[GitHub/mt8127/android_kernel_alcatel_ttab.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 (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 (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 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
	193	if (pn_addr(src) == pn_addr(dst)) {
	194	skb_reset_mac_header(skb);
	195	skb->pkt_type = PACKET_LOOPBACK;
	196	skb_orphan(skb);
be0c52bf RDC	197	if (irq)
	198	netif_rx(skb);
	199	else
	200	netif_rx_ni(skb);
107d0d9b RDC	201	err = 0;
	202	} else {
	203	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
	204	NULL, NULL, skb->len);
	205	if (err < 0) {
	206	err = -EHOSTUNREACH;
	207	goto drop;
	208	}
	209	err = dev_queue_xmit(skb);
	210	}
	211
	212	return err;
	213	drop:
	214	kfree_skb(skb);
	215	return err;
	216	}
	217
be0c52bf RDC	218	static int pn_raw_send(const void data, int len, struct net_device dev,
	219	u16 dst, u16 src, u8 res)
	220	{
	221	struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
	222	if (skb == NULL)
	223	return -ENOMEM;
	224
	225	skb_reserve(skb, MAX_PHONET_HEADER);
	226	__skb_put(skb, len);
	227	skb_copy_to_linear_data(skb, data, len);
	228	return pn_send(skb, dev, dst, src, res, 1);
	229	}
	230
107d0d9b RDC	231	/*
	232	* Create a Phonet header for the skb and send it out. Returns
	233	* non-zero error code if failed. The skb is freed then.
	234	*/
	235	int pn_skb_send(struct sock sk, struct sk_buff skb,
	236	const struct sockaddr_pn *target)
	237	{
	238	struct net_device *dev;
	239	struct pn_sock *pn = pn_sk(sk);
	240	int err;
	241	u16 src;
	242	u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR;
	243
	244	err = -EHOSTUNREACH;
	245	if (sk->sk_bound_dev_if)
	246	dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
	247	else
	248	dev = phonet_device_get(sock_net(sk));
	249	if (!dev \|\| !(dev->flags & IFF_UP))
	250	goto drop;
	251
	252	saddr = phonet_address_get(dev, daddr);
	253	if (saddr == PN_NO_ADDR)
	254	goto drop;
	255
	256	src = pn->sobject;
	257	if (!pn_addr(src))
	258	src = pn_object(saddr, pn_obj(src));
	259
	260	err = pn_send(skb, dev, pn_sockaddr_get_object(target),
be0c52bf	261	src, pn_sockaddr_get_resource(target), 0);
107d0d9b RDC	262	dev_put(dev);
	263	return err;
	264
	265	drop:
	266	kfree_skb(skb);
	267	if (dev)
	268	dev_put(dev);
	269	return err;
	270	}
	271	EXPORT_SYMBOL(pn_skb_send);
	272
be0c52bf RDC	273	/* Do not send an error message in response to an error message */
	274	static inline int can_respond(struct sk_buff *skb)
	275	{
	276	const struct phonethdr *ph;
	277	const struct phonetmsg *pm;
	278	u8 submsg_id;
	279
	280	if (!pskb_may_pull(skb, 3))
	281	return 0;
	282
	283	ph = pn_hdr(skb);
be0c52bf RDC	284	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
be0c52bf RDC	285	return 0;
c3a90c78 RDC	286	if (ph->pn_res == PN_COMMGR) /* indications */
c3a90c78 RDC	287	return 0;
be0c52bf RDC	288
	289	ph = pn_hdr(skb); /* re-acquires the pointer */
	290	pm = pn_msg(skb);
	291	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
	292	return 1;
	293	submsg_id = (ph->pn_res == PN_PREFIX)
	294	? pm->pn_e_submsg_id : pm->pn_submsg_id;
	295	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
	296	pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
	297	return 1;
	298	return 0;
	299	}
	300
	301	static int send_obj_unreachable(struct sk_buff *rskb)
	302	{
	303	const struct phonethdr *oph = pn_hdr(rskb);
	304	const struct phonetmsg *opm = pn_msg(rskb);
	305	struct phonetmsg resp;
	306
	307	memset(&resp, 0, sizeof(resp));
	308	resp.pn_trans_id = opm->pn_trans_id;
	309	resp.pn_msg_id = PN_COMMON_MESSAGE;
	310	if (oph->pn_res == PN_PREFIX) {
	311	resp.pn_e_res_id = opm->pn_e_res_id;
	312	resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	313	resp.pn_e_orig_msg_id = opm->pn_msg_id;
	314	resp.pn_e_status = 0;
	315	} else {
	316	resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	317	resp.pn_orig_msg_id = opm->pn_msg_id;
	318	resp.pn_status = 0;
	319	}
	320	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
	321	pn_object(oph->pn_sdev, oph->pn_sobj),
	322	pn_object(oph->pn_rdev, oph->pn_robj),
	323	oph->pn_res);
	324	}
	325
	326	static int send_reset_indications(struct sk_buff *rskb)
	327	{
	328	struct phonethdr *oph = pn_hdr(rskb);
	329	static const u8 data[4] = {
	330	0x00 /* trans ID /, 0x10 / subscribe msg */,
	331	0x00 /* subscription count /, 0x00 / dummy */
	332	};
	333
	334	return pn_raw_send(data, sizeof(data), rskb->dev,
	335	pn_object(oph->pn_sdev, 0x00),
c3a90c78 RDC	336	pn_object(oph->pn_rdev, oph->pn_robj),
c3a90c78 RDC	337	PN_COMMGR);
be0c52bf RDC	338	}
	339
	340
4b07b3f6 RDC	341	/* packet type functions */
	342
	343	/*
	344	* Stuff received packets to associated sockets.
	345	* On error, returns non-zero and releases the skb.
	346	*/
	347	static int phonet_rcv(struct sk_buff skb, struct net_device dev,
	348	struct packet_type *pkttype,
	349	struct net_device *orig_dev)
	350	{
4b8f704b	351	struct net *net = dev_net(dev);
4b07b3f6 RDC	352	struct phonethdr *ph;
	353	struct sockaddr_pn sa;
	354	u16 len;
	355
4b07b3f6 RDC	356	/* check we have at least a full Phonet header */
	357	if (!pskb_pull(skb, sizeof(struct phonethdr)))
	358	goto out;
	359
	360	/* check that the advertised length is correct */
	361	ph = pn_hdr(skb);
	362	len = get_unaligned_be16(&ph->pn_length);
	363	if (len < 2)
	364	goto out;
	365	len -= 2;
	366	if ((len > skb->len) \|\| pskb_trim(skb, len))
	367	goto out;
	368	skb_reset_transport_header(skb);
	369
	370	pn_skb_get_dst_sockaddr(skb, &sa);
4b07b3f6	371
4b8f704b	372	/* check if we are the destination */
	373	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
	374	/* Phonet packet input */
	375	struct sock *sk = pn_find_sock_by_sa(net, &sa);
	376
	377	if (sk)
	378	return sk_receive_skb(sk, skb, 0);
	379
be0c52bf RDC	380	if (can_respond(skb)) {
	381	send_obj_unreachable(skb);
	382	send_reset_indications(skb);
	383	}
be0c52bf	384	}
ba113a94	385
4b07b3f6 RDC	386	out:
	387	kfree_skb(skb);
	388	return NET_RX_DROP;
	389	}
	390
7546dd97	391	static struct packet_type phonet_packet_type __read_mostly = {
09640e63	392	.type = cpu_to_be16(ETH_P_PHONET),
4b07b3f6 RDC	393	.func = phonet_rcv,
	394	};
	395
4b07b3f6 RDC	396	int __init_or_module phonet_proto_register(int protocol,
	397	struct phonet_protocol *pp)
	398	{
	399	int err = 0;
	400
	401	if (protocol >= PHONET_NPROTO)
	402	return -EINVAL;
	403
	404	err = proto_register(pp->prot, 1);
	405	if (err)
	406	return err;
	407
	408	spin_lock(&proto_tab_lock);
	409	if (proto_tab[protocol])
	410	err = -EBUSY;
	411	else
	412	proto_tab[protocol] = pp;
	413	spin_unlock(&proto_tab_lock);
	414
	415	return err;
	416	}
	417	EXPORT_SYMBOL(phonet_proto_register);
	418
	419	void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
	420	{
	421	spin_lock(&proto_tab_lock);
	422	BUG_ON(proto_tab[protocol] != pp);
	423	proto_tab[protocol] = NULL;
	424	spin_unlock(&proto_tab_lock);
	425	proto_unregister(pp->prot);
	426	}
	427	EXPORT_SYMBOL(phonet_proto_unregister);
	428
4b07b3f6 RDC	429	/* Module registration */
	430	static int __init phonet_init(void)
	431	{
	432	int err;
	433
76e02cf6	434	err = phonet_device_init();
	435	if (err)
	436	return err;
	437
4b07b3f6 RDC	438	err = sock_register(&phonet_proto_family);
	439	if (err) {
	440	printk(KERN_ALERT
	441	"phonet protocol family initialization failed\n");
76e02cf6	442	goto err_sock;
4b07b3f6 RDC	443	}
	444
	445	dev_add_pack(&phonet_packet_type);
87ab4e20	446	phonet_sysctl_init();
107d0d9b RDC	447
	448	err = isi_register();
	449	if (err)
	450	goto err;
4b07b3f6	451	return 0;
107d0d9b RDC	452
107d0d9b RDC	453	err:
87ab4e20	454	phonet_sysctl_exit();
25532824	455	sock_unregister(PF_PHONET);
107d0d9b	456	dev_remove_pack(&phonet_packet_type);
76e02cf6	457	err_sock:
107d0d9b RDC	458	phonet_device_exit();
107d0d9b RDC	459	return err;
4b07b3f6 RDC	460	}
	461
	462	static void __exit phonet_exit(void)
	463	{
107d0d9b	464	isi_unregister();
87ab4e20	465	phonet_sysctl_exit();
25532824	466	sock_unregister(PF_PHONET);
4b07b3f6	467	dev_remove_pack(&phonet_packet_type);
f8ff6028	468	phonet_device_exit();
4b07b3f6 RDC	469	}
	470
	471	module_init(phonet_init);
	472	module_exit(phonet_exit);
	473	MODULE_DESCRIPTION("Phonet protocol stack for Linux");
	474	MODULE_LICENSE("GPL");
25532824	475	MODULE_ALIAS_NETPROTO(PF_PHONET);