diff options
Diffstat (limited to 'net/rxrpc/peer_event.c')
| -rw-r--r-- | net/rxrpc/peer_event.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c new file mode 100644 index 000000000000..8940674b5e08 --- /dev/null +++ b/net/rxrpc/peer_event.c @@ -0,0 +1,281 @@ +/* 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 <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" + +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; + int error_report; + + _enter(""); + + error_report = READ_ONCE(peer->error_report); + + _debug("ISSUE ERROR %d", error_report); + + 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); + + write_lock(&call->state_lock); + if (call->state != RXRPC_CALL_COMPLETE && + call->state < RXRPC_CALL_NETWORK_ERROR) { + call->error_report = error_report; + call->state = RXRPC_CALL_NETWORK_ERROR; + set_bit(RXRPC_CALL_EV_RCVD_ERROR, &call->events); + rxrpc_queue_call(call); + } + write_unlock(&call->state_lock); + } + + spin_unlock_bh(&peer->lock); + + rxrpc_put_peer(peer); + _leave(""); +} |