[mirror_ubuntu-bionic-kernel.git] / net / phonet / af_phonet.c

/*
 * File: af_phonet.c
 *
 * Phonet protocols family
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/unaligned.h>
#include <net/sock.h>

#include <linux/if_phonet.h>
#include <linux/phonet.h>
#include <net/phonet/phonet.h>
#include <net/phonet/pn_dev.h>

/* Transport protocol registration */
static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
static DEFINE_SPINLOCK(proto_tab_lock);

static struct phonet_protocol *phonet_proto_get(int protocol)
{
	struct phonet_protocol *pp;

	if (protocol >= PHONET_NPROTO)
		return NULL;

	spin_lock(&proto_tab_lock);
	pp = proto_tab[protocol];
	if (pp && !try_module_get(pp->prot->owner))
		pp = NULL;
	spin_unlock(&proto_tab_lock);

	return pp;
}

static inline void phonet_proto_put(struct phonet_protocol *pp)
{
	module_put(pp->prot->owner);
}

/* protocol family functions */

static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
{
	struct sock *sk;
	struct pn_sock *pn;
	struct phonet_protocol *pnp;
	int err;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	if (protocol == 0) {
		/* Default protocol selection */
		switch (sock->type) {
		case SOCK_DGRAM:
			protocol = PN_PROTO_PHONET;
			break;
		case SOCK_SEQPACKET:
			protocol = PN_PROTO_PIPE;
			break;
		default:
			return -EPROTONOSUPPORT;
		}
	}

	pnp = phonet_proto_get(protocol);
	if (pnp == NULL &&
	    request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
		pnp = phonet_proto_get(protocol);

	if (pnp == NULL)
		return -EPROTONOSUPPORT;
	if (sock->type != pnp->sock_type) {
		err = -EPROTONOSUPPORT;
		goto out;
	}

	sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
	if (sk == NULL) {
		err = -ENOMEM;
		goto out;
	}

	sock_init_data(sock, sk);
	sock->state = SS_UNCONNECTED;
	sock->ops = pnp->ops;
	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
	sk->sk_protocol = protocol;
	pn = pn_sk(sk);
	pn->sobject = 0;
	pn->resource = 0;
	sk->sk_prot->init(sk);
	err = 0;

out:
	phonet_proto_put(pnp);
	return err;
}

static const struct net_proto_family phonet_proto_family = {
	.family = PF_PHONET,
	.create = pn_socket_create,
	.owner = THIS_MODULE,
};

/* Phonet device header operations */
static int pn_header_create(struct sk_buff *skb, struct net_device *dev,
				unsigned short type, const void *daddr,
				const void *saddr, unsigned len)
{
	u8 *media = skb_push(skb, 1);

	if (type != ETH_P_PHONET)
		return -1;

	if (!saddr)
		saddr = dev->dev_addr;
	*media = *(const u8 *)saddr;
	return 1;
}

static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr)
{
	const u8 *media = skb_mac_header(skb);
	*haddr = *media;
	return 1;
}

struct header_ops phonet_header_ops = {
	.create = pn_header_create,
	.parse = pn_header_parse,
};
EXPORT_SYMBOL(phonet_header_ops);

/*
 * Prepends an ISI header and sends a datagram.
 */
static int pn_send(struct sk_buff *skb, struct net_device *dev,
			u16 dst, u16 src, u8 res, u8 irq)
{
	struct phonethdr *ph;
	int err;

	if (skb->len + 2 > 0xffff /* Phonet length field limit */ ||
	    skb->len + sizeof(struct phonethdr) > dev->mtu) {
		err = -EMSGSIZE;
		goto drop;
	}

	/* Broadcast sending is not implemented */
	if (pn_addr(dst) == PNADDR_BROADCAST) {
		err = -EOPNOTSUPP;
		goto drop;
	}

	skb_reset_transport_header(skb);
	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
	skb_push(skb, sizeof(struct phonethdr));
	skb_reset_network_header(skb);
	ph = pn_hdr(skb);
	ph->pn_rdev = pn_dev(dst);
	ph->pn_sdev = pn_dev(src);
	ph->pn_res = res;
	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
	ph->pn_robj = pn_obj(dst);
	ph->pn_sobj = pn_obj(src);

	skb->protocol = htons(ETH_P_PHONET);
	skb->priority = 0;
	skb->dev = dev;

	if (skb->pkt_type == PACKET_LOOPBACK) {
		skb_reset_mac_header(skb);
		skb_orphan(skb);
		if (irq)
			netif_rx(skb);
		else
			netif_rx_ni(skb);
		err = 0;
	} else {
		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
					NULL, NULL, skb->len);
		if (err < 0) {
			err = -EHOSTUNREACH;
			goto drop;
		}
		err = dev_queue_xmit(skb);
	}

	return err;
drop:
	kfree_skb(skb);
	return err;
}

static int pn_raw_send(const void *data, int len, struct net_device *dev,
			u16 dst, u16 src, u8 res)
{
	struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
	if (skb == NULL)
		return -ENOMEM;

	if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
		skb->pkt_type = PACKET_LOOPBACK;

	skb_reserve(skb, MAX_PHONET_HEADER);
	__skb_put(skb, len);
	skb_copy_to_linear_data(skb, data, len);
	return pn_send(skb, dev, dst, src, res, 1);
}

/*
 * Create a Phonet header for the skb and send it out. Returns
 * non-zero error code if failed. The skb is freed then.
 */
int pn_skb_send(struct sock *sk, struct sk_buff *skb,
		const struct sockaddr_pn *target)
{
	struct net *net = sock_net(sk);
	struct net_device *dev;
	struct pn_sock *pn = pn_sk(sk);
	int err;
	u16 src;
	u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR;

	err = -EHOSTUNREACH;
	if (sk->sk_bound_dev_if)
		dev = dev_get_by_index(net, sk->sk_bound_dev_if);
	else if (phonet_address_lookup(net, daddr) == 0) {
		dev = phonet_device_get(net);
		skb->pkt_type = PACKET_LOOPBACK;
	} else
		dev = phonet_route_output(net, daddr);

	if (!dev || !(dev->flags & IFF_UP))
		goto drop;

	saddr = phonet_address_get(dev, daddr);
	if (saddr == PN_NO_ADDR)
		goto drop;

	src = pn->sobject;
	if (!pn_addr(src))
		src = pn_object(saddr, pn_obj(src));

	err = pn_send(skb, dev, pn_sockaddr_get_object(target),
			src, pn_sockaddr_get_resource(target), 0);
	dev_put(dev);
	return err;

drop:
	kfree_skb(skb);
	if (dev)
		dev_put(dev);
	return err;
}
EXPORT_SYMBOL(pn_skb_send);

/* Do not send an error message in response to an error message */
static inline int can_respond(struct sk_buff *skb)
{
	const struct phonethdr *ph;
	const struct phonetmsg *pm;
	u8 submsg_id;

	if (!pskb_may_pull(skb, 3))
		return 0;

	ph = pn_hdr(skb);
	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
		return 0;
	if (ph->pn_res == PN_COMMGR) /* indications */
		return 0;

	ph = pn_hdr(skb); /* re-acquires the pointer */
	pm = pn_msg(skb);
	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
		return 1;
	submsg_id = (ph->pn_res == PN_PREFIX)
		? pm->pn_e_submsg_id : pm->pn_submsg_id;
	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
		pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
		return 1;
	return 0;
}

static int send_obj_unreachable(struct sk_buff *rskb)
{
	const struct phonethdr *oph = pn_hdr(rskb);
	const struct phonetmsg *opm = pn_msg(rskb);
	struct phonetmsg resp;

	memset(&resp, 0, sizeof(resp));
	resp.pn_trans_id = opm->pn_trans_id;
	resp.pn_msg_id = PN_COMMON_MESSAGE;
	if (oph->pn_res == PN_PREFIX) {
		resp.pn_e_res_id = opm->pn_e_res_id;
		resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
		resp.pn_e_orig_msg_id = opm->pn_msg_id;
		resp.pn_e_status = 0;
	} else {
		resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
		resp.pn_orig_msg_id = opm->pn_msg_id;
		resp.pn_status = 0;
	}
	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
				pn_object(oph->pn_sdev, oph->pn_sobj),
				pn_object(oph->pn_rdev, oph->pn_robj),
				oph->pn_res);
}

static int send_reset_indications(struct sk_buff *rskb)
{
	struct phonethdr *oph = pn_hdr(rskb);
	static const u8 data[4] = {
		0x00 /* trans ID */, 0x10 /* subscribe msg */,
		0x00 /* subscription count */, 0x00 /* dummy */
	};

	return pn_raw_send(data, sizeof(data), rskb->dev,
				pn_object(oph->pn_sdev, 0x00),
				pn_object(oph->pn_rdev, oph->pn_robj),
				PN_COMMGR);
}


/* packet type functions */

/*
 * Stuff received packets to associated sockets.
 * On error, returns non-zero and releases the skb.
 */
static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
			struct packet_type *pkttype,
			struct net_device *orig_dev)
{
	struct net *net = dev_net(dev);
	struct phonethdr *ph;
	struct sockaddr_pn sa;
	u16 len;

	/* check we have at least a full Phonet header */
	if (!pskb_pull(skb, sizeof(struct phonethdr)))
		goto out;

	/* check that the advertised length is correct */
	ph = pn_hdr(skb);
	len = get_unaligned_be16(&ph->pn_length);
	if (len < 2)
		goto out;
	len -= 2;
	if ((len > skb->len) || pskb_trim(skb, len))
		goto out;
	skb_reset_transport_header(skb);

	pn_skb_get_dst_sockaddr(skb, &sa);

	/* check if this is broadcasted */
	if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
		pn_deliver_sock_broadcast(net, skb);
		goto out;
	}

	/* check if we are the destination */
	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
		/* Phonet packet input */
		struct sock *sk = pn_find_sock_by_sa(net, &sa);

		if (sk)
			return sk_receive_skb(sk, skb, 0);

		if (can_respond(skb)) {
			send_obj_unreachable(skb);
			send_reset_indications(skb);
		}
	}

out:
	kfree_skb(skb);
	return NET_RX_DROP;
}

static struct packet_type phonet_packet_type __read_mostly = {
	.type = cpu_to_be16(ETH_P_PHONET),
	.func = phonet_rcv,
};

int __init_or_module phonet_proto_register(int protocol,
						struct phonet_protocol *pp)
{
	int err = 0;

	if (protocol >= PHONET_NPROTO)
		return -EINVAL;

	err = proto_register(pp->prot, 1);
	if (err)
		return err;

	spin_lock(&proto_tab_lock);
	if (proto_tab[protocol])
		err = -EBUSY;
	else
		proto_tab[protocol] = pp;
	spin_unlock(&proto_tab_lock);

	return err;
}
EXPORT_SYMBOL(phonet_proto_register);

void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
{
	spin_lock(&proto_tab_lock);
	BUG_ON(proto_tab[protocol] != pp);
	proto_tab[protocol] = NULL;
	spin_unlock(&proto_tab_lock);
	proto_unregister(pp->prot);
}
EXPORT_SYMBOL(phonet_proto_unregister);

/* Module registration */
static int __init phonet_init(void)
{
	int err;

	err = phonet_device_init();
	if (err)
		return err;

	err = sock_register(&phonet_proto_family);
	if (err) {
		printk(KERN_ALERT
			"phonet protocol family initialization failed\n");
		goto err_sock;
	}

	dev_add_pack(&phonet_packet_type);
	phonet_sysctl_init();

	err = isi_register();
	if (err)
		goto err;
	return 0;

err:
	phonet_sysctl_exit();
	sock_unregister(PF_PHONET);
	dev_remove_pack(&phonet_packet_type);
err_sock:
	phonet_device_exit();
	return err;
}

static void __exit phonet_exit(void)
{
	isi_unregister();
	phonet_sysctl_exit();
	sock_unregister(PF_PHONET);
	dev_remove_pack(&phonet_packet_type);
	phonet_device_exit();
}

module_init(phonet_init);
module_exit(phonet_exit);
MODULE_DESCRIPTION("Phonet protocol stack for Linux");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_PHONET);
Commit	Line	Data
4b07b3f6 RDC	1	/*
	2	* File: af_phonet.c
	3	*
	4	* Phonet protocols family
	5	*
	6	* Copyright (C) 2008 Nokia Corporation.
	7	*
	8	* Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
	9	* Original author: Sakari Ailus <sakari.ailus@nokia.com>
	10	*
	11	* This program is free software; you can redistribute it and/or
	12	* modify it under the terms of the GNU General Public License
	13	* version 2 as published by the Free Software Foundation.
	14	*
	15	* This program is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU General Public License
	21	* along with this program; if not, write to the Free Software
	22	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
	23	* 02110-1301 USA
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/module.h>
	28	#include <asm/unaligned.h>
	29	#include <net/sock.h>
	30
	31	#include <linux/if_phonet.h>
	32	#include <linux/phonet.h>
	33	#include <net/phonet/phonet.h>
f8ff6028	34	#include <net/phonet/pn_dev.h>
4b07b3f6	35
566521d6 AD	36	/* Transport protocol registration */
	37	static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
	38	static DEFINE_SPINLOCK(proto_tab_lock);
	39
	40	static struct phonet_protocol *phonet_proto_get(int protocol)
	41	{
	42	struct phonet_protocol *pp;
	43
	44	if (protocol >= PHONET_NPROTO)
	45	return NULL;
	46
	47	spin_lock(&proto_tab_lock);
	48	pp = proto_tab[protocol];
	49	if (pp && !try_module_get(pp->prot->owner))
	50	pp = NULL;
	51	spin_unlock(&proto_tab_lock);
	52
	53	return pp;
	54	}
	55
	56	static inline void phonet_proto_put(struct phonet_protocol *pp)
	57	{
	58	module_put(pp->prot->owner);
	59	}
4b07b3f6 RDC	60
	61	/* protocol family functions */
	62
	63	static int pn_socket_create(struct net net, struct socket sock, int protocol)
	64	{
ba113a94 RDC	65	struct sock *sk;
ba113a94 RDC	66	struct pn_sock *pn;
4b07b3f6 RDC	67	struct phonet_protocol *pnp;
	68	int err;
	69
4b07b3f6 RDC	70	if (!capable(CAP_SYS_ADMIN))
	71	return -EPERM;
	72
	73	if (protocol == 0) {
	74	/* Default protocol selection */
	75	switch (sock->type) {
	76	case SOCK_DGRAM:
	77	protocol = PN_PROTO_PHONET;
	78	break;
9641458d RDC	79	case SOCK_SEQPACKET:
	80	protocol = PN_PROTO_PIPE;
	81	break;
4b07b3f6 RDC	82	default:
	83	return -EPROTONOSUPPORT;
	84	}
	85	}
	86
	87	pnp = phonet_proto_get(protocol);
25532824 RDC	88	if (pnp == NULL &&
	89	request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
	90	pnp = phonet_proto_get(protocol);
95a5afca	91
4b07b3f6 RDC	92	if (pnp == NULL)
	93	return -EPROTONOSUPPORT;
	94	if (sock->type != pnp->sock_type) {
	95	err = -EPROTONOSUPPORT;
	96	goto out;
	97	}
	98
ba113a94 RDC	99	sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
	100	if (sk == NULL) {
	101	err = -ENOMEM;
	102	goto out;
	103	}
	104
	105	sock_init_data(sock, sk);
	106	sock->state = SS_UNCONNECTED;
	107	sock->ops = pnp->ops;
	108	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
	109	sk->sk_protocol = protocol;
	110	pn = pn_sk(sk);
	111	pn->sobject = 0;
	112	pn->resource = 0;
	113	sk->sk_prot->init(sk);
	114	err = 0;
4b07b3f6 RDC	115
	116	out:
	117	phonet_proto_put(pnp);
	118	return err;
	119	}
	120
ec1b4cf7	121	static const struct net_proto_family phonet_proto_family = {
25532824	122	.family = PF_PHONET,
4b07b3f6 RDC	123	.create = pn_socket_create,
	124	.owner = THIS_MODULE,
	125	};
	126
5f77076d RDC	127	/* Phonet device header operations */
	128	static int pn_header_create(struct sk_buff skb, struct net_device dev,
	129	unsigned short type, const void *daddr,
	130	const void *saddr, unsigned len)
	131	{
	132	u8 *media = skb_push(skb, 1);
	133
	134	if (type != ETH_P_PHONET)
	135	return -1;
	136
	137	if (!saddr)
	138	saddr = dev->dev_addr;
	139	media = (const u8 *)saddr;
	140	return 1;
	141	}
	142
	143	static int pn_header_parse(const struct sk_buff skb, unsigned char haddr)
	144	{
	145	const u8 *media = skb_mac_header(skb);
	146	haddr = media;
	147	return 1;
	148	}
	149
	150	struct header_ops phonet_header_ops = {
	151	.create = pn_header_create,
	152	.parse = pn_header_parse,
	153	};
	154	EXPORT_SYMBOL(phonet_header_ops);
	155
107d0d9b RDC	156	/*
	157	* Prepends an ISI header and sends a datagram.
	158	*/
	159	static int pn_send(struct sk_buff skb, struct net_device dev,
be0c52bf	160	u16 dst, u16 src, u8 res, u8 irq)
107d0d9b RDC	161	{
	162	struct phonethdr *ph;
	163	int err;
	164
ebfe92ca RDC	165	if (skb->len + 2 > 0xffff /* Phonet length field limit */ \|\|
ebfe92ca RDC	166	skb->len + sizeof(struct phonethdr) > dev->mtu) {
107d0d9b RDC	167	err = -EMSGSIZE;
	168	goto drop;
	169	}
	170
18a1166d RDC	171	/* Broadcast sending is not implemented */
	172	if (pn_addr(dst) == PNADDR_BROADCAST) {
	173	err = -EOPNOTSUPP;
	174	goto drop;
	175	}
	176
107d0d9b RDC	177	skb_reset_transport_header(skb);
	178	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
	179	skb_push(skb, sizeof(struct phonethdr));
	180	skb_reset_network_header(skb);
	181	ph = pn_hdr(skb);
	182	ph->pn_rdev = pn_dev(dst);
	183	ph->pn_sdev = pn_dev(src);
	184	ph->pn_res = res;
	185	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
	186	ph->pn_robj = pn_obj(dst);
	187	ph->pn_sobj = pn_obj(src);
	188
	189	skb->protocol = htons(ETH_P_PHONET);
	190	skb->priority = 0;
	191	skb->dev = dev;
	192
aa6c45f3	193	if (skb->pkt_type == PACKET_LOOPBACK) {
107d0d9b	194	skb_reset_mac_header(skb);
107d0d9b	195	skb_orphan(skb);
be0c52bf RDC	196	if (irq)
	197	netif_rx(skb);
	198	else
	199	netif_rx_ni(skb);
107d0d9b RDC	200	err = 0;
	201	} else {
	202	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
	203	NULL, NULL, skb->len);
	204	if (err < 0) {
	205	err = -EHOSTUNREACH;
	206	goto drop;
	207	}
	208	err = dev_queue_xmit(skb);
	209	}
	210
	211	return err;
	212	drop:
	213	kfree_skb(skb);
	214	return err;
	215	}
	216
be0c52bf RDC	217	static int pn_raw_send(const void data, int len, struct net_device dev,
	218	u16 dst, u16 src, u8 res)
	219	{
	220	struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
	221	if (skb == NULL)
	222	return -ENOMEM;
	223
aa6c45f3 RDC	224	if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
	225	skb->pkt_type = PACKET_LOOPBACK;
	226
be0c52bf RDC	227	skb_reserve(skb, MAX_PHONET_HEADER);
	228	__skb_put(skb, len);
	229	skb_copy_to_linear_data(skb, data, len);
	230	return pn_send(skb, dev, dst, src, res, 1);
	231	}
	232
107d0d9b RDC	233	/*
	234	* Create a Phonet header for the skb and send it out. Returns
	235	* non-zero error code if failed. The skb is freed then.
	236	*/
	237	int pn_skb_send(struct sock sk, struct sk_buff skb,
	238	const struct sockaddr_pn *target)
	239	{
aa6c45f3	240	struct net *net = sock_net(sk);
107d0d9b RDC	241	struct net_device *dev;
	242	struct pn_sock *pn = pn_sk(sk);
	243	int err;
	244	u16 src;
	245	u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR;
	246
	247	err = -EHOSTUNREACH;
	248	if (sk->sk_bound_dev_if)
aa6c45f3 RDC	249	dev = dev_get_by_index(net, sk->sk_bound_dev_if);
	250	else if (phonet_address_lookup(net, daddr) == 0) {
	251	dev = phonet_device_get(net);
	252	skb->pkt_type = PACKET_LOOPBACK;
	253	} else
	254	dev = phonet_route_output(net, daddr);
	255
107d0d9b RDC	256	if (!dev \|\| !(dev->flags & IFF_UP))
	257	goto drop;
	258
	259	saddr = phonet_address_get(dev, daddr);
	260	if (saddr == PN_NO_ADDR)
	261	goto drop;
	262
	263	src = pn->sobject;
	264	if (!pn_addr(src))
	265	src = pn_object(saddr, pn_obj(src));
	266
	267	err = pn_send(skb, dev, pn_sockaddr_get_object(target),
be0c52bf	268	src, pn_sockaddr_get_resource(target), 0);
107d0d9b RDC	269	dev_put(dev);
	270	return err;
	271
	272	drop:
	273	kfree_skb(skb);
	274	if (dev)
	275	dev_put(dev);
	276	return err;
	277	}
	278	EXPORT_SYMBOL(pn_skb_send);
	279
be0c52bf RDC	280	/* Do not send an error message in response to an error message */
	281	static inline int can_respond(struct sk_buff *skb)
	282	{
	283	const struct phonethdr *ph;
	284	const struct phonetmsg *pm;
	285	u8 submsg_id;
	286
	287	if (!pskb_may_pull(skb, 3))
	288	return 0;
	289
	290	ph = pn_hdr(skb);
be0c52bf RDC	291	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
be0c52bf RDC	292	return 0;
c3a90c78 RDC	293	if (ph->pn_res == PN_COMMGR) /* indications */
c3a90c78 RDC	294	return 0;
be0c52bf RDC	295
	296	ph = pn_hdr(skb); /* re-acquires the pointer */
	297	pm = pn_msg(skb);
	298	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
	299	return 1;
	300	submsg_id = (ph->pn_res == PN_PREFIX)
	301	? pm->pn_e_submsg_id : pm->pn_submsg_id;
	302	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
	303	pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
	304	return 1;
	305	return 0;
	306	}
	307
	308	static int send_obj_unreachable(struct sk_buff *rskb)
	309	{
	310	const struct phonethdr *oph = pn_hdr(rskb);
	311	const struct phonetmsg *opm = pn_msg(rskb);
	312	struct phonetmsg resp;
	313
	314	memset(&resp, 0, sizeof(resp));
	315	resp.pn_trans_id = opm->pn_trans_id;
	316	resp.pn_msg_id = PN_COMMON_MESSAGE;
	317	if (oph->pn_res == PN_PREFIX) {
	318	resp.pn_e_res_id = opm->pn_e_res_id;
	319	resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	320	resp.pn_e_orig_msg_id = opm->pn_msg_id;
	321	resp.pn_e_status = 0;
	322	} else {
	323	resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	324	resp.pn_orig_msg_id = opm->pn_msg_id;
	325	resp.pn_status = 0;
	326	}
	327	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
	328	pn_object(oph->pn_sdev, oph->pn_sobj),
	329	pn_object(oph->pn_rdev, oph->pn_robj),
	330	oph->pn_res);
	331	}
	332
	333	static int send_reset_indications(struct sk_buff *rskb)
	334	{
	335	struct phonethdr *oph = pn_hdr(rskb);
	336	static const u8 data[4] = {
	337	0x00 /* trans ID /, 0x10 / subscribe msg */,
	338	0x00 /* subscription count /, 0x00 / dummy */
	339	};
	340
	341	return pn_raw_send(data, sizeof(data), rskb->dev,
	342	pn_object(oph->pn_sdev, 0x00),
c3a90c78 RDC	343	pn_object(oph->pn_rdev, oph->pn_robj),
c3a90c78 RDC	344	PN_COMMGR);
be0c52bf RDC	345	}
	346
	347
4b07b3f6 RDC	348	/* packet type functions */
	349
	350	/*
	351	* Stuff received packets to associated sockets.
	352	* On error, returns non-zero and releases the skb.
	353	*/
	354	static int phonet_rcv(struct sk_buff skb, struct net_device dev,
	355	struct packet_type *pkttype,
	356	struct net_device *orig_dev)
	357	{
4b8f704b	358	struct net *net = dev_net(dev);
4b07b3f6 RDC	359	struct phonethdr *ph;
	360	struct sockaddr_pn sa;
	361	u16 len;
	362
4b07b3f6 RDC	363	/* check we have at least a full Phonet header */
	364	if (!pskb_pull(skb, sizeof(struct phonethdr)))
	365	goto out;
	366
	367	/* check that the advertised length is correct */
	368	ph = pn_hdr(skb);
	369	len = get_unaligned_be16(&ph->pn_length);
	370	if (len < 2)
	371	goto out;
	372	len -= 2;
	373	if ((len > skb->len) \|\| pskb_trim(skb, len))
	374	goto out;
	375	skb_reset_transport_header(skb);
	376
	377	pn_skb_get_dst_sockaddr(skb, &sa);
4b07b3f6	378
f14001fc RDC	379	/* check if this is broadcasted */
	380	if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
	381	pn_deliver_sock_broadcast(net, skb);
	382	goto out;
	383	}
	384
4b8f704b	385	/* check if we are the destination */
	386	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
	387	/* Phonet packet input */
	388	struct sock *sk = pn_find_sock_by_sa(net, &sa);
	389
	390	if (sk)
	391	return sk_receive_skb(sk, skb, 0);
	392
be0c52bf RDC	393	if (can_respond(skb)) {
	394	send_obj_unreachable(skb);
	395	send_reset_indications(skb);
	396	}
be0c52bf	397	}
ba113a94	398
4b07b3f6 RDC	399	out:
	400	kfree_skb(skb);
	401	return NET_RX_DROP;
	402	}
	403
7546dd97	404	static struct packet_type phonet_packet_type __read_mostly = {
09640e63	405	.type = cpu_to_be16(ETH_P_PHONET),
4b07b3f6 RDC	406	.func = phonet_rcv,
	407	};
	408
4b07b3f6 RDC	409	int __init_or_module phonet_proto_register(int protocol,
	410	struct phonet_protocol *pp)
	411	{
	412	int err = 0;
	413
	414	if (protocol >= PHONET_NPROTO)
	415	return -EINVAL;
	416
	417	err = proto_register(pp->prot, 1);
	418	if (err)
	419	return err;
	420
	421	spin_lock(&proto_tab_lock);
	422	if (proto_tab[protocol])
	423	err = -EBUSY;
	424	else
	425	proto_tab[protocol] = pp;
	426	spin_unlock(&proto_tab_lock);
	427
	428	return err;
	429	}
	430	EXPORT_SYMBOL(phonet_proto_register);
	431
	432	void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
	433	{
	434	spin_lock(&proto_tab_lock);
	435	BUG_ON(proto_tab[protocol] != pp);
	436	proto_tab[protocol] = NULL;
	437	spin_unlock(&proto_tab_lock);
	438	proto_unregister(pp->prot);
	439	}
	440	EXPORT_SYMBOL(phonet_proto_unregister);
	441
4b07b3f6 RDC	442	/* Module registration */
	443	static int __init phonet_init(void)
	444	{
	445	int err;
	446
76e02cf6	447	err = phonet_device_init();
	448	if (err)
	449	return err;
	450
4b07b3f6 RDC	451	err = sock_register(&phonet_proto_family);
	452	if (err) {
	453	printk(KERN_ALERT
	454	"phonet protocol family initialization failed\n");
76e02cf6	455	goto err_sock;
4b07b3f6 RDC	456	}
	457
	458	dev_add_pack(&phonet_packet_type);
87ab4e20	459	phonet_sysctl_init();
107d0d9b RDC	460
	461	err = isi_register();
	462	if (err)
	463	goto err;
4b07b3f6	464	return 0;
107d0d9b RDC	465
107d0d9b RDC	466	err:
87ab4e20	467	phonet_sysctl_exit();
25532824	468	sock_unregister(PF_PHONET);
107d0d9b	469	dev_remove_pack(&phonet_packet_type);
76e02cf6	470	err_sock:
107d0d9b RDC	471	phonet_device_exit();
107d0d9b RDC	472	return err;
4b07b3f6 RDC	473	}
	474
	475	static void __exit phonet_exit(void)
	476	{
107d0d9b	477	isi_unregister();
87ab4e20	478	phonet_sysctl_exit();
25532824	479	sock_unregister(PF_PHONET);
4b07b3f6	480	dev_remove_pack(&phonet_packet_type);
f8ff6028	481	phonet_device_exit();
4b07b3f6 RDC	482	}
	483
	484	module_init(phonet_init);
	485	module_exit(phonet_exit);
	486	MODULE_DESCRIPTION("Phonet protocol stack for Linux");
	487	MODULE_LICENSE("GPL");
25532824	488	MODULE_ALIAS_NETPROTO(PF_PHONET);