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-rw-r--r--net/rxrpc/peer_event.c281
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 000000000..8940674b5
--- /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("");
+}