pppoe.c

linux 内核源代码

	struct pppox_sock *po = pppox_sk(sk);
	int error;

	lock_sock(sk);

	error = -EINVAL;
	if (sp->sa_protocol != PX_PROTO_OE)
		goto end;

	/* Check for already bound sockets */
	error = -EBUSY;
	if ((sk->sk_state & PPPOX_CONNECTED) && sp->sa_addr.pppoe.sid)
		goto end;

	/* Check for already disconnected sockets, on attempts to disconnect */
	error = -EALREADY;
	if ((sk->sk_state & PPPOX_DEAD) && !sp->sa_addr.pppoe.sid )
		goto end;

	error = 0;
	if (po->pppoe_pa.sid) {
		pppox_unbind_sock(sk);

		/* Delete the old binding */
		delete_item(po->pppoe_pa.sid,po->pppoe_pa.remote,po->pppoe_ifindex);

		if(po->pppoe_dev)
			dev_put(po->pppoe_dev);

		memset(sk_pppox(po) + 1, 0,
		       sizeof(struct pppox_sock) - sizeof(struct sock));

		sk->sk_state = PPPOX_NONE;
	}

	/* Don't re-bind if sid==0 */
	if (sp->sa_addr.pppoe.sid != 0) {
		dev = dev_get_by_name(&init_net, sp->sa_addr.pppoe.dev);

		error = -ENODEV;
		if (!dev)
			goto end;

		po->pppoe_dev = dev;
		po->pppoe_ifindex = dev->ifindex;

		write_lock_bh(&pppoe_hash_lock);
		if (!(dev->flags & IFF_UP)){
			write_unlock_bh(&pppoe_hash_lock);
			goto err_put;
		}

		memcpy(&po->pppoe_pa,
		       &sp->sa_addr.pppoe,
		       sizeof(struct pppoe_addr));

		error = __set_item(po);
		write_unlock_bh(&pppoe_hash_lock);
		if (error < 0)
			goto err_put;

		po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
				   dev->hard_header_len);

		po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
		po->chan.private = sk;
		po->chan.ops = &pppoe_chan_ops;

		error = ppp_register_channel(&po->chan);
		if (error)
			goto err_put;

		sk->sk_state = PPPOX_CONNECTED;
	}

	po->num = sp->sa_addr.pppoe.sid;

 end:
	release_sock(sk);
	return error;
err_put:
	if (po->pppoe_dev) {
		dev_put(po->pppoe_dev);
		po->pppoe_dev = NULL;
	}
	goto end;
}


static int pppoe_getname(struct socket *sock, struct sockaddr *uaddr,
		  int *usockaddr_len, int peer)
{
	int len = sizeof(struct sockaddr_pppox);
	struct sockaddr_pppox sp;

	sp.sa_family	= AF_PPPOX;
	sp.sa_protocol	= PX_PROTO_OE;
	memcpy(&sp.sa_addr.pppoe, &pppox_sk(sock->sk)->pppoe_pa,
	       sizeof(struct pppoe_addr));

	memcpy(uaddr, &sp, len);

	*usockaddr_len = len;

	return 0;
}


static int pppoe_ioctl(struct socket *sock, unsigned int cmd,
		unsigned long arg)
{
	struct sock *sk = sock->sk;
	struct pppox_sock *po = pppox_sk(sk);
	int val;
	int err;

	switch (cmd) {
	case PPPIOCGMRU:
		err = -ENXIO;

		if (!(sk->sk_state & PPPOX_CONNECTED))
			break;

		err = -EFAULT;
		if (put_user(po->pppoe_dev->mtu -
			     sizeof(struct pppoe_hdr) -
			     PPP_HDRLEN,
			     (int __user *) arg))
			break;
		err = 0;
		break;

	case PPPIOCSMRU:
		err = -ENXIO;
		if (!(sk->sk_state & PPPOX_CONNECTED))
			break;

		err = -EFAULT;
		if (get_user(val,(int __user *) arg))
			break;

		if (val < (po->pppoe_dev->mtu
			   - sizeof(struct pppoe_hdr)
			   - PPP_HDRLEN))
			err = 0;
		else
			err = -EINVAL;
		break;

	case PPPIOCSFLAGS:
		err = -EFAULT;
		if (get_user(val, (int __user *) arg))
			break;
		err = 0;
		break;

	case PPPOEIOCSFWD:
	{
		struct pppox_sock *relay_po;

		err = -EBUSY;
		if (sk->sk_state & (PPPOX_BOUND | PPPOX_ZOMBIE | PPPOX_DEAD))
			break;

		err = -ENOTCONN;
		if (!(sk->sk_state & PPPOX_CONNECTED))
			break;

		/* PPPoE address from the user specifies an outbound
		   PPPoE address which frames are forwarded to */
		err = -EFAULT;
		if (copy_from_user(&po->pppoe_relay,
				   (void __user *)arg,
				   sizeof(struct sockaddr_pppox)))
			break;

		err = -EINVAL;
		if (po->pppoe_relay.sa_family != AF_PPPOX ||
		    po->pppoe_relay.sa_protocol!= PX_PROTO_OE)
			break;

		/* Check that the socket referenced by the address
		   actually exists. */
		relay_po = get_item_by_addr(&po->pppoe_relay);

		if (!relay_po)
			break;

		sock_put(sk_pppox(relay_po));
		sk->sk_state |= PPPOX_RELAY;
		err = 0;
		break;
	}

	case PPPOEIOCDFWD:
		err = -EALREADY;
		if (!(sk->sk_state & PPPOX_RELAY))
			break;

		sk->sk_state &= ~PPPOX_RELAY;
		err = 0;
		break;

	default:
		err = -ENOTTY;
	}

	return err;
}


static int pppoe_sendmsg(struct kiocb *iocb, struct socket *sock,
		  struct msghdr *m, size_t total_len)
{
	struct sk_buff *skb;
	struct sock *sk = sock->sk;
	struct pppox_sock *po = pppox_sk(sk);
	int error;
	struct pppoe_hdr hdr;
	struct pppoe_hdr *ph;
	struct net_device *dev;
	char *start;

	lock_sock(sk);
	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) {
		error = -ENOTCONN;
		goto end;
	}

	hdr.ver = 1;
	hdr.type = 1;
	hdr.code = 0;
	hdr.sid = po->num;

	dev = po->pppoe_dev;

	error = -EMSGSIZE;
 	if (total_len > (dev->mtu + dev->hard_header_len))
		goto end;


	skb = sock_wmalloc(sk, total_len + dev->hard_header_len + 32,
			   0, GFP_KERNEL);
	if (!skb) {
		error = -ENOMEM;
		goto end;
	}

	/* Reserve space for headers. */
	skb_reserve(skb, dev->hard_header_len);
	skb_reset_network_header(skb);

	skb->dev = dev;

	skb->priority = sk->sk_priority;
	skb->protocol = __constant_htons(ETH_P_PPP_SES);

	ph = (struct pppoe_hdr *) skb_put(skb, total_len + sizeof(struct pppoe_hdr));
	start = (char *) &ph->tag[0];

	error = memcpy_fromiovec(start, m->msg_iov, total_len);

	if (error < 0) {
		kfree_skb(skb);
		goto end;
	}

	error = total_len;
	dev_hard_header(skb, dev, ETH_P_PPP_SES,
			po->pppoe_pa.remote, NULL, total_len);

	memcpy(ph, &hdr, sizeof(struct pppoe_hdr));

	ph->length = htons(total_len);

	dev_queue_xmit(skb);

end:
	release_sock(sk);
	return error;
}


/************************************************************************
 *
 * xmit function for internal use.
 *
 ***********************************************************************/
static int __pppoe_xmit(struct sock *sk, struct sk_buff *skb)
{
	struct pppox_sock *po = pppox_sk(sk);
	struct net_device *dev = po->pppoe_dev;
	struct pppoe_hdr *ph;
	int data_len = skb->len;

	if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED))
		goto abort;

	if (!dev)
		goto abort;

	/* Copy the data if there is no space for the header or if it's
	 * read-only.
	 */
	if (skb_cow_head(skb, sizeof(*ph) + dev->hard_header_len))
		goto abort;

	__skb_push(skb, sizeof(*ph));
	skb_reset_network_header(skb);

	ph = pppoe_hdr(skb);
	ph->ver	= 1;
	ph->type = 1;
	ph->code = 0;
	ph->sid	= po->num;
	ph->length = htons(data_len);

	skb->protocol = __constant_htons(ETH_P_PPP_SES);
	skb->dev = dev;

	dev_hard_header(skb, dev, ETH_P_PPP_SES,
			po->pppoe_pa.remote, NULL, data_len);

	dev_queue_xmit(skb);

	return 1;

abort:
	kfree_skb(skb);
	return 1;
}


/************************************************************************
 *
 * xmit function called by generic PPP driver
 * sends PPP frame over PPPoE socket
 *
 ***********************************************************************/
static int pppoe_xmit(struct ppp_channel *chan, struct sk_buff *skb)
{
	struct sock *sk = (struct sock *) chan->private;
	return __pppoe_xmit(sk, skb);
}


static struct ppp_channel_ops pppoe_chan_ops = {
	.start_xmit = pppoe_xmit,
};

static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
		  struct msghdr *m, size_t total_len, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *skb;
	int error = 0;

	if (sk->sk_state & PPPOX_BOUND) {
		error = -EIO;
		goto end;
	}

	skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
				flags & MSG_DONTWAIT, &error);

	if (error < 0)
		goto end;

	m->msg_namelen = 0;

	if (skb) {
		struct pppoe_hdr *ph = pppoe_hdr(skb);
		const int len = ntohs(ph->length);

		error = memcpy_toiovec(m->msg_iov, (unsigned char *) &ph->tag[0], len);
		if (error == 0)
			error = len;
	}

	kfree_skb(skb);
end:
	return error;
}

#ifdef CONFIG_PROC_FS
static int pppoe_seq_show(struct seq_file *seq, void *v)
{
	struct pppox_sock *po;
	char *dev_name;
	DECLARE_MAC_BUF(mac);

	if (v == SEQ_START_TOKEN) {
		seq_puts(seq, "Id       Address              Device\n");
		goto out;
	}

	po = v;
	dev_name = po->pppoe_pa.dev;

	seq_printf(seq, "%08X %s %8s\n",
		   po->pppoe_pa.sid, print_mac(mac, po->pppoe_pa.remote), dev_name);
out:
	return 0;
}

static __inline__ struct pppox_sock *pppoe_get_idx(loff_t pos)
{
	struct pppox_sock *po;
	int i = 0;

	for (; i < PPPOE_HASH_SIZE; i++) {
		po = item_hash_table[i];
		while (po) {
			if (!pos--)
				goto out;
			po = po->next;
		}
	}
out:
	return po;
}

static void *pppoe_seq_start(struct seq_file *seq, loff_t *pos)
{
	loff_t l = *pos;

	read_lock_bh(&pppoe_hash_lock);
	return l ? pppoe_get_idx(--l) : SEQ_START_TOKEN;
}

static void *pppoe_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct pppox_sock *po;

	++*pos;
	if (v == SEQ_START_TOKEN) {
		po = pppoe_get_idx(0);
		goto out;
	}
	po = v;
	if (po->next)
		po = po->next;
	else {
		int hash = hash_item(po->pppoe_pa.sid, po->pppoe_pa.remote);

		while (++hash < PPPOE_HASH_SIZE) {
			po = item_hash_table[hash];
			if (po)
				break;
		}
	}
out:
	return po;
}

static void pppoe_seq_stop(struct seq_file *seq, void *v)
{
	read_unlock_bh(&pppoe_hash_lock);
}

static struct seq_operations pppoe_seq_ops = {
	.start		= pppoe_seq_start,
	.next		= pppoe_seq_next,
	.stop		= pppoe_seq_stop,
	.show		= pppoe_seq_show,
};

static int pppoe_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &pppoe_seq_ops);
}

static const struct file_operations pppoe_seq_fops = {
	.owner		= THIS_MODULE,
	.open		= pppoe_seq_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

static int __init pppoe_proc_init(void)
{
	struct proc_dir_entry *p;

	p = create_proc_entry("pppoe", S_IRUGO, init_net.proc_net);
	if (!p)
		return -ENOMEM;

	p->proc_fops = &pppoe_seq_fops;
	return 0;
}
#else /* CONFIG_PROC_FS */
static inline int pppoe_proc_init(void) { return 0; }
#endif /* CONFIG_PROC_FS */

static const struct proto_ops pppoe_ops = {
    .family		= AF_PPPOX,
    .owner		= THIS_MODULE,
    .release		= pppoe_release,
    .bind		= sock_no_bind,
    .connect		= pppoe_connect,
    .socketpair		= sock_no_socketpair,
    .accept		= sock_no_accept,
    .getname		= pppoe_getname,
    .poll		= datagram_poll,
    .listen		= sock_no_listen,
    .shutdown		= sock_no_shutdown,
    .setsockopt		= sock_no_setsockopt,
    .getsockopt		= sock_no_getsockopt,
    .sendmsg		= pppoe_sendmsg,
    .recvmsg		= pppoe_recvmsg,
    .mmap		= sock_no_mmap,
    .ioctl		= pppox_ioctl,
};

static struct pppox_proto pppoe_proto = {
    .create	= pppoe_create,
    .ioctl	= pppoe_ioctl,
    .owner	= THIS_MODULE,
};


static int __init pppoe_init(void)
{
	int err = proto_register(&pppoe_sk_proto, 0);

	if (err)
		goto out;

 	err = register_pppox_proto(PX_PROTO_OE, &pppoe_proto);
	if (err)
		goto out_unregister_pppoe_proto;

	err = pppoe_proc_init();
	if (err)
		goto out_unregister_pppox_proto;

	dev_add_pack(&pppoes_ptype);
	dev_add_pack(&pppoed_ptype);
	register_netdevice_notifier(&pppoe_notifier);
out:
	return err;
out_unregister_pppox_proto:
	unregister_pppox_proto(PX_PROTO_OE);
out_unregister_pppoe_proto:
	proto_unregister(&pppoe_sk_proto);
	goto out;
}

static void __exit pppoe_exit(void)
{
	unregister_pppox_proto(PX_PROTO_OE);
	dev_remove_pack(&pppoes_ptype);
	dev_remove_pack(&pppoed_ptype);
	unregister_netdevice_notifier(&pppoe_notifier);
	remove_proc_entry("pppoe", init_net.proc_net);
	proto_unregister(&pppoe_sk_proto);
}

module_init(pppoe_init);
module_exit(pppoe_exit);

MODULE_AUTHOR("Michal Ostrowski <[e-mail]>");
MODULE_DESCRIPTION("PPP over Ethernet driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETPROTO(PF_PPPOX);