[linux-2.6-block.git] / net / rxrpc / ar-accept.c

/* incoming call handling
 *
 * Copyright (C) 2007 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 License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/errqueue.h>
#include <linux/udp.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/icmp.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
#include "ar-internal.h"

/*
 * generate a connection-level abort
 */
static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx,
		      struct rxrpc_header *hdr)
{
	struct msghdr msg;
	struct kvec iov[1];
	size_t len;
	int ret;

	_enter("%d,,", local->debug_id);

	msg.msg_name	= &srx->transport.sin;
	msg.msg_namelen	= sizeof(srx->transport.sin);
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	hdr->seq	= 0;
	hdr->type	= RXRPC_PACKET_TYPE_BUSY;
	hdr->flags	= 0;
	hdr->userStatus	= 0;
	hdr->_rsvd	= 0;

	iov[0].iov_base	= hdr;
	iov[0].iov_len	= sizeof(*hdr);

	len = iov[0].iov_len;

	hdr->serial = htonl(1);
	_proto("Tx BUSY %%%u", ntohl(hdr->serial));

	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
	if (ret < 0) {
		_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
		return -EAGAIN;
	}

	_leave(" = 0");
	return 0;
}

/*
 * accept an incoming call that needs peer, transport and/or connection setting
 * up
 */
static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
				      struct rxrpc_sock *rx,
				      struct sk_buff *skb,
				      struct sockaddr_rxrpc *srx)
{
	struct rxrpc_connection *conn;
	struct rxrpc_transport *trans;
	struct rxrpc_skb_priv *sp, *nsp;
	struct rxrpc_peer *peer;
	struct rxrpc_call *call;
	struct sk_buff *notification;
	int ret;

	_enter("");

	sp = rxrpc_skb(skb);

	/* get a notification message to send to the server app */
	notification = alloc_skb(0, GFP_NOFS);
	rxrpc_new_skb(notification);
	notification->mark = RXRPC_SKB_MARK_NEW_CALL;

	peer = rxrpc_get_peer(srx, GFP_NOIO);
	if (IS_ERR(peer)) {
		_debug("no peer");
		ret = -EBUSY;
		goto error;
	}

	trans = rxrpc_get_transport(local, peer, GFP_NOIO);
	rxrpc_put_peer(peer);
	if (IS_ERR(trans)) {
		_debug("no trans");
		ret = -EBUSY;
		goto error;
	}

	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
	rxrpc_put_transport(trans);
	if (IS_ERR(conn)) {
		_debug("no conn");
		ret = PTR_ERR(conn);
		goto error;
	}

	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
	rxrpc_put_connection(conn);
	if (IS_ERR(call)) {
		_debug("no call");
		ret = PTR_ERR(call);
		goto error;
	}

	/* attach the call to the socket */
	read_lock_bh(&local->services_lock);
	if (rx->sk.sk_state == RXRPC_CLOSE)
		goto invalid_service;

	write_lock(&rx->call_lock);
	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
		rxrpc_get_call(call);

		spin_lock(&call->conn->state_lock);
		if (sp->hdr.securityIndex > 0 &&
		    call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
			_debug("await conn sec");
			list_add_tail(&call->accept_link, &rx->secureq);
			call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
			atomic_inc(&call->conn->usage);
			set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
			rxrpc_queue_conn(call->conn);
		} else {
			_debug("conn ready");
			call->state = RXRPC_CALL_SERVER_ACCEPTING;
			list_add_tail(&call->accept_link, &rx->acceptq);
			rxrpc_get_call(call);
			nsp = rxrpc_skb(notification);
			nsp->call = call;

			ASSERTCMP(atomic_read(&call->usage), >=, 3);

			_debug("notify");
			spin_lock(&call->lock);
			ret = rxrpc_queue_rcv_skb(call, notification, true,
						  false);
			spin_unlock(&call->lock);
			notification = NULL;
			BUG_ON(ret < 0);
		}
		spin_unlock(&call->conn->state_lock);

		_debug("queued");
	}
	write_unlock(&rx->call_lock);

	_debug("process");
	rxrpc_fast_process_packet(call, skb);

	_debug("done");
	read_unlock_bh(&local->services_lock);
	rxrpc_free_skb(notification);
	rxrpc_put_call(call);
	_leave(" = 0");
	return 0;

invalid_service:
	_debug("invalid");
	read_unlock_bh(&local->services_lock);

	read_lock_bh(&call->state_lock);
	if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
		rxrpc_get_call(call);
		rxrpc_queue_call(call);
	}
	read_unlock_bh(&call->state_lock);
	rxrpc_put_call(call);
	ret = -ECONNREFUSED;
error:
	rxrpc_free_skb(notification);
	_leave(" = %d", ret);
	return ret;
}

/*
 * accept incoming calls that need peer, transport and/or connection setting up
 * - the packets we get are all incoming client DATA packets that have seq == 1
 */
void rxrpc_accept_incoming_calls(struct work_struct *work)
{
	struct rxrpc_local *local =
		container_of(work, struct rxrpc_local, acceptor);
	struct rxrpc_skb_priv *sp;
	struct sockaddr_rxrpc srx;
	struct rxrpc_sock *rx;
	struct sk_buff *skb;
	__be16 service_id;
	int ret;

	_enter("%d", local->debug_id);

	read_lock_bh(&rxrpc_local_lock);
	if (atomic_read(&local->usage) > 0)
		rxrpc_get_local(local);
	else
		local = NULL;
	read_unlock_bh(&rxrpc_local_lock);
	if (!local) {
		_leave(" [local dead]");
		return;
	}

process_next_packet:
	skb = skb_dequeue(&local->accept_queue);
	if (!skb) {
		rxrpc_put_local(local);
		_leave("\n");
		return;
	}

	_net("incoming call skb %p", skb);

	sp = rxrpc_skb(skb);

	/* determine the remote address */
	memset(&srx, 0, sizeof(srx));
	srx.srx_family = AF_RXRPC;
	srx.transport.family = local->srx.transport.family;
	srx.transport_type = local->srx.transport_type;
	switch (srx.transport.family) {
	case AF_INET:
		srx.transport_len = sizeof(struct sockaddr_in);
		srx.transport.sin.sin_port = udp_hdr(skb)->source;
		srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
		break;
	default:
		goto busy;
	}

	/* get the socket providing the service */
	service_id = sp->hdr.serviceId;
	read_lock_bh(&local->services_lock);
	list_for_each_entry(rx, &local->services, listen_link) {
		if (rx->service_id == service_id &&
		    rx->sk.sk_state != RXRPC_CLOSE)
			goto found_service;
	}
	read_unlock_bh(&local->services_lock);
	goto invalid_service;

found_service:
	_debug("found service %hd", ntohs(rx->service_id));
	if (sk_acceptq_is_full(&rx->sk))
		goto backlog_full;
	sk_acceptq_added(&rx->sk);
	sock_hold(&rx->sk);
	read_unlock_bh(&local->services_lock);

	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
	if (ret < 0)
		sk_acceptq_removed(&rx->sk);
	sock_put(&rx->sk);
	switch (ret) {
	case -ECONNRESET: /* old calls are ignored */
	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
	case 0:
		goto process_next_packet;
	case -ECONNREFUSED:
		goto invalid_service;
	case -EBUSY:
		goto busy;
	case -EKEYREJECTED:
		goto security_mismatch;
	default:
		BUG();
	}

backlog_full:
	read_unlock_bh(&local->services_lock);
busy:
	rxrpc_busy(local, &srx, &sp->hdr);
	rxrpc_free_skb(skb);
	goto process_next_packet;

invalid_service:
	skb->priority = RX_INVALID_OPERATION;
	rxrpc_reject_packet(local, skb);
	goto process_next_packet;

	/* can't change connection security type mid-flow */
security_mismatch:
	skb->priority = RX_PROTOCOL_ERROR;
	rxrpc_reject_packet(local, skb);
	goto process_next_packet;
}

/*
 * handle acceptance of a call by userspace
 * - assign the user call ID to the call at the front of the queue
 */
struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
				     unsigned long user_call_ID)
{
	struct rxrpc_call *call;
	struct rb_node *parent, **pp;
	int ret;

	_enter(",%lx", user_call_ID);

	ASSERT(!irqs_disabled());

	write_lock(&rx->call_lock);

	ret = -ENODATA;
	if (list_empty(&rx->acceptq))
		goto out;

	/* check the user ID isn't already in use */
	ret = -EBADSLT;
	pp = &rx->calls.rb_node;
	parent = NULL;
	while (*pp) {
		parent = *pp;
		call = rb_entry(parent, struct rxrpc_call, sock_node);

		if (user_call_ID < call->user_call_ID)
			pp = &(*pp)->rb_left;
		else if (user_call_ID > call->user_call_ID)
			pp = &(*pp)->rb_right;
		else
			goto out;
	}

	/* dequeue the first call and check it's still valid */
	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	list_del_init(&call->accept_link);
	sk_acceptq_removed(&rx->sk);

	write_lock_bh(&call->state_lock);
	switch (call->state) {
	case RXRPC_CALL_SERVER_ACCEPTING:
		call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
		break;
	case RXRPC_CALL_REMOTELY_ABORTED:
	case RXRPC_CALL_LOCALLY_ABORTED:
		ret = -ECONNABORTED;
		goto out_release;
	case RXRPC_CALL_NETWORK_ERROR:
		ret = call->conn->error;
		goto out_release;
	case RXRPC_CALL_DEAD:
		ret = -ETIME;
		goto out_discard;
	default:
		BUG();
	}

	/* formalise the acceptance */
	call->user_call_ID = user_call_ID;
	rb_link_node(&call->sock_node, parent, pp);
	rb_insert_color(&call->sock_node, &rx->calls);
	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
		BUG();
	if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
		BUG();
	rxrpc_queue_call(call);

	rxrpc_get_call(call);
	write_unlock_bh(&call->state_lock);
	write_unlock(&rx->call_lock);
	_leave(" = %p{%d}", call, call->debug_id);
	return call;

	/* if the call is already dying or dead, then we leave the socket's ref
	 * on it to be released by rxrpc_dead_call_expired() as induced by
	 * rxrpc_release_call() */
out_release:
	_debug("release %p", call);
	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
		rxrpc_queue_call(call);
out_discard:
	write_unlock_bh(&call->state_lock);
	_debug("discard %p", call);
out:
	write_unlock(&rx->call_lock);
	_leave(" = %d", ret);
	return ERR_PTR(ret);
}

/*
 * handle rejectance of a call by userspace
 * - reject the call at the front of the queue
 */
int rxrpc_reject_call(struct rxrpc_sock *rx)
{
	struct rxrpc_call *call;
	int ret;

	_enter("");

	ASSERT(!irqs_disabled());

	write_lock(&rx->call_lock);

	ret = -ENODATA;
	if (list_empty(&rx->acceptq))
		goto out;

	/* dequeue the first call and check it's still valid */
	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	list_del_init(&call->accept_link);
	sk_acceptq_removed(&rx->sk);

	write_lock_bh(&call->state_lock);
	switch (call->state) {
	case RXRPC_CALL_SERVER_ACCEPTING:
		call->state = RXRPC_CALL_SERVER_BUSY;
		if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
			rxrpc_queue_call(call);
		ret = 0;
		goto out_release;
	case RXRPC_CALL_REMOTELY_ABORTED:
	case RXRPC_CALL_LOCALLY_ABORTED:
		ret = -ECONNABORTED;
		goto out_release;
	case RXRPC_CALL_NETWORK_ERROR:
		ret = call->conn->error;
		goto out_release;
	case RXRPC_CALL_DEAD:
		ret = -ETIME;
		goto out_discard;
	default:
		BUG();
	}

	/* if the call is already dying or dead, then we leave the socket's ref
	 * on it to be released by rxrpc_dead_call_expired() as induced by
	 * rxrpc_release_call() */
out_release:
	_debug("release %p", call);
	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	    !test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
		rxrpc_queue_call(call);
out_discard:
	write_unlock_bh(&call->state_lock);
	_debug("discard %p", call);
out:
	write_unlock(&rx->call_lock);
	_leave(" = %d", ret);
	return ret;
}

/**
 * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
 * @sock: The socket on which the impending call is waiting
 * @user_call_ID: The tag to attach to the call
 *
 * Allow a kernel service to accept an incoming call, assuming the incoming
 * call is still valid.
 */
struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock,
					    unsigned long user_call_ID)
{
	struct rxrpc_call *call;

	_enter(",%lx", user_call_ID);
	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	_leave(" = %p", call);
	return call;
}

EXPORT_SYMBOL(rxrpc_kernel_accept_call);

/**
 * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
 * @sock: The socket on which the impending call is waiting
 *
 * Allow a kernel service to reject an incoming call with a BUSY message,
 * assuming the incoming call is still valid.
 */
int rxrpc_kernel_reject_call(struct socket *sock)
{
	int ret;

	_enter("");
	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	_leave(" = %d", ret);
	return ret;
}

EXPORT_SYMBOL(rxrpc_kernel_reject_call);
Commit	Line	Data
17926a79 DH	1	/* incoming call handling
	2	*
	3	* Copyright (C) 2007 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 License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/module.h>
	13	#include <linux/net.h>
	14	#include <linux/skbuff.h>
	15	#include <linux/errqueue.h>
	16	#include <linux/udp.h>
	17	#include <linux/in.h>
	18	#include <linux/in6.h>
	19	#include <linux/icmp.h>
	20	#include <net/sock.h>
	21	#include <net/af_rxrpc.h>
	22	#include <net/ip.h>
	23	#include "ar-internal.h"
	24
	25	/*
	26	* generate a connection-level abort
	27	*/
	28	static int rxrpc_busy(struct rxrpc_local local, struct sockaddr_rxrpc srx,
	29	struct rxrpc_header *hdr)
	30	{
	31	struct msghdr msg;
	32	struct kvec iov[1];
	33	size_t len;
	34	int ret;
	35
	36	_enter("%d,,", local->debug_id);
	37
	38	msg.msg_name = &srx->transport.sin;
	39	msg.msg_namelen = sizeof(srx->transport.sin);
	40	msg.msg_control = NULL;
	41	msg.msg_controllen = 0;
	42	msg.msg_flags = 0;
	43
	44	hdr->seq = 0;
	45	hdr->type = RXRPC_PACKET_TYPE_BUSY;
	46	hdr->flags = 0;
	47	hdr->userStatus = 0;
	48	hdr->_rsvd = 0;
	49
	50	iov[0].iov_base = hdr;
	51	iov[0].iov_len = sizeof(*hdr);
	52
	53	len = iov[0].iov_len;
	54
	55	hdr->serial = htonl(1);
	56	_proto("Tx BUSY %%%u", ntohl(hdr->serial));
	57
	58	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
	59	if (ret < 0) {
	60	_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
	61	return -EAGAIN;
	62	}
	63
	64	_leave(" = 0");
65	return 0;
66	}
67
68	/*
69	* accept an incoming call that needs peer, transport and/or connection setting
70	* up
71	*/
72	static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
73	struct rxrpc_sock *rx,
74	struct sk_buff *skb,
75	struct sockaddr_rxrpc *srx)
76	{
77	struct rxrpc_connection *conn;
78	struct rxrpc_transport *trans;
79	struct rxrpc_skb_priv sp, nsp;
80	struct rxrpc_peer *peer;
81	struct rxrpc_call *call;
82	struct sk_buff *notification;
83	int ret;
84
85	_enter("");
86
87	sp = rxrpc_skb(skb);
88
89	/* get a notification message to send to the server app */
90	notification = alloc_skb(0, GFP_NOFS);
91	rxrpc_new_skb(notification);
92	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
93
94	peer = rxrpc_get_peer(srx, GFP_NOIO);
95	if (IS_ERR(peer)) {
96	_debug("no peer");
97	ret = -EBUSY;
98	goto error;
99	}
100
101	trans = rxrpc_get_transport(local, peer, GFP_NOIO);
102	rxrpc_put_peer(peer);
34093d05	103	if (IS_ERR(trans)) {
17926a79 DH	104	_debug("no trans");
	105	ret = -EBUSY;
	106	goto error;
	107	}
	108
	109	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
	110	rxrpc_put_transport(trans);
	111	if (IS_ERR(conn)) {
	112	_debug("no conn");
	113	ret = PTR_ERR(conn);
	114	goto error;
	115	}
	116
	117	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
	118	rxrpc_put_connection(conn);
	119	if (IS_ERR(call)) {
	120	_debug("no call");
	121	ret = PTR_ERR(call);
	122	goto error;
	123	}
	124
	125	/* attach the call to the socket */
	126	read_lock_bh(&local->services_lock);
	127	if (rx->sk.sk_state == RXRPC_CLOSE)
	128	goto invalid_service;
	129
	130	write_lock(&rx->call_lock);
	131	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
	132	rxrpc_get_call(call);
	133
	134	spin_lock(&call->conn->state_lock);
	135	if (sp->hdr.securityIndex > 0 &&
	136	call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
	137	_debug("await conn sec");
	138	list_add_tail(&call->accept_link, &rx->secureq);
	139	call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
	140	atomic_inc(&call->conn->usage);
	141	set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
651350d1	142	rxrpc_queue_conn(call->conn);
17926a79 DH	143	} else {
	144	_debug("conn ready");
	145	call->state = RXRPC_CALL_SERVER_ACCEPTING;
	146	list_add_tail(&call->accept_link, &rx->acceptq);
	147	rxrpc_get_call(call);
	148	nsp = rxrpc_skb(notification);
	149	nsp->call = call;
	150
	151	ASSERTCMP(atomic_read(&call->usage), >=, 3);
	152
	153	_debug("notify");
	154	spin_lock(&call->lock);
	155	ret = rxrpc_queue_rcv_skb(call, notification, true,
	156	false);
	157	spin_unlock(&call->lock);
	158	notification = NULL;
163e3cb7	159	BUG_ON(ret < 0);
17926a79 DH	160	}
	161	spin_unlock(&call->conn->state_lock);
	162
	163	_debug("queued");
	164	}
	165	write_unlock(&rx->call_lock);
	166
	167	_debug("process");
	168	rxrpc_fast_process_packet(call, skb);
	169
	170	_debug("done");
	171	read_unlock_bh(&local->services_lock);
	172	rxrpc_free_skb(notification);
	173	rxrpc_put_call(call);
	174	_leave(" = 0");
	175	return 0;
	176
	177	invalid_service:
	178	_debug("invalid");
	179	read_unlock_bh(&local->services_lock);
	180
	181	read_lock_bh(&call->state_lock);
	182	if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
	183	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
	184	rxrpc_get_call(call);
651350d1	185	rxrpc_queue_call(call);
17926a79 DH	186	}
	187	read_unlock_bh(&call->state_lock);
	188	rxrpc_put_call(call);
	189	ret = -ECONNREFUSED;
	190	error:
	191	rxrpc_free_skb(notification);
	192	_leave(" = %d", ret);
	193	return ret;
	194	}
	195
	196	/*
	197	* accept incoming calls that need peer, transport and/or connection setting up
	198	* - the packets we get are all incoming client DATA packets that have seq == 1
	199	*/
	200	void rxrpc_accept_incoming_calls(struct work_struct *work)
	201	{
	202	struct rxrpc_local *local =
	203	container_of(work, struct rxrpc_local, acceptor);
	204	struct rxrpc_skb_priv *sp;
	205	struct sockaddr_rxrpc srx;
	206	struct rxrpc_sock *rx;
	207	struct sk_buff *skb;
	208	__be16 service_id;
	209	int ret;
	210
	211	_enter("%d", local->debug_id);
	212
	213	read_lock_bh(&rxrpc_local_lock);
	214	if (atomic_read(&local->usage) > 0)
	215	rxrpc_get_local(local);
	216	else
	217	local = NULL;
	218	read_unlock_bh(&rxrpc_local_lock);
	219	if (!local) {
	220	_leave(" [local dead]");
	221	return;
	222	}
	223
	224	process_next_packet:
	225	skb = skb_dequeue(&local->accept_queue);
	226	if (!skb) {
	227	rxrpc_put_local(local);
	228	_leave("\n");
	229	return;
	230	}
	231
	232	_net("incoming call skb %p", skb);
	233
	234	sp = rxrpc_skb(skb);
	235
	236	/* determine the remote address */
	237	memset(&srx, 0, sizeof(srx));
	238	srx.srx_family = AF_RXRPC;
	239	srx.transport.family = local->srx.transport.family;
	240	srx.transport_type = local->srx.transport_type;
	241	switch (srx.transport.family) {
	242	case AF_INET:
	243	srx.transport_len = sizeof(struct sockaddr_in);
	244	srx.transport.sin.sin_port = udp_hdr(skb)->source;
	245	srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
	246	break;
	247	default:
	248	goto busy;
	249	}
250
251	/* get the socket providing the service */
252	service_id = sp->hdr.serviceId;
253	read_lock_bh(&local->services_lock);
254	list_for_each_entry(rx, &local->services, listen_link) {
255	if (rx->service_id == service_id &&
256	rx->sk.sk_state != RXRPC_CLOSE)
257	goto found_service;
258	}
259	read_unlock_bh(&local->services_lock);
260	goto invalid_service;
261
262	found_service:
263	_debug("found service %hd", ntohs(rx->service_id));
264	if (sk_acceptq_is_full(&rx->sk))
265	goto backlog_full;
266	sk_acceptq_added(&rx->sk);
267	sock_hold(&rx->sk);
268	read_unlock_bh(&local->services_lock);
269
270	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
271	if (ret < 0)
272	sk_acceptq_removed(&rx->sk);
273	sock_put(&rx->sk);
274	switch (ret) {
275	case -ECONNRESET: /* old calls are ignored */
276	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
277	case 0:
278	goto process_next_packet;
279	case -ECONNREFUSED:
280	goto invalid_service;
281	case -EBUSY:
282	goto busy;
283	case -EKEYREJECTED:
284	goto security_mismatch;
285	default:
286	BUG();
287	}
288
289	backlog_full:
290	read_unlock_bh(&local->services_lock);
291	busy:
292	rxrpc_busy(local, &srx, &sp->hdr);
293	rxrpc_free_skb(skb);
294	goto process_next_packet;
295
296	invalid_service:
297	skb->priority = RX_INVALID_OPERATION;
298	rxrpc_reject_packet(local, skb);
299	goto process_next_packet;
300
301	/* can't change connection security type mid-flow */
302	security_mismatch:
303	skb->priority = RX_PROTOCOL_ERROR;
304	rxrpc_reject_packet(local, skb);
305	goto process_next_packet;
306	}
307
308	/*
309	* handle acceptance of a call by userspace
310	* - assign the user call ID to the call at the front of the queue
311	*/
651350d1 DH	312	struct rxrpc_call rxrpc_accept_call(struct rxrpc_sock rx,
651350d1 DH	313	unsigned long user_call_ID)
17926a79 DH	314	{
	315	struct rxrpc_call *call;
	316	struct rb_node parent, *pp;
	317	int ret;
	318
	319	_enter(",%lx", user_call_ID);
	320
	321	ASSERT(!irqs_disabled());
	322
	323	write_lock(&rx->call_lock);
	324
	325	ret = -ENODATA;
	326	if (list_empty(&rx->acceptq))
	327	goto out;
	328
	329	/* check the user ID isn't already in use */
	330	ret = -EBADSLT;
	331	pp = &rx->calls.rb_node;
	332	parent = NULL;
	333	while (*pp) {
	334	parent = *pp;
	335	call = rb_entry(parent, struct rxrpc_call, sock_node);
	336
	337	if (user_call_ID < call->user_call_ID)
	338	pp = &(*pp)->rb_left;
	339	else if (user_call_ID > call->user_call_ID)
	340	pp = &(*pp)->rb_right;
	341	else
	342	goto out;
	343	}
	344
	345	/* dequeue the first call and check it's still valid */
	346	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	347	list_del_init(&call->accept_link);
	348	sk_acceptq_removed(&rx->sk);
	349
	350	write_lock_bh(&call->state_lock);
	351	switch (call->state) {
	352	case RXRPC_CALL_SERVER_ACCEPTING:
	353	call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
	354	break;
	355	case RXRPC_CALL_REMOTELY_ABORTED:
	356	case RXRPC_CALL_LOCALLY_ABORTED:
	357	ret = -ECONNABORTED;
	358	goto out_release;
	359	case RXRPC_CALL_NETWORK_ERROR:
	360	ret = call->conn->error;
	361	goto out_release;
	362	case RXRPC_CALL_DEAD:
	363	ret = -ETIME;
	364	goto out_discard;
	365	default:
	366	BUG();
	367	}
	368
	369	/* formalise the acceptance */
	370	call->user_call_ID = user_call_ID;
	371	rb_link_node(&call->sock_node, parent, pp);
	372	rb_insert_color(&call->sock_node, &rx->calls);
	373	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
	374	BUG();
	375	if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
	376	BUG();
651350d1	377	rxrpc_queue_call(call);
17926a79	378
651350d1	379	rxrpc_get_call(call);
17926a79 DH	380	write_unlock_bh(&call->state_lock);
17926a79 DH	381	write_unlock(&rx->call_lock);
651350d1 DH	382	_leave(" = %p{%d}", call, call->debug_id);
	383	return call;
	384
	385	/* if the call is already dying or dead, then we leave the socket's ref
	386	* on it to be released by rxrpc_dead_call_expired() as induced by
	387	* rxrpc_release_call() */
	388	out_release:
	389	_debug("release %p", call);
	390	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	391	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
	392	rxrpc_queue_call(call);
	393	out_discard:
	394	write_unlock_bh(&call->state_lock);
	395	_debug("discard %p", call);
	396	out:
	397	write_unlock(&rx->call_lock);
	398	_leave(" = %d", ret);
	399	return ERR_PTR(ret);
	400	}
	401
	402	/*
	403	* handle rejectance of a call by userspace
	404	* - reject the call at the front of the queue
	405	*/
	406	int rxrpc_reject_call(struct rxrpc_sock *rx)
	407	{
	408	struct rxrpc_call *call;
	409	int ret;
	410
	411	_enter("");
	412
	413	ASSERT(!irqs_disabled());
	414
	415	write_lock(&rx->call_lock);
	416
	417	ret = -ENODATA;
	418	if (list_empty(&rx->acceptq))
	419	goto out;
	420
	421	/* dequeue the first call and check it's still valid */
	422	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	423	list_del_init(&call->accept_link);
	424	sk_acceptq_removed(&rx->sk);
	425
	426	write_lock_bh(&call->state_lock);
	427	switch (call->state) {
	428	case RXRPC_CALL_SERVER_ACCEPTING:
	429	call->state = RXRPC_CALL_SERVER_BUSY;
	430	if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
	431	rxrpc_queue_call(call);
	432	ret = 0;
	433	goto out_release;
	434	case RXRPC_CALL_REMOTELY_ABORTED:
	435	case RXRPC_CALL_LOCALLY_ABORTED:
	436	ret = -ECONNABORTED;
	437	goto out_release;
	438	case RXRPC_CALL_NETWORK_ERROR:
	439	ret = call->conn->error;
	440	goto out_release;
	441	case RXRPC_CALL_DEAD:
	442	ret = -ETIME;
	443	goto out_discard;
	444	default:
	445	BUG();
446	}
17926a79 DH	447
	448	/* if the call is already dying or dead, then we leave the socket's ref
	449	* on it to be released by rxrpc_dead_call_expired() as induced by
	450	* rxrpc_release_call() */
	451	out_release:
	452	_debug("release %p", call);
	453	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	454	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
651350d1	455	rxrpc_queue_call(call);
17926a79 DH	456	out_discard:
	457	write_unlock_bh(&call->state_lock);
	458	_debug("discard %p", call);
	459	out:
	460	write_unlock(&rx->call_lock);
	461	_leave(" = %d", ret);
	462	return ret;
	463	}
651350d1 DH	464
	465	/**
	466	* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
	467	* @sock: The socket on which the impending call is waiting
	468	* @user_call_ID: The tag to attach to the call
	469	*
	470	* Allow a kernel service to accept an incoming call, assuming the incoming
	471	* call is still valid.
	472	*/
	473	struct rxrpc_call rxrpc_kernel_accept_call(struct socket sock,
	474	unsigned long user_call_ID)
	475	{
	476	struct rxrpc_call *call;
	477
	478	_enter(",%lx", user_call_ID);
	479	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	480	_leave(" = %p", call);
	481	return call;
	482	}
	483
	484	EXPORT_SYMBOL(rxrpc_kernel_accept_call);
	485
	486	/**
	487	* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
	488	* @sock: The socket on which the impending call is waiting
	489	*
	490	* Allow a kernel service to reject an incoming call with a BUSY message,
	491	* assuming the incoming call is still valid.
	492	*/
	493	int rxrpc_kernel_reject_call(struct socket *sock)
	494	{
	495	int ret;
	496
	497	_enter("");
	498	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	499	_leave(" = %d", ret);
	500	return ret;
	501	}
	502
	503	EXPORT_SYMBOL(rxrpc_kernel_reject_call);