409 строки
9.8 KiB
C
409 строки
9.8 KiB
C
/* AF_RXRPC local endpoint management
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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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 <net/sock.h>
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#include <net/af_rxrpc.h>
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#include <generated/utsrelease.h>
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#include "ar-internal.h"
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static const char rxrpc_version_string[65] = "linux-" UTS_RELEASE " AF_RXRPC";
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static LIST_HEAD(rxrpc_locals);
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DEFINE_RWLOCK(rxrpc_local_lock);
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static DECLARE_RWSEM(rxrpc_local_sem);
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static DECLARE_WAIT_QUEUE_HEAD(rxrpc_local_wq);
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static void rxrpc_destroy_local(struct work_struct *work);
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static void rxrpc_process_local_events(struct work_struct *work);
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/*
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* allocate a new local
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*/
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static
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struct rxrpc_local *rxrpc_alloc_local(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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INIT_WORK(&local->destroyer, &rxrpc_destroy_local);
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INIT_WORK(&local->acceptor, &rxrpc_accept_incoming_calls);
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INIT_WORK(&local->rejecter, &rxrpc_reject_packets);
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INIT_WORK(&local->event_processor, &rxrpc_process_local_events);
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INIT_LIST_HEAD(&local->services);
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INIT_LIST_HEAD(&local->link);
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init_rwsem(&local->defrag_sem);
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skb_queue_head_init(&local->accept_queue);
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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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spin_lock_init(&local->lock);
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rwlock_init(&local->services_lock);
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atomic_set(&local->usage, 1);
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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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}
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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_sem writelocked
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*/
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static int rxrpc_create_local(struct rxrpc_local *local)
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{
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struct sock *sock;
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int ret, opt;
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_enter("%p{%d}", local, local->srx.transport_type);
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/* create a socket to represent the local endpoint */
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ret = sock_create_kern(&init_net, PF_INET, local->srx.transport_type,
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IPPROTO_UDP, &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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/* if a local address was supplied then bind it */
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if (local->srx.transport_len > sizeof(sa_family_t)) {
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_debug("bind");
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ret = kernel_bind(local->socket,
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(struct sockaddr *) &local->srx.transport,
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local->srx.transport_len);
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if (ret < 0) {
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_debug("bind failed");
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goto error;
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}
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}
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/* we want to receive ICMP errors */
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opt = 1;
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ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
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(char *) &opt, sizeof(opt));
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if (ret < 0) {
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_debug("setsockopt failed");
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goto error;
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}
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/* we want to set the don't fragment bit */
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opt = IP_PMTUDISC_DO;
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ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
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(char *) &opt, sizeof(opt));
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if (ret < 0) {
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_debug("setsockopt failed");
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goto error;
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}
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write_lock_bh(&rxrpc_local_lock);
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list_add(&local->link, &rxrpc_locals);
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write_unlock_bh(&rxrpc_local_lock);
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/* set the socket up */
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sock = local->socket->sk;
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sock->sk_user_data = local;
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sock->sk_data_ready = rxrpc_data_ready;
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sock->sk_error_report = rxrpc_UDP_error_report;
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_leave(" = 0");
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return 0;
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error:
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kernel_sock_shutdown(local->socket, SHUT_RDWR);
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local->socket->sk->sk_user_data = NULL;
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sock_release(local->socket);
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local->socket = NULL;
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_leave(" = %d", ret);
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return ret;
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}
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/*
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* create a new local endpoint using the specified UDP address
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*/
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struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *srx)
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{
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struct rxrpc_local *local;
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int ret;
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_enter("{%d,%u,%pI4+%hu}",
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srx->transport_type,
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srx->transport.family,
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&srx->transport.sin.sin_addr,
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ntohs(srx->transport.sin.sin_port));
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down_write(&rxrpc_local_sem);
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/* see if we have a suitable local local endpoint already */
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read_lock_bh(&rxrpc_local_lock);
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list_for_each_entry(local, &rxrpc_locals, link) {
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_debug("CMP {%d,%u,%pI4+%hu}",
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local->srx.transport_type,
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local->srx.transport.family,
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&local->srx.transport.sin.sin_addr,
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ntohs(local->srx.transport.sin.sin_port));
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if (local->srx.transport_type != srx->transport_type ||
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local->srx.transport.family != srx->transport.family)
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continue;
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switch (srx->transport.family) {
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case AF_INET:
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if (local->srx.transport.sin.sin_port !=
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srx->transport.sin.sin_port)
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continue;
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if (memcmp(&local->srx.transport.sin.sin_addr,
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&srx->transport.sin.sin_addr,
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sizeof(struct in_addr)) != 0)
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continue;
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goto found_local;
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default:
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BUG();
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}
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}
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read_unlock_bh(&rxrpc_local_lock);
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/* we didn't find one, so we need to create one */
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local = rxrpc_alloc_local(srx);
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if (!local) {
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up_write(&rxrpc_local_sem);
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return ERR_PTR(-ENOMEM);
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}
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ret = rxrpc_create_local(local);
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if (ret < 0) {
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up_write(&rxrpc_local_sem);
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kfree(local);
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_leave(" = %d", ret);
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return ERR_PTR(ret);
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}
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up_write(&rxrpc_local_sem);
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_net("LOCAL new %d {%d,%u,%pI4+%hu}",
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local->debug_id,
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local->srx.transport_type,
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local->srx.transport.family,
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&local->srx.transport.sin.sin_addr,
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ntohs(local->srx.transport.sin.sin_port));
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_leave(" = %p [new]", local);
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return local;
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found_local:
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rxrpc_get_local(local);
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read_unlock_bh(&rxrpc_local_lock);
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up_write(&rxrpc_local_sem);
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_net("LOCAL old %d {%d,%u,%pI4+%hu}",
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local->debug_id,
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local->srx.transport_type,
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local->srx.transport.family,
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&local->srx.transport.sin.sin_addr,
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ntohs(local->srx.transport.sin.sin_port));
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_leave(" = %p [reuse]", local);
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return local;
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}
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/*
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* release 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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_enter("%p{u=%d}", local, atomic_read(&local->usage));
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ASSERTCMP(atomic_read(&local->usage), >, 0);
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/* to prevent a race, the decrement and the dequeue must be effectively
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* atomic */
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write_lock_bh(&rxrpc_local_lock);
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if (unlikely(atomic_dec_and_test(&local->usage))) {
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_debug("destroy local");
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rxrpc_queue_work(&local->destroyer);
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}
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write_unlock_bh(&rxrpc_local_lock);
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_leave("");
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}
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/*
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* destroy a local endpoint
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*/
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static void rxrpc_destroy_local(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, destroyer);
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_enter("%p{%d}", local, atomic_read(&local->usage));
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down_write(&rxrpc_local_sem);
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write_lock_bh(&rxrpc_local_lock);
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if (atomic_read(&local->usage) > 0) {
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write_unlock_bh(&rxrpc_local_lock);
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up_read(&rxrpc_local_sem);
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_leave(" [resurrected]");
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return;
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}
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list_del(&local->link);
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local->socket->sk->sk_user_data = NULL;
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write_unlock_bh(&rxrpc_local_lock);
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downgrade_write(&rxrpc_local_sem);
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ASSERT(list_empty(&local->services));
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ASSERT(!work_pending(&local->acceptor));
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ASSERT(!work_pending(&local->rejecter));
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ASSERT(!work_pending(&local->event_processor));
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/* finish cleaning up the local descriptor */
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rxrpc_purge_queue(&local->accept_queue);
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rxrpc_purge_queue(&local->reject_queue);
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rxrpc_purge_queue(&local->event_queue);
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kernel_sock_shutdown(local->socket, SHUT_RDWR);
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sock_release(local->socket);
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up_read(&rxrpc_local_sem);
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_net("DESTROY LOCAL %d", local->debug_id);
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kfree(local);
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if (list_empty(&rxrpc_locals))
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wake_up_all(&rxrpc_local_wq);
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_leave("");
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}
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/*
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* preemptively destroy all local local endpoint rather than waiting for
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* them to be destroyed
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*/
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void __exit rxrpc_destroy_all_locals(void)
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{
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DECLARE_WAITQUEUE(myself,current);
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_enter("");
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/* we simply have to wait for them to go away */
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if (!list_empty(&rxrpc_locals)) {
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set_current_state(TASK_UNINTERRUPTIBLE);
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add_wait_queue(&rxrpc_local_wq, &myself);
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while (!list_empty(&rxrpc_locals)) {
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schedule();
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set_current_state(TASK_UNINTERRUPTIBLE);
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}
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remove_wait_queue(&rxrpc_local_wq, &myself);
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set_current_state(TASK_RUNNING);
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}
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_leave("");
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}
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/*
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* Reply to a version request
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*/
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static void rxrpc_send_version_request(struct rxrpc_local *local,
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struct rxrpc_header *hdr,
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struct sk_buff *skb)
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{
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struct sockaddr_in sin;
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struct msghdr msg;
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struct kvec iov[2];
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size_t len;
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int ret;
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_enter("");
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sin.sin_family = AF_INET;
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sin.sin_port = udp_hdr(skb)->source;
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sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
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msg.msg_name = &sin;
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msg.msg_namelen = sizeof(sin);
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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msg.msg_flags = 0;
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hdr->seq = 0;
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hdr->serial = 0;
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hdr->type = RXRPC_PACKET_TYPE_VERSION;
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hdr->flags = RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED);
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hdr->userStatus = 0;
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hdr->_rsvd = 0;
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iov[0].iov_base = hdr;
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iov[0].iov_len = sizeof(*hdr);
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iov[1].iov_base = (char *)rxrpc_version_string;
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iov[1].iov_len = sizeof(rxrpc_version_string);
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len = iov[0].iov_len + iov[1].iov_len;
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_proto("Tx VERSION (reply)");
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ret = kernel_sendmsg(local->socket, &msg, iov, 2, len);
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if (ret < 0)
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_debug("sendmsg failed: %d", ret);
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_leave("");
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}
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/*
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* Process event packets targetted at a local endpoint.
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*/
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static void rxrpc_process_local_events(struct work_struct *work)
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{
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struct rxrpc_local *local = container_of(work, struct rxrpc_local, event_processor);
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struct sk_buff *skb;
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char v;
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_enter("");
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atomic_inc(&local->usage);
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while ((skb = skb_dequeue(&local->event_queue))) {
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struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
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kdebug("{%d},{%u}", local->debug_id, sp->hdr.type);
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switch (sp->hdr.type) {
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case RXRPC_PACKET_TYPE_VERSION:
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if (skb_copy_bits(skb, 0, &v, 1) < 0)
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return;
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_proto("Rx VERSION { %02x }", v);
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if (v == 0)
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rxrpc_send_version_request(local, &sp->hdr, skb);
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break;
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default:
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/* Just ignore anything we don't understand */
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break;
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}
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rxrpc_put_local(local);
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rxrpc_free_skb(skb);
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}
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rxrpc_put_local(local);
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_leave("");
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}
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