[linux-2.6-block.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 &&
		    refcount_read(&peer->ref) > 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)
		_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
	return peer;
}

/*
 * assess the MTU size for the network interface through which this peer is
 * reached
 */
static void rxrpc_assess_MTU_size(struct rxrpc_local *local,
				  struct rxrpc_peer *peer)
{
	struct net *net = local->net;
	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,
				    enum rxrpc_peer_trace why)
{
	struct rxrpc_peer *peer;

	_enter("");

	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	if (peer) {
		refcount_set(&peer->ref, 1);
		peer->local = rxrpc_get_local(local, rxrpc_local_get_peer);
		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);

		peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
		trace_rxrpc_peer(peer->debug_id, 1, why);
	}

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

/*
 * Initialise peer record.
 */
static void rxrpc_init_peer(struct rxrpc_local *local, struct rxrpc_peer *peer,
			    unsigned long hash_key)
{
	peer->hash_key = hash_key;
	rxrpc_assess_MTU_size(local, 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, rxrpc_peer_new_client);
	if (peer) {
		memcpy(&peer->srx, srx, sizeof(*srx));
		rxrpc_init_peer(local, peer, hash_key);
	}

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

static void rxrpc_free_peer(struct rxrpc_peer *peer)
{
	trace_rxrpc_peer(peer->debug_id, 0, rxrpc_peer_free);
	rxrpc_put_local(peer->local, rxrpc_local_put_peer);
	kfree_rcu(peer, rcu);
}

/*
 * 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_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(local, 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_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, rxrpc_peer_get_lookup_client))
		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(&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, rxrpc_peer_get_lookup_client))
			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(&rxnet->peer_hash_lock);

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

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

/*
 * Get a ref on a peer record.
 */
struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
{
	int r;

	__refcount_inc(&peer->ref, &r);
	trace_rxrpc_peer(peer->debug_id, r + 1, why);
	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,
					enum rxrpc_peer_trace why)
{
	int r;

	if (peer) {
		if (__refcount_inc_not_zero(&peer->ref, &r))
			trace_rxrpc_peer(peer->debug_id, r + 1, why);
		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(&rxnet->peer_hash_lock);
	hash_del_rcu(&peer->hash_link);
	list_del_init(&peer->keepalive_link);
	spin_unlock(&rxnet->peer_hash_lock);

	rxrpc_free_peer(peer);
}

/*
 * Drop a ref on a peer record.
 */
void rxrpc_put_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
{
	unsigned int debug_id;
	bool dead;
	int r;

	if (peer) {
		debug_id = peer->debug_id;
		dead = __refcount_dec_and_test(&peer->ref, &r);
		trace_rxrpc_peer(debug_id, r - 1, why);
		if (dead)
			__rxrpc_put_peer(peer);
	}
}

/*
 * 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,
			       refcount_read(&peer->ref),
			       &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
 * @_srtt: Where to store the SRTT value.
 *
 * Get the call's peer smoothed RTT in uS.
 */
bool rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call,
			   u32 *_srtt)
{
	struct rxrpc_peer *peer = call->peer;

	if (peer->rtt_count == 0) {
		*_srtt = 1000000; /* 1S */
		return false;
	}

	*_srtt = call->peer->srtt_us >> 3;
	return true;
}
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	123	if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
a0575429	124	refcount_read(&peer->ref) > 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);
e969c92c	141	if (peer)
a0575429	142	_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
be6e6707 DH	143	return peer;
be6e6707 DH	144	}
17926a79	145
224711df DH	146	/*
	147	* assess the MTU size for the network interface through which this peer is
	148	* reached
	149	*/
8a758d98	150	static void rxrpc_assess_MTU_size(struct rxrpc_local *local,
5e33a23b	151	struct rxrpc_peer *peer)
224711df	152	{
8a758d98	153	struct net *net = local->net;
75b54cb5	154	struct dst_entry *dst;
224711df	155	struct rtable *rt;
75b54cb5 DH	156	struct flowi fl;
75b54cb5 DH	157	struct flowi4 *fl4 = &fl.u.ip4;
d1912747	158	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5	159	struct flowi6 *fl6 = &fl.u.ip6;
d1912747	160	#endif
224711df DH	161
	162	peer->if_mtu = 1500;
	163
75b54cb5 DH	164	memset(&fl, 0, sizeof(fl));
	165	switch (peer->srx.transport.family) {
	166	case AF_INET:
	167	rt = ip_route_output_ports(
5e33a23b	168	net, fl4, NULL,
75b54cb5 DH	169	peer->srx.transport.sin.sin_addr.s_addr, 0,
	170	htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
	171	if (IS_ERR(rt)) {
	172	_leave(" [route err %ld]", PTR_ERR(rt));
	173	return;
	174	}
	175	dst = &rt->dst;
	176	break;
	177
d1912747	178	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	179	case AF_INET6:
	180	fl6->flowi6_iif = LOOPBACK_IFINDEX;
	181	fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
	182	fl6->flowi6_proto = IPPROTO_UDP;
	183	memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
	184	sizeof(struct in6_addr));
	185	fl6->fl6_dport = htons(7001);
	186	fl6->fl6_sport = htons(7000);
5e33a23b	187	dst = ip6_route_output(net, NULL, fl6);
07096f61 DH	188	if (dst->error) {
07096f61 DH	189	_leave(" [route err %d]", dst->error);
75b54cb5 DH	190	return;
	191	}
	192	break;
d1912747	193	#endif
75b54cb5 DH	194
	195	default:
	196	BUG();
224711df DH	197	}
224711df DH	198
75b54cb5 DH	199	peer->if_mtu = dst_mtu(dst);
75b54cb5 DH	200	dst_release(dst);
224711df	201
a6a62b69	202	_leave(" [if_mtu %u]", peer->if_mtu);
224711df DH	203	}
224711df DH	204
17926a79	205	/*
be6e6707	206	* Allocate a peer.
17926a79	207	*/
47c810a7 DH	208	struct rxrpc_peer rxrpc_alloc_peer(struct rxrpc_local local, gfp_t gfp,
47c810a7 DH	209	enum rxrpc_peer_trace why)
17926a79 DH	210	{
	211	struct rxrpc_peer *peer;
	212
	213	_enter("");
	214
	215	peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
	216	if (peer) {
a0575429	217	refcount_set(&peer->ref, 1);
0fde882f	218	peer->local = rxrpc_get_local(local, rxrpc_local_get_peer);
f66d7490	219	INIT_HLIST_HEAD(&peer->error_targets);
aa390bbe	220	peer->service_conns = RB_ROOT;
8496af50	221	seqlock_init(&peer->service_conn_lock);
17926a79	222	spin_lock_init(&peer->lock);
c1e15b49	223	spin_lock_init(&peer->rtt_input_lock);
17926a79	224	peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
f7aec129	225
c410bf01 DH	226	rxrpc_peer_init_rtt(peer);
c410bf01 DH	227
1fc4fa2a	228	peer->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
c838f1a7	229	trace_rxrpc_peer(peer->debug_id, 1, why);
be6e6707 DH	230	}
	231
	232	_leave(" = %p", peer);
	233	return peer;
	234	}
	235
248f219c DH	236	/*
	237	* Initialise peer record.
	238	*/
8a758d98	239	static void rxrpc_init_peer(struct rxrpc_local local, struct rxrpc_peer peer,
5e33a23b	240	unsigned long hash_key)
248f219c	241	{
08a39685	242	peer->hash_key = hash_key;
8a758d98	243	rxrpc_assess_MTU_size(local, peer);
248f219c	244	peer->mtu = peer->if_mtu;
0d4b103c	245	peer->rtt_last_req = ktime_get_real();
248f219c	246
75b54cb5 DH	247	switch (peer->srx.transport.family) {
75b54cb5 DH	248	case AF_INET:
248f219c	249	peer->hdrsize = sizeof(struct iphdr);
75b54cb5	250	break;
d1912747	251	#ifdef CONFIG_AF_RXRPC_IPV6
75b54cb5 DH	252	case AF_INET6:
	253	peer->hdrsize = sizeof(struct ipv6hdr);
	254	break;
d1912747	255	#endif
75b54cb5 DH	256	default:
	257	BUG();
	258	}
	259
	260	switch (peer->srx.transport_type) {
	261	case SOCK_DGRAM:
	262	peer->hdrsize += sizeof(struct udphdr);
	263	break;
	264	default:
248f219c DH	265	BUG();
	266	}
	267
	268	peer->hdrsize += sizeof(struct rxrpc_wire_header);
	269	peer->maxdata = peer->mtu - peer->hdrsize;
	270	}
	271
be6e6707 DH	272	/*
	273	* Set up a new peer.
	274	*/
8a758d98	275	static struct rxrpc_peer rxrpc_create_peer(struct rxrpc_local local,
be6e6707 DH	276	struct sockaddr_rxrpc *srx,
	277	unsigned long hash_key,
	278	gfp_t gfp)
	279	{
	280	struct rxrpc_peer *peer;
	281
	282	_enter("");
	283
47c810a7	284	peer = rxrpc_alloc_peer(local, gfp, rxrpc_peer_new_client);
be6e6707	285	if (peer) {
17926a79	286	memcpy(&peer->srx, srx, sizeof(*srx));
8a758d98	287	rxrpc_init_peer(local, peer, hash_key);
248f219c	288	}
17926a79	289
248f219c DH	290	_leave(" = %p", peer);
	291	return peer;
	292	}
17926a79	293
beacff50 ET	294	static void rxrpc_free_peer(struct rxrpc_peer *peer)
beacff50 ET	295	{
47c810a7	296	trace_rxrpc_peer(peer->debug_id, 0, rxrpc_peer_free);
0fde882f	297	rxrpc_put_local(peer->local, rxrpc_local_put_peer);
beacff50 ET	298	kfree_rcu(peer, rcu);
	299	}
	300
248f219c	301	/*
0099dc58 DH	302	* Set up a new incoming peer. There shouldn't be any other matching peers
	303	* since we've already done a search in the list from the non-reentrant context
	304	* (the data_ready handler) that is the only place we can add new peers.
248f219c	305	*/
8a758d98	306	void rxrpc_new_incoming_peer(struct rxrpc_local local, struct rxrpc_peer peer)
248f219c	307	{
2baec2c3	308	struct rxrpc_net *rxnet = local->rxnet;
248f219c DH	309	unsigned long hash_key;
248f219c DH	310
0099dc58	311	hash_key = rxrpc_peer_hash_key(local, &peer->srx);
8a758d98	312	rxrpc_init_peer(local, peer, hash_key);
248f219c	313
2baec2c3	314	spin_lock(&rxnet->peer_hash_lock);
0099dc58 DH	315	hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
0099dc58 DH	316	list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
2baec2c3	317	spin_unlock(&rxnet->peer_hash_lock);
17926a79 DH	318	}
	319
	320	/*
	321	* obtain a remote transport endpoint for the specified address
	322	*/
8a758d98	323	struct rxrpc_peer rxrpc_lookup_peer(struct rxrpc_local local,
be6e6707	324	struct sockaddr_rxrpc *srx, gfp_t gfp)
17926a79 DH	325	{
17926a79 DH	326	struct rxrpc_peer peer, candidate;
2baec2c3	327	struct rxrpc_net *rxnet = local->rxnet;
be6e6707	328	unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
17926a79	329
75b54cb5	330	_enter("{%pISp}", &srx->transport);
17926a79 DH	331
17926a79 DH	332	/* search the peer list first */
be6e6707 DH	333	rcu_read_lock();
be6e6707 DH	334	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
47c810a7	335	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
be6e6707 DH	336	peer = NULL;
	337	rcu_read_unlock();
	338
	339	if (!peer) {
	340	/* The peer is not yet present in hash - create a candidate
	341	* for a new record and then redo the search.
	342	*/
8a758d98	343	candidate = rxrpc_create_peer(local, srx, hash_key, gfp);
be6e6707 DH	344	if (!candidate) {
	345	_leave(" = NULL [nomem]");
	346	return NULL;
	347	}
17926a79	348
3dd9c8b5	349	spin_lock(&rxnet->peer_hash_lock);
17926a79	350
be6e6707 DH	351	/* Need to check that we aren't racing with someone else */
be6e6707 DH	352	peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
47c810a7	353	if (peer && !rxrpc_get_peer_maybe(peer, rxrpc_peer_get_lookup_client))
be6e6707	354	peer = NULL;
ace45bec	355	if (!peer) {
2baec2c3	356	hash_add_rcu(rxnet->peer_hash,
be6e6707	357	&candidate->hash_link, hash_key);
330bdcfa DH	358	list_add_tail(&candidate->keepalive_link,
330bdcfa DH	359	&rxnet->peer_keepalive_new);
ace45bec	360	}
17926a79	361
3dd9c8b5	362	spin_unlock(&rxnet->peer_hash_lock);
17926a79	363
be6e6707	364	if (peer)
beacff50	365	rxrpc_free_peer(candidate);
be6e6707 DH	366	else
	367	peer = candidate;
	368	}
17926a79	369
a0575429	370	_leave(" = %p {u=%d}", peer, refcount_read(&peer->ref));
17926a79	371	return peer;
17926a79 DH	372	}
	373
	374	/*
1159d4b4	375	* Get a ref on a peer record.
17926a79	376	*/
47c810a7	377	struct rxrpc_peer rxrpc_get_peer(struct rxrpc_peer peer, enum rxrpc_peer_trace why)
1159d4b4	378	{
a0575429	379	int r;
1159d4b4	380
a0575429	381	__refcount_inc(&peer->ref, &r);
c838f1a7	382	trace_rxrpc_peer(peer->debug_id, r + 1, why);
1159d4b4 DH	383	return peer;
	384	}
	385
	386	/*
	387	* Get a ref on a peer record unless its usage has already reached 0.
	388	*/
47c810a7 DH	389	struct rxrpc_peer rxrpc_get_peer_maybe(struct rxrpc_peer peer,
47c810a7 DH	390	enum rxrpc_peer_trace why)
1159d4b4	391	{
a0575429	392	int r;
1159d4b4 DH	393
1159d4b4 DH	394	if (peer) {
a0575429	395	if (__refcount_inc_not_zero(&peer->ref, &r))
47c810a7	396	trace_rxrpc_peer(peer->debug_id, r + 1, why);
1159d4b4 DH	397	else
	398	peer = NULL;
	399	}
	400	return peer;
	401	}
	402
1159d4b4 DH	403	/*
	404	* Discard a peer record.
	405	*/
	406	static void __rxrpc_put_peer(struct rxrpc_peer *peer)
17926a79	407	{
2baec2c3 DH	408	struct rxrpc_net *rxnet = peer->local->rxnet;
2baec2c3 DH	409
f66d7490	410	ASSERT(hlist_empty(&peer->error_targets));
17926a79	411
3dd9c8b5	412	spin_lock(&rxnet->peer_hash_lock);
be6e6707	413	hash_del_rcu(&peer->hash_link);
330bdcfa	414	list_del_init(&peer->keepalive_link);
3dd9c8b5	415	spin_unlock(&rxnet->peer_hash_lock);
17926a79	416
beacff50	417	rxrpc_free_peer(peer);
17926a79	418	}
8324f0bc	419
1159d4b4 DH	420	/*
	421	* Drop a ref on a peer record.
	422	*/
47c810a7	423	void rxrpc_put_peer(struct rxrpc_peer *peer, enum rxrpc_peer_trace why)
1159d4b4	424	{
55f6c98e	425	unsigned int debug_id;
a0575429 DH	426	bool dead;
a0575429 DH	427	int r;
1159d4b4 DH	428
1159d4b4 DH	429	if (peer) {
55f6c98e	430	debug_id = peer->debug_id;
a0575429	431	dead = __refcount_dec_and_test(&peer->ref, &r);
47c810a7	432	trace_rxrpc_peer(debug_id, r - 1, why);
a0575429	433	if (dead)
1159d4b4 DH	434	__rxrpc_put_peer(peer);
	435	}
	436	}
	437
17226f12 DH	438	/*
	439	* Make sure all peer records have been discarded.
	440	*/
	441	void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
	442	{
	443	struct rxrpc_peer *peer;
	444	int i;
	445
	446	for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
	447	if (hlist_empty(&rxnet->peer_hash[i]))
	448	continue;
	449
	450	hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
	451	pr_err("Leaked peer %u {%u} %pISp\n",
	452	peer->debug_id,
a0575429	453	refcount_read(&peer->ref),
17226f12 DH	454	&peer->srx.transport);
	455	}
	456	}
	457	}
	458
8324f0bc DH	459	/**
	460	* rxrpc_kernel_get_peer - Get the peer address of a call
	461	* @sock: The socket on which the call is in progress.
	462	* @call: The call to query
	463	* @_srx: Where to place the result
	464	*
	465	* Get the address of the remote peer in a call.
	466	*/
	467	void rxrpc_kernel_get_peer(struct socket sock, struct rxrpc_call call,
	468	struct sockaddr_rxrpc *_srx)
	469	{
	470	*_srx = call->peer->srx;
	471	}
	472	EXPORT_SYMBOL(rxrpc_kernel_get_peer);
f4d15fb6 DH	473
f4d15fb6 DH	474	/**
c410bf01	475	* rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT
f4d15fb6 DH	476	* @sock: The socket on which the call is in progress.
f4d15fb6 DH	477	* @call: The call to query
1d4adfaf	478	* @_srtt: Where to store the SRTT value.
f4d15fb6	479	*
1d4adfaf	480	* Get the call's peer smoothed RTT in uS.
f4d15fb6	481	*/
1d4adfaf DH	482	bool rxrpc_kernel_get_srtt(struct socket sock, struct rxrpc_call call,
1d4adfaf DH	483	u32 *_srtt)
f4d15fb6	484	{
1d4adfaf DH	485	struct rxrpc_peer *peer = call->peer;
	486
	487	if (peer->rtt_count == 0) {
	488	_srtt = 1000000; / 1S */
	489	return false;
	490	}
	491
	492	*_srtt = call->peer->srtt_us >> 3;
	493	return true;
f4d15fb6	494	}
c410bf01	495	EXPORT_SYMBOL(rxrpc_kernel_get_srtt);