diff options
Diffstat (limited to 'net/phonet/af_phonet.c')
| -rw-r--r-- | net/phonet/af_phonet.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c new file mode 100644 index 000000000000..0cfea9bc994a --- /dev/null +++ b/net/phonet/af_phonet.c @@ -0,0 +1,216 @@ +/* + * File: af_phonet.c + * + * Phonet protocols family + * + * 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/module.h> +#include <asm/unaligned.h> +#include <net/sock.h> + +#include <linux/if_phonet.h> +#include <linux/phonet.h> +#include <net/phonet/phonet.h> + +static struct net_proto_family phonet_proto_family; +static struct phonet_protocol *phonet_proto_get(int protocol); +static inline void phonet_proto_put(struct phonet_protocol *pp); + +/* protocol family functions */ + +static int pn_socket_create(struct net *net, struct socket *sock, int protocol) +{ + struct phonet_protocol *pnp; + int err; + + if (net != &init_net) + return -EAFNOSUPPORT; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (protocol == 0) { + /* Default protocol selection */ + switch (sock->type) { + case SOCK_DGRAM: + protocol = PN_PROTO_PHONET; + break; + default: + return -EPROTONOSUPPORT; + } + } + + pnp = phonet_proto_get(protocol); + if (pnp == NULL) + return -EPROTONOSUPPORT; + if (sock->type != pnp->sock_type) { + err = -EPROTONOSUPPORT; + goto out; + } + + /* TODO: create and init the struct sock */ + err = -EPROTONOSUPPORT; + +out: + phonet_proto_put(pnp); + return err; +} + +static struct net_proto_family phonet_proto_family = { + .family = AF_PHONET, + .create = pn_socket_create, + .owner = THIS_MODULE, +}; + +/* packet type functions */ + +/* + * Stuff received packets to associated sockets. + * On error, returns non-zero and releases the skb. + */ +static int phonet_rcv(struct sk_buff *skb, struct net_device *dev, + struct packet_type *pkttype, + struct net_device *orig_dev) +{ + struct phonethdr *ph; + struct sockaddr_pn sa; + u16 len; + + if (dev_net(dev) != &init_net) + goto out; + + /* check we have at least a full Phonet header */ + if (!pskb_pull(skb, sizeof(struct phonethdr))) + goto out; + + /* check that the advertised length is correct */ + ph = pn_hdr(skb); + len = get_unaligned_be16(&ph->pn_length); + if (len < 2) + goto out; + len -= 2; + if ((len > skb->len) || pskb_trim(skb, len)) + goto out; + skb_reset_transport_header(skb); + + pn_skb_get_dst_sockaddr(skb, &sa); + if (pn_sockaddr_get_addr(&sa) == 0) + goto out; /* currently, we cannot be device 0 */ + + /* TODO: put packets to sockets backlog */ + +out: + kfree_skb(skb); + return NET_RX_DROP; +} + +static struct packet_type phonet_packet_type = { + .type = __constant_htons(ETH_P_PHONET), + .dev = NULL, + .func = phonet_rcv, +}; + +/* Transport protocol registration */ +static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; +static DEFINE_SPINLOCK(proto_tab_lock); + +int __init_or_module phonet_proto_register(int protocol, + struct phonet_protocol *pp) +{ + int err = 0; + + if (protocol >= PHONET_NPROTO) + return -EINVAL; + + err = proto_register(pp->prot, 1); + if (err) + return err; + + spin_lock(&proto_tab_lock); + if (proto_tab[protocol]) + err = -EBUSY; + else + proto_tab[protocol] = pp; + spin_unlock(&proto_tab_lock); + + return err; +} +EXPORT_SYMBOL(phonet_proto_register); + +void phonet_proto_unregister(int protocol, struct phonet_protocol *pp) +{ + spin_lock(&proto_tab_lock); + BUG_ON(proto_tab[protocol] != pp); + proto_tab[protocol] = NULL; + spin_unlock(&proto_tab_lock); + proto_unregister(pp->prot); +} +EXPORT_SYMBOL(phonet_proto_unregister); + +static struct phonet_protocol *phonet_proto_get(int protocol) +{ + struct phonet_protocol *pp; + + if (protocol >= PHONET_NPROTO) + return NULL; + + spin_lock(&proto_tab_lock); + pp = proto_tab[protocol]; + if (pp && !try_module_get(pp->prot->owner)) + pp = NULL; + spin_unlock(&proto_tab_lock); + + return pp; +} + +static inline void phonet_proto_put(struct phonet_protocol *pp) +{ + module_put(pp->prot->owner); +} + +/* Module registration */ +static int __init phonet_init(void) +{ + int err; + + err = sock_register(&phonet_proto_family); + if (err) { + printk(KERN_ALERT + "phonet protocol family initialization failed\n"); + return err; + } + + dev_add_pack(&phonet_packet_type); + return 0; +} + +static void __exit phonet_exit(void) +{ + sock_unregister(AF_PHONET); + dev_remove_pack(&phonet_packet_type); +} + +module_init(phonet_init); +module_exit(phonet_exit); +MODULE_DESCRIPTION("Phonet protocol stack for Linux"); +MODULE_LICENSE("GPL"); |