Phonet: common socket glue

This provides the socket API for the Phonet protocols family.

Signed-off-by: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 311 insertions, 0 deletions

diff --git a/net/phonet/socket.c b/net/phonet/socket.c
new file mode 100644
index 0000000..99a4945
--- /dev/null
+++ b/net/phonet/socket.c
@@ -0,0 +1,311 @@
+/*
+ * 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);