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-rw-r--r--net/rxrpc/local_object.c492
1 files changed, 492 insertions, 0 deletions
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
new file mode 100644
index 000000000..2c66ee981
--- /dev/null
+++ b/net/rxrpc/local_object.c
@@ -0,0 +1,492 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Local endpoint object management
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/udp.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+static void rxrpc_local_processor(struct work_struct *);
+static void rxrpc_local_rcu(struct rcu_head *);
+
+/*
+ * Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
+ * same or greater than.
+ *
+ * We explicitly don't compare the RxRPC service ID as we want to reject
+ * conflicting uses by differing services. Further, we don't want to share
+ * addresses with different options (IPv6), so we don't compare those bits
+ * either.
+ */
+static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
+ const struct sockaddr_rxrpc *srx)
+{
+ long diff;
+
+ diff = ((local->srx.transport_type - srx->transport_type) ?:
+ (local->srx.transport_len - srx->transport_len) ?:
+ (local->srx.transport.family - srx->transport.family));
+ if (diff != 0)
+ return diff;
+
+ switch (srx->transport.family) {
+ case AF_INET:
+ /* If the choice of UDP port is left up to the transport, then
+ * the endpoint record doesn't match.
+ */
+ return ((u16 __force)local->srx.transport.sin.sin_port -
+ (u16 __force)srx->transport.sin.sin_port) ?:
+ memcmp(&local->srx.transport.sin.sin_addr,
+ &srx->transport.sin.sin_addr,
+ sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ /* If the choice of UDP6 port is left up to the transport, then
+ * the endpoint record doesn't match.
+ */
+ return ((u16 __force)local->srx.transport.sin6.sin6_port -
+ (u16 __force)srx->transport.sin6.sin6_port) ?:
+ memcmp(&local->srx.transport.sin6.sin6_addr,
+ &srx->transport.sin6.sin6_addr,
+ sizeof(struct in6_addr));
+#endif
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Allocate a new local endpoint.
+ */
+static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
+ const struct sockaddr_rxrpc *srx)
+{
+ struct rxrpc_local *local;
+
+ local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
+ if (local) {
+ refcount_set(&local->ref, 1);
+ atomic_set(&local->active_users, 1);
+ local->rxnet = rxnet;
+ INIT_HLIST_NODE(&local->link);
+ INIT_WORK(&local->processor, rxrpc_local_processor);
+ init_rwsem(&local->defrag_sem);
+ skb_queue_head_init(&local->reject_queue);
+ skb_queue_head_init(&local->event_queue);
+ local->client_bundles = RB_ROOT;
+ spin_lock_init(&local->client_bundles_lock);
+ spin_lock_init(&local->lock);
+ rwlock_init(&local->services_lock);
+ local->debug_id = atomic_inc_return(&rxrpc_debug_id);
+ memcpy(&local->srx, srx, sizeof(*srx));
+ local->srx.srx_service = 0;
+ trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, NULL);
+ }
+
+ _leave(" = %p", local);
+ return local;
+}
+
+/*
+ * create the local socket
+ * - must be called with rxrpc_local_mutex locked
+ */
+static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
+{
+ struct sock *usk;
+ int ret;
+
+ _enter("%p{%d,%d}",
+ local, local->srx.transport_type, local->srx.transport.family);
+
+ /* create a socket to represent the local endpoint */
+ ret = sock_create_kern(net, local->srx.transport.family,
+ local->srx.transport_type, 0, &local->socket);
+ if (ret < 0) {
+ _leave(" = %d [socket]", ret);
+ return ret;
+ }
+
+ /* set the socket up */
+ usk = local->socket->sk;
+ inet_sk(usk)->mc_loop = 0;
+
+ /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
+ inet_inc_convert_csum(usk);
+
+ rcu_assign_sk_user_data(usk, local);
+
+ udp_sk(usk)->encap_type = UDP_ENCAP_RXRPC;
+ udp_sk(usk)->encap_rcv = rxrpc_input_packet;
+ udp_sk(usk)->encap_destroy = NULL;
+ udp_sk(usk)->gro_receive = NULL;
+ udp_sk(usk)->gro_complete = NULL;
+
+ udp_encap_enable();
+#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
+ if (local->srx.transport.family == AF_INET6)
+ udpv6_encap_enable();
+#endif
+ usk->sk_error_report = rxrpc_error_report;
+
+ /* 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 %d", ret);
+ goto error;
+ }
+ }
+
+ switch (local->srx.transport.family) {
+ case AF_INET6:
+ /* we want to receive ICMPv6 errors */
+ ip6_sock_set_recverr(local->socket->sk);
+
+ /* Fall through and set IPv4 options too otherwise we don't get
+ * errors from IPv4 packets sent through the IPv6 socket.
+ */
+ fallthrough;
+ case AF_INET:
+ /* we want to receive ICMP errors */
+ ip_sock_set_recverr(local->socket->sk);
+
+ /* we want to set the don't fragment bit */
+ ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
+
+ /* We want receive timestamps. */
+ sock_enable_timestamps(local->socket->sk);
+ break;
+
+ default:
+ BUG();
+ }
+
+ _leave(" = 0");
+ return 0;
+
+error:
+ kernel_sock_shutdown(local->socket, SHUT_RDWR);
+ local->socket->sk->sk_user_data = NULL;
+ sock_release(local->socket);
+ local->socket = NULL;
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Look up or create a new local endpoint using the specified local address.
+ */
+struct rxrpc_local *rxrpc_lookup_local(struct net *net,
+ const struct sockaddr_rxrpc *srx)
+{
+ struct rxrpc_local *local;
+ struct rxrpc_net *rxnet = rxrpc_net(net);
+ struct hlist_node *cursor;
+ const char *age;
+ long diff;
+ int ret;
+
+ _enter("{%d,%d,%pISp}",
+ srx->transport_type, srx->transport.family, &srx->transport);
+
+ mutex_lock(&rxnet->local_mutex);
+
+ hlist_for_each(cursor, &rxnet->local_endpoints) {
+ local = hlist_entry(cursor, struct rxrpc_local, link);
+
+ diff = rxrpc_local_cmp_key(local, srx);
+ if (diff != 0)
+ continue;
+
+ /* Services aren't allowed to share transport sockets, so
+ * reject that here. It is possible that the object is dying -
+ * but it may also still have the local transport address that
+ * we want bound.
+ */
+ if (srx->srx_service) {
+ local = NULL;
+ goto addr_in_use;
+ }
+
+ /* Found a match. We want to replace a dying object.
+ * Attempting to bind the transport socket may still fail if
+ * we're attempting to use a local address that the dying
+ * object is still using.
+ */
+ if (!rxrpc_use_local(local))
+ break;
+
+ age = "old";
+ goto found;
+ }
+
+ local = rxrpc_alloc_local(rxnet, srx);
+ if (!local)
+ goto nomem;
+
+ ret = rxrpc_open_socket(local, net);
+ if (ret < 0)
+ goto sock_error;
+
+ if (cursor) {
+ hlist_replace_rcu(cursor, &local->link);
+ cursor->pprev = NULL;
+ } else {
+ hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
+ }
+ age = "new";
+
+found:
+ mutex_unlock(&rxnet->local_mutex);
+
+ _net("LOCAL %s %d {%pISp}",
+ age, local->debug_id, &local->srx.transport);
+
+ _leave(" = %p", local);
+ return local;
+
+nomem:
+ ret = -ENOMEM;
+sock_error:
+ mutex_unlock(&rxnet->local_mutex);
+ if (local)
+ call_rcu(&local->rcu, rxrpc_local_rcu);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+
+addr_in_use:
+ mutex_unlock(&rxnet->local_mutex);
+ _leave(" = -EADDRINUSE");
+ return ERR_PTR(-EADDRINUSE);
+}
+
+/*
+ * Get a ref on a local endpoint.
+ */
+struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
+{
+ const void *here = __builtin_return_address(0);
+ int r;
+
+ __refcount_inc(&local->ref, &r);
+ trace_rxrpc_local(local->debug_id, rxrpc_local_got, r + 1, here);
+ return local;
+}
+
+/*
+ * Get a ref on a local endpoint unless its usage has already reached 0.
+ */
+struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
+{
+ const void *here = __builtin_return_address(0);
+ int r;
+
+ if (local) {
+ if (__refcount_inc_not_zero(&local->ref, &r))
+ trace_rxrpc_local(local->debug_id, rxrpc_local_got,
+ r + 1, here);
+ else
+ local = NULL;
+ }
+ return local;
+}
+
+/*
+ * Queue a local endpoint and pass the caller's reference to the work item.
+ */
+void rxrpc_queue_local(struct rxrpc_local *local)
+{
+ const void *here = __builtin_return_address(0);
+ unsigned int debug_id = local->debug_id;
+ int r = refcount_read(&local->ref);
+
+ if (rxrpc_queue_work(&local->processor))
+ trace_rxrpc_local(debug_id, rxrpc_local_queued, r + 1, here);
+ else
+ rxrpc_put_local(local);
+}
+
+/*
+ * Drop a ref on a local endpoint.
+ */
+void rxrpc_put_local(struct rxrpc_local *local)
+{
+ const void *here = __builtin_return_address(0);
+ unsigned int debug_id;
+ bool dead;
+ int r;
+
+ if (local) {
+ debug_id = local->debug_id;
+
+ dead = __refcount_dec_and_test(&local->ref, &r);
+ trace_rxrpc_local(debug_id, rxrpc_local_put, r, here);
+
+ if (dead)
+ call_rcu(&local->rcu, rxrpc_local_rcu);
+ }
+}
+
+/*
+ * Start using a local endpoint.
+ */
+struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local)
+{
+ local = rxrpc_get_local_maybe(local);
+ if (!local)
+ return NULL;
+
+ if (!__rxrpc_use_local(local)) {
+ rxrpc_put_local(local);
+ return NULL;
+ }
+
+ return local;
+}
+
+/*
+ * Cease using a local endpoint. Once the number of active users reaches 0, we
+ * start the closure of the transport in the work processor.
+ */
+void rxrpc_unuse_local(struct rxrpc_local *local)
+{
+ if (local) {
+ if (__rxrpc_unuse_local(local)) {
+ rxrpc_get_local(local);
+ rxrpc_queue_local(local);
+ }
+ }
+}
+
+/*
+ * Destroy a local endpoint's socket and then hand the record to RCU to dispose
+ * of.
+ *
+ * Closing the socket cannot be done from bottom half context or RCU callback
+ * context because it might sleep.
+ */
+static void rxrpc_local_destroyer(struct rxrpc_local *local)
+{
+ struct socket *socket = local->socket;
+ struct rxrpc_net *rxnet = local->rxnet;
+
+ _enter("%d", local->debug_id);
+
+ local->dead = true;
+
+ mutex_lock(&rxnet->local_mutex);
+ hlist_del_init_rcu(&local->link);
+ mutex_unlock(&rxnet->local_mutex);
+
+ rxrpc_clean_up_local_conns(local);
+ rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
+ ASSERT(!local->service);
+
+ if (socket) {
+ local->socket = NULL;
+ kernel_sock_shutdown(socket, SHUT_RDWR);
+ socket->sk->sk_user_data = NULL;
+ sock_release(socket);
+ }
+
+ /* At this point, there should be no more packets coming in to the
+ * local endpoint.
+ */
+ rxrpc_purge_queue(&local->reject_queue);
+ rxrpc_purge_queue(&local->event_queue);
+}
+
+/*
+ * Process events on an endpoint. The work item carries a ref which
+ * we must release.
+ */
+static void rxrpc_local_processor(struct work_struct *work)
+{
+ struct rxrpc_local *local =
+ container_of(work, struct rxrpc_local, processor);
+ bool again;
+
+ if (local->dead)
+ return;
+
+ trace_rxrpc_local(local->debug_id, rxrpc_local_processing,
+ refcount_read(&local->ref), NULL);
+
+ do {
+ again = false;
+ if (!__rxrpc_use_local(local)) {
+ rxrpc_local_destroyer(local);
+ break;
+ }
+
+ if (!skb_queue_empty(&local->reject_queue)) {
+ rxrpc_reject_packets(local);
+ again = true;
+ }
+
+ if (!skb_queue_empty(&local->event_queue)) {
+ rxrpc_process_local_events(local);
+ again = true;
+ }
+
+ __rxrpc_unuse_local(local);
+ } while (again);
+
+ rxrpc_put_local(local);
+}
+
+/*
+ * Destroy a local endpoint after the RCU grace period expires.
+ */
+static void rxrpc_local_rcu(struct rcu_head *rcu)
+{
+ struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
+
+ _enter("%d", local->debug_id);
+
+ ASSERT(!work_pending(&local->processor));
+
+ _net("DESTROY LOCAL %d", local->debug_id);
+ kfree(local);
+ _leave("");
+}
+
+/*
+ * Verify the local endpoint list is empty by this point.
+ */
+void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
+{
+ struct rxrpc_local *local;
+
+ _enter("");
+
+ flush_workqueue(rxrpc_workqueue);
+
+ if (!hlist_empty(&rxnet->local_endpoints)) {
+ mutex_lock(&rxnet->local_mutex);
+ hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
+ pr_err("AF_RXRPC: Leaked local %p {%d}\n",
+ local, refcount_read(&local->ref));
+ }
+ mutex_unlock(&rxnet->local_mutex);
+ BUG();
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 03:24:36 +0000