diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/net/ppp/pppolac.c')
-rw-r--r-- | ANDROID_3.4.5/drivers/net/ppp/pppolac.c | 449 |
1 files changed, 0 insertions, 449 deletions
diff --git a/ANDROID_3.4.5/drivers/net/ppp/pppolac.c b/ANDROID_3.4.5/drivers/net/ppp/pppolac.c deleted file mode 100644 index a5d3d634..00000000 --- a/ANDROID_3.4.5/drivers/net/ppp/pppolac.c +++ /dev/null @@ -1,449 +0,0 @@ -/* 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"); |