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/* Service connection 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.
*/
#include <linux/slab.h>
#include "ar-internal.h"
/*
* get a record of an incoming connection
*/
struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *local,
struct sockaddr_rxrpc *srx,
struct sk_buff *skb)
{
struct rxrpc_connection *conn, *candidate = NULL;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_peer *peer;
struct rb_node *p, **pp;
const char *new = "old";
u32 epoch, cid;
_enter("");
peer = rxrpc_lookup_peer(local, srx, GFP_NOIO);
if (!peer) {
_debug("no peer");
return ERR_PTR(-EBUSY);
}
ASSERT(sp->hdr.flags & RXRPC_CLIENT_INITIATED);
epoch = sp->hdr.epoch;
cid = sp->hdr.cid & RXRPC_CIDMASK;
/* search the connection list first */
read_lock_bh(&peer->conn_lock);
p = peer->service_conns.rb_node;
while (p) {
conn = rb_entry(p, struct rxrpc_connection, service_node);
_debug("maybe %x", conn->proto.cid);
if (epoch < conn->proto.epoch)
p = p->rb_left;
else if (epoch > conn->proto.epoch)
p = p->rb_right;
else if (cid < conn->proto.cid)
p = p->rb_left;
else if (cid > conn->proto.cid)
p = p->rb_right;
else
goto found_extant_connection;
}
read_unlock_bh(&peer->conn_lock);
/* not yet present - create a candidate for a new record and then
* redo the search */
candidate = rxrpc_alloc_connection(GFP_NOIO);
if (!candidate) {
rxrpc_put_peer(peer);
_leave(" = -ENOMEM");
return ERR_PTR(-ENOMEM);
}
candidate->proto.epoch = sp->hdr.epoch;
candidate->proto.cid = sp->hdr.cid & RXRPC_CIDMASK;
candidate->params.local = local;
candidate->params.peer = peer;
candidate->params.service_id = sp->hdr.serviceId;
candidate->security_ix = sp->hdr.securityIndex;
candidate->out_clientflag = 0;
candidate->state = RXRPC_CONN_SERVICE;
if (candidate->params.service_id)
candidate->state = RXRPC_CONN_SERVICE_UNSECURED;
write_lock_bh(&peer->conn_lock);
pp = &peer->service_conns.rb_node;
p = NULL;
while (*pp) {
p = *pp;
conn = rb_entry(p, struct rxrpc_connection, service_node);
if (epoch < conn->proto.epoch)
pp = &(*pp)->rb_left;
else if (epoch > conn->proto.epoch)
pp = &(*pp)->rb_right;
else if (cid < conn->proto.cid)
pp = &(*pp)->rb_left;
else if (cid > conn->proto.cid)
pp = &(*pp)->rb_right;
else
goto found_extant_second;
}
/* we can now add the new candidate to the list */
set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &candidate->flags);
rb_link_node(&candidate->service_node, p, pp);
rb_insert_color(&candidate->service_node, &peer->service_conns);
attached:
conn = candidate;
candidate = NULL;
rxrpc_get_peer(peer);
rxrpc_get_local(local);
write_unlock_bh(&peer->conn_lock);
write_lock(&rxrpc_connection_lock);
list_add_tail(&conn->link, &rxrpc_connections);
write_unlock(&rxrpc_connection_lock);
new = "new";
success:
_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->proto.cid);
rxrpc_put_peer(peer);
_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
return conn;
/* we found the connection in the list immediately */
found_extant_connection:
if (!rxrpc_get_connection_maybe(conn)) {
set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &candidate->flags);
rb_replace_node(&conn->service_node,
&candidate->service_node,
&peer->service_conns);
clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags);
goto attached;
}
if (sp->hdr.securityIndex != conn->security_ix) {
read_unlock_bh(&peer->conn_lock);
goto security_mismatch_put;
}
read_unlock_bh(&peer->conn_lock);
goto success;
/* we found the connection on the second time through the list */
found_extant_second:
if (sp->hdr.securityIndex != conn->security_ix) {
write_unlock_bh(&peer->conn_lock);
goto security_mismatch;
}
rxrpc_get_connection(conn);
write_unlock_bh(&peer->conn_lock);
kfree(candidate);
goto success;
security_mismatch_put:
rxrpc_put_connection(conn);
security_mismatch:
kfree(candidate);
_leave(" = -EKEYREJECTED");
return ERR_PTR(-EKEYREJECTED);
}
/*
* 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)
{
struct rxrpc_peer *peer = conn->params.peer;
write_lock_bh(&peer->conn_lock);
if (test_and_clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags))
rb_erase(&conn->service_node, &peer->service_conns);
write_unlock_bh(&peer->conn_lock);
}
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