[deliverable/linux.git] / net / rxrpc / conn_service.c

/* 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);
}
Commit	Line	Data
7877a4a4 DH	1	/* Service connection management
	2	*
	3	* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/slab.h>
	13	#include "ar-internal.h"
	14
	15	/*
	16	* get a record of an incoming connection
	17	*/
	18	struct rxrpc_connection rxrpc_incoming_connection(struct rxrpc_local local,
d991b4a3	19	struct sockaddr_rxrpc *srx,
7877a4a4 DH	20	struct sk_buff *skb)
	21	{
	22	struct rxrpc_connection conn, candidate = NULL;
	23	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
d991b4a3	24	struct rxrpc_peer *peer;
7877a4a4 DH	25	struct rb_node p, *pp;
	26	const char *new = "old";
	27	u32 epoch, cid;
	28
	29	_enter("");
	30
d991b4a3 DH	31	peer = rxrpc_lookup_peer(local, srx, GFP_NOIO);
	32	if (!peer) {
	33	_debug("no peer");
	34	return ERR_PTR(-EBUSY);
	35	}
	36
7877a4a4 DH	37	ASSERT(sp->hdr.flags & RXRPC_CLIENT_INITIATED);
	38
	39	epoch = sp->hdr.epoch;
	40	cid = sp->hdr.cid & RXRPC_CIDMASK;
	41
	42	/* search the connection list first */
	43	read_lock_bh(&peer->conn_lock);
	44
	45	p = peer->service_conns.rb_node;
	46	while (p) {
	47	conn = rb_entry(p, struct rxrpc_connection, service_node);
	48
	49	_debug("maybe %x", conn->proto.cid);
	50
	51	if (epoch < conn->proto.epoch)
	52	p = p->rb_left;
	53	else if (epoch > conn->proto.epoch)
	54	p = p->rb_right;
	55	else if (cid < conn->proto.cid)
	56	p = p->rb_left;
	57	else if (cid > conn->proto.cid)
	58	p = p->rb_right;
	59	else
	60	goto found_extant_connection;
	61	}
	62	read_unlock_bh(&peer->conn_lock);
	63
	64	/* not yet present - create a candidate for a new record and then
	65	* redo the search */
	66	candidate = rxrpc_alloc_connection(GFP_NOIO);
	67	if (!candidate) {
d991b4a3	68	rxrpc_put_peer(peer);
7877a4a4 DH	69	_leave(" = -ENOMEM");
	70	return ERR_PTR(-ENOMEM);
	71	}
	72
7877a4a4 DH	73	candidate->proto.epoch = sp->hdr.epoch;
7877a4a4 DH	74	candidate->proto.cid = sp->hdr.cid & RXRPC_CIDMASK;
7877a4a4 DH	75	candidate->params.local = local;
	76	candidate->params.peer = peer;
	77	candidate->params.service_id = sp->hdr.serviceId;
	78	candidate->security_ix = sp->hdr.securityIndex;
	79	candidate->out_clientflag = 0;
	80	candidate->state = RXRPC_CONN_SERVICE;
	81	if (candidate->params.service_id)
	82	candidate->state = RXRPC_CONN_SERVICE_UNSECURED;
	83
	84	write_lock_bh(&peer->conn_lock);
	85
	86	pp = &peer->service_conns.rb_node;
	87	p = NULL;
	88	while (*pp) {
	89	p = *pp;
	90	conn = rb_entry(p, struct rxrpc_connection, service_node);
	91
	92	if (epoch < conn->proto.epoch)
	93	pp = &(*pp)->rb_left;
	94	else if (epoch > conn->proto.epoch)
	95	pp = &(*pp)->rb_right;
	96	else if (cid < conn->proto.cid)
	97	pp = &(*pp)->rb_left;
	98	else if (cid > conn->proto.cid)
	99	pp = &(*pp)->rb_right;
	100	else
	101	goto found_extant_second;
	102	}
	103
	104	/* we can now add the new candidate to the list */
001c1122 DH	105	set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &candidate->flags);
	106	rb_link_node(&candidate->service_node, p, pp);
	107	rb_insert_color(&candidate->service_node, &peer->service_conns);
	108	attached:
7877a4a4 DH	109	conn = candidate;
7877a4a4 DH	110	candidate = NULL;
7877a4a4 DH	111	rxrpc_get_peer(peer);
	112	rxrpc_get_local(local);
	113
	114	write_unlock_bh(&peer->conn_lock);
	115
	116	write_lock(&rxrpc_connection_lock);
	117	list_add_tail(&conn->link, &rxrpc_connections);
	118	write_unlock(&rxrpc_connection_lock);
	119
	120	new = "new";
	121
	122	success:
	123	_net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->proto.cid);
	124
d991b4a3	125	rxrpc_put_peer(peer);
7877a4a4 DH	126	_leave(" = %p {u=%d}", conn, atomic_read(&conn->usage));
	127	return conn;
	128
	129	/* we found the connection in the list immediately */
	130	found_extant_connection:
001c1122 DH	131	if (!rxrpc_get_connection_maybe(conn)) {
	132	set_bit(RXRPC_CONN_IN_SERVICE_CONNS, &candidate->flags);
	133	rb_replace_node(&conn->service_node,
	134	&candidate->service_node,
	135	&peer->service_conns);
	136	clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags);
	137	goto attached;
	138	}
	139
7877a4a4 DH	140	if (sp->hdr.securityIndex != conn->security_ix) {
7877a4a4 DH	141	read_unlock_bh(&peer->conn_lock);
001c1122	142	goto security_mismatch_put;
7877a4a4	143	}
7877a4a4 DH	144	read_unlock_bh(&peer->conn_lock);
	145	goto success;
	146
	147	/* we found the connection on the second time through the list */
	148	found_extant_second:
	149	if (sp->hdr.securityIndex != conn->security_ix) {
	150	write_unlock_bh(&peer->conn_lock);
	151	goto security_mismatch;
	152	}
	153	rxrpc_get_connection(conn);
	154	write_unlock_bh(&peer->conn_lock);
	155	kfree(candidate);
	156	goto success;
	157
001c1122 DH	158	security_mismatch_put:
001c1122 DH	159	rxrpc_put_connection(conn);
7877a4a4 DH	160	security_mismatch:
	161	kfree(candidate);
	162	_leave(" = -EKEYREJECTED");
	163	return ERR_PTR(-EKEYREJECTED);
	164	}
001c1122 DH	165
	166	/*
	167	* Remove the service connection from the peer's tree, thereby removing it as a
	168	* target for incoming packets.
	169	*/
	170	void rxrpc_unpublish_service_conn(struct rxrpc_connection *conn)
	171	{
	172	struct rxrpc_peer *peer = conn->params.peer;
	173
	174	write_lock_bh(&peer->conn_lock);
	175	if (test_and_clear_bit(RXRPC_CONN_IN_SERVICE_CONNS, &conn->flags))
	176	rb_erase(&conn->service_node, &peer->service_conns);
	177	write_unlock_bh(&peer->conn_lock);
	178	}