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474 lines
11 KiB
474 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* Local endpoint object management |
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* |
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* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. |
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* Written by David Howells ([email protected]) |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/module.h> |
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#include <linux/net.h> |
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#include <linux/skbuff.h> |
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#include <linux/slab.h> |
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#include <linux/udp.h> |
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#include <linux/ip.h> |
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#include <linux/hashtable.h> |
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#include <net/sock.h> |
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#include <net/udp.h> |
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#include <net/udp_tunnel.h> |
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#include <net/af_rxrpc.h> |
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#include "ar-internal.h" |
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static void rxrpc_local_processor(struct work_struct *); |
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static void rxrpc_local_rcu(struct rcu_head *); |
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/* |
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* Compare a local to an address. Return -ve, 0 or +ve to indicate less than, |
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* same or greater than. |
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* |
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* We explicitly don't compare the RxRPC service ID as we want to reject |
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* conflicting uses by differing services. Further, we don't want to share |
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* addresses with different options (IPv6), so we don't compare those bits |
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* either. |
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*/ |
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static long rxrpc_local_cmp_key(const struct rxrpc_local *local, |
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const struct sockaddr_rxrpc *srx) |
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{ |
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long diff; |
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diff = ((local->srx.transport_type - srx->transport_type) ?: |
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(local->srx.transport_len - srx->transport_len) ?: |
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(local->srx.transport.family - srx->transport.family)); |
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if (diff != 0) |
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return diff; |
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switch (srx->transport.family) { |
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case AF_INET: |
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/* If the choice of UDP port is left up to the transport, then |
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* the endpoint record doesn't match. |
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*/ |
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return ((u16 __force)local->srx.transport.sin.sin_port - |
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(u16 __force)srx->transport.sin.sin_port) ?: |
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memcmp(&local->srx.transport.sin.sin_addr, |
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&srx->transport.sin.sin_addr, |
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sizeof(struct in_addr)); |
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#ifdef CONFIG_AF_RXRPC_IPV6 |
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case AF_INET6: |
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/* If the choice of UDP6 port is left up to the transport, then |
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* the endpoint record doesn't match. |
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*/ |
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return ((u16 __force)local->srx.transport.sin6.sin6_port - |
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(u16 __force)srx->transport.sin6.sin6_port) ?: |
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memcmp(&local->srx.transport.sin6.sin6_addr, |
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&srx->transport.sin6.sin6_addr, |
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sizeof(struct in6_addr)); |
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#endif |
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default: |
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BUG(); |
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} |
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} |
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/* |
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* Allocate a new local endpoint. |
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*/ |
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static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, |
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const struct sockaddr_rxrpc *srx) |
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{ |
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struct rxrpc_local *local; |
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local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); |
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if (local) { |
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refcount_set(&local->ref, 1); |
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atomic_set(&local->active_users, 1); |
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local->rxnet = rxnet; |
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INIT_HLIST_NODE(&local->link); |
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INIT_WORK(&local->processor, rxrpc_local_processor); |
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init_rwsem(&local->defrag_sem); |
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skb_queue_head_init(&local->reject_queue); |
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skb_queue_head_init(&local->event_queue); |
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local->client_bundles = RB_ROOT; |
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spin_lock_init(&local->client_bundles_lock); |
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spin_lock_init(&local->lock); |
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rwlock_init(&local->services_lock); |
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local->debug_id = atomic_inc_return(&rxrpc_debug_id); |
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memcpy(&local->srx, srx, sizeof(*srx)); |
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local->srx.srx_service = 0; |
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trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, NULL); |
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} |
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_leave(" = %p", local); |
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return local; |
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} |
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/* |
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* create the local socket |
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* - must be called with rxrpc_local_mutex locked |
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*/ |
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static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net) |
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{ |
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struct udp_tunnel_sock_cfg tuncfg = {NULL}; |
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struct sockaddr_rxrpc *srx = &local->srx; |
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struct udp_port_cfg udp_conf = {0}; |
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struct sock *usk; |
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int ret; |
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_enter("%p{%d,%d}", |
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local, srx->transport_type, srx->transport.family); |
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udp_conf.family = srx->transport.family; |
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udp_conf.use_udp_checksums = true; |
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if (udp_conf.family == AF_INET) { |
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udp_conf.local_ip = srx->transport.sin.sin_addr; |
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udp_conf.local_udp_port = srx->transport.sin.sin_port; |
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#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6) |
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} else { |
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udp_conf.local_ip6 = srx->transport.sin6.sin6_addr; |
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udp_conf.local_udp_port = srx->transport.sin6.sin6_port; |
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udp_conf.use_udp6_tx_checksums = true; |
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udp_conf.use_udp6_rx_checksums = true; |
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#endif |
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} |
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ret = udp_sock_create(net, &udp_conf, &local->socket); |
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if (ret < 0) { |
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_leave(" = %d [socket]", ret); |
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return ret; |
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} |
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tuncfg.encap_type = UDP_ENCAP_RXRPC; |
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tuncfg.encap_rcv = rxrpc_input_packet; |
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tuncfg.encap_err_rcv = rxrpc_encap_err_rcv; |
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tuncfg.sk_user_data = local; |
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setup_udp_tunnel_sock(net, local->socket, &tuncfg); |
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/* set the socket up */ |
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usk = local->socket->sk; |
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usk->sk_error_report = rxrpc_error_report; |
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switch (srx->transport.family) { |
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case AF_INET6: |
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/* we want to receive ICMPv6 errors */ |
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ip6_sock_set_recverr(usk); |
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/* Fall through and set IPv4 options too otherwise we don't get |
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* errors from IPv4 packets sent through the IPv6 socket. |
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*/ |
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fallthrough; |
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case AF_INET: |
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/* we want to receive ICMP errors */ |
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ip_sock_set_recverr(usk); |
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/* we want to set the don't fragment bit */ |
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ip_sock_set_mtu_discover(usk, IP_PMTUDISC_DO); |
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/* We want receive timestamps. */ |
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sock_enable_timestamps(usk); |
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break; |
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default: |
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BUG(); |
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} |
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_leave(" = 0"); |
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return 0; |
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} |
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/* |
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* Look up or create a new local endpoint using the specified local address. |
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*/ |
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struct rxrpc_local *rxrpc_lookup_local(struct net *net, |
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const struct sockaddr_rxrpc *srx) |
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{ |
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struct rxrpc_local *local; |
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struct rxrpc_net *rxnet = rxrpc_net(net); |
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struct hlist_node *cursor; |
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const char *age; |
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long diff; |
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int ret; |
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_enter("{%d,%d,%pISp}", |
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srx->transport_type, srx->transport.family, &srx->transport); |
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mutex_lock(&rxnet->local_mutex); |
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hlist_for_each(cursor, &rxnet->local_endpoints) { |
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local = hlist_entry(cursor, struct rxrpc_local, link); |
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diff = rxrpc_local_cmp_key(local, srx); |
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if (diff != 0) |
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continue; |
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/* Services aren't allowed to share transport sockets, so |
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* reject that here. It is possible that the object is dying - |
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* but it may also still have the local transport address that |
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* we want bound. |
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*/ |
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if (srx->srx_service) { |
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local = NULL; |
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goto addr_in_use; |
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} |
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/* Found a match. We want to replace a dying object. |
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* Attempting to bind the transport socket may still fail if |
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* we're attempting to use a local address that the dying |
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* object is still using. |
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*/ |
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if (!rxrpc_use_local(local)) |
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break; |
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age = "old"; |
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goto found; |
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} |
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local = rxrpc_alloc_local(rxnet, srx); |
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if (!local) |
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goto nomem; |
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ret = rxrpc_open_socket(local, net); |
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if (ret < 0) |
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goto sock_error; |
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if (cursor) { |
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hlist_replace_rcu(cursor, &local->link); |
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cursor->pprev = NULL; |
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} else { |
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hlist_add_head_rcu(&local->link, &rxnet->local_endpoints); |
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} |
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age = "new"; |
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found: |
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mutex_unlock(&rxnet->local_mutex); |
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_net("LOCAL %s %d {%pISp}", |
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age, local->debug_id, &local->srx.transport); |
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_leave(" = %p", local); |
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return local; |
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nomem: |
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ret = -ENOMEM; |
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sock_error: |
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mutex_unlock(&rxnet->local_mutex); |
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if (local) |
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call_rcu(&local->rcu, rxrpc_local_rcu); |
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_leave(" = %d", ret); |
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return ERR_PTR(ret); |
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addr_in_use: |
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mutex_unlock(&rxnet->local_mutex); |
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_leave(" = -EADDRINUSE"); |
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return ERR_PTR(-EADDRINUSE); |
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} |
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/* |
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* Get a ref on a local endpoint. |
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*/ |
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struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local) |
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{ |
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const void *here = __builtin_return_address(0); |
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int r; |
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__refcount_inc(&local->ref, &r); |
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trace_rxrpc_local(local->debug_id, rxrpc_local_got, r + 1, here); |
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return local; |
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} |
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/* |
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* Get a ref on a local endpoint unless its usage has already reached 0. |
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*/ |
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struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local) |
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{ |
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const void *here = __builtin_return_address(0); |
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int r; |
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if (local) { |
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if (__refcount_inc_not_zero(&local->ref, &r)) |
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trace_rxrpc_local(local->debug_id, rxrpc_local_got, |
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r + 1, here); |
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else |
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local = NULL; |
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} |
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return local; |
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} |
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/* |
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* Queue a local endpoint and pass the caller's reference to the work item. |
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*/ |
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void rxrpc_queue_local(struct rxrpc_local *local) |
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{ |
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const void *here = __builtin_return_address(0); |
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unsigned int debug_id = local->debug_id; |
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int r = refcount_read(&local->ref); |
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if (rxrpc_queue_work(&local->processor)) |
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trace_rxrpc_local(debug_id, rxrpc_local_queued, r + 1, here); |
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else |
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rxrpc_put_local(local); |
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} |
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/* |
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* Drop a ref on a local endpoint. |
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*/ |
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void rxrpc_put_local(struct rxrpc_local *local) |
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{ |
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const void *here = __builtin_return_address(0); |
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unsigned int debug_id; |
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bool dead; |
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int r; |
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if (local) { |
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debug_id = local->debug_id; |
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dead = __refcount_dec_and_test(&local->ref, &r); |
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trace_rxrpc_local(debug_id, rxrpc_local_put, r, here); |
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if (dead) |
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call_rcu(&local->rcu, rxrpc_local_rcu); |
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} |
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} |
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/* |
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* Start using a local endpoint. |
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*/ |
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struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local) |
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{ |
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local = rxrpc_get_local_maybe(local); |
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if (!local) |
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return NULL; |
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if (!__rxrpc_use_local(local)) { |
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rxrpc_put_local(local); |
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return NULL; |
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} |
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return local; |
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} |
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/* |
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* Cease using a local endpoint. Once the number of active users reaches 0, we |
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* start the closure of the transport in the work processor. |
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*/ |
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void rxrpc_unuse_local(struct rxrpc_local *local) |
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{ |
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if (local) { |
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if (__rxrpc_unuse_local(local)) { |
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rxrpc_get_local(local); |
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rxrpc_queue_local(local); |
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} |
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} |
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} |
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/* |
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* Destroy a local endpoint's socket and then hand the record to RCU to dispose |
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* of. |
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* |
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* Closing the socket cannot be done from bottom half context or RCU callback |
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* context because it might sleep. |
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*/ |
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static void rxrpc_local_destroyer(struct rxrpc_local *local) |
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{ |
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struct socket *socket = local->socket; |
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struct rxrpc_net *rxnet = local->rxnet; |
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_enter("%d", local->debug_id); |
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local->dead = true; |
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mutex_lock(&rxnet->local_mutex); |
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hlist_del_init_rcu(&local->link); |
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mutex_unlock(&rxnet->local_mutex); |
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rxrpc_clean_up_local_conns(local); |
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rxrpc_service_connection_reaper(&rxnet->service_conn_reaper); |
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ASSERT(!local->service); |
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if (socket) { |
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local->socket = NULL; |
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kernel_sock_shutdown(socket, SHUT_RDWR); |
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socket->sk->sk_user_data = NULL; |
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sock_release(socket); |
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} |
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/* At this point, there should be no more packets coming in to the |
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* local endpoint. |
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*/ |
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rxrpc_purge_queue(&local->reject_queue); |
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rxrpc_purge_queue(&local->event_queue); |
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} |
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/* |
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* Process events on an endpoint. The work item carries a ref which |
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* we must release. |
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*/ |
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static void rxrpc_local_processor(struct work_struct *work) |
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{ |
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struct rxrpc_local *local = |
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container_of(work, struct rxrpc_local, processor); |
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bool again; |
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if (local->dead) |
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return; |
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trace_rxrpc_local(local->debug_id, rxrpc_local_processing, |
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refcount_read(&local->ref), NULL); |
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do { |
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again = false; |
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if (!__rxrpc_use_local(local)) { |
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rxrpc_local_destroyer(local); |
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break; |
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} |
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if (!skb_queue_empty(&local->reject_queue)) { |
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rxrpc_reject_packets(local); |
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again = true; |
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} |
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if (!skb_queue_empty(&local->event_queue)) { |
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rxrpc_process_local_events(local); |
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again = true; |
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} |
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__rxrpc_unuse_local(local); |
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} while (again); |
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rxrpc_put_local(local); |
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} |
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/* |
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* Destroy a local endpoint after the RCU grace period expires. |
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*/ |
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static void rxrpc_local_rcu(struct rcu_head *rcu) |
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{ |
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struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); |
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_enter("%d", local->debug_id); |
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ASSERT(!work_pending(&local->processor)); |
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_net("DESTROY LOCAL %d", local->debug_id); |
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kfree(local); |
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_leave(""); |
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} |
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/* |
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* Verify the local endpoint list is empty by this point. |
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*/ |
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void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet) |
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{ |
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struct rxrpc_local *local; |
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_enter(""); |
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flush_workqueue(rxrpc_workqueue); |
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if (!hlist_empty(&rxnet->local_endpoints)) { |
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mutex_lock(&rxnet->local_mutex); |
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hlist_for_each_entry(local, &rxnet->local_endpoints, link) { |
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pr_err("AF_RXRPC: Leaked local %p {%d}\n", |
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local, refcount_read(&local->ref)); |
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} |
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mutex_unlock(&rxnet->local_mutex); |
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BUG(); |
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} |
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}
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