Phonet: Phonet datagram transport protocol

This provides the basic SOCK_DGRAM transport protocol for Phonet.

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

3 files changed, 304 insertions, 0 deletions

diff --git a/net/phonet/Makefile b/net/phonet/Makefile
index c1d671de7835..d218abc3f06a 100644
--- a/net/phonet/Makefile
+++ b/net/phonet/Makefile
@@ -4,4 +4,5 @@ phonet-objs := \
         pn_dev.o \
         pn_netlink.o \
         socket.o \
+        datagram.o \
         af_phonet.o
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c
index ba54d53020ff..e6771d3961cf 100644
--- a/net/phonet/af_phonet.c
+++ b/net/phonet/af_phonet.c
@@ -99,6 +99,101 @@ static struct net_proto_family phonet_proto_family = {
         .owner = THIS_MODULE,
 };
 
+/*
+ * 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)
+{
+        struct phonethdr *ph;
+        int err;
+
+        if (skb->len + 2 > 0xffff) {
+                /* Phonet length field would overflow */
+                err = -EMSGSIZE;
+                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 (pn_addr(src) == pn_addr(dst)) {
+                skb_reset_mac_header(skb);
+                skb->pkt_type = PACKET_LOOPBACK;
+                skb_orphan(skb);
+                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;
+}
+
+/*
+ * 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_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(sock_net(sk), sk->sk_bound_dev_if);
+        else
+                dev = phonet_device_get(sock_net(sk));
+        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));
+        dev_put(dev);
+        return err;
+
+drop:
+        kfree_skb(skb);
+        if (dev)
+                dev_put(dev);
+        return err;
+}
+EXPORT_SYMBOL(pn_skb_send);
+
 /* packet type functions */
 
 /*
@@ -226,11 +321,22 @@ static int __init phonet_init(void)
         phonet_device_init();
         dev_add_pack(&phonet_packet_type);
         phonet_netlink_register();
+
+        err = isi_register();
+        if (err)
+                goto err;
         return 0;
+
+err:
+        sock_unregister(AF_PHONET);
+        dev_remove_pack(&phonet_packet_type);
+        phonet_device_exit();
+        return err;
 }
 
 static void __exit phonet_exit(void)
 {
+        isi_unregister();
         sock_unregister(AF_PHONET);
         dev_remove_pack(&phonet_packet_type);
         phonet_device_exit();
diff --git a/net/phonet/datagram.c b/net/phonet/datagram.c
new file mode 100644
index 000000000000..e087862ed7e4
--- /dev/null
+++ b/net/phonet/datagram.c
@@ -0,0 +1,197 @@
+/*
+ * File: datagram.c
+ *
+ * Datagram (ISI) 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/socket.h>
+#include <asm/ioctls.h>
+#include <net/sock.h>
+
+#include <linux/phonet.h>
+#include <net/phonet/phonet.h>
+
+static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb);
+
+/* associated socket ceases to exist */
+static void pn_sock_close(struct sock *sk, long timeout)
+{
+        sk_common_release(sk);
+}
+
+static int pn_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+        struct sk_buff *skb;
+        int answ;
+
+        switch (cmd) {
+        case SIOCINQ:
+                lock_sock(sk);
+                skb = skb_peek(&sk->sk_receive_queue);
+                answ = skb ? skb->len : 0;
+                release_sock(sk);
+                return put_user(answ, (int __user *)arg);
+        }
+
+        return -ENOIOCTLCMD;
+}
+
+/* Destroy socket. All references are gone. */
+static void pn_destruct(struct sock *sk)
+{
+        skb_queue_purge(&sk->sk_receive_queue);
+}
+
+static int pn_init(struct sock *sk)
+{
+        sk->sk_destruct = pn_destruct;
+        return 0;
+}
+
+static int pn_sendmsg(struct kiocb *iocb, struct sock *sk,
+                        struct msghdr *msg, size_t len)
+{
+        struct sockaddr_pn *target;
+        struct sk_buff *skb;
+        int err;
+
+        if (msg->msg_flags & MSG_OOB)
+                return -EOPNOTSUPP;
+
+        if (msg->msg_name == NULL)
+                return -EDESTADDRREQ;
+
+        if (msg->msg_namelen < sizeof(struct sockaddr_pn))
+                return -EINVAL;
+
+        target = (struct sockaddr_pn *)msg->msg_name;
+        if (target->spn_family != AF_PHONET)
+                return -EAFNOSUPPORT;
+
+        skb = sock_alloc_send_skb(sk, MAX_PHONET_HEADER + len,
+                                        msg->msg_flags & MSG_DONTWAIT, &err);
+        if (skb == NULL)
+                return err;
+        skb_reserve(skb, MAX_PHONET_HEADER);
+
+        err = memcpy_fromiovec((void *)skb_put(skb, len), msg->msg_iov, len);
+        if (err < 0) {
+                kfree_skb(skb);
+                return err;
+        }
+
+        /*
+         * Fill in the Phonet header and
+         * finally pass the packet forwards.
+         */
+        err = pn_skb_send(sk, skb, target);
+
+        /* If ok, return len. */
+        return (err >= 0) ? len : err;
+}
+
+static int pn_recvmsg(struct kiocb *iocb, struct sock *sk,
+                        struct msghdr *msg, size_t len, int noblock,
+                        int flags, int *addr_len)
+{
+        struct sk_buff *skb = NULL;
+        struct sockaddr_pn sa;
+        int rval = -EOPNOTSUPP;
+        int copylen;
+
+        if (flags & MSG_OOB)
+                goto out_nofree;
+
+        if (addr_len)
+                *addr_len = sizeof(sa);
+
+        skb = skb_recv_datagram(sk, flags, noblock, &rval);
+        if (skb == NULL)
+                goto out_nofree;
+
+        pn_skb_get_src_sockaddr(skb, &sa);
+
+        copylen = skb->len;
+        if (len < copylen) {
+                msg->msg_flags |= MSG_TRUNC;
+                copylen = len;
+        }
+
+        rval = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copylen);
+        if (rval) {
+                rval = -EFAULT;
+                goto out;
+        }
+
+        rval = (flags & MSG_TRUNC) ? skb->len : copylen;
+
+        if (msg->msg_name != NULL)
+                memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn));
+
+out:
+        skb_free_datagram(sk, skb);
+
+out_nofree:
+        return rval;
+}
+
+/* Queue an skb for a sock. */
+static int pn_backlog_rcv(struct sock *sk, struct sk_buff *skb)
+{
+        int err = sock_queue_rcv_skb(sk, skb);
+        if (err < 0)
+                kfree_skb(skb);
+        return err ? NET_RX_DROP : NET_RX_SUCCESS;
+}
+
+/* Module registration */
+static struct proto pn_proto = {
+        .close          = pn_sock_close,
+        .ioctl          = pn_ioctl,
+        .init           = pn_init,
+        .sendmsg        = pn_sendmsg,
+        .recvmsg        = pn_recvmsg,
+        .backlog_rcv    = pn_backlog_rcv,
+        .hash           = pn_sock_hash,
+        .unhash         = pn_sock_unhash,
+        .get_port       = pn_sock_get_port,
+        .obj_size       = sizeof(struct pn_sock),
+        .owner          = THIS_MODULE,
+        .name           = "PHONET",
+};
+
+static struct phonet_protocol pn_dgram_proto = {
+        .ops            = &phonet_dgram_ops,
+        .prot           = &pn_proto,
+        .sock_type      = SOCK_DGRAM,
+};
+
+int __init isi_register(void)
+{
+        return phonet_proto_register(PN_PROTO_PHONET, &pn_dgram_proto);
+}
+
+void __exit isi_unregister(void)
+{
+        phonet_proto_unregister(PN_PROTO_PHONET, &pn_dgram_proto);
+}