[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / phonet / af_phonet.c

/*
 * File: af_phonet.c
 *
 * Phonet protocols family
 *
 * Copyright (C) 2008 Nokia Corporation.
 *
 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
 *          Rémi Denis-Courmont
 *
 * 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 <linux/slab.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 struct phonet_protocol *phonet_proto_get(unsigned int protocol)
{
	struct phonet_protocol *pp;

	if (protocol >= PHONET_NPROTO)
		return NULL;

	rcu_read_lock();
	pp = rcu_dereference(proto_tab[protocol]);
	if (pp && !try_module_get(pp->prot->owner))
		pp = NULL;
	rcu_read_unlock();

	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,
			    int kern)
{
	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->dobject = 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 int 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);
		err = (irq ? netif_rx(skb) : netif_rx_ni(skb)) ? -ENOBUFS : 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);
		if (unlikely(err > 0))
			err = net_xmit_errno(err);
	}

	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, dst;
	u8 daddr, saddr, res;

	src = pn->sobject;
	if (target != NULL) {
		dst = pn_sockaddr_get_object(target);
		res = pn_sockaddr_get_resource(target);
	} else {
		dst = pn->dobject;
		res = pn->resource;
	}
	daddr = pn_addr(dst);

	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 if (dst == 0) {
		/* Resource routing (small race until phonet_rcv()) */
		struct sock *sk = pn_find_sock_by_res(net, res);
		if (sk)	{
			sock_put(sk);
			dev = phonet_device_get(net);
			skb->pkt_type = PACKET_LOOPBACK;
		} else
			dev = phonet_route_output(net, daddr);
	} 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;

	if (!pn_addr(src))
		src = pn_object(saddr, pn_obj(src));

	err = pn_send(skb, dev, dst, src, res, 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;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
		return NET_RX_DROP;

	/* 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;
	}

	/* resource routing */
	if (pn_sockaddr_get_object(&sa) == 0) {
		struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource);
		if (sk)
			return sk_receive_skb(sk, skb, 0);
	}

	/* 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);
		}
	} else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
		goto out; /* Race between address deletion and loopback */
	else {
		/* Phonet packet routing */
		struct net_device *out_dev;

		out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
		if (!out_dev) {
			LIMIT_NETDEBUG(KERN_WARNING"No Phonet route to %02X\n",
					pn_sockaddr_get_addr(&sa));
			goto out;
		}

		__skb_push(skb, sizeof(struct phonethdr));
		skb->dev = out_dev;
		if (out_dev == dev) {
			LIMIT_NETDEBUG(KERN_ERR"Phonet loop to %02X on %s\n",
					pn_sockaddr_get_addr(&sa), dev->name);
			goto out_dev;
		}
		/* Some drivers (e.g. TUN) do not allocate HW header space */
		if (skb_cow_head(skb, out_dev->hard_header_len))
			goto out_dev;

		if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
					skb->len) < 0)
			goto out_dev;
		dev_queue_xmit(skb);
		dev_put(out_dev);
		return NET_RX_SUCCESS;
out_dev:
		dev_put(out_dev);
	}

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,
};

static DEFINE_MUTEX(proto_tab_lock);

int __init_or_module phonet_proto_register(unsigned 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;

	mutex_lock(&proto_tab_lock);
	if (proto_tab[protocol])
		err = -EBUSY;
	else
		rcu_assign_pointer(proto_tab[protocol], pp);
	mutex_unlock(&proto_tab_lock);

	return err;
}
EXPORT_SYMBOL(phonet_proto_register);

void phonet_proto_unregister(unsigned int protocol, struct phonet_protocol *pp)
{
	mutex_lock(&proto_tab_lock);
	BUG_ON(proto_tab[protocol] != pp);
	RCU_INIT_POINTER(proto_tab[protocol], NULL);
	mutex_unlock(&proto_tab_lock);
	synchronize_rcu();
	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;

	pn_sock_init();
	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	*
31fdc555 RDC	8	* Authors: Sakari Ailus <sakari.ailus@nokia.com>
31fdc555 RDC	9	* Rémi Denis-Courmont
4b07b3f6 RDC	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>
5a0e3ad6	28	#include <linux/slab.h>
4b07b3f6 RDC	29	#include <asm/unaligned.h>
	30	#include <net/sock.h>
	31
	32	#include <linux/if_phonet.h>
	33	#include <linux/phonet.h>
	34	#include <net/phonet/phonet.h>
f8ff6028	35	#include <net/phonet/pn_dev.h>
4b07b3f6	36
566521d6 AD	37	/* Transport protocol registration */
566521d6 AD	38	static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
566521d6	39
facb4edc	40	static struct phonet_protocol *phonet_proto_get(unsigned int protocol)
566521d6 AD	41	{
	42	struct phonet_protocol *pp;
	43
	44	if (protocol >= PHONET_NPROTO)
	45	return NULL;
	46
7ed0132f	47	rcu_read_lock();
b2a5decd	48	pp = rcu_dereference(proto_tab[protocol]);
566521d6 AD	49	if (pp && !try_module_get(pp->prot->owner))
566521d6 AD	50	pp = NULL;
7ed0132f	51	rcu_read_unlock();
566521d6 AD	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
3f378b68 EP	63	static int pn_socket_create(struct net net, struct socket sock, int protocol,
3f378b68 EP	64	int kern)
4b07b3f6	65	{
ba113a94 RDC	66	struct sock *sk;
ba113a94 RDC	67	struct pn_sock *pn;
4b07b3f6 RDC	68	struct phonet_protocol *pnp;
	69	int err;
	70
4b07b3f6 RDC	71	if (!capable(CAP_SYS_ADMIN))
	72	return -EPERM;
	73
	74	if (protocol == 0) {
	75	/* Default protocol selection */
	76	switch (sock->type) {
	77	case SOCK_DGRAM:
	78	protocol = PN_PROTO_PHONET;
	79	break;
9641458d RDC	80	case SOCK_SEQPACKET:
	81	protocol = PN_PROTO_PIPE;
	82	break;
4b07b3f6 RDC	83	default:
	84	return -EPROTONOSUPPORT;
	85	}
	86	}
	87
	88	pnp = phonet_proto_get(protocol);
25532824 RDC	89	if (pnp == NULL &&
	90	request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
	91	pnp = phonet_proto_get(protocol);
95a5afca	92
4b07b3f6 RDC	93	if (pnp == NULL)
	94	return -EPROTONOSUPPORT;
	95	if (sock->type != pnp->sock_type) {
	96	err = -EPROTONOSUPPORT;
	97	goto out;
	98	}
	99
ba113a94 RDC	100	sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
	101	if (sk == NULL) {
	102	err = -ENOMEM;
	103	goto out;
	104	}
	105
	106	sock_init_data(sock, sk);
	107	sock->state = SS_UNCONNECTED;
	108	sock->ops = pnp->ops;
	109	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
	110	sk->sk_protocol = protocol;
	111	pn = pn_sk(sk);
	112	pn->sobject = 0;
a8059512	113	pn->dobject = 0;
ba113a94 RDC	114	pn->resource = 0;
	115	sk->sk_prot->init(sk);
	116	err = 0;
4b07b3f6 RDC	117
	118	out:
	119	phonet_proto_put(pnp);
	120	return err;
	121	}
	122
ec1b4cf7	123	static const struct net_proto_family phonet_proto_family = {
25532824	124	.family = PF_PHONET,
4b07b3f6 RDC	125	.create = pn_socket_create,
	126	.owner = THIS_MODULE,
	127	};
	128
5f77076d RDC	129	/* Phonet device header operations */
	130	static int pn_header_create(struct sk_buff skb, struct net_device dev,
	131	unsigned short type, const void *daddr,
95c96174	132	const void *saddr, unsigned int len)
5f77076d RDC	133	{
	134	u8 *media = skb_push(skb, 1);
	135
	136	if (type != ETH_P_PHONET)
	137	return -1;
	138
	139	if (!saddr)
	140	saddr = dev->dev_addr;
	141	media = (const u8 *)saddr;
	142	return 1;
	143	}
	144
	145	static int pn_header_parse(const struct sk_buff skb, unsigned char haddr)
	146	{
	147	const u8 *media = skb_mac_header(skb);
	148	haddr = media;
	149	return 1;
	150	}
	151
	152	struct header_ops phonet_header_ops = {
	153	.create = pn_header_create,
	154	.parse = pn_header_parse,
	155	};
	156	EXPORT_SYMBOL(phonet_header_ops);
	157
107d0d9b RDC	158	/*
	159	* Prepends an ISI header and sends a datagram.
	160	*/
	161	static int pn_send(struct sk_buff skb, struct net_device dev,
be0c52bf	162	u16 dst, u16 src, u8 res, u8 irq)
107d0d9b RDC	163	{
	164	struct phonethdr *ph;
	165	int err;
	166
ebfe92ca RDC	167	if (skb->len + 2 > 0xffff /* Phonet length field limit */ \|\|
ebfe92ca RDC	168	skb->len + sizeof(struct phonethdr) > dev->mtu) {
107d0d9b RDC	169	err = -EMSGSIZE;
	170	goto drop;
	171	}
	172
18a1166d RDC	173	/* Broadcast sending is not implemented */
	174	if (pn_addr(dst) == PNADDR_BROADCAST) {
	175	err = -EOPNOTSUPP;
	176	goto drop;
	177	}
	178
107d0d9b RDC	179	skb_reset_transport_header(skb);
	180	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
	181	skb_push(skb, sizeof(struct phonethdr));
	182	skb_reset_network_header(skb);
	183	ph = pn_hdr(skb);
	184	ph->pn_rdev = pn_dev(dst);
	185	ph->pn_sdev = pn_dev(src);
	186	ph->pn_res = res;
	187	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
	188	ph->pn_robj = pn_obj(dst);
	189	ph->pn_sobj = pn_obj(src);
	190
	191	skb->protocol = htons(ETH_P_PHONET);
	192	skb->priority = 0;
	193	skb->dev = dev;
	194
aa6c45f3	195	if (skb->pkt_type == PACKET_LOOPBACK) {
107d0d9b	196	skb_reset_mac_header(skb);
107d0d9b	197	skb_orphan(skb);
b765e84f	198	err = (irq ? netif_rx(skb) : netif_rx_ni(skb)) ? -ENOBUFS : 0;
107d0d9b RDC	199	} else {
	200	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
	201	NULL, NULL, skb->len);
	202	if (err < 0) {
	203	err = -EHOSTUNREACH;
	204	goto drop;
	205	}
	206	err = dev_queue_xmit(skb);
b765e84f RDC	207	if (unlikely(err > 0))
b765e84f RDC	208	err = net_xmit_errno(err);
107d0d9b RDC	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;
a8059512 RDC	244	u16 src, dst;
	245	u8 daddr, saddr, res;
	246
	247	src = pn->sobject;
	248	if (target != NULL) {
	249	dst = pn_sockaddr_get_object(target);
	250	res = pn_sockaddr_get_resource(target);
	251	} else {
	252	dst = pn->dobject;
	253	res = pn->resource;
	254	}
	255	daddr = pn_addr(dst);
107d0d9b RDC	256
	257	err = -EHOSTUNREACH;
	258	if (sk->sk_bound_dev_if)
aa6c45f3 RDC	259	dev = dev_get_by_index(net, sk->sk_bound_dev_if);
	260	else if (phonet_address_lookup(net, daddr) == 0) {
	261	dev = phonet_device_get(net);
	262	skb->pkt_type = PACKET_LOOPBACK;
c69d4407	263	} else if (dst == 0) {
b6a563b2	264	/* Resource routing (small race until phonet_rcv()) */
c69d4407	265	struct sock *sk = pn_find_sock_by_res(net, res);
b6a563b2 RDC	266	if (sk) {
	267	sock_put(sk);
	268	dev = phonet_device_get(net);
	269	skb->pkt_type = PACKET_LOOPBACK;
	270	} else
	271	dev = phonet_route_output(net, daddr);
aa6c45f3 RDC	272	} else
	273	dev = phonet_route_output(net, daddr);
	274
107d0d9b RDC	275	if (!dev \|\| !(dev->flags & IFF_UP))
	276	goto drop;
	277
	278	saddr = phonet_address_get(dev, daddr);
	279	if (saddr == PN_NO_ADDR)
	280	goto drop;
	281
107d0d9b RDC	282	if (!pn_addr(src))
	283	src = pn_object(saddr, pn_obj(src));
	284
a8059512	285	err = pn_send(skb, dev, dst, src, res, 0);
107d0d9b RDC	286	dev_put(dev);
	287	return err;
	288
	289	drop:
	290	kfree_skb(skb);
	291	if (dev)
	292	dev_put(dev);
	293	return err;
	294	}
	295	EXPORT_SYMBOL(pn_skb_send);
	296
be0c52bf RDC	297	/* Do not send an error message in response to an error message */
	298	static inline int can_respond(struct sk_buff *skb)
	299	{
	300	const struct phonethdr *ph;
	301	const struct phonetmsg *pm;
	302	u8 submsg_id;
	303
	304	if (!pskb_may_pull(skb, 3))
	305	return 0;
	306
	307	ph = pn_hdr(skb);
be0c52bf RDC	308	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
be0c52bf RDC	309	return 0;
c3a90c78 RDC	310	if (ph->pn_res == PN_COMMGR) /* indications */
c3a90c78 RDC	311	return 0;
be0c52bf RDC	312
	313	ph = pn_hdr(skb); /* re-acquires the pointer */
	314	pm = pn_msg(skb);
	315	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
	316	return 1;
	317	submsg_id = (ph->pn_res == PN_PREFIX)
	318	? pm->pn_e_submsg_id : pm->pn_submsg_id;
	319	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
	320	pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
	321	return 1;
	322	return 0;
	323	}
	324
	325	static int send_obj_unreachable(struct sk_buff *rskb)
	326	{
	327	const struct phonethdr *oph = pn_hdr(rskb);
	328	const struct phonetmsg *opm = pn_msg(rskb);
	329	struct phonetmsg resp;
	330
	331	memset(&resp, 0, sizeof(resp));
	332	resp.pn_trans_id = opm->pn_trans_id;
	333	resp.pn_msg_id = PN_COMMON_MESSAGE;
	334	if (oph->pn_res == PN_PREFIX) {
	335	resp.pn_e_res_id = opm->pn_e_res_id;
	336	resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	337	resp.pn_e_orig_msg_id = opm->pn_msg_id;
	338	resp.pn_e_status = 0;
	339	} else {
	340	resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	341	resp.pn_orig_msg_id = opm->pn_msg_id;
	342	resp.pn_status = 0;
	343	}
	344	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
	345	pn_object(oph->pn_sdev, oph->pn_sobj),
	346	pn_object(oph->pn_rdev, oph->pn_robj),
	347	oph->pn_res);
	348	}
	349
	350	static int send_reset_indications(struct sk_buff *rskb)
	351	{
	352	struct phonethdr *oph = pn_hdr(rskb);
	353	static const u8 data[4] = {
	354	0x00 /* trans ID /, 0x10 / subscribe msg */,
	355	0x00 /* subscription count /, 0x00 / dummy */
	356	};
	357
	358	return pn_raw_send(data, sizeof(data), rskb->dev,
	359	pn_object(oph->pn_sdev, 0x00),
c3a90c78 RDC	360	pn_object(oph->pn_rdev, oph->pn_robj),
c3a90c78 RDC	361	PN_COMMGR);
be0c52bf RDC	362	}
	363
	364
4b07b3f6 RDC	365	/* packet type functions */
	366
	367	/*
	368	* Stuff received packets to associated sockets.
	369	* On error, returns non-zero and releases the skb.
	370	*/
	371	static int phonet_rcv(struct sk_buff skb, struct net_device dev,
	372	struct packet_type *pkttype,
	373	struct net_device *orig_dev)
	374	{
4b8f704b	375	struct net *net = dev_net(dev);
4b07b3f6 RDC	376	struct phonethdr *ph;
	377	struct sockaddr_pn sa;
	378	u16 len;
	379
4734f536 ED	380	skb = skb_share_check(skb, GFP_ATOMIC);
	381	if (!skb)
	382	return NET_RX_DROP;
	383
4b07b3f6 RDC	384	/* check we have at least a full Phonet header */
	385	if (!pskb_pull(skb, sizeof(struct phonethdr)))
	386	goto out;
	387
	388	/* check that the advertised length is correct */
	389	ph = pn_hdr(skb);
	390	len = get_unaligned_be16(&ph->pn_length);
	391	if (len < 2)
	392	goto out;
	393	len -= 2;
	394	if ((len > skb->len) \|\| pskb_trim(skb, len))
	395	goto out;
	396	skb_reset_transport_header(skb);
	397
	398	pn_skb_get_dst_sockaddr(skb, &sa);
4b07b3f6	399
f14001fc RDC	400	/* check if this is broadcasted */
	401	if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
	402	pn_deliver_sock_broadcast(net, skb);
	403	goto out;
	404	}
	405
b6a563b2 RDC	406	/* resource routing */
	407	if (pn_sockaddr_get_object(&sa) == 0) {
	408	struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource);
	409	if (sk)
	410	return sk_receive_skb(sk, skb, 0);
	411	}
	412
4b8f704b	413	/* check if we are the destination */
	414	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
	415	/* Phonet packet input */
	416	struct sock *sk = pn_find_sock_by_sa(net, &sa);
	417
	418	if (sk)
	419	return sk_receive_skb(sk, skb, 0);
	420
be0c52bf RDC	421	if (can_respond(skb)) {
	422	send_obj_unreachable(skb);
	423	send_reset_indications(skb);
	424	}
86a0a1e5 RDC	425	} else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
	426	goto out; /* Race between address deletion and loopback */
	427	else {
	428	/* Phonet packet routing */
	429	struct net_device *out_dev;
	430
	431	out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
	432	if (!out_dev) {
	433	LIMIT_NETDEBUG(KERN_WARNING"No Phonet route to %02X\n",
	434	pn_sockaddr_get_addr(&sa));
	435	goto out;
	436	}
	437
	438	__skb_push(skb, sizeof(struct phonethdr));
	439	skb->dev = out_dev;
	440	if (out_dev == dev) {
	441	LIMIT_NETDEBUG(KERN_ERR"Phonet loop to %02X on %s\n",
	442	pn_sockaddr_get_addr(&sa), dev->name);
	443	goto out_dev;
	444	}
	445	/* Some drivers (e.g. TUN) do not allocate HW header space */
	446	if (skb_cow_head(skb, out_dev->hard_header_len))
	447	goto out_dev;
	448
	449	if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
	450	skb->len) < 0)
	451	goto out_dev;
	452	dev_queue_xmit(skb);
	453	dev_put(out_dev);
	454	return NET_RX_SUCCESS;
	455	out_dev:
	456	dev_put(out_dev);
be0c52bf	457	}
ba113a94	458
4b07b3f6 RDC	459	out:
	460	kfree_skb(skb);
	461	return NET_RX_DROP;
	462	}
	463
7546dd97	464	static struct packet_type phonet_packet_type __read_mostly = {
09640e63	465	.type = cpu_to_be16(ETH_P_PHONET),
4b07b3f6 RDC	466	.func = phonet_rcv,
	467	};
	468
7ed0132f RDC	469	static DEFINE_MUTEX(proto_tab_lock);
7ed0132f RDC	470
facb4edc	471	int __init_or_module phonet_proto_register(unsigned int protocol,
4b07b3f6 RDC	472	struct phonet_protocol *pp)
	473	{
	474	int err = 0;
	475
	476	if (protocol >= PHONET_NPROTO)
	477	return -EINVAL;
	478
	479	err = proto_register(pp->prot, 1);
	480	if (err)
	481	return err;
	482
7ed0132f	483	mutex_lock(&proto_tab_lock);
4b07b3f6 RDC	484	if (proto_tab[protocol])
	485	err = -EBUSY;
	486	else
cf778b00	487	rcu_assign_pointer(proto_tab[protocol], pp);
7ed0132f	488	mutex_unlock(&proto_tab_lock);
4b07b3f6 RDC	489
	490	return err;
	491	}
	492	EXPORT_SYMBOL(phonet_proto_register);
	493
facb4edc	494	void phonet_proto_unregister(unsigned int protocol, struct phonet_protocol *pp)
4b07b3f6	495	{
7ed0132f	496	mutex_lock(&proto_tab_lock);
4b07b3f6	497	BUG_ON(proto_tab[protocol] != pp);
a9b3cd7f	498	RCU_INIT_POINTER(proto_tab[protocol], NULL);
7ed0132f RDC	499	mutex_unlock(&proto_tab_lock);
7ed0132f RDC	500	synchronize_rcu();
4b07b3f6 RDC	501	proto_unregister(pp->prot);
	502	}
	503	EXPORT_SYMBOL(phonet_proto_unregister);
	504
4b07b3f6 RDC	505	/* Module registration */
	506	static int __init phonet_init(void)
	507	{
	508	int err;
	509
76e02cf6	510	err = phonet_device_init();
	511	if (err)
	512	return err;
	513
6b0d07ba	514	pn_sock_init();
4b07b3f6 RDC	515	err = sock_register(&phonet_proto_family);
	516	if (err) {
	517	printk(KERN_ALERT
	518	"phonet protocol family initialization failed\n");
76e02cf6	519	goto err_sock;
4b07b3f6 RDC	520	}
	521
	522	dev_add_pack(&phonet_packet_type);
87ab4e20	523	phonet_sysctl_init();
107d0d9b RDC	524
	525	err = isi_register();
	526	if (err)
	527	goto err;
4b07b3f6	528	return 0;
107d0d9b RDC	529
107d0d9b RDC	530	err:
87ab4e20	531	phonet_sysctl_exit();
25532824	532	sock_unregister(PF_PHONET);
107d0d9b	533	dev_remove_pack(&phonet_packet_type);
76e02cf6	534	err_sock:
107d0d9b RDC	535	phonet_device_exit();
107d0d9b RDC	536	return err;
4b07b3f6 RDC	537	}
	538
	539	static void __exit phonet_exit(void)
	540	{
107d0d9b	541	isi_unregister();
87ab4e20	542	phonet_sysctl_exit();
25532824	543	sock_unregister(PF_PHONET);
4b07b3f6	544	dev_remove_pack(&phonet_packet_type);
f8ff6028	545	phonet_device_exit();
4b07b3f6 RDC	546	}
	547
	548	module_init(phonet_init);
	549	module_exit(phonet_exit);
	550	MODULE_DESCRIPTION("Phonet protocol stack for Linux");
	551	MODULE_LICENSE("GPL");
25532824	552	MODULE_ALIAS_NETPROTO(PF_PHONET);