[mirror_ubuntu-zesty-kernel.git] / net / rxrpc / peer_object.c

/* RxRPC remote transport endpoint record management
 *
 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/slab.h>
#include <linux/hashtable.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/ip6_route.h>
#include "ar-internal.h"

static DEFINE_HASHTABLE(rxrpc_peer_hash, 10);
static DEFINE_SPINLOCK(rxrpc_peer_hash_lock);

/*
 * Hash a peer key.
 */
static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
					 const struct sockaddr_rxrpc *srx)
{
	const u16 *p;
	unsigned int i, size;
	unsigned long hash_key;

	_enter("");

	hash_key = (unsigned long)local / __alignof__(*local);
	hash_key += srx->transport_type;
	hash_key += srx->transport_len;
	hash_key += srx->transport.family;

	switch (srx->transport.family) {
	case AF_INET:
		hash_key += (u16 __force)srx->transport.sin.sin_port;
		size = sizeof(srx->transport.sin.sin_addr);
		p = (u16 *)&srx->transport.sin.sin_addr;
		break;
#ifdef CONFIG_AF_RXRPC_IPV6
	case AF_INET6:
		hash_key += (u16 __force)srx->transport.sin.sin_port;
		size = sizeof(srx->transport.sin6.sin6_addr);
		p = (u16 *)&srx->transport.sin6.sin6_addr;
		break;
#endif
	default:
		WARN(1, "AF_RXRPC: Unsupported transport address family\n");
		return 0;
	}

	/* Step through the peer address in 16-bit portions for speed */
	for (i = 0; i < size; i += sizeof(*p), p++)
		hash_key += *p;

	_leave(" 0x%lx", hash_key);
	return hash_key;
}

/*
 * Compare a peer to a key.  Return -ve, 0 or +ve to indicate less than, same
 * or greater than.
 *
 * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
 * buckets and mid-bucket insertion, so we don't make full use of this
 * information at this point.
 */
static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
			       struct rxrpc_local *local,
			       const struct sockaddr_rxrpc *srx,
			       unsigned long hash_key)
{
	long diff;

	diff = ((peer->hash_key - hash_key) ?:
		((unsigned long)peer->local - (unsigned long)local) ?:
		(peer->srx.transport_type - srx->transport_type) ?:
		(peer->srx.transport_len - srx->transport_len) ?:
		(peer->srx.transport.family - srx->transport.family));
	if (diff != 0)
		return diff;

	switch (srx->transport.family) {
	case AF_INET:
		return ((u16 __force)peer->srx.transport.sin.sin_port -
			(u16 __force)srx->transport.sin.sin_port) ?:
			memcmp(&peer->srx.transport.sin.sin_addr,
			       &srx->transport.sin.sin_addr,
			       sizeof(struct in_addr));
#ifdef CONFIG_AF_RXRPC_IPV6
	case AF_INET6:
		return ((u16 __force)peer->srx.transport.sin6.sin6_port -
			(u16 __force)srx->transport.sin6.sin6_port) ?:
			memcmp(&peer->srx.transport.sin6.sin6_addr,
			       &srx->transport.sin6.sin6_addr,
			       sizeof(struct in6_addr));
#endif
	default:
		BUG();
	}
}

/*
 * Look up a remote transport endpoint for the specified address using RCU.
 */
static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
	struct rxrpc_local *local,
	const struct sockaddr_rxrpc *srx,
	unsigned long hash_key)
{
	struct rxrpc_peer *peer;

	hash_for_each_possible_rcu(rxrpc_peer_hash, peer, hash_link, hash_key) {
		if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0) {
			if (atomic_read(&peer->usage) == 0)
				return NULL;
			return peer;
		}
	}

	return NULL;
}

/*
 * Look up a remote transport endpoint for the specified address using RCU.
 */
struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
					 const struct sockaddr_rxrpc *srx)
{
	struct rxrpc_peer *peer;
	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);

	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	if (peer) {
		_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
		_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
	}
	return peer;
}

/*
 * assess the MTU size for the network interface through which this peer is
 * reached
 */
static void rxrpc_assess_MTU_size(struct rxrpc_peer *peer)
{
	struct dst_entry *dst;
	struct rtable *rt;
	struct flowi fl;
	struct flowi4 *fl4 = &fl.u.ip4;
#ifdef CONFIG_AF_RXRPC_IPV6
	struct flowi6 *fl6 = &fl.u.ip6;
#endif

	peer->if_mtu = 1500;

	memset(&fl, 0, sizeof(fl));
	switch (peer->srx.transport.family) {
	case AF_INET:
		rt = ip_route_output_ports(
			&init_net, fl4, NULL,
			peer->srx.transport.sin.sin_addr.s_addr, 0,
			htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
		if (IS_ERR(rt)) {
			_leave(" [route err %ld]", PTR_ERR(rt));
			return;
		}
		dst = &rt->dst;
		break;

#ifdef CONFIG_AF_RXRPC_IPV6
	case AF_INET6:
		fl6->flowi6_iif = LOOPBACK_IFINDEX;
		fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
		fl6->flowi6_proto = IPPROTO_UDP;
		memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
		       sizeof(struct in6_addr));
		fl6->fl6_dport = htons(7001);
		fl6->fl6_sport = htons(7000);
		dst = ip6_route_output(&init_net, NULL, fl6);
		if (dst->error) {
			_leave(" [route err %d]", dst->error);
			return;
		}
		break;
#endif

	default:
		BUG();
	}

	peer->if_mtu = dst_mtu(dst);
	dst_release(dst);

	_leave(" [if_mtu %u]", peer->if_mtu);
}

/*
 * Allocate a peer.
 */
struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp)
{
	struct rxrpc_peer *peer;

	_enter("");

	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	if (peer) {
		atomic_set(&peer->usage, 1);
		peer->local = local;
		INIT_HLIST_HEAD(&peer->error_targets);
		INIT_WORK(&peer->error_distributor,
			  &rxrpc_peer_error_distributor);
		peer->service_conns = RB_ROOT;
		seqlock_init(&peer->service_conn_lock);
		spin_lock_init(&peer->lock);
		peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
	}

	_leave(" = %p", peer);
	return peer;
}

/*
 * Initialise peer record.
 */
static void rxrpc_init_peer(struct rxrpc_peer *peer, unsigned long hash_key)
{
	peer->hash_key = hash_key;
	rxrpc_assess_MTU_size(peer);
	peer->mtu = peer->if_mtu;
	peer->rtt_last_req = ktime_get_real();

	switch (peer->srx.transport.family) {
	case AF_INET:
		peer->hdrsize = sizeof(struct iphdr);
		break;
#ifdef CONFIG_AF_RXRPC_IPV6
	case AF_INET6:
		peer->hdrsize = sizeof(struct ipv6hdr);
		break;
#endif
	default:
		BUG();
	}

	switch (peer->srx.transport_type) {
	case SOCK_DGRAM:
		peer->hdrsize += sizeof(struct udphdr);
		break;
	default:
		BUG();
	}

	peer->hdrsize += sizeof(struct rxrpc_wire_header);
	peer->maxdata = peer->mtu - peer->hdrsize;
}

/*
 * Set up a new peer.
 */
static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_local *local,
					    struct sockaddr_rxrpc *srx,
					    unsigned long hash_key,
					    gfp_t gfp)
{
	struct rxrpc_peer *peer;

	_enter("");

	peer = rxrpc_alloc_peer(local, gfp);
	if (peer) {
		memcpy(&peer->srx, srx, sizeof(*srx));
		rxrpc_init_peer(peer, hash_key);
	}

	_leave(" = %p", peer);
	return peer;
}

/*
 * Set up a new incoming peer.  The address is prestored in the preallocated
 * peer.
 */
struct rxrpc_peer *rxrpc_lookup_incoming_peer(struct rxrpc_local *local,
					      struct rxrpc_peer *prealloc)
{
	struct rxrpc_peer *peer;
	unsigned long hash_key;

	hash_key = rxrpc_peer_hash_key(local, &prealloc->srx);
	prealloc->local = local;
	rxrpc_init_peer(prealloc, hash_key);

	spin_lock(&rxrpc_peer_hash_lock);

	/* Need to check that we aren't racing with someone else */
	peer = __rxrpc_lookup_peer_rcu(local, &prealloc->srx, hash_key);
	if (peer && !rxrpc_get_peer_maybe(peer))
		peer = NULL;
	if (!peer) {
		peer = prealloc;
		hash_add_rcu(rxrpc_peer_hash, &peer->hash_link, hash_key);
	}

	spin_unlock(&rxrpc_peer_hash_lock);
	return peer;
}

/*
 * obtain a remote transport endpoint for the specified address
 */
struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
				     struct sockaddr_rxrpc *srx, gfp_t gfp)
{
	struct rxrpc_peer *peer, *candidate;
	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);

	_enter("{%pISp}", &srx->transport);

	/* search the peer list first */
	rcu_read_lock();
	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	if (peer && !rxrpc_get_peer_maybe(peer))
		peer = NULL;
	rcu_read_unlock();

	if (!peer) {
		/* The peer is not yet present in hash - create a candidate
		 * for a new record and then redo the search.
		 */
		candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
		if (!candidate) {
			_leave(" = NULL [nomem]");
			return NULL;
		}

		spin_lock_bh(&rxrpc_peer_hash_lock);

		/* Need to check that we aren't racing with someone else */
		peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
		if (peer && !rxrpc_get_peer_maybe(peer))
			peer = NULL;
		if (!peer)
			hash_add_rcu(rxrpc_peer_hash,
				     &candidate->hash_link, hash_key);

		spin_unlock_bh(&rxrpc_peer_hash_lock);

		if (peer)
			kfree(candidate);
		else
			peer = candidate;
	}

	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);

	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
	return peer;
}

/*
 * Discard a ref on a remote peer record.
 */
void __rxrpc_put_peer(struct rxrpc_peer *peer)
{
	ASSERT(hlist_empty(&peer->error_targets));

	spin_lock_bh(&rxrpc_peer_hash_lock);
	hash_del_rcu(&peer->hash_link);
	spin_unlock_bh(&rxrpc_peer_hash_lock);

	kfree_rcu(peer, rcu);
}

/**
 * rxrpc_kernel_get_peer - Get the peer address of a call
 * @sock: The socket on which the call is in progress.
 * @call: The call to query
 * @_srx: Where to place the result
 *
 * Get the address of the remote peer in a call.
 */
void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
			   struct sockaddr_rxrpc *_srx)
{
	*_srx = call->peer->srx;
}
EXPORT_SYMBOL(rxrpc_kernel_get_peer);
Commit	Line	Data
be6e6707	1	/* RxRPC remote transport endpoint record management
17926a79	2	*
be6e6707	3	* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
17926a79 DH	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	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.
	10	*/
	11
9b6d5398 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9b6d5398 JP	13
17926a79 DH	14	#include <linux/module.h>
	15	#include <linux/net.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/udp.h>
	18	#include <linux/in.h>
75b54cb5	19	#include <linux/in6.h>
5a0e3ad6	20	#include <linux/slab.h>
be6e6707	21	#include <linux/hashtable.h>
17926a79 DH	22	#include <net/sock.h>
	23	#include <net/af_rxrpc.h>
	24	#include <net/ip.h>
224711df	25	#include <net/route.h>
75b54cb5	26	#include <net/ip6_route.h>
17926a79 DH	27	#include "ar-internal.h"
17926a79 DH	28
be6e6707 DH	29	static DEFINE_HASHTABLE(rxrpc_peer_hash, 10);
be6e6707 DH	30	static DEFINE_SPINLOCK(rxrpc_peer_hash_lock);
17926a79	31
be6e6707 DH	32	/*
	33	* Hash a peer key.
	34	*/
	35	static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
	36	const struct sockaddr_rxrpc *srx)
	37	{
	38	const u16 *p;
	39	unsigned int i, size;
	40	unsigned long hash_key;
	41
	42	_enter("");
	43
	44	hash_key = (unsigned long)local / __alignof__(*local);
	45	hash_key += srx->transport_type;
	46	hash_key += srx->transport_len;
	47	hash_key += srx->transport.family;
	48
	49	switch (srx->transport.family) {
	50	case AF_INET:
	51	hash_key += (u16 __force)srx->transport.sin.sin_port;
	52	size = sizeof(srx->transport.sin.sin_addr);
	53	p = (u16 *)&srx->transport.sin.sin_addr;
	54	break;
d1912747	55	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	56	case AF_INET6:
	57	hash_key += (u16 __force)srx->transport.sin.sin_port;
	58	size = sizeof(srx->transport.sin6.sin6_addr);
	59	p = (u16 *)&srx->transport.sin6.sin6_addr;
	60	break;
d1912747	61	#endif
2f9f9f52 AB	62	default:
	63	WARN(1, "AF_RXRPC: Unsupported transport address family\n");
	64	return 0;
be6e6707 DH	65	}
	66
	67	/* Step through the peer address in 16-bit portions for speed */
	68	for (i = 0; i < size; i += sizeof(*p), p++)
	69	hash_key += *p;
	70
	71	_leave(" 0x%lx", hash_key);
	72	return hash_key;
	73	}
	74
	75	/*
	76	* Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
	77	* or greater than.
	78	*
	79	* Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
	80	* buckets and mid-bucket insertion, so we don't make full use of this
	81	* information at this point.
	82	*/
	83	static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
	84	struct rxrpc_local *local,
	85	const struct sockaddr_rxrpc *srx,
	86	unsigned long hash_key)
	87	{
	88	long diff;
	89
	90	diff = ((peer->hash_key - hash_key) ?:
	91	((unsigned long)peer->local - (unsigned long)local) ?:
	92	(peer->srx.transport_type - srx->transport_type) ?:
	93	(peer->srx.transport_len - srx->transport_len) ?:
	94	(peer->srx.transport.family - srx->transport.family));
	95	if (diff != 0)
	96	return diff;
	97
	98	switch (srx->transport.family) {
	99	case AF_INET:
	100	return ((u16 __force)peer->srx.transport.sin.sin_port -
	101	(u16 __force)srx->transport.sin.sin_port) ?:
	102	memcmp(&peer->srx.transport.sin.sin_addr,
	103	&srx->transport.sin.sin_addr,
	104	sizeof(struct in_addr));
d1912747	105	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	106	case AF_INET6:
	107	return ((u16 __force)peer->srx.transport.sin6.sin6_port -
	108	(u16 __force)srx->transport.sin6.sin6_port) ?:
	109	memcmp(&peer->srx.transport.sin6.sin6_addr,
	110	&srx->transport.sin6.sin6_addr,
	111	sizeof(struct in6_addr));
d1912747	112	#endif
be6e6707 DH	113	default:
	114	BUG();
	115	}
	116	}
	117
	118	/*
	119	* Look up a remote transport endpoint for the specified address using RCU.
	120	*/
	121	static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
	122	struct rxrpc_local *local,
	123	const struct sockaddr_rxrpc *srx,
	124	unsigned long hash_key)
	125	{
	126	struct rxrpc_peer *peer;
	127
	128	hash_for_each_possible_rcu(rxrpc_peer_hash, peer, hash_link, hash_key) {
	129	if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0) {
	130	if (atomic_read(&peer->usage) == 0)
	131	return NULL;
	132	return peer;
	133	}
	134	}
	135
	136	return NULL;
	137	}
	138
	139	/*
	140	* Look up a remote transport endpoint for the specified address using RCU.
	141	*/
	142	struct rxrpc_peer rxrpc_lookup_peer_rcu(struct rxrpc_local local,
	143	const struct sockaddr_rxrpc *srx)
	144	{
	145	struct rxrpc_peer *peer;
	146	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
	147
	148	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	149	if (peer) {
75b54cb5	150	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
be6e6707 DH	151	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
	152	}
	153	return peer;
	154	}
17926a79	155
224711df DH	156	/*
	157	* assess the MTU size for the network interface through which this peer is
	158	* reached
	159	*/
	160	static void rxrpc_assess_MTU_size(struct rxrpc_peer *peer)
	161	{
75b54cb5	162	struct dst_entry *dst;
224711df	163	struct rtable *rt;
75b54cb5 DH	164	struct flowi fl;
75b54cb5 DH	165	struct flowi4 *fl4 = &fl.u.ip4;
d1912747	166	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5	167	struct flowi6 *fl6 = &fl.u.ip6;
d1912747	168	#endif
224711df DH	169
	170	peer->if_mtu = 1500;
	171
75b54cb5 DH	172	memset(&fl, 0, sizeof(fl));
	173	switch (peer->srx.transport.family) {
	174	case AF_INET:
	175	rt = ip_route_output_ports(
	176	&init_net, fl4, NULL,
	177	peer->srx.transport.sin.sin_addr.s_addr, 0,
	178	htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
	179	if (IS_ERR(rt)) {
	180	_leave(" [route err %ld]", PTR_ERR(rt));
	181	return;
	182	}
	183	dst = &rt->dst;
	184	break;
	185
d1912747	186	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	187	case AF_INET6:
	188	fl6->flowi6_iif = LOOPBACK_IFINDEX;
	189	fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
	190	fl6->flowi6_proto = IPPROTO_UDP;
	191	memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
	192	sizeof(struct in6_addr));
	193	fl6->fl6_dport = htons(7001);
	194	fl6->fl6_sport = htons(7000);
	195	dst = ip6_route_output(&init_net, NULL, fl6);
07096f61 DH	196	if (dst->error) {
07096f61 DH	197	_leave(" [route err %d]", dst->error);
75b54cb5 DH	198	return;
	199	}
	200	break;
d1912747	201	#endif
75b54cb5 DH	202
	203	default:
	204	BUG();
224711df DH	205	}
224711df DH	206
75b54cb5 DH	207	peer->if_mtu = dst_mtu(dst);
75b54cb5 DH	208	dst_release(dst);
224711df	209
a6a62b69	210	_leave(" [if_mtu %u]", peer->if_mtu);
224711df DH	211	}
224711df DH	212
17926a79	213	/*
be6e6707	214	* Allocate a peer.
17926a79	215	*/
be6e6707	216	struct rxrpc_peer rxrpc_alloc_peer(struct rxrpc_local local, gfp_t gfp)
17926a79 DH	217	{
	218	struct rxrpc_peer *peer;
	219
	220	_enter("");
	221
	222	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	223	if (peer) {
be6e6707 DH	224	atomic_set(&peer->usage, 1);
be6e6707 DH	225	peer->local = local;
f66d7490 DH	226	INIT_HLIST_HEAD(&peer->error_targets);
	227	INIT_WORK(&peer->error_distributor,
	228	&rxrpc_peer_error_distributor);
aa390bbe	229	peer->service_conns = RB_ROOT;
8496af50	230	seqlock_init(&peer->service_conn_lock);
17926a79	231	spin_lock_init(&peer->lock);
17926a79	232	peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
be6e6707 DH	233	}
	234
	235	_leave(" = %p", peer);
	236	return peer;
	237	}
	238
248f219c DH	239	/*
	240	* Initialise peer record.
	241	*/
	242	static void rxrpc_init_peer(struct rxrpc_peer *peer, unsigned long hash_key)
	243	{
08a39685	244	peer->hash_key = hash_key;
248f219c DH	245	rxrpc_assess_MTU_size(peer);
248f219c DH	246	peer->mtu = peer->if_mtu;
0d4b103c	247	peer->rtt_last_req = ktime_get_real();
248f219c	248
75b54cb5 DH	249	switch (peer->srx.transport.family) {
75b54cb5 DH	250	case AF_INET:
248f219c	251	peer->hdrsize = sizeof(struct iphdr);
75b54cb5	252	break;
d1912747	253	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	254	case AF_INET6:
	255	peer->hdrsize = sizeof(struct ipv6hdr);
	256	break;
d1912747	257	#endif
75b54cb5 DH	258	default:
	259	BUG();
	260	}
	261
	262	switch (peer->srx.transport_type) {
	263	case SOCK_DGRAM:
	264	peer->hdrsize += sizeof(struct udphdr);
	265	break;
	266	default:
248f219c DH	267	BUG();
	268	}
	269
	270	peer->hdrsize += sizeof(struct rxrpc_wire_header);
	271	peer->maxdata = peer->mtu - peer->hdrsize;
	272	}
	273
be6e6707 DH	274	/*
	275	* Set up a new peer.
	276	*/
	277	static struct rxrpc_peer rxrpc_create_peer(struct rxrpc_local local,
	278	struct sockaddr_rxrpc *srx,
	279	unsigned long hash_key,
	280	gfp_t gfp)
	281	{
	282	struct rxrpc_peer *peer;
	283
	284	_enter("");
	285
	286	peer = rxrpc_alloc_peer(local, gfp);
	287	if (peer) {
17926a79	288	memcpy(&peer->srx, srx, sizeof(*srx));
248f219c DH	289	rxrpc_init_peer(peer, hash_key);
248f219c DH	290	}
17926a79	291
248f219c DH	292	_leave(" = %p", peer);
	293	return peer;
	294	}
17926a79	295
248f219c DH	296	/*
	297	* Set up a new incoming peer. The address is prestored in the preallocated
	298	* peer.
	299	*/
	300	struct rxrpc_peer rxrpc_lookup_incoming_peer(struct rxrpc_local local,
	301	struct rxrpc_peer *prealloc)
	302	{
	303	struct rxrpc_peer *peer;
	304	unsigned long hash_key;
	305
	306	hash_key = rxrpc_peer_hash_key(local, &prealloc->srx);
	307	prealloc->local = local;
	308	rxrpc_init_peer(prealloc, hash_key);
	309
	310	spin_lock(&rxrpc_peer_hash_lock);
	311
	312	/* Need to check that we aren't racing with someone else */
	313	peer = __rxrpc_lookup_peer_rcu(local, &prealloc->srx, hash_key);
	314	if (peer && !rxrpc_get_peer_maybe(peer))
	315	peer = NULL;
	316	if (!peer) {
	317	peer = prealloc;
	318	hash_add_rcu(rxrpc_peer_hash, &peer->hash_link, hash_key);
17926a79 DH	319	}
17926a79 DH	320
248f219c	321	spin_unlock(&rxrpc_peer_hash_lock);
17926a79 DH	322	return peer;
	323	}
	324
	325	/*
	326	* obtain a remote transport endpoint for the specified address
	327	*/
be6e6707 DH	328	struct rxrpc_peer rxrpc_lookup_peer(struct rxrpc_local local,
be6e6707 DH	329	struct sockaddr_rxrpc *srx, gfp_t gfp)
17926a79 DH	330	{
17926a79 DH	331	struct rxrpc_peer peer, candidate;
be6e6707	332	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
17926a79	333
75b54cb5	334	_enter("{%pISp}", &srx->transport);
17926a79 DH	335
17926a79 DH	336	/* search the peer list first */
be6e6707 DH	337	rcu_read_lock();
	338	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	339	if (peer && !rxrpc_get_peer_maybe(peer))
	340	peer = NULL;
	341	rcu_read_unlock();
	342
	343	if (!peer) {
	344	/* The peer is not yet present in hash - create a candidate
	345	* for a new record and then redo the search.
	346	*/
	347	candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
	348	if (!candidate) {
	349	_leave(" = NULL [nomem]");
	350	return NULL;
	351	}
17926a79	352
248f219c	353	spin_lock_bh(&rxrpc_peer_hash_lock);
17926a79	354
be6e6707 DH	355	/* Need to check that we aren't racing with someone else */
	356	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	357	if (peer && !rxrpc_get_peer_maybe(peer))
	358	peer = NULL;
	359	if (!peer)
	360	hash_add_rcu(rxrpc_peer_hash,
	361	&candidate->hash_link, hash_key);
17926a79	362
248f219c	363	spin_unlock_bh(&rxrpc_peer_hash_lock);
17926a79	364
be6e6707 DH	365	if (peer)
	366	kfree(candidate);
	367	else
	368	peer = candidate;
	369	}
17926a79	370
75b54cb5	371	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
17926a79	372
be6e6707	373	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
17926a79	374	return peer;
17926a79 DH	375	}
	376
	377	/*
be6e6707	378	* Discard a ref on a remote peer record.
17926a79	379	*/
be6e6707	380	void __rxrpc_put_peer(struct rxrpc_peer *peer)
17926a79	381	{
f66d7490	382	ASSERT(hlist_empty(&peer->error_targets));
17926a79	383
248f219c	384	spin_lock_bh(&rxrpc_peer_hash_lock);
be6e6707	385	hash_del_rcu(&peer->hash_link);
248f219c	386	spin_unlock_bh(&rxrpc_peer_hash_lock);
17926a79	387
be6e6707	388	kfree_rcu(peer, rcu);
17926a79	389	}
8324f0bc DH	390
	391	/**
	392	* rxrpc_kernel_get_peer - Get the peer address of a call
	393	* @sock: The socket on which the call is in progress.
	394	* @call: The call to query
	395	* @_srx: Where to place the result
	396	*
	397	* Get the address of the remote peer in a call.
	398	*/
	399	void rxrpc_kernel_get_peer(struct socket sock, struct rxrpc_call call,
	400	struct sockaddr_rxrpc *_srx)
	401	{
	402	*_srx = call->peer->srx;
	403	}
	404	EXPORT_SYMBOL(rxrpc_kernel_get_peer);