[mirror_ubuntu-bionic-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"

/*
 * 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;
	struct rxrpc_net *rxnet = local->rxnet;

	hash_for_each_possible_rcu(rxnet->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);

		if (RXRPC_TX_SMSS > 2190)
			peer->cong_cwnd = 2;
		else if (RXRPC_TX_SMSS > 1095)
			peer->cong_cwnd = 3;
		else
			peer->cong_cwnd = 4;
	}

	_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;
	struct rxrpc_net *rxnet = local->rxnet;
	unsigned long hash_key;

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

	spin_lock(&rxnet->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(rxnet->peer_hash, &peer->hash_link, hash_key);
	}

	spin_unlock(&rxnet->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;
	struct rxrpc_net *rxnet = local->rxnet;
	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(&rxnet->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(rxnet->peer_hash,
				     &candidate->hash_link, hash_key);

		spin_unlock_bh(&rxnet->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)
{
	struct rxrpc_net *rxnet = peer->local->rxnet;

	ASSERT(hlist_empty(&peer->error_targets));

	spin_lock_bh(&rxnet->peer_hash_lock);
	hash_del_rcu(&peer->hash_link);
	spin_unlock_bh(&rxnet->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);

/**
 * rxrpc_kernel_get_rtt - Get a call's peer RTT
 * @sock: The socket on which the call is in progress.
 * @call: The call to query
 *
 * Get the call's peer RTT.
 */
u64 rxrpc_kernel_get_rtt(struct socket *sock, struct rxrpc_call *call)
{
	return call->peer->rtt;
}
EXPORT_SYMBOL(rxrpc_kernel_get_rtt);
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	/*
	30	* Hash a peer key.
	31	*/
	32	static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
	33	const struct sockaddr_rxrpc *srx)
	34	{
	35	const u16 *p;
	36	unsigned int i, size;
	37	unsigned long hash_key;
	38
	39	_enter("");
	40
	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;
	45
	46	switch (srx->transport.family) {
	47	case AF_INET:
	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;
	51	break;
d1912747	52	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	53	case AF_INET6:
	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;
	57	break;
d1912747	58	#endif
2f9f9f52 AB	59	default:
	60	WARN(1, "AF_RXRPC: Unsupported transport address family\n");
	61	return 0;
be6e6707 DH	62	}
	63
	64	/* Step through the peer address in 16-bit portions for speed */
	65	for (i = 0; i < size; i += sizeof(*p), p++)
	66	hash_key += *p;
	67
	68	_leave(" 0x%lx", hash_key);
	69	return hash_key;
	70	}
	71
	72	/*
	73	* Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
	74	* or greater than.
	75	*
	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.
	79	*/
	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)
	84	{
	85	long diff;
	86
	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));
	92	if (diff != 0)
	93	return diff;
	94
	95	switch (srx->transport.family) {
	96	case AF_INET:
	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));
d1912747	102	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	103	case AF_INET6:
	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));
d1912747	109	#endif
be6e6707 DH	110	default:
	111	BUG();
	112	}
	113	}
	114
	115	/*
	116	* Look up a remote transport endpoint for the specified address using RCU.
	117	*/
	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)
	122	{
	123	struct rxrpc_peer *peer;
2baec2c3	124	struct rxrpc_net *rxnet = local->rxnet;
be6e6707	125
2baec2c3	126	hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
be6e6707 DH	127	if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0) {
	128	if (atomic_read(&peer->usage) == 0)
	129	return NULL;
	130	return peer;
	131	}
	132	}
	133
	134	return NULL;
	135	}
	136
	137	/*
	138	* Look up a remote transport endpoint for the specified address using RCU.
	139	*/
	140	struct rxrpc_peer rxrpc_lookup_peer_rcu(struct rxrpc_local local,
	141	const struct sockaddr_rxrpc *srx)
	142	{
	143	struct rxrpc_peer *peer;
	144	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
	145
	146	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	147	if (peer) {
75b54cb5	148	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
be6e6707 DH	149	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
	150	}
	151	return peer;
	152	}
17926a79	153
224711df DH	154	/*
	155	* assess the MTU size for the network interface through which this peer is
	156	* reached
	157	*/
	158	static void rxrpc_assess_MTU_size(struct rxrpc_peer *peer)
	159	{
75b54cb5	160	struct dst_entry *dst;
224711df	161	struct rtable *rt;
75b54cb5 DH	162	struct flowi fl;
75b54cb5 DH	163	struct flowi4 *fl4 = &fl.u.ip4;
d1912747	164	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5	165	struct flowi6 *fl6 = &fl.u.ip6;
d1912747	166	#endif
224711df DH	167
	168	peer->if_mtu = 1500;
	169
75b54cb5 DH	170	memset(&fl, 0, sizeof(fl));
	171	switch (peer->srx.transport.family) {
	172	case AF_INET:
	173	rt = ip_route_output_ports(
	174	&init_net, fl4, NULL,
	175	peer->srx.transport.sin.sin_addr.s_addr, 0,
	176	htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
	177	if (IS_ERR(rt)) {
	178	_leave(" [route err %ld]", PTR_ERR(rt));
	179	return;
	180	}
	181	dst = &rt->dst;
	182	break;
	183
d1912747	184	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	185	case AF_INET6:
	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(&init_net, NULL, fl6);
07096f61 DH	194	if (dst->error) {
07096f61 DH	195	_leave(" [route err %d]", dst->error);
75b54cb5 DH	196	return;
	197	}
	198	break;
d1912747	199	#endif
75b54cb5 DH	200
	201	default:
	202	BUG();
224711df DH	203	}
224711df DH	204
75b54cb5 DH	205	peer->if_mtu = dst_mtu(dst);
75b54cb5 DH	206	dst_release(dst);
224711df	207
a6a62b69	208	_leave(" [if_mtu %u]", peer->if_mtu);
224711df DH	209	}
224711df DH	210
17926a79	211	/*
be6e6707	212	* Allocate a peer.
17926a79	213	*/
be6e6707	214	struct rxrpc_peer rxrpc_alloc_peer(struct rxrpc_local local, gfp_t gfp)
17926a79 DH	215	{
	216	struct rxrpc_peer *peer;
	217
	218	_enter("");
	219
	220	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	221	if (peer) {
be6e6707 DH	222	atomic_set(&peer->usage, 1);
be6e6707 DH	223	peer->local = local;
f66d7490 DH	224	INIT_HLIST_HEAD(&peer->error_targets);
	225	INIT_WORK(&peer->error_distributor,
	226	&rxrpc_peer_error_distributor);
aa390bbe	227	peer->service_conns = RB_ROOT;
8496af50	228	seqlock_init(&peer->service_conn_lock);
17926a79	229	spin_lock_init(&peer->lock);
17926a79	230	peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
f7aec129 DH	231
	232	if (RXRPC_TX_SMSS > 2190)
	233	peer->cong_cwnd = 2;
	234	else if (RXRPC_TX_SMSS > 1095)
	235	peer->cong_cwnd = 3;
	236	else
	237	peer->cong_cwnd = 4;
be6e6707 DH	238	}
	239
	240	_leave(" = %p", peer);
	241	return peer;
	242	}
	243
248f219c DH	244	/*
	245	* Initialise peer record.
	246	*/
	247	static void rxrpc_init_peer(struct rxrpc_peer *peer, unsigned long hash_key)
	248	{
08a39685	249	peer->hash_key = hash_key;
248f219c DH	250	rxrpc_assess_MTU_size(peer);
248f219c DH	251	peer->mtu = peer->if_mtu;
0d4b103c	252	peer->rtt_last_req = ktime_get_real();
248f219c	253
75b54cb5 DH	254	switch (peer->srx.transport.family) {
75b54cb5 DH	255	case AF_INET:
248f219c	256	peer->hdrsize = sizeof(struct iphdr);
75b54cb5	257	break;
d1912747	258	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	259	case AF_INET6:
	260	peer->hdrsize = sizeof(struct ipv6hdr);
	261	break;
d1912747	262	#endif
75b54cb5 DH	263	default:
	264	BUG();
	265	}
	266
	267	switch (peer->srx.transport_type) {
	268	case SOCK_DGRAM:
	269	peer->hdrsize += sizeof(struct udphdr);
	270	break;
	271	default:
248f219c DH	272	BUG();
	273	}
	274
	275	peer->hdrsize += sizeof(struct rxrpc_wire_header);
	276	peer->maxdata = peer->mtu - peer->hdrsize;
	277	}
	278
be6e6707 DH	279	/*
	280	* Set up a new peer.
	281	*/
	282	static struct rxrpc_peer rxrpc_create_peer(struct rxrpc_local local,
	283	struct sockaddr_rxrpc *srx,
	284	unsigned long hash_key,
	285	gfp_t gfp)
	286	{
	287	struct rxrpc_peer *peer;
	288
	289	_enter("");
	290
	291	peer = rxrpc_alloc_peer(local, gfp);
	292	if (peer) {
17926a79	293	memcpy(&peer->srx, srx, sizeof(*srx));
248f219c DH	294	rxrpc_init_peer(peer, hash_key);
248f219c DH	295	}
17926a79	296
248f219c DH	297	_leave(" = %p", peer);
	298	return peer;
	299	}
17926a79	300
248f219c DH	301	/*
	302	* Set up a new incoming peer. The address is prestored in the preallocated
	303	* peer.
	304	*/
	305	struct rxrpc_peer rxrpc_lookup_incoming_peer(struct rxrpc_local local,
	306	struct rxrpc_peer *prealloc)
	307	{
	308	struct rxrpc_peer *peer;
2baec2c3	309	struct rxrpc_net *rxnet = local->rxnet;
248f219c DH	310	unsigned long hash_key;
	311
	312	hash_key = rxrpc_peer_hash_key(local, &prealloc->srx);
	313	prealloc->local = local;
	314	rxrpc_init_peer(prealloc, hash_key);
	315
2baec2c3	316	spin_lock(&rxnet->peer_hash_lock);
248f219c DH	317
	318	/* Need to check that we aren't racing with someone else */
	319	peer = __rxrpc_lookup_peer_rcu(local, &prealloc->srx, hash_key);
	320	if (peer && !rxrpc_get_peer_maybe(peer))
	321	peer = NULL;
	322	if (!peer) {
	323	peer = prealloc;
2baec2c3	324	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
17926a79 DH	325	}
17926a79 DH	326
2baec2c3	327	spin_unlock(&rxnet->peer_hash_lock);
17926a79 DH	328	return peer;
	329	}
	330
	331	/*
	332	* obtain a remote transport endpoint for the specified address
	333	*/
be6e6707 DH	334	struct rxrpc_peer rxrpc_lookup_peer(struct rxrpc_local local,
be6e6707 DH	335	struct sockaddr_rxrpc *srx, gfp_t gfp)
17926a79 DH	336	{
17926a79 DH	337	struct rxrpc_peer peer, candidate;
2baec2c3	338	struct rxrpc_net *rxnet = local->rxnet;
be6e6707	339	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
17926a79	340
75b54cb5	341	_enter("{%pISp}", &srx->transport);
17926a79 DH	342
17926a79 DH	343	/* search the peer list first */
be6e6707 DH	344	rcu_read_lock();
	345	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	346	if (peer && !rxrpc_get_peer_maybe(peer))
	347	peer = NULL;
	348	rcu_read_unlock();
	349
	350	if (!peer) {
	351	/* The peer is not yet present in hash - create a candidate
	352	* for a new record and then redo the search.
	353	*/
	354	candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
	355	if (!candidate) {
	356	_leave(" = NULL [nomem]");
	357	return NULL;
	358	}
17926a79	359
2baec2c3	360	spin_lock_bh(&rxnet->peer_hash_lock);
17926a79	361
be6e6707 DH	362	/* Need to check that we aren't racing with someone else */
	363	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	364	if (peer && !rxrpc_get_peer_maybe(peer))
	365	peer = NULL;
	366	if (!peer)
2baec2c3	367	hash_add_rcu(rxnet->peer_hash,
be6e6707	368	&candidate->hash_link, hash_key);
17926a79	369
2baec2c3	370	spin_unlock_bh(&rxnet->peer_hash_lock);
17926a79	371
be6e6707 DH	372	if (peer)
	373	kfree(candidate);
	374	else
	375	peer = candidate;
	376	}
17926a79	377
75b54cb5	378	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
17926a79	379
be6e6707	380	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
17926a79	381	return peer;
17926a79 DH	382	}
	383
	384	/*
be6e6707	385	* Discard a ref on a remote peer record.
17926a79	386	*/
be6e6707	387	void __rxrpc_put_peer(struct rxrpc_peer *peer)
17926a79	388	{
2baec2c3 DH	389	struct rxrpc_net *rxnet = peer->local->rxnet;
2baec2c3 DH	390
f66d7490	391	ASSERT(hlist_empty(&peer->error_targets));
17926a79	392
2baec2c3	393	spin_lock_bh(&rxnet->peer_hash_lock);
be6e6707	394	hash_del_rcu(&peer->hash_link);
2baec2c3	395	spin_unlock_bh(&rxnet->peer_hash_lock);
17926a79	396
be6e6707	397	kfree_rcu(peer, rcu);
17926a79	398	}
8324f0bc DH	399
	400	/**
	401	* rxrpc_kernel_get_peer - Get the peer address of a call
	402	* @sock: The socket on which the call is in progress.
	403	* @call: The call to query
	404	* @_srx: Where to place the result
	405	*
	406	* Get the address of the remote peer in a call.
	407	*/
	408	void rxrpc_kernel_get_peer(struct socket sock, struct rxrpc_call call,
	409	struct sockaddr_rxrpc *_srx)
	410	{
	411	*_srx = call->peer->srx;
	412	}
	413	EXPORT_SYMBOL(rxrpc_kernel_get_peer);
f4d15fb6 DH	414
	415	/**
	416	* rxrpc_kernel_get_rtt - Get a call's peer RTT
	417	* @sock: The socket on which the call is in progress.
	418	* @call: The call to query
	419	*
	420	* Get the call's peer RTT.
	421	*/
	422	u64 rxrpc_kernel_get_rtt(struct socket sock, struct rxrpc_call call)
	423	{
	424	return call->peer->rtt;
	425	}
	426	EXPORT_SYMBOL(rxrpc_kernel_get_rtt);