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 = skb_dequeue(&sk->sk_error_queue); 41 if (!skb) { 42 _leave("UDP socket errqueue empty"); 43 return; 44 } 45 46 rxrpc_new_skb(skb); 47 48 serr = SKB_EXT_ERR(skb); 49 addr = *(__be32 *)(skb_network_header(skb) + serr->addr_offset); 50 port = serr->port; 51 52 _net("Rx UDP Error from %pI4:%hu", &addr, ntohs(port)); 53 _debug("Msg l:%d d:%d", skb->len, skb->data_len); 54 55 peer = rxrpc_find_peer(local, addr, port); 56 if (IS_ERR(peer)) { 57 rxrpc_free_skb(skb); 58 _leave(" [no peer]"); 59 return; 60 } 61 62 trans = rxrpc_find_transport(local, peer); 63 if (!trans) { 64 rxrpc_put_peer(peer); 65 rxrpc_free_skb(skb); 66 _leave(" [no trans]"); 67 return; 68 } 69 70 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && 71 serr->ee.ee_type == ICMP_DEST_UNREACH && 72 serr->ee.ee_code == ICMP_FRAG_NEEDED 73 ) { 74 u32 mtu = serr->ee.ee_info; 75 76 _net("Rx Received ICMP Fragmentation Needed (%d)", mtu); 77 78 /* wind down the local interface MTU */ 79 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { 80 peer->if_mtu = mtu; 81 _net("I/F MTU %u", mtu); 82 } 83 84 /* ip_rt_frag_needed() may have eaten the info */ 85 if (mtu == 0) 86 mtu = ntohs(icmp_hdr(skb)->un.frag.mtu); 87 88 if (mtu == 0) { 89 /* they didn't give us a size, estimate one */ 90 if (mtu > 1500) { 91 mtu >>= 1; 92 if (mtu < 1500) 93 mtu = 1500; 94 } else { 95 mtu -= 100; 96 if (mtu < peer->hdrsize) 97 mtu = peer->hdrsize + 4; 98 } 99 } 100 101 if (mtu < peer->mtu) { 102 spin_lock_bh(&peer->lock); 103 peer->mtu = mtu; 104 peer->maxdata = peer->mtu - peer->hdrsize; 105 spin_unlock_bh(&peer->lock); 106 _net("Net MTU %u (maxdata %u)", 107 peer->mtu, peer->maxdata); 108 } 109 } 110 111 rxrpc_put_peer(peer); 112 113 /* pass the transport ref to error_handler to release */ 114 skb_queue_tail(&trans->error_queue, skb); 115 rxrpc_queue_work(&trans->error_handler); 116 117 /* reset and regenerate socket error */ 118 spin_lock_bh(&sk->sk_error_queue.lock); 119 sk->sk_err = 0; 120 skb = skb_peek(&sk->sk_error_queue); 121 if (skb) { 122 sk->sk_err = SKB_EXT_ERR(skb)->ee.ee_errno; 123 spin_unlock_bh(&sk->sk_error_queue.lock); 124 sk->sk_error_report(sk); 125 } else { 126 spin_unlock_bh(&sk->sk_error_queue.lock); 127 } 128 129 _leave(""); 130} 131 132/* 133 * deal with UDP error messages 134 */ 135void rxrpc_UDP_error_handler(struct work_struct *work) 136{ 137 struct sock_extended_err *ee; 138 struct sock_exterr_skb *serr; 139 struct rxrpc_transport *trans = 140 container_of(work, struct rxrpc_transport, error_handler); 141 struct sk_buff *skb; 142 int local, err; 143 144 _enter(""); 145 146 skb = skb_dequeue(&trans->error_queue); 147 if (!skb) 148 return; 149 150 serr = SKB_EXT_ERR(skb); 151 ee = &serr->ee; 152 153 _net("Rx Error o=%d t=%d c=%d e=%d", 154 ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno); 155 156 err = ee->ee_errno; 157 158 switch (ee->ee_origin) { 159 case SO_EE_ORIGIN_ICMP: 160 local = 0; 161 switch (ee->ee_type) { 162 case ICMP_DEST_UNREACH: 163 switch (ee->ee_code) { 164 case ICMP_NET_UNREACH: 165 _net("Rx Received ICMP Network Unreachable"); 166 err = ENETUNREACH; 167 break; 168 case ICMP_HOST_UNREACH: 169 _net("Rx Received ICMP Host Unreachable"); 170 err = EHOSTUNREACH; 171 break; 172 case ICMP_PORT_UNREACH: 173 _net("Rx Received ICMP Port Unreachable"); 174 err = ECONNREFUSED; 175 break; 176 case ICMP_FRAG_NEEDED: 177 _net("Rx Received ICMP Fragmentation Needed (%d)", 178 ee->ee_info); 179 err = 0; /* dealt with elsewhere */ 180 break; 181 case ICMP_NET_UNKNOWN: 182 _net("Rx Received ICMP Unknown Network"); 183 err = ENETUNREACH; 184 break; 185 case ICMP_HOST_UNKNOWN: 186 _net("Rx Received ICMP Unknown Host"); 187 err = EHOSTUNREACH; 188 break; 189 default: 190 _net("Rx Received ICMP DestUnreach code=%u", 191 ee->ee_code); 192 break; 193 } 194 break; 195 196 case ICMP_TIME_EXCEEDED: 197 _net("Rx Received ICMP TTL Exceeded"); 198 break; 199 200 default: 201 _proto("Rx Received ICMP error { type=%u code=%u }", 202 ee->ee_type, ee->ee_code); 203 break; 204 } 205 break; 206 207 case SO_EE_ORIGIN_LOCAL: 208 _proto("Rx Received local error { error=%d }", 209 ee->ee_errno); 210 local = 1; 211 break; 212 213 case SO_EE_ORIGIN_NONE: 214 case SO_EE_ORIGIN_ICMP6: 215 default: 216 _proto("Rx Received error report { orig=%u }", 217 ee->ee_origin); 218 local = 0; 219 break; 220 } 221 222 /* terminate all the affected calls if there's an unrecoverable 223 * error */ 224 if (err) { 225 struct rxrpc_call *call, *_n; 226 227 _debug("ISSUE ERROR %d", err); 228 229 spin_lock_bh(&trans->peer->lock); 230 trans->peer->net_error = err; 231 232 list_for_each_entry_safe(call, _n, &trans->peer->error_targets, 233 error_link) { 234 write_lock(&call->state_lock); 235 if (call->state != RXRPC_CALL_COMPLETE && 236 call->state < RXRPC_CALL_NETWORK_ERROR) { 237 call->state = RXRPC_CALL_NETWORK_ERROR; 238 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 239 rxrpc_queue_call(call); 240 } 241 write_unlock(&call->state_lock); 242 list_del_init(&call->error_link); 243 } 244 245 spin_unlock_bh(&trans->peer->lock); 246 } 247 248 if (!skb_queue_empty(&trans->error_queue)) 249 rxrpc_queue_work(&trans->error_handler); 250 251 rxrpc_free_skb(skb); 252 rxrpc_put_transport(trans); 253 _leave(""); 254} 255