Linux 5.7.7
[linux/fpc-iii.git] / net / rxrpc / peer_object.c
blobca29976bb193efd37fb9bc7f83cbdd4aa51f1737
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)
6 */
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>
14 #include <linux/in.h>
15 #include <linux/in6.h>
16 #include <linux/slab.h>
17 #include <linux/hashtable.h>
18 #include <net/sock.h>
19 #include <net/af_rxrpc.h>
20 #include <net/ip.h>
21 #include <net/route.h>
22 #include <net/ip6_route.h>
23 #include "ar-internal.h"
26 * Hash a peer key.
28 static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
29 const struct sockaddr_rxrpc *srx)
31 const u16 *p;
32 unsigned int i, size;
33 unsigned long hash_key;
35 _enter("");
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) {
43 case AF_INET:
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;
47 break;
48 #ifdef CONFIG_AF_RXRPC_IPV6
49 case AF_INET6:
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;
53 break;
54 #endif
55 default:
56 WARN(1, "AF_RXRPC: Unsupported transport address family\n");
57 return 0;
60 /* Step through the peer address in 16-bit portions for speed */
61 for (i = 0; i < size; i += sizeof(*p), p++)
62 hash_key += *p;
64 _leave(" 0x%lx", hash_key);
65 return hash_key;
69 * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
70 * or greater than.
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)
81 long diff;
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));
88 if (diff != 0)
89 return diff;
91 switch (srx->transport.family) {
92 case AF_INET:
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
99 case AF_INET6:
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));
105 #endif
106 default:
107 BUG();
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 atomic_read(&peer->usage) > 0)
125 return peer;
128 return NULL;
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);
141 if (peer) {
142 _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
143 _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
145 return peer;
149 * assess the MTU size for the network interface through which this peer is
150 * reached
152 static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
153 struct rxrpc_peer *peer)
155 struct net *net = sock_net(&rx->sk);
156 struct dst_entry *dst;
157 struct rtable *rt;
158 struct flowi fl;
159 struct flowi4 *fl4 = &fl.u.ip4;
160 #ifdef CONFIG_AF_RXRPC_IPV6
161 struct flowi6 *fl6 = &fl.u.ip6;
162 #endif
164 peer->if_mtu = 1500;
166 memset(&fl, 0, sizeof(fl));
167 switch (peer->srx.transport.family) {
168 case AF_INET:
169 rt = ip_route_output_ports(
170 net, fl4, NULL,
171 peer->srx.transport.sin.sin_addr.s_addr, 0,
172 htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
173 if (IS_ERR(rt)) {
174 _leave(" [route err %ld]", PTR_ERR(rt));
175 return;
177 dst = &rt->dst;
178 break;
180 #ifdef CONFIG_AF_RXRPC_IPV6
181 case AF_INET6:
182 fl6->flowi6_iif = LOOPBACK_IFINDEX;
183 fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
184 fl6->flowi6_proto = IPPROTO_UDP;
185 memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
186 sizeof(struct in6_addr));
187 fl6->fl6_dport = htons(7001);
188 fl6->fl6_sport = htons(7000);
189 dst = ip6_route_output(net, NULL, fl6);
190 if (dst->error) {
191 _leave(" [route err %d]", dst->error);
192 return;
194 break;
195 #endif
197 default:
198 BUG();
201 peer->if_mtu = dst_mtu(dst);
202 dst_release(dst);
204 _leave(" [if_mtu %u]", peer->if_mtu);
208 * Allocate a peer.
210 struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp)
212 const void *here = __builtin_return_address(0);
213 struct rxrpc_peer *peer;
215 _enter("");
217 peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
218 if (peer) {
219 atomic_set(&peer->usage, 1);
220 peer->local = rxrpc_get_local(local);
221 INIT_HLIST_HEAD(&peer->error_targets);
222 peer->service_conns = RB_ROOT;
223 seqlock_init(&peer->service_conn_lock);
224 spin_lock_init(&peer->lock);
225 spin_lock_init(&peer->rtt_input_lock);
226 peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
228 rxrpc_peer_init_rtt(peer);
230 if (RXRPC_TX_SMSS > 2190)
231 peer->cong_cwnd = 2;
232 else if (RXRPC_TX_SMSS > 1095)
233 peer->cong_cwnd = 3;
234 else
235 peer->cong_cwnd = 4;
236 trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here);
239 _leave(" = %p", peer);
240 return 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) {
255 case AF_INET:
256 peer->hdrsize = sizeof(struct iphdr);
257 break;
258 #ifdef CONFIG_AF_RXRPC_IPV6
259 case AF_INET6:
260 peer->hdrsize = sizeof(struct ipv6hdr);
261 break;
262 #endif
263 default:
264 BUG();
267 switch (peer->srx.transport_type) {
268 case SOCK_DGRAM:
269 peer->hdrsize += sizeof(struct udphdr);
270 break;
271 default:
272 BUG();
275 peer->hdrsize += sizeof(struct rxrpc_wire_header);
276 peer->maxdata = peer->mtu - peer->hdrsize;
280 * Set up a new peer.
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,
286 gfp_t gfp)
288 struct rxrpc_peer *peer;
290 _enter("");
292 peer = rxrpc_alloc_peer(local, gfp);
293 if (peer) {
294 memcpy(&peer->srx, srx, sizeof(*srx));
295 rxrpc_init_peer(rx, peer, hash_key);
298 _leave(" = %p", peer);
299 return peer;
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 */
336 rcu_read_lock();
337 peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
338 if (peer && !rxrpc_get_peer_maybe(peer))
339 peer = NULL;
340 rcu_read_unlock();
342 if (!peer) {
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);
347 if (!candidate) {
348 _leave(" = NULL [nomem]");
349 return NULL;
352 spin_lock_bh(&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))
357 peer = NULL;
358 if (!peer) {
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_bh(&rxnet->peer_hash_lock);
367 if (peer)
368 kfree(candidate);
369 else
370 peer = candidate;
373 _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
375 _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
376 return peer;
380 * Get a ref on a peer record.
382 struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
384 const void *here = __builtin_return_address(0);
385 int n;
387 n = atomic_inc_return(&peer->usage);
388 trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n, here);
389 return peer;
393 * Get a ref on a peer record unless its usage has already reached 0.
395 struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer)
397 const void *here = __builtin_return_address(0);
399 if (peer) {
400 int n = atomic_fetch_add_unless(&peer->usage, 1, 0);
401 if (n > 0)
402 trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n + 1, here);
403 else
404 peer = NULL;
406 return peer;
410 * Discard a peer record.
412 static void __rxrpc_put_peer(struct rxrpc_peer *peer)
414 struct rxrpc_net *rxnet = peer->local->rxnet;
416 ASSERT(hlist_empty(&peer->error_targets));
418 spin_lock_bh(&rxnet->peer_hash_lock);
419 hash_del_rcu(&peer->hash_link);
420 list_del_init(&peer->keepalive_link);
421 spin_unlock_bh(&rxnet->peer_hash_lock);
423 rxrpc_put_local(peer->local);
424 kfree_rcu(peer, rcu);
428 * Drop a ref on a peer record.
430 void rxrpc_put_peer(struct rxrpc_peer *peer)
432 const void *here = __builtin_return_address(0);
433 unsigned int debug_id;
434 int n;
436 if (peer) {
437 debug_id = peer->debug_id;
438 n = atomic_dec_return(&peer->usage);
439 trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
440 if (n == 0)
441 __rxrpc_put_peer(peer);
446 * Drop a ref on a peer record where the caller already holds the
447 * peer_hash_lock.
449 void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
451 const void *here = __builtin_return_address(0);
452 unsigned int debug_id = peer->debug_id;
453 int n;
455 n = atomic_dec_return(&peer->usage);
456 trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
457 if (n == 0) {
458 hash_del_rcu(&peer->hash_link);
459 list_del_init(&peer->keepalive_link);
460 rxrpc_put_local(peer->local);
461 kfree_rcu(peer, rcu);
466 * Make sure all peer records have been discarded.
468 void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
470 struct rxrpc_peer *peer;
471 int i;
473 for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
474 if (hlist_empty(&rxnet->peer_hash[i]))
475 continue;
477 hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
478 pr_err("Leaked peer %u {%u} %pISp\n",
479 peer->debug_id,
480 atomic_read(&peer->usage),
481 &peer->srx.transport);
487 * rxrpc_kernel_get_peer - Get the peer address of a call
488 * @sock: The socket on which the call is in progress.
489 * @call: The call to query
490 * @_srx: Where to place the result
492 * Get the address of the remote peer in a call.
494 void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
495 struct sockaddr_rxrpc *_srx)
497 *_srx = call->peer->srx;
499 EXPORT_SYMBOL(rxrpc_kernel_get_peer);
502 * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
503 * @sock: The socket on which the call is in progress.
504 * @call: The call to query
506 * Get the call's peer smoothed RTT.
508 u32 rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call)
510 return call->peer->srtt_us >> 3;
512 EXPORT_SYMBOL(rxrpc_kernel_get_srtt);