+++ /dev/null
-/* 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");
projects / firefly-linux-kernel-4.4.55.git / commitdiff