1 /* RxRPC remote transport endpoint record management
3 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/module.h>
15 #include <linux/net.h>
16 #include <linux/skbuff.h>
17 #include <linux/udp.h>
19 #include <linux/in6.h>
20 #include <linux/slab.h>
21 #include <linux/hashtable.h>
23 #include <net/af_rxrpc.h>
25 #include <net/route.h>
26 #include <net/ip6_route.h>
27 #include "ar-internal.h"
32 static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
33 const struct sockaddr_rxrpc *srx)
37 unsigned long hash_key;
41 hash_key = (unsigned long)local / __alignof__(*local);
42 hash_key += srx->transport_type;
43 hash_key += srx->transport_len;
44 hash_key += srx->transport.family;
46 switch (srx->transport.family) {
48 hash_key += (u16 __force)srx->transport.sin.sin_port;
49 size = sizeof(srx->transport.sin.sin_addr);
50 p = (u16 *)&srx->transport.sin.sin_addr;
52 #ifdef CONFIG_AF_RXRPC_IPV6
54 hash_key += (u16 __force)srx->transport.sin.sin_port;
55 size = sizeof(srx->transport.sin6.sin6_addr);
56 p = (u16 *)&srx->transport.sin6.sin6_addr;
60 WARN(1, "AF_RXRPC: Unsupported transport address family\n");
64 /* Step through the peer address in 16-bit portions for speed */
65 for (i = 0; i < size; i += sizeof(*p), p++)
68 _leave(" 0x%lx", hash_key);
73 * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
76 * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
77 * buckets and mid-bucket insertion, so we don't make full use of this
78 * information at this point.
80 static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
81 struct rxrpc_local *local,
82 const struct sockaddr_rxrpc *srx,
83 unsigned long hash_key)
87 diff = ((peer->hash_key - hash_key) ?:
88 ((unsigned long)peer->local - (unsigned long)local) ?:
89 (peer->srx.transport_type - srx->transport_type) ?:
90 (peer->srx.transport_len - srx->transport_len) ?:
91 (peer->srx.transport.family - srx->transport.family));
95 switch (srx->transport.family) {
97 return ((u16 __force)peer->srx.transport.sin.sin_port -
98 (u16 __force)srx->transport.sin.sin_port) ?:
99 memcmp(&peer->srx.transport.sin.sin_addr,
100 &srx->transport.sin.sin_addr,
101 sizeof(struct in_addr));
102 #ifdef CONFIG_AF_RXRPC_IPV6
104 return ((u16 __force)peer->srx.transport.sin6.sin6_port -
105 (u16 __force)srx->transport.sin6.sin6_port) ?:
106 memcmp(&peer->srx.transport.sin6.sin6_addr,
107 &srx->transport.sin6.sin6_addr,
108 sizeof(struct in6_addr));
116 * Look up a remote transport endpoint for the specified address using RCU.
118 static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
119 struct rxrpc_local *local,
120 const struct sockaddr_rxrpc *srx,
121 unsigned long hash_key)
123 struct rxrpc_peer *peer;
124 struct rxrpc_net *rxnet = local->rxnet;
126 hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
127 if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
128 atomic_read(&peer->usage) > 0)
136 * Look up a remote transport endpoint for the specified address using RCU.
138 struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
139 const struct sockaddr_rxrpc *srx)
141 struct rxrpc_peer *peer;
142 unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
144 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
146 _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
147 _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
153 * assess the MTU size for the network interface through which this peer is
156 static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
157 struct rxrpc_peer *peer)
159 struct net *net = sock_net(&rx->sk);
160 struct dst_entry *dst;
163 struct flowi4 *fl4 = &fl.u.ip4;
164 #ifdef CONFIG_AF_RXRPC_IPV6
165 struct flowi6 *fl6 = &fl.u.ip6;
170 memset(&fl, 0, sizeof(fl));
171 switch (peer->srx.transport.family) {
173 rt = ip_route_output_ports(
175 peer->srx.transport.sin.sin_addr.s_addr, 0,
176 htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
178 _leave(" [route err %ld]", PTR_ERR(rt));
184 #ifdef CONFIG_AF_RXRPC_IPV6
186 fl6->flowi6_iif = LOOPBACK_IFINDEX;
187 fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
188 fl6->flowi6_proto = IPPROTO_UDP;
189 memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
190 sizeof(struct in6_addr));
191 fl6->fl6_dport = htons(7001);
192 fl6->fl6_sport = htons(7000);
193 dst = ip6_route_output(net, NULL, fl6);
195 _leave(" [route err %d]", dst->error);
205 peer->if_mtu = dst_mtu(dst);
208 _leave(" [if_mtu %u]", peer->if_mtu);
214 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp)
216 struct rxrpc_peer *peer;
220 peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
222 atomic_set(&peer->usage, 1);
223 peer->local = rxrpc_get_local(local);
224 INIT_HLIST_HEAD(&peer->error_targets);
225 peer->service_conns = RB_ROOT;
226 seqlock_init(&peer->service_conn_lock);
227 spin_lock_init(&peer->lock);
228 spin_lock_init(&peer->rtt_input_lock);
229 peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
231 if (RXRPC_TX_SMSS > 2190)
233 else if (RXRPC_TX_SMSS > 1095)
239 _leave(" = %p", peer);
244 * Initialise peer record.
246 static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer,
247 unsigned long hash_key)
249 peer->hash_key = hash_key;
250 rxrpc_assess_MTU_size(rx, peer);
251 peer->mtu = peer->if_mtu;
252 peer->rtt_last_req = ktime_get_real();
254 switch (peer->srx.transport.family) {
256 peer->hdrsize = sizeof(struct iphdr);
258 #ifdef CONFIG_AF_RXRPC_IPV6
260 peer->hdrsize = sizeof(struct ipv6hdr);
267 switch (peer->srx.transport_type) {
269 peer->hdrsize += sizeof(struct udphdr);
275 peer->hdrsize += sizeof(struct rxrpc_wire_header);
276 peer->maxdata = peer->mtu - peer->hdrsize;
282 static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx,
283 struct rxrpc_local *local,
284 struct sockaddr_rxrpc *srx,
285 unsigned long hash_key,
288 struct rxrpc_peer *peer;
292 peer = rxrpc_alloc_peer(local, gfp);
294 memcpy(&peer->srx, srx, sizeof(*srx));
295 rxrpc_init_peer(rx, peer, hash_key);
298 _leave(" = %p", peer);
302 static void rxrpc_free_peer(struct rxrpc_peer *peer)
304 rxrpc_put_local(peer->local);
305 kfree_rcu(peer, rcu);
309 * Set up a new incoming peer. There shouldn't be any other matching peers
310 * since we've already done a search in the list from the non-reentrant context
311 * (the data_ready handler) that is the only place we can add new peers.
313 void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local,
314 struct rxrpc_peer *peer)
316 struct rxrpc_net *rxnet = local->rxnet;
317 unsigned long hash_key;
319 hash_key = rxrpc_peer_hash_key(local, &peer->srx);
320 rxrpc_init_peer(rx, peer, hash_key);
322 spin_lock(&rxnet->peer_hash_lock);
323 hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
324 list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
325 spin_unlock(&rxnet->peer_hash_lock);
329 * obtain a remote transport endpoint for the specified address
331 struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx,
332 struct rxrpc_local *local,
333 struct sockaddr_rxrpc *srx, gfp_t gfp)
335 struct rxrpc_peer *peer, *candidate;
336 struct rxrpc_net *rxnet = local->rxnet;
337 unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
339 _enter("{%pISp}", &srx->transport);
341 /* search the peer list first */
343 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
344 if (peer && !rxrpc_get_peer_maybe(peer))
349 /* The peer is not yet present in hash - create a candidate
350 * for a new record and then redo the search.
352 candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp);
354 _leave(" = NULL [nomem]");
358 spin_lock_bh(&rxnet->peer_hash_lock);
360 /* Need to check that we aren't racing with someone else */
361 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
362 if (peer && !rxrpc_get_peer_maybe(peer))
365 hash_add_rcu(rxnet->peer_hash,
366 &candidate->hash_link, hash_key);
367 list_add_tail(&candidate->keepalive_link,
368 &rxnet->peer_keepalive_new);
371 spin_unlock_bh(&rxnet->peer_hash_lock);
374 rxrpc_free_peer(candidate);
379 _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
381 _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
386 * Get a ref on a peer record.
388 struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
390 const void *here = __builtin_return_address(0);
393 n = atomic_inc_return(&peer->usage);
394 trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n, here);
399 * Get a ref on a peer record unless its usage has already reached 0.
401 struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer)
403 const void *here = __builtin_return_address(0);
406 int n = atomic_fetch_add_unless(&peer->usage, 1, 0);
408 trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n + 1, here);
416 * Discard a peer record.
418 static void __rxrpc_put_peer(struct rxrpc_peer *peer)
420 struct rxrpc_net *rxnet = peer->local->rxnet;
422 ASSERT(hlist_empty(&peer->error_targets));
424 spin_lock_bh(&rxnet->peer_hash_lock);
425 hash_del_rcu(&peer->hash_link);
426 list_del_init(&peer->keepalive_link);
427 spin_unlock_bh(&rxnet->peer_hash_lock);
429 rxrpc_free_peer(peer);
433 * Drop a ref on a peer record.
435 void rxrpc_put_peer(struct rxrpc_peer *peer)
437 const void *here = __builtin_return_address(0);
438 unsigned int debug_id;
442 debug_id = peer->debug_id;
443 n = atomic_dec_return(&peer->usage);
444 trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
446 __rxrpc_put_peer(peer);
451 * Drop a ref on a peer record where the caller already holds the
454 void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
456 const void *here = __builtin_return_address(0);
457 unsigned int debug_id = peer->debug_id;
460 n = atomic_dec_return(&peer->usage);
461 trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
463 hash_del_rcu(&peer->hash_link);
464 list_del_init(&peer->keepalive_link);
465 rxrpc_free_peer(peer);
470 * Make sure all peer records have been discarded.
472 void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
474 struct rxrpc_peer *peer;
477 for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
478 if (hlist_empty(&rxnet->peer_hash[i]))
481 hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
482 pr_err("Leaked peer %u {%u} %pISp\n",
484 atomic_read(&peer->usage),
485 &peer->srx.transport);
491 * rxrpc_kernel_get_peer - Get the peer address of a call
492 * @sock: The socket on which the call is in progress.
493 * @call: The call to query
494 * @_srx: Where to place the result
496 * Get the address of the remote peer in a call.
498 void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
499 struct sockaddr_rxrpc *_srx)
501 *_srx = call->peer->srx;
503 EXPORT_SYMBOL(rxrpc_kernel_get_peer);
506 * rxrpc_kernel_get_rtt - Get a call's peer RTT
507 * @sock: The socket on which the call is in progress.
508 * @call: The call to query
510 * Get the call's peer RTT.
512 u64 rxrpc_kernel_get_rtt(struct socket *sock, struct rxrpc_call *call)
514 return call->peer->rtt;
516 EXPORT_SYMBOL(rxrpc_kernel_get_rtt);