[net-next-2.6.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);
	if (!notification) {
		_debug("no memory");
		ret = -ENOMEM;
		goto error_nofree;
	}
	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);
error_nofree:
	_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);
c3824d21 TH	91	if (!notification) {
	92	_debug("no memory");
	93	ret = -ENOMEM;
	94	goto error_nofree;
	95	}
17926a79 DH	96	rxrpc_new_skb(notification);
	97	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
	98
	99	peer = rxrpc_get_peer(srx, GFP_NOIO);
	100	if (IS_ERR(peer)) {
	101	_debug("no peer");
	102	ret = -EBUSY;
	103	goto error;
	104	}
	105
	106	trans = rxrpc_get_transport(local, peer, GFP_NOIO);
	107	rxrpc_put_peer(peer);
34093d05	108	if (IS_ERR(trans)) {
17926a79 DH	109	_debug("no trans");
	110	ret = -EBUSY;
	111	goto error;
	112	}
	113
	114	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
	115	rxrpc_put_transport(trans);
	116	if (IS_ERR(conn)) {
	117	_debug("no conn");
	118	ret = PTR_ERR(conn);
	119	goto error;
	120	}
	121
	122	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
	123	rxrpc_put_connection(conn);
	124	if (IS_ERR(call)) {
	125	_debug("no call");
	126	ret = PTR_ERR(call);
	127	goto error;
	128	}
	129
	130	/* attach the call to the socket */
	131	read_lock_bh(&local->services_lock);
	132	if (rx->sk.sk_state == RXRPC_CLOSE)
	133	goto invalid_service;
	134
	135	write_lock(&rx->call_lock);
	136	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
	137	rxrpc_get_call(call);
	138
	139	spin_lock(&call->conn->state_lock);
	140	if (sp->hdr.securityIndex > 0 &&
	141	call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
	142	_debug("await conn sec");
	143	list_add_tail(&call->accept_link, &rx->secureq);
	144	call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
	145	atomic_inc(&call->conn->usage);
	146	set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
651350d1	147	rxrpc_queue_conn(call->conn);
17926a79 DH	148	} else {
	149	_debug("conn ready");
	150	call->state = RXRPC_CALL_SERVER_ACCEPTING;
	151	list_add_tail(&call->accept_link, &rx->acceptq);
	152	rxrpc_get_call(call);
	153	nsp = rxrpc_skb(notification);
	154	nsp->call = call;
	155
	156	ASSERTCMP(atomic_read(&call->usage), >=, 3);
	157
	158	_debug("notify");
	159	spin_lock(&call->lock);
	160	ret = rxrpc_queue_rcv_skb(call, notification, true,
	161	false);
	162	spin_unlock(&call->lock);
	163	notification = NULL;
163e3cb7	164	BUG_ON(ret < 0);
17926a79 DH	165	}
	166	spin_unlock(&call->conn->state_lock);
	167
	168	_debug("queued");
	169	}
	170	write_unlock(&rx->call_lock);
	171
	172	_debug("process");
	173	rxrpc_fast_process_packet(call, skb);
	174
	175	_debug("done");
	176	read_unlock_bh(&local->services_lock);
	177	rxrpc_free_skb(notification);
	178	rxrpc_put_call(call);
	179	_leave(" = 0");
	180	return 0;
	181
	182	invalid_service:
	183	_debug("invalid");
	184	read_unlock_bh(&local->services_lock);
	185
	186	read_lock_bh(&call->state_lock);
	187	if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
	188	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
	189	rxrpc_get_call(call);
651350d1	190	rxrpc_queue_call(call);
17926a79 DH	191	}
	192	read_unlock_bh(&call->state_lock);
	193	rxrpc_put_call(call);
	194	ret = -ECONNREFUSED;
	195	error:
	196	rxrpc_free_skb(notification);
c3824d21	197	error_nofree:
17926a79 DH	198	_leave(" = %d", ret);
	199	return ret;
	200	}
	201
	202	/*
	203	* accept incoming calls that need peer, transport and/or connection setting up
	204	* - the packets we get are all incoming client DATA packets that have seq == 1
	205	*/
	206	void rxrpc_accept_incoming_calls(struct work_struct *work)
	207	{
	208	struct rxrpc_local *local =
	209	container_of(work, struct rxrpc_local, acceptor);
	210	struct rxrpc_skb_priv *sp;
	211	struct sockaddr_rxrpc srx;
	212	struct rxrpc_sock *rx;
	213	struct sk_buff *skb;
	214	__be16 service_id;
	215	int ret;
	216
	217	_enter("%d", local->debug_id);
	218
	219	read_lock_bh(&rxrpc_local_lock);
	220	if (atomic_read(&local->usage) > 0)
	221	rxrpc_get_local(local);
	222	else
	223	local = NULL;
	224	read_unlock_bh(&rxrpc_local_lock);
	225	if (!local) {
	226	_leave(" [local dead]");
	227	return;
	228	}
	229
	230	process_next_packet:
	231	skb = skb_dequeue(&local->accept_queue);
	232	if (!skb) {
	233	rxrpc_put_local(local);
	234	_leave("\n");
	235	return;
	236	}
	237
	238	_net("incoming call skb %p", skb);
	239
	240	sp = rxrpc_skb(skb);
	241
	242	/* determine the remote address */
	243	memset(&srx, 0, sizeof(srx));
	244	srx.srx_family = AF_RXRPC;
	245	srx.transport.family = local->srx.transport.family;
	246	srx.transport_type = local->srx.transport_type;
	247	switch (srx.transport.family) {
	248	case AF_INET:
	249	srx.transport_len = sizeof(struct sockaddr_in);
	250	srx.transport.sin.sin_port = udp_hdr(skb)->source;
	251	srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
	252	break;
	253	default:
	254	goto busy;
	255	}
	256
	257	/* get the socket providing the service */
	258	service_id = sp->hdr.serviceId;
	259	read_lock_bh(&local->services_lock);
	260	list_for_each_entry(rx, &local->services, listen_link) {
	261	if (rx->service_id == service_id &&
262	rx->sk.sk_state != RXRPC_CLOSE)
263	goto found_service;
264	}
265	read_unlock_bh(&local->services_lock);
266	goto invalid_service;
267
268	found_service:
269	_debug("found service %hd", ntohs(rx->service_id));
270	if (sk_acceptq_is_full(&rx->sk))
271	goto backlog_full;
272	sk_acceptq_added(&rx->sk);
273	sock_hold(&rx->sk);
274	read_unlock_bh(&local->services_lock);
275
276	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
277	if (ret < 0)
278	sk_acceptq_removed(&rx->sk);
279	sock_put(&rx->sk);
280	switch (ret) {
281	case -ECONNRESET: /* old calls are ignored */
282	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
283	case 0:
284	goto process_next_packet;
285	case -ECONNREFUSED:
286	goto invalid_service;
287	case -EBUSY:
288	goto busy;
289	case -EKEYREJECTED:
290	goto security_mismatch;
291	default:
292	BUG();
293	}
294
295	backlog_full:
296	read_unlock_bh(&local->services_lock);
297	busy:
298	rxrpc_busy(local, &srx, &sp->hdr);
299	rxrpc_free_skb(skb);
300	goto process_next_packet;
301
302	invalid_service:
303	skb->priority = RX_INVALID_OPERATION;
304	rxrpc_reject_packet(local, skb);
305	goto process_next_packet;
306
307	/* can't change connection security type mid-flow */
308	security_mismatch:
309	skb->priority = RX_PROTOCOL_ERROR;
310	rxrpc_reject_packet(local, skb);
311	goto process_next_packet;
312	}
313
314	/*
315	* handle acceptance of a call by userspace
316	* - assign the user call ID to the call at the front of the queue
317	*/
651350d1 DH	318	struct rxrpc_call rxrpc_accept_call(struct rxrpc_sock rx,
651350d1 DH	319	unsigned long user_call_ID)
17926a79 DH	320	{
	321	struct rxrpc_call *call;
	322	struct rb_node parent, *pp;
	323	int ret;
	324
	325	_enter(",%lx", user_call_ID);
	326
	327	ASSERT(!irqs_disabled());
	328
	329	write_lock(&rx->call_lock);
	330
	331	ret = -ENODATA;
	332	if (list_empty(&rx->acceptq))
	333	goto out;
	334
	335	/* check the user ID isn't already in use */
	336	ret = -EBADSLT;
	337	pp = &rx->calls.rb_node;
	338	parent = NULL;
	339	while (*pp) {
	340	parent = *pp;
	341	call = rb_entry(parent, struct rxrpc_call, sock_node);
	342
	343	if (user_call_ID < call->user_call_ID)
	344	pp = &(*pp)->rb_left;
	345	else if (user_call_ID > call->user_call_ID)
	346	pp = &(*pp)->rb_right;
	347	else
	348	goto out;
	349	}
	350
	351	/* dequeue the first call and check it's still valid */
	352	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	353	list_del_init(&call->accept_link);
	354	sk_acceptq_removed(&rx->sk);
	355
	356	write_lock_bh(&call->state_lock);
	357	switch (call->state) {
	358	case RXRPC_CALL_SERVER_ACCEPTING:
	359	call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
	360	break;
	361	case RXRPC_CALL_REMOTELY_ABORTED:
	362	case RXRPC_CALL_LOCALLY_ABORTED:
	363	ret = -ECONNABORTED;
	364	goto out_release;
	365	case RXRPC_CALL_NETWORK_ERROR:
	366	ret = call->conn->error;
	367	goto out_release;
	368	case RXRPC_CALL_DEAD:
	369	ret = -ETIME;
	370	goto out_discard;
	371	default:
	372	BUG();
	373	}
	374
	375	/* formalise the acceptance */
	376	call->user_call_ID = user_call_ID;
	377	rb_link_node(&call->sock_node, parent, pp);
	378	rb_insert_color(&call->sock_node, &rx->calls);
	379	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
	380	BUG();
	381	if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
	382	BUG();
651350d1	383	rxrpc_queue_call(call);
17926a79	384
651350d1	385	rxrpc_get_call(call);
17926a79 DH	386	write_unlock_bh(&call->state_lock);
17926a79 DH	387	write_unlock(&rx->call_lock);
651350d1 DH	388	_leave(" = %p{%d}", call, call->debug_id);
	389	return call;
	390
	391	/* if the call is already dying or dead, then we leave the socket's ref
	392	* on it to be released by rxrpc_dead_call_expired() as induced by
	393	* rxrpc_release_call() */
	394	out_release:
	395	_debug("release %p", call);
	396	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	397	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
	398	rxrpc_queue_call(call);
	399	out_discard:
	400	write_unlock_bh(&call->state_lock);
	401	_debug("discard %p", call);
	402	out:
	403	write_unlock(&rx->call_lock);
	404	_leave(" = %d", ret);
	405	return ERR_PTR(ret);
	406	}
	407
	408	/*
	409	* handle rejectance of a call by userspace
	410	* - reject the call at the front of the queue
	411	*/
	412	int rxrpc_reject_call(struct rxrpc_sock *rx)
	413	{
	414	struct rxrpc_call *call;
	415	int ret;
	416
	417	_enter("");
	418
	419	ASSERT(!irqs_disabled());
	420
	421	write_lock(&rx->call_lock);
	422
	423	ret = -ENODATA;
	424	if (list_empty(&rx->acceptq))
	425	goto out;
	426
	427	/* dequeue the first call and check it's still valid */
	428	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	429	list_del_init(&call->accept_link);
	430	sk_acceptq_removed(&rx->sk);
	431
	432	write_lock_bh(&call->state_lock);
	433	switch (call->state) {
	434	case RXRPC_CALL_SERVER_ACCEPTING:
	435	call->state = RXRPC_CALL_SERVER_BUSY;
	436	if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
	437	rxrpc_queue_call(call);
	438	ret = 0;
	439	goto out_release;
	440	case RXRPC_CALL_REMOTELY_ABORTED:
	441	case RXRPC_CALL_LOCALLY_ABORTED:
	442	ret = -ECONNABORTED;
	443	goto out_release;
	444	case RXRPC_CALL_NETWORK_ERROR:
	445	ret = call->conn->error;
	446	goto out_release;
	447	case RXRPC_CALL_DEAD:
	448	ret = -ETIME;
	449	goto out_discard;
	450	default:
	451	BUG();
452	}
17926a79 DH	453
	454	/* if the call is already dying or dead, then we leave the socket's ref
	455	* on it to be released by rxrpc_dead_call_expired() as induced by
	456	* rxrpc_release_call() */
	457	out_release:
	458	_debug("release %p", call);
	459	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	460	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
651350d1	461	rxrpc_queue_call(call);
17926a79 DH	462	out_discard:
	463	write_unlock_bh(&call->state_lock);
	464	_debug("discard %p", call);
	465	out:
	466	write_unlock(&rx->call_lock);
	467	_leave(" = %d", ret);
	468	return ret;
	469	}
651350d1 DH	470
	471	/**
	472	* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
	473	* @sock: The socket on which the impending call is waiting
	474	* @user_call_ID: The tag to attach to the call
	475	*
	476	* Allow a kernel service to accept an incoming call, assuming the incoming
	477	* call is still valid.
	478	*/
	479	struct rxrpc_call rxrpc_kernel_accept_call(struct socket sock,
	480	unsigned long user_call_ID)
	481	{
	482	struct rxrpc_call *call;
	483
	484	_enter(",%lx", user_call_ID);
	485	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	486	_leave(" = %p", call);
	487	return call;
	488	}
	489
	490	EXPORT_SYMBOL(rxrpc_kernel_accept_call);
	491
	492	/**
	493	* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
	494	* @sock: The socket on which the impending call is waiting
	495	*
	496	* Allow a kernel service to reject an incoming call with a BUSY message,
	497	* assuming the incoming call is still valid.
	498	*/
	499	int rxrpc_kernel_reject_call(struct socket *sock)
	500	{
	501	int ret;
	502
	503	_enter("");
	504	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	505	_leave(" = %d", ret);
	506	return ret;
	507	}
	508
	509	EXPORT_SYMBOL(rxrpc_kernel_reject_call);