[linux.git] / net / phonet / af_phonet.c

/*
 * File: af_phonet.c
 *
 * Phonet protocols family
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Contact: Remi Denis-Courmont <[email protected]>
 * Original author: Sakari Ailus <[email protected]>
 *
 * 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>

static struct net_proto_family phonet_proto_family;
static struct phonet_protocol *phonet_proto_get(int protocol);

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 (net != &init_net)
		return -EAFNOSUPPORT;

	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 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 would overflow */
		err = -EMSGSIZE;
		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 (pn_addr(src) == pn_addr(dst)) {
		skb_reset_mac_header(skb);
		skb->pkt_type = PACKET_LOOPBACK;
		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;

	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_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(sock_net(sk), sk->sk_bound_dev_if);
	else
		dev = phonet_device_get(sock_net(sk));
	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 (phonet_address_get(skb->dev, ph->pn_rdev) != ph->pn_rdev)
		return 0; /* we are not the destination */
	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 phonethdr *ph;
	struct sock *sk;
	struct sockaddr_pn sa;
	u16 len;

	if (dev_net(dev) != &init_net)
		goto out;

	/* 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);
	if (pn_sockaddr_get_addr(&sa) == 0)
		goto out; /* currently, we cannot be device 0 */

	sk = pn_find_sock_by_sa(&sa);
	if (sk == NULL) {
		if (can_respond(skb)) {
			send_obj_unreachable(skb);
			send_reset_indications(skb);
		}
		goto out;
	}

	/* Push data to the socket (or other sockets connected to it). */
	return sk_receive_skb(sk, skb, 0);

out:
	kfree_skb(skb);
	return NET_RX_DROP;
}

static struct packet_type phonet_packet_type = {
	.type = __constant_htons(ETH_P_PHONET),
	.dev = NULL,
	.func = phonet_rcv,
};

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

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);

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;
}

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

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

	phonet_device_init();
	dev_add_pack(&phonet_packet_type);
	phonet_netlink_register();
	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);
	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 <[email protected]>
	9	* Original author: Sakari Ailus <[email protected]>
	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 RDC	35
	36	static struct net_proto_family phonet_proto_family;
	37	static struct phonet_protocol *phonet_proto_get(int protocol);
5c7f0333 HH	38
	39	static inline void phonet_proto_put(struct phonet_protocol *pp)
	40	{
	41	module_put(pp->prot->owner);
	42	}
4b07b3f6 RDC	43
	44	/* protocol family functions */
	45
	46	static int pn_socket_create(struct net net, struct socket sock, int protocol)
	47	{
ba113a94 RDC	48	struct sock *sk;
ba113a94 RDC	49	struct pn_sock *pn;
4b07b3f6 RDC	50	struct phonet_protocol *pnp;
	51	int err;
	52
	53	if (net != &init_net)
	54	return -EAFNOSUPPORT;
	55
	56	if (!capable(CAP_SYS_ADMIN))
	57	return -EPERM;
	58
	59	if (protocol == 0) {
	60	/* Default protocol selection */
	61	switch (sock->type) {
	62	case SOCK_DGRAM:
	63	protocol = PN_PROTO_PHONET;
	64	break;
9641458d RDC	65	case SOCK_SEQPACKET:
	66	protocol = PN_PROTO_PIPE;
	67	break;
4b07b3f6 RDC	68	default:
	69	return -EPROTONOSUPPORT;
	70	}
	71	}
	72
	73	pnp = phonet_proto_get(protocol);
25532824 RDC	74	if (pnp == NULL &&
	75	request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
	76	pnp = phonet_proto_get(protocol);
95a5afca	77
4b07b3f6 RDC	78	if (pnp == NULL)
	79	return -EPROTONOSUPPORT;
	80	if (sock->type != pnp->sock_type) {
	81	err = -EPROTONOSUPPORT;
	82	goto out;
	83	}
	84
ba113a94 RDC	85	sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
	86	if (sk == NULL) {
	87	err = -ENOMEM;
	88	goto out;
	89	}
	90
	91	sock_init_data(sock, sk);
	92	sock->state = SS_UNCONNECTED;
	93	sock->ops = pnp->ops;
	94	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
	95	sk->sk_protocol = protocol;
	96	pn = pn_sk(sk);
	97	pn->sobject = 0;
	98	pn->resource = 0;
	99	sk->sk_prot->init(sk);
	100	err = 0;
4b07b3f6 RDC	101
	102	out:
	103	phonet_proto_put(pnp);
	104	return err;
	105	}
	106
	107	static struct net_proto_family phonet_proto_family = {
25532824	108	.family = PF_PHONET,
4b07b3f6 RDC	109	.create = pn_socket_create,
	110	.owner = THIS_MODULE,
	111	};
	112
5f77076d RDC	113	/* Phonet device header operations */
	114	static int pn_header_create(struct sk_buff skb, struct net_device dev,
	115	unsigned short type, const void *daddr,
	116	const void *saddr, unsigned len)
	117	{
	118	u8 *media = skb_push(skb, 1);
	119
	120	if (type != ETH_P_PHONET)
	121	return -1;
	122
	123	if (!saddr)
	124	saddr = dev->dev_addr;
	125	media = (const u8 *)saddr;
	126	return 1;
	127	}
	128
	129	static int pn_header_parse(const struct sk_buff skb, unsigned char haddr)
	130	{
	131	const u8 *media = skb_mac_header(skb);
	132	haddr = media;
	133	return 1;
	134	}
	135
	136	struct header_ops phonet_header_ops = {
	137	.create = pn_header_create,
	138	.parse = pn_header_parse,
	139	};
	140	EXPORT_SYMBOL(phonet_header_ops);
	141
107d0d9b RDC	142	/*
	143	* Prepends an ISI header and sends a datagram.
	144	*/
	145	static int pn_send(struct sk_buff skb, struct net_device dev,
be0c52bf	146	u16 dst, u16 src, u8 res, u8 irq)
107d0d9b RDC	147	{
	148	struct phonethdr *ph;
	149	int err;
	150
	151	if (skb->len + 2 > 0xffff) {
	152	/* Phonet length field would overflow */
	153	err = -EMSGSIZE;
	154	goto drop;
	155	}
	156
	157	skb_reset_transport_header(skb);
	158	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
	159	skb_push(skb, sizeof(struct phonethdr));
	160	skb_reset_network_header(skb);
	161	ph = pn_hdr(skb);
	162	ph->pn_rdev = pn_dev(dst);
	163	ph->pn_sdev = pn_dev(src);
	164	ph->pn_res = res;
	165	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
	166	ph->pn_robj = pn_obj(dst);
	167	ph->pn_sobj = pn_obj(src);
	168
	169	skb->protocol = htons(ETH_P_PHONET);
	170	skb->priority = 0;
	171	skb->dev = dev;
	172
	173	if (pn_addr(src) == pn_addr(dst)) {
	174	skb_reset_mac_header(skb);
	175	skb->pkt_type = PACKET_LOOPBACK;
	176	skb_orphan(skb);
be0c52bf RDC	177	if (irq)
	178	netif_rx(skb);
	179	else
	180	netif_rx_ni(skb);
107d0d9b RDC	181	err = 0;
	182	} else {
	183	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
	184	NULL, NULL, skb->len);
	185	if (err < 0) {
	186	err = -EHOSTUNREACH;
	187	goto drop;
	188	}
	189	err = dev_queue_xmit(skb);
	190	}
	191
	192	return err;
	193	drop:
	194	kfree_skb(skb);
	195	return err;
	196	}
	197
be0c52bf RDC	198	static int pn_raw_send(const void data, int len, struct net_device dev,
	199	u16 dst, u16 src, u8 res)
	200	{
	201	struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
	202	if (skb == NULL)
	203	return -ENOMEM;
	204
	205	skb_reserve(skb, MAX_PHONET_HEADER);
	206	__skb_put(skb, len);
	207	skb_copy_to_linear_data(skb, data, len);
	208	return pn_send(skb, dev, dst, src, res, 1);
	209	}
	210
107d0d9b RDC	211	/*
	212	* Create a Phonet header for the skb and send it out. Returns
	213	* non-zero error code if failed. The skb is freed then.
	214	*/
	215	int pn_skb_send(struct sock sk, struct sk_buff skb,
	216	const struct sockaddr_pn *target)
	217	{
	218	struct net_device *dev;
	219	struct pn_sock *pn = pn_sk(sk);
	220	int err;
	221	u16 src;
	222	u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR;
	223
	224	err = -EHOSTUNREACH;
	225	if (sk->sk_bound_dev_if)
	226	dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
	227	else
	228	dev = phonet_device_get(sock_net(sk));
	229	if (!dev \|\| !(dev->flags & IFF_UP))
	230	goto drop;
	231
	232	saddr = phonet_address_get(dev, daddr);
	233	if (saddr == PN_NO_ADDR)
	234	goto drop;
	235
	236	src = pn->sobject;
	237	if (!pn_addr(src))
	238	src = pn_object(saddr, pn_obj(src));
	239
	240	err = pn_send(skb, dev, pn_sockaddr_get_object(target),
be0c52bf	241	src, pn_sockaddr_get_resource(target), 0);
107d0d9b RDC	242	dev_put(dev);
	243	return err;
	244
	245	drop:
	246	kfree_skb(skb);
	247	if (dev)
	248	dev_put(dev);
	249	return err;
	250	}
	251	EXPORT_SYMBOL(pn_skb_send);
	252
be0c52bf RDC	253	/* Do not send an error message in response to an error message */
	254	static inline int can_respond(struct sk_buff *skb)
	255	{
	256	const struct phonethdr *ph;
	257	const struct phonetmsg *pm;
	258	u8 submsg_id;
	259
	260	if (!pskb_may_pull(skb, 3))
	261	return 0;
	262
	263	ph = pn_hdr(skb);
	264	if (phonet_address_get(skb->dev, ph->pn_rdev) != ph->pn_rdev)
	265	return 0; /* we are not the destination */
	266	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
	267	return 0;
c3a90c78 RDC	268	if (ph->pn_res == PN_COMMGR) /* indications */
c3a90c78 RDC	269	return 0;
be0c52bf RDC	270
	271	ph = pn_hdr(skb); /* re-acquires the pointer */
	272	pm = pn_msg(skb);
	273	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
	274	return 1;
	275	submsg_id = (ph->pn_res == PN_PREFIX)
	276	? pm->pn_e_submsg_id : pm->pn_submsg_id;
	277	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
	278	pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
	279	return 1;
	280	return 0;
	281	}
	282
	283	static int send_obj_unreachable(struct sk_buff *rskb)
	284	{
	285	const struct phonethdr *oph = pn_hdr(rskb);
	286	const struct phonetmsg *opm = pn_msg(rskb);
	287	struct phonetmsg resp;
	288
	289	memset(&resp, 0, sizeof(resp));
	290	resp.pn_trans_id = opm->pn_trans_id;
	291	resp.pn_msg_id = PN_COMMON_MESSAGE;
	292	if (oph->pn_res == PN_PREFIX) {
	293	resp.pn_e_res_id = opm->pn_e_res_id;
	294	resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	295	resp.pn_e_orig_msg_id = opm->pn_msg_id;
	296	resp.pn_e_status = 0;
	297	} else {
	298	resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	299	resp.pn_orig_msg_id = opm->pn_msg_id;
	300	resp.pn_status = 0;
	301	}
	302	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
	303	pn_object(oph->pn_sdev, oph->pn_sobj),
	304	pn_object(oph->pn_rdev, oph->pn_robj),
	305	oph->pn_res);
	306	}
	307
	308	static int send_reset_indications(struct sk_buff *rskb)
	309	{
	310	struct phonethdr *oph = pn_hdr(rskb);
	311	static const u8 data[4] = {
	312	0x00 /* trans ID /, 0x10 / subscribe msg */,
	313	0x00 /* subscription count /, 0x00 / dummy */
	314	};
	315
	316	return pn_raw_send(data, sizeof(data), rskb->dev,
	317	pn_object(oph->pn_sdev, 0x00),
c3a90c78 RDC	318	pn_object(oph->pn_rdev, oph->pn_robj),
c3a90c78 RDC	319	PN_COMMGR);
be0c52bf RDC	320	}
	321
	322
4b07b3f6 RDC	323	/* packet type functions */
	324
	325	/*
	326	* Stuff received packets to associated sockets.
	327	* On error, returns non-zero and releases the skb.
	328	*/
	329	static int phonet_rcv(struct sk_buff skb, struct net_device dev,
	330	struct packet_type *pkttype,
	331	struct net_device *orig_dev)
	332	{
	333	struct phonethdr *ph;
ba113a94	334	struct sock *sk;
4b07b3f6 RDC	335	struct sockaddr_pn sa;
	336	u16 len;
	337
	338	if (dev_net(dev) != &init_net)
	339	goto out;
	340
	341	/* check we have at least a full Phonet header */
	342	if (!pskb_pull(skb, sizeof(struct phonethdr)))
	343	goto out;
	344
	345	/* check that the advertised length is correct */
	346	ph = pn_hdr(skb);
	347	len = get_unaligned_be16(&ph->pn_length);
	348	if (len < 2)
	349	goto out;
	350	len -= 2;
	351	if ((len > skb->len) \|\| pskb_trim(skb, len))
	352	goto out;
	353	skb_reset_transport_header(skb);
	354
	355	pn_skb_get_dst_sockaddr(skb, &sa);
	356	if (pn_sockaddr_get_addr(&sa) == 0)
	357	goto out; /* currently, we cannot be device 0 */
	358
ba113a94	359	sk = pn_find_sock_by_sa(&sa);
be0c52bf RDC	360	if (sk == NULL) {
	361	if (can_respond(skb)) {
	362	send_obj_unreachable(skb);
	363	send_reset_indications(skb);
	364	}
ba113a94	365	goto out;
be0c52bf	366	}
ba113a94 RDC	367
	368	/* Push data to the socket (or other sockets connected to it). */
	369	return sk_receive_skb(sk, skb, 0);
4b07b3f6 RDC	370
	371	out:
	372	kfree_skb(skb);
	373	return NET_RX_DROP;
	374	}
	375
	376	static struct packet_type phonet_packet_type = {
	377	.type = __constant_htons(ETH_P_PHONET),
	378	.dev = NULL,
	379	.func = phonet_rcv,
	380	};
	381
	382	/* Transport protocol registration */
	383	static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
	384	static DEFINE_SPINLOCK(proto_tab_lock);
	385
	386	int __init_or_module phonet_proto_register(int protocol,
	387	struct phonet_protocol *pp)
	388	{
	389	int err = 0;
	390
	391	if (protocol >= PHONET_NPROTO)
	392	return -EINVAL;
	393
	394	err = proto_register(pp->prot, 1);
	395	if (err)
	396	return err;
	397
	398	spin_lock(&proto_tab_lock);
	399	if (proto_tab[protocol])
	400	err = -EBUSY;
	401	else
	402	proto_tab[protocol] = pp;
	403	spin_unlock(&proto_tab_lock);
	404
	405	return err;
	406	}
	407	EXPORT_SYMBOL(phonet_proto_register);
	408
	409	void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
	410	{
	411	spin_lock(&proto_tab_lock);
	412	BUG_ON(proto_tab[protocol] != pp);
	413	proto_tab[protocol] = NULL;
	414	spin_unlock(&proto_tab_lock);
	415	proto_unregister(pp->prot);
	416	}
	417	EXPORT_SYMBOL(phonet_proto_unregister);
	418
	419	static struct phonet_protocol *phonet_proto_get(int protocol)
	420	{
	421	struct phonet_protocol *pp;
	422
	423	if (protocol >= PHONET_NPROTO)
	424	return NULL;
	425
	426	spin_lock(&proto_tab_lock);
	427	pp = proto_tab[protocol];
	428	if (pp && !try_module_get(pp->prot->owner))
	429	pp = NULL;
	430	spin_unlock(&proto_tab_lock);
	431
	432	return pp;
	433	}
434
4b07b3f6 RDC	435	/* Module registration */
	436	static int __init phonet_init(void)
	437	{
	438	int err;
	439
	440	err = sock_register(&phonet_proto_family);
	441	if (err) {
	442	printk(KERN_ALERT
	443	"phonet protocol family initialization failed\n");
	444	return err;
	445	}
	446
f8ff6028	447	phonet_device_init();
4b07b3f6	448	dev_add_pack(&phonet_packet_type);
8fb39740	449	phonet_netlink_register();
87ab4e20	450	phonet_sysctl_init();
107d0d9b RDC	451
	452	err = isi_register();
	453	if (err)
	454	goto err;
4b07b3f6	455	return 0;
107d0d9b RDC	456
107d0d9b RDC	457	err:
87ab4e20	458	phonet_sysctl_exit();
25532824	459	sock_unregister(PF_PHONET);
107d0d9b RDC	460	dev_remove_pack(&phonet_packet_type);
	461	phonet_device_exit();
	462	return err;
4b07b3f6 RDC	463	}
	464
	465	static void __exit phonet_exit(void)
	466	{
107d0d9b	467	isi_unregister();
87ab4e20	468	phonet_sysctl_exit();
25532824	469	sock_unregister(PF_PHONET);
4b07b3f6	470	dev_remove_pack(&phonet_packet_type);
f8ff6028	471	phonet_device_exit();
4b07b3f6 RDC	472	}
	473
	474	module_init(phonet_init);
	475	module_exit(phonet_exit);
	476	MODULE_DESCRIPTION("Phonet protocol stack for Linux");
	477	MODULE_LICENSE("GPL");
25532824	478	MODULE_ALIAS_NETPROTO(PF_PHONET);