1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Local endpoint object management
4 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/module.h>
11 #include <linux/net.h>
12 #include <linux/skbuff.h>
13 #include <linux/slab.h>
14 #include <linux/udp.h>
16 #include <linux/hashtable.h>
19 #include <net/udp_tunnel.h>
20 #include <net/af_rxrpc.h>
21 #include "ar-internal.h"
23 static void rxrpc_local_rcu(struct rcu_head *);
26 * Handle an ICMP/ICMP6 error turning up at the tunnel. Push it through the
27 * usual mechanism so that it gets parsed and presented through the UDP
28 * socket's error_report().
30 static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err,
31 __be16 port, u32 info, u8 *payload)
33 if (ip_hdr(skb)->version == IPVERSION)
34 return ip_icmp_error(sk, skb, err, port, info, payload);
35 if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6))
36 return ipv6_icmp_error(sk, skb, err, port, info, payload);
40 * Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
41 * same or greater than.
43 * We explicitly don't compare the RxRPC service ID as we want to reject
44 * conflicting uses by differing services. Further, we don't want to share
45 * addresses with different options (IPv6), so we don't compare those bits
48 static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
49 const struct sockaddr_rxrpc *srx)
53 diff = ((local->srx.transport_type - srx->transport_type) ?:
54 (local->srx.transport_len - srx->transport_len) ?:
55 (local->srx.transport.family - srx->transport.family));
59 switch (srx->transport.family) {
61 /* If the choice of UDP port is left up to the transport, then
62 * the endpoint record doesn't match.
64 return ((u16 __force)local->srx.transport.sin.sin_port -
65 (u16 __force)srx->transport.sin.sin_port) ?:
66 memcmp(&local->srx.transport.sin.sin_addr,
67 &srx->transport.sin.sin_addr,
68 sizeof(struct in_addr));
69 #ifdef CONFIG_AF_RXRPC_IPV6
71 /* If the choice of UDP6 port is left up to the transport, then
72 * the endpoint record doesn't match.
74 return ((u16 __force)local->srx.transport.sin6.sin6_port -
75 (u16 __force)srx->transport.sin6.sin6_port) ?:
76 memcmp(&local->srx.transport.sin6.sin6_addr,
77 &srx->transport.sin6.sin6_addr,
78 sizeof(struct in6_addr));
86 * Allocate a new local endpoint.
88 static struct rxrpc_local *rxrpc_alloc_local(struct net *net,
89 const struct sockaddr_rxrpc *srx)
91 struct rxrpc_local *local;
94 local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
96 refcount_set(&local->ref, 1);
97 atomic_set(&local->active_users, 1);
99 local->rxnet = rxrpc_net(net);
100 INIT_HLIST_NODE(&local->link);
101 init_rwsem(&local->defrag_sem);
102 init_completion(&local->io_thread_ready);
103 skb_queue_head_init(&local->rx_queue);
104 INIT_LIST_HEAD(&local->conn_attend_q);
105 INIT_LIST_HEAD(&local->call_attend_q);
106 local->client_bundles = RB_ROOT;
107 spin_lock_init(&local->client_bundles_lock);
108 spin_lock_init(&local->lock);
109 rwlock_init(&local->services_lock);
110 local->debug_id = atomic_inc_return(&rxrpc_debug_id);
111 memcpy(&local->srx, srx, sizeof(*srx));
112 local->srx.srx_service = 0;
113 idr_init(&local->conn_ids);
114 get_random_bytes(&tmp, sizeof(tmp));
118 idr_set_cursor(&local->conn_ids, tmp);
119 spin_lock_init(&local->conn_lock);
121 trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1);
124 _leave(" = %p", local);
129 * create the local socket
130 * - must be called with rxrpc_local_mutex locked
132 static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
134 struct udp_tunnel_sock_cfg tuncfg = {NULL};
135 struct sockaddr_rxrpc *srx = &local->srx;
136 struct udp_port_cfg udp_conf = {0};
137 struct task_struct *io_thread;
142 local, srx->transport_type, srx->transport.family);
144 udp_conf.family = srx->transport.family;
145 udp_conf.use_udp_checksums = true;
146 if (udp_conf.family == AF_INET) {
147 udp_conf.local_ip = srx->transport.sin.sin_addr;
148 udp_conf.local_udp_port = srx->transport.sin.sin_port;
149 #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
151 udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
152 udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
153 udp_conf.use_udp6_tx_checksums = true;
154 udp_conf.use_udp6_rx_checksums = true;
157 ret = udp_sock_create(net, &udp_conf, &local->socket);
159 _leave(" = %d [socket]", ret);
163 tuncfg.encap_type = UDP_ENCAP_RXRPC;
164 tuncfg.encap_rcv = rxrpc_encap_rcv;
165 tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
166 tuncfg.sk_user_data = local;
167 setup_udp_tunnel_sock(net, local->socket, &tuncfg);
169 /* set the socket up */
170 usk = local->socket->sk;
171 usk->sk_error_report = rxrpc_error_report;
173 switch (srx->transport.family) {
175 /* we want to receive ICMPv6 errors */
176 ip6_sock_set_recverr(usk);
178 /* Fall through and set IPv4 options too otherwise we don't get
179 * errors from IPv4 packets sent through the IPv6 socket.
183 /* we want to receive ICMP errors */
184 ip_sock_set_recverr(usk);
186 /* we want to set the don't fragment bit */
187 ip_sock_set_mtu_discover(usk, IP_PMTUDISC_DO);
189 /* We want receive timestamps. */
190 sock_enable_timestamps(usk);
197 io_thread = kthread_run(rxrpc_io_thread, local,
198 "krxrpcio/%u", ntohs(udp_conf.local_udp_port));
199 if (IS_ERR(io_thread)) {
200 ret = PTR_ERR(io_thread);
204 wait_for_completion(&local->io_thread_ready);
205 local->io_thread = io_thread;
210 kernel_sock_shutdown(local->socket, SHUT_RDWR);
211 local->socket->sk->sk_user_data = NULL;
212 sock_release(local->socket);
213 local->socket = NULL;
218 * Look up or create a new local endpoint using the specified local address.
220 struct rxrpc_local *rxrpc_lookup_local(struct net *net,
221 const struct sockaddr_rxrpc *srx)
223 struct rxrpc_local *local;
224 struct rxrpc_net *rxnet = rxrpc_net(net);
225 struct hlist_node *cursor;
229 _enter("{%d,%d,%pISp}",
230 srx->transport_type, srx->transport.family, &srx->transport);
232 mutex_lock(&rxnet->local_mutex);
234 hlist_for_each(cursor, &rxnet->local_endpoints) {
235 local = hlist_entry(cursor, struct rxrpc_local, link);
237 diff = rxrpc_local_cmp_key(local, srx);
241 /* Services aren't allowed to share transport sockets, so
242 * reject that here. It is possible that the object is dying -
243 * but it may also still have the local transport address that
246 if (srx->srx_service) {
251 /* Found a match. We want to replace a dying object.
252 * Attempting to bind the transport socket may still fail if
253 * we're attempting to use a local address that the dying
254 * object is still using.
256 if (!rxrpc_use_local(local, rxrpc_local_use_lookup))
262 local = rxrpc_alloc_local(net, srx);
266 ret = rxrpc_open_socket(local, net);
271 hlist_replace_rcu(cursor, &local->link);
272 cursor->pprev = NULL;
274 hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
278 mutex_unlock(&rxnet->local_mutex);
279 _leave(" = %p", local);
285 mutex_unlock(&rxnet->local_mutex);
287 call_rcu(&local->rcu, rxrpc_local_rcu);
288 _leave(" = %d", ret);
292 mutex_unlock(&rxnet->local_mutex);
293 _leave(" = -EADDRINUSE");
294 return ERR_PTR(-EADDRINUSE);
298 * Get a ref on a local endpoint.
300 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local,
301 enum rxrpc_local_trace why)
305 u = atomic_read(&local->active_users);
306 __refcount_inc(&local->ref, &r);
307 trace_rxrpc_local(local->debug_id, why, r + 1, u);
312 * Get a ref on a local endpoint unless its usage has already reached 0.
314 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local,
315 enum rxrpc_local_trace why)
319 if (local && __refcount_inc_not_zero(&local->ref, &r)) {
320 u = atomic_read(&local->active_users);
321 trace_rxrpc_local(local->debug_id, why, r + 1, u);
329 * Drop a ref on a local endpoint.
331 void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
333 unsigned int debug_id;
338 debug_id = local->debug_id;
340 u = atomic_read(&local->active_users);
341 dead = __refcount_dec_and_test(&local->ref, &r);
342 trace_rxrpc_local(debug_id, why, r, u);
345 call_rcu(&local->rcu, rxrpc_local_rcu);
350 * Start using a local endpoint.
352 struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local,
353 enum rxrpc_local_trace why)
355 local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use);
359 if (!__rxrpc_use_local(local, why)) {
360 rxrpc_put_local(local, rxrpc_local_put_for_use);
368 * Cease using a local endpoint. Once the number of active users reaches 0, we
369 * start the closure of the transport in the I/O thread..
371 void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
373 unsigned int debug_id;
377 debug_id = local->debug_id;
378 r = refcount_read(&local->ref);
379 u = atomic_dec_return(&local->active_users);
380 trace_rxrpc_local(debug_id, why, r, u);
382 kthread_stop(local->io_thread);
387 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
390 * Closing the socket cannot be done from bottom half context or RCU callback
391 * context because it might sleep.
393 void rxrpc_destroy_local(struct rxrpc_local *local)
395 struct socket *socket = local->socket;
396 struct rxrpc_net *rxnet = local->rxnet;
398 _enter("%d", local->debug_id);
402 mutex_lock(&rxnet->local_mutex);
403 hlist_del_init_rcu(&local->link);
404 mutex_unlock(&rxnet->local_mutex);
406 rxrpc_clean_up_local_conns(local);
407 rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
408 ASSERT(!local->service);
411 local->socket = NULL;
412 kernel_sock_shutdown(socket, SHUT_RDWR);
413 socket->sk->sk_user_data = NULL;
414 sock_release(socket);
417 /* At this point, there should be no more packets coming in to the
420 rxrpc_purge_queue(&local->rx_queue);
421 rxrpc_destroy_client_conn_ids(local);
425 * Destroy a local endpoint after the RCU grace period expires.
427 static void rxrpc_local_rcu(struct rcu_head *rcu)
429 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
431 rxrpc_see_local(local, rxrpc_local_free);
436 * Verify the local endpoint list is empty by this point.
438 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
440 struct rxrpc_local *local;
444 flush_workqueue(rxrpc_workqueue);
446 if (!hlist_empty(&rxnet->local_endpoints)) {
447 mutex_lock(&rxnet->local_mutex);
448 hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
449 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
450 local, refcount_read(&local->ref));
452 mutex_unlock(&rxnet->local_mutex);