 b26ba202e0
			
		
	
	
	b26ba202e0
	
	
	
		
			
			It doesn't seem like an protocols are setting anything other than the default, and allowing to arbitrarily disable checksums for a whole protocol seems dangerous. This can be done on a per socket basis. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			805 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			805 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * L2TPv3 IP encapsulation support for IPv6
 | |
|  *
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|  * Copyright (c) 2012 Katalix Systems Ltd
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|  *
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|  *	This program is free software; you can redistribute it and/or
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|  *	modify it under the terms of the GNU General Public License
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|  *	as published by the Free Software Foundation; either version
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|  *	2 of the License, or (at your option) any later version.
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|  */
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| 
 | |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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| 
 | |
| #include <linux/icmp.h>
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| #include <linux/module.h>
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| #include <linux/skbuff.h>
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| #include <linux/random.h>
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| #include <linux/socket.h>
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| #include <linux/l2tp.h>
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| #include <linux/in.h>
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| #include <linux/in6.h>
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| #include <net/sock.h>
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| #include <net/ip.h>
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| #include <net/icmp.h>
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| #include <net/udp.h>
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| #include <net/inet_common.h>
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| #include <net/inet_hashtables.h>
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| #include <net/tcp_states.h>
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| #include <net/protocol.h>
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| #include <net/xfrm.h>
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| 
 | |
| #include <net/transp_v6.h>
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| #include <net/addrconf.h>
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| #include <net/ip6_route.h>
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| 
 | |
| #include "l2tp_core.h"
 | |
| 
 | |
| struct l2tp_ip6_sock {
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| 	/* inet_sock has to be the first member of l2tp_ip6_sock */
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| 	struct inet_sock	inet;
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| 
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| 	u32			conn_id;
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| 	u32			peer_conn_id;
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| 
 | |
| 	/* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
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| 	   inet6_sk_generic */
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| 	struct ipv6_pinfo	inet6;
 | |
| };
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| 
 | |
| static DEFINE_RWLOCK(l2tp_ip6_lock);
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| static struct hlist_head l2tp_ip6_table;
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| static struct hlist_head l2tp_ip6_bind_table;
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| 
 | |
| static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
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| {
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| 	return (struct l2tp_ip6_sock *)sk;
 | |
| }
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| 
 | |
| static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
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| 					   struct in6_addr *laddr,
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| 					   int dif, u32 tunnel_id)
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| {
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| 	struct sock *sk;
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| 
 | |
| 	sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
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| 		const struct in6_addr *addr = inet6_rcv_saddr(sk);
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| 		struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
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| 
 | |
| 		if (l2tp == NULL)
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| 			continue;
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| 
 | |
| 		if ((l2tp->conn_id == tunnel_id) &&
 | |
| 		    net_eq(sock_net(sk), net) &&
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| 		    !(addr && ipv6_addr_equal(addr, laddr)) &&
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| 		    !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif))
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| 			goto found;
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| 	}
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| 
 | |
| 	sk = NULL;
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| found:
 | |
| 	return sk;
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| }
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| 
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| static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,
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| 						struct in6_addr *laddr,
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| 						int dif, u32 tunnel_id)
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| {
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| 	struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);
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| 	if (sk)
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| 		sock_hold(sk);
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| 
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| 	return sk;
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| }
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| 
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| /* When processing receive frames, there are two cases to
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|  * consider. Data frames consist of a non-zero session-id and an
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|  * optional cookie. Control frames consist of a regular L2TP header
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|  * preceded by 32-bits of zeros.
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|  *
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|  * L2TPv3 Session Header Over IP
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|  *
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|  *  0                   1                   2                   3
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|  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |                           Session ID                          |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |               Cookie (optional, maximum 64 bits)...
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  *                                                                 |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  *
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|  * L2TPv3 Control Message Header Over IP
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|  *
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|  *  0                   1                   2                   3
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|  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |                      (32 bits of zeros)                       |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |T|L|x|x|S|x|x|x|x|x|x|x|  Ver  |             Length            |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |                     Control Connection ID                     |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  * |               Ns              |               Nr              |
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|  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|  *
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|  * All control frames are passed to userspace.
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|  */
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| static int l2tp_ip6_recv(struct sk_buff *skb)
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| {
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| 	struct sock *sk;
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| 	u32 session_id;
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| 	u32 tunnel_id;
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| 	unsigned char *ptr, *optr;
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| 	struct l2tp_session *session;
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| 	struct l2tp_tunnel *tunnel = NULL;
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| 	int length;
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| 
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| 	/* Point to L2TP header */
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| 	optr = ptr = skb->data;
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| 
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| 	if (!pskb_may_pull(skb, 4))
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| 		goto discard;
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| 
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| 	session_id = ntohl(*((__be32 *) ptr));
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| 	ptr += 4;
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| 
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| 	/* RFC3931: L2TP/IP packets have the first 4 bytes containing
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| 	 * the session_id. If it is 0, the packet is a L2TP control
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| 	 * frame and the session_id value can be discarded.
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| 	 */
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| 	if (session_id == 0) {
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| 		__skb_pull(skb, 4);
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| 		goto pass_up;
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| 	}
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| 
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| 	/* Ok, this is a data packet. Lookup the session. */
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| 	session = l2tp_session_find(&init_net, NULL, session_id);
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| 	if (session == NULL)
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| 		goto discard;
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| 
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| 	tunnel = session->tunnel;
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| 	if (tunnel == NULL)
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| 		goto discard;
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| 
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| 	/* Trace packet contents, if enabled */
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| 	if (tunnel->debug & L2TP_MSG_DATA) {
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| 		length = min(32u, skb->len);
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| 		if (!pskb_may_pull(skb, length))
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| 			goto discard;
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| 
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| 		pr_debug("%s: ip recv\n", tunnel->name);
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| 		print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length);
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| 	}
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| 
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| 	l2tp_recv_common(session, skb, ptr, optr, 0, skb->len,
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| 			 tunnel->recv_payload_hook);
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| 	return 0;
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| 
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| pass_up:
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| 	/* Get the tunnel_id from the L2TP header */
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| 	if (!pskb_may_pull(skb, 12))
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| 		goto discard;
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| 
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| 	if ((skb->data[0] & 0xc0) != 0xc0)
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| 		goto discard;
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| 
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| 	tunnel_id = ntohl(*(__be32 *) &skb->data[4]);
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| 	tunnel = l2tp_tunnel_find(&init_net, tunnel_id);
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| 	if (tunnel != NULL)
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| 		sk = tunnel->sock;
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| 	else {
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| 		struct ipv6hdr *iph = ipv6_hdr(skb);
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| 
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| 		read_lock_bh(&l2tp_ip6_lock);
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| 		sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr,
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| 					    0, tunnel_id);
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| 		read_unlock_bh(&l2tp_ip6_lock);
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| 	}
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| 
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| 	if (sk == NULL)
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| 		goto discard;
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| 
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| 	sock_hold(sk);
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| 
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| 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
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| 		goto discard_put;
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| 
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| 	nf_reset(skb);
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| 
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| 	return sk_receive_skb(sk, skb, 1);
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| 
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| discard_put:
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| 	sock_put(sk);
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| 
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| discard:
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| 	kfree_skb(skb);
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| 	return 0;
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| }
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| 
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| static int l2tp_ip6_open(struct sock *sk)
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| {
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| 	/* Prevent autobind. We don't have ports. */
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| 	inet_sk(sk)->inet_num = IPPROTO_L2TP;
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| 
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| 	write_lock_bh(&l2tp_ip6_lock);
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| 	sk_add_node(sk, &l2tp_ip6_table);
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| 	write_unlock_bh(&l2tp_ip6_lock);
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| 
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| 	return 0;
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| }
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| 
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| static void l2tp_ip6_close(struct sock *sk, long timeout)
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| {
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| 	write_lock_bh(&l2tp_ip6_lock);
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| 	hlist_del_init(&sk->sk_bind_node);
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| 	sk_del_node_init(sk);
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| 	write_unlock_bh(&l2tp_ip6_lock);
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| 
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| 	sk_common_release(sk);
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| }
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| 
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| static void l2tp_ip6_destroy_sock(struct sock *sk)
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| {
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| 	struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk);
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| 
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| 	lock_sock(sk);
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| 	ip6_flush_pending_frames(sk);
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| 	release_sock(sk);
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| 
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| 	if (tunnel) {
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| 		l2tp_tunnel_closeall(tunnel);
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| 		sock_put(sk);
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| 	}
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| 
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| 	inet6_destroy_sock(sk);
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| }
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| 
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| static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
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| {
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| 	struct inet_sock *inet = inet_sk(sk);
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| 	struct ipv6_pinfo *np = inet6_sk(sk);
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| 	struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr;
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| 	__be32 v4addr = 0;
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| 	int addr_type;
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| 	int err;
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| 
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| 	if (!sock_flag(sk, SOCK_ZAPPED))
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| 		return -EINVAL;
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| 	if (addr->l2tp_family != AF_INET6)
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| 		return -EINVAL;
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| 	if (addr_len < sizeof(*addr))
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| 		return -EINVAL;
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| 
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| 	addr_type = ipv6_addr_type(&addr->l2tp_addr);
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| 
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| 	/* l2tp_ip6 sockets are IPv6 only */
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| 	if (addr_type == IPV6_ADDR_MAPPED)
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| 		return -EADDRNOTAVAIL;
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| 
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| 	/* L2TP is point-point, not multicast */
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| 	if (addr_type & IPV6_ADDR_MULTICAST)
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| 		return -EADDRNOTAVAIL;
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| 
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| 	err = -EADDRINUSE;
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| 	read_lock_bh(&l2tp_ip6_lock);
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| 	if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr,
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| 				   sk->sk_bound_dev_if, addr->l2tp_conn_id))
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| 		goto out_in_use;
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| 	read_unlock_bh(&l2tp_ip6_lock);
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| 
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| 	lock_sock(sk);
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| 
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| 	err = -EINVAL;
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| 	if (sk->sk_state != TCP_CLOSE)
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| 		goto out_unlock;
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| 
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| 	/* Check if the address belongs to the host. */
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| 	rcu_read_lock();
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| 	if (addr_type != IPV6_ADDR_ANY) {
 | |
| 		struct net_device *dev = NULL;
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| 
 | |
| 		if (addr_type & IPV6_ADDR_LINKLOCAL) {
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| 			if (addr_len >= sizeof(struct sockaddr_in6) &&
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| 			    addr->l2tp_scope_id) {
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| 				/* Override any existing binding, if another
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| 				 * one is supplied by user.
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| 				 */
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| 				sk->sk_bound_dev_if = addr->l2tp_scope_id;
 | |
| 			}
 | |
| 
 | |
| 			/* Binding to link-local address requires an
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| 			   interface */
 | |
| 			if (!sk->sk_bound_dev_if)
 | |
| 				goto out_unlock_rcu;
 | |
| 
 | |
| 			err = -ENODEV;
 | |
| 			dev = dev_get_by_index_rcu(sock_net(sk),
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| 						   sk->sk_bound_dev_if);
 | |
| 			if (!dev)
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| 				goto out_unlock_rcu;
 | |
| 		}
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| 
 | |
| 		/* ipv4 addr of the socket is invalid.  Only the
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| 		 * unspecified and mapped address have a v4 equivalent.
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| 		 */
 | |
| 		v4addr = LOOPBACK4_IPV6;
 | |
| 		err = -EADDRNOTAVAIL;
 | |
| 		if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0))
 | |
| 			goto out_unlock_rcu;
 | |
| 	}
 | |
| 	rcu_read_unlock();
 | |
| 
 | |
| 	inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
 | |
| 	sk->sk_v6_rcv_saddr = addr->l2tp_addr;
 | |
| 	np->saddr = addr->l2tp_addr;
 | |
| 
 | |
| 	l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id;
 | |
| 
 | |
| 	write_lock_bh(&l2tp_ip6_lock);
 | |
| 	sk_add_bind_node(sk, &l2tp_ip6_bind_table);
 | |
| 	sk_del_node_init(sk);
 | |
| 	write_unlock_bh(&l2tp_ip6_lock);
 | |
| 
 | |
| 	sock_reset_flag(sk, SOCK_ZAPPED);
 | |
| 	release_sock(sk);
 | |
| 	return 0;
 | |
| 
 | |
| out_unlock_rcu:
 | |
| 	rcu_read_unlock();
 | |
| out_unlock:
 | |
| 	release_sock(sk);
 | |
| 	return err;
 | |
| 
 | |
| out_in_use:
 | |
| 	read_unlock_bh(&l2tp_ip6_lock);
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr,
 | |
| 			    int addr_len)
 | |
| {
 | |
| 	struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr;
 | |
| 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
 | |
| 	struct in6_addr	*daddr;
 | |
| 	int	addr_type;
 | |
| 	int rc;
 | |
| 
 | |
| 	if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	if (addr_len < sizeof(*lsa))
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	if (usin->sin6_family != AF_INET6)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	addr_type = ipv6_addr_type(&usin->sin6_addr);
 | |
| 	if (addr_type & IPV6_ADDR_MULTICAST)
 | |
| 		return -EINVAL;
 | |
| 
 | |
| 	if (addr_type & IPV6_ADDR_MAPPED) {
 | |
| 		daddr = &usin->sin6_addr;
 | |
| 		if (ipv4_is_multicast(daddr->s6_addr32[3]))
 | |
| 			return -EINVAL;
 | |
| 	}
 | |
| 
 | |
| 	rc = ip6_datagram_connect(sk, uaddr, addr_len);
 | |
| 
 | |
| 	lock_sock(sk);
 | |
| 
 | |
| 	l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id;
 | |
| 
 | |
| 	write_lock_bh(&l2tp_ip6_lock);
 | |
| 	hlist_del_init(&sk->sk_bind_node);
 | |
| 	sk_add_bind_node(sk, &l2tp_ip6_bind_table);
 | |
| 	write_unlock_bh(&l2tp_ip6_lock);
 | |
| 
 | |
| 	release_sock(sk);
 | |
| 
 | |
| 	return rc;
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_disconnect(struct sock *sk, int flags)
 | |
| {
 | |
| 	if (sock_flag(sk, SOCK_ZAPPED))
 | |
| 		return 0;
 | |
| 
 | |
| 	return udp_disconnect(sk, flags);
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,
 | |
| 			    int *uaddr_len, int peer)
 | |
| {
 | |
| 	struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr;
 | |
| 	struct sock *sk = sock->sk;
 | |
| 	struct ipv6_pinfo *np = inet6_sk(sk);
 | |
| 	struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk);
 | |
| 
 | |
| 	lsa->l2tp_family = AF_INET6;
 | |
| 	lsa->l2tp_flowinfo = 0;
 | |
| 	lsa->l2tp_scope_id = 0;
 | |
| 	lsa->l2tp_unused = 0;
 | |
| 	if (peer) {
 | |
| 		if (!lsk->peer_conn_id)
 | |
| 			return -ENOTCONN;
 | |
| 		lsa->l2tp_conn_id = lsk->peer_conn_id;
 | |
| 		lsa->l2tp_addr = sk->sk_v6_daddr;
 | |
| 		if (np->sndflow)
 | |
| 			lsa->l2tp_flowinfo = np->flow_label;
 | |
| 	} else {
 | |
| 		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 | |
| 			lsa->l2tp_addr = np->saddr;
 | |
| 		else
 | |
| 			lsa->l2tp_addr = sk->sk_v6_rcv_saddr;
 | |
| 
 | |
| 		lsa->l2tp_conn_id = lsk->conn_id;
 | |
| 	}
 | |
| 	if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
 | |
| 		lsa->l2tp_scope_id = sk->sk_bound_dev_if;
 | |
| 	*uaddr_len = sizeof(*lsa);
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb)
 | |
| {
 | |
| 	int rc;
 | |
| 
 | |
| 	/* Charge it to the socket, dropping if the queue is full. */
 | |
| 	rc = sock_queue_rcv_skb(sk, skb);
 | |
| 	if (rc < 0)
 | |
| 		goto drop;
 | |
| 
 | |
| 	return 0;
 | |
| 
 | |
| drop:
 | |
| 	IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS);
 | |
| 	kfree_skb(skb);
 | |
| 	return -1;
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_push_pending_frames(struct sock *sk)
 | |
| {
 | |
| 	struct sk_buff *skb;
 | |
| 	__be32 *transhdr = NULL;
 | |
| 	int err = 0;
 | |
| 
 | |
| 	skb = skb_peek(&sk->sk_write_queue);
 | |
| 	if (skb == NULL)
 | |
| 		goto out;
 | |
| 
 | |
| 	transhdr = (__be32 *)skb_transport_header(skb);
 | |
| 	*transhdr = 0;
 | |
| 
 | |
| 	err = ip6_push_pending_frames(sk);
 | |
| 
 | |
| out:
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| /* Userspace will call sendmsg() on the tunnel socket to send L2TP
 | |
|  * control frames.
 | |
|  */
 | |
| static int l2tp_ip6_sendmsg(struct kiocb *iocb, struct sock *sk,
 | |
| 			    struct msghdr *msg, size_t len)
 | |
| {
 | |
| 	struct ipv6_txoptions opt_space;
 | |
| 	DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
 | |
| 	struct in6_addr *daddr, *final_p, final;
 | |
| 	struct ipv6_pinfo *np = inet6_sk(sk);
 | |
| 	struct ipv6_txoptions *opt = NULL;
 | |
| 	struct ip6_flowlabel *flowlabel = NULL;
 | |
| 	struct dst_entry *dst = NULL;
 | |
| 	struct flowi6 fl6;
 | |
| 	int addr_len = msg->msg_namelen;
 | |
| 	int hlimit = -1;
 | |
| 	int tclass = -1;
 | |
| 	int dontfrag = -1;
 | |
| 	int transhdrlen = 4; /* zero session-id */
 | |
| 	int ulen = len + transhdrlen;
 | |
| 	int err;
 | |
| 
 | |
| 	/* Rough check on arithmetic overflow,
 | |
| 	   better check is made in ip6_append_data().
 | |
| 	 */
 | |
| 	if (len > INT_MAX)
 | |
| 		return -EMSGSIZE;
 | |
| 
 | |
| 	/* Mirror BSD error message compatibility */
 | |
| 	if (msg->msg_flags & MSG_OOB)
 | |
| 		return -EOPNOTSUPP;
 | |
| 
 | |
| 	/*
 | |
| 	 *	Get and verify the address.
 | |
| 	 */
 | |
| 	memset(&fl6, 0, sizeof(fl6));
 | |
| 
 | |
| 	fl6.flowi6_mark = sk->sk_mark;
 | |
| 
 | |
| 	if (lsa) {
 | |
| 		if (addr_len < SIN6_LEN_RFC2133)
 | |
| 			return -EINVAL;
 | |
| 
 | |
| 		if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6)
 | |
| 			return -EAFNOSUPPORT;
 | |
| 
 | |
| 		daddr = &lsa->l2tp_addr;
 | |
| 		if (np->sndflow) {
 | |
| 			fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK;
 | |
| 			if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 | |
| 				flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 | |
| 				if (flowlabel == NULL)
 | |
| 					return -EINVAL;
 | |
| 			}
 | |
| 		}
 | |
| 
 | |
| 		/*
 | |
| 		 * Otherwise it will be difficult to maintain
 | |
| 		 * sk->sk_dst_cache.
 | |
| 		 */
 | |
| 		if (sk->sk_state == TCP_ESTABLISHED &&
 | |
| 		    ipv6_addr_equal(daddr, &sk->sk_v6_daddr))
 | |
| 			daddr = &sk->sk_v6_daddr;
 | |
| 
 | |
| 		if (addr_len >= sizeof(struct sockaddr_in6) &&
 | |
| 		    lsa->l2tp_scope_id &&
 | |
| 		    ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL)
 | |
| 			fl6.flowi6_oif = lsa->l2tp_scope_id;
 | |
| 	} else {
 | |
| 		if (sk->sk_state != TCP_ESTABLISHED)
 | |
| 			return -EDESTADDRREQ;
 | |
| 
 | |
| 		daddr = &sk->sk_v6_daddr;
 | |
| 		fl6.flowlabel = np->flow_label;
 | |
| 	}
 | |
| 
 | |
| 	if (fl6.flowi6_oif == 0)
 | |
| 		fl6.flowi6_oif = sk->sk_bound_dev_if;
 | |
| 
 | |
| 	if (msg->msg_controllen) {
 | |
| 		opt = &opt_space;
 | |
| 		memset(opt, 0, sizeof(struct ipv6_txoptions));
 | |
| 		opt->tot_len = sizeof(struct ipv6_txoptions);
 | |
| 
 | |
| 		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
 | |
| 					    &hlimit, &tclass, &dontfrag);
 | |
| 		if (err < 0) {
 | |
| 			fl6_sock_release(flowlabel);
 | |
| 			return err;
 | |
| 		}
 | |
| 		if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) {
 | |
| 			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 | |
| 			if (flowlabel == NULL)
 | |
| 				return -EINVAL;
 | |
| 		}
 | |
| 		if (!(opt->opt_nflen|opt->opt_flen))
 | |
| 			opt = NULL;
 | |
| 	}
 | |
| 
 | |
| 	if (opt == NULL)
 | |
| 		opt = np->opt;
 | |
| 	if (flowlabel)
 | |
| 		opt = fl6_merge_options(&opt_space, flowlabel, opt);
 | |
| 	opt = ipv6_fixup_options(&opt_space, opt);
 | |
| 
 | |
| 	fl6.flowi6_proto = sk->sk_protocol;
 | |
| 	if (!ipv6_addr_any(daddr))
 | |
| 		fl6.daddr = *daddr;
 | |
| 	else
 | |
| 		fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */
 | |
| 	if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr))
 | |
| 		fl6.saddr = np->saddr;
 | |
| 
 | |
| 	final_p = fl6_update_dst(&fl6, opt, &final);
 | |
| 
 | |
| 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 | |
| 		fl6.flowi6_oif = np->mcast_oif;
 | |
| 	else if (!fl6.flowi6_oif)
 | |
| 		fl6.flowi6_oif = np->ucast_oif;
 | |
| 
 | |
| 	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 | |
| 
 | |
| 	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
 | |
| 	if (IS_ERR(dst)) {
 | |
| 		err = PTR_ERR(dst);
 | |
| 		goto out;
 | |
| 	}
 | |
| 
 | |
| 	if (hlimit < 0)
 | |
| 		hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 | |
| 
 | |
| 	if (tclass < 0)
 | |
| 		tclass = np->tclass;
 | |
| 
 | |
| 	if (dontfrag < 0)
 | |
| 		dontfrag = np->dontfrag;
 | |
| 
 | |
| 	if (msg->msg_flags & MSG_CONFIRM)
 | |
| 		goto do_confirm;
 | |
| 
 | |
| back_from_confirm:
 | |
| 	lock_sock(sk);
 | |
| 	err = ip6_append_data(sk, ip_generic_getfrag, msg->msg_iov,
 | |
| 			      ulen, transhdrlen, hlimit, tclass, opt,
 | |
| 			      &fl6, (struct rt6_info *)dst,
 | |
| 			      msg->msg_flags, dontfrag);
 | |
| 	if (err)
 | |
| 		ip6_flush_pending_frames(sk);
 | |
| 	else if (!(msg->msg_flags & MSG_MORE))
 | |
| 		err = l2tp_ip6_push_pending_frames(sk);
 | |
| 	release_sock(sk);
 | |
| done:
 | |
| 	dst_release(dst);
 | |
| out:
 | |
| 	fl6_sock_release(flowlabel);
 | |
| 
 | |
| 	return err < 0 ? err : len;
 | |
| 
 | |
| do_confirm:
 | |
| 	dst_confirm(dst);
 | |
| 	if (!(msg->msg_flags & MSG_PROBE) || len)
 | |
| 		goto back_from_confirm;
 | |
| 	err = 0;
 | |
| 	goto done;
 | |
| }
 | |
| 
 | |
| static int l2tp_ip6_recvmsg(struct kiocb *iocb, struct sock *sk,
 | |
| 			    struct msghdr *msg, size_t len, int noblock,
 | |
| 			    int flags, int *addr_len)
 | |
| {
 | |
| 	struct ipv6_pinfo *np = inet6_sk(sk);
 | |
| 	DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name);
 | |
| 	size_t copied = 0;
 | |
| 	int err = -EOPNOTSUPP;
 | |
| 	struct sk_buff *skb;
 | |
| 
 | |
| 	if (flags & MSG_OOB)
 | |
| 		goto out;
 | |
| 
 | |
| 	if (addr_len)
 | |
| 		*addr_len = sizeof(*lsa);
 | |
| 
 | |
| 	if (flags & MSG_ERRQUEUE)
 | |
| 		return ipv6_recv_error(sk, msg, len, addr_len);
 | |
| 
 | |
| 	skb = skb_recv_datagram(sk, flags, noblock, &err);
 | |
| 	if (!skb)
 | |
| 		goto out;
 | |
| 
 | |
| 	copied = skb->len;
 | |
| 	if (len < copied) {
 | |
| 		msg->msg_flags |= MSG_TRUNC;
 | |
| 		copied = len;
 | |
| 	}
 | |
| 
 | |
| 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 | |
| 	if (err)
 | |
| 		goto done;
 | |
| 
 | |
| 	sock_recv_timestamp(msg, sk, skb);
 | |
| 
 | |
| 	/* Copy the address. */
 | |
| 	if (lsa) {
 | |
| 		lsa->l2tp_family = AF_INET6;
 | |
| 		lsa->l2tp_unused = 0;
 | |
| 		lsa->l2tp_addr = ipv6_hdr(skb)->saddr;
 | |
| 		lsa->l2tp_flowinfo = 0;
 | |
| 		lsa->l2tp_scope_id = 0;
 | |
| 		lsa->l2tp_conn_id = 0;
 | |
| 		if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL)
 | |
| 			lsa->l2tp_scope_id = IP6CB(skb)->iif;
 | |
| 	}
 | |
| 
 | |
| 	if (np->rxopt.all)
 | |
| 		ip6_datagram_recv_ctl(sk, msg, skb);
 | |
| 
 | |
| 	if (flags & MSG_TRUNC)
 | |
| 		copied = skb->len;
 | |
| done:
 | |
| 	skb_free_datagram(sk, skb);
 | |
| out:
 | |
| 	return err ? err : copied;
 | |
| }
 | |
| 
 | |
| static struct proto l2tp_ip6_prot = {
 | |
| 	.name		   = "L2TP/IPv6",
 | |
| 	.owner		   = THIS_MODULE,
 | |
| 	.init		   = l2tp_ip6_open,
 | |
| 	.close		   = l2tp_ip6_close,
 | |
| 	.bind		   = l2tp_ip6_bind,
 | |
| 	.connect	   = l2tp_ip6_connect,
 | |
| 	.disconnect	   = l2tp_ip6_disconnect,
 | |
| 	.ioctl		   = udp_ioctl,
 | |
| 	.destroy	   = l2tp_ip6_destroy_sock,
 | |
| 	.setsockopt	   = ipv6_setsockopt,
 | |
| 	.getsockopt	   = ipv6_getsockopt,
 | |
| 	.sendmsg	   = l2tp_ip6_sendmsg,
 | |
| 	.recvmsg	   = l2tp_ip6_recvmsg,
 | |
| 	.backlog_rcv	   = l2tp_ip6_backlog_recv,
 | |
| 	.hash		   = inet_hash,
 | |
| 	.unhash		   = inet_unhash,
 | |
| 	.obj_size	   = sizeof(struct l2tp_ip6_sock),
 | |
| #ifdef CONFIG_COMPAT
 | |
| 	.compat_setsockopt = compat_ipv6_setsockopt,
 | |
| 	.compat_getsockopt = compat_ipv6_getsockopt,
 | |
| #endif
 | |
| };
 | |
| 
 | |
| static const struct proto_ops l2tp_ip6_ops = {
 | |
| 	.family		   = PF_INET6,
 | |
| 	.owner		   = THIS_MODULE,
 | |
| 	.release	   = inet6_release,
 | |
| 	.bind		   = inet6_bind,
 | |
| 	.connect	   = inet_dgram_connect,
 | |
| 	.socketpair	   = sock_no_socketpair,
 | |
| 	.accept		   = sock_no_accept,
 | |
| 	.getname	   = l2tp_ip6_getname,
 | |
| 	.poll		   = datagram_poll,
 | |
| 	.ioctl		   = inet6_ioctl,
 | |
| 	.listen		   = sock_no_listen,
 | |
| 	.shutdown	   = inet_shutdown,
 | |
| 	.setsockopt	   = sock_common_setsockopt,
 | |
| 	.getsockopt	   = sock_common_getsockopt,
 | |
| 	.sendmsg	   = inet_sendmsg,
 | |
| 	.recvmsg	   = sock_common_recvmsg,
 | |
| 	.mmap		   = sock_no_mmap,
 | |
| 	.sendpage	   = sock_no_sendpage,
 | |
| #ifdef CONFIG_COMPAT
 | |
| 	.compat_setsockopt = compat_sock_common_setsockopt,
 | |
| 	.compat_getsockopt = compat_sock_common_getsockopt,
 | |
| #endif
 | |
| };
 | |
| 
 | |
| static struct inet_protosw l2tp_ip6_protosw = {
 | |
| 	.type		= SOCK_DGRAM,
 | |
| 	.protocol	= IPPROTO_L2TP,
 | |
| 	.prot		= &l2tp_ip6_prot,
 | |
| 	.ops		= &l2tp_ip6_ops,
 | |
| };
 | |
| 
 | |
| static struct inet6_protocol l2tp_ip6_protocol __read_mostly = {
 | |
| 	.handler	= l2tp_ip6_recv,
 | |
| };
 | |
| 
 | |
| static int __init l2tp_ip6_init(void)
 | |
| {
 | |
| 	int err;
 | |
| 
 | |
| 	pr_info("L2TP IP encapsulation support for IPv6 (L2TPv3)\n");
 | |
| 
 | |
| 	err = proto_register(&l2tp_ip6_prot, 1);
 | |
| 	if (err != 0)
 | |
| 		goto out;
 | |
| 
 | |
| 	err = inet6_add_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
 | |
| 	if (err)
 | |
| 		goto out1;
 | |
| 
 | |
| 	inet6_register_protosw(&l2tp_ip6_protosw);
 | |
| 	return 0;
 | |
| 
 | |
| out1:
 | |
| 	proto_unregister(&l2tp_ip6_prot);
 | |
| out:
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| static void __exit l2tp_ip6_exit(void)
 | |
| {
 | |
| 	inet6_unregister_protosw(&l2tp_ip6_protosw);
 | |
| 	inet6_del_protocol(&l2tp_ip6_protocol, IPPROTO_L2TP);
 | |
| 	proto_unregister(&l2tp_ip6_prot);
 | |
| }
 | |
| 
 | |
| module_init(l2tp_ip6_init);
 | |
| module_exit(l2tp_ip6_exit);
 | |
| 
 | |
| MODULE_LICENSE("GPL");
 | |
| MODULE_AUTHOR("Chris Elston <celston@katalix.com>");
 | |
| MODULE_DESCRIPTION("L2TP IP encapsulation for IPv6");
 | |
| MODULE_VERSION("1.0");
 | |
| 
 | |
| /* Use the value of SOCK_DGRAM (2) directory, because __stringify doesn't like
 | |
|  * enums
 | |
|  */
 | |
| MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 2, IPPROTO_L2TP);
 |