// SPDX-License-Identifier: GPL-2.0-or-later
/* Local endpoint object management
*
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells ([email protected])
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/udp.h>
#include <linux/ip.h>
#include <linux/hashtable.h>
#include <net/sock.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
static void rxrpc_local_rcu(struct rcu_head *);
/*
* Handle an ICMP/ICMP6 error turning up at the tunnel. Push it through the
* usual mechanism so that it gets parsed and presented through the UDP
* socket's error_report().
*/
static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err,
__be16 port, u32 info, u8 *payload)
{
if (ip_hdr(skb)->version == IPVERSION)
return ip_icmp_error(sk, skb, err, port, info, payload);
if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6))
return ipv6_icmp_error(sk, skb, err, port, info, payload);
}
/*
* Set or clear the Don't Fragment flag on a socket.
*/
void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set)
{
if (set)
ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
else
ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DONT);
}
/*
* Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
* same or greater than.
*
* We explicitly don't compare the RxRPC service ID as we want to reject
* conflicting uses by differing services. Further, we don't want to share
* addresses with different options (IPv6), so we don't compare those bits
* either.
*/
static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
const struct sockaddr_rxrpc *srx)
{
long diff;
diff = ((local->srx.transport_type - srx->transport_type) ?:
(local->srx.transport_len - srx->transport_len) ?:
(local->srx.transport.family - srx->transport.family));
if (diff != 0)
return diff;
switch (srx->transport.family) {
case AF_INET:
/* If the choice of UDP port is left up to the transport, then
* the endpoint record doesn't match.
*/
return ((u16 __force)local->srx.transport.sin.sin_port -
(u16 __force)srx->transport.sin.sin_port) ?:
memcmp(&local->srx.transport.sin.sin_addr,
&srx->transport.sin.sin_addr,
sizeof(struct in_addr));
#ifdef CONFIG_AF_RXRPC_IPV6
case AF_INET6:
/* If the choice of UDP6 port is left up to the transport, then
* the endpoint record doesn't match.
*/
return ((u16 __force)local->srx.transport.sin6.sin6_port -
(u16 __force)srx->transport.sin6.sin6_port) ?:
memcmp(&local->srx.transport.sin6.sin6_addr,
&srx->transport.sin6.sin6_addr,
sizeof(struct in6_addr));
#endif
default:
BUG();
}
}
static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
{
struct rxrpc_local *local =
container_of(timer, struct rxrpc_local, client_conn_reap_timer);
if (!local->kill_all_client_conns &&
test_and_set_bit(RXRPC_CLIENT_CONN_REAP_TIMER, &local->client_conn_flags))
rxrpc_wake_up_io_thread(local);
}
/*
* Allocate a new local endpoint.
*/
static struct rxrpc_local *rxrpc_alloc_local(struct net *net,
const struct sockaddr_rxrpc *srx)
{
struct rxrpc_local *local;
u32 tmp;
local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
if (local) {
refcount_set(&local->ref, 1);
atomic_set(&local->active_users, 1);
local->net = net;
local->rxnet = rxrpc_net(net);
INIT_HLIST_NODE(&local->link);
init_completion(&local->io_thread_ready);
#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
skb_queue_head_init(&local->rx_delay_queue);
#endif
skb_queue_head_init(&local->rx_queue);
INIT_LIST_HEAD(&local->conn_attend_q);
INIT_LIST_HEAD(&local->call_attend_q);
local->client_bundles = RB_ROOT;
spin_lock_init(&local->client_bundles_lock);
local->kill_all_client_conns = false;
INIT_LIST_HEAD(&local->idle_client_conns);
timer_setup(&local->client_conn_reap_timer,
rxrpc_client_conn_reap_timeout, 0);
spin_lock_init(&local->lock);
rwlock_init(&local->services_lock);
local->debug_id = atomic_inc_return(&rxrpc_debug_id);
memcpy(&local->srx, srx, sizeof(*srx));
local->srx.srx_service = 0;
idr_init(&local->conn_ids);
get_random_bytes(&tmp, sizeof(tmp));
tmp &= 0x3fffffff;
if (tmp == 0)
tmp = 1;
idr_set_cursor(&local->conn_ids, tmp);
INIT_LIST_HEAD(&local->new_client_calls);
spin_lock_init(&local->client_call_lock);
trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1);
}
_leave(" = %p", local);
return local;
}
/*
* create the local socket
* - must be called with rxrpc_local_mutex locked
*/
static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
{
struct udp_tunnel_sock_cfg tuncfg = {NULL};
struct sockaddr_rxrpc *srx = &local->srx;
struct udp_port_cfg udp_conf = {0};
struct task_struct *io_thread;
struct sock *usk;
int ret;
_enter("%p{%d,%d}",
local, srx->transport_type, srx->transport.family);
udp_conf.family = srx->transport.family;
udp_conf.use_udp_checksums = true;
if (udp_conf.family == AF_INET) {
udp_conf.local_ip = srx->transport.sin.sin_addr;
udp_conf.local_udp_port = srx->transport.sin.sin_port;
#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
} else {
udp_conf.local_ip6 = srx->transport.sin6.sin6_addr;
udp_conf.local_udp_port = srx->transport.sin6.sin6_port;
udp_conf.use_udp6_tx_checksums = true;
udp_conf.use_udp6_rx_checksums = true;
#endif
}
ret = udp_sock_create(net, &udp_conf, &local->socket);
if (ret < 0) {
_leave(" = %d [socket]", ret);
return ret;
}
tuncfg.encap_type = UDP_ENCAP_RXRPC;
tuncfg.encap_rcv = rxrpc_encap_rcv;
tuncfg.encap_err_rcv = rxrpc_encap_err_rcv;
tuncfg.sk_user_data = local;
setup_udp_tunnel_sock(net, local->socket, &tuncfg);
/* set the socket up */
usk = local->socket->sk;
usk->sk_error_report = rxrpc_error_report;
switch (srx->transport.family) {
case AF_INET6:
/* we want to receive ICMPv6 errors */
ip6_sock_set_recverr(usk);
/* Fall through and set IPv4 options too otherwise we don't get
* errors from IPv4 packets sent through the IPv6 socket.
*/
fallthrough;
case AF_INET:
/* we want to receive ICMP errors */
ip_sock_set_recverr(usk);
/* we want to set the don't fragment bit */
rxrpc_local_dont_fragment(local, true);
/* We want receive timestamps. */
sock_enable_timestamps(usk);
break;
default:
BUG();
}
io_thread = kthread_run(rxrpc_io_thread, local,
"krxrpcio/%u", ntohs(udp_conf.local_udp_port));
if (IS_ERR(io_thread)) {
ret = PTR_ERR(io_thread);
goto error_sock;
}
wait_for_completion(&local->io_thread_ready);
local->io_thread = io_thread;
_leave(" = 0");
return 0;
error_sock:
kernel_sock_shutdown(local->socket, SHUT_RDWR);
local->socket->sk->sk_user_data = NULL;
sock_release(local->socket);
local->socket = NULL;
return ret;
}
/*
* Look up or create a new local endpoint using the specified local address.
*/
struct rxrpc_local *rxrpc_lookup_local(struct net *net,
const struct sockaddr_rxrpc *srx)
{
struct rxrpc_local *local;
struct rxrpc_net *rxnet = rxrpc_net(net);
struct hlist_node *cursor;
long diff;
int ret;
_enter("{%d,%d,%pISp}",
srx->transport_type, srx->transport.family, &srx->transport);
mutex_lock(&rxnet->local_mutex);
hlist_for_each(cursor, &rxnet->local_endpoints) {
local = hlist_entry(cursor, struct rxrpc_local, link);
diff = rxrpc_local_cmp_key(local, srx);
if (diff != 0)
continue;
/* Services aren't allowed to share transport sockets, so
* reject that here. It is possible that the object is dying -
* but it may also still have the local transport address that
* we want bound.
*/
if (srx->srx_service) {
local = NULL;
goto addr_in_use;
}
/* Found a match. We want to replace a dying object.
* Attempting to bind the transport socket may still fail if
* we're attempting to use a local address that the dying
* object is still using.
*/
if (!rxrpc_use_local(local, rxrpc_local_use_lookup))
break;
goto found;
}
local = rxrpc_alloc_local(net, srx);
if (!local)
goto nomem;
ret = rxrpc_open_socket(local, net);
if (ret < 0)
goto sock_error;
if (cursor) {
hlist_replace_rcu(cursor, &local->link);
cursor->pprev = NULL;
} else {
hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
}
found:
mutex_unlock(&rxnet->local_mutex);
_leave(" = %p", local);
return local;
nomem:
ret = -ENOMEM;
sock_error:
mutex_unlock(&rxnet->local_mutex);
if (local)
call_rcu(&local->rcu, rxrpc_local_rcu);
_leave(" = %d", ret);
return ERR_PTR(ret);
addr_in_use:
mutex_unlock(&rxnet->local_mutex);
_leave(" = -EADDRINUSE");
return ERR_PTR(-EADDRINUSE);
}
/*
* Get a ref on a local endpoint.
*/
struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local,
enum rxrpc_local_trace why)
{
int r, u;
u = atomic_read(&local->active_users);
__refcount_inc(&local->ref, &r);
trace_rxrpc_local(local->debug_id, why, r + 1, u);
return local;
}
/*
* Get a ref on a local endpoint unless its usage has already reached 0.
*/
struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local,
enum rxrpc_local_trace why)
{
int r, u;
if (local && __refcount_inc_not_zero(&local->ref, &r)) {
u = atomic_read(&local->active_users);
trace_rxrpc_local(local->debug_id, why, r + 1, u);
return local;
}
return NULL;
}
/*
* Drop a ref on a local endpoint.
*/
void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
{
unsigned int debug_id;
bool dead;
int r, u;
if (local) {
debug_id = local->debug_id;
u = atomic_read(&local->active_users);
dead = __refcount_dec_and_test(&local->ref, &r);
trace_rxrpc_local(debug_id, why, r, u);
if (dead)
call_rcu(&local->rcu, rxrpc_local_rcu);
}
}
/*
* Start using a local endpoint.
*/
struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local,
enum rxrpc_local_trace why)
{
local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use);
if (!local)
return NULL;
if (!__rxrpc_use_local(local, why)) {
rxrpc_put_local(local, rxrpc_local_put_for_use);
return NULL;
}
return local;
}
/*
* Cease using a local endpoint. Once the number of active users reaches 0, we
* start the closure of the transport in the I/O thread..
*/
void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why)
{
unsigned int debug_id;
int r, u;
if (local) {
debug_id = local->debug_id;
r = refcount_read(&local->ref);
u = atomic_dec_return(&local->active_users);
trace_rxrpc_local(debug_id, why, r, u);
if (u == 0)
kthread_stop(local->io_thread);
}
}
/*
* Destroy a local endpoint's socket and then hand the record to RCU to dispose
* of.
*
* Closing the socket cannot be done from bottom half context or RCU callback
* context because it might sleep.
*/
void rxrpc_destroy_local(struct rxrpc_local *local)
{
struct socket *socket = local->socket;
struct rxrpc_net *rxnet = local->rxnet;
_enter("%d", local->debug_id);
local->dead = true;
mutex_lock(&rxnet->local_mutex);
hlist_del_init_rcu(&local->link);
mutex_unlock(&rxnet->local_mutex);
rxrpc_clean_up_local_conns(local);
rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
ASSERT(!local->service);
if (socket) {
local->socket = NULL;
kernel_sock_shutdown(socket, SHUT_RDWR);
socket->sk->sk_user_data = NULL;
sock_release(socket);
}
/* At this point, there should be no more packets coming in to the
* local endpoint.
*/
#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
rxrpc_purge_queue(&local->rx_delay_queue);
#endif
rxrpc_purge_queue(&local->rx_queue);
rxrpc_purge_client_connections(local);
if (local->tx_alloc.va)
__page_frag_cache_drain(virt_to_page(local->tx_alloc.va),
local->tx_alloc.pagecnt_bias);
}
/*
* Destroy a local endpoint after the RCU grace period expires.
*/
static void rxrpc_local_rcu(struct rcu_head *rcu)
{
struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
rxrpc_see_local(local, rxrpc_local_free);
kfree(local);
}
/*
* Verify the local endpoint list is empty by this point.
*/
void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
{
struct rxrpc_local *local;
_enter("");
flush_workqueue(rxrpc_workqueue);
if (!hlist_empty(&rxnet->local_endpoints)) {
mutex_lock(&rxnet->local_mutex);
hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
pr_err("AF_RXRPC: Leaked local %p {%d}\n",
local, refcount_read(&local->ref));
}
mutex_unlock(&rxnet->local_mutex);
BUG();
}
}
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