kernel-ark/net/rxrpc/ar-error.c
David S. Miller 46517008e1 ipv4: Kill ip_rt_frag_needed().
There is zero point to this function.

It's only real substance is to perform an extremely outdated BSD4.2
ICMP check, which we can safely remove.  If you really have a MTU
limited link being routed by a BSD4.2 derived system, here's a nickel
go buy yourself a real router.

The other actions of ip_rt_frag_needed(), checking and conditionally
updating the peer, are done by the per-protocol handlers of the ICMP
event.

TCP, UDP, et al. have a handler which will receive this event and
transmit it back into the associated route via dst_ops->update_pmtu().

This simplification is important, because it eliminates the one place
where we do not have a proper route context in which to make an
inetpeer lookup.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-11 02:08:59 -07:00

248 lines
5.7 KiB
C

/* Error message handling (ICMP)
*
* 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"
/*
* handle an error received on the local endpoint
*/
void rxrpc_UDP_error_report(struct sock *sk)
{
struct sock_exterr_skb *serr;
struct rxrpc_transport *trans;
struct rxrpc_local *local = sk->sk_user_data;
struct rxrpc_peer *peer;
struct sk_buff *skb;
__be32 addr;
__be16 port;
_enter("%p{%d}", sk, local->debug_id);
skb = skb_dequeue(&sk->sk_error_queue);
if (!skb) {
_leave("UDP socket errqueue empty");
return;
}
rxrpc_new_skb(skb);
serr = SKB_EXT_ERR(skb);
addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset);
port = serr->port;
_net("Rx UDP Error from %pI4:%hu", &addr, ntohs(port));
_debug("Msg l:%d d:%d", skb->len, skb->data_len);
peer = rxrpc_find_peer(local, addr, port);
if (IS_ERR(peer)) {
rxrpc_free_skb(skb);
_leave(" [no peer]");
return;
}
trans = rxrpc_find_transport(local, peer);
if (!trans) {
rxrpc_put_peer(peer);
rxrpc_free_skb(skb);
_leave(" [no trans]");
return;
}
if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
serr->ee.ee_type == ICMP_DEST_UNREACH &&
serr->ee.ee_code == ICMP_FRAG_NEEDED
) {
u32 mtu = serr->ee.ee_info;
_net("Rx Received 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 */
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);
}
}
rxrpc_put_peer(peer);
/* pass the transport ref to error_handler to release */
skb_queue_tail(&trans->error_queue, skb);
rxrpc_queue_work(&trans->error_handler);
/* reset and regenerate socket error */
spin_lock_bh(&sk->sk_error_queue.lock);
sk->sk_err = 0;
skb = skb_peek(&sk->sk_error_queue);
if (skb) {
sk->sk_err = SKB_EXT_ERR(skb)->ee.ee_errno;
spin_unlock_bh(&sk->sk_error_queue.lock);
sk->sk_error_report(sk);
} else {
spin_unlock_bh(&sk->sk_error_queue.lock);
}
_leave("");
}
/*
* deal with UDP error messages
*/
void rxrpc_UDP_error_handler(struct work_struct *work)
{
struct sock_extended_err *ee;
struct sock_exterr_skb *serr;
struct rxrpc_transport *trans =
container_of(work, struct rxrpc_transport, error_handler);
struct sk_buff *skb;
int err;
_enter("");
skb = skb_dequeue(&trans->error_queue);
if (!skb)
return;
serr = SKB_EXT_ERR(skb);
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");
err = ENETUNREACH;
break;
case ICMP_HOST_UNREACH:
_net("Rx Received ICMP Host Unreachable");
err = EHOSTUNREACH;
break;
case ICMP_PORT_UNREACH:
_net("Rx Received ICMP Port Unreachable");
err = ECONNREFUSED;
break;
case ICMP_FRAG_NEEDED:
_net("Rx Received ICMP Fragmentation Needed (%d)",
ee->ee_info);
err = 0; /* dealt with elsewhere */
break;
case ICMP_NET_UNKNOWN:
_net("Rx Received ICMP Unknown Network");
err = ENETUNREACH;
break;
case ICMP_HOST_UNKNOWN:
_net("Rx Received ICMP Unknown Host");
err = EHOSTUNREACH;
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_LOCAL:
_proto("Rx Received local error { error=%d }",
ee->ee_errno);
break;
case SO_EE_ORIGIN_NONE:
case SO_EE_ORIGIN_ICMP6:
default:
_proto("Rx Received error report { orig=%u }",
ee->ee_origin);
break;
}
/* terminate all the affected calls if there's an unrecoverable
* error */
if (err) {
struct rxrpc_call *call, *_n;
_debug("ISSUE ERROR %d", err);
spin_lock_bh(&trans->peer->lock);
trans->peer->net_error = err;
list_for_each_entry_safe(call, _n, &trans->peer->error_targets,
error_link) {
write_lock(&call->state_lock);
if (call->state != RXRPC_CALL_COMPLETE &&
call->state < RXRPC_CALL_NETWORK_ERROR) {
call->state = RXRPC_CALL_NETWORK_ERROR;
set_bit(RXRPC_CALL_RCVD_ERROR, &call->events);
rxrpc_queue_call(call);
}
write_unlock(&call->state_lock);
list_del_init(&call->error_link);
}
spin_unlock_bh(&trans->peer->lock);
}
if (!skb_queue_empty(&trans->error_queue))
rxrpc_queue_work(&trans->error_handler);
rxrpc_free_skb(skb);
rxrpc_put_transport(trans);
_leave("");
}