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- // 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 ([email protected])
- */
- #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/udp_tunnel.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 udp_tunnel_sock_cfg tuncfg = {NULL};
- struct sockaddr_rxrpc *srx = &local->srx;
- struct udp_port_cfg udp_conf = {0};
- struct sock *usk;
- int ret;
- _enter("%p{%d,%d}",
- local, srx->transport_type, srx->transport.family);
- udp_conf.family = srx->transport.family;
- udp_conf.use_udp_checksums = true;
- if (udp_conf.family == AF_INET) {
- udp_conf.local_ip = srx->transport.sin.sin_addr;
- udp_conf.local_udp_port = srx->transport.sin.sin_port;
- #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
- } else {
- udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
- udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
- udp_conf.use_udp6_tx_checksums = true;
- udp_conf.use_udp6_rx_checksums = true;
- #endif
- }
- ret = udp_sock_create(net, &udp_conf, &local->socket);
- if (ret < 0) {
- _leave(" = %d [socket]", ret);
- return ret;
- }
- tuncfg.encap_type = UDP_ENCAP_RXRPC;
- tuncfg.encap_rcv = rxrpc_input_packet;
- tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
- tuncfg.sk_user_data = local;
- setup_udp_tunnel_sock(net, local->socket, &tuncfg);
- /* set the socket up */
- usk = local->socket->sk;
- usk->sk_error_report = rxrpc_error_report;
- switch (srx->transport.family) {
- case AF_INET6:
- /* we want to receive ICMPv6 errors */
- ip6_sock_set_recverr(usk);
- /* 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(usk);
- /* we want to set the don't fragment bit */
- ip_sock_set_mtu_discover(usk, IP_PMTUDISC_DO);
- /* We want receive timestamps. */
- sock_enable_timestamps(usk);
- break;
- default:
- BUG();
- }
- _leave(" = 0");
- return 0;
- }
- /*
- * 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();
- }
- }
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