[thirdparty/linux.git] / net / rxrpc / peer_object.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC remote transport endpoint record management
 *
 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#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 &&
		    atomic_read(&peer->usage) > 0)
			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_sock *rx,
				  struct rxrpc_peer *peer)
{
	struct net *net = sock_net(&rx->sk);
	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(
			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(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)
{
	const void *here = __builtin_return_address(0);
	struct rxrpc_peer *peer;

	_enter("");

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

		rxrpc_peer_init_rtt(peer);

		if (RXRPC_TX_SMSS > 2190)
			peer->cong_cwnd = 2;
		else if (RXRPC_TX_SMSS > 1095)
			peer->cong_cwnd = 3;
		else
			peer->cong_cwnd = 4;
		trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here);
	}

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

/*
 * Initialise peer record.
 */
static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer,
			    unsigned long hash_key)
{
	peer->hash_key = hash_key;
	rxrpc_assess_MTU_size(rx, 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_sock *rx,
					    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(rx, peer, hash_key);
	}

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

/*
 * Set up a new incoming peer.  There shouldn't be any other matching peers
 * since we've already done a search in the list from the non-reentrant context
 * (the data_ready handler) that is the only place we can add new peers.
 */
void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local,
			     struct rxrpc_peer *peer)
{
	struct rxrpc_net *rxnet = local->rxnet;
	unsigned long hash_key;

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

	spin_lock(&rxnet->peer_hash_lock);
	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
	spin_unlock(&rxnet->peer_hash_lock);
}

/*
 * obtain a remote transport endpoint for the specified address
 */
struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx,
				     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(rx, 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);
			list_add_tail(&candidate->keepalive_link,
				      &rxnet->peer_keepalive_new);
		}

		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;
}

/*
 * Get a ref on a peer record.
 */
struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
{
	const void *here = __builtin_return_address(0);
	int n;

	n = atomic_inc_return(&peer->usage);
	trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n, here);
	return peer;
}

/*
 * Get a ref on a peer record unless its usage has already reached 0.
 */
struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer)
{
	const void *here = __builtin_return_address(0);

	if (peer) {
		int n = atomic_fetch_add_unless(&peer->usage, 1, 0);
		if (n > 0)
			trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n + 1, here);
		else
			peer = NULL;
	}
	return peer;
}

/*
 * Discard a peer record.
 */
static 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);
	list_del_init(&peer->keepalive_link);
	spin_unlock_bh(&rxnet->peer_hash_lock);

	rxrpc_put_local(peer->local);
	kfree_rcu(peer, rcu);
}

/*
 * Drop a ref on a peer record.
 */
void rxrpc_put_peer(struct rxrpc_peer *peer)
{
	const void *here = __builtin_return_address(0);
	unsigned int debug_id;
	int n;

	if (peer) {
		debug_id = peer->debug_id;
		n = atomic_dec_return(&peer->usage);
		trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
		if (n == 0)
			__rxrpc_put_peer(peer);
	}
}

/*
 * Drop a ref on a peer record where the caller already holds the
 * peer_hash_lock.
 */
void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
{
	const void *here = __builtin_return_address(0);
	unsigned int debug_id = peer->debug_id;
	int n;

	n = atomic_dec_return(&peer->usage);
	trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
	if (n == 0) {
		hash_del_rcu(&peer->hash_link);
		list_del_init(&peer->keepalive_link);
		rxrpc_put_local(peer->local);
		kfree_rcu(peer, rcu);
	}
}

/*
 * Make sure all peer records have been discarded.
 */
void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
{
	struct rxrpc_peer *peer;
	int i;

	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
		if (hlist_empty(&rxnet->peer_hash[i]))
			continue;

		hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
			pr_err("Leaked peer %u {%u} %pISp\n",
			       peer->debug_id,
			       atomic_read(&peer->usage),
			       &peer->srx.transport);
		}
	}
}

/**
 * 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_srtt - Get a call's peer smoothed RTT
 * @sock: The socket on which the call is in progress.
 * @call: The call to query
 *
 * Get the call's peer smoothed RTT.
 */
u32 rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call)
{
	return call->peer->srtt_us >> 3;
}
EXPORT_SYMBOL(rxrpc_kernel_get_srtt);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
be6e6707	2	/* RxRPC remote transport endpoint record management
17926a79	3	*
be6e6707	4	* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
17926a79	5	* Written by David Howells (dhowells@redhat.com)
17926a79 DH	6	*/
17926a79 DH	7
9b6d5398 JP	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9b6d5398 JP	9
17926a79 DH	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>
75b54cb5	15	#include <linux/in6.h>
5a0e3ad6	16	#include <linux/slab.h>
be6e6707	17	#include <linux/hashtable.h>
17926a79 DH	18	#include <net/sock.h>
	19	#include <net/af_rxrpc.h>
	20	#include <net/ip.h>
224711df	21	#include <net/route.h>
75b54cb5	22	#include <net/ip6_route.h>
17926a79 DH	23	#include "ar-internal.h"
17926a79 DH	24
be6e6707 DH	25	/*
	26	* Hash a peer key.
	27	*/
	28	static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
	29	const struct sockaddr_rxrpc *srx)
	30	{
	31	const u16 *p;
	32	unsigned int i, size;
	33	unsigned long hash_key;
	34
	35	_enter("");
	36
	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;
	41
	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;
d1912747	48	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	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;
d1912747	54	#endif
2f9f9f52 AB	55	default:
	56	WARN(1, "AF_RXRPC: Unsupported transport address family\n");
	57	return 0;
be6e6707 DH	58	}
	59
	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;
	63
	64	_leave(" 0x%lx", hash_key);
	65	return hash_key;
	66	}
	67
	68	/*
	69	* Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
	70	* or greater than.
	71	*
	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.
	75	*/
	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)
	80	{
	81	long diff;
	82
	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;
	90
	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));
d1912747	98	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	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));
d1912747	105	#endif
be6e6707 DH	106	default:
	107	BUG();
	108	}
	109	}
	110
	111	/*
	112	* Look up a remote transport endpoint for the specified address using RCU.
	113	*/
	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)
	118	{
	119	struct rxrpc_peer *peer;
2baec2c3	120	struct rxrpc_net *rxnet = local->rxnet;
be6e6707	121
2baec2c3	122	hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
0099dc58 DH	123	if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
0099dc58 DH	124	atomic_read(&peer->usage) > 0)
be6e6707	125	return peer;
be6e6707 DH	126	}
	127
	128	return NULL;
	129	}
	130
	131	/*
	132	* Look up a remote transport endpoint for the specified address using RCU.
	133	*/
	134	struct rxrpc_peer rxrpc_lookup_peer_rcu(struct rxrpc_local local,
	135	const struct sockaddr_rxrpc *srx)
	136	{
	137	struct rxrpc_peer *peer;
	138	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
	139
	140	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
	141	if (peer) {
75b54cb5	142	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
be6e6707 DH	143	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
	144	}
	145	return peer;
	146	}
17926a79	147
224711df DH	148	/*
	149	* assess the MTU size for the network interface through which this peer is
	150	* reached
	151	*/
5e33a23b DH	152	static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
5e33a23b DH	153	struct rxrpc_peer *peer)
224711df	154	{
5e33a23b	155	struct net *net = sock_net(&rx->sk);
75b54cb5	156	struct dst_entry *dst;
224711df	157	struct rtable *rt;
75b54cb5 DH	158	struct flowi fl;
75b54cb5 DH	159	struct flowi4 *fl4 = &fl.u.ip4;
d1912747	160	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5	161	struct flowi6 *fl6 = &fl.u.ip6;
d1912747	162	#endif
224711df DH	163
	164	peer->if_mtu = 1500;
	165
75b54cb5 DH	166	memset(&fl, 0, sizeof(fl));
	167	switch (peer->srx.transport.family) {
	168	case AF_INET:
	169	rt = ip_route_output_ports(
5e33a23b	170	net, fl4, NULL,
75b54cb5 DH	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;
	176	}
	177	dst = &rt->dst;
	178	break;
	179
d1912747	180	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	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);
5e33a23b	189	dst = ip6_route_output(net, NULL, fl6);
07096f61 DH	190	if (dst->error) {
07096f61 DH	191	_leave(" [route err %d]", dst->error);
75b54cb5 DH	192	return;
	193	}
	194	break;
d1912747	195	#endif
75b54cb5 DH	196
	197	default:
	198	BUG();
224711df DH	199	}
224711df DH	200
75b54cb5 DH	201	peer->if_mtu = dst_mtu(dst);
75b54cb5 DH	202	dst_release(dst);
224711df	203
a6a62b69	204	_leave(" [if_mtu %u]", peer->if_mtu);
224711df DH	205	}
224711df DH	206
17926a79	207	/*
be6e6707	208	* Allocate a peer.
17926a79	209	*/
be6e6707	210	struct rxrpc_peer rxrpc_alloc_peer(struct rxrpc_local local, gfp_t gfp)
17926a79	211	{
033b2c7f	212	const void *here = __builtin_return_address(0);
17926a79 DH	213	struct rxrpc_peer *peer;
	214
	215	_enter("");
	216
	217	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	218	if (peer) {
be6e6707	219	atomic_set(&peer->usage, 1);
9ebeddef	220	peer->local = rxrpc_get_local(local);
f66d7490	221	INIT_HLIST_HEAD(&peer->error_targets);
aa390bbe	222	peer->service_conns = RB_ROOT;
8496af50	223	seqlock_init(&peer->service_conn_lock);
17926a79	224	spin_lock_init(&peer->lock);
c1e15b49	225	spin_lock_init(&peer->rtt_input_lock);
17926a79	226	peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
f7aec129	227
c410bf01 DH	228	rxrpc_peer_init_rtt(peer);
c410bf01 DH	229
f7aec129 DH	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;
2f184393	236	trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here);
be6e6707 DH	237	}
	238
	239	_leave(" = %p", peer);
	240	return peer;
	241	}
	242
248f219c DH	243	/*
	244	* Initialise peer record.
	245	*/
5e33a23b DH	246	static void rxrpc_init_peer(struct rxrpc_sock rx, struct rxrpc_peer peer,
5e33a23b DH	247	unsigned long hash_key)
248f219c	248	{
08a39685	249	peer->hash_key = hash_key;
5e33a23b	250	rxrpc_assess_MTU_size(rx, peer);
248f219c	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	*/
5e33a23b DH	282	static struct rxrpc_peer rxrpc_create_peer(struct rxrpc_sock rx,
5e33a23b DH	283	struct rxrpc_local *local,
be6e6707 DH	284	struct sockaddr_rxrpc *srx,
	285	unsigned long hash_key,
	286	gfp_t gfp)
	287	{
	288	struct rxrpc_peer *peer;
	289
	290	_enter("");
	291
	292	peer = rxrpc_alloc_peer(local, gfp);
	293	if (peer) {
17926a79	294	memcpy(&peer->srx, srx, sizeof(*srx));
5e33a23b	295	rxrpc_init_peer(rx, peer, hash_key);
248f219c	296	}
17926a79	297
248f219c DH	298	_leave(" = %p", peer);
	299	return peer;
	300	}
17926a79	301
248f219c	302	/*
0099dc58 DH	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.
248f219c	306	*/
5e33a23b DH	307	void rxrpc_new_incoming_peer(struct rxrpc_sock rx, struct rxrpc_local local,
5e33a23b DH	308	struct rxrpc_peer *peer)
248f219c	309	{
2baec2c3	310	struct rxrpc_net *rxnet = local->rxnet;
248f219c DH	311	unsigned long hash_key;
248f219c DH	312
0099dc58	313	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
5e33a23b	314	rxrpc_init_peer(rx, peer, hash_key);
248f219c	315
2baec2c3	316	spin_lock(&rxnet->peer_hash_lock);
0099dc58 DH	317	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
0099dc58 DH	318	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
2baec2c3	319	spin_unlock(&rxnet->peer_hash_lock);
17926a79 DH	320	}
	321
	322	/*
	323	* obtain a remote transport endpoint for the specified address
	324	*/
5e33a23b DH	325	struct rxrpc_peer rxrpc_lookup_peer(struct rxrpc_sock rx,
5e33a23b DH	326	struct rxrpc_local *local,
be6e6707	327	struct sockaddr_rxrpc *srx, gfp_t gfp)
17926a79 DH	328	{
17926a79 DH	329	struct rxrpc_peer peer, candidate;
2baec2c3	330	struct rxrpc_net *rxnet = local->rxnet;
be6e6707	331	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
17926a79	332
75b54cb5	333	_enter("{%pISp}", &srx->transport);
17926a79 DH	334
17926a79 DH	335	/* search the peer list first */
be6e6707 DH	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();
	341
	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.
	345	*/
5e33a23b	346	candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp);
be6e6707 DH	347	if (!candidate) {
	348	_leave(" = NULL [nomem]");
	349	return NULL;
	350	}
17926a79	351
2baec2c3	352	spin_lock_bh(&rxnet->peer_hash_lock);
17926a79	353
be6e6707 DH	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;
ace45bec	358	if (!peer) {
2baec2c3	359	hash_add_rcu(rxnet->peer_hash,
be6e6707	360	&candidate->hash_link, hash_key);
330bdcfa DH	361	list_add_tail(&candidate->keepalive_link,
330bdcfa DH	362	&rxnet->peer_keepalive_new);
ace45bec	363	}
17926a79	364
2baec2c3	365	spin_unlock_bh(&rxnet->peer_hash_lock);
17926a79	366
be6e6707 DH	367	if (peer)
	368	kfree(candidate);
	369	else
	370	peer = candidate;
	371	}
17926a79	372
75b54cb5	373	_net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
17926a79	374
be6e6707	375	_leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
17926a79	376	return peer;
17926a79 DH	377	}
	378
	379	/*
1159d4b4	380	* Get a ref on a peer record.
17926a79	381	*/
1159d4b4 DH	382	struct rxrpc_peer rxrpc_get_peer(struct rxrpc_peer peer)
	383	{
	384	const void *here = __builtin_return_address(0);
	385	int n;
	386
	387	n = atomic_inc_return(&peer->usage);
55f6c98e	388	trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n, here);
1159d4b4 DH	389	return peer;
	390	}
	391
	392	/*
	393	* Get a ref on a peer record unless its usage has already reached 0.
	394	*/
	395	struct rxrpc_peer rxrpc_get_peer_maybe(struct rxrpc_peer peer)
	396	{
	397	const void *here = __builtin_return_address(0);
	398
	399	if (peer) {
bfc18e38	400	int n = atomic_fetch_add_unless(&peer->usage, 1, 0);
1159d4b4	401	if (n > 0)
55f6c98e	402	trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n + 1, here);
1159d4b4 DH	403	else
	404	peer = NULL;
	405	}
	406	return peer;
	407	}
	408
1159d4b4 DH	409	/*
	410	* Discard a peer record.
	411	*/
	412	static void __rxrpc_put_peer(struct rxrpc_peer *peer)
17926a79	413	{
2baec2c3 DH	414	struct rxrpc_net *rxnet = peer->local->rxnet;
2baec2c3 DH	415
f66d7490	416	ASSERT(hlist_empty(&peer->error_targets));
17926a79	417
2baec2c3	418	spin_lock_bh(&rxnet->peer_hash_lock);
be6e6707	419	hash_del_rcu(&peer->hash_link);
330bdcfa	420	list_del_init(&peer->keepalive_link);
2baec2c3	421	spin_unlock_bh(&rxnet->peer_hash_lock);
17926a79	422
9ebeddef	423	rxrpc_put_local(peer->local);
be6e6707	424	kfree_rcu(peer, rcu);
17926a79	425	}
8324f0bc	426
1159d4b4 DH	427	/*
	428	* Drop a ref on a peer record.
	429	*/
	430	void rxrpc_put_peer(struct rxrpc_peer *peer)
	431	{
	432	const void *here = __builtin_return_address(0);
55f6c98e	433	unsigned int debug_id;
1159d4b4 DH	434	int n;
	435
	436	if (peer) {
55f6c98e	437	debug_id = peer->debug_id;
1159d4b4	438	n = atomic_dec_return(&peer->usage);
55f6c98e	439	trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
1159d4b4 DH	440	if (n == 0)
	441	__rxrpc_put_peer(peer);
	442	}
	443	}
	444
60034d3d DH	445	/*
	446	* Drop a ref on a peer record where the caller already holds the
	447	* peer_hash_lock.
	448	*/
	449	void rxrpc_put_peer_locked(struct rxrpc_peer *peer)
	450	{
	451	const void *here = __builtin_return_address(0);
55f6c98e	452	unsigned int debug_id = peer->debug_id;
60034d3d DH	453	int n;
	454
	455	n = atomic_dec_return(&peer->usage);
55f6c98e	456	trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here);
60034d3d DH	457	if (n == 0) {
	458	hash_del_rcu(&peer->hash_link);
	459	list_del_init(&peer->keepalive_link);
9ebeddef	460	rxrpc_put_local(peer->local);
60034d3d DH	461	kfree_rcu(peer, rcu);
	462	}
	463	}
	464
17226f12 DH	465	/*
	466	* Make sure all peer records have been discarded.
	467	*/
	468	void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
	469	{
	470	struct rxrpc_peer *peer;
	471	int i;
	472
	473	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
	474	if (hlist_empty(&rxnet->peer_hash[i]))
	475	continue;
	476
	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);
	482	}
	483	}
	484	}
	485
8324f0bc DH	486	/**
	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
	491	*
	492	* Get the address of the remote peer in a call.
	493	*/
	494	void rxrpc_kernel_get_peer(struct socket sock, struct rxrpc_call call,
	495	struct sockaddr_rxrpc *_srx)
	496	{
	497	*_srx = call->peer->srx;
	498	}
	499	EXPORT_SYMBOL(rxrpc_kernel_get_peer);
f4d15fb6 DH	500
f4d15fb6 DH	501	/**
c410bf01	502	* rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
f4d15fb6 DH	503	* @sock: The socket on which the call is in progress.
	504	* @call: The call to query
	505	*
c410bf01	506	* Get the call's peer smoothed RTT.
f4d15fb6	507	*/
c410bf01	508	u32 rxrpc_kernel_get_srtt(struct socket sock, struct rxrpc_call call)
f4d15fb6	509	{
c410bf01	510	return call->peer->srtt_us >> 3;
f4d15fb6	511	}
c410bf01	512	EXPORT_SYMBOL(rxrpc_kernel_get_srtt);