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100644 511 lines (443 sloc) 12.2 KB
Dec 10, 2011
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/* incoming call handling
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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/errqueue.h>
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#include <linux/udp.h>
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#include <linux/in.h>
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#include <linux/in6.h>
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#include <linux/icmp.h>
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#include <linux/gfp.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include <net/ip.h>
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#include "ar-internal.h"
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/*
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* generate a connection-level abort
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*/
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static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
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struct rxrpc_header *hdr)
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{
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struct msghdr msg;
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struct kvec iov[1];
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size_t len;
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int ret;
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_enter("%d,,", local->debug_id);
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msg.msg_name = &srx->transport.sin;
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msg.msg_namelen = sizeof(srx->transport.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->type = RXRPC_PACKET_TYPE_BUSY;
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hdr->flags = 0;
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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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len = iov[0].iov_len;
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hdr->serial = htonl(1);
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_proto("Tx BUSY %%%u", ntohl(hdr->serial));
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ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
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if (ret < 0) {
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_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
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return -EAGAIN;
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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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* accept an incoming call that needs peer, transport and/or connection setting
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* up
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*/
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static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
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struct rxrpc_sock *rx,
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struct sk_buff *skb,
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struct sockaddr_rxrpc *srx)
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{
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struct rxrpc_connection *conn;
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struct rxrpc_transport *trans;
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struct rxrpc_skb_priv *sp, *nsp;
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struct rxrpc_peer *peer;
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struct rxrpc_call *call;
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struct sk_buff *notification;
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int ret;
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_enter("");
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sp = rxrpc_skb(skb);
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/* get a notification message to send to the server app */
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notification = alloc_skb(0, GFP_NOFS);
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if (!notification) {
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_debug("no memory");
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ret = -ENOMEM;
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goto error_nofree;
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}
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rxrpc_new_skb(notification);
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notification->mark = RXRPC_SKB_MARK_NEW_CALL;
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peer = rxrpc_get_peer(srx, GFP_NOIO);
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if (IS_ERR(peer)) {
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_debug("no peer");
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ret = -EBUSY;
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goto error;
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}
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trans = rxrpc_get_transport(local, peer, GFP_NOIO);
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rxrpc_put_peer(peer);
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if (IS_ERR(trans)) {
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_debug("no trans");
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ret = -EBUSY;
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goto error;
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}
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conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
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rxrpc_put_transport(trans);
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if (IS_ERR(conn)) {
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_debug("no conn");
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ret = PTR_ERR(conn);
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goto error;
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}
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call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
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rxrpc_put_connection(conn);
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if (IS_ERR(call)) {
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_debug("no call");
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ret = PTR_ERR(call);
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goto error;
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}
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/* attach the call to the socket */
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read_lock_bh(&local->services_lock);
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if (rx->sk.sk_state == RXRPC_CLOSE)
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goto invalid_service;
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write_lock(&rx->call_lock);
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if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
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rxrpc_get_call(call);
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spin_lock(&call->conn->state_lock);
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if (sp->hdr.securityIndex > 0 &&
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call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
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_debug("await conn sec");
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list_add_tail(&call->accept_link, &rx->secureq);
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call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
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atomic_inc(&call->conn->usage);
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set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
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rxrpc_queue_conn(call->conn);
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} else {
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_debug("conn ready");
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call->state = RXRPC_CALL_SERVER_ACCEPTING;
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list_add_tail(&call->accept_link, &rx->acceptq);
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rxrpc_get_call(call);
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nsp = rxrpc_skb(notification);
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nsp->call = call;
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ASSERTCMP(atomic_read(&call->usage), >=, 3);
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_debug("notify");
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spin_lock(&call->lock);
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ret = rxrpc_queue_rcv_skb(call, notification, true,
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false);
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spin_unlock(&call->lock);
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notification = NULL;
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BUG_ON(ret < 0);
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}
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spin_unlock(&call->conn->state_lock);
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_debug("queued");
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}
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write_unlock(&rx->call_lock);
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_debug("process");
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rxrpc_fast_process_packet(call, skb);
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_debug("done");
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read_unlock_bh(&local->services_lock);
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rxrpc_free_skb(notification);
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rxrpc_put_call(call);
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_leave(" = 0");
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return 0;
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invalid_service:
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_debug("invalid");
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read_unlock_bh(&local->services_lock);
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read_lock_bh(&call->state_lock);
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if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
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!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
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rxrpc_get_call(call);
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rxrpc_queue_call(call);
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}
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read_unlock_bh(&call->state_lock);
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rxrpc_put_call(call);
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ret = -ECONNREFUSED;
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error:
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rxrpc_free_skb(notification);
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error_nofree:
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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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* accept incoming calls that need peer, transport and/or connection setting up
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* - the packets we get are all incoming client DATA packets that have seq == 1
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*/
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void rxrpc_accept_incoming_calls(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, acceptor);
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struct rxrpc_skb_priv *sp;
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struct sockaddr_rxrpc srx;
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struct rxrpc_sock *rx;
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struct sk_buff *skb;
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__be16 service_id;
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int ret;
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_enter("%d", local->debug_id);
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read_lock_bh(&rxrpc_local_lock);
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if (atomic_read(&local->usage) > 0)
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rxrpc_get_local(local);
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else
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local = NULL;
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read_unlock_bh(&rxrpc_local_lock);
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if (!local) {
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_leave(" [local dead]");
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return;
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}
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process_next_packet:
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skb = skb_dequeue(&local->accept_queue);
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if (!skb) {
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rxrpc_put_local(local);
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_leave("\n");
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return;
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}
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_net("incoming call skb %p", skb);
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sp = rxrpc_skb(skb);
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/* determine the remote address */
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memset(&srx, 0, sizeof(srx));
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srx.srx_family = AF_RXRPC;
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srx.transport.family = local->srx.transport.family;
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srx.transport_type = local->srx.transport_type;
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switch (srx.transport.family) {
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case AF_INET:
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srx.transport_len = sizeof(struct sockaddr_in);
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srx.transport.sin.sin_port = udp_hdr(skb)->source;
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srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
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break;
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default:
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goto busy;
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}
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/* get the socket providing the service */
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service_id = sp->hdr.serviceId;
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read_lock_bh(&local->services_lock);
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list_for_each_entry(rx, &local->services, listen_link) {
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if (rx->service_id == service_id &&
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rx->sk.sk_state != RXRPC_CLOSE)
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goto found_service;
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}
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read_unlock_bh(&local->services_lock);
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goto invalid_service;
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found_service:
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_debug("found service %hd", ntohs(rx->service_id));
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if (sk_acceptq_is_full(&rx->sk))
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goto backlog_full;
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sk_acceptq_added(&rx->sk);
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sock_hold(&rx->sk);
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read_unlock_bh(&local->services_lock);
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ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
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if (ret < 0)
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sk_acceptq_removed(&rx->sk);
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sock_put(&rx->sk);
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switch (ret) {
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case -ECONNRESET: /* old calls are ignored */
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case -ECONNABORTED: /* aborted calls are reaborted or ignored */
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case 0:
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goto process_next_packet;
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case -ECONNREFUSED:
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goto invalid_service;
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case -EBUSY:
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goto busy;
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case -EKEYREJECTED:
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goto security_mismatch;
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default:
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BUG();
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}
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backlog_full:
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read_unlock_bh(&local->services_lock);
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busy:
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rxrpc_busy(local, &srx, &sp->hdr);
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rxrpc_free_skb(skb);
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goto process_next_packet;
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invalid_service:
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skb->priority = RX_INVALID_OPERATION;
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rxrpc_reject_packet(local, skb);
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goto process_next_packet;
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/* can't change connection security type mid-flow */
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security_mismatch:
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skb->priority = RX_PROTOCOL_ERROR;
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rxrpc_reject_packet(local, skb);
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goto process_next_packet;
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}
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/*
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* handle acceptance of a call by userspace
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* - assign the user call ID to the call at the front of the queue
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*/
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struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
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unsigned long user_call_ID)
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{
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struct rxrpc_call *call;
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struct rb_node *parent, **pp;
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int ret;
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_enter(",%lx", user_call_ID);
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ASSERT(!irqs_disabled());
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330
write_lock(&rx->call_lock);
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ret = -ENODATA;
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if (list_empty(&rx->acceptq))
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goto out;
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/* check the user ID isn't already in use */
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ret = -EBADSLT;
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pp = &rx->calls.rb_node;
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parent = NULL;
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while (*pp) {
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parent = *pp;
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call = rb_entry(parent, struct rxrpc_call, sock_node);
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if (user_call_ID < call->user_call_ID)
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pp = &(*pp)->rb_left;
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else if (user_call_ID > call->user_call_ID)
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pp = &(*pp)->rb_right;
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else
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goto out;
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}
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/* dequeue the first call and check it's still valid */
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call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
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list_del_init(&call->accept_link);
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sk_acceptq_removed(&rx->sk);
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357
write_lock_bh(&call->state_lock);
358
switch (call->state) {
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case RXRPC_CALL_SERVER_ACCEPTING:
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call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
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break;
362
case RXRPC_CALL_REMOTELY_ABORTED:
363
case RXRPC_CALL_LOCALLY_ABORTED:
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ret = -ECONNABORTED;
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goto out_release;
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case RXRPC_CALL_NETWORK_ERROR:
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ret = call->conn->error;
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goto out_release;
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case RXRPC_CALL_DEAD:
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ret = -ETIME;
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goto out_discard;
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default:
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BUG();
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}
375
376
/* formalise the acceptance */
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call->user_call_ID = user_call_ID;
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rb_link_node(&call->sock_node, parent, pp);
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rb_insert_color(&call->sock_node, &rx->calls);
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if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
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BUG();
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if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
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BUG();
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rxrpc_queue_call(call);
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386
rxrpc_get_call(call);
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write_unlock_bh(&call->state_lock);
388
write_unlock(&rx->call_lock);
389
_leave(" = %p{%d}", call, call->debug_id);
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return call;
391
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/* if the call is already dying or dead, then we leave the socket's ref
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* on it to be released by rxrpc_dead_call_expired() as induced by
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* rxrpc_release_call() */
395
out_release:
396
_debug("release %p", call);
397
if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
398
!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
399
rxrpc_queue_call(call);
400
out_discard:
401
write_unlock_bh(&call->state_lock);
402
_debug("discard %p", call);
403
out:
404
write_unlock(&rx->call_lock);
405
_leave(" = %d", ret);
406
return ERR_PTR(ret);
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}
408
409
/*
410
* handle rejectance of a call by userspace
411
* - reject the call at the front of the queue
412
*/
413
int rxrpc_reject_call(struct rxrpc_sock *rx)
414
{
415
struct rxrpc_call *call;
416
int ret;
417
418
_enter("");
419
420
ASSERT(!irqs_disabled());
421
422
write_lock(&rx->call_lock);
423
424
ret = -ENODATA;
425
if (list_empty(&rx->acceptq))
426
goto out;
427
428
/* dequeue the first call and check it's still valid */
429
call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
430
list_del_init(&call->accept_link);
431
sk_acceptq_removed(&rx->sk);
432
433
write_lock_bh(&call->state_lock);
434
switch (call->state) {
435
case RXRPC_CALL_SERVER_ACCEPTING:
436
call->state = RXRPC_CALL_SERVER_BUSY;
437
if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
438
rxrpc_queue_call(call);
439
ret = 0;
440
goto out_release;
441
case RXRPC_CALL_REMOTELY_ABORTED:
442
case RXRPC_CALL_LOCALLY_ABORTED:
443
ret = -ECONNABORTED;
444
goto out_release;
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case RXRPC_CALL_NETWORK_ERROR:
446
ret = call->conn->error;
447
goto out_release;
448
case RXRPC_CALL_DEAD:
449
ret = -ETIME;
450
goto out_discard;
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default:
452
BUG();
453
}
454
455
/* if the call is already dying or dead, then we leave the socket's ref
456
* on it to be released by rxrpc_dead_call_expired() as induced by
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* rxrpc_release_call() */
458
out_release:
459
_debug("release %p", call);
460
if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
461
!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
462
rxrpc_queue_call(call);
463
out_discard:
464
write_unlock_bh(&call->state_lock);
465
_debug("discard %p", call);
466
out:
467
write_unlock(&rx->call_lock);
468
_leave(" = %d", ret);
469
return ret;
470
}
471
472
/**
473
* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
474
* @sock: The socket on which the impending call is waiting
475
* @user_call_ID: The tag to attach to the call
476
*
477
* Allow a kernel service to accept an incoming call, assuming the incoming
478
* call is still valid.
479
*/
480
struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock,
481
unsigned long user_call_ID)
482
{
483
struct rxrpc_call *call;
484
485
_enter(",%lx", user_call_ID);
486
call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
487
_leave(" = %p", call);
488
return call;
489
}
490
491
EXPORT_SYMBOL(rxrpc_kernel_accept_call);
492
493
/**
494
* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
495
* @sock: The socket on which the impending call is waiting
496
*
497
* Allow a kernel service to reject an incoming call with a BUSY message,
498
* assuming the incoming call is still valid.
499
*/
500
int rxrpc_kernel_reject_call(struct socket *sock)
501
{
502
int ret;
503
504
_enter("");
505
ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
506
_leave(" = %d", ret);
507
return ret;
508
}
509
510
EXPORT_SYMBOL(rxrpc_kernel_reject_call);