linux/net/phonet/datagram.c
Lin Zhang 548ec11470 net: phonet: mark phonet_protocol as const
The phonet_protocol structs don't need to be written by anyone and
so can be marked as const.

Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07 23:15:08 +01:00

213 lines
4.7 KiB
C

/*
* File: datagram.c
*
* Datagram (ISI) Phonet sockets
*
* Copyright (C) 2008 Nokia Corporation.
*
* Authors: Sakari Ailus <sakari.ailus@nokia.com>
* Rémi Denis-Courmont
*
* 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/slab.h>
#include <linux/socket.h>
#include <asm/ioctls.h>
#include <net/sock.h>
#include <linux/phonet.h>
#include <linux/export.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);
case SIOCPNADDRESOURCE:
case SIOCPNDELRESOURCE: {
u32 res;
if (get_user(res, (u32 __user *)arg))
return -EFAULT;
if (res >= 256)
return -EINVAL;
if (cmd == SIOCPNADDRESOURCE)
return pn_sock_bind_res(sk, res);
else
return pn_sock_unbind_res(sk, res);
}
}
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 sock *sk, struct msghdr *msg, size_t len)
{
DECLARE_SOCKADDR(struct sockaddr_pn *, target, msg->msg_name);
struct sk_buff *skb;
int err;
if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
MSG_CMSG_COMPAT))
return -EOPNOTSUPP;
if (target == NULL)
return -EDESTADDRREQ;
if (msg->msg_namelen < sizeof(struct sockaddr_pn))
return -EINVAL;
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_from_msg((void *)skb_put(skb, len), msg, 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 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_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_NOSIGNAL|
MSG_CMSG_COMPAT))
goto out_nofree;
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_msg(skb, 0, msg, copylen);
if (rval) {
rval = -EFAULT;
goto out;
}
rval = (flags & MSG_TRUNC) ? skb->len : copylen;
if (msg->msg_name != NULL) {
__sockaddr_check_size(sizeof(sa));
memcpy(msg->msg_name, &sa, sizeof(sa));
*addr_len = sizeof(sa);
}
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 const 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);
}