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