Commit ba113a94 authored by Remi Denis-Courmont's avatar Remi Denis-Courmont Committed by David S. Miller
Browse files

Phonet: common socket glue



This provides the socket API for the Phonet protocols family.

Signed-off-by: default avatarRemi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8fb39740
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+3 −0
Original line number Diff line number Diff line
@@ -32,6 +32,9 @@
#define PNADDR_ANY		0
#define PNPORT_RESOURCE_ROUTING	0

/* ioctls */
#define SIOCPNGETOBJECT		(SIOCPROTOPRIVATE + 0)

/* Phonet protocol header */
struct phonethdr {
	__u8	pn_rdev;
+23 −0
Original line number Diff line number Diff line
@@ -29,6 +29,28 @@
 */
#define MAX_PHONET_HEADER	8

/*
 * Every Phonet* socket has this structure first in its
 * protocol-specific structure under name c.
 */
struct pn_sock {
	struct sock	sk;
	u16		sobject;
	u8		resource;
};

static inline struct pn_sock *pn_sk(struct sock *sk)
{
	return (struct pn_sock *)sk;
}

extern const struct proto_ops phonet_dgram_ops;

struct sock *pn_find_sock_by_sa(const struct sockaddr_pn *sa);
void pn_sock_hash(struct sock *sk);
void pn_sock_unhash(struct sock *sk);
int pn_sock_get_port(struct sock *sk, unsigned short sport);

static inline struct phonethdr *pn_hdr(struct sk_buff *skb)
{
	return (struct phonethdr *)skb_network_header(skb);
@@ -64,6 +86,7 @@ void pn_skb_get_dst_sockaddr(struct sk_buff *skb, struct sockaddr_pn *sa)

/* Protocols in Phonet protocol family. */
struct phonet_protocol {
	const struct proto_ops	*ops;
	struct proto		*prot;
	int			sock_type;
};
+1 −0
Original line number Diff line number Diff line
@@ -3,4 +3,5 @@ obj-$(CONFIG_PHONET) += phonet.o
phonet-objs := \
	pn_dev.o \
	pn_netlink.o \
	socket.o \
	af_phonet.o
+25 −3
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ static inline void phonet_proto_put(struct phonet_protocol *pp);

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;

@@ -69,8 +71,22 @@ static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
		goto out;
	}

	/* TODO: create and init the struct sock */
	err = -EPROTONOSUPPORT;
	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);
@@ -94,6 +110,7 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
			struct net_device *orig_dev)
{
	struct phonethdr *ph;
	struct sock *sk;
	struct sockaddr_pn sa;
	u16 len;

@@ -118,7 +135,12 @@ static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
	if (pn_sockaddr_get_addr(&sa) == 0)
		goto out; /* currently, we cannot be device 0 */

	/* TODO: put packets to sockets backlog */
	sk = pn_find_sock_by_sa(&sa);
	if (sk == NULL)
		goto out;

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

out:
	kfree_skb(skb);

net/phonet/socket.c

0 → 100644
+311 −0
Original line number Diff line number Diff line
/*
 * File: socket.c
 *
 * Phonet sockets
 *
 * 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/net.h>
#include <net/sock.h>
#include <net/tcp_states.h>

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

static int pn_socket_release(struct socket *sock)
{
	struct sock *sk = sock->sk;

	if (sk) {
		sock->sk = NULL;
		sk->sk_prot->close(sk, 0);
	}
	return 0;
}

static struct  {
	struct hlist_head hlist;
	spinlock_t lock;
} pnsocks = {
	.hlist = HLIST_HEAD_INIT,
	.lock = __SPIN_LOCK_UNLOCKED(pnsocks.lock),
};

/*
 * Find address based on socket address, match only certain fields.
 * Also grab sock if it was found. Remember to sock_put it later.
 */
struct sock *pn_find_sock_by_sa(const struct sockaddr_pn *spn)
{
	struct hlist_node *node;
	struct sock *sknode;
	struct sock *rval = NULL;
	u16 obj = pn_sockaddr_get_object(spn);
	u8 res = spn->spn_resource;

	spin_lock_bh(&pnsocks.lock);

	sk_for_each(sknode, node, &pnsocks.hlist) {
		struct pn_sock *pn = pn_sk(sknode);
		BUG_ON(!pn->sobject); /* unbound socket */

		if (pn_port(obj)) {
			/* Look up socket by port */
			if (pn_port(pn->sobject) != pn_port(obj))
				continue;
		} else {
			/* If port is zero, look up by resource */
			if (pn->resource != res)
				continue;
		}
		if (pn_addr(pn->sobject)
		 && pn_addr(pn->sobject) != pn_addr(obj))
			continue;

		rval = sknode;
		sock_hold(sknode);
		break;
	}

	spin_unlock_bh(&pnsocks.lock);

	return rval;

}

void pn_sock_hash(struct sock *sk)
{
	spin_lock_bh(&pnsocks.lock);
	sk_add_node(sk, &pnsocks.hlist);
	spin_unlock_bh(&pnsocks.lock);
}
EXPORT_SYMBOL(pn_sock_hash);

void pn_sock_unhash(struct sock *sk)
{
	spin_lock_bh(&pnsocks.lock);
	sk_del_node_init(sk);
	spin_unlock_bh(&pnsocks.lock);
}
EXPORT_SYMBOL(pn_sock_unhash);

static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);
	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
	int err;
	u16 handle;
	u8 saddr;

	if (sk->sk_prot->bind)
		return sk->sk_prot->bind(sk, addr, len);

	if (len < sizeof(struct sockaddr_pn))
		return -EINVAL;
	if (spn->spn_family != AF_PHONET)
		return -EAFNOSUPPORT;

	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
	saddr = pn_addr(handle);
	if (saddr && phonet_address_lookup(saddr))
		return -EADDRNOTAVAIL;

	lock_sock(sk);
	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
		err = -EINVAL; /* attempt to rebind */
		goto out;
	}
	err = sk->sk_prot->get_port(sk, pn_port(handle));
	if (err)
		goto out;

	/* get_port() sets the port, bind() sets the address if applicable */
	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
	pn->resource = spn->spn_resource;

	/* Enable RX on the socket */
	sk->sk_prot->hash(sk);
out:
	release_sock(sk);
	return err;
}

static int pn_socket_autobind(struct socket *sock)
{
	struct sockaddr_pn sa;
	int err;

	memset(&sa, 0, sizeof(sa));
	sa.spn_family = AF_PHONET;
	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
				sizeof(struct sockaddr_pn));
	if (err != -EINVAL)
		return err;
	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
	return 0; /* socket was already bound */
}

static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
				int *sockaddr_len, int peer)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);

	memset(addr, 0, sizeof(struct sockaddr_pn));
	addr->sa_family = AF_PHONET;
	if (!peer) /* Race with bind() here is userland's problem. */
		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
					pn->sobject);

	*sockaddr_len = sizeof(struct sockaddr_pn);
	return 0;
}

static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
				unsigned long arg)
{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);

	if (cmd == SIOCPNGETOBJECT) {
		struct net_device *dev;
		u16 handle;
		u8 saddr;

		if (get_user(handle, (__u16 __user *)arg))
			return -EFAULT;

		lock_sock(sk);
		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))
			saddr = phonet_address_get(dev, pn_addr(handle));
		else
			saddr = PN_NO_ADDR;
		release_sock(sk);

		if (dev)
			dev_put(dev);
		if (saddr == PN_NO_ADDR)
			return -EHOSTUNREACH;

		handle = pn_object(saddr, pn_port(pn->sobject));
		return put_user(handle, (__u16 __user *)arg);
	}

	return sk->sk_prot->ioctl(sk, cmd, arg);
}

static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
				struct msghdr *m, size_t total_len)
{
	struct sock *sk = sock->sk;

	if (pn_socket_autobind(sock))
		return -EAGAIN;

	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
}

const struct proto_ops phonet_dgram_ops = {
	.family		= AF_PHONET,
	.owner		= THIS_MODULE,
	.release	= pn_socket_release,
	.bind		= pn_socket_bind,
	.connect	= sock_no_connect,
	.socketpair	= sock_no_socketpair,
	.accept		= sock_no_accept,
	.getname	= pn_socket_getname,
	.poll		= datagram_poll,
	.ioctl		= pn_socket_ioctl,
	.listen		= sock_no_listen,
	.shutdown	= sock_no_shutdown,
	.setsockopt	= sock_no_setsockopt,
	.getsockopt	= sock_no_getsockopt,
#ifdef CONFIG_COMPAT
	.compat_setsockopt = sock_no_setsockopt,
	.compat_getsockopt = sock_no_getsockopt,
#endif
	.sendmsg	= pn_socket_sendmsg,
	.recvmsg	= sock_common_recvmsg,
	.mmap		= sock_no_mmap,
	.sendpage	= sock_no_sendpage,
};

static DEFINE_MUTEX(port_mutex);

/* allocate port for a socket */
int pn_sock_get_port(struct sock *sk, unsigned short sport)
{
	static int port_cur;
	struct pn_sock *pn = pn_sk(sk);
	struct sockaddr_pn try_sa;
	struct sock *tmpsk;

	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
	try_sa.spn_family = AF_PHONET;

	mutex_lock(&port_mutex);

	if (!sport) {
		/* search free port */
		int port, pmin = 0x40, pmax = 0x7f;

		for (port = pmin; port <= pmax; port++) {
			port_cur++;
			if (port_cur < pmin || port_cur > pmax)
				port_cur = pmin;

			pn_sockaddr_set_port(&try_sa, port_cur);
			tmpsk = pn_find_sock_by_sa(&try_sa);
			if (tmpsk == NULL) {
				sport = port_cur;
				goto found;
			} else
				sock_put(tmpsk);
		}
	} else {
		/* try to find specific port */
		pn_sockaddr_set_port(&try_sa, sport);
		tmpsk = pn_find_sock_by_sa(&try_sa);
		if (tmpsk == NULL)
			/* No sock there! We can use that port... */
			goto found;
		else
			sock_put(tmpsk);
	}
	mutex_unlock(&port_mutex);

	/* the port must be in use already */
	return -EADDRINUSE;

found:
	mutex_unlock(&port_mutex);
	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
	return 0;
}
EXPORT_SYMBOL(pn_sock_get_port);