[deliverable/linux.git] / net / rxrpc / call_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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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_wire_header *whdr)
{
	struct msghdr msg;
	struct kvec iov[1];
	size_t len;
	int ret;

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

	whdr->type	= RXRPC_PACKET_TYPE_BUSY;
	whdr->serial	= htonl(1);

	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;

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

	len = iov[0].iov_len;

	_proto("Tx BUSY %%1");

	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_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_lookup_peer(local, srx, GFP_NOIO);
	if (!peer) {
		_debug("no peer");
		ret = -EBUSY;
		goto error;
	}

	conn = rxrpc_incoming_connection(local, peer, skb);
	rxrpc_put_peer(peer);
	if (IS_ERR(conn)) {
		_debug("no conn");
		ret = PTR_ERR(conn);
		goto error;
	}

	call = rxrpc_incoming_call(rx, conn, skb);
	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;
			rxrpc_get_connection(call->conn);
			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_RELEASED, &call->flags) &&
	    !test_and_set_bit(RXRPC_CALL_EV_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 rxrpc_local *local)
{
	struct rxrpc_skb_priv *sp;
	struct sockaddr_rxrpc srx;
	struct rxrpc_sock *rx;
	struct rxrpc_wire_header whdr;
	struct sk_buff *skb;
	int ret;

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

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

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

	sp = rxrpc_skb(skb);

	/* Set up a response packet header in case we need it */
	whdr.epoch	= htonl(sp->hdr.epoch);
	whdr.cid	= htonl(sp->hdr.cid);
	whdr.callNumber	= htonl(sp->hdr.callNumber);
	whdr.seq	= htonl(sp->hdr.seq);
	whdr.serial	= 0;
	whdr.flags	= 0;
	whdr.type	= 0;
	whdr.userStatus	= 0;
	whdr.securityIndex = sp->hdr.securityIndex;
	whdr._rsvd	= 0;
	whdr.serviceId	= htons(sp->hdr.serviceId);

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

found_service:
	_debug("found service %hd", rx->srx.srx_service);
	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:
		return;
	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, &whdr);
	rxrpc_free_skb(skb);
	return;

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

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

/*
 * 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_EV_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_EV_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 rejection 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_EV_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_EV_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
9b6d5398 JP	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9b6d5398 JP	13
17926a79 DH	14	#include <linux/module.h>
	15	#include <linux/net.h>
	16	#include <linux/skbuff.h>
	17	#include <linux/errqueue.h>
	18	#include <linux/udp.h>
	19	#include <linux/in.h>
	20	#include <linux/in6.h>
	21	#include <linux/icmp.h>
5a0e3ad6	22	#include <linux/gfp.h>
17926a79 DH	23	#include <net/sock.h>
	24	#include <net/af_rxrpc.h>
	25	#include <net/ip.h>
	26	#include "ar-internal.h"
	27
	28	/*
	29	* generate a connection-level abort
	30	*/
	31	static int rxrpc_busy(struct rxrpc_local local, struct sockaddr_rxrpc srx,
0d12f8a4	32	struct rxrpc_wire_header *whdr)
17926a79 DH	33	{
	34	struct msghdr msg;
	35	struct kvec iov[1];
	36	size_t len;
	37	int ret;
	38
	39	_enter("%d,,", local->debug_id);
	40
0d12f8a4 DH	41	whdr->type = RXRPC_PACKET_TYPE_BUSY;
	42	whdr->serial = htonl(1);
	43
17926a79 DH	44	msg.msg_name = &srx->transport.sin;
	45	msg.msg_namelen = sizeof(srx->transport.sin);
	46	msg.msg_control = NULL;
	47	msg.msg_controllen = 0;
	48	msg.msg_flags = 0;
	49
0d12f8a4 DH	50	iov[0].iov_base = whdr;
0d12f8a4 DH	51	iov[0].iov_len = sizeof(*whdr);
17926a79 DH	52
	53	len = iov[0].iov_len;
	54
0d12f8a4	55	_proto("Tx BUSY %%1");
17926a79 DH	56
	57	ret = kernel_sendmsg(local->socket, &msg, iov, 1, len);
	58	if (ret < 0) {
	59	_leave(" = -EAGAIN [sendmsg failed: %d]", ret);
	60	return -EAGAIN;
	61	}
	62
	63	_leave(" = 0");
	64	return 0;
	65	}
	66
	67	/*
	68	* accept an incoming call that needs peer, transport and/or connection setting
	69	* up
	70	*/
	71	static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
	72	struct rxrpc_sock *rx,
	73	struct sk_buff *skb,
	74	struct sockaddr_rxrpc *srx)
	75	{
	76	struct rxrpc_connection *conn;
17926a79 DH	77	struct rxrpc_skb_priv sp, nsp;
	78	struct rxrpc_peer *peer;
	79	struct rxrpc_call *call;
	80	struct sk_buff *notification;
	81	int ret;
	82
	83	_enter("");
	84
	85	sp = rxrpc_skb(skb);
	86
	87	/* get a notification message to send to the server app */
	88	notification = alloc_skb(0, GFP_NOFS);
c3824d21 TH	89	if (!notification) {
	90	_debug("no memory");
	91	ret = -ENOMEM;
	92	goto error_nofree;
	93	}
17926a79 DH	94	rxrpc_new_skb(notification);
	95	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
	96
be6e6707	97	peer = rxrpc_lookup_peer(local, srx, GFP_NOIO);
0e4699e4	98	if (!peer) {
17926a79 DH	99	_debug("no peer");
	100	ret = -EBUSY;
	101	goto error;
	102	}
	103
aa390bbe	104	conn = rxrpc_incoming_connection(local, peer, skb);
17926a79	105	rxrpc_put_peer(peer);
17926a79 DH	106	if (IS_ERR(conn)) {
	107	_debug("no conn");
	108	ret = PTR_ERR(conn);
	109	goto error;
	110	}
	111
42886ffe	112	call = rxrpc_incoming_call(rx, conn, skb);
17926a79 DH	113	rxrpc_put_connection(conn);
	114	if (IS_ERR(call)) {
	115	_debug("no call");
	116	ret = PTR_ERR(call);
	117	goto error;
	118	}
	119
	120	/* attach the call to the socket */
	121	read_lock_bh(&local->services_lock);
	122	if (rx->sk.sk_state == RXRPC_CLOSE)
	123	goto invalid_service;
	124
	125	write_lock(&rx->call_lock);
	126	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
	127	rxrpc_get_call(call);
	128
	129	spin_lock(&call->conn->state_lock);
	130	if (sp->hdr.securityIndex > 0 &&
	131	call->conn->state == RXRPC_CONN_SERVER_UNSECURED) {
	132	_debug("await conn sec");
	133	list_add_tail(&call->accept_link, &rx->secureq);
	134	call->conn->state = RXRPC_CONN_SERVER_CHALLENGING;
5627cc8b	135	rxrpc_get_connection(call->conn);
17926a79	136	set_bit(RXRPC_CONN_CHALLENGE, &call->conn->events);
651350d1	137	rxrpc_queue_conn(call->conn);
17926a79 DH	138	} else {
	139	_debug("conn ready");
	140	call->state = RXRPC_CALL_SERVER_ACCEPTING;
	141	list_add_tail(&call->accept_link, &rx->acceptq);
	142	rxrpc_get_call(call);
	143	nsp = rxrpc_skb(notification);
	144	nsp->call = call;
	145
	146	ASSERTCMP(atomic_read(&call->usage), >=, 3);
	147
	148	_debug("notify");
	149	spin_lock(&call->lock);
	150	ret = rxrpc_queue_rcv_skb(call, notification, true,
	151	false);
	152	spin_unlock(&call->lock);
	153	notification = NULL;
163e3cb7	154	BUG_ON(ret < 0);
17926a79 DH	155	}
	156	spin_unlock(&call->conn->state_lock);
	157
	158	_debug("queued");
	159	}
	160	write_unlock(&rx->call_lock);
	161
	162	_debug("process");
	163	rxrpc_fast_process_packet(call, skb);
	164
	165	_debug("done");
	166	read_unlock_bh(&local->services_lock);
	167	rxrpc_free_skb(notification);
	168	rxrpc_put_call(call);
	169	_leave(" = 0");
	170	return 0;
	171
	172	invalid_service:
	173	_debug("invalid");
	174	read_unlock_bh(&local->services_lock);
	175
	176	read_lock_bh(&call->state_lock);
e721498a	177	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	178	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) {
17926a79	179	rxrpc_get_call(call);
651350d1	180	rxrpc_queue_call(call);
17926a79 DH	181	}
	182	read_unlock_bh(&call->state_lock);
	183	rxrpc_put_call(call);
	184	ret = -ECONNREFUSED;
	185	error:
	186	rxrpc_free_skb(notification);
c3824d21	187	error_nofree:
17926a79 DH	188	_leave(" = %d", ret);
	189	return ret;
	190	}
	191
	192	/*
	193	* accept incoming calls that need peer, transport and/or connection setting up
	194	* - the packets we get are all incoming client DATA packets that have seq == 1
	195	*/
4f95dd78	196	void rxrpc_accept_incoming_calls(struct rxrpc_local *local)
17926a79	197	{
17926a79 DH	198	struct rxrpc_skb_priv *sp;
	199	struct sockaddr_rxrpc srx;
	200	struct rxrpc_sock *rx;
0d12f8a4	201	struct rxrpc_wire_header whdr;
17926a79	202	struct sk_buff *skb;
17926a79 DH	203	int ret;
	204
	205	_enter("%d", local->debug_id);
	206
17926a79 DH	207	skb = skb_dequeue(&local->accept_queue);
17926a79 DH	208	if (!skb) {
17926a79 DH	209	_leave("\n");
	210	return;
	211	}
	212
	213	_net("incoming call skb %p", skb);
	214
	215	sp = rxrpc_skb(skb);
	216
0d12f8a4 DH	217	/* Set up a response packet header in case we need it */
	218	whdr.epoch = htonl(sp->hdr.epoch);
	219	whdr.cid = htonl(sp->hdr.cid);
	220	whdr.callNumber = htonl(sp->hdr.callNumber);
	221	whdr.seq = htonl(sp->hdr.seq);
	222	whdr.serial = 0;
	223	whdr.flags = 0;
	224	whdr.type = 0;
	225	whdr.userStatus = 0;
	226	whdr.securityIndex = sp->hdr.securityIndex;
	227	whdr._rsvd = 0;
	228	whdr.serviceId = htons(sp->hdr.serviceId);
	229
17926a79 DH	230	/* determine the remote address */
	231	memset(&srx, 0, sizeof(srx));
	232	srx.srx_family = AF_RXRPC;
	233	srx.transport.family = local->srx.transport.family;
	234	srx.transport_type = local->srx.transport_type;
	235	switch (srx.transport.family) {
	236	case AF_INET:
	237	srx.transport_len = sizeof(struct sockaddr_in);
	238	srx.transport.sin.sin_port = udp_hdr(skb)->source;
	239	srx.transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
	240	break;
	241	default:
	242	goto busy;
	243	}
	244
	245	/* get the socket providing the service */
17926a79 DH	246	read_lock_bh(&local->services_lock);
17926a79 DH	247	list_for_each_entry(rx, &local->services, listen_link) {
0d12f8a4	248	if (rx->srx.srx_service == sp->hdr.serviceId &&
17926a79 DH	249	rx->sk.sk_state != RXRPC_CLOSE)
	250	goto found_service;
	251	}
	252	read_unlock_bh(&local->services_lock);
	253	goto invalid_service;
	254
	255	found_service:
0d12f8a4	256	_debug("found service %hd", rx->srx.srx_service);
17926a79 DH	257	if (sk_acceptq_is_full(&rx->sk))
	258	goto backlog_full;
	259	sk_acceptq_added(&rx->sk);
	260	sock_hold(&rx->sk);
	261	read_unlock_bh(&local->services_lock);
	262
	263	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
	264	if (ret < 0)
	265	sk_acceptq_removed(&rx->sk);
	266	sock_put(&rx->sk);
	267	switch (ret) {
	268	case -ECONNRESET: /* old calls are ignored */
	269	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
	270	case 0:
4f95dd78	271	return;
17926a79 DH	272	case -ECONNREFUSED:
	273	goto invalid_service;
	274	case -EBUSY:
	275	goto busy;
	276	case -EKEYREJECTED:
	277	goto security_mismatch;
	278	default:
	279	BUG();
	280	}
	281
	282	backlog_full:
	283	read_unlock_bh(&local->services_lock);
	284	busy:
0d12f8a4	285	rxrpc_busy(local, &srx, &whdr);
17926a79	286	rxrpc_free_skb(skb);
4f95dd78	287	return;
17926a79 DH	288
	289	invalid_service:
	290	skb->priority = RX_INVALID_OPERATION;
	291	rxrpc_reject_packet(local, skb);
4f95dd78	292	return;
17926a79 DH	293
	294	/* can't change connection security type mid-flow */
	295	security_mismatch:
	296	skb->priority = RX_PROTOCOL_ERROR;
	297	rxrpc_reject_packet(local, skb);
4f95dd78	298	return;
17926a79 DH	299	}
	300
	301	/*
	302	* handle acceptance of a call by userspace
	303	* - assign the user call ID to the call at the front of the queue
	304	*/
651350d1 DH	305	struct rxrpc_call rxrpc_accept_call(struct rxrpc_sock rx,
651350d1 DH	306	unsigned long user_call_ID)
17926a79 DH	307	{
	308	struct rxrpc_call *call;
	309	struct rb_node parent, *pp;
	310	int ret;
	311
	312	_enter(",%lx", user_call_ID);
	313
	314	ASSERT(!irqs_disabled());
	315
	316	write_lock(&rx->call_lock);
	317
	318	ret = -ENODATA;
	319	if (list_empty(&rx->acceptq))
	320	goto out;
	321
	322	/* check the user ID isn't already in use */
	323	ret = -EBADSLT;
	324	pp = &rx->calls.rb_node;
	325	parent = NULL;
	326	while (*pp) {
	327	parent = *pp;
	328	call = rb_entry(parent, struct rxrpc_call, sock_node);
	329
	330	if (user_call_ID < call->user_call_ID)
	331	pp = &(*pp)->rb_left;
	332	else if (user_call_ID > call->user_call_ID)
	333	pp = &(*pp)->rb_right;
	334	else
	335	goto out;
	336	}
	337
	338	/* dequeue the first call and check it's still valid */
	339	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	340	list_del_init(&call->accept_link);
	341	sk_acceptq_removed(&rx->sk);
	342
	343	write_lock_bh(&call->state_lock);
	344	switch (call->state) {
	345	case RXRPC_CALL_SERVER_ACCEPTING:
	346	call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
	347	break;
	348	case RXRPC_CALL_REMOTELY_ABORTED:
	349	case RXRPC_CALL_LOCALLY_ABORTED:
	350	ret = -ECONNABORTED;
	351	goto out_release;
	352	case RXRPC_CALL_NETWORK_ERROR:
	353	ret = call->conn->error;
	354	goto out_release;
	355	case RXRPC_CALL_DEAD:
	356	ret = -ETIME;
	357	goto out_discard;
	358	default:
	359	BUG();
	360	}
	361
	362	/* formalise the acceptance */
	363	call->user_call_ID = user_call_ID;
	364	rb_link_node(&call->sock_node, parent, pp);
	365	rb_insert_color(&call->sock_node, &rx->calls);
	366	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
	367	BUG();
4c198ad1	368	if (test_and_set_bit(RXRPC_CALL_EV_ACCEPTED, &call->events))
17926a79	369	BUG();
651350d1	370	rxrpc_queue_call(call);
17926a79	371
651350d1	372	rxrpc_get_call(call);
17926a79 DH	373	write_unlock_bh(&call->state_lock);
17926a79 DH	374	write_unlock(&rx->call_lock);
651350d1 DH	375	_leave(" = %p{%d}", call, call->debug_id);
	376	return call;
	377
	378	/* if the call is already dying or dead, then we leave the socket's ref
	379	* on it to be released by rxrpc_dead_call_expired() as induced by
	380	* rxrpc_release_call() */
	381	out_release:
	382	_debug("release %p", call);
	383	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	384	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
651350d1 DH	385	rxrpc_queue_call(call);
	386	out_discard:
	387	write_unlock_bh(&call->state_lock);
	388	_debug("discard %p", call);
	389	out:
	390	write_unlock(&rx->call_lock);
	391	_leave(" = %d", ret);
	392	return ERR_PTR(ret);
	393	}
	394
	395	/*
b4f1342f	396	* Handle rejection of a call by userspace
651350d1 DH	397	* - reject the call at the front of the queue
	398	*/
	399	int rxrpc_reject_call(struct rxrpc_sock *rx)
	400	{
	401	struct rxrpc_call *call;
	402	int ret;
	403
	404	_enter("");
	405
	406	ASSERT(!irqs_disabled());
	407
	408	write_lock(&rx->call_lock);
	409
	410	ret = -ENODATA;
	411	if (list_empty(&rx->acceptq))
	412	goto out;
	413
	414	/* dequeue the first call and check it's still valid */
	415	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	416	list_del_init(&call->accept_link);
	417	sk_acceptq_removed(&rx->sk);
	418
	419	write_lock_bh(&call->state_lock);
	420	switch (call->state) {
	421	case RXRPC_CALL_SERVER_ACCEPTING:
	422	call->state = RXRPC_CALL_SERVER_BUSY;
4c198ad1	423	if (test_and_set_bit(RXRPC_CALL_EV_REJECT_BUSY, &call->events))
651350d1 DH	424	rxrpc_queue_call(call);
	425	ret = 0;
	426	goto out_release;
	427	case RXRPC_CALL_REMOTELY_ABORTED:
	428	case RXRPC_CALL_LOCALLY_ABORTED:
	429	ret = -ECONNABORTED;
	430	goto out_release;
	431	case RXRPC_CALL_NETWORK_ERROR:
	432	ret = call->conn->error;
	433	goto out_release;
	434	case RXRPC_CALL_DEAD:
	435	ret = -ETIME;
	436	goto out_discard;
	437	default:
	438	BUG();
	439	}
17926a79 DH	440
	441	/* if the call is already dying or dead, then we leave the socket's ref
	442	* on it to be released by rxrpc_dead_call_expired() as induced by
	443	* rxrpc_release_call() */
	444	out_release:
	445	_debug("release %p", call);
	446	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	447	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
651350d1	448	rxrpc_queue_call(call);
17926a79 DH	449	out_discard:
	450	write_unlock_bh(&call->state_lock);
	451	_debug("discard %p", call);
	452	out:
	453	write_unlock(&rx->call_lock);
	454	_leave(" = %d", ret);
	455	return ret;
	456	}
651350d1 DH	457
	458	/**
	459	* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
	460	* @sock: The socket on which the impending call is waiting
	461	* @user_call_ID: The tag to attach to the call
	462	*
	463	* Allow a kernel service to accept an incoming call, assuming the incoming
	464	* call is still valid.
	465	*/
	466	struct rxrpc_call rxrpc_kernel_accept_call(struct socket sock,
	467	unsigned long user_call_ID)
	468	{
	469	struct rxrpc_call *call;
	470
	471	_enter(",%lx", user_call_ID);
	472	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	473	_leave(" = %p", call);
	474	return call;
	475	}
651350d1 DH	476	EXPORT_SYMBOL(rxrpc_kernel_accept_call);
	477
	478	/**
	479	* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
	480	* @sock: The socket on which the impending call is waiting
	481	*
	482	* Allow a kernel service to reject an incoming call with a BUSY message,
	483	* assuming the incoming call is still valid.
	484	*/
	485	int rxrpc_kernel_reject_call(struct socket *sock)
	486	{
	487	int ret;
	488
	489	_enter("");
	490	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	491	_leave(" = %d", ret);
	492	return ret;
	493	}
651350d1	494	EXPORT_SYMBOL(rxrpc_kernel_reject_call);