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

/* incoming call handling
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * 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 <linux/gfp.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 ([email protected])
	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>
5a0e3ad6	20	#include <linux/gfp.h>
17926a79 DH	21	#include <net/sock.h>
	22	#include <net/af_rxrpc.h>
	23	#include <net/ip.h>
	24	#include "ar-internal.h"
	25
	26	/*
	27	* generate a connection-level abort
	28	*/
	29	static int rxrpc_busy(struct rxrpc_local local, struct sockaddr_rxrpc srx,
	30	struct rxrpc_header *hdr)
	31	{
	32	struct msghdr msg;
	33	struct kvec iov[1];
	34	size_t len;
	35	int ret;
	36
	37	_enter("%d,,", local->debug_id);
	38
	39	msg.msg_name = &srx->transport.sin;
	40	msg.msg_namelen = sizeof(srx->transport.sin);
	41	msg.msg_control = NULL;
	42	msg.msg_controllen = 0;
	43	msg.msg_flags = 0;
	44
	45	hdr->seq = 0;
	46	hdr->type = RXRPC_PACKET_TYPE_BUSY;
	47	hdr->flags = 0;
	48	hdr->userStatus = 0;
	49	hdr->_rsvd = 0;
	50
	51	iov[0].iov_base = hdr;
	52	iov[0].iov_len = sizeof(*hdr);
	53
	54	len = iov[0].iov_len;
	55
	56	hdr->serial = htonl(1);
	57	_proto("Tx BUSY %%%u", ntohl(hdr->serial));
	58
	59	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
	60	if (ret < 0) {
	61	_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
	62	return -EAGAIN;
	63	}
	64
	65	_leave(" = 0");
	66	return 0;
	67	}
	68
	69	/*
	70	* accept an incoming call that needs peer, transport and/or connection setting
	71	* up
	72	*/
	73	static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
	74	struct rxrpc_sock *rx,
	75	struct sk_buff *skb,
	76	struct sockaddr_rxrpc *srx)
	77	{
	78	struct rxrpc_connection *conn;
	79	struct rxrpc_transport *trans;
	80	struct rxrpc_skb_priv sp, nsp;
	81	struct rxrpc_peer *peer;
	82	struct rxrpc_call *call;
	83	struct sk_buff *notification;
	84	int ret;
85
86	_enter("");
87
88	sp = rxrpc_skb(skb);
89
90	/* get a notification message to send to the server app */
91	notification = alloc_skb(0, GFP_NOFS);
c3824d21 TH	92	if (!notification) {
	93	_debug("no memory");
	94	ret = -ENOMEM;
	95	goto error_nofree;
	96	}
17926a79 DH	97	rxrpc_new_skb(notification);
	98	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
	99
	100	peer = rxrpc_get_peer(srx, GFP_NOIO);
	101	if (IS_ERR(peer)) {
	102	_debug("no peer");
	103	ret = -EBUSY;
	104	goto error;
	105	}
	106
	107	trans = rxrpc_get_transport(local, peer, GFP_NOIO);
	108	rxrpc_put_peer(peer);
34093d05	109	if (IS_ERR(trans)) {
17926a79 DH	110	_debug("no trans");
	111	ret = -EBUSY;
	112	goto error;
	113	}
	114
	115	conn = rxrpc_incoming_connection(trans, &sp->hdr, GFP_NOIO);
	116	rxrpc_put_transport(trans);
	117	if (IS_ERR(conn)) {
	118	_debug("no conn");
	119	ret = PTR_ERR(conn);
	120	goto error;
	121	}
	122
	123	call = rxrpc_incoming_call(rx, conn, &sp->hdr, GFP_NOIO);
	124	rxrpc_put_connection(conn);
	125	if (IS_ERR(call)) {
	126	_debug("no call");
	127	ret = PTR_ERR(call);
	128	goto error;
	129	}
	130
	131	/* attach the call to the socket */
	132	read_lock_bh(&local->services_lock);
	133	if (rx->sk.sk_state == RXRPC_CLOSE)
	134	goto invalid_service;
	135
	136	write_lock(&rx->call_lock);
	137	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
	138	rxrpc_get_call(call);
	139
	140	spin_lock(&call->conn->state_lock);
	141	if (sp->hdr.securityIndex > 0 &&
	142	call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
	143	_debug("await conn sec");
	144	list_add_tail(&call->accept_link, &rx->secureq);
	145	call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
	146	atomic_inc(&call->conn->usage);
	147	set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
651350d1	148	rxrpc_queue_conn(call->conn);
17926a79 DH	149	} else {
	150	_debug("conn ready");
	151	call->state = RXRPC_CALL_SERVER_ACCEPTING;
	152	list_add_tail(&call->accept_link, &rx->acceptq);
	153	rxrpc_get_call(call);
	154	nsp = rxrpc_skb(notification);
	155	nsp->call = call;
	156
	157	ASSERTCMP(atomic_read(&call->usage), >=, 3);
	158
	159	_debug("notify");
	160	spin_lock(&call->lock);
	161	ret = rxrpc_queue_rcv_skb(call, notification, true,
	162	false);
	163	spin_unlock(&call->lock);
	164	notification = NULL;
163e3cb7	165	BUG_ON(ret < 0);
17926a79 DH	166	}
	167	spin_unlock(&call->conn->state_lock);
	168
	169	_debug("queued");
	170	}
	171	write_unlock(&rx->call_lock);
	172
	173	_debug("process");
	174	rxrpc_fast_process_packet(call, skb);
	175
	176	_debug("done");
	177	read_unlock_bh(&local->services_lock);
	178	rxrpc_free_skb(notification);
	179	rxrpc_put_call(call);
	180	_leave(" = 0");
	181	return 0;
	182
	183	invalid_service:
	184	_debug("invalid");
	185	read_unlock_bh(&local->services_lock);
	186
	187	read_lock_bh(&call->state_lock);
	188	if (!test_bit(RXRPC_CALL_RELEASE, &call->flags) &&
	189	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) {
	190	rxrpc_get_call(call);
651350d1	191	rxrpc_queue_call(call);
17926a79 DH	192	}
	193	read_unlock_bh(&call->state_lock);
	194	rxrpc_put_call(call);
	195	ret = -ECONNREFUSED;
	196	error:
	197	rxrpc_free_skb(notification);
c3824d21	198	error_nofree:
17926a79 DH	199	_leave(" = %d", ret);
	200	return ret;
	201	}
	202
	203	/*
	204	* accept incoming calls that need peer, transport and/or connection setting up
	205	* - the packets we get are all incoming client DATA packets that have seq == 1
	206	*/
	207	void rxrpc_accept_incoming_calls(struct work_struct *work)
	208	{
	209	struct rxrpc_local *local =
	210	container_of(work, struct rxrpc_local, acceptor);
	211	struct rxrpc_skb_priv *sp;
	212	struct sockaddr_rxrpc srx;
	213	struct rxrpc_sock *rx;
	214	struct sk_buff *skb;
	215	__be16 service_id;
	216	int ret;
	217
	218	_enter("%d", local->debug_id);
	219
	220	read_lock_bh(&rxrpc_local_lock);
	221	if (atomic_read(&local->usage) > 0)
	222	rxrpc_get_local(local);
	223	else
	224	local = NULL;
	225	read_unlock_bh(&rxrpc_local_lock);
	226	if (!local) {
	227	_leave(" [local dead]");
	228	return;
	229	}
	230
	231	process_next_packet:
	232	skb = skb_dequeue(&local->accept_queue);
	233	if (!skb) {
	234	rxrpc_put_local(local);
	235	_leave("\n");
	236	return;
	237	}
	238
	239	_net("incoming call skb %p", skb);
	240
	241	sp = rxrpc_skb(skb);
	242
	243	/* determine the remote address */
	244	memset(&srx, 0, sizeof(srx));
	245	srx.srx_family = AF_RXRPC;
	246	srx.transport.family = local->srx.transport.family;
	247	srx.transport_type = local->srx.transport_type;
	248	switch (srx.transport.family) {
	249	case AF_INET:
	250	srx.transport_len = sizeof(struct sockaddr_in);
	251	srx.transport.sin.sin_port = udp_hdr(skb)->source;
	252	srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
	253	break;
	254	default:
	255	goto busy;
	256	}
	257
	258	/* get the socket providing the service */
	259	service_id = sp->hdr.serviceId;
	260	read_lock_bh(&local->services_lock);
	261	list_for_each_entry(rx, &local->services, listen_link) {
	262	if (rx->service_id == service_id &&
263	rx->sk.sk_state != RXRPC_CLOSE)
264	goto found_service;
265	}
266	read_unlock_bh(&local->services_lock);
267	goto invalid_service;
268
269	found_service:
270	_debug("found service %hd", ntohs(rx->service_id));
271	if (sk_acceptq_is_full(&rx->sk))
272	goto backlog_full;
273	sk_acceptq_added(&rx->sk);
274	sock_hold(&rx->sk);
275	read_unlock_bh(&local->services_lock);
276
277	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
278	if (ret < 0)
279	sk_acceptq_removed(&rx->sk);
280	sock_put(&rx->sk);
281	switch (ret) {
282	case -ECONNRESET: /* old calls are ignored */
283	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
284	case 0:
285	goto process_next_packet;
286	case -ECONNREFUSED:
287	goto invalid_service;
288	case -EBUSY:
289	goto busy;
290	case -EKEYREJECTED:
291	goto security_mismatch;
292	default:
293	BUG();
294	}
295
296	backlog_full:
297	read_unlock_bh(&local->services_lock);
298	busy:
299	rxrpc_busy(local, &srx, &sp->hdr);
300	rxrpc_free_skb(skb);
301	goto process_next_packet;
302
303	invalid_service:
304	skb->priority = RX_INVALID_OPERATION;
305	rxrpc_reject_packet(local, skb);
306	goto process_next_packet;
307
308	/* can't change connection security type mid-flow */
309	security_mismatch:
310	skb->priority = RX_PROTOCOL_ERROR;
311	rxrpc_reject_packet(local, skb);
312	goto process_next_packet;
313	}
314
315	/*
316	* handle acceptance of a call by userspace
317	* - assign the user call ID to the call at the front of the queue
318	*/
651350d1 DH	319	struct rxrpc_call rxrpc_accept_call(struct rxrpc_sock rx,
651350d1 DH	320	unsigned long user_call_ID)
17926a79 DH	321	{
	322	struct rxrpc_call *call;
	323	struct rb_node parent, *pp;
	324	int ret;
	325
	326	_enter(",%lx", user_call_ID);
	327
	328	ASSERT(!irqs_disabled());
	329
	330	write_lock(&rx->call_lock);
	331
	332	ret = -ENODATA;
	333	if (list_empty(&rx->acceptq))
	334	goto out;
	335
	336	/* check the user ID isn't already in use */
	337	ret = -EBADSLT;
	338	pp = &rx->calls.rb_node;
	339	parent = NULL;
	340	while (*pp) {
	341	parent = *pp;
	342	call = rb_entry(parent, struct rxrpc_call, sock_node);
	343
	344	if (user_call_ID < call->user_call_ID)
	345	pp = &(*pp)->rb_left;
	346	else if (user_call_ID > call->user_call_ID)
	347	pp = &(*pp)->rb_right;
	348	else
	349	goto out;
	350	}
	351
	352	/* dequeue the first call and check it's still valid */
	353	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	354	list_del_init(&call->accept_link);
	355	sk_acceptq_removed(&rx->sk);
	356
	357	write_lock_bh(&call->state_lock);
	358	switch (call->state) {
	359	case RXRPC_CALL_SERVER_ACCEPTING:
	360	call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
	361	break;
	362	case RXRPC_CALL_REMOTELY_ABORTED:
	363	case RXRPC_CALL_LOCALLY_ABORTED:
	364	ret = -ECONNABORTED;
	365	goto out_release;
	366	case RXRPC_CALL_NETWORK_ERROR:
	367	ret = call->conn->error;
	368	goto out_release;
	369	case RXRPC_CALL_DEAD:
	370	ret = -ETIME;
	371	goto out_discard;
	372	default:
	373	BUG();
	374	}
	375
	376	/* formalise the acceptance */
	377	call->user_call_ID = user_call_ID;
	378	rb_link_node(&call->sock_node, parent, pp);
	379	rb_insert_color(&call->sock_node, &rx->calls);
	380	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
	381	BUG();
	382	if (test_and_set_bit(RXRPC_CALL_ACCEPTED, &call->events))
	383	BUG();
651350d1	384	rxrpc_queue_call(call);
17926a79	385
651350d1	386	rxrpc_get_call(call);
17926a79 DH	387	write_unlock_bh(&call->state_lock);
17926a79 DH	388	write_unlock(&rx->call_lock);
651350d1 DH	389	_leave(" = %p{%d}", call, call->debug_id);
	390	return call;
	391
	392	/* if the call is already dying or dead, then we leave the socket's ref
	393	* on it to be released by rxrpc_dead_call_expired() as induced by
	394	* rxrpc_release_call() */
	395	out_release:
	396	_debug("release %p", call);
	397	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	398	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
	399	rxrpc_queue_call(call);
	400	out_discard:
	401	write_unlock_bh(&call->state_lock);
	402	_debug("discard %p", call);
	403	out:
	404	write_unlock(&rx->call_lock);
	405	_leave(" = %d", ret);
	406	return ERR_PTR(ret);
	407	}
	408
	409	/*
	410	* handle rejectance of a call by userspace
	411	* - reject the call at the front of the queue
	412	*/
	413	int rxrpc_reject_call(struct rxrpc_sock *rx)
	414	{
	415	struct rxrpc_call *call;
	416	int ret;
	417
	418	_enter("");
	419
	420	ASSERT(!irqs_disabled());
	421
	422	write_lock(&rx->call_lock);
	423
	424	ret = -ENODATA;
	425	if (list_empty(&rx->acceptq))
	426	goto out;
	427
	428	/* dequeue the first call and check it's still valid */
	429	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	430	list_del_init(&call->accept_link);
	431	sk_acceptq_removed(&rx->sk);
	432
	433	write_lock_bh(&call->state_lock);
	434	switch (call->state) {
	435	case RXRPC_CALL_SERVER_ACCEPTING:
	436	call->state = RXRPC_CALL_SERVER_BUSY;
	437	if (test_and_set_bit(RXRPC_CALL_REJECT_BUSY, &call->events))
	438	rxrpc_queue_call(call);
	439	ret = 0;
	440	goto out_release;
	441	case RXRPC_CALL_REMOTELY_ABORTED:
	442	case RXRPC_CALL_LOCALLY_ABORTED:
	443	ret = -ECONNABORTED;
	444	goto out_release;
	445	case RXRPC_CALL_NETWORK_ERROR:
	446	ret = call->conn->error;
	447	goto out_release;
	448	case RXRPC_CALL_DEAD:
	449	ret = -ETIME;
	450	goto out_discard;
	451	default:
	452	BUG();
453	}
17926a79 DH	454
	455	/* if the call is already dying or dead, then we leave the socket's ref
	456	* on it to be released by rxrpc_dead_call_expired() as induced by
	457	* rxrpc_release_call() */
	458	out_release:
	459	_debug("release %p", call);
	460	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
	461	!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events))
651350d1	462	rxrpc_queue_call(call);
17926a79 DH	463	out_discard:
	464	write_unlock_bh(&call->state_lock);
	465	_debug("discard %p", call);
	466	out:
	467	write_unlock(&rx->call_lock);
	468	_leave(" = %d", ret);
	469	return ret;
	470	}
651350d1 DH	471
	472	/**
	473	* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
	474	* @sock: The socket on which the impending call is waiting
	475	* @user_call_ID: The tag to attach to the call
	476	*
	477	* Allow a kernel service to accept an incoming call, assuming the incoming
	478	* call is still valid.
	479	*/
	480	struct rxrpc_call rxrpc_kernel_accept_call(struct socket sock,
	481	unsigned long user_call_ID)
	482	{
	483	struct rxrpc_call *call;
	484
	485	_enter(",%lx", user_call_ID);
	486	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	487	_leave(" = %p", call);
	488	return call;
	489	}
	490
	491	EXPORT_SYMBOL(rxrpc_kernel_accept_call);
	492
	493	/**
	494	* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
	495	* @sock: The socket on which the impending call is waiting
	496	*
	497	* Allow a kernel service to reject an incoming call with a BUSY message,
	498	* assuming the incoming call is still valid.
	499	*/
	500	int rxrpc_kernel_reject_call(struct socket *sock)
	501	{
	502	int ret;
	503
	504	_enter("");
	505	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	506	_leave(" = %d", ret);
	507	return ret;
	508	}
	509
	510	EXPORT_SYMBOL(rxrpc_kernel_reject_call);