[deliverable/linux.git] / net / rxrpc / peer_event.c

/* Peer event handling, typically ICMP messages.
 *
 * Copyright (C) 2007 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.
 */

#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/errqueue.h>
#include <linux/udp.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/icmp.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
#include "ar-internal.h"

static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *);

/*
 * Find the peer associated with an ICMP packet.
 */
static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
						     const struct sk_buff *skb)
{
	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
	struct sockaddr_rxrpc srx;

	_enter("");

	memset(&srx, 0, sizeof(srx));
	srx.transport_type = local->srx.transport_type;
	srx.transport.family = local->srx.transport.family;

	/* Can we see an ICMP4 packet on an ICMP6 listening socket?  and vice
	 * versa?
	 */
	switch (srx.transport.family) {
	case AF_INET:
		srx.transport.sin.sin_port = serr->port;
		srx.transport_len = sizeof(struct sockaddr_in);
		switch (serr->ee.ee_origin) {
		case SO_EE_ORIGIN_ICMP:
			_net("Rx ICMP");
			memcpy(&srx.transport.sin.sin_addr,
			       skb_network_header(skb) + serr->addr_offset,
			       sizeof(struct in_addr));
			break;
		case SO_EE_ORIGIN_ICMP6:
			_net("Rx ICMP6 on v4 sock");
			memcpy(&srx.transport.sin.sin_addr,
			       skb_network_header(skb) + serr->addr_offset + 12,
			       sizeof(struct in_addr));
			break;
		default:
			memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr,
			       sizeof(struct in_addr));
			break;
		}
		break;

	default:
		BUG();
	}

	return rxrpc_lookup_peer_rcu(local, &srx);
}

/*
 * Handle an MTU/fragmentation problem.
 */
static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
{
	u32 mtu = serr->ee.ee_info;

	_net("Rx ICMP Fragmentation Needed (%d)", mtu);

	/* wind down the local interface MTU */
	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
		peer->if_mtu = mtu;
		_net("I/F MTU %u", mtu);
	}

	if (mtu == 0) {
		/* they didn't give us a size, estimate one */
		mtu = peer->if_mtu;
		if (mtu > 1500) {
			mtu >>= 1;
			if (mtu < 1500)
				mtu = 1500;
		} else {
			mtu -= 100;
			if (mtu < peer->hdrsize)
				mtu = peer->hdrsize + 4;
		}
	}

	if (mtu < peer->mtu) {
		spin_lock_bh(&peer->lock);
		peer->mtu = mtu;
		peer->maxdata = peer->mtu - peer->hdrsize;
		spin_unlock_bh(&peer->lock);
		_net("Net MTU %u (maxdata %u)",
		     peer->mtu, peer->maxdata);
	}
}

/*
 * Handle an error received on the local endpoint.
 */
void rxrpc_error_report(struct sock *sk)
{
	struct sock_exterr_skb *serr;
	struct rxrpc_local *local = sk->sk_user_data;
	struct rxrpc_peer *peer;
	struct sk_buff *skb;

	_enter("%p{%d}", sk, local->debug_id);

	skb = sock_dequeue_err_skb(sk);
	if (!skb) {
		_leave("UDP socket errqueue empty");
		return;
	}
	rxrpc_new_skb(skb);
	serr = SKB_EXT_ERR(skb);
	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
		_leave("UDP empty message");
		rxrpc_free_skb(skb);
		return;
	}

	rcu_read_lock();
	peer = rxrpc_lookup_peer_icmp_rcu(local, skb);
	if (peer && !rxrpc_get_peer_maybe(peer))
		peer = NULL;
	if (!peer) {
		rcu_read_unlock();
		rxrpc_free_skb(skb);
		_leave(" [no peer]");
		return;
	}

	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
	     serr->ee.ee_type == ICMP_DEST_UNREACH &&
	     serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
		rxrpc_adjust_mtu(peer, serr);
		rcu_read_unlock();
		rxrpc_free_skb(skb);
		rxrpc_put_peer(peer);
		_leave(" [MTU update]");
		return;
	}

	rxrpc_store_error(peer, serr);
	rcu_read_unlock();
	rxrpc_free_skb(skb);

	/* The ref we obtained is passed off to the work item */
	rxrpc_queue_work(&peer->error_distributor);
	_leave("");
}

/*
 * Map an error report to error codes on the peer record.
 */
static void rxrpc_store_error(struct rxrpc_peer *peer,
			      struct sock_exterr_skb *serr)
{
	struct sock_extended_err *ee;
	int err;

	_enter("");

	ee = &serr->ee;

	_net("Rx Error o=%d t=%d c=%d e=%d",
	     ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);

	err = ee->ee_errno;

	switch (ee->ee_origin) {
	case SO_EE_ORIGIN_ICMP:
		switch (ee->ee_type) {
		case ICMP_DEST_UNREACH:
			switch (ee->ee_code) {
			case ICMP_NET_UNREACH:
				_net("Rx Received ICMP Network Unreachable");
				break;
			case ICMP_HOST_UNREACH:
				_net("Rx Received ICMP Host Unreachable");
				break;
			case ICMP_PORT_UNREACH:
				_net("Rx Received ICMP Port Unreachable");
				break;
			case ICMP_NET_UNKNOWN:
				_net("Rx Received ICMP Unknown Network");
				break;
			case ICMP_HOST_UNKNOWN:
				_net("Rx Received ICMP Unknown Host");
				break;
			default:
				_net("Rx Received ICMP DestUnreach code=%u",
				     ee->ee_code);
				break;
			}
			break;

		case ICMP_TIME_EXCEEDED:
			_net("Rx Received ICMP TTL Exceeded");
			break;

		default:
			_proto("Rx Received ICMP error { type=%u code=%u }",
			       ee->ee_type, ee->ee_code);
			break;
		}
		break;

	case SO_EE_ORIGIN_NONE:
	case SO_EE_ORIGIN_LOCAL:
		_proto("Rx Received local error { error=%d }", err);
		err += RXRPC_LOCAL_ERROR_OFFSET;
		break;

	case SO_EE_ORIGIN_ICMP6:
	default:
		_proto("Rx Received error report { orig=%u }", ee->ee_origin);
		break;
	}

	peer->error_report = err;
}

/*
 * Distribute an error that occurred on a peer
 */
void rxrpc_peer_error_distributor(struct work_struct *work)
{
	struct rxrpc_peer *peer =
		container_of(work, struct rxrpc_peer, error_distributor);
	struct rxrpc_call *call;
	enum rxrpc_call_completion compl;
	int error;

	_enter("");

	error = READ_ONCE(peer->error_report);
	if (error < RXRPC_LOCAL_ERROR_OFFSET) {
		compl = RXRPC_CALL_NETWORK_ERROR;
	} else {
		compl = RXRPC_CALL_LOCAL_ERROR;
		error -= RXRPC_LOCAL_ERROR_OFFSET;
	}

	_debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error);

	spin_lock_bh(&peer->lock);

	while (!hlist_empty(&peer->error_targets)) {
		call = hlist_entry(peer->error_targets.first,
				   struct rxrpc_call, error_link);
		hlist_del_init(&call->error_link);
		rxrpc_see_call(call);

		if (rxrpc_set_call_completion(call, compl, 0, error))
			rxrpc_notify_socket(call);
	}

	spin_unlock_bh(&peer->lock);

	rxrpc_put_peer(peer);
	_leave("");
}
Commit	Line	Data
f66d7490	1	/* Peer event handling, typically ICMP messages.
17926a79 DH	2	*
	3	* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
	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
	12	#include <linux/module.h>
	13	#include <linux/net.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/errqueue.h>
	16	#include <linux/udp.h>
	17	#include <linux/in.h>
	18	#include <linux/in6.h>
	19	#include <linux/icmp.h>
	20	#include <net/sock.h>
	21	#include <net/af_rxrpc.h>
	22	#include <net/ip.h>
	23	#include "ar-internal.h"
	24
f66d7490 DH	25	static void rxrpc_store_error(struct rxrpc_peer , struct sock_exterr_skb );
f66d7490 DH	26
be6e6707 DH	27	/*
	28	* Find the peer associated with an ICMP packet.
	29	*/
	30	static struct rxrpc_peer rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local local,
	31	const struct sk_buff *skb)
	32	{
	33	struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
	34	struct sockaddr_rxrpc srx;
	35
	36	_enter("");
	37
	38	memset(&srx, 0, sizeof(srx));
	39	srx.transport_type = local->srx.transport_type;
	40	srx.transport.family = local->srx.transport.family;
	41
	42	/* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice
	43	* versa?
	44	*/
	45	switch (srx.transport.family) {
	46	case AF_INET:
	47	srx.transport.sin.sin_port = serr->port;
	48	srx.transport_len = sizeof(struct sockaddr_in);
	49	switch (serr->ee.ee_origin) {
	50	case SO_EE_ORIGIN_ICMP:
	51	_net("Rx ICMP");
	52	memcpy(&srx.transport.sin.sin_addr,
	53	skb_network_header(skb) + serr->addr_offset,
	54	sizeof(struct in_addr));
	55	break;
	56	case SO_EE_ORIGIN_ICMP6:
	57	_net("Rx ICMP6 on v4 sock");
	58	memcpy(&srx.transport.sin.sin_addr,
	59	skb_network_header(skb) + serr->addr_offset + 12,
	60	sizeof(struct in_addr));
	61	break;
	62	default:
	63	memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr,
	64	sizeof(struct in_addr));
	65	break;
	66	}
	67	break;
	68
	69	default:
	70	BUG();
	71	}
	72
	73	return rxrpc_lookup_peer_rcu(local, &srx);
	74	}
	75
1a70c05b DH	76	/*
	77	* Handle an MTU/fragmentation problem.
	78	*/
	79	static void rxrpc_adjust_mtu(struct rxrpc_peer peer, struct sock_exterr_skb serr)
	80	{
	81	u32 mtu = serr->ee.ee_info;
	82
	83	_net("Rx ICMP Fragmentation Needed (%d)", mtu);
	84
	85	/* wind down the local interface MTU */
	86	if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
	87	peer->if_mtu = mtu;
	88	_net("I/F MTU %u", mtu);
	89	}
	90
	91	if (mtu == 0) {
	92	/* they didn't give us a size, estimate one */
	93	mtu = peer->if_mtu;
	94	if (mtu > 1500) {
	95	mtu >>= 1;
	96	if (mtu < 1500)
	97	mtu = 1500;
	98	} else {
	99	mtu -= 100;
	100	if (mtu < peer->hdrsize)
	101	mtu = peer->hdrsize + 4;
	102	}
	103	}
	104
	105	if (mtu < peer->mtu) {
	106	spin_lock_bh(&peer->lock);
	107	peer->mtu = mtu;
	108	peer->maxdata = peer->mtu - peer->hdrsize;
	109	spin_unlock_bh(&peer->lock);
	110	_net("Net MTU %u (maxdata %u)",
	111	peer->mtu, peer->maxdata);
	112	}
	113	}
	114
17926a79	115	/*
f66d7490	116	* Handle an error received on the local endpoint.
17926a79	117	*/
abe89ef0	118	void rxrpc_error_report(struct sock *sk)
17926a79 DH	119	{
17926a79 DH	120	struct sock_exterr_skb *serr;
17926a79 DH	121	struct rxrpc_local *local = sk->sk_user_data;
	122	struct rxrpc_peer *peer;
	123	struct sk_buff *skb;
17926a79 DH	124
	125	_enter("%p{%d}", sk, local->debug_id);
	126
364a9e93	127	skb = sock_dequeue_err_skb(sk);
17926a79 DH	128	if (!skb) {
	129	_leave("UDP socket errqueue empty");
	130	return;
	131	}
248f219c	132	rxrpc_new_skb(skb);
c247f053 WB	133	serr = SKB_EXT_ERR(skb);
c247f053 WB	134	if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
49ca0d8b	135	_leave("UDP empty message");
248f219c	136	rxrpc_free_skb(skb);
49ca0d8b WB	137	return;
49ca0d8b WB	138	}
17926a79	139
be6e6707 DH	140	rcu_read_lock();
	141	peer = rxrpc_lookup_peer_icmp_rcu(local, skb);
	142	if (peer && !rxrpc_get_peer_maybe(peer))
	143	peer = NULL;
	144	if (!peer) {
	145	rcu_read_unlock();
17926a79 DH	146	rxrpc_free_skb(skb);
	147	_leave(" [no peer]");
	148	return;
	149	}
	150
1a70c05b DH	151	if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
	152	serr->ee.ee_type == ICMP_DEST_UNREACH &&
	153	serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
	154	rxrpc_adjust_mtu(peer, serr);
f66d7490	155	rcu_read_unlock();
1a70c05b	156	rxrpc_free_skb(skb);
f66d7490 DH	157	rxrpc_put_peer(peer);
	158	_leave(" [MTU update]");
	159	return;
17926a79 DH	160	}
17926a79 DH	161
f66d7490	162	rxrpc_store_error(peer, serr);
be6e6707	163	rcu_read_unlock();
f66d7490	164	rxrpc_free_skb(skb);
17926a79	165
f66d7490 DH	166	/* The ref we obtained is passed off to the work item */
f66d7490 DH	167	rxrpc_queue_work(&peer->error_distributor);
17926a79 DH	168	_leave("");
	169	}
	170
	171	/*
f66d7490	172	* Map an error report to error codes on the peer record.
17926a79	173	*/
f66d7490 DH	174	static void rxrpc_store_error(struct rxrpc_peer *peer,
f66d7490 DH	175	struct sock_exterr_skb *serr)
17926a79 DH	176	{
17926a79 DH	177	struct sock_extended_err *ee;
c9d10c49	178	int err;
17926a79 DH	179
	180	_enter("");
	181
17926a79 DH	182	ee = &serr->ee;
	183
	184	_net("Rx Error o=%d t=%d c=%d e=%d",
	185	ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
	186
	187	err = ee->ee_errno;
	188
	189	switch (ee->ee_origin) {
	190	case SO_EE_ORIGIN_ICMP:
17926a79 DH	191	switch (ee->ee_type) {
	192	case ICMP_DEST_UNREACH:
	193	switch (ee->ee_code) {
	194	case ICMP_NET_UNREACH:
	195	_net("Rx Received ICMP Network Unreachable");
17926a79 DH	196	break;
	197	case ICMP_HOST_UNREACH:
	198	_net("Rx Received ICMP Host Unreachable");
17926a79 DH	199	break;
	200	case ICMP_PORT_UNREACH:
	201	_net("Rx Received ICMP Port Unreachable");
17926a79 DH	202	break;
	203	case ICMP_NET_UNKNOWN:
	204	_net("Rx Received ICMP Unknown Network");
17926a79 DH	205	break;
	206	case ICMP_HOST_UNKNOWN:
	207	_net("Rx Received ICMP Unknown Host");
17926a79 DH	208	break;
	209	default:
	210	_net("Rx Received ICMP DestUnreach code=%u",
	211	ee->ee_code);
	212	break;
	213	}
	214	break;
	215
	216	case ICMP_TIME_EXCEEDED:
	217	_net("Rx Received ICMP TTL Exceeded");
	218	break;
	219
	220	default:
	221	_proto("Rx Received ICMP error { type=%u code=%u }",
	222	ee->ee_type, ee->ee_code);
	223	break;
	224	}
	225	break;
	226
f66d7490	227	case SO_EE_ORIGIN_NONE:
17926a79	228	case SO_EE_ORIGIN_LOCAL:
fe77d5fc	229	_proto("Rx Received local error { error=%d }", err);
f66d7490	230	err += RXRPC_LOCAL_ERROR_OFFSET;
17926a79 DH	231	break;
17926a79 DH	232
17926a79 DH	233	case SO_EE_ORIGIN_ICMP6:
17926a79 DH	234	default:
fe77d5fc	235	_proto("Rx Received error report { orig=%u }", ee->ee_origin);
17926a79 DH	236	break;
	237	}
	238
f66d7490 DH	239	peer->error_report = err;
	240	}
	241
	242	/*
	243	* Distribute an error that occurred on a peer
	244	*/
	245	void rxrpc_peer_error_distributor(struct work_struct *work)
	246	{
	247	struct rxrpc_peer *peer =
	248	container_of(work, struct rxrpc_peer, error_distributor);
	249	struct rxrpc_call *call;
f5c17aae	250	enum rxrpc_call_completion compl;
f5c17aae	251	int error;
f66d7490 DH	252
f66d7490 DH	253	_enter("");
17926a79	254
f5c17aae DH	255	error = READ_ONCE(peer->error_report);
	256	if (error < RXRPC_LOCAL_ERROR_OFFSET) {
	257	compl = RXRPC_CALL_NETWORK_ERROR;
	258	} else {
	259	compl = RXRPC_CALL_LOCAL_ERROR;
	260	error -= RXRPC_LOCAL_ERROR_OFFSET;
	261	}
17926a79	262
f5c17aae	263	_debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error);
17926a79	264
f66d7490	265	spin_lock_bh(&peer->lock);
17926a79	266
f66d7490 DH	267	while (!hlist_empty(&peer->error_targets)) {
	268	call = hlist_entry(peer->error_targets.first,
	269	struct rxrpc_call, error_link);
	270	hlist_del_init(&call->error_link);
e34d4234	271	rxrpc_see_call(call);
f66d7490	272
248f219c DH	273	if (rxrpc_set_call_completion(call, compl, 0, error))
248f219c DH	274	rxrpc_notify_socket(call);
17926a79 DH	275	}
17926a79 DH	276
f66d7490	277	spin_unlock_bh(&peer->lock);
17926a79	278
f66d7490	279	rxrpc_put_peer(peer);
17926a79 DH	280	_leave("");
17926a79 DH	281	}