1/* Error message handling (ICMP) 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 25/* 26 * handle an error received on the local endpoint 27 */ 28void rxrpc_UDP_error_report(struct sock *sk) 29{ 30 struct sock_exterr_skb *serr; 31 struct rxrpc_transport *trans; 32 struct rxrpc_local *local = sk->sk_user_data; 33 struct rxrpc_peer *peer; 34 struct sk_buff *skb; 35 __be32 addr; 36 __be16 port; 37 38 _enter("%p{%d}", sk, local->debug_id); 39 40 skb = sock_dequeue_err_skb(sk); 41 if (!skb) { 42 _leave("UDP socket errqueue empty"); 43 return; 44 } 45 serr = SKB_EXT_ERR(skb); 46 if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { 47 _leave("UDP empty message"); 48 kfree_skb(skb); 49 return; 50 } 51 52 rxrpc_new_skb(skb); 53 54 addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset); 55 port = serr->port; 56 57 _net("Rx UDP Error from %pI4:%hu", &addr, ntohs(port)); 58 _debug("Msg l:%d d:%d", skb->len, skb->data_len); 59 60 peer = rxrpc_find_peer(local, addr, port); 61 if (IS_ERR(peer)) { 62 rxrpc_free_skb(skb); 63 _leave(" [no peer]"); 64 return; 65 } 66 67 trans = rxrpc_find_transport(local, peer); 68 if (!trans) { 69 rxrpc_put_peer(peer); 70 rxrpc_free_skb(skb); 71 _leave(" [no trans]"); 72 return; 73 } 74 75 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && 76 serr->ee.ee_type == ICMP_DEST_UNREACH && 77 serr->ee.ee_code == ICMP_FRAG_NEEDED 78 ) { 79 u32 mtu = serr->ee.ee_info; 80 81 _net("Rx Received ICMP Fragmentation Needed (%d)", mtu); 82 83 /* wind down the local interface MTU */ 84 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { 85 peer->if_mtu = mtu; 86 _net("I/F MTU %u", mtu); 87 } 88 89 if (mtu == 0) { 90 /* they didn't give us a size, estimate one */ 91 mtu = peer->if_mtu; 92 if (mtu > 1500) { 93 mtu >>= 1; 94 if (mtu < 1500) 95 mtu = 1500; 96 } else { 97 mtu -= 100; 98 if (mtu < peer->hdrsize) 99 mtu = peer->hdrsize + 4; 100 } 101 } 102 103 if (mtu < peer->mtu) { 104 spin_lock_bh(&peer->lock); 105 peer->mtu = mtu; 106 peer->maxdata = peer->mtu - peer->hdrsize; 107 spin_unlock_bh(&peer->lock); 108 _net("Net MTU %u (maxdata %u)", 109 peer->mtu, peer->maxdata); 110 } 111 } 112 113 rxrpc_put_peer(peer); 114 115 /* pass the transport ref to error_handler to release */ 116 skb_queue_tail(&trans->error_queue, skb); 117 rxrpc_queue_work(&trans->error_handler); 118 119 _leave(""); 120} 121 122/* 123 * deal with UDP error messages 124 */ 125void rxrpc_UDP_error_handler(struct work_struct *work) 126{ 127 struct sock_extended_err *ee; 128 struct sock_exterr_skb *serr; 129 struct rxrpc_transport *trans = 130 container_of(work, struct rxrpc_transport, error_handler); 131 struct sk_buff *skb; 132 int err; 133 134 _enter(""); 135 136 skb = skb_dequeue(&trans->error_queue); 137 if (!skb) 138 return; 139 140 serr = SKB_EXT_ERR(skb); 141 ee = &serr->ee; 142 143 _net("Rx Error o=%d t=%d c=%d e=%d", 144 ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno); 145 146 err = ee->ee_errno; 147 148 switch (ee->ee_origin) { 149 case SO_EE_ORIGIN_ICMP: 150 switch (ee->ee_type) { 151 case ICMP_DEST_UNREACH: 152 switch (ee->ee_code) { 153 case ICMP_NET_UNREACH: 154 _net("Rx Received ICMP Network Unreachable"); 155 err = ENETUNREACH; 156 break; 157 case ICMP_HOST_UNREACH: 158 _net("Rx Received ICMP Host Unreachable"); 159 err = EHOSTUNREACH; 160 break; 161 case ICMP_PORT_UNREACH: 162 _net("Rx Received ICMP Port Unreachable"); 163 err = ECONNREFUSED; 164 break; 165 case ICMP_FRAG_NEEDED: 166 _net("Rx Received ICMP Fragmentation Needed (%d)", 167 ee->ee_info); 168 err = 0; /* dealt with elsewhere */ 169 break; 170 case ICMP_NET_UNKNOWN: 171 _net("Rx Received ICMP Unknown Network"); 172 err = ENETUNREACH; 173 break; 174 case ICMP_HOST_UNKNOWN: 175 _net("Rx Received ICMP Unknown Host"); 176 err = EHOSTUNREACH; 177 break; 178 default: 179 _net("Rx Received ICMP DestUnreach code=%u", 180 ee->ee_code); 181 break; 182 } 183 break; 184 185 case ICMP_TIME_EXCEEDED: 186 _net("Rx Received ICMP TTL Exceeded"); 187 break; 188 189 default: 190 _proto("Rx Received ICMP error { type=%u code=%u }", 191 ee->ee_type, ee->ee_code); 192 break; 193 } 194 break; 195 196 case SO_EE_ORIGIN_LOCAL: 197 _proto("Rx Received local error { error=%d }", 198 ee->ee_errno); 199 break; 200 201 case SO_EE_ORIGIN_NONE: 202 case SO_EE_ORIGIN_ICMP6: 203 default: 204 _proto("Rx Received error report { orig=%u }", 205 ee->ee_origin); 206 break; 207 } 208 209 /* terminate all the affected calls if there's an unrecoverable 210 * error */ 211 if (err) { 212 struct rxrpc_call *call, *_n; 213 214 _debug("ISSUE ERROR %d", err); 215 216 spin_lock_bh(&trans->peer->lock); 217 trans->peer->net_error = err; 218 219 list_for_each_entry_safe(call, _n, &trans->peer->error_targets, 220 error_link) { 221 write_lock(&call->state_lock); 222 if (call->state != RXRPC_CALL_COMPLETE && 223 call->state < RXRPC_CALL_NETWORK_ERROR) { 224 call->state = RXRPC_CALL_NETWORK_ERROR; 225 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 226 rxrpc_queue_call(call); 227 } 228 write_unlock(&call->state_lock); 229 list_del_init(&call->error_link); 230 } 231 232 spin_unlock_bh(&trans->peer->lock); 233 } 234 235 if (!skb_queue_empty(&trans->error_queue)) 236 rxrpc_queue_work(&trans->error_handler); 237 238 rxrpc_free_skb(skb); 239 rxrpc_put_transport(trans); 240 _leave(""); 241} 242