[linux-2.6-block.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 <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(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->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);
		}
	} 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(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(int protocol, struct phonet_protocol *pp)
{
	mutex_lock(&proto_tab_lock);
	BUG_ON(proto_tab[protocol] != pp);
	rcu_assign_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	*
	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>
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 AD	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
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;
	113	pn->resource = 0;
	114	sk->sk_prot->init(sk);
	115	err = 0;
4b07b3f6 RDC	116
	117	out:
	118	phonet_proto_put(pnp);
	119	return err;
	120	}
	121
ec1b4cf7	122	static const struct net_proto_family phonet_proto_family = {
25532824	123	.family = PF_PHONET,
4b07b3f6 RDC	124	.create = pn_socket_create,
	125	.owner = THIS_MODULE,
	126	};
	127
5f77076d RDC	128	/* Phonet device header operations */
	129	static int pn_header_create(struct sk_buff skb, struct net_device dev,
	130	unsigned short type, const void *daddr,
	131	const void *saddr, unsigned len)
	132	{
	133	u8 *media = skb_push(skb, 1);
	134
	135	if (type != ETH_P_PHONET)
	136	return -1;
	137
	138	if (!saddr)
	139	saddr = dev->dev_addr;
	140	media = (const u8 *)saddr;
	141	return 1;
	142	}
	143
	144	static int pn_header_parse(const struct sk_buff skb, unsigned char haddr)
	145	{
	146	const u8 *media = skb_mac_header(skb);
	147	haddr = media;
	148	return 1;
	149	}
	150
	151	struct header_ops phonet_header_ops = {
	152	.create = pn_header_create,
	153	.parse = pn_header_parse,
	154	};
	155	EXPORT_SYMBOL(phonet_header_ops);
	156
107d0d9b RDC	157	/*
	158	* Prepends an ISI header and sends a datagram.
	159	*/
	160	static int pn_send(struct sk_buff skb, struct net_device dev,
be0c52bf	161	u16 dst, u16 src, u8 res, u8 irq)
107d0d9b RDC	162	{
	163	struct phonethdr *ph;
	164	int err;
	165
ebfe92ca RDC	166	if (skb->len + 2 > 0xffff /* Phonet length field limit */ \|\|
ebfe92ca RDC	167	skb->len + sizeof(struct phonethdr) > dev->mtu) {
107d0d9b RDC	168	err = -EMSGSIZE;
	169	goto drop;
	170	}
	171
18a1166d RDC	172	/* Broadcast sending is not implemented */
	173	if (pn_addr(dst) == PNADDR_BROADCAST) {
	174	err = -EOPNOTSUPP;
	175	goto drop;
	176	}
	177
107d0d9b RDC	178	skb_reset_transport_header(skb);
	179	WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
	180	skb_push(skb, sizeof(struct phonethdr));
	181	skb_reset_network_header(skb);
	182	ph = pn_hdr(skb);
	183	ph->pn_rdev = pn_dev(dst);
	184	ph->pn_sdev = pn_dev(src);
	185	ph->pn_res = res;
	186	ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
	187	ph->pn_robj = pn_obj(dst);
	188	ph->pn_sobj = pn_obj(src);
	189
	190	skb->protocol = htons(ETH_P_PHONET);
	191	skb->priority = 0;
	192	skb->dev = dev;
	193
aa6c45f3	194	if (skb->pkt_type == PACKET_LOOPBACK) {
107d0d9b	195	skb_reset_mac_header(skb);
107d0d9b	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
aa6c45f3 RDC	225	if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
	226	skb->pkt_type = PACKET_LOOPBACK;
	227
be0c52bf RDC	228	skb_reserve(skb, MAX_PHONET_HEADER);
	229	__skb_put(skb, len);
	230	skb_copy_to_linear_data(skb, data, len);
	231	return pn_send(skb, dev, dst, src, res, 1);
	232	}
	233
107d0d9b RDC	234	/*
	235	* Create a Phonet header for the skb and send it out. Returns
	236	* non-zero error code if failed. The skb is freed then.
	237	*/
	238	int pn_skb_send(struct sock sk, struct sk_buff skb,
	239	const struct sockaddr_pn *target)
	240	{
aa6c45f3	241	struct net *net = sock_net(sk);
107d0d9b RDC	242	struct net_device *dev;
	243	struct pn_sock *pn = pn_sk(sk);
	244	int err;
	245	u16 src;
	246	u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR;
	247
	248	err = -EHOSTUNREACH;
	249	if (sk->sk_bound_dev_if)
aa6c45f3 RDC	250	dev = dev_get_by_index(net, sk->sk_bound_dev_if);
	251	else if (phonet_address_lookup(net, daddr) == 0) {
	252	dev = phonet_device_get(net);
	253	skb->pkt_type = PACKET_LOOPBACK;
	254	} else
	255	dev = phonet_route_output(net, daddr);
	256
107d0d9b RDC	257	if (!dev \|\| !(dev->flags & IFF_UP))
	258	goto drop;
	259
	260	saddr = phonet_address_get(dev, daddr);
	261	if (saddr == PN_NO_ADDR)
	262	goto drop;
	263
	264	src = pn->sobject;
	265	if (!pn_addr(src))
	266	src = pn_object(saddr, pn_obj(src));
	267
	268	err = pn_send(skb, dev, pn_sockaddr_get_object(target),
be0c52bf	269	src, pn_sockaddr_get_resource(target), 0);
107d0d9b RDC	270	dev_put(dev);
	271	return err;
	272
	273	drop:
	274	kfree_skb(skb);
	275	if (dev)
	276	dev_put(dev);
	277	return err;
	278	}
	279	EXPORT_SYMBOL(pn_skb_send);
	280
be0c52bf RDC	281	/* Do not send an error message in response to an error message */
	282	static inline int can_respond(struct sk_buff *skb)
	283	{
	284	const struct phonethdr *ph;
	285	const struct phonetmsg *pm;
	286	u8 submsg_id;
	287
	288	if (!pskb_may_pull(skb, 3))
	289	return 0;
	290
	291	ph = pn_hdr(skb);
be0c52bf RDC	292	if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
be0c52bf RDC	293	return 0;
c3a90c78 RDC	294	if (ph->pn_res == PN_COMMGR) /* indications */
c3a90c78 RDC	295	return 0;
be0c52bf RDC	296
	297	ph = pn_hdr(skb); /* re-acquires the pointer */
	298	pm = pn_msg(skb);
	299	if (pm->pn_msg_id != PN_COMMON_MESSAGE)
	300	return 1;
	301	submsg_id = (ph->pn_res == PN_PREFIX)
	302	? pm->pn_e_submsg_id : pm->pn_submsg_id;
	303	if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
	304	pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
	305	return 1;
	306	return 0;
	307	}
	308
	309	static int send_obj_unreachable(struct sk_buff *rskb)
	310	{
	311	const struct phonethdr *oph = pn_hdr(rskb);
	312	const struct phonetmsg *opm = pn_msg(rskb);
	313	struct phonetmsg resp;
	314
	315	memset(&resp, 0, sizeof(resp));
	316	resp.pn_trans_id = opm->pn_trans_id;
	317	resp.pn_msg_id = PN_COMMON_MESSAGE;
	318	if (oph->pn_res == PN_PREFIX) {
	319	resp.pn_e_res_id = opm->pn_e_res_id;
	320	resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	321	resp.pn_e_orig_msg_id = opm->pn_msg_id;
	322	resp.pn_e_status = 0;
	323	} else {
	324	resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
	325	resp.pn_orig_msg_id = opm->pn_msg_id;
	326	resp.pn_status = 0;
	327	}
	328	return pn_raw_send(&resp, sizeof(resp), rskb->dev,
	329	pn_object(oph->pn_sdev, oph->pn_sobj),
	330	pn_object(oph->pn_rdev, oph->pn_robj),
	331	oph->pn_res);
	332	}
	333
	334	static int send_reset_indications(struct sk_buff *rskb)
	335	{
	336	struct phonethdr *oph = pn_hdr(rskb);
	337	static const u8 data[4] = {
	338	0x00 /* trans ID /, 0x10 / subscribe msg */,
	339	0x00 /* subscription count /, 0x00 / dummy */
	340	};
	341
	342	return pn_raw_send(data, sizeof(data), rskb->dev,
	343	pn_object(oph->pn_sdev, 0x00),
c3a90c78 RDC	344	pn_object(oph->pn_rdev, oph->pn_robj),
c3a90c78 RDC	345	PN_COMMGR);
be0c52bf RDC	346	}
	347
	348
4b07b3f6 RDC	349	/* packet type functions */
	350
	351	/*
	352	* Stuff received packets to associated sockets.
	353	* On error, returns non-zero and releases the skb.
	354	*/
	355	static int phonet_rcv(struct sk_buff skb, struct net_device dev,
	356	struct packet_type *pkttype,
	357	struct net_device *orig_dev)
	358	{
4b8f704b	359	struct net *net = dev_net(dev);
4b07b3f6 RDC	360	struct phonethdr *ph;
	361	struct sockaddr_pn sa;
	362	u16 len;
	363
4b07b3f6 RDC	364	/* check we have at least a full Phonet header */
	365	if (!pskb_pull(skb, sizeof(struct phonethdr)))
	366	goto out;
	367
	368	/* check that the advertised length is correct */
	369	ph = pn_hdr(skb);
	370	len = get_unaligned_be16(&ph->pn_length);
	371	if (len < 2)
	372	goto out;
	373	len -= 2;
	374	if ((len > skb->len) \|\| pskb_trim(skb, len))
	375	goto out;
	376	skb_reset_transport_header(skb);
	377
	378	pn_skb_get_dst_sockaddr(skb, &sa);
4b07b3f6	379
f14001fc RDC	380	/* check if this is broadcasted */
	381	if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
	382	pn_deliver_sock_broadcast(net, skb);
	383	goto out;
	384	}
	385
4b8f704b	386	/* check if we are the destination */
	387	if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
	388	/* Phonet packet input */
	389	struct sock *sk = pn_find_sock_by_sa(net, &sa);
	390
	391	if (sk)
	392	return sk_receive_skb(sk, skb, 0);
	393
be0c52bf RDC	394	if (can_respond(skb)) {
	395	send_obj_unreachable(skb);
	396	send_reset_indications(skb);
	397	}
86a0a1e5 RDC	398	} else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
	399	goto out; /* Race between address deletion and loopback */
	400	else {
	401	/* Phonet packet routing */
	402	struct net_device *out_dev;
	403
	404	out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
	405	if (!out_dev) {
	406	LIMIT_NETDEBUG(KERN_WARNING"No Phonet route to %02X\n",
	407	pn_sockaddr_get_addr(&sa));
	408	goto out;
	409	}
	410
	411	__skb_push(skb, sizeof(struct phonethdr));
	412	skb->dev = out_dev;
	413	if (out_dev == dev) {
	414	LIMIT_NETDEBUG(KERN_ERR"Phonet loop to %02X on %s\n",
	415	pn_sockaddr_get_addr(&sa), dev->name);
	416	goto out_dev;
	417	}
	418	/* Some drivers (e.g. TUN) do not allocate HW header space */
	419	if (skb_cow_head(skb, out_dev->hard_header_len))
	420	goto out_dev;
	421
	422	if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
	423	skb->len) < 0)
	424	goto out_dev;
	425	dev_queue_xmit(skb);
	426	dev_put(out_dev);
	427	return NET_RX_SUCCESS;
	428	out_dev:
	429	dev_put(out_dev);
be0c52bf	430	}
ba113a94	431
4b07b3f6 RDC	432	out:
	433	kfree_skb(skb);
	434	return NET_RX_DROP;
	435	}
	436
7546dd97	437	static struct packet_type phonet_packet_type __read_mostly = {
09640e63	438	.type = cpu_to_be16(ETH_P_PHONET),
4b07b3f6 RDC	439	.func = phonet_rcv,
	440	};
	441
7ed0132f RDC	442	static DEFINE_MUTEX(proto_tab_lock);
7ed0132f RDC	443
4b07b3f6 RDC	444	int __init_or_module phonet_proto_register(int protocol,
	445	struct phonet_protocol *pp)
	446	{
	447	int err = 0;
	448
	449	if (protocol >= PHONET_NPROTO)
	450	return -EINVAL;
	451
	452	err = proto_register(pp->prot, 1);
	453	if (err)
	454	return err;
	455
7ed0132f	456	mutex_lock(&proto_tab_lock);
4b07b3f6 RDC	457	if (proto_tab[protocol])
	458	err = -EBUSY;
	459	else
7ed0132f RDC	460	rcu_assign_pointer(proto_tab[protocol], pp);
7ed0132f RDC	461	mutex_unlock(&proto_tab_lock);
4b07b3f6 RDC	462
	463	return err;
	464	}
	465	EXPORT_SYMBOL(phonet_proto_register);
	466
	467	void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
	468	{
7ed0132f	469	mutex_lock(&proto_tab_lock);
4b07b3f6	470	BUG_ON(proto_tab[protocol] != pp);
7ed0132f RDC	471	rcu_assign_pointer(proto_tab[protocol], NULL);
	472	mutex_unlock(&proto_tab_lock);
	473	synchronize_rcu();
4b07b3f6 RDC	474	proto_unregister(pp->prot);
	475	}
	476	EXPORT_SYMBOL(phonet_proto_unregister);
	477
4b07b3f6 RDC	478	/* Module registration */
	479	static int __init phonet_init(void)
	480	{
	481	int err;
	482
76e02cf6	483	err = phonet_device_init();
	484	if (err)
	485	return err;
	486
6b0d07ba	487	pn_sock_init();
4b07b3f6 RDC	488	err = sock_register(&phonet_proto_family);
	489	if (err) {
	490	printk(KERN_ALERT
	491	"phonet protocol family initialization failed\n");
76e02cf6	492	goto err_sock;
4b07b3f6 RDC	493	}
	494
	495	dev_add_pack(&phonet_packet_type);
87ab4e20	496	phonet_sysctl_init();
107d0d9b RDC	497
	498	err = isi_register();
	499	if (err)
	500	goto err;
4b07b3f6	501	return 0;
107d0d9b RDC	502
107d0d9b RDC	503	err:
87ab4e20	504	phonet_sysctl_exit();
25532824	505	sock_unregister(PF_PHONET);
107d0d9b	506	dev_remove_pack(&phonet_packet_type);
76e02cf6	507	err_sock:
107d0d9b RDC	508	phonet_device_exit();
107d0d9b RDC	509	return err;
4b07b3f6 RDC	510	}
	511
	512	static void __exit phonet_exit(void)
	513	{
107d0d9b	514	isi_unregister();
87ab4e20	515	phonet_sysctl_exit();
25532824	516	sock_unregister(PF_PHONET);
4b07b3f6	517	dev_remove_pack(&phonet_packet_type);
f8ff6028	518	phonet_device_exit();
4b07b3f6 RDC	519	}
	520
	521	module_init(phonet_init);
	522	module_exit(phonet_exit);
	523	MODULE_DESCRIPTION("Phonet protocol stack for Linux");
	524	MODULE_LICENSE("GPL");
25532824	525	MODULE_ALIAS_NETPROTO(PF_PHONET);