link);
+ init_rwsem(&local->defrag_sem);
+ skb_queue_head_init(&local->accept_queue);
+ skb_queue_head_init(&local->reject_queue);
+ spin_lock_init(&local->lock);
+ rwlock_init(&local->services_lock);
+ atomic_set(&local->usage, 1);
+ local->debug_id = atomic_inc_return(&rxrpc_debug_id);
+ memcpy(&local->srx, srx, sizeof(*srx));
+ }
+
+ _leave(" = %p", local);
+ return local;
+}
+
+/*
+ * create the local socket
+ * - must be called with rxrpc_local_sem writelocked
+ */
+static int rxrpc_create_local(struct rxrpc_local *local)
+{
+ struct sock *sock;
+ int ret, opt;
+
+ _enter("%p{%d}", local, local->srx.transport_type);
+
+ /* create a socket to represent the local endpoint */
+ ret = sock_create_kern(PF_INET, local->srx.transport_type, IPPROTO_UDP,
+ &local->socket);
+ if (ret < 0) {
+ _leave(" = %d [socket]", ret);
+ return ret;
+ }
+
+ /* if a local address was supplied then bind it */
+ if (local->srx.transport_len > sizeof(sa_family_t)) {
+ _debug("bind");
+ ret = kernel_bind(local->socket,
+ (struct sockaddr *) &local->srx.transport,
+ local->srx.transport_len);
+ if (ret < 0) {
+ _debug("bind failed");
+ goto error;
+ }
+ }
+
+ /* we want to receive ICMP errors */
+ opt = 1;
+ ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
+ (char *) &opt, sizeof(opt));
+ if (ret < 0) {
+ _debug("setsockopt failed");
+ goto error;
+ }
+
+ /* we want to set the don't fragment bit */
+ opt = IP_PMTUDISC_DO;
+ ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
+ (char *) &opt, sizeof(opt));
+ if (ret < 0) {
+ _debug("setsockopt failed");
+ goto error;
+ }
+
+ write_lock_bh(&rxrpc_local_lock);
+ list_add(&local->link, &rxrpc_locals);
+ write_unlock_bh(&rxrpc_local_lock);
+
+ /* set the socket up */
+ sock = local->socket->sk;
+ sock->sk_user_data = local;
+ sock->sk_data_ready = rxrpc_data_ready;
+ sock->sk_error_report = rxrpc_UDP_error_report;
+ _leave(" = 0");
+ return 0;
+
+error:
+ local->socket->ops->shutdown(local->socket, 2);
+ local->socket->sk->sk_user_data = NULL;
+ sock_release(local->socket);
+ local->socket = NULL;
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * create a new local endpoint using the specified UDP address
+ */
+struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *srx)
+{
+ struct rxrpc_local *local;
+ int ret;
+
+ _enter("{%d,%u,%u.%u.%u.%u+%hu}",
+ srx->transport_type,
+ srx->transport.family,
+ NIPQUAD(srx->transport.sin.sin_addr),
+ ntohs(srx->transport.sin.sin_port));
+
+ down_write(&rxrpc_local_sem);
+
+ /* see if we have a suitable local local endpoint already */
+ read_lock_bh(&rxrpc_local_lock);
+
+ list_for_each_entry(local, &rxrpc_locals, link) {
+ _debug("CMP {%d,%u,%u.%u.%u.%u+%hu}",
+ local->srx.transport_type,
+ local->srx.transport.family,
+ NIPQUAD(local->srx.transport.sin.sin_addr),
+ ntohs(local->srx.transport.sin.sin_port));
+
+ if (local->srx.transport_type != srx->transport_type ||
+ local->srx.transport.family != srx->transport.family)
+ continue;
+
+ switch (srx->transport.family) {
+ case AF_INET:
+ if (local->srx.transport.sin.sin_port !=
+ srx->transport.sin.sin_port)
+ continue;
+ if (memcmp(&local->srx.transport.sin.sin_addr,
+ &srx->transport.sin.sin_addr,
+ sizeof(struct in_addr)) != 0)
+ continue;
+ goto found_local;
+
+ default:
+ BUG();
+ }
+ }
+
+ read_unlock_bh(&rxrpc_local_lock);
+
+ /* we didn't find one, so we need to create one */
+ local = rxrpc_alloc_local(srx);
+ if (!local) {
+ up_write(&rxrpc_local_sem);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ ret = rxrpc_create_local(local);
+ if (ret < 0) {
+ up_write(&rxrpc_local_sem);
+ kfree(local);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+ }
+
+ up_write(&rxrpc_local_sem);
+
+ _net("LOCAL new %d {%d,%u,%u.%u.%u.%u+%hu}",
+ local->debug_id,
+ local->srx.transport_type,
+ local->srx.transport.family,
+ NIPQUAD(local->srx.transport.sin.sin_addr),
+ ntohs(local->srx.transport.sin.sin_port));
+
+ _leave(" = %p [new]", local);
+ return local;
+
+found_local:
+ rxrpc_get_local(local);
+ read_unlock_bh(&rxrpc_local_lock);
+ up_write(&rxrpc_local_sem);
+
+ _net("LOCAL old %d {%d,%u,%u.%u.%u.%u+%hu}",
+ local->debug_id,
+ local->srx.transport_type,
+ local->srx.transport.family,
+ NIPQUAD(local->srx.transport.sin.sin_addr),
+ ntohs(local->srx.transport.sin.sin_port));
+
+ _leave(" = %p [reuse]", local);
+ return local;
+}
+
+/*
+ * release a local endpoint
+ */
+void rxrpc_put_local(struct rxrpc_local *local)
+{
+ _enter("%p{u=%d}", local, atomic_read(&local->usage));
+
+ ASSERTCMP(atomic_read(&local->usage), >, 0);
+
+ /* to prevent a race, the decrement and the dequeue must be effectively
+ * atomic */
+ write_lock_bh(&rxrpc_local_lock);
+ if (unlikely(atomic_dec_and_test(&local->usage))) {
+ _debug("destroy local");
+ schedule_work(&local->destroyer);
+ }
+ write_unlock_bh(&rxrpc_local_lock);
+ _leave("");
+}
+
+/*
+ * destroy a local endpoint
+ */
+static void rxrpc_destroy_local(struct work_struct *work)
+{
+ struct rxrpc_local *local =
+ container_of(work, struct rxrpc_local, destroyer);
+
+ _enter("%p{%d}", local, atomic_read(&local->usage));
+
+ down_write(&rxrpc_local_sem);
+
+ write_lock_bh(&rxrpc_local_lock);
+ if (atomic_read(&local->usage) > 0) {
+ write_unlock_bh(&rxrpc_local_lock);
+ up_read(&rxrpc_local_sem);
+ _leave(" [resurrected]");
+ return;
+ }
+
+ list_del(&local->link);
+ local->socket->sk->sk_user_data = NULL;
+ write_unlock_bh(&rxrpc_local_lock);
+
+ downgrade_write(&rxrpc_local_sem);
+
+ ASSERT(list_empty(&local->services));
+ ASSERT(!work_pending(&local->acceptor));
+ ASSERT(!work_pending(&local->rejecter));
+
+ /* finish cleaning up the local descriptor */
+ rxrpc_purge_queue(&local->accept_queue);
+ rxrpc_purge_queue(&local->reject_queue);
+ local->socket->ops->shutdown(local->socket, 2);
+ sock_release(local->socket);
+
+ up_read(&rxrpc_local_sem);
+
+ _net("DESTROY LOCAL %d", local->debug_id);
+ kfree(local);
+
+ if (list_empty(&rxrpc_locals))
+ wake_up_all(&rxrpc_local_wq);
+
+ _leave("");
+}
+
+/*
+ * preemptively destroy all local local endpoint rather than waiting for
+ * them to be destroyed
+ */
+void __exit rxrpc_destroy_all_locals(void)
+{
+ DECLARE_WAITQUEUE(myself,current);
+
+ _enter("");
+
+ /* we simply have to wait for them to go away */
+ if (!list_empty(&rxrpc_locals)) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ add_wait_queue(&rxrpc_local_wq, &myself);
+
+ while (!list_empty(&rxrpc_locals)) {
+ schedule();
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ }
+
+ remove_wait_queue(&rxrpc_local_wq, &myself);
+ set_current_state(TASK_RUNNING);
+ }
+
+ _leave("");
+}

Privacy Policy