/* 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;
#ifdef [31mCONFIG_AF_RXRPC_IPV6[0m
case AF_INET6:
srx.transport.sin6.sin6_port = serr->port;
srx.transport_len = sizeof(struct sockaddr_in6);
switch (serr->ee.ee_origin) {
case SO_EE_ORIGIN_ICMP6:
_net("Rx ICMP6");
memcpy(&srx.transport.sin6.sin6_addr,
skb_network_header(skb) + serr->addr_offset,
sizeof(struct in6_addr));
break;
case SO_EE_ORIGIN_ICMP:
_net("Rx ICMP on v6 sock");
memcpy(srx.transport.sin6.sin6_addr.s6_addr + 12,
skb_network_header(skb) + serr->addr_offset,
sizeof(struct in_addr));
break;
default:
memcpy(&srx.transport.sin6.sin6_addr,
&ipv6_hdr(skb)->saddr,
sizeof(struct in6_addr));
break;
}
break;
#endif
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;
}
rxrpc_new_skb(skb, rxrpc_skb_rx_received);
serr = SKB_EXT_ERR(skb);
if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
_leave("UDP empty message");
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
return;
}
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, rxrpc_skb_rx_freed);
_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_skb_rx_freed);
rxrpc_put_peer(peer);
_leave(" [MTU update]");
return;
}
rxrpc_store_error(peer, serr);
rcu_read_unlock();
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
/* 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;
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);
rxrpc_see_call(call);
if (rxrpc_set_call_completion(call, compl, 0, error))
rxrpc_notify_socket(call);
}
spin_unlock_bh(&peer->lock);
rxrpc_put_peer(peer);
_leave("");
}
/*
* Add RTT information to cache. This is called in softirq mode and has
* exclusive access to the peer RTT data.
*/
void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
rxrpc_serial_t send_serial, rxrpc_serial_t resp_serial,
ktime_t send_time, ktime_t resp_time)
{
struct rxrpc_peer *peer = call->peer;
s64 rtt;
u64 sum = peer->rtt_sum, avg;
u8 cursor = peer->rtt_cursor, usage = peer->rtt_usage;
rtt = ktime_to_ns(ktime_sub(resp_time, send_time));
if (rtt < 0)
return;
/* Replace the oldest datum in the RTT buffer */
sum -= peer->rtt_cache[cursor];
sum += rtt;
peer->rtt_cache[cursor] = rtt;
peer->rtt_cursor = (cursor + 1) & (RXRPC_RTT_CACHE_SIZE - 1);
peer->rtt_sum = sum;
if (usage < RXRPC_RTT_CACHE_SIZE) {
usage++;
peer->rtt_usage = usage;
}
/* Now recalculate the average */
if (usage == RXRPC_RTT_CACHE_SIZE) {
avg = sum / RXRPC_RTT_CACHE_SIZE;
} else {
avg = sum;
do_div(avg, usage);
}
peer->rtt = avg;
trace_rxrpc_rtt_rx(call, why, send_serial, resp_serial, rtt,
usage, avg);
}