[mirror_ubuntu-bionic-kernel.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_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;

	conn = rxrpc_incoming_connection(local, srx, skb);
	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_SERVICE_UNSECURED) {
			_debug("await conn sec");
			list_add_tail(&call->accept_link, &rx->secureq);
			call->conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
			set_bit(RXRPC_CONN_EV_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);
			atomic_inc(&call->skb_count);
			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);

	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
		goto drop;

	/* 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;

drop:
	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	77	struct rxrpc_skb_priv sp, nsp;
17926a79 DH	78	struct rxrpc_call *call;
	79	struct sk_buff *notification;
	80	int ret;
	81
	82	_enter("");
	83
	84	sp = rxrpc_skb(skb);
	85
	86	/* get a notification message to send to the server app */
	87	notification = alloc_skb(0, GFP_NOFS);
c3824d21 TH	88	if (!notification) {
	89	_debug("no memory");
	90	ret = -ENOMEM;
	91	goto error_nofree;
	92	}
17926a79 DH	93	rxrpc_new_skb(notification);
	94	notification->mark = RXRPC_SKB_MARK_NEW_CALL;
	95
d991b4a3	96	conn = rxrpc_incoming_connection(local, srx, skb);
17926a79 DH	97	if (IS_ERR(conn)) {
	98	_debug("no conn");
	99	ret = PTR_ERR(conn);
	100	goto error;
	101	}
	102
42886ffe	103	call = rxrpc_incoming_call(rx, conn, skb);
17926a79 DH	104	rxrpc_put_connection(conn);
	105	if (IS_ERR(call)) {
	106	_debug("no call");
	107	ret = PTR_ERR(call);
	108	goto error;
	109	}
	110
	111	/* attach the call to the socket */
	112	read_lock_bh(&local->services_lock);
	113	if (rx->sk.sk_state == RXRPC_CLOSE)
	114	goto invalid_service;
	115
	116	write_lock(&rx->call_lock);
	117	if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) {
	118	rxrpc_get_call(call);
	119
	120	spin_lock(&call->conn->state_lock);
	121	if (sp->hdr.securityIndex > 0 &&
bba304db	122	call->conn->state == RXRPC_CONN_SERVICE_UNSECURED) {
17926a79 DH	123	_debug("await conn sec");
17926a79 DH	124	list_add_tail(&call->accept_link, &rx->secureq);
bba304db	125	call->conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
bba304db	126	set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
651350d1	127	rxrpc_queue_conn(call->conn);
17926a79 DH	128	} else {
	129	_debug("conn ready");
	130	call->state = RXRPC_CALL_SERVER_ACCEPTING;
	131	list_add_tail(&call->accept_link, &rx->acceptq);
	132	rxrpc_get_call(call);
372ee163	133	atomic_inc(&call->skb_count);
17926a79 DH	134	nsp = rxrpc_skb(notification);
	135	nsp->call = call;
	136
	137	ASSERTCMP(atomic_read(&call->usage), >=, 3);
	138
	139	_debug("notify");
	140	spin_lock(&call->lock);
	141	ret = rxrpc_queue_rcv_skb(call, notification, true,
	142	false);
	143	spin_unlock(&call->lock);
	144	notification = NULL;
163e3cb7	145	BUG_ON(ret < 0);
17926a79 DH	146	}
	147	spin_unlock(&call->conn->state_lock);
	148
	149	_debug("queued");
	150	}
	151	write_unlock(&rx->call_lock);
	152
	153	_debug("process");
	154	rxrpc_fast_process_packet(call, skb);
	155
	156	_debug("done");
	157	read_unlock_bh(&local->services_lock);
	158	rxrpc_free_skb(notification);
	159	rxrpc_put_call(call);
	160	_leave(" = 0");
	161	return 0;
	162
	163	invalid_service:
	164	_debug("invalid");
	165	read_unlock_bh(&local->services_lock);
	166
	167	read_lock_bh(&call->state_lock);
e721498a	168	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	169	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) {
17926a79	170	rxrpc_get_call(call);
651350d1	171	rxrpc_queue_call(call);
17926a79 DH	172	}
	173	read_unlock_bh(&call->state_lock);
	174	rxrpc_put_call(call);
	175	ret = -ECONNREFUSED;
	176	error:
	177	rxrpc_free_skb(notification);
c3824d21	178	error_nofree:
17926a79 DH	179	_leave(" = %d", ret);
	180	return ret;
	181	}
	182
	183	/*
	184	* accept incoming calls that need peer, transport and/or connection setting up
	185	* - the packets we get are all incoming client DATA packets that have seq == 1
	186	*/
4f95dd78	187	void rxrpc_accept_incoming_calls(struct rxrpc_local *local)
17926a79	188	{
17926a79 DH	189	struct rxrpc_skb_priv *sp;
	190	struct sockaddr_rxrpc srx;
	191	struct rxrpc_sock *rx;
0d12f8a4	192	struct rxrpc_wire_header whdr;
17926a79	193	struct sk_buff *skb;
17926a79 DH	194	int ret;
	195
	196	_enter("%d", local->debug_id);
	197
17926a79 DH	198	skb = skb_dequeue(&local->accept_queue);
17926a79 DH	199	if (!skb) {
17926a79 DH	200	_leave("\n");
	201	return;
	202	}
	203
	204	_net("incoming call skb %p", skb);
	205
	206	sp = rxrpc_skb(skb);
	207
0d12f8a4 DH	208	/* Set up a response packet header in case we need it */
	209	whdr.epoch = htonl(sp->hdr.epoch);
	210	whdr.cid = htonl(sp->hdr.cid);
	211	whdr.callNumber = htonl(sp->hdr.callNumber);
	212	whdr.seq = htonl(sp->hdr.seq);
	213	whdr.serial = 0;
	214	whdr.flags = 0;
	215	whdr.type = 0;
	216	whdr.userStatus = 0;
	217	whdr.securityIndex = sp->hdr.securityIndex;
	218	whdr._rsvd = 0;
	219	whdr.serviceId = htons(sp->hdr.serviceId);
	220
d991b4a3 DH	221	if (rxrpc_extract_addr_from_skb(&srx, skb) < 0)
d991b4a3 DH	222	goto drop;
17926a79 DH	223
17926a79 DH	224	/* get the socket providing the service */
17926a79 DH	225	read_lock_bh(&local->services_lock);
17926a79 DH	226	list_for_each_entry(rx, &local->services, listen_link) {
0d12f8a4	227	if (rx->srx.srx_service == sp->hdr.serviceId &&
17926a79 DH	228	rx->sk.sk_state != RXRPC_CLOSE)
	229	goto found_service;
	230	}
	231	read_unlock_bh(&local->services_lock);
	232	goto invalid_service;
	233
	234	found_service:
0d12f8a4	235	_debug("found service %hd", rx->srx.srx_service);
17926a79 DH	236	if (sk_acceptq_is_full(&rx->sk))
	237	goto backlog_full;
	238	sk_acceptq_added(&rx->sk);
	239	sock_hold(&rx->sk);
	240	read_unlock_bh(&local->services_lock);
	241
	242	ret = rxrpc_accept_incoming_call(local, rx, skb, &srx);
	243	if (ret < 0)
	244	sk_acceptq_removed(&rx->sk);
	245	sock_put(&rx->sk);
	246	switch (ret) {
	247	case -ECONNRESET: /* old calls are ignored */
	248	case -ECONNABORTED: /* aborted calls are reaborted or ignored */
	249	case 0:
4f95dd78	250	return;
17926a79 DH	251	case -ECONNREFUSED:
	252	goto invalid_service;
	253	case -EBUSY:
	254	goto busy;
	255	case -EKEYREJECTED:
	256	goto security_mismatch;
	257	default:
	258	BUG();
	259	}
	260
	261	backlog_full:
	262	read_unlock_bh(&local->services_lock);
	263	busy:
0d12f8a4	264	rxrpc_busy(local, &srx, &whdr);
17926a79	265	rxrpc_free_skb(skb);
4f95dd78	266	return;
17926a79	267
d991b4a3 DH	268	drop:
	269	rxrpc_free_skb(skb);
	270	return;
	271
17926a79 DH	272	invalid_service:
	273	skb->priority = RX_INVALID_OPERATION;
	274	rxrpc_reject_packet(local, skb);
4f95dd78	275	return;
17926a79 DH	276
	277	/* can't change connection security type mid-flow */
	278	security_mismatch:
	279	skb->priority = RX_PROTOCOL_ERROR;
	280	rxrpc_reject_packet(local, skb);
4f95dd78	281	return;
17926a79 DH	282	}
	283
	284	/*
	285	* handle acceptance of a call by userspace
	286	* - assign the user call ID to the call at the front of the queue
	287	*/
651350d1 DH	288	struct rxrpc_call rxrpc_accept_call(struct rxrpc_sock rx,
651350d1 DH	289	unsigned long user_call_ID)
17926a79 DH	290	{
	291	struct rxrpc_call *call;
	292	struct rb_node parent, *pp;
	293	int ret;
	294
	295	_enter(",%lx", user_call_ID);
	296
	297	ASSERT(!irqs_disabled());
	298
	299	write_lock(&rx->call_lock);
	300
	301	ret = -ENODATA;
	302	if (list_empty(&rx->acceptq))
	303	goto out;
	304
	305	/* check the user ID isn't already in use */
	306	ret = -EBADSLT;
	307	pp = &rx->calls.rb_node;
	308	parent = NULL;
	309	while (*pp) {
	310	parent = *pp;
	311	call = rb_entry(parent, struct rxrpc_call, sock_node);
	312
	313	if (user_call_ID < call->user_call_ID)
	314	pp = &(*pp)->rb_left;
	315	else if (user_call_ID > call->user_call_ID)
	316	pp = &(*pp)->rb_right;
	317	else
	318	goto out;
	319	}
	320
	321	/* dequeue the first call and check it's still valid */
	322	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	323	list_del_init(&call->accept_link);
	324	sk_acceptq_removed(&rx->sk);
	325
	326	write_lock_bh(&call->state_lock);
	327	switch (call->state) {
	328	case RXRPC_CALL_SERVER_ACCEPTING:
	329	call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
	330	break;
	331	case RXRPC_CALL_REMOTELY_ABORTED:
	332	case RXRPC_CALL_LOCALLY_ABORTED:
	333	ret = -ECONNABORTED;
	334	goto out_release;
	335	case RXRPC_CALL_NETWORK_ERROR:
	336	ret = call->conn->error;
	337	goto out_release;
	338	case RXRPC_CALL_DEAD:
	339	ret = -ETIME;
	340	goto out_discard;
	341	default:
	342	BUG();
	343	}
	344
	345	/* formalise the acceptance */
	346	call->user_call_ID = user_call_ID;
	347	rb_link_node(&call->sock_node, parent, pp);
	348	rb_insert_color(&call->sock_node, &rx->calls);
	349	if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
	350	BUG();
4c198ad1	351	if (test_and_set_bit(RXRPC_CALL_EV_ACCEPTED, &call->events))
17926a79	352	BUG();
651350d1	353	rxrpc_queue_call(call);
17926a79	354
651350d1	355	rxrpc_get_call(call);
17926a79 DH	356	write_unlock_bh(&call->state_lock);
17926a79 DH	357	write_unlock(&rx->call_lock);
651350d1 DH	358	_leave(" = %p{%d}", call, call->debug_id);
	359	return call;
	360
	361	/* if the call is already dying or dead, then we leave the socket's ref
	362	* on it to be released by rxrpc_dead_call_expired() as induced by
	363	* rxrpc_release_call() */
	364	out_release:
	365	_debug("release %p", call);
	366	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	367	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
651350d1 DH	368	rxrpc_queue_call(call);
	369	out_discard:
	370	write_unlock_bh(&call->state_lock);
	371	_debug("discard %p", call);
	372	out:
	373	write_unlock(&rx->call_lock);
	374	_leave(" = %d", ret);
	375	return ERR_PTR(ret);
	376	}
	377
	378	/*
b4f1342f	379	* Handle rejection of a call by userspace
651350d1 DH	380	* - reject the call at the front of the queue
	381	*/
	382	int rxrpc_reject_call(struct rxrpc_sock *rx)
	383	{
	384	struct rxrpc_call *call;
	385	int ret;
	386
	387	_enter("");
	388
	389	ASSERT(!irqs_disabled());
	390
	391	write_lock(&rx->call_lock);
	392
	393	ret = -ENODATA;
	394	if (list_empty(&rx->acceptq))
	395	goto out;
	396
	397	/* dequeue the first call and check it's still valid */
	398	call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
	399	list_del_init(&call->accept_link);
	400	sk_acceptq_removed(&rx->sk);
	401
	402	write_lock_bh(&call->state_lock);
	403	switch (call->state) {
	404	case RXRPC_CALL_SERVER_ACCEPTING:
	405	call->state = RXRPC_CALL_SERVER_BUSY;
4c198ad1	406	if (test_and_set_bit(RXRPC_CALL_EV_REJECT_BUSY, &call->events))
651350d1 DH	407	rxrpc_queue_call(call);
	408	ret = 0;
	409	goto out_release;
	410	case RXRPC_CALL_REMOTELY_ABORTED:
	411	case RXRPC_CALL_LOCALLY_ABORTED:
	412	ret = -ECONNABORTED;
	413	goto out_release;
	414	case RXRPC_CALL_NETWORK_ERROR:
	415	ret = call->conn->error;
	416	goto out_release;
	417	case RXRPC_CALL_DEAD:
	418	ret = -ETIME;
	419	goto out_discard;
	420	default:
	421	BUG();
	422	}
17926a79 DH	423
	424	/* if the call is already dying or dead, then we leave the socket's ref
	425	* on it to be released by rxrpc_dead_call_expired() as induced by
	426	* rxrpc_release_call() */
	427	out_release:
	428	_debug("release %p", call);
	429	if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
4c198ad1	430	!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
651350d1	431	rxrpc_queue_call(call);
17926a79 DH	432	out_discard:
	433	write_unlock_bh(&call->state_lock);
	434	_debug("discard %p", call);
	435	out:
	436	write_unlock(&rx->call_lock);
	437	_leave(" = %d", ret);
	438	return ret;
	439	}
651350d1 DH	440
	441	/**
	442	* rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call
	443	* @sock: The socket on which the impending call is waiting
	444	* @user_call_ID: The tag to attach to the call
	445	*
	446	* Allow a kernel service to accept an incoming call, assuming the incoming
	447	* call is still valid.
	448	*/
	449	struct rxrpc_call rxrpc_kernel_accept_call(struct socket sock,
	450	unsigned long user_call_ID)
	451	{
	452	struct rxrpc_call *call;
	453
	454	_enter(",%lx", user_call_ID);
	455	call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID);
	456	_leave(" = %p", call);
	457	return call;
	458	}
651350d1 DH	459	EXPORT_SYMBOL(rxrpc_kernel_accept_call);
	460
	461	/**
	462	* rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call
	463	* @sock: The socket on which the impending call is waiting
	464	*
	465	* Allow a kernel service to reject an incoming call with a BUSY message,
	466	* assuming the incoming call is still valid.
	467	*/
	468	int rxrpc_kernel_reject_call(struct socket *sock)
	469	{
	470	int ret;
	471
	472	_enter("");
	473	ret = rxrpc_reject_call(rxrpc_sk(sock->sk));
	474	_leave(" = %d", ret);
	475	return ret;
	476	}
651350d1	477	EXPORT_SYMBOL(rxrpc_kernel_reject_call);