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-rw-r--r--net/rxrpc/peer_event.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
new file mode 100644
index 000000000..be032850a
--- /dev/null
+++ b/net/rxrpc/peer_event.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Peer event handling, typically ICMP messages.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#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 *);
+static void rxrpc_distribute_error(struct rxrpc_peer *, int,
+ enum rxrpc_call_completion);
+
+/*
+ * 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 sockaddr_rxrpc *srx)
+{
+ struct sock_exterr_skb *serr = SKB_EXT_ERR(skb);
+
+ _enter("");
+
+ memset(srx, 0, sizeof(*srx));
+ srx->transport_type = local->srx.transport_type;
+ srx->transport_len = local->srx.transport_len;
+ 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_len = sizeof(srx->transport.sin);
+ srx->transport.family = AF_INET;
+ srx->transport.sin.sin_port = serr->port;
+ 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 CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ switch (serr->ee.ee_origin) {
+ case SO_EE_ORIGIN_ICMP6:
+ _net("Rx ICMP6");
+ srx->transport.sin6.sin6_port = serr->port;
+ 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");
+ srx->transport_len = sizeof(srx->transport.sin);
+ srx->transport.family = AF_INET;
+ srx->transport.sin.sin_port = serr->port;
+ memcpy(&srx->transport.sin.sin_addr,
+ 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 sockaddr_rxrpc srx;
+ struct rxrpc_local *local;
+ struct rxrpc_peer *peer;
+ struct sk_buff *skb;
+
+ rcu_read_lock();
+ local = rcu_dereference_sk_user_data(sk);
+ if (unlikely(!local)) {
+ rcu_read_unlock();
+ return;
+ }
+ _enter("%p{%d}", sk, local->debug_id);
+
+ /* Clear the outstanding error value on the socket so that it doesn't
+ * cause kernel_sendmsg() to return it later.
+ */
+ sock_error(sk);
+
+ skb = sock_dequeue_err_skb(sk);
+ if (!skb) {
+ rcu_read_unlock();
+ _leave("UDP socket errqueue empty");
+ return;
+ }
+ rxrpc_new_skb(skb, rxrpc_skb_received);
+ serr = SKB_EXT_ERR(skb);
+ if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) {
+ _leave("UDP empty message");
+ rcu_read_unlock();
+ rxrpc_free_skb(skb, rxrpc_skb_freed);
+ return;
+ }
+
+ peer = rxrpc_lookup_peer_icmp_rcu(local, skb, &srx);
+ if (peer && !rxrpc_get_peer_maybe(peer))
+ peer = NULL;
+ if (!peer) {
+ rcu_read_unlock();
+ rxrpc_free_skb(skb, rxrpc_skb_freed);
+ _leave(" [no peer]");
+ return;
+ }
+
+ trace_rxrpc_rx_icmp(peer, &serr->ee, &srx);
+
+ 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_freed);
+ rxrpc_put_peer(peer);
+ _leave(" [MTU update]");
+ return;
+ }
+
+ rxrpc_store_error(peer, serr);
+ rcu_read_unlock();
+ rxrpc_free_skb(skb, rxrpc_skb_freed);
+ rxrpc_put_peer(peer);
+
+ _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)
+{
+ enum rxrpc_call_completion compl = RXRPC_CALL_NETWORK_ERROR;
+ struct sock_extended_err *ee;
+ int err;
+
+ _enter("");
+
+ ee = &serr->ee;
+
+ 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);
+ compl = RXRPC_CALL_LOCAL_ERROR;
+ break;
+
+ case SO_EE_ORIGIN_ICMP6:
+ if (err == EACCES)
+ err = EHOSTUNREACH;
+ fallthrough;
+ default:
+ _proto("Rx Received error report { orig=%u }", ee->ee_origin);
+ break;
+ }
+
+ rxrpc_distribute_error(peer, err, compl);
+}
+
+/*
+ * Distribute an error that occurred on a peer.
+ */
+static void rxrpc_distribute_error(struct rxrpc_peer *peer, int error,
+ enum rxrpc_call_completion compl)
+{
+ struct rxrpc_call *call;
+
+ hlist_for_each_entry_rcu(call, &peer->error_targets, error_link) {
+ rxrpc_see_call(call);
+ rxrpc_set_call_completion(call, compl, 0, -error);
+ }
+}
+
+/*
+ * Perform keep-alive pings.
+ */
+static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet,
+ struct list_head *collector,
+ time64_t base,
+ u8 cursor)
+{
+ struct rxrpc_peer *peer;
+ const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+ time64_t keepalive_at;
+ int slot;
+
+ spin_lock_bh(&rxnet->peer_hash_lock);
+
+ while (!list_empty(collector)) {
+ peer = list_entry(collector->next,
+ struct rxrpc_peer, keepalive_link);
+
+ list_del_init(&peer->keepalive_link);
+ if (!rxrpc_get_peer_maybe(peer))
+ continue;
+
+ if (__rxrpc_use_local(peer->local)) {
+ spin_unlock_bh(&rxnet->peer_hash_lock);
+
+ keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME;
+ slot = keepalive_at - base;
+ _debug("%02x peer %u t=%d {%pISp}",
+ cursor, peer->debug_id, slot, &peer->srx.transport);
+
+ if (keepalive_at <= base ||
+ keepalive_at > base + RXRPC_KEEPALIVE_TIME) {
+ rxrpc_send_keepalive(peer);
+ slot = RXRPC_KEEPALIVE_TIME;
+ }
+
+ /* A transmission to this peer occurred since last we
+ * examined it so put it into the appropriate future
+ * bucket.
+ */
+ slot += cursor;
+ slot &= mask;
+ spin_lock_bh(&rxnet->peer_hash_lock);
+ list_add_tail(&peer->keepalive_link,
+ &rxnet->peer_keepalive[slot & mask]);
+ rxrpc_unuse_local(peer->local);
+ }
+ rxrpc_put_peer_locked(peer);
+ }
+
+ spin_unlock_bh(&rxnet->peer_hash_lock);
+}
+
+/*
+ * Perform keep-alive pings with VERSION packets to keep any NAT alive.
+ */
+void rxrpc_peer_keepalive_worker(struct work_struct *work)
+{
+ struct rxrpc_net *rxnet =
+ container_of(work, struct rxrpc_net, peer_keepalive_work);
+ const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1;
+ time64_t base, now, delay;
+ u8 cursor, stop;
+ LIST_HEAD(collector);
+
+ now = ktime_get_seconds();
+ base = rxnet->peer_keepalive_base;
+ cursor = rxnet->peer_keepalive_cursor;
+ _enter("%lld,%u", base - now, cursor);
+
+ if (!rxnet->live)
+ return;
+
+ /* Remove to a temporary list all the peers that are currently lodged
+ * in expired buckets plus all new peers.
+ *
+ * Everything in the bucket at the cursor is processed this
+ * second; the bucket at cursor + 1 goes at now + 1s and so
+ * on...
+ */
+ spin_lock_bh(&rxnet->peer_hash_lock);
+ list_splice_init(&rxnet->peer_keepalive_new, &collector);
+
+ stop = cursor + ARRAY_SIZE(rxnet->peer_keepalive);
+ while (base <= now && (s8)(cursor - stop) < 0) {
+ list_splice_tail_init(&rxnet->peer_keepalive[cursor & mask],
+ &collector);
+ base++;
+ cursor++;
+ }
+
+ base = now;
+ spin_unlock_bh(&rxnet->peer_hash_lock);
+
+ rxnet->peer_keepalive_base = base;
+ rxnet->peer_keepalive_cursor = cursor;
+ rxrpc_peer_keepalive_dispatch(rxnet, &collector, base, cursor);
+ ASSERT(list_empty(&collector));
+
+ /* Schedule the timer for the next occupied timeslot. */
+ cursor = rxnet->peer_keepalive_cursor;
+ stop = cursor + RXRPC_KEEPALIVE_TIME - 1;
+ for (; (s8)(cursor - stop) < 0; cursor++) {
+ if (!list_empty(&rxnet->peer_keepalive[cursor & mask]))
+ break;
+ base++;
+ }
+
+ now = ktime_get_seconds();
+ delay = base - now;
+ if (delay < 1)
+ delay = 1;
+ delay *= HZ;
+ if (rxnet->live)
+ timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
+
+ _leave("");
+}
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