v4.19.13 snapshot.
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
new file mode 100644
index 0000000..5691b7d
--- /dev/null
+++ b/net/rxrpc/peer_object.c
@@ -0,0 +1,490 @@
+/* RxRPC remote transport endpoint record management
+ *
+ * Copyright (C) 2007, 2016 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+#include "ar-internal.h"
+
+/*
+ * Hash a peer key.
+ */
+static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local,
+ const struct sockaddr_rxrpc *srx)
+{
+ const u16 *p;
+ unsigned int i, size;
+ unsigned long hash_key;
+
+ _enter("");
+
+ hash_key = (unsigned long)local / __alignof__(*local);
+ hash_key += srx->transport_type;
+ hash_key += srx->transport_len;
+ hash_key += srx->transport.family;
+
+ switch (srx->transport.family) {
+ case AF_INET:
+ hash_key += (u16 __force)srx->transport.sin.sin_port;
+ size = sizeof(srx->transport.sin.sin_addr);
+ p = (u16 *)&srx->transport.sin.sin_addr;
+ break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ hash_key += (u16 __force)srx->transport.sin.sin_port;
+ size = sizeof(srx->transport.sin6.sin6_addr);
+ p = (u16 *)&srx->transport.sin6.sin6_addr;
+ break;
+#endif
+ default:
+ WARN(1, "AF_RXRPC: Unsupported transport address family\n");
+ return 0;
+ }
+
+ /* Step through the peer address in 16-bit portions for speed */
+ for (i = 0; i < size; i += sizeof(*p), p++)
+ hash_key += *p;
+
+ _leave(" 0x%lx", hash_key);
+ return hash_key;
+}
+
+/*
+ * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same
+ * or greater than.
+ *
+ * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted
+ * buckets and mid-bucket insertion, so we don't make full use of this
+ * information at this point.
+ */
+static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer,
+ struct rxrpc_local *local,
+ const struct sockaddr_rxrpc *srx,
+ unsigned long hash_key)
+{
+ long diff;
+
+ diff = ((peer->hash_key - hash_key) ?:
+ ((unsigned long)peer->local - (unsigned long)local) ?:
+ (peer->srx.transport_type - srx->transport_type) ?:
+ (peer->srx.transport_len - srx->transport_len) ?:
+ (peer->srx.transport.family - srx->transport.family));
+ if (diff != 0)
+ return diff;
+
+ switch (srx->transport.family) {
+ case AF_INET:
+ return ((u16 __force)peer->srx.transport.sin.sin_port -
+ (u16 __force)srx->transport.sin.sin_port) ?:
+ memcmp(&peer->srx.transport.sin.sin_addr,
+ &srx->transport.sin.sin_addr,
+ sizeof(struct in_addr));
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ return ((u16 __force)peer->srx.transport.sin6.sin6_port -
+ (u16 __force)srx->transport.sin6.sin6_port) ?:
+ memcmp(&peer->srx.transport.sin6.sin6_addr,
+ &srx->transport.sin6.sin6_addr,
+ sizeof(struct in6_addr));
+#endif
+ default:
+ BUG();
+ }
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+static struct rxrpc_peer *__rxrpc_lookup_peer_rcu(
+ struct rxrpc_local *local,
+ const struct sockaddr_rxrpc *srx,
+ unsigned long hash_key)
+{
+ struct rxrpc_peer *peer;
+ struct rxrpc_net *rxnet = local->rxnet;
+
+ hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) {
+ if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 &&
+ atomic_read(&peer->usage) > 0)
+ return peer;
+ }
+
+ return NULL;
+}
+
+/*
+ * Look up a remote transport endpoint for the specified address using RCU.
+ */
+struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local,
+ const struct sockaddr_rxrpc *srx)
+{
+ struct rxrpc_peer *peer;
+ unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+ peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+ if (peer) {
+ _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
+ _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
+ }
+ return peer;
+}
+
+/*
+ * assess the MTU size for the network interface through which this peer is
+ * reached
+ */
+static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx,
+ struct rxrpc_peer *peer)
+{
+ struct net *net = sock_net(&rx->sk);
+ struct dst_entry *dst;
+ struct rtable *rt;
+ struct flowi fl;
+ struct flowi4 *fl4 = &fl.u.ip4;
+#ifdef CONFIG_AF_RXRPC_IPV6
+ struct flowi6 *fl6 = &fl.u.ip6;
+#endif
+
+ peer->if_mtu = 1500;
+
+ memset(&fl, 0, sizeof(fl));
+ switch (peer->srx.transport.family) {
+ case AF_INET:
+ rt = ip_route_output_ports(
+ net, fl4, NULL,
+ peer->srx.transport.sin.sin_addr.s_addr, 0,
+ htons(7000), htons(7001), IPPROTO_UDP, 0, 0);
+ if (IS_ERR(rt)) {
+ _leave(" [route err %ld]", PTR_ERR(rt));
+ return;
+ }
+ dst = &rt->dst;
+ break;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ fl6->flowi6_iif = LOOPBACK_IFINDEX;
+ fl6->flowi6_scope = RT_SCOPE_UNIVERSE;
+ fl6->flowi6_proto = IPPROTO_UDP;
+ memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr,
+ sizeof(struct in6_addr));
+ fl6->fl6_dport = htons(7001);
+ fl6->fl6_sport = htons(7000);
+ dst = ip6_route_output(net, NULL, fl6);
+ if (dst->error) {
+ _leave(" [route err %d]", dst->error);
+ return;
+ }
+ break;
+#endif
+
+ default:
+ BUG();
+ }
+
+ peer->if_mtu = dst_mtu(dst);
+ dst_release(dst);
+
+ _leave(" [if_mtu %u]", peer->if_mtu);
+}
+
+/*
+ * Allocate a peer.
+ */
+struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp)
+{
+ struct rxrpc_peer *peer;
+
+ _enter("");
+
+ peer = kzalloc(sizeof(struct rxrpc_peer), gfp);
+ if (peer) {
+ atomic_set(&peer->usage, 1);
+ peer->local = local;
+ INIT_HLIST_HEAD(&peer->error_targets);
+ peer->service_conns = RB_ROOT;
+ seqlock_init(&peer->service_conn_lock);
+ spin_lock_init(&peer->lock);
+ spin_lock_init(&peer->rtt_input_lock);
+ peer->debug_id = atomic_inc_return(&rxrpc_debug_id);
+
+ if (RXRPC_TX_SMSS > 2190)
+ peer->cong_cwnd = 2;
+ else if (RXRPC_TX_SMSS > 1095)
+ peer->cong_cwnd = 3;
+ else
+ peer->cong_cwnd = 4;
+ }
+
+ _leave(" = %p", peer);
+ return peer;
+}
+
+/*
+ * Initialise peer record.
+ */
+static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer,
+ unsigned long hash_key)
+{
+ peer->hash_key = hash_key;
+ rxrpc_assess_MTU_size(rx, peer);
+ peer->mtu = peer->if_mtu;
+ peer->rtt_last_req = ktime_get_real();
+
+ switch (peer->srx.transport.family) {
+ case AF_INET:
+ peer->hdrsize = sizeof(struct iphdr);
+ break;
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case AF_INET6:
+ peer->hdrsize = sizeof(struct ipv6hdr);
+ break;
+#endif
+ default:
+ BUG();
+ }
+
+ switch (peer->srx.transport_type) {
+ case SOCK_DGRAM:
+ peer->hdrsize += sizeof(struct udphdr);
+ break;
+ default:
+ BUG();
+ }
+
+ peer->hdrsize += sizeof(struct rxrpc_wire_header);
+ peer->maxdata = peer->mtu - peer->hdrsize;
+}
+
+/*
+ * Set up a new peer.
+ */
+static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx,
+ struct rxrpc_local *local,
+ struct sockaddr_rxrpc *srx,
+ unsigned long hash_key,
+ gfp_t gfp)
+{
+ struct rxrpc_peer *peer;
+
+ _enter("");
+
+ peer = rxrpc_alloc_peer(local, gfp);
+ if (peer) {
+ memcpy(&peer->srx, srx, sizeof(*srx));
+ rxrpc_init_peer(rx, peer, hash_key);
+ }
+
+ _leave(" = %p", peer);
+ return peer;
+}
+
+/*
+ * Set up a new incoming peer. There shouldn't be any other matching peers
+ * since we've already done a search in the list from the non-reentrant context
+ * (the data_ready handler) that is the only place we can add new peers.
+ */
+void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local,
+ struct rxrpc_peer *peer)
+{
+ struct rxrpc_net *rxnet = local->rxnet;
+ unsigned long hash_key;
+
+ hash_key = rxrpc_peer_hash_key(local, &peer->srx);
+ peer->local = local;
+ rxrpc_init_peer(rx, peer, hash_key);
+
+ spin_lock(&rxnet->peer_hash_lock);
+ hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
+ list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new);
+ spin_unlock(&rxnet->peer_hash_lock);
+}
+
+/*
+ * obtain a remote transport endpoint for the specified address
+ */
+struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx,
+ struct rxrpc_local *local,
+ struct sockaddr_rxrpc *srx, gfp_t gfp)
+{
+ struct rxrpc_peer *peer, *candidate;
+ struct rxrpc_net *rxnet = local->rxnet;
+ unsigned long hash_key = rxrpc_peer_hash_key(local, srx);
+
+ _enter("{%pISp}", &srx->transport);
+
+ /* search the peer list first */
+ rcu_read_lock();
+ peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+ if (peer && !rxrpc_get_peer_maybe(peer))
+ peer = NULL;
+ rcu_read_unlock();
+
+ if (!peer) {
+ /* The peer is not yet present in hash - create a candidate
+ * for a new record and then redo the search.
+ */
+ candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp);
+ if (!candidate) {
+ _leave(" = NULL [nomem]");
+ return NULL;
+ }
+
+ spin_lock_bh(&rxnet->peer_hash_lock);
+
+ /* Need to check that we aren't racing with someone else */
+ peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
+ if (peer && !rxrpc_get_peer_maybe(peer))
+ peer = NULL;
+ if (!peer) {
+ hash_add_rcu(rxnet->peer_hash,
+ &candidate->hash_link, hash_key);
+ list_add_tail(&candidate->keepalive_link,
+ &rxnet->peer_keepalive_new);
+ }
+
+ spin_unlock_bh(&rxnet->peer_hash_lock);
+
+ if (peer)
+ kfree(candidate);
+ else
+ peer = candidate;
+ }
+
+ _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport);
+
+ _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage));
+ return peer;
+}
+
+/*
+ * Get a ref on a peer record.
+ */
+struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer)
+{
+ const void *here = __builtin_return_address(0);
+ int n;
+
+ n = atomic_inc_return(&peer->usage);
+ trace_rxrpc_peer(peer, rxrpc_peer_got, n, here);
+ return peer;
+}
+
+/*
+ * Get a ref on a peer record unless its usage has already reached 0.
+ */
+struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer)
+{
+ const void *here = __builtin_return_address(0);
+
+ if (peer) {
+ int n = atomic_fetch_add_unless(&peer->usage, 1, 0);
+ if (n > 0)
+ trace_rxrpc_peer(peer, rxrpc_peer_got, n + 1, here);
+ else
+ peer = NULL;
+ }
+ return peer;
+}
+
+/*
+ * Discard a peer record.
+ */
+static void __rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+ struct rxrpc_net *rxnet = peer->local->rxnet;
+
+ ASSERT(hlist_empty(&peer->error_targets));
+
+ spin_lock_bh(&rxnet->peer_hash_lock);
+ hash_del_rcu(&peer->hash_link);
+ list_del_init(&peer->keepalive_link);
+ spin_unlock_bh(&rxnet->peer_hash_lock);
+
+ kfree_rcu(peer, rcu);
+}
+
+/*
+ * Drop a ref on a peer record.
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+ const void *here = __builtin_return_address(0);
+ int n;
+
+ if (peer) {
+ n = atomic_dec_return(&peer->usage);
+ trace_rxrpc_peer(peer, rxrpc_peer_put, n, here);
+ if (n == 0)
+ __rxrpc_put_peer(peer);
+ }
+}
+
+/*
+ * Make sure all peer records have been discarded.
+ */
+void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet)
+{
+ struct rxrpc_peer *peer;
+ int i;
+
+ for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) {
+ if (hlist_empty(&rxnet->peer_hash[i]))
+ continue;
+
+ hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) {
+ pr_err("Leaked peer %u {%u} %pISp\n",
+ peer->debug_id,
+ atomic_read(&peer->usage),
+ &peer->srx.transport);
+ }
+ }
+}
+
+/**
+ * rxrpc_kernel_get_peer - Get the peer address of a call
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ * @_srx: Where to place the result
+ *
+ * Get the address of the remote peer in a call.
+ */
+void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call,
+ struct sockaddr_rxrpc *_srx)
+{
+ *_srx = call->peer->srx;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_peer);
+
+/**
+ * rxrpc_kernel_get_rtt - Get a call's peer RTT
+ * @sock: The socket on which the call is in progress.
+ * @call: The call to query
+ *
+ * Get the call's peer RTT.
+ */
+u64 rxrpc_kernel_get_rtt(struct socket *sock, struct rxrpc_call *call)
+{
+ return call->peer->rtt;
+}
+EXPORT_SYMBOL(rxrpc_kernel_get_rtt);