![David Howells](/assets/img/avatar_default.png)
Do a little bit of tidying in the ICMP processing code. Signed-off-by: David Howells <dhowells@redhat.com>
291 lines
6.6 KiB
C
291 lines
6.6 KiB
C
/* Error message handling (ICMP)
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/net.h>
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#include <linux/skbuff.h>
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#include <linux/errqueue.h>
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#include <linux/udp.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/icmp.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include <net/ip.h>
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#include "ar-internal.h"
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/*
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* Find the peer associated with an ICMP packet.
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*/
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static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local,
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const struct sk_buff *skb)
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{
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struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
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struct sockaddr_rxrpc srx;
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_enter("");
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memset(&srx, 0, sizeof(srx));
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srx.transport_type = local->srx.transport_type;
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srx.transport.family = local->srx.transport.family;
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/* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice
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* versa?
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*/
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switch (srx.transport.family) {
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case AF_INET:
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srx.transport.sin.sin_port = serr->port;
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srx.transport_len = sizeof(struct sockaddr_in);
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switch (serr->ee.ee_origin) {
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case SO_EE_ORIGIN_ICMP:
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_net("Rx ICMP");
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memcpy(&srx.transport.sin.sin_addr,
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skb_network_header(skb) + serr->addr_offset,
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sizeof(struct in_addr));
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break;
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case SO_EE_ORIGIN_ICMP6:
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_net("Rx ICMP6 on v4 sock");
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memcpy(&srx.transport.sin.sin_addr,
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skb_network_header(skb) + serr->addr_offset + 12,
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sizeof(struct in_addr));
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break;
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default:
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memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr,
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sizeof(struct in_addr));
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break;
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}
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break;
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default:
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BUG();
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}
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return rxrpc_lookup_peer_rcu(local, &srx);
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}
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/*
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* Handle an MTU/fragmentation problem.
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*/
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static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr)
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{
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u32 mtu = serr->ee.ee_info;
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_net("Rx ICMP Fragmentation Needed (%d)", mtu);
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/* wind down the local interface MTU */
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if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) {
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peer->if_mtu = mtu;
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_net("I/F MTU %u", mtu);
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}
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if (mtu == 0) {
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/* they didn't give us a size, estimate one */
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mtu = peer->if_mtu;
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if (mtu > 1500) {
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mtu >>= 1;
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if (mtu < 1500)
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mtu = 1500;
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} else {
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mtu -= 100;
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if (mtu < peer->hdrsize)
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mtu = peer->hdrsize + 4;
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}
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}
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if (mtu < peer->mtu) {
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spin_lock_bh(&peer->lock);
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peer->mtu = mtu;
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peer->maxdata = peer->mtu - peer->hdrsize;
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spin_unlock_bh(&peer->lock);
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_net("Net MTU %u (maxdata %u)",
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peer->mtu, peer->maxdata);
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}
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}
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/*
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* handle an error received on the local endpoint
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*/
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void rxrpc_error_report(struct sock *sk)
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{
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struct sock_exterr_skb *serr;
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struct rxrpc_transport *trans;
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struct rxrpc_local *local = sk->sk_user_data;
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struct rxrpc_peer *peer;
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struct sk_buff *skb;
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_enter("%p{%d}", sk, local->debug_id);
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skb = sock_dequeue_err_skb(sk);
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if (!skb) {
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_leave("UDP socket errqueue empty");
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return;
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}
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serr = SKB_EXT_ERR(skb);
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if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
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_leave("UDP empty message");
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kfree_skb(skb);
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return;
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}
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rxrpc_new_skb(skb);
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rcu_read_lock();
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peer = rxrpc_lookup_peer_icmp_rcu(local, skb);
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if (peer && !rxrpc_get_peer_maybe(peer))
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peer = NULL;
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if (!peer) {
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rcu_read_unlock();
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rxrpc_free_skb(skb);
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_leave(" [no peer]");
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return;
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}
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trans = rxrpc_find_transport(local, peer);
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if (!trans) {
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rcu_read_unlock();
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rxrpc_put_peer(peer);
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rxrpc_free_skb(skb);
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_leave(" [no trans]");
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return;
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}
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if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP &&
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serr->ee.ee_type == ICMP_DEST_UNREACH &&
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serr->ee.ee_code == ICMP_FRAG_NEEDED)) {
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rxrpc_adjust_mtu(peer, serr);
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rxrpc_free_skb(skb);
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skb = NULL;
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goto out;
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}
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out:
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rcu_read_unlock();
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rxrpc_put_peer(peer);
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if (skb) {
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/* pass the transport ref to error_handler to release */
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skb_queue_tail(&trans->error_queue, skb);
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rxrpc_queue_work(&trans->error_handler);
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} else {
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rxrpc_put_transport(trans);
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}
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_leave("");
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}
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/*
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* deal with UDP error messages
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*/
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void rxrpc_UDP_error_handler(struct work_struct *work)
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{
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struct sock_extended_err *ee;
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struct sock_exterr_skb *serr;
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struct rxrpc_transport *trans =
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container_of(work, struct rxrpc_transport, error_handler);
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struct sk_buff *skb;
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int err;
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_enter("");
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skb = skb_dequeue(&trans->error_queue);
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if (!skb)
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return;
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serr = SKB_EXT_ERR(skb);
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ee = &serr->ee;
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_net("Rx Error o=%d t=%d c=%d e=%d",
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ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno);
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err = ee->ee_errno;
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switch (ee->ee_origin) {
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case SO_EE_ORIGIN_ICMP:
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switch (ee->ee_type) {
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case ICMP_DEST_UNREACH:
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switch (ee->ee_code) {
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case ICMP_NET_UNREACH:
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_net("Rx Received ICMP Network Unreachable");
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break;
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case ICMP_HOST_UNREACH:
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_net("Rx Received ICMP Host Unreachable");
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break;
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case ICMP_PORT_UNREACH:
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_net("Rx Received ICMP Port Unreachable");
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break;
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case ICMP_NET_UNKNOWN:
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_net("Rx Received ICMP Unknown Network");
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break;
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case ICMP_HOST_UNKNOWN:
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_net("Rx Received ICMP Unknown Host");
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break;
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default:
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_net("Rx Received ICMP DestUnreach code=%u",
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ee->ee_code);
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break;
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}
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break;
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case ICMP_TIME_EXCEEDED:
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_net("Rx Received ICMP TTL Exceeded");
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break;
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default:
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_proto("Rx Received ICMP error { type=%u code=%u }",
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ee->ee_type, ee->ee_code);
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break;
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}
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break;
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case SO_EE_ORIGIN_LOCAL:
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_proto("Rx Received local error { error=%d }", err);
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break;
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case SO_EE_ORIGIN_NONE:
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case SO_EE_ORIGIN_ICMP6:
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default:
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_proto("Rx Received error report { orig=%u }", ee->ee_origin);
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break;
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}
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/* terminate all the affected calls if there's an unrecoverable
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* error */
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if (err) {
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struct rxrpc_call *call, *_n;
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_debug("ISSUE ERROR %d", err);
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spin_lock_bh(&trans->peer->lock);
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trans->peer->net_error = err;
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list_for_each_entry_safe(call, _n, &trans->peer->error_targets,
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error_link) {
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write_lock(&call->state_lock);
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if (call->state != RXRPC_CALL_COMPLETE &&
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call->state < RXRPC_CALL_NETWORK_ERROR) {
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call->state = RXRPC_CALL_NETWORK_ERROR;
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set_bit(RXRPC_CALL_EV_RCVD_ERROR, &call->events);
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rxrpc_queue_call(call);
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}
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write_unlock(&call->state_lock);
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list_del_init(&call->error_link);
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}
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spin_unlock_bh(&trans->peer->lock);
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}
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if (!skb_queue_empty(&trans->error_queue))
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rxrpc_queue_work(&trans->error_handler);
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rxrpc_free_skb(skb);
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rxrpc_put_transport(trans);
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_leave("");
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}
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