This is the basis for the Phonet protocol families, and introduces the ETH_P_PHONET packet type and the PF_PHONET socket family. Signed-off-by: Remi Denis-Courmont <remi.denis-courmont@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
216 lines
4.8 KiB
C
216 lines
4.8 KiB
C
/*
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* File: af_phonet.c
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*
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* Phonet protocols family
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*
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* Copyright (C) 2008 Nokia Corporation.
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*
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* Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
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* Original author: Sakari Ailus <sakari.ailus@nokia.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <asm/unaligned.h>
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#include <net/sock.h>
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#include <linux/if_phonet.h>
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#include <linux/phonet.h>
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#include <net/phonet/phonet.h>
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static struct net_proto_family phonet_proto_family;
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static struct phonet_protocol *phonet_proto_get(int protocol);
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static inline void phonet_proto_put(struct phonet_protocol *pp);
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/* protocol family functions */
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static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
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{
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struct phonet_protocol *pnp;
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int err;
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if (net != &init_net)
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return -EAFNOSUPPORT;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (protocol == 0) {
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/* Default protocol selection */
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switch (sock->type) {
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case SOCK_DGRAM:
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protocol = PN_PROTO_PHONET;
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break;
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default:
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return -EPROTONOSUPPORT;
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}
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}
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pnp = phonet_proto_get(protocol);
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if (pnp == NULL)
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return -EPROTONOSUPPORT;
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if (sock->type != pnp->sock_type) {
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err = -EPROTONOSUPPORT;
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goto out;
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}
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/* TODO: create and init the struct sock */
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err = -EPROTONOSUPPORT;
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out:
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phonet_proto_put(pnp);
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return err;
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}
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static struct net_proto_family phonet_proto_family = {
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.family = AF_PHONET,
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.create = pn_socket_create,
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.owner = THIS_MODULE,
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};
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/* packet type functions */
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/*
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* Stuff received packets to associated sockets.
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* On error, returns non-zero and releases the skb.
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*/
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static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
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struct packet_type *pkttype,
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struct net_device *orig_dev)
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{
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struct phonethdr *ph;
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struct sockaddr_pn sa;
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u16 len;
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if (dev_net(dev) != &init_net)
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goto out;
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/* check we have at least a full Phonet header */
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if (!pskb_pull(skb, sizeof(struct phonethdr)))
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goto out;
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/* check that the advertised length is correct */
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ph = pn_hdr(skb);
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len = get_unaligned_be16(&ph->pn_length);
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if (len < 2)
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goto out;
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len -= 2;
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if ((len > skb->len) || pskb_trim(skb, len))
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goto out;
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skb_reset_transport_header(skb);
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pn_skb_get_dst_sockaddr(skb, &sa);
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if (pn_sockaddr_get_addr(&sa) == 0)
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goto out; /* currently, we cannot be device 0 */
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/* TODO: put packets to sockets backlog */
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out:
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kfree_skb(skb);
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return NET_RX_DROP;
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}
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static struct packet_type phonet_packet_type = {
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.type = __constant_htons(ETH_P_PHONET),
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.dev = NULL,
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.func = phonet_rcv,
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};
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/* Transport protocol registration */
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static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
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static DEFINE_SPINLOCK(proto_tab_lock);
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int __init_or_module phonet_proto_register(int protocol,
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struct phonet_protocol *pp)
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{
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int err = 0;
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if (protocol >= PHONET_NPROTO)
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return -EINVAL;
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err = proto_register(pp->prot, 1);
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if (err)
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return err;
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spin_lock(&proto_tab_lock);
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if (proto_tab[protocol])
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err = -EBUSY;
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else
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proto_tab[protocol] = pp;
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spin_unlock(&proto_tab_lock);
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return err;
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}
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EXPORT_SYMBOL(phonet_proto_register);
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void phonet_proto_unregister(int protocol, struct phonet_protocol *pp)
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{
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spin_lock(&proto_tab_lock);
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BUG_ON(proto_tab[protocol] != pp);
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proto_tab[protocol] = NULL;
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spin_unlock(&proto_tab_lock);
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proto_unregister(pp->prot);
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}
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EXPORT_SYMBOL(phonet_proto_unregister);
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static struct phonet_protocol *phonet_proto_get(int protocol)
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{
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struct phonet_protocol *pp;
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if (protocol >= PHONET_NPROTO)
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return NULL;
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spin_lock(&proto_tab_lock);
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pp = proto_tab[protocol];
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if (pp && !try_module_get(pp->prot->owner))
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pp = NULL;
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spin_unlock(&proto_tab_lock);
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return pp;
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}
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static inline void phonet_proto_put(struct phonet_protocol *pp)
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{
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module_put(pp->prot->owner);
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}
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/* Module registration */
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static int __init phonet_init(void)
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{
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int err;
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err = sock_register(&phonet_proto_family);
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if (err) {
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printk(KERN_ALERT
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"phonet protocol family initialization failed\n");
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return err;
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}
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dev_add_pack(&phonet_packet_type);
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return 0;
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}
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static void __exit phonet_exit(void)
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{
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sock_unregister(AF_PHONET);
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dev_remove_pack(&phonet_packet_type);
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}
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module_init(phonet_init);
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module_exit(phonet_exit);
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MODULE_DESCRIPTION("Phonet protocol stack for Linux");
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MODULE_LICENSE("GPL");
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