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 "NIPQUAD_FMT":%hu", 53 NIPQUAD(addr), ntohs(port)); 54 _debug("Msg l:%d d:%d", skb->len, skb->data_len); 55 56 peer = rxrpc_find_peer(local, addr, port); 57 if (IS_ERR(peer)) { 58 rxrpc_free_skb(skb); 59 _leave(" [no peer]"); 60 return; 61 } 62 63 trans = rxrpc_find_transport(local, peer); 64 if (!trans) { 65 rxrpc_put_peer(peer); 66 rxrpc_free_skb(skb); 67 _leave(" [no trans]"); 68 return; 69 } 70 71 if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && 72 serr->ee.ee_type == ICMP_DEST_UNREACH && 73 serr->ee.ee_code == ICMP_FRAG_NEEDED 74 ) { 75 u32 mtu = serr->ee.ee_info; 76 77 _net("Rx Received ICMP Fragmentation Needed (%d)", mtu); 78 79 /* wind down the local interface MTU */ 80 if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { 81 peer->if_mtu = mtu; 82 _net("I/F MTU %u", mtu); 83 } 84 85 /* ip_rt_frag_needed() may have eaten the info */ 86 if (mtu == 0) 87 mtu = ntohs(icmp_hdr(skb)->un.frag.mtu); 88 89 if (mtu == 0) { 90 /* they didn't give us a size, estimate one */ 91 if (mtu > 1500) { 92 mtu >>= 1; 93 if (mtu < 1500) 94 mtu = 1500; 95 } else { 96 mtu -= 100; 97 if (mtu < peer->hdrsize) 98 mtu = peer->hdrsize + 4; 99 } 100 } 101 102 if (mtu < peer->mtu) { 103 spin_lock_bh(&peer->lock); 104 peer->mtu = mtu; 105 peer->maxdata = peer->mtu - peer->hdrsize; 106 spin_unlock_bh(&peer->lock); 107 _net("Net MTU %u (maxdata %u)", 108 peer->mtu, peer->maxdata); 109 } 110 } 111 112 rxrpc_put_peer(peer); 113 114 /* pass the transport ref to error_handler to release */ 115 skb_queue_tail(&trans->error_queue, skb); 116 rxrpc_queue_work(&trans->error_handler); 117 118 /* reset and regenerate socket error */ 119 spin_lock_bh(&sk->sk_error_queue.lock); 120 sk->sk_err = 0; 121 skb = skb_peek(&sk->sk_error_queue); 122 if (skb) { 123 sk->sk_err = SKB_EXT_ERR(skb)->ee.ee_errno; 124 spin_unlock_bh(&sk->sk_error_queue.lock); 125 sk->sk_error_report(sk); 126 } else { 127 spin_unlock_bh(&sk->sk_error_queue.lock); 128 } 129 130 _leave(""); 131} 132 133/* 134 * deal with UDP error messages 135 */ 136void rxrpc_UDP_error_handler(struct work_struct *work) 137{ 138 struct sock_extended_err *ee; 139 struct sock_exterr_skb *serr; 140 struct rxrpc_transport *trans = 141 container_of(work, struct rxrpc_transport, error_handler); 142 struct sk_buff *skb; 143 int local, err; 144 145 _enter(""); 146 147 skb = skb_dequeue(&trans->error_queue); 148 if (!skb) 149 return; 150 151 serr = SKB_EXT_ERR(skb); 152 ee = &serr->ee; 153 154 _net("Rx Error o=%d t=%d c=%d e=%d", 155 ee->ee_origin, ee->ee_type, ee->ee_code, ee->ee_errno); 156 157 err = ee->ee_errno; 158 159 switch (ee->ee_origin) { 160 case SO_EE_ORIGIN_ICMP: 161 local = 0; 162 switch (ee->ee_type) { 163 case ICMP_DEST_UNREACH: 164 switch (ee->ee_code) { 165 case ICMP_NET_UNREACH: 166 _net("Rx Received ICMP Network Unreachable"); 167 err = ENETUNREACH; 168 break; 169 case ICMP_HOST_UNREACH: 170 _net("Rx Received ICMP Host Unreachable"); 171 err = EHOSTUNREACH; 172 break; 173 case ICMP_PORT_UNREACH: 174 _net("Rx Received ICMP Port Unreachable"); 175 err = ECONNREFUSED; 176 break; 177 case ICMP_FRAG_NEEDED: 178 _net("Rx Received ICMP Fragmentation Needed (%d)", 179 ee->ee_info); 180 err = 0; /* dealt with elsewhere */ 181 break; 182 case ICMP_NET_UNKNOWN: 183 _net("Rx Received ICMP Unknown Network"); 184 err = ENETUNREACH; 185 break; 186 case ICMP_HOST_UNKNOWN: 187 _net("Rx Received ICMP Unknown Host"); 188 err = EHOSTUNREACH; 189 break; 190 default: 191 _net("Rx Received ICMP DestUnreach code=%u", 192 ee->ee_code); 193 break; 194 } 195 break; 196 197 case ICMP_TIME_EXCEEDED: 198 _net("Rx Received ICMP TTL Exceeded"); 199 break; 200 201 default: 202 _proto("Rx Received ICMP error { type=%u code=%u }", 203 ee->ee_type, ee->ee_code); 204 break; 205 } 206 break; 207 208 case SO_EE_ORIGIN_LOCAL: 209 _proto("Rx Received local error { error=%d }", 210 ee->ee_errno); 211 local = 1; 212 break; 213 214 case SO_EE_ORIGIN_NONE: 215 case SO_EE_ORIGIN_ICMP6: 216 default: 217 _proto("Rx Received error report { orig=%u }", 218 ee->ee_origin); 219 local = 0; 220 break; 221 } 222 223 /* terminate all the affected calls if there's an unrecoverable 224 * error */ 225 if (err) { 226 struct rxrpc_call *call, *_n; 227 228 _debug("ISSUE ERROR %d", err); 229 230 spin_lock_bh(&trans->peer->lock); 231 trans->peer->net_error = err; 232 233 list_for_each_entry_safe(call, _n, &trans->peer->error_targets, 234 error_link) { 235 write_lock(&call->state_lock); 236 if (call->state != RXRPC_CALL_COMPLETE && 237 call->state < RXRPC_CALL_NETWORK_ERROR) { 238 call->state = RXRPC_CALL_NETWORK_ERROR; 239 set_bit(RXRPC_CALL_RCVD_ERROR, &call->events); 240 rxrpc_queue_call(call); 241 } 242 write_unlock(&call->state_lock); 243 list_del_init(&call->error_link); 244 } 245 246 spin_unlock_bh(&trans->peer->lock); 247 } 248 249 if (!skb_queue_empty(&trans->error_queue)) 250 rxrpc_queue_work(&trans->error_handler); 251 252 rxrpc_free_skb(skb); 253 rxrpc_put_transport(trans); 254 _leave(""); 255} 256