linux/net/rxrpc/conn_service.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* Service connection management
 *
 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#include <linux/slab.h>
#include "ar-internal.h"

/*
 * Find a service connection under RCU conditions.
 *
 * We could use a hash table, but that is subject to bucket stuffing by an
 * attacker as the client gets to pick the epoch and cid values and would know
 * the hash function.  So, instead, we use a hash table for the peer and from
 * that an rbtree to find the service connection.  Under ordinary circumstances
 * it might be slower than a large hash table, but it is at least limited in
 * depth.
 */
struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *peer,
						     struct sk_buff *skb)
{ … }

/*
 * Insert a service connection into a peer's tree, thereby making it a target
 * for incoming packets.
 */
static void rxrpc_publish_service_conn(struct rxrpc_peer *peer,
				       struct rxrpc_connection *conn)
{ … }

/*
 * Preallocate a service connection.  The connection is placed on the proc and
 * reap lists so that we don't have to get the lock from BH context.
 */
struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *rxnet,
							   gfp_t gfp)
{ … }

/*
 * Set up an incoming connection.  This is called in BH context with the RCU
 * read lock held.
 */
void rxrpc_new_incoming_connection(struct rxrpc_sock *rx,
				   struct rxrpc_connection *conn,
				   const struct rxrpc_security *sec,
				   struct sk_buff *skb)
{ … }

/*
 * Remove the service connection from the peer's tree, thereby removing it as a
 * target for incoming packets.
 */
void rxrpc_unpublish_service_conn(struct rxrpc_connection *conn)
{ … }