1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC remote transport endpoint record management
4 * Copyright (C) 2007, 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/udp.h>
15 #include <linux/in6.h>
16 #include <linux/slab.h>
17 #include <linux/hashtable.h>
19 #include <net/af_rxrpc.h>
21 #include <net/route.h>
22 #include <net/ip6_route.h>
23 #include "ar-internal.h"
28 static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
29 const struct sockaddr_rxrpc *srx)
33 unsigned long hash_key;
37 hash_key = (unsigned long)local / __alignof__(*local);
38 hash_key += srx->transport_type;
39 hash_key += srx->transport_len;
40 hash_key += srx->transport.family;
42 switch (srx->transport.family) {
44 hash_key += (u16 __force)srx->transport.sin.sin_port;
45 size = sizeof(srx->transport.sin.sin_addr);
46 p = (u16 *)&srx->transport.sin.sin_addr;
48 #ifdef CONFIG_AF_RXRPC_IPV6
50 hash_key += (u16 __force)srx->transport.sin.sin_port;
51 size = sizeof(srx->transport.sin6.sin6_addr);
52 p = (u16 *)&srx->transport.sin6.sin6_addr;
56 WARN(1, "AF_RXRPC: Unsupported transport address family\n");
60 /* Step through the peer address in 16-bit portions for speed */
61 for (i = 0; i < size; i += sizeof(*p), p++)
64 _leave(" 0x%lx", hash_key);
69 * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
72 * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
73 * buckets and mid-bucket insertion, so we don't make full use of this
74 * information at this point.
76 static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
77 struct rxrpc_local *local,
78 const struct sockaddr_rxrpc *srx,
79 unsigned long hash_key)
83 diff = ((peer->hash_key - hash_key) ?:
84 ((unsigned long)peer->local - (unsigned long)local) ?:
85 (peer->srx.transport_type - srx->transport_type) ?:
86 (peer->srx.transport_len - srx->transport_len) ?:
87 (peer->srx.transport.family - srx->transport.family));
91 switch (srx->transport.family) {
93 return ((u16 __force)peer->srx.transport.sin.sin_port -
94 (u16 __force)srx->transport.sin.sin_port) ?:
95 memcmp(&peer->srx.transport.sin.sin_addr,
96 &srx->transport.sin.sin_addr,
97 sizeof(struct in_addr));
98 #ifdef CONFIG_AF_RXRPC_IPV6
100 return ((u16 __force)peer->srx.transport.sin6.sin6_port -
101 (u16 __force)srx->transport.sin6.sin6_port) ?:
102 memcmp(&peer->srx.transport.sin6.sin6_addr,
103 &srx->transport.sin6.sin6_addr,
104 sizeof(struct in6_addr));
112 * Look up a remote transport endpoint for the specified address using RCU.
114 static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
115 struct rxrpc_local *local,
116 const struct sockaddr_rxrpc *srx,
117 unsigned long hash_key)
119 struct rxrpc_peer *peer;
120 struct rxrpc_net *rxnet = local->rxnet;
122 hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
123 if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
124 refcount_read(&peer->ref) > 0)
132 * Look up a remote transport endpoint for the specified address using RCU.
134 struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
135 const struct sockaddr_rxrpc *srx)
137 struct rxrpc_peer *peer;
138 unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
140 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
142 _leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
147 * assess the MTU size for the network interface through which this peer is
150 static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
151 struct rxrpc_peer *peer)
153 struct net *net = sock_net(&rx->sk);
154 struct dst_entry *dst;
157 struct flowi4 *fl4 = &fl.u.ip4;
158 #ifdef CONFIG_AF_RXRPC_IPV6
159 struct flowi6 *fl6 = &fl.u.ip6;
164 memset(&fl, 0, sizeof(fl));
165 switch (peer->srx.transport.family) {
167 rt = ip_route_output_ports(
169 peer->srx.transport.sin.sin_addr.s_addr, 0,
170 htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
172 _leave(" [route err %ld]", PTR_ERR(rt));
178 #ifdef CONFIG_AF_RXRPC_IPV6
180 fl6->flowi6_iif = LOOPBACK_IFINDEX;
181 fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
182 fl6->flowi6_proto = IPPROTO_UDP;
183 memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
184 sizeof(struct in6_addr));
185 fl6->fl6_dport = htons(7001);
186 fl6->fl6_sport = htons(7000);
187 dst = ip6_route_output(net, NULL, fl6);
189 _leave(" [route err %d]", dst->error);
199 peer->if_mtu = dst_mtu(dst);
202 _leave(" [if_mtu %u]", peer->if_mtu);
208 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp,
209 enum rxrpc_peer_trace why)
211 struct rxrpc_peer *peer;
215 peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
217 refcount_set(&peer->ref, 1);
218 peer->local = rxrpc_get_local(local, rxrpc_local_get_peer);
219 INIT_HLIST_HEAD(&peer->error_targets);
220 peer->service_conns = RB_ROOT;
221 seqlock_init(&peer->service_conn_lock);
222 spin_lock_init(&peer->lock);
223 spin_lock_init(&peer->rtt_input_lock);
224 peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
226 rxrpc_peer_init_rtt(peer);
228 peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
229 trace_rxrpc_peer(peer->debug_id, 1, why);
232 _leave(" = %p", peer);
237 * Initialise peer record.
239 static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer,
240 unsigned long hash_key)
242 peer->hash_key = hash_key;
243 rxrpc_assess_MTU_size(rx, peer);
244 peer->mtu = peer->if_mtu;
245 peer->rtt_last_req = ktime_get_real();
247 switch (peer->srx.transport.family) {
249 peer->hdrsize = sizeof(struct iphdr);
251 #ifdef CONFIG_AF_RXRPC_IPV6
253 peer->hdrsize = sizeof(struct ipv6hdr);
260 switch (peer->srx.transport_type) {
262 peer->hdrsize += sizeof(struct udphdr);
268 peer->hdrsize += sizeof(struct rxrpc_wire_header);
269 peer->maxdata = peer->mtu - peer->hdrsize;
275 static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx,
276 struct rxrpc_local *local,
277 struct sockaddr_rxrpc *srx,
278 unsigned long hash_key,
281 struct rxrpc_peer *peer;
285 peer = rxrpc_alloc_peer(local, gfp, rxrpc_peer_new_client);
287 memcpy(&peer->srx, srx, sizeof(*srx));
288 rxrpc_init_peer(rx, peer, hash_key);
291 _leave(" = %p", peer);
295 static void rxrpc_free_peer(struct rxrpc_peer *peer)
297 trace_rxrpc_peer(peer->debug_id, 0, rxrpc_peer_free);
298 rxrpc_put_local(peer->local, rxrpc_local_put_peer);
299 kfree_rcu(peer, rcu);
303 * Set up a new incoming peer. There shouldn't be any other matching peers
304 * since we've already done a search in the list from the non-reentrant context
305 * (the data_ready handler) that is the only place we can add new peers.
307 void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local,
308 struct rxrpc_peer *peer)
310 struct rxrpc_net *rxnet = local->rxnet;
311 unsigned long hash_key;
313 hash_key = rxrpc_peer_hash_key(local, &peer->srx);
314 rxrpc_init_peer(rx, peer, hash_key);
316 spin_lock(&rxnet->peer_hash_lock);
317 hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
318 list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
319 spin_unlock(&rxnet->peer_hash_lock);
323 * obtain a remote transport endpoint for the specified address
325 struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx,
326 struct rxrpc_local *local,
327 struct sockaddr_rxrpc *srx, gfp_t gfp)
329 struct rxrpc_peer *peer, *candidate;
330 struct rxrpc_net *rxnet = local->rxnet;
331 unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
333 _enter("{%pISp}", &srx->transport);
335 /* search the peer list first */
337 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
338 if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
343 /* The peer is not yet present in hash - create a candidate
344 * for a new record and then redo the search.
346 candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp);
348 _leave(" = NULL [nomem]");
352 spin_lock(&rxnet->peer_hash_lock);
354 /* Need to check that we aren't racing with someone else */
355 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
356 if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
359 hash_add_rcu(rxnet->peer_hash,
360 &candidate->hash_link, hash_key);
361 list_add_tail(&candidate->keepalive_link,
362 &rxnet->peer_keepalive_new);
365 spin_unlock(&rxnet->peer_hash_lock);
368 rxrpc_free_peer(candidate);
373 _leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
378 * Get a ref on a peer record.
380 struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
384 __refcount_inc(&peer->ref, &r);
385 trace_rxrpc_peer(peer->debug_id, r + 1, why);
390 * Get a ref on a peer record unless its usage has already reached 0.
392 struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer,
393 enum rxrpc_peer_trace why)
398 if (__refcount_inc_not_zero(&peer->ref, &r))
399 trace_rxrpc_peer(peer->debug_id, r + 1, why);
407 * Discard a peer record.
409 static void __rxrpc_put_peer(struct rxrpc_peer *peer)
411 struct rxrpc_net *rxnet = peer->local->rxnet;
413 ASSERT(hlist_empty(&peer->error_targets));
415 spin_lock(&rxnet->peer_hash_lock);
416 hash_del_rcu(&peer->hash_link);
417 list_del_init(&peer->keepalive_link);
418 spin_unlock(&rxnet->peer_hash_lock);
420 rxrpc_free_peer(peer);
424 * Drop a ref on a peer record.
426 void rxrpc_put_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
428 unsigned int debug_id;
433 debug_id = peer->debug_id;
434 dead = __refcount_dec_and_test(&peer->ref, &r);
435 trace_rxrpc_peer(debug_id, r - 1, why);
437 __rxrpc_put_peer(peer);
442 * Make sure all peer records have been discarded.
444 void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
446 struct rxrpc_peer *peer;
449 for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
450 if (hlist_empty(&rxnet->peer_hash[i]))
453 hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
454 pr_err("Leaked peer %u {%u} %pISp\n",
456 refcount_read(&peer->ref),
457 &peer->srx.transport);
463 * rxrpc_kernel_get_peer - Get the peer address of a call
464 * @sock: The socket on which the call is in progress.
465 * @call: The call to query
466 * @_srx: Where to place the result
468 * Get the address of the remote peer in a call.
470 void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
471 struct sockaddr_rxrpc *_srx)
473 *_srx = call->peer->srx;
475 EXPORT_SYMBOL(rxrpc_kernel_get_peer);
478 * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
479 * @sock: The socket on which the call is in progress.
480 * @call: The call to query
481 * @_srtt: Where to store the SRTT value.
483 * Get the call's peer smoothed RTT in uS.
485 bool rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call,
488 struct rxrpc_peer *peer = call->peer;
490 if (peer->rtt_count == 0) {
491 *_srtt = 1000000; /* 1S */
495 *_srtt = call->peer->srtt_us >> 3;
498 EXPORT_SYMBOL(rxrpc_kernel_get_srtt);