/* Peer event handling, typically ICMP messages. * * 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 #include #include #include #include #include #include #include #include #include #include #include "ar-internal.h" static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *); /* * Find the peer associated with an ICMP packet. */ static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local, const struct sk_buff *skb) { struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); struct sockaddr_rxrpc srx; _enter(""); memset(&srx, 0, sizeof(srx)); srx.transport_type = local->srx.transport_type; srx.transport.family = local->srx.transport.family; /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice * versa? */ switch (srx.transport.family) { case AF_INET: srx.transport.sin.sin_port = serr->port; srx.transport_len = sizeof(struct sockaddr_in); switch (serr->ee.ee_origin) { case SO_EE_ORIGIN_ICMP: _net("Rx ICMP"); memcpy(&srx.transport.sin.sin_addr, skb_network_header(skb) + serr->addr_offset, sizeof(struct in_addr)); break; case SO_EE_ORIGIN_ICMP6: _net("Rx ICMP6 on v4 sock"); memcpy(&srx.transport.sin.sin_addr, skb_network_header(skb) + serr->addr_offset + 12, sizeof(struct in_addr)); break; default: memcpy(&srx.transport.sin.sin_addr, &ip_hdr(skb)->saddr, sizeof(struct in_addr)); break; } break; default: BUG(); } return rxrpc_lookup_peer_rcu(local, &srx); } /* * Handle an MTU/fragmentation problem. */ static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, struct sock_exterr_skb *serr) { u32 mtu = serr->ee.ee_info; _net("Rx 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); } } /* * Handle an error received on the local endpoint. */ void rxrpc_error_report(struct sock *sk) { struct sock_exterr_skb *serr; struct rxrpc_local *local = sk->sk_user_data; struct rxrpc_peer *peer; struct sk_buff *skb; _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); rcu_read_lock(); peer = rxrpc_lookup_peer_icmp_rcu(local, skb); if (peer && !rxrpc_get_peer_maybe(peer)) peer = NULL; if (!peer) { rcu_read_unlock(); rxrpc_free_skb(skb); _leave(" [no peer]"); return; } if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && serr->ee.ee_type == ICMP_DEST_UNREACH && serr->ee.ee_code == ICMP_FRAG_NEEDED)) { rxrpc_adjust_mtu(peer, serr); rcu_read_unlock(); rxrpc_free_skb(skb); rxrpc_put_peer(peer); _leave(" [MTU update]"); return; } rxrpc_store_error(peer, serr); rcu_read_unlock(); rxrpc_free_skb(skb); /* The ref we obtained is passed off to the work item */ rxrpc_queue_work(&peer->error_distributor); _leave(""); } /* * Map an error report to error codes on the peer record. */ static void rxrpc_store_error(struct rxrpc_peer *peer, struct sock_exterr_skb *serr) { struct sock_extended_err *ee; int err; _enter(""); 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"); break; case ICMP_HOST_UNREACH: _net("Rx Received ICMP Host Unreachable"); break; case ICMP_PORT_UNREACH: _net("Rx Received ICMP Port Unreachable"); break; case ICMP_NET_UNKNOWN: _net("Rx Received ICMP Unknown Network"); break; case ICMP_HOST_UNKNOWN: _net("Rx Received ICMP Unknown Host"); 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_NONE: case SO_EE_ORIGIN_LOCAL: _proto("Rx Received local error { error=%d }", err); err += RXRPC_LOCAL_ERROR_OFFSET; break; case SO_EE_ORIGIN_ICMP6: default: _proto("Rx Received error report { orig=%u }", ee->ee_origin); break; } peer->error_report = err; } /* * Distribute an error that occurred on a peer */ void rxrpc_peer_error_distributor(struct work_struct *work) { struct rxrpc_peer *peer = container_of(work, struct rxrpc_peer, error_distributor); struct rxrpc_call *call; enum rxrpc_call_completion compl; bool queue; int error; _enter(""); error = READ_ONCE(peer->error_report); if (error < RXRPC_LOCAL_ERROR_OFFSET) { compl = RXRPC_CALL_NETWORK_ERROR; } else { compl = RXRPC_CALL_LOCAL_ERROR; error -= RXRPC_LOCAL_ERROR_OFFSET; } _debug("ISSUE ERROR %s %d", rxrpc_call_completions[compl], error); spin_lock_bh(&peer->lock); while (!hlist_empty(&peer->error_targets)) { call = hlist_entry(peer->error_targets.first, struct rxrpc_call, error_link); hlist_del_init(&call->error_link); queue = false; write_lock(&call->state_lock); if (__rxrpc_set_call_completion(call, compl, 0, error)) { set_bit(RXRPC_CALL_EV_RCVD_ERROR, &call->events); queue = true; } write_unlock(&call->state_lock); if (queue) rxrpc_queue_call(call); } spin_unlock_bh(&peer->lock); rxrpc_put_peer(peer); _leave(""); }