| /* Local endpoint object management |
| * |
| * Copyright (C) 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 Licence |
| * as published by the Free Software Foundation; either version |
| * 2 of the Licence, 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/slab.h> |
| #include <linux/udp.h> |
| #include <linux/ip.h> |
| #include <linux/hashtable.h> |
| #include <net/sock.h> |
| #include <net/udp.h> |
| #include <net/af_rxrpc.h> |
| #include "ar-internal.h" |
| |
| static void rxrpc_local_processor(struct work_struct *); |
| static void rxrpc_local_rcu(struct rcu_head *); |
| |
| /* |
| * 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(); |
| } |
| } |
| |
| /* |
| * Allocate a new local endpoint. |
| */ |
| static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, |
| const struct sockaddr_rxrpc *srx) |
| { |
| struct rxrpc_local *local; |
| |
| local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); |
| if (local) { |
| atomic_set(&local->usage, 1); |
| local->rxnet = rxnet; |
| INIT_LIST_HEAD(&local->link); |
| INIT_WORK(&local->processor, rxrpc_local_processor); |
| init_rwsem(&local->defrag_sem); |
| skb_queue_head_init(&local->reject_queue); |
| skb_queue_head_init(&local->event_queue); |
| local->client_conns = RB_ROOT; |
| spin_lock_init(&local->client_conns_lock); |
| 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; |
| trace_rxrpc_local(local, rxrpc_local_new, 1, NULL); |
| } |
| |
| _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 sock *usk; |
| int ret, opt; |
| |
| _enter("%p{%d,%d}", |
| local, local->srx.transport_type, local->srx.transport.family); |
| |
| /* create a socket to represent the local endpoint */ |
| ret = sock_create_kern(net, local->srx.transport.family, |
| local->srx.transport_type, 0, &local->socket); |
| if (ret < 0) { |
| _leave(" = %d [socket]", ret); |
| return ret; |
| } |
| |
| /* set the socket up */ |
| usk = local->socket->sk; |
| inet_sk(usk)->mc_loop = 0; |
| |
| /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */ |
| inet_inc_convert_csum(usk); |
| |
| rcu_assign_sk_user_data(usk, local); |
| |
| udp_sk(usk)->encap_type = UDP_ENCAP_RXRPC; |
| udp_sk(usk)->encap_rcv = rxrpc_input_packet; |
| udp_sk(usk)->encap_destroy = NULL; |
| udp_sk(usk)->gro_receive = NULL; |
| udp_sk(usk)->gro_complete = NULL; |
| |
| udp_encap_enable(); |
| #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6) |
| if (local->srx.transport.family == AF_INET6) |
| udpv6_encap_enable(); |
| #endif |
| usk->sk_error_report = rxrpc_error_report; |
| |
| /* if a local address was supplied then bind it */ |
| if (local->srx.transport_len > sizeof(sa_family_t)) { |
| _debug("bind"); |
| ret = kernel_bind(local->socket, |
| (struct sockaddr *)&local->srx.transport, |
| local->srx.transport_len); |
| if (ret < 0) { |
| _debug("bind failed %d", ret); |
| goto error; |
| } |
| } |
| |
| switch (local->srx.transport.family) { |
| case AF_INET6: |
| /* we want to receive ICMPv6 errors */ |
| opt = 1; |
| ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR, |
| (char *) &opt, sizeof(opt)); |
| if (ret < 0) { |
| _debug("setsockopt failed"); |
| goto error; |
| } |
| |
| /* we want to set the don't fragment bit */ |
| opt = IPV6_PMTUDISC_DO; |
| ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_MTU_DISCOVER, |
| (char *) &opt, sizeof(opt)); |
| if (ret < 0) { |
| _debug("setsockopt failed"); |
| goto error; |
| } |
| |
| /* Fall through and set IPv4 options too otherwise we don't get |
| * errors from IPv4 packets sent through the IPv6 socket. |
| */ |
| /* Fall through */ |
| case AF_INET: |
| /* we want to receive ICMP errors */ |
| opt = 1; |
| ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, |
| (char *) &opt, sizeof(opt)); |
| if (ret < 0) { |
| _debug("setsockopt failed"); |
| goto error; |
| } |
| |
| /* we want to set the don't fragment bit */ |
| opt = IP_PMTUDISC_DO; |
| ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, |
| (char *) &opt, sizeof(opt)); |
| if (ret < 0) { |
| _debug("setsockopt failed"); |
| goto error; |
| } |
| |
| /* We want receive timestamps. */ |
| opt = 1; |
| ret = kernel_setsockopt(local->socket, SOL_SOCKET, SO_TIMESTAMPNS_OLD, |
| (char *)&opt, sizeof(opt)); |
| if (ret < 0) { |
| _debug("setsockopt failed"); |
| goto error; |
| } |
| break; |
| |
| default: |
| BUG(); |
| } |
| |
| _leave(" = 0"); |
| return 0; |
| |
| error: |
| kernel_sock_shutdown(local->socket, SHUT_RDWR); |
| local->socket->sk->sk_user_data = NULL; |
| sock_release(local->socket); |
| local->socket = NULL; |
| |
| _leave(" = %d", ret); |
| 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 list_head *cursor; |
| const char *age; |
| long diff; |
| int ret; |
| |
| _enter("{%d,%d,%pISp}", |
| srx->transport_type, srx->transport.family, &srx->transport); |
| |
| mutex_lock(&rxnet->local_mutex); |
| |
| for (cursor = rxnet->local_endpoints.next; |
| cursor != &rxnet->local_endpoints; |
| cursor = cursor->next) { |
| local = list_entry(cursor, struct rxrpc_local, link); |
| |
| diff = rxrpc_local_cmp_key(local, srx); |
| if (diff < 0) |
| continue; |
| if (diff > 0) |
| break; |
| |
| /* 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 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_get_local_maybe(local)) { |
| cursor = cursor->next; |
| list_del_init(&local->link); |
| break; |
| } |
| |
| age = "old"; |
| goto found; |
| } |
| |
| local = rxrpc_alloc_local(rxnet, srx); |
| if (!local) |
| goto nomem; |
| |
| ret = rxrpc_open_socket(local, net); |
| if (ret < 0) |
| goto sock_error; |
| |
| list_add_tail(&local->link, cursor); |
| age = "new"; |
| |
| found: |
| mutex_unlock(&rxnet->local_mutex); |
| |
| _net("LOCAL %s %d {%pISp}", |
| age, local->debug_id, &local->srx.transport); |
| |
| _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) |
| { |
| const void *here = __builtin_return_address(0); |
| int n; |
| |
| n = atomic_inc_return(&local->usage); |
| trace_rxrpc_local(local, rxrpc_local_got, n, here); |
| 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) |
| { |
| const void *here = __builtin_return_address(0); |
| |
| if (local) { |
| int n = atomic_fetch_add_unless(&local->usage, 1, 0); |
| if (n > 0) |
| trace_rxrpc_local(local, rxrpc_local_got, n + 1, here); |
| else |
| local = NULL; |
| } |
| return local; |
| } |
| |
| /* |
| * Queue a local endpoint. |
| */ |
| void rxrpc_queue_local(struct rxrpc_local *local) |
| { |
| const void *here = __builtin_return_address(0); |
| |
| if (rxrpc_queue_work(&local->processor)) |
| trace_rxrpc_local(local, rxrpc_local_queued, |
| atomic_read(&local->usage), here); |
| } |
| |
| /* |
| * A local endpoint reached its end of life. |
| */ |
| static void __rxrpc_put_local(struct rxrpc_local *local) |
| { |
| _enter("%d", local->debug_id); |
| rxrpc_queue_work(&local->processor); |
| } |
| |
| /* |
| * Drop a ref on a local endpoint. |
| */ |
| void rxrpc_put_local(struct rxrpc_local *local) |
| { |
| const void *here = __builtin_return_address(0); |
| int n; |
| |
| if (local) { |
| n = atomic_dec_return(&local->usage); |
| trace_rxrpc_local(local, rxrpc_local_put, n, here); |
| |
| if (n == 0) |
| __rxrpc_put_local(local); |
| } |
| } |
| |
| /* |
| * 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. |
| */ |
| static void rxrpc_local_destroyer(struct rxrpc_local *local) |
| { |
| struct socket *socket = local->socket; |
| struct rxrpc_net *rxnet = local->rxnet; |
| |
| _enter("%d", local->debug_id); |
| |
| /* We can get a race between an incoming call packet queueing the |
| * processor again and the work processor starting the destruction |
| * process which will shut down the UDP socket. |
| */ |
| if (local->dead) { |
| _leave(" [already dead]"); |
| return; |
| } |
| local->dead = true; |
| |
| mutex_lock(&rxnet->local_mutex); |
| list_del_init(&local->link); |
| mutex_unlock(&rxnet->local_mutex); |
| |
| ASSERT(RB_EMPTY_ROOT(&local->client_conns)); |
| 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. |
| */ |
| rxrpc_purge_queue(&local->reject_queue); |
| rxrpc_purge_queue(&local->event_queue); |
| |
| _debug("rcu local %d", local->debug_id); |
| call_rcu(&local->rcu, rxrpc_local_rcu); |
| } |
| |
| /* |
| * Process events on an endpoint |
| */ |
| static void rxrpc_local_processor(struct work_struct *work) |
| { |
| struct rxrpc_local *local = |
| container_of(work, struct rxrpc_local, processor); |
| bool again; |
| |
| trace_rxrpc_local(local, rxrpc_local_processing, |
| atomic_read(&local->usage), NULL); |
| |
| do { |
| again = false; |
| if (atomic_read(&local->usage) == 0) |
| return rxrpc_local_destroyer(local); |
| |
| if (!skb_queue_empty(&local->reject_queue)) { |
| rxrpc_reject_packets(local); |
| again = true; |
| } |
| |
| if (!skb_queue_empty(&local->event_queue)) { |
| rxrpc_process_local_events(local); |
| again = true; |
| } |
| } while (again); |
| } |
| |
| /* |
| * 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); |
| |
| _enter("%d", local->debug_id); |
| |
| ASSERT(!work_pending(&local->processor)); |
| |
| _net("DESTROY LOCAL %d", local->debug_id); |
| kfree(local); |
| _leave(""); |
| } |
| |
| /* |
| * 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 (!list_empty(&rxnet->local_endpoints)) { |
| mutex_lock(&rxnet->local_mutex); |
| list_for_each_entry(local, &rxnet->local_endpoints, link) { |
| pr_err("AF_RXRPC: Leaked local %p {%d}\n", |
| local, atomic_read(&local->usage)); |
| } |
| mutex_unlock(&rxnet->local_mutex); |
| BUG(); |
| } |
| } |