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 000000000000..99a4945d565d
--- /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);