net: add PPP on PPTP Network Server (PPPoPNS) driver. (e7e501c6) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/net/ppp/Kconfig

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Original line number	Diff line number	Diff line
		@@ -158,6 +158,14 @@ config PPPOLAC
		and a PPP channel, but only permits one session per socket. Thus it is
		fairly simple and suited for clients.

		config PPPOPNS
		tristate "PPP on PPTP Network Server"
		depends on PPP && INET
		help
		PPTP (RFC 2637) is a tunneling protocol widely used in virtual private
		networks. This driver handles PPTP data packets between a RAW socket
		and a PPP channel. It is fairly simple and easy to use.

		config PPP_ASYNC
		tristate "PPP support for async serial ports"
		depends on PPP

drivers/net/ppp/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -12,3 +12,4 @@ obj-$(CONFIG_PPPOE) += pppox.o pppoe.o
		obj-$(CONFIG_PPPOL2TP) += pppox.o
		obj-$(CONFIG_PPTP) += pppox.o pptp.o
		obj-$(CONFIG_PPPOLAC) += pppox.o pppolac.o
		obj-$(CONFIG_PPPOPNS) += pppox.o pppopns.o

drivers/net/ppp/pppopns.c

0 → 100644

+322 −0

Original line number	Diff line number	Diff line
		/* drivers/net/pppopns.c
		*
		* Driver for PPP on PPTP Network Server / PPPoPNS Socket (RFC 2637)
		*
		* Copyright (C) 2009 Google, Inc.
		* Author: Chia-chi Yeh <chiachi@android.com>
		*
		* 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 PPTP data packets between a RAW socket and a PPP channel.
		* The socket is created in the kernel space and connected to the same address
		* of the control socket. To keep things simple, packets are always sent with
		* sequence but without acknowledgement. This driver should work on both IPv4
		* and IPv6. */

		#include <linux/module.h>
		#include <linux/skbuff.h>
		#include <linux/file.h>
		#include <linux/net.h>
		#include <linux/ppp_defs.h>
		#include <linux/if.h>
		#include <linux/if_ppp.h>
		#include <linux/if_pppox.h>
		#include <linux/ppp_channel.h>

		#define GRE_HEADER_SIZE 8

		#define PPTP_GRE_MASK htons(0x2001)
		#define PPTP_GRE_SEQ_MASK htons(0x1000)
		#define PPTP_GRE_ACK_MASK htons(0x0080)
		#define PPTP_GRE_TYPE htons(0x880B)

		#define PPP_ADDR 0xFF
		#define PPP_CTRL 0x03

		struct header {
		__u16 bits;
		__u16 type;
		__u16 length;
		__u16 call;
		__u32 sequence;
		} __attribute__((packed));

		static void pppopns_recv(struct sock *sk_raw, int length)
		{
		struct sock *sk;
		struct pppopns_opt *opt;
		struct sk_buff *skb;
		struct header *hdr;

		/* Lock sk_raw to prevent sk from being closed. */
		lock_sock(sk_raw);
		sk = (struct sock *)sk_raw->sk_user_data;
		if (!sk) {
		release_sock(sk_raw);
		return;
		}
		sock_hold(sk);
		release_sock(sk_raw);
		opt = &pppox_sk(sk)->proto.pns;

		/* Process packets from the receive queue. */
		while ((skb = skb_dequeue(&sk_raw->sk_receive_queue))) {
		skb_pull(skb, skb_transport_header(skb) - skb->data);

		/* Drop the packet if it is too short. */
		if (skb->len < GRE_HEADER_SIZE)
		goto drop;

		/* Check the header. */
		hdr = (struct header *)skb->data;
		if (hdr->type != PPTP_GRE_TYPE \|\| hdr->call != opt->local \|\|
		(hdr->bits & PPTP_GRE_MASK) != PPTP_GRE_MASK)
		goto drop;

		/* Skip all fields including optional ones. */
		if (!skb_pull(skb, GRE_HEADER_SIZE +
		(hdr->bits & PPTP_GRE_SEQ_MASK ? 4 : 0) +
		(hdr->bits & PPTP_GRE_ACK_MASK ? 4 : 0)))
		goto drop;

		/* Check the length. */
		if (skb->len != ntohs(hdr->length))
		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;

		/* Deliver the packet to PPP channel. We have to lock sk to
		* prevent another thread from calling pppox_unbind_sock(). */
		skb_orphan(skb);
		lock_sock(sk);
		ppp_input(&pppox_sk(sk)->chan, skb);
		release_sock(sk);
		continue;
		drop:
		kfree_skb(skb);
		}
		sock_put(sk);
		}

		static int pppopns_xmit(struct ppp_channel chan, struct sk_buff skb)
		{
		struct sock sk_raw = (struct sock )chan->private;
		struct pppopns_opt *opt = &pppox_sk(sk_raw->sk_user_data)->proto.pns;
		struct msghdr msg = {.msg_flags = MSG_NOSIGNAL \| MSG_DONTWAIT};
		struct kvec iov;
		struct header *hdr;
		__u16 length;

		/* Install PPP address and control. */
		skb_push(skb, 2);
		skb->data[0] = PPP_ADDR;
		skb->data[1] = PPP_CTRL;
		length = skb->len;

		/* Install PPTP GRE header. */
		hdr = (struct header *)skb_push(skb, 12);
		hdr->bits = PPTP_GRE_MASK \| PPTP_GRE_SEQ_MASK;
		hdr->type = PPTP_GRE_TYPE;
		hdr->length = htons(length);
		hdr->call = opt->remote;
		hdr->sequence = htonl(opt->sequence);
		opt->sequence++;

		/* Now send the packet via RAW socket. */
		iov.iov_base = skb->data;
		iov.iov_len = skb->len;
		kernel_sendmsg(sk_raw->sk_socket, &msg, &iov, 1, skb->len);
		kfree_skb(skb);
		return 1;
		}

		/******************************************************************************/

		static struct ppp_channel_ops pppopns_channel_ops = {
		.start_xmit = pppopns_xmit,
		};

		static int pppopns_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_pppopns addr = (struct sockaddr_pppopns )useraddr;
		struct sockaddr_storage ss;
		struct socket *sock_tcp = NULL;
		struct socket *sock_raw = NULL;
		struct sock *sk_raw;
		int error;

		if (addrlen != sizeof(struct sockaddr_pppopns))
		return -EINVAL;

		lock_sock(sk);
		error = -EALREADY;
		if (sk->sk_state != PPPOX_NONE)
		goto out;

		sock_tcp = sockfd_lookup(addr->tcp_socket, &error);
		if (!sock_tcp)
		goto out;
		error = -EPROTONOSUPPORT;
		if (sock_tcp->sk->sk_protocol != IPPROTO_TCP)
		goto out;
		addrlen = sizeof(struct sockaddr_storage);
		error = kernel_getpeername(sock_tcp, (struct sockaddr *)&ss, &addrlen);
		if (error)
		goto out;

		error = sock_create(ss.ss_family, SOCK_RAW, IPPROTO_GRE, &sock_raw);
		if (error)
		goto out;
		error = kernel_connect(sock_raw, (struct sockaddr *)&ss, addrlen, 0);
		if (error)
		goto out;
		sk_raw = sock_raw->sk;

		po->chan.hdrlen = 14;
		po->chan.private = sk_raw;
		po->chan.ops = &pppopns_channel_ops;
		po->chan.mtu = PPP_MTU - 80;
		po->proto.pns.local = addr->local;
		po->proto.pns.remote = addr->remote;

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

		sk->sk_state = PPPOX_CONNECTED;
		sk_raw->sk_user_data = sk;
		sk_raw->sk_data_ready = pppopns_recv;

		out:
		if (sock_tcp)
		sockfd_put(sock_tcp);
		if (error && sock_raw)
		sock_release(sock_raw);
		release_sock(sk);
		return error;
		}

		static int pppopns_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_raw = (struct sock )pppox_sk(sk)->chan.private;
		lock_sock(sk_raw);
		pppox_unbind_sock(sk);
		sk_raw->sk_user_data = NULL;
		release_sock(sk_raw);
		sock_release(sk_raw->sk_socket);
		}

		sock_orphan(sk);
		sock->sk = NULL;
		release_sock(sk);
		sock_put(sk);
		return 0;
		}

		/******************************************************************************/

		static struct proto pppopns_proto = {
		.name = "PPPOPNS",
		.owner = THIS_MODULE,
		.obj_size = sizeof(struct pppox_sock),
		};

		static struct proto_ops pppopns_proto_ops = {
		.family = PF_PPPOX,
		.owner = THIS_MODULE,
		.release = pppopns_release,
		.bind = sock_no_bind,
		.connect = pppopns_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 pppopns_create(struct net net, struct socket sock)
		{
		struct sock *sk;

		sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppopns_proto);
		if (!sk)
		return -ENOMEM;

		sock_init_data(sock, sk);
		sock->state = SS_UNCONNECTED;
		sock->ops = &pppopns_proto_ops;
		sk->sk_protocol = PX_PROTO_OPNS;
		sk->sk_state = PPPOX_NONE;
		return 0;
		}

		/******************************************************************************/

		static struct pppox_proto pppopns_pppox_proto = {
		.create = pppopns_create,
		.owner = THIS_MODULE,
		};

		static int __init pppopns_init(void)
		{
		int error;

		error = proto_register(&pppopns_proto, 0);
		if (error)
		return error;

		error = register_pppox_proto(PX_PROTO_OPNS, &pppopns_pppox_proto);
		if (error)
		proto_unregister(&pppopns_proto);
		return error;
		}

		static void __exit pppopns_exit(void)
		{
		unregister_pppox_proto(PX_PROTO_OPNS);
		proto_unregister(&pppopns_proto);
		}

		module_init(pppopns_init);
		module_exit(pppopns_exit);

		MODULE_DESCRIPTION("PPP on PPTP Network Server (PPPoPNS)");
		MODULE_AUTHOR("Chia-chi Yeh <chiachi@android.com>");
		MODULE_LICENSE("GPL");

include/linux/if_pppopns.h

0 → 100644

+32 −0

Original line number	Diff line number	Diff line
		/* include/linux/if_pppopns.h
		*
		* Header for PPP on PPTP Network Server / PPPoPNS Socket (RFC 2637)
		*
		* Copyright (C) 2009 Google, Inc.
		* Author: Chia-chi Yeh <chiachi@android.com>
		*
		* 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.
		*/

		#ifndef __LINUX_IF_PPPOPNS_H
		#define __LINUX_IF_PPPOPNS_H

		#include <linux/socket.h>
		#include <linux/types.h>

		struct sockaddr_pppopns {
		sa_family_t sa_family; /* AF_PPPOX */
		unsigned int sa_protocol; /* PX_PROTO_OPNS */
		int tcp_socket;
		__u16 local;
		__u16 remote;
		} __attribute__((packed));

		#endif /* __LINUX_IF_PPPOPNS_H */

include/linux/if_pppox.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,12 @@ struct pppolac_opt {
		__u8 sequencing;
		};

		struct pppopns_opt {
		__u16 local;
		__u16 remote;
		__u32 sequence;
		};

		#include <net/sock.h>

		struct pppox_sock {
		@@ -60,6 +66,7 @@ struct pppox_sock {
		struct pppoe_opt pppoe;
		struct pptp_opt pptp;
		struct pppolac_opt lac;
		struct pppopns_opt pns;
		} proto;
		__be16 num;
		};