net/phonet/socket.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/gfp.h>
 #include <linux/kernel.h>
 #include <linux/net.h>
 #include <linux/poll.h>
 #include <net/sock.h>
 #include <net/tcp_states.h>

 #include <linux/phonet.h>
 #include <linux/export.h>
 #include <net/phonet/phonet.h>
 #include <net/phonet/pep.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;
 }

 #define PN_HASHSIZE	16
 #define PN_HASHMASK	(PN_HASHSIZE-1)


 static struct  {
 	struct hlist_head hlist[PN_HASHSIZE];
 	struct mutex lock;
 } pnsocks;

 void __init pn_sock_init(void)
 {
 	unsigned i;

 	for (i = 0; i < PN_HASHSIZE; i++)
 		INIT_HLIST_HEAD(pnsocks.hlist + i);
 	mutex_init(&pnsocks.lock);
 }

 static struct hlist_head *pn_hash_list(u16 obj)
 {
 	return pnsocks.hlist + (obj & PN_HASHMASK);
 }

 /*
  * 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(struct net *net, 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;
 	struct hlist_head *hlist = pn_hash_list(obj);

 	rcu_read_lock();
 	sk_for_each_rcu(sknode, node, hlist) {
 		struct pn_sock *pn = pn_sk(sknode);
 		BUG_ON(!pn->sobject); /* unbound socket */

 		if (!net_eq(sock_net(sknode), net))
 			continue;
 		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;
 	}
 	rcu_read_unlock();

 	return rval;
 }

 /* Deliver a broadcast packet (only in bottom-half) */
 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 {
 	struct hlist_head *hlist = pnsocks.hlist;
 	unsigned h;

 	rcu_read_lock();
 	for (h = 0; h < PN_HASHSIZE; h++) {
 		struct hlist_node *node;
 		struct sock *sknode;

 		sk_for_each(sknode, node, hlist) {
 			struct sk_buff *clone;

 			if (!net_eq(sock_net(sknode), net))
 				continue;
 			if (!sock_flag(sknode, SOCK_BROADCAST))
 				continue;

 			clone = skb_clone(skb, GFP_ATOMIC);
 			if (clone) {
 				sock_hold(sknode);
 				sk_receive_skb(sknode, clone, 0);
 			}
 		}
 		hlist++;
 	}
 	rcu_read_unlock();
 }

 void pn_sock_hash(struct sock *sk)
 {
 	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);

 	mutex_lock(&pnsocks.lock);
 	sk_add_node_rcu(sk, hlist);
 	mutex_unlock(&pnsocks.lock);
 }
 EXPORT_SYMBOL(pn_sock_hash);

 void pn_sock_unhash(struct sock *sk)
 {
 	mutex_lock(&pnsocks.lock);
 	sk_del_node_init_rcu(sk);
 	mutex_unlock(&pnsocks.lock);
 	pn_sock_unbind_all_res(sk);
 	synchronize_rcu();
 }
 EXPORT_SYMBOL(pn_sock_unhash);

 static DEFINE_MUTEX(port_mutex);

 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(sock_net(sk), saddr))
 		return -EADDRNOTAVAIL;

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

 	/* 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_port:
 	mutex_unlock(&port_mutex);
 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_connect(struct socket *sock, struct sockaddr *addr,
 		int len, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct pn_sock *pn = pn_sk(sk);
 	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 	struct task_struct *tsk = current;
 	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 	int err;

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

 	lock_sock(sk);

 	switch (sock->state) {
 	case SS_UNCONNECTED:
 		if (sk->sk_state != TCP_CLOSE) {
 			err = -EISCONN;
 			goto out;
 		}
 		break;
 	case SS_CONNECTING:
 		err = -EALREADY;
 		goto out;
 	default:
 		err = -EISCONN;
 		goto out;
 	}

 	pn->dobject = pn_sockaddr_get_object(spn);
 	pn->resource = pn_sockaddr_get_resource(spn);
 	sock->state = SS_CONNECTING;

 	err = sk->sk_prot->connect(sk, addr, len);
 	if (err) {
 		sock->state = SS_UNCONNECTED;
 		pn->dobject = 0;
 		goto out;
 	}

 	while (sk->sk_state == TCP_SYN_SENT) {
 		DEFINE_WAIT(wait);

 		if (!timeo) {
 			err = -EINPROGRESS;
 			goto out;
 		}
 		if (signal_pending(tsk)) {
 			err = sock_intr_errno(timeo);
 			goto out;
 		}

 		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
 						TASK_INTERRUPTIBLE);
 		release_sock(sk);
 		timeo = schedule_timeout(timeo);
 		lock_sock(sk);
 		finish_wait(sk_sleep(sk), &wait);
 	}

 	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
 		err = 0;
 	else if (sk->sk_state == TCP_CLOSE_WAIT)
 		err = -ECONNRESET;
 	else
 		err = -ECONNREFUSED;
 	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
 out:
 	release_sock(sk);
 	return err;
 }

 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 				int flags)
 {
 	struct sock *sk = sock->sk;
 	struct sock *newsk;
 	int err;

 	if (unlikely(sk->sk_state != TCP_LISTEN))
 		return -EINVAL;

 	newsk = sk->sk_prot->accept(sk, flags, &err);
 	if (!newsk)
 		return err;

 	lock_sock(newsk);
 	sock_graft(newsk, newsock);
 	newsock->state = SS_CONNECTED;
 	release_sock(newsk);
 	return 0;
 }

 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 unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 					poll_table *wait)
 {
 	struct sock *sk = sock->sk;
 	struct pep_sock *pn = pep_sk(sk);
 	unsigned int mask = 0;

 	poll_wait(file, sk_sleep(sk), wait);

 	if (sk->sk_state == TCP_CLOSE)
 		return POLLERR;
 	if (!skb_queue_empty(&sk->sk_receive_queue))
 		mask |= POLLIN | POLLRDNORM;
 	if (!skb_queue_empty(&pn->ctrlreq_queue))
 		mask |= POLLPRI;
 	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 		return POLLHUP;

 	if (sk->sk_state == TCP_ESTABLISHED &&
 		atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
 		atomic_read(&pn->tx_credits))
 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

 	return mask;
 }

 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_listen(struct socket *sock, int backlog)
 {
 	struct sock *sk = sock->sk;
 	int err = 0;

 	if (pn_socket_autobind(sock))
 		return -ENOBUFS;

 	lock_sock(sk);
 	if (sock->state != SS_UNCONNECTED) {
 		err = -EINVAL;
 		goto out;
 	}

 	if (sk->sk_state != TCP_LISTEN) {
 		sk->sk_state = TCP_LISTEN;
 		sk->sk_ack_backlog = 0;
 	}
 	sk->sk_max_ack_backlog = backlog;
 out:
 	release_sock(sk);
 	return err;
 }

 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,
 };

 const struct proto_ops phonet_stream_ops = {
 	.family		= AF_PHONET,
 	.owner		= THIS_MODULE,
 	.release	= pn_socket_release,
 	.bind		= pn_socket_bind,
 	.connect	= pn_socket_connect,
 	.socketpair	= sock_no_socketpair,
 	.accept		= pn_socket_accept,
 	.getname	= pn_socket_getname,
 	.poll		= pn_socket_poll,
 	.ioctl		= pn_socket_ioctl,
 	.listen		= pn_socket_listen,
 	.shutdown	= sock_no_shutdown,
 	.setsockopt	= sock_common_setsockopt,
 	.getsockopt	= sock_common_getsockopt,
 #ifdef CONFIG_COMPAT
 	.compat_setsockopt = compat_sock_common_setsockopt,
 	.compat_getsockopt = compat_sock_common_getsockopt,
 #endif
 	.sendmsg	= pn_socket_sendmsg,
 	.recvmsg	= sock_common_recvmsg,
 	.mmap		= sock_no_mmap,
 	.sendpage	= sock_no_sendpage,
 };
 EXPORT_SYMBOL(phonet_stream_ops);

 /* allocate port for a socket */
 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 {
 	static int port_cur;
 	struct net *net = sock_net(sk);
 	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;
 	WARN_ON(!mutex_is_locked(&port_mutex));
 	if (!sport) {
 		/* search free port */
 		int port, pmin, pmax;

 		phonet_get_local_port_range(&pmin, &pmax);
 		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(net, &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(net, &try_sa);
 		if (tmpsk == NULL)
 			/* No sock there! We can use that port... */
 			goto found;
 		else
 			sock_put(tmpsk);
 	}
 	/* the port must be in use already */
 	return -EADDRINUSE;

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

 #ifdef CONFIG_PROC_FS
 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 {
 	struct net *net = seq_file_net(seq);
 	struct hlist_head *hlist = pnsocks.hlist;
 	struct hlist_node *node;
 	struct sock *sknode;
 	unsigned h;

 	for (h = 0; h < PN_HASHSIZE; h++) {
 		sk_for_each_rcu(sknode, node, hlist) {
 			if (!net_eq(net, sock_net(sknode)))
 				continue;
 			if (!pos)
 				return sknode;
 			pos--;
 		}
 		hlist++;
 	}
 	return NULL;
 }

 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 {
 	struct net *net = seq_file_net(seq);

 	do
 		sk = sk_next(sk);
 	while (sk && !net_eq(net, sock_net(sk)));

 	return sk;
 }

 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(rcu)
 {
 	rcu_read_lock();
 	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 }

 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct sock *sk;

 	if (v == SEQ_START_TOKEN)
 		sk = pn_sock_get_idx(seq, 0);
 	else
 		sk = pn_sock_get_next(seq, v);
 	(*pos)++;
 	return sk;
 }

 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 	__releases(rcu)
 {
 	rcu_read_unlock();
 }

 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 {
 	int len;

 	if (v == SEQ_START_TOKEN)
 		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 			"  uid inode ref pointer drops", &len);
 	else {
 		struct sock *sk = v;
 		struct pn_sock *pn = pn_sk(sk);

 		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 			"%d %pK %d%n",
 			sk->sk_protocol, pn->sobject, pn->dobject,
 			pn->resource, sk->sk_state,
 			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 			sock_i_uid(sk), sock_i_ino(sk),
 			atomic_read(&sk->sk_refcnt), sk,
 			atomic_read(&sk->sk_drops), &len);
 	}
 	seq_printf(seq, "%*s\n", 127 - len, "");
 	return 0;
 }

 static const struct seq_operations pn_sock_seq_ops = {
 	.start = pn_sock_seq_start,
 	.next = pn_sock_seq_next,
 	.stop = pn_sock_seq_stop,
 	.show = pn_sock_seq_show,
 };

 static int pn_sock_open(struct inode *inode, struct file *file)
 {
 	return seq_open_net(inode, file, &pn_sock_seq_ops,
 				sizeof(struct seq_net_private));
 }

 const struct file_operations pn_sock_seq_fops = {
 	.owner = THIS_MODULE,
 	.open = pn_sock_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = seq_release_net,
 };
 #endif

 static struct  {
 	struct sock *sk[256];
 } pnres;

 /*
  * Find and hold socket based on resource.
  */
 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
 {
 	struct sock *sk;

 	if (!net_eq(net, &init_net))
 		return NULL;

 	rcu_read_lock();
 	sk = rcu_dereference(pnres.sk[res]);
 	if (sk)
 		sock_hold(sk);
 	rcu_read_unlock();
 	return sk;
 }

 static DEFINE_MUTEX(resource_mutex);

 int pn_sock_bind_res(struct sock *sk, u8 res)
 {
 	int ret = -EADDRINUSE;

 	if (!net_eq(sock_net(sk), &init_net))
 		return -ENOIOCTLCMD;
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (pn_socket_autobind(sk->sk_socket))
 		return -EAGAIN;

 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == NULL) {
 		sock_hold(sk);
 		RCU_INIT_POINTER(pnres.sk[res], sk);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);
 	return ret;
 }

 int pn_sock_unbind_res(struct sock *sk, u8 res)
 {
 	int ret = -ENOENT;

 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;

 	mutex_lock(&resource_mutex);
 	if (pnres.sk[res] == sk) {
 		RCU_INIT_POINTER(pnres.sk[res], NULL);
 		ret = 0;
 	}
 	mutex_unlock(&resource_mutex);

 	if (ret == 0) {
 		synchronize_rcu();
 		sock_put(sk);
 	}
 	return ret;
 }

 void pn_sock_unbind_all_res(struct sock *sk)
 {
 	unsigned res, match = 0;

 	mutex_lock(&resource_mutex);
 	for (res = 0; res < 256; res++) {
 		if (pnres.sk[res] == sk) {
 			RCU_INIT_POINTER(pnres.sk[res], NULL);
 			match++;
 		}
 	}
 	mutex_unlock(&resource_mutex);

 	while (match > 0) {
 		__sock_put(sk);
 		match--;
 	}
 	/* Caller is responsible for RCU sync before final sock_put() */
 }

 #ifdef CONFIG_PROC_FS
 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
 {
 	struct net *net = seq_file_net(seq);
 	unsigned i;

 	if (!net_eq(net, &init_net))
 		return NULL;

 	for (i = 0; i < 256; i++) {
 		if (pnres.sk[i] == NULL)
 			continue;
 		if (!pos)
 			return pnres.sk + i;
 		pos--;
 	}
 	return NULL;
 }

 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
 {
 	struct net *net = seq_file_net(seq);
 	unsigned i;

 	BUG_ON(!net_eq(net, &init_net));

 	for (i = (sk - pnres.sk) + 1; i < 256; i++)
 		if (pnres.sk[i])
 			return pnres.sk + i;
 	return NULL;
 }

 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(resource_mutex)
 {
 	mutex_lock(&resource_mutex);
 	return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 }

 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct sock **sk;

 	if (v == SEQ_START_TOKEN)
 		sk = pn_res_get_idx(seq, 0);
 	else
 		sk = pn_res_get_next(seq, v);
 	(*pos)++;
 	return sk;
 }

 static void pn_res_seq_stop(struct seq_file *seq, void *v)
 	__releases(resource_mutex)
 {
 	mutex_unlock(&resource_mutex);
 }

 static int pn_res_seq_show(struct seq_file *seq, void *v)
 {
 	int len;

 	if (v == SEQ_START_TOKEN)
 		seq_printf(seq, "%s%n", "rs   uid inode", &len);
 	else {
 		struct sock **psk = v;
 		struct sock *sk = *psk;

 		seq_printf(seq, "%02X %5d %lu%n",
 			   (int) (psk - pnres.sk), sock_i_uid(sk),
 			   sock_i_ino(sk), &len);
 	}
 	seq_printf(seq, "%*s\n", 63 - len, "");
 	return 0;
 }

 static const struct seq_operations pn_res_seq_ops = {
 	.start = pn_res_seq_start,
 	.next = pn_res_seq_next,
 	.stop = pn_res_seq_stop,
 	.show = pn_res_seq_show,
 };

 static int pn_res_open(struct inode *inode, struct file *file)
 {
 	return seq_open_net(inode, file, &pn_res_seq_ops,
 				sizeof(struct seq_net_private));
 }

 const struct file_operations pn_res_seq_fops = {
 	.owner = THIS_MODULE,
 	.open = pn_res_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
 	.release = seq_release_net,
 };
 #endif
	/*
	* 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/gfp.h>
	#include <linux/kernel.h>
	#include <linux/net.h>
	#include <linux/poll.h>
	#include <net/sock.h>
	#include <net/tcp_states.h>

	#include <linux/phonet.h>
	#include <linux/export.h>
	#include <net/phonet/phonet.h>
	#include <net/phonet/pep.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;
	}

	#define PN_HASHSIZE 16
	#define PN_HASHMASK (PN_HASHSIZE-1)


	static struct {
	struct hlist_head hlist[PN_HASHSIZE];
	struct mutex lock;
	} pnsocks;

	void __init pn_sock_init(void)
	{
	unsigned i;

	for (i = 0; i < PN_HASHSIZE; i++)
	INIT_HLIST_HEAD(pnsocks.hlist + i);
	mutex_init(&pnsocks.lock);
	}

	static struct hlist_head *pn_hash_list(u16 obj)
	{
	return pnsocks.hlist + (obj & PN_HASHMASK);
	}

	/*
	* 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(struct net net, 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;
	struct hlist_head *hlist = pn_hash_list(obj);

	rcu_read_lock();
	sk_for_each_rcu(sknode, node, hlist) {
	struct pn_sock *pn = pn_sk(sknode);
	BUG_ON(!pn->sobject); /* unbound socket */

	if (!net_eq(sock_net(sknode), net))
	continue;
	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;
	}
	rcu_read_unlock();

	return rval;
	}

	/* Deliver a broadcast packet (only in bottom-half) */
	void pn_deliver_sock_broadcast(struct net net, struct sk_buff skb)
	{
	struct hlist_head *hlist = pnsocks.hlist;
	unsigned h;

	rcu_read_lock();
	for (h = 0; h < PN_HASHSIZE; h++) {
	struct hlist_node *node;
	struct sock *sknode;

	sk_for_each(sknode, node, hlist) {
	struct sk_buff *clone;

	if (!net_eq(sock_net(sknode), net))
	continue;
	if (!sock_flag(sknode, SOCK_BROADCAST))
	continue;

	clone = skb_clone(skb, GFP_ATOMIC);
	if (clone) {
	sock_hold(sknode);
	sk_receive_skb(sknode, clone, 0);
	}
	}
	hlist++;
	}
	rcu_read_unlock();
	}

	void pn_sock_hash(struct sock *sk)
	{
	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);

	mutex_lock(&pnsocks.lock);
	sk_add_node_rcu(sk, hlist);
	mutex_unlock(&pnsocks.lock);
	}
	EXPORT_SYMBOL(pn_sock_hash);

	void pn_sock_unhash(struct sock *sk)
	{
	mutex_lock(&pnsocks.lock);
	sk_del_node_init_rcu(sk);
	mutex_unlock(&pnsocks.lock);
	pn_sock_unbind_all_res(sk);
	synchronize_rcu();
	}
	EXPORT_SYMBOL(pn_sock_unhash);

	static DEFINE_MUTEX(port_mutex);

	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(sock_net(sk), saddr))
	return -EADDRNOTAVAIL;

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

	/* 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_port:
	mutex_unlock(&port_mutex);
	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_connect(struct socket sock, struct sockaddr addr,
	int len, int flags)
	{
	struct sock *sk = sock->sk;
	struct pn_sock *pn = pn_sk(sk);
	struct sockaddr_pn spn = (struct sockaddr_pn )addr;
	struct task_struct *tsk = current;
	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
	int err;

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

	lock_sock(sk);

	switch (sock->state) {
	case SS_UNCONNECTED:
	if (sk->sk_state != TCP_CLOSE) {
	err = -EISCONN;
	goto out;
	}
	break;
	case SS_CONNECTING:
	err = -EALREADY;
	goto out;
	default:
	err = -EISCONN;
	goto out;
	}

	pn->dobject = pn_sockaddr_get_object(spn);
	pn->resource = pn_sockaddr_get_resource(spn);
	sock->state = SS_CONNECTING;

	err = sk->sk_prot->connect(sk, addr, len);
	if (err) {
	sock->state = SS_UNCONNECTED;
	pn->dobject = 0;
	goto out;
	}

	while (sk->sk_state == TCP_SYN_SENT) {
	DEFINE_WAIT(wait);

	if (!timeo) {
	err = -EINPROGRESS;
	goto out;
	}
	if (signal_pending(tsk)) {
	err = sock_intr_errno(timeo);
	goto out;
	}

	prepare_to_wait_exclusive(sk_sleep(sk), &wait,
	TASK_INTERRUPTIBLE);
	release_sock(sk);
	timeo = schedule_timeout(timeo);
	lock_sock(sk);
	finish_wait(sk_sleep(sk), &wait);
	}

	if ((1 << sk->sk_state) & (TCPF_SYN_RECV\|TCPF_ESTABLISHED))
	err = 0;
	else if (sk->sk_state == TCP_CLOSE_WAIT)
	err = -ECONNRESET;
	else
	err = -ECONNREFUSED;
	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
	out:
	release_sock(sk);
	return err;
	}

	static int pn_socket_accept(struct socket sock, struct socket newsock,
	int flags)
	{
	struct sock *sk = sock->sk;
	struct sock *newsk;
	int err;

	if (unlikely(sk->sk_state != TCP_LISTEN))
	return -EINVAL;

	newsk = sk->sk_prot->accept(sk, flags, &err);
	if (!newsk)
	return err;

	lock_sock(newsk);
	sock_graft(newsk, newsock);
	newsock->state = SS_CONNECTED;
	release_sock(newsk);
	return 0;
	}

	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 unsigned int pn_socket_poll(struct file file, struct socket sock,
	poll_table *wait)
	{
	struct sock *sk = sock->sk;
	struct pep_sock *pn = pep_sk(sk);
	unsigned int mask = 0;

	poll_wait(file, sk_sleep(sk), wait);

	if (sk->sk_state == TCP_CLOSE)
	return POLLERR;
	if (!skb_queue_empty(&sk->sk_receive_queue))
	mask \|= POLLIN \| POLLRDNORM;
	if (!skb_queue_empty(&pn->ctrlreq_queue))
	mask \|= POLLPRI;
	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
	return POLLHUP;

	if (sk->sk_state == TCP_ESTABLISHED &&
	atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
	atomic_read(&pn->tx_credits))
	mask \|= POLLOUT \| POLLWRNORM \| POLLWRBAND;

	return mask;
	}

	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_listen(struct socket *sock, int backlog)
	{
	struct sock *sk = sock->sk;
	int err = 0;

	if (pn_socket_autobind(sock))
	return -ENOBUFS;

	lock_sock(sk);
	if (sock->state != SS_UNCONNECTED) {
	err = -EINVAL;
	goto out;
	}

	if (sk->sk_state != TCP_LISTEN) {
	sk->sk_state = TCP_LISTEN;
	sk->sk_ack_backlog = 0;
	}
	sk->sk_max_ack_backlog = backlog;
	out:
	release_sock(sk);
	return err;
	}

	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,
	};

	const struct proto_ops phonet_stream_ops = {
	.family = AF_PHONET,
	.owner = THIS_MODULE,
	.release = pn_socket_release,
	.bind = pn_socket_bind,
	.connect = pn_socket_connect,
	.socketpair = sock_no_socketpair,
	.accept = pn_socket_accept,
	.getname = pn_socket_getname,
	.poll = pn_socket_poll,
	.ioctl = pn_socket_ioctl,
	.listen = pn_socket_listen,
	.shutdown = sock_no_shutdown,
	.setsockopt = sock_common_setsockopt,
	.getsockopt = sock_common_getsockopt,
	#ifdef CONFIG_COMPAT
	.compat_setsockopt = compat_sock_common_setsockopt,
	.compat_getsockopt = compat_sock_common_getsockopt,
	#endif
	.sendmsg = pn_socket_sendmsg,
	.recvmsg = sock_common_recvmsg,
	.mmap = sock_no_mmap,
	.sendpage = sock_no_sendpage,
	};
	EXPORT_SYMBOL(phonet_stream_ops);

	/* allocate port for a socket */
	int pn_sock_get_port(struct sock *sk, unsigned short sport)
	{
	static int port_cur;
	struct net *net = sock_net(sk);
	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;
	WARN_ON(!mutex_is_locked(&port_mutex));
	if (!sport) {
	/* search free port */
	int port, pmin, pmax;

	phonet_get_local_port_range(&pmin, &pmax);
	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(net, &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(net, &try_sa);
	if (tmpsk == NULL)
	/* No sock there! We can use that port... */
	goto found;
	else
	sock_put(tmpsk);
	}
	/* the port must be in use already */
	return -EADDRINUSE;

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

	#ifdef CONFIG_PROC_FS
	static struct sock pn_sock_get_idx(struct seq_file seq, loff_t pos)
	{
	struct net *net = seq_file_net(seq);
	struct hlist_head *hlist = pnsocks.hlist;
	struct hlist_node *node;
	struct sock *sknode;
	unsigned h;

	for (h = 0; h < PN_HASHSIZE; h++) {
	sk_for_each_rcu(sknode, node, hlist) {
	if (!net_eq(net, sock_net(sknode)))
	continue;
	if (!pos)
	return sknode;
	pos--;
	}
	hlist++;
	}
	return NULL;
	}

	static struct sock pn_sock_get_next(struct seq_file seq, struct sock *sk)
	{
	struct net *net = seq_file_net(seq);

	do
	sk = sk_next(sk);
	while (sk && !net_eq(net, sock_net(sk)));

	return sk;
	}

	static void pn_sock_seq_start(struct seq_file seq, loff_t *pos)
	__acquires(rcu)
	{
	rcu_read_lock();
	return pos ? pn_sock_get_idx(seq, pos - 1) : SEQ_START_TOKEN;
	}

	static void pn_sock_seq_next(struct seq_file seq, void v, loff_t pos)
	{
	struct sock *sk;

	if (v == SEQ_START_TOKEN)
	sk = pn_sock_get_idx(seq, 0);
	else
	sk = pn_sock_get_next(seq, v);
	(*pos)++;
	return sk;
	}

	static void pn_sock_seq_stop(struct seq_file seq, void v)
	__releases(rcu)
	{
	rcu_read_unlock();
	}

	static int pn_sock_seq_show(struct seq_file seq, void v)
	{
	int len;

	if (v == SEQ_START_TOKEN)
	seq_printf(seq, "%s%n", "pt loc rem rs st tx_queue rx_queue "
	" uid inode ref pointer drops", &len);
	else {
	struct sock *sk = v;
	struct pn_sock *pn = pn_sk(sk);

	seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
	"%d %pK %d%n",
	sk->sk_protocol, pn->sobject, pn->dobject,
	pn->resource, sk->sk_state,
	sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
	sock_i_uid(sk), sock_i_ino(sk),
	atomic_read(&sk->sk_refcnt), sk,
	atomic_read(&sk->sk_drops), &len);
	}
	seq_printf(seq, "%*s\n", 127 - len, "");
	return 0;
	}

	static const struct seq_operations pn_sock_seq_ops = {
	.start = pn_sock_seq_start,
	.next = pn_sock_seq_next,
	.stop = pn_sock_seq_stop,
	.show = pn_sock_seq_show,
	};

	static int pn_sock_open(struct inode inode, struct file file)
	{
	return seq_open_net(inode, file, &pn_sock_seq_ops,
	sizeof(struct seq_net_private));
	}

	const struct file_operations pn_sock_seq_fops = {
	.owner = THIS_MODULE,
	.open = pn_sock_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release_net,
	};
	#endif

	static struct {
	struct sock *sk[256];
	} pnres;

	/*
	* Find and hold socket based on resource.
	*/
	struct sock pn_find_sock_by_res(struct net net, u8 res)
	{
	struct sock *sk;

	if (!net_eq(net, &init_net))
	return NULL;

	rcu_read_lock();
	sk = rcu_dereference(pnres.sk[res]);
	if (sk)
	sock_hold(sk);
	rcu_read_unlock();
	return sk;
	}

	static DEFINE_MUTEX(resource_mutex);

	int pn_sock_bind_res(struct sock *sk, u8 res)
	{
	int ret = -EADDRINUSE;

	if (!net_eq(sock_net(sk), &init_net))
	return -ENOIOCTLCMD;
	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;
	if (pn_socket_autobind(sk->sk_socket))
	return -EAGAIN;

	mutex_lock(&resource_mutex);
	if (pnres.sk[res] == NULL) {
	sock_hold(sk);
	RCU_INIT_POINTER(pnres.sk[res], sk);
	ret = 0;
	}
	mutex_unlock(&resource_mutex);
	return ret;
	}

	int pn_sock_unbind_res(struct sock *sk, u8 res)
	{
	int ret = -ENOENT;

	if (!capable(CAP_SYS_ADMIN))
	return -EPERM;

	mutex_lock(&resource_mutex);
	if (pnres.sk[res] == sk) {
	RCU_INIT_POINTER(pnres.sk[res], NULL);
	ret = 0;
	}
	mutex_unlock(&resource_mutex);

	if (ret == 0) {
	synchronize_rcu();
	sock_put(sk);
	}
	return ret;
	}

	void pn_sock_unbind_all_res(struct sock *sk)
	{
	unsigned res, match = 0;

	mutex_lock(&resource_mutex);
	for (res = 0; res < 256; res++) {
	if (pnres.sk[res] == sk) {
	RCU_INIT_POINTER(pnres.sk[res], NULL);
	match++;
	}
	}
	mutex_unlock(&resource_mutex);

	while (match > 0) {
	__sock_put(sk);
	match--;
	}
	/* Caller is responsible for RCU sync before final sock_put() */
	}

	#ifdef CONFIG_PROC_FS
	static struct sock *pn_res_get_idx(struct seq_file seq, loff_t pos)
	{
	struct net *net = seq_file_net(seq);
	unsigned i;

	if (!net_eq(net, &init_net))
	return NULL;

	for (i = 0; i < 256; i++) {
	if (pnres.sk[i] == NULL)
	continue;
	if (!pos)
	return pnres.sk + i;
	pos--;
	}
	return NULL;
	}

	static struct sock *pn_res_get_next(struct seq_file seq, struct sock **sk)
	{
	struct net *net = seq_file_net(seq);
	unsigned i;

	BUG_ON(!net_eq(net, &init_net));

	for (i = (sk - pnres.sk) + 1; i < 256; i++)
	if (pnres.sk[i])
	return pnres.sk + i;
	return NULL;
	}

	static void pn_res_seq_start(struct seq_file seq, loff_t *pos)
	__acquires(resource_mutex)
	{
	mutex_lock(&resource_mutex);
	return pos ? pn_res_get_idx(seq, pos - 1) : SEQ_START_TOKEN;
	}

	static void pn_res_seq_next(struct seq_file seq, void v, loff_t pos)
	{
	struct sock **sk;

	if (v == SEQ_START_TOKEN)
	sk = pn_res_get_idx(seq, 0);
	else
	sk = pn_res_get_next(seq, v);
	(*pos)++;
	return sk;
	}

	static void pn_res_seq_stop(struct seq_file seq, void v)
	__releases(resource_mutex)
	{
	mutex_unlock(&resource_mutex);
	}

	static int pn_res_seq_show(struct seq_file seq, void v)
	{
	int len;

	if (v == SEQ_START_TOKEN)
	seq_printf(seq, "%s%n", "rs uid inode", &len);
	else {
	struct sock **psk = v;
	struct sock sk = psk;

	seq_printf(seq, "%02X %5d %lu%n",
	(int) (psk - pnres.sk), sock_i_uid(sk),
	sock_i_ino(sk), &len);
	}
	seq_printf(seq, "%*s\n", 63 - len, "");
	return 0;
	}

	static const struct seq_operations pn_res_seq_ops = {
	.start = pn_res_seq_start,
	.next = pn_res_seq_next,
	.stop = pn_res_seq_stop,
	.show = pn_res_seq_show,
	};

	static int pn_res_open(struct inode inode, struct file file)
	{
	return seq_open_net(inode, file, &pn_res_seq_ops,
	sizeof(struct seq_net_private));
	}

	const struct file_operations pn_res_seq_fops = {
	.owner = THIS_MODULE,
	.open = pn_res_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release_net,
	};
	#endif