/* 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 = sock_dequeue_err_skb(sk); if (!skb) { _leave("UDP socket errqueue empty"); return; } serr = SKB_EXT_ERR(skb); if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { _leave("UDP empty message"); kfree_skb(skb); return; } rxrpc_new_skb(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 */ mtu = peer->if_mtu; 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); _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(""); }