Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 449 insertions, 0 deletions

diff --git a/drivers/net/ppp/pppolac.c b/drivers/net/ppp/pppolac.c
new file mode 100644
index 00000000..a5d3d634
--- /dev/null
+++ b/drivers/net/ppp/pppolac.c
@@ -0,0 +1,449 @@
+/* drivers/net/pppolac.c
+ *
+ * Driver for PPP on L2TP Access Concentrator / PPPoLAC Socket (RFC 2661)
+ *
+ * Copyright (C) 2009 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+/* This driver handles L2TP data packets between a UDP socket and a PPP channel.
+ * The socket must keep connected, and only one session per socket is permitted.
+ * Sequencing of outgoing packets is controlled by LNS. Incoming packets with
+ * sequences are reordered within a sliding window of one second. Currently
+ * reordering only happens when a packet is received. It is done for simplicity
+ * since no additional locks or threads are required. This driver only works on
+ * IPv4 due to the lack of UDP encapsulation support in IPv6. */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+#include <linux/skbuff.h>
+#include <linux/file.h>
+#include <linux/netdevice.h>
+#include <linux/net.h>
+#include <linux/udp.h>
+#include <linux/ppp_defs.h>
+#include <linux/if_ppp.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_channel.h>
+#include <net/tcp_states.h>
+#include <asm/uaccess.h>
+
+#define L2TP_CONTROL_BIT	0x80
+#define L2TP_LENGTH_BIT		0x40
+#define L2TP_SEQUENCE_BIT	0x08
+#define L2TP_OFFSET_BIT		0x02
+#define L2TP_VERSION		0x02
+#define L2TP_VERSION_MASK	0x0F
+
+#define PPP_ADDR	0xFF
+#define PPP_CTRL	0x03
+
+union unaligned {
+	__u32 u32;
+} __attribute__((packed));
+
+static inline union unaligned *unaligned(void *ptr)
+{
+	return (union unaligned *)ptr;
+}
+
+struct meta {
+	__u32 sequence;
+	__u32 timestamp;
+};
+
+static inline struct meta *skb_meta(struct sk_buff *skb)
+{
+	return (struct meta *)skb->cb;
+}
+
+/******************************************************************************/
+
+static int pppolac_recv_core(struct sock *sk_udp, struct sk_buff *skb)
+{
+	struct sock *sk = (struct sock *)sk_udp->sk_user_data;
+	struct pppolac_opt *opt = &pppox_sk(sk)->proto.lac;
+	struct meta *meta = skb_meta(skb);
+	__u32 now = jiffies;
+	__u8 bits;
+	__u8 *ptr;
+
+	/* Drop the packet if L2TP header is missing. */
+	if (skb->len < sizeof(struct udphdr) + 6)
+		goto drop;
+
+	/* Put it back if it is a control packet. */
+	if (skb->data[sizeof(struct udphdr)] & L2TP_CONTROL_BIT)
+		return opt->backlog_rcv(sk_udp, skb);
+
+	/* Skip UDP header. */
+	skb_pull(skb, sizeof(struct udphdr));
+
+	/* Check the version. */
+	if ((skb->data[1] & L2TP_VERSION_MASK) != L2TP_VERSION)
+		goto drop;
+	bits = skb->data[0];
+	ptr = &skb->data[2];
+
+	/* Check the length if it is present. */
+	if (bits & L2TP_LENGTH_BIT) {
+		if ((ptr[0] << 8 | ptr[1]) != skb->len)
+			goto drop;
+		ptr += 2;
+	}
+
+	/* Skip all fields including optional ones. */
+	if (!skb_pull(skb, 6 + (bits & L2TP_SEQUENCE_BIT ? 4 : 0) +
+			(bits & L2TP_LENGTH_BIT ? 2 : 0) +
+			(bits & L2TP_OFFSET_BIT ? 2 : 0)))
+		goto drop;
+
+	/* Skip the offset padding if it is present. */
+	if (bits & L2TP_OFFSET_BIT &&
+			!skb_pull(skb, skb->data[-2] << 8 | skb->data[-1]))
+		goto drop;
+
+	/* Check the tunnel and the session. */
+	if (unaligned(ptr)->u32 != opt->local)
+		goto drop;
+
+	/* Check the sequence if it is present. */
+	if (bits & L2TP_SEQUENCE_BIT) {
+		meta->sequence = ptr[4] << 8 | ptr[5];
+		if ((__s16)(meta->sequence - opt->recv_sequence) < 0)
+			goto drop;
+	}
+
+	/* Skip PPP address and control if they are present. */
+	if (skb->len >= 2 && skb->data[0] == PPP_ADDR &&
+			skb->data[1] == PPP_CTRL)
+		skb_pull(skb, 2);
+
+	/* Fix PPP protocol if it is compressed. */
+	if (skb->len >= 1 && skb->data[0] & 1)
+		skb_push(skb, 1)[0] = 0;
+
+	/* Drop the packet if PPP protocol is missing. */
+	if (skb->len < 2)
+		goto drop;
+
+	/* Perform reordering if sequencing is enabled. */
+	atomic_set(&opt->sequencing, bits & L2TP_SEQUENCE_BIT);
+	if (bits & L2TP_SEQUENCE_BIT) {
+		struct sk_buff *skb1;
+
+		/* Insert the packet into receive queue in order. */
+		skb_set_owner_r(skb, sk);
+		skb_queue_walk(&sk->sk_receive_queue, skb1) {
+			struct meta *meta1 = skb_meta(skb1);
+			__s16 order = meta->sequence - meta1->sequence;
+			if (order == 0)
+				goto drop;
+			if (order < 0) {
+				meta->timestamp = meta1->timestamp;
+				skb_insert(skb1, skb, &sk->sk_receive_queue);
+				skb = NULL;
+				break;
+			}
+		}
+		if (skb) {
+			meta->timestamp = now;
+			skb_queue_tail(&sk->sk_receive_queue, skb);
+		}
+
+		/* Remove packets from receive queue as long as
+		 * 1. the receive buffer is full,
+		 * 2. they are queued longer than one second, or
+		 * 3. there are no missing packets before them. */
+		skb_queue_walk_safe(&sk->sk_receive_queue, skb, skb1) {
+			meta = skb_meta(skb);
+			if (atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
+					now - meta->timestamp < HZ &&
+					meta->sequence != opt->recv_sequence)
+				break;
+			skb_unlink(skb, &sk->sk_receive_queue);
+			opt->recv_sequence = (__u16)(meta->sequence + 1);
+			skb_orphan(skb);
+			ppp_input(&pppox_sk(sk)->chan, skb);
+		}
+		return NET_RX_SUCCESS;
+	}
+
+	/* Flush receive queue if sequencing is disabled. */
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_orphan(skb);
+	ppp_input(&pppox_sk(sk)->chan, skb);
+	return NET_RX_SUCCESS;
+drop:
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static int pppolac_recv(struct sock *sk_udp, struct sk_buff *skb)
+{
+	sock_hold(sk_udp);
+	sk_receive_skb(sk_udp, skb, 0);
+	return 0;
+}
+
+static struct sk_buff_head delivery_queue;
+
+static void pppolac_xmit_core(struct work_struct *delivery_work)
+{
+	mm_segment_t old_fs = get_fs();
+	struct sk_buff *skb;
+
+	set_fs(KERNEL_DS);
+	while ((skb = skb_dequeue(&delivery_queue))) {
+		struct sock *sk_udp = skb->sk;
+		struct kvec iov = {.iov_base = skb->data, .iov_len = skb->len};
+		struct msghdr msg = {
+			.msg_iov = (struct iovec *)&iov,
+			.msg_iovlen = 1,
+			.msg_flags = MSG_NOSIGNAL | MSG_DONTWAIT,
+		};
+		sk_udp->sk_prot->sendmsg(NULL, sk_udp, &msg, skb->len);
+		kfree_skb(skb);
+	}
+	set_fs(old_fs);
+}
+
+static DECLARE_WORK(delivery_work, pppolac_xmit_core);
+
+static int pppolac_xmit(struct ppp_channel *chan, struct sk_buff *skb)
+{
+	struct sock *sk_udp = (struct sock *)chan->private;
+	struct pppolac_opt *opt = &pppox_sk(sk_udp->sk_user_data)->proto.lac;
+
+	/* Install PPP address and control. */
+	skb_push(skb, 2);
+	skb->data[0] = PPP_ADDR;
+	skb->data[1] = PPP_CTRL;
+
+	/* Install L2TP header. */
+	if (atomic_read(&opt->sequencing)) {
+		skb_push(skb, 10);
+		skb->data[0] = L2TP_SEQUENCE_BIT;
+		skb->data[6] = opt->xmit_sequence >> 8;
+		skb->data[7] = opt->xmit_sequence;
+		skb->data[8] = 0;
+		skb->data[9] = 0;
+		opt->xmit_sequence++;
+	} else {
+		skb_push(skb, 6);
+		skb->data[0] = 0;
+	}
+	skb->data[1] = L2TP_VERSION;
+	unaligned(&skb->data[2])->u32 = opt->remote;
+
+	/* Now send the packet via the delivery queue. */
+	skb_set_owner_w(skb, sk_udp);
+	skb_queue_tail(&delivery_queue, skb);
+	schedule_work(&delivery_work);
+	return 1;
+}
+
+/******************************************************************************/
+
+static struct ppp_channel_ops pppolac_channel_ops = {
+	.start_xmit = pppolac_xmit,
+};
+
+static int pppolac_connect(struct socket *sock, struct sockaddr *useraddr,
+	int addrlen, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct pppox_sock *po = pppox_sk(sk);
+	struct sockaddr_pppolac *addr = (struct sockaddr_pppolac *)useraddr;
+	struct socket *sock_udp = NULL;
+	struct sock *sk_udp;
+	int error;
+
+	if (addrlen != sizeof(struct sockaddr_pppolac) ||
+			!addr->local.tunnel || !addr->local.session ||
+			!addr->remote.tunnel || !addr->remote.session) {
+		return -EINVAL;
+	}
+
+	lock_sock(sk);
+	error = -EALREADY;
+	if (sk->sk_state != PPPOX_NONE)
+		goto out;
+
+	sock_udp = sockfd_lookup(addr->udp_socket, &error);
+	if (!sock_udp)
+		goto out;
+	sk_udp = sock_udp->sk;
+	lock_sock(sk_udp);
+
+	/* Remove this check when IPv6 supports UDP encapsulation. */
+	error = -EAFNOSUPPORT;
+	if (sk_udp->sk_family != AF_INET)
+		goto out;
+	error = -EPROTONOSUPPORT;
+	if (sk_udp->sk_protocol != IPPROTO_UDP)
+		goto out;
+	error = -EDESTADDRREQ;
+	if (sk_udp->sk_state != TCP_ESTABLISHED)
+		goto out;
+	error = -EBUSY;
+	if (udp_sk(sk_udp)->encap_type || sk_udp->sk_user_data)
+		goto out;
+	if (!sk_udp->sk_bound_dev_if) {
+		struct dst_entry *dst = sk_dst_get(sk_udp);
+		error = -ENODEV;
+		if (!dst)
+			goto out;
+		sk_udp->sk_bound_dev_if = dst->dev->ifindex;
+		dst_release(dst);
+	}
+
+	po->chan.hdrlen = 12;
+	po->chan.private = sk_udp;
+	po->chan.ops = &pppolac_channel_ops;
+	po->chan.mtu = PPP_MRU - 80;
+	po->proto.lac.local = unaligned(&addr->local)->u32;
+	po->proto.lac.remote = unaligned(&addr->remote)->u32;
+	atomic_set(&po->proto.lac.sequencing, 1);
+	po->proto.lac.backlog_rcv = sk_udp->sk_backlog_rcv;
+
+	error = ppp_register_channel(&po->chan);
+	if (error)
+		goto out;
+
+	sk->sk_state = PPPOX_CONNECTED;
+	udp_sk(sk_udp)->encap_type = UDP_ENCAP_L2TPINUDP;
+	udp_sk(sk_udp)->encap_rcv = pppolac_recv;
+	sk_udp->sk_backlog_rcv = pppolac_recv_core;
+	sk_udp->sk_user_data = sk;
+out:
+	if (sock_udp) {
+		release_sock(sk_udp);
+		if (error)
+			sockfd_put(sock_udp);
+	}
+	release_sock(sk);
+	return error;
+}
+
+static int pppolac_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (!sk)
+		return 0;
+
+	lock_sock(sk);
+	if (sock_flag(sk, SOCK_DEAD)) {
+		release_sock(sk);
+		return -EBADF;
+	}
+
+	if (sk->sk_state != PPPOX_NONE) {
+		struct sock *sk_udp = (struct sock *)pppox_sk(sk)->chan.private;
+		lock_sock(sk_udp);
+		skb_queue_purge(&sk->sk_receive_queue);
+		pppox_unbind_sock(sk);
+		udp_sk(sk_udp)->encap_type = 0;
+		udp_sk(sk_udp)->encap_rcv = NULL;
+		sk_udp->sk_backlog_rcv = pppox_sk(sk)->proto.lac.backlog_rcv;
+		sk_udp->sk_user_data = NULL;
+		release_sock(sk_udp);
+		sockfd_put(sk_udp->sk_socket);
+	}
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+	release_sock(sk);
+	sock_put(sk);
+	return 0;
+}
+
+/******************************************************************************/
+
+static struct proto pppolac_proto = {
+	.name = "PPPOLAC",
+	.owner = THIS_MODULE,
+	.obj_size = sizeof(struct pppox_sock),
+};
+
+static struct proto_ops pppolac_proto_ops = {
+	.family = PF_PPPOX,
+	.owner = THIS_MODULE,
+	.release = pppolac_release,
+	.bind = sock_no_bind,
+	.connect = pppolac_connect,
+	.socketpair = sock_no_socketpair,
+	.accept = sock_no_accept,
+	.getname = sock_no_getname,
+	.poll = sock_no_poll,
+	.ioctl = pppox_ioctl,
+	.listen = sock_no_listen,
+	.shutdown = sock_no_shutdown,
+	.setsockopt = sock_no_setsockopt,
+	.getsockopt = sock_no_getsockopt,
+	.sendmsg = sock_no_sendmsg,
+	.recvmsg = sock_no_recvmsg,
+	.mmap = sock_no_mmap,
+};
+
+static int pppolac_create(struct net *net, struct socket *sock)
+{
+	struct sock *sk;
+
+	sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppolac_proto);
+	if (!sk)
+		return -ENOMEM;
+
+	sock_init_data(sock, sk);
+	sock->state = SS_UNCONNECTED;
+	sock->ops = &pppolac_proto_ops;
+	sk->sk_protocol = PX_PROTO_OLAC;
+	sk->sk_state = PPPOX_NONE;
+	return 0;
+}
+
+/******************************************************************************/
+
+static struct pppox_proto pppolac_pppox_proto = {
+	.create = pppolac_create,
+	.owner = THIS_MODULE,
+};
+
+static int __init pppolac_init(void)
+{
+	int error;
+
+	error = proto_register(&pppolac_proto, 0);
+	if (error)
+		return error;
+
+	error = register_pppox_proto(PX_PROTO_OLAC, &pppolac_pppox_proto);
+	if (error)
+		proto_unregister(&pppolac_proto);
+	else
+		skb_queue_head_init(&delivery_queue);
+	return error;
+}
+
+static void __exit pppolac_exit(void)
+{
+	unregister_pppox_proto(PX_PROTO_OLAC);
+	proto_unregister(&pppolac_proto);
+}
+
+module_init(pppolac_init);
+module_exit(pppolac_exit);
+
+MODULE_DESCRIPTION("PPP on L2TP Access Concentrator (PPPoLAC)");
+MODULE_AUTHOR("Chia-chi Yeh <chiachi@android.com>");
+MODULE_LICENSE("GPL");